检索结果-南通市图书馆

Screening current in ultra-high-field non-insulated superconducting magnets

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2024年第7期67卷 2255-2273页

作者： ZHOU BenZhe WANG Lei CHEN Yong WANG QiuLiang WANG KangShuai ZHANG ZiLi LIU JianHua University of Chinese academy of sciences Beijing 100049China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China

Screening current is recognized as one of the critical elements limiting the progression of superconducting magnets toward achieving higher magnetic fields. Currently, most non-insulated(NI) superconducting magnets consider the magnet as insulated when addressing the issue of screening current. However, the bypass current in the NI magnet can modify the actual history of magnetization, so the screening current in NI magnet will be different from that in the insulated magnet. This paper presents a novel method based on the homogenized T-A formulation(T is the current vector potential, and A is the magnetic vector potential), which enables real-time simulation of both the bypass current behavior and the implications of screening current in NI superconducting magnets, even when these magnets contain tens of thousands of turns. We have developed a 32 T NI hybrid superconducting magnet and validated the effectiveness of this method through experiments. Employing this efficacious method,we conducted a comprehensive calculation of screening current in NI magnets, comparing them with insulated magnets in terms of screening current-induced stress(SCIS), screening current-induced field(SCIF), and losses. The results indicate that in the NI insert coils, the sequential excitation of background coils and insert coils induces a reverse screening current, resulting in slightly lower SCIF and SCIS compared to those in the insulated magnets. The method and results can contribute to the enhancement of magnet design and provide valuable insights for the development of ultra-high fields(UHF) NI magnets.

关键词： ultra-high-field superconducting magnet screening current REBCO coil NI coil stress loss

Density peak clustering using tensor network

在线全文

学校读者我要写书评

暂无评论

Science China(Information sciences) 2024年第3期67卷 321-322页

作者： Xiao SHI Yun SHANG Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical sciences University of Chinese Academy of Sciences National Center for Mathematics and Interdisciplinary sciences Key Laboratory of ManagementDecision and Information SystemsAcademy of Mathematics and Systems ScienceChinese Academy of Sciences

Tensor networks have been a powerful tool in simulating many-body physics and have recently gained recognition in the machine learning community due to their remarkable representation capabilities. However, using tens... 详细信息

关键词： Tensors

Genetic dissection and validation of a major QTL for grain weight on chromosome 3B in bread wheat(Triticum aestivum L.)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第1期23卷 77-92页

作者： Simin Liao Zhibin Xu Xiaoli Fan Qiang Zhou Xiaofeng Liu Cheng Jiang Liangen Chen Dian Lin Bo Feng Tao Wang Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041China University of Chinese academy of sciences Beijing 100049China The Innovative academy of Seed Design Chinese Academy of SciencesBeijing 100101China

Grain weight is one of the key components of wheat(Triticum aestivum L.)*** manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.A recombinant inbred line(RIL)population derived from a cross between W7268 and Chuanyu 12(CY12)was employed to detect quantitative trait loci(QTLs)for thousand-grain weight(TGW),grain length(GL),grain width(GW),and the ratio of grain length to width(GLW)in six *** major QTLs,***-2D,***-2D,***-3B,***-4B.1,***-2D.1,***-2D.1 and ***-3B.1,were consistently identified in at least four environments and the best linear unbiased estimation(BLUE)datasets,and they explained 2.61 to 34.85%of the phenotypic *** interactions were detected between the two major TGW QTLs and three major GW *** addition,***-3B.1 and ***-3B were co-located,and the improved TGW at this locus was contributed by *** other loci,***-3B.1/***-3B had no effect on grain number per spike(GNS).They were further validated in advanced lines using Kompetitive Allele Specific PCR(KASP)markers,and a comparison analysis indicated that ***-3B.1/***-3B is likely a novel *** haplotypes were identified in the region of this QTL and their distribution frequencies varied between the landraces and *** to gene annotation,spatial expression patterns,ortholog analysis and sequence variation,the candidate gene of ***-3B.1/***-3B was ***,the major QTLs and KASP markers reported here provide valuable information for elucidating the genetic architecture of grain weight and for molecular marker-assisted breeding in grain yield improvement.

