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991.
A convenient method was developed to diagnose pancreatic degenerative atrophy (PDA) in small animal practice based on the observations, that feeding crude soybean increases faecal protease activity in dogs with normal pancreatic function, while PDA-dogs remain completely negative in faecal protease activity.When PDA is suspected, 1 or 2 faecal samples should be investigated with the X-ray film method based on incubation for 2 h at 37°G. If any activity is seen the dog should be considered non-PDA. If no activity is seen the dog should be given food supplemented with 1 g crude soybean/kg body weight twice daily for a few days and a new faecal sample should be collected. If the activity remains negative the diagnosis of PDA is reliable.As the amount of crude soybean in the food increased, a dose dependent increase of faecal protease and amylase was seen as measured with the radial enzyme diffusion method (RED).  相似文献   
992.
旱塬地膜玉米播期密度施肥量试验   总被引:5,自引:0,他引:5  
采用回归正交旋转组合设计和计算机模拟选优方法,优化出了旱塬地区地膜玉米667m^2产量750kg以上的适宜播种期为4月6-11日,密度为4000-4200株/667m^2,施肥量为N8.39kg/667m^2、P2O5 4.59kg/667m^2,经反馈验证,优化方案切实可行。  相似文献   
993.
国内外膜上移栽机械化的发展状况   总被引:4,自引:0,他引:4  
综合介绍了国内外膜上移栽机械化发展的现状和目前在生产中广泛使用的几种膜上移栽机的主要特点,对如何尽快发展我国膜上移栽机械化的提出了的建议。  相似文献   
994.
The purpose of this study was to investigate the ecological effect of full biodegradable film mulching and its effect on the production of spring wheat, and to seek a green, efficient and sustainable coverage in the semi-arid area of the Northwest Loess Plateau. Taking the uncovered land as the control (CK), to systematically studied the effects of full biodegradable film mulching (BM) and the polyethylene film mulching (PM) with bunch planting on soil water status, rain fallow efficiency and its impact on yield and water use efficiency of dryland spring wheat from 2015 to 2018. The results showed that both BM and PM significantly increased the water storage of 0-200 cm soil layer and rain fallow efficiency in each growth period of spring wheat, but there was not significant differences between BM and PM. From 2015 to 2018, the water storage of BM increased by 9.5 mm, 14.2 mm, 25.0 mm, and 39.0 mm respectively compared with CK. In the fourth year of continuous cropping, the water storage of PM, BM and CK 0-200 cm soil layers were 347.5 mm, 345.5 mm and 320.0 mm, respectively. Compared with CK, the rain fallow efficiency of BM and PM increased by 39.63% and 43.98%, respectively, which effectively alleviated the risk of spring drought in the next season. BM was similar to PM in seedling rate, the number of productive ears and the percentage of productive spike, and significantly higher than CK. The number of BM seedlings increased by 15.87% compared with CK in dry year, the number of productive ears increased by 14.70% on average in other years except 2015, and the percentage of productive spike increased by 3.08% on average in four years. The total amount of dry matter accumulation of BM was basically the same as PM, and before anthesis was slightly lower than PM, but higher than PM after anthesis, which was more conducive to grain filling and yield formation, and the amount of dry matter accumulation of both BM and PM are significantly higher than CK in each growth period. The annual average water consumption of PM, BM and CK was 287.46 mm, 289.76 mm, and 276.06 mm, respectively, and compared with PM, BM increased the evaporation water consumption. Compared with CK, the grain yield of BM and PM increased 48.07% and 54.95% respectively, and water use efficiency increased 46.08% and 56.07% in four years, there was not significant differences between BM and PM. There was not significant differences in soil water effect and yield effect between the full biodegradable film and PE film, and the full biodegradable film can be applied to the whole field soil-plastic mulching with bunch planting of spring wheat in dry land and provide technical support for the green and efficient production of wheat in dry land.  相似文献   
995.
塑料薄膜覆盖育壮蚕的生理生化研究   总被引:5,自引:0,他引:5  
时连根  徐俊良 《蚕业科学》2001,27(3):189-192
研究了打孔塑料薄膜覆盖育壮蚕 (4~ 5龄 )的部分生理生化变化。发现壮蚕每日用打孔塑料薄膜覆盖2 0h ,并将给桑次数减少为 1日 2回 ,其蚕座内CO2 浓度显著高于不覆盖对照区 ,但仍大大低于能引起蚕产生不良反应的水平。同时 ,超氧化物歧化和过氧化氢酶的活性均未发生明显的不良变化。此结果为生产上用打孔塑料薄膜覆盖省力化饲育壮蚕提供了科学依据  相似文献   
996.
OBJECTIVE: To evaluate the topical effect of various agents, currently used in the treatment of melting ulcers, on gelatinase activity present in the tear film of normal dogs. ANIMAL STUDIED: Eight normal adult beagles. PROCEDURES: Each animal received the following agents: cyclosporine A 1%, N-acetylcysteine 10%, ciprofloxacin 0.3%, ethylenediaminetetraacetic acid (EDTA) 1%, doxycycline 0.001%, polysulfated glycosaminoglycans (PSGAG) 5%, autoserum, and artificial tears during a 48-h period following a Latin square design. Tear samples were collected with micro-capillary pipettes following a corneal surface irrigation of each eye with sterile saline on four different occasions. Basal and total gelatinase activities were evaluated by optical density after processing in a commercial gelatinase activity assay. From the optical density ratio, a semi-quantitative measure of gelatinase activity was obtained. Basal and total activities were measured in all samples. RESULTS: The lowest total gelatinase activity, representing a percent decline in the enzyme activity although not significant, was observed 1 h after the last treatment in seven out of the eight ophthalmic agents; EDTA (68%), ciprofloxacin (76%), cyclosporine A (68%), doxycycline (47%), artificial tears (26%), PSGAG (25%), and N-acetylcysteine (20%). However, only the reduction observed with EDTA 6 h after the last treatment was significantly lower compared to the reduction observed with the artificial tears. CONCLUSION: This study indicated that only EDTA was able to significantly reduce the gelatinase activity in a persistent manner in the tear film of normal canine eyes. Further studies will be required to evaluate the effect of EDTA under ulcerative conditions and to more accurately ascertain the potential in vivo effect of the other agents.  相似文献   
997.
