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412篇 您的检索式:作者名="Dongsheng Zhang"
    题名 作者 年代 出处 被引量
1Spatial patterns and driving forces of land use change in China during the early 21st century显示文摘Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the 'Grain for Green' policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of 'Western Development', 'Revitalization of Northeast', coupled with rapidly economic development during this period.LIU Jiyuan ZHANG Zengxiang XU Xinliang KUANG Wenhui ZHOU Wancun ZHANG Shuwen LI Rendong YAN Changzhen YU Dongsheng WU Shixin JIANG Nan 2010Journal of Geographical Sciences2010,20,4:154
2Spatiotemporal characteristics, patterns, and causes of land-use changes in China since the late 1980s显示文摘Land-use/land-cover 变化(LUCC ) 有连接到人和自然相互作用。瓷器 Land-Use/cover 数据集(CLUD ) 从 1980 年代末在 5 年的间隔定期被更新到 2010,与基于 Landsat TMETM+ 图象的标准过程。陆地使用动态区域化方法被建议分析主要陆地使用变换。在国家规模的陆地使用变化的空间与时间的特征,差别,和原因然后被检验。主要调查结果如下被总结。越过中国的陆地使用变化(LUC ) 在最后 20 年(19902010 ) 里在空间、时间的特征显示了一个重要变化。农田变化的区域在南方减少了并且在北方,而是仍然是的全部的区域增加了几乎未改变。回收农田从东北被转移到西北。布满建筑物陆地很快膨胀了,主要在东方被散布,并且逐渐地展开到中央、西方的中国。树林首先减少了,然后增加但是荒芜的区域是反面。草地继续减少。在中国的 LUC 的不同空间模式被发现在之间迟了第 20 世纪并且早第 21 世纪。原版 13 个 LUC 地区在一些地区被边界的变化由 15 个单位代替。包括的这些变化(1 ) 的主要空间特征加速的扩大布满建筑物在 Huang-Huai-Hai 区域,东南的沿海的区域,长江的中流区域,和四川盆登陆;(2 ) 从东北中国和东方内部蒙古在北方转移了陆地开垦到绿洲在西北中国的农业区域;(3 ) 从在到稻的东北中国的喂雨的农田的连续转变回答;并且(4 ) 为在内部蒙古,黄土高原,和西南的多山的区域的南部的农业牧剧的交错群落的格林工程的谷物的有效性。在最后二十年,尽管在北方的气候变化在农田影响了变化,政策规定和经济驱动力仍然是越过中国的 LUC 的主要原因。在第 21 世纪的第一十年期间,在陆地使用模式驾驶了变化的人为的因素从单程的陆地开发转移了强调到开发和保存。动态区域化方法被用来在单位的 zoning 边界,地区的内部特征,和生长和减少的空间模式分析变化。结果揭示了变化过程的模式,也就是 LUC 的过程和在在不同阶段的特征的地区性的差别。地区的生长和减少在这动态 LUC zoning,在统一边界的变化,和在前者和后者十年之间的变化紧张的特征期间被检验。在为在不同类型和陆地使用的不同区域的变化的陆地使用和原因的模式和过程之间的其他的转变的模式被探索。LIU Jiyuan KUANG Wenhui ZHANG Zengxiang XU Xinliang QIN Yuanwei NING Jia ZHOU Wancun ZHANG Shuwen LI Rendong YAN Changzhe WU Shixin SHI Xuezheng JIANG Nan YU Dongsheng PAN Xianzhang CHI Wenfeng 2014Journal of Geographical Sciences2014,24,2:245
3Mechanism for the formation of the January 2013 heavy haze pollution episode over central and eastern China显示文摘In January 2013,a long-lasting episode of severe haze occurred in central and eastern China,and it attracted attention from all sectors of society.The process and evolution of haze pollution episodes were observed by the'Forming Mechanism and Control Strategies of Haze in China'group using an intensive aerosol and trace gases campaign that simultaneously obtained data at 11 ground-based observing sites in the CARE-China network.The characteristics and formation mechanism of haze pollution episodes were discussed.Five haze pollution episodes were identified in the Beijing-Tianjin-Hebei(Jing-Jin-Ji)area;the two most severe episodes occurred during 9–15 January and 25–31 January.During these two haze pollution episodes,the maximum hourly PM2.5mass concentrations in Beijing were 680 and 530μg m 3,respectively.The process and evolution of haze pollution episodes in other major cities in the Jing-Jin-Ji area,such as Shijiazhuang and Tianjin were almost the same as those observed in Beijing.The external cause of the severe haze episodes was the unusual atmospheric circulation,the