全文获取类型
收费全文 | 18069篇 |
免费 | 304篇 |
专业分类
各国政治 | 486篇 |
工人农民 | 1457篇 |
世界政治 | 775篇 |
外交国际关系 | 575篇 |
法律 | 11006篇 |
中国共产党 | 34篇 |
中国政治 | 127篇 |
政治理论 | 3777篇 |
综合类 | 136篇 |
出版年
2021年 | 62篇 |
2020年 | 149篇 |
2019年 | 131篇 |
2018年 | 1424篇 |
2017年 | 1386篇 |
2016年 | 1242篇 |
2015年 | 282篇 |
2014年 | 237篇 |
2013年 | 856篇 |
2012年 | 415篇 |
2011年 | 1151篇 |
2010年 | 1175篇 |
2009年 | 821篇 |
2008年 | 1029篇 |
2007年 | 997篇 |
2006年 | 334篇 |
2005年 | 361篇 |
2004年 | 466篇 |
2003年 | 381篇 |
2002年 | 264篇 |
2001年 | 356篇 |
2000年 | 331篇 |
1999年 | 258篇 |
1998年 | 165篇 |
1997年 | 122篇 |
1996年 | 160篇 |
1995年 | 143篇 |
1994年 | 149篇 |
1993年 | 127篇 |
1992年 | 199篇 |
1991年 | 253篇 |
1990年 | 212篇 |
1989年 | 199篇 |
1988年 | 221篇 |
1987年 | 201篇 |
1986年 | 220篇 |
1985年 | 192篇 |
1984年 | 173篇 |
1983年 | 166篇 |
1982年 | 109篇 |
1981年 | 125篇 |
1980年 | 102篇 |
1979年 | 106篇 |
1978年 | 96篇 |
1977年 | 86篇 |
1976年 | 64篇 |
1975年 | 64篇 |
1974年 | 65篇 |
1973年 | 77篇 |
1969年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
Iezzoni LI 《Journal of health politics, policy and law》2000,25(6):1157-1167
972.
Zhu BL Oritani S Shimotouge K Ishida K Quan L Fujita MQ Ogawa M Maeda H 《Forensic science international》2000,113(1-3):443-447
To outline the recent features of methamphetamine-related fatalities from the medico-legal point of view, a retrospective investigation of forensic autopsy cases involving methamphetamine during a 5-year period (1994-1998) in the southern half of Osaka city and surrounding areas (about 1.57 million population) was undertaken. Among 646 autopsy cases, methamphetamine was detected in 15 victims (nine males, six females; 16-71 years of age; most frequently in males in their thirties). Primary scenes of fatal events were concentrated in the middle of the city. About half of them were transferred from emergency medical centers (survival time, up to 30 h). The cause and manner of death were: methamphetamine poisoning (n=4), homicide (n=4), accidental falls and aspiration from drug abuse (n=4), fire death (n=1), myocardial infarction (n=1), and cerebral hemorrhage (n=1) under drug influence. Usually injection scars and fresh puncture sites were found. Blood methamphetamine concentrations were 2.29-17.05 micromol/dl in the fatal poisoning, 0. 44-3.80 micromol/dl in deaths from other extrinsic causes (trauma), and 1.35-2.17 micromol/dl in cardio- and cerebrovascular strokes. Common complications were cardiomyopathy, cerebral perivasculitis and liver cirrhosis/interstitial hepatitis. Fatal and nonfatal methamphetamine poisonings are separately dealt with by the administrative medical examiner's office and in emergency medical centers. Tightly cooperative approaches of clinical and medico-legal experts are required for the effective social and medical management of drug abuse. 相似文献
973.
This paper describes a collaborative exercise organised under the auspices of the European Network of Forensic Science Institutes (ENFSI). The purpose of this EU (European Union) funded group is to carry out research to enable STR loci to be compared between European laboratories, ultimately leading to the formation of a pan-European database. Accordingly, an exercise was designed to evaluate a prototype STR multiplex system manufactured by Applied Biosystems (ABD). Each laboratory was sent 12 samples to analyse along with a multiplex kit. Of specific interest was the definition of parameters to define the efficiency of the system. Stutter, split allelic peaks (differing by one base), pull-up, heterozygous balance and between locus balance were all objectively measured. Once the important parameters are defined it is possible to directly compare performances of different multiplexes and the different laboratories carrying out the tests. Since the multiplex used was a prototype system, this exercise cannot be regarded as a proficiency test. 相似文献
974.
975.
976.
977.
978.
979.
980.
应用40Hz听觉相关电位与听性脑干反应评估听阈 总被引:5,自引:2,他引:3
对 42例 74耳(正常听力组 32耳,检案中主诉听力下降 42耳)分别进行纯音测定,声导抗测定,听性脑干反应 (Auditory Brainstem Response,ABR)及 0.5~ 2kHz范围的 40Hz听觉相关电位 (40Hertz Auditory Event- related Potential,40Hz AERP)测定,对其中 20耳进行睡眠及清醒两种状态的 40Hz AERP测定。将纯音听阈、 40Hz AERP反应阈、 ABR反应阈三者之间进行比较分析。结果表明,正常听力耳 40Hz AERP反应阈值较纯音测听阈值高,在不同频率的校正值 (差值 )不同, 0.5 kHz为 12.7± 6.4(dBnHL); 1kHz为 14.7± 6.3(dBnHL); 2 kHz为 15± 5.6(dBnHL)。 ABR阈值比行为听阈高,校正值为 8.9± 5.3(dBnHL)。睡眠状态时 40Hz AERP阈值较清醒状态阈值高,校正值为 9.7± 2.45(dBnHL)。检案中主诉听力下降者主、客观语音频率均值之间明显不相符 ,误差率为 61%。本研究表明单纯使用 ABR、纯音测听中任何一种方法估计语音频率听阈均有一定的误差。 相似文献