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

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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 li.ng 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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Study of thermal decoherence of harmonic oscillators

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原子与分子物理学报 2025年第5期42卷 108-114页

作者： li Jian ZHOU Gao-li.ng YAn Zheng-xin liU wei WAng Zhao-qi College of Science Xi’an University of Science and TechnologyXi’an 710054China

The thermal decoherence of harmonic oscillators is investigated *** quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental *** are various environmental oscillators with different angular frequency(below an ultraviolet cutoff).At the beginning,the quantum system is a pure state and the environmental oscillators are in thermodynamic equilibrium with *** a period,the system-environment interactions inspire significant decoherence of the quantum *** decoherence is displayed by explicit calculations of the purity and von neumann entropy of the quantum *** is worth noting that the decoherence could be significant even in the weak coupling and low temperature case due to the large amount of environmental degrees of *** the decoherence process is inspired between the quantum system and an ordinary thermal environment here,the thermal decoherence result is quite general.

关键词： Quantum decoherence Grand canonical ensemble Oscillators

Purification of specularite by centrifugation instead of flotation to produce iron oxide red pigment

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International Journal of Minerals,Metallurgy and Materials 2021年第1期28卷 56-65页

作者： xi Zhang Shun-wei Zhu Yu-jiang li Yong-li li qiang Guo Tao qi national Engineering Laboratory of Hydrometallurgical Cleaner Production Technology Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Environmental Science and Engineering Shandong UniversityQingdao 266200China Zhengzhou Institute of Emerging Industrial Technology Zhengzhou 450003China

This study used specularite, a high-gradient magnetic separation concentrate, as a raw material in reverse *** iron concentrate with a grade of 65.1 wt% and a recovery rate of 75.31% were obtained.A centrifugal concentrator served as the deep purification equipment for the preparation of iron oxide red pigments, and its optimal rotating drum speed, feed concentration, and other conditions were *** optimal conditions, a high-purity iron oxide concentrate with a grade of 69.38 wt% and a recovery rate of 80.89% were obtained and used as a raw material for preparing iron oxide red *** with sulfuric acid produced iron red pigments with different ***, middlings with a grade of 60.20 wt% and a recovery rate of 17.51% were obtained and could be used in blast furnace ***-value utilization of specularite beneficiation products was thus achieved.

关键词： specularite reconcentration centrifugal concentrator iron oxide red pigment

有Bernoulli中断休假和随机启动时间的n-策略多重休假M=G=1排队的队长分析

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应用数学 2025年第1期38卷 276-293页

作者：李茜唐应辉余玅妙魏瑛源四川师范大学数学科学学院四川成都610068 河西学院数学与统计学院甘肃张掖734000

本文研究一个有Bernoulli中断休假和随机启动时间的n-策略多重休假M/G/1排队模型,其中Bernoulli中断休假是指:如果在休假中有顾客到达,服务员以概率p(0≤p≤1)立即中断休假回到系统中并启动服务设施,以概率(1−p)不中断休假直到此次休假... 详细信息

本文研究一个有Bernoulli中断休假和随机启动时间的n-策略多重休假M/G/1排队模型,其中Bernoulli中断休假是指:如果在休假中有顾客到达,服务员以概率p(0≤p≤1)立即中断休假回到系统中并启动服务设施,以概率(1−p)不中断休假直到此次休假结束后才回到系统启动服务设施.当系统的启动完成后,若系统中顾客数大于等于事先设置的阈值n(≥1),则服务员开始为顾客服务直到系统再次变空.运用全概率分解技术和更新过程理论讨论了系统在时刻t队长的瞬态概率分布,得到了队长瞬态概率分布的拉普拉斯变换表达式.在瞬态分析的基础上,使用洛必达法则和一些代数运算推导出了队长稳态概率分布的递推表达式,以及其它一些排队指标,如队长稳态概率分布的母函数、平均队长和附加队长的概率分布等.最后,讨论了一些特殊情形.

