全文获取类型
收费全文 | 186篇 |
免费 | 10篇 |
专业分类
林业 | 8篇 |
农学 | 23篇 |
基础科学 | 2篇 |
28篇 | |
综合类 | 10篇 |
农作物 | 25篇 |
水产渔业 | 13篇 |
畜牧兽医 | 56篇 |
园艺 | 11篇 |
植物保护 | 20篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 13篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有196条查询结果,搜索用时 15 毫秒
1.
2.
3.
Balamurugan Vinayagamurthy Alamuri Anusha Bharathkumar K. Patil Sharanagouda Siddanagouda Govindaraj Gurrappa Naidu Nagalingam Mohandoss Krishnamoorthy Paramanandham Rahman Habibur Shome Bibek Ranjan 《Tropical animal health and production》2018,50(5):1131-1138
Tropical Animal Health and Production - In this study, the seroprevalence and distribution of Leptospira in dairy cattle in endemic states of India were investigated in association with... 相似文献
4.
Roger D Magarey Sarah SH Klammer Thomas M Chappell Christina M Trexler Godshen R Pallipparambil Ernie F Hain 《Pest management science》2019,75(12):3129-3134
Agricultural industrialization and the subsequent reliance on pesticides has resulted in numerous unintended consequences, such as impacts upon the environment and by extension human health. Eco‐efficiency is a strategy for sustainably increasing production, while simultaneously decreasing these externalities on ecological systems. Eco‐efficiency is defined as the ratio of production to environmental impacts. It has been widely adopted to improve chemical production, but we investigate the challenges of applying eco‐efficiency to pesticide use. Eco‐efficiency strategies include technological innovation, investment in research and development, improvement of business processes, and accounting for market forces. These components are often part of integrated pest management (IPM) systems that include alternatives to pesticides, but its implementation is often thwarted by commercial realities and technical challenges. We propose the creation and adoption of an eco‐efficiency index for pesticide use so that the broad benefits of eco‐efficient strategies such as IPM can be more readily quantified. We propose an index based upon the ratio of crop yield to a risk quotient (RQ) calculated from pesticide toxicity. Eco‐efficiency is an operational basis for optimizing pest management for sustainability. It naturally favors adoption of IPM and should be considered by regulators, researchers, and practitioners involved in pest management. © 2019 Society of Chemical Industry 相似文献
5.
PJ Waller G Bernes SM Thamsborg A Sukura SH Richter K Ingebrigtsen J H?glund 《Acta veterinaria Scandinavica》2001,42(1):31-44
Preparations derived from plants were the original therapeutic interventions used by man to control diseases (including parasites), both within humans and livestock. Development of herbal products depended upon local botanical flora with the result that different remedies tended to develop in different parts of the world. Nevertheless, in some instances, the same or related plants were used over wide geographic regions, which also was the result of communication and/or the importation of plant material of high repute. Thus, the Nordic countries have an ancient, rich and diverse history of plant derived anthelmintic medications for human and animal use. Although some of the more commonly used herbal de-wormers were derived from imported plants, or their products, many are from endemic plants or those that thrive in the Scandinavian environment. With the advent of the modern chemotherapeutic era, and the discovery, development and marketing of a seemingly unlimited variety of highly efficacious, safe synthetic chemicals with very wide spectra of activities, herbal remedies virtually disappeared from the consciousness--at least in the Western world. This attitude is now rapidly changing. There is a widespread resurgence in natural product medication, driven by major threats posed by multi-resistant pest, or disease, organisms and the diminishing public perceptions that synthetic chemicals are the panacea to health and disease control. This review attempts to provide a comprehensive account of the depth of historical Nordic information available on herbal de-wormers, with emphasis on livestock and to provide some insights on potentially rewarding areas of "re-discovery" and scientific evaluation in this field. 相似文献
6.
T.N. Patil J.N. Telford F.W. Plapp R.B. Koch 《Pesticide biochemistry and physiology》1979,12(1):95-104
A water-soluble Mg2+-dependent ATPase (coupling factor F1) was isolated from the mitochondria of housefly thorax. It comprised about 14% of the proteins from a crude preparation. The F1 preparation was nearly homogeneous as assessed by gel electrophoresis, isoelectric focusing, and electron microscopy. It was composed of five subunits with the following apparent molecular weights: α, 68,000; β, 61,000; γ, 38,000; δ, 27,000; and ?, 17,500. The isoelectric pH (pI) of this protein was 7.3. F1 had a pH optimum of 8.2 and a temperature optimum between 37 and 45°C. The enzyme was fairly stable at 25°C. Nearly complete loss of activity was noticed at 0°C, while at 0 or 25°C, glycerol (20%) partially stabilized the enzyme activity against such inactivation. The Km value of the enzyme with respect to ATP was 0.4 mM. The activity was stimulated by low concentrations of 2,4-dinitrophenol. The enzyme was inhibited by azide, p-hydroxymercuribenzoate, and guanidine hydrochloride. Oligomycin and the pesticides pyrethrin, cyhexatin, and DDT have no effect on the enzyme activity. However, all of these chemicals inhibited intact Mg2+- ATPase. The results are discussed in the light of differential responses of soluble and intact ATPase to these pesticides. 相似文献
7.
