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Techniques of High Tibial Osteotomy: A Review 认领
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作者 Mohammad Jawed Aqil Liyong Gang +2 位作者 Abdul Qadir Nawabi Jinan Wei Nasir Ahmad Haidari 《矫形学期刊(英文)》 2020年第5期93-109,共17页
Main intention of the research is to understand about significance of techniques associated with HTO. This research reviewed the techniques of high tibial osteotomy namely high tibial osteotomy, open wedge high tibial... Main intention of the research is to understand about significance of techniques associated with HTO. This research reviewed the techniques of high tibial osteotomy namely high tibial osteotomy, open wedge high tibial osteotomy, closedhigh tibial osteotomy. Patients who are suffering from knee arthritis, high tibial osteotomy assists to prevent or delay the requirement for total or partial replacement of knee to preserve damaged tissue of joint. High tibial osteotomy technique is mainly suitable for active and young patients with knee osteoarthritis. Age plays a main factor in success rate of high tibial osteotomy technique. It could be done in open wedge or closed wedge high tibial osteotomy. For some cases, surgery could be done in combined method (open wedge and closed wedge high tibial osteotomy). When compared with clinical outcomes of closed wedge high tibial osteotomy and open wedge high tibial osteotomy, open wedge high tibial osteotomy performs well in reducing the pain, duration of weight-bearing and return to normal life as soon as possible. 展开更多
关键词 HIGH TIBIAL OSTEOTOMY Open WEDGE HIGH TIBIAL OSTEOTOMY KNEE OSTEOARTHRITIS Closed WEDGE HIGH TIBIAL OSTEOTOMY
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Deposition of Magnetic Carbon Nano Tubes with Chromium Seed 认领
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作者 Nelson Ordonez 《纳米科学与工程(英文)》 2020年第2期27-35,共9页
In this work, was obtained metallic decorated, single wall Carbon Nanotubes (SWCNTs) using High Density Chemical Vapor Deposition (HDPCVD) system on chromium thin films on a silicon wafers substrate. The characteristi... In this work, was obtained metallic decorated, single wall Carbon Nanotubes (SWCNTs) using High Density Chemical Vapor Deposition (HDPCVD) system on chromium thin films on a silicon wafers substrate. The characteristics of this deposition method are capacity of the segregation of metallic nanoparticlesas seed for the SWCNT growing. Use of magnetic particle decorated carbon nanotubes increases the applications in magnetic devices, magnetic memory, and magnetic oriented drug delivery. The CNTs’ spectra show a unique emission band, but due to the presence of the chromium, the spectra obtained in this work showed many bands that are related to the CNTs with different diameters. The CNTs obtained by the HDPCVD system are highly aligned and showed metallic features. Results of this work proved the possibility of obtaining the controlled deposition of aligned single-walled CNTs forest films decorated with chromium and suggested future studies in magnetic devices applications. 展开更多
关键词 CNTs Forest High Density Plasma Deposition High-Aligned CNTs NANOMATERIALS
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Household Solid Waste Generation and Composition: A Case Study in Palapye, Botswana 认领
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作者 Ronald Dikole Moatlhodi Wise Letshwenyo 《环境保护(英文)》 2020年第2期110-123,共14页
The purpose of this case study was to conduct a case study in the generation rate, composition, and characterise solid wastes from low, middle and high income households during weekdays and weekends in Palapye, Botswa... The purpose of this case study was to conduct a case study in the generation rate, composition, and characterise solid wastes from low, middle and high income households during weekdays and weekends in Palapye, Botswana. The study was conducted through sampling and analysis of the wastes from sampled households from each of the three categories. Palapye village does not have an engineered solid waste management system in place;hence the study can be used as a starting point. The village is rapidly urbanising with many shopping complexes coming up which will generate high amounts of solid wastes of different compositions. The lowest generation rate was 0.038 kg/capita/day from low income households during weekends and the highest was 0.364 kg/capita/day generated from high income households during weekends. The composition of the wastes was dominated by food wastes ranging from 46.44% to 80.78% with low income households generating the highest percentage during weekdays. The average moisture contents of samples from low, middle and high income households were 71% ± 0.0%, 66.3% ± 1.25% and 74.3% ± 2.2% respectively during weekdays compared to 77% ± 0.0%, 66.5% ± 3.5% and 69.3% ± 3.3% during weekends. The average moisture contents from low, middle and high income households were 71% ± 0.0%, 66.3% ± 1.25% and 74.3% ± 2.2% respectively during weekdays compared to 77% ± 0.0%, 66.5% ± 3.5% and 69.3% ± 3.3% during weekends. The results can be used as part of the waste management planning purpose by the Administrative Council of the area. 展开更多
