全文获取类型
收费全文 | 10384篇 |
免费 | 249篇 |
国内免费 | 312篇 |
专业分类
教育 | 6266篇 |
科学研究 | 1840篇 |
各国文化 | 22篇 |
体育 | 859篇 |
综合类 | 730篇 |
文化理论 | 20篇 |
信息传播 | 1208篇 |
出版年
2024年 | 6篇 |
2023年 | 18篇 |
2022年 | 120篇 |
2021年 | 265篇 |
2020年 | 196篇 |
2019年 | 134篇 |
2018年 | 107篇 |
2017年 | 150篇 |
2016年 | 128篇 |
2015年 | 380篇 |
2014年 | 608篇 |
2013年 | 653篇 |
2012年 | 822篇 |
2011年 | 869篇 |
2010年 | 818篇 |
2009年 | 761篇 |
2008年 | 738篇 |
2007年 | 779篇 |
2006年 | 702篇 |
2005年 | 636篇 |
2004年 | 382篇 |
2003年 | 365篇 |
2002年 | 347篇 |
2001年 | 292篇 |
2000年 | 231篇 |
1999年 | 116篇 |
1998年 | 66篇 |
1997年 | 58篇 |
1996年 | 54篇 |
1995年 | 45篇 |
1994年 | 31篇 |
1993年 | 19篇 |
1992年 | 16篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1979年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
考虑一类含有范数有界参数不确定性和混合时滞的中立型系统的严格正实状态反馈控制问题,利用线性矩阵不等式(LMI),给出了状态反馈控制器存在的充分条件,使得对所有的参数不确定性,闭环系统是鲁棒稳定且扩展严格正实的;并得到了控制器的设计方法,数值例子表明了设计方法的有效性。 相似文献
102.
103.
104.
The purpose of the current study was to investigate a two-stage model in which parent-related stress and hopelessness each served as mediators of the relationship between perceived parental bonding and South Korean adolescent peer victimization. This study also examined whether the mediating relationships differed by the gender of parents and adolescents. A casual chain with three links and four sets of variables were analyzed using structural equation modeling. Data were collected from 800 adolescents attending 10 middle schools in the Busan region of South Korea. Results indicated that both maternal and paternal parental bonding were negatively associated with stress, stress was positively associated with hopelessness, and hopelessness was positively associated with South Korean adolescent peer victimization. Most importantly, the significant negative associations between both maternal and paternal parental bonding and peer victimization were mediated by both stress and hopelessness. Furthermore, gender differences in these relationships existed for both parents and adolescents. Limitations and implications to practice were discussed. 相似文献
105.
Li-na Pan Yuan Zhang Chang-jun Zhu Zhi-xiong Dong 《Journal of Zhejiang University. Science. B》2017,18(12):1046-1054
Multidrug resistance (MDR) is the major impediment to cancer chemotherapy. The expression of lung resistance-related protein (LRP), a non-ATP-binding cassette (ABC) transporter, is high in tumor cells, resulting in their resistance to a variety of cytotoxic drugs. However, the function of LRP in tumor drug resistance is not yet explicit. Our previous studies had shown that Kinesin KIF4A was overexpressed in cisplatin (DDP)-resistant human lung adenocarcinoma cells (A549/DDP cells) compared with A549 cells. The expression of KIF4A in A549 or A549/DDP cells significantly affects cisplatin resistance but the detailed mechanisms remain unclear. Here, we performed co-immunoprecipitation experiments to show that the tail domain of KIF4A interacted with the N-terminal of LRP. Immunofluorescence images showed that both the ability of binding to LRP and the motility of KIF4A were essential for the dispersed cytoplasm distribution of LRP. Altogether, our results shed light on a potential mechanism in that motor protein KIF4A promotes drug resistance of lung adenocarcinoma cells through transporting LRP-based vaults along microtubules towards the cell membrane. Thus KIF4A might be a cisplatin resistance-associated protein and serves as a potential target for chemotherapeutic drug resistance in lung cancer. 相似文献
106.
方宁 《宁波广播电视大学学报》2003,1(2):78-80
文化多元是现代社会的重要标志之一,在现代的法治社会中一元法治与多元文化既协调统一又存在矛盾冲突。要实现现代社会的协调发展,人们必须在法治的前提下实践宽容的政治理念,合理维护多元文化的发展,将法治与社会的多元文化整合为统一体。 相似文献
107.
通过对投标施工组织设计作用及特点的分析,阐述了投标施工组织设计在招投标过程中的重要性并指出了投标施工组织设计编制过程中一些经常易被忽视的重要问题。目的在于引导读者如何编制好投标施工组织设计文件。 相似文献
108.
DNA甲基化是真核生物DNA的正常内源性修饰方式 ,它由DNA甲基化转移酶催化发生。但DNA甲基化异常在肿瘤发生中却起着极为重要的作用 ,它主要表现为抑癌基因高甲基化所致的基因失活和原癌基因低甲基化所致的基因激活 ,引起与细胞增殖、分化相关基因表达异常 ,造成细胞恶变形成肿瘤。文章总结了DNA甲基化异常对肿瘤相关基因表达的影响 ,在肿瘤发生中的可能机制及针对高甲基化的治疗方案 相似文献
109.
110.