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91.
陕西红河谷森林公园夏季整体环境舒适度研究   总被引:2,自引:0,他引:2  
基于可行性与科学性的原则,选取空气环境、声环境、气候环境及康健环境4个层面构建整体环境舒适度评价体系,并在夏季游客活动时间于红河谷森林公园内4个海拔高度各选取广场、林内、滨水3种景观空间类型进行实地监测与评价,分析整体环境舒适度的影响因素。结果表明:单项环境因子在不同时间、海拔、景观类型间存在差异。整体环境舒适度指数随时间先上升后下降,随海拔的升高而降低,在3种景观类型间差异明显,表现为广场最高,滨水次之,林内最低。红河谷森林公园的整体环境舒适度于8:00及18:00前后处于Ⅱ级水平,适宜从事游憩休养活动;其余时间段均处于Ⅲ级水平,较为适宜外出游乐康养。夏季遮蔽物愈多,空气颗粒物浓度愈低,温度愈低,空气负离子浓度愈高,相对湿度越大,整体环境就愈舒适。  相似文献   
92.
2014年春季对来自镇江蚕种场、苏州大学、无锡西漳蚕种场、山东广通蚕种集团有限公司及山东农业大学的5对桑蚕新品种,秋季对来自苏州大学、西南大学、中国农业科学院蚕业研究所的3对桑蚕新品种进行了实验室鉴定。通过龄期观察和生命率、茧质、产茧量调查与分析,客观反映参鉴品种在陕西试验点的饲育表现和性状特点。  相似文献   
93.
夏镇卿  路海东 《玉米科学》2020,28(3):99-104
土壤温度对作物的生长发育具有很强的调控作用。在全球气候变化背景下,根区土壤温度对玉米生长的影响及其调控机制已成为当前研究的一个热点。结合目前农业生产中土壤低温和高温对玉米造成危害的现状,从土壤温度对作物根区土壤环境以及玉米根系生长、冠层发育与产量形成的影响方面,综述土壤温度对玉米生长发育调控作用的研究进展,介绍改变土壤温度的措施以及对玉米土壤温度研究的发展方向进行展望,为今后的研究提供参考。  相似文献   
94.
为了探讨两种同期发清处理方法和不同年龄阶段对非繁殖季节奶山羊同期发情效果的影响,选用12∽15月龄初产奶山羊和4∽5胎经产奶山羊分为两组,采用孕激素耳栓埋植和阴道栓塞两种处理,并辅以肌注PMSG及PG-CL、E2,每组试验重复2次.结果显示:孕激素耳栓埋植法和阴道栓塞法两种同期发情处理方法处理初产组奶山羊总发情率分别达到87.5%和100.0%,经产组分别达到77.8%和83.3%,均无显著差异(P>0.05).但两种方法0∽24 h内的同期发情率初产组阴道栓法平均为94.1%,耳栓法平均为37.5%,差异显著(P<0.05),经产组阴道栓法平均为61.1%,耳栓法平均为44.4%,差异亦显著(P<0.05);无论初产、经产组奶山羊阴道栓法处理0∽24 h内的同期发情率(分别为94.1%、61.1%)显著高于24∽36 h发情率(分别为5.9%、22.2%)(P<0.05).用阴道栓同一种方法处理初产和经产奶山羊,初产组24 h的同期发情率(86.7%)显著高于经产组(60.0%)(P<0.05).阴道栓法处理同期发情效果优于耳栓法,初产奶山羊的同期发情效果优于经产奶山羊.  相似文献   
95.
Estimating spatial mean soil water contents from point-scale measurements is important to improve soil water management in sloping land of semiarid areas. Temporal stability analysis, as a statistical technique to estimate soil water content, is an effective tool in terms of facilitating the upscaling estimation of mean values. The objective of this study was to examine temporal stability of soil water profiles (0–20, 20–40, 40–60 and 0–60 cm) in sloping jujube (Zizyphus jujuba) orchards and to estimate field mean root-zone soil water based on temporal stability analysis in the Yuanzegou catchment of the Chinese Loess Plateau, using soil water observations under both dry and wet soil conditions. The results showed that different time-stable locations were identified for different depths and the temporal stability of soil water content in 20–40 cm was significantly (P < 0.05) weaker than that in other depths. Moreover, these time-stable locations had relatively high clay contents, relatively mild slopes and relatively planar surfaces compared to the corresponding field means. Statistical analysis revealed that the temporal stability of root zone soil water (0–60 cm) was higher in either dry or wet season than that including both, and soil water exhibited very low temporal stability during the transition period from dry to wet. Based on the temporal stability analysis, field mean soil water contents were estimated reasonably (R2 from 0.9560 to 0.9873) from the point measurements of these time-stable locations. Since the terrains in this study are typical in the hilly regions of the Loess Plateau, the results presented here should improve soil water management in sloping orchards in the Loess Plateau.  相似文献   
96.
[目的]研究不同移栽日期、密度处理下丹参根干重变化规律,为丹参大田高产栽培管理提供理论依据。[方法]以大田栽培丹参为研究对象,设移栽日期T1(冬栽,2009年11月26日移栽)、T2(春栽Ⅰ,2010年3月9日移栽)、T3(春栽Ⅱ,2010年3月27日移栽)和密度(株距×行距)D1(20cm×25cm)、D2(25cm×25cm)、D3(25cm×30cm)共9个处理,通过定期采集样品测定丹参根干重变化曲线,以归一化的生长度日用曲线拟合软件对其进行拟合。[结果]丹参根干重变化符合Logistic曲线,曲线分析表明丹参根生长分为前慢期、速生期和后慢期3个时期。[结论]丹参移栽后生长度日在1900~2200℃·d之间即9月份根干重进入快速生长期。  相似文献   
97.
