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文章速递Benefits and Limitations of Volumetric Modulated Arc Therapy in Treating Bilateral Breast Cancer with Regional Lymph Nodes 认领
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作者 R. P. Srivastava K. Vandeputte C. De Wagter 《乳腺癌(英文)》 2020年第4期119-126,共8页
<strong>Purpose:</strong><span style="font-family:""><span style="font-family:Verdana;"> The study was performed comparing dosimetric characteristics of volumetric modu... <strong>Purpose:</strong><span style="font-family:""><span style="font-family:Verdana;"> The study was performed comparing dosimetric characteristics of volumetric modulated arc therapy (VMAT) and field-in-field (FiF) techniques on a patient with synchronous bilateral breast carcinoma. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> The patients with bilateral breast cancer treatment were included in this study. A total dose of 40.05 Gy in 15 fractions was prescribed to the Planning Target Volume (PTV) of the whole bilateral breast cancer with the supraclavicular and infraclavicular nodes, with a complementary boost of 10 Gy in 4 fractions to the surgical bed (PTV</span><sub><span style="font-family:Verdana;">boost</span></sub><span style="font-family:Verdana;">). For both radiotherapy techniques, several V</span><sub><span style="font-family:Verdana;">xGy</span></sub><span style="font-family:Verdana;"> parameters were analyzed for the PTVs, together with the Conformity index (CI), the Homogeneity index (HI) and the critical organs at risk (OARs), lungs and heart. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The patient was treated by the VMAT technique and the daily treatment time was less than 20 minutes with daily CBCT imaging. In the VMAT plan, the PTV 95% dose covered 38.89 ± 0.81 Gy, compared to 37.26 ± 1.02 Gy in the FiF technique. The VMAT plan improved the dose homogeneity index and lower dose in lung towards high dose region. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> The study demonstrates the viability of the VMAT technique in the treatment of bilateral breast cancer. The introduced single isocentric VMAT technique is fast to deliver and it increases the dose homogeneity of the target volume with some limitations. The treatment was well tolerated, without interruption of the treatment courses caused by treatment</span></span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">related toxicities.</span> 展开更多
关键词 Bilateral Breast Cancer (BCC) Volumetric Modulated Arc Therapy (VMAT) Field in Field (FiF) Planning Target Volume (PTV) Organ’s Volume That Receives x Gy of Dose (VxGy)
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Complex Target Volume Delineation and Treatment Planning in Radiotherapy for Malignant Pleural Mesothelioma (MPM) 认领
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作者 Aaron Innocent Bogmis Adrian Raducu Popa +4 位作者 Daniela Adam Violeta Ciocâltei Nicoleta Alina Guraliuc Florin Ciubotaru Ion-Christian Chiricuță 《医学物理学、临床工程、放射肿瘤学(英文)》 2020年第3期125-140,共16页
<strong>Introduction:</strong> Radiotherapy alone or combined with surgery and/or chemotherapy is being investigated in the treatment of malignant pleural mesothelioma (MPM). This study aimed to simulate a... <strong>Introduction:</strong> Radiotherapy alone or combined with surgery and/or chemotherapy is being investigated in the treatment of malignant pleural mesothelioma (MPM). This study aimed to simulate a Volumetric Modulated Arc Therapy (VMAT) treatment of a patient with MPM. <strong>Materials and Methods:</strong> CT images from a patient with intact lungs were imported via DICOM into the Pinnacle3 treatment planning (TP) system (TPS) and used as a model for MPM to delineate organs at risk (OAR) and both clinical and planning target volumes (CTV and PTV) with a margin of 5 mm. Elekta Synergy with 6 MV photons and 80 leafs MLCi2 was employed. VMAT plans were generated using two coplanar arcs with gantry rotation angles of 178<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&deg</span> - 182<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&deg</span>, the collimator angles of each arc were set to 90<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&deg</span>, Octavius<span style="white-space:nowrap;"><sup>&reg;</sup></span> 4D 729 was employed for quality assurance while the calculated and measured doses were compared using VeriSoft. <strong>Results:</strong> A TP was achieved. The Gamma volume analysis with criteria of 3 mm distance to agreement and 3% dose difference yielded the gamma passing rate = 99.9%. The reference isodose was 42.75 Gy with the coverage constraints for the PTV D95 and V95 = 95.0% of 45 Gy. The remaining dosimetric parameters met the recommendations from the clinically acceptable guidelines for the radiotherapy of MPM. <strong>Conclusion:</strong> Using well-defined TV and VMAT, a consistent TP compared to similar ones from publications was achieved. We obtained a high agreement between the 3D dose reconstructed and the dose calculated. 展开更多