depression of strong cold air activities and the very unfavorable dispersion due to geographical and meteorological conditions.However,the internal cause was the quick secondary transformation of primary gaseous pollutants to secondary aerosols,which contributed to the'explosive growth'and'sustained growth'of PM2.5.Particularly,the abnormally high amount of nitric oxide(NOx)in the haze episodes,produced by fossil fuel combustion and vehicle emissions,played a direct or indirect role in the quick secondary transformation of coal-burning sulphur dioxide(SO2)to sulphate aerosols.Furthermore,gaseous pollutants were transformed into secondary aerosols through heterogeneous reactions on the surface of fine particles,which can change the particle’s size and chemical composition.Consequently,the proportion of secondary inorganic ions,such as sulphate and nitrate,gradually increased,which enhances particle hygroscopicity and thereby accelerating formation of the haze pollution.WANG YueSi YAO Li WANG LiLi LIU ZiRui JI DongSheng TANG GuiQian ZHANG JunKe SUN Yang HU Bo XIN JinYuan 2014Science China Earth Sciences2014,57,1:189
4Contrasting trends of PM2.5 and surface-ozone concentrations in China from 2013 to 2017显示文摘Although much attention has been paid to investigating and controlling air pollution in China,the trends of air-pollutant concentrations on a national scale have remained unclear.Here,we quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017,during which Chinese government made major efforts to reduce anthropogenic emission in polluted regions.Our results show a significant decreasing trend in the PM2.5 concentration in heavily polluted regions of eastern China,with an annual decrease of〜7%compared with measurements in 2013.The measured decreased concentrations of SO2>NO2 and CO(a proxy for anthropogenic volatile organic compounds)could explain a large fraction of the decreased PM2.5 concentrations in different regions.As a consequence;the heavily polluted days decreased significantly in corresponding regions.Concentrations of organic aerosol;nitrate;sulfate,ammonium and chloride measured in urban Beijing revealed a remarkable reduction from 2013 to 2017;connecting the decreases in aerosol precursors with corresponding chemical components closely.However;surface-ozone concentrations showed increasing trends in most urban stations from 2013 to 2017;which indicates stronger photochemical pollution.The boundary-layer height in capital c让ies of eastern China showed no significant trends over the Beijing-Tianjin-Hebei,Yangtze River Delta and Pearl River Delta regions from 2013 to 2017;which confirmed the reduction in anthropogenic emissions.Our results demonstrated that the Chinese government was successful in the reduction of particulate matter in urban areas from 2013 to 2017,although the ozone concentration has increased significantly;suggesting a more complex mechanism of improving Chinese air quality in the future.Yonghong Wang Wenkang Gao Shuai Wang Tao Song Zhengyu Gong Dongsheng Ji Lili Wang Zirui Liu Guiqian Tang Yanfeng Huo Shili Tian Jiayun Li Mingge Li Yuan Yang Biwu Chu Tuukka Petaja Veli-Matti Kerminen Hong He Jiming Hao Markku Kulmala Yuesi Wang Yuanhang Zhang 2020National Science Review2020,7,8:51
