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Co3O4 modified Ag/g-C3N4 composite as a bifunctional cathode for lithium-oxygen battery

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Journal of Energy Chemistry 2020年第2期29卷 185-193页

作者： Qi Guo Chenwei zhang Chaofeng zhang Sen Xin Pengchao zhang Qiufan Shi dawei zhang Ya You School of Chemistry and Chemical Engineering School of Materials Science and EngineeringHefei University of TechnologyHefei 230009AnhuiChina Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China

Rechargeable lithium-oxygen(Li-O2)batteries have appeal to enormous attention because they demonstrate higher energy density than the state-of-the-art Li-ion ***,their practical application is impeded by several challenging problems,such as the low energy round trip efficiencies and the insufficient cycle life,due to the cathode passivation caused by the accumulation of discharge *** efficient catalyst for oxygen reduction and evolution reactions is effective to reduce the overpotentials in *** our work,we report a Co3O4modified Ag/g-C3N4nanocomposite as a bifunctional cathode catalyst for *** g-C3N4substrate prevents the accumulation of Ag and Co3O4nanoparticles and the presence of Ag NPs improves the surface area of g-C3N4and electronic conductivity,significantly improving the oxygen reduction/evolution capabilities of *** to a synergetic effect,the Ag/g-C3N4/Co3O4nanocomposite demonstrates a higher catalytic activity than each individual constituent of Co3O4or Ag/g-C3N4for the ORR/OER on as catalysts in *** a result,the Ag/gC3N4/Co3O4composite shows impressive electrochemical performance in a Li-O2battery,including high discharge capacity,small gap between charge and discharge potential,and high cycling stability.

关键词： Lithium-oxygen batteries Cathode material Electrocatalyst Oxygen reduction reaction Oxygen evolution reaction

计及可中断负荷参与应急调度的备用容量优化配置方法

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智慧电力 2024年第7期52卷 10-15,39页

作者：张大伟赵静席骊瑭刘升郭亮蔡帜国网四川省电力公司四川成都610041 中国电力科学研究院有限公司北京100192

新能源大规模并网增加了电网频率失稳的风险。针对大功率缺失下的频率安全问题,提出1种计及可中断负荷参与应急调度的备用容量优化配置方法。相较于传统的备用容量优化方案,所提方法考虑应急调度过程中常规机组和可中断负荷的响应时间... 详细信息

新能源大规模并网增加了电网频率失稳的风险。针对大功率缺失下的频率安全问题,提出1种计及可中断负荷参与应急调度的备用容量优化配置方法。相较于传统的备用容量优化方案,所提方法考虑应急调度过程中常规机组和可中断负荷的响应时间和爬坡速率,构建考虑分段频率下限值约束的应急备用容量优化模型,以提高电网的应急处理能力。算例分析表明,所提方法能够兼顾电力系统经济调度和频率稳定目标,提高电网安全经济运行水平。

关键词：可中断负荷应急调度频率安全备用容量优化

Folding of EK peptide and its dependence on salt concentration and pH: A computational study

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Science China Chemistry 2011年第12期54卷 1974-1981页

作者： MEI Ye zhang dawei DUAN Li zhang QingGang zhang John ZengHui State Key Laboratory of Precision Spectroscopy East China Normal University Shanghai 200062 China Institute of Theoretical and Computational Science East China Normal University Shanghai 200062 China Division of Chemistry and Biological Chemistry School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore College of Physics and Electronics Shandong Normal University Jinan 250014 China Department of Chemistry New York University New York 10003 USA

In this study, we apply both palrwise AMBER03 force field and the recently developed polarized force field to study the folding process of EK peptide under various ion strength and pH conditions. The polarized force field is based on our newly proposed adaptive hydrogen bond-specific charge （AHBC） scheme. These two force fields differ only by the atomic charges. Solvent effect is described with generalized Born models （IGB5 in AMBER 10 package）. The result shows that although when applying AMBER03 charge, the helical structure is preferred, its dependence on salt concentration and pH is qualitatively wrong. While using AHBC the peptide finds its native structure within 10 ns, and then fluctuates around this folded state. Under high salt concentration or extreme pH conditions the calculated helical structure probability drops, which is in qualitative agreement with the experiment. Analysis of the atomic charges and the interaction between the donor-acceptor pair in main hydrogen bonds shows that the helical structure is stabilized when polarization effect is counted. It again shows that polarization effect is a very important improvement over traditional force field and is essential for protein folding. We also prove that the salt bridge interaction between 4-residue apart GLU and LYS residues is not critical to the stability of helical structure of EK peptide, but is merely an auxiliary factor, also in agreement with the experiment.

