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Minimizing chemical interference errors for the determination of lithium in brines by flame atomic absorption spectroscopy analysis

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Rare Metals 2006年第4期25卷 309-315页

作者： wen Xianming MA Peihua zhu Geqin WU Zhiming Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining 810008 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Chemical interferences （ionization and oxide/hydroxide formation） on the atomic absorbance signal of lithium in FAAS analysis of brine samples are elaborated in this article. It is suggested that inadequate or overaddition of deionization buffers can lead to loss of sensitivities under particular operating conditions. In the analysis of brine samples, signal enhancing and oxide/hydroxide formation inducing signal reduction resulting from overaddition of deionization buffers can be seen with varying amounts of chemical buffers. Based on experimental results, the authors have arrived at the optimized operating conditions for the detection of lithium, under which both ionization and stable compound formation can be suppressed. This is a simplified and quick method with adequate accuracy and precision for the determination of lithium in routine brine samples from chemical plants or R＆D laboratories, which contain comparable amounts of lithium with some other components.

关键词： analytical chemistry simplified method FAAS lithium brine deionization oxide/hydroxide formation

Single silicon waveguide MRR based Fano resonance in the whole spectral bands

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Optoelectronics Letters 2022年第7期18卷 398-403页

作者： LU Lidan WANG shuai ZENG Zhoumo DONG Mingli zhu Lianqing School of Instrument Science and Opto Electronics Engineering Beijing Information Science and Technology UniversityBeijing 100016China Department of Precision Instrument Engineering Tianjin UniversityTianjin 300072China

To improve the integration of Fano devices,we design a T-shaped waveguide coupling micro-ring resonator(MRR)structure to achieve a single cavity with Fano resonance in the whole spectral *** mathematical relationship between the phase factor,the coupling coefficient of the bus waveguide,and the Fano resonance slope extinction ratio(ER)is *** electron beam exposure process is used to obtain a device with an insertion loss of~3 *** maximum ER of the Fano lineshape exceeds 15 dB,and the slope ratio(SR)is 251.3 dB/*** design improves the compactness of the Fano resonant device.

关键词： waveguide Fano resonator

Palladium/Xu-Phos-catalyzed enantioselective arylalkoxylation reaction ofγ-hydroxyalkenes at room temperature

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Chinese Chemical Letters 2024年第11期35卷 355-360页

作者： shuai zhu Mingjie Chen Haichao Shen Hanming Ding wenbo Li Junliang Zhang State Key Laboratory of Petroleum Molecular&Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200241China Department of Chemistry Fudan UniversityShanghai 200438China

Metal-catalyzed alkene arylalkoxylation is a powerful complexity-building strategy for the synthesis of oxygen heterocycles from simpleγ-unsaturated alcohols,but only a few examples of catalytic enantioselective methods ***,an efficient palladium-catalyzed enantioselective arylalkoxylation ofγ-hydroxyalkenes with aryl halides is *** salient features of this transformation include a remarkable broad substrate scope,mild reaction conditions,and good functional group tolerance,delivering a series of chiral tetrahydrofurans containing a tertiary or quaternary stereocenter in good yields with up to 95%*** Xu10 ligand with a suitable side-arm was responsible for the high reactivity and good enantioselectivity of this transformation.

关键词： Palladium-catalysis Xu-Phos Enantioselective Arylalkoxylation γ-Hydroxyalkenes

Performance Analysis and Improvement of Flat Torque Converters Using DOE Method

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Chinese Journal of Mechanical Engineering 2018年第4期31卷 101-109页

作者： Guang-Qiang Wu Jie Chen wen-Jie zhu School of Automotive Studies Tongji University Institute of Industrial Science The University of Tokyo

