全文获取类型
收费全文 | 7267篇 |
免费 | 153篇 |
专业分类
各国政治 | 379篇 |
工人农民 | 193篇 |
世界政治 | 458篇 |
外交国际关系 | 279篇 |
法律 | 4593篇 |
中国共产党 | 1篇 |
中国政治 | 19篇 |
政治理论 | 1406篇 |
综合类 | 92篇 |
出版年
2020年 | 61篇 |
2019年 | 83篇 |
2018年 | 123篇 |
2017年 | 130篇 |
2016年 | 150篇 |
2015年 | 109篇 |
2014年 | 127篇 |
2013年 | 771篇 |
2012年 | 199篇 |
2011年 | 194篇 |
2010年 | 153篇 |
2009年 | 162篇 |
2008年 | 194篇 |
2007年 | 173篇 |
2006年 | 185篇 |
2005年 | 144篇 |
2004年 | 150篇 |
2003年 | 154篇 |
2002年 | 160篇 |
2001年 | 302篇 |
2000年 | 275篇 |
1999年 | 219篇 |
1998年 | 81篇 |
1997年 | 102篇 |
1996年 | 77篇 |
1995年 | 80篇 |
1994年 | 90篇 |
1993年 | 79篇 |
1992年 | 156篇 |
1991年 | 175篇 |
1990年 | 155篇 |
1989年 | 170篇 |
1988年 | 148篇 |
1987年 | 141篇 |
1986年 | 164篇 |
1985年 | 126篇 |
1984年 | 125篇 |
1983年 | 130篇 |
1982年 | 77篇 |
1981年 | 75篇 |
1980年 | 57篇 |
1979年 | 110篇 |
1978年 | 63篇 |
1977年 | 61篇 |
1976年 | 56篇 |
1975年 | 66篇 |
1974年 | 81篇 |
1973年 | 76篇 |
1972年 | 67篇 |
1971年 | 60篇 |
排序方式: 共有7420条查询结果,搜索用时 15 毫秒
301.
The authors gratefully acknowledge helpful comments from Charles Rowley, Robert Tollison, and a referee of this journal. 相似文献
302.
In this paper a new economic approach to standardization has been presented. Standardization has been regarded as a problem ofgradual choice. An individual chooses to apply more or less standards within a hierarchy of standards. With this decomposition of standards, the problem of strategic market power becomes less important than in the traditional models of standardization. It becomes possible to analyze the problems of network externalities within a framework of non-strategic behavior and to apply the tools of the traditional theory of externalities and public goods. While decentralized action may lead to too little standardization, committees may overcome this deficiency to some extent, but bureaucracies are likely to lead to overstandardization. In the empirical section of the paper it has been shown that our approach can be applied to the standard-setting process in languages, railroads, and telecommunications. In all three cases the tendency of bureaucracies to generate more standardization than committees has been corroborated.The authors are indebted for helpful comments to the participants of the Berlin Seminar on Political Economy and of the colloquium Algemene Economie, Rijksuniversiteit Groningen, and to A. Roemer, Saarbrücken. 相似文献
303.
This paper presents evidence that voter participation does not depend on the probability that one vote is decisive. An extensive summary of the empirical participation literature is provided which shows that most but not all studies have found that turnout in an electoral district is higher when the race is closer. Individual-level vote regressions for the 1979 and 1980 Canadian national elections are estimated using objective measures of closeness (as opposed to self-reported measures). The main finding is that a citizen is no more likely to vote in a close election than in a lands-lide election. District-level turnout regressions for the same elections are also estimated, and a significant relation between closeness and turnout is observed. This suggests that aggregation bias may generate a spurious closeness-turnout relation in district-level regressions. 相似文献
304.
This longitudinal study investigates parent and child predictors of adolescents' perceived social support from peers. Adolescents (285) and their parents filled out surveys when students were 11 and 15 years of age. Parent reports of their own social support and child reports of parental support to them, depression, and self-esteem were used as predictors of adolescents' peer social support. Path analyses revealed functional dissimilarity in the predictive model, for boys and girls. For boys and girls, the amount of spousal support parents' reported impacted the amount of parent to child support that children reported. For boys, this relationship impacted their perceptions of peer support indirectly through depression. However, for girls, parents' own supportive relationships directly impacted both their self-esteem and depression, above and beyond parent to child support, which then impacted girls' peer social support. 相似文献
305.
Counseling skills were evaluated in a telephone counseling service for Vietnam veterans. Thirty simulated crisis calls were made to telephone counselors by experienced clinical psychologists. The counselors' responses were rated on dimensions that indexed general counseling skills, knowledge of veteran needs, and provision of appropriate advice. Whereas the majority of callers demonstrated adequate counseling skills, many lacked knowledge of veterans' posttraumatic stress, common veteran terminology, and the nature of veterans' experiences. The findings suggest that telephone counseling services that target specific populations should employ comprehensive training to ensure that counselors possess adequate and relevant knowledge about callers and their presenting problems. The simulated caller paradigm appears to be an effective paradigm for training and evaluation of telephone counselors. 相似文献
306.
307.
308.
A 33 year-old Polish field-worker was found by his colleagues kneeling in front of his trailer, with a bloody stab wound in the heart region. In spite of prompt surgical intervention, the man died from his injury a few hours later. Upon examination of the dead man's trailer a blood-smeared vegetable-knife was found in the sink, and on the floor, a pullover with a slit-like cut. On the wall hung a jacket on a hook with a cut in the inner surface of the left breast pocket but not in the outside layer. The examination of the clothes, the autopsy and a reconstruction of the sequence of events led to the following conclusion: The knife had been placed into the breast pocket of the jacket with the tip facing downwards. As the man put down a sack of potatoes, the knife hooked into a pre-existing gap in the sack and was driven into the chest cavity by the pressure weight of the heavy sack. 相似文献
309.
An intoxication following administration of morphine, tramadol and atracurium in a suicide case is reported. The route of administration and the amount of the particular drug were known from the investigation of the death scene and the findings of the postmortem examination. Tramadol was present in the gastric contents as well as in blood, liver, kidney and brain samples, whereas the drug could not be detected in muscle. All body fluids and tissues investigated contained morphine as well as its 3- and 6-glucuronides with the exception of muscle tissue. The concentrations of morphine and its glucuronide metabolites were determined by LC/MS following solid phase extraction. Interestingly, the concentration of M6G in brain, liver and kidney were close to the concentration of M3G in the particular tissue. This phenomenon might be explained by a preferential hydrolysis of M3G or by a preferential formation of M6G postmortem. Measurement of morphine and M6G in femoral blood and cerebrospinal fluid may be a useful indicator in rapid deaths. 相似文献
310.
Phillips SA Lowe A Marshall M Hubbard P Burmeister SG Williams DR 《Journal of forensic sciences》2000,45(2):324-332
Recent criminal acts in the United Kingdom, United States and other countries have demonstrated the dangers to public safety from the criminal use of improvised explosives on a large scale. Four sets of trials were carried out over four years, partly in collaboration with the United States Federal Bureau of Investigation, involving the firing of large bombs, mostly fertilizer based. The principal objectives of the firings were to measure the physical effects of the explosions upon objects representative of those that would be found at a real bomb scene and to recover any chemical traces deposited on these objects. The results are intended for use as an aid in determining the approximate size and type of an explosive employed in a terrorist attack. This paper describes the background behind the trials, the procedures for preparation of witness materials and charges, and the collection and analysis of physical and chemical evidence. 相似文献