OBJECTIVE: To assess the efficacy and kinetics of a continuous infusion modality for topical ophthalmic drug delivery via subpalpebral lavage in horses. ANIMALS STUDIED: Five ophthalmically normal horses PROCEDURES: A constant-rate continuous delivery pump was used to apply 0.01% fluorescein solution to the eyes of five ophthalmically normal horses via subpalpebral lavage. Fluorescein was applied at a rate of 0.14 mL/h for 72 h. Tear samples were collected from the ventral conjunctival fornix at regular intervals via capillary tube and tear fluorescein concentrations were determined via spectral assay. Laboratory studies to evaluate the procedures used in the study also were performed. RESULTS: Overall mean tear film fluorescein concentration was approximately 20% of the applied concentration of fluorescein. However, tear film fluorescein concentrations varied considerably between horses and over time. Dilution varied from 0.62% to 60% of the applied concentration. Air pockets sporadically appeared in subpalpebral lavage tubing lines, resulting in discontinuous topical application of fluorescein. CONCLUSIONS: Constant-rate delivery of ophthalmic medications using a continuous infusion pump may provide a valuable method of topical drug delivery if tear film dilution of drugs is taken into account.  相似文献   
998.
Studies were conducted to evaluate the effect of a kaolin-based particle film against the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). The effect of the particle film on development, survival and host plant selection was tested on calabrese seedlings, Brassica oleracea italica Plenck cv. Fiesta F(1), under controlled environmental conditions in the laboratory. Survival to adulthood was significantly reduced and development time increased on kaolin-treated compared with water-treated host plants. The hatch rate of neonate P. xylostella larvae from eggs laid on an artificial substrate was unaffected by the particle film applied after oviposition. Experiments showed that, when given the choice, significantly fewer larvae first made contact with the kaolin-treated compared with the water-treated plant material and that after 24 h there were still significantly fewer larvae present on kaolin-treated leaves. Adult females, however, deposited more eggs on host plants coated with the kaolin particle film. As part of this series of experiments the water control treatment was compared with plant material which had been sprayed with kaolin on the upper surface only and on both leaf surfaces. In general, any observed treatment effect was enhanced with an increase in the particle film coverage. The results warrant the extension of investigations of kaolin-based particle films to field-based P. xylostella management strategies.  相似文献   
999.
根据2003年在黑龙江省甘南县进行的大豆垄间覆膜试验,通过数据处理分析,研究了垄间覆膜的增产效果。结果表明,覆膜的增产率达到14.6%,百粒重增加8.3%。  相似文献   
1000.
探索全膜双垄膜下秸秆还田添加腐解剂对旱地耕层土壤碳氮积累及土壤肥力性状的影响。2015-2017年在甘肃省农业科学院庄浪试验站,实施了以常规种植(CP)、常规种植+秸秆还田(CPS)、常规种植+秸秆还田+腐解剂(CPSD)、全膜双垄种植(FMRF)、全膜双垄种植+秸秆还田(FMRFS)和全膜双垄种植+秸秆还田+腐解剂(FMRFSD)为处理的田间定位试验。测定了耕层0~30 cm土壤有机质(SOM)、土壤全氮(TN)、全磷(TP)、全钾(TK)和速效氮(AN)、速效磷(AP)、速效钾(AK)、土壤容重(BD)和土壤pH,计算了耕层秸秆固存率(CSE)和碳氮积累量。结果表明,FMRFSD通过改善水热环境协同秸秆微生物腐解剂生产增效作用,加速了还田秸秆腐解与养分释放,产生的有机物抵消了土壤有机氮矿化损失,释放的养分补充了作物生长对土壤养分的消耗;改善后的水热肥条件又促进作物旺盛生长,使更多的有机物(落叶、根茬)回归土壤,从而显著促进了耕层SOC和TN的积累、提高了土壤TN、TP、TK和AN、AP、AK的含量,尤其是显著提高AP和AK的含量(P<0.05)。与CP比,FMRFSD 3年累计固存了41.17%的秸秆碳, 耕层年均增加SOC和TN贮量0.79 mg C·hm-2和0.04 mg N·hm-2;使耕层TN、TP、TK和AN、AP、AK 含量提高了0.05、0.03、3.05 g·kg-1和10.80、8.90、101.50 mg·kg-1,相应地增加了6.87%、6.94%、15.28%、10.24%、56.69%、55.34%。同时,FMRFSD使土壤BD和pH值分别降低了3.9%和0.2%。土壤碳氮贮量、氮磷钾养分含量的增加以及土壤BD和pH 值的降低,增加了土壤供肥能力、改善了土壤结构和性状,从而显著提高了肥力。因此,FMRFSD是适合当地的最有效的农田碳氮库土壤肥力管理模式。  相似文献   
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