关键词 Malignant Pleural Mesothelioma Radiation Therapy RADIOTHERAPY Volumetric Modulated Arc Therapy VMAT Target Volume Delineation Treatment Planning CTV PTV
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EVS耦合地层-岩性三维地质建模方法在南宁地铁工程中的应用 认领
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作者 周念清 杨浩博 +1 位作者 杨磊 刘先林 《隧道建设(中英文)》 北大核心 2020年第2期238-245,共8页
为解决地质建模软件Earth Volumetric Studio(EVS)存在的地层建模方法无法对钻孔揭露地层比较复杂的情形进行层序划分,岩性建模方法无法生成连续光滑的层间界面等问题,以南宁市轨道交通3号线青秀山站至博艺路站区间段为研究对象,提出一... 为解决地质建模软件Earth Volumetric Studio(EVS)存在的地层建模方法无法对钻孔揭露地层比较复杂的情形进行层序划分,岩性建模方法无法生成连续光滑的层间界面等问题,以南宁市轨道交通3号线青秀山站至博艺路站区间段为研究对象,提出一种同时具有表达复杂透镜体和清晰的地质层面能力的EVS地层-岩性建模方法。通过工程实例将该方法分别与地层建模和岩性建模方法进行对比分析和交叉验证计算,结果表明采用地层-岩性建模方法建立的模型比单独使用地层模型和岩性模型更能反映实际的地质情况,且模型具有更高的精度,模型的相对误差和均方根误差较地层建模方法明显降低。 展开更多
关键词 三维地质建模 Earth VOLUMETRIC Studio(EVS) 地铁线路 岩性模型 城市轨道交通
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Characterisation of Early Age Deformations in Cement Paste: Case of Chemical and Autogenous Shrinkage 认领
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作者 Nkwenti Flavious Tanue Tubuo Fabian +1 位作者 Fokwa Didier Tchemou Gilbert 《矿物质和材料特性和工程(英文)》 2020年第4期223-239,共17页
Concrete is commonly seen as a durable and long-lasting construction material. However, the long-term performance of a concrete structure can be greatly compromised by early-age cracking. This work is an experimental ... Concrete is commonly seen as a durable and long-lasting construction material. However, the long-term performance of a concrete structure can be greatly compromised by early-age cracking. This work is an experimental contribution to study early age deformations of cement paste. Its aim is, firstly, to develop an experimental dispositive for assessing chemical and autogenous shrinkage, and secondly, to measure these volumetric deformations in cement paste. The setup was done following the gravimetric method of measurement, which exploits the Archimedes’ principle. It is made up of an electronic balance, a data accusation unit, a temperature control unit and a buoyancy bath. Investigations were done on Portland cement (CPA-CEM II) at the following W/C ratios: 0.25, 0.3, 0.35, 0.4 and 0.5. It was noticed that the water-cement ratio does not influence the magnitude of the chemical shrinkage in a significant manner but had a kinetic effect;a lower W/C induces a faster rate of chemical shrinkage. Autogenous shrinkage was discovered to be highly inversely proportional to the W/C and was also noticed to be in a function of chemical shrinkage within the first 2 to 4 hours when the paste was still liquid. 展开更多
关键词 Autogenous Shrinkage Chemical Shrinkage Volumetric Deformation Water-Cement Ratio
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Experimental and numerical analysis of the hydraulic and thermal performances of the gradually-varied porous volumetric solar receiver 认领
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作者 DU Shen LI ZengYao +3 位作者 HE YaLing LI Dong XIE XiangQian GAO Yang 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2020年第7期1224-1234,共11页
A gradually-varied porous structure is designed to increase the thermal performance of the porous volumetric solar receiver.Based on the replica method and multilayer recoating technique, the silicon carbide porous ce... A gradually-varied porous structure is designed to increase the thermal performance of the porous volumetric solar receiver.Based on the replica method and multilayer recoating technique, the silicon carbide porous ceramic with linear-changed geometrical parameters is fabricated. The performances of the uniform and gradually-varied porous volumetric solar receivers are studied by both experiment and numerical simulation. An optimization method combining genetic algorithm and computational fluid dynamics analysis is applied to determine the optimum porosity distribution. The results present that porous volumetric solar receiver with linear-changed geometrical parameters exhibits better thermal performance than the uniform porous volumetric solar receivers, especially when the thickness of the receiver is small. Larger porosity in the front is beneficial for increasing the solar radiation penetration depth, which limits the reflectance and thermal radiative losses. Smaller porosity in the rear traps more solar radiation and increases the convective heat transfer. When the receiver’s thickness is larger, the performance of the gradually-varied volumetric solar receiver is nearly identical to that of the uniform receiver with largest porosity. The double-layer configuration is found to be the optimized structure of the gradually-varied porous volumetric solar receiver. The thermal efficiency could be further improved using genetic algorithm with an 11 K increase of the outlet temperature. 展开更多
关键词 gradually-varied porous volumetric solar receiver replica method local thermal non-equilibrium heat transfer analysis optimization design
In-situ growth of vertically aligned nickel cobalt sulfide nanowires on carbon nanotube fibers for high capacitance all-solid-state asymmetric fiber-supercapacitors 认领