5Transmission Dynamics of an Outbreak of the COVID-19 Delta Variant B.1.617.2——Guangdong Province,China,May-June 2021显示文摘On May 21,2021,a local case of coronavirus disease 2019(COVID-19)was confirmed in a 75-year-old woman(experienced onset of symptoms on May 18)in Liwan District,Guangzhou City,Guangdong Province,China.The number of infections has increased in the following 10 days and led to 5 generations of transmission.Meng Zhang Jianpeng Xiao Aiping Deng Yingtao Zhang Yali Zhuang Ting Hu Jiansen Li Hongwei Tu Bosheng Li Yan Zhou Jun Yuan Lei Luo Zimian Liang Youzhi Huang Guoqiang Ye Mingwei Cai Gongli Li Bo Yang Bin Xu Ximing Huang Yazun Cui Dongsheng Ren Yanping Zhang Min Kang Yan Li 2021China CDC weekly2021,3,27:51
6In vitro derivation of functional insulin-producing cells from human embryonic stem cells显示文摘为人的胚胎的茎(ES ) 的自强和区别的能力细胞为对待类型 Idiabetes mellitus 为胰腺的贝它细胞的产生使他们成为潜在的来源。这里,我们报导一最新发展了并且有效方法,在aserum免费的系统执行了,区分进生产胰岛素的 cells.Activin A 的导致的人的 ES 房间它在起始的阶段被使用从人的 EScells 导致权威的内胚叶区别,是由权威的内胚叶标记 Sox17 和 Brachyury.Further 的表示检测了, all-trans retinoic 酸( RA )被用来支持胰腺的区别,由早胰腺的抄写因素 pdx1 和 hlxb9 的表示显示了。在成熟 inDMEM/F12 以后有 bFGF 和菸碱的没有浆液的媒介,区分的房间表示了小岛特定的标记象 C 肽,胰岛素,胰高血糖素和 glut2 那样。百分比 ofC-peptide-positive 房间超过了 15% 。由这些房间的胰岛素和 C 肽的分泌物在葡萄糖层次对应于变化。当移植了进肾的囊时, ofStreptozotocin (STZ ) 对待裸体老鼠,这些区分的人的 ES 房间熬过并且维持贝它房间标记基因的表示包括 C 肽, pdx1, glucokinase, nkx6.1, IAPP, pax6and Tcf1。百分之三十只移植裸体老鼠展出了 stableeuglycemia 的明显的恢复;并且改正的显型被支撑超过六个星期。我们的新方法为学习人的胰开发的机制提供一个有希望的试管内区别模特儿并且说明为类型 Idiabetes mellitus 的处理使用人的 ES 房间的潜力。Wei Jiang Yan Shi Dongxin Zhao Song Chen Jun Yong Jing Zhang Tingting Qing Xiaoning Sun Peng Zhang Mingxiao Ding Dongsheng Li Hongkui Deng 2007Cell Research2007,17,4:38
7Review of nanofluids for heat transfer applications显示文摘Research on nanofluids has progressed rapidly since its enhanced thermal conductivity was first reported about a decade ago,though much controversy and inconsistency have been reported,and insufficient understanding of the formulation and mechanism of nanofluids further limits their applications.This work presents a critical review of research on heat transfer applications of nanofluids with the aim of identifying the limiting factors so as to push forward their further development.Dongsheng Wen Guiping Lin Saeid Vafaei Kai Zhang 2009Particuology2009,7,2:30
8Modeling net primary productivity of the terrestrial ecosystem in China from 1961 to 2005显示文摘网络主要生产率(NPP ) 是代表生态系统的结构和函数的最重要的索引。NPP 能被动态全球植被模型(DGVM ) 模仿,它被设计相对环境变化代表植被动力学。这研究在气候,土壤,和地形学上与数据基于 DGVM 综合生物圈模拟器(朱鹭) 模仿了瓷器生态系统的 NPP。在瓷器陆上的生态系统的 NPP 模拟的朱鹭的适用性首先被验证。有另外的相关研究的比较显示范围和模拟的吝啬的价值通常在观察的限制以内;全面模式和全部的年度 NPP 接近与另外的模型一起进行的模拟。模拟基于遥感离 NPP 评价也靠近。确认证明那朱鹭能在瓷器自然生态系统在 NPP 的大规模模拟被利用。我们然后从 1961 ~ 2005 与气候变化数据模仿了 NPP,当温暖是特别地惹人注目的时。下列是模拟的结果。(1 ) 全部的 NPP 在过去的 45 年里从 3.61 GtC/yr 变化了到 4.24 GtC/yr 并且展出了最小的重要线性增加或减少。(2 ) 在增加的地区性的差别或在 NPP 的减少大,但是展出了一个不足道的全面线性趋势。NPP 在大多数部分衰退了东方并且华中,特别在黄土高原。(3 ) 类似于年度 NPP 的变化法律,季节的 NPP 也显示了不足道的增加或减少;趋势线在一般水平以内。(4 ) 在季节的 NPP 变化的地区性的差别大。NPP 在黄土高原在春天,夏天,和秋天衰退了,但是在西藏的高原的大多数部分增加了。YUAN Quanzhi WU Shaohong ZHAO Dongsheng DAI Erfu CHEN Li ZHANG Lei 2014Journal of Geographical Sciences2014,24,1:27
