检索结果-南通市图书馆

One family of 13315 stable periodic orbits of non-hierarchical unequal-mass triple systems

Science China(Physics,Mechanics & Astronomy) 2021年第1期64卷 108-113页

作者： XiaoMing li xiaochen li ShiJun liao MOE Key Laboratory of Disaster Forecast and Control in Engineering School of Mechanics and Construction EngineeringJinan UniversityGuangzhou510632China Department of Earth Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridge02139USA School of Civil Engineering and Transportation South China University of TechnologyGuangzhou510641China Department of Engineering Science University of OxfordOxfordOX13PJUK Center of Advanced Computing School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai200240China

The three-body problem can be traced back to Newton in 1687,but it is still an open question *** that only a few periodic orbits of three-body systems were found in 300 years after Newton mentioned this famous *** triple systems are common in astronomy,practically all observed periodic triple systems are hierarchical(similar to the Sun,Earth and Moon).It has traditionally been believed that non-hierarchical triple systems would be unstable and thus should disintegrate into a stable binary system and a single star,and consequently stable periodic orbits of non-hierarchical triple systems have been expected to be rather ***,we report here one family of 135445 periodic orbits of non-hierarchical triple systems with unequal masses;13315 among them are *** with the narrow mass range(only 10-5)in which stable"Figure-eight"periodic orbits of three-body systems exist,our newly found stable periodic orbits have fairly large mass *** find that many of these numerically found stable non-hierarchical periodic orbits have mass ratios close to those of hierarchical triple systems that have been measured with astronomical *** implies that these stable periodic orbits of non-hierarchical triple systems with distinctly unequal masses quite possibly can be observed in *** investigation also suggests that there should exist an infinite number of stable periodic orbits of non-hierarchical triple systems with distinctly unequal *** that our approach has general meaning:in a similar way,every known family of periodic orbits of three-body systems with two or three equal masses can be used as a starting point to generate thousands of new periodic orbits of triple systems with distinctly unequal masses.

关键词： three-body problem non-hierarchical system periodic orbits

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sequential Propagation of Chaos for Mean-Field BSDE Systems

引用

Chinese Annals of Mathematics,Series B 2024年第1期45卷 11-40页

作者： xiaochen li Kai DU Shanghai Center for Mathematical Sciences Fudan UniversityShanghai 200433China. Shanghai Artificial Intelligence Laboratory 701 Yunjin RoadShanghai 200433China

A new class of backward particle systems with sequential interaction is proposed to approximate the mean-field backward stochastic differential *** is proven that the weighted empirical measure of this particle system converges to the law of the McKean-Vlasov system as the number of particles *** on the Wasserstein met-ric,quantitative propagation of chaos results are obtained for both linear and quadratic growth ***,numerical experiments are conducted to validate our theoretical results.

关键词： Backward propagation of chaos Particle system Sequential interaction McKean-Vlasov BSDE Convergence rate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pattern transition of two-dimensional Faraday waves at an extremely shallow depth

引用

Science China(Physics,Mechanics & Astronomy) 2016年第11期59卷 58-60页

作者： xiaochen li XiaoMing li ShiJun liao School of Naval Architecture Ocean and Civil EngineeringShanghai Jiaotong UniversityShanghai 200240China Collaborative Innovative Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240China State Key Laboratory of Ocean Engineering Shanghai 200240China

In this paper, we experimentally investigate the pattern transition of two-dimensional Faraday waves at an extremely shallow depth in a Hele-Shaw cell. Several patterns of Faraday waves are observed, which have some significant differences in wave profile,wave height and wave length. It is found that, in a wide range of the forcing frequency f, there always exists a region of the acceleration amplitude A, in which there exist the so-called hysteretic jumps between different patterns of Faraday waves. All of these experimental observations could enrich our knowledges about the Faraday waves and would be helpful to the further theoretical studies on the related topic in future.

关键词： Faraday waves extremely shallow water experimental observation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Forecasting complex group behavior via multiple plan recognition

引用

Frontiers of Computer Science 2012年第1期6卷 102-110页

作者： xiaochen li Wenji MAO Daniel ZENG State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China

Group behavior forecasting is an emergent re- search and application field in social computing. Most of the existing group behavior forecasting methods have heavily re- lied on structured data which is usually hard to obtain. To ease the heavy reliance on structured data, in this paper, we pro- pose a computational approach based on the recognition of multiple plans/intentions underlying group behavior. We fur- ther conduct human experiment to empirically evaluate the effectiveness of our proposed approach.

