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Virus rejection with two model human enteric viruses in membrane bioreactor system

Science china Chemistry 2007年第3期50卷 397-404页

作者： ZHENG Xiang1,2 & LIU JunXin1 1 Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, beijing 100085, china 2 school of environment & natural resources, renmin university of china, beijing 100872, china 1. Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China 2. school of environment & natural resources Renmin University of China Beijing 100872 China

A membrane bioreactor (MBR) with gravity drain was tested for virus rejection with two coliphages, T4 and f2, which were used as surrogates for human enteric viruses. Virus rejection was investigated by PVDF and PP membrane modules, with the pore sizes of 0.22 and 0.1 μm, respectively. In tap water system, 2.1 lg rejection of coliphage T4 could be achieved by PVDF membrane compared with complete rejection by PP membrane, while for coliphage f2 with smaller diameter, 0.3―0.5 lg rejection of the influent virus was removed by the two membranes. In domestic wastewater system, cake layer and gel layer on the membrane surface changed the cut-off size of the membrane so that there was no significant difference between PP and PVDF for each coliphage. The removal ratios of coliphage T4 and f2 in the MBR were more than 5.5 and 3.0 lg, respectively. Compared with 5.5 lg removal for virus T4 in the MBR system, only 2.1 lg (96.8%―99.9%) removal rate was observed in the conventional activated sludge system with the influent virus concentration fluctuating from 1830 to 57000 PFU/mL. Only 0.8%―22% virus removal was the effect of adsorption to activated sludge, which showed a decreasing tendency with the retention time, while 75%―98% was the effect of virus inactivation by microbial activity. It indicated that the major mechanism of virus removal was not the transfer of viruses from the water phase to the sludge phase but inactivation in the biological treatment process.

关键词： MBR model virus enteric virus inactivation

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Emission Patterns under Alternative Congestion and Motor Vehicle Pollution Mitigation Policies in Shanghai

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Chinese Journal of Population,resources and environment 2007年第2期5卷 41-48页

作者： Chen Hongfeng1, Li Fen1, Li Xiangling2 1. school of environment and natural resources, renmin university of china, beijing 100872, china 2. school of natural resources and environment, Hefei university of Technology, Hefei Anhui 230009, china school of environment and natural resources Renmin University of China Beijing 100872 China school of natural resources and environment Hefei University of Technology Hefei Anhui 230009 China

As a megacity with thriving economy, Shanghai is experiencing rapid motorisation and confronted with traffic congestion problems despite its low car ownership. It is of value to look into the policies on emission control of motor vehicle and congestion reduction in such a city to explore how to reconcile mobility enhancement with the environment. Results of a dynamic simulation displayed time paths of emissions from motor vehicles in Shanghai over the period from 2000 to 2020. The simulation results showed that early policies on emission control of motor vehicle could bring about far-reaching effects on emission reduc- tion, and take advantage of available low-polluting technologies and technical innovation over time. Travel demand management would play an important role in curbing congestion and reducing motor vehicle pollution by calming down car ownership rise and deterring inefficient trips as well as reducing fuel waste caused by congestion.

关键词： dynamic simulation motorisation motor vehicle emission traffic congestion travel demand management low-polluting technologies

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Ruin probability of the renewal model with risky investment and large claims

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Science china Mathematics 2009年第7期52卷 1539-1545页

作者： WEI Li school of Finance,renmin university of china,beijing 100872,china 1. school of Finance Renmin University of China Beijing 100872 China

The ruin probability of the renewal risk model with investment strategy for a capital market index is investigated in this *** claim sizes with common distribution of extended regular variation,we study the asymptotic behaviour of the ruin *** a corollary,we establish a simple asymptotic formula for the ruin probability for the case of Pareto-like claims.

关键词： asymptotics extended regular variation renewal risk model risky investment strategy ruin probability 60G70 60K30 60K37

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ANALYSIS OF CAPITAL FLOW WITH GIS——Two Approaches for Regional Investment in china

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Chinese Geographical Science 2003年第1期13卷 2-8页

作者： YAO Yong-ling ( Public Administration school, renmin university of china, beijing 100872, P. R. china) Public Administration school Renmin University of China Beijing 100872 P. R. China

GIS technology has been mostly concerned with handling physical data andmodeling physical environment. However, the retirements of GIS for handling socio-economicinformation in many cases are different from those concerning phenomena in the physical *** of capital flow among regions requires the transitions both from economic values tophysical landscape and from physical surface to economic explanation. Rapid growth of Chineseeconomy comes mainly from investment. There are two main ways for obtaining high growth ofinvestment. One is government expenditure which usually invests in regional facility and amenityblock, which is regarded as stimulus for attracting investment. The other is the creation ofinvesting center and corresponding capital source areas, both of which need the central city withthe highest growth rate of investment among regions. This paper presents the cluster areas of bothgovernment revenue and total investment, the potential situation of capital flow between centralcity Shanghai and its neighbor provinces by using Classification' and Interpolation' functions ofArcView GIS.

