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Science China Chemistry 2015年第3期58卷 434-435页

作者： zhen xi College of Chemistry Nankai University

Redox-based post-translational modification of protein thiols has become an attractive strategy in cellular homeostasis and cell signaling. Due to the reductive end of the redox buffer network, the vicinal dithiol-containing proteins （VDPs） maintains an appropriate oxidation-reduction state of proteins through the reversible transformation from vicinal dithiols to disulfide, which is responsible for a variety of diseases, such as cancer, diabetes and neuro-degeneration.

关键词：氧化还原状态活细胞调控诱捕比例蛋白质二硫醇细胞信号

A Study on the Technique of Observing Interplanetary Scintillation with Simultaneous Dual-Frequency Measurements

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Chinese Journal of Astronomy and Astrophysics 2007年第5期7卷 712-720页

作者： xi-zhen Zhang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Ground-based observation of Interplanetary Scintillation （IPS） is an important approach of monitoring solar wind speed. We describe both the principle and method of observing the solar wind speed by using the normalized cross-spectrum of simultaneous dualfrequency IPS measurement. The effects of the solar wind properties and the angular size of the scintillation source on the measurement of solar wind speed are investigated by numerical analysis. We carry out a comparison of this method with the traditional single station-single frequency method. We outline a new IPS observation system using this method now under construction at the National Astronomical Observatories, CAS （NAOC）.

关键词： interplanetary scintillation -- method -- instrument -- telescope

Synthesis and in vitro Fungicidal Activity of a Series of Novel N-（Heterocycly）phthalimides

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Chinese Journal of Chemistry 2011年第3期29卷 515-520页

作者： Ban, Shurong Chen, Wenbin xi, zhen School of Pharmaceutical Science Shanxi Medical University Taiyuan Shanxi 030001 China Elemento-Organic Chemistry Institute State-Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China

A series of novel phthalimides was prepared and tested for antifungal activity in vitro against seven phytopa- thogenic fungi： Rhizoctonia solani, Fusarium oxysporum ***. cucumerinum Owen., Botrytis cinerea, Fulvia fulva, Sclerotinia sclerotiorum de Bary, Phytophthora capsici, Botryosphaeria berengeriama. The results showed that those compounds holding the structure of 6-methylpyridin-2-yl exhibited good activity against Phytophthora capsici and Botrytis cinerea.

关键词： phthalimides synthesis biological activity antifungal agents

Preparation of CS-CMC Bipolar Membrane and its Application in Electro-generated FeO_4^(2-)

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Chinese Chemical Letters 2006年第11期17卷 1527-1530页

作者： Yu xi REN zhen CHEN Ri Yao CHEN xi zhen Ya Ming GENG College of Chemistry and Materials Science Experiment Center Fujian Normal University Fuzhou 350007

CS-CMC bipolar membrane was prepared and the cross-section photograph of CS-CMC BM was observed by SEM. FT-IR spectrum indicated that CS-CMC BM contained -N=CRH2^＋ and -COO^- functional groups. The charge density of -N--CRH2^＋ in CS membrane was about 14.13 mmol/g and the charge density of -COO in CMC membrane was about 9.01 mmol/g. The electrochemistry properties of CS-CMC BM were also studied. CS-CMC BM not only can effectively stop FeO4^2- from diffusing into the cathode chamber, but also plays an important role in the supply of OH＂ consumed during the electro-generated FeO4^2- process.

关键词： Bipolar membrane (BM) cylinder electrolysis bath carboxymethylcellulose (CMC),chitosan (CS) ferrate (FeO4^2-) colloid titration.

Research on the steam–gas pressurizer model with Relap5 code

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Nuclear Science and Techniques 2017年第5期28卷 1-8页

作者： xi-zhen Ma Hai-Jun Jia Yang Liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University Beijing 100084 China

Steam–gas pressurizers are self-pressurizing, and since steam and noncondensable gas are used to sustain their pressure, they experience very complicated thermal–hydraulic phenomena owing to the presence of the latter. A steam–gas pressurizer model was developed using Relap5 code to investigate such a pressurizer's thermal–hydraulic *** important thermal–hydraulic processes occurring in the pressurizer model include bulk flashing, rainout, wall condensation with noncondensable gas, and interfacial heat and mass transfer. The pressurizer model was verified using results from insurge experiments performed at the Massachusetts Institute of Technology. It was found that noncondensable gas was one of the important factors governing the pressure response, and the accuracy of the developed model would change with different mass fractions and types of noncondensable gas.

关键词： Relap5 code Noncondensable gas Heat and mass transfer Steam–gas pressurizer Condensation

DNA damage in nucleosomes

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Science China Chemistry 2019年第5期62卷 561-570页

作者： Mengtian Ren Jing Bai zhen xi Chuanzheng Zhou State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology College of ChemistryNankai University

Eukaryotic genomic DNA is packed into chromatin, whose fundamental structural unit is the nucleosome. As DNA-histone protein complexes, nucleosomes show different properties toward exogenous and endogenous DNA-damaging agents. This review summarizes nucleosome DNA damage due to different sources, including alkylating agents, radicals, UV radiation and reactive DNA damage intermediates. In most cases, the histone core protects the associated DNA against damage via its structure and/or scavenging of damaging agents. In contrast, histones react with damaged DNA and, in some instances, catalyze DNA damage in the nucleosome. The biological consequence of nucleosome DNA damage and future prospects in this field are briefly discussed.

