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The Economics of Competing Water Uses under a FERC Licensing Agreement: Estimation of Property Value, Recreation, and Hydroelectric Impacts
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作者 Matthew Bingham Jason Kinnell 《Journal of Water Resource and Protection》 CAS 2024年第6期414-428,共15页
Reservoirs provide a variety of services with economic values across multiple sectors. As demands for reservoir services continue to grow and precipitation patterns evolve, it becomes ever more important to consider t... Reservoirs provide a variety of services with economic values across multiple sectors. As demands for reservoir services continue to grow and precipitation patterns evolve, it becomes ever more important to consider the integrated suite of values and tradeoffs that attend changes in water uses and availability. Section 316 (b) of the Clean Water Act requires that owners of certain water cooled power plants evaluate technologies and operational measures that can reduce their impacts to aquatic organisms. The studies must discuss the social costs and benefits of alternative technologies including cooling towers (79 Fed. Reg. 158, 48300 - 48439). Cooling towers achieve their effect through evaporation. This manuscript estimates the property value, recreation, and hydroelectric generation impacts that could result from the evaporative water loss associated with installing cooling towers at the McGuire Nuclear Generating Station (McGuire) located on Lake Norman, North Carolina. Although this study specifically evaluates the effects of evaporative water loss from cooling towers, its methods are applicable to estimating the economic benefits and costs of a new water user or reduced water input in any complex reservoir system that supports steam electric generation, hydroelectric generation, residential properties, recreation, irrigation, and municipal water use. 展开更多
关键词 property Value FERC Hydroelectric RECREATION Water Levels
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Machine learning-guided accelerated discovery of structure-property correlations in lean magnesium alloys for biomedical applications
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作者 Sreenivas Raguraman Maitreyee Sharma Priyadarshini +5 位作者 Tram Nguyen Ryan McGovern Andrew Kim Adam J.Griebel Paulette Clancy Timothy P.Weihs 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第6期2267-2283,共17页
Magnesium alloys are emerging as promising alternatives to traditional orthopedic implant materials thanks to their biodegradability,biocompatibility,and impressive mechanical characteristics.However,their rapid in-vi... Magnesium alloys are emerging as promising alternatives to traditional orthopedic implant materials thanks to their biodegradability,biocompatibility,and impressive mechanical characteristics.However,their rapid in-vivo degradation presents challenges,notably in upholding mechanical integrity over time.This study investigates the impact of high-temperature thermal processing on the mechanical and degradation attributes of a lean Mg-Zn-Ca-Mn alloy,ZX10.Utilizing rapid,cost-efficient characterization methods like X-ray diffraction and optical microscopy,we swiftly examine microstructural changes post-thermal treatment.Employing Pearson correlation coefficient analysis,we unveil the relationship between microstructural properties and critical targets(properties):hardness and corrosion resistance.Additionally,leveraging the least absolute shrinkage and selection operator(LASSO),we pinpoint the dominant microstructural factors among closely correlated variables.Our findings underscore the significant role of grain size refinement in strengthening and the predominance of the ternary Ca_(2)Mg_(6)Zn_(3)phase in corrosion behavior.This suggests that achieving an optimal blend of strength and corrosion resistance is attainable through fine grains and reduced concentration of ternary phases.This thorough investigation furnishes valuable insights into the intricate interplay of processing,structure,and properties in magnesium alloys,thereby advancing the development of superior biodegradable implant materials. 展开更多
