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Search Results: 1 - 10 of 34435 matches for " ZHOU Nianxing "
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Spatial simulation of the responses of species extinction to human-caused habitat destruction at different time scales

Liu Huiyu,Lin Zhenshan,Zhou Nianxing,

生态学报 , 2007,
Abstract: Human-caused habitat destruction is one of the greatest threats to species diversity. In spatially implicit model, habitat destruction is just a single parameter, a reduction of the fraction of available sites, while in spatially explicitly model, habitat fragmentation has been taken into consideration. Therefore, contrast to spatially implicit model, spatially explicit model is more close to reality. Cellular automation is one of the most widely used(popular) spatially explicit models. Cellular automata models provide realistic, effective and reliable models of the spatiotemporal dynamics of metapopulation. Therefore, in this article cellular automation model was constructed to simulate the responses of species diversity to human-caused habitat destruction at ten-thousand year time scale, millenary time scale and century time scale, respectively. The results show that: The bigger q is, the longer the species extinction time is. So, the characteristics of species response to habitat destruction are deeply influenced by the metapopulation structures. Species go extinct in ranked competitive order (i.e., species 1 followed by 2, by 3 ) at ten thousand time scale, while at millenary time scale, the order of species extinction will greatly depend on the structure of metapopulation. When q (the proportion of occupied patches by best competitors) is bigger, species will go extinct from the best to the worst before complete destruction, and the survivals will go extinct collectively when complete destruction; when q is smaller, because the differences of species abundance and dispersal abilities among different species are not significant, the order of species extinction is not deterministic, and it is possible for the best competitor go extinct finally. While at century time scale, species will go extinct collectively at the moment of complete habitat destruction because the habitat destruction is so intensive and quick that species have no time to response. Therefore, the order of species extinction is influenced not only by the dispersal abilities, but also by the different speeds of habitat destruction and the structure of metapopulation. Therefore, to preserve different species, we should exploit different habitat at different rates.
Spatial distribution characteristics and influencing factors of health services in China

XIE Yinyin
,ZHOU Nianxing,MA Huanhuan,MA Zhifei

- , 2018,
Abstract: 医疗卫生服务是公共服务的重要组成部分,也是建设健康中国的着力点.因此,医疗卫生服务水平的空间分布特征是健康地理学关注的重要问题.建立合理的指标体系,运用因子分析、标准差椭圆法以及空间计量分析模型计算了2004年、2009年以及2014年中国大陆各省份医疗服务水平并分析其空间分布特征和影响因素.结果表明:1)公立医院和民营医院的医疗卫生服务水平均呈现明显的东南-西北分化特征;2)医疗卫生服务水平的高值区为长三角地区、珠三角地区等经济发达地区和四川、河南等人口众多的省份,水平较低的地区分布在内蒙古自治区、青海省和西藏自治区等西部地区.3)空间计量回归模型结果发现,居民消费水平、一级医院数量、抚养比是影响公立医院医疗卫生服务水平的重要因素;居民消费水平、二级医院数量、抚养比和传染病的发病率对于民营医院影响显著.该研究对医疗卫生服务区域均衡政策的制定具有现实意义.
The analysis of time-space evolution of consumption level and influencing factors based on spatial econometric model

申鹏鹏,周年兴,张允翔,谢引引,马欢欢,王 坤
SHEN Pengpeng
,ZHOU Nianxing,ZHANG Yunxiang,XIE Yinyin,MA Huanhuan,WANG Kun

