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Transfer of mitochondria from mesenchymal stem cells derived from induced pluripotent stem cells attenuates hypoxia-ischemia-induced mitochondrial dysfunction in PC12 cells 预览
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作者 Yan Yang Gen Ye +5 位作者 Yue-Lin Zhang Hai-Wei He Bao-Qi Yu Yi-Mei Hong Wei You Xin Li 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第3期464-472,共9页
Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury.Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology,the mechanisms are not fully... Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury.Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology,the mechanisms are not fully understood.To address this issue,we first co-cultured 1.5×10^5 PC12 cells with mesenchymal stem cells that were derived from induced pluripotent stem cells at a ratio of 1:1,and then intervened with cobalt chloride(CoCl2)for 24 hours.Reactive oxygen species in PC12 cells was measured by Mito-sox.Mitochondrial membrane potential(ΔΨm)in PC12 cells was determined by JC-1 staining.Apoptosis of PC12 cells was detected by terminal deoxynucleotidal transferase-mediated dUTP nick end-labeling staining.Mitochondrial morphology in PC12 cells was examined by transmission electron microscopy.Transfer of mitochondria from the mesenchymal stem cells derived from induced pluripotent stem cells to damaged PC12 cells was measured by flow cytometry.Mesenchymal stem cells were induced from pluripotent stem cells by lentivirus infection containing green fluorescent protein in mitochondria.Then they were co-cultured with PC12 cells in Transwell chambers and treated with CoCl2 for 24 hours to detect adenosine triphosphate level in PC12 cells.CoCl2-induced PC12 cell damage was dose-dependent.Co-culture with mesenchymal stem cells significantly reduced apoptosis and restoredΔΨm in the injured PC12 cells under CoCl2 challenge.Co-culture with mesenchymal stem cells ameliorated mitochondrial swelling,the disappearance of cristae,and chromatin margination in the injured PC12 cells.After direct co-culture,mitochondrial transfer from the mesenchymal stem cells stem cells to PC12 cells was detected via formed tunneling nanotubes between these two types of cells.The transfer efficiency was greatly enhanced in the presence of CoCl2.More importantly,inhibition of tunneling nanotubes partially abrogated the beneficial effects of mesenchymal stem cells on CoCl2-induced PC12 cell injury.Mesenchymal stem cells reduced CoCl2-induced 展开更多
关键词 apoptosis brain injury HYPOXIA-ISCHEMIA INDUCED pluripotent STEM CELLS mesenchymal STEM CELLS MITOCHONDRIAL membrane potential MITOCHONDRIAL TRANSFER PC12 CELLS tunneling nanotubes
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Two-dimensional XSe2(X = Mn,V) based magnetic tunneling junctions with high Curie temperature
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作者 潘龙飞 文宏玉 +4 位作者 黄乐 陈龙 邓惠雄 夏建白 魏钟鸣 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期109-114,共6页
Two-dimensional(2D) magnetic crystals have attracted great attention due to their emerging new physical phenomena. They provide ideal platforms to study the fundamental physics of magnetism in low dimensions. In this ... Two-dimensional(2D) magnetic crystals have attracted great attention due to their emerging new physical phenomena. They provide ideal platforms to study the fundamental physics of magnetism in low dimensions. In this research,magnetic tunneling junctions(MTJs) based on XSe2(X = Mn, V) with room-temperature ferromagnetism were studied using first-principles calculations. A large tunneling magnetoresistance(TMR) of 725.07% was obtained in the MTJs based on monolayer MnSe2. Several schemes were proposed to improve the TMR of these devices. Moreover, the results of our non-equilibrium transport calculations showed that the large TMR was maintained in these devices under a finite bias.The transmission spectrum was analyzed according to the orbital components and the electronic structure of the monolayer XSe2(X = Mn, V). The results in this paper demonstrated that the MTJs based on a 2D ferromagnet with room-temperature ferromagnetism exhibited reliable performance. Therefore, such devices show the possibility for potential applications in spintronics. 展开更多