关键词 Food WASTES High INCOME Households MIDDLE INCOME Households LOWER INCOME Households Solid WASTE Generation Rate
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Prevalence and Factors Associated High Blood Pressure among Women at the Market of Dantokpa in Benin in 2017 认领
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作者 Mama Cisse Ibrahim Alassani Adébayo +4 位作者 Adjobimey Mènonli Alpha Bio Issifou Amadou Mikponhoue Rose Hinsou Antoine Vikkey Ayelo Paul 《职业病与环境医学(英文)》 2020年第3期91-98,共8页
<strong>Introduction:</strong> Cardiovascular disease (CVD) is the leading cause of death worldwide. Among these CVDs, high blood pressure (hypertension) is the main one. The purpose of this study is to in... <strong>Introduction:</strong> Cardiovascular disease (CVD) is the leading cause of death worldwide. Among these CVDs, high blood pressure (hypertension) is the main one. The purpose of this study is to investigate the prevalence and factors associated with hypertension in women in the market of Dantokpa. <strong>Study Method:</strong> This is a cross-sectional, descriptive and analytical survey undertaken on women selling in the Dantokpa market. The dependent variable is hypertension. Data analysis was done using Epi data 3.1 software. <strong>Results:</strong> A total of 255 women were enrolled in the study. The average age was 41.6 ± 12.13 years with extremes of 18 and 84 years. Among women, 114 (34%) were suffering from hypertension. The factors associated with hypertension in women in the Dantokpa market were above 40 years old, educated women, physical inactivity, family history of hypertension, salty food. <strong>Conclusion:</strong> At the end of this study, it appears that the prevalence of hypertension in women in the Dantokpa market is higher than that of the general female population. Therapeutic and preventive measures are necessary. 展开更多
关键词 High Blood Pressure PREVALENCE Associated Factors Dantokpa BENIN
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Coexistence of plastic and partially diffusive phases in a helium-methane compound 认领
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作者 Hao Gao Cong Liu +5 位作者 Andreas Hermann Richard J.Needs Chris J.Pickard Hui-Tian Wang Dingyu Xing Jian Sun 《国家科学评论:英文版》 SCIE EI CSCD 2020年第10期1540-1547,共8页
Helium and methane are major components of gian icy planets and are abundant in the universe.However,helium is the most inert element in the periodic table and methane is one of the most hydrophobic molecules,thus whe... Helium and methane are major components of gian icy planets and are abundant in the universe.However,helium is the most inert element in the periodic table and methane is one of the most hydrophobic molecules,thus whether they can react with each other is of fundamental importance.Here,our crystal structure searches and first-principles calculations predict that a He3CH4 compound is stable over a wide range of pressures from 55 to 155 GPa and a HeCH4 com pound becomes stable around 105 GPa.As nice examples of pure van der Waals crystals;the insertion of helium atoms changes the original packing of pure methane molecules and also largely hinders the polymerization of methane at higher pressures.After analyzing the diffusive properties during the melting of He3CH4 at high pressure and high temperature,in addition to a plastic methane phase,we have discovered an unusual phase which exhibits coexistence of diffusive helium and plastic methane.In addition,the range of the diffusive behavior within the helium-methane phase diagram is found to be much narrower compared to that of previously predicted helium-water compounds.This may be due to the weaker van der Waals interactions between methane molecules compared to those in helium-water compounds;and that the helium-methane compound melts more easily. 展开更多
关键词 crystal structure prediction ab initio molecular dynamics ab initio calculations high pressure and high temperature melting and phase transition collective motion