关键词 Magnesium alloys Machine learning Corrosion Mechanical properties Rapid characterization
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Mechanical Property and Microstructure of Cement Mortar with Carbonated Recycled Powder
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作者 丁亚红 张美香 +3 位作者 YANG Xiaolin XU Ping SUN Bo GUO Shuqi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期689-697,共9页
Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbon... Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect. 展开更多
关键词 recycled powder carbonation activation compound carbonation activity index mechanical property MICROsTRUCTURE
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Adhesion property of AlCrNbSiTi high-entropy alloy coating on zirconium:experimental and theoretical studies
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作者 Bao‑Liang Zhang Wen‑Guan Liu +5 位作者 Meng‑He Tu Can Fang Yan Liu Yu‑Hui Wang Yong Hu Hui Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第8期79-91,共13页
Experimental scratch tests and first-principles calculations were used to investigate the adhesion property of AlCrNbSiTi high-entropy alloy(HEA)coatings on zirconium substrates.AlCrNbSiTi HEA and Cr coatings were dep... Experimental scratch tests and first-principles calculations were used to investigate the adhesion property of AlCrNbSiTi high-entropy alloy(HEA)coatings on zirconium substrates.AlCrNbSiTi HEA and Cr coatings were deposited on Zr alloy substrates using multi-arc ion plating technology,and scratch tests were subsequently conducted to estimate the adhesion property of the coatings.The results indicated that Cr coatings had better adhesion strength than HEA coatings,and the HEA coatings showed brittleness.The special quasi-random structure approach was used to build HEA models,and Cr/Zr and HEA/Zr interface models were employed to investigate the cohesion between the coatings and Zr substrate using first-principles calculations.The calculated interface energies showed that the cohesion between the Cr coating and the Zr substrate was stronger than that of the HEA coating with Zr.In contrary to Al or Si in the HEA coating,Cr,Nb,and Ti atoms binded strongly with Zr substrate.Based on the calculated elastic constants,it was found that low Cr and high Al content decreased the mechanical performances of HEA coatings.Finally,this study demonstrated the utilization of a combined approach involving first-principles calculations and experimental studies for future HEA coating development. 展开更多
关键词 High-entropy alloy coating Cr coating Adhesion property scratch test First-principles calculation
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Effect of Cryogenic Treatment on Microstructure and Tribological Property Evolution of Electron Beam Melted Ti6Al4V
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作者 黄西娜 MA Xiaowen XU Tianyi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期1010-1017,共8页