关键词 TWO-DIMENSIONAL material MAGNETIC TUNNELING JUNCTIONS TUNNELING MAGNETORESISTANCE FERROMAGNETISM
Single-electron transport through single and coupling dopant atoms in silicon junctionless nanowire transistor
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作者 张晓迪 韩伟华 +5 位作者 刘雯 赵晓松 郭仰岩 杨冲 陈俊东 杨富华 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第12期315-319,共5页
We investigated single-electron tunneling through single and coupling dopant-induced quantum dots(QDs) in silicon junctionless nanowire transistor(JNT) by varying temperatures and bias voltages. We observed that two p... We investigated single-electron tunneling through single and coupling dopant-induced quantum dots(QDs) in silicon junctionless nanowire transistor(JNT) by varying temperatures and bias voltages. We observed that two possible charge states of the isolated QD confined in the axis of the initial narrowest channel are successively occupied as the temperature increases above 30 K. The resonance states of the double single-electron peaks emerge below the Hubbard band, at which several subpeaks are clearly observed respectively in the double oscillated current peaks due to the coupling of the QDs in the atomic scale channel. The electric field of bias voltage between the source and the drain could remarkably enhance the tunneling possibility of the single-electron current and the coupling strength of several dopant atoms. This finding demonstrates that silicon JNTs are the promising potential candidates to realize the single dopant atom transistors operating at room temperature. 展开更多
关键词 silicon nanowire transistor single electron tunneling dopant-induced quantum dots tunneling current spectroscopy
Endoscopic trans-esophageal submucosal tunneling surgery:A new therapeutic approach for diseases located around the aorta ventralis 预览
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作者 Ying Xiong Qian-Qian Chen +3 位作者 Ning-Li Chai Shun-Chang Jiao En-Qiang Ling Hu 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第1期85-94,共10页
AIM To assess the efficiency of endoscopic trans-esophageal submucosal tunneling surgery(EESTS)technique for diseases located around the aorta ventralis.METHODS Nine pigs were assigned to EESTs.The procedures were as ... AIM To assess the efficiency of endoscopic trans-esophageal submucosal tunneling surgery(EESTS)technique for diseases located around the aorta ventralis.METHODS Nine pigs were assigned to EESTs.The procedures were as follows:First,a long esophageal submucosal tunnel was established.Second,full-thickness myotomy was created.Third,an endoscope was entered into the abdominal cavity through a muscle incision and the endoscope was around the aorta ventralis.Eventually,celiac trunk ganglion neurolysis,partial hepatectomy and splenectomy,partial tissue resection in the area of the posterior peritoneum,and endoscopic submucosal dissection(ESD)combined with lymph node dissection were performed.The animals were given antibiotics for 5 d and necropsied 7 d after surgery.RESULTS In all surgeries,one pig died from intraperitoneal hemorrhage after doing partial splenectomy,while the other pigs were alive after successfully operating other surgeries.For surgery of celiac trunk ganglion damage,at necropsy,there was no exudation in the abdominal cavity.Regarding surgery of partial hepatectomy,the wound with part healing was observed in the left hepatic lobe,and no bleeding or obvious exudation was seen.In surgery of partial splenectomy,massive hemorrhage was observed on the splenic wound surface,and the metal clips could not stop bleeding.After surgery of retroperitoneal tissue resection,mild tissue adhesion was observed in the abdominal cavity of one animal,and another one suffered from severe infection.For surgery of ESD and lymph node dissection,a moderate tissue adhesion was observed.CONCLUSION EESTS is a feasible and safe technique for diseases located around the aorta ventralis. 展开更多
