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Science China Chemistry 2017年第9期60卷 1236-1242页

作者： Fang Wei Jian Liu Ya-Nan Zhu Xiao-Shi Wang Chang-Yan Cao Wei-Guo Song Laboratory of Molecular Nanostructures and Nanotechnology Institute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Noble metal nanoparticles(Pd,Ag,Pt,Au) with small and relatively uniform sizes were loaded on polydopamine nanospheres through in situ galvanic replacement reaction in aqueous *** additional reductant,surfactant or organic solvent was needed.X-ray photoelectron spectroscopy results revealed that the amount of quinone increased,while the amount of phenolic hydroxyl decreased on PDA nanospheres,indicating that the galvanic displacement reaction occurred between catechol groups and noble metal *** as-prepared PDA/Pd exhibited high catalytic activity and excellent stability in styrene ***,PDA spheres retains the photo-thermal effect to serve as a nano-sized heater to accelerate the catalytic reactions under near-infrared illumination.

关键词： polydopamine, noble metal, facile loading, multifunctional catalysis

Formation and evolution mechanisms of large-clusters during rapid solidification process of liquid metal Al

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Science China(Physics,Mechanics & Astronomy) 2005年第1期48卷 101-112页

作者： LIU Rangsu, DONG Kejun, LIU Fengxiang, ZHENG Caixing, LIU Hairong & LI Jiyong Department of Applied Physics, Hunan University, Changsha 410082, China College of Materials Science and Engineering, Hunan University, Changsha 410082, China College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China Department of Applied Physics Hunan University Changsha 410082 China College of Materials Science and Engineering Hunan University Changsha 410082 China College of Chemistry and Chemical Engineering Hunan University Changsha 410082 China

A molecular dynamics simulation study has been performed for the formation and evolution characteristics of nano-clusters in a large-scale system consisting of 400000 atoms of liquid metal Al. The center-atom method combined with pair-bond analysis technique and cluster-type index method (CTIM) has been applied here to describe the structural configurations of various basic clusters. It is demonstrated that both the 1551 bond-type and the icosahedral cluster (12 0 12 0) constructed by 1551 bond-types are dominant among all the bond-types and cluster-types, respectively, in the system and play a critical role in the microstructure transitions of liquid metal Al. The nano-clusters (containing up to 150 atoms) are formed by the combination of some middle and small clusters with distinctly different sizes, through mutual competition by unceasing annex and evolution in a seesaw manner (in turn of obtaining and losing),which do not occur as the multi-shell structures accumulated with an atom as the center and the surrounding atoms are arranged according to a certain rule. This is the essential distinction of nano-cluster in liquid metal from those obtained by gaseous deposition, ionic spray methods, and so on. Though the nano-clusters differ from each other in shape and size, all of them possess protruding corners that could become the starting points of various dendrite structures in the solidification processes of liquid metals.

关键词： liquid metal, solidification process, large-cluster configuration, evolution mechanism, computer simulation.

Size distributions and magic number characteristics of cluster configurations formed during solidification processes of liquid metal Al

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Science China(Technological Sciences) 2006年第2期49卷 172-187页

作者： LIU Rangsu1, LIU Fengxiang1, DONG Kejun1, ZHENG Caixing1, LIU Hairong2, PENG Ping2 & LI Jiyong3 1. Department of Physics, Hunan University, Changsha 410082, China 2. Department of Material Science and Engineering, Hunan University, Changsha 410082, China 3. Department of Chemistry, Hunan University, Changsha 410082, China Department of Physics Hunan University

A molecular dynamics simulation study has been performed for a large systemconsisting of 100000 liquid metal Al atoms to investigate the formation and magic numbercharacteristics of the cluster configurations formed during the rapid solidification processes. Thecluster-type index method (CTIM) has been adopted to describe various types of clusterconfigurations. The results indicate that the icosahedral clusters (12 0 12 0) and theircombinations play the most important role in the rnicrostructure transitions during solidificationprocesses; for the cluster configurations of different levels formed by various combinations withdiffering numbers of basic clusters, their size distributions possess obvious magic number sequencewhich is in turn as 13(13), 19(21), 26-28(27), 32-33(32), 39-40, 43-44, 48..., (those in bracket arethe corresponding value in liquid state); the magic numbers correspond to the peak value positionsof the cluster numbers for corresponding level formed with various combinations by 1, 2, 3, 4, 5, 6,7, ...basic clusters, respectively. This magic number sequence is in good agreement with theexperimental results obtained by Harris et al. At the same time, this simulation study also gives ascientific and reasonable explanation to these experimental results.