关键词： EK peptide polarization salt concentration pH

Expanding application of CRISPR-Cas9 system in microorganisms

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Synthetic and Systems Biotechnology 2020年第4期5卷 269-276页

作者： Jing Zhao Huan Fang dawei zhang Tianjin Institute of Industrial Biotechnology Chinese Academy of SciencesTianjin300308People's Republic of China Key Laboratory of Systems Microbial Biotechnology Chinese Academy of SciencesTianjin300308People's Republic of China University of Chinese Academy of Sciences Beijing100049People's Republic of China

The development of CRISPR-Cas9 based genetic manipulation tools represents a huge breakthrough in life sciences and has been stimulating research on metabolic engineering,synthetic biology,and systems *** CRISPR-Cas9 and its derivative tools are one of the best choices for precise genome editing,multiplexed genome editing,and reversible gene expression control in ***,challenges remain for applying CRISPR-Cas9 in novel microorganisms,especially those industrial microorganism hosts that are intractable using traditional genetic manipulation *** to further extend CRISPR-Cas9 to these microorganisms is being an urgent *** this review,we first introduce the mechanism and application of CRISPR-Cas9,then discuss how to optimize CRISPR-Cas9 as genome editing tools,including but not limited to how to reduce off-target effects and Cas9 related toxicity,and how to increase on-target efficiency by optimizing crRNA and sgRNA design.

关键词： CRISPR-Cas9 system Microorganisms Off-target Cas9 toxicity sgRNA

Exergy analysis on eco-industrial systems

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Science China Chemistry 2006年第3期49卷 281-288页

作者： YANG Li HU Shanying CHEN Dingjiang zhang dawei Center for Industrial Ecology Tsinghua University Beijing 100084 China Center for Industrial Ecology Tsinghua University Beijing 100084 China Center for Industrial Ecology Tsinghua University Beijing 100084 China Center for Industrial Ecology Tsinghua University Beijing 100084 China

Exergy analysis of eco-industrial systems reflects the thermodynamic characteristics of resource utilization by studying complicated material flow patterns to an industrial system. Different indicators based on exergy analysis are presented, such as system exergy depletion index, cycling ratio of material exergy, etc. which can be used to evaluate the efficiency of resource utilization and the environmental potential effect. The interrelations of these exergy indicators and their interpretation on industrial ecology are further discussed. Finally, the result of case study suggests effectiveness of exergy analysis methods and practicability of these exergy estimate indices.

关键词： eco-industrial system, exergy, analysis.

Cloning and expression of three thaumatin-like protein genes from Polyporus umbellatus

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Acta Pharmaceutica Sinica B 2017年第3期7卷 373-380页

作者： Mengmeng Liu dawei zhang Yongmei Xing Shunxing Guo Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of Education Institute of Medicinal Plant Development Chinese Academy of Medical Sciences & Peking Union Medical College Institute of Bioinformatics and Medical Engineering School of Electrical and Information Engineering Jiangsu University of Technology

Genes encoding thaumatin-like protein(TLPs) are frequently found in fungal ***, information on TLP genes in Polyporus umbellatus is still limited. In this study, three TLP genes were cloned from P. umbellatus. The full-length coding sequence of PuTLP1, PuTLP2 and PuTLP3 were 768, 759 and 561 bp long, respectively, encoding for 256, 253 and 187 amino acids. Phylogenetic trees showed that P. umbellatus PuTLP1, PuTLP2 and PuTLP3 were clustered with sequences from Gloeophyllum trabeum, Trametes versicolor and Stereum hirsutum, respectively. The expression patterns of the three TLP genes were higher in P. umbellatus with Armillaria mellea infection than in the sclerotia without A. mellea. Furthermore, over-expression of three PuTLPs were carried out in Escherichia coli BL21(DE3) strain, and high quality proteins were obtained using Ni-NTA resin that can be used for preparation of specific antibodies. These results suggest that PuTLP1, PuTLP2 and PuTLP3 in P. umbellatus may be involved in the defense response to A. mellea infections.