Cryogenic treatment was used to improve the tribological properties of Ti6Al4V artificial hip joint implants.Cryogenic treatment at-196℃with different holding time were carried out on Ti6Al4V specimens fabricated usi... Cryogenic treatment was used to improve the tribological properties of Ti6Al4V artificial hip joint implants.Cryogenic treatment at-196℃with different holding time were carried out on Ti6Al4V specimens fabricated using electron beam melting(EBM),and their microstructure and tribological properties evolution were systematically analyzed by scanning electron microscopy(SEM),vickers hardness,and wear tests.The experimental results show that the as-fabricated specimen consists of lamellarαphase andβcolumnar crystal.While,the thickness of lamellarαphase decreased after cryogenic treatment.In addition,it can be found that the fineαphase was precipitated and dispersed between the lamellarαphase with the holding time increase.Vickers hardness shows a trend of first increasing and then decreasing.The wear rate of the specimen cryogenic treated for 24 h is the minimum and the average friction coefficient is 0.50,which is reduced by 14.61%compared with the as-fabricated.The wear mechanism of the as-fabricated specimen is severe exfoliation,adhesive,abrasive,and slight fatigue wear.However,the specimen cryogenic treated for 24 h shows slight adhesive and abrasive wear.It can be concluded that it is feasibility of utilizing cryogenic treatment to reduce the wear of EBMed Ti6Al4V. 展开更多
关键词 electron beam melting(EBM) cryogenic treatment MICROsTRUCTURE vickers hardness tribological property
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Capillary Property of Entangled Porous Metallic Wire materials and Its Application in Fluid Buffers:Theoretical Analysis and Experimental Study
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作者 Yu Tang Yiwan Wu +1 位作者 Hu Cheng Rong Liu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期400-416,共17页
Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property en... Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of equipment.Based on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of EPMWM.The calculation model of the damping force of the composite buffer was established.The low-speed impact test of the composite buffer was conducted.The parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was obtained.The test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.). 展开更多
关键词 Entangled porous metallic wire materials Capillary property Viscousfluid Low-speed impact Damping force
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Fluid property identification of the Lower Cretaceous reservoirs with complex oil-water contacts in Deseo Basin,Chad
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作者 Xinxin Zhang Lianfeng Zhu +4 位作者 Tianjiao Wang Xiaokang Shi Bo Han Jian Shen Hailei Gao 《Energy Geoscience》 EI 2024年第1期89-98,共10页
Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,com... Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,complex oil-water contact within and faint responses of the oil zone,which causes the lower accuracy of reservoir fluid property identification with conventional mudlogging and wirelogging techniques.Applying the geochemical logging,fluorescent logging,mud logging and cutting logging technology,in combination with formation test data,this paper distinguishes the crude oil types,analyzes the logging response characteristics of oil zone after water washing,and establishes the interpretation charts and parameter standards for reservoir fluid properties.The crude oil can be divided into two types,namely viscous-heavy and thin-light,based on total hydrocarbon content and component concentration tested by mud logging,features of pyrolysis gas chromatogram and fluorescence spectroscopy.The general characteristics of oil layers experienced