关键词： liquid metal, solidification processes, cluster configuration, magic numbers, computer simulation.

Avoidance Reaction of Penaeus Chinensis to Heavy metals (Pb, Cr,Zn) and Heavy metal Mixtures (Pb-Cr, Pb-Zn)

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Marine Science Bulletin 2001年第1期3卷 91-96页

作者： Chen Minshan(陈民山) Yellow Sea Fisheries Research Institute CAFS Qingdao 266071

Study on the avoidance response of Penaeus chinensis to heavy metals (Pb, Cr, Zn) and heavy metal mixtures (Pb-Cr, Pb-Zn) is carred out using a Y-model avoidance apparatus. The concentrations calculated to induce 50% avoidance rate byPenaeus chinensis are 11.4, 33.2 and 238. 1 mg/L for Pb, Cr and Zn, respectively. Mixtures of Pb-Cr and Pb-Zn produce additive effect in the avoidance test using Penaeus chinesis. But when the mixed Pb-Zn solution has 0.5 toxic unit Pb and 0.5 toxic unit Zn, the mixture seems to have synergistic effect.

关键词： Penaeus chinensis, heavy metal, avoidance reaction, joint action

Chemical forms of heavy metal contaminants in sediments of Miyun reservoir

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Science China Earth Sciences 2005年第Z2期48卷 341-350页

作者： LIU Xiaoduan, XU Qing, GE Xiaoli, LIU Liu & WU Dianwei National Research Center of Geoanalysis, Beijing 100037, China The Occupational Disease Research Institute of Beijing, Beijing 100020, China The Hydrology Main Station of Beijing, Beijing 100039, China National Research Center of Geoanalysis Beijing 100037 China The Occupational Disease Research Institute of Beijing Beijing 100020 China The Hydrology Main Station of Beijing Beijing 100039 China

The chemical forms, spatial distribution and sources of As, Hg, Cd, Pb and Zn in sediments of the Miyun reservoir were studied. The results of sequential extraction demonstrate that most of As, Pb and Zn were bound to the residual fraction, Hg was associated with the sulfide fraction while Cd was associated with the carbonate fraction and the residual fraction. On the vertical profiles the concentrations of the heavy metals in total and each fractions mostly decreased with increasing depths in sediments, suggesting that the heavy metals input from the upstream watershed increases yearly. Summation of the residual fraction, the sulfide fraction and the carbonate fraction accounts for 60.03%―85.60% of the total heavy metal contents in the sediments, which represent the geochemical background values of the elements and relate closely to soil erosion. Results of the main factor analysis show that most sediments of the reservoir come from the upstream soil erosion, the point source pollution and domestic waste. Moreover, the microbial activities taking place on the sediment-water interface are also one of the major factors to cause the increasing content of the organic matter fraction and the iron-manganese oxide fraction. Environmental change of the reservoir water could make the removability of the heavy metals increase, leading to the increase of their concentrations in pore water in sediments, and imperiling water quality of the reservoir.

关键词： Miyun reservoir, sediments, chemical forms, heavy metal, factor analysis.

Density functional calculations of large systems containing heavy elements by means of the regionalization algorithm

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Science China Chemistry 2004年第6期47卷 453-465页

作者： HU Xiangqian LI Lemin State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

The regionalized computational method is extended to the non-relativistic, scalar and 2-component relativistic density functional calculation of large systems containing transition series or heavy main-group metal elements. A large system is divided into several regions which can be considered as relatively independent quantum mechanical subsystems. Taking into account the Coulomb and exchange-correlation potentials as well as the Pauli repulsion exerted by the other subsystems, the Kohn-Sham equation related to subsystem K can be written as: $(F^K + F_P^K )C^K = S^K C^K \varepsilon ^K K = A,B,C \cdots ,$ where F K , C K , S K , ε K are the Fock matrix, the matrix of combination coefficients of orbitals, the overlap matrix of basis sets and the energy eigenvalue matrix, respectively. The matrix F K K reflects the Pauli repulsion from the other subsystems. F K may be non-relativistic, scalar or 2-component relativistic Fock matrix determined by the theoretical method related to the density functional calculations. The other matrices are mated with F K . Solving the Kohn-Sham equation for every subsystem and combining the results from the subsystem calculations, the electronic structural information of the whole system is derived. The density functional calculation of several molecules containing transition metal Ni or heavy main-group metal TI or Bi is performed by the afore-mentioned regionalization algorithm. The obtained results for each molecule are compared with those from the density functional calculation of that molecule in its entirety in order to check the feasibility of the regionalization algorithm. It is found that with sufficiently large regional basis set in the subsystem calculation the accuracy of the results calculated by the regionalization algorithm is essentially the same as that from the calculation of the molecule in its entirety. With proper smaller regional basis sets the accuracy of the results calculated with the regionalization algorithm c

关键词： density functional calculation, large system, transition metal, heavy element, regionalization algorithm.

