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111.
Simulation of transpiration, drainage, N uptake, nitrate leaching, and N uptake concentration in tomato grown in open substrate 总被引:3,自引:0,他引:3
M. Gallardo J.S. Rodríguez M.D. Fernández J.J. Magán 《Agricultural Water Management》2009,96(12):1773-1784
Free-drainage or “open” substrate system used for vegetable production in greenhouses is associated with appreciable NO3− leaching losses and drainage volumes. Simulation models of crop N uptake, N leaching, water use and drainage of crops in these systems will be useful for crop and water resource management, and environmental assessment. This work (i) modified the TOMGRO model to simulate N uptake for tomato grown in greenhouses in SE Spain, (ii) modified the PrHo model to simulate transpiration of tomato grown in substrate and (iii) developed an aggregated model combining TOMGRO and PrHo to calculate N uptake concentrations and drainage NO3− concentration. The component models simulate NO3−-N leached by subtracting simulated N uptake from measured applied N, and drainage by subtracting simulated transpiration from measured irrigation. Three tomato crops grown sequentially in free-draining rock wool in a plastic greenhouse were used for calibration and validation. Measured daily transpiration was determined by the water balance method from daily measurements of irrigation and drainage. Measured N uptake was determined by N balance, using data of volumes and of concentrations of NO3− and NH4+ in applied nutrient solution and drainage. Accuracy of the two modified component models and aggregated model was assessed by comparing simulated to measured values using linear regression analysis, comparison of slope and intercept values of regression equations, and root mean squared error (RMSE) values. For the three crops, the modified TOMGRO provided accurate simulations of cumulative crop N uptake, (RMSE = 6.4, 1.9 and 2.6% of total N uptake) and NO3−-N leached (RMSE = 11.0, 10.3, and 6.1% of total NO3−-N leached). The modified PrHo provided accurate simulation of cumulative transpiration (RMSE = 4.3, 1.7 and 2.4% of total transpiration) and cumulative drainage (RMSE = 13.8, 6.9, 7.4% of total drainage). For the four cumulative parameters, slopes and intercepts of the linear regressions were mostly not statistically significant (P < 0.05) from one and zero, respectively, and coefficient of determination (r2) values were 0.96-0.98. Simulated values of total drainage volumes for the three crops were +21, +1 and −13% of measured total drainage volumes. The aggregated TOMGRO-PrHo model generally provided accurate simulation of crop N uptake concentration after 30-40 days of transplanting, with an average RMSE of approximately 2 mmol L−1. Simulated values of average NO3− concentration in drainage, obtained with the aggregated model, were −7, +18 and +31% of measured values. 相似文献