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作者 Na Liu Zhenghui Pan +6 位作者 Xiaoyu Ding Jie Yang Guoguang Xu Linge Li Qi Wang Meinan Liu Yuegang Zhang 《能源化学:英文版》 SCIE EI CAS CSCD 2020年第2期209-215,共7页
Fiber-supercapacitors(FSCs)are promising power sources for miniature portable and wearable electronic devices.However,the development and practical application of these FSCs have been severely hindered by their low vo... Fiber-supercapacitors(FSCs)are promising power sources for miniature portable and wearable electronic devices.However,the development and practical application of these FSCs have been severely hindered by their low volumetric capacitance and narrow operating voltage.In this work,vertically aligned nickel cobalt sulfide(Ni Co2S4)nanowires grown on carbon nanotube(CNT)fibers were achieved through an in-situ two-step hydrothermal reaction method.The as-prepared Ni Co2S4@CNT fiber electrode exhibits a high volumetric capacitance of 2332 F cm-3,benefiting from its superior electric conductivity,large surface area,and rich Faradic redox reaction sites.Furthermore,a Ni Co2S4@CNT//VN@CNT(vanadium nitride nanosheets grown on CNT fibers)asymmetric fiber-supercapacitor(AFSC)was successfully fabricated.The device exhibits an operating voltage up to 1.6 V and a high volumetric energy density of 30.64m Wh cm-3.The device also possesses outstanding flexibility as evidenced by no obvious performance degradation under various bending angles and maintaining high capacitance after 5000 bending cycles.This work promotes the practical application of flexible wearable energy-storage devices. 展开更多
关键词 Fiber-supercapacitors Volumetric energy density NICKEL COBALT SULFIDE NANOWIRES Carbon nanotube FIBER Wearable energy storage devices
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Intercalating Ultrathin MoO_3 Nanobelts into MXene Film with Ultrahigh Volumetric Capacitance and Excellent Deformation for High-Energy-Density Devices 认领
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作者 Yuanming Wang Xue Wang +5 位作者 Xiaolong Li Rong Liu Yang Bai Huanhao Xiao Yang Liu Guohui Yuan 《纳微快报:英文版》 SCIE EI CAS CSCD 2020年第9期109-122,共14页
The restacking hindrance of MXene films restricts their development for high volumetric energy density of flexible supercapacitors toward applications in miniature,portable,wearable or implantable electronic devices.A... The restacking hindrance of MXene films restricts their development for high volumetric energy density of flexible supercapacitors toward applications in miniature,portable,wearable or implantable electronic devices.A valid solution is construction of rational heterojunction to achieve a synergistic property enhancement.The introduction of spacers such as graphene,CNTs,cellulose and the like demonstrates limited enhancement in rate capability.The combination of currently reported pseudocapacitive materials and MXene tends to express the potential capacitance of pseudocapacitive materials rather than MXene,leading to low volumetric capacitance.Therefore,it is necessary to exploit more ideal candidate materials to couple with MXene for fully expressing both potentials.Herein,for the first time,high electrochemically active materials of ultrathin MoO3 nanobelts are intercalated into MXene films.In the composites,MoO3 nanobelts not only act as pillaring components to prevent restacking of MXene nanosheets for fully expressing the MXene pseudocapacitance in acidic environment but also provide considerable pseudocapacitive contribution.As a result,the optimal M/MoO3 electrode not only achieves a breakthrough in volumetric capacitance(1817 F cm-3 and 545 F g-1),but also maintains good rate capability and excellent flexibility.Moreover,the corresponding symmetric supercapacitor likewise shows a remarkable energy density of 44.6 Wh L-1(13.4 Wh kg-1),rendering the flexible electrode a promising candidate for application in high-energy-density energy storage devices. 展开更多
关键词 MXene MoO3 nanobelts Hybrid film Ultrahigh volumetric capacitance SUPERCAPACITORS
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Electrostatic self-assembly of MXene and edge-rich CoAl layered double hydroxide on molecular-scale with superhigh volumetric performances 认领
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作者 Hao Niu Xue Yang +7 位作者 Qian Wang Xiaoyan Jing Kui Cheng Kai Zhu Ke Ye Guiling Wang Dianxue Cao Jun Yan 《能源化学:英文版》 SCIE EI CAS CSCD 2020年第7期105-113,I0004,共10页
