检索结果-南通市图书馆

Biomedical and Environmental Sciences 2023年第11期36卷 1084-1089页

作者： LI Yu Jian KAN xuan Department of Pediatrics General Hospital of Tianjin Medical UniversityTianjin 300052China

Caesarean section is a well-established surgical procedure that allows for maximum fetal rescue under special circumstances,such as intrauterine distress and intrauterine hypoxia,and minimizes injuries to pregnant women who cannot tolerate vaginal *** caesarean section is a special type of caesarean section that plays an important role in protecting the lives of pregnant mothers and fetuses[1].

关键词： Blood injuries Emergency

A combined survey to evaluate the thermal behavior of loess for a landslide-prone slope on the Heifangtai terrace in Northwest China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2021年第12期18卷 3247-3260页

作者： ZHANG Hao ZHANG De-xuan Department of Civil Engineering Shanghai Normal UniversityShanghai 201418China

A combined survey including infrared thermography(IRT)and field-laboratory tests were conducted to analyze the thermal responses and thermal properties of loess on a landslide-prone loess slope in the Heifangtai terrace in Northwest China aiming at preliminarily demonstrating the potential of IRT as a complementary technique to the investigation of irrigation-induced loess *** thermographic surveys corresponding to various solar radiation intensities during the afternoon were carried out on the landslide-prone loess ***,the spatiotemporal distribution of the thermal responses within the observed slope surface was analyzed qualitatively and ***,field and laboratory investigations were also performed on the thermal properties of different landslide *** results indicate that loess,a landslide-prone deposit that usually has a relatively high water content,exhibits different thermal properties and anomalies,including a lower surface temperature and greater thermal inertia,compared to surrounding zones without *** groundwater table and corresponding seepage line could also be obtained by determining the potential boundary between the thermal response distribution of landslide scarps and that of saturated deposits in the presence of *** results of these investigations are expected to provide insight for future endeavors combining infrared thermography with other efficient survey methodologies(e.g.,InSAR,which can monitor the active displacement of a loess slope)to evaluate the activity of this kind of excessive irrigation-induced loess landslide.

关键词： Infrared Thermography Loess landslide The Heifangtai terrace Thermal response Water content

数据中心多能互补分布式能源系统设计与运行优化研究

在线全文

学校读者我要写书评

暂无评论

西安交通大学学报 2025年第1期59卷 93-104页

作者：任效效李小龙薛凯吴炫韩小渠王进仕严俊杰西安交通大学动力工程多相流国家重点实验室西安710049 中国电力工程顾问集团西北电力设计院有限公司西安710075

为实现数据中心的低碳转型和能效提升,提出了一种集成多种可再生能源和储能设备的多能互补分布式能源系统作为其供能系统。建立了包含生命周期成本、碳排放、能耗、电网购电率和热量浪费率等指标的优化目标体系。制定了两种考虑负荷特... 详细信息

为实现数据中心的低碳转型和能效提升,提出了一种集成多种可再生能源和储能设备的多能互补分布式能源系统作为其供能系统。建立了包含生命周期成本、碳排放、能耗、电网购电率和热量浪费率等指标的优化目标体系。制定了两种考虑负荷特征的运行策略,采用改进的多目标蝗虫优化算法对系统容量配置进行求解。为了分析优化目标和运行策略对系统优化的影响,通过组合不同优化目标和运行策略形成了多种优化设计方案,采用层次分析法和熵权法确定评价指标的权重,并利用多准则妥协解排序法进行评价排序。针对青海省某数据中心的案例,获得其能源系统的优化设计与运行方案。研究表明:运行策略主要影响吸收式制冷机和地源热泵的容量,而优化目标主要影响储能设备的容量;在相同的运行策略下,增加优化目标可提升系统的综合性能;对于不同的方案,生命周期成本、碳排放、能耗等基础优化目标值变化较小,而电网购电率和热量浪费率变化较大;通过实施五目标优化,即在基础优化目标的基础上增加热量浪费率、电网购电率,系统的综合性能得到了显著提升,其中热量浪费率和电网购电率分别降低了62.30%和25.92%,可再生能源发电占比增加了2%。

关键词：数据中心多能互补分布式能源系统优化设计运行策略多目标蝗虫优化算法

同方期刊数据库

Comparison of the topologies for a hybrid energy-storage system of electric vehicles via a novel optimization method

