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Search Results: 1 - 10 of 120083 matches for " Keqiang Wang "
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Calculation methodology of marine environmental capacity for heavy metal: A case study in Jiaozhou Bay, China
KeQiang Li,XiuLin Wang
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5395-5
Abstract: Results from past pollution control practices show that environmental quality can be ensured by controlling the actual amount of pollutants formed in the environment. Therefore, the marine environmental capacity for heavy metals was introduced. Marine environmental capacity for heavy metals is defined as the maximum amount of heavy metals permitted in the marine environment system to preserve the benign cycle of materials in the oceansphere, and to limit the adverse effects of heavy metals on the biosphere, hydrosphere, atmosphere, and lithosphere. Based on the box or three-dimensional model in the target coastal region, including the self-purification and output of heavy metals, the marine environmental capacity for heavy metals can be calculated within a given criterion and time. In this study, a method was proposed to calculate the marine environmental capacity for heavy metals which includes four steps: (1) gathering the basis information of target coastal ecosystem, (2) selection of water control points and water quality criteria for these points, (3) development of numerical models for the biogeochemical cycling of heavy metals in target coastal region, and (4) calculation of environmental capacity using the developed model. According to the proposed method, the marine environmental capacity for lead is approximately 60 tons per year if Grade I seawater quality is set as the control criterion in Jiaozhou Bay. An effective seawater quality management plan can also be framed based on the environmental capacity for metals.
The Strategies of Fostering Students’ Cross-Cultural Awareness in Secondary School English Teaching  [PDF]
Keqiang Xu
Open Journal of Social Sciences (JSS) , 2016, DOI: 10.4236/jss.2016.46018
Abstract: Based on the previous study on the framework of cultivating cross-cultural awareness, this study focuses on strategies in practice for Secondary School English teaching. It aims at explaining how to effectively promote the target culture teaching and learning and develop key competencies of cross-cultural awareness in the context of Chinese learners of English. The author proposes different methods and strategies for cultivating Secondary English students’ cross-cultural awareness in accordance with features of two aspects of teaching and learning, namely at curricular and extracurricular time.
The Synergistic Effects Study of C-myc and C-erbB-2 in the Carcinogenesis of Gastric Carcinoma  [PDF]
Keqiang Wang, Jiangang Liu, Yanchao Duan, Shengyi Dongye, Jiafeng Wu, Yiren Wang, Zhenzhong Liu, Guoxin Han
Open Journal of Gastroenterology (OJGas) , 2017, DOI: 10.4236/ojgas.2017.712032
Abstract: Objective: To study the significance of c-myc and c-erbB-2 oncogene expression in gastric cancer. Methods: 81 gastric cancer specimens were detected for c-myc and c-erbB-2 oncogene amplification using non-radioactive in situ hybridization method. Results: The amplification rates for c-myc and c-erbB-2 were 67.9% and 50.6% respectively, and there were significant correlation in the amplification of these two genes (χ2 = 7.26, P < 0.01). Conclusions: The amplification of c-myc and c-erbB-2 may play an important role in gastric cancer development, and these two genes may have synergistic effect.
Effect of Si and P on Microstructure and Mechanical Properties of Mg-7Al-1Zn-3.597Cu-xSi Alloys
Keqiang Qiu,Xiaocheng Wang,Junhua You
Research of Materials Science , 2013,
Abstract: In order to improve the heat resistant properties of magnesium alloys, the effects of P modification on phase constituent, microstructure and mechanical properties of Mg-7Al-1Zn-3.597Cu-xSi (x=1, 2, 3) alloys were investigated by means of x-ray diffractometer (XRD), scanning electron microscopy (SEM), and universal electronic testing machine. The results indicate that the Mg2Si phase presented in the form of Chinese script shape was observed in the microstructure of the alloy without P element. The addition of P element can refine the microstructure by making Mg2Si phase change from Chinese script shape into block shape. The optimum properties with tensile strength, yield strength and elongation of 192.91 MPa, 115.42 MPa and 4.6% respectively are obtained for the alloy by adding 0.5% P and 1% Si elements. The mechanical properties of the alloys decrease with further increasing the Si content.
The Main Geological Events of the Chinese Archaean and Proterozoic Eons  [PDF]
Keqiang He, Rulin Du
Open Journal of Geology (OJG) , 2012, DOI: 10.4236/ojg.2012.23012
Abstract: A systematic review and comparison of the time, sequence, nature, and characteristics of the major geological events of worldwide Archean and Chinese Precambrian and their interrelationships reveals that these events reveals the spatial-temporal pattern of the events and their significance in geological evolution. The study also touches upon relationship between Early Precambrian Era and plate tectonics. A comparison between the Precambrian major geological events and those elsewhere on the earth proves that the crustal evolution is characterized by striking irreversibility, gradualism, and synchronism. The geological events in China have their unique features, which shows that China has a relatively complete record of formation and evolution of rocks, strata, structures, and organisms spanning 3800 Ma to 540 Ma. The Archean underwent multiple-stage complex metamorphism and deformation; metamorphism is on the higher end; komatiite is absent in the greenstone belts; cratonization occurred rather late and varied between the north and the south. The research results above provide main theoretical basis for deeply systematic researching the early dynamic evolution laws of the earth and the dynamic evolution characteristics of the tectonic plates.
How freezing and thawing processes affect black-soil aggregate stability in northeastern China