It is highly desirable to design and synthesize two-dimensional nanostructured electrode materials with high electrical conductivity,large electrolyte-accessible surface area and more exposed active sites for energy s... It is highly desirable to design and synthesize two-dimensional nanostructured electrode materials with high electrical conductivity,large electrolyte-accessible surface area and more exposed active sites for energy storage applications.Herein,MXene/Co Al-LDH heterostructure has been prepared through electrostatic ordered hetero-assembly of monolayer MXene and edge-rich Co Al-LDH nanosheets in a faceto-face manner on molecular-scale for supercapacitor applications.Benefiting from the unique structure,strong interfacial interaction and synergistic effects between MXene and Co Al-LDH nanosheets,the electrical conductivity and exposed electrolyte-accessible active sites are significantly enhanced.The asprepared MXene/Co Al-LDH-80%(ML-80)film exhibits high volumetric capacity of 2472 C cm-3 in 3 M KOH electrolyte with high rate capability of 70.6%at 20 A g-1.Notably,to the best of our knowledge,the high volumetric capacity is the highest among other previously reported values for supercapacitors in aqueous electrolytes.Furthermore,our asymmetric supercapacitor device fabricated with ML-80 and MXene/graphene composite as cathode and anode,respectively,exhibits impressive volumetric energy density of 85.4 Wh L-1 with impressive cycling stability of 94.4%retention ratio after 30,000 continuous charge/discharge cycles. 展开更多
关键词 MXene Hetero-assembly SUPERCAPACITOR Volumetric performance HETEROSTRUCTURE
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Facial Tightening Following a Single Acoustic Wave Treatment Using Focused and Radial Acoustic Waves 认领
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作者 Kuriko Kimura Yohei Tanaka 《化妆品、皮肤病及应用期刊(英文)》 2019年第4期321-328,共8页
Background: Acoustic wave has been used for many medical purposes, and although it is widely applied in cosmetic procedures, it has not been conducted for facial rejuvenation and tightening. Acoustic wave has been pro... Background: Acoustic wave has been used for many medical purposes, and although it is widely applied in cosmetic procedures, it has not been conducted for facial rejuvenation and tightening. Acoustic wave has been proven to penetrate deeper than subcutaneous tissue, independent of skin color, and to be beneficial for skin tightening and body contouring. Objective: To evaluate the effectiveness of a single acoustic wave treatment session using unique focused and radial acoustic waves for facial tightening. Participants: Sixty Asian patients were treated between the years 2016 and 2018. The single acoustic wave treatment session consists of focused long planar acoustic pulses thought to have an effect on cells and their metabolism resulting in an increased release of fat, and radial short acoustic pulses thought to have an effect on tissues activating blood and lymphatic flow. Patients did not undergo any form of medical aesthetic treatment during the study. Measurements: Digital photographs and three-dimensional imaging were used to evaluate the results. Results: Objective assessments with digital photographs and superimposed three-dimensional color images showed preferable facial tightening effects and marked volumetric reduction on the lower one-third of the face. These results were obtained without the edematous reactions observed in laser and radiofrequency therapies, and were sustained up to 12 months. All of the patients reported satisfaction with the results and convenience of the procedure. Complications were minor and transitory, consisting of a slight tingly sensation to the teeth during the treatment, and mild erythema resolving within 5 hours. Side effects were not observed. Conclusions: The advantages of the single acoustic wave treatment are the high potency of facial tightening effects, reduction of discomfort and side effects. Taken together, these characteristics facilitate the ability to give repeated treatments and provide an alternative or adjunct treatment for patients with improved results. 展开更多
关键词 ACOUSTIC Wave Treatment FACIAL TIGHTENING FOCUSED ACOUSTIC WAVES RADIAL ACOUSTIC WAVES Volumetric Reduction
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Treatment-Plan Comparison of Three Advanced Radiation Treatment Modalities for Fractionated Stereotactic Radiotherapy to the Head and Neck 认领
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作者 He Wang James N. Yang +19 位作者 Xiaodong Zhang Jing Li Steven J. Frank Zhongxiang Zhao Dershan Luo Xiaorong Zhu Congjun Wang Samuel Tung Adam S. Garden David I. Rosenthal Clifton David Fuller Gary Brandon Gunn Amol J. Ghia Jay P. Reddy Shaan M. Raza Franco De Monte Mark S. Chambers Paul D. Brown Shirley Su Jack Phan 《医学物理学、临床工程、放射肿瘤学(英文)》 2019年第2期106-120,共15页
