检索结果-南通市图书馆

Chinese Physics B 2020年第5期29卷 464-468页

作者： Lu-Wei Qi Xiao-Yu Liu Jin Meng de-hai zhang Jing-Tao Zhou Key Laboratory of Microwave Remote Sensing National Space Science CenterChinese Academy of SciencesBeijing 100190China Institute of Microelectronics of the Chinese Academy of Sciences Beijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The excellent reverse breakdown characteristics of Schottky barrier varactor(SBV)are crucially required for the application of high power and high efficiency *** SBV with a novel Schottky structure named metal-brim is fabricated and systemically *** with normal structure,the reverse breakdown voltage of the new type SBV improves from-7.31 V to-8.75 *** simulation of the Schottky metal-brim SBV is also *** factors,namely distribution of leakage current,the electric field,and the area of space charge region are mostly concerned to explain the physical *** metal-brim structure is a promising approach to improve the reverse breakdown voltage and reduce leakage current by eliminating the accumulation of charge at Schottky electrode edge.

关键词： breakdown characteristics Schottky metal-brim Schottky barrier varactor GaAs

Existence of a-Cores for Games Without Compact Assumptions

在线全文

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2024年第2期12卷 520-527页

作者： hai-Qun zhang School of International Economics and Trade Shanghai Lixin University of Accounting and Fin Shanghai201209China

Following the representation of Kajii(J Econ Theory 56:194-205,1992),we provide some existence theorems ofα-cores for games without ordered preferences and compact *** applications,we obtain some existence results of... 详细信息

关键词： α-Core Existence Preference Noncompactness

Bi-Frobenius Algebra Structures on Quantum Complete Intersections

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

Acta Mathematica Sinica,English Series 2024年第6期40卷 1481-1504页

作者： hai JIN Pu zhang School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240P.R.China

This paper is to look for bi-Frobenius algebra structures on quantum complete intersections over field *** find a class of comultiplications,such that if√−1∈k,then a quantum complete intersection becomes a bi-Frobenius algebra with comultiplication of this form if and only if all the parameters qij=±***,it is proved that if√−1∈k then a quantum exterior algebra in two variables admits a bi-Frobenius algebra structure if and only if the parameter q=±√*** if−1/∈k,then the exterior algebra with two variables admits no bi-Frobenius algebra *** prove that the quantum complete intersections admit a bialgebra structure if and only if it admits a Hopf algebra structure,if and only if it is commutative,the characteristic of k is a prime p,and every ai a power of *** also provides a large class of examples of bi-Frobenius algebras which are not bialgebras(and hence not Hopf algebras).In commutative case,other two comultiplications on complete intersection rings are given,such that they admit non-isomorphic bi-Frobenius algebra structures.

关键词： Bi-Frobenius algebras coalgebras bialgebras Hopf algebras quantum complete intersections quantum exterior algebras

Highly Transparent Fire-resistant Coatings with Intumescent Three-source Integration

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第7期42卷 907-915,I0005页

作者： Xiao-Liang Zeng Xin-Sheng Lan Yan Wang Lin zhang de-Ming Guo hai-Bo Zhao State Grid Sichuan Electric Power Research Institute Chengdu610041China The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(Ministry of Education) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu610064China

Wood,a readily available and sustainable natural resource,has found widespread use in construction and ***,its inherent flammability poses a potential fire *** intumescent fire-retardant coatings effectively mitigate this risk,achieving high transparency in such coatings presents a significant *** our approach,we employed a cross-linked network of phytic acid anion and N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium cation to create a transparent"three-in-one"intumescent *** collaborative P/N/Si flame-retardant effect markedly improved the intumescent char-forming capability,preventing the wood from rapid *** resulted in a substantial reduction in heat release(13.9%decrease in THR)and an increased limiting oxygen index(LOI)value of 35.5%.Crucially,the high transparency of the coating ensured minimal impact on the wood's appearance,allowing the natural wood grains to remain clearly *** innovative approach provides a straightforward method for developing transparent intumescent flame-retardant coatings suitable for wooden *** potential applications extend to preserving ancient buildings and heritage conservation efforts.

关键词： Fire-resistant coating Flame retardancy Wood Transparency

Dynamics of a Reaction-diffusion-Ode System in a Heterogeneous Media

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 275-301页

作者： Cong-hui zhang hai-feng zhang Mei-rong zhang School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013China department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The existence and stability of stationary solutions for a reaction-diffusion-Ode system are investigated in this *** first show that there exist both continuous and discontinuous stationary *** a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate *** addition,we demonstrate the influences of the diffusion coefficient on stationary *** results we obtained are based on the super-/sub-solution method and the generalized mountain pass ***,some numerical simulations are given to illustrate the theoretical results.

关键词： reaction-diffusion-Ode system discontinuous stationary solutions stability asymptotic behavior monotone solutions

Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous Jiufotang Formation of western Liaoning,China and its paleobiogeographic significance

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第3期13卷 547-562页

作者： Li-Jun zhang Shu-An Ji hai-Chun zhang South China Sea Culture Museum Hainan Tropical Ocean UniversitySanya 572022Hainan ProvinceChina Key Laboratory of Stratigraphy and Paleontology Ministry of Natural ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008Jiangsu ProvinceChina

The water-living reptile genus Hyphalosaurus was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western Liaoning,*** complete skeletons of Hyphalosaurus are reported for the first time from the Jiufotang Formation bearing the late Jehol Biota at two sites in western *** show the typical characteristics of Hyphalosaurus baitaigouensis in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae,and therefore are assigned to *** discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying Jiufotang *** paper further briefly compares the main characteristics of the two skeletons,summarizes the temporal and spatial distribution of Hyphalosaurus,and discusses the palaeogeographic evolution of western Liaoning at the middle and late Jehol Biota stages based on the aquatic habits of Hyphalosaurus and the geological background of western *** analytical results show that the volcanic downwarped lakes,with distinct geographical divisions in western Liaoning during the deposition of the Yixian Formation,had not completely disappeared till the deposition of the Jiufotang *** palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation,expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large *** palaeo-Dalinghe River,which connected the main basins in western Liaoning during the depositional period of the Jiufotang Formation,was formed simultaneously.

