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Pentacoordinate Phosphoranes as Versatile Reagents in Fluoroalkylation Reactions

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CCS Chemistry 2024年第1期6卷 165-176页

作者： Huanhuan Song weihao li Xiaoying Wang Kaiteng Wang Jingwen li Shuai liu Pin Gao Xin-Hua Duan Jinbo Hu Mingyou Hu School of Chemistry Engineering Research Center of Energy Storage Materials and DevicesMinistry of EducationXi’an Key Laboratory of Sustainable Energy Material ChemistryXi’an Jiaotong UniversityXi’an 710049 Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032

A general method for the synthesis of bench-stable bis(difluoromethyl)pentacoordinate phosphoranes has been *** reaction is rapid,operationally simple,and easily *** pentacoordinate phosphoranes can generate both difluoromethyl radical(·CF_(2)H)and difluorocarbene(:CF_(2))***,a variety of fluoroalkylation transformations havebeen achieved by·CF_(2)H,such asoxidativedifluoromethylation of electron-deficient heterocycles,nickel/photoredox dual-catalyzed difluoromethylation of aryl bromides,and photoredox difluoromethylation of alkenes,or by:CF_(2),such as gem-difluorocyclopropanation of alkenes,base-promoted difluoromethylation of heteroatom nucleophiles,Pd-catalyzed difluoromethylation of arylboronic acids,and Cu-mediated trifluoromethylation of aryl iodides(via:CF_(2) and recombined CF_(3)-).These fluoroalkylation methods have been successfully applied to late-stage fluoroalkylation of drugs and drug-like molecules.

关键词： pentacoordinate phosphorane difluoromethyl radical difluorocarbene difluoromethylation fluoroalkylation

Giant Magneto-Optical Effect in van der Waals Room-Temperature Ferromagnet Fe_(3)GaTe_(2)

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Chinese Physics Letters 2024年第6期41卷 148-155页

作者：张晓敏王健朱文凯张佳茜李伟浩张菁王开友 State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Materials Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

The discovery of ferromagnetic two-dimensional(2D)van der Waals(vdWs)materials provides an opportunity to explore intriguing physics and to develop innovative spin electronic ***,the main challenge for practical applications of vd Ws ferromagnetic crystals lies in the weak intrinsic ferromagnetism and small perpendicular magnetic anisotropy(PMA)above room ***,we report the intrinsic vd Ws ferromagnetic crystal Fe_(3)GaTe_(2),synthesized by the self-flux method,exhibiting a Curie temperature(TC)of 370 K,a high saturation magnetization of 33.47 emu/g,and a large PMA energy density of approximately 4.17×10^(5)J/m^(3).Furthermore,the magneto-optical effect is systematically investigated in Fe_(3)GaTe_(2).The doubly degenerate E_(2g)(Γ)mode reverses the helicity of incident photons,indicating the existence of pseudoangular-momentum(PAM)and ***,the non-degenerate non-chiral A_(1g)(Γ)phonon exhibits a significant magneto-Raman effect under an external out-of-plane magnetic *** results lay the groundwork for studying phonon chirality and magneto-optical phenomena in 2D magnetic materials,providing the feasibility for further fundamental research and applications in spintronic devices.

关键词： field ferromagnetic degenerate

数字流通平台助推中国式现代化的作用表现和重点问题

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商业经济与管理 2024年第1期 5-19页

作者：谢莉娟李伟豪中国人民大学商学院北京100872 中国人民大学市场流通经济研究中心北京100872

数字流通平台是数字经济时代的新型流通组织形式,其规范健康持续发展对于推动实现中国式现代化具有重要意义。凭借先进数字技术所赋予或强化的运行特征,数字流通平台有助于从助力现代流通体系建设以服务超大规模内需市场、促进高质量充... 详细信息

