首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13423篇
  免费   719篇
各国政治   797篇
工人农民   421篇
世界政治   1110篇
外交国际关系   688篇
法律   7593篇
中国政治   87篇
政治理论   3313篇
综合类   133篇
  2023年   76篇
  2021年   92篇
  2020年   254篇
  2019年   316篇
  2018年   350篇
  2017年   409篇
  2016年   418篇
  2015年   321篇
  2014年   358篇
  2013年   1798篇
  2012年   323篇
  2011年   349篇
  2010年   375篇
  2009年   405篇
  2008年   331篇
  2007年   388篇
  2006年   371篇
  2005年   402篇
  2004年   411篇
  2003年   364篇
  2002年   370篇
  2001年   436篇
  2000年   370篇
  1999年   329篇
  1998年   193篇
  1997年   155篇
  1996年   160篇
  1995年   172篇
  1994年   183篇
  1993年   173篇
  1992年   236篇
  1991年   251篇
  1990年   212篇
  1989年   228篇
  1988年   190篇
  1987年   204篇
  1986年   193篇
  1985年   201篇
  1984年   153篇
  1983年   183篇
  1982年   128篇
  1981年   133篇
  1980年   93篇
  1979年   145篇
  1978年   105篇
  1977年   94篇
  1976年   84篇
  1975年   60篇
  1974年   70篇
  1973年   70篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
Reticuline (a precursor of opium alkaloids) was detected and characterised as its trimethylsilyl ethers, acetyl esters and methyl ethers by GC-EIMS and GC-CIMS in opium and the urine of opium users after hydrolysis by acid or beta-glucuronidase as coextractive of morphine. Because this compound cannot be detected in heroin and poppy seeds, it is suggested as a differentiating marker between opium and heroin use, opium and poppy seeds use, or opium and "pharmaceutical" codeine use in cases when opiate use has been confirmed by detection of morphine and codeine in the urine. As well as being a constituent of opium, reticuline in the urine of opium users may also result from the metabolic demethylation of the three other benzyltetrahydroisoquinoline opium alkaloids: codamine, laudanosine and laudanine.  相似文献   
962.
Firearm-related injuries are a leading cause of morbidity and mortality in South Africa. This retrospective autopsy study included all firearm-related fatalities seen at a central mortuary in Durban. These cases had initially been assessed by a clinician before death, from July 1998 to June 1999.A total of 322 cases of fatal gunshot wounds were reviewed. Medical records and postmortem findings were compared by data capture onto a spreadsheet. Twenty-eight cases were excluded because of surgical alteration of the wounds, making autopsy evaluation impossible. In 50.7% of cases, the number of wounds was correctly identified and in 55.1% the position was correctly identified. In only 36.1% of cases were the entry and exit wounds correctly identified. The total number of missed wounds was 504 (48.3% of cases). The majority of missed wounds were on the upper limbs (25%), with the anterior trunk (21.8%) and lower limbs (18.5%) making up the remainder. This study demonstrates that physicians in South Africa do not adequately document and interpret gunshot wounds, which may influence the treatment of the patient and have medicolegal consequences. Emphasis should be placed on undergraduate and postgraduate teaching for physicians to correctly identify, interpret, and document firearm wounds.  相似文献   
963.
Pulmonary thromboembolism is an often fatal complication of venous thrombosis. Any component or combination of the components composing Virchow's triad (venostasis, hypercoagulability, and endothelial damage) increases the propensity for a thrombophilic state. Hypercoagulable states may be inherited or acquired. While the etiology in many cases may be evident either on physical examination or on evaluation of the decedent's medical history, this is often not the case. We conducted a retrospective study of cases presenting to the Jefferson County Coroner/Medical Examiner's Office in Birmingham, Alabama, who were given a diagnosis of pulmonary embolism. A search of cases within the past 23 years yielded 81 cases. An underlying cause was determined in 70 cases (86%). The remaining 11 (14%) cases had no identifiable cause. We believe that a number of these cases may represent an underlying thrombophilic disorder. Since these disorders may be of an inherited or acquired nature, the determination of an etiology may be relevant to the decedent's family. Postmortem blood analyses may in selected cases be useful and appropriate for the detection of some of these disorders. However, such analyses are not practical in all cases, with each case having to be evaluated on its own merits.  相似文献   
964.
965.
This study explored the effects of judges' personal characteristics (gender, race, age, and political affiliation) and case characteristics on the outcomes of federal cases of hostile environment sexual harassment. Results revealed that even after controlling for the effects of relevant case characteristics (e.g., severity of the harassment), judges' personal characteristics influenced case outcomes. Specifically, younger judges and Democrat judges were more likely to find for the plaintiff (the alleged victim of harassment). The probability that the decision would favor the plaintiff was only 16% when the case was heard by an older judge but 45% when heard by a younger judge. The probability that the decision would favor the plaintiff was only 18% when the case was heard by a judge who had been appointed by a Republican president but 46% when the judge had been appointed by a Democrat president.  相似文献   
966.
Reported is a case of an assault causing extensive blunt force injuries in which the clinical, radiologic, and postmortem findings were all consistent with death resulting from brain damage arising from the assault. The assailant was charged with murder. Subsequent full neuropathologic (including histologic) examination revealed the unsuspected finding of a widespread meningoencephalitis but no evidence of significant traumatic brain damage. The contributions of the infective process and of the trauma to death were felt to be unclear and a guilty plea to attempted murder was accepted. This case highlights the importance of a full neuropathologic examination, including histology, in cases of trauma to the head, even when the cause of death may initially appear obvious.  相似文献   
967.
Suffocation by inhaled gases has been reported involving a variety of gases. We report a case of suicidal asphyxiation by forced replacement of oxygen with helium by using a complex homemade mask. In this case, a young woman researched suicide on the Internet and found an advocated method of suicide using helium. To our knowledge, there is only 1 previously reported case of suicidal asphyxia by using helium.  相似文献   
968.
969.
970.
Three experiments were conducted to explore whether children's recall of an occurrence of a repeated event could be improved by encouraging them to consider various details that occurred across a series of events prior to making a judgement about which details were included in the target (to-be-recalled) occurrence. Experiment 1 explored whether children's recall of the target occurrence was better after the interviewer presented all the items from the series prior to the child identifying the final item. Experiment 2 explored whether having the children generate all the items facilitated their subsequent recall of the target occurrence. Finally, Experiment 3 directly compared the effectiveness of the above 2 procedures. Regardless of the children's age, the retention interval, or the type of item, children's capacity to identify which details were included in a target occurrence was enhanced when they were initially provided with all the possible details from the series of events. However, without relying on the interviewer to generate the options, the benefit of the technique was directly contingent on the children's ability to generate content details; this was a distinct source of difficulty for the children. Indeed, having children generate options had no beneficial effect on decisions about the temporal position of items unless performance was made conditional on the children's ability to remember the relevant details in the first place. The implications of the findings for the legal setting and for future research are discussed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号