检索结果-南通市图书馆

Journal of Pharmaceutical Analysis 2010年第3期22卷 183-187页

作者： Fei-Long Sun1,2,Min Jin3,Zhi-Gang Qiu3,Zhi-Qiang Shen3,Xin-Wei Wang3,Jun-Wen Li31.School of Life Science and Technology,Xi’an Jiaotong University,Xi’an 710049 2.School of environmental and Chemical Engineering,Xi’an Polytechnic University,Xi’an 710048 3.institute of environment and health,tianjin 300050,china School of Life Science and Technology Xi'an Jiaotong University Xi'an 710049 China School of environmental and Chemical Engineering Xi'an Polytechnic University Xi'an 710048 China institute of environment and health Tianjin 300050 China

Objective To construct reference standards for detection and quantification of Klebsiella pneumoniae(***)with SYBR Green I-based real-time PCR *** Primers were designed based on the published sequence of the phoE gene of *** standard was prepared by cell culture,PCR and T-A clone methods,and was identified by colony PCR and DNA *** The standard curve showed a very good linear negative regression between threshold cycle(Ct)and Log starting quantity of copy *** detection range was from 5.2 to 5.2×106 copies per reaction,and the detection limit was 6 copies per *** coefficients of variance(CVs)of three parallel experiments were in the range of 0.05%-0.91%.Conclusion The reference standards have high stability and *** can be used in the quantitative detection of ***.

关键词： cloning vector Klebsiella pneumoniae real-time PCR standard

Randomization of protein encoding gene during species evolution

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第4期43卷 299-303页

作者： GE Weiwen 1 and HE Fuchu 2 1. institute of Hygiene and environment Medicine, tianjin 300050, china 2. institute of Radiation Medicine, Beijing 100850, china institute of Hygiene and environment Medicine Tianjin China institute of Radiation Medicine Beijing China

Employing chi_square test, the authors observed the bias of 4 kinds of bases’ locating in 3 codon positions in gene sequence, and proved that there is a positive correlation between higher chi_square value and protein coding structure. By this, the observation that genes undergo progressive reduction in chi_values along evolution direction will reflect the progressive randomization of gene structures and the loss of the characteristics of protein coding sequences. The result proposed that during the evolution of life, genes are unexpectedly degenerating.

关键词： chi_square test gene sequence randomization evolution.

Detection of enteroviruses and hepatitis a virus in water by consensus primer multiplex RT-PCR

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2002年第4期8卷 699-702页

作者： Jun-Wen Li Xin-Wei Wang Chang-Qing Yuan Jin-Lai Zheng Min Jin Nong Song Xiu-Quan Shi Fu-Huan Chao Department of environment and health,institute of health and environmental Medicine of Tianiin,1 Da Li Road.tianjin 300050,china Department of environment and health Institute of Health and Environmental Medicine of Tjianjin 1 Da Li Road Tianjin 300050 China. junwenli@***

AIM: To develop a rapid detection method ofenteroviruses and Hepatitis A virus (HAV).METHODS: A one-step, single-tube consensus primersmultiplex RT-PCR was developed to simultaneouslydetect Poliovirus, Coxsackie virus, Echovirus and HAV.A general upstream primer and a HAV primer and fourdifferent sets of primers (5 primers) specific forPoliovirus, Coxsacki evirus, Echovirus and HAV cDNAwere mixed in the PCR mixture to reverse transcriptand amplify the target *** distinct amplified DNAsegments representing Poliovirus, Coxsackie virus,Echovirus and HAV were identified by gelelectrophoresis as 589-,671-, 1084-, and 1128bpsequences, respectively. Semi-nested PCR was used toconfirm the amplified products for each enterovirus ***: All four kinds of viral genome RNA weredetected, and producing four bands which could bedifferentiated by the band size on the *** confirmthe specificity of the multiplex PCR products, semi-nested PCR was performed. For all the four strainstested gave positive results .The detection sensitivityof multiplex PCR was similar to that of monoplex RT-PCR which was 24 PFU for Poliovrus, 21 PFU forCoxsackie virus,60 PFU for Echovirus and 105 TCID50for HAV. The minimum amount of enteric viral RNAdetected by semi-nested PCR was equivalent to 2.4 PFUfor Poliovrus, 2.1 PFU for Coxsackie virus, 6.0 PFU forEchovirus and 10.5 TCID50 for ***: The consensus primers multiplex RT-PCRhas more advantages over monoplex RT-PCR for entericviruses detection, namely, the rapid turnaround timeand cost effectiveness.