关键词： group behavior forecasting multiple planrecognition graph search

来源：

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

混凝土中多点聚集爆炸效应起爆参数优化设计

引用

爆炸与冲击 2025年第1期45卷 015201-1-015201-15页

作者：时本军李杰徐小辉徐天涵郭纬李孝臣李超李干陆军工程大学爆炸冲击防灾减灾全国重点实验室江苏南京210007

混凝土介质中多点同时或彼此微差爆炸可产生复杂的地冲击波叠加聚集效应，从而使特定作用区域内的地冲击波压力显著增强，大大提升爆炸的毁伤威力。为获取多点爆源不同排布方式下爆炸聚集效应及地冲击传播衰减规律，进行了混凝土中单点... 详细信息

混凝土介质中多点同时或彼此微差爆炸可产生复杂的地冲击波叠加聚集效应，从而使特定作用区域内的地冲击波压力显著增强，大大提升爆炸的毁伤威力。为获取多点爆源不同排布方式下爆炸聚集效应及地冲击传播衰减规律，进行了混凝土中单点和七点聚集爆炸的现场和数值模拟试验，基于正交设计方法和灰色系统理论对多点起爆参数进行了优化设计，建立了比例装药间距、比例有源装药高度和比例起爆微差等因素与不同爆心距下峰值压力间的灰色关联度系数及灰色关联度，确定了起爆参数的优选组合，并开展了数值模拟试验检验。分析结果表明：影响地冲击聚集效应的主要因素为比例装药间距，其次为比例起爆微差，最次为比例有源装药高度。在本模拟试验情况下，采用优化的起爆参数时，即在比例装药间距为0.549 m/kg1/3、比例起爆微差为0.239 m/kg1/3和比例有源装药高度为0 m/kg1/3时，地冲击波聚集效应达到最佳，最大可达单点同等装药量产生的地冲击压力的4.7倍。

关键词：灰色理论聚集爆炸混凝土关联度优化设计

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A reaction-and-assembly approach using monoamine zinc porphyrin for highly stable large-area perovskite solar cells

引用

Science China Chemistry 2020年第6期63卷 777-784页

作者： xiaochen li Chunling li Yiying Wu Jing Cao Yu Tang State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China Department of Chemistry and Biochemistry The Ohio State UniversityColumbusOhio 43210USA

Inhibiting the irreversible escape of organic cations and iodide species in perovskite films is crucial for the fabrication of efficient and stable perovskite solar cells(PSCs).Here,we develop a reaction-and-assembly approach using monoamine zinc porphyrin(ZnP)to modify methylammonium(MA^+)lead iodide perovskite *** amine group in ZnP reacts with MA^+and I^-ions to yield monoammonium zinc porphyrin(ZnP-H+I-).The resultant films show no escape of iodide when immersed in ether *** from space-charge limited currents and transient photoluminescence indicate the modified films have reduced density of *** results suggest the formed ZnP-H^+I^-is bound on the surface and grain boundary of perovskite film to retard migrations of *** calculations also show that the energy alignment between ZnP-H^+and perovskite facilitates the electron transfer and reduces charge recombination at the perovskite ***,post-treating the Zn Pdoped film with ZnP again results in the formation of a one dimension zig-zag coordination polymer on the surface of the perovskite *** single crystal structure of ZnP shows the polymer layer is formed through the coordination interaction between the Zn(II)metal center and a neighboring *** polymer facilitates the interfacial charge transfer,and reduces the escape of organic cations and iodide species in perovskite films,thereby keeping the excellent cell performance(20.0%)and further realizing the ion ***,the modified PSCs retain over 90%of its original efficiency over2,000 h at 85°C or AM 1.5 G continuous illumination,or over 6,000 h in 45%humidity without *** work affords a new strategy to achieve the efficient ions immobilization and encapsulation by in situ reaction and coordination assembly of mono-amine zinc porphyrin.

关键词： ions immobilization reaction-and-assembly monoamine porphyrin perovskite solar cells

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of width on the properties of Faraday waves in Hele-Shaw cells

引用

Science China(Physics,Mechanics & Astronomy) 2019年第7期62卷 89-94页

作者： xiaochen li Jing li XiaoMing li ShiJun liao ChaoHe Chen School of Civil Engineering and Transportation South China University of Technology State Key Laboratory of Ocean Engineering School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University

The effect of container geometry on the Faraday waves in Hele-Shaw cells has been investigated. The wave heights increase with the width of the cell and a linear function is selected to express the relation between these data and parameters. The wave lengths also increase with the width and are in good agreement with the dispersion relation. In order to reveal the real nature behind these phenomena, we have developed a gap-averaged model to numerically solve this issue and give an analysis of the result to show how these Faraday waves are formed in a Hele-Shaw cell.

