Minimally Invasive Spine Surgery in Small Animals     

《Veterinary Clinics of North America: Small Animal Practice》2018,48(1):153-168

  相似文献   

基于关键词统计分析看我国关于开放获取的研究     

李树霞 《河北农业大学学报(农林教育版)》2012,14(1):129-131,134

以CNKI系列数据库中的中国期刊全文数据库为数据源，运用关键词统计方法主要对开放获取的国内研究涉及的学科颔域、主要研究机构、政策与出版、出版形式、用户等方面进行了分析，通过统计分析，了解到我国关于开放获取研究论文的主题内容和研究进展情况并指出研究中存在的问题。  相似文献   

Entropy, non-linearity and hierarchy in ecosystems     

T.M. Addiscott 《Geoderma》2010,160(1):57-35

Soil-plant systems are open systems thermodynamically because they exchange both energy and matter with their surroundings. Thus they are properly described by the second and third of the three stages of thermodynamics defined by Prigogine and Stengers (1984). The second stage describes a system in which the flow is linearly related to the force. Such a system tends towards a steady state in which entropy production is minimized, but it depends on the capacity of the system for self-organization. In a third stage system, flow is non-linearly related to force, and the system can move far from equilibrium. This system maximizes entropy production but in so doing facilitates self-organization. The second stage system was suggested earlier to provide a useful analogue of the behaviour of natural and agricultural ecosystems subjected to perturbations, but it needs the capacity for self-organization. Considering an ecosystem as a hierarchy suggests that this capacity is provided by the soil population, which releases from dead plant matter nutrients such as nitrate, phosphate and cations needed for growth of new plants and the renewal of the whole ecosystem. This release of small molecules from macromolecules increases entropy, and the soil population maximizes entropy production by releasing nutrients and carbon dioxide as vigorously as conditions allow. In so doing it behaves as a third stage thermodynamic system.Other authors (Schneider and Kay, 1994, 1995) consider that it is the plants in an ecosystem that maximize entropy, mainly through transpiration, but studies on transpiration efficiency suggest that this is questionable.  相似文献   

Elsevier和Springer两大数据库中海洋学期刊SCI收录及开放获取情况分析     

张晓琨 《安徽农业科学》2013,41(13):6033-6034,6038

在对Elsevier和Springer两大最常用外文期刊数据库所收录的海洋学期刊进行详细调查的基础上,分析了两大数据库中海洋学期刊的SCI收录情况、影响因子在最近5年的变化情况以及这些期刊的开放获取情况。调查结果不仅反映了海洋学学术研究在近年的发展情况,而且为海洋学科图书馆借助开放存取资源进行馆藏建设提供了依据。  相似文献   

农业院校电子通信类专业实验室建设探索     

铁风莲 《计算机与农业》2008,(2):84-85

从农业院校自身的特色为出发点，结合我校信息学院的实验室建设工作，对如何构建有农校特色的电子通信专业实验室，特别是对实验室创新性、开放性等方面进行了探讨，目的是为了推进和快速提升电子信息专业的竞争力，提高实验室建设水平，从而为培养学生应用能力提供有效支撑。  相似文献   

天山中部林区疏林地分类及改造措施的初步研究     

潘存德  杨智年  张国林 《陕西林业科技》1998,(1):13-17,23

以天山中部林区人为不合理采伐形成的天山云杉疏林为研究对象，根据调查收集的４５块疏林地典型样地资料，从分析天山云杉疏林地的立地条件和林分特征入手，采用主分量分析，聚类分析的方法，将天山中部林区天山云杉疏林地划分为四种类型，并按因地，因地制宜的原则，提出了相应的改造利用措施。  相似文献   

商业步行街区的人性化设计探索     

张静 《安徽农业科学》2011,39(29):17990-17991,17994

分析了我国商业步行街区设计的重要性及存在的主要问题,从原则和空间环境特征两方面提出商业步行街区人性化设计需注意的关键环节,并从空间序列、空间尺度、空间意象出发,深刻分析了商业步行街区人性化的设计方式,指出当前我国商业步行街区人性化设计的基本思路。  相似文献   

贵州省本科院校图书馆OA资源开发利用调查分析     

唐圣琴 《农业图书情报学刊》2012,24(8):30-35

以网站访问形式,调查了贵州省17所本科院校图书馆开发利用OA资源的现状,并分析存在的主要问题,提出适合贵州省特点的开发利用OA资源的主要方式,为各馆的资源建设以及提高OA资源利用率提供一定参考。  相似文献   

开顶箱内自然气流的湍流统计特性     

ZHANG Jun-hui HAN Shi-jie SONG Guo-zheng 《林业研究》2005,16(4):303-305

The turbulence statistics parameters （variables） of natural airflow within a large Open Top Chamber （OTC）, 4 m in high height and 3 m in diameter, were measured with a three-dimensional ultrasonic anemometer/thermometer at Research Station of Changbai Mountain Forest Ecosystems Jilin Province, China in May 2004, for improving the field application of OTP. Results showed that because of the physical limitation, turbulence within OTC exhibited unique map compared with that of natural environments. There were clear daily pat- terns for most parameters. Turbulence here seemed to be isotropic and closely linked at all directions. Shape of eddies looked like a ＇cylinder＇ which was very similar to the shape of OTC. Continuous airflow was always interpreted by large scale eddies from top of OTC and showed high interactive intermittence at all directions.  相似文献   

切花月季在三亚引种试验与品种选择研究   总被引：2，自引：0，他引：2  

陈冠铭  林亚琼  许惠秋  汪李平  乔顺法 《安徽农业科学》2012,40(11):6392-6393,6396

[目的]海南岛夏秋季节高温、高湿的气候条件以及栽培品种、栽培技术等制约了切花月季商业化生产。该研究旨在优选出综合性状优良,适宜在三亚等热带地区商业化推广的切花月季品种。[方法]设计引种试验和生产试验,观察各品种农艺和经济性状。在三亚建立月季资源圃,通过观察从资源圃中挑选出18个品种进行引种筛选试验,初步选择8个品种进行生产试验。[结果]芬得拉、金奖章、萨曼莎、坦尼克的适应性最佳;卡罗拉、黑魔术、金奖章等切花质量可达1级;影星、金奖章和黑魔术产量超过100万枝/hm2;除了金奖章外其余7个品种切花插瓶期超过10 d;卡罗拉、我的选择和豆蔻年华等抗病虫性较好。[结论]切花月季品种能在三亚地区正常生长发育,三亚地区是切花月季生产的适宜地区;生产中应重点防治蓟马和黑斑病。卡罗拉、黑魔术、梅朗口红、坦尼克、金奖章、萨曼莎、芬得拉和影星8个品种综合表现最佳,可大面积推广种植。  相似文献