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171.
The term minimally invasive surgery refers to procedures performed using endoscopic guidance to enter a part of the body (e.g., laparoscopy, thoracoscopy, arthroscopy, rhinoscopy, gastroscopy). Endoscope-assisted procedures generally use a rigid endoscope to improve visualization and/or access or permit completion of the procedure extracorporeally to access internal body structures through small openings compared with traditional “open” incision techniques. Endoscope-assisted procedures currently performed in exotics include, but are not limited to, exploratory laparoscopy/coelioscopy/thoracoscopy, procurement of thoracic and abdominal organ biopsies, intestinal foreign body removal, cystotomy, and reproductive sterilization.  相似文献   
172.
BACKGROUND: Economic costs of spotted wing drosophila (SWD) include yield and associated revenue losses, labor and material costs for monitoring and management and revenue losses due to the closure of export markets should fruit from SWD‐infested regions be banned by trading partners. This analysis focuses on two types of loss in the California raspberry and strawberry industries: yield losses in the absence of management, and insecticide material costs on a per treatment basis. It computes the cost of a specific management program for raspberries in California's Central Coast region. RESULTS: Insecticide material and application costs per treatment and the cost of the management program are small relative to the yield losses in the absence of management that are observed by growers, researchers and others in initial infestations. CONCLUSION: It is difficult to evaluate precisely the share of pest management program costs due to SWD because insecticides are sometimes used to manage multiple pests, and because labor‐intensive field sanitation efforts to control SWD are recommended practices already. Given these considerations, this analysis finds that the benefits to SWD management well outweigh the costs examined here. Evaluating the efficacy of managing SWD is essential in assessing the risks that SWD poses and the benefits of pest management programs. Copyright © 2011 Society of Chemical Industry  相似文献   
173.
Shoot:root (S:R) response in four winter C3-grasses (cereals) viz. wheat (Triticum aestivum L.), rye (Secale cereale L.), barley (Hordeum vulgare L.) and oats (Avena sativa L.) was investigated under eight different NPK sources (S1 = 20-20-20, S2 = 20-27-5, S3 = 7-22-8, S4 = 10-10-10-20S, S5 = 11-15-11, S6 = 31-11-11, S7 = 24-8-16, and S8 = 19-6-12) in pot experiment at Dryland Agriculture Institute, West Texas A&M University, Canyon, Texas, USA during winter 2009–2010. The experiment was performed in completely randomized design (CRD) with three repeats. The objective of this experiment was to investigate whether the S:R of winter cereals differ or not when applied with different NPK sources. Considerable variations in the shoot: root was noticed in the four grasses at different growth stages, i.e., 30, 60 and 90 days after emergence (DAE) when applied with different NPK fertilizers sources. Wheat had the highest S:R of 3.4 at 30 days after emergence (DAE), barley at 60 DAE (6.5), while oats at 90 DAE (3.9). Among the NPK sources, crops had the highest S:R of 3.6, 6.2 and 3.7 when applied with S3, S2, and S6 at 30, 60 and 90 DAE, respectively. Shoot to root ratio showed positive relationship with increase in shoot weight and negative relationship with increase in root weight. The NPK fertilizer S6 (31: 11: 11), an acid loving fertilizer had negative effects on the shoot and root development of cool season cereals, but among these cereals under study, barley and oats roots were affected more than wheat and rye. It was concluded from this present study, that the four cool season cereals responded differently in terms of shoot: root to different NPK fertilizers at different growth stages.  相似文献   
174.
密云水库水源涵养林对水质的影响   总被引:14,自引:2,他引:14       下载免费PDF全文
 为给密云水库流域的水质保护规划和控制措施提供理论依据,以密云县北庄镇为试验区对水源涵养林进行调查,对地表水进行监测,分析水质中存在的主要问题及其产生的原因。自2000年密云水库流域开始实施“退耕还林”工程以来,森林面积不断增加,减少了由于农田施肥造成的非点源污染,使地表水水质的浑浊度和氨氮指标有所下降。以油松林和板栗林为例,对降雨流经森林生态系统各环节的水质进行监测、分析,说明密云水库流域水源涵养林与降雨之间的淋溶、交换、吸附等过程对降雨具有净化作用。  相似文献   
175.