关键词： Faraday waves Hele-Shaw cell numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Automatic interval management for aircraft based on dynamic fuzzy speed control considering uncertainty

引用

Chinese Journal of Aeronautics 2023年第11期36卷 354-372页

作者： Jie YUAN Yang PEI Yan XU xiaochen li Yuxue GE School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China School of Aerospace Transport and ManufacturingCranfield UniversityCranfield MK430ALUnited Kingdom

A novel real-time autonomous Interval Management System(IMS)is proposed to automate interval management,which considers the effect of wind uncertainty using the Dynamic Fuzzy Velocity Decision(DFVD)*** membership function can be generated dynamically based on the True Air Speed(TAS)limitation changes in real time and the interval criterion of the adjacent aircraft,and combined with human cognition to formulate fuzzy rules for speed adjusting *** groups of experiments were conducted during the en-route descent stage to validate the proposed IMS and DFVD performances,and to analyze the impact factors of the *** verification experimental results show that compared with actual flight status data under controllers’command,the IMS reduces the descent time by approaching 30%with favorable wind uncertainty suppression *** analysis shows that the ability improvement of DFVD is mainly affected by the boundary value of the membership ***,the dynamic generation of the velocity membership function has greater advantages than the static method in terms of safety and *** the analysis of influencing factors,we found that the interval criterion and aircraft category have no significant effect on the capability of *** a higher initial altitude scenario,the initial interval should be appropriately increased to enhance safety and efficiency during the descent *** prototype system could evolve into a realtime Flight-deck Interval Management(FIM)tool in the future.

关键词： Air traffic control Air transportation Fuzzy logic Safety interval Wind uncertainty

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Toward accurate detection on change barriers

引用

Science China(Information Sciences) 2021年第3期64卷 88-104页

作者： Tingting LV Zhilei REN xiaochen li Guojun GAO He JIANG School of Software Dalian University of Technology

In software development, it is easy to introduce code smells owing to the complexity of projects and the negligence of programmers. Code smells reduce code comprehensibility and maintainability, making programs error-prone. Hence, code smell detection is extremely important. Recently, machine learning-based technologies turn to be the mainstream detection approaches, which show promising performance. However,existing machine learning methods have two limitations:(1) most studies only focus on common smells, and(2) the proposed metrics are not effective when being used for uncommon code smell detection, e.g., change barrier based code smells. To overcome these limitations, this paper investigates the detection of uncommon change barrier based code smells. We study three typical code smells, i.e., Divergent Change, Shotgun Surgery, and Parallel Inheritance, which all belong to change barriers. We analyze the characteristics of change barriers and extract domain-specific metrics to train a Logistic Regression model for detection. The experimental results show that our method achieves 81.8%–100% precision and recall, outperforming existing algorithms by 10%–30%. In addition, we analyze the correlation and importance of the utilized metrics. We find our domain-specific metrics are important for the detection of change barriers. The results would help practitioners better design detection tools for such code smells.

关键词： code smells change barrier logical regression machine learning software development

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Mechanochemical synthesis of MAPbBr_(3)/carbon sphere composites for boosting carrier-involved superoxide species

引用

Journal of Environmental Sciences 2021年第6期33卷 399-414页

作者： Qun Wang Ming Ma Kai Cui xiaochen li Yan Zhou Yang li Xiaohong Wu School of Chemistry and Chemical Engineering MIITKey Laboratory of Critical Materials Technology for New Energy Conversion and StorageHarbin Institute of TechnologyHarbin 150001China

Lead halide perovskites MAPbX_(3)(MA = CH_(3)NH_(3) or Cs;X = I, Br, Cl) are well considered to be potential candidates for photocatalytic reaction due to its excellent photoelectrical properties, but they still suffer from the low charge separation efficiency and slow catalytic reaction dynamics. To tackle the drawbacks, herein, MAPbBr_(3)/carbon sphere(CS) composite photocatalysts using glucose as the carbon source were elaborately designed and fabricated via a dry mechanochemical grinding process. The interfacial interaction Pb-O-C chemical bonds were constructed between MAPbBr_(3) and the carbon sphere surface containing organic functional groups. By optimizing the content of CSs, the enhanced photocatalytic degradation kinetic rate of Malachite Green(MG) pollutants(92% within 20 min) for MAPbBr_(3)/CS x( x = 17 wt.%) is about 3.6-fold of that for pristine MAPbBr_(3), which is attributed to the corporative adsorption and enhanced carrier transportation and separation of MAPbBr_(3)/CS x. Furthermore, the possible degradation mechanism was proposed on basis of the electrochemical, mass spectrometry and optical characterization results. Owing to the robust interfacial interaction, effective electron extraction rate( k et = 4.6 × 10^(7) sec^(-1)) from MAPbBr_(3) to CS can be established, which driven oxygen activation where superoxide radicals(·O^(2-)) played an important role in MG degradation. It is expected that mechanochemistry strategy may provide a new route to design efficient lead halide perovskite-carbon or metal oxide or sulfide composite photocatalysts.

关键词： Lead halide perovskites Carbon sphere Mechanochemistry Carrier separation Superoxide

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：