关键词： Polyporus umbellatus Thaumatin-like protein Defense Gene cloning Expression

Electron-beam irradiation induced optical transmittance enhancement for Au/ITO and ITO/Au/ITO multilayer thin films

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Journal of Materials Science & Technology 2017年第10期33卷 1107-1112页

作者： Wenzuo Wei Ruijin Hong Jinxia Wang Chunxian Tao dawei zhang Engineering Research Center of Optical Instrument and System Ministry of Education and Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology Shanghai 200093 China

Electron beam（EB） irradiation experiments on Au/ITO and ITO/Au/ITO multilayer thin films are *** structure and the optical-electrical properties of the samples were investigated by X-ray diffraction,atomic force microscopy, four-point probe resistivity measurement system, and UV–vis-NIR double beam spectrometer, respectively. Those results show that the EB irradiation has the effects of improving the crystalline of samples, widening the optical band gap of both thin films, reducing the sheet resistance,and improving the transmittance of samples.

关键词： EB irradiation Multilayer thin films Structure Optical-electrical properties Transmittance

Finite element modeling of counter-roller spinning for large-sized aluminum alloy cylindrical parts

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Frontiers of Mechanical Engineering 2019年第3期14卷 351-357页

作者： dawei zhang Fan LI Shuaipeng LI Shengdun ZHAO School of Mechanical Engineering Xi'an Jiaotong University Xi'an 710049 China

Counter-roller spinning (CRS), where the mandrel is replaced by rollers, is an effective means of manufacturing large-sized, thin-walled, cylindrical parts with more than 2500 mm diameter. CRS is very complex because of multi-axis rotation, multi-local loading along the circumference, and radial-axial compound deformation. Analytical or experimental methods cannot fully understand CRS. Meanwhile, numerical simulation is an adequate approach to investigate CRS with comprehensive understanding and a low cost. Thus, a finite element (FE) model of CRS was developed with the FORGE code via meshing technology, material modeling, determining the friction condition, and so on. The local fine mesh moving with the roller is one of highlights of the model. The developed 3D-FE model was validated through a CRS experiment by using a tubular blank with a 720 mm outer diameter. The developed 3D-FE model of CRS can provide a basis for parameter optimization, process control, die design, and so on. The data on force and energy predicted by the 3D-FE model can offer reasonable suggestions for determining the main mechanical parameters of CRS machines and selecting the motors. With the predicted data, an all-electric servo-drive system/machine with distributed power was designed in this work for CRS with four pairs of rollers to manufacture a large-sized, thinwalled, cylindrical part with 6000 mm diameter.

关键词： large-sized cylindrical part counter-roller spinning aluminum alloy finite element method distributed power

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桑黄酚A和荜茇明宁碱的合成和纯度检测

绿色科技 2024年第12期26卷 251-256页

作者：许世坤张大为陈玉中南民族大学化学与材料科学学院湖北武汉430074

以乙酰丙酮和3,4-二羟基苯甲醛为原料通过Pabon反应合成得到桑黄酚A;以胡椒碱为原料,经水解酸化后得到胡椒酸,后者在偶联剂HATU的作用下与异丁胺缩合得荜茇明宁碱,总产率分别为70%和50%,目标分子的结构得到了NMR和HR-ESI-MS的表征。薄... 详细信息

以乙酰丙酮和3,4-二羟基苯甲醛为原料通过Pabon反应合成得到桑黄酚A;以胡椒碱为原料,经水解酸化后得到胡椒酸,后者在偶联剂HATU的作用下与异丁胺缩合得荜茇明宁碱,总产率分别为70%和50%,目标分子的结构得到了NMR和HR-ESI-MS的表征。薄层色谱和高效液相色谱检测其纯度都在99%以上。按上述方法合成桑黄酚A和荜茇明宁碱具有起始原料易得,反应条件温和,后处理简单,纯度高的特点。

关键词：桑黄酚A 荜茇明宁碱有机合成纯度检测

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