9Neoproterozoic Mafic Dykes and Basalts in the Southern Margin of Tarim,Northwest China:Age,Geochemistry and Geodynamic Implications显示文摘Neoproterozoic 裂缝相关的 mafic 火的岩石广泛地在塔里姆·布洛克,的北、南部的边缘两个都被散布 NW 中国。这里,我们沿着 Tarim 的南部的边缘报导地球年代学和 Neoproterozoic mafic 女同性恋和暗岩的系统的整个岩石的地球化学。在有在他们的炮兵阵地年龄的 stratigraphic 限制的联合,我们的锆石 U-Pb 年龄显示 mafic 女同性恋在 ca 被使结晶。802 妈,和暗岩,与 ca 可能同时代。在在 Tarim 的北边缘的 Quruqtagh 的 740 妈暴烈的岩石。元素并且女同性恋和暗岩建议的 mafic 的 Nd 同位素地球化学他们的原始岩浆分别地从 asthenospheric 披风(象 OIB 一样) 和 lithospheric 披风被导出,与外壳的材料的可变吸收。集成在现在的学习和那供应的数据在 Tarim 的北边缘以前报导了,我们认出 Neoproterozoic mafic 的披风来源的二种类型在 Tarim 的火的岩石,也就是在北边缘的 matasomatized subcontinental lithospheric 披风( SCLM )和在南部的边缘的 asthenospheric 披风。在整个塔里姆·布洛克的 Neoproterozoic 火的岩石的全面合成在 ca 导致了 Neoproterozoic 火的活动的二个主要事件的识别。820800 妈和 ca。780740 妈分别地。火的活动的这二个事件与在许多另外的 Rodinian 大陆的那些是并发的并且在 Rodinia 的分散期间与披风羽毛活动有关是最可能的。ZHANG Chuanhn YANG Dongsheng WANG Hongyan DONG Yongguan YE Haimin 2010Acta Geologica Sinica(English Edition)2010,84,3:26
10Trends in particulate matter and its chemical compositions in China from 2013–2017显示文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemical components(MI)dropped by 70%,24%and 13%in BTH,the PRD and the Fenhe and Weihe River Plain,respectively.The change in the PM2.5 chemical composition is consistent with the decrease of the PM2.5mass concentration.(3)In 2015,the mean OM concentration contributions to fine particles and coarse particles were 13-46%and 46-57%,respectively,and the mean MI concentration contributions to fine particles and coarse and particles were 31-60%and 39-73%,respectively;these values are lower than the 2013 values from the key regions,which is the most important factor behind the decrease of the particulate matter mass concentration.From 2013 to 2015,among the chemical components of different particle size fractions,the peak value of the coarse particle size fraction decreased significantly,and the fine particle size fractions of SO42-,NO3-,and NH4+decreased with the decrease of the particulate matter mass concentration in different particle size fractions.The fine-particle size peaks of SO42-,NO3-and NH4+shifted from 0.65-1.1μm to the finer size range of0.43-0.65μm during the same time frame.Yuesi WANG Wenjie LI Wenkang GAO Zirui LIU Shili TIAN Rongrong SHEN Dongsheng JI Shuai WANG Lili WANG Guiqian TANG Tao SONG Mengtian CHENG Gehui WANG Zhengyu GONG Jiming HAO Yuanhang ZHANG 2019Science China Earth Sciences2019,62,12:23
11Characterization of volatile organic compounds in the urban area of Beijing from 2000 to 2007显示文摘Beijing is one of the most polluted cities in the world.In this study,the long-term and continuous measurements of volatile organic compounds (VOCs) in the urban area of Beijing,specifically at Beijing 325 m Meteorological Tower,were conducted from 2000 to 2007.The annual record of VOC trends exhibited in two different phases was separated in 2003.Records show that VOC concentrations increased from 2000 to 2003 due to the abrupt increase in vehicle number.Contrarily,since 2003,there had been a decrease in VOCs