全文获取类型
收费全文 | 84982篇 |
免费 | 9847篇 |
国内免费 | 5943篇 |
专业分类
林业 | 6636篇 |
农学 | 4538篇 |
基础科学 | 3934篇 |
7977篇 | |
综合类 | 43585篇 |
农作物 | 6721篇 |
水产渔业 | 4448篇 |
畜牧兽医 | 12651篇 |
园艺 | 6688篇 |
植物保护 | 3594篇 |
出版年
2025年 | 44篇 |
2024年 | 1952篇 |
2023年 | 2033篇 |
2022年 | 3958篇 |
2021年 | 3869篇 |
2020年 | 3631篇 |
2019年 | 3542篇 |
2018年 | 2507篇 |
2017年 | 4107篇 |
2016年 | 2644篇 |
2015年 | 4118篇 |
2014年 | 4415篇 |
2013年 | 5265篇 |
2012年 | 7416篇 |
2011年 | 7419篇 |
2010年 | 6935篇 |
2009年 | 6178篇 |
2008年 | 6400篇 |
2007年 | 5987篇 |
2006年 | 4858篇 |
2005年 | 3985篇 |
2004年 | 2436篇 |
2003年 | 1523篇 |
2002年 | 1755篇 |
2001年 | 1482篇 |
2000年 | 1345篇 |
1999年 | 491篇 |
1998年 | 66篇 |
1997年 | 41篇 |
1996年 | 20篇 |
1995年 | 35篇 |
1994年 | 31篇 |
1993年 | 35篇 |
1992年 | 39篇 |
1991年 | 29篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1981年 | 5篇 |
1965年 | 3篇 |
1964年 | 4篇 |
1963年 | 4篇 |
1962年 | 17篇 |
1961年 | 5篇 |
1959年 | 3篇 |
1958年 | 3篇 |
1957年 | 11篇 |
1956年 | 32篇 |
1955年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
CHEN Wei-zhen ZHANG Yong LU Han-ping LIANG Chang-sheng XIE Yao LIU Chang-zheng 《园艺学报》2007,23(10):2051-2053
AIM: To investigate the effect of 188Re labeled monoclonal antibody on prostatic specific membrane antigen 7E11C5.3,radioimmunotherapy for the treatment of human prostate cancer cell line LNCaP in vitro.METHODS: 188Re-7E11C5.3 was prepared by direct 2-mercaptoethanol reduction method.Labeling efficiency and radiochemical purity was measured by paper chromatography.Immunoreactive fraction was determined by linear extrapolation.Cytotoxicity to LNCaP cells was determined by MTT assay.RESULTS: The labeling yield of 188Re-7E11C5.3 was (93.16±2.18)%,the radiochemical purity was (95.62±0.48)%,and the immunoreactive fraction was (74.86±1.86)%.The inhibitory effect of 188Re-7E11C5.3 on cell proliferation of LNCaP cells was significantly higher than that of 188Re-mIgG or 188ReO-4.The 50% inhibitory doses (IC50) of 188Re-7E11C5.3,188Re-mIgG,and 188ReO-4 were (23.38±3.73)×107 Bq/L,(59.21±8.02)×107 Bq/L and (68.89±10.91)×107 Bq/L,respectively.CONCLUSION: 188Re-7E11C5.3 can effectively inhibit the growth of in vitro cultured prostate cancer cells and shows much potential for prostate cancer radioimmunotherapy. 相似文献
24.
超抗原以极低的浓度就能引起机体免疫细胞、细胞因子和抗体的巨大变化,引起机体一系列病理生理过程。鉴于超抗原的这种特性,医学上已成功将其用于癌症和病毒病的辅助治疗。在兽医科学上,超抗原有望在兽医病理学、兽医药理学、兽医临床治疗和兽医预防方面得到广泛的应用。 相似文献
25.
26.
27.
TONG Xia-sheng LI Chang-chong RUAN Zheng-ying CHEN Hao GUO Hai-yuan FAN Guang-min 《园艺学报》2006,22(7):1397-1401
AIM:To observe the changes of polymorphonuclear leukocytes (PMN), neutrophil elastase (NE) and myeloperoxidase (MPO) expression in rat asthma. METHODS:Eighteen rats were randomly divided into two groups on average, including asthma group and control group. The rat model of asthma was established by the ovalbumin (OVA) challenge methods. Blood PMN were isolated andpurified. The protein expression of MPO were detected by immunohistochemistry and chromatometry techniques. NE was detected by ELISA. RESULTS:(1) Immunohistochemistry showed that the levels of MPO expression around bronchus and in purified PMN in asthma group were significantly increased compared with those in control group (P<0.01). Activities of MPO were significantly increased in bronchoalveolar lavage fluid (BALF) and lung tissue in asthma group compared with those in control group (P<0.05, P<0.01). (2) Levels of NE were significantly increased in BALF and PMN in asthma group compared with control group (P<0.01). (3) Number of PMN were significantly higher in BALF, bronchus and lung tissue in asthma group than those in control group (P<0.01). CONCLUSION:Levels of PMN counting and expression of MPO and NEare significantly increased in experimental asthma rats. PMN may be involved in inflammation in asthma via increasing the levels of NE and MPO. 相似文献
28.
29.
30.