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991.
992.
Hei-Zhao Lin Yong-Jian Liu Jian-Guo He Wen-Hui Zheng & Li-Xia Tian 《Aquaculture Research》2007,38(15):1605-1611
The aim of this study was to investigate the effects of different oils on growth performance and lipid metabolism of the grouper, Epinephelus coioides. Five experimental fish meal‐based isonitrogenous and isolipidic diets were formulated containing either 5.5%‐added fish oil (FO), soybean oil (SBO), corn oil (CO), sunflower oil (SFO) or peanut oil (PO). Each diet was fed to triplicate groups of 20 fish (initial body weight 13.2±0.02 g) grown in seawater at 28.0–30.5 °C for 8 weeks. Fish were fed twice a day to visual satiety. No significant differences in the survival, weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio or hepatosomatic index were found between fish fed the FO or vegetable oils (VO) diets. Dietary lipid sources did not affect whole‐body composition among grouper fed the various diets. Muscle of fish fed the FO diet had significantly higher levels of 14:0, 16:0, 16:1n‐7, 20:5n‐3[eicosapentaenoic acid (EPA)] and docosahexaenoic acid (DHA)+EPA (except for PO fed fish) compared with those of fish fed VO diets. However, the levels of 18:1n‐9, 18:2n‐6 and DHA/EPA ratios in the muscle of fish fed FO diet were significantly lower than those of fish fed the VO diets. The liver of fish fed the FO diet had significantly higher levels of 18:0, 20:5n‐3, 22:6n‐3, n‐3 highly unsaturated fatty acids and DHA+EPA than those of fish fed the VO diets, whereas increases in 18:1n‐9, 18:2n‐6 and mono‐unsaturated fatty acid levels were observed in the liver of fish fed the VO diets. 相似文献
993.
994.
Yong Wang Yong-Jian Liu Li-Xia Tian Zhen-Yu Du Ji-Teng Wang Sheng Wang & Wei Ping Xiao 《Aquaculture Research》2005,36(14):1408-1413
A growth trial was conducted to feed juvenile tilapia (initial weight, 9.1±0.1 g), Oreochromis niloticus×O. aureus, isonitrogenous diets for 8 weeks. Six diets were formulated containing 29% crude protein from casein and gelatin, 10% crude fat from soybean oil and refined soybean lecithin and varying levels of corn starch ranging from 6% to 46% at increments of 8%, with corresponding energy to protein (E/P) ratios of 35.6, 37.9, 40.2, 42.5, 44.8 and 47.1 kJ g?1. Weight gain (WG), specific growth rate, feed efficiency ratio and protein efficiency ratio were significantly higher in fish fed diets with starch ≥22% (or E/P ratio ≥40.2 kJ g?1) than in fish fed diets with 6% or 14% starch (or E/P ratio of 35.6 or 37.9 kJ g?1). No further improvement was measured when dietary starch content increased beyond 22%. Body protein retention showed the same general pattern as WG, and was highest in fish fed the 22% starch diet. Body composition was significantly affected by dietary starch level. Fish fed diets with starch ≥30% had significantly higher lipid content than fish fed diets with 6% or 14% starch. Ash content was negatively correlated with starch inclusion level, but moisture and protein contents did not show discernible trends among treatments. Results indicate that hybrid tilapia can utilize 46% dietary starch without growth retardation, while 22% starch in feed for juvenile tilapia containing 29% protein and 10% lipid, or an E/P ratio of 37.9 kJ g?1 is optimal. 相似文献
995.