concentrations as the policy on gasoline and air pollution was implemented.Toluene,benzene,and i-pentane are the chemicals that abound in and are directly related to vehicle activity,such as in vehicle exhaust and gasoline evaporation.Furthermore,records indicate that there had been seasonal variation in VOCs levels in that VOCs level in summer is higher than that in winter.As such,temperature is considered to significantly contribute to VOCs in Beijing.Records also show that VOCs level was high in the morning and during rush hours in the evening.In contrast,VOCs level was low during midday due to photochemical destruction with OH radical and dilution effect.In this study,a particular benzene to toluene ratio range (0.4-1.0) was used as the indicator of air propelled by vehicular exhaust.We also applied the correlation coefficients between BTEX and i-pentane to evaluate evaporation influence to ambient BTEX in the Beijing urban area.Yuesi Wang Xiyan Ren Dongsheng Ji Junqang Zhang Jie Sun Fankun Wu 2012Journal of Environmental Sciences2012,24,1:21
12NPP vulnerability of the potential vegetation of China to climate change in the past and future显示文摘用综合生物圈模拟器,一个动态植被模型,这研究开始模仿了网过去的 55 年(1961-2015 ) 里并且在未来的瓷器潜在的植被的主要生产率(NPP ) 动力学 35 年(2016-2050 ) 。然后,在平均气候拿潜在的植被的 NPP 作为评估的基础在 1986-2005 期间调节,这研究检验了潜在的植被是否适应气候变化。同时,无适应性的度被评估。最后,潜在的植被的 NPP 危险被综合评估到气候的无适应性的频率和度变化。在过去的 55 年里,在 Tianshan 山的南方的荒芜的生态系统和在中国的北方并且在西方的西藏的高原的草地生态系统的 NPP 对气候变化的效果敏感。大多数森林生态系统的 NPP 不对气候变化的影响敏感。对气候变化的低 NPP 弱点常绿树阔叶、具球果的森林被观察。而且,在在中央、东方的西藏的高原的 Tianshan 山脉和草地生态系统的北方的荒芜的生态系统的 NPP 也有低危险到气候变化。在下一 35 年里,对气候变化的 NPP 弱点将在中央、西方的西藏的高原在 Songliao 平原,在温暖的适度的地区的脱落阔叶的森林,和高山的大草原减少森林大草原。NPP 危险将显著地在 Kunlun 山在 Junggar 盆和高山的沙漠适度的沙漠增加。NPP 危险副热带常绿树阔叶的森林将也增加。有增加的危险的区域的区域将说明 27.5% 中国。YUAN Quanzhi WU Shaohong DAI Erfu ZHAO Dongsheng REN Ping ZHANG Xueru 2017Journal of Geographical Sciences2017,27,2:21
13Meteorological mechanism for a large-scale persistent severe ozone pollution event over eastern China in 2017显示文摘An intensive and persistent regional ozone pollution event occurred over eastern China from 25 June to 5 July 2017.73 out of 96 selected cities,most located in the Beijing-TianjinHebei and the surrounding area(BTHS),suffered severe ozone pollution.A north-south contrast ozone distribution,with higher ozone(199±33μg/m3)in the BTHS and lower ozone(118±25μg/m^3)in the Yangtze River Delta(YRD),was found to be dominated by the position of the West Pacific Subtropical High(WPSH)and mid-high latitude wave activities.In the BTHS,the positive anomalies of geopotential height at 500 hPa and temperature at the surface indicated favorable meteorological conditions for local ozone formation.Prevailing northwesterly winds in the mid-high troposphere and warm advection induced by weak southerly winds in the low troposphere resulted in low-moderate relative humidity(RH),less total cloud cover(TGC),strong solar radiation and high temperatures.Moreover,southerly winds prevailing over the BTHS aggravated the pollution due to regional transportation of O3 and its precursors.On one hand,the deep sinking motion and inversion layer suppressed the dispersion of pollutants.On