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第7期58卷 1173-1185页

作者： ZHANG Shuo XIONG Rui ZHOU xuan National Engineering Laboratory for Electric Vehicles School of Mechanical EngineeringBeijing Institute of Technology Collaborative Innovation Center of Electric Vehicles in Beijing Beijing Institute of Technology Electrical and Computer Engineering Department Kettering University

The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric *** aspects of such combination efforts were considered for evaluating the four types of hybrid energy-storage system(HESS)***,a novel optimization framework was proposed and implemented to optimize the voltage level of a battery pack and an ultracapacitor pack for the four types of HESS *** the optimization process,the dynamic programming(DP)algorithm was iteratively applied to determine the optimal control *** simulation results with DP were used to evaluate the energy efficiency of different HESS topologies at different voltage ***,the optimized voltage level of the battery and ultracapacitor in each topology indicates that a higher voltage level usually results in a better system *** simulation results also illustrate that the optimized rated voltage level of the battery pack is approximately 499.5 V,while for the ultracapacitor pack,the optimized voltage level is at its maximum allowed *** that the constraint of the battery voltage is initialized at200–600 ***,the control rules for different HESS topologies were obtained through the systematic analysis of the simulation *** addition,advantages and disadvantages of the four topologies were summarized through evaluation of the efficiency and operating currents of the batteries and the ultracapacitor.

关键词： electric vehicles lithium-ion battery ultracapacitor hybrid energy-storage system topology dynamic programming

Molecular regulation and genetic control of rice thermal response

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2021年第3期9卷 497-505页

作者： Yi Kan Hong-xuan Lin National Key Laboratory of Plant Molecular Genetics CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics&DevelopmentShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China University of the Chinese Academy of Sciences Beijing 100049China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China

Global warming threatens food ***(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive *** we summarize putative mechanisms of high-temperature perception(via RNA secondary structure,the phyB gene,and phase separation)and response(membrane fluidity,heat shock factors,heat shock proteins,and ROS(reactive oxygen species)scavenging)in *** describe how rice responds to heat stress at different cell-component levels(membrane,endoplasmic reticulum,chloroplasts,and mitochondria)and functional levels(denatured protein elimination,ROS scavenging,stabilization of DNA and RNA,translation,and metabolic flux changes).We list temperature-sensitive genetic male sterility loci available for use in rice hybrid breeding and explain the regulatory mechanisms associated with some of *** thermotolerant rice species without yield penalties via natural alleles mining and transgenic editing should be the focus of future work.

关键词： Rice Thermotolerance Thermal response Thermosensitivity Molecular regulation

New Structure of Silicon—on—Insulator Metal—Oxide—Semiconductor Field Effect Transistor to Suppress the Floating Body Effect

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2003年第5期20卷 767-769页

作者： ZHUMing ZHANGZheng-xuan LINCheng-Lu StateKeyLaboratoryofFunctionalMaterialsforInformatics ShanghaiInstituteInstituteofMicrosystemandInformationTechnologyChineseAcademyofSciencesShanghai200050

Considering that the silicon-on-insulator (SOI) devices have an inherent floating body effect, which may cause substantial influences in the performance of SOI device and circuit, we propose a novel device structure to suppress the floating body effect. In the new structure there is a buried p+ region under the n+ source and that region is extended to outside of the source, and this additional p+ region provides a path for accumulated holes to flow out of the body. Numerical simulations were carried out with Medici, and the output characteristics and gate characteristics were compared with those of conventional SOI counterparts. The simulated results show the suppression of floating body effect in the novel SOI device as expected.

关键词：金属氧化物半导体晶体管结构数值仿真 SOI装置

Synthesis and Structure Characterization of N-Phenyl-(2S)-hydroxy-3-[(2-hydroxybenzylidene)amino]propionamide

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2005年第7期24卷 799-804,738页

作者： LIBin SHENZong-xuan ZHANGYong ZHANGDe-Chun CollegeofChemistryandChemicalEngineering SuzhouUniversitySuzhou215006China

A new Schiff base, N-phenyl-(2S)-hydroxy-3-[(2-hydroxybenzylidene)amino]pro- pionamide, has been synthesized by using (S)-isoserine as the starting material. Its crystal struc- ture with solvent benzene was determined by X-ray single-crystal diffraction, elemental analysis and 1H NMR. The crystal belongs to the monoclinic system with space group P21, a = 5.673(3), b = 15.486(8), c = 18.753(9) ?, β = 90.086(7)o, C16H16O3N2?1/2C6H6, Mr = 323.36, V = 1647.7(14) ?3, Z = 4, Dc = 1.304 g/cm3, μ = 0.089 cm-1, F(000) = 684.00, the final R = 0.0624 and wR = 0.1320 for 2613 observed reflections (I > 2σ(I)). The asymmetric unit of the crystal has two crystallographically different molecules with the same configuration and one solvent benzene molecule, and they are not planar. In the crystal, molecules are stacked through H-bonds along [100] and the stacks are laterally interacted through H-bonds and extended along [010]. In the third direction [101], molecules interact through C–H…π interaction, which is one of the major factors stabilizing the crystal structure.