water washing include the decrease of total hydrocarbon content and component concentration from mud logging,the decrease of S1 and PS values from geochemical logging,the decrease of hydrocarbon abundance and absence of some light components in pyrolysis gas chromatogram,and the decrease of fluorescence area and intensity from fluorescence logging.According to crude oil types,the cross plots of S1 versus peak-baseline ratio,and the cross plots of rock wettability versus fluorescence area ratio are drawn and used to interpret reservoir fluid property.Meanwhile,the standards of reservoir fluid parameter are established combining with the parameters of PS and the parameters in above charts,and comprehensive multiparameter correlation in both vertical and horizontal ways is also performed to interpret reservoir fluid property.The application in the Doseo Basin achieved great success,improving interpretation ability of fluid property in the reservoir with complex oil-water contact,and also provided technical reference for the efficient exploration and development of similar reservoirs. 展开更多
关键词 Doseo Basin Reservoir interpretation Oil-water contact Fluid property Crude oil type
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Preparation and property of seal coating for gas turbine compressor
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作者 余沛坰 刘中华 +2 位作者 郑健生 徐伏根 陈千宝 《China Welding》 CAS 2024年第1期60-64,共5页
Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atm... Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atmospheric plasma spraying and top coating was prepared by flame spraying.The microstructure,mechanical properties and abradability of the coating were characterized by scanning elec-tron microscope(SEM),hardness tester,universal testing machine,thermal shock testing machine and abradability testing machine.The res-ults show that the overall spraying structure of the seal coating is uniform,the nickel metal phase is the skeleton supporting the entire coat-ing,and the coating is well bonded without separation.The seal coating has a bonding strength of not less than 7.7 MPa,excellent thermal stability,and thermal shock resistance cycle numbers at 500℃more than 50;the scratch length,deepest invasion depth and wear amount of the coating increase with rise of test temperature,with almost no coating adhesion,indicating that the seal coating has excellent abradability. 展开更多
关键词 gas turbine compressor seal coating MICROsTRUCTURE mechanical property abradability
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Unveiling the cellular microstructure-property relations in martensitic stainless steel via laser powder bed fusion
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作者 Lingzhi Wu Cong Zhang +7 位作者 Dil Faraz Khan Ruijie Zhang Yongwei Wang Xue Jiang Haiqing Yin Xuanhui Qu Geng Liu Jie Su 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第11期2476-2487,共12页
Laser powder bed fusion(LPBF)is a widely recognized additive manufacturing technology that can fabricate complex components rapidly through layer-by-layer formation.However,there is a paucity of research on the effect... Laser powder bed fusion(LPBF)is a widely recognized additive manufacturing technology that can fabricate complex components rapidly through layer-by-layer formation.However,there is a paucity of research on the effect of laser scanning speed on the cellular microstructure and mechanical properties of martensitic stainless steel.This study systematically investigated the influence of laser scanning speed on the cellular microstructure and mechanical properties of a developed Fe11Cr8Ni5Co3Mo martensitic stainless steel produced by LPBF.The