the other hand,O3-rich air in the upper layer was maintained at night due to temperature inversion,which facilitated O3 vertical transport to the surface in the next-day morning due to elevated convection.Generally,temperature,UV radiation,and RH showed good correlations with O3 in the BTHS,with rates of 8.51(μg/m^3)/℃(within the temperature range of 20-38℃),59.54(μg/m^3)/(MJ/m^2)and-1.93(μg/m^3)/%,respectively.Jia Mao Lili Wang Chuhan Lu Jingda Liu Mingge Li Guiqian Tang Dongsheng Ji Nan Zhang Yuesi Wang 2020Journal of Environmental Sciences2020,32,6:18
14Type Synthesis of Two-Degrees-of-Freedom Rotational Parallel Mechanism with Two Continuous Rotational Axes显示文摘The two-rotational-degrees-of-freedom(2R) parallel mechanism(PM) with two continuous rotational axes(CRAs) has a simple kinematic model.It is therefore easy to implement trajectory planning,parameter calibration,and motion control,which allows for a variety of application prospects.However,no systematic analysis on structural constraints of the 2R-PM with two CRAs has been performed,and there are only a few types of 2R-PM with two CRAs.Thus,a theory regarding the type synthesis of the 2R-PM with two CRAs is systematically established.First,combining the theories of reciprocal screw and space geometry,the spatial arrangement relationships of the constraint forces applied to the moving platform by the branches are explored,which give the 2R-PM two CRAs.The different distributions of the constraint forces in each branch are also studied.On the basis of the obtained structural constraints of branches,and considering the geometric relationships of constraint forces in each branch,the appropriate kinematic chains are constructed.Through the reasonable configuration of branch kinematic chains corresponding to every structural constraint,a series of new 2R-PMs with two CRAs are finally obtained.XU Yundou ZHANG Dongsheng WANG Min YAO Jiantao ZHAO Yongsheng 2016Chinese Journal of Mechanical Engineering2016,29,4:17
15Groundwater arsenic removal by coagulation using ferric(Ⅲ)sulfate and polyferric sulfate: A comparative and mechanistic study显示文摘Elevated arsenic(As) in groundwater poses a great threat to human health. Coagulation using mono- and poly-Fe salts is becoming one of the most cost-effective processes for groundwater As removal. However, a limitation comes from insufficient understanding of the As removal mechanism from groundwater matrices in the coagulation process, which is critical for groundwater treatment and residual solid disposal. Here, we overcame this hurdle by utilizing microscopic techniques to explore molecular As surface complexes on the freshly formed Fe flocs and compared ferric(III) sulfate(FS) and polyferric sulfate(PFS)performance, and finally provided a practical solution in As-geogenic areas. FS and PFS exhibited a similar As removal efficiency in coagulation and coagulation/filtration in a two-bucket system using 5 mg/L Ca(ClO)_2. By using the two-bucket system combining coagulation and sand filtration, 500 L of As-safe water(< 10 μg/L) was achieved during five treatment cycles by washing the sand layer after each