Feng Wang,XiaoZeng Han,LiangHao Li,KeQiang Zhang,

寒旱区科学 , 2010,
Abstract:
The Electrocatalysis of Multi-walled Carbon Nanotubes (MWCNTs) for Oxygen Reduction Reaction (ORR) in Room Temperature Ionic Liquids (RTILs)
Ding,Keqiang;
Portugaliae Electrochimica Acta , 2009,
Abstract: oxygen reduction reaction (orr) was investigated on a multi-walled carbon nanotubes (mwcnts)-modified edge plane pyrolytic graphite (eppg) electrode using cyclic voltammetry (cv) in three kinds of room temperature ionic liquids (rtils), i.e., 1-ethyl-3-methylimidazolium tetrafluoroborate (emibf4), 1-n-propyl-3-methylimida-zolium tetrafluoroborate (pmibf4), and 1-n-butyl-3-methylimidazolium tetrafluoro-borate (bmibf4). the results demonstrated that, after being modified by mwcnts on the eppg electrode, both the reduction peak current of oxygen and the oxidation peak current of superoxide anion were all dramatically increased, and the values of standard rate constant, κs, corresponding to orr, were greatly enhanced. under the same condition, in pmibf4, mwcnts-modified eppg electrode exhibited the most satisfied electrocatalysis for orr, in which standard rate constant, κs, was improved from 2.9 × 10-3 cm s-1 on a eppg electrode, to 10.4 × 10-3 cm s-1. while in emibf4 and bmibf4, after being modified by mwcnts, the value of κs was increased from 4.3 × 10-3 to 8.3 × 10-3 and 2.3 × 10-3 to 4.2 × 10-3 cm s-1, respectively. for the catalysis of mwcnts-modified eppg electrode towards orr, the enhanced surface area of electrode and the increased amount of ?defect? sites on electrode were thought to be the main reasons for our obtained results.
The Electrocatalysis of Multi-walled Carbon Nanotubes (MWCNTs) for Oxygen Reduction Reaction (ORR) in Room Temperature Ionic Liquids (RTILs)
Keqiang Ding
Portugaliae Electrochimica Acta , 2009,
Abstract: Oxygen reduction reaction (ORR) was investigated on a multi-walled carbon nanotubes (MWCNTs)-modified edge plane pyrolytic graphite (EPPG) electrode using cyclic voltammetry (CV) in three kinds of room temperature ionic liquids (RTILs), i.e., 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), 1-n-propyl-3-methylimida-zolium tetrafluoroborate (PMIBF4), and 1-n-butyl-3-methylimidazolium tetrafluoro-borate (BMIBF4). The results demonstrated that, after being modified by MWCNTs on the EPPG electrode, both the reduction peak current of oxygen and the oxidation peak current of superoxide anion were all dramatically increased, and the values of standard rate constant, κs, corresponding to ORR, were greatly enhanced. Under the same condition, in PMIBF4, MWCNTs-modified EPPG electrode exhibited the most satisfied electrocatalysis for ORR, in which standard rate constant, κs, was improved from 2.9 × 10-3 cm s-1 on a EPPG electrode, to 10.4 × 10-3 cm s-1. While in EMIBF4 and BMIBF4, after being modified by MWCNTs, the value of κs was increased from 4.3 × 10-3 to 8.3 × 10-3 and 2.3 × 10-3 to 4.2 × 10-3 cm s-1, respectively. For the catalysis of MWCNTs-modified EPPG electrode towards ORR, the enhanced surface area of electrode and the increased amount of “defect” sites on electrode were thought to be the main reasons for our obtained results.
Hydrothermal Synthesis of Leaf-Shaped Ferric Oxide Particles
Keqiang Ding
Journal of Chemistry , 2009, DOI: 10.1155/2009/389765
Abstract:
DISPLACEMENT FRACTAL PARAMETER HURST INDEX AND ITS APPLICATION TO PREDICTION OF DEBRIS LANDSLIDES
滑坡位移分形参数Hurst指数及其在堆积层滑坡预报中的应用

HE Keqiang,SUN Linna,WANG Sijing,
贺可强
,孙林娜,王思敬

岩石力学与工程学报 , 2009,
Abstract: 在系统分析堆积层滑坡的物质组成和位移失稳规律的基础上,根据分形理论基本原理,对该类滑坡的位移失稳过程所具有的非线性、突变性和分形降维特性进行较为深入的分析与研究.运用分形理论R/S分析法,确定滑坡位移时序分形动力学参数位移Hurst指数,并分别以三峡库区典型堆积层滑坡--新滩滑坡和黄蜡石滑坡为例,计算滑坡位移失稳过程的Hurst指数.分析和评价位移Hurst指数与边坡稳定性的关系,发现Hurst指数随着边坡由稳定向失稳的演化出现明显降维突变规律,且降维时间与滑坡整体失稳时间相吻合.这表明位移Hurst指数是堆积层边坡稳定性评价的一种有效非线性分形动力学参数,可以运用这个非线性分形参数对该类滑坡失稳演化趋势与规律进行非线性动力学评价与预测.
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