Frequency Control of Power System with Renewable Power Sources by HVDC Interconnection Line and Battery Considering Energy Balancing 认领
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作者 Shoyu Onuka Atsushi Umemura +4 位作者 Rion Takahashi Junji Tamura Atsushi Sakahara Fumihito Tosaka Ryosuke Nakamoto 《电力能源(英文)》 2020年第4期11-24,共14页
Recently, introduction of renewable energy sources like wind power generation and photovoltaic power generation has been increasing from the viewpoint of environmental problems. However, renewable energy power supplie... Recently, introduction of renewable energy sources like wind power generation and photovoltaic power generation has been increasing from the viewpoint of environmental problems. However, renewable energy power supplies have unstable output due to the influence of weather conditions such as wind speed variations, which may cause fluctuations of voltage and frequency in the power system. This paper proposes fuzzy PD based virtual inertia control system to decrease frequency fluctuations in power system caused by fluctuating output of renewable energy sources. The proposed new method is based on the coordinated control of HVDC interconnection line and battery, and energy balancing control is also incorporated in it. Finally, it is concluded that the proposed system is very effective for suppressing the frequency fluctuations of the power system due to the large-scale wind power generation and solar power generation and also for keeping the energy balancing in the HVDC transmission line. 展开更多
关键词 High Voltage Direct Current (HVDC) Transmission POWER System Frequency CONTROL COORDINATED CONTROL BATTERY RENEWABLE POWER Energy Balancing
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Improvement of Mongolian Height System Using a Satellite Technology 认领
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作者 Sodnom Enkhtuya Damdinsuren Amarsaikhan 《应用科学(英文)》 2020年第4期154-168,共15页
In recent years, development of a proper country-specific height system has become a major challenge for the scholars and specialists working in the field of geodesy. The National Geodetic Services of many countries a... In recent years, development of a proper country-specific height system has become a major challenge for the scholars and specialists working in the field of geodesy. The National Geodetic Services of many countries are trying to establish a new system that can provide the customers and decision-makers with high accuracy basic geodetic data obtained by modern satellite measurements. Although, Mongolia has a long tradition with geodesy and land surveying, the country still lacks a refined height system that can be effectively used for mapping and other purposes. In the present study, we tried to solve the problem related to the Mongolian height system using of a modern satellite technology. The research had some very important results: 1) evaluation of the main height network and height system of Mongolia, 2) development of a new method for calculating the normal height system in Mongolia, and 3) creation of the height unified system by considering surface potential of the global ellipsoidal level as normal. 展开更多
关键词 HEIGHT System ASTRONOMY GEODETIC Control NETWORK (AGCN) High ACCURACY GEODETIC NETWORK (HAGN) State GEODETIC NETWORK (SGN)
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Research and Application of an Environmental-Friendly Low-Damage and High Salt-Resistance Slick Water Fracturing Fluid System 认领
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作者 Qingwen Zeng Peng Fu +3 位作者 Lei Meng Hua Shi Hong Zhou Weichu Yu 《长江油气:英文版》 2020年第3期131-143,共13页
The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce... The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce water resources on the site. These unfavorable factors have brought great difficulties to the on-site mining process. Now, a nano-composite green environmental protection slick water fracturing fluid system CQFR can be quickly dissolved because of the larger specific surface area, and the small molecular size makes the damage to the reservoir less than 5%, and the average drag reduction effect can reach more than 73%. It can quickly and well dissolve and maintain performance under high salinity conditions and fracturing flowback fluids. It responds well to the complex reservoir conditions on the construction site and makes the flowback fluid recyable, which greatly reduces the consumption of water resources on the construction site and effectively improves the construction efficiency and economic benefits. 展开更多
