全文获取类型
收费全文 | 433篇 |
免费 | 31篇 |
国内免费 | 4篇 |
专业分类
教育 | 259篇 |
科学研究 | 127篇 |
体育 | 10篇 |
综合类 | 29篇 |
文化理论 | 1篇 |
信息传播 | 42篇 |
出版年
2024年 | 1篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 14篇 |
2017年 | 10篇 |
2016年 | 2篇 |
2015年 | 18篇 |
2014年 | 29篇 |
2013年 | 27篇 |
2012年 | 35篇 |
2011年 | 25篇 |
2010年 | 25篇 |
2009年 | 32篇 |
2008年 | 34篇 |
2007年 | 33篇 |
2006年 | 28篇 |
2005年 | 31篇 |
2004年 | 15篇 |
2003年 | 8篇 |
2002年 | 17篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有468条查询结果,搜索用时 156 毫秒
1.
OA期刊出版模式下的版权平衡——Zwolle原则及其应用分析 总被引:8,自引:0,他引:8
开放存取运动其实质是寻求学术交流领域的利益平衡.Zwolle原则是一个支持学术界进行积极有效的版权管理的一般性原则,对于OA期刊出版中的版权平衡具有积极的指导意义.借鉴Zwolle原则,应从权利配置、版权管理和利益协调三方面着手以实现OA期刊出版模式下的版权平衡. 相似文献
2.
以 8 0 86/ 80 88汇编语言为例 ,通过两个程序的介绍 ,加以比较、分析 ,指出对汇编语言的理解与应用不能简单只留在指令的字面意义上 ,应清楚指令的实际执行的情况 相似文献
3.
Recognizing inconsistencies between the extant fear appeal theories and emotion literature, this research integrated cognitive appraisal theory and functional emotion theory into a fear appeal literature and proposed a model that describes a process through which both fear and anxiety can contribute to adaptive responses. Findings from an experiment (N = 927) supported the predictions. Fear and anxiety emerged as distinct constructs. Perceived susceptibility was a stronger predictor of anxiety than fear, while perceived severity was a stronger predictor of fear than anxiety. In addition, greater fear and anxiety led to greater response efficacy through increased motivation to obtain protection-related information and heightened attention to such information, thus mediating the threat and coping appraisal processes. The SEM model testing the predictions showed that perceived susceptibility had the strongest total effects on protection intention, followed by anxiety, perceived severity, and fear. 相似文献
4.
Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6~84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P<0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P<0.01). (3) Soil iodine value was 0.11~2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution. 相似文献
5.
旷为荣 《康定民族师范高等专科学校学报》2005,14(1):65-68
为了提高党的领导水平和执政水平,必须巩固党的执政基础。本文着重讨论了巩固党的执政基础的三个方面:深厚而广泛的群众基础是中国共产党永葆执政地位的力量源泉;严格而有力的组织基础是确保中国共产党执政地位的根本政治保证;与中国时代特征相结合的马克思主义理论基础是确保中国共产党执政地位的内在要求。 相似文献
6.
在现行的初中物理二力平衡条件中,演示实验存在以下的不足:首先实验是在水平桌面上进行,不利于学生是观察实验现象;直接影响了实验的演示效果。其次是在水平桌面上的小车所受的力不是两个力,而是多个力,有重力、支持力、两个拉力、如果小车运动或有运动趋势,还必须考虑摩擦力。在教学中不好处理这个问题,只讲小车受到的两个拉力而不全面分析小车的受力,这不符合实际,对于具有一定思考 相似文献
7.
Jing-Yang Hu Zi-Qian Hao Laurent Frantz Shi-Fang Wu Wu Chen Yun-Fang Jiang Hong Wu Wei-Min Kuang Haipeng Li Ya-Ping Zhang Li Yu 《国家科学评论(英文版)》2020,7(4):798
Pangolins are among the most critically endangered animals due to heavy poaching and worldwide trafficking. However, their demographic histories and the genomic consequences of their recent population declines remain unknown. We generated high-quality de novo reference genomes for critically endangered Malayan (Manis javanica, MJ) and Chinese (M. pentadactyla, MP) pangolins and re-sequencing population genomic data from 74 MJs and 23 MPs. We recovered the population identities of illegally traded pangolins and previously unrecognized genetic populations that should be protected as evolutionarily distinct conservation units. Demographic reconstruction suggested environmental changes have resulted in a population size fluctuation of pangolins. Additionally, recent population size declines due to human activities have resulted in an increase in inbreeding and genetic load. Deleterious mutations were enriched in genes related to cancer/diseases and cholesterol homeostasis, which may have increased their susceptibility to diseases and decreased their survival potential to adapt to environmental changes and high-cholesterol diets. This comprehensive study provides not only high-quality pangolin reference genomes, but also valuable information concerning the driving factors of long-term population size fluctuations and the genomic impact of recent population size declines due to human activities, which is essential for pangolin conservation management and global action planning. 相似文献
8.
本文以交通运输行业企业社会责任履行对企业财务绩效的影响为立足点,采用利益相关者理论进行多维度社会责任指标划分,通过静态回归分析、动态滞后模型对2011-2015年期间在沪深证券交易所上市的37家交通运输行业公司进行实证研究并提出对策建议。研究结果表明:交通运输行业企业社会责任的履行及企业的成长性均对当期财务绩效指标存在明显的正向作用,而公司的规模对当期财务绩效有明显的负向影响。财务绩效将同时受到滞后一期及滞后两期企业社会责任的正向影响,且时间越长,当期社会责任对后期财务绩效的影响越弱。无论对于当期或后期财务绩效指标而言,企业社会责任均对会计指标衡量的财务绩效产生较市场指标衡量更为显著的正向作用。 相似文献
9.
10.
艺术体操竞赛规则的改变与技术发展 总被引:3,自引:1,他引:2
邝丽 《北京体育大学学报》1993,(4)
近10年来艺术体操规则3次修订,在比赛项目、裁判组织、分值结构、难度动作等方面,都有很多变化,对艺术体操技术的发展有着重要的影响,促进着训练方法与训练手段的改进,并对运动员技术的全面性提出了更高的要求。艺术体操教练员、运动员和裁判员都应切实把握规则变化的实质,改进训练工作和裁判工作,以迅速提高我国艺术体操竞技水平。 相似文献