关键词 ENDOSCOPIC trans-esophageal SUBMUCOSAL TUNNELING SURGERY Diseases around the AORTA ventralis ENDOSCOPIC SUBMUCOSAL TUNNELING technique Abdominal SURGERY Animal model
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下穿隧道开挖引起的挤土桩沉降控制分析方法
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作者 莫品强 高新慰 +1 位作者 黄子丰 马丹阳 《岩土力学》 EI CAS CSCD 北大核心 2019年第10期3823-3832,3843共11页
随着地下空间开发利用的立体式发展,地下近接工程中结构相互作用问题日益突显。针对盾构隧道下穿既有挤土桩问题,提出了基于岩土介质小孔扩张(收缩)理论的分析方法。通过基于统一砂黏土本构模型和大应变假设推导的小孔扩张-收缩排水解析... 随着地下空间开发利用的立体式发展,地下近接工程中结构相互作用问题日益突显。针对盾构隧道下穿既有挤土桩问题,提出了基于岩土介质小孔扩张(收缩)理论的分析方法。通过基于统一砂黏土本构模型和大应变假设推导的小孔扩张-收缩排水解析解,建立了隧-桩相互作用力学模型;提出了隧道开挖影响下桩基的承载力衰减因子,并采用荷载-沉降曲线预测了桩基沉降。由分析结果可知,隧道地层损失引起的桩侧承载力减小、桩端承载力减小和桩端刚度损失,三者共同作用促使桩基发生沉降失稳,并提出了桩基的承载力控制准则、稳定控制准则和变形控制准则。此外,研究得到了桩基失稳时隧道地层损失与各因素之间的相关关系。其结果为揭示隧道与邻近结构相互作用机制、保障地下结构稳定性提供了有效的分析手段和必要的理论依据。 展开更多
关键词 隧道工程 挤土桩 小孔扩张理论 弹塑性本构 大应变
掘进工作面降耗措施分析 预览
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作者 邢素忠 《机械管理开发》 2019年第7期276-277,共2页
为有效降低掘进工作面的电能消耗,针对变压器、电动机以及输送机等关键设备,详细分析其耗能原因,分别针对性地提出了变压器、电动机以及输送机的具体节能措施,为整个掘进工作面的节能工作奠定基础。
关键词 煤矿 掘进 电气设备 节能 有功功率
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Scanning tunneling microscopic investigation on morphology of magnetic Weyl semimetal YbMnBi2
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作者 朱朕 严冬 +10 位作者 聂晓昂 徐豪科 杨旭 管丹丹 王世勇 李耀义 刘灿华 刘军伟 罗惠霞 郑浩 贾金锋 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期87-90,共4页
YbMnBi2 is a recently discovered time-reversal-symmetry breaking type-Ⅱ Weyl semimetal.However, as a representation of the new category of topological matters, the scanning tunneling microcopy(STM) results on such im... YbMnBi2 is a recently discovered time-reversal-symmetry breaking type-Ⅱ Weyl semimetal.However, as a representation of the new category of topological matters, the scanning tunneling microcopy(STM) results on such important material are still absent.Here, we report the STM investigations on the morphology of vacuum cleaved single crystalline YbMnBi2 samples.A hill and valley type of topography is observed on the YbMnBi2 surface, which is consistent with the non-layer nature of its crystal structure.Analysis of STM images yields the information of the index of the vicinal surface.Our results here lay a playground of future atomic scale research on YbMnBi2. 展开更多
关键词 WEYL SEMIMETAL topological INSULATOR SCANNING TUNNELING microscopy
煤矿斜井施工技术分析 预览
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作者 张志龙 《建筑技术开发》 2019年第12期39-40,共2页
在矿山的建设过程中,斜井是其非常重要的组成部分,由于地址情况、施工工艺以及施工条件的影响,导致其施工难度较大,存在较多的不安全因素。为了保障煤矿斜井施工的顺利进行,就需要对整个施工过程进行系统全面的分析研究,并采取有针对性... 在矿山的建设过程中,斜井是其非常重要的组成部分,由于地址情况、施工工艺以及施工条件的影响,导致其施工难度较大,存在较多的不安全因素。为了保障煤矿斜井施工的顺利进行,就需要对整个施工过程进行系统全面的分析研究,并采取有针对性的斜井施工技术,确保各项施工措施的顺利实施以及确保斜井的施工质量符合要求。 展开更多
关键词 煤矿 斜井 掘进
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煤矿掘进巷道锚杆支护技术研究 预览
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作者 路瑞龙 《当代化工研究》 2019年第7期164-165,共2页
本文阐述了煤矿矿井的掘进巷道支护发展现状以及在矿井掘进工作中进行巷道锚杆支护的作用,并在巷道锚杆孔位和支护设计等角度分析了锚杆支护进行设计及施工方面的要求,某种程度上提高了煤矿矿井作业的安全性。
关键词 矿井 锚杆支护 掘进
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关于土压平衡盾构施工监理控制的要求 预览
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作者 朱佑洪 《现代交通技术研究》 2019年第2期94-99,共6页
随着社会经济的发展城市人口增多、规模变大现有的城市交通已经不能满足城市发展的需要、经济发达的城市逐步修建地下工程,轨道盾构施工技术普遍应用于地铁工程中。盾构在地下工程施工中越来越得到重视,盾构施工前盾构机的安装,始发、... 随着社会经济的发展城市人口增多、规模变大现有的城市交通已经不能满足城市发展的需要、经济发达的城市逐步修建地下工程,轨道盾构施工技术普遍应用于地铁工程中。盾构在地下工程施工中越来越得到重视,盾构施工前盾构机的安装,始发、掘进、接收等施工时我们工程监理人控制中的重点。其盾构井下安装中盾构机内外拼装焊接质量,是在盾构隧道区间中重中之重,并将影响盾构区间的质量,当然盾构机前期的研发制作也是相关人员控制的重要质量,如施工中控制不妥,必将产生地表隆起或下沉,管片破裂一致成型隧道漏渗严重,其相关后果必将造成隧道的质量问题,并最终影响地下隧道的使用寿命。 展开更多
关键词 盾构安装 始发 掘进 接收 盾构管片破裂风险控制
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大跨度框架下穿多股道顶进施工时铁路线路加固技术研究 预览
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作者 魏亚茹 《价值工程》 2019年第19期162-165,共4页
