全文获取类型
收费全文 | 15156篇 |
免费 | 461篇 |
国内免费 | 518篇 |
专业分类
教育 | 10533篇 |
科学研究 | 2526篇 |
各国文化 | 113篇 |
体育 | 683篇 |
综合类 | 996篇 |
文化理论 | 22篇 |
信息传播 | 1262篇 |
出版年
2024年 | 9篇 |
2023年 | 109篇 |
2022年 | 170篇 |
2021年 | 330篇 |
2020年 | 458篇 |
2019年 | 376篇 |
2018年 | 312篇 |
2017年 | 301篇 |
2016年 | 378篇 |
2015年 | 465篇 |
2014年 | 545篇 |
2013年 | 973篇 |
2012年 | 1152篇 |
2011年 | 1151篇 |
2010年 | 670篇 |
2009年 | 763篇 |
2008年 | 1067篇 |
2007年 | 1184篇 |
2006年 | 1279篇 |
2005年 | 1077篇 |
2004年 | 896篇 |
2003年 | 668篇 |
2002年 | 509篇 |
2001年 | 346篇 |
2000年 | 294篇 |
1999年 | 143篇 |
1998年 | 92篇 |
1997年 | 85篇 |
1996年 | 76篇 |
1995年 | 48篇 |
1994年 | 46篇 |
1993年 | 42篇 |
1992年 | 32篇 |
1991年 | 26篇 |
1990年 | 19篇 |
1989年 | 21篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
基于ontology智能检索系统的底层数据结构设计 总被引:3,自引:0,他引:3
本文提出了构建基于ontology检索系统的底层数据结构应具有面向对象的特性 ,同时也提出了数据结构设计中会出现的问题和解决办法 相似文献
22.
孙凡 《现代图书情报技术》2004,(Z1)
根据金融管理信息系统互联互通的发展要求 ,提出了借鉴美国国防信息基础设施公共操作环境 ( DII COE)的思想进行系统的技术体系结构设计的思路 ,并结合我国商业银行管理信息系统的实例进行了分析 相似文献
23.
24.
Veronika Karnowski Larissa Leonhard Anna Sophie Kümpel 《Communication Research Reports》2018,35(2):91-100
Social media have become an integral part of online news use, affecting how individuals find, consume, and share news. By applying the Theory of Reasoned Action (TRA), this study investigates the effects of motives, attitude, and intention on news-sharing behavior among German social media users (n = 333). Findings show that news-sharing attitude and subjective norms have a positive effect on news-sharing intention, which in turn has a positive effect on actual news-sharing behavior. Taken together, we see that a new media behavior in the early phases of its societal diffusion—like social media news sharing in Germany in 2015—can mainly be explained by a rational choice logic and is rooted in the motives of socializing and information seeking. This finding thus reflects the double nature of social media as a means for both information retrieval and social grooming. 相似文献
25.
Holly Thompson 《Medical reference services quarterly》2018,37(1):97-104
The National Institutes of Health (NIH) library instruction program provides training services to staff, clinicians, and researchers across NIH and several Department of Health and Human Services (HHS) operating divisions. The audience, training needs, and training topics are diverse and constantly changing. The NIH library has developed several new services and class topics to meet the needs of its NIH and HHS communities. Context, strategies, and future directions for the NIH library instruction program are described. 相似文献
26.
Lotta Haglund Annikki Roos Petra Wallgren‐Björk 《Health information and libraries journal》2018,35(3):251-255
Librarians in Sweden are facing huge challenges in meeting the demands of their organisations and users. This article looks at four key areas: coping with open science/open access initiatives; increasing demands from researchers for support doing systematic reviews; understanding user experiences in Swedish health science libraries; and the consequences of expanding roles for recruitment and continuing professional development. With regard to changing roles, there is an increasing shift from the generalist towards the expert role. The authors raise the issue as to how to prepare those new to the profession to the changing environment of health science libraries. 相似文献
27.
HE Zhen-zhen YANG Yu-dong 《课程.教材.教法》2008,28(4):49-52
课堂教学的多因素综合评估是个复杂问题,是一个软信息的、多判据的决策过程。用模糊数学方法建立的人工智能评估模型可以较为全面地对课堂教学进行评估。使用改进后模型编制的软件对若干数学录像课做分析,结果表明,软信息等级判据评估有望克服简单加权平均的弊端。 相似文献
28.
Yunlong CHENG Shu LIAN Shuhui LI Yusheng LU Jie WANG Xiaoxiao DENG Shengyi ZHAI Lee JIA 《Journal of Zhejiang University. Science. B》2022,23(11):943
ObjectivePrimary tumor treatment through surgical resection and adjuvant therapy has been extensively studied, but there is a lack of effective strategies and drugs for the treatment of tumor metastases. Here, we describe a functional product based on a combination of compounds, which can be used as an adjuvant therapy and has well-known mechanisms for inhibiting cancer metastases, improving anti-cancer treatment, and enhancing immunity and antioxidant capacity. Our designed combination, named MVBL, consists of four inexpensive compounds: L-selenium-methylselenocysteine (MSC), D-α-tocopheryl succinic acid (VES), β-carotene (β-Ca), and L-lysine (Lys).MethodsThe effects of MVBL on cell viability, cell cycle, cell apoptosis, cell migration, cell invasion, reactive oxygen species (ROS), and paclitaxel (PTX)-combined treatment were studied in vitro. The inhibition of tumor metastasis, antioxidation, and immune enhancement capacity of MVBL were determined in vivo.ResultsMVBL exhibited higher toxicity to tumor cells than to normal cells. It did not significantly affect the cell cycle of cancer cells, but increased their apoptosis. Wound healing, adhesion, and transwell assays showed that MVBL significantly inhibited tumor cell migration, adhesion, and invasion. MVBL sensitized MDA-MB-231 breast cancer cells to PTX, indicating that it can be used as an adjuvant to enhance the therapeutic effect of chemotherapy drugs. In mice, experimental data showed that MVBL inhibited tumor metastasis, prolonged their survival time, and enhanced their antioxidant capacity and immune function.ConclusionsThis study revealed the roles of MVBL in improving immunity and antioxidation, preventing tumor growth, and inhibiting metastasis in vitro and in vivo. MVBL may be used as an adjuvant drug in cancer therapy for improving the survival and quality of life of cancer patients. 相似文献
29.
30.
波士顿咨询集团矩阵是对企业经营的全部产品或者业务组合进行整体分析的一种重要的战略工具。本文分析大学利用波士顿咨询集团矩阵进行学科规划的情况,并且对大学利用波士顿咨询集团矩阵进行学科和专业规划的情况进行评价。 相似文献