关键词 Tight Sandstone Recyclable Backwater Green Environmentally Friendly Low-Damage High Salt-Resistance Slick Water
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Mesoscale Impacts on Cold Season PM<sub>2.5</sub>in the Yukon Flats 认领
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作者 Stanley G. Edwin Nicole M?lders 《环境保护(英文)》 2020年第3期215-240,共26页
Near-surface PM2.5 and meteorological observations were performed in three rural communities in the high latitude Yukon Flats valley at various times during the cold season (October to April). These data were synthesi... Near-surface PM2.5 and meteorological observations were performed in three rural communities in the high latitude Yukon Flats valley at various times during the cold season (October to April). These data were synthesized with data from other meteorological sites, NCEP reanalysis and MAIAC retrieved aerosol optical depths data to analyze the role of mesoscale processes and radiation on air quality. Under weak large-scale forcing mountain-valley circulations develop that are driven by the differences in insolation. During the long dark nights, radiative cooling occurs in the near-surface layer of the mountain slopes of the Brooks, Ogilvie and White Mountains Ranges and at the bottom of the valley. Here surface-based inversions (SBI)—known as roof-top inversions—forms, while the cold air drains from the slopes. A frontal wedge forms when the cold air slides over the relatively colder air in the valley. Drainage of cold air from the Brooks Range governed the circulation and cold air pooling in the valley. Concentrations during times with and without SBI differed significantly (at 95% confidence) at two sites indicating that local emissions were the major contributor. At the site, which is closest to the mountains, concentrations marginally changed in the presence of inversions. At all sites, 24-h mean PM2.5 remained below the National Ambient Air Quality Standard. 展开更多
关键词 YUKON Flats AIR Quality Winter Roof-Top Inversions High Latitudes MESOSCALE Circulations Radiative Cooling COLD AIR Pooling Aerosols PM2.5
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High wall-plug efficiency 808-nm laser diodes with a power up to 30.1 W 认领
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作者 Zhanqiang Ren Qingmin Li +1 位作者 Bo Li Kechang Song 《半导体学报:英文版》 EI CAS CSCD 2020年第3期59-61,共3页
A very highly efficient InGaAlAs/AlGaAs quantum-well structure was designed for 808 nm emission,and laser diode chips 390-μm-wide aperture and 2-mm-long cavity length were fabricated.Special pretreatment and passivat... A very highly efficient InGaAlAs/AlGaAs quantum-well structure was designed for 808 nm emission,and laser diode chips 390-μm-wide aperture and 2-mm-long cavity length were fabricated.Special pretreatment and passivation for the chip facets were performed to achieve improved reliability performance.The laser chips were p-side-down mounted on the AlN submount,and then tested at continuous wave(CW)operation with the heat-sink temperature setting to 25℃using a thermoelectric cooler(TEC).As high as 60.5%of the wall-plug efficiency(WPE)was achieved at the injection current of 11 A.The maximum output power of 30.1 W was obtained at 29.5 A when the TEC temperature was set to 12°C.Accelerated life-time test showed that the laser diodes had lifetimes of over 62111 h operating at rated power of 10 W. 展开更多
关键词 HIGH POWER semiconductor LASERS HIGH wall-plug EFFICIENCY COMD
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High Throughput Sequencing of circRNAs in Tomato Leaves Responding to Multiple Stresses of Drought and Heat 认领
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作者 Rong Zhou Xiaqing Yu +1 位作者 Carl-Otto Ottosen Tongmin Zhao 《园艺学报:英文版》 2020年第1期34-38,共5页
Our aim is to study the roles of a new emerging group of non-coding RNAs, circRNAs, in tomato(Solanum lycopersicum L.) plants grown at the combination of drought and heat, two of the most usual stress conditions known... Our aim is to study the roles of a new emerging group of non-coding RNAs, circRNAs, in tomato(Solanum lycopersicum L.) plants grown at the combination of drought and heat, two of the most usual stress conditions known to frequently happen in field. Tomato seedlings from cultivar‘Jinling Meiyu’ were treated without stresses(control), at water shortage, high temperature and subjected the multiple stresses. In total, 467 circRNAs were identified with 87.82% from exon using high throughput sequencing technology. Among the circRNAs, 70 were from chr1 with the range from 23 to 