关键词： DNA damage DNA alkylation DNA-protein cross-link nucleosome radical reactive intermediate

Molecular Drug Resistance Prediction for Acetohydroxyacid Synthase Mutants Against Chlorsulfuron Using MB-QSAR

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Chinese Journal of Chemistry 2013年第9期31卷 1171-1180页

作者： Yinwu He Congwei Niu xin Wen zhen xi State Key Laboratory of Elemento-Organic Chemistry Department of Chemical Biology Nankai University Tianjin 300071 China

Chlorsulfuron is the first commercialized sulfonylurea herbicide, which targets acetohydroxyacid synthase （AHAS）. Mutations in AHAS have caused serious herbicide resistance to chlorsulfuron. Quantitative description of the herbicide resistance in molecular level will benefit the understanding of the resistance mechanism and aid the design of resistance-evading herbicide. We have recently established a MB-QSAR （Mutation-dependent Biomac- romolecular Quantitative Structure-Activity Relationship） method to conduct the 3D-QSAR study in biomacro- molecules. Herein, based on the herbicide resistance data measured for a series of AHAS mutants against chlorsul- furon, we constructed MB-QSAR models to quantitatively predict the herbicide resistance and interpret the struc- ture resistance relationships for AHAS mutants against chlorsulfuron. Quite well correlations between the experi- mental and the predicted pKi values were achieved for MB-QSAR/CoMFA （q^2=0.705, r^2=0.918, r^2pred=0.635） and MB-QSAR/CoMSIA （q^2=0.558, r^2=0.940, r^2pred=0.527） models, and interpretation of the MB-QSAR models gave chemical intuitive information to guide the resistance-evading herbicide design.

关键词： MB-QSAR QSAR drug resistance prediction acetohydroxyacid synthase chlorsulfuron

Electro-generation of TGA by Ni-mSA-mCS bipolar membrane

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Chinese Chemical Letters 2007年第11期18卷 1411-1415页

作者： zhen xia Huang xi zheng Ri Yao Chen xiao Chen zhen Chen Experiment Center College of Chemistry and Materials Science Fujian Normal University Fuzhou 350007 China

Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.

关键词： Bipolar membrane Modified sodium alginate Modified chitosan Thioglycolic acid Dithiodiglycolic acid

Application of Improved Fuzzy Controller in Networked Control System

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Journal of China University of Mining and Technology 2006年第4期16卷 500-504页

作者： ZHANG Qian GUO xi-jin WANG zhen TIAN xi-lan School of Information and Electrical Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

Aiming at the problem of network-induced delay and data dropout in networked control system, an improved fuzzy controller is proposed in this paper. Considering the great influence of a controller on the performance of control system, an improved controller with a second order fuzzy controller and network-induced delay compensator being added to the basic fuzzy controller is proposed to realize self-regulation on-line. For this type of controller, neither plant model nor measurement of network delay is required. So it is capable of automatically adjusting quantified factor, pro- portional factor, and integral factor according to the control system error and its derivative. The design makes full use of the advantages of quickness in operation and reduction of steady state error because of its integral function. The con- troller has a good control effect on time-delay and can keep a better performance by self-regulation on-line in the net- work with data dropout and interference. It is good in quickness, adaptability, and robustness, which is favorable for controlling the long time-delay system.

关键词： networked control system improved fuzzy controller network-induced delay data dropout

Isothermal Crystallization of iPP in Environment-friendly Diluents:Effect of Binary Diluents and Crystallization Temperature on Crystallization Kinetics

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Chinese Journal of Polymer Science 2019年第6期37卷 617-626页

作者： Yu-Jie Wang Su-Ying Yan Zhi-Ping Zhao zhen-Yu xi School of Chemistry and Chemical Engineering Beijing Institute of Technology Environmental Protection Research Institute Beijing Research Institute of Chemical IndustrySINOPEC

The growing demand for non-toxic solvents for membrane preparation has motivated the studies for green and sustainable alternatives of solvents. The effect of droplet isothermal growth within the liquid-liquid phase separation region on isothermal spherulitic growth rate of isotactic polypropylene(iPP) was investigated. The results showed that the droplets grew up at a rate of 0.0172 μm·s^(-1). The larger droplets slowed down the isothermal spherulitic growth rate of iPP. Higher mass ratio of carnauba wax(Cwax)/soybean oil(SO)resulted in faster droplet growth due to weak interaction with polymers. The isothermal crystallization behaviors of iPP in environmentfriendly binary diluents consisting of Cwax and SO mixture were further investigated experimentally using polarized optical *** was demonstrated that the isothermal spherulitic growth rate of iPP in diluents decreased nonlinearly with the increasing crystallization temperature. Compared with virgin iPP, isothermal spherulitic growth rate of iPP in SO diluent was significantly slowed down. The spherulitic growth was further retarded after the addition of Cwax in mixed diluents, resulting in a lower crystallization rate than that in SO. Moreover, the crystal form of iPP membranes was found to be α type through the characterization of small angle X-ray scattering and wide angle X-ray diffraction.

关键词： Isotactic polypropylene Carnauba wax Isothermal crystallization kinetics PP membrane