全文获取类型
收费全文 | 31550篇 |
免费 | 1438篇 |
专业分类
各国政治 | 1322篇 |
工人农民 | 1334篇 |
世界政治 | 2386篇 |
外交国际关系 | 1062篇 |
法律 | 20162篇 |
中国共产党 | 3篇 |
中国政治 | 167篇 |
政治理论 | 6300篇 |
综合类 | 252篇 |
出版年
2021年 | 157篇 |
2020年 | 581篇 |
2019年 | 636篇 |
2018年 | 825篇 |
2017年 | 877篇 |
2016年 | 983篇 |
2015年 | 705篇 |
2014年 | 802篇 |
2013年 | 3249篇 |
2012年 | 805篇 |
2011年 | 846篇 |
2010年 | 801篇 |
2009年 | 850篇 |
2008年 | 859篇 |
2007年 | 876篇 |
2006年 | 871篇 |
2005年 | 758篇 |
2004年 | 777篇 |
2003年 | 698篇 |
2002年 | 717篇 |
2001年 | 1174篇 |
2000年 | 1084篇 |
1999年 | 875篇 |
1998年 | 485篇 |
1997年 | 384篇 |
1996年 | 366篇 |
1995年 | 372篇 |
1994年 | 395篇 |
1993年 | 367篇 |
1992年 | 563篇 |
1991年 | 599篇 |
1990年 | 571篇 |
1989年 | 561篇 |
1988年 | 553篇 |
1987年 | 548篇 |
1986年 | 584篇 |
1985年 | 581篇 |
1984年 | 494篇 |
1983年 | 474篇 |
1982年 | 394篇 |
1981年 | 366篇 |
1980年 | 302篇 |
1979年 | 425篇 |
1978年 | 259篇 |
1977年 | 219篇 |
1976年 | 193篇 |
1975年 | 205篇 |
1974年 | 239篇 |
1973年 | 183篇 |
1972年 | 182篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
An improved method has been developed for the reliable classification of different C1R genetic variant forms from human serum or plasma. The method combines the use of neuraminidase-digested samples followed by monodimensional isoelectric focusing in the pH range 5 to 8 followed by immunoblotting. The method yields a simple pattern, with one major band in homozygote and two major bands in heterozygote cases. 相似文献
132.
Dilutions of 100 serum samples of various GM phenotypes were dotted onto a nitrocellulose membrane. The serum dot-blots were detected with peroxidase-labeled anti-G3M T monoclonal antibody (anti-G3M T MAb). Up to a 1 : 256 dilution could be G3M T-typed correctly. By use of anti-G3M T MAb and peroxidase-labeled anti-mouse IgG or the biotin-avidin system instead of use of labeled anti-G3M T MAb, up to a 1 : 512 or 1 : 1024, respectively, dilution was typable. As with previous work with G3M G MAb, the dot immunobinding (DIB) method for G3M T typing was found very simple and practical. 相似文献
133.
Finding audiences, changing beliefs: the structure of research use in Canadian health policy 总被引:1,自引:0,他引:1
J Lomas 《Journal of health politics, policy and law》1990,15(3):525-542
The impact of research information depends on its ability to change beliefs or policy assumptions within the relevant audiences. As a hybrid of American and British systems, Canada's chosen decision-making structure for policy-making and its legislative framework for health insurance make these audiences unclear and not readily accessible. This factor and historical characteristics of the research community which made them only partially responsive to the values of decisionmakers provide an explanation for the limited past use of research information in Canadian health policy. More recently, improved responsiveness by researchers and an emerging definition of the audiences by legislative policymakers are bringing about a gradual increase in the potential impact of research at the levels of administrative and clinical policy. Because of continuing decision-making constraints on legislative policy, however, impact at this level is predicted to remain diffuse, with only cautious acceptance of the changes in beliefs implied by research. 相似文献
134.
M Moniri 《Journal of forensic sciences》1990,35(1):181-185
A technique was developed for Gm/Km typing of bloodstains and sera in U-bottom microtiter plates. Gm/Km typing of sweat and urine samples was also attempted with limited success. 相似文献
135.
136.
137.
D M Fox 《Journal of health politics, policy and law》1990,15(2):341-355
HIV infection is now perceived as the end stage of a chronic disease that is spreading most rapidly among blacks and Hispanics. The politics of the HIV epidemic in the 1980s were dominated by four interacting factors: fear and fascination; who had the disease and to whom it seemed to be spreading; the endemic problems of United States social policy; and the impact on policy of advances in scientific knowledge. This paper analyzes the political history of each of these factors and describes the dominant policies of the federal government and the states regarding HIV in the areas of surveillance, prevention, research, and financing. Four uncertainties will have a profound influence on the future politics of the HIV epidemic: how the states and the federal government will address the general problems of paying for the care of people with chronic diseases and providing access to care for the uninsured and the underinsured; the number and distribution of the sexual behaviors that transmit infection with HIV and the effectiveness of policies to persuade people to modify these behaviors; precisely who uses addictive drugs and the effectiveness of measures to change their behavior; and the natural history of the virus. 相似文献
138.
Andrew J. Nathan 《当代中国》1993,2(4):3-13
China's experiments with democracy in this century were few in number, short in duration, and limited in their democratic characteristics. Democratic institutions malfunctioned in numerous ways. Nine sets of causes for the failure of Chinese democracy can be suggested: ideology, internal and external war, military intervention, Chinese political culture, underdevelopment, a peasant mass, flaws in the design of Chinese constitutions, moral failures by democratic politicians, or the lack of transactional benefits for military‐based elites in the process of democratic transition. Each of these factors is reviewed critically with an eye to its possible lessons. 相似文献
139.
Postmortem changes in sulfide concentrations in body tissues were examined in autopsied rats exposed to hydrogen sulfide concentrations of 550 to 650 ppm, and in nonexposed rats and humans. Analyses were made by gas chromatography, following an extractive alkylation. Sulfide concentrations in the blood, liver, and kidneys of rats increased in both the exposed and nonexposed groups, depending on the lapse of time after death. On the other hand, the lung, brain, and muscle showed little or no change in sulfide concentration with elapse of time after death. The data obtained from human tissues were almost the same as those for rats, except data for blood, in which no or little increase of sulfide was observed. 相似文献
140.
C J Kim B H Kwak S D Kim S P Kim 《The American journal of forensic medicine and pathology》1992,13(3):211-213
A 22-year-old Korean soldier, who had received blows to the neck and epigastrium from an officer 10 h earlier, suddenly died after massive hematemesis. He had been in relatively good health except for episodes of blood-tinged vomiting approximately 5 and 7 months prior to this event. Postmortem examination revealed angiodysplasia involving the gastroesophageal junction, and the stomach was distended with blood. No abnormal findings were present around the whole viscera, and the duodenum was free of blood. The pathologic significance of upper gastrointestinal angiodysplasia as a potential source of bleeding and a chronologic correlation between the trauma and bleeding are discussed. 相似文献