results show that increasing the laser scanning speed from 400 to 1000 mm/s does not lead to a noticeable change in the phase fraction,but it reduces the average size of the cellular microstructure from 0.60 to 0.35μm.The scanning speeds of 400 and 1000 mm/s both had adverse effects on performances of sample,resulting in inadequate fusion and keyhole defects respectively.The optimal scanning speed for fabricating samples was determined to be 800 mm/s,which obtained the highest room temperature tensile strength and elongation,with the ultimate tensile strength measured at(1088.3±2.0)MPa and the elongation of(16.76±0.10)%.Furthermore,the mechanism of the evolution of surface morphology,defects,and energy input were clarified,and the relationship between cellular microstructure size and mechanical properties was also established. 展开更多
关键词 laser powder bed fusion martensitic stainless steel cellular microstructure mechanical properties strengthening mechanism
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Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy
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作者 Wen-ning Liu Wei Zhang +6 位作者 Peng-yue Wang Yi-xian Liu Xiang-yi Jiao Ao-xiang Wan Cheng-gang Wang Guo-dong Tong Shou-mei Xiong 《China Foundry》 SCIE EI CAS CSCD 2024年第1期11-19,共9页
The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron mi... The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg alloy.The AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg alloy.Refining elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-Al.At a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and net-shrinkage.With an increase in slow shot speed,the size and number of ESCs and porosities significantly reduce.In addition,the distribution of ESCs is more dispersed and the net-shrinkage disappears.The tensile property is greatly improved by adopting a higher slow shot speed.The ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%). 展开更多
关键词 hypoeutectic Al-si alloy high pressure die casting POROsITY externally solidified crystal tensile property
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Effect of Property Tax on Optimization and Upgrading of Industrial Structure
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作者 Zulong HUANG Zirun ZHANG Zhengjie ZHANG 《Asian Agricultural Research》 2024年第7期24-27,共4页
China's economic growth and economic development has entered a new stage,and the optimization and upgrading of industrial structure is the core driving force for China to achieve high-quality economic development ... China's economic growth and economic development has entered a new stage,and the optimization and upgrading of industrial structure is the core driving force for China to achieve high-quality economic development during the"14 th Five-Year Plan"period.Property tax has a conductive effect on the upgrading of industrial structure.Therefore,from the perspective of property tax and industrial structure adjustment and the relationship between them,this study summarizes the relevant research of domestic and foreign scholars.On the basis of the research,the paper puts forward some relevant policy suggestions on improving China's property tax and promoting the optimization and upgrading of China's industrial structure. 展开更多
关键词 property tax COLLECTION Industrial structure Optimization and upgrading
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Scientific Data Intellectual Property Research by Literature Statistics
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作者 ZHANG Jia WANG Xirong 《Cultural and Religious Studies》 2024年第2期87-94,共8页