龙象公路在象山煤矿东侧下穿侯西铁路、运煤专线及编组站专用线等5条铁轨,公路设置2-14m框架下穿铁路。针对本项目为大跨度框架下穿铁路5股道顶进施工,施工难度高,安全压力大。通过采取纵横抬梁法+吊轨梁对既有铁路5股道进行线路加固,... 龙象公路在象山煤矿东侧下穿侯西铁路、运煤专线及编组站专用线等5条铁轨,公路设置2-14m框架下穿铁路。针对本项目为大跨度框架下穿铁路5股道顶进施工,施工难度高,安全压力大。通过采取纵横抬梁法+吊轨梁对既有铁路5股道进行线路加固,并顶进中运用了石蜡、黄油及塑料薄膜组成复合滑动层,滚杠、定向滑轮等措施,减小了框构桥顶进施工时的摩阻力,加快了施工进度,提高了顶进过程的安全性。 展开更多
关键词 大跨度框架 顶进施工 线路加固技术 减摩措施
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Resection of early esophageal neoplasms:The pendulum swings from surgical to endoscopic management 预览
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作者 Vedha Sanghi Hina Amin +1 位作者 Madhusudhan R Sanaka Prashanthi N Thota 《世界胃肠内镜杂志:英文版(电子版)》 2019年第10期491-503,共13页
Esophageal cancer is a highly lethal disease and is the sixth leading cause of cancer related mortality in the world.The standard treatment is esophagectomy which is associated with significant morbidity and mortality... Esophageal cancer is a highly lethal disease and is the sixth leading cause of cancer related mortality in the world.The standard treatment is esophagectomy which is associated with significant morbidity and mortality.This led to development of minimally invasive,organ sparing endoscopic therapies which have comparable outcomes to esophagectomy in early cancer.These include endoscopic mucosal resection and endoscopic submucosal dissection.In early squamous cell cancer,endoscopic submucosal dissection is preferred as it is associated with cause specific 5-year survival rates of 100%for M1 and M2 tumors and 85%for M3 and SM1 tumors and low recurrence rates.In early adenocarcinoma,endoscopic resection of visible abnormalities is followed by ablation of the remaining flat Barrett’s mucosa to prevent recurrences.Radiofrequency ablation is the most widely used ablation modality with others being cryotherapy and argon plasma coagulation.Focal endoscopic mucosal resection followed by radiofrequency ablation leads to eradication of neoplasia in 93.4%of patients and eradication of intestinal metaplasia in 73.1%of patients.Innovative techniques such as submucosal tunneling with endoscopic resection are developed for management of submucosal tumors of the esophagus.This review includes a discussion of various endoscopic techniques and their clinical outcomes in early squamous cell cancer,adenocarcinoma and submucosal tumors.An overview of comparison between esophagectomy and endoscopic therapy are also presented. 展开更多
关键词 Esophageal cancer SUBMUCOSAL tumors SUBMUCOSAL tunneling Barrett’s esophagus DYSPLASIA Adenocarcinoma ENDOSCOPIC therapy Radiofrequency ablation ENDOSCOPIC MUCOSAL RESECTION
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煤矿软岩巷道掘进支护技术探讨 预览
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作者 荆彦军 《当代化工研究》 2019年第7期17-18,共2页
掘进支护技术在软岩巷道施工建设中的应用效果,对整个巷道的稳固性和作业人员的人身安全起着重要作用,对保证煤矿企业的安全生产也具有重要意义。在对软岩巷道进行掘进支护过程中,出现了很多问题,比如软岩强度不高导致围岩应力水平较高... 掘进支护技术在软岩巷道施工建设中的应用效果,对整个巷道的稳固性和作业人员的人身安全起着重要作用,对保证煤矿企业的安全生产也具有重要意义。在对软岩巷道进行掘进支护过程中,出现了很多问题,比如软岩强度不高导致围岩应力水平较高,岩层中存在吸水膨胀特性的黏土矿物质会对软岩巷道的支护结构产生影响。所以为了降低围岩变形对巷道掘进支护工作带来的不利影响,需要采用一些方法措施来提高围岩强度和支护表力。目前在软岩巷道掘进作业中最常用的支护技术就是锚杆联合支护与锚网喷支护,合理掘进支护方式的选择要根据当地矿井的地质特点来决定。 展开更多
关键词 软岩巷道 掘进 支护技术
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The influence of hand hole on the ultimate strength and crack pattern of shield tunnel segment joints by scaled model test
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作者 Shaochun WANG Xi JIANG Yun BAI 《结构与土木工程前沿:英文版》 EI CSCD 2019年第5期1200-1213,共14页
