全文获取类型
收费全文 | 10432篇 |
免费 | 583篇 |
专业分类
各国政治 | 419篇 |
工人农民 | 354篇 |
世界政治 | 808篇 |
外交国际关系 | 303篇 |
法律 | 7071篇 |
中国共产党 | 1篇 |
中国政治 | 54篇 |
政治理论 | 1965篇 |
综合类 | 40篇 |
出版年
2021年 | 60篇 |
2020年 | 192篇 |
2019年 | 232篇 |
2018年 | 231篇 |
2017年 | 293篇 |
2016年 | 295篇 |
2015年 | 245篇 |
2014年 | 268篇 |
2013年 | 985篇 |
2012年 | 235篇 |
2011年 | 302篇 |
2010年 | 288篇 |
2009年 | 299篇 |
2008年 | 285篇 |
2007年 | 256篇 |
2006年 | 273篇 |
2005年 | 248篇 |
2004年 | 249篇 |
2003年 | 232篇 |
2002年 | 237篇 |
2001年 | 462篇 |
2000年 | 418篇 |
1999年 | 291篇 |
1998年 | 181篇 |
1997年 | 148篇 |
1996年 | 123篇 |
1995年 | 117篇 |
1994年 | 144篇 |
1993年 | 131篇 |
1992年 | 196篇 |
1991年 | 217篇 |
1990年 | 203篇 |
1989年 | 212篇 |
1988年 | 205篇 |
1987年 | 190篇 |
1986年 | 231篇 |
1985年 | 206篇 |
1984年 | 159篇 |
1983年 | 169篇 |
1982年 | 112篇 |
1981年 | 121篇 |
1980年 | 85篇 |
1979年 | 134篇 |
1978年 | 74篇 |
1977年 | 73篇 |
1976年 | 69篇 |
1974年 | 73篇 |
1973年 | 66篇 |
1972年 | 66篇 |
1970年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
891.
Beer consumption is commonly an issue in a medico-legal setting, requiring estimates either of a likely blood alcohol concentration (BAC) for a given pattern of consumption or vice versa. Four hundred and four beers and malt beverages available for sale in the State of Washington were tested by gas chromatography for their alcohol content. Considerable variability in the alcoholic strength was found, even within the same class. Overall the range of concentrations was 2.92%v/v to 15.66%v/v. The mean alcohol concentration for ales was 5.51%v/v (SD 1.23%v/v), and for lagers, 5.32% (SD 1.43%v/v). Some specialty brews had characteristically higher or lower mean concentrations: ice beers 6.07%v/v, malt liquor 7.23%v/v, light beer 4.13%v/v, seasonal ales 6.30%v/v. Six brands of lager and four light beers account for the majority of all beer sales in the United States, and the mean alcohol concentration for these products was measured as 4.73%v/v and 4.10%v/v respectively. Few of the beers (17%) were labeled with respect to alcohol content, and in some cases, there was a significant disparity between the concentration listed on the label, and the measured alcohol concentration. Toxicologists need to exercise caution when performing Widmark type calculations, using all available information to select the most appropriate estimate for alcoholic strength of a beer or malt beverage. 相似文献
892.
Accidental hypothermia has been described in the forensic literature but reports of occurrence in hospitalized patients are rare. Associated anatomic lesions include acute hemorrhagic pancreatitis and characteristic acute gastric ulcers termed Wischnewski ulcers. We report here two patients with cirrhosis and ascites; one also had hepatocellular carcinoma. Portal vein thrombosis, acute hemorrhagic pancreatitis and Wischnewski ulcers were present in both. The clinical records documented hypothermia that progressed over several days. Temperature nadirs of 31.0 degrees C (87.8 degrees F) and 32.2 degrees C (90.0 degrees F) were recorded in each patient, respectively, one day before death, although each transiently reached temperatures that did not register on standard monitoring devices. This is the first report that chronicles antemortem body temperatures in hypothermic patients with Wischnewski ulcers and pancreatitis at autopsy. Also, the association of these findings with portal vein thrombosis and cirrhosis has not been previously described. We discuss this constellation of findings with regard to possible mechanistic interrelations. 相似文献
893.
894.
895.
Shirley S. Angrist Richard Mickelsen Anthony N. Penna 《Journal of youth and adolescence》1977,6(2):179-186
Studies of college freshmen find that men are more sexist in their attitudes than women. Does this hold also for high school students? This paper reports the relationship of (1) sex-role attitudes to selected school and family characteristics and (2) attitudes toward family life to sex-role conceptions for women and men. The study is based on 529 students in grades 9 to 12 attending four high schools. The findings show that males are more sexist than females and Blacks more so than Whites. Women who are bright, from upper class backgrounds, and whose mothers work are more equalitarian in sex-role conceptions. For men, family background is unimportant, but attending an elite public school seems to foster equalitarian sex-role conceptions. Men's sex-role attitudes are harder to explain than women's, and, unlike women, their role attitudes have little connection to their family orientation. 相似文献
896.
897.
898.
899.
900.
大多数人拥有住房所有权是新加坡公共住房制度的主要特征。从整体上看,公共住房制度对资产构建起到了积极作用。对于物质资产和人力资产构建而言,建立在住房所有权基础上的公共住房制度创造了一种提高劳动生产率和经济增长的机制,这最终使人们可能拥有更大面积的住房。对于社会资产构建而言,公共住房制度有助于家属关系、种族关系和社区关系的改善。住房所有权的资产构建性创造了一种推动社会全面发展的机制。 相似文献