全文获取类型
收费全文 | 17289篇 |
免费 | 457篇 |
专业分类
各国政治 | 717篇 |
工人农民 | 684篇 |
世界政治 | 1442篇 |
外交国际关系 | 584篇 |
法律 | 10358篇 |
中国共产党 | 2篇 |
中国政治 | 80篇 |
政治理论 | 3692篇 |
综合类 | 187篇 |
出版年
2020年 | 215篇 |
2019年 | 256篇 |
2018年 | 332篇 |
2017年 | 402篇 |
2016年 | 421篇 |
2015年 | 298篇 |
2014年 | 343篇 |
2013年 | 1694篇 |
2012年 | 412篇 |
2011年 | 433篇 |
2010年 | 350篇 |
2009年 | 386篇 |
2008年 | 446篇 |
2007年 | 466篇 |
2006年 | 439篇 |
2005年 | 405篇 |
2004年 | 401篇 |
2003年 | 421篇 |
2002年 | 385篇 |
2001年 | 681篇 |
2000年 | 616篇 |
1999年 | 509篇 |
1998年 | 288篇 |
1997年 | 245篇 |
1996年 | 204篇 |
1995年 | 207篇 |
1994年 | 246篇 |
1993年 | 219篇 |
1992年 | 338篇 |
1991年 | 370篇 |
1990年 | 327篇 |
1989年 | 346篇 |
1988年 | 318篇 |
1987年 | 333篇 |
1986年 | 338篇 |
1985年 | 333篇 |
1984年 | 288篇 |
1983年 | 317篇 |
1982年 | 255篇 |
1981年 | 240篇 |
1980年 | 179篇 |
1979年 | 248篇 |
1978年 | 166篇 |
1977年 | 146篇 |
1976年 | 133篇 |
1975年 | 120篇 |
1974年 | 137篇 |
1973年 | 119篇 |
1972年 | 112篇 |
1971年 | 94篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Thirty-two self-immolation deaths by fire, representing about 1% of suicides, occurred in the province of Ontario (population 9 million), Canada, from 1986 through 1988. The victims, mostly male (male/female ratio, 26:6), were between 21 and 71 years old (mean age, 38 years). Although the scene of self-immolation was usually familiar to the deceased, some chose remote locations. Eleven were found dead in motor vehicles. An accelerant, usually gasoline, was used in most cases. Many of these individuals had, at some time, indicated their intent to commit suicide, a few by self-immolation, but only about half had a diagnosed psychiatric illness. Most of the victims had a reason to kill themselves, but the factors that motivated them to chose self-immolation by fire were uncertain. Fourteen individuals died in hospitals from severe burn complications. The remainder were found dead at the scene. The postmortem findings of soot in the airway and elevated carbon monoxide in the blood of most of these victims [the carboxyhemoglobin (COHb) concentration was in one case less than 10%, in ten cases greater than or equal to 10 to 50%, and in seven cases greater than 50%] were helpful in determining that the individuals were not only alive at the time of the fire but also that a significant number died from smoke inhalation and carbon monoxide poisoning. The highest levels of carbon monoxide were observed in victims discovered in motor vehicles. 相似文献
992.
993.
994.
K S Blisard C Martin G W Brown J E Smialek L E Davis P J McFeeley 《Journal of forensic sciences》1988,33(6):1457-1462
The causes of death of 53 severely to profoundly developmentally disabled patients who died in an intermediate care facility were reviewed. Respiratory disease, predominantly pneumonia and aspiration, accounted for 72% of deaths. Seven patients died of nonrespiratory causes, and in 8 patients, no cause of death could be determined, even after a complete autopsy or investigation. The median age at death was 20 years. The weights of these patients' organs at autopsy were lower than those for normal individuals of the same age. The lifespan of these severely impaired individuals continues to be significantly shortened, even with improved methods of care. 相似文献
995.
996.
A sensitive method for the detection of anti-A and anti-B hemagglutinins in fresh saliva has been developed. The method utilizes a bromelin treated erythrocyte suspension as indicator cells and includes a simple procedure to concentrate these hemagglutinins. Antiserum directed against immunoglobulin A enhances the hemagglutination assay. We find that these salivary hemagglutinins are present in over 90% of the population and that their titer remains stable over a period of two months. These hemagglutinins can be used to blood type the donor of a saliva sample and can be used in a confirmatory test that complements the commonly used absorption-inhibition test which is used to detect salivary blood group agglutinogens. In preliminary studies we have determined that hemagglutinins can be successfully isolated and analyzed from dried saliva stains. 相似文献
997.
998.
999.
1000.
Ink lines made by porous tip and roller ball pens have been examined by high performance thin layer chromatography (HPTLC) and by transmission microspectrophotometry (VM) in the visible region. Better discrimination between apparently similar coloured inks was obtained with HPTLC but VM has value as an additional technique for ink examination. 相似文献