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New geometric flows

National Science Review 2018年第4期5卷 534-541页

作者： Gang tian School of Mathematical Sciences Peking University Department of Mathematics Princeton University

This is an expository paper on geometric flows. I will start with a brief tour on Ricci flow, then I will discuss two geometric flows introduced in my joint work with J. Streets and some recent works on them.

关键词： Ricci flow metrics AMMP K?hler Hermitian symplectic

A Blockchain-Based Access Control Scheme for Reputation Value Attributes of the Internet of Things

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Computers, Materials & Continua 2024年第1期78卷 1297-1310页

作者： Hongliang tian Junyuan tian College of Electrical Engineering Northeast Electric Power UniversityJilin132012China

The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data *** address these issues,a blockchain-based IoT reputation value attribute access control scheme is ***,writing the reputation value as an attribute into the access control policy,and then deploying the access control policy in the smart contract of the blockchain system can enable the system to provide more fine-grained access control;Secondly,storing a large amount of resources fromthe Internet of Things in Inter Planetary File System(IPFS)to improve system throughput;Finally,map resource access operations to qualification tokens to improve the performance of the access control *** simulation experiments based on the Hyperledger Fabric *** simulation experimental results,it can be seen that the access control system can achieve more fine-grained and dynamic access control while maintaining high throughput and low time delay,providing sufficient reliability and security for access control of IoT devices.

关键词： Blockchain IoT access control Hyperledger Fabric

锆基金属有机框架捕获黄连中的生物碱类药物活性成分

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分析测试学报 2025年第1期44卷 188-194页

作者：司甜甜赵薇王慧张红玉刘小烨容蓉冯娟娟山东中医药大学药学院济南大学化学化工学院

采用溶剂热法制备了锆基MOF-808，利用其结构优势实现了中药黄连中生物碱类药物活性成分的富集与捕获，并结合其结构特点探讨了其协同低共熔溶剂捕获生物碱类活性成分过程中的相互作用。通过优化孵育捕获等条件，对黄连粗提液中药根碱... 详细信息

采用溶剂热法制备了锆基MOF-808，利用其结构优势实现了中药黄连中生物碱类药物活性成分的富集与捕获，并结合其结构特点探讨了其协同低共熔溶剂捕获生物碱类活性成分过程中的相互作用。通过优化孵育捕获等条件，对黄连粗提液中药根碱的回收率达到85.78%，结合高效液相色谱技术建立了检测黄连粗提液中5种生物碱类活性成分的方法。方法的线性范围为0.1～300μg·L-1，检出限为0.02～0.05μg·L-1，相对标准偏差为0.40%～4.7%，加标回收率达到69.7%～128%。该研究实现了中药黄连中生物碱类活性成分的高效、快速富集与捕获，为MOFs材料在选择性捕获与富集中药有效成分等领域的研究提供了新思路。

关键词：金属有机框架选择性富集色谱分离生物碱活性成分黄连

Evolutionary Generation Approach of Test Data for Multiple Paths Coverage of Message-passing Parallel Programs

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Chinese Journal of Electronics 2014年第2期23卷 291-296页

作者： tian tian GONG Dunwei School of Information and Electrical Engineering China University of Mining and Technology

Test data generation, the premise of software testing, has attracted scholars in the software engineering community in recent years. Influenced by task partitioning, process scheduling, and network delays, parallel programs are executed in a non-deterministic way, which makes test data generation of parallel programs different from that of serial programs in essence. This paper investigated the problem of generating test data for multiple paths coverage of message-passing parallel programs. A mathematical model of the above problem was built based on each given path and its equivalent ones. It was solved by using a genetic algorithm to generate all desired data in one run. The proposed method was applied to five benchmark programs, and compared with the existing *** experimental results show that the proposed method greatly shortens the number of iterations and time consumption without reducing the coverage rate.

