全文获取类型
收费全文 | 3101篇 |
免费 | 174篇 |
国内免费 | 208篇 |
专业分类
林业 | 253篇 |
农学 | 188篇 |
基础科学 | 70篇 |
473篇 | |
综合类 | 1241篇 |
农作物 | 259篇 |
水产渔业 | 94篇 |
畜牧兽医 | 520篇 |
园艺 | 135篇 |
植物保护 | 250篇 |
出版年
2024年 | 15篇 |
2023年 | 50篇 |
2022年 | 87篇 |
2021年 | 88篇 |
2020年 | 117篇 |
2019年 | 96篇 |
2018年 | 78篇 |
2017年 | 111篇 |
2016年 | 126篇 |
2015年 | 124篇 |
2014年 | 154篇 |
2013年 | 145篇 |
2012年 | 213篇 |
2011年 | 223篇 |
2010年 | 203篇 |
2009年 | 192篇 |
2008年 | 180篇 |
2007年 | 198篇 |
2006年 | 177篇 |
2005年 | 126篇 |
2004年 | 111篇 |
2003年 | 87篇 |
2002年 | 73篇 |
2001年 | 55篇 |
2000年 | 56篇 |
1999年 | 41篇 |
1998年 | 46篇 |
1997年 | 45篇 |
1996年 | 27篇 |
1995年 | 38篇 |
1994年 | 34篇 |
1993年 | 21篇 |
1992年 | 30篇 |
1991年 | 22篇 |
1990年 | 20篇 |
1989年 | 14篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有3483条查询结果,搜索用时 15 毫秒
31.
Five greengram varieties, viz. Mg 161, M3, Co2, Pusa 8793 and Pusa baisakhi, were analyzed for phytic acid, tannic acid and trypsin activity. Significant varietal variation in tannin (310 to 400 mg percent), phytic acid (201.33 to 265.33 mg percent) and trypsin inhibitor activity (55.74 to 97.70 TIU/mg) were observed. 相似文献
32.
AIM: To investigate the oncogenic effect of microRNA-106a (miR-106a) on normal gastric mucous epithelial cells and gastric cancer cells.METHODS: The miR-106a mimic was transfected into normal gastric mucous epithelial cell line GES-1 using liposome. The change of cell growth was measured by MTT assay. The miR-106a inhibitor was transfected into gastric cancer cell lines MGC-803 and SGC-7901 using liposome, and the changes of cell cycle distribution and cell cycle-related protein expression were measured by flow cytometry and Western blotting,respectively. The growth of gastric cancer was also observed using nude mouse xenograft model. RESULTS: The miR-106a mimic increased the growth of GES-1 cells in a dose-dependent manner. By decreasing the expression of cyclin-dependent kinase (CDK) 1 and CDK2, the miR-106a inhibitor arrested MGC-803 cells at G0/G1 and G2/M phases. The miR-106a inhibitor also arrested SGC-7901 cells at G2/M phase by decreasing the expression of CDK1. The results of animal experiments showed that the miR-106a inhibitor significantly suppressed the tumor growth in a dose-dependent manner.CONCLUSION: miR-106a may play an important role in the development of gastric cancer. 相似文献
33.
34.
Yoshiaki Nakagawa Yoshihiro Soya Katsumi Nakai Nobuhiro Oikawa Keiichiro Nishimura Tamio Ueno Toshio Fujita Norio Kurihara 《Pest management science》1995,43(4):339-345
The ability to stimulate N-acetylglucosamine (GluNAc) incorporation in-vitro of a number of N-tert-butyl-N,N′-dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in-vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in-vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in-vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle. 相似文献
35.
Grau-Bassas ER Kociba GJ Couto CG 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(1):81-85
Platelet aggregation before and after administration of 0.5 mg/m2 of vincristine (VCR) was evaluated in 7 dogs with spontaneously occuring lymphoma. Aggregation on platelet-rich plasma separated from blood collected in 3.8% sodium citrate was performed using adenosine diphosphate (ADP), arachidonic acid (AA), and collagen (COL) as agonists. The slope for aggregation in response to ADP was significantly lower after administration of VCR (P = .032). Maximal aggregation after administration of VCR was significantly lower in response to ADP, COL, and AA (P = .03, P = .04, and P = .03, respectively). 相似文献
36.
恒河猴血液细胞、生化和凝血功能正常参考指标的测定 总被引:2,自引:0,他引:2
测定分析人工饲养及在非麻醉(清醒)状态下108只健康成年恒河猴的血常规、血液生化及血小板和凝血功能正常值,并分析各项检测数据的性别差异。血常规测定值17项,其中,雌猴较雄猴极显著高(P<0·01)的项目为红细胞分布宽度(RDW)。血液生化测定值17项,其中,雌猴比雄猴显著低(P<0·05)的项目有丙氨酸转氨酶(ALT),显著高(P<0·05)的项目有碱性磷酸酶(ALP)。血小板和凝血功能测定值9项,其中,雌猴比雄猴明显高(P<0·05)的项目为活化部分凝血活酶时间(APTT),极显著高(P<0.01)的项目为凝血酶时间(TT)。建立了人工饲养条件下健康成年恒河猴的血常规、血液生化、血小板和凝血功能正常参考值指标,丰富和完善了恒河猴动物实验和疾病诊断中血液分析的基础知识。 相似文献
37.
38.
本文首次报道了象虫金小蜂在中国的分布,并用图文简要地描述其特征。该蜂是四纹豆象、米象、谷象、玉米象、烟草甲和药材甲等重要贮藏物害虫的天敌。 相似文献
39.
40.
AIM:To investigate the role of caspase 3 inhibitor Ac-DEVD-CHO in caspase 3 signaling pathway and NF-κB activation induced by 10-hydroxycamptothecin (HCPT) in human breast carcinoma cells. METHODS:The cell growth inhibition was measured by MTT assay. Agarose gel electrophoresis was performed for detecting cell apoptosis. Western blotting was used for determining protein expression. DIG-EMSA was conducted to measure the DNA-binding activation of NF-κB. RESULTS:Caspase 3 inhibitor Ac-DEVD-CHO attenuated HCPT-induced apoptosis in human breast carcinoma. Ac-DEVD-CHO also suppressed the degradation of caspase 3 and IκBα,and arrested the activation of NF-κB. CONCLUSION:Caspase 3 inhibitor Ac-DEVD-CHO regulates the activation of caspase 3 and NF-κB,and attenuates apoptosis in Bcap37 cell line induced by HCPT. 相似文献