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91.
脂质是一类具有独特生理功能活性的化合物,参与调节多种植物应答非生物胁迫过程,对维持植 物组织中生理动态平衡至关重要。脂质组学(Lipidomics)自 2003 年被提出后,已迅速发展成为对脂质整体系 统分析的一门新兴学科,为传统代谢组学注入新的技术支撑,有助于阐明脂类物质在植物中的代谢调控机制。 同时,质谱成像技术因其具有无标记、非特异性、高灵敏度、多物质同时分析等优势,被广泛应用到植物组织 中各类脂质分子的空间分布研究。介绍了脂质组学和质谱成像技术的研究现状,重点综述脂质分析技术在植物 种子脂质代谢调控研究中的最新进展,特别是新兴质谱成像技术在植物种子中脂类物质的成像应用。脂质组学 和质谱成像技术作为目前多组学技术的重要补充,将为植物代谢途径和调控机制的深入探究提供新的契机。亚 微米级高空间分辨率质谱成像技术的不断发展,将进一步推动植物在空间分辨水平的脂质代谢调控网络的深入 解析和前沿应用研究。  相似文献   
92.
巨菌草根际土壤微生物群落代谢功能多样性分析   总被引:2,自引:0,他引:2  
【目的】研究福州平潭巨菌草根际土壤与非根际土壤微生物对不同碳源利用,明确巨菌草对根际土壤微生物功能多样性的影响,为巨菌草生态治理提供理论依据。【方法】在福州平潭基地采集巨菌草(Pennisetum giganteum)根际土和非根际土壤样品,采用Biolog-ECO 技术研究巨菌草根际土与非根际土壤微生物对不同碳源利用特性,揭示不同碳源利用的不同及影响差异的主要因素。【结果】与对照相比,巨菌草根际土壤微生物的代谢活性高于非根际土壤;多样性分析结果表明,与非根际土壤相比,巨菌草根际土壤样品的Simpson指数、Shannon指数、Brillouin多样性指数略高,差异不显著;主成分分析结果表明,对主成分一和主成分二贡献大的碳源种类分别为22 种和6种,糖类是巨菌草根际土壤微生物利用的主要碳源类型。【结论】与非根际土壤相比,巨菌草根际土壤微生物群落在碳源利用及代谢功能多样性高于非根际土壤。  相似文献   
93.

Background

In EMS‐associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5′‐Adenosine‐monophosphate‐activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR.

Hypothesis/Objectives

To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge.

Animals

Twenty‐two mixed‐breed ponies.

Methods

Immunohistochemistry and immunoblotting for total AMPK and phospho(P)‐AMPK and RT‐qPCR for AMPK‐responsive genes were performed on laminar, liver, and skeletal muscle samples collected after a 7‐day feeding protocol in which ponies stratified on body condition score (BCS; obese or lean) were fed either a low‐CHO diet (ESC + starch, approximately 7% DM; n = 5 obese, 5 lean) or a high‐CHO diet (ESC + starch, approximately 42% DM; n = 6 obese, 6 lean).

Results

5′‐Adenosine‐monophosphate‐activated protein kinase was immunolocalized to laminar keratinocytes, dermal constituents, and hepatocytes. A high‐CHO diet resulted in significantly decreased laminar [P‐AMPK] in lean ponies (P = .03), but no changes in skeletal muscle (lean, P = .33; obese, P = .43) or liver (lean, P = .84; obese, P = .13) [P‐AMPK]. An inverse correlation existed between [blood glucose] and laminar [P‐AMPK] in obese ponies on a high‐CHO diet.

