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Unified Symmetry of Hamilton Systems

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Communications in Theoretical Physics 2005年第5X期44卷 769-772页

作者： XU Xue-Jun QIN Mao-Chang mei Feng-Xiang Department of Mechanics Beijing Institute of Technology Beijing 100081 China Department of Physics Zhejiang Normal University Jinhua 321004 China

The definition and the criterion of a unified symmetry for a Hamilton system are presented. The sufficient condition under which the Noether symmetry is a unified symmetry for the system is given. A new conserved quantity,as well as the Noether conserved quantity and the Hojman conserved quantity, deduced from the unified symmetry, is obtained. An example is finally given to illustrate the application of the results.

关键词： Hamilton system unified symmetry conserved quantity

Ab initio Study of the Potential Energy Surface and Product Branching Ratios for Reaction of O（^1D） with C2H5CI

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Chinese Journal of Chemical Physics 2009年第1期22卷 87-96页

作者： Chong-fu Song Zhi-mei Tian Quan-xin Li Tian-jing He Department of Chemistry Fuyang Teacher's College Fuyang 236041 China Department of Chemical Physics University of Science and Technology of China Hefei 230026 China

The potential energy surface of O（^1D）＋C2H5Cl reaction was studied using QCISD（T）/6- 311＋＋G（d,p）//MP2/6-31G（d,p） method. The calculations reveal an insertion-elimination mechanism. The insertion reaction of O（^1D） and C2H5Cl produces two energy-rich intermediates, IM1 and IM2, which subsequently decompose into various products. The calculations of the branching ratios of various products formed through the two intermediates were carried out using RRKM （Rice-Ramsperger-Kassel-Marcus） theory at the collision energies of 0, 20.9, 41.8, 62.7, 83.6, 104.5, and 125.4 kJ/mol. HCl is the main decomposition product for IM1; CH2OH is the main decomposition product for IM2. Since IM1 is more stable than IM2, HCl is probably the main product of the O（^1D）＋C2H5Cl reaction.

关键词： C2H5Cl Branching ratio Rate constant

产教融合视域下服务地方产业集群发展的高职专业群建设探析

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职业技术 2025年第1期24卷 68-73页

作者：梅阳寒陈永刚范四立东莞职业技术学院广东东莞523808

随着产教融合在服务区域经济发展中重要性日益凸显,高职院校专业群建设成为服务地方产业的重要举措。政府政策的支持为产教融合提供了良好环境,市场需求的增长促进了产教融合规模的扩大与深化。针对产业升级需求,专业群建设依托资源整合... 详细信息

随着产教融合在服务区域经济发展中重要性日益凸显,高职院校专业群建设成为服务地方产业的重要举措。政府政策的支持为产教融合提供了良好环境,市场需求的增长促进了产教融合规模的扩大与深化。针对产业升级需求,专业群建设依托资源整合,提升教育质量,增强学生就业竞争力,同时优化专业结构布局,推动校企深化合作。通过分析专业群与产业集群融合发展的机遇与挑战,提出加强顶层设计、深化产教融合、创新驱动发展等策略。

关键词：产教融合职业教育专业群产业集群人才培养

Water incubation-induced fluctuating release of heavy metals in two smelter-contaminated soils

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Journal of Environmental Sciences 2019年第8期31卷 14-23页

作者： Bin Yang Yunzhe Cao Jie Ren mei Wang Huilong Luo Fasheng Li College of Water Science Beijing Normal University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences School of Ecology and Environment Inner Mongolia University

The soil moisture regime can affect the release of heavy metals in soil. In the previous studies, slightly polluted soils or artificially contaminated soil samples were considered to investigate the effect of soil moisture. We used highly smelter-contaminated and aged soils to study the release of typical heavy metals(Cu, Zn, Cd and Pb) induced by water incubation in batch experiments with characterization via speciation and X-ray diffraction analyses(XRD). The results show that the leachable concentrations of the heavy metals increased slightly in the first 30 days, decreased drastically between 30 and 90 days, and immobilized relatively constant thereafter. The fluctuation was ascribed to the changes of soil Eh and pH, the reductive dissolution of crystalline iron oxides, the formation of new amorphous iron oxides, the absorption of dissolved organic matter and the precipitation of metal sulfide. Speciation analysis indicated that a proportion of the soil heavy metals was transformed from an exchangeable fraction to a less labile fraction after water incubation. And the presence of a lead iron oxide phase and the peak increasing of zinc sulfide were observed via XRD analyses. Finally, water incubation restrained the release of heavy metals after 180 days of incubation, and reduced the leachability of Cu, Zn, Cd and Pb by as much as 1.61%–7.21% for soil A and 0.43%–3.36% for soil B, respectively. The study findings have implications for the formulation of risk control and management strategies for heavy metals in smelter-contaminated soils.

