Investigations on physical properties and ablation processes of snow cover during the spring snowmelt period in the headwater region of the Irtysh River,Chinese Altai Mountains   总被引：1，自引：0，他引：1  

Wei Zhang  Yongping Shen  Ninglian Wang  Jianqiao He  An’an Chen  Jian Zhou 《Environmental Earth Sciences》2016,75(3):199

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GIS-based nitrogen removal model for assessing Florida’s surficial aquifer vulnerability     

Celena Cui  Wendy Zhou  Mengistu Geza 《Environmental Earth Sciences》2016,75(6):526

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Study on the Global Carbon Assimilation System Based on Multisource Remote Sensing Data     

Ju Weimin  Fang Hongliang  Tian Xiangjun  Jiang Fei  Zhan Wenfeng  Liu Yang  Wang Zhengxing  He Jianfeng  Wang Shaoqiang  Peng Shushi  Zhang Yongguang  Zhou Yanlian  Jia Binghao  Yang Dongxu  Fu Yu  Li Rong  Liu Jingxian  Wang Haikun  Li Guicai  Chen Zhuoqi 《地球科学进展》2016,31(11):1105-1110

The Paris agreement signed in April, 2016 aims to balance global anthropogenic carbon emissions and terrestrial carbon sinks by the middle of the 21^st century. To fulfill this goal, it is necessary to calculate carbon fluxes of different regions reliably. The global carbon assimilation system is an effective technique for achieving this goal. The Ministry of Science and Technology of China supports the project entitled as study on the global carbon assimilation system based on multisource remote sensing data through the national key research and development programs for global change and adaptation during the thirteen-five period. This project will develop synergic inversion techniques for retrieving key parameters of biological and atmospheric cycles and for assimilating multisource remote sensing and ground based data. Then, the high resolution global carbon assimilation system coupled with an ecological model will be constructed. This system is able to assimilate jointly multisource observation data and to optimize key model parameters, photosynthesis and respiration carbon fluxes of global terrestrial ecosystems, and anthropogenic carbon emission fluxes of key regions. This system will be used to study quantitatively the spatial and temporal patterns of carbon fluxes of global terrestrial ecosystems and anthropogenic carbon emission fluxes of key regions and to identify the mechanisms driving the global terrestrial carbon sinks and sources. The outputs of this study will be helpful for the fulfillment of the key research and development programs for global change and adaptation and provide valuable data and technical support for the decision-making in China.  相似文献   

Coevolution between Terrestrial Ecosystem and Earth Environment     

Zhou Zhekun  Zhou Zhonghe  Wang Yi 《地球科学进展》2016,31(7):682-688

Coevolution between terrestrial ecosystem and Earth environment is a hot research topic in both biology and geology. Last progresses in these field are reported from following research subjects: evolution of jawed vertebrates(gnathostomata) from Silurian; occurrence of earliest forests from Devonian of Xinjiang; biodiversity of insects in amber from Cretaceous of Myanmar; Evolution of primates and geochemistry studies from Eocene/Oligocene; studies of Longdan fauna from Lingxia basin, Gansu Province of earlier Pleistocene and endemic cloven-breast fishes from Pliocene Tibet; the correlations thick-boned fish,Hsianwenia wui, and the aridification of the Qaidam Basin; monsoon climate and its impact on biodiversity; study on the flora from Mankang, Tibet of Miocene and its palaeoclimate; depositional environment and its impact on the preservation of fossils; contraction of high resolution Stratigraphic series by using data of paleomagnetism and mammal fossils.  相似文献   

页岩孔隙系统研究实验方法     

张天付  鲍征宇  李东  唐俊红  周闻达 《地质科技情报》2016,(4):192-198

基于页岩孔隙系统的特殊性,讨论了FESEM-QEMSCAN、FIB-FESEM、NANO-CT、氮气吸附法、小角中子散射等几种页岩孔隙系统研究方法的特点和适用范围。指出场发射扫描电镜以及与之结合的能谱和矿物定量评价系统(FESEM-QEMSCAN)是研究页岩纳米级孔隙类型、大小、形态以及矿物分布的基础手段;聚焦离子束扫描电镜、微纳米CT可刻画页岩孔隙系统在三维空间的展布特征,利用获得的三维数据体进行数值模拟,可进一步计算孔隙度、渗透率等物性参数;氮气吸附法可对小于100nm的极微孔隙的孔径、形态进行求算;小角中子散射则可利用孔隙中存在的气体分子,获得孔隙系统连通性等重要参数。最后从页岩岩石组构的角度,探讨了页岩孔隙控制因素,指出有机质含量与成熟度,黏土矿物类型、含量,碎屑颗粒的含量以及成岩强度是影响页岩孔隙系统的主要因素。  相似文献   