49 from the other chromosomes. In detail, 156 circRNAs were shared in the four libraries, while 21, 17 and 36 circRNAs were only shown in drought, heat and multiple stresses libraries, respectively. Through a differential expression analysis, four, seven and nine circRNAs were differentially regulated in tomato at drought, heat and multiple stresses as compared with control. These circRNAs played roles on photosynthesis, starch and sucrose metabolism, RNA transport, RNA degradation, spliceosome, ribosome, etc. Our study underlined the potential role of circRNAs involved in the abiotic stress response in tomato, which might pave the way for studying biological roles of circRNAs responding to multiple stresses in plants. 展开更多
关键词 SOLANUM lycopersicum circRNAs HIGH THROUGHPUT SEQUENCING HIGH temperature Water SHORTAGE
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Cardiac Safety with High Cumulative Dose of Pegylated Liposomal Doxorubicin in Patients with Metastatic Breast Cancer Previously Treated with Conventional Anthracyclines 认领
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作者 Ahmed Refaat Dalia O. Mohamed +1 位作者 Elsayed Mostafa Ali Salah Mabrouk Khallaf 《乳腺癌(英文)》 2020年第3期55-65,共11页
<strong>Introduction:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The treatment of meta... <strong>Introduction:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The treatment of metastatic breast cancer (MBC) is still challenging.</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Many studies documented the efficacy of</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">pegylated liposomal doxorubicin (PLD) in patients with MBC, but there is a limited data about the cardiac safety with high cumulative dose (HCD) of PLD. </span><b><span style="font-family:Verdana;">Aim of the work:</span></b></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">We conducted this trial to outline the cardiac safety of HCD of PLD in patients </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">with MBC who previously received conventional anthracyclines. </span><b><span style="font-family:Verdana;">Methods:</span></b> <span style="font-family:Verdana;">During the period of nine years (January 2011 to December 2019). We extracted</span><span style="font-family:Verdana;"> the data of the patients with MBC receiving PLD at Medical Oncology Department, South Egypt Cancer Institute, Assiut University. These included patients’ demographics and therapeutic data including the full data of PLD, prior conventional anthracyclines, prior trastuzumab, and prior radiotherapy. Also, data about comorbidities as well as cardiac and other toxicities of PLD were obtained. The data was analysed using SPSS v. 21. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> For all 81 eligible patients, the mean age was 43.9 ye 展开更多
关键词 Metastatic Breast Cancer Pegylated Liposomal Doxorubicin High Cumulative Dose Cardiac Toxicity
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基于垂直带谱的南北过渡带1:5万植被类型图遥感制图研究——以太白山为例 认领
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作者 姚永慧 索南东主 张俊瑶 《地理学报:英文版》 SCIE CSCD 2020年第2期267-280,共14页
The compilation of 1:250,000 vegetation type map in the North-South transitional zone and 1:50,000 vegetation type maps in typical mountainous areas is one of the main tasks of Integrated Scientific Investigation of t... The compilation of 1:250,000 vegetation type map in the North-South transitional zone and 1:50,000 vegetation type maps in typical mountainous areas is one of the main tasks of Integrated Scientific Investigation of the North-South Transitional Zone of China.In the past,vegetation type maps were compiled by a large number of ground field surveys.Although the field survey method is accurate,it is not only time-consuming,but also only covers a small area due to the limitations of physical environment conditions.Remote sensing data can make up for the limitation of field survey because of its full coverage.However,there are still some difficulties and bottlenecks in the extraction of remote sensing information of vegetation types,especially in the automatic extraction.As an example of the compilation of 1:50,000 vegetation type map,this paper explores and studies the remote sensing extraction and mapping methods of vegetation type with medium and large scales based on mountain altitudinal belts of Taibai Mountain,using multi-temporal high resolution remote sensing data,ground survey data,previous vegetation type map and forest survey data.The results show that:1)mountain altitudinal belts can effectively support remote