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Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

Science China Chemistry 2025年

作者： shuai zhang Pei-Zhi Liu Yan-Bo Li Qi zhang Jun-Zhao Xiao Yi-Fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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开发区升格政策能促进企业创新增量提质吗?

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太原学院学报（社会科学版） 2025年第1期26卷 92-106页

作者：张帅王筱依太原学院财经系山西太原030032

通过构建多时点DID模型实证检验开发区升格政策对企业创新数量和创新质量的影响,结果表明:省级开发区升格通过降低制度性交易成本、提升市场化程度和加速创新要素流入对企业创新产出数量和产出质量产生促进作用,该政策对非民营企业、非... 详细信息

通过构建多时点DID模型实证检验开发区升格政策对企业创新数量和创新质量的影响,结果表明:省级开发区升格通过降低制度性交易成本、提升市场化程度和加速创新要素流入对企业创新产出数量和产出质量产生促进作用,该政策对非民营企业、非高技术制造行业、高新区和小规模城市的作用效果更强。因此,要充分发挥开发区“以升促建”的创新激励效应,不仅要注重有为政府和有效市场的结合,还要根据城市固有经济特征优化开发区制度环境。

关键词：开发区升格创新数量创新质量

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Effects of ZnO,FeO and Fe_(2)O_(3)on the spinel formation,microstructure and physicochemical properties of augite-based glass ceramics

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International Journal of Minerals,Metallurgy and Materials 2023年第6期30卷 1207-1216页

作者： shuai zhang Yanling zhang Shaowen Wu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Augite-based glass ceramics were synthesised using ZnO,FeO,and Fe_(2)O_(3)as additives,and the spinel formation,matrix structure,crystallisation thermodynamics,and physicochemical properties were *** results showed that oxides resulted in numerous preliminary spinels in the glass ***,ZnO,and Fe_(2)O_(3)influenced the formation of spinel,while FeO simplified the glass *** and ZnO promoted bulk crystallisation of the parent *** adding oxides,the grains of augite phase were refined,and the relative quantities of augite crystal planes were also *** samples displayed good mechanical properties and chemical *** 2wt%ZnO-doping sample displayed the maximum flexural strength(170.3 MPa).Chromium leaching amount values of all the samples were less than the national standard(1.5 mg/L),confirming the safety of the *** conclusion,an appropriate amount of zinc-containing raw material is beneficial for the preparation of augite-based glass ceramics.

关键词： spinel network structure thermodynamics microstructure glass ceramics

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Review of the development of power system out-of-step splitting control and some thoughts on the impact of large-scale access of renewable energy

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Energy and AI 2024年第2期16卷 497-511页

作者： shuai zhang School of Control Science and Engineering Shandong UniversityJinan 250061China

Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispensable means, which could protect the system from major shocks of out-of-step oscillation. After years of development, it has achieved certain amount of research results. Have the existing methods been able to meet the requirements of out-of-step splitting? What improvements are needed? Under this background, this review is written. It combs the development of out-of-step splitting control technologies and analyzes the technical routes and characteristics of different methods. It points out the contradiction between rapidity and optimality is the biggest technical problem, existing in both the traditional local measurement based out-of-step splitting protection and the wide-area information based out-of-step splitting protection. It further points out that the advantages of the two types of protections can be combined with the unique physical characteristics of the out-of-step center to form a more advantageous splitting strategy. Besides, facing the fact of large-scale renewable energy access to power grid in recent years, this review also analyzes the challenges brought by it and provides some corresponding suggestions. It is hoped to provide some guidance for the subsequent research work.

关键词： Out-of-step oscillation Out-of-step splitting control Wide-area measurement information Contradiction between rapidity and optimality Large-scale renewable energy access

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Review on Security Defense Technology Research in Edge Computing Environment

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Chinese Journal of Electronics 2024年第1期33卷 1-18页

作者： Ke SHANG Weizhen HE shuai zhang National Digital Switching System Engineering and Technological R&D Center

Edge computing, which achieves quick data processing by sinking data computing and storage to the network edge, has grown rapidly along with the Internet of things. The new network architecture of edge computing brings new security challenges. Based on this, this paper investigates the edge computing security literature published in recent years and summarizes and analyzes research work on edge computing security from different attack surfaces. We start with the definition and architecture of edge computing. From the attack surface between device and edge server, as well as on edge servers, the research describes the security threats and defense methods of edge computing. In addition, the cause of the attack and the pros and cons of defense methods is introduced. The challenges and future research directions of edge computing are given.

关键词： Cloud computing Systems architecture Computer architecture Network architecture Data processing Security Servers

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Peridynamic modeling and simulation of thermo-mechanical de-icing process with modified ice failure criterion

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Defence Technology（防务技术） 2021年第1期17卷 15-35页

作者： Ying Song Shaofan Li shuai zhang College of Shipbuilding Engineering Harbin Engineering UniversityHarbinChina Department of Civil and Environmental Engineering University of CaliforniaBerkeleyUSA

De-icing technology has become an increasingly important subject in numerous applications in recent ***,the direct numerical modeling and simulation the physical process of thermomechanical deicing is *** work is focusing on developing a numerical model and tool to direct simulate the de-icing process in the framework of the coupled thermo-mechanical peridynamics ***,we adopted the fully coupled thermo-mechanical bond-based peridynamics(TM-BB-PD)method for modeling and simulation of *** the framework of TM-BB-PD,the ice constitutive model is established by considering the influence of the temperature difference between two material points,and a modified failure criteria is proposed,which takes into account temperature effect to predict the damage of quasi-brittle ice ***,thermal boundary condition is used to simulate the thermal load in the de-icing *** comparing with the experimental results and the previous reported finite element modeling,our numerical model shows good agreement with the previous *** on the numerical results,we find that the developed method can not only predict crack initiation and propagation in the ice,but also predict the temperature distribution and heat conduction during the de-icing ***,the influence of the temperature for the ice crack growth pattern is discussed *** conclusion,the coupled thermal-mechanical peridynamics formulation with modified failure criterion is capable of providing a modeling tool for engineering applications of de-icing technology.