关键词： capital flow geographic information system (GIS) regional investment cluster analysis

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An application of the Riemann-Roch theorem

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Science china Mathematics 2008年第4期51卷 765-772页

作者： WANG ShiKun~1 ZHANG HuiPing~(2+) 1 KLMM and IAM AMSS Chinese Academy of Sciences beijing 100080 china 2 school of Information renmin university of china beijing 100872 china 1. KLMM and IAM AMSS Chinese Academy of Sciences Beijing 100080 China 2. school of Information Renmin University of China Beijing 100872 China

Applying the Riemann-Roch theorem,we calculate the dimension of a kind of mero- morphicλ-differentials’ space on compact Riemann *** we also construct a basis of theλ-differentials’ *** the main result,the Cauchy ... 详细信息

关键词： Riemann-Roch theorem λ-differential annulus domain Cauchy integral formula 14C40

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Pioneer organisms after F-F mass extinction in Dushan region,Guizhou Province,and their significance in establishing new ecosystem

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Science china Earth Sciences 2006年第5期49卷 449-460页

作者： WANG Yue1, 2, WANG Xunlian1 & SHI Xiaoying1 1. school of Earth Sciences and resources, china university of Geosciences, beijing 100083, china 2. school of resources and environment, Guizhou university, Guiyang 550003, china 1. school of Earth Sciences and resources China University of Geosciences Beijing 100083 China 2. school of resources and environment Guizhou University Guiyang 550003 China

After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in the “ecologically barren area” is very important for revealing the evo- lution after bio-mass extinctions. In the Dushan region, Guizhou Province, china, the trace fossils appeared and flourished evidently earlier than body fossils after Frasnian-Famennian (F-F) mass extinction. The pioneer organisms and pathfinders in the “ecologically barren areas” are the trace-makers that are deposit-feeders with relatively simple structure and conformation on or near the deposit surface. The trace-makers have undergone an evolutionary process that their trace structures changed from simple to complex, and their living and moving areas and spaces enlarged from linear to planar and then to three-dimension spaces. Those characters show that the ability of the trace-makers to deposits and their efficiency of looking for food have been enhanced gradually and that those trace-makers constructed gradually a base for the new ecosystem. This process is similar to that of the trace fossils near the Precambrian-Cambrian boundary. In the Dushan area, only the recovery intervals have been identified for the Famennian body fossils, with no eminent radiation interval recognizable due to the Devonian-Carboniferous (C-D) mass ex- tinction. However, both the recovery and radiation intervals may be clearly recognized in the Famen- nian trace fossils based on their conformation and diversity. The evolution and diversification of the trace fossils in the “ecologically barren area” is considered to have played a role of necessary foun- dation for the recovery of body fossils in the ecological chain. With the gradual disappearance of the unfavourable environment factors resulting in the F-F mass extinction, a new ecosystem was reconstructed in the “ecologically barren area” through a three-

关键词： pioneer organisms, reconstruction of ecosystem, trace fossils, F-F mass extinction, Later Devonian, Dushan region, Guizhou Province, china.

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The genus distributions for a certain type of permutation graphs in orientable surfaces

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Science china Mathematics 2007年第12期50卷 1748-1754页

作者： Rong-xia HAO~(1+) Wei-li HE~1 Yan-pei LIU~1 Er-ling WEI~2 ~1 Department of Mathematics,beijing Jiaotong university,beijing 100044,china ~2 school of Information,renmin university of china,beijing 100872,china Department of Mathematics Beijing Jiaotong University Beijing 100044 China school of Information Renmin University of China Beijing 100872 China

A circuit is a connected nontrivial 2-regular graph. A graph G is a permutation graph over a circuit C, if G can be obtained from two copies of C by joining these two copies with a perfect matching. In this paper, based on the joint tree method introduced by Liu, the genus polynomials for a certain type of permutation graphs in orientable surfaces are given.

关键词： graph, genus distribution, genus, surfaces

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A Study on The Management of Municipal Residential Solid Waste in china

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Chinese Journal of Population,resources and environment 2004年第1期2卷 54-56页

作者： Lu Mingzhong, Shao Tianyi, Li Huayouenvironmental and natural resources school, renmin university of china, beijing 100089, china environmental and natural resources school Ren m in University of China Beijing 700089 China

As the main organic pollutant in municipal living waste , kitchen waste causes secondary pollution in the course of its being gathered and transported to the landfill by mixing with other refuse and by decomposition. This makes pollution prevention more difficult and raises the cost of landfill engineering. However, the amount of solid waste to be treated can be decreased and such pollution burden lessened by disposing of the solid waste in local municipal areas. The program in beijing also shows that this works well with our situation in china and can accelerate marketization and public participation.

关键词： kitchen waste secondary pollution municipal areas marketization of treating solid waste

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Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

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Science china(Technological Sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1 & LIU Changming1, 2 1. school of environmental Sciences, beijing Normal university, beijing 100875, china 2. Institute of Geographic Science and natural resources Research, beijing 100101, china beijing Normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1982—1998, soil moisture of all layers of soil-profile (0—1 m) in the Yellow River basin over the 17 years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1982 to 1988 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 17 years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.

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Approximation for a scheduling problem with application in wireless networks

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Science china Mathematics 2010年第6期53卷 1643-1655页

作者： ZHU QingHua & LI DeYing Key Laboratory of Data Engineering and Knowledge Engineering,MOE,school of Information,renmin university of china,beijing 100872,china 1. Key Laboratory of Data Engineering and Knowledge Engineering MOE School of Information Renmin University of China Beijing 100872 China

A network of many sensors and a base station that are deployed over a region is *** sensor has a transmission range,an interference range and a carrier sensing range,which are r,αr and βr,*** this paper,we study the minimum latency conflict-aware many-to-one data aggregation scheduling problem:Given locations of sensors along with a base station,a subset of all sensors,and parameters r,α and β,to find a schedule in which the data of each sensor in the subset can be transmitted to the base station with no conflicts,such that the latency is *** designe an algorithm based on maximal independent sets,which has a latency bound of(a+19b)R + Δb-a + 5 time slots,where a and b are two constant integers relying on α and β,Δ is the maximum degree of network topology,and R is the trivial lower bound of *** Δ contributes to an additive factor instead of a multiplicative one,thus our algorithm is nearly a constant(a+19b)-ratio.

关键词： approximation algorithm conflict-aware many-to-one data aggregation latency wireless sensor network

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