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1.
天山北坡水资源开发对地下水资源的影响及其合理利用   总被引:3,自引:0,他引:3  
本文论述了包括乌鲁木齐市在内的天山北坡山前平原范围内的地下水资源数量、补给关系及开采利用条件,以及地下水开发后对该地区地下水位、数量、质量及泉水渗出等方面的影响,并对如何合理利用本地区地下水资源提出了意见。  相似文献   
2.
本试验旨在简化基于康奈尔净碳水化合物与蛋白质体系(CNCPS)评定瘤胃非降解蛋白质(RUP)小肠可吸收氨基酸流量的技术。小肠可吸收氨基酸来自菌体蛋白和RUP,CNCPS根据溶解性将饲料粗蛋白质(CP)分为A、B1、B2、B3和C共5种组分,只有3种B组分可以过瘤胃并在小肠中消化。为评定RUP小肠可吸收氨基酸的贡献,CNCPS需要分别测定3种B组分的瘤胃降解率,3种过瘤胃B组分的小肠消化率需采用不同常数。选择18份饲料样品,其中精料12份,粗料6份,测定CNCPS评定RUP小肠可吸收氨基酸流量所需数据,同时对饲料CP的瘤胃动态降解率及不同时间点RUP的体外小肠消化率进行了测定,通过这些数据提出简化评定方法。结果表明:1)精料和粗料均以8 h的CP瘤胃降解率(X,%)与有效降解率(Y,%)间相关性最强,二者间呈线性相关,精料和粗料方程分别为Y=12.652+0.828X,r=0.990,P0.000 1和Y=10.967+0.886X,r=0.980,P=0.000 6。2)精料2 h RUP小肠消化率(X,%)与RUP小肠有效消化率(Y,%)间相关性最强,方程为Y=0.026+0.879X,r=0.970,P0.000 1;粗料8h RUP小肠消化率(X,%)与RUP小肠有效消化率(Y,%)间相关性最强,方程为Y=-0.002+0.960 X,r=0.995,P0.000 1。3)简化方案经可靠性评估得出,8 h CP瘤胃降解率和RUP小肠消化率简化CNCPS模型预测的小肠氨基酸流量(X,‰)与CNCPS预测的小肠氨基酸流量(Y,‰)相关性最强,精料方程为Y=-0.056+1.409X,r=0.999,P0.000 1;粗料方程为Y=0.003+2.120 X,r=0.999,P0.000 1。精料和粗料的简化评定结果与CNCPS评定结果的均方根误差分别为0.245和0.005,变异系数分别为7.08%和4.49%。综合得出,基于CNCPS,得到了预测RUP小肠可吸收氨基酸流量的简化模型,简化后的精料和粗料模型分别为Y=-0.056+1.409×[AA×(100-D8)×CP×ID8],r=0.999,P0.000 1和Y=0.002+2.120×[AA×(100-D8)×CP×ID8],r=0.999,P0.000 1,Y为RUP中的某种氨基酸小肠可吸收流量(‰),D8为CP的8 h瘤胃降解率(%),ID8为RUP的8 h小肠消化率(%),AA为不溶性蛋白质中该氨基酸含量(%)。  相似文献   
3.
韩潮  余玉敏 《安徽农业科学》2014,(24):8304-8305,8313
主要是对河南省河流普查成果进行简要分析和评价,主要内容包括河流普查成果概述及山地河流特征分析.对河南省境内普查河流的河流长度和流域面积的关系、河流比降的区域分布进行了简要分析,并在河流长度、流域面积和河流数量等方面与以往的资料内容进行了对比分析.总之,该次河湖普查成果取得了很大成就,但仍然存在一些问题.  相似文献   
4.
内蒙古草原陆面通量和边界层结构数值模拟   总被引:5,自引:0,他引:5  
殷达中  陈家宜 《草地学报》1998,6(4):282-292
本文用中尺度MMS模式和修正法国陆面过程模式耦合的中尺度模拟系统模拟了内蒙古草原土壤-植被-大气相互作用(IMGRASS)中尺度实验区生长季后期的地面水分能量通量和边界层结构。结果表明,没有降水时的草场白天大部分时刻潜热通量大于感热通量,降水可使潜热通量变大,波纹比变小,草地波纹比正负转变时间为早8点和晚19点。以乌日图为例的内蒙古沙地白天波纹比大于1,正负转变时间是早7点和晚20点。在降水量不大时,土地利用类型比降水对地面通量影响大。边界层温度廓线符合中纬度陆地边界层日夜演变规律,沙地对流边界层形成早于草原,湿度和风廓线与温度廓线的对应关系较好。  相似文献   
5.