sensing classification and mapping of 1:50,000 vegetation type map in mountain areas.Terrain constraint factors with mountain altitudinal belt information can be generated by mountain altitudinal belts and 1:10,000 Digital Surface Model(DSM)data of Taibai Mountain.Combining the terrain constraint factors with multi-temporal and high-resolution remote sensing data,ground survey data and previous small-scale vegetation type map data,the vegetation types at all levels can be extracted effectively.2)The basic remote sensing interpretation and mapping process for typical mountains is interpretation of vegetation type-groups→interpretation of vegetation formation groups,formations and subformations→interpretation and classification of vegetation types&subtypes,which is a combination method of top-down m 展开更多
关键词 vegetation type map high resolution REMOTE SENSING data MOUNTAIN altitudinal BELTS REMOTE SENSING interpretation Taibai MOUNTAIN
High pressure and high temperature induced polymerization of C60 quantum dots 认领
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作者 阮世豪 韩春淼 +2 位作者 李福禄 李冰 刘冰冰 《中国物理B:英文版》 SCIE EI CAS CSCD 2020年第2期396-400,共5页
We synthesized C60 quantum dots(QDs) with a uniform size by a modified ultrasonic process and studied its polymerization under high pressure and high temperature(HPHT).Raman spectra showed that a phase assemblage of a... We synthesized C60 quantum dots(QDs) with a uniform size by a modified ultrasonic process and studied its polymerization under high pressure and high temperature(HPHT).Raman spectra showed that a phase assemblage of a dimer(D) phase(62 vol%) and a one-dimensional chain orthorhombic(O) phase(38 vol%) was obtained at 1.5 GPa and 300℃.At 2.0 GPa and 430℃,the proportion of the O phase increased to 46 vol%,while the corresponding D phase decreased to 54 vol%.Compared with bulk and nanosized C60,C60 QDs cannot easily form a high-dimensional polymeric structure.This fact is probably caused by the small particle size,orientation of the disordered structure of C60 QDs,and the barrier of oxide function groups between C60 molecules.Our studies enhance the understanding of the polymerization behavior of low-dimension C60 nanomaterials under HPHT conditions. 展开更多
关键词 C60 quantum DOTS HIGH pressure and HIGH temperature FULLERENE polymer
Best Practice Standards and Methodology for Crane Operator Training—A Global Perspective 认领
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作者 Richard Skiba 《交通科技期刊(英文)》 2020年第3期265-279,共15页
Crane operators control mobile or stationary cranes to lift, move and place objects at locations such as building and construction sites, wharves and shi<span>pyards. This activity occurs all over the world and ... Crane operators control mobile or stationary cranes to lift, move and place objects at locations such as building and construction sites, wharves and shi<span>pyards. This activity occurs all over the world and is a high risk task with many</span><span> noted examples of serious incidents and accidents. There are identifiable key causes that have been noted through analysis of the well documented cases </span><span>and many of these causes are preventable through effective training programs</span><span>. Internationally, there are not currently consistent approaches to crane operator training program content or duration. Leading causes of crane accidents are firstly discussed and identified as areas for inclusion in training programs. A number of current training approaches from a range of countries are then </span><span>considered and these are used to outline the basis of a generic competency </span><span>standard for crane operation, as it was found that there are not common standards</span><span> in place. The proposed competency standard can be adapted by training regulators, training providers, government agencies, industry bodies and </span><span>enterprises as a benchmark for the development of effective training pr</span><span>ograms.</span> 展开更多
关键词 Health and Safety Vocational Training Crane Operation Work Practices Risk Management High Risk Work
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Three-dimensional carbon framework as high-proportion sulfur host for high-performance lithium-sulfur batteries 认领
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作者 Xianbin Liu Zechen Xiao +6 位作者 Changgan Lai Shuai Zou Ming Zhang Kaixi Liu Yanhong Yin Tongxiang Liang Ziping Wu 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第13期84-91,共8页