关键词： Western liaoning Jehol biota Jiufotang formation Hyphalosaurus baitaigouensis Palaeobiogeography

Learning topological defects formation with neural networks in a quantum phase transition

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第5期76卷 68-76页

作者： Han-Qing Shi hai-Qing zhang Center for Gravitational Physics Department of Space ScienceBeihang UniversityBeijing 100191China Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China

Neural networks possess formidable representational power,rendering them invaluable in solving complex quantum many-body *** they excel at analyzing static solutions,nonequilibrium processes,including critical dynamics during a quantum phase transition,pose a greater challenge for neural *** address this,we utilize neural networks and machine learning algorithms to investigate time evolutions,universal statistics,and correlations of topological defects in a one-dimensional transverse-field quantum Ising ***,our analysis involves computing the energy of the system during a quantum phase transition following a linear quench of the transverse magnetic field *** excitation energies satisfy a power-law relation to the quench rate,indicating a proportional relationship between the excitation energy and the kink ***,we establish a universal power-law relationship between the first three cumulants of the kink numbers and the quench rate,indicating a binomial distribution of the ***,the normalized kink-kink correlations are also investigated and it is found that the numerical values are consistent with the analytic formula.

关键词： neural networks machine learning transverse-field quantum Ising model kibble-zurek mechanism

derivation of Expanded Isospectral-Nonisospectral Integrable Hierarchies via the Column-vector Loop Algebra

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第3期40卷 778-800页

作者： hai-feng WANG Yu-feng zhang School of Science Jimei UniversityXiamen 361021China School of Mathematics China University of Mining and TechnologyXuzhou 221116China

A scheme for generating nonisospectral integrable hierarchies is *** on the method,we deduce a nonisospectral hierarchy of soliton equations by considering a linear spectral *** follows that the corresponding expanded isospectral and nonisospectral integrable hierarchies are deduced based on a 6 dimensional complex linear space ■.By reducing these integrable hierarchies,we obtain the expanded isospectral and nonisospectral derivative nonlinear Schr?dinger *** using the trace identity,the biHamiltonian structure of these two hierarchies are also ***,some symmetries and conserved quantities of the resulting hierarchy are discussed.

关键词： expanded isospectral-nonisospectral integrable hierarchies column-vector loop algebra bi-Hamiltonian structure symmetry

design optimization of a hexapod vibration isolation system for electro-optical payload

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 330-342页

作者： Jing LI Weipeng LI Xiaoyan zhang hai HUANG School of Astronautics Beihang UniversityBeijing 100191China

The electro-optical payloads on mobile platforms generally suffer undesirable vibrations generated by maneuvers and *** vibrations are in six degrees of freedom and cause line-of-sight jitters,resulting in image blurring and loss of tracking *** this paper,a Hexapod Vibration Isolation System(HVIS)is proposed and optimized to solve this *** optimization aims to centralize and minimize the natural frequencies of HVIS,for expanding the vibration isolation bandwidth and improving the vibration isolation in the higher frequency *** that the design space for HVIS is limited and interfered with the frames of the mobile platform,a non-collision algorithm is proposed and applied in the optimization to obtain the feasible optimal *** optimization result shows that the natural frequency bandwidth has been reduced by 42.9%,and the maximum natural frequency is reduced by 30.2%.The prototypes of initial and optimal designs are manufactured and *** simulated and experimental results demonstrate the validity of the optimization,and the optimal design provides a maximum of 15 dB more isolation in rotation direction than the initial design.

关键词： Electro-optical payload Vibrations Isolation system Hexapod Optimization Non-collision design

An artificial intelligence approach for particle transport velocity prediction in horizontal flows

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第9期92卷 234-250页

作者： Haoyu Chen Zhiguo Wang hai Huang Jun zhang College of Petroleum Engineering Xi'an Shiyou UniversityXi'an710065China Shaanxi Key Laboratory of Carbon Dioxide Sequestration and Enhanced Oil Recovery Xi'an710065China College of New Energy Xi'an Shiyou UniversityXi'an710065China Engineering Research Center of Smart Energy and Carbon Neutral in Oil&Gas Field Universities of Shaanxi ProvinceChina The Erosion/Corrosion Research Center The University of TulsaOK74104United States

Particle entrainment is an inevitable phenomenon in pipeline systems,especially during the development and extraction phases of oil and gas *** predicting the critical velocity for particle transport is a key focus for implementing effective sand control *** work presents a semi-supervised learning–deep hybrid kernel extreme learning machine(SSL-DHKELM)model for predicting the critical velocity,which integrates multiple machine learning theories including the deep learning approach,which is adept at advanced feature ***,the SSL framework enhances the model's capabilities when data availability is *** improved slime mould algorithm is also employed to optimize the model's *** proposed model has high accuracy on both the sample dataset and out-of-sample *** trained with only 10%of the data,the model's error still did not increase ***,this model achieves superior predictive accuracy compared to existing mechanistic models,demonstrating its impressive performance and robustness.

关键词： Particle transport Critical velocity deep learning Semi-supervised learning Extreme learning machine