全文获取类型
收费全文 | 13580篇 |
免费 | 350篇 |
专业分类
各国政治 | 637篇 |
工人农民 | 474篇 |
世界政治 | 1054篇 |
外交国际关系 | 477篇 |
法律 | 8076篇 |
中国政治 | 187篇 |
政治理论 | 2863篇 |
综合类 | 162篇 |
出版年
2020年 | 151篇 |
2019年 | 219篇 |
2018年 | 283篇 |
2017年 | 273篇 |
2016年 | 267篇 |
2015年 | 181篇 |
2014年 | 262篇 |
2013年 | 1408篇 |
2012年 | 330篇 |
2011年 | 440篇 |
2010年 | 410篇 |
2009年 | 400篇 |
2008年 | 372篇 |
2007年 | 348篇 |
2006年 | 373篇 |
2005年 | 305篇 |
2004年 | 362篇 |
2003年 | 332篇 |
2002年 | 294篇 |
2001年 | 526篇 |
2000年 | 448篇 |
1999年 | 393篇 |
1998年 | 189篇 |
1997年 | 184篇 |
1996年 | 131篇 |
1995年 | 138篇 |
1994年 | 141篇 |
1993年 | 138篇 |
1992年 | 246篇 |
1991年 | 295篇 |
1990年 | 262篇 |
1989年 | 274篇 |
1988年 | 241篇 |
1987年 | 277篇 |
1986年 | 251篇 |
1985年 | 243篇 |
1984年 | 240篇 |
1983年 | 227篇 |
1982年 | 171篇 |
1981年 | 167篇 |
1980年 | 136篇 |
1979年 | 169篇 |
1978年 | 130篇 |
1977年 | 90篇 |
1976年 | 95篇 |
1975年 | 98篇 |
1974年 | 117篇 |
1973年 | 126篇 |
1972年 | 92篇 |
1970年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
761.
Despite recent and growing media attention surrounding obesity in the United States, the so-called obesity epidemic remains a highly contested scientific and social fact. This article examines the contemporary obesity debate through systematic examination of the claims and claimants involved in the controversy. We argue that four primary groups-antiobesity researchers, antiobesity activists, fat acceptance researchers, and fat acceptance activists-are at the forefront of this controversy and that these groups are fundamentally engaged in framing contests over the nature and consequences of excess body weight. While members of the fat acceptance groups embrace a body diversity frame, presenting fatness as a natural and largely inevitable form of diversity, members of the antiobesity camp frame higher weights as risky behavior akin to smoking, implying that body weight is under personal control and that people have a moral and medical responsibility to manage their weight. Both groups sometimes frame obesity as an illness, which limits blame by suggesting that weight is biologically or genetically determined but simultaneously stigmatizes fat bodies as diseased. While the antiobesity camp frames obesity as an epidemic to increase public attention, fat acceptance activists argue that concern over obesity is distracting attention from a host of more important health issues for fat Americans. We examine the strategies claimants use to establish their own credibility or discredit their opponents, and explain how the fat acceptance movement has exploited structural opportunities and cultural resources created by AIDS activism and feminism to wield some influence over U.S. public health approaches. We conclude that notions of morality play a central role in the controversy over obesity, as in many medical disputes, and illustrate how medical arguments about body weight can be used to stymie rights claims and justify morality-based fears. 相似文献
762.
A study was performed to acquire urine, serum and oral fluid samples in cases of suspected driving under the influence of drugs of abuse. Oral fluid was collected using a novel sampling/testing device (Dr?ger DrugTest System). The aim of the study was to evaluate oral fluid and urine as a predictor of blood samples positive for drugs and impairment symptoms. Analysis for cannabinoids, amphetamine and its derivatives, opiates and cocaine was performed in urine using the Mahsan Kombi/DOA4-test, in serum using immunoassay and gas chromatography-mass spectrometry (GC-MS) confirmation and in oral fluid by GC-MS. Police and medical officer observations of impairment symptoms were rated and evaluated using a threshold value for the classification of driving inability. Accuracy in correlating drug detection in oral fluid and serum were >90% for all substances and also >90% in urine and serum except for THC (71.0%). Of the cases with oral fluid positive for any drug 97.1% of corresponding serum samples were also positive for at least one drug; of drug-positive urine samples this were only 82.4%. In 119 of 146 cases, impairment symptoms above threshold were observed (81.5%). Of the cases with drugs detected in serum, 19.1% appeared not impaired which were the same with drug-positive oral fluid while more persons with drug-positive urine samples appeared uninfluenced (32.7%). The data demonstrate that oral fluid is superior to urine in correlating with serum analytical data and impairment symptoms of drivers under the influence of drugs of abuse. 相似文献
763.
Renita?R.?Glaser M.?Lee?Van.?Horn Michael?W.?ArthurEmail author J.?David.?Hawkins Richard?F.?Catalano 《Journal of Quantitative Criminology》2005,21(1):73-102
Prevention science has produced information about risk and protective factors that predict adolescent drug use and related problem behaviors. This paper investigates the Communities That Care Youth Survey that measures multiple risk and protective factors. Using a sample of 172,628 students who participated in surveys administered in seven states in 1998, analyses were conducted to test the factor structure of these risk and protective factors and to test the equivalence of the factor models across five racial/ethnic groups (African Americans, Asians or Pacific Islanders, Caucasians, Hispanic Americans, and Native Americans), four grade levels (6th, 8th, 10th, and 12th) and both gender groups. Results support the construct validity of the surveys risk and protective factor scales and indicate that the measures are equally reliable across males and females and five racial/ethnic groups. Implications of these findings for science-based prevention planning are discussed. 相似文献
764.
The consumption of Delta9-tetrahydrocannabinol (THC) as cannabis has been shown to result in impaired and culpable driving. Testing drivers for the presence of THC in blood is problematic as THC and its metabolites may remain in the blood for several days following its consumption, even though the drug may no longer have an influence on driving performance. In the present study, the aim was to assess whether performance on the standardised field sobriety tests (SFSTs) provides a sensitive measure of impaired driving behaviour following the consumption of THC. In a repeated measures design, 40 participants consumed cigarettes that contained either 0% THC (placebo), 1.74% THC (low dose) or 2.93% THC (high dose). For each condition, after smoking a cigarette, participants performed the SFSTs on three occasions (5, 55 and 105 min after the smoking procedure had been completed) as well as a simulated driving test on two occasions (30 and 80 min after the smoking procedure had been completed). The results revealed that driving performance was not significantly impaired 30 min after the consumption of THC but was significantly impaired 80 min after the consumption of THC in both the low and high dose conditions. The percentage of participants whose driving performance was correctly classified as either impaired or not impaired based on the SFSTs ranged between 65.8 and 76.3%, across the two THC conditions. The results suggest that performance on the SFSTs provides a moderate predictor of driving impairment following the consumption of THC and as such, the SFSTs may provide an appropriate screening tool for authorities that wish to assess the driving capabilities of individuals suspected of being under the influence of a drug other than alcohol. 相似文献
765.
766.
767.
768.
769.
The mathematical and anatomical methods of estimating living stature from long limb bones are discussed. In forensic cases, when one has a nearly complete skeleton, the anatomical method is preferable to the mathematical method. The anatomical method may also be used to derive stature estimation equations in samples where living statures or cadaver lengths are unavailable, such as some dissection hall and museum collections. 相似文献
770.
K Simpson 《The Medico-legal journal》1968,36(2):Suppl 4:58-Suppl 4:71