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Trace metals distribution in synodontis membranaceus, sediments, Asystasia Gangetica and Platostoma Africanium from Ofuafor River around Delta Glass Factory in Ughelli North Local Government Area, Delta state Nigeria

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Journal of Environmental sciences 2002年第1期14卷 79-82页

作者： NWAJEI, G.E. (Faculty of science, department of Chemistry, Delta state university, Abraka, Nigeria) Faculty of science Department of Chemistry Delta State University 尼日利亚 Abraka

The trace metals analysis in synodontis membranaceus (head and tail), bottom sediments, Asystasia Gangetica and Platostoma Africanium were carried out using atomic absorption spectrometer of model Perkin Elmer 3110. Metals analysed were copper, nickel, mangenese, chromium, iron lead and cobalt. These metals were detected in the above samples. Vegetation samples concentration in copper, manganese, chromium, iron and cobalt were higher than those obtained in bottom sediments. The tail part of the fish contents of trace metals were also higher than those of the head. The results obtained in this work exceeded the results of water analysis carried out by Omoregha on the same river. Metals such as copper, nickel, manganese and chromium were below detection limit in the water from the same river. The bioaccumulation of these trace metals in these samples were traced to activities of Delta Glass Factory.

关键词： trace metals Ofuafor River bioaccumulation of metals contamination industrial effluents Delta Glass Factory

Aggregation and assembly of crescent foldamers

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science China Chemistry 2010年第1期53卷 45-51页

作者： GONG Bing department of Chemistry,university at Buffalo,The state university of New York,Buffalo,New York 14.60,{4. 1. department of Chemistry University at Buffalo The State University of New York Buffalo New York 14260 USA

Recent studies have started to provide initial insights into the aggregation and assembly of two classes of back-rigidified foldamers with flat,curved backbones consisting of aromatic *** their persistent shape that presents large,well-defined aromatic surface areas,these crescent foldamers were found to undergo size-dependent aggregation in solution and pack into 1D assemblies in the solid *** aromatic oligoamides undergo stacking interactions not only in polar solvents but also in nonpolar ones,a unique property that is not associated with many other molecules that associate via π-π stacking *** stacking of oligo(m-phenylene ethynylenes) is similar to aromatic hydrocarbons,being promoted in polar solvents such as methanol while being discouraged in nonpolar solvents such as *** ready synthetic availability of crescent foldamers makes it possible to directly control the intermolecular interaction by tuning surface ***,the columnar assembly of these cavity-containing molecules provides a new strategy for constructing supramolecular nanotubular structures.

关键词： foldamer folding hydrogen bond π-π stacking aggregation assembly

Relationships between bacterial-algal proliferating and mass extinction in the Late Devonian Frasnian-Famennian transition:Enlightening from carbon isotopes and molecular fossils

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science China Earth sciences 2005年第10期48卷 1656-1665页

作者： GONG Yiming1,2, XU Ran1, TANG Zhongdao1, SI Yuanlan3 & LI Baohua4.1. Faculty of Earth science and state Key Laboratory of geological Processes and Mineral Resources, China university of Geosciences, Wuhan 4.0074. China 2. Institute of Resources & Environments, Henan Polytechnic university, Jiaozuo 4.4.03, China 3. department of Computer science, South-Central university for Nationalities, Wuhan 4.0074. China 4. Laboratory of Marine Geology, Tongji university, Shanghai 200092, China Faculty of Earth science and state Key Laboratory of geological Processes and Mineral Resources China university of Geosciences Wuhan China Institute of Resources & Environments Henan Polytechnic university Jiaozuo China department of Computer science South-Central university for Nationalities Wuhan China Laboratory of Marine Geology Tongji university Shanghai China

Studies show positive shifts of inorganic and organic carbon isotope values (δ 13Ccarb and δ 13Ckerogen) from +0.4. (‰ V-PDB) to +3.54.(‰ V-PDB) and from ?29.38 (‰ V-PDB) to ?24.14.(‰ V-PDB), respectively, B* (Ba* = Ba/ (Al2O3 X 15%)) values from 0.015 to 0.14., TOC values from 0.02% to 0.21%, V/Cr values from 0.3 to 2.0, Sr/Ba values from 3.20 to 4..50 in the Late Devonian Frasnian Upper rhenana zone to the top linguiformis zone of the Yangdi sec-tion deposited in carbonate slope facies of Guilin, Guangxi, South China, which indicates that biomass, productivity, organic carbon burial and salinity increase and that oxygenation near the boundary between sediments and waters decreases from the Late Devonian Frasnian Upper rhenana zone to the top linguiformis zone. Abundance of molecular fossils increases and normal alkanes, isoprenoid hydrocarbon, terpanes and steranes are dominated from the Late Devonian Frasnian to the bottom of Famennian, which shows that the predecessors of molecular fossils of the Frasnian-Famennian (F-F) transition are dominated by marine phytoplankton, zooplankton and benthic bacteria with no photosynthesis. Therefore, it is considered that the F-F transitional mass extinction with a multistage, selection and global synchronizing was caused by bacte-rial-algal proliferating, continuing deterioration of the shallow marine ecoenvironment of the mid-dle-lower latitudes. A simple cause and effect chain can be expressed as: appearance of seed plants and multi-storied forests → enhanced chemical and biochemical weathering and pe-dogenesis → wide development of soils → increasing riverine nutrient fluxes in epicontinental sea → from superoligotrophic to eutrophic in epicontinental sea → proliferating of marine phyto-plankton and zooplankton → frequent red tide and anoxia → mass extinction of shallow marine organisms in the middle-lower latitudes. It is worth notice that the factor drawdown of atmos-pheric Pco2, climatic cooling and sea level falling c

