全文获取类型
收费全文 | 7114篇 |
免费 | 175篇 |
专业分类
各国政治 | 424篇 |
工人农民 | 308篇 |
世界政治 | 438篇 |
外交国际关系 | 270篇 |
法律 | 4395篇 |
中国政治 | 40篇 |
政治理论 | 1365篇 |
综合类 | 49篇 |
出版年
2020年 | 71篇 |
2019年 | 87篇 |
2018年 | 116篇 |
2017年 | 139篇 |
2016年 | 145篇 |
2015年 | 105篇 |
2014年 | 136篇 |
2013年 | 764篇 |
2012年 | 144篇 |
2011年 | 153篇 |
2010年 | 148篇 |
2009年 | 144篇 |
2008年 | 176篇 |
2007年 | 186篇 |
2006年 | 188篇 |
2005年 | 150篇 |
2004年 | 142篇 |
2003年 | 163篇 |
2002年 | 130篇 |
2001年 | 274篇 |
2000年 | 232篇 |
1999年 | 223篇 |
1998年 | 95篇 |
1997年 | 79篇 |
1996年 | 71篇 |
1995年 | 64篇 |
1994年 | 75篇 |
1993年 | 67篇 |
1992年 | 121篇 |
1991年 | 159篇 |
1990年 | 155篇 |
1989年 | 142篇 |
1988年 | 148篇 |
1987年 | 165篇 |
1986年 | 159篇 |
1985年 | 148篇 |
1984年 | 131篇 |
1983年 | 120篇 |
1982年 | 81篇 |
1981年 | 91篇 |
1980年 | 68篇 |
1979年 | 126篇 |
1978年 | 86篇 |
1977年 | 72篇 |
1976年 | 56篇 |
1975年 | 82篇 |
1974年 | 86篇 |
1973年 | 83篇 |
1972年 | 56篇 |
1971年 | 57篇 |
排序方式: 共有7289条查询结果,搜索用时 359 毫秒
791.
792.
793.
794.
795.
A high selective screening test (Ad-Tip method) for methamphetamine in human urine has been devised. The method involves a brief extraction from a urine sample with an Ad-Tip (ODS-silica minicolumn), washing, eluting with modified Simon's reagent, and coloration with carbonate buffer. Detection limit of methamphetamine in urine is 1 microgram/ml and the test takes within 3 min/sample. The results of the Ad-Tip method were almost identical to those of laboratory analyses. 相似文献
796.
Presented is a case of murder by means of chloroquine, committed on a 36-year-old male. The wife of the deceased had confessed to have secretely administered chloroquine-containing tablets to her husband. She was lawfully sentenced to life-imprisonment. The toxicological findings of this case are compared to the results of two chloroquine suicide cases and discussed in the context of the referring literature. An additional case where chloroquine intoxication was doubtful is introduced because of the unusual circumstances under which it occurred. 相似文献
797.
Commotio cordis, revisited 总被引:1,自引:0,他引:1
Nonpenetrating cardiac injuries due to direct precordial blunt impacts are a commonly encountered phenomenon in medicolegal offices. These injuries vary from contusions to valvular lacerations, or papillary muscle rupture to coronary arterial injury with resulting infarction. A less commonly occurring manifestation of nonpenetrating injury is a concussion of the heart (commotio cordis), often with dramatic physiological consequences but no morphologic cardiac injury. We describe four case reports of this entity. The cases were collected over a 5-year period (1978-1983) from the Wayne County Medical Examiner's Office in Detroit, Michigan. 相似文献
798.
799.
Sudden unexpected nocturnal death syndrome (SUNDS) is a distinct clinical entity in previously healthy, young, Southeast Asian males. It is well known in the Philippines and more recently recognized in the U.S. by nonspecific autopsy findings, with no evidence of underlying disease and absence of toxic drug or alcohol levels. In 1973-89, 14 cases of apparent SUNDS came to coroner's autopsy in the Commonwealth of the Northern Marianas (CNMI) and Guam. All 14 cases, with the exception of one Yapese, were previously healthy, male Filipinos, aged 23 to 55, who were either found dead in bed, or described by their colleagues as having nocturnal seizure activity consisting of gurgling, frothing, and tongue biting immediately prior to death. Autopsy findings showed no anatomic findings to account for death. Comprehensive serum and urine drug analyses were negative. All decedents showed absence of significant atherosclerosis or grossly detectable structural cardiac anomaly, while four showed cardiomegaly. Migrants from Southeast Asia carry with them a pre-disposition to this syndrome, which appears to decline with longer residence in the new country. The mechanism of death in SUNDS is believed to be ventricular fibrillation, possibly precipitated by sudden sympathetic discharge. Studies suggest at least some deaths may be associated with an abnormal cardiac conduction system. Acute pancreatitis has been a finding in some series, but not our cases. Why the condition is virtually limited to males and seemingly sleep-triggered, has not been adequately explained. Stress and depression are believed to be predisposing factors. 相似文献
800.