With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint e... With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint especially when the circumferential axial force is extremely high. Despite the wide application of steel fiber or synthetic fiber in t|ie tunneling, limited researches focus on the structural responses of segment joint with macro structural synthetic fiber (MSSF). In this paper, a 1:2 reduced-scale experiment was conducted to study the structural perfonnance of the segment joint with different types of hand holes under ultra-high axial force. Special attention is paid to failure mode and structural performance (bearing capacity, deformation, cracking, and toughness). Moreover, segment joints with MSSF are also tested to evaluate the effects of MSSF on the failure mode and structural performance of the segment joints. The experiment results show that the hand hole becomes the weakest point of the segment joint under ultra-high axial force. A\/-type crack pattern is always observed before the final failure of the segment joints. Different types and sizes of the hand hole have different degree of influences on the structural behavior of segment joints. The segment joint with MSSF shows higher ultimate bearing capacity and toughness compared to segment joint with common concrete. Besides, the MSSF improves the initial cracking load and anti-spallling resistance of the segment joint. 展开更多
关键词 SHIELD TUNNELING structural synthetic fiber concrete HAND HOLE SEGMENT joint ULTIMATE bearing capacity crack pattern
Controlled growth of uniform two-dimensional ZnO overlayers on Au(111)and surface hydroxylation
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作者 Hao Wu Qiang Fu +8 位作者 Yifan Li Yi Cui Rui Wang Nan Su Le Lin Aiyi Dong Yanxiao Ning Fan Yang Xinhe Bao 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第9期2348-2354,共7页
Ultrathin ZnO nano structures prese nt in teresti ng two-dimensi on al(2D)graphene-like structure in contrast to wurtzite structure in bulk ZnO.Growth on Au(111)has been regarded as a well-established route to the 2D ... Ultrathin ZnO nano structures prese nt in teresti ng two-dimensi on al(2D)graphene-like structure in contrast to wurtzite structure in bulk ZnO.Growth on Au(111)has been regarded as a well-established route to the 2D ZnO layers while controlled growth of uniform ZnO nano structures remains as a challe nge.Here,reactive deposition of Zn in O3 and NO2 was employed,which is investigated by sea nning tunneling microscopy and X-ray photoelectr on spectroscopy(XPS).We dem on strate that uniform ZnO mono layer nanoislands and films can be obtained on Au(111)using O3 and uniform ZnO bilayer nanoislands and films form on Au(111)using NO2,respectively.Formation of atomic oxyge n overlayers on Au(111)via exposure to O3 is critical to the formatio n of uniform ZnO mono layer nano structures atop.Near ambient pressure XPS studies revealed that n early full hydroxy lati on occurs on mono layer ZnO structures upon exposure to near ambient pressure water vapor or atomic hydrogen species,while partial surface hydroxylation happens on bilayer ZnO under the same gaseous exposure conditions. 展开更多
关键词 graphene-like ZNO TWO-DIMENSIONAL materials HYDROXYLATION near ambient pressure X-ray PHOTOELECTRON spectroscopy(NAP-XPS) seanning tunneling microscopy(STM)
Modified criterion for prediction of tunnel deformation in non-squeezing ground conditions 预览
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作者 Ako Daraei Shokrollah Zare 《现代交通学报:英文版》 2019年第1期11-24,共14页
The strength factor-based criterion for tunnel deformation prediction proposed by Hoek in 2000 is reckoned to be the most practical criterion among the tunnel deformation criteria since 1980s.In view of the fact that ... The strength factor-based criterion for tunnel deformation prediction proposed by Hoek in 2000 is reckoned to be the most practical criterion among the tunnel deformation criteria since 1980s.In view of the fact that Hoek’s criterion was obtained based on case studies under squeezing ground conditions,it has a limited range of applications,applicable mainly in squeezing tunnels.In this work,this criterion was modified by taking into consideration the conditions of eight unstable stations in three non-squeezing tunnels in Iran to amplify its application range.Relative displacements and strength factor(defined as a strength-to-stress ratio)were obtained in unstable stations first.Then,the parametric values were plotted on a Cartesian coordinate’s plane.By using the optimal regression line passing through all