Study on the hydrochemical characteristics of groundwater along the Taklimakan Desert Highway   总被引：1，自引：0，他引：1  

Pengpeng Zhou  Zhimin Wang  Jiangyi Zhang  Zaixing Yang  Xiaolei Li 《Environmental Earth Sciences》2016,75(20):1378

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Regional runoff variation and its response to climate change and human activities in Northwest China   总被引：1，自引：0，他引：1  

Jia Qin  Yuexia Liu  Yaping Chang  Shiwei Liu  Hongzheng Pu  Jiaxin Zhou 《Environmental Earth Sciences》2016,75(20):1366

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五硼酸铷溶液的物化性质及物种分布          下载免费PDF全文

苗军涛  房艳  房春晖  朱发岩  刘红艳  周永全  戈海文  孙鹏超  赵晓婵 《盐湖研究》2016,24(1)

碳酸铷、硼酸化学计量比混合,蒸发溶液,直至五硼酸铷RbB5O8·4H2O晶体析出。经粉末X射线衍射（XRD）、拉曼光谱（Raman spectroscopy）、热重/微商热重/差示扫描量热（TG/DTG/DSC）、原子吸收光谱等实验方法,确定其化学组成及结构。298.15、333.15K时测量溶液的物理化学性质（密度、电导、pH）,并与经验方程进行拟合,研究五硼酸铷溶液的物化性质随浓度、温度的变化规律。根据文献报道的平衡常数,实验测量的pH数据,采用牛顿迭代法进一步研究五硼酸铷溶液中主要存在的硼酸根离子对类型、含量以及物种的形成。  相似文献   

A new assessment model for evacuation vulnerability in urban areas     

Xiaoyi Ma  Ci Song  Chenghu Zhou 《International journal of geographical information science》2016,30(12):2401-2420

In the high-speed urbanization process of China, the urban population has been increasing significantly, leading to a high-density aggregation of population. However, the sharp increase in population density has not produced commensurate improvements in the road networks. On the contrary, the population increase induced a serious evacuation vulnerability, which cities experience during various hazards and catastrophic events. Therefore, research on evacuation vulnerability is important to urban planning. To assess the evacuation vulnerability, the optimal and worst scenarios should be considered because all possible evacuation plans occur between these extremes. However, most previous evacuation vulnerability studies are based on the worst-case scenario, only providing an upper bound of a potential evacuation assessment. To provide a more comprehensive theoretical basis for decision-makers to understand the consequences caused by all possible evacuations, this paper proposes an optimal evacuation vulnerability assessment model that provides the lower bound on potential evacuation difficulties. The model is solved by a stepwise spreading algorithm based on Graph Theory. Subsequently, to evaluate the effectiveness of the model, the study adopts the model to assess the evacuation capability of different road network topologies. A comparison with previous research was performed. The model was demonstrated in an application to the South Luogu Alley of Beijing, China. The significance of this paper is that the combination of our model with previous research may provide a more complete theoretical basis for an evacuation vulnerability assessment.  相似文献   

深圳农民工集聚空间的演变特征及影响机制   总被引：6，自引：3，他引：3  

周春山  杨高  王少剑 《地理科学》2016,36(11):1643-1653

以2000年、2010年人口普查数据和2008年珠江三角洲外来农民工问卷调查为基础数据,以街道为单元,运用数理统计分析和GIS空间技术揭示深圳农民工集聚空间演变特征及其影响机制。研究发现：① 深圳农民工以青年为主体,具有受教育水平高、职业转型模式多样、留城意愿较低和社会空间分异度较高等特征。② 农民工规模呈现西北部最高、中部其次、沿海最低的地带性分布规律,农民工高密度地区主要分布在工业集中区和城市中心区;热点区（高聚集区）集中在西部和北部的宝安区和龙华新区,冷点区（低聚集区）则分布在南部的中心城区,与传统制造业布局相一致。③ 农民工空间演化格局相对稳定,全市农民工分布重心逐步向西北偏移;全市农民工集中度略有上升,热点区基本稳定,冷点区有所扩大;农民工人口密度高值由“1个高中心+1个外围中心”逐步演变为“1个高中心+2个外围中心”;农民工空间变化差异较大,增长演变类型呈多样化。④ 深圳农民工分布的时空演变特征与常住人口存在较为明显的差异。⑤ 农民工集聚空间的分布演变受住房因素、就业机会、交通条件、社会网络、城市规划共同影响。  相似文献