Conclusions and Clinical Importance

Laminar tissue exhibited a normal response to a high‐CHO diet (decreased [P‐AMPK]), whereas this response was not observed in liver and skeletal muscle in both lean (skeletal muscle, P = .33; liver, P = .84) and obese (skeletal muscle, P = .43; liver, P = .13) ponies.  相似文献   
94.
95.
The challenge for sustainable organic dairy farming is identification of cows that are well adapted to forage‐based production systems. Therefore, the aim of this study was to compare the grazing behaviour, physical activity and metabolic profile of two different Holstein strains kept in an organic grazing system without concentrate supplementation. Twelve Swiss (HCH; 566 kg body weight (BW) and 12 New Zealand Holstein‐Friesian (HNZ; 530 kg BW) cows in mid‐lactation were kept in a rotational grazing system. After an adaptation period, the milk yield, nutrient intake, physical activity and grazing behaviour were recorded for each cow for 7 days. On three consecutive days, blood was sampled at 07:00, 12:00 and 17:00 h from each cow by jugular vein puncture. Data were analysed using linear mixed models. No differences were found in milk yield, but milk fat (3.69 vs. 4.05%, = 0.05) and milk protein percentage (2.92 vs. 3.20%, < 0.01) were lower in HCH than in HNZ cows. Herbage intake did not differ between strains, but organic matter digestibility was greater (= 0.01) in HCH compared to HNZ cows. The HCH cows spent less (P = 0.04) time ruminating (439 vs. 469 min/day) and had a lower (= 0.02) number of ruminating boli when compared to the HNZ cows. The time spent eating and physical activity did not differ between strains. Concentrations of IGF‐1 and T3 were lower ( 0.05) in HCH than HNZ cows. In conclusion, HCH cows were not able to increase dry matter intake in order to express their full genetic potential for milk production when kept in an organic grazing system without concentrate supplementation. On the other hand, HNZ cows seem to compensate for the reduced nutrient availability better than HCH cows but could not use that advantage for increased production efficiency.  相似文献   
96.
Thermal acclimation may directly modify muscle metabolic capacities, or may modify them indirectly via effects upon physiological processes such as growth, reproduction or senescence. To evaluate these interacting effects, we examined the influence of thermal acclimation and acclimatization upon muscle metabolic capacities and tissue masses in 1 + stickleback, Gasterosteus aculeatus, in which confounding interactions between temperature and senescense should be absent. Furthermore, we examined the influence of thermal acclimation upon individual growth rate, muscle enzyme levels and tissue masses in 2 + stickleback sampled at the beginning of their final reproductive season. For 1 + stickleback, cold acclimation more than doubles mitochondrial enzyme levels in the axial muscle. Thermal acclimation did not change the condition of 1 + stickleback at feeding levels which could not maintain the condition of 2+ stickleback. Compensatory metabolic responses to temperature were not apparent in field acclimatized 1 + stickleback. The growth rate of 2 + stickleback was markedly affected by temperature: warm-acclimated fish generally lost mass even at very high levels of feeding (up to 78 enchytraid worms per day) while cold-acclimated fish gained mass. This suggests that warm temperatures accelerate the senescence of 2 + stickleback. Generally, muscle enzyme activities increased with growth rate. In axial muscle, the relationships between CS activity and growth rate differed with acclimation temperature. Independent of the influence of growth rate, CS activities were consistently higher in cold- than warm-acclimated 2 + stickleback, suggesting compensatory increases of CS activity with cold acclimation. Corresponding author; This paper is dedicated to the memory of Gerry J. FitzGerald who passed away on March 14, 1994.  相似文献   
97.
One of the principal components of equine metabolic syndrome (EMS) is hyperinsulinaemia combined with insulin resistance. It has long been known that hyperinsulinaemia occurs after the development of insulin resistance. But it is also known that hyperinsulinaemia itself can induce insulin resistance and obesity and might play a key role in the development of metabolic syndrome. This review focuses on the physiology of glucose and insulin metabolism and the pathophysiological mechanisms in glucose homeostasis in the horse (compared with what is already known in humans) in order to gain insight into the pathophysiological principles underlying EMS. The review summarizes new insights on the oral uptake of glucose by the gut and the enteroinsular axis, the role of diet in incretin hormone and postprandial insulin responses, the handling of glucose by the liver, muscle and fat tissue, and the production and secretion of insulin by the pancreas under healthy and disrupted glucose homeostatic conditions in horses.  相似文献   
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99.
100.
Three-spined stickleback Gasterosteus aculeatus, males were implanted with Silastic capsules filled with different aromatase inhibitors; 1,4,6-androstatriene-3,17-dione or the non-steroidal CGS16949 A, 4-(5,6,7,8-tetrahydrimidazol [1,5-a]pyridin-5-yl) benzonitrile monohydrochloride or empty capsules. The fish were then exposed to long or short photoperiod. Under the long photoperiod most fish in all treatments displayed a hypertrophied kidney (a secondary sexual character in sticklebacks) and completed, quiescent spermatogenesis, similar as in the natural spawning period. Under the short photoperiod the controls had unstimulated kidneys and an active spermatogenesis, whereas the males implanted with both aromatase inhibitors had stimulated kidneys, though not to the extent as in the long photoperiod, and completed, quiescent spermatogenesis. These findings suggest that aromatization is of importance for the inhibitory effects of short photoperiod on reproduction in the stickleback. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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