关键词： Bernoulli中断休假随机启动时间 n-策略全概率分解队长分布

Electrochemical performance of lini_(0.5)Mn_(0.5)O_2 with different synthesis methods

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Rare Metals 2015年第8期34卷 580-585页

作者： Hong li qiang Xu xi-xi Shi Da-wei Song lian-qi Zhang Department of Applied Chemistry School of Chemical and Engineering Tianjin University School of Materials Science and Engineering Tianjin University of Technology

li ni0.5Mn0.5O2 as a cathode material for li-ion battery was prepared by the metal acetate decomposition method, sol–gel method, and carbonate co-precipitation method, respectively. The influences of synthesis methods on the physical and electrochemical behaviors of li ni0.5Mn0.5O2 were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and electrochemical tests. XRD patterns show that both the sol–gel and carbonate co-precipitation methods can form single phase of layered structure, while a trace of ni O impurity is observed via the metal acetate decomposition method. SEM results show the as-prepared carbonate particle has a spherical morphology with an average diameter of 10 lm, consisted of primary nano-sized particles with particle diameter of200 nm. The sample prepared by the carbonate co-precipitation method exhibits the highest discharge specific capacity and the best cycling stability, which results from the steady homogeneity of precursor constant by the fixation of CO2-3group. It can deliver an initial discharge specific capacity of 186.3 m Ahág-1, and retain 170 m Ahág-1after100 cycles at a current rate of 20 m Aág-1in the voltage range of 2.5–4.7 V at 25 °C. Moreover, even at the high temperature of 55 °C, it still delivers a reversible specific capacity of 222.6 m Ahág-1with little capacity loss after 30 cycles.

关键词： Sol–gel Carbonate co-precipitation lini0.5Mn0.5O2

Patterns,magnitude,and controlling factors of hydraulic redistribution of soil water by Tamarix ramosissima roots

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Journal of Arid Land 2013年第3期5卷 396-407页

作者： TengFei YU qi FEng JianHua SI HaiYang xi wei li Research School of Arid Environment and Climate Change Lanzhou University Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Gansu Hydrology and Water Resources Engineering Research Center

Tamarix spp. （Saltcedar） is a facultative phreatophyte that can tolerate drought when groundwater is not accessed. In addition to deep water uptake, hydraulic redistribution （HR） is another factor contributing to the drought tolerance of Tarnarix spp. In this study, data on soil volumetric moisture content （0）, lateral root sap flow, and relevant climate variables were used to investigate the patterns, magnitude, and controlling factors of HR of soil water by roots of Tamarix ramosissima Ledeb. in an extremely arid land in northwest China. Results showed evident diurnal fluctuations in 0 at the depths of 30 and 50 cm, indicating ＂hydraulic lift＂（HL）. 0 increased remarkably at 10 and 140 cm but decreased at 30 and 50 cm and slightly changed at 80 cm after rainfall, suggesting a possible ＂hydraulic descent＂（HD）. However, no direct evidence was observed in the negative flow of lateral roots, supporting HR （including HL and HD） of T. ramosissima. The HR pathway unlikely occurred via lateral roots; instead, HR possibly occurred through adventitious roots with a diameter of 2-5 mm and a length of 60-100 cm. HR at depths of 20-60 cm ranged from 0.01-1.77 mm/d with an average of 0.43 mm/d, which accounted for an average of 22% of the estimated seasonal total water depletion at 0-160 cm during the growing season. The climate factors, particularly vapor pressure deficit and soil water potential gradient, accounted for at least 33% and 45% of HR variations with depths and years, respectively. In summary, T. ramosissima can be added to the wide list of existing species involved in HR. High levels of HR may represent a considerable fraction of daily soil water depletion and substantially improve plant water status. HR could vary tremendously in terms of years and depths, and this variation could be attributed to climate factors and soil water potential gradient.

关键词： drought tolerance phreatophyte hydraulic redistribution root sap flow Tamarix ramosissima

Low‑Temperature Oxidation Induced Phase Evolution with Gradient Magnetic Heterointerfaces for Superior Electromagnetic Wave Absorption

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nano-Micro Letters 2025年第1期17卷 191-204页

作者： Zizhuang He lingzi Shi Ran Sun lianfei Ding Mukun He Jiaming li Hua Guo Tiande Gao Panbo liu School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710129People’s Republic of China School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China

Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significant challenging in regulating local phase ***,accordion-shaped Co/Co_(3)O_(4)@n-doped carbon nanosheets(Co/Co_(3)O_(4)@nC)with gradient magnetic heterointerfaces have been fabricated via the cooperative high-temperature carbonization and lowtemperature oxidation *** results indicate that the surface epitaxial growth of crystal Co_(3)O_(4) domains on local Co nanoparticles realizes the adjustment of magnetic-heteroatomic components,which are beneficial for optimizing impedance matching and interfacial ***,gradient magnetic heterointerfaces simultaneously realize magnetic coupling,and long-range magnetic ***,the synthesized Co/Co_(3)O_(4)@nC absorbents display the strong electromagnetic wave attenuation capability of−53.5 dB at a thickness of 3.0 mm with an effective absorption bandwidth of 5.36 GHz,both are superior to those of single magnetic domains embedded in carbon *** design concept provides us an inspiration in optimizing interfacial polarization,regulating magnetic coupling and promoting electromagnetic wave absorption.

关键词： Magnetic heterointerfaces Phase evolution Interfacial polarization Magnetic coupling Electromagnetic wave absorption

Primary amine coupling on nanocarbon catalysts: Reaction mechanism and kinetics via fluorescence probe analysis

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Green Energy & Environment 2020年第4期5卷 453-460页

作者： Fan li Xueya Dai wei qi Shenyang national Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

non-metallic nanocarbon materials catalyzed coupling reactions of primary amines to produce imine is an efficient,green and sustainable synthetic route,which has a wide application prospect in fine chemicals or pharmaceutical *** the present study,we show firstly the relatively high catalytic activity of graphene oxide in the reaction of oxidative coupling of benzylamine(OCB),which is even comparable with typical metal-based catalysts,indicating the great potential of nanocarbon materials in this reaction *** importantly,a novel twophoton fluorescence probe molecule(n-propyl-4-hydrazinyl-1,8-naphthalimide,nA)with special chemical structure of hydrazine functionality was *** probe nA could selectively react with aldehyde or ketone compounds,leading to the photoluminescence enhancement via inhibition of photo induced electron transfer(PET)*** synthesized nA was applied as probe in carbon catalyzed OCB system to predict the existence of reaction intermediate benzaldehyde(BA),indicating the reaction pathway of oxidation-deamination-condensation in nanocarbon catalyzed OCB *** proposed luminescence-probe strategy for revealing the kinetics and mechanism may also shed light in other reaction systems concerning the intermediates or products of ketones or aldehydes.

关键词： nanocarbon Benzylamine coupling reaction Fluorescence probe Reaction mechanism

酚酸基纳米金修饰电极检测食品中的亚硝酸盐和亚硫酸盐

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食品工业科技 2025年第1期46卷 274-282页

作者：陈林林吴松遥郝熙李伟张铭张海鹏李昕彤张娜哈尔滨商业大学食品工程学院黑龙江哈尔滨150028

基于酚酸良好的还原性和无污染性建立酚酸基纳米金传感体系,以实现亚硝酸盐和亚硫酸盐的灵敏检测。采用不同酚酸还原氯金酸制备纳米金(Gold nanoparticles,AunPs),通过紫外光谱和交流阻抗法获得还原效果最佳的酚酸为没食子酸(Gallic aci... 详细信息

基于酚酸良好的还原性和无污染性建立酚酸基纳米金传感体系,以实现亚硝酸盐和亚硫酸盐的灵敏检测。采用不同酚酸还原氯金酸制备纳米金(Gold nanoparticles,AunPs),通过紫外光谱和交流阻抗法获得还原效果最佳的酚酸为没食子酸(Gallic acid,GA)。利用电沉积法制备GA@AunPs@Au电极,并由线性扫描伏安法(linear scanning voltammetry,LSV)表征亚硝酸盐和亚硫酸盐的电化学行为。优化体系条件为:GA浓度1 mmol/L、孵育温度70℃、反应时间60 min、pH6.0磷酸盐缓冲溶液浓度0.15 mol/L。亚硝酸盐和亚硫酸盐浓度在0.001~7 mmol/L范围内与氧化峰电流分别呈良好的线性关系(R2>0.994),检出限分别为0.20μmol/L和0.24μmol/L(S/n=3)。该修饰电极的重现性和稳定性良好,可用于实际样品中亚硝酸盐和亚硫酸盐的同时测定。

关键词：酚酸纳米金修饰电极亚硝酸盐亚硫酸盐