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Effect of incubation temperature and wet-dry cycle on the availabilities of Cd,Pb and Zn in soil

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Journal of Environmental Sciences 2006年第6期18卷 1119-1123页

作者： SI Ji-tao tian Bao-guo WANG Hong-tao Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

The effect of incubation temperature and wet-dry cycle on the availabilities of Cd, Pb and Zn was studied. Three soils with pH ranging from 3.8 to 7.3, organic carbon （OC） from 0.7% to 2.4%, and clay from 12.3% to 35.6% were selected. Soils were spiked with reagent grade Cd（NO3）2, Pb（NO3）2, and Zn（NO3）2 at concentrations of 30 mg Cd/kg soil, 300 mg Zn/kg soil and 2000 mg Pb/kg soil. The soils were incubated at 35, 60, 105℃, respectively and went through four wet-dry cycles. Metal availability in soils was estimated by soil extraction with 0.1 mol/L Ca（NO3）2. According to this study, the effect of the spiking temperature on the metal availabilities was different among the metals, soils and wet-dry cycles. Mostly, 35 ~C was the first recommended spiking temperature for Cd and Pb while no spiking temperature was obviously better than others for Zn. Three wet-dry cycles was recommended regardless of the type of metals and incubation temperature.

关键词： availability wet-dry cycle cadmium (Cd) zinc (Zn) lead (Pb)

New Developments and Perspectives in Physical Geography in China

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Chinese Geographical Science 2019年第3期29卷 363-371页

作者： FU Bojie tian tao LIU Yanxu ZHAO Wenwu State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical Science Beijing Normal University

Physical geography is the cornerstone of geography. In this article, the starting points of disciplines in physical geography in recent years in China are discussed. With the coupling of systems set as the research object, and sustainable development as the ultimate goal, the upgrade of physical geography can be deconstructed into three steps: deepen physical geography from the perspective of pattern-process coupling, improve the focus of physical geography from ecosystem processes to ecosystem services, and increase the understanding of the physical geography ‘pattern, process, service, sustainability' research cascade. The incorporation of human activities into physical geographic processes is essential to conduct integrated analysis on physical and human factors at different scales. The development of ecosystem service models that couple supply-demand and sustainable development are of great importance to bridge the role of ecosystem services between the natural environment and human well-being. Moreover, human-land systems and sustainable development have become the core areas and frontiers of integrated physical geography and even geography in general. China faces the great strategic demand of constructing an ecological civilization in a new era, and the development of the disciplines of physical geography should give full access to the advantages of intersecting and comprehensive disciplines, focus on the human-land system patterns,processes, and services in key research areas, and provide disciplinary support for regional, national, and global sustainable development.

关键词： pattern-process coupling ecosystem services sustainability human-land system China’s national demands

Nicotine enhances migration and invasion of human esophageal squamous carcinoma cells which is inhibited by nimesulide

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World Journal of Gastroenterology 2009年第20期15卷 2500-2505页

作者： Ye Zong Shu-tian Zhang Sheng-tao Zhu Department of Gastroenterology Beijing Friendship Hospital Affiliated to the Capital Medical University Beijing Digestive Disease Center Beijing 100050 China

AIM： To study the effect of nicotine on the migration and invasion of human esophageal squamous carcinoma cells and to investigate whether nimesulide can inhibit the effect of ***： The esophageal squamous carcinoma cell line （TE-13） was treated with different concentrations of nicotine （100 μg/mL and 200 μg/mL） or 200 μg/mL nicotine plus 100 μmol/L nimesulide. Cell migration and invasion were measured using migration and invasion chamber systems. COX-2 expression was determined by Western blotting. Matrix metalloproteinase-2 （MMP-2） was analyzed by zymography and ***： Nicotine （100 μg/mL, 200 μg/mL） enhanced TE-13 cells migration and invasion, and increased the protein expression of COX-2 and the activity of MMP-2. Nicotine （200 μ/mL） stimulated TE-13 cells migration and invasion which were partly blocked by nimesulide. This was associated with decreased protein expression of COX-2 and decreased activity and protein expression of MMP-2. CONCLUSION： Nicotine enhances the migration and invasion of the esophageal squamous carcinoma cell line, and nimesulide partly blocks the effect ofnicotine-enhanced esophageal squamous carcinoma cell migration and invasion.

