全文获取类型
收费全文 | 13517篇 |
免费 | 411篇 |
专业分类
各国政治 | 612篇 |
工人农民 | 555篇 |
世界政治 | 961篇 |
外交国际关系 | 563篇 |
法律 | 7774篇 |
中国共产党 | 35篇 |
中国政治 | 148篇 |
政治理论 | 3105篇 |
综合类 | 175篇 |
出版年
2021年 | 94篇 |
2020年 | 207篇 |
2019年 | 189篇 |
2018年 | 301篇 |
2017年 | 359篇 |
2016年 | 395篇 |
2015年 | 299篇 |
2014年 | 313篇 |
2013年 | 1427篇 |
2012年 | 323篇 |
2011年 | 379篇 |
2010年 | 298篇 |
2009年 | 399篇 |
2008年 | 480篇 |
2007年 | 483篇 |
2006年 | 428篇 |
2005年 | 406篇 |
2004年 | 396篇 |
2003年 | 327篇 |
2002年 | 331篇 |
2001年 | 423篇 |
2000年 | 387篇 |
1999年 | 325篇 |
1998年 | 215篇 |
1997年 | 168篇 |
1996年 | 183篇 |
1995年 | 168篇 |
1994年 | 176篇 |
1993年 | 167篇 |
1992年 | 227篇 |
1991年 | 296篇 |
1990年 | 237篇 |
1989年 | 239篇 |
1988年 | 253篇 |
1987年 | 237篇 |
1986年 | 267篇 |
1985年 | 205篇 |
1984年 | 186篇 |
1983年 | 187篇 |
1982年 | 131篇 |
1981年 | 141篇 |
1980年 | 126篇 |
1979年 | 119篇 |
1978年 | 107篇 |
1977年 | 91篇 |
1976年 | 79篇 |
1975年 | 71篇 |
1974年 | 84篇 |
1973年 | 85篇 |
1971年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
961.
The authors describe the results obtained using the scanning electron microscope (SEM) to study drowned lungs and control lungs. Results are compared with a previous study carried out using laboratory animals. The results from both studies are analogous, in the absence of chronic pulmonary emphysema. The diagnosis of chronic pulmonary emphysema is simple with the SEM even when dealing with autoptic material obtained 24 to 48 h after death, but the diagnosis of drowning becomes difficult in lungs with chronic emphysema. 相似文献
962.
963.
Aryeh L. Unger 《欧亚研究》1977,29(2):306-316
964.
Richard L. Abel 《Law & social inquiry》1985,10(1):5-79
The author surveys and compares the legal professions of 15 nations, including both civil law and common law countries. The essay is organized around the ways that legal professionals control their markets—first by controlling "production of producers" or who and how many enter the profession (with formal education or apprenticeship requirements, examinations, access to entry-level positions). Legal professionals also control "production by producers"—both external competitors and lawyers themselves. This occurs, for example, through definition and defense of the professional monopoly, control of competition between licensed professionals, and creation of demand. The discussion takes place against the background of the legal profession's recent history—assessing changes in its composition (by race, age, gender), in lawyers' practice settings, in the categories of work they perform, and in the income and status associated with these categories and with the profession in general. 相似文献
965.
966.
967.
968.
969.
Because of difficulties collecting sales taxes on Internet sales, several states have engaged in an effort (the Streamlined Sales Tax Project, SSTP) to simplify their sales tax systems. One hope among SSTP proponents is that a simplified system will result in Internet vendors voluntarily collecting the sales tax. We address two issues:
- ? Will states adopt the extensive reforms proposed by the SSTP?
- ? Will vendors voluntarily collect the sales tax?
970.
Schneider PM Bender K Mayr WR Parson W Hoste B Decorte R Cordonnier J Vanek D Morling N Karjalainen M Marie-Paule Carlotti C Sabatier M Hohoff C Schmitter H Pflug W Wenzel R Patzelt D Lessig R Dobrowolski P O'Donnell G Garafano L Dobosz M De Knijff P Mevag B Pawlowski R Gusmão L Conceicao Vide M Alonso Alonso A García Fernández O Sanz Nicolás P Kihlgreen A Bär W Meier V Teyssier A Coquoz R Brandt C Germann U Gill P Hallett J Greenhalgh M 《Forensic science international》2004,139(2-3):123-134
Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts. 相似文献