Seventy-six rhizobial isolates belonging to four different genera were obtained from the root nodules of several legumes (Vicia sativa, Vicia faba, Medicago sativa, Melilotus sp., Glycine max and Lotus corniculatus). The action of five commonly used herbicides [2,4-dichlorophenoxyacetic acid (2,4-D), glyphosate (GF), dicamba, atrazine and metsulfuron-methyl] on the growth of rhizobial strains was assessed. Subsequently, GF and 2,4-D were tested in a minimum broth as C and energy sources for 20 tolerant strains. The ability of these strains to metabolize different carbon sources was studied in order to detect further differences among them. Tolerance of the bacteria to agrochemicals varied; 2,4-D and GF in solid medium inhibited and diminished growth, respectively, in slow-growing rhizobial strains. Among slow-growing strains we detected Bradyrhizobium sp. SJ140 that grew well in broth + GF as the sole C and energy source. No strain was found which could use 2,4-D as sole C source. The 20 strains studied exhibited different patterns of C sources utilization. Cluster analysis revealed three groups, corresponding to four genera of rhizobia: Rhizobium (group I), Sinorhizobium (group II) and Mesorhizobium–Bradyrhizobium (group III). On the basis of the results obtained on responses to herbicides and C sources utilization by the isolates investigated, it was possible to differentiate them at the level of strains. These results evidenced a considerable diversity in rhizobial populations that had not been previously described for Argentinean soils, and suggested a physiological potential to use natural and xenobiotic C sources.  相似文献   
176.
大豆种质资源对食叶性害虫抗性的鉴定   总被引:11,自引:4,他引:11  
崔章林  盖钧镒 《大豆科学》1997,16(2):93-102
在南京经过6年鉴定,从6724份国内外大豆资源中,发掘出对本地大豆食叶性害虫表现抗性的资源20份,包括对豆卷叶螟、斜纹夜蛾、大造桥虫等具有综合抗性的6份;主要抗豆卷叶螟的8份;主要抗斜纹夜蛾、大造桥虫的6份;主要抗豆卷叶螟的8份;主要抗斜纹夜蛾、大造桥虫的6份。其中大多数材料的抗性水平高于目前国际上常用的3个食叶性害虫抗源PI171451、PI227687、PI229358。一些抗性资源综合农艺性  相似文献   
177.
针对重庆市村镇严峻的生态环境,为有效地处理生活垃圾,减少环境污染,选取3类典型的村镇,通过走访调查、实地采样、实验室检测等方法,对重庆市3类典型村镇生活垃圾特点、成分因素进行了分析,对不同村镇类型的收运体系进行了探讨。通过调查研究,结果发现,3类村镇生活垃圾在产量、成分上差异较大。传统村镇以灰土竹木垃圾为主,占40.22%,其次是人畜粪便,占12.07%,可回收及有害垃圾含量较少;城乡统筹村镇以砖瓦、灰土为主,两者占到了39.11%,其次是厨余类和橡塑类分别占15.90%和12.05%;旅游型村镇以厨余类为主,占28.60%,其次是塑料类和砖瓦类分别占14.95%和14.90%。在此基础上,提出针对3类村镇垃圾源头分类的方法和收运模式,希望能为重庆村镇生活垃圾的规范处理提供支持。  相似文献   
178.
Abstract –  Threespine stickleback ( Gasterosteus aculeatus ) samples from Prator Lake in southcentral Alaska consist of the relatively rare form of weakly armoured individuals with few lateral plates and no pelvic spines. Prator Lake has been sampled for threespine stickleback since 1983. Exotic northern pike ( Esox lucius ) were first observed in this lake in 1996. The appearance of pike corresponds with a dramatic decrease in stickleback numbers and apparent local extinction. The stickleback population may have been vulnerable to an exotic predator because Prator Lake lacks native piscivorous fishes, and this population had extreme armour reduction.  相似文献   
179.
沙打旺黄萎病菌(Verticiliumdahliae,营养体亲和群VCG2B)在5~30℃均能生长,适温20~25℃,在35℃时不能生长。在pH值4~10范围内都能生长,25℃时最适pH值为5.0~9.0。该菌利用可溶性淀粉、葡萄糖、蔗糖、乳糖、麦芽糖或甘油作碳源时均能正常生长,并生成微菌核,利用硝酸钾、尿素、甘氨酸作氮源时生长较快,以蛋白胨作氮源时,生长较慢,且不能生成微菌核  相似文献   
180.
A simple randomized field experiment was conducted for two years to test the comparative efficacy of three sources of leaf-applied phosphorus (sodium dihydrogen orthophosphate, diammonium phosphate and monocalcium superphosphate) on the yield performance of mustard ( Brassica juncea L. Czern. and Coss.) var. Varuna. The quantity of P was 3.5 kg ha−1. In addition, 20 kg N and 2 (or 6) kg S ha−1 were included in the spray applied in two equal splits at 70 and 90 days as supplement to the basal application of 60 kg N, 17.5 kg P and 33.2 kg K ha−1. The two-year data revealed that spray treatments were significantly efficacious in augmenting most of the yield attributing parameters as well as seed and oil yield by about 20% over the water-sprayed control. However, as the three sources of phosphorus proved equally effective, commercial grade monocalcium superphosphate could be preferred over others due to its cost effectiveness and easy availability.  相似文献   
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