采用离心洗涤法去除精浆后,对精液进行冷冻处理。发现:1、除精浆精子冻后的活率、Ⅰ类顶体率和精子畸形率与未除精浆组存在显著差异(P<0.05);2、除精浆使稀释后精液精浆中GOT和LDH活性明显升高(P<0.05)。从平衡后到解冻后各组GOT和LDH活性都呈上升趋势。但除精浆试验组比未除精浆试验组上升缓慢;3、除精浆试验组精子的穿卵率、卵内平均精子数都显著高于未除精浆试验组(P<0.05);4除精浆离心洗涤液用生理盐水和脱脂乳-卵柠液.两者之间无显著差异(P>0.05)。  相似文献   
98.
牛Myostatin基因单核苷酸多态性分析   总被引:10,自引:0,他引:10  
Myostatin基因即肌肉生长抑制素,是一种肌肉生长的负调控因子。应运PCR-SSCP和测序的方法对中国秦川牛、南阳牛以及国外引入品种皮埃蒙特牛双肌基因的第三外显子进行了多态性分析。结果表明:第三外显子938处G→A的单核苷酸的突变造成了南阳牛、皮埃蒙特牛第三外显子扩增片段多态性,秦川牛则不然。  相似文献   
99.
A field experiment was conducted in 2003 and 2004 growing seasons to evaluate the effects of regulated deficit irrigation on yield performance in spring wheat (Triticum aestivum) in an arid area. Three regulated deficit irrigation treatments designed to subject the crops to various degrees of soil water deficit at different stages of crop development and a no-soil-water-deficit control was established. Soil moisture was measured gravimetrically in the increment of 0–20 cm every five to seven days in the given growth periods, while that in 20 increments to 40, 40–60, 60–80, and 80–100 cm depth measured by neutron probe. Compared to the no-soil-water-deficit treatment, grain yield, biomass, harvest index, water use efficiency (WUE), and water supply use efficiency (WsUE) in spring wheat were all greatly improved by 16.6–25.0, 12.4–19.2, 23.5–27.3, 32.7–39.9, and 44.6–58.8% under regulated deficit irrigation, and better yield components such as thousand-grain weight, grain weight per spike, number of grain, length of spike, and fertile spikelet number were also obtained, but irrigation water was substantially decreased by 14.0–22.9%. The patterns of soil moisture were similar in the regulated deficit treatments, and the soil moisture contents were greatly decreased by regulated deficit irrigation during wheat growing seasons. Significant differences were found between the no-soil-water-deficit treatment and the regulated soil water deficit treatments in grain yield, yield components, biomass, harvest index, WUE, and WsUE, but no significant differences occurred within the regulated soil water deficit treatments. Yield performance proved that regulated deficit irrigation treatment subjected to medium soil water deficit both during the middle vegetative stage (jointing) and the late reproductive stages (filling and maturity or filling) while subjected to no-soil-water-deficit both during the late vegetative stage (booting) and the early reproductive stage (heading) (MNNM) had the highest yield increase of 25.0 and 14.0% of significant water-saving, therefore, the optimum controlled soil water deficit levels in this study should range 50–60% of field water capacity (FWC) at the middle vegetative growth period (jointing), and 65–70% of FWC at both of the late vegetative period (booting) and early reproductive period (heading) followed by 50–60% of FWC at the late reproductive periods (the end of filling or filling and maturity) in treatment MNNM, with the corresponding optimum total irrigation water of 338 mm. In addition, the relationships among grain yield, biomass, and harvest index, the relationship between grain yield and WUE, WsUE, and the relationship between harvest index and WUE, WsUE under regulated deficit irrigation were also estimated through linear or non-linear regression models, which indicate that the highest grain yield was associated with the maximum biomass, harvest index, and water supply use efficiency, but not with the highest water use efficiency, which was reached by appropriate controlling soil moisture content and water consumption. The relations also indicate that the harvest index was associated with the maximum biomass and water supply use efficiency, but not with the highest water use efficiency.  相似文献   
100.
The average productivity of rice–wheat sequence is quite impressive in the Trans Indo-Gangetic Plain (India) but these gains are over-shadowed due to declining groundwater, particularly in the areas, where groundwater quality is either good or marginal. The groundwater decline can be reversed through artificial groundwater recharge and by adopting suitable land and water management practices. Groundwater recharge is found technically feasible through vertical shafts conducting water from the ground surface directly to aquifers, after it has been passed through a sand-gravel filter. The recharge rate through this system is almost equal to a shallow cavity/filter well yield (about 11 l/s) and its cost is estimated at about INR 10/100 m3 (1 US$ = 45 INR). Further study in the Kaithal and Karnal districts of Haryana for stabilizing watertable within 6–7 m, which permits continuous use of shallow tubewell technology, indicated that the rice area could be supported at 60% of cultivable command area (CCA) and wheat between 65 and 80% of CCA with the existing management practices. The cultivation of wheat crop is sustainable in larger area, mainly due to its medium water requirement, salt resistance characteristics and consistent market demand resulting in assured returns. There is a possibility of supporting rice at a higher level, if part of the area (up to 10%) is left fallow and used for rainwater conservation and recharge. The fallow area may be subsequently put under early rabi (winter) crops like mustard, gram and other pulses. The effect of varying irrigation and fallowing would increase 23% equivalent wheat yield by changing land and water management practices. The analysis further indicated that the adoption of proposed irrigation management practices might stabilize watertable at desired level of 6–7 m in 10–15 years in high (3–4 m), 5 years in medium (5–10 m) and 40 years in deep (>10 m) watertable areas.  相似文献   
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