关键词： thousand-grain weight QTL mapping haplotype analysis candidate gene

Flame Synthesis of Zr/ZSM-5 Catalysts with Tunable Acidity for the Oxidative Dehydrogenation of Propane to Propene

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第1期33卷 268-283页

作者： DANIEL Samuel FONZEU MONGUEN Cedric Karel WU Lingnan TIAN Zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese academy of sciences Beijing 100049China

Tuning the surface acidity of ZSM-5 catalyst is essential to achieve desired propene selectivity and *** several ratios of Zr were utilized to modify ZSM-5 via flame spray pyrolysis technique coupled with a pulse spray evaporation *** interaction between Zr and ZSM-5 in the flame influenced the physicochemical and acidity properties of the Zr/*** increasing Zr ratio in ZSM-5 shows coated layers of irregular nano-sized Zr with an increase in crystallite sizes due to the synergetic effect between Zr and *** surface chemical analysis revealed increased lattice oxygen on the Zr modified ZSM-5(1:4) sample compared to other *** acidity analysis revealed the Lewis and Br?nsted acid distribution in the weak and medium acid sites on the catalyst ***,the increase in Zr loading decreased the concentration of Br?nsted acid sites and tuned the catalyst surface to more Lewis acidity,promoting propene selectivity and hindering the over-oxidation of *** modified ZSM-5 catalysts were examined in a fixed bed reactor within 300℃-700℃ at a gas hourly space velocity(GHSV) of 6000 mL·g(catalysts)^(-1)·h^(-1) for the oxidative dehydrogenation of propane(ODHP) to *** the catalysts,Zr/ZSM-5(1:4) exhibited the best propene yield, with 57.19% propane conversion and 75.54% selectivity to propene and the highest *** work provides a promising strategy for tuning the surface acidity of ZSM-5 with Zr for ODHP applications.

关键词： flame synthesis Zr modified ZSM-5 catalyst ODHP surface acidity lattice oxygen

Isoscaling properties for neutron-rich fragments in highly asymmetric heavy ion collision systems

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第6期48卷 136-144页

作者：彭丹马春旺乔春源刘星泉魏慧玲 Institute of Particle and Nuclear Physics College of PhysicsHenan Normal UniversityXinxiang 453007China Institute of Nuclear Science and Technology Henan Academy of SciencesZhengzhou 450046China Key Laboratory of Radiation Physics and Technology of the Ministry of Education Sichuan UniversityChengdu 610064China

Traditionally,isoscaling has been interpreted and applied within the framework of the grand canonical ensemble,based on the assumption that fragment production occurs following the attainment of a statistical equilibrium ***,the influence of the symmetry energy can lead to differences in the neutron and density distribution in neutron-rich *** in turn may impact the iso scaling parameters(usually denoted byαandβ).We examine the isoscaling properties for neutron-rich fragments produced in highly asymmetric systems on inverse kinematics,namely^(40,48)Ca and ^(58,64)Ni+^(9)Be at 140 MeV per *** evaluate α and β values and sort them as a function of the neutron excess I≡*** significant differences in a extracted from fragments within different ranges of I emphasize the importance of understanding the dependence of isoscaling parameters on fragments generated in various collision ***,the|β(N)|/α(Z)value for a specific fragment in small size and highly iso spin asymmetry systems can serve as a probe to detect the variations in neutron density and proton density in different regions of the nucleus and indicate the limitations of theoretical models in investigating these issues.

关键词： isoscaling symmetry energy nuclear density neutron-rich fragment heavy ion collision

Numerical simulation of the dynamic migration mechanism and prediction of saturation of tight sandstone oil

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2024年第1期67卷 179-195页

作者： Gaohui CAO Mian LIN Likuan ZHANG Lili JI Wenbin JIANG Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