Purpose: Fractionated stereotactic radiosurgery (FSRS) can be given with at least three modalities: Gamma Knife, with the noninvasive frameless extend system (GKE);linear accelerator-based volumetric modulated arc the... Purpose: Fractionated stereotactic radiosurgery (FSRS) can be given with at least three modalities: Gamma Knife, with the noninvasive frameless extend system (GKE);linear accelerator-based volumetric modulated arc therapy (VMAT);and intensity-modulated proton therapy (IMPT). We extracted treatment plans for patients who had received FSRS with GKE for recurrent skull base or intracranial tumors, created corresponding plans for VMAT and IMPT, and compared the quality of the three sets of plans. Methods and materials: Plans were extracted for 9 patients with recurrent malignant skull-base tumors (n = 6) or large intracranial tumors (n = 3) who had received FSRS with GKE (median dose 24 Gy in 3 fractions) in 2013 through 2015. Plans for VMAT were generated with a TrueBeam STx LINAC machine using 6-MV photons, and plans for IMPT were generated with multi-field optimization. The optimized VMAT and IMPT plans were normalized to achieve the best possible target coverage while meeting the same dose-volume constraints on organs at risk (OARs) as the GKE plans. Plans were evaluated on the basis of target coverage, conformity index, homogeneity index, gradient index, and treatment efficiency. Results: The median target volume was 10.2 cm3 (range 1.9 - 33.8 cm3). The VMAT and IMPT plans met all OAR constraints, and target coverage and conformity were comparable among all plans. VMAT and IMPT plans showed significantly better target uniformity and treatment delivery efficiency (P P Conclusion: FSRS for skull base and large intracranial lesions delivered by VMAT and IMPT can achieve comparable target coverage, conformity, and sparing of critical structure as the GKE while providing superior target uniformity and treatment delivery efficiency. The GKE had superior high-dose gradients outside the target and thus better protected surrounding normal structures. 展开更多
关键词 Gamma Knife Extend System STEREOTACTIC RADIOSURGERY Volumetric Modulated Arc THERAPY INTENSITY-MODULATED PROTON THERAPY Spot Scanning PROTON THERAPY
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Triphenylmethanol and Tris(2-(hydroxymethyl)phenol) Derivatives: Synthesis and Application as Indicators for Acid-Base Volumetric Titration 认领
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作者 Ryan Beni William Boadi +11 位作者 Jawzah Alnakhli Samiyah Alhamed Tiffany Robinson Melanie Mootry Nahom Iyob Jamill Jackson Natalie Spicer Anterrial Harris Ibrahim Bamidad Renner Antwi Shania Richardson Tralynn Williams 《分析科学方法和仪器期刊(英文)》 2019年第2期13-21,共9页
Polyphenols are naturally occurring compounds found largely in fruits, vegetables, cereals and beverages. Currently, there is much interest in the potential health benefits of dietary plant polyphenols as antioxidants... Polyphenols are naturally occurring compounds found largely in fruits, vegetables, cereals and beverages. Currently, there is much interest in the potential health benefits of dietary plant polyphenols as antioxidants. The effect of polyphenols on human cancer cells is most often protective and induces a reduction in the number of tumors or rate of growth. During our course of study on anticancer prodrugs, twelve triphenylmethanol and one tris(2-(hydroxymethyl) phenol derivatives were synthesized as a carrier of several drugs with optimized lipophilicity. Besides application of these compounds as a foundation for anticancer drug delivery systems, these compounds were evaluated as indicators for the acid-base volumetric titration of a standard solution of hydrochloric acid with a standard solution of sodium hydroxide. The experiments indicated a moderate-to-sharp color transition of the solutions near the neutralization point for most indicators. These indicators may have potential applications for acid-base titrations in a narrow range. 展开更多
关键词 Polyphenols Triphenylmethanol ACID-BASE INDICATORS VOLUMETRIC TITRATION NEUTRALIZATION
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Training and evaluation of a knowledge-based model for automated treatment planning of multiple brain metastases 认领
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作者 Vishruta A. Dumane Tsu-Chi Tseng +5 位作者 Ren-Dih Sheu Yeh-Chi Lo Vishal Gupta Audrey Saitta Kenneth E. Rosenzweig Sheryl Green 《癌症转移与治疗:英文版》 2019年第5期62-71,共10页
Aim: Volumetric modulated arc therapy (VMAT) has been utilized to plan and treat multiple cranial metastases using a single isocenter due to its ability to provide steep dose gradients around targets as well as low do... Aim: Volumetric modulated arc therapy (VMAT) has been utilized to plan and treat multiple cranial metastases using a single isocenter due to its ability to provide steep dose gradients around targets as well as low doses to critical structures. VMAT treatment is delivered in a much shorter time compared to using a single isocenter for the treatment of each lesion. However, there is a need to develop methods to reduce the treatment planning time for these cases while also standardizing the plan quality. In this work we demonstrate the use of RapidPlan, which is knowledge-based treatment (KBP) planning software to plan multiple cranial SRS cases. Methods: The 66 patient plans with 125 lesions (range 1-4, median 1) were used to train a model. In addition, the model was validated using 10 cases that were previously treated and chosen randomly. The clinical plans were compared to plans generated by RapidPlan for target coverage and critical organ dose. Results: Coverage to the target volume, gradient index, conformity index and minimum dose to the target showed no significant difference between the original clinical plan vs. the plan generated by KBP. A comparison of doses to the critical organs namely the brainstem, brain, chiasm, eyes, optic nerves and lenses showed no significant difference. Target dose homogeneity was slightly better with the clinical plan, however this difference was also statistically insignificant. ;Conclusion: This work demonstrates that KBP can be trained and efficiently utilized to help not only speed up the planning process but also help standardize the treatment plan quality. 展开更多