数字流通平台是数字经济时代的新型流通组织形式,其规范健康持续发展对于推动实现中国式现代化具有重要意义。凭借先进数字技术所赋予或强化的运行特征,数字流通平台有助于从助力现代流通体系建设以服务超大规模内需市场、促进高质量充分就业以助力全体人民共同富裕、提供丰裕物质和精神产品以促进人的全面发展、带动引领经济社会绿色低碳发展、推进高水平对外开放五个方面助推中国式现代化。在中国式现代化实现进程中,数字流通平台的运行要打破资本逻辑至上而坚持以人本逻辑为主,具体要重视带动供给侧结构性改革以提高供给质量、保护劳动者权益和克服两极分化、保护消费者权益和构建新商业文明、全面推进发展方式绿色转型和持续提高国际化经营水平五大重点问题,并加强与之对应的治理。

关键词：中国式现代化数字流通平台数字经济平台经济

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山西省ETC拓展服务平台设计

山西交通科技 2024年第1期 118-121,129页

作者：李为浩山西省交通规划勘察设计院有限公司山西太原030032

拓展ETC服务到停车场、加油站、充电站、洗车等城市生活场景,对提升用户服务体验和ETC设备使用效率具有重要作用。以城市多场景ETC联机交易为切入点,结合山西省“晋e行”App、小程序,通过对停车场、加油站、充电桩等商户轻量化改造,实现... 详细信息

拓展ETC服务到停车场、加油站、充电站、洗车等城市生活场景,对提升用户服务体验和ETC设备使用效率具有重要作用。以城市多场景ETC联机交易为切入点,结合山西省“晋e行”App、小程序,通过对停车场、加油站、充电桩等商户轻量化改造,实现ETC无感或轻感支付,提升智慧化水平,有效解决停车、加油等服务场景交通拥堵、人民群众出行体验差的问题,为智慧城市赋能,驱动智慧城市数字交通经济快速发展,从而实现智慧城市数字交通经济发展模式的转型。

关键词： ETC拓展交易智慧城市数字交通

Pipelines vibration analysis and control based on clamps'locations optimization of multi-pump system

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Chinese Journal of Aeronautics 2022年第6期35卷 352-366页

作者： Xin li weihao li Jian SHI Qiang li Shaoping WANG School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China School of Automation Science and Electric Engineering Beihang UniversityBeijing 100191China

The violent vibration of hydraulic pipelines in aircraft may cause faults or even an accident,especially for the large aircraft with the multi-pump system because of different vibration sources and complex pipelines *** to the vibration analysis and control of the multipump system,this paper proposed the clamps’locations optimization to minimize the system impedance at vibration ***,the models of the flexible clamp and other components in multi-pump system were established,based on which,the system impedance was calculated by using Transfer Matrix Method(TMM);Secondly,the objective function is defined as weighted sum of system impedance at frequencies of different vibration ***,the clamps’locations were altered to change the system ***,The Chaotic Swarm Particle Optimization(CPSO)algorithm was applied to obtain the optimal clamps’locations and the minimum value of objective function which decreased by 36.4%compared to the value of original clamps’locations;Finally,the experiments from vibration and pressure test with original and optimized clamps’locations verified the effectiveness of the system impedance calculation and clamps’locations optimization method.

关键词： Clamp CPSO Impedance Multi-pump Pipeline TMM Vibration

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基于生成对抗神经网络的流量生成方法研究

网络安全与数据治理 2024年第6期43卷 33-41页

作者：康未李维皓刘桐菊华北计算机系统工程研究所北京100083

网络仿真中的流量生成对于确保仿真效果至关重要。目前常见的网络流量生成器通常基于某种随机模型,生成的流量只能服从指定的随机分布。实际网络中的随机模型往往难以确定,导致现有模型对真实网络流量的仿真有一定的偏差。为了解决这些... 详细信息

网络仿真中的流量生成对于确保仿真效果至关重要。目前常见的网络流量生成器通常基于某种随机模型,生成的流量只能服从指定的随机分布。实际网络中的随机模型往往难以确定,导致现有模型对真实网络流量的仿真有一定的偏差。为了解决这些问题,提出了基于生成对抗神经网络的时空相关流量生成模型;对网络流量数据改进了其编码方式,并使用Z-score处理流量数据,使数据趋于标准正态分布;提出了一种网络流量时空相关性的度量方法。实验结果表明,相较于现有的基线生成方式,所提出的方法在真实性和相关性的度量上平均提高了9%。