关键词： Carcinoma Cyclooxygenase 2 inhibitors Esophagus Nicotine Squamous cell

ANALYSIS OF FIRST TRANSIENT PRESSURE OSCILLATION FOR LEAKDETECTION IN A SINGLE PIPELINE

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Journal of Hydrodynamics 2012年第3期24卷 363-370页

作者： YANG Kai-lin LI Fu-tian WANG tao FU hui State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of WaterResources and Hydropower Research Beijing 100038 China

The leak detection is of great importance in the reliable operation and management of a pipeline system. Recently, attention is shifted to the use of the time domain or frequency domain methods based on the transient analysis. These methods sometimes require accurate pressure signals obtained during the transient period or by creating ideal conditions in testing. This paper proposes a method that does not require transient simulations over the whole or an extended period of time, but uses the first transient pressure oscillation to detect leaks. The method considers the propagation of the pressure oscillation wave created from a fast valve closure and the reflected damp wave from the leak. A leak in the pipe gives rise to reflected waves which in turn create discontinuities in the observed signal at the measurement section. The timing of the reflected damp wave and the magnitude represent the location and the size of the leak, respectively. An analytical expression is derived based on the Method Of Characteristic （MOC） for the relationship between the leakage and the reflected magnitude. The leak detection procedure based on the method is also given. Then the reliability of the method is tested on numerically simulated pressure signals and experimental pressure signals with calibrated leak parameters, and the results indicate a successful application and the promising features of the method.

关键词： leak detection hydraulic transient pressure oscillation pipeline

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电阻焊网机的优化改造技术

煤炭技术 2025年第1期44卷 238-241页

作者：胡兴伟陈兆彬田涛陕西博选科技有限公司西安710026

为解决目前电阻焊网机单套焊接胎具只能焊接4种直径筛网,制作多种直径筛网时需频繁更换焊接胎具问题,提出了一种焊接多规格直径筛网焊接胎具结构改进方案,计算了主要结构的技术参数,制定了制作方案并完成了试行工作。结果表明改进后的... 详细信息

为解决目前电阻焊网机单套焊接胎具只能焊接4种直径筛网,制作多种直径筛网时需频繁更换焊接胎具问题,提出了一种焊接多规格直径筛网焊接胎具结构改进方案,计算了主要结构的技术参数,制定了制作方案并完成了试行工作。结果表明改进后的焊接胎具可以解决在焊接多种直径筛网时需频繁更换焊接胎具的问题,使得生产效率提高了100%,同时降低了劳动强度和用工成本。

关键词：筛网焊接胎具结构改进电阻焊网机

Zinc modulates hippocampus CA1 neurons excitability and glutamatergic synaptic transmission

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生物物理学报 2009年第S1期25卷 272-273页

作者： Yu tao tian Zhuo Yang tao Zhang College of Life Science Nankai UniversityTianjin 300071China College of Medicine Science Nankai UniversityTianjin 300071China

Zinc ion is key physiological importance in mammalian tissues. It is a major structural component of many proteins and acts as co-factors for the activity of many enzymes that

关键词： zinc hippocampus neuron spontaneous discharges miniature EPSC spontaneous EPSC

Novel hybrid method to predict the ground-displacement field caused by shallow tunnel excavation

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Science China(Technological Sciences) 2023年第1期66卷 101-114页

作者： KONG FanChao LU DeChun MA YiDing tian tao YU Haitao DU XiuLi Institute of Geotechnical and Underground Engineering Bejing University of TechnologyBejing 100124China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China

