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In-situ synthesis and sintering of mullite glass composites by SPS

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Journal of Advanced Ceramics 2014年第2期3卷 165-170页

作者： Jinyong zhanG hai zhan Zhengyi FU Richard TODD State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Department of Materials University of OxfordOxfordUK

The main subject of this work is an investigation of the effects of heating rate and current on the crystallisation of amorphous precursors in spark plasma sintering(SPS).For this,dry gel of Al_(2)O_(3)-SiO_(2) with a molar ratio of 1:1,was synthesized and sintered in-situ by SPS,and also by hot pressing(HP)for *** analysis showed that the only crystalline product in both cases was mullite,whose Al_(2)O_(3) content was lower in the SPS *** microstructures showed a low volume fraction of large mullite fibers in the SPS specimens,whereas a high volume fraction of fine equiaxed grains was present in the HP *** main difference in microstructure between HP and SPS specimens could be explained in terms of the higher heating rate of the SPS *** size of the SPS die also affected the size and aspect ratio of the mullite fibers produced,which might have been due to either the different electrical current required or a difference in specimen temperature profile.

关键词： spark plasma sintering(SPS) synthesis extra-field mullite

LADA strategy for the synthesis of unnatural amino acids and direct modifications of peptides

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Science China Chemistry 2023年第6期66卷 1788-1794页

作者： Jun-liang Zhou Yun-Qi Liu zhan-Kui Sun Shanghai Frontiers Science Center for Drug Target Identification and Drug Delivery School of Pharmaceutical SciencesShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Pharm-X CenterSchool of Pharmaceutical SciencesShanghai Jiao Tong UniversityShanghai 200240China AI Pharma Center Zhangjiang Institute for Advanced StudyShanghai Jiao Tong UniversityShanghai 200240China Shanghai Artificial Intelligence Laboratory Shanghai 200232China

Unnatural amino acids(UAAs)are important building blocks in organic synthesis and drug *** are also frequently integrated into peptides or proteins for biological ***,the direct and simplified synthesis of UAAs remains a great *** the same time,vast known peptide modifications are based on carbon-heteroatom *** are no general methods for peptide modifications via the construction of C–C *** address this challenge,herein we propose the LADA strategy,which is composed of two steps:the selective labeling and activation of cysteine residues,the desulfurization to generate carbon-centered radical and the radical addition to alkenes to build C–C *** one-pot protocol has obvious advantages such as good functional group tolerance,biocompatible reaction conditions,and retained *** strategy was successfully utilized for the synthesis of unnatural amino acids and direct modifications of peptides.

关键词： unnatural amino acids peptide modifications desulfurization cysteine radical addition

A Novel Micro-hole Electrode Used to Investigate Electron Transfer Reactions at ITIES

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Chinese Chemical Letters 2002年第3期13卷 273-276页

作者： Dong Ping zhan Bing liang WU Department of Chemistry Wuhan UniversityWuhan430072

A novel micro-hole electrode was fabricated to investigate the electron transfer reaction at the interface between two immiscible electrolyte solutions (ITIES). The electron transfer reaction between ferro/ferricyanide in aqueous phase (W) and ferrocene in 1, 2-dichloroethane (O) phase was studied as a test experiment. The results showed that the diffusion coefficient obtained from the micro-hole electrode was consistent with that obtained at macro-interface. Due to its simplicity and the very small IR drop it will be a useful tool for the study of ITIES systems.

关键词： Micro-hole electrode electron transfer ITIES.

Strain rate analyses during elliptical vibration cutting of Inconel 718 using finite element analysis,Taguchi method,and ANOVA

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Advances in Manufacturing 2020年第3期8卷 316-330页

作者： hai-Bo Xie Zi-Qing Yang Na Qin zhan-Jiang Wang Tribology Research Institute Department of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu610031People’s Republic of China