cycle. Fe k-edge X-ray absorption near-edge structure(XANES) and As k-edge extended X-ray absorption fine structure(EXAFS) analysis of the solid residue indicated that As formed a bidentate binuclear complex on ferrihydrite, with no observation of scorodite or poorly-crystalline ferric arsenate. Such a stable surface complex is beneficial for As immobilization in the solid residue, as confirmed by the achievement of much lower leachate As(0.9 μg/L–0.487 mg/L)than the US EPA regulatory limit(5 mg/L). Finally, PFS is superior to FS because of its lower dose, much lower solid residue, and lower cost for As-safe drinking water.Jinli Cui Chuanyong Jing Dongsheng Che Jianfeng Zhang Shuxuan Duan 2015Journal of Environmental Sciences2015,27,6:16
16Underground pressure characteristics analysis in back-gully mining of shallow coal seam under a bedrock gully slope显示文摘我们在一个基岩溪谷斜坡下面在浅煤缝接在背溪谷采矿期间学习了地下的压力和它的机制,借助于物理模拟,数字建模并且地监视。结果证明地下的压力的紧张与它在 coalface 的相对位置有关。地下的压力是集中的,当 coalface 在溪谷的底部时,支持抵抗到达最大值,而地下的压力是中等的并且当 coalface 传递溪谷时,逐渐地减少。当斜坡在不稳定的、多边的块依赖了的采矿和形式组织的背溪谷期间在一个颠倒的方向旋转了到斜坡剧降时,这些变化的机制被分析,由于滑倒。当块破碎是小的时,多边的块的沉淀是可观的,导致在地下的压力的庞大的变化。随块身体的团的增加,块排水量将被减少与一起一增加在废矿由未破损的岩石和破岩石夹钳效果,导致地下的压力的减少。Wang Xufeng Zhang Dongsheng Fan Gangwei Zhang Chengguo 2011Mining Science and Technology2011,21,1:16
17Supercritical fluids technology for clean biofuel production显示文摘Biofuels are liquid or gaseous fuels that are predominantly produced from biomass for transport sector applications. As biofuels are renewable, sustainable, carbon neutral and environmentally benign, they have been proposed as promising alternative fuels for gasoline and diesel engines. This paper reviews state-of-the-art application of the supercritical fluid (SCF) technique in biofuels production that includes biodiesel from vegetable oils via the transesterification process, bio-hydrogen from the gasification and bio-oil from the lique- faction of biomass, with biodiesel production as the main focus. The global biofuel situation and biofuel economics are also reviewed. The SCF has been shown to be a promising technique for future large-scale biofuel production, especially for biodiesel production from waster oil and fat. Compared with conventional biofuel production methods, the SCF technology possesses a number of advantages that includes fast kinetics, high fuel production rate, ease of continuous operation and elimination of the necessity of catalysts. The harsh operation environment, i.e. the high temperature and high pressure, and its request on the materials and associated cost are the main concerns for its wide application.Dongsheng Wen H. Jiang Kai Zhang 2009Progress in Natural Science:Materials International2009,19,3:15
