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Numerical simulation of a complex moving rigid body under the impingement of a shock wave in 3D

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Advances in Aerodynamics 2022年第1期4卷 147-175页

作者： Shihao Liu Ziqiang Cheng Yan Jiang Jianfang Lu Mengping Zhang Shuhai Zhang School of Mathematical Sciences University of Science and Technology of ChinaHefei230026AnhuiChina School of Mathematics Hefei University of TechnologyHefei230000AnhuiChina School of Mathematics South China University of TechnologyGuangzhou510641GuangdongChina State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang621000SichuanChina

In this paper,we take a numerical simulation of a complex moving rigid body under the impingement of a shock wave in three-dimensional space.Both compressible inviscid fluid and viscous fluid are considered with suitable boundary conditions.We develop a high order numerical boundary treatment for the complex moving geometries based on finite difference methods on fixed Cartesian meshes.The method is an extension of the inverse Lax-Wendroff(ILW)procedure in our works(cheng et al.,Appl Math Mech(Engl Ed)42:841-854,2021;Liu et al.)for 2D problems.Different from the 2D case,the local coordinate rotation in 3D required in the ILW procedure is not unique.We give a theoretical analysis to show that the boundary treatment is independent of the choice of the rotation,ensuring the method is feasible and valid.Both translation and rotation of the body are taken into account in this paper.In particular,we reformulate the material derivative for inviscid fluid on the moving boundary with no-penetration condition,which plays a key role in the proposed algorithm.Numerical simulations on the cylinder and sphere are given,demonstrating the good performance of our numerical boundary treatments.

关键词： Inverse Lax-Wendroff procedure High order accuracy Complex moving boundary treatment Compressible inviscid fluid Compressible viscous fluid 3D

Short-Term Electricity Price Forecasting Using Random Forest Model with Parameters Tuned by Grey Wolf Algorithm Optimization

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Journal of Systems Science and Information 2022年第2期10卷 167-180页

作者： Junshuang ZHANG ziqiang LEI Runkun cheng Huiping ZHANG State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong UniversityXi’an 710049China State Grid East Inner Mongolia Electric Power Co. Ltd.Hohhot 010010China Economics and Management School North China Electric Power UniversityBeijing 102206China

Accurately forecasting short-term electricity prices is of great significance to electricity market participants.Compared with the time series forecasting methods,machine learning forecasting methods can consider more external factors.The forecasting accuracy of machine learning models is greatly affected by the parameters,meanwhile,the manual selection of parameters usually cannot guarantee the accuracy and stability of the forecasting.Therefore,this paper proposes a random forest(RF)electricity price forecasting model based on the grey wolf optimizer(GWO)to improve the accuracy of forecasting.Among them,RF has a good ability to deal with the problem of non-linear and unstable electricity prices.The optimization of model parameters by GWO can overcome the instability of the forecasting accuracy of manually tune parameters.On this basis,the short-term electricity prices of the PJM power market in four seasons are separately predicted.Experimental results show that the RF algorithm can better predict the short-term electricity price,and the optimization of the RF forecasting model by GWO can effectively improve the accuracy of the RF forecasting model.

关键词： short-term electricity price forecasting random forest grey wolf optimizer electricity market

Facing small and biased data dilemma in drug discovery with enhanced federated learning approaches

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Science China(Life Sciences) 2022年第3期65卷 529-539页

作者： Zhaoping Xiong Ziqiang Cheng Xinyuan Lin Chi Xu Xiaohong Liu Dingyan Wang Xiaomin Luo Yong Zhang Hualiang Jiang Nan Qiao Mingyue Zheng Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and TechnologyShanghaiTech UniversityShanghai 200031China Drug Discovery and Design Center State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China School of Information Science and Technology University of Science and Technology of ChinaHefei 230000China Laboratory of Health Intelligence Huawei Technologies Co.LtdShenzhen 518100China

Artificial intelligence(AI)models usually require large amounts of high-quality training data,which is in striking contrast to the situation of small and biased data faced by current drug discovery pipelines.The concept of federated learning has been proposed to utilize distributed data from different sources without leaking sensitive information of the data.This emerging decentralized machine learning paradigm is expected to dramatically improve the success rate of AI-powered drug discovery.Here,we simulated the federated learning process with different property and activity datasets from different sources,among which overlapping molecules with high or low biases exist in the recorded values.Beyond the benefit of gaining more data,we also demonstrated that federated training has a regularization effect superior to centralized training on the pooled datasets with high biases.Moreover,different network architectures for clients and aggregation algorithms for coordinators have been compared on the performance of federated learning,where personalized federated learning shows promising results.Our work demonstrates the applicability of federated learning in predicting drug-related properties and highlights its promising role in addressing the small and biased data dilemma in drug discovery.