- , 2018,
Abstract: 扩大内需是维系经济平稳运行的重要举措.对2002年~2013年间江苏省区内消费差异的总体变化与时空演变特征进行分析,并采用空间面板计量模型诊断消费水平的主要影响因素,旨在为针对性提高区域消费水平提供政策依据.结果表明:1)2002年来区内消费差异基本稳定且趋于下降,但空间集聚分异格局加剧.2)区内消费水平呈南高北低抱团式发展,这种空间不均衡是区域自身与周围地区长期共同作用的结果.3)空间面板数据模型可有效解析各变量对消费的时空作用方向与影响大小.其中,固定资产投资、人均财政支出及外资利用显著有助于促进地区消费的提高;居民收入的提高有利于促进消费;而地区经济发展、公路货运量及第三产业占GDP比重对区域消费的影响显著为负;居民储蓄款及就业率在不同固定效应背景下对消费水平的影响方向不一.最后给出了一些对策建议.
Development Status, Problems and Countermeasures of Large- and Intermediate-Scale Biogas Projects in Beijing’s Mountainous Counties  [PDF]
Zhongren Zhou, Zhujun Zhou
Journal of Power and Energy Engineering (JPEE) , 2013, DOI: 10.4236/jpee.2013.15010
Abstract: Developing large- and intermediate-scale biogas project is an important gripper ofBeijingrural energy construction and “Green Beijing” construction. The existing projects have made obvious energy and environment benefits, but the overall effects have not been fully exerted. There is still a large gap betweenBeijing’s ecological civilization goal and the operation effect. This paper takes biogas projects ofBeijingseven mountainous counties as examples, the development status, ecological environment construction and existing problems of operating are explained respectively. Finally, some countermeasures and suggestions are proposed for promoting the sustainable development of biogas project inBeijing, such as strengthening technical innovation and setting standards, innovating development patterns and planning reasonable layout, improve the maintenance mechanism and intensify policy support.
An oversampling system for ECG acquisition  [PDF]
Yu Zhou
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.27075
Abstract: Traditional ECG acquisition system lacks for flexibility. To improve the flexibility of ECG acquisition system and the signal-to-noise ratio of ECG, a new ECG acquisition system was designed based on DAQ card and Labview and oversampling was implemented in Labview. And analog signal conditioning circuit was improved on. The result indicated that the system could detect ECG signal accurately with high signal-to-noise ratio and the signal processing methods could be adjusted easily. So the new system can satisfy many kinds of ECG acquisition. It is a flexible experiment platform for exploring new ECG acquisition methods.
The Structure of Reflective Function of Higher Dimensional Differential System  [PDF]
Zhengxin Zhou
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.11009
Abstract: In this article, we discuss the structure of reflective function of the higher dimensional differential systems and apply the results to study the existence of periodic solutions of these systems.
Towards Capability Maturity Model of e-Learning Process  [PDF]
Yong Zhou
Intelligent Information Management (IIM) , 2012, DOI: 10.4236/iim.2012.44015
Abstract: ePCMM (e-Learning Process Capability Maturity Model) is used for evaluating the capability and maturity of an institution engaged in e-Learning based on e-Learning key process areas. It is a stepwise process improvement which can be implemented by both staged model and continues model.
Carbon Emission: Invalid Strategy and Ecological Rule  [PDF]
Li Zhou
Low Carbon Economy (LCE) , 2012, DOI: 10.4236/lce.2012.323011
Abstract: Carbon emission is a problem of global concern because it scares humanity’s living. While CCS (carbon capture and sequestration/storage) strategy received global attention, some scholars argued that the present warming is just a natural step in a long range periodic change of climate. Here we show that it isn’t a natural phenomenon, nor is something con- trollable by the CCS strategy. Carbon emission is governed by an ecological rule of the earth: global carbon emission is linearly correlated to the world population when the latter is larger than 1.3 × 109. Therefore, birth control is an essential component of low carbon economy.
An Improved Fuzzy ISODATA Algorithm for Credit Risk Assessment of the EIT Enterprises  [PDF]
Zongfang Zhou
Modern Economy (ME) , 2012, DOI: 10.4236/me.2012.35088
Abstract: We proposed an improved fuzzy ISODATA algorithm for credit risk assessment of the emerging information technol-ogy enterprise in this paper. Firstly, as the uncertainty of the EIT enterprise is relatively large, we set a reference sample and an initial clustering center matrix so that we overcame the shortcomings of traditional ISODATA algorithm and improved the reliability of fuzzy clustering analysis. Secondly, we proposed the steps of evaluating the EIT enterprises’ credit risk with improved fuzzy ISODATA algorithm. Last but not least, we assessed 10 EIT enterprises’ credit risk of a certain city, which proved the effectiveness and operability.
Conventional Sugarcane Breeding in South Africa: Progress and Future Prospects  [PDF]
Marvellous Zhou
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.42025
Abstract: Initial sugarcane production in South Africa relied on imported varieties. When imported varieties succumbed to diseases, the industry established the South African Research Institute (SASRI) with the mandate to develop sugarcane varieties. The popular and highly successful varieties, NCo310 and NCo376 were selected from crosses imported from India. NCo310 and NCo376 were grown successfully in several countries across the world where they produced high yield and ratooning ability. Later, crossing was established at SASRI based on flowers initiated in the glasshouse and photoperiod house under controlled temperature and photoperiod conditions. A five stage program is currently being implemented in the variety development process. More than 60 varieties have been released from the breeding programs. Other achievements include development of germplasm that is currently being used to enhance sugar cane variety development in South Africa. Currently, high realised selection gains are evident in most of the advanced selection populations. The released varieties show genetic gains over time. Efforts to enhance the breeding program include introgression, family evaluation, selection models and use of molecular markers.
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