关键词：肝炎病毒肠病毒 RT-PCR 病毒检测

Effect of sediment on concentration of dissolved phosphorus in the Three Gorges Reservoir

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2011年第1期26卷 87-95页

作者： CAO Zhijing~1,ZHANG Xinbao~2,and AI Nanshan~3.institute of Architecture and environment,Sichuan University,Chengdu 610065,china, institute of Mountain Hazards and environment,Chinese Academy of Sciences,Chengdu 610041, china, institute of Architecture and environment,Sichuan University,Chengdu 610065,china, Lecturer Institute of Architecture and Environment Sichuan University Chengdu 610065 China Prof. Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Prof. Institute of Architecture and Environment Sichuan University Chengdu 610065 China

Eutrophication and algal bloom has been occurring in the Three Gorges Reservoir ever since the reservoir’s impoundment in *** concentration of dissolved phosphorus(DP) is one of the main controlling factors for algal *** sediment adsorbs DP thereby affecting the concentration of DP. The effect of the sediment reduction on the DP concentration of the Three Gorges Reservoir is discussed in this *** were taken from the Yangtze River and its tributaries,*** Minjiang River and the Tuojiang *** DP concentration of the water samples and the available phosphorus,total phosphorus,and phosphorus-fixing capacity of the sediment samples were *** amount of phosphorus adsorbed by the sediment was about 3%of the total DP load in the Yangtze *** experiment was done in the lab simulating the DP concentration,sediment concentration,and turbulence. The results showed that quite a high amount of DP was adsorbed by the *** adsorption capacity of the sediment was 135 mg/kg and the highest rate of adsorption was 29 mg/kg·*** Xiluodu Dam is located at nearly 1,100 km upstream of the Three Gorges *** Xiloudu Dam will trap sediment and thence reduce the sediment load entering the Three Gorges Reservoir after impoundment in *** is estimated that the sediment reduction due to the Xiluodu Dam may result in an increase of the DP concentration in the Three Gorges Reservoir by 6.8%.

关键词： Dissolved phosphorus Sediment load reduction Three Gorges Reservoir Adsorption capacity Eutrophication

A method of analysis of macro water environmental systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of environmental Sciences 1994年第4期6卷 496-503页

作者： Bao Jingling (tianjin institute of environment Protection Science, tianjin 300191 china) Yang Baochen Zhang Shiying(Department of Engineering Economics & Systems Engineering,tianjin University, tianjin 300072, china)

The phases of water environmental system (WES) and their emphatic intersections areanalysed in this paper. and from the view point of system analysis , an analytical process of WES is provided. Based on the balance network of WES, a goal programming model for regional water environmentalplanning and the main computational result for a coastal city are provided , thus proving its usefulness andeffectiveness.

关键词： water environmental system balance network of water environmental system goal program-ming.

Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & WANG Yibo3 1. institute of Mountain Hazards and environment, Chinese Academy of Sciences, Chengdu 610041, china 2. Cold and Arid Regions environmental and Engineering Research institute, Chinese Academy of Sciences, Lanzhou 730000, china 3. Resource and environment School, Lanzhou University, Lanzhou 730000, china institute of Mountain Hazards and environment Chinese Academy of Sciences Chengdu China Resource and environment School Lanzhou University Lanzhou China Cold and Arid Regions environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

Impact of land-use change on hydrological processes in the Maying River basin, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3, ZHANG Yu2, LIU Guimin2 & CHEN Lin3 1. institute of Mountain Hazards and environment, Chinese Academy of Sciences, Chengdu 610041, china 2. Cold and Arid Regions environmental and Engineering Research institute, Chinese Academy of Sciences, Lanzhou 730000, china 3. Resource and environment School, Lanzhou University, Lanzhou 730000, china institute of Mountain Hazards and environment Chinese Academy of Sciences Chengdu China Resource and environment School Lanzhou University Lanzhou China Cold and Arid Regions environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 35.32%, a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

