全文获取类型
收费全文 | 152篇 |
免费 | 3篇 |
专业分类
各国政治 | 8篇 |
工人农民 | 8篇 |
世界政治 | 20篇 |
外交国际关系 | 9篇 |
法律 | 76篇 |
中国政治 | 1篇 |
政治理论 | 32篇 |
综合类 | 1篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 1篇 |
2014年 | 8篇 |
2013年 | 17篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 2篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 1篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.
47.
Sylvia Lane 《政策研究评论》1983,2(3):419-428
Government intervention in the form of consumer protection is appropriate where consumers have less than the required amount of information to protect themselves, where transaction costs act to reduce consumer self-protection below acceptable levels, where consumer welfare is not sufficiently considered in oligopolistic markets, where private costs and social costs diverge due to externalities, where a certain level of quality assurance is necessary if markets are to function and where riskier products removal from the market lowers firms' insurance premiums as well as serves the interest of public health and safety. Consumer protection is a public good which will not be available in optimal quantities without government intervention. 相似文献
48.
49.
50.
A capillary zone electrophoresis (CZE) method was developed for the analysis of amphetamine and 13 amphetamine analogues. A full factorial design was used to screen for important design variables (i.e. carrier electrolyte concentration, pH, and separation temperature), and a modified simplex was employed in a final optimisation step. The resolution values of the target compounds were used as responses in the screening and optimisation phases. This approach made it possible to control the effects of the design variables on the separation of the target compounds. The best results were obtained using a 100mM Tris/phosphate buffer (pH 3.1) at a separation temperature of 10 degrees C, and the analysis time was 23 min under these conditions. After slight modification, the method also enabled baseline resolution of the most commonly encountered amphetamine derivatives, as well as cocaine and heroin, within 7 min. There was a linear relationship between peak area and concentration for all substances, with correlation coefficients in the range of 0.9975-0.9999. Moreover, the technique was repeatable and exhibited relative standard deviation (R.S.D.) values in the ranges of 0.01-0.11% and 0.54-1.60% for relative migration time and corrected peak area, respectively. Lastly, the method was successfully applied to analyse street samples. 相似文献