Flickinger EA Schreijen EM Patil AR Hussein HS Grieshop CM Merchen NR Fahey GC 《Journal of animal science》2003,81(8):2008-2018
Fructans are fermentable carbohydrates and include short-chain fructooligosaccharides (scFOS), inulin, and hydrolyzed inulin (oligofructose, OF). Two studies with dogs were designed to examine the effects of low concentrations of fructans on nutrient digestibilities, fecal microbial populations, and endproducts of protein fermentation, and fecal characteristics. In Exp. 1, 11 adult male beagles were fed corn-based, kibbled diets supplemented with or without OF to provide 1.9 +/- 0.6 g/d. Dietary inclusion of OF decreased (P < 0.05) nutrient digestibilities, but did not affect fecal characteristics. Increasing OF concentration tended (P < 0.06) to linearly decrease fecal ammonia concentrations, but not those of branched-chain fatty acids (BCFA), amines, indole, or phenols. Fecal concentrations of total short-chain fatty acids (SCFA) and butyrate tended to be higher in OF-supplemented dogs (P < 0.10), as was the ratio of bifidobacteria to total anaerobes (P = 0.15). In Exp. 2, ileally cannulated adult female hounds were fed a meat-based kibbled diet and were assigned to four scFOS treatments (0, 1, 2, or 3 g/d) in a 4 x 4 Latin square design. Ileal nutrient digestibilities tended to increase (P < 0.15) with increasing concentrations of scFOS. On a DMI basis, fecal output tended to decrease linearly (P < 0.10) in response to increasing scFOS supplementation, whereas fecal score tended to exhibit a quadratic response (P = 0.12). In general, fecal concentrations of SCFA, BCFA, ammonia, phenols, and indoles were not altered by supplemental scFOS. Supplementation of scFOS increased fecal concentrations of total aerobes (P < 0.05) and decreased concentrations of Clostridium perfringens (P < 0.05). From these data, it seems that low levels of supplemental fructans have divergent effects on nutrient digestibility and fermentative endproducts, but do not adversely affect nutrient digestibility or fecal characteristics and may improve colonic microbial ecology in dogs. 相似文献
8.
Brassica juncea , cv. Pusa Bold, and Brassica campestris , cv. Pusa Kalyani, were raised under field conditions with varying levels of N fertilization, i.e. 0, 40, 80 and 120 kg N ha−1 . Changes in dry matter accumulation in various plant parts as influenced by N supply were measured throughout the crop ontogeny. N supply up to 120 kg had an increasing effect on the growth of leaves, stem and pods during the entire period till maturity. Analysis on the assimilate distribution pattern revealed that 84–87% of the total was accumulated during the post-flowering phase. Dry matter partitioning profile during the ontogeny indicated that about 72–83 % of the total DM was accumulated in the leaves, while 17–28 % in the stem, in the preflowering phase. This trend was found nearly opposite during the postflowering phase. At maturity, however, stem and pods accounted for nearly equal amounts of dry matter accumulation. Among the genotypes, Pusa Bold recorded significantly higher DM accumulation and seed yield over Pusa Kalyani which, on the other hand, exhibited a better assimilate-partioning ability than the former. Nitrogen levels had a favourable effect on LAI, LAD and CGR in both genotypes. Highly significant correlations were obtained between seed yield vs. LAI, LAD and CGR. N fertilization up to 120 kg ha−1 was found beneficial in enhancing growth and yield of rapeseed-mustard. 相似文献
9.
A study was conducted to standardize a protocol for cryopreservation of spermatozoa of the endangered mahseer, Tor khudree (Sykes) and T. putitora (Hamilton). The suitability of the cryoprotectants, dimethyl sulphoxide (DMSO) and glycerol, and the combination of the two were tested. Four equilibration periods and four freezing rates were also tested for their standardization. A combination of 9% DMSO and 11% glycerol gave significantly higher mean percentage of hatching in both T. khudree (45.59±1.86%) (control 71.08±0.59%) and T. putitora (45.00±1.25%) (control 73.48±1.19%) among the eight different treatments. Among the four different equilibration periods tested, the equilibration period of 30 min?1 yielded the highest mean hatching percentage in T. khudree (39.46±1.94%) (control 71.70±0.61%) and T. putitora (38.28±1.06%) (control 73.11±0.82%). Freezing straws at a height of 8 cm above LN2 surface for 10 min?1 gave higher hatching percentages for both T. khudree (41.75±1.72%) (control 73.99±1.17%) and T. putitora (41.34±2.04%) (control 72.48±1.51%). The study reports the superior performance of the combination of DMSO and glycerol for the first time. 相似文献
10.