在线全文

学校读者我要写书评

暂无评论

青海都兰夏尔雅玛可布遗址调查报告

考古与文物 2024年第5期 22-33页

作者：方丹(绘图) 姜淼(绘图) 郭梦肖永明闫红贤陈洪海中国-中亚人类与环境“一带一路”联合实验室(西北大学) 青海省文物考古研究院

2019年,西北大学与青海省文物考古研究所联合对青海省都兰县夏尔雅玛可布遗址进行考古调查,重点记录了石墙、土坯墙、墓葬等遗迹现象,采集到陶片、石制品等遗物,明确了该遗址是一处由居址区和墓葬区组成的大规模诺木洪文化聚落,并发现... 详细信息

2019年,西北大学与青海省文物考古研究所联合对青海省都兰县夏尔雅玛可布遗址进行考古调查,重点记录了石墙、土坯墙、墓葬等遗迹现象,采集到陶片、石制品等遗物,明确了该遗址是一处由居址区和墓葬区组成的大规模诺木洪文化聚落,并发现居址区防御体系是由双重或三重石墙构成。碳十四测年结果显示该遗址距今3400~3000年。作为目前规模最大、功能齐全的诺木洪文化遗址,对夏尔雅玛可布的进一步研究将为揭示诺木洪文化内涵、探索青铜时代青藏高原东北缘与周邻地区的人群交往和文化融合等议题提供重要资料。

关键词：都兰县夏尔雅玛可布遗址诺木洪文化青铜时代

GHG emission reductions and costs to achieve Kyoto target

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2003年第4期15卷 541-547页

作者： CHEN Wen\|ying (Energy, environment and Economy Research institute, Tsinghua University, Beijing 100084, china.) Energy Environment and Economy Research Institute Tsinghua University 北京 100084

Emission projection and marginal abatement cost curves(MACs) are the central components of any assessment of future carbon market, such as CDM (clean development mechanism) potentials, carbon quota price etc. However, they are products of very complex, dynamic systems driven by forces like population growth, economic development, resource endowments, technology progress and so on. The modeling approaches for emission projection and MACs evaluation were summarized, and some major models and their results were compared. Accordingly, reduction and cost requirements to achieve the Kyoto target were estimated. It is concluded that Annex I Parties' total reduction requirements range from 503—1304 MtC with USA participation and decrease significantly to 140—612 MtC after USA's withdrawal. Total costs vary from 21—77 BUSD with USA and from 5—36 BUSD without USA if only domestic reduction actions are taken. The costs would sharply reduce while considering the three flexible mechanisms defined in the Kyoto Protocol with domestic actions' share in the all mitigation strategies drops to only 0—16%.

关键词： Kyoto Protocol emission reduction abatement cost flexible mechanisms

CHARACTERISTICS OF THE INTERANNUAL AND INTERDECADAL TIMESCALES OF EVAPORATION IN NORTHERN china IN THE RECENT 115 YEARS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2006年第5期18卷 593-596页

作者： RONG Yan-shu TU Qi-pu DUAN Li-yao College of Water Resources and environment Hohai University Nanjing 210098 China Tianjin Institute of Meteorological Science Tianjin 300074 China tianjin institute of Meteorological Science Tianjin 300074 China Nanjing University of Information Science and Technology Nanjing 210044 China tianjin Climate Centre Tianjin 300074 China

Evaporation plays an important role in water balance on the land surface. In Northern china, the evaporation series of the recent 115 years was reconstructed on the basis of Yhornthwaite evaporation formula. The characteristics of the reconstructed series were analyzed using 10-year running mean filter, power spectrum method, and running t-text of abrupt changes on the paper. The results showed that there were remarkable interannual fluctuations with timescales of about quasi-8-year, 3-4-year, and quasi-2-year, and interdecadal oscillations with timescales of 57.5-year, quasi-23-year, and l l.5-year. Meanwhile, the abrupt changes of the evaporation series were also of interdecadal timescale. Either interannual fluctuations or interdecadal oscillations of evaporation were closely related to variations in air temperatures and precipitation.

关键词： reconstructed evaporation series interannual timescale interdecadal timescale Northern china