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Plasma-processed homogeneous magnesium hydride/ carbon nanocomposites for highly stable lithium storage

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Nano Research 2018年第5期11卷 2724-2732页

作者： Xinghua Chang Xinyao zheng Yanru Guo Jun Chen jie zheng Xingguo Li Beijing National Laboratory for Molecular Sciences (BNLMS) College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Academy for Advanced and Interdisciplinary Studies Peking University Beijing 100871 China

Magnesium hydride （MgH2） is a high-capacity anode material for lithium ion batteries, which suffers from poor cycling stability. In this stud）~ we describe a thermal plasma-based approach to prepare homogeneous MgH2/C nanocomposites with very high cycling stability. In this process, magnesium evaporation is coupled with carbon generation from the plasma decomposition of acetylene, leading to a homogeneous Mg/C nanocomposite, which can be easily converted to MgH2/C by hydrogenation. The MgH2/C nanocomposite achieves a high reversible capacity of up to 620 mAh·g^-1 after 1,000 cycles with an ultralow decay rate of only 0.0036% per cycle, which represents a significantly improved performance compared to previous results.

关键词： magnesium hydride anode lithium-ion batteries thermal plasma nanocomposite

Ultrafine Sn nanocrystals in a hierarchically porous N-doped carbon for lithium ion batteries

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Nano Research 2017年第6期10卷 1950-1958页

作者： Xinghua Chang Teng Wang Zhiliang Liu Xinyao zheng jie zheng Xingguo Li Beijing National Laboratory for Molecular Sciences (BNLMS) College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Academy for Advanced Interdisciplinary Studies Peking University Beijing 100871 China

We report a simple method of preparing a high performance, Sn-based anode material for lithium ion batteries （LIBs）. Adding H2O2 to an aqueous solution containing Sn2＋ and aniline results in simultaneous polymerization of aniline and oxidation of Sn2＋ to SnO2, leading to a homogeneous composite of polyaniline and SnO2. Hydrogen thermal reduction of the above composite yields N-doped carbon with hierarchical porosity and homogeneously distributed, ultrafine Sn particles. The nanocomposite exhibits excellent performance as an anode material for lithium ion batteries, showing a high reversible specific capacity of 788 mAh·g^-1 at a current density of 100 mA·g^-1 after 300 cycles and very good stability up to 5,000 mA·g^-1. The simple preparation method combined with the good electro- chemical performance is highly promising to promote the application of Sn based anode materials.

关键词： Sn polyaniline nanocomposite lithium ion battery (LIB)

Synthesis and dehydrogenation properties of NaZn(BH4)3·en and NaZn(BH4)3·2en(en= ethylene diamine)

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Journal of Energy Chemistry 2020年第3期29卷 233-236页

作者： Yong Wu Yue Qi jie zheng Xingguo Li Beijing National Laboratory for Molecular Sciences(BNLMS) College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Two new hydrogen storage compounds,Na Zn(BH4)3·en and Na Zn(BH4)3·2en(en=ethylene diamine)are synthesized by a solution *** can release 6.4 wt%and 6.3 wt%pure hydrogen below 200℃,respectively,demonstrating the potential to be used as hydrogen ***,their dehydrogenation products,thermodynamics and kinetics are well characterized and *** shows that the stronger Zn-N interactions and the Hδ+–Hδ-interactions are significant for their stability below 100℃,relatively low decomposition temperatures and elimination of gas impurities.

关键词： Borohydride Ethylene diamine Hydrogen storage

Improved Ligand-Field Theoretical Calculations of R-Line Thermal Broadenings of MgO:Cr^(3+) and MgO:V^(2+)

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Communications in Theoretical Physics 2008年第11期50卷 1245-1248页

作者： ZHANG zheng-jie MA Dong-Ping Department of Physics Chengdu University of Technology Chengdu 610059 China Department of Applied Physics Sichuan University Chengdu 610065 China

With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been *** results are in very good agreement with the experimental *** is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of *** elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).

