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| 1 | Investigation of RQD variation with scanline length and optimal threshold based on three-dimensional fracture network modeling显示文摘Rock-quality designation(RQD) plays a significant role in rock mass analysis and is an important parameter in geotechnical and geological engineering.However,the RQD variation with scanline length has not yet been comprehensively considered in RQD.In this study,three-dimensional fracture network modeling was used to simulate actual rock mass,and numerous scanlines were set in the fracture network for investigation on RQD variation.Models and equations(i.e.,models A-A,N-N,and A-A-S,as well as the Priest-Hudson and Sen-Kazi equations) were summarized for the study.A corrected equation was proposed to eliminate the errors from using the Priest-Hudson and Sen-Kazi equations.In addition,inhomogeneous and anisotropic features were investigated,and the optimal thresholds for RQD calculation were determined,which varied with the study orientation and rock mass feature.When the inhomogeneity was studied in the x direction,the optimal threshold was found to be 4 m.When anisotropy was studied,the optimal threshold was found to be 3 m. | ZHANG Wen CHEN JianPing WANG Qing MA DongHe NIU CenCen ZHANG Wu | 2013 | Chinese Science Bulletin2013，58，7： | 2 |
| 2 | Determination of water environment standards based on water quality criteria in China:Limitations and feasibilities显示文摘There is a need to formulate water environment standards(WESs) from the current water quality criteria(WQC) in China.To this end,we briefly summarize typical mechanisms applied in several countries with longer histories of developing WESs,and three limitations to formulating WESs in China were identified.After analyzing the feasibility factors including economic development,scientific support capability and environmental policies,we realized that China is still not ready for a complete change from its current nation-wide unified WES system to a local-standard-based system.Thus,we proposed a framework for transformation from WQC to WESs in China.The framework consists of three parts,including responsibilities,processes and policies.The responsibilities include research authorization,development of guidelines,and collection of information,at both national and local levels;the processes include four steps and an impact factor system to establish water quality standards;and the policies include seven specific proposals. | Tieyu Wang Yunqiao Zhou Cencen Bi Yonglong Lu Guizhen He John P.Giesy | 2017 | Journal of Environmental Sciences2017，29，7： | 1 |
| 3 | Perfluorinated compounds in water and sediment from coastal regions of the northern Bohai Sea, China显示文摘 | Chunli Chen Tieyu Wang JongSeong Khim Wei Luo Wentao Jiao Yonglong Lu JonathanE. Naile Wenyou Hu Xiang Zhang Jing Geng Cencen Bi Jing Li JohnP. Giesy | 2011 | Chemistry and Ecology2011，，2： | 1 |
| 4 | Application of principal component analysis to evaluation of black soil degradation in Jilin显示文摘Principal Component Analysis(PCA) can simplify the structure of database by replacing multi-dimensional parameters with relatively less comprehensive variables in order to ensure the minimum lost in initial data.In this paper,eighteen black soil samples from different sites were tested and thirteen distinctive indexes were chosen to evaluate the degeneration of black soil.By using principal component analysis,variables of thirteen dimensions can be diminished to six unrelated principal indexes.Analysis shows that the soluble salt content,Fulvic acids(FA) and aggregation degree have a high weighing coefficient,indicating these three indexes are the major parts for the evaluation of black soil degradation.It also provides a new path to the degenerated black soil treatment in Northeast China. | NIU Cencen WANG Qing WEN Xiuyu GUO Yuan ZHAGN Penglei ZHU Rongyue HE Xianhui | 2011 | Global Geology2011，14，1： | 1 |
| 5 | Hierarchical charge distribution controls self-assembly process of silk in vitro显示文摘 | YiZHANG Cencen ZHANG Lijie LIU David L. KAPLAN Hesun ZHU Qiang LU | 2015 | Frontiers of Materials Science2015，9，4： | 0 |