Quantitative characterization of tight sandstone oil migration and accumulation is an emerging research frontier in the field of oil and gas *** this study,a conceptual model containing multiple basic geological elements is developed,and a nonlinear seepage numerical model for tight sandstone oil migration and accumulation is *** effects of the slip effect,overpressure driving force,buoyancy,and capillary force on the migration and accumulation of tight oil are *** results showed that(1)the differences in oil migration and accumulation between tight and conventional reservoirs are reflected in the growth mode of oil saturation,distribution characteristics of oil and water,and extent of the effect of the formation dip angle;(2)the slip effect has a significant impact when the average pore throat radius is less than 150 nm and the overpressure driving force and capillary force are the main mechanical mechanisms controlling oil migration and accumulation in tight sandstone,while the coupling effect of buoyancy,capillary force,and overpressure driving force controls the upper and lower limits of oil ***,a dimensional and dimensionless identification chart for rapidly predicting the oil saturation of tight sandstone is proposed and verified using the measured *** study provides a basis for analyzing the migration and accumulation mechanisms of tight sandstone oil and a new approach for predicting oil ***,we developed digital and visual analysis methods for the migration results,enriching the expression of the dynamics of hydrocarbon accumulation.

关键词： Tight sandstone Migration and accumulation Dynamics Oil saturation Numerical simulation

Genetic and lipidomic analyses reveal the key role of lipid metabolism for cold tolerance in maize

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2024年第3期51卷 326-337页

作者： Lei Gao Haifang Jiang Minze Li Danfeng Wang Hongtao Xiang Rong Zeng Limei Chen Xiaoyan Zhang Jianru Zuo Shuhua Yang Yiting Shi State Key Laboratory of Plant Environmental Resilience College of Biological SciencesFrontiers Science Center for Molecular Design BreedingCenter for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijing 100193China State Key Laboratory of Wheat&Maize Crop Science College of Life SciencesHenan Agricultural UniversityZhengzhouHenan 450002China State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese academy of sciences Beijing 100049China Suihua Branch of Heilongjiang academy of Agricultural Machinery sciences SuihuaHeilongjiang 152052China

Lipid remodeling is crucial for cold tolerance in ***,the precise alternations of lipidomics during cold responses remain elusive,especially in maize(Zea mays L.).In addition,the key genes responsible for cold tolerance in maize lipid metabolism have not been ***,we integrate lipidomic,transcriptomic,and genetic analysis to determine the profile of lipid remodeling caused by cold *** find that the homeostasis of cellular lipid metabolism is essential for maintaining cold tolerance of ***,we detect 210 lipid species belonging to 13 major classes,covering phospholipids,glycerides,glycolipids,and free fatty *** lipid metabolites undergo specific and selective alterations in response to cold stress,especially mono-/di-unsaturated lysophosphatidic acid,lysophosphatidylcholine,phosphatidylcholine,and phosphatidylinositol,as well as polyunsaturated phosphatidic acid,monogalactosyldiacylglycerol,diacylglycerol,and *** addition,we identify a subset of key enzymes,including ketoacyl-acyl-carrier protein synthase II(KAS II),acyl-carrier protein 2(ACP2),male sterility33(Ms33),and stearoyl-acyl-carrier protein desaturase 2(SAD2)involved in glycerolipid biosynthetic pathways are positive regulators of maize cold *** results reveal a comprehensive lipidomic profile during the cold response of maize and provide genetic resources for enhancing cold tolerance in crops.

关键词： Maize Cold stress Lipid metabolism Transcriptome Lipidomic

Threshold Selection and Resource Allocation for Quantized Identification

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 Science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying LI Xin ZHAO Yanlong ZHANG Ji-Feng Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. Secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. In addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.

A Deep Learning Method for Computing Eigenvalues of the Fractional Schrödinger Operator

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第2期37卷 391-412页

作者： GUO Yixiao MING Pingbing LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical sciences University of Chinese Academy of SciencesBeijing 100049China

The authors present a novel deep learning method for computing eigenvalues of the fractional Schrödinger *** proposed approach combines a newly developed loss function with an innovative neural network architecture that incorporates prior knowledge of the *** improvements enable the proposed method to handle both high-dimensional problems and problems posed on irregular bounded *** authors successfully compute up to the first 30 eigenvalues for various fractional Schrödinger *** an application,the authors share a conjecture to the fractional order isospectral problem that has not yet been studied.

关键词： Eigenvalue problem deep learning fractional Schrödinger operator isospectral problem