Based on machine-learning(ML) and analytical methods, a hybrid method is developed herein to predict the ground-displacement field(GDF) caused by tunneling. The extreme learning machine(ELM), as a single hidden layer feedforward neural network, is used as an ML model to predict maximum settlement smaxof the ground surface. The particle swarm optimization(PSO) algorithm is applied to optimize the parameters for the ELM method, namely, weight and bias values from the input layer to the hidden layer. The mean square error of the k-fold cross validation sets is considered the fitness function of the PSO algorithm. For 38 data samples from published papers, 30 samples are used as the training set, and 8 samples are used as the test set. For the test samples, the error of five samples ranges between-5 and 5 mm. The error of only one sample is slightly greater than 10 mm. The proposed PSO-ELM method demonstrates good prediction performance of smax. A deformation parameter of the nonuniform displacement mode for the tunnel cross-section is calibrated based on predicted smax. When the determined nonuniform displacement mode is used as the boundary condition of the tunnel cross-section, the GDF of a shallow circular tunnel is analytically predicted based on the complex-variable method prior to tunnel excavation. For a specific engineering case,i.e., the Heathrow Express tunnel, the proposed PSO-ELM-analytical method can well predict the surface-settlement trough curve, horizontal displacements at different depths, and vertical displacements above the tunnel.

关键词： extreme learning machine particle swarm optimization complex-variable method analytical solution of a shallow tunnel prediction method of ground-displacement field

Chemical Composition of Summertime PM_(2.5) and Its Relationship to Aerosol Optical Properties in Guangzhou,China

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Atmospheric and Oceanic Science Letters 2012年第2期5卷 88-94页

作者： tao Jun Cheng tian-tao Zhang Ren-Jian South China Institute of Environmental Sciences Guangzhou 510655 China Department of Environment Science and Engineering Fudan University Shanghai 200433 China Key Laboratory of Regional Climate-Environment Research for Temperate East Asia (RCE-TEA) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric *** of the chemical composition of PM 2.5 and in situ measurements of the optical properties of aerosols were conducted in July 2008 at an urban site in Guangzhou,Southern *** mean PM 2.5 concentration for the entire period was 53.7±23.2 μg m *** mean PM 2.5 concentration (82.7±25.4 μg m 3) on hazy days was roughly two times higher than that on clear days (38.8±8.7 μg m 3).The total water-soluble ion species and the total average carbon accounted for 47.9%±4.3% and 35.2%±4.5%,respectively,of the major components of PM *** increase of secondary and carbonaceous aerosols,in particular ammonium sulfate,played an important role in the formation of haze *** mean absorption and scattering coefficients and the single scattering albedo over the whole period were 53±20 M m 1,226±111 M m 1,and 0.80±0.04,*** 2.5 had a high linear correlation with the aerosol extinction coefficient,elemental carbon (EC) was correlated with aerosol absorption,and organic carbon (OC) and SO 4 2 were tightly linked to aerosol scattering.

关键词： fine aerosol particle chemical composition aerosol optical coefficient

Effects of ZrO_2 on the structure and magnetic properties of CoPt thin films

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Rare Metals 2007年第1期26卷 23-27页

作者： SHEN Xiaohua XU Xiaohong JIANG Fengxian LV Baohua tian Baoqiang JIN tao School of Chemistry and Materials Science Shanxi Normal University Linfen 041004 China

[CoPt 1.5 ml/ZrO2 xnm]10 multilayer films were deposited on glass substrates by magnetron sputtering and then annealed in vacuum at 600℃ for 30 min. Their structures and magnetic properties were investigated as a function of ZrO2 content. The results show that the grain size and coercivity first increase and then decrease with the increase in ZrO2 content. The maximum coercivity and grain size are obtained at 37 vol.% of ZrO2. The content of ZrO2 in the film plays an important role in the separation of CoPt grains and in the reduction of intergrain exchange interaction. On the basis of the studies of angular dependent coercivity, it is found that the magnetization reversal of CoPt films with （111 ） texture is different from either the domain wall motion or the S-W type of rotation mode.

关键词： [CoPt/ZrO2]10 thin fllms grain size magnetron sputtering ZrO2 content