关键词： Software testing Parallel program Multiple paths Test data Genetic algorithm

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美丽园区建设的路径研究

生态经济 2025年第1期41卷 44-51页

作者：陈吕军严坤田金平清华大学环境学院北京100084 清华大学生态文明研究中心北京100084 清华大学碳中和研究院北京100084

建设美丽中国是全面建设社会主义现代化国家、实现中华民族永续发展的重要举措。中国工业园区历经四十多年发展历程,已经成为建设实体经济、引领区域发展的先行者,目前已聚集全国80%的工业企业,推动工业园区建设成为人与自然和谐共生的... 详细信息

建设美丽中国是全面建设社会主义现代化国家、实现中华民族永续发展的重要举措。中国工业园区历经四十多年发展历程,已经成为建设实体经济、引领区域发展的先行者,目前已聚集全国80%的工业企业,推动工业园区建设成为人与自然和谐共生的美丽园区,对我国生态文明建设意义重大。论文回顾了中国工业园区的发展历程,面向新发展阶段存在的新挑战和新机遇,提出了工业园区在新时代需承担的高质量发展使命任务。在此基础上,本文针对园区社会、经济、自然三个子系统,从六个方面解析并详细阐述了中国工业园区打造美丽园区、支撑美丽中国建设的关键内涵。进一步地,根据国家对美丽中国建设提出的目标和计划,结合我国生态工业园区发展过程中形成的实践经验,从八个维度提出工业园区推进美丽中国建设的关键行动,支撑工业园区生态文明建设和美丽中国行动。

关键词：美丽中国工业园区美丽园区绿色发展生态文明

基于Vision Transformer的车辆重识别模型优化

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郑州大学学报（理学版） 2025年第1期57卷 46-52页

作者：张震张亚斌田鸿朋郑州大学电气与信息工程学院河南郑州450001

针对车辆重识别任务中样本类内差异性大和类间相似度高的问题,提出了一种Vision Transformer框架下的车辆重识别方法。设计一种关键区域选择模块,整合Transformer中注意力分数矩阵,加强车辆的具有辨别性区域的关注程度,减小局部区域过... 详细信息

针对车辆重识别任务中样本类内差异性大和类间相似度高的问题,提出了一种Vision Transformer框架下的车辆重识别方法。设计一种关键区域选择模块,整合Transformer中注意力分数矩阵,加强车辆的具有辨别性区域的关注程度,减小局部区域过度集中的注意力权重;构建一种包含对比损失和中心损失的混合损失函数,对比损失函数的引入增强了模型捕捉和比较样本之间的差异的能力,中心损失使得同一类别的样本更加紧密地聚集在一起,增强类间样本的区分度。实验结果验证了其有效性。

关键词：车辆重识别自注意力机制注意力权重区域选择

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Thermal-flow-electric coupling performance analysis of a liquid-immersed battery thermal management system

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Science China Technological Sciences 2025年第1期 157-176页

作者： Qiang GAO Jun tian Chujin BAO Yangfan ZHONG Chengbin ZHANG Yongping CHEN School of Energy and Environment Southeast University Battery Testing Center China North Vehicle Research Institute Zhejiang Immertech Co. Ltd. Alibaba Cloud Computing Co. Ltd.

Ensuring the safety and performance of lithium-ion batteries(LIBs) is a significant challenge for electric *** tackle this issue, an innovative liquid-immersed battery thermal management system(LIBTMS) using bionic baffles with fish-like perforations is developed. The thermal-flow-electric coupling characteristics of LIBTMSs with different baffle structures(no baffle, conventional baffle, baffle with circular perforations and baffle with fish-like perforations) are systematically investigated using experimental and numerical methods. The results indicate that the forced flow scheme exhibits better thermal management performance and voltage equalization than static flow. Moreover, the LIB temperatures and voltage deviations of different LIBTMSs increase quickly with increasing discharge rates. More importantly, the innovative LIBTMS exhibits the best thermoelectric performance due to its excellent thermoelectric equilibrium behavior caused by high electrical and temperature consistency, as well as the best overall performance involving the balance between the pressure loss and heat transfer capacity of the system. Compared with other structures, the innovative LIBTMS using baffles with fish-like perforations exhibits a maximum reduction of 10.1%, 15.2%, 25.8% and 9.0% in LIB maximum temperature, maximum temperature difference, system pressure drop and voltage deviation, respectively, under the same operating ***, for the LIBTMS using baffles with fish-like perforations, the bottom inlet and top outlet configuration and coolant precooling are suggested to enhance cooling performance.

