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941.
俄罗斯野麦草引种试验 总被引:1,自引:0,他引:1
俄罗斯野麦草青草产量,47370kg/hm^2,种子产量为2295kg/hm^2,抗逆性强,适应范围广,返青早,枯黄期迟,青绿期长,利用价值高,适宜甘肃省绝大多数牧区和半农半牧区推广种植。 相似文献
942.
D.A. Stone 《Soil Use and Management》2000,16(4):285-292
Abstract. There is a need to develop sustainable nitrogen (N) management systems that minimize environmental losses by maximizing the use efficiency of applied fertilizers, particularly with wide-row annual crops that are often poor at utilizing N. A key approach is to match nitrogen supply with crop demand using improved methods of fertilizer application and timing. One technique is to target liquid 'starter' fertilizers close to the seed, or around the roots of transplants, and to omit or reduce conventional broadcast applications. This paper examines the effects of starter fertilizer combined with various rates of seedbed and/or top-dressed N on the growth and yield of bulb onion ( Allium cepa L.), crisp lettuce ( Lactuca sativa L.), forage maize ( Zea mays Bonaf.) and sugarbeet ( Beta vulgaris L.). Starter fertilizer improved early growth and, in combination with reduced rates of supplementary N, gave yields comparable with higher rates of base N with each crop, except sugarbeet. The use of top-dressed N was as effective as base N in supplementing starter fertilizer and had the benefit that it allowed a top-dressing requirement to be estimated accurately using a simple nitrogen balance equation. These results, taken with earlier work, show that starter fertilizers offer clear opportunities for reducing N inputs, while maintaining yield and quality of these crops. 相似文献
943.
短周期间歇光照对肉用仔鸡生产性能的影响 总被引:2,自引:0,他引:2
在7日龄时,肉服仔鸡由接近全日制光照改变为1h光照,3h黑暗的短周期简歇光照。结果表明,短周期间歇光照的肉仔鸡饲料报酬和饲料利用率提高,氮平衡试验表明,增加肉用仔鸡的光周期,粪氮分泌量减少,饲料氮在鸡体内的沉积增加,而饲料氮的摄入量并未增加,因而使得饲料氮的利用率和到提高。 相似文献
944.
Enhancing dry matter production with higher partitioning to fruit bunches is important for sustainable intensification of oil palm. A series of best management practices including site-specific nutrient management, canopy management, and harvesting has been developed for oil palm plantations. However, the effects of these practices on dry matter production and partitioning, and how the effects vary with climatic and soil conditions of plantation sites, remain largely unknown. We established a four-year field trial including 30 paired commercial blocks across Sumatra and Kalimantan, Indonesia. The paired treatments included site-specific best management practices, and standard estate practices as the control. The annual production of aboveground dry matter was 30.0 ± 0.5 t ha−1 yr−1 (mean ± se) under best management practices, higher than 28.8 ± 0.5 t ha−1 yr−1 under standard estate practices. The bunch index, an indicator of the fruit production efficiency, increased by 12% under best management practices compared to standard estate practices. Partitioning of dry matter to the fronds decreased by 8% under best management practices, compared to standard estate practices. The positive effect of best management practices on the annual production of total aboveground dry matter was stronger in the plantation site with higher annual rainfall. These results are useful for optimizing management practices to improve sustainable intensification of oil palm. 相似文献
945.
Abstract. A five year field experiment was conducted to assess the influence of crop rotation and field pea residue incorporation into the soil on maize yield. The data indicated a 30% increase in maize yield grown in rotation with field pea compared to when it was grown after wheat and a further increase of 35% when field pea residues were incorporated into the soil. The effect of field pea and residue incorporation was greater in the presence of fertilizer nitrogen indicating the enhanced capacity of the crop to utilize N from the residue. Legume residue management in sub-tropical regions of the world, having coarse textured soils low in organic matter, could help to increase the yield of cereals besides saving some of the expensive fertilizer input. 相似文献
946.