Automotive torque converters have recently been designed with an increasingly narrower profile for the purpose of achieving a smaller axial size and reducing weight. Design of experiment(DOE) and computational fluid dynamics(CFD) techniques are applied to improve the performance of a flat torque converter. Four torque converters with different flatness ratios(0.204, 0.186, 0.172, and 0.158) are designed and simulated first to investigate the effects of flatness ratio on their overall performance, including efficiency, torque ratio, and impeller torque factor. The simulation results show that the overall performance tends to deteriorate as the flatness ratio decreases. Then a parametric study covering six geometric parameters, namely, inlet and outlet angles of impeller, turbine, and stator is carried out. The results demonstrate that the inlet and outlet angles play an important role in determining the performance characteristics of a torque converter. Furthermore, the relative importance of the six design parameters is investigated using DOE method for each response(stall torque ratio and peak efficiency). The turbine outlet angle is found to exert the greatest influence on both responses. After DOE analysis, an optimized design for the flat torque converter geometry is obtained. Compared to the conventional product, the width of the optimized flat torque converter torus is reduced by about 20% while the values of stall torque ratio and peak efficiency are only decreased by 0.4% and 1.7%, *** proposed new optimization strategy based on DOE method together with desirability function approach can be used for performance enhancement in the design process of flat torque converters.

关键词： Torque converter Flatness ratio Computational fluid dynamics(CFD) Parametric study Design of experiment(DOE)

Structure of the HRV-C 3C-Rupintrivir Complex Provides New Insights for Inhibitor Design

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Virologica Sinica 2020年第4期35卷 445-454页

作者： shuai Yuan Kaiyue Fan Zhonghao Chen Yao Sun Hai Hou Ling zhu CAS Key Laboratory of Infection and Immunity CAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China Key Laboratory for Space Bioscience and Space Biotechnology School of Life SciencesNorthwestern Polytechnical UniversityXi’an 710072China Beijing Forestry University No.35 Tsinghua East RoadHaidian DistrictBeijing 100083China Institute of Medical Research Northwestern Polytechnical UniversityXi’an 710072China Department of Molecular Biophysics and Biochemistry Yale UniversityNew HavenCT 06511USA

Human rhinoviruses(HRVs)are the predominant infectious agents for the common cold *** HRV-C species cause severe illnesses in children and are closely related to acute exacerbations of asthma.3C protease,a highly conserved enzyme,cleaves the viral polyprotein during replication and assists the virus in escaping the host immune *** key roles make 3C protease an important drug target.A few structures of 3Cs complexed with an irreversible inhibitor rupintrivir have been *** structures shed light on the determinants of drug *** we describe the structures of HRV-C153C in free and inhibitor-bound *** volume-decreased S1'subsite and half-closed S2 subsite,which were thought to be unique features of enterovirus A 3C proteases,appear in the HRV-C 3C *** assumes an“intermediate”conformation in the complex,which might open up additional avenues for the design of potent antiviral *** of the features of the three-dimensional structures and the amino acid sequences of 3C proteases suggest new applications for existing drugs.

关键词： Human rhinoviruses(HRVs) 3C protease Three-dimensional structures Inhibitors Rupintrivir(AG7088)

Flow-Induced Vibration of Four Cantilever Cylinders Arranged in A Square Configuration

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China Ocean Engineering 2021年第6期35卷 891-904页

作者： zhu Hong-jun LIU wen-li WANG Jun-lei State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450000China

Flow-induced vibration(FIV)of four separately mounted cantilever cylinders are experimentally investigated in a water *** four cylinders with top ends screwed vertically into a turntable platform are subjected to uniform flows with Reynolds number ranging from 3840 to 16520.A non-intrusive measurement with high-speed cameras is employed to simultaneously capture the time-varying in-line and cross-flow vibrations in the reduced velocity range of *** results highlight the continuous adjustment of flow regime caused by the spatial-temporal alteration of ***,the space-time varying flow interference contributes to the occurrence of multiple response *** transition from a dominant frequency to a broad-band response illustrates the enhancement of wake *** combination of wake flow interactions results in the irregular oscillation trajectories and the appearance of a response trough with the associated switching in vortex shedding *** dual-resonance phenomenon is observed in the four cylinders due to the complicated wake-structure *** greatest mechanical energy possessed by the four cylinders in an in-line square arrangement is mainly resulted from the downstream cylinders,signifying the positive role of wake excitation in extracting hydrokinetic energy from ambient flow.

