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The Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by 2-Methylquinoline Derived Chiral Ligands

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Chinese Chemical Letters 2001年第5期12卷 395-396页

作者： qian yong xu Guo Xing WANG Xin Fu PAN Department of Chemistry National Laboratory of Applied Organic ChemistryLanzhou UniversityLanzhou 730000

Readily available 2-methylquinoline derived chiral ligands 1 and 2 have been applied in the enantioselective addition of diethylzinc to aldehydes with up to 91.4% ee being recorded.

关键词： Methylquinoline enantioselective addition diethylzinc.

Estimation of OCDD degradation rate in soil

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Journal of Environmental Sciences 2005年第6期17卷 981-983页

作者： ZHAO Xing-ru ZHENG Ming-hui ZHANG Bing qian yong xu Xiao-bai State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of ScienceBeijing 100085 China

The current concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDD/Fs） were determined in soils contaminated with Chinese technical product sodium pentachlorophenate （ Na- PCP）. The estimated half-life of octachlorodioxin （OCDD） was about 14 years in contaminated soils based on the local historical record and mass balance calculation during the past 43 years（ 1960-2003）. The isomer profiles remained the same regardless of paddy field soil or riverbank soil. The results indicated that the congenerspecific information was efficient in estimating the PCDD/Fs fate in contaminated soils.

关键词： OCDD degradation rate Na-PCP

The Steric Effect of trans-(1S,2S)-1-Substituted-2-(N,N-dialkyl-amino)-1-indanol Derivatives as Chiral Ligands in the Catalytic Enantioselective Addition of Diethylzinc to Aldehydes

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Chinese Chemical Letters 2002年第11期13卷 1029-1032页

作者： qian yong xu Hong Fang YANG Xin Fu PAN Guang Ming ZHU Northwest Institute of Nuclear Technology P.O.Box 69Xi'an 710024 Department of Chemistry National Laboratory of Applied Organic ChemistryLanzhou UniversityLanzhou 730000 Department of Chemical Engineering Northwestern Polytechnic UniversityXi'an 710062

Optically active trans-(1S,2S)-1-substituted-2-(N,N-dialkylamino)-1-indanol derivatives have been prepared and used in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol in good yield with up to 9... 详细信息

关键词： Diethylzinc enantioselective alkylation indanol derivative.

Investigation of the interaction between indigotin and two serum albumins by spectroscopic approaches

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Journal of Pharmaceutical Analysis 2013年第4期3卷 257-269页

作者： Zheng-Jun Cheng Hong-Mei Zhao qian-yong xu Rong Liu Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province China West Normal University Nanchong Petrochemical School

The binding characteristics of indigotin with human serum albumin （HSA） and bovine serum albumin （BSA） have been investigated by various spectroscopic techniques. Spectroscopic analysis revealed that the quenching mechanism between indigotin and HSA/BSA belonged to the static quenching. The displacement experiments suggested that indigotin primarily bound to tryptophan residues on proteins within site I. The thermodynamic parameters indicated that the binding of indigoti^HSA/BSA mainly depended on the hydrophobic interaction. The binding distance of indigotin to HSA/BSA was evaluated. The results by synchronous fluorescence, three- dimensional fluorescence, Fourier Transform Infrared spectroscopy （FT-IR） and circular dichroism （CD） spectra showed that the conformation of proteins altered in the presence of indigotin.

关键词： Human serm albumin Bovine serum albumin Indigoiin Fluorescence spectro-scopy Binding constants

Creep aging behavior of retrogression and re-aged 7150 aluminum alloy

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Transactions of Nonferrous Metals Society of China 2020年第10期30卷 2599-2612页

作者： Qing WANG Li-hua ZHAN yong-qian xu Chun-hui LIU Xing ZHAO Ling-zhi xu You-liang YANG Yi-xian CAI School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Light Alloy Research Institute of Central South University Changsha 410083China