关键词 Brain metastases RADIOTHERAPY volumetric modulated arc therapy knowledge-based planning STEREOTACTIC RADIOSURGERY
Co-continuous Composite Material Design Using the Volumetric Distance Field Based on Analytic Shape Functions 认领
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作者 Huimin Han Dong-Jin Yoo Yan Liang 《哈尔滨工业大学学报:英文版》 EI CAS 2019年第1期88-96,共9页
An effective and simple design method for co-continuous composite material construction is proposed by using a hybrid methodology with triply periodic minimal surface (TPMS) cellular topology and the volumetric distan... An effective and simple design method for co-continuous composite material construction is proposed by using a hybrid methodology with triply periodic minimal surface (TPMS) cellular topology and the volumetric distance field (VDF). After generating a set of VDF-based features for the given exterior shape and desired internal core structure, a series of simple modifications in distance fields enabled us to obtain an arbitrarily-shaped complex co-continuous composite material computational model. Design results and manufactured prototypes through 3D printing technology show that the proposed methodology has the potential to open a new paradigm for producing multifunctional next generation co-continuous composite materials which are impossible to design and manufacture using traditional CAD and CAM. 展开更多
关键词 triply periodic MINIMAL surface (TPMS) cellular topology VOLUMETRIC distance field (VDF) co-continuous COMPOSITE material model basic feature 3D printing technology
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Volumetric changes in the focal areas of seismic events corresponding to destress blasting 认领
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作者 P.Konicek J.Schreiber L.Nazarova 《矿业科学技术学报:英文版》 EI CSCD 2019年第4期541-547,共7页
The typical development of total volumetric change in the focal areas of seismic events,corresponding to destress blasting,is characterized as an explosive phase followed by an implosive phase and with alternating add... The typical development of total volumetric change in the focal areas of seismic events,corresponding to destress blasting,is characterized as an explosive phase followed by an implosive phase and with alternating additional phases following on from that.In a few cases,a non-typical development of volumetric change was identified,where the first phase was implosive and the second phase,explosive.This development is mainly typical for induced seismic events recorded during mining,not for destress blasting.Seismic events were recorded during longwall mining in the Czech part of the Upper Silesian Coal Basin,where the destress blasting technique is used as a rockburst prevention active measure.Kinematic source processes in the focal areas of selected seismic events were analyzed by the seismic moment tensor inversion method,as well as by studying geomechanical rock mass conditions at the localities of the seismic events.The main goal of the analysis was to attempt to identify the reasons for non-typical development of volumetric changes in these cases.Volumetric changes were analyzed for seismic events with energy greater than 104 J,recorded in the period of time from 1993 to 2009(1109 events).80%(891)of the recorded seismic events were induced seismic events that were registered during longwall mining and 20%(218)corresponded to destress blasting events.Research shows that the main reason for the non-typical development of volumetric changes in the focal areas of seismic events is an association with destress blasting in the rock mass,which is very close to rock mass overstressing.The detonation of explosives in boreholes,which would dominate the first phase of volumetric changes,probably obscured stress release in the rock mass,as manifested in the first implosion phase of the volumetric changes in this case. 展开更多
关键词 Destress BLASTING Seismic EVENT VOLUMETRIC CHANGES Stress release
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Thermal Analysis of a Volumetric Solar Receiver 认领
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作者 CHEN Longfei YANG Ming +5 位作者 LI Jinping BAI Yakai LI Xiaoxia TANG Wenxue YANG Nancong WANG Zhifeng 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第6期1176-1185,共10页