The main obstacle to the open sharing of scientific data is the lack of a legal protection system for intellectual property.This article analyzes the progress of research papers on intellectual property in scientific ... The main obstacle to the open sharing of scientific data is the lack of a legal protection system for intellectual property.This article analyzes the progress of research papers on intellectual property in scientific data in China through literature search and statistics.Currently,research subjects are unbalanced,research content is uneven,research methods are intellectual single,and research depth is insufficient.It is recommended that different stakeholders engage in deep cross disciplinary cooperation,further improve China’s legal and policy protection system for scientific data intellectual property,and promote the open sharing of scientific data. 展开更多
关键词 scientific data intellectual property BIBLIOMETRICs sTAKEHOLDERs INTERDIsCIPLINARY
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First-Principle Study on the Electronic Structure and Optical Property of New Diluted Magnetic Semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO
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作者 Zhou Wenjie 《材料科学与工程(中英文B版)》 2024年第1期14-20,共7页
The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first... The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first-principles calculation.The calculation results indicate that(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO is a direct bandgap semiconductor with a bandgap of 1.1 eV.The Fermi surface is asymmetric and exhibits spin splitting phenomenon.The new type of dilute magnetic semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO exhibits significant light loss around 70 eV,with light reflection gradually increasing after 30 eV,and light absorption mainly occurring around 8-30 eV.These results also provide a basis for the discovery of more types of 1111 phase new dilute magnetic semiconductors in the future. 展开更多
关键词 First-principles calculation electronic structure optical property new diluted magnetic semiconductor
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Analysis of Porter’s Five Forces Competitive Model in China’s Property Rights Trading Market
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作者 Weinong Wang 《Proceedings of Business and Economic Studies》 2024年第3期206-211,共6页
In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of th... In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of the property rights market through Porter’s five forces competition model,then find out the problems and defects in the development,thereby promoting the better development and progress of China’s property rights trading market. 展开更多
关键词 Porter’s five forces competitive model Market optimization Innovative development
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2022年四川芦山M_(S)6.1地震前应力状态研究
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作者 张致伟 曾宪伟 +4 位作者 王迪 路茜 王玮铭 杨鹏 龙锋 《地震研究》 CSCD 北大核心 2024年第4期483-492,共10页
为研究2022年6月1日四川芦山M_(S)6.1地震的孕育和发生过程,采用CAP方法反演了2013年芦山M_(S)7.0主震及M_(S)≥5.0余震的震源机制解,并基于应力张量方差与b值时空分布特征,探讨了芦山M_(S)6.1地震的力学机制和震源区的应力状态。结果表... 为研究2022年6月1日四川芦山M_(S)6.1地震的孕育和发生过程,采用CAP方法反演了2013年芦山M_(S)7.0主震及M_(S)≥5.0余震的震源机制解,并基于应力张量方差与b值时空分布特征,探讨了芦山M_(S)6.1地震的力学机制和震源区的应力状态。结果表明:2022年芦山M_(S)6.1地震震源机制表现出与2013年芦山M_(S)7.0主震和5级余震相似的逆冲型破裂特征,压应力轴方位与龙门山断裂带南段区域应力场一致。2013年芦山M_(S)7.0地震后震中及附近的应力张量方差和b值长期处于低值状态,2022年芦山M_(S)6.1地震前震中及附近出现了应力张量方差和b值的低值异常,表明芦山余震区处于较高的应力水平。分析认为:巴颜喀拉块体持续东向运动受到华南块体的阻挡,震中所在区域长期受挤压逆冲作用,从而使芦山余震区长期处于应力积累的状态,芦山M_(S)6.1地震也是在这种动力学背景下发生的。 展开更多
关键词 芦山M_(s)6.1地震 芦山M_(s)7.0地震 震源机制解 应力张量方差 B值 应力状态
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阴道卷曲乳杆菌S层蛋白多样性研究