Creep aging behavior of retrogression and re-aged(RRAed)7150 aluminum alloy(AA7150)was systematically investigated using the creep aging experiments,mechanical properties tests,electrical conductivity tests and transmission electron microscope(TEM)*** aging results show that the steady-state creep mechanism of RRAed alloys is mainly dislocation climb(stress exponent≈5.8),which is insensitive to the grain interior and boundary ***,the total creep deformation increases over the re-aging *** addition,the yield strength and tensile strength of the four RRAed samples are essentially the same after creep aging at 140℃ for 16 h,but the elongation decreases slightly with the re-aging ***’s more,the retrogression and re-aging treatment are beneficial to increase the hardness and electrical conductivity of the creep-aged 7150 aluminum *** can be concluded that the retrogression and re-aging treatment before creep aging forming process can improve the microstructure within grain and at grain boundary,forming efficiency and comprehensive performance of mechanical properties and electrical conductivity of 7150 aluminum alloy.

关键词： creep aging forming creep behavior mechanical properties electrical conductivity aging precipitates Al−Zn−Mg−Cu alloy

The Essential 2-rank for Classical Groups

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2169-2186页

作者： Jian Bei AN yong xu Department of Mathematics University of AucklandAucklandNew Zealand School of Mathematics and Statistics He’nan University of Science and TechnologyLuoyang 471023P.R.China

Let G be a symplectic or orthogonal group defined over a finite field with odd characteristic and let D≤G be a Sylow *** this paper,we classify the essential 2-subgroups and determine the essential 2-rank of the Frobenius category FD(G).Together with the results of An–Dietrich and Cao–An–Zeng,this completes the work of essential subgroups and essential ranks of classical groups.

关键词： Frobenius category conjugation families essential 2-rank symplectic groups orthogonal groups

Accurate Analysis of Multi-Mode Interferometric Optical Fiber Sensor

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Photonic Sensors 2024年第1期14卷 48-58页

作者： Lijun LI Congying JIA qian MA Tianzong xu College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590.China State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Qingdao 266590China

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and *** suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,*** method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis *** the same time,this method is also beneficial to solve the repetitive problem of such sensors.

关键词： Window function FFT optical fiber interferometric sensor analysis method

Further Results on Stability Analysis for Sampled-Data Systems via Refined Semi-Looped-Functional

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Journal of Systems Science & Complexity 2024年第1期37卷 318-328页

作者： SHENG Zhaoliang xu Shengyuan MA qian ZHANG Baoyong School of Automation Nanjing University of Science and TechnologyNanjing 210094China

This paper investigates the stability problem for sampled-data systems by adopting a refined semi-looped-functional,which is with the following two ***,the new functional term is with a new integral vectorη0,which contains sampling information of the systems and associates two commonly used ***,the vectorη0 is combined into various zero equations for processing the functional,especially where a new equation is derived fromη*** on the refined functional,further stability results for sampled-data systems are *** the effectiveness of the results is numerically verified through two examples at the end.

关键词： Integral vector sampled-data systems semi-looped-functional stability analysis.

Experimental distillation of tripartite quantum steering with an optimal local filtering operation

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Photonics Research 2024年第3期12卷 552-562页

作者： qian-XI ZHANG XIAO-xu FANG HE LU School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Shenzhen Research Institute of Shandong University Shenzhen 518057China

Multipartite Einstein-Podolsky-Rosen(EPR)steering admits multipartite entanglement in the presence of uncharacterized verifiers,enabling practical applications in semi-device-independent *** applications generally require stronger steerability,while the unavoidable noise weakens steerability and consequently degrades the performance of quantum information ***,we propose the local filtering operation that can maximally distill genuine tripartite EPR steering from N copies of three-qubit generalized Greenberger-Horne-Zeilinger states,in the context of two semi-device-independent *** optimal filtering operation is determined by the maximization of assemblage *** and numerical results indicate the advantage of the proposed filtering operation when N is finite and the steerability of initial assemblages is ***,a proof-of-principle demonstration of two-copy distillation is realized with the optical *** advantage of the optimal local filtering operation is confirmed by the distilled assemblage in terms of higher assemblage fidelity with perfectly genuine tripartite steerable assemblages,as well as the greater violation of the inequality to witness genuine tripartite steerable *** results benefit the distillation of multipartite EPR steering in practice,where the number of copies of initial assemblages is generally finite.

关键词： filtering distillation optimal