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K. Hammer J. Gebauer S. Al Khanjari A. Buerkert 《Genetic Resources and Crop Evolution》2009,56(4):547-560
During the past years the Sultanate of Oman which is located at the south-eastern tip of the Arabian peninsula has been studied
for its cultivated plant genetic resources. Data from this study, that commenced in 2002 and information from the literature
have been combined to document the millenia-old cultivation history of many agri- and horticultural crop plants in this country
at the cross-roads of inter-regional exchange. The resulting checklist comprises 194 species from 133 genera and 53 families
and 11 geoelements of 136 selected species. Notable inputs came from South and Southeast Asia with 21.3%, from the Near East
and East Mediterranean with 20.6%, and from Central and South America with 15.4%. Most elements are allochthonous while real
autochthonous elements such as Boswellia sacra Flueck. and Prunus arabica (Oliv.) Meikle are rare. A remarkable infraspecific variation in several crop species and evidence of introgession were found
indicating an evolutionary power of Oman that is similar to that of South Italy. 相似文献
104.
Xavier Santos José C. Brito Antonio J. Abril Neftalí Sillero 《Biological conservation》2009,142(2):344-352
During the Pleistocene, climatic fluctuations due to glacial and interglacial periods greatly modified the distribution of boreal organisms. One direct effect of these distribution shifts is that, along the southern edge of the range of some boreal species, populations persist only in isolated patches of suitable habitats, surrounded by less suitable areas. Isolated populations in marginal habitat are vulnerable to several threats, including climate change, anthropogenic threats, and stochastic events. We developed habitat-suitability models using Ecological Niche Factor Analysis for populations of the smooth snake, Coronella austriaca, at the southernmost limit of the species range. These models were based on historical and current records of occurrence, coupled with remote sensing data including elevation, slope, and climatic variables. Our results indicated that C. austriaca in the Iberian Peninsula occurred in areas associated with high slope and precipitation, low temperatures, and low variation in seasonal temperature and precipitation compared to areas of non-occurrence. At a broad scale, the areas classified as highly suitable for the species in the southern Iberian Peninsula were small and fragmented. At a local scale, extensive field work demonstrated that C. austriaca occurs in low densities in these areas. In addition, we detected several human-induced threats like habitat loss, favoured by temperature increase and rainfall reduction. Several life-history traits, such as dietary specialization and low frequency reproduction, also may contribute to the vulnerability of these populations to local extinctions. Although the most suitable southernmost areas are included in protected reserves, specific guidelines for management are needed to assess conservation needs. 相似文献
105.
对2009年7月17日夜间山东半岛北部的特大暴雨过程进行了总结分析。环流形势分析表明:副高边缘暖湿气流、冷空气和低涡切变线的共同影响,是造成此次半岛北部特大暴雨的主要原因,暴雨区与588线和切变线位置密切相关;17日夜间副高长时间稳定少动是造成此次强降水非常重要的原因之一;不稳定的大气层结、K≥36℃对夏季大尺度系统背景下局地强对流的预报具有指示意义。雷达资料分析表明,此次特大暴雨是混合性降水,从渤海不断有平行的条状强降水回波带生成发展东移,回波带中有对流单体不断加强,强降水回波持续时间较长,导致特大暴雨的产生;对于局地强降水,数值预报产品预报的降水量远远小于实况,实际工作中要综合分析,不可偏信。 相似文献
106.
[目的]分析山东半岛一次冷流降雪过程。[方法]利用常规天气观测资料、NCEP/NCAR 1°×1°网格点逐6 h再分析资料,采用天气学原理和天气动力学诊断分析方法,对2008年12月4~6日山东半岛冷流降雪进行分析和总结。[结果]造成此次山东半岛冷流降雪的大尺度环流形式为冷涡深槽;850 hPa西北风风力增强时,山东半岛冷流降雪将加强;暴雪发生时,925~750 hPa相对湿度90%,90%相对湿度线所围成的面积大小与强降雪时段有较好的对应,相对湿度线的变化反映了海面暖湿水汽往高处输送的变化,海平面暖湿水汽往高空输送越多,越有利于山东半岛冬季冷流降雪的形成;冷流降雪具有明显的时空分布特征,并与垂直上升运动区相对应。[结论]该研究为山东半岛冷流降雪的短时和临近预报准确率的提高提供了一定的参考。 相似文献
107.
A Systematic Scoping Study of the Socio‐Economic Impact of Rift Valley Fever: Research Gaps and Needs
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M. Peyre V. Chevalier S. Abdo‐Salem A. Velthuis N. Antoine‐Moussiaux E. Thiry F. Roger 《Zoonoses and public health》2015,62(5):309-325
Rift Valley fever (RVF) is a severe mosquito‐borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio‐economic impact induced by RVF disease and the attempts to evaluate them. Of the 52 papers selected for this review, 13 types of socio‐economic impact were identified according to the sector impacted, the level and temporal scale of the impact. RVF has a dramatic impact on producers and livestock industries, affecting public and animal health, food security and the livelihood of the pastoralist communities. RVF also has an impact on international trade and other agro‐industries. The risk of introducing RVF into disease‐free countries via the importation of an infected animal or mosquito is real, and the consequent restriction of access to export markets may induce dramatic economic consequences for national and local economies. Despite the important threat of RVF, few studies have been conducted to assess the socio‐economic impact of the disease. The 17 studies identified for quantitative analysis in this review relied only on partial cost analysis, with limited reference to mid‐ and long‐term impact, public health or risk mitigation measures. However, the estimated impacts were high (ranging from $5 to $470 million USD losses). To reduce the impact of RVF, early detection and rapid response should be implemented. Comprehensive disease impact studies are required to provide decision‐makers with science‐based information on the best intervention measure to implement ensuring efficient resource allocation. Through the analysis of RVF socio‐economic impact, this scoping study proposes insights into the mechanisms underpinning its often‐underestimated importance. This study highlights the need for comparative socio‐economic studies to help decision‐makers with their choices related to RVF disease management. 相似文献
108.