关键词：网络仿真网络流量生成生成对抗神经网络时空相关性

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移民视角下湘鄂赣地区传统民居知识图谱分析

中外建筑 2024年第1期 132-137页

作者：严钧涂若川李维灏长沙理工大学建筑学院长沙理工大学

湘鄂赣地区传统民居的形成与发展受明清时期移民活动影响较大。为了探究当地传统民居研究的发展脉络,通过CiteSpace数据分析软件对CNKI数据库中的研究成果进行处理,分析其关键词的群聚性特征、发展路径以及突现特征。结果表明,湘、鄂、... 详细信息

湘鄂赣地区传统民居的形成与发展受明清时期移民活动影响较大。为了探究当地传统民居研究的发展脉络,通过CiteSpace数据分析软件对CNKI数据库中的研究成果进行处理,分析其关键词的群聚性特征、发展路径以及突现特征。结果表明,湘、鄂、赣三大地区的民居研究主要沿着四个方向发展;学科交叉的研究方法逐渐成熟;移民视角下的传统民居研究数量逐渐增多,并且逐渐具体化和深入化,但区域研究发展水平不一。在国内外新形势和新技术的背景下,拓展研究对象的范围,将定性和定量两种不同的研究方法相结合,以及继续回应时事政策的思路可以作为当下研究的主要目标。

关键词：知识图谱传统民居移民湘鄂赣地区 CiteSpace

Detection of endogenous foreign bodies in Chinese hickory nuts by hyperspectral spectral imaging at the pixel level

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 204-210页

作者： Zhe Feng weihao li Di Cui College of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058China Key Laboratory of On Site Processing Equipment for Agricultural Products Ministry of Agriculture and Rural AffairsHangzhou 310058China

It is difficult to differentiate small,but harmful,shell fragments of Chinese hickory nuts from their kernels since they are very similar in *** shell fragments of Chinese hickory nuts by mistake may create safety hazards for ***,there is a need to develop an effective method to differentiate the shells from the kernels of Chinese hickory *** this study,a deep learning approach based on a two-dimensional convolutional neural network(2D CNN)and long short-term memory(LSTM)integrated with hyperspectral imaging for distinguishing the shells and kernels of Chinese hickory nuts at the pixel level was *** classical classification methods,principal component analysis-K-nearest neighbors(PCA-KNN)and the support vector machine(SVM),were employed to establish identification models for *** results showed that the 2D CNN-LSTM model achieved the best performance with an overall classification accuracy of 99.0%.Moreover,the shells in mixtures of shells and kernels were detected based on the proposed deep learning method and visualized for subsequent operations for the removal of foreign bodies.

关键词： Chinese hickory nut endogenous foreign body hyperspectral spectral imaging pixel level detection

Coordinated voltage control of renewable energy power plants in weak sending-end power grid

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Global Energy Interconnection 2020年第4期3卷 365-374页

作者： Yongning Chi weihao li Qiuwei Wu Chao liu Department of Renewable Energy China Electric Power Research InstituteBeijing 100031P.R.China School of Electrical Engineering Shandong UniversityJinan 250000P.R.China Center for Electric Power and Energy Department of Electrical EngineeringTechnical University of DenmarkKgs.LyngbyDenmark

The utilization of renewable energy in sending-end power grids is increasing rapidly,which brings difficulties to voltage *** paper proposes a coordinated voltage control strategy based on model predictive control(MPC)for the renewable energy power plants of wind and solar power connected to a weak sending-end power grid(WSPG).Wind turbine generators(WTGs),photovoltaic arrays(PVAs),and a static synchronous compensator are coordinated to maintain voltage within a feasible range during *** results in the full use of the reactive power capability of WTGs and *** addition,the impact of the active power outputs of WTGs and PVAs on voltage control are considered because of the high R/X ratio of a collector *** analytical method is used for calculating sensitivity coefficients to improve computation efficiency.A renewable energy power plant with 80 WTGs and 20 PVAs connected to a WSPG is used to verify the proposed voltage control *** studies show that the coordinated voltage control strategy can achieve good voltage control performance,which improves the voltage quality of the entire power plant.

关键词： Coordinated voltage control Model predictive control(MPC) Renewable energy Weak sending-end power grid Wind turbine generators(WTGs) Photovoltaic arrays(PVAs) STATCOM