全文获取类型
收费全文 | 1175篇 |
免费 | 127篇 |
国内免费 | 3篇 |
专业分类
林业 | 105篇 |
农学 | 42篇 |
基础科学 | 12篇 |
247篇 | |
综合类 | 114篇 |
农作物 | 47篇 |
水产渔业 | 59篇 |
畜牧兽医 | 569篇 |
园艺 | 16篇 |
植物保护 | 94篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 15篇 |
2020年 | 19篇 |
2019年 | 20篇 |
2018年 | 33篇 |
2017年 | 18篇 |
2016年 | 31篇 |
2015年 | 37篇 |
2014年 | 46篇 |
2013年 | 56篇 |
2012年 | 69篇 |
2011年 | 99篇 |
2010年 | 57篇 |
2009年 | 45篇 |
2008年 | 77篇 |
2007年 | 79篇 |
2006年 | 83篇 |
2005年 | 68篇 |
2004年 | 69篇 |
2003年 | 66篇 |
2002年 | 70篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 16篇 |
1998年 | 12篇 |
1997年 | 13篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 18篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1977年 | 7篇 |
1975年 | 3篇 |
1971年 | 5篇 |
1970年 | 6篇 |
1968年 | 4篇 |
排序方式: 共有1305条查询结果,搜索用时 0 毫秒
1.
Summary The use of Cruden's index (1977), for studying okra sexual reproductive allocations, indicates a facultative autogamy mode. The purpose of the research described is to obtain more accurate information on the self-fertilization process. For this, self-pollen grain germination was stopped at different times of the day. Twelve varieties of Abelmoschus esculentus were used. Self-fertilization kinetics—expressed by the setting rate—displayed an increase between 7.00 to 16.00 hr. Study of obtained progenies, by stimulated allogamy, confirmed the process and showed that allo-pollen grains deposited on a stigma after midday had only a very little chance of contributing to fertilization. As a result, the polymorphism of the flower structure and particularly the distance between anther and stigmas, insect types and movement habits play major roles in governing okra allogamy. We also show that self-fertilization kinetics can be used to improve controlled hybrid production. 相似文献
2.
F Bernard R Furneaux C Adrega Da Silva J-F Bardet 《Veterinary and comparative orthopaedics and traumatology》2008,21(1):64-68
rhBMP-2 solution on a collagen sponge was placed along the diaphysis of an atrophicradius, which had a history of recurring fractures. Two months after rhBMP-2 treatment, new mineralized bone was present, which significantly increased the diameter of the radius and allowed the removal of the external skeletal fixator (ESF). Due to carpo-metacarpal joint compromise, a pancarpal arthrodesis was performed seven months later. At follow-up evaluation two years later the dog was only very mildly lame. 相似文献
3.
MacLeod MG Valentine J Cowan A Wade A McNeill L Bernard K 《British poultry science》2008,49(3):368-377
1. Naked oats belong to the same species as 'common oats', Avena sativa, but have a non-lignified husk which readily becomes detached during harvesting. The absence of the indigestible husk can be predicted to give an increased metabolisable energy (ME) content for poultry. 2. Measurements of true metabolisable energy (TME(N)) were performed on 3-week-old broiler chicks (Cobb males), adult cockerels (ISA Brown, greater than one year old) and 7-week-old turkeys (BUT T8 males). The measurements were repeated in 2000, 2001 and 2002, with some measurements on a subset of varieties in 2004. 3. High-oil naked oat lines yielded 12% more energy (TME(N)) than wheat. Naked oats, excluding the experimental high-oil lines, yielded 8.5% more energy than simultaneously assayed wheat samples. 4. In samples from the 2004 harvest, conventional oats gave TME(N) values about 13% lower than those of wheat. 5. The addition of beta-glucanase produced an increase of about 4% in the apparent metabolisable energy (AME) of oats for broiler chickens. This effect was associated with a 70% decrease in the jejunal viscosity of broilers receiving a 500 g/kg naked-oat diet. 6. The oil content of naked oats was about 5 times greater than that of wheat, with the high-oil lines rising to more than 6 times greater. Naked oats had a lower starch content than wheat but not sufficiently lower to negate the energy benefits of the higher oil content. The crude protein (CP) contents of naked oats were similar to those of wheat, with the high-oil varieties tending to be higher in CP also. 相似文献
4.
5.
Vouldoukis I Rougier S Dugas B Pino P Mazier D Woehrlé F 《Veterinary parasitology》2006,135(2):137-146
The control of canine leishmaniasis largely depends on the success of treatment. Drugs currently available to treat this disease are toxic and partially effective. The curative effect of marbofloxacin, a third-generation fluoroquinolone developed for veterinarian individual treatment, was evaluated in vitro in the presence of Leishmania infantum promastigotes and dog-monocyte-derived macrophages; meglumine antimoniate and sodium stibogluconate were used as comparative treatments. We observed that the killing of Leishmania promastigotes and intracellular amastigotes by marbofloxacin was dose-dependent. We demonstrated that successful treatment of canine infected macrophages for 48 h was possible with 500 microg/ml of marbofloxacin. Leishmanicidal activity acted through a TNF-alpha and nitric oxide pathway and correlated with the generation of nitric oxide (NO(2)) production by monocytes derived macrophages from infected (23+/-5 microM) or healthy (21+/-6 microM) dogs, in comparison with NO(2) concentration in infected/non-treated macrophages (< 3 microM, P<0.01). This significant induced parasiticidal effect correlated with extensive elimination of amastigotes by macrophages derived from infected (11+/-5) and healthy dogs (6+/-2), when compared to infected/non-treated macrophages (530+/-105 and 472+/-86 amastigotes, respectively, P< 0.01). Marbofloxacin was shown to be non-toxic at 500 microg/ml in vitro and no cell apoptosis was observed. The molecule was able to induce a parasitic process after significant elimination of amastigotes in leishmania-infected dog macrophages. We propose that marbofloxacin, compared to standard chemotherapeutic agents (meglumine antimoniate and sodium stibogluconate), could be an effective and pragmatic oral route alternative to treat canine leishmaniasis. 相似文献
6.
7.
Objective To study the course of intraocular pressure (IOP) after cataract surgery in 50 dogs. Design Prospective study. Animals Fifty dogs without preoperative ocular hypertension were selected for cataract surgery. Methods All dogs underwent cataract surgery: 25 by manual extracapsular extraction and 25 by phacoemulsification. For each dog, intraocular pressure was measured before surgery, and 1, 3, 5, 18 h, 1 week and 1 month post surgery. Results No significant difference of mean intraocular pressure between the two surgical methods was observed for each time measurement. Nine dogs had postoperative hypertension (IOP > 25 mmHg) during the first 5 hours post surgery. Incidence of postoperative hypertension was not significantly different with manual extracapsular extraction (16%) vs. phacoemulsification (20%). A decrease of mean IOP was observed 1 h after surgery (8.49 mmHg vs. 10.91 mmHg), then an increase 3 and 5 h post surgery (12.3 and 13.32 mmHg, respectively). At 18 h, 1 week and 1 month post surgery, mean IOP decreased. Mean IOP was 10.38, 10.38 and 8.84 mmHg, respectively. Conclusion In this study incidence of POH is not high. However, a follow‐up of IOP in the first hours after cataract surgery is required to avoid complications of the retina and optic nerve and to administer hypotensive treatment if necessary. 相似文献
8.
9.
10.