Quick biodiversity studies on poorly studied taxa and areas are increasingly popular for setting conservation priorities over a wide range of spatial scales. However, the implementation of such studies is complicated by the variable extent to which the different criteria used in prioritisation are correlated to each other. Using methods of constrained ordination, we examined the species-habitat relationships of carabid beetles based on ground beetle assemblages from 22 sites in the Picos de Europa National Park, northern Spain. We found characteristic species assemblages for subalpine meadows, Genista shrublands, and pastures, whereas mown meadows, heathlands, beech and riparian woodlands were occupied by more habitat generalist species. Species associated with subalpine meadows and Genista shrublands tended to be mostly brachypterous and to have geographic ranges restricted to northern Spain. In contrast, we found no relationship between the degree of species' association with pastures and geographic range-wing size type. Although the species richness was higher in riparian woodlands and mown meadows, we suggest a higher conservation value for subalpine meadows and Genista shrublands across the landscape because they sustain characteristic assemblages dominated by species with restricted ranges and reduced powers of dispersal. Our study suggests that preserving areas in the landscape supporting higher biodiversity will not necessarily preserve those species potentially more susceptible to habitat loss and fragmentation. It also supports the feasibility of biodiversity studies based on multivariate techniques for setting conservation priorities over complex landscapes. 相似文献
109.
Bulk snow samples were collected from the snowpack in open areas along two sampling lines running to the west from the Cu-Ni smelters at Nikel and Monchegorsk, NW Russia, during 1991–1993. The aim of the study was to estimate the area affected by sulphur and heavy metal deposition from the smelters. Snowpack quality was used as an indicator of deposition during winter time. The total sulphur, copper and nickel concentrations in the snowpack decreased significantly (p<0.001) with=" increasing=" distance=" from=" the=" smelters=" along=" the=" sampling=" line=" running=" directly=" to=" the=" west=" from=" monchegorsk.=" the=" deposition=" pattern=" was=" similar=" each=" winter=" during=" 1991–1993.=" the=" ph=" values=" did=" not=" correlate=" with=" the=" corresponding=" sulphur=" concentrations,=" and=" there=" was=" no=" decreasing=" ph=" gradient=" in=" the=" snowpack=" on=" moving=" towards=" monchegorsk.=" the=" effects=" of=" sulphur=" emissions=" from=" monchegorsk=" on=" snowpack=" chemistry=" were=" not=" detectable=" on=" the=" finnish=" side=" of=" the=" border.=" the=" 3-year=" mean=" of=" the=" total=" sulphur=" concentration=" was=" 0.27=" mg/kg,=" and=" of=" the=" ph=" values=" 4.92,=" along=" the=" sampling=" line=" running=" to=" the=" west=" of=" monchegorsk.=" the=" total=" sulphur=" concentrations=" near=" the=" smelters=">0.001)>< 20=" km)=" varied=" between=" 0.37=" and=" 0.95=" mg/kg.=" the=" effect=" of=" the=" cu-ni=" smelters=" at=" nikel=" on=" snowpack=" quality=" was=" not=" detectable=" in=" northern=" finnish=" lapland.=" the=" 3-year=" mean=" for=" total=" sulphur=" was=" 0.20=" mg/kg=" and=" for=" ph=" 4.96=" along=" the=" sampling=" line=" running=" to=" the=" west=" of="> 相似文献
110.
城市土地经济密度区域差异及其动态演变格局——基于山东半岛蓝色经济区的实证分析 总被引:3,自引:0,他引:3
[目的]揭示山东半岛蓝色经济区城市土地经济密度时空差异特征,为统筹该区域土地利用提供参考。[方法]利用变差系数、空间自相关等方法对山东半岛蓝色经济区36个县(区)在2005—2011年的城市土地经济密度时空差异特征进行研究。[结果](1)山东半岛蓝色经济区平均城市土地经济密度由5.46亿元/km2增长到9.72亿元/km2,总体呈不断上涨趋势,但城市间土地经济密度差异明显,其高值点主要集中在蓬莱市、龙口市和招远市形成的空间集聚区;(2)城市间土地经济密度的区域动态差异呈不断减小趋势,相对发展速率存在明显差异,其中龙口市最高,蓬莱市最低,且呈负向发展态势;(3)土地经济密度在整体空间分布格局上差异不断减小,局域的集聚中心由荣成市和文登市移动到蓬莱市、龙口市和招远市。[结论]山东半岛蓝色经济区城市土地经济密度空间分布不均,整体上东部城市土地经济密度明显高于西部城市。 相似文献