| 6 | Temporal Changes of Ecosystem Carbon Stocks in Rubber Plantationsin Xishuangbanna; Southwest China显示文摘Rubber(Hevea brasiliensis) plantations have been expanded rapidly in tropical regions of Southwest China and cover more than20% of land area in Xishuangbanna.Several studies have addressed changes of soil C stocks in rubber plantations;however,estimates of total ecosystem C stocks and their temporal changes in rubber plantations have been inadequately studied.This study calculated C stocks in soil,biomass,litter,and dry rubber(latex),and estimated the total ecosystem C stocks of rubber plantations in an age sequence of 3-,7-,9-,21-,27-,and 34-year-old in Xishuangbanna,Southwest China.The total C stocks in rubber plantations ranged from 150.3 to 283.7 Mg C ha^(-1),with a mean of 213.4 Mg C ha^(-1).The plantations≤9-year-old had significantly lower(P<0.05)total C stocks than those older than 9 years.Carbon stocks in soil(mass equivalent) were between 107.1–170.5 Mg C ha^(-1) and in living biomass were between 2.8–95.7 Mg C ha^(-1),representing the largest and the second largest C components in a rubber plantation ecosystem.Neglect of dry rubber C stock resulted in an underestimate of 7.8%–14.2% of the total C stock in the rubber plantations older than 9 years,which was much larger than the contribution of litter C stock(less than 2%). | SUN Yanci MA Youxin CAO Kunfang LI Hongmei SHEN Jinxiang LIU Wenjun DI Liang MEI Cencen | 2017 | Pedosphere2017，27，4： | 0 |
| 7 | Experimental study on grain size and soluble salt of saline soil in western Jilin Province, China显示文摘Western Jilin Province is a typical seasonal frost region, and is also one of the severest salinization areas of China. In this study, we aim to examine the saline soil in Da'an and Wukesong areas, western Jilin Province, and mainly analyze the granulometric composition and distribution of salt in soil profiles. Four sampling sites, two in Da'an and two in Wukesong respectively, are chosen for study. The granulometric composition, especially silt and clay content change in different sites and soil depths are analyzed. Analysis of total and components of soluble salt shows that the surface soil is weak carbonate saline, in which the main cation is Na+ and the main anion is HCO3-. The total amount of soluble salt presents a decreasing tendency with increasing depth. The comprehensive analysis of granulometric composition and soluble salt shows that the clay content and soluble salt content present similar variation tendency with an increase of depth. | Tian Wen Yu Qing Wang XuDong Zhang Xin Zhou Gang Wang CenCen Niu | 2015 | Research in Cold and Arid Regions2015，7，5： | 0 |
| 8 | A study of soil dispersivity in Qian'an, western Jilin Province of China显示文摘Saline soil is vulnerable to water erosion because of its dispersivity. This characteristic has a great influence on dam and slope engineering. There is a large area of saline soil in western Jilin Province, the seasonal frost zone, and this soil is highly dispersive. We studied the properties of soil samples collected from vertical holes near Qian'an Dabusu Lake, assessing the particle size distribution and the chemical components. We also comprehensively identified the level of soil dispersivity by three standard methods, the pinhole test, the crumb test, and the double-hydrometer test. The soil composition and basic physicochemical properties are proved to be the most important factors which determine the dispersion degree of the saline soil. Our results showed that, within depth ranges from 0 to 1 m, silt particles highly influenced the soil dispersivity, and the total soluble salt accounted for ≥0.3%. At the first sampling point, in a tall soil column, the dispersion degree decreased with increasing depth, but this was not as obvious at the second sampling point, which was in a flat area. Nevertheless, the superficial soils of these two sampling sites were strongly dispersive, which must be taken into consideration for soil engineering in this region. | XuDong Zhang Qing Wang TianWen Yu ShuoChao Bao Gang Wang Xin Zhou CenCen Niu | 2015 | Research in Cold and Arid Regions2015，7，5： | 0 |
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