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Numerical simulation for 2D double-diffusive convection(DDC) in rectangular enclosures based on a high resolution upwind compact streamfunction model Ⅰ: numerical method and code validation

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Applied Mathematics and Mechanics(English Edition) 2022年第9期43卷 1431-1448页

作者： Yaping YAN Shuang WU Kaiyuan tian Zhenfu tian Institute of Mechanics and Computational Engineering Department of Aeronautics and AstronauticsFudan UniversityShanghai 200433China College of Science Liaoning Technical UniversityFuxin 123000Liaoning ProvinceChina Research Institute of Intelligent Complex Systems Fudan UniversityShanghai 200433China School of Life Sciences Fudan UniversityShanghai 200433China

A high resolution upwind compact streamfunction numerical algorithm for two-dimensional(2D)double-diffusive convection(DDC)is *** unsteady Navier-Stokes(N-S)equations in the streamfunction-velocity form and the scalar temperature and concentration equations are *** optimized third-order upwind compact(UCD3 opt)scheme with a low dispersion error for the first derivatives is utilized to approximate the third derivatives of the streamfunction in the advection terms of the N-S equations and the first derivatives in the advection terms of the scalar temperature and concentration *** remaining first derivatives of the streamfunction(velocity),temperature,and concentration variables used in the governing equations are discretized by the fourth-order compact Pade(SCD4)*** the temperature and concentration variables and their approximate values of the first derivatives obtained by the SCD4 schemes,the explicit fourth-order compact schemes are suggested to approximate the second derivatives of temperature and concentration in the diffusion terms of the energy and concentration *** discretization of the temporal term is executed with the second-order Crank-Nicolson(C-N)*** assess the spatial behavior capability of the established numerical algorithm and verify the developed computer code,the DDC flow is numerically *** obtained results agree well with the benchmark solutions and some accurate results available in the literature,verifying the accuracy,effectiveness,and robustness of the provided ***,a preliminary application of the proposed method to the DDC is carried out.

关键词： double diffusive convection(DDC) high resolution heat and mass transfer upwind compact difference streamfunction formulation

The“harmful algae and algal toxins in coastal waters of China:investigation and database”project

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Journal of Oceanology and Limnology 2022年第6期40卷 2081-2093页

作者： tian YAN CAS Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Ecology and Environmental Science Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

The“harmful algae and algal toxins in coastal waters of China:investigation and database”project(HAATC)is funded(US$2.3 million)by the Ministry of Science and Technology of China for 60 months starting on the 1st Jan *** the 1990s,national projects and other related work have greatly improved harmful algal bloom(HAB)research in ***,the existing research on HABs is often limited to specific sea areas or specific algal bloom disasters,which is insufficient for understanding the long-term evolution of HAB occurrence under the influence of intensified human activity and global *** HAATC project intends to determine the overall distribution of marine harmful microalgae and macroalgae,and marine algal toxins(in phytoplankton and shellfish)through a large-scale investigation in the coastal waters of China and continuous investigation in key sea *** also aims to observe biotic and abiotic processes during harmful red tides and green tides,and establish an open database and query platform of HABs in *** research consortium,led by chief scientist *** YAN,includes approximately 100 scientists and *** than 2 years of work have shown the increased distribution of HAB species(including cysts)and algal toxins in China’s coastal waters,the increased occurrence of macroalgae blooms(mainly by Ulva prolifera and Sargassum horneri)in the Southern Yellow Sea,increased amount of causative species being identified due to the use of molecular technologies in taxonomy,and new records of algal toxins such as azaspiracid,cycloimines and neurotoxinsβ-N-methylamino-l-alanine have been detected,which complicates the research in algal toxins and ***,the project will provide systematic basic data and techniques for the rapid and accurate identification of harmful algae species to support the research,monitoring,and control of harmful algal blooms,as well as seafood safety management in China.

关键词： harmful algae algal toxins coastal waters of China database