Lithium-sulfur(Li-S)batteries are anticipated as one of the most promising candidates for the highenergy-density storage systems.However,the insulating nature and shuttling effect of sulfur severely limits their perfo... Lithium-sulfur(Li-S)batteries are anticipated as one of the most promising candidates for the highenergy-density storage systems.However,the insulating nature and shuttling effect of sulfur severely limits their performance.The incorporation of sulfur with carbon materials has been deemed as one of the most powerful strategies to improve electrical conductivity and suppress soluble polysulfide shuttling.Herein,a novel three-dimensional carbon framework(3DCF)is prepared and employed as a sulfur host(3DCF@S)for Li-S batteries.The 3DCF not only supplies abundant paths for lithium ion diffusion and electron transport,but also strengthens polysulfide immobilization during the lithium/sulfur conversion reactions.As a result,the 3DCF@S with high sulfur content of 90%exhibits a high capacity of 1366 mA h/g at 0.1 C and excellent cycling stability with a satisfactory capacity of 601 mA h/g after 600 cycles at 2.0 C.The resultant Li-S button battery based 3DCF@S electrode could power a light-emitting diode for 2 h.The acquired 3DCF@S is expected to be widely used in Li-S batteries and this study will promote developments of carbon/sulfur composites for Li-S batteries. 展开更多
关键词 3D carbon framework High sulfur proportion Lithium-sulfur battery High capacity Outstanding cycling stability
Regulation mechanism of catalyst structure on diamond crystal morphology under HPHT process 认领
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作者 李亚东 程永珊 +5 位作者 宿梦洁 冉启甫 王春晓 马红安 房超 陈良超 《中国物理B:英文版》 SCIE EI CAS CSCD 2020年第7期555-559,共5页
To elucidate the regulation mechanism of catalyst geometry structure to diamond growth,we establish three catalyst modes with different structures.The simulation results show that with the decrease of the protruding h... To elucidate the regulation mechanism of catalyst geometry structure to diamond growth,we establish three catalyst modes with different structures.The simulation results show that with the decrease of the protruding height of the catalyst,the low-temperature region gradually moves toward the center of the catalyst,which causes the distribution characteristics of the temperature and convection field in the catalyst to change.The temperature difference in vertical direction of the catalyst decreases gradually and increases in the horizontal direction,while the catalyst convection velocity has the same variation regularity in the corresponding directions.The variation of temperature difference and convection velocity lead the crystal growth rate in different crystal orientations to change,which directly affects the crystal morphology of the synthetic diamond.The simulation results are consistent with the experimental results,which shows the correctness of the theoretical rational analysis.This work is expected to be able to facilitate the understanding of catalyst structure regulation mechanism on diamond morphology and the providing of an important theoretical basis for the controllable growth of special crystal shape diamond under HPHT process. 展开更多
关键词 DIAMOND single crystal growth high pressure and high TEMPERATURE crystal morphology
Congruent melting of tungsten phosphide at 5 GPa and 3200℃ for growing its large single crystals 认领
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作者 向晓君 宋国柱 +13 位作者 周雪峰 梁浩 徐月 覃湜俊 王俊普 洪芳 戴建红 周博文 梁文嘉 殷云宇 赵予生 彭放 于晓辉 王善民 《中国物理B:英文版》 SCIE EI CAS CSCD 2020年第8期501-506,共6页
As one of important members of refractory materials,tungsten phosphide(WP)holds great potential for fundamental study and industrial applications in many fields of science and technology,due to its excellent propertie... As one of important members of refractory materials,tungsten phosphide(WP)holds great potential for fundamental study and industrial applications in many fields of science and technology,due to its excellent properties such as superconductivity and as-predicted topological band structure.However,synthesis of high-quality WP crystals is still a challenge by using tradition synthetic methods,because the synthesis temperature for growing its large crystals is very stringently required to be as high as 3000℃,which is far beyond the temperature capability of most laboratory-based devices for crystal growth.In addition,high temperature often induces the decomposition of metal phosphides,leading to off-stoichiometric samples based on which the materials'intrinsic properties cannot be explored.In this work,we report a high-pressure synthesis of single-crystal WP through a direct