关键词： federated learning drug discovery Fed AMP Non-IID data

Congruences on Orthodox Semirings Whose Additive Idempotents Satisfy Permutation Identities

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Journal of Mathematical Research with Applications 2013年第5期33卷 569-577页

作者： Shiju PAN Yuanlan ZHOU Ziqiang Cheng Department of Mathematics Jiangxi Normal University

The investigation of congruences on generalized inverse semigroups is initiated.Following some properties of such semigroups,the congruences on an orthodox semiring whose idempotents satisfy permutation identities are... 详细信息

关键词： inverse semiring congruence band semiring.

AgAuSe quantum dots with absolute photoluminescence quantum yield of 87.2%:The effect of capping ligand chain length

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Nano Research 2022年第9期15卷 8555-8563页

作者： ziqiang Sun cheng Liu Hongchao Yang Xiaohu Yang Yejun Zhang Hongzhen Lin Youyong Li Qiangbin Wang School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory of Nano-Bio Interface Division of Nanobiomedicine and i-LabSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China

Surface ligands of colloidal quantum dots(QDs)have a profound influence on their surface states,which has been verified in the studies of the effect of ligand head groups on the photoluminescence(PL)properties of QDs.However,the investigation of the ligand chain length is limited.Here,we systematically explored the effect of chain length on the Ag_(2)Se QDs by selecting three ligands,1-octanethiol(OTT),1-dodecanethiol(DDT),and 1-hexadecanethiol(HDT),with diverse chain lengths.We found that the PL intensity of Ag_(2)Se QDs increased with the decrease of the ligand chain length due to the enhanced passivation of surface defects emerging from the robust QD-ligand interface binding affinity and the weaker hydrophobic chain–chain interaction.Subsequently,AgAuSe QDs terminated with OTT were obtained by alloying parent OTT-Ag_(2)Se QDs with Au precursor with a record absolute PL quantum yield(PLQY)of 87.2%at 970 nm,facilitating ultrasensitive in vivo angiography imaging in a nude mouse model.We expect that our finding of the important role of the ligand chain length on the optical properties of QDs will be suggestive to the design and synthesis of high-quality QDs,and also look forward to the clinical applications of the ultra-bright AgAuSe QDs.

关键词： quantum dots surface ligand ligand chain length photoluminescence quantum yield bioimaging

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新时代加强党内政治文化建设的理论思考

学术前沿 2023年第3期 100-107页

作者：杨子强陈诚中国人民大学习近平新时代中国特色社会主义思想研究院

加强党内政治文化建设是推进新时代党的建设新的伟大工程的重要任务。党内政治文化是在党内政治生活中生成和发展的,党内政治文化建设必须以党内政治生活为实践基础,构建党内政治生活、政治生态、政治文化相辅相成的有机整体。政治属性... 详细信息

加强党内政治文化建设是推进新时代党的建设新的伟大工程的重要任务。党内政治文化是在党内政治生活中生成和发展的,党内政治文化建设必须以党内政治生活为实践基础,构建党内政治生活、政治生态、政治文化相辅相成的有机整体。政治属性是党内政治文化的第一属性,党内政治文化建设是解决大党独有难题的重要政治保障。党内政治文化建设既具有立党兴党强党的内部功能,又具有引领社风民风的外部功能。党员作为党内政治文化建设的主体,在与党内政治生活核心要素的互动中,构建了以天下为公、忠诚老实、实事求是、公道正派、清正廉洁等为核心的党内政治文化内容体系。

关键词：党内政治文化党内政治生活党内政治生态

A high order boundary scheme to simulate complex moving rigid body under impingement of shock wave

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Applied Mathematics and Mechanics(English Edition) 2021年第6期42卷 841-854页

作者： Ziqiang Cheng Shibao LIU Yan JIANG Jianfang LU Mengping ZHANG Shuhai ZHANG School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China South China Research Center for Applied Mathematics and Interdisciplinary Studies South China Normal UniversityGuangzhou 510631Chins State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang 621000Sichuan ProvinceChina

In the paper, we study a high order numerical boundary scheme for solving the complex moving boundary problem on a fixed Cartesian mesh, and numerically investigate the moving rigid body with the complex boundary under the impingement of an inviscid shock wave. Based on the high order inverse Lax-Wendroff(ILW) procedure developed in the previous work(TAN, S. and SHU, C. W. A high order moving boundary treatment for compressible inviscid flows. Journal of Computational Physics, 230(15),6023–6036(2011)), in which the authors only considered the translation of the rigid body,we consider both translation and rotation of the body in this paper. In particular, we reformulate the material derivative on the moving boundary with no-penetration condition, and the newly obtained formula plays a key role in the proposed algorithm. Several numerical examples, including cylinder, elliptic cylinder, and NACA0012 airfoil, are given to indicate the effectiveness and robustness of the present method.