关键词： mass extinction, bacteria-algae, carbon isotopes, molecular fossils, biodiversity, Late Devonian, Guangxi, South China.

Integrating　Knowledge－Based　Simulation　with　Aspiration－Directed　Model－based　Decision　Support　System

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Journal of Systems Engineering and Electronics 1996年第2期7卷 25-33页

作者： Feng Shan & Li D. Xu(department of Automatic Control Engineering,Huazhong university of science and Technology Wuhan, Hubei 4.0074. China)(department of Management science and Information systems Wright state university, Dayton, oh 4.4.5, usa) department of Automatic Control Engineering Huazhong University of Science and Technology Wuhan Hubei 430074 China department of Management science and Information Systems Wright state university Dayton OH 45435 USA

This paper reports an aspiration-directed, model-based decision support system (AMDSS) integrated with a knowledge-based simulation system. The system is designed to study China's mid-range economic development strategy. The capacity of the system is enhanced by the knowledge-based component which provides a knowledge-based simulation environment for model management. Currently the system has passed the stage of prototype and achieves its implementation capacity. The paper first presents the mathematical aspects of decision making including aspiration-directed decision making, then discusses the architecture of the system. The purpose of the paper is to provide insights into how such an integrated system could provide decision support for complex decision analysis.

关键词： Knowledge-based simulation Model-based reasoning Decision support system

LOD score exclusion analyses for candidate disease susceptibility genes using case-parents design

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Progress in Natural science:Materials International 2006年第1期16卷 30-38页

作者： DENG Hongwen1,2,3 and GAO Guimin2,4.(1.Laboratory of Molecular and Statistical Genetics, College of Life sciences, Hunan Normal university, Changsha 4.0081, China 2.Osteoporosis Research Center, Creighton university Medical Center, Omaha NE 68131, usa 3. {4. of Biomedical sciences, Creighton university, Omaha NE 68131, usa 4. Virginia Bioin format ics Institute and {4. of Statistics, Virginia Polytechnic Institute and state university, Blacksburg VA 24.61-0315, usa) [a]Laboratory of Molecular and Statistical Genetics College of Life Sciences Human National University Changsha China [b]Osteoporosis Research Center Creighton University Medical Center Omaha NE USA [c]department of Biomedical sciences Creighton University Omaha NE USA [d]Virginia Bioinformatics Institute and department of Statistics Virginia Polytechnic Institute and State University Blacksburg VA USA

The focus of almost all the association studies of candidate genes is to test for their importance. We recently developed a LOD score approach that can be used to test against the importance of candidate genes for complex diseases and quantitative traits in random samples. As a complementary method to regular association analyses, our LOD score approach is powerful but still affected by the population admixture, though it is more conservative. To control the confounding effect of population heterogeneity, we develop here a LOD score exclusion analysis using case-parents design, the basic design of the transmission disequilibrium test (TDT) approach that is immune to population admixture. In the analysis, specific genetic effects and inheritance models at candidate genes can be analyzed and if a LOD score is ≤ - 2. 0, the locus can be excluded from having an effect larger than that specified. Simulations show that this approach has reasonable power to exclude a candidate gene having small genetic effects if it is not a disease susceptibility locus (DSL) with sample size often employed in TDT studies. Similar to association analyses with the TDT in nuclear families, our exclusion analyses are generally not affected by population admixture. The exclusion analyses may be implemented to rule out candidate genes with no or minor genetic effects as supplemental analyses for the TDT. The utility of the approach is illustrated with an application to test the importance of vitamin D receptor (VDR) gene underlying the differential risk to osteoporosis.

关键词： association studies candidate genes case-parents design disease susceptibility locus exclusion mapping LOD score.

A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

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Chinese Journal of Polymer science 2002年第4期20卷 377-380页

作者： Qiang Wu Bao-jun Qu state Key Laboratory of Fire science and department of Polymer science and Engineering {4. of science and Technology of China, Hefei 230026 China Univ Sci & Technol China State Key Lab Fire Sci Hefei 230026 Peoples R China Univ Sci & Technol China Dept Polymer Sci & Engn Hefei 230026 Peoples R China

The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94.test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). The LOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGA data show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500degreesC). The FTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higher rate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on the carbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exerts synergistic effects with the IFR by increasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures on the burning PP surface.