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The reuse of saline treated industrial wastewater generated by textile firms mixed with municipal domestic effluent for irrigation was used to asses its effect on the mineral content of three olive (Olea europaea L.) cultivars under greenhouse and field conditions during two complete vegetative cycles. Chemical analysis of the treated wastewater indicated that the element concentrations fall within the permissible range of irrigation water used for plants. However, little impermissible accumulation of Na and Mg higher than the recommended maximum concentration was observed. Irrigation water with six electrical conductivities (EC = 0.78, 1.0, 2.0, 3.0, 4.0 and 5.0 dS m−1 in treatments T0, T1, T2, T3, T4, T5, respectively) were compared in the greenhouse experiment. The olive trees in the field experiment were trickle irrigated with potable water and treated wastewater (average EC = 4.2 dS m−1). The results of the greenhouse experiment showed that leaf N, Cu, Mn, Fe, Pb, and Na contents increased with increasing salinity of the treated wastewater. This increase was accompanied with a decrease in K and Mg contents. Leaf Ca and Cl concentrations were not considerably affected. Ion analysis in roots indicated that the contents of P, Na, Cl, Mn, and Pb increased while K decreased as treated wastewater salinity increased. Consequently, in most cases T4 and T5 gave a highly significant increase or decrease in accumulation of the previously mentioned minerals. A considerable variation in the studied cultivars was noticed. ‘Nabali’ was considered the most tolerant cultivar for the high salinity levels of the treated wastewater; its transporting selectivity of Na from root to leaf was higher and more Na was retained in the roots. Tissue analysis of leaves indicated that the element concentrations were within the adequate levels except those of Fe in ‘Nabali’ and ‘Manzanillo’, Na in ‘Improved Nabali’ and Cu in ‘Nabali’ and ‘Manzanillo’. In view of these findings, the negligible accumulation of minerals in leaves and roots indicated that this kind of textile effluent can be used as a valid alternative for irrigation of olive orchards with continuous monitoring of mineral levels. 相似文献
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不同灌溉模式对杂交水稻生育后期根系生理特性和剑叶光合特性的影响 总被引:24,自引:0,他引:24
对杂交水稻组合红莲优6和两优1193在淹水灌溉和湿润灌溉两种灌溉模式下生育后期的根系和光合生理特性进行了比较分析。结果显示,湿润灌溉增大了水稻根系密度,提高了根系活力,相关分析显示根系密度与根系活力呈正相关(r1=0.66, r2=0.68)。齐穗期剑叶叶绿素含量处理间差异不显著,但成熟期湿润灌溉显著高于淹水灌溉,推测湿润灌溉有利于剑叶功能期的延长和光合速率的提高。湿润灌溉条件下,群体生长率和相对生长率均显著高于淹水灌溉,表明湿润灌溉有利于水稻生殖生长期的干物质积累。上述结果可能是湿灌处理条件下水稻单位面积的产量极显著高于淹灌处理的主要原因。 相似文献
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利用室内对峙培养与发酵液处理病原菌研究了黄绿木霉(Trichoderma aureoviride)对大豆根腐病几种镰刀菌(Fusarium spp.)的拮抗作用,并利用盆栽试验研究了黄绿木霉对苗期大豆根腐病发生的影响.拮抗试验结果表明,黄绿木霉在与镰刀菌对峙培养中,菌丝交叉、接触与纠结,接触后镰刀菌菌丝被破坏;发酵产物只可延长镰刀菌孢子萌发的时间,但对孢子最终萌发率没有影响,发酵产物对菌丝生长速率的影响以山梨醇、葡萄糖及蔗糖作为碳源时,抑菌效果好,抑菌能力分别可达63%、51%、58%;盆栽试验证明黄绿木霉对大豆根腐病有较好的防治效果,防效可达73.2%,处理后幼苗株高与干重均高于未处理的对照. 相似文献
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甘蔗(Saccharum spp. hybrid)是我国食糖生产的重要原料,当前生产中普遍存在施氮量高而氮肥利用率低的问题。除了优化施肥管理,种植氮高效的甘蔗品种也是减氮增效的重要途径之一。本研究以云南蔗区推广的早熟高产高糖甘蔗品种‘云蔗05-51’和‘云蔗081609’为试验材料,设置0、0.1、0.5、1、5、10 mmol/L 6个供氮水平开展水培试验,在苗期测定植株生物量、根系形态、氮浓度与累积量、氮素吸收利用效率等指标。结果表明:(1)2个品种地上部、根系及整株生物量均随供氮水平的升高呈先升后降趋势,‘云蔗081609’根系生物量先于其地上部达到峰值,‘云蔗05-51’则相反,‘云蔗05-51’和‘云蔗081609’达到最佳生长需要的供氮量分别为0.5、1 mmol/L,相同供氮水平下‘云蔗081609’生物量高于‘云蔗05-51’;(2)随供氮水平上升,2个品种的根系总长度和平均根直径先上升后趋于稳定,根表面积持续增加,比根长先升后降,相同供氮水平下‘云蔗081609’的根系总长度、平均根直径和根表面积高于‘云蔗05-51’,比根长则低于‘云蔗05-51’;(3)2个品种植株氮浓度及累积量随供氮水平的升高总体呈先上升后稳定的趋势,相同供氮水平下‘云蔗081609’的植株氮累积量高于‘云蔗05-51’;(4)随供氮水平的增加,2个品种的单位根长吸氮量呈先升后稳定的趋势,单位根表面积吸氮量则呈先升后降并趋于平稳,氮素生理利用效率均随供氮水平升高显著降低,在0.1~10 mmol/L范围内‘云蔗081609’单位根长的吸氮量高于‘云蔗05-51’,但单位根表面积吸氮量变化趋势基本一致,品种间氮素生理利用效率无差异。综上表明,‘云蔗081609’在苗期对氮的吸收量高于‘云蔗05-51’主要得益于更好的根系生长,苗期适宜需氮量低于‘云蔗05-51’。 相似文献