关键词： Schiff base synthesis crystal structure C–H…π interaction crystal growth

CLASSICAL AND HOMOGENIZED EXPRESSIONS FOR BUCKLING SOLUTIONS OF FUNCTIONALLY GRADED MATERIAL LEVINSON BEAMS

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2015年第5期28卷 592-604页

作者： Shirong Li xuan Wang Zeqing Wan Department of Civil Engineering Yangzhou University

The relationship between the critical buckling loads of functionally graded material （FGM） Levinson beams （LBs） and those of the corresponding homogeneous Euler-Bernoulli beams （HEBBs） is investigated. Properties of the beam are assumed to vary continuously in the depth direction. The governing equations of the FGM beam are derived based on the Levinson beam theory, in which a quadratic variation of the transverse shear strain through the depth is included. By eliminating the axial displacement as well as the rotational angle in the governing equations, an ordinary differential equation in terms of the deflection of the FGM LBs is derived, the form of which is the same as that of HEBBs except for the definition of the load parameter. By solving the eigenvalue problem of ordinary differential equations under different boundary conditions clamped （C）, simply-supported （S）, roller （R） and free （F） edges combined, a uniform analytical formulation of buckling loads of FGM LBs with S-S, C-C, C-F, C-R and S-R edges is presented for those of HEBBs with the same boundary conditions. For the C-S beam the above-mentioned equation does not hold. Instead, a transcendental equation is derived to find the critical buckling load for the FGM LB which is similar to that for HEBB with the same ends. The significance of this work lies in that the solution of the critical buckling load of a FGM LB can be reduced to that of the HEBB and calculation of three constants whose values only depend upon the through- the-depth gradient of the material properties and the geometry of the beam. So, a homogeneous and classical expression for the buckling solution of FGM LBs is accomplished.

关键词： FCM beam Levinson beam theory buckling critical load Euler-Bernoulli beam

Evaluation of the Interface Between Two Plates by the Lamb Wave

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第11期18卷 1483-1486页

作者： WANG Xiao-Min LIAN Guo-xuan LI Ming-xuan Institute of Acoustics Chinese Academy of SciencesBeijing 100080

A new expression of the dispersion equation of the Lamb wave in an adhesive two-layered plate is presented. The bond rigidity of the adhesive plate is accounted for in terms of a spring model. The influence of the variations of the compliance constants of the spring on the dispersion feature of Lamb modes is numerically studied. The numerical results indicate that the deterioration of the bond rigidity may cause the phase velocity decrease and the frequency-shift for a given Lamb mode, thus having a possibility for the evaluation of the bonding state of the adhesive plate by using ultrasonic wave velocity measurements. The phase-tracing method is used to measure the phase velocities experimentally and the results for an adhesive plate of aluminium-aluminium are given to verify the theoretical predictions.

关键词： plate rigidity dispersion

Dual-quaternion-based modeling and control for motion tracking of a tumbling target

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2019年第5期30卷 985-994页

作者： PENG xuan SHI Xiaoping GONG Yupeng Control and Simulation Center Harbin Institute of TechnologyHarbin 150001China Research Center of Satellite Technology Harbin Institute of TechnologyHarbin 150001China

This paper investigates the problem of controlling a chasing spacecraft(chaser)to track and rendezvous with an uncontrolled *** on the actual situation,the torque-free motion of an axisymmetric prolate rigid body is employed to represent the short-term attitude motion of the tumbling *** taking advantage of the dual quaternion’s compact and efficient description of the general rigid motion,the coupled and integrated model of the 6-degree-of-freedom(6-DOF)relative motion between the chaser and the tumbling target is derived in the chaser’s body fixed frame after taking full consideration of coordinate *** on the logarithm of dual quaternion,a sliding mode control(SMC)law based on the exponential reaching law and the continuous relay function is brought forward to address the problem of synchronization control of the 6-DOF relative *** results illustrate the effectiveness of the proposed method.

关键词： tumbling target dual-quaternion coupled dynamics relative motion