Linking Land-use, Water Body Type and Water Quality in Southern New Zealand   总被引:3,自引:0,他引:3  
Land-use and vegetation cover have been linked to the nutrient levels (nitrogen, phosphorus) of surface waters in several countries. However, the links generally relate to streams and rivers, or to specific types of standing water, for example shallow lakes in a geologically defined region. We measured physical variables and nutrient chemistry of 45 water bodies representative of the wide range of lentic wetland environments (swamps, riverine wetlands, estuaries, reservoirs, shallow lakes, deep lakes) in Otago, New Zealand, and related these to catchment variables and land-use in order to assess the potential influence of catchment modification on water quality of these diverse wetlands. Catchment boundaries and land cover were derived from maps using ArcView GIS software. Our predictions that concentrations of nutrients and other components of water quality would correlate positively with the nature and intensity of catchment modification were confirmed in multivariate analyses. Physical and chemical measures were positively related to the extent of modification in the catchment (percentage of the catchment in pasture, planted forest, scrub and urban areas), and negatively related to lack of catchment modification (more of the catchment in bare ground, tussock grassland and indigenous forest). The strong negative correlations between nutrient concentrations, suspended sediment, water colour and the percentage of tussock cover in the catchment imply that increased conversion of the␣native tussock grassland to pastoral farming in␣Otago will increase nutrient concentrations and␣reduce water quality of the diverse lentic ecosystems.  相似文献   
6.
土地利用数据是进行流域农业面源污染治理的重要基础资料。以国产地理信息系统软件SupMap作为开发平台建立的杭埠河流域1: 5万土地利用数据库系统具有批量数据采集、管理、更新功能,以及运行稳定、安全可靠和很好的可扩展性特点。文章详细介绍了系统数据采集方法、数据组织方式、数据更新和数据库应用系统功能实现。  相似文献   
7.
The salt‐sensitive Glycine max N23674 cultivar, the salt‐born Glycine soja BB52 population, and their hybrid 4076 strain (F5) selected for salt tolerance generation by generation were used as the experimental materials in this study. First, the effects of NaCl stress on seed germination, tissue damage, and time‐course ionic absorption and transportation were compared. When qualitatively compared with seed germination appearance in culture dishes, and tissue damages on roots or leaves of seedlings, or quantitatively compared with the relative salt injury rate, the inhibition on N23674 was all the most remarkable. After the exposure of 140 mm NaCl for 1 h, 4 h, 8 h, 12 h, 2 days and 4 days, the content of Cl? gradually increased in the roots and leaves of seedlings of BB52, 4076 and 23674. Interestingly, the extents of the Cl? rise in roots of the three experimental soybean materials were BB52 > 4076 > N23674, whereas those in leaves were just on the contrary. Secondly, by using the scanning ion‐selective electrode technique (SIET), fluxes of Na+ and Cl? in roots and protoplasts isolated from roots and leaves were also investigated among the three experimental soybean materials. After 140 mm NaCl stress for 2, 4 and 6 days, and when compared with N23674, slighter net Cl? influxes were observed in root tissue and protoplasts of roots and leaves of BB52 and 4076 seedlings, especially at the cellular protoplast level. The results indicate that with regard to the ionic effect of NaCl stress, Cl? was the main determinant salt ion for salt tolerance in G. soja, G. max and their hybrid, and the difference in their Cl?/salt tolerance is mainly attributed to the capacity of Cl? restriction to the plant above‐ground parts such as leaves.  相似文献   
8.
The method to determine the crystallinity of solid slag film is established by analyzing the DSC curve of solid slag film and corresponding quenched slag. The accuracy of the method is investigated by measurements of prepared samples whose crystallinity is given. In addition, the solid slag films of mold slags used to cast medium carbon steel and low carbon steel are obtained by heat flux simulator in laboratory, and the crystallinity of the two kinds of slag film are also measured by DSC method. Experimental results indicates that the crystallinity of solid slag film can be determined by comparing the crystallization enthalpy of solid slag film and corresponding quenched slag during heating process, and the relative error is within 5.03%. For medium carbon steel, the crystalline fraction of solid slag film is 88.6%, while the crystalline fraction of solid slag film corresponding to low carbon steel is 55.0%. The results are consistent with actual structure of solid slag films.  相似文献   
9.
In the irrigated western U.S. disposal of drainage water has become a significant economic and environmental liability. Development of irrigation water management practices that reduce drainage water volumes is essential. One strategy combines restricted drainage outflow (by plugging the drains) with deficit irrigation to maximize shallow groundwater consumption by crops, thus reducing drainage that needs disposal. This approach is not without potential pitfalls; upward movement of groundwater in response to crop water uptake may increase salt and sodium concentrations in the root zone. The purposes for this study were: to observe changes in the spatial and temporal distributions of SAR (sodium adsorption ratio) and salt in a field managed to minimize drainage discharge; to determine if in situ drainage reduction strategy affects SAR distribution in the soil profile; and to identify soil or management factors that can help explain field wide variability. We measured SAR, soil salinity (EC1:1) and soil texture over 3 years in a 60-ha irrigated field on the west side of the San Joaquin Valley, California. At the time we started our measurements, the field was beginning to be managed according to a shallow groundwater/drainage reduction strategy. Soil salinity and SAR were found to be highly correlated in the field. The observed spatial and temporal variability in SAR was largely a product of soil textural variations within the field and their associated variations in apparent leaching fraction. During the 3-year study period, the percentage of the field in which the lower profile (90-180 cm) depth averaged SAR was above 10, increased from 20 to 40%. Since salinity was increasing concomitantly with SAR, and because the soil contained gypsum, sodium hazard was not expected to become a limiting factor for long term shallow groundwater management by drain control. It is anticipated that the technology will be viable for future seasons.  相似文献   
10.
从经济全球化的要求出发,为迎接国际市场的挑战,结合我国排灌机械行业的现状,提出了行业战略管理的若干设想。  相似文献   
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