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选取大棚蔬菜种植园为实例,根据当地的水文地质特征、水源条件、大棚分布以及蔬菜种植结构,详细计算并校核了滴灌系统的总体分布、灌溉均匀度、允许灌溉强度、设计湿润比、灌水器选择、毛管极限长度等设计标准参数。通过灌溉制度的制定,计算各级管道管径、水头损失,选择过滤器,确定水泵型号,完成了滴灌系统的整体设计。该滴灌设计案例分析过程详细,结果合理,可作为相关滴灌工程设计参考依据。 相似文献
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为探究粳稻种质资源遗传多样性,提高粳稻育种组合选配的针对性和育种效率,通过变异系数、遗传多样性指数、聚类分析、相关分析、主成分分析、二维排序分析和逐步回归分析方法对不同生态区80份粳稻种质资源的8个表型性状的多样性水平进行了分析。结果表明:8个表型性状的变异系数为11.06%~36.97%,其中,千粒重的变异系数最小,每穗总粒数的变异系数最大;8个表型性状的遗传多样性指数为1.54~2.06,其中,单株有效穗数的遗传多样性指数最高,结实率的遗传多样性指数最低;在欧式距离9.0处,可将80份参试材料分为4类,各类表型性状差异明显;根据主成分分析和综合评价结果,80份粳稻种质资源中贵州的毕大香6号综合性状排名第1位,同时筛选到每穗实粒数、千粒重、株高、穗长和单株有效穗数性状可作为粳稻种质资源综合评价的关键指标;利用主成分二维排序分析筛选到矮秆、大穗、分蘖能力强及结实率高的4类优异种质资源,结合二维排序结果,大方晚糯是在二维排序重叠种质,可作为育种中间材料。同时基于主成分构建了粳稻种质资源的综合评价方程。 相似文献
64.
校院两级管理是高等院校内部管理体制改革创新的必然趋势,对高等院校盘活存量、激活增量具有重要作用.文章系统梳理了国内外高等院校内部管理体制改革和校院两级管理模式以及教科研指标体系的差异和特征,着重聚焦当前地方农业高校教科研指标体系构建中存在的问题,探析地方农业高校校院两级管理教科研指标体系构建的关键因素和环节,提出了"核... 相似文献
65.
基于AHP的土地整理综合效益评价实证研究 总被引:12,自引:0,他引:12
运用AHP,从社会、经济、生态和景观4个方面构建了土地整理综合效益评价指标体系,并对湖南省5个土地整理项目的综合效益进行了定量评价.结果表明:江华县涛圩镇土地整理项目综合效益较好,应尽快实施;其他4个项目综合效益一般,可根据实际情况择优实施. 相似文献
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用品种稳定性参数及高稳系数(HSC),对2004~2005年参加国家甜菜区试中的5个品种在甘肃武威市黄羊镇和酒泉地区的试验结果进行了综合分析,结果表明:BTS356的丰产、稳产性好.两年平均根产量和产糖量分别较对照陇糖2号增产40.62%和39.94%,差异达极显著水平,含糖率18.73%;对黄化病、白粉病、立枯病的抗性优于对照,具有较高的应用价值,适宜在甘肃省河西走廊生态条件下推广种植。 相似文献
69.
Water use of spring wheat to raise water productivity 总被引:1,自引:0,他引:1
In semi-arid environments with a shortage of water resources and a risk of overexplotation of water supplies, spring wheat (Triticum aestivum L.) is a crop that can reduce water use and increase water productivity, because it takes advantage of spring rainfall and is harvested before the evaporative demands of summer. We carried out an experiment in 2003 at “Las Tiesas” farm, located between Barrax and Albacete (Central Spain), to improve accuracy in the estimation of wheat evapotranspiration (ETc) by using a weighing lysimeter. The measured seasonal ETc averages (5.63 mm day−1) measured in the lysimeter was 417 mm compared to the calculated ETc values (5.31 mm day−1) calculated with the standard FAO methodology of 393 mm. The evapotranspiration crop coefficient (Kc) derived from lysimetric measurements was Kc-mid: 1.20 and Kc-end: 0.15. The daily lysimeter Kc values were fit to the evolution linearly related to the green cover fraction (fc), which follows the crop development pattern. Seasonal soil evaporation was estimated as 135 mm and the basal crop coefficient approach was calculated in this study, Kcb which separates crop transpiration from soil evaporation (evaporation coefficient, Ke) was calculated and related to the green cover fraction (fc) and the Normalized Difference Vegetation Index (NDVI) obtained by field radiometry in case of wheat. The results obtained by this research will permit the reduction of water use and improvement of water productivity for wheat, which is of vital importance in areas of limited water resources. 相似文献
70.
Temporary water trading is an established and growing phenomenon in the Australian irrigation sector. However, decision support and planning tools that incorporate economic and biophysical factors associated with temporary water trading are lacking. In this paper the integration of an economic trading model with a hydrologic water allocation model is discussed. The integrated model is used to estimate the impacts of temporary water trading and physical water transfers. The model can incorporate economic and biophysical drivers of water trading. The economic model incorporates the key trade drivers of commodity prices, seasonal water allocations and irrigation deliveries. The hydrologic model is based on the Resource Allocation Model (REALM) framework, which facilitates hydrologic network simulation modelling. It incorporates water delivery system properties and operating rules for the main irrigation and urban centres in a study area.The proposed integration method has been applied to a case study area in northern Victoria, Australia. Simulations were conducted for wet and dry spells, a range of commodity prices and different irrigation distribution system configurations. Some example analyses of scenarios incorporating water trading were undertaken. From these analyses potential bottlenecks to trade that constrain the economic benefits from temporary water trading were identified. Furthermore, it was found that in certain areas of the system, trading can make impacts of long drought spells worse for water users, e.g. irrigators. Thus, the integrated model can be used to quantify short-term and long-term third party impacts arising from temporary water trading. These findings also highlight the need to link “paper trades” (estimated by economic models) to physical water transfers (estimated by biophysical models). 相似文献