关键词： flow-induced vibration mechanical energy cantilever cylinder time-varying spacing attack angle

Twinned Martensitic Substructure in a Water Quenched Fe–1.0 wt%C Alloy

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Acta Metallurgica Sinica(English Letters) 2022年第7期35卷 1157-1163页

作者： Haidong Sun Zuohua Wang shuai Zhang Ning Liu Pinwen zhu Dongli Yu Hongwang Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China Liren College of Yanshan University Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

A Fe–1.0 wt%C alloy was quenched into water from 1100 ℃,leading to lath martensite and plate martensite of body-centered tetragonal *** these two martensites have the twinned substructure that generates mirror symmetric diff raction patterns with extra diff raction spots around n/3(112).The twinned substructure has the origin from twinned martensitic variants,namely twin-related crystals separated by{110},rather than{112}deformation *** eff ect on the electron double diff raction of twinned variants was discussed.

关键词： Twinned martensitic substructure Twinned variant Lath martensite Plate martensite

Trace Semantics and Algebraic Laws for Total Store Order Memory Model

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Journal of Computer Science & Technology 2021年第6期36卷 1269-1290页

作者： Li-Li Xiao Hui-Biao zhu Qi-wen Xu Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai 200062China Department of Computer and Information Science Faculty of Science and TechnologyUniversity of Macao MacaoChina

Modern multiprocessors deploy a variety of weak memory models(WMMs).Total Store Order(TSO)is a widely-used weak memory model in SPARC implementations and x86 *** omits the store-load constraint by allowing each core to employ a write *** this paper,we apply Unifying Theories of Programming(abbreviated as UTP)in investigating the trace semantics for TSO,acting in the denotational semantics style.A trace is expressed as a sequence of snapshots,which records the changes in registers,write buffers and the shared *** the valid execution results containing reorderings can be described after kicking out those that do not satisfy program order and modification *** paper also presents a set of algebraic laws for *** study the concept of head normal form,and every program can be expressed in the head normal form of the guarded choice which is able to model the execution of a program with *** the linearizability of the TSO model is ***,we consider the linking between trace semantics and algebraic *** linking is achieved through deriving trace semantics from algebraic semantics,and the derivation strategy under the TSO model is provided.

关键词： weak memory model Total Store Order(TSO) trace semantics algebraic law Unifying Theories of Programming(UTP)

An effective and green H2O2/H2O/O3 oxidation method for carbon nanotube to reinforce epoxy resin

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Journal of Materials Science & Technology 2020年第5期40卷 24-30页

作者： Qi Wang wen Shi Bo zhu Dang Sheng Su School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China Shenyang National Laboratory for Materials Science Shenyang 110016China Jiangsu Gunuo New Materials Technology Go. Ltd.Yancheng 224051China

Facile green oxidation methods are always desired to functionalize carbon nanotubes(CNTs)in the production of advanced CNT/epoxy *** the present work,an optimized H2O2/H2O/O3 oxidation method was developed,and performances of the H2O2/H2O/O3 oxidized CNT in epoxy matrix were tested and compared with that of the H2O/O3 oxidized CNT and the most commonly used concentrated HNO3 oxidized *** physical and chemical characteristics of the obtained oxidized CNTs were systematically characterized via transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS)and *** performances of the obtained composites were explored by tensile tests,impact tests,dynamic mechanical analysis(DMA)and fracture toughness *** was found that the H2O2/H2O/O3 oxidized CNT exhibited all-around overwhelming advantages over the concentrated HNO3 oxidized CNT on reinforcing the epoxy matrix,while the H2O/O3 oxidized CNT only improved the material *** mechanisms for the different methods oxidized CNTs were studied and *** optimized H2O2/H2O/O3 oxidation method makes scaled production possible,avoids environment pollutions,and holds great potentials to replace the most commonly used concentrated HNO3 oxidation method to oxidize CNT during the preparation of the advanced CNT/epoxy composite.

关键词： Green oxidation method Carbon nanotube Epoxy composite Mechanical properties Interfacial interaction