全文获取类型
收费全文 | 7154篇 |
免费 | 201篇 |
专业分类
各国政治 | 235篇 |
工人农民 | 244篇 |
世界政治 | 480篇 |
外交国际关系 | 214篇 |
法律 | 4883篇 |
中国政治 | 47篇 |
政治理论 | 1215篇 |
综合类 | 37篇 |
出版年
2020年 | 92篇 |
2019年 | 112篇 |
2018年 | 130篇 |
2017年 | 159篇 |
2016年 | 162篇 |
2015年 | 109篇 |
2014年 | 157篇 |
2013年 | 641篇 |
2012年 | 169篇 |
2011年 | 186篇 |
2010年 | 160篇 |
2009年 | 156篇 |
2008年 | 188篇 |
2007年 | 214篇 |
2006年 | 222篇 |
2005年 | 179篇 |
2004年 | 185篇 |
2003年 | 201篇 |
2002年 | 164篇 |
2001年 | 314篇 |
2000年 | 291篇 |
1999年 | 220篇 |
1998年 | 85篇 |
1997年 | 69篇 |
1996年 | 75篇 |
1995年 | 68篇 |
1994年 | 76篇 |
1993年 | 61篇 |
1992年 | 141篇 |
1991年 | 153篇 |
1990年 | 136篇 |
1989年 | 155篇 |
1988年 | 134篇 |
1987年 | 149篇 |
1986年 | 134篇 |
1985年 | 152篇 |
1984年 | 118篇 |
1983年 | 139篇 |
1982年 | 93篇 |
1981年 | 93篇 |
1980年 | 69篇 |
1979年 | 99篇 |
1978年 | 74篇 |
1977年 | 66篇 |
1976年 | 57篇 |
1975年 | 46篇 |
1974年 | 57篇 |
1973年 | 59篇 |
1971年 | 50篇 |
1970年 | 46篇 |
排序方式: 共有7355条查询结果,搜索用时 15 毫秒
361.
362.
Campman SC Holmes JF Sokolove PE Romero JA Yost BA Lie JT 《The American journal of forensic medicine and pathology》2000,21(1):69-73
Arterial fibromuscular dysplasia (FMD) represents a collection of noninflammatory and nonatherosclerotic vascular diseases with a poorly understood etiology. Classically occurring in renal and cerebral arteries, this entity has also been reported in coronary, carotid, and other medium and small arteries. One case occurring in the pulmonary vasculature has been reported. Fatal hemothorax and lung hemorrhage have multiple causes, including other vascular malformations and connective tissue disorders; however, cases of pulmonary FMD are exceedingly rare. We report what appears to be the second such association, occurring in a 69-year-old man. The patient presented with a 3-week history of increasing dyspnea, fatigue, and productive cough; 3 days of increasing back and chest pain; and syncope. Chest radiograph showed a "white-out" of the left lung. The patient died shortly after admission from a fulminant respiratory disease of undetermined etiology. At autopsy he was found to have a massive left hemothorax resulting from an unsuspected pulmonary arterial fibromuscular dysplasia. 相似文献
363.
364.
Determination of formic acid tissue and fluid concentrations in three fatalities due to methanol poisoning 总被引:1,自引:0,他引:1
Hantson P Haufroid V Mahieu P 《The American journal of forensic medicine and pathology》2000,21(4):335-338
Three fatalities caused by methanol ingestion are reported. Admission blood methanol concentrations ranged from 0.28 to 4.6 g/L. Two patients had been admitted after a significant delay (>20 hours), and one patient was observed within 90 minutes following ingestion. Formic acid levels were determined in blood samples at admission and ranged from 302 to 680 mg/L. The patients died 44, 55, and 82 hours after poisoning. Formic acid determinations in postmortem tissues were performed by a gas chromatograph method. The authors found great variability in formic acid distribution among the patients and among organs. 相似文献
365.
366.
Steadman HJ Silver E Monahan J Appelbaum PS Robbins PC Mulvey EP Grisso T Roth LH Banks S 《Law and human behavior》2000,24(1):83-100
Since the 1970s, a wide body of research has suggested that the accuracy of clinical risk assessments of violence might be increased if clinicians used actuarial tools. Despite considerable progress in recent years in the development of such tools for violence risk assessment, they remain primarily research instruments, largely ignored in daily clinical practice. We argue that because most existing actuarial tools are based on a main effects regression approach, they do not adequately reflect the contingent nature of the clinical assessment processes. To enhance the use of actuarial violence risk assessment tools, we propose a classification tree rather than a main effects regression approach. In addition, we suggest that by employing two decision thresholds for identifying high- and low-risk cases--instead of the standard single threshold--the use of actuarial tools to make dichotomous risk classification decisions may be further enhanced. These claims are supported with empirical data from the MacArthur Violence Risk Assessment Study. 相似文献
367.
368.
369.
Dettmeyer R Schmidt P Musshoff F Dreisvogt C Madea B 《Forensic science international》2000,110(2):87-96
Pulmonary edema complicating heroin overdosage is a well recognized entity and regarded as the major mechanism contributing to death in heroin addicts. It's pathogenesis is unknown, several mechanisms are discussed: hypoxia-induced increase of pulmonary capillary permeability, depressed myocardial contractility, centrally induced respiratory depression, primary toxic effects on the alveolar capillaries and acute anaphylactic shock. The present study included opiate-related deaths (n=23) and a control group of sudden cardiovascular deaths (n=12) to verify the hypothesis, that defects of the alveolar capillary membranes and/or an acute anaphylactic reaction leads to pulmonary congestion, edema and hemorrhages. Lung specimens were obtained from these 35 autopsies of persons autopsied in the Institute of Forensic Medicine, University of Bonn, in 1997 and 1998. All specimens were examined with hematoxylin-eosin, prussian blue and investigated with immunohistological methods using primary antibodies against collagen IV, laminin and IgE. Defects of the basal laminae of the alveoli were found, demonstrated by laminin and collagen IV, and the number of IgE-positive cells was counted in both groups. There was an increased but not significant number of IgE-positive cells in the heroin-group and defects of the epithelial and endothelial basal laminae were found in both groups without significant differences. 相似文献
370.
Clauwaert KM Van Bocxlaer JF Lambert WE De Leenheer AP 《Forensic science international》2000,110(3):157-166
Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29-316 ng/mg of hair for cocaine, 0.43-141 ng/mg of hair for benzoylecgonine and 0.93-1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage. 相似文献