The high strain rate in metal cutting significantly affects the mechanical properties of the work piece by altering its *** study outlines the material strain rates during elliptical vibration *** finite element analysis,Taguchi method,and analysis of variance(ANOVA)were employed to analyze the effects and contributions of cutting and vibration process parameters(feed rate,rake angle,tangential amplitude,and frequency of vibration)on the variation of strain rates during machining of Inconel *** signal-to-noise analysis on an L18(2^1×3^3)orthogonal array was used to determine the optimum parametric combination for the maximum strain rate,and ANOVA was applied to evaluate the significance of control parameter factors on the strain *** results of the finite element analysis under different conditions illustrated that the feed rate and rake angle were negatively related to the strain rate,whereas the tangential amplitude and frequency had a positive ***,ANOVA results indicated that the effect of the feed rate,tool rake angle,vibration frequency,and tangential amplitude on the strain rate were all statistically significant,with a reliability level of 95%.Of these,the dominant parameter affecting the strain rate was the feed rate,with a percentage contribution of 40.36%.The estimation of the optimum strain rate and confirmation tests proved that the Taguchi method could successfully optimize the working conditions to obtain the desired maximum strain rate.

关键词： Elliptical vibration cutting Strain rate Finite element(FE) Taguchi method Analysis of variance(ANOVA)

Agro-climatic adaptation of cropping systems under climate change in Shanghai

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Frontiers of Earth Science 2015年第3期9卷 487-496页

作者： Zhuoran liang Tingting GU zhan TIAN Honglin ZHONG Yuqi liang Hangzhou Meteorological Service Hangzhou 310051 China Shanghai Climate Center Shanghai Meteorological Service Shanghai 200030 China Zhejiang Meteorological Service Center Hangzhou 310017 China Department of Geographical Sciences University of Maryland College Park MD 20742 USA Department of Physics and Technology Nanjing Normal University Nanjing 210023 China

Climate change affects the heat and water resources required by agriculture, thus shifting cropping rotation and intensity. Shanghai is located in the Taihu Lake basin, a transition zone for various cropping systems. In the basin, moderate climate changes can cause major shifts in cropping intensity and rotation. In the present study, we integrated observational climate data, one regional climate model, land use maps, and agricultural statistics to analyze the relationship between heat resources and multi-cropping potential in Shanghai. The results of agro-climatic assessment showed that climate change over the past 50 years has significantly enhanced regional agro- climatic resources, rendering a shift from double cropping to triple cropping possible. However, a downward trend is evident in the actual multi-cropping index, caused principally by the increasing costs of farming and limitations in the supply of labor. We argue that improving the utilization rate of the enhanced agro-climatic resources is possible by introducing new combinations of cultivars, adopting more laborsaving technologies, and providing incentives to farmers.

关键词： climate change cropping systems multicropping index double rice Cold Dew wind

Numerical Simulation of Welding Deformation for Hull Superstructure Steel Based on the Finite Element Analysis

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Journal of Materials Science & Technology 2003年第z1期19卷 212-214页

作者： Liu, LM liang, GL Liu, YJ zhan, Z Dalian Univ Technol Dalian 116024 Peoples R China Dalian Dockyard Dalian 116020 Peoples R China Harbin Inst Technol State Key Adv Welding Prod Technol Harbin 150001 Peoples R China

Using finite analysis element software, the transient displacement field of automatic submerged arc welding is established. It was also considered that the thermal physical properties changes were depended on the temperatureand the heat loss on the surface. At the same time, it analyzed the influence of the deformation and stress, whichgenerated in the plate butt-welding process, to the superstructure steel welding deformation. The result showedthat the deformation and stress generated in the steel plate butt-welding process are considered to be the mainfactors to influence the welding deformation of superstructure steel. It found the effective ways to reduce the weldingdeformation of the hull superstructure steel is to relieve the butt-welding deformation and release butt-welding stressbefore welding the hull superstructure steel.