关键词： Smelter-contaminated soil Heavy metals Water incubation Release Fraction

Effects of different cooking methods on health-promoting compounds of broccoli

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第8期10卷 580-588页

作者： Gao-feng YUAN Bo SUN Jing YUAN Qiao-mei WANG Department of Horticulture Zhejiang University Hangzhou 310029 China Key Laboratory of Horticultural Plant Growth Development and Quality Improvement Ministry of Agriculture Hangzhou 310029 China

The effects of five domestic cooking methods,including steaming,microwaving,boiling,stir-frying,and stir-frying followed by boiling(stir-frying/boiling),on the nutrients and health-promoting compounds of broccoli were *** results show that all cooking treatments,except steaming,caused significant losses of chlorophyll and vitamin C and significant decreases of total soluble proteins and soluble *** aliphatic and indole glucosinolates were significantly modified by all cooking treatments but not by *** general,the steaming led to the lowest loss of total glucosinolates,while stir-frying and stir-frying/boiling presented the highest ***-frying and stir-frying/boiling,the two most popular methods for most homemade dishes in China,cause great losses of chlorophyll,soluble protein,soluble sugar,vitamin C,and glucosinolates,but the steaming method appears the best in retention of the nutrients in cooking broccoli.

关键词： Broccoli Cooking Glucosinolates Vitamin C Chlorophyll Soluble sugar

Synthesis of 1,1'-binaphthyl-2,2'-diamine from 2-naphthol under atmospheric pressure

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Chinese Chemical Letters 2009年第10期20卷 1150-1152页

作者： Qiang Feng Chao Zhang Qiang Tang mei Ming Luo Key Laboratory of Green Chemistry & Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 China

A practical protocol to obtain 1,1′-binaphthyl-2,2′-diamine was developed from 2-naphthol and 2-naphthylhydrazine under mild conditions： solvent-free, 125-130 ℃, atmospheric pressure. The convenient procedure make... 详细信息

关键词： 1,1′-Binaphthyl-2,2′-diamine 2-Naphthol 2-Naphthylhydrazine Synthesis

Effects of Br^- and I^- concentrations on Zn electrodeposition from ammoniacal electrolytes

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International Journal of Minerals,Metallurgy and Materials 2015年第7期22卷 682-687页

作者： Zhi-mei Xia Sheng-hai Yang Liang-hong Duan Mo-tang Tang School of Metallurgy and Environment Central South University School of Metallurgical Engineering Hunan University of Technology

The effects of Br- and I- concentrations on the cell voltage, anodic polarization, current efficiency （CE）, and energy consumption （EC） of zinc electrodeposition from ammoniacal ammonium chloride solutions were investigated. The surface morphology of zinc deposits was also examined. Scanning electron microscopy （SEM） and X-ray diffraction （XRD） were used to characterize the morphology of zinc deposits and the phase of anodic sediments produced during electrolysis. The results clearly showed that the CE slightly increased from approximately 95.12% in the absence of F and Br- to 97.08% in the presence of 10 g·L-1 Br; in contrast, the CE significantly decreased to less than 83% in the presence of 10 g·L-1 I- . The addition of Br and I- positively affected the EC, which decreased from 2514 kW·h·t-1 to approximately 2300 kW·h·t-1. The results of anodic polarization measurements showed that the voltage drops were 130 and 510 mV when the concentrations of Br- and I- were 10 g·L-1 at a eUlTent density of 400 A·m2, respectively. SEM images showed that the addition of Br- and I- caused different crystal growth mechanisms, which resulted in the production of compact and smooth zinc deposits. The anodic reactions of I were also studied.

关键词： zinc electrodeposition bromide iodide ammonium chloride current efficiency energy consumption

An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr^(3+) removal capacity

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International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 850-857页

作者： Peng-cheng Lei Xian-jiang Shen Yang Li Min Guo mei Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investigations were carried out regarding the capacity of zeolite 4A to remove Cr（III） from aqueous solutions with relatively low initial concentrations of Cr（III）（5–100 mg·L^（-1））. It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environmental pollution caused by the dumping of bauxite tailings. The Cr（III） removal capacity highly depends on the initial p H value and concentration of Cr（III） in the solution. The maximum removal capacity of Cr（III） was evaluated to be 85.1 mg×g^（-1） for zeolite 4A, measured at an initial p H value of 4 and an initial Cr（III） concentration of 5 mg·L^（-1）. This approach enables a higher removal capacity at lower concentrations of Cr（III）, which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr（III） by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr（III）.

关键词： bauxite tailings zeolite trivalent chromium wastewater treatment

Molecular newborn screening for four genetic diseases in Guizhou Province

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Molecular newborn screening for four genetic diseases in Gui...