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作者 李娜 刘好静 +2 位作者 张婷 张茜 李娇 《川北医学院学报》 CAS 2024年第9期1167-1170,1175,共5页
目的:分析比较西安市女性阴道卷曲乳杆菌S层蛋白的多样性及NCBI数据库中阴道来源卷曲乳杆菌S层蛋白的多样性。方法:选取100例妇科患者的阴道分泌物标本作为研究对象,从其中10例标本中分离得到480株卷曲乳杆菌,其中两株卷曲乳杆菌S层蛋... 目的:分析比较西安市女性阴道卷曲乳杆菌S层蛋白的多样性及NCBI数据库中阴道来源卷曲乳杆菌S层蛋白的多样性。方法:选取100例妇科患者的阴道分泌物标本作为研究对象,从其中10例标本中分离得到480株卷曲乳杆菌,其中两株卷曲乳杆菌S层蛋白有明显差异,对其进行全基因组测序;并从NCBI数据库中下载人阴道源的卷曲乳杆菌全基因组数据,分析并比较西安市来源与数据库来源的卷曲乳杆菌S层蛋白的多样性。结果:S层蛋白注释基因具有菌株内和菌株间的多样性,同一套基因组中有多个S层蛋白注释基因,菌株间的相似性偏差较大,通过系统发育分析发现,中国人阴道卷曲乳杆菌的S层蛋白基因与其他人种的具有系统发育相似性。结论:阴道卷曲乳杆菌S层蛋白具有菌种间和菌株间多样性的特征,不同人种的卷曲乳杆菌具有相似性。 展开更多
关键词 阴道 卷曲乳杆菌 s层蛋白 多样性
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结合主动光源和改进YOLOv5s模型的夜间柑橘检测方法 被引量:2
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作者 熊俊涛 霍钊威 +4 位作者 黄启寅 陈浩然 杨振刚 黄煜华 苏颖苗 《华南农业大学学报》 CAS CSCD 北大核心 2024年第1期97-107,共11页
【目的】解决夜间环境下遮挡和较小柑橘难以准确识别的问题,实现采摘机器人全天候智能化作业。【方法】提出一种结合主动光源的夜间柑橘识别方法。首先,通过分析主动光源下颜色特征不同的夜间柑橘图像,选择最佳的光源色并进行图像采集... 【目的】解决夜间环境下遮挡和较小柑橘难以准确识别的问题,实现采摘机器人全天候智能化作业。【方法】提出一种结合主动光源的夜间柑橘识别方法。首先,通过分析主动光源下颜色特征不同的夜间柑橘图像,选择最佳的光源色并进行图像采集。然后,提出一种夜间柑橘检测模型BI-YOLOv5s,该模型采用双向特征金字塔网络(Bi-FPN)进行多尺度交叉连接和加权特征融合,提高对遮挡和较小果实的识别能力;引入Coordinate attention(CA)注意力机制模块,进一步加强对目标位置信息的提取;采用融入Transformer结构的C3TR模块,在减少计算量的同时更好地提取全局信息。【结果】本文提出的BI-YOLOv5s模型在测试集上的精准率、召回率、平均准确率分别为93.4%、92.2%和97.1%,相比YOLOv5s模型分别提升了3.2、1.5和2.3个百分点。在所采用的光源色环境下,模型对夜间柑橘识别的正确率为95.3%,相比白光环境下提高了10.4个百分点。【结论】本文提出的方法对夜间环境下遮挡和小目标柑橘的识别具有较高的准确性,可为夜间果蔬智能化采摘的视觉精准识别提供技术支持。 展开更多
关键词 柑橘 夜间检测 主动光源 双向特征金字塔网络 YOLOv5s HsV颜色空间
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献血者HBVs基因变异的生物信息学分析
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作者 范加诚 李青 +2 位作者 陈秀丽 刘世香 陈烨 《中国输血杂志》 CAS 2024年第8期933-939,共7页
目的分析HBV DNA+/HBsAg-献血者的传染性指标、S区基因序列突变情况及生物信息学特征变化。方法通过PCR方法筛查出1份HBV DNA+/HBsAg-的标本,应用酶联免疫和化学发光方法检测该标本乙肝病毒5项指标,对该标本HBVs区基因片段测序并分析变... 目的分析HBV DNA+/HBsAg-献血者的传染性指标、S区基因序列突变情况及生物信息学特征变化。方法通过PCR方法筛查出1份HBV DNA+/HBsAg-的标本,应用酶联免疫和化学发光方法检测该标本乙肝病毒5项指标,对该标本HBVs区基因片段测序并分析变异情况,应用分析软件对所测序列进行生物信息学分析。结果该标本HBV DNA+、HBsAg-、HBsAb+、HBeAg+、HBeAb-、HBcAb+;HBVs区基因序列内发生氨基酸单位点突变(P151L),空间结构发生改变。结论HBVs区基因序列空间结构改变,可能是导致检测结果出现血清学HBsAg-/HBsAb+/HBV DNA+的原因。 展开更多
关键词 HBV OBI s基因 献血者 生物信息学
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在片S参数计量比对结果浅析
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作者 刘晨 高岭 +7 位作者 栾鹏 陈婷 黄英龙 李艳奎 金诚 邹喜跃 陆景 陈科元 《计量学报》 CSCD 北大核心 2024年第9期1401-1406,共6页
中国电子科技集团公司第十三研究所作为主导实验室开展了在片S参数计量比对工作,对参比实验室提交的在片S参数测量结果进行了汇总分析,并用E_n值对各参比实验室测量结果进行了评价。通过在片S参数计量比对,确保了量值传递的准确、可靠,... 中国电子科技集团公司第十三研究所作为主导实验室开展了在片S参数计量比对工作,对参比实验室提交的在片S参数测量结果进行了汇总分析,并用E_n值对各参比实验室测量结果进行了评价。通过在片S参数计量比对,确保了量值传递的准确、可靠,特别是对在片S参数测量不确定度的主要来源统一了认识。同时也为业内提供了在片S参数测量一致性的比较平台。 展开更多
关键词 无线电计量 在片s参数 计量比对 矢量网络分析仪
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基于数值模拟的高速公路S型曲线积水规律分析
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作者 吴文亮 曾威凯 +1 位作者 李智 王晓飞 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第8期56-64,共9页
S型曲线由于特殊的线型几何特征形成了易积水的路面区域,对于积水规律的掌握有利于在设计和建造阶段提前预防和处理积水路段的危害。该文基于计算流体力学软件Fluent,结合计算流体力学分析中基于欧拉-拉格朗日方法的欧拉液膜模型EWF(Eul... S型曲线由于特殊的线型几何特征形成了易积水的路面区域,对于积水规律的掌握有利于在设计和建造阶段提前预防和处理积水路段的危害。该文基于计算流体力学软件Fluent,结合计算流体力学分析中基于欧拉-拉格朗日方法的欧拉液膜模型EWF(Eulerian Wall Film),针对精细化处理的典型S型曲线双向多车道道路模型进行模拟计算。模拟包含了几何特征与降雨量等不同变量因素,得出了积水的水膜厚度以及流速分布规律。模拟结果表明:在降雨阶段,S型曲线横坡坡度0%~1%路段为积水路段,横坡坡度1%~2%路段为易积水路段,横坡坡度大于2%的路段积水情况受到降雨强度影响;在排水阶段,S型曲线横坡坡度0%~1%路段为排水困难路段,横坡坡度1%~2%路段为排水不畅路段,横坡坡度大于2%的路段排水顺畅,在排水时间结束时,路面在不同的几何条件和降雨条件下均能将积水排除至水膜厚度小于2 cm,横坡的大小与渐变影响了积水的横向分布与纵向分布,横向呈现中间高两边低、横断面上标高大的位置水膜厚度小和标高小的位置水膜厚度大的水膜厚度分布规律,总体呈现S型的分布规律;水膜流速在积水阶段呈现纵向上中间低两边高、水膜厚度大则水膜流速大的水膜厚度分布规律,在排水阶段则为纵向上中间高两边低的水膜流速分布规律。道路宽度影响了降雨落到路面的积水总量,进而对积水水膜厚度产生了影响;超高缓和率则主要使得积水路段、易积水路段增长,从而影响了积水分布的范围。 展开更多
关键词 计算流体力学 s型曲线 路面积水 积水规律
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