关键词： Hull superstructure steel, Finite element analysis, Welding deformation

Glycosyltransferases and non-alcoholic fatty liver disease

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World Journal of Gastroenterology 2016年第8期22卷 2483-2493页

作者： Yu-Tao zhan hai-Ying Su Wei An Department of Gastroenterology Beijing Tongren Hospital Capital Medical University Department of Obstetrics and Gynecology Shandong Jining First People’s Hospital Department of Cell Biology Municipal Laboratory for Liver Protection and Regulation of Regeneration Capital Medical University

Non-alcoholic fatty liver disease(NAFLD) is the most common form of chronic liver disease and its incidence is increasing worldwide. However, the underlying mechanisms leading to the development of NAFLD are still not fully understood. Glycosyltransferases(GTs) are a diverse class of enzymes involved in catalyzing the transfer of one or multiple sugar residues to a wide range of acceptor molecules. GTs mediate a wide range of functions from structure and storage to signaling, and play a key role in many fundamental biological processes. Therefore, it is anticipated that GTs have a role in the pathogenesis of NAFLD. In this article, we present an overview of the basic information on NAFLD, particularly GTs and glycosylation modification of certain molecules and their association with NAFLD pathogenesis. In addition, the effects and mechanisms of some GTs in the development of NAFLD are summarized.

关键词： Non-alcoholic fatty liver disease Pathogenesis Glycosyltransferases Glycosylation

Design method of pile-slab structure roadbed of ballastless track on soil subgrade

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Journal of Central South University 2013年第7期20卷 2072-2082页

作者： zhan Yong-xiang YAO hai-lin JIANG Guan-lu Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China State Key Laboratory of Geomechanics and Geotechnical Engineering (Institute of Rock and soil Mechanics Chinese Academy of Sciences) Wuhan 430071 China School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

Pile-slab structure roadbed is a new form of ballastless track for high speed railway. Due to lack of corresponding design code, based on the analysis of its structure characteristics and application requirements, it is proposed to carry out load effect combination according to ultimate limit state and serviceability limit state, and the most unfavorable combination of each state is chosen to carry through design calculation for pile-slab structure. Space model of pile-slab structure can be simplified as a plane flame model, by using the orthogonal test method, and the design parameter of pile-slab structure is optimized. Moreover, based on the engineering background of Suining-Chongqing high-speed railway, the dynamic deformation characteristics of pile-slab structure roadbed are further researched by carrying on the indoor dynamic model test. The test results show that the settlement after construction of subgrade satisfies the requirement of settlement control to build ballastless track on soil subgrade for high-speed railway. Slab structure plays the role of arch shell as load is transmitted from slab to pile, and the vertical dynamic stress of subgrade soil is approximately of ＂K＂ form distribution with the depth. The distribution of pile stress is closely related to soil characteristics, which has an upset triangle shape where the large dynamic stress is at the top. Pile compared with soil shares most dynamic stress. Pile structure expands the depth of the dynamic response of subgrade has limited effect on dynamic response. These results can provide subgrade. and improves the stress of subgrade soil, and the speed of train scientific basis for pile-slab structure roadbed used on soil

关键词： soil subgrade ballastless track pile-slab structure roadbed load combination dynamic model test

Optimization and Characterization of Nicosulfuron-Degrading Enzyme from Bacillus subtilis Strain YB1

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Journal of Integrative Agriculture 2012年第9期11卷 1485-1492页

作者： KANG zhan-hai Dong Jin-gao zhanG Jin-lin College of Plant Protection Agricultural University of Hebei Baoding 071001 P.R China College of Life Sciences Agricultural University of Hebei Baoding 071001 P.R.China

A strain of Bacillus subtilis strain YB 1, isolated and preserved in our lab., showed a high nicosulfuron-degrading activity. Optimization of culture conditions on production of nicosulfuron-degrading enzyme from Bacillus subtilis strain YB 1 was carried out through mono-factor experiments. The characterization of degrading enzyme（s） was studied in this paper. The results showed that B. subtilis YB1 can use nicosulfuron as sole carbon source under aerobic condition. The key enzyme（s） involved in the initial biodegradation of nicosulfuron was localized to extracellular proteins and showed to be induced expressed. Enzyme-specific activity was up to 89.34 U mg-1 at pH 8.0 and 30℃, incubation for 96 h, inoculum 4.5x108 CFU mL-1 in Luria-Bertani liquid medium with nicosulfuron of 40 mg L-1. The maximum degradation rate of extracellular crude enzymes on nicosulfuron was 66% at pH 9.0, 35℃ in the enzymatic reaction system with nicosulfuron of 5 mg L-1. This degrading enzyme（s） was sensitive to high temperature, but kept high activity under alkaline conditions.

关键词： Bacillus subtilis nicosulfuron microbial degradation enzyme