关键词： Crack growth De-icing Peridynamics Failure criteria Temperature effect Thermal mechanical coupling

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Chromium enrichment in different crystalline phases of Cr-containing slag under various basicities and equilibrium temperatures

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Journal of Iron and Steel Research International 2022年第9期29卷 1412-1422页

作者： Shao-wen Wu Yan-ling zhang shuai zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The effects of basicities and equilibrium temperatures on the enrichment of chromium in different mineral phases of synthesized argon-oxygen decarburization slags were investigated to understand the Cr concentrating behavior into Mg(Cr,Al)2O4 spinel phase and to determine the leaching stability of Cr-containing *** results showed that when the basicity decreased from 1.0 to 0.6 and temperatures decreased from 1600 to 800℃,the Cr content of amorphous phase and crystalline phase gradually decreased,with a subsequent increase in the Cr content of spinel *** range of Cr enrichment in spinel of slags S1,S2,and S3 is 92.03-96.89,91.63-96.36,and 90.67-95.42,*** mass fraction and the size of spinel increased with the decreasing equilibrium temperatures,and the Cr leaching values decreased ***,the trend of the amount of Cr-related ions in the leachate was consistent with the trend of Cr in the amorphous phase,diopside,and *** results suggest that the lower basicity and equilibrium temperatures could be conducive to stabilizing Cr into spinel phase to minimize Cr leaching into the environment.

关键词： Chromium enrichment Leaching behavior Basicity Temperature Cr-containing slag

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STPGTN-AMulti-Branch Parameters Identification Method Considering Spatial Constraints and Transient Measurement Data

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 2635-2654页

作者： shuai zhang Liguo Weng Jiangsu Key Laboratory of Big Data Analysis Technology Nanjing University of Information Science and TechnologyNanjing210044China

Transmission line(TL)Parameter Identification(PI)method plays an essential role in the transmission *** existing PI methods usually have two limitations:(1)These methods only model for single TL,and can not consider the topology connection of multiple branches for simultaneous identification.(2)Transient bad data is ignored by methods,and the random selection of terminal section data may cause the distortion of PI and have serious ***,a multi-task PI model considering multiple TLs’spatial constraints and massive electrical section data is proposed in this *** Graph Attention Network module is used to draw a single TL into a node and calculate its influence coefficient in the transmission ***-Task strategy of Hard Parameter Sharing is used to identify the conductance ofmultiple branches *** show that themethod has good accuracy and *** to the consideration of spatial constraints,the method can also obtain more accurate conductance values under different training and testing conditions.

关键词： Transmission lines parameter identification graph modeling method deep learning

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Efficient Bayesian networks for slope safety evaluation with large quantity monitoring information

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Geoscience Frontiers 2018年第6期9卷 1679-1687页

作者： Xueyou Li Limin zhang shuai zhang Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology

New sensing and wireless technologies generate massive data. This paper proposes an efficient Bayesian network to evaluate the slope safety using large-quantity field monitoring information with underlying physical mechanisms. A Bayesian network for a slope involving correlated material properties and dozens of observational points is constructed.

关键词： Slope reliability Monitoring information Bayesian networks Risk management Value of information Big data

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Spatial and Temporal Changes in Vapor Pressure Deficit and Their Impacts on Crop Yields in China during 1980–2008

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Journal of Meteorological Research 2017年第4期31卷 800-808页

作者： shuai zhang Fulu TAO Zhao zhang Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University

Vapor pressure deficit（VPD） is a widely used measure of atmospheric water demand. It is closely related to crop evapotranspiration and consequently has major impacts on crop growth and yields. Most previous studies have focused on the impacts of temperature, precipitation, and solar radiation on crop yields, but the impact of VPD is poorly understood. Here, we investigated the spatial and temporal changes in VPD and their impacts on yields of major crops in China from 1980 to 2008. The results showed that VPD during the growing period of rice, maize, and soybean increased by more than 0.10kPa（10 yr）^–1 in northeastern and southeastern China, although it increased the least during the wheat growing period. Increases in VPD had different impacts on yields for different crops and in different regions. Crop yields generally decreased due to increased VPD, except for wheat in southeastern China. Maize yield was sensitive to VPD in more counties than other crops. Soybean was the most sensitive and rice was the least sensitive to VPD among the major crops. In the past three decades, due to the rising trend in VPD, wheat, maize, and soybean yields declined by more than 10.0% in parts of northeastern China and the North China Plain, while rice yields were little affected. For China as a whole, the trend in VPD during 1980–2008 increased rice yields by 1.32%,but reduced wheat, maize, and soybean yields by 6.02%, 3.19%, and 7.07%, respectively. Maize and soybean in the arid and semi-arid regions in northern China were more sensitive to the increase in VPD. These findings highlight that climate change can affect crop growth and yield through increasing VPD, and water-saving technologies and agronomic management need to be strongly encouraged to adapt to ongoing climate change.

关键词： agriculture climate change vapor pressure deficit evapotranspiration water stress

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