The volumetric receiver has received wide attention due to its high thermal efficiency. This paper studied a new type of a solid-liquid composite volumetric receiver. The heat transfer in a solid-liquid composite volu... The volumetric receiver has received wide attention due to its high thermal efficiency. This paper studied a new type of a solid-liquid composite volumetric receiver. The heat transfer in a solid-liquid composite volumetric solar receiver was analyzed using a one-dimensional unsteady simulation model of the solid-liquid receiver. The model included absorption of the incident solar radiation by the glass window, the silicon carbide porous ceramic heat absorber panel and the water. The results were verified against experimental data for a volumetric receiver and the error did not exceed 10%. It can be used to predict the heat transfer in solid-liquid composite volumetric receivers. 展开更多
关键词 SOLAR receiver SOLID-LIQUID composite ABSORBER silicon CARBIDE porous ceramic VOLUMETRIC SOLAR COLLECTOR
A Volumetric Model for Evaluating Tight Sandstone Gas Reserves in the Permian Sulige Gas Field,Ordos Basin,Central China 认领
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作者 CUI Mingming FAN Aiping +3 位作者 WANG Zongxiu GAO Wanli LI Jinbu LI Yijun 《地质学报:英文版》 CAS CSCD 2019年第2期386-399,共14页
To accurately measure and evaluate reserves is critical for ensuring successful production of unconventional oil and gas. This work proposes a volumetric model to evaluate the tight sandstone gas reserves of the Permi... To accurately measure and evaluate reserves is critical for ensuring successful production of unconventional oil and gas. This work proposes a volumetric model to evaluate the tight sandstone gas reserves of the Permian Sulige gas field in the Ordos Basin. The reserves can be determined by four major parameters of reservoir cutoffs, net pay, gas-bearing area and compression factor Z, which are controlled by reservoir characteristics and sedimentation. Well logging, seismic analysis, core analysis and gas testing, as well as thin section identification and SEM analysis were used to analyze the pore evolution and pore-throat structure. The porosity and permeability cutoffs are determined by distribution function curve,empirical statistics and intersection plot. Net pay and gas-bearing area are determined based on the cutoffs, gas testing and sand body distribution, and the compression factor Z is obtained by gas component. The results demonstrate that the reservoir in the Sulige gas field is characterized by ultralow porosity and permeability, and the cutoffs of porosity and permeability are 5% and 0.15×10–3 μm2, respectively. The net pay and gas-bearing area are mainly affected by the sedimentary facies, sand body types and distribution. The gas component is dominated by methane which accounts for more than 90%, and the compression factor Z of H8(P2h8) and S1(P1s1) are 0.98 and 0.985, respectively. The distributary channels stacked and overlapped, forming a wide and thick sand body with good developed intergranular pores and intercrystalline pores. The upper part of channel sand with good porosity and permeability can be sweet spot for gas exploration. The complete set of calculation systems proposed for tight gas reserve calculation has proved to be effective based on application and feedback. This model provides a new concept and consideration for reserve prediction and calculation in other areas. 展开更多
关键词 tight sandstone reservoir volumetric GAS reserve PERMIAN SULIGE GAS field ORDOS Basin
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Experimental study on unsaturated soil water diffusivity in different soils in Hebei Piedmont Plain 认领
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作者 GAO Ye-xin LIU Ji-chao +2 位作者 FENG Xin ZHANG Ying-ping ZHANG Bing 《地下水科学与工程:英文版》 2019年第2期165-172,共8页
Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological we... Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological wet fronts were different. The sandy loam had the fastest migration rate, the loam followed, and the clay loam was the slowest, but the law of change is the same among the three lithologies. The volumetric water content affects the change of Boltzmann parameter λ. When the volumetric water content is between 0.35-0.45 cm^3/cm^3,λ approaches stability. When the volumetric water content is less than 0.35 cm^3/cm^3, the λ value decreases rapidly with the decrease of water content. The water diffusion rate is related to the volumetric water content and particle size. The greater the moisture content is, the greater the diffusion rate will be. The larger the particle size, the larger the diffusion rate. The diffusivity of sandy loam is 10-30 times larger than that of loam and clay loam. The relationship between water content and diffusion rate is in accordance with the exponential function . 展开更多
关键词 Hebei PIEDMONT plain Soil WATER DIFFUSIVITY BOLTZMANN parameter VOLUMETRIC WATER content
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Numerical study of MHD mixed convection under volumetric heat source in vertical square duct with wall effects 认领
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作者 Zhi-Hong Liu Ming-Jiu Ni Nian-Mei Zhang 《力学快报:英文版》 CAS CSCD 2019年第3期152-160,共9页