Optimal dietary protein requirement of grouper Epinephelus coioides juveniles fed isoenergetic diets in floating net cages 总被引:3,自引:0,他引:3
An experiment to determine the optimal protein requirement of grouper Epinephelus coioides juveniles was conducted in floating net cages (1.5 m × 1 m × 1.5 m). Six isoenergetic fishmeal–casein‐based experimental diets containing 350–600 g kg?1 crude protein (CP) were fed to triplicate groups of 20 fish (10.7 ± 0.2 g) for 56 days. Weight gain (WG) and specific growth rate (SGR) increased with increasing dietary protein level from 350 to 450 g kg?1 and then plateaued above these levels. Feed intake (FI) showed no significant difference among fish fed more than 350 g kg?1 CP. Lowest feed conversion ratio (FCR) was found for fish fed 500 g kg?1 CP but this was not significantly different from that of fish fed the 450 and 600 g kg?1 CP. Lowest protein efficiency ratio (PER) was found for fish fed 550 and 600 g kg?1 CP. Fish fed the 600 g kg?1 CP had the highest body protein and moisture contents but the lowest body lipid content. Body ash content was unaffected by protein level for fish fed >400 g kg?1 CP. Dietary protein level had no significant effect on hepatosomatic index (HSI). Fish fed the 350 g kg?1 CP had significantly lower condition factor (CF) and viscerosomatic index (VSI). Based on broken‐line regression analysis of SGR the optimal dietary protein requirement for E. coioides juveniles was determined to be close to 480 g kg?1. 相似文献
996.
开菲尔粒中微生物菌群及分离鉴定研究进展 总被引:1,自引:0,他引:1
开菲尔粒是发酵开菲尔的传统发酵剂,是由乳酸菌与酵母菌等众多微生物之间的共生作用而形成的粒状结构。因为其微生物菌群组成复杂且分布不均,一直是众多学者的研究重点。本文主要介绍了开菲尔粒中的微生物菌群及其之间的相互关系,并简介了各个菌种分离鉴定方法的研究进展。 相似文献
997.
牛场地表土壤中芽孢杆菌的分离与鉴定 总被引:1,自引:0,他引:1
以呼和浩特市某牛场地表土壤为研究对象,通过传统的微生物培养方法和基于16S r RNA基因序列的新型分子生物学方法对其中的微生物进行了分析。结果显示在牛场地表土壤中共鉴定出蜡样芽孢杆菌(Bacillus cereus)、苏云金芽孢杆菌(Bacillus thuringiensis)、地衣芽孢杆菌(Bacillus lincheniformis)、产芽孢梭菌(Clostridium sporogenes)、纯黄肠球菌(Enterococcus gilvus)和拜氏梭菌(Clostridium beijerinckii)共40株,并通过16S r RNA基因序列的系统发育树研究得到蜡样芽孢杆菌、苏云金芽孢杆菌、地衣芽孢杆菌这三种优势芽孢杆菌之间的亲缘关系。该研究为后续开发应用于无抗饲料添加剂和生物农药的绿色、安全、高效的益生芽孢杆菌微生态制剂提供一定的数据基础。 相似文献
998.
根据长叶红砂转录组数据信息,选取在盐胁迫处理后表达上调明显且注释结果为WRKY 转录因子的两个cDNA 片段。通过cDNA 末端快速扩增技术(rapidamplificationofcDNAends,RACE),从长叶红砂中克隆获得2个WRKY基因。在NCBI数据库比对与拟南芥At WRKY 33同源性分别为79%和87%,因此命名为Rt WRKY33-1和Rt WRKY 33-2。其中Rt WRKY33-2的cDNA 全长2163bp,开放阅读框(openreadingframe,ORF)长度为1681bp,编码573个氨基酸;Rt WRKY 33-1的cDNA 全长2155bp,开放阅读框长度为1776bp,编码591个氨基酸。氨基酸序列分析表明这两个基因均具有两个WRKY 结构域,属于典型的I类WRKY 转录因子。蛋白结构预测分析发现,两个蛋白的一级结构和二级结构在WRKY 结构域的氨基酸序列和结构特性的相似性较高,但是在非保守结构域部分,尤其是N 末端(1~80aa之间)、第1个WRKY 结构域之前(190~240aa之间)和两个WRKY 结构域之间(430~450aa之间)等位置的差异明显,可能对两个基因功能有一定影响。半定量RT-PCR 分析表明,4 种非生物胁迫均能诱导这两个基因的表达,但是盐、冷和ABA 对Rt WRKY 33-2诱导尤为明显,同时Rt WRKY 33-2对干旱胁迫的响应更快,因此这两个基因在长叶红砂抵御非生物胁迫的应答反应中发挥的作用可能不同。本研究为深入探索WRKY33转录因子在长叶红砂中的作用机制奠定了基础。 相似文献
999.
1000.