Helical ternary complexes of alkaline earth picrates with open-chain crown ether

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Science China Chemistry 2003年第4期46卷 399-406页

作者：刘伟生温永红刘雪原谭民裕 Department of Chemistry and National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

Four solid complexes of alkaline earth picrates with N,N,N′,N′-tetraphenyl-3,6,9-trioxaundecanediamide (TTD), M (Pic)2TTD (1, M = Mg; 2, M = Ca; 3, M = Sr; 4, M = Ba), have been prepared and characterized by elemental analysis, conductivity measurement, IR spectra, 1H NMR spectra and TG-DTA techniques. Crystal structure of complex 3 shows that the Sr(II) ion is 9-coordinated by five oxygen atoms from TTD and four oxygen atoms from two bidentate picrates, and the coordination polyhedron is distorted tricapped trigonal prism. TTD as a pentadentate ligand forms a right-handed helical coordination structure. The chelating helical chain has a relative fixed radius and then shows a high coordination selectivity to metal ion. The high selectivity of TTD to alkaline earth ions is explained elementarily from the special coordination structures.

关键词： alkaline earth metal, open chain crown ether, complex, helix coordination structure.

Progress in Research on Materials Under Microgravity in China

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空间科学学报 2004年第Z1期24卷 138-149页

作者： CHEN Nuofu CHEN Wanchun LUO Xinghong YE Yude Key Laboratory of Semiconductor Materials Sciences Institute of Semiconductors The Chinese Academy of Sciences Beijing 100083 China National Laboratory of Microgravity Institute of Mechanics The Chinese Academy of Sciences Beijing 100080 China Institute of Physics The Chinese Academy of Sciences Beijing 100080 China National Laboratory of Microgravity Institute of Mechanics The Chinese Academy of Sciences Beijing 100080 China Institute of Metal Research The Chinese Academy of Sciences Shenyang 110016 China Key Laboratory of Semiconductor Materials Sciences Institute of Semiconductors The Chinese Academy of Sciences Beijing 100083 China

Research on materials under microgravity in China began in the 1980s, sparked by Prof. Lanying Lin (academician of CAS), Prof. Xiji Wang (academician of CAS), Prof. Guirong Min (academician of CAS), and Prof. Huabao Lin (academician of CAS), and others. The first semiconductor crystal, first optical crystal, and first alloys were grown in space on board a recoverable satellite in 1987. Since then, microgravity materials science became a new scientific branch in *** and technical activities on space crystal growth and solidification are carried out through two major programs: ground-based studies and orbital experiments. The main results obtained during 2001-2003 are reported below.

关键词： Microgravity, Semiconductor, metal, Crystal

Synthesis of zeolites using fly ash and their application in removing heavy metals from waters

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Science China Earth Sciences 2003年第9期46卷 967-976页

作者：王焰新郭永龙杨志华蔡鹤生 Xavier Querol Department of Hydrogeology and Environmental Engineering China University of Geosciences Wuhan 430074 China Coal Resource Laboratory of the Ministry of Education of China China University of Mining and Technology Beijing 100083 China Institute of Earth Sciences "Jaume Almera" CSIC 08028 Barcelona Spain

Three types of zeolite (NaP1 zeolite, analcime and chabazite) were hydrothermally synthesized by reacting fly ash with NaOH solution. The maximum conversion rate from fly ash to single zeolite is about 40%—75%, and the total conversion rate 60%—80%. The synthesis experimental results indicate that factors including vortex, viscosity, temperature, reaction time, and NaOH concentration in the reaction system strongly affect the type and conversion rate of zeolites. The batch experiments of removing Cu2+, Pb2+ and Cd2+ from wastewaters show that the adsorption capacity of zeolites synthesized is higher than that of fly ash.

关键词： coal fly ash, hydrothermal synthesis, zeolite, heavy metal, wastewater, adsorption.