全文获取类型
收费全文 | 146905篇 |
免费 | 8511篇 |
国内免费 | 823篇 |
专业分类
林业 | 5613篇 |
农学 | 4313篇 |
基础科学 | 1125篇 |
17066篇 | |
综合类 | 28415篇 |
农作物 | 5503篇 |
水产渔业 | 6883篇 |
畜牧兽医 | 76550篇 |
园艺 | 1861篇 |
植物保护 | 8910篇 |
出版年
2019年 | 1440篇 |
2018年 | 2073篇 |
2017年 | 2398篇 |
2016年 | 2168篇 |
2015年 | 2003篇 |
2014年 | 2338篇 |
2013年 | 5382篇 |
2012年 | 4374篇 |
2011年 | 5418篇 |
2010年 | 3525篇 |
2009年 | 3489篇 |
2008年 | 4977篇 |
2007年 | 4745篇 |
2006年 | 4420篇 |
2005年 | 4149篇 |
2004年 | 3812篇 |
2003年 | 3868篇 |
2002年 | 3676篇 |
2001年 | 4435篇 |
2000年 | 4559篇 |
1999年 | 3517篇 |
1998年 | 1428篇 |
1997年 | 1383篇 |
1995年 | 1561篇 |
1994年 | 1393篇 |
1993年 | 1345篇 |
1992年 | 2974篇 |
1991年 | 3239篇 |
1990年 | 3103篇 |
1989年 | 3055篇 |
1988年 | 2891篇 |
1987年 | 3017篇 |
1986年 | 3080篇 |
1985年 | 2839篇 |
1984年 | 2368篇 |
1983年 | 2028篇 |
1982年 | 1385篇 |
1979年 | 2151篇 |
1978年 | 1762篇 |
1977年 | 1502篇 |
1976年 | 1499篇 |
1975年 | 1565篇 |
1974年 | 2061篇 |
1973年 | 2035篇 |
1972年 | 1960篇 |
1971年 | 1795篇 |
1970年 | 1748篇 |
1969年 | 1618篇 |
1968年 | 1355篇 |
1967年 | 1430篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
RNA was extracted from single or small groups of ovine ovarian follicles after treatment of ewes with FSH and/or LH. The content of mRNA for the alpha-inhibin and beta A-inhibin subunits was analyzed by hybridization with specific cDNA probes. All ewes were treated with progestin vaginal pessaries to suppress spontaneous preovulatory follicle maturation and ewes were given three intramuscular injections of gonadotropins at 8-hr intervals starting 24 hr prior to collection of ovaries. In experiment I, both Schering-FSH and NIDDK-oFSH-17 (oFSH) significantly increased alpha- and beta A-inhibin mRNA per ewe in 2-5 mm follicles and tended to increase alpha- and beta A-inhibin mRNA in large (greater than 5 mm) follicles. In experiment II, oFSH and NIDDK-oLH-25 (oLH) were administered in a 2X2 factorial arrangement. Separate administration of oFSH or oLH increased (P less than .05) the alpha-inhibin mRNA concentration in large follicles. alpha-inhibin mRNA concentration in 4-5 mm follicles was also increased by oFSH but was decreased by oLH. Concomitant treatment with oFSH and oLH did not change alpha-inhibin mRNA concentrations from those measured in oFSH treated ewes. In experiment II, beta A mRNA concentrations followed a pattern similar to that of alpha A mRNA, but the differences were not statistically significant. We conclude that, in the ewe, exogenous FSH increases the concentration of inhibin mRNA in the whole follicle. The ability of exogenous oLH to alter expression of the inhibin subunit genes may depend upon the stage of follicle maturation. 相似文献
62.
L A Janssens 《Veterinary surgery : VS》1991,20(4):274-278
Seven foci of pain (trigger points) were identified in the triceps brachii, infraspinatus, adductor-pectineus, peroneus longus, gluteus medius, ileocostorum lumborum, and quadriceps femoris muscles in 48 lame dogs. The dogs had been lame for 1 day to 150 weeks (mean, 24 weeks). Thirty-one dogs had been treated unsuccessfully with corticosteroids, nonsteroidal anti-inflammatory drugs, analgesics, or acupuncture. Palpating the trigger points induced severe pain. Treatment consisted of weekly stimulation of the trigger points by needling or injection of a local anesthetic. The mean treatment period was 2.8 weeks. Excellent results and complete recovery were observed in 34 dogs (60%). 相似文献
63.
R. Iori O. Leoni L. Lazzeri G. Mosca S. Palmieri 《Journal of Agronomy and Crop Science》1991,167(2):91-95
Samples of rapeseed from three Italian growing environments (Bologna, Perugia and Palermo) were analysed for glucose content and dry weight of 1000 seeds every three or four days starting from the end of flowering until complete ripening. In addition, the content of oil, soluble and total proteins, glucosinolates and myrosinase activity was determined in samples of mature seeds. The cultivars used were jet Neuf and Lingot (type 0) and Tandem, Jade and Santana (type 00). From the results it emerged that the point of intersection of the two branches of the linear regression plots for different glucose-consumption kinetics found during seed filling, in addition to being strongly affected by the climate of the test environment, is correlated with quantitative and qualitative production, independently of the genotype. 相似文献
64.
65.
66.
67.
68.
Jennifer L Davis 《Veterinary Clinics of North America: Equine Practice》2003,19(3):765-778
In summary, peritonitis in the horse is a potentially life-threatening disease that must be treated promptly and aggressively. Therapy should be aimed at reducing systemic shock and hypovolemia, correction of the primary cause, antibiotic and anti-inflammatory therapy, and abdominal drainage and lavage. The prognosis depends on the ability to diagnose and treat the underlying cause and prevent the development of complications. Mortality rates can be as high as 59.7%, with horses developing postoperative peritonitis having a 56% mortality rate. Long-term complications like adhesion formation or internal abscesses may further reduce the survival rate. The prognosis is best determined by an early and quick response to aggressive treatment. 相似文献
69.
70.
Colitis cystica profunda in dogs has been diagnosed in one case only. The two own cases were characterized by repeated, partly bloody diarrhea, vomitus, and painful defecation. The disease was diagnosed by clinical examination and colonoscopy with the ensuing histological examination of biopsy specimens. The disease could be managed by administration of a diet, sulfasalazine and corticosteroids. 相似文献