关键词： improved ligand-field theory electron-phonon interaction R line thermal broadening elastic Raman scattering

DELAYED FLOWERING, an Arabidopsis Gene That Acts in the Autonomous Flowering Promotion Pathway and Is Required for Normal Development

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Journal of Integrative Plant Biology 2006年第1期48卷 27-34页

作者： Ming-jie Chen zheng Yuan Hai Huang Key Laboratory of Molecular Genetics Shanghai Institute of Plant Physiology and Ecology Graduate School of the Chinese Academy of Sciences Shanghai 200032 China

The control of flowering time in higher plants is one of the most important physiological processes and is critical for their reproductive success. To investigate the mechanisms controlling flowering time, we screened for Arabidopsis mutants with late-flowering phenotypes. One mutant, designated delayed flowering （dfr） in the Landsberg erecta （Ler） ecotype, was identified with delayed flowering time. Genetic analysis revealed that dfr is a single gene recessive nuclear mutant and the mutation was mapped to a locus tightly linked to UFO on chromosome 1. To our knowledge, no gene regulating flowering time has been reported yet in this region. The dfrmutant plant showed a delayed flowering time under the different growth conditions examined, including long- and short-day photoperiods and gibberellic acid GA3 treatments, suggesting that DFR is a gene involved in the autonomous flowering promotion pathway. The Arabidopsis gene FLOWERING LOCUS C （FLC） plays a central role in repressing flowering and its transcripts are undetectable in wild-type Ler. However, FLCexpression was upregulated in the dfrmutant, suggesting that DFR is a negative regulator of FLC. In addition, the dfr mutant plant displayed altered valve shapes of the silique and the number of trichomes and branches of each trichome were both reduced, indicating that the DRFgene is also required for normal plant development. Moreover, dfr leafy-5 （Ify-5） double mutant plants showed a much later flowering time than either dfr or Ify-5 single mutants, indicating that DFR and LFY act synergistically to promote flowering in Arabidopsis.

关键词： Arabidopsis autonomous pathway dfr, flowering time trichome.

Energy equalizing routing for fast data gathering in wireless sensor networks

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The Journal of China Universities of Posts and Telecommunications 2007年第4期14卷 13-21页

作者： zheng jie GUO Shu-jie QU Yu-gui ZHAO Bao-hua Department of Electronic Engineering and Information Science Universityof Science and Technology of China Hefei 230027 China Department of Computer University of Science and Technology of ChinaHefei 230027 China

Energy saving and fast responding of data gathering are two crucial factors for the performance of wireless sensor networks. A dynamic tree based energy equalizing routing scheme （DTEER） was proposed to make an effort to gather data along with low energy consumption and low time delay. DTEER introduces a dynamic multi-hop route selecting scheme based on weight-value and height-value to form a dynamic tree and a mechanism similar to token passing to elect the root of the tree. DTEER can simply and rapidly organize all the nodes with low overhead and is robust enough to the topology changes. When compared with power-efficient gathering in sensor information systems （PEGASIS） and the hybrid, energy- efficient, distributed clustering approach （HEED）, the simulation results show that DTEER achieves its intention of consuming less energy, equalizing the energy consumption of all the nodes, alleviating the data gathering delay, as well as extending the network lifetime perfectly.

关键词： wireless sensor networks energy equalizing,dynamic tree fast data gathering delay

Deselenization and detellurization of precious-metal ore concentrates by swelling oxidizing roasting and successive alkaline leaching

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 147-155页

作者： Fu-yuan Zhang Ya-jie zheng Guo-min Peng School of Metallurgy and Environment Central South University Changsha 410083 China Henan Zhongyuan Gold Smelter Co. Ltd. Sanmenxia 472000 China Key Laboratory of Comprehensive Utilization of Gold Resource Sanmenxia 472000 China