Magnetohydrodynamic (MHD) mixed convection under strong magnetic field and volumetric heat source for buoyancy-assisted flows are studied numerically in this paper. Blanket is one of key components for energy conversi... Magnetohydrodynamic (MHD) mixed convection under strong magnetic field and volumetric heat source for buoyancy-assisted flows are studied numerically in this paper. Blanket is one of key components for energy conversion in Tokamak fusion reactor. The physical model employed for simulations is refined from dual-coolant lead-lithium (DCLL) blanket. A magnetic-convection code based on a consistent and conservative scheme is developed with the help of finite volume method, and validated by some Benchmark analytical solutions. The flows inside duct with thermal insulating and electric conducting walls under exponential neutron volumetric heat source are simulated. Based on Boussinesq assumption, the influences of wall electrical conductivity and buoyancy on velocity fields, temperature distributions and Nusselt numbers are investigated. Results illustrates that the wall conductance ratio dominates the flow at low Grashof numbers and high wall conductance ratio, while buoyancy effect dominates the jet flow near side wall at a high Grashof number. In addition, the velocity along flow direction substantially impacts features of the Nusselt number and temperature distribution. Besides, the jet flow results in a higher Nusselt number and lower temperature. 展开更多
关键词 Mixed CONVECTION MAGNETOHYDRODYNAMIC (MHD) VOLUMETRIC heat source
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Practice and knowledge of volumetric development of deep fractured-vuggy carbonate reservoirs in Tarim Basin, NW China 认领
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作者 JIAO Fangzheng 《石油勘探与开发:英文版》 2019年第3期576-582,共7页
Different from the continental layered sandstone and fracture-pore carbonate reservoirs, the fractured-vuggy carbonate reservoirs in the Tarim Basin are mainly composed of fractured-vuggy bodies of different sizes and... Different from the continental layered sandstone and fracture-pore carbonate reservoirs, the fractured-vuggy carbonate reservoirs in the Tarim Basin are mainly composed of fractured-vuggy bodies of different sizes and shapes. Based on years of study on the geological features, flow mechanisms, high-precision depiction and the recovery mode of fractured-vuggy bodies, the idea of “volumetric development” is proposed and put into practice. A “body by body” production methodology is established with respect to volumetric unit of fractures and vugs based on vuggy body’s spatial allocation and reserves. A variety of development wells, various technological methods, and multi-type injection media are used to develop this type of reservoirs in an all-around way. As a result, the resource and production structures of the Tahe oilfield are significantly improved and a highly efficient development is achieved. 展开更多
关键词 Tahe OILFIELD fractured-vuggy RESERVOIR fractured-vuggy body 3D depiction RESERVOIR STIMULATION DEVELOPMENT mode VOLUMETRIC DEVELOPMENT
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Photosynthetic stimulation of saplings by the interaction of CO2 and water stress 认领
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作者 Na Zhao Ping Meng Xinxiao Yu 《林业研究:英文版》 SCIE CAS CSCD 2019年第4期1233-1243,共11页
Climate change necessitates research into interactions between elevated carbon dioxide(CO2)concentrations and drought on plant photosynthetic physiology.This study describes the physiological properties of Platycladus... Climate change necessitates research into interactions between elevated carbon dioxide(CO2)concentrations and drought on plant photosynthetic physiology.This study describes the physiological properties of Platycladus orientalis(Chinese thuja)and Quercus variabilis(Chinese cork oak)saplings cultivated through orthogonal treatments of four CO2 concentrations combined with five soil volumetric water contents(SWC).It highlights the differences between the interactive effects from the treatments.Water stress had little effect on photosynthetic traits until the soil volumetric water contents exceeded 70–80 or 100%.Similar variations in carbon-13 isotope abundance(δ^13C)of water soluble compounds(δ^13CWSC)extracted from leaves of two species have been observed.Whether soil volumetric water contents exceeded or fell below the water threshold values(70–80%of field capacity for P.orientalis and 100%of field capacity for Q.variabilis),instantaneous water use efficiency decreased.Elevated carbon dioxide could increase iWUE and enhance drought tolerance,depending on stimulating net photosynthetic rates and declining stomatal conductance and transpiration rates.Augmenting either drought,excess water,or ambient carbon dioxide could alleviate the physiological inhibition caused by the stresses described above. 展开更多
关键词 δ13C Instantaneous WATER efficiency Orthogonal tests PHOTOSYNTHESIS Soil VOLUMETRIC WATER content
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