关键词： silicotungistic acid synergistic effect intumescent flame retardant polypropylene

Particle swarm optimization algorithm for partner selection in virtual enterprise

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Progress in Natural science:Materials International 2008年第11期18卷 1445-1452页

作者： Qiang Zhao~a Xinhui Zhang~(b,*) Renbin Xiao~c a School of Mechanical science and Engineering,Huazhong university of science and Technology,Wuhan 4.0074.China b department of Biomedical,Industrial & Human Factors Engineering,Wright {4. university,Dayton,oh 4.4.5,usa c Institute of Systems Engineering,Huazhong university of science and Technology,Wuhan 4.0074.China School of Mechanical science and Engineering Huazhong University of Science and Technology Wuhan 430074 China department of Biomedical Industrial & Human Factors Engineering Wright State University Dayton OH 45435 USA Institute of Systems Engineering Huazhong University of Science and Technology Wuhan 430074 China

Partner selection is a fundamental problem in the formation and success of a virtual *** partner selection problem with precedence and due date constraint is the basis of the various extensions and is studied in this paper.A nonlinear integer program model for the partner selection problem is *** problem is shown to be NP-complete by reduction to the knapsack problem,and therefore no polynomial time algorithm *** solve it efficiently,a particle swarm optimization(PSO)algorithm is adopted,and several mechanisms that include initialization expansion mechanism,variance mechanism and local searching mechanism have been developed to improve the performance of the proposed PSO algorithm.A set of experiments have been conducted using real examples and numerical simulation,and have shown that the PSO algorithm is an effective and efficient way to solve the partner selection problems with precedence and due date constraints.

关键词： Virtual enterprise Partner selection PSO NP-complete

Ab initio molecular dynamics simulation of the atom packing and density of Al-Ni amorphous alloys

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science China(Technological sciences) 2010年第12期53卷 3175-3182页

作者： YU ChunYan1, HUI XiDong1, CHEN Xiaohua1, LIU XingJun1, LIN DeYe1, LIU ZiKui2 & CHEN GuoLiang1 1 state Key Laboratory for Advanced Metals and Materials, university of science and Technology Beijing, Beijing 100083, China 2 department of Materials science and Engineering, Pennsylvania state university, university Park, PA 16802, usa 1. state Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China2. Department of Materials Science and Engineering Pennsylvania State University University Park PA 16802 USA

Al-Ni alloys have better glass forming ability (GFA) than other Al-based alloys. However, the relationship among the atomic arrangement, glass transition, packing density and composition hasn’t been systematically studied. In this paper the ab initio molecular dynamics simulation (AIMD) was performed on the atom packing and density of AlxNi100-x (x=80, 83, 85, 86, 87 and 90) alloys. The pair correlation function and Voronoi tessellation indicated that there are obvious topological and chemical short-range orders in these alloys. The topological structure consists of Al-centered icosahedra like and Ni-centered tri-capped trigonal prism (TTP) like polyhedra. There is strong chemical short-range ordering between Al and Ni atoms indicated by the bond-length of Al-Ni pair shorter than the sum of the radii of Al and Ni atoms, which increases with the increasing of Ni content. It is shown that the densities of amorphous alloys don’t agree with the linear law with a peak at x=85. Based on the features of the structure and density, it is concluded that Al-Ni alloys at x=84.86 have high GFA, which can be extended to multi-component Al-based alloys.

关键词： AIMD Al-Ni alloys density short-range order chemical short-range order

Two-Dimensional Riemann Problems for the Compressible Euler System

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Chinese Annals of Mathematics,Series B 2009年第6期30卷 845-858页

作者： Yuxi ZHENG Dedicated to Professor Andrew Majda for his 60th Birthday

Riemann problems for the compressible Euler system in two space dimensions are complicated and difficult,but a viable alternative remains *** author lists merits of one-dimensional Riemann problems and compares them with those for the current two-dimensional Riemann problems,to illustrate their ***-dimensional Riemann problems are approached via the methodology promoted by Andy Majda in the spirits of modern applied mathematics;that is,simplified model is built via asymptotic analysis,numerical simulation and theoretical analysis.A simplified model called the pressure gradient system is derived from the full Euler system via an asymptotic ***-of-the-art numerical methods in numerical simulations are used to discern small-scale structures of the solutions,e.g.,semi-hyperbolic *** methods are used to establish the validity of the structure revealed in the numerical *** entire process,used in many of Majda's programs,is shown here for the two-dimensional Riemann problems for the compressible Euler systems of conservation laws.

关键词： Characteristic decomposition Guderley reflection Hodograph transform Pressure gradient system Self-similar Semi-hyperbolic wave Triple point paradox Riemann problem Riemann variable