现有的微波发出功率多采用时间间断式控制,磁控管的发射功率恒定,通过改变磁控管的通断时间实现微波平均输出功率的调节,这种方式不能改变微波的瞬间功率,微波功率输出控制不精确,对物料品质影响较大。为此,设计了一种微波耦合干燥装置,通过改变磁控管高压回路的电容,使磁控管高压回路的阻抗发生改变,以达到微波发出功率的线性可调。以马铃薯为试验研究对象,在热风温度为60°C、电容值魏0、0.25、0.33、0.5、1!F)的条件下进行干燥对比试验,试验结果表明:热风微波耦合的干燥效率明显优于单一热风干燥,速度快、能耗低。热风微波耦合干燥是一种快速,高效和节能的干燥方式,在农产品和食品干燥中具有广阔的应用前景。 相似文献
947.
基于向量自回归模型,通过协整分析、Granger因果检验、脉冲响应分析和方差分解分析,实证研究了能源价格与能源效率之间的关系。研究结果表明:从长期来看,中国能源价格的上涨能促进能源效率的提升。从短期来看,中国能源价格的上涨是促进能源效率提升的原因,但反之不成立。能源价格的正向冲击会促使能源效率提升,这种效应在短期内增长较快并能够长期保持。 相似文献
948.
《Journal of plant nutrition》2013,36(8):1457-1470
Abstract The influence of silicon (Si) on water use efficiency (WUE) in maize plants (Zea mays L. cv. Nongda108) was investigated and the results showed that plants treated with 2 mmol L?1 silicic acid (Si) had 20% higher WUE than that of plants without Si application. The WUE was increased up to 35% when the plants were exposed to water stress and this was accounted for by reductions in leaf transpiration and water flow rate in xylem vessels. To examine the effect of silicon on transpiration, changes in stomata opening were compared between Si-treated and nontreated leaves by measuring transpiration rate and leaf resistance. The results showed that the reduction in transpiration following the application of silicon was largely due to a reduction in transpiration rate through stomata, indicating that silicon influences stomata movement. In xylem sap of plants treated with 2 mmol L?1 silicic acid, the Si concentration was 200-fold higher, while the Ca concentration which is mainly determined by the transpiration rate, was 2.5-fold lower than that of plants grown without Si. Furthermore, the water flow rate in xylem vessels of plants with and without Si was compared. Flow rate in plants with 2 mmol L?1 Si was 20% lower than that without Si, which was accounted for by the increased affinity for water in xylem vessels induced by silica deposits. These results demonstrated the role of Si in improving WUE in maize plants. 相似文献
949.
为了研究内蒙古河套灌区农业化肥面源污染检测和治理措施,采用大田土壤淋溶试验,分析了河套灌区农田在保水材料处理下,玉米生育期内土壤硝态氮、铵态氮累积量及动态变化特征。结果表明,与CK相比,保水材料处理玉米苗期土壤NO_3~--N累积量平均提高20.49%,收获期平均降低13.98%;苗期土壤NH_4~+-N累积量平均提高35.21%,收获期平均降低28.93%。保水材料有效地抑制了氮素的淋溶损失,提高了氮素利用率,同时保证了玉米生育后期有效氮的供应,避免短时间内氮素的大量累积,在一定程度上减少了化肥面源污染,为农业面源污染治理提供有力措施。 相似文献
950.
一年两熟设施葡萄栽培系统的能耗研究具有很强的典型性和现实意义,但传统的能耗分析具有人工计算繁琐、易出错、工作效率低等缺陷。为了解决以上问题,本研究通过分析一年两熟设施葡萄的生产流程和系统特点,建立了其能源投入产出指标,构建了DEA-BCC模型和Malmquist指数法相结合的能源效率评估模型。模型首先基于投入主导型的DEA-BCC模型测算出一年两熟设施葡萄园的技术效率、纯技术效率和规模效率这3个关键能源效率参数;然后,通过引入Malmquist函数,将生产效率变动分解为技术效率变动指数、技术进步指数和规模效率变动指数,探索能源效率增长的动力,以此对设施葡萄能源效率进行全面评估。最后基于JavaEE平台下的MVC模式的B/S结构,结合Matlab Builder JA功能开发了面向一年两熟设施葡萄的能源消耗评估系统。应用测试表明,系统各功能正常运行,显著提高了能耗研究的计算效率和准确性,为一年两熟栽培模式能耗问题研究提供了可靠的数据处理支撑。 相似文献