crystallization from cooling the congruent W-P melts at 5 GPa and~3200℃.In combination of x-ray diffraction,electron microscope,and thermal analysis,the crystal structure,morphology,and stability of recovered sample are well investigated.The final product is phase-pure and nearly stoichiometric WP in a single-crystal form with a large grain size,in excess of one millimeter,thus making it feasible to implement most experimental measurements,especially,for the case where a large crystal is required.Success in synthesis of high-quality WP crystals at high pressure can offer great opportunities for determining their intrinsic properties and also making more efforts to study the family of transition-metal phosphides. 展开更多
关键词 congruent melting tungsten phosphide single crystals high pressure and high temperature
Phase change,micro-structure and reaction mechanism during high temperature roasting of high grade rare earth concentrate 认领
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作者 Huihui Wang Mei Li +4 位作者 Dongliang Zhang Kai Gao Jianfei Li Zongxi Weng Wei Xu 《稀土学报:英文版》 SCIE EI CAS CSCD 2020年第10期1140-1150,I0005,共12页
The deposit of Bayan Obo in Inner Mongolia is the world’s largest rare earth element(abbreviated as REE)resource.The exploration of the theory of mineral formation of Bayan Obo is an important foundation for mineralo... The deposit of Bayan Obo in Inner Mongolia is the world’s largest rare earth element(abbreviated as REE)resource.The exploration of the theory of mineral formation of Bayan Obo is an important foundation for mineralogical research,and is the scientific basis for mining,industrial beneficiation,smelting and extraction,and processing and utilization.With the rapid development of science and technology,the demand for the utilization of rare earth elements is increasing,and the separation process between rare earth elements needs to be developed.The purpose of this paper is to provide high temperature experimental information for the formation and application of rare earth minerals.To this end,the mineral evolution of high-grade rare earth concentrates with increasing temperature and the migration of rare earths at different stages and their reaction mechanisms were studied.According to thermogravimetric analysis and differential scanning calorimetry(TG-DSC),calcination was carried out at different temperature ranges,and the calcined products were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron micro scope and energy dispers ive spectrometer(SEM-EDS)and other analytical techniques.The re sults are shown in this process,the ra re earth phase is first converted into rare earth oxide and rare earth oxyfluoride.As the temperature increases,Ca5(PO4)3 F and a large number of self-shaped spherical Ca-RE-OF and Ca-RE-PO4 particles are formed,and the separation of La and Ce elements is discovered.Acco rding to the phase diagram analysis,the production of Ca5(PO4)3 F is due to the reaction of monazite and fluorite,and the phases CeF2 and Ce F3 are formed during the reaction.When it reaches 1500℃,barium ferrite is produced and a new substance containing Ba2+is formed. 展开更多
关键词 High grade concentrates High-temperature roasting Rare-earth phase Decomposed Mechanism
Research on Sales Strategy Based on Supermarket Pipeline Data 认领
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作者 Hongwei Wen 《数据分析和信息处理(英文)》 2020年第3期99-109,共11页
“Low profit and high sales” is a strategy to increase sales volume by reducing the profit of unit goods, so that businesses can gain more profits. For flexible goods, price reduction can increase the total revenue, ... “Low profit and high sales” is a strategy to increase sales volume by reducing the profit of unit goods, so that businesses can gain more profits. For flexible goods, price reduction can increase the total revenue, but when the goods are lack of flexibility, price reduction will reduce the total revenue. In this paper, according to the sales data provided by a supermarket, we preprocess the data, establish appropriate indicators to measure the daily discount strength of the mall, and establish a mathematical model between the discount strength, sales and profit margin. Through these models, we found that meager profits do bring up sales, but too low discounts can also hurt total profits. In addition, when shopping malls implement discount promotions, they will also bring some negative effects, and we give some suggestions for this. 展开更多
关键词 Low Profit and High Sales Profit Margin Discount Rate Price Elasticity of Demand
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