points,a criterion for prediction of tunnel deformation was proposed finally.A comparison made between the measured values and the ones predicted by the new criterion shows that the variance accounted for was 77%and the root mean square error was 2%,an acceptable accuracy and a small error implying the effectiveness of the new criterion in tunnel deformation prediction.In addition,the results show that the strength factor of 0.38 can be used to determine the boundary between squeezing and non-squeezing conditions;the behavior and type of failure of the tunnel would be predictable by use of the strength factor. 展开更多
关键词 Strength factor TUNNEL DEFORMATION Monitoring Failure type TUNNELING
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基于GNS3的IPSec-VPN仿真设计与实现 预览
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作者 吴志森 《九江职业技术学院学报》 2019年第1期21-23,17共4页
利用GNS3网络模拟器构建IPSec-VPN网络,实现密钥管理和交换、认证和数据篡改的安全机制。通过Ping工具和Wireshark对数据包进行测试和验证分析,保证了同一网络不同站点之间进行数据交换时对数据包是加密的。
关键词 GNS3 VPN IPSEC 隧道
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Charge trapping memory device based on the Ga2O3 films as trapping and blocking layer
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作者 白冰 王宏 +9 位作者 李岩 郝云霞 张博 王博平 王子航 杨红旗 高启航 吕超 张庆顺 闫小兵 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期101-104,共4页
We present a new charge trapping memory(CTM) device with the Au/Ga2O3/SiO2/Si structure, which is fabricated by using the magnetron sputtering, high-temperature annealing, and vacuum evaporation techniques. Transmissi... We present a new charge trapping memory(CTM) device with the Au/Ga2O3/SiO2/Si structure, which is fabricated by using the magnetron sputtering, high-temperature annealing, and vacuum evaporation techniques. Transmission electron microscopy diagrams show that the thickness of the SiO2 tunneling layer can be controlled by the annealing temperature.When the devices are annealed at 760℃, the measured C-V hysteresis curves exhibit a maximum 6 V memory window under a ±13 V sweeping voltage. In addition, a slight degradation of the device voltage and capacitance indicates the robust retention properties of flat-band voltage and high/low state capacitance. These distinctive advantages are attributed to oxygen vacancies and inter-diffusion layers, which play a critical role in the charge trapping process. 展开更多
关键词 CHARGE TRAPPING memory SiO2 TUNNELING layer ANNEALING temperature
Method of Hill Tunneling via Weighted Simplex Centroid for Continuous Piecewise Linear Programming
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作者 Zhiming Xu Yu Bai +1 位作者 Kuangyu Liu Shuning Wang 《清华大学学报自然科学版(英文版)》 EI CAS CSCD 2019年第3期301-316,共16页
This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. pr... This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. programming and concave optimization over a polyhedron. Considering that the super-level sets of concave piecewise linear functions are polyhedra, we propose the Hill Tunneling via Weighted Simplex Centroid(HTWSC) algorithm, which can escape a local optimum to reach the other side of its contour surface by cutting across the super-level set. The searching path for hill tunneling is established via the weighted centroid of a constructed simplex. In the numerical experiments, different weighting methods are studied first, and the best is chosen for the proposed HTWSC algorithm. Then, the HTWSC algorithm is compared with the hill detouring method and the software CPLEX for the equivalent mixed integer programming, with results indicating its superior performance in terms of numerical efficiency and the global search capability. 展开更多
关键词 global optimization PIECEWISE linear CONCAVE minimization cutting plane METHOD HILL TUNNELING
EJM340/4-2掘锚一体机在凉水井矿的应用
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作者 王佃武 《煤矿机械》 北大核心 2019年第3期118-120,共3页
针对采掘衔接紧张、掘进技术落后的现状,凉水井矿采用掘支运平行作业理念,结合4-2煤的地质条件和巷道规格,引入国产掘锚一体机,优化掘、支、运工艺,提高掘进自动化和智能化水平,实现了掘进效率的大幅提升。
关键词 掘锚一体机 掘进 平行作业
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