关键词： inverse Lax-Wendroff(ILW)procedure complex moving boundary scheme Cartesian mesh high order accuracy compressible inviscid shock wave

Asymmetric growth of Au-core/Ag-shell nanorods with a strong octupolar plasmon resonance and an efficient second-harmonic generation

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Nano Research 2018年第2期11卷 686-695页

作者： Sijing Ding Dajie Yang Xiaoli Liu Fan Nan ziqiang cheng Song-Jin Im Li Zhou Jianfang Wang Ququan Wang Department of Physics Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education Wuhan University Wuhan China Department of Physics The Chinese University of Hong Kong Shatin Hong Kong China The Institute for Advanced Studies Wuhan University Wuhan China Department of Physics Qufu Normal University Qufu China Department of Physics Kim Il Sung University Pyongyang Democratic People’s Republic of Korea

Colloidal Au-core/Ag-shell nanorods with an asymmetric transverse cross- section and a strong octupolar plasmon resonance are synthesized by the controlled growth of Ag shells on one side of the Au cores. A largely enhanced second harmonic generation （SHG） from these asymmetric core-shell nanorods is demonstrated for the first time by tuning the dipolar and the octupolar plasmon modes to make them resonant with the fundamental and harmonic frequencies, respectively. The SHG intensity of the Au-Ag nanorods with dual-frequency resonances is enhanced by 21 times compared to that of the bare Au nanorods. The co-existence of the dipolar, quadrupolar, and octupolar radiations in the SHG is revealed. Additionally, the cellular uptake of the Au-Ag nanorods is monitored and the evolution of the membrane bleb is successfully observed by the SHG imaging. Our observations provide a strategy for enhancing the SHG of the colloidal metal nanoparticles and can have applications in chemical process monitoring and biological sensing.

关键词： gold-core/silver-shellnanorods,asymmetric growth,octupole surface plasmonresonance,second-harmonic generation

Enhanced N_(2)-to-NH_(3)conversion efficiency on Cu3P nanoribbon electrocatalyst

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Nano Research 2022年第8期15卷 7134-7138页

作者： Qian Liu Yiting Lin Shuang Gu Ziqiang Cheng Lisi Xie Shengjun Sun Longcheng Zhang Yongsong Luo Abdulmohsen Ali Alshehri Mohamed SHamdy Qingquan Kong Jiahong Wang Xuping Sun Institute for Advanced Study Chengdu UniversityChengdu 610106China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Shenzhen Engineering Center for the Fabrication of Two-Dimensional Atomic Crystals Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Chemistry Department Faculty of Science&Center of Excellence for Advanced Materials ResearchKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia Catalysis Research Group(CRG) Department of ChemistryCollege of ScienceKing Khalid UniversityP.O.Box 9004Abha 61413Saudi Arabia

Ambient electroreduction of nitrogen(N_(2))is considered as a green and feasible approach for ammonia(NH_(3))synthesis,which urgently demands for efficient electrocatalyst.Morphology has close relationship with catalytic activity of heterogeneous catalysts.Nanoribbon is attractive nanostructure,which possesses the flexibility of one-dimensional nanomaterials,the large surface area of two-dimensional nanomaterials,and lateral size confinement effects.In this work,Cu_(3)P nanoribbon is proposed as a highly efficient electrocatalyst for N_(2)-to-NH_(3)conversion under benign conditions.When measured in N_(2)-saturated 0.1 M HCl,such Cu_(3)P nanoribbon achieves high performance with an excellent Faradaic efficiency as high as 37.8%and a large yield of 18.9μg·h^(−1)·mgcat.−1 at−0.2 V.It also demonstrates outstanding stability in long-term electrolysis test at least for 45 h.

关键词： Cu_(3)P nanoribbon nitrogen reduction reaction ammonia electrosynthesis electrocatalysis