A new technique of swelling oxidizing roasting and alkaline leaching was proposed for deselenization and detellurization of pre- cious-metal ore concentrates. Alkali-metal and alkaline-earth-metal chlorides and carbonates were preliminarily selected as swelling agents. The roasting removal rate and alkaline leaching rate of selenium and tellurium were investigated, and NaCl was selected as an appropriate swelling agent. Furthermore, the effects of various factors on the selenium gasification rate and leaching rate of selenium and tellurium were investigated. The results show that the selenium gasification rate reaches 88.41% after swelling oxidizing roasting for 2 h at 510~C using an NaC1 dosage coefficient of 100 and a sulfuric acid dosage coefficient of 1.3; the amorphous elemental tellurium is completely transformed into TeO2. The roasted product is subjected to alkaline leaching using a 100 g/L NaOH solution, which results in a selenium leaching rate of 10.51%, a total selenium removal rate of 98.92%, and a tellurium leaching rate of 97.64%. In the alkaline leaching residue, the contents of selenium, tellurium, gold, platinum, and palladium are 0.7825%, 5.492%, 8.333%, 0.2587%, and 1.113%, respectively; the precious metals are enriched approximately sixfold.

关键词： ore treatment precious metals roasting leaching selenium removal tellurium removal

On composite foundation with different vertical reinforcing elements under vertical loading:a physical model testing study

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第2期11卷 80-87页

作者： Xian-zhi WANG Jun-jie zheng Jian-hua YIN Department of Water Resources Guangdong Technical College of Water Resources and Electric Engineering Guangzhou 510635 China School of Civil Engineering and Mechanics Huazhong University of Science & Technology Wuhan 430074 China Department of Civil and Structural Engineering The Hong Kong Polytechnic University Hong Kong China

Aphysical model facility was designed, built, and setup for conducting model tests on a composite foundation in a soil ground. The model tests were carried out on a composite foundation with different combinations of vertical reinforcement elements in the same soil ground. Via the analysis of the collected data the characteristics of the composite foundation with different reinforcing elements were obtained, including the characteristics of load-settlement curves, column stresses, stresses of the intercolumn soil, pile-soil stress ratio, and load-sharing ratios of columns and soil. Results from the model tests reveal the mechanism of a composite foundation with different reinforcing elements quantitatively. It is concluded that both a composite foundation with a combination of steel pipe pile and sand column and that with a combination of concrete pile and lime column have a higher bearing capacity than the composite foundation with only sand columns with the same conditions of soil ground and loading. A composite foundation with lime column and sand column embodies no much better performance than that with sand colunms only.

关键词： Steel pipe pile Concrete pile Lime column Sand column Composite foundation Model test Pile-soil stress ratio

MCM-41 supported nano-sized CuO-CeO2 for catalytic combustion of chlorobenzene

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Journal of Rare Earths 2020年第9期38卷 933-940,I0001页

作者： jie zheng Zhu Chen Jianfei Fang Zhuo Wang Shufeng Zuo Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process Shaoxing UniversityShaoxing 312000China Quality and Technical Supervision Inspection Center of Yongkang Yongkang 321300China

In this paper,MCM-41 was synthesized by a soft template technique and MCM-41 supported CuO-CeO2 nano-sized catalysts with different Cu/Ce molar ratios were prepared by a deposition-precipitation method.N2 adsorption,HRTEM-EDS,H2-TPR,XPS characterization,as well as catalytic activity and durability tests for the catalytic combustion of chlorobenzene(CB)were conducted to explore the relationship between the structure and catalytic performance of the *** is revealed that cuCe(6:1)/MCM-41 has the highest activity and can completely catalyze the degradation of CB at 260℃.The reasons for the high activity of the catalysts are as follows:MCM-41,a type of mesoporous material which has large pore size and large specific surface area,is suitable as a catalyst *** average diameter of nano-sized CuO and CeO2 particles is about 3-5 nm and adding CeO2 improves the dispersion of active component CuO,which are highly and evenly dispersed on the surface of *** results also explain why MCM-41 supported CuO-CeO2 with appropriate proportion can highly enhance the catalytic *** reason is that CeO2 acting as an oxygen-rich material can improve the mobility of oxygen species through continuous redox between Ce4^+and Ce3^+,and improve the catalytic performance of CuO for CB ***,CuCe(6:1)/MCM-41 also displays good durability for CB combustion,both in the humid condition and in the presence of benzene,making it a promising catalytic material for the elimination of chlorinated VOCs.

关键词： CuO-CeO2 MCM-41 Nano-sized Chlorobenzene Catalytic combustion Rare earths