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871.
以根蘖型苜蓿Medicago sativa的根、茎、叶为材料,利用紫外分光光度计和凝胶电泳法比较了改良CTAB法和TRNzol试剂盒法等4种方法提取的苜蓿总RNA的产率和纯度。结果表明:改良CTAB法提取的RNA的OD260nm/OD230nm大于2.0,并且OD260nm/OD280nm接近1.8,具有较高的纯度。凝胶电泳结果表明,改良CTAB法有28S rRNA和18S rRNA 2条清晰的条带,且很少有降解;TRNzol试剂盒法获得的RNA品质也较好,但存在降解和弥散现象;其他2种方法提取效果较差。这证明改良CTAB法提取的总RNA具有很高的纯度,可以满足进一步分子生物学研究的要求;TRNzol试剂盒法也可以满足实验的下一步要求,但需要进一步纯化。 相似文献
872.
硝基咪唑类药物检测技术研究进展 总被引:2,自引:0,他引:2
本文介绍了硝基咪唑类药物的理化性质、作用、应用现状及检测方法,重点论述了动物组织,产品及排泄物中药物残留和饲料中原药的检测技术。 相似文献
873.
874.
以文心兰切花品种"黄金3代"(Oncidium Gower Ramsey‘Gold 3')为试验材料,研究和比较不同等级(A~D级)、不同采收成熟度(5~8分熟)的文心兰鲜切花瓶插寿命,以及去除花苞或花朵后的切花瓶插寿命影响.结果表明,在25℃和70%~80%相对湿度条件下用清水瓶插,文心兰鲜切花最佳采收成熟度为6分熟(A级)、7分熟(B级)和8分熟(C和D级).文心兰鲜切花全部去除花朵后,与对照相比其花苞开放率略高,瓶插寿命延长2.3 d;而全部去除花苞后,其瓶插寿命比对照延长0.6 d,表明花苞与花朵之间存在营养竞争关系.同时,测定和分析了最佳采收成熟度的文心兰鲜切花在瓶插保鲜液条件下的生理生化性状变化.研究结果可为确定文心兰切花生产的最佳采收时间提供科学依据. 相似文献
875.
君子兰花粉生活力测定及贮藏方法筛选 总被引:5,自引:1,他引:4
以大花君子兰品种胜利为试材,利用单因子试验比较了固体培养基中蔗糖、硼、钙、镁、钾及琼脂质量浓度对花粉萌发的影响,在此基础上进行正交试验。结果表明,适宜的花粉培养基为蔗糖100 g/L+H3BO3150 mg/L+CaCl2100 mg/L+琼脂4 g/L,新鲜花粉萌发率最高达91.4%。用醋酸洋红染色法和I-KI染色法测定君子兰花粉生活力分别为88.1%和89.4%,比培养基法(78.7%)略高。不同贮藏方法对君子兰花粉生活力影响差异较大,最佳贮藏方法为-20℃冷冻干燥贮藏,贮藏120 d后花粉生活力为24.4%。 相似文献
876.
877.
878.
被子植物叶片气孔制片方法研究 总被引:1,自引:0,他引:1
通过叶片气孔制片方法可研究植物有机体的生理代谢和生理功能,总结了常用的气孔制片方法,以为不同叶片材料和不同观察要求下选用合适的制片方法提供参考依据。 相似文献
879.
Restoring altered forest landscapes toward their ranges of natural variability (RNV) may enhance ecosystem sustainability and resiliency, but such efforts can be hampered by complex land ownership and management patterns. We evaluated restoration potential for southern-boreal forests in the ∼2.1 million ha Border Lakes Region of northern Minnesota (U.S.A.) and Ontario (Canada), where spatially distinct timber harvest and fire suppression histories have differentially altered forest conditions (composition, age–class distribution, and landscape structure) among major management areas, effectively resulting in forest landscape “bifurcation.” We used a forest landscape simulation model to evaluate potential for four hypothetical management and two natural disturbance scenarios to restore forest conditions and reduce bifurcation, including: (1) a current management scenario that simulated timber harvest and fire suppression practices among major landowners; (2) three restoration scenarios that simulated combinations of wildland fire use and cross-boundary timber harvest designed to emulate natural disturbance patterns; (3) a historical natural disturbance scenario that simulated pre-EuroAmerican settlement fire regimes and windthrow; and (4) a contemporary fire regime that simulated fire suppression, but no timber harvest. Forest composition and landscape structure for a 200-year model period were compared among scenarios, among major land management regions within scenarios, and to six RNV benchmarks. The current management scenario met only one RNV benchmark and did not move forest composition, age–class distribution, or landscape structures toward the RNV, and it increased forest landscape bifurcation between primarily timber-managed and wilderness areas. The historical natural disturbance scenario met five RNV benchmarks and the restoration scenarios as many as five, by generally restoring forest composition, age–class distributions, and landscape structures, and reducing bifurcation of forest conditions. The contemporary natural disturbance scenario met only one benchmark and generally created a forest landscape dominated by large patches of late-successional, fire-prone forests. Some forest types (e.g., white and red pine) declined in all scenarios, despite simulated restoration strategies. It may not be possible to achieve all objectives under a single management scenario, and complications, such as fire-risk, may limit strategies. However, our model suggests that timber harvest and fire regimes that emulate natural disturbance patterns can move forest landscapes toward the RNV. 相似文献
880.
Jiaxin Chen Stephen J. Colombo Michael T. Ter-Mikaelian Linda S. Heath 《Forest Ecology and Management》2010
Forest and harvested wood products (HWP) carbon (C) stocks between 2001 and 2100 for Ontario's managed forests were projected using FORCARB-ON, an adaptation of the U.S. national forest C budget model known as FORCARB2. A fire disturbance module was introduced to FORCARB-ON to simulate the effects of wildfire on C, and some of the model's C pools were re-parameterized using data from Canadian forests. Forest C stocks were estimated using allometric equations that represent the relationships between C and net merchantable volume and forest age based on forest inventory statistics. Other pools were included using results from ecological studies related to forest inventory variables. Data from future forest development projections adopted in approved management plans were used as model input to produce forest C budgets for the province's Crown forest management units. The estimates were extended to other types of managed forests in Ontario: parks, measured fire management zones, and private forest lands. Carbon in HWP was estimated in four categories: wood in use, wood in landfill, wood burned for energy, and C emitted by wood decomposition or burning without energy generation. We projected that the C stocks in Ontario's managed forests and HWP (in use and in landfills) would increase by 465.3 Mt from 2001 to 2100, of which 47.9 Mt is from increases in forest C and 417.4 Mt is from HWP C. 相似文献