18Ages of the Laocheng Granitoids and Crustal Growth in the South Qinling Tectonic Domain,Central China:Zircon U-Pb and Lu-Hf Isotopic Constraints显示文摘Laocheng granitoid pluton 位于 Qinling erogenic 带的南方 Qinling 构造领域,南部的 Shaanxi 省,并且由石英闪长岩, granodiorite 和 monzogranite 主要组成。LA-ICP-MS 锆石 U-Pb 与阴极射线发光图象一起,同位素的标明日期表明石英闪长岩和 granodiorite 是从 220 妈的 emplaced 到 216 妈,当 monzogranite 是在 210 妈的 emplaced 时。在原处,锆石 Hf 同位素的分析证明从 8.1 的石英闪长岩和到 +1.3 的 granodiorite 范围的 Hf (t)价值,和单个阶段的 Hf 从 809 妈为年龄建模到 1171 妈,当 monzogranite 的 Hf (t)价值是 14.5 到 +16.7 和单个阶段的 Hf 时,从 189 妈为年龄建模到 1424 妈。这些 Hf 同位素的特征表明石英闪长岩, granodiorite 和 monzogranite 从混合从弄空的披风和更低的大陆的部分融化导出的岩浆被形成外壳的材料,并且在 Neoproterozoic ( 800 妈)和 Indosinian ( 210 妈)期间有大陆人外壳生长的二个阶段分别地,时代在 Qinling orogrnic 的南方 Qinling 构造领域系上带子,华中。YANG Pengtao LIU Shuwen LI Qiugen ZHANG Fan WANG Zongqi WANG Dongsheng WANG Ruiting YAN Quanren YAN Zhen 2011Acta Geologica Sinica(English Edition)2011,85,4:15
19Porosity and permeability evolution and evaluation in anisotropic porosity multiscale-multiphase-multicomponent structure显示文摘Based on the hybrid hypersingular integral equation-lattice Boltzmann methods (HHIE-LBM), the porosity and permeability evolution and evaluation process in anisotropic saturated porosity multiscale-multiphase-multicomponent (ASP-MS-MP-MC) structures under ultra high temperature and pressure conditions was analyzed on parallel CPU and GPU platforms. First, virtual physical models at multi-spatial scales (2 μm, 5 μm and 10 μm) were restructured by computerized microtomography technology and data. Second, using HHIE-LBM methods, the anisotropic porosity and permeability tensor at core level and pore level under ultra high temperature and pressure conditions were calculated. Third, the evolution and evaluation process of the porosity and permeability as a function of multi temporal spatial scales was investigated. Finally, the relationship between porosity and permeability and ASP-MS-MP-MC structures (micro-meso-macro-scale) was explored.ZHU BoJing CHENG HuiHong QIAO YanChao LIU Chang SHI YaoLin ZHANG Kai SUN DongSheng LIN WeiRen 2012Chinese Science Bulletin2012,57,4:11
20Enhancement of Fenton oxidation for removing organic matter from hypersaline solution by accelerating ferric system with hydroxylamine hydrochloride and benzoquinone显示文摘Fenton oxidation is generally inhibited in the presence of a high concentration of chloride ions.This study investigated the feasibility of using benzoquinone(BQ) and hydroxylamine hydrochloride(HA) as Fenton enhancers for the removal of glycerin from saline water under ambient temperature by accelerating the ferric system.It was found that organics removal was not obviously affected by chloride ions of low concentration(less than 0.1 mol/L),while the mineralization rate was strongly inhibited in the presence of a large amount of chloride ions.In addition,ferric hydrolysis-precipitation was significantly alleviated in the presence of HA and BQ,and HA was more effective in reducing ferric ions into ferrous ions than HA,while the H_2O_2 decomposition rate was higher in the BQ-Fenton system.Electron spin resonance analysis revealed that OH production was reduced in high salinity conditions,while it was enhanced after the addition of HA and BQ(especially HA).This study provided a possible solution to control and alleviate the inhibitory effect of chloride ions on the Fenton process for organics removal.Siwei Peng Weijun Zhang Jie He Xiaofang Yang Dongsheng Wang Guisheng Zeng 2016Journal of Environmental Sciences2016,28,3:10
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