全文获取类型
收费全文 | 849篇 |
免费 | 45篇 |
专业分类
各国政治 | 79篇 |
工人农民 | 67篇 |
世界政治 | 78篇 |
外交国际关系 | 56篇 |
法律 | 407篇 |
中国共产党 | 2篇 |
中国政治 | 12篇 |
政治理论 | 187篇 |
综合类 | 6篇 |
出版年
2023年 | 14篇 |
2022年 | 11篇 |
2021年 | 10篇 |
2020年 | 30篇 |
2019年 | 39篇 |
2018年 | 57篇 |
2017年 | 50篇 |
2016年 | 47篇 |
2015年 | 33篇 |
2014年 | 31篇 |
2013年 | 132篇 |
2012年 | 41篇 |
2011年 | 36篇 |
2010年 | 39篇 |
2009年 | 34篇 |
2008年 | 22篇 |
2007年 | 32篇 |
2006年 | 34篇 |
2005年 | 38篇 |
2004年 | 20篇 |
2003年 | 26篇 |
2002年 | 21篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有894条查询结果,搜索用时 15 毫秒
841.
Objectives
We argue that assessing the level of crime concentration across cities has four challenges: (1) how much variability should we expect to observe; (2) whether concentration should be measured across different types of macro units of different sizes; (3) a statistical challenge for measuring crime concentration; (4) the temporal assumption employed when measuring high crime locations.Methods
We use data for 42 cities in southern California with at least 40,000 population to assess the level of crime concentration in them for five different Part 1 crimes and total Part 1 crimes over 2005–2012. We demonstrate that the traditional measure of crime concentration is confounded by crimes that may simply spatially locate due to random chance. We also use two measures employing different temporal assumptions: a historically adjusted crime concentration measure, and a temporally adjusted crime concentration measure (a novel approximate solution that is simple for researchers to implement).Results
There is much variability in crime concentration over cities in the top 5 % of street segments. The standard deviation across cities over years for the temporally adjusted crime concentration measure is between 10 and 20 % across crime types (with the average range typically being about 15–90 %). The historically adjusted concentration has similar variability and typically ranges from about 35 to 100 %.Conclusions
The study provides evidence of variability in the level of crime concentration across cities, but also raises important questions about the temporal scale when measuring this concentration. The results open an exciting new area of research exploring why levels of crime concentration may vary over cities? Either micro- or macro- theories may help researchers in exploring this new direction.842.
843.
This study examines how creditors in illicit drug markets manage debtors’ inability to repay “fronted” drugs. Based on qualitative interviews with 40 incarcerated drug dealers in Norway, we explore four outcomes of unpaid drug debts. Two modes of governance dominated the credit reciprocation processes: Cooperative governance included strategies of accepting loss and refinancing debt and required mutual trust between creditor and debtor. Adversarial governance included extortion of debtors and revenge and was based on threats of violence. We found that creditors preferred refinancing debt or extorting debtors over accepting loss or using violence. We argue that the negotiated outcomes of drug debt have been neglected in research on drug markets, and explore how they require investment from the creditor, either in building trust or in deterring malfeasance through threats of violence. Using insights from economic sociology, the study highlights the importance of social control in illegal drug markets. 相似文献
844.
845.
Within a social learning model, family-of-origin violence places men at risk for developing negative communication in their adult relationships. Thirty young men exposed to family-of-origin violence (exposed group) and 30 unexposed young men were videotaped discussing a conflict topic with their female dating partners. Relative to the unexposed group, the exposed men and women reported higher relationship aggression and during discussion showed more negative communication, were more domineering, and the men reported more negative affect. There were no differences between the groups on cognition or heart rate. The conflict management deficits and aggression evident in the exposed group suggest that these partners are at high risk for future relationship aggression and distress. 相似文献
846.
Kacinko SL Barnes AJ Kim I Moolchan ET Wilson L Cooper GA Reid C Baldwin D Hand CW Huestis MA 《Forensic science international》2004,141(1):41-48
Oral fluid is an interesting alternative matrix for drug testing in many environments, including law enforcement, workplace drug testing, and drug treatment facilities. Performance characteristics of the FDA-cleared, qualitative, Cozart RapiScan Opiate Oral Fluid Drug Testing System (Opiate Cozart RapiScan System or Opiate CRS) were compared to the semi-quantitative Cozart Microplate EIA Opiate Oral Fluid Kit (Opiate ELISA) and to gas chromatography/mass spectrometry (GC/MS). The following oral fluid opiate cutoffs were evaluated: the GC/MS limit of quantification (LOQ) of 2.5 mg/l; 15 microg/l currently used for oral fluid testing in the United Kingdom (UK); 30 microg/l (Opiate CRS cutoff); and 40 microg/l, the proposed Substance Abuse and Mental Health Services Administration (SAMHSA) cutoff. Subjects provided informed consent to participate in this IRB-approved research and resided on the closed research ward throughout the study. Three oral codeine doses of 60 mg/70 kg were administered over a 7-day period. After a 3-week break, subjects received three doses of 120 mg/70 kg within 7 days. Oral fluid specimens (N = 1273) were analyzed for codeine (COD), norcodeine (NCOD), morphine (MOR) and normorphine (NMOR) by GC/MS with an LOQ of 2.5 microg/l for all analytes. MOR and NMOR were not detected in any sample; 26.5% of the specimens were positive for COD and 13.7% for NCOD. Opiate CRS uses a preset, qualitative cutoff of 10 microg/l; this is equivalent to 30 microg/l in undiluted oral fluid as the oral fluid collection process involves a 1:3 dilution with buffer. Sensitivity, specificity, and efficiency of Opiate CRS compared to Opiate ELISA were 98.6, 98.1, and 98.2% at a 30 microg/l cutoff and 99.0, 96.2, and 96.6% at a 40 microg/l cutoff. Compared to the much lower GC/MS LOQ of 2.5 microg/l, sensitivity, specificity and efficiency were 66.8, 99.3 and 90.7%. Increasing the GC/MS cutoff to the current UK level yielded performance characteristics of 81.5% (sensitivity), 99.3% (specificity), and 95.4% (efficiency). Using a GC/MS cutoff identical to the preset Opiate CRS cutoff yielded sensitivity, specificity, and efficiency of 88.5, 99.2, and 97.5%, respectively. At the proposed SAMSHA confirmation cutoff of 40 microg/l, sensitivity increased with little change in specificity and efficiency (91.3% sensitivity, 98.9% specificity, and 97.5% efficiency). Oral fluid is a suitable matrix for detecting drugs of abuse. Opiate CRS, with a 30 microg/l cutoff, is sufficiently sensitive, specific and efficient for oral fluid opiate analysis, performing similarly to Opiate ELISA at the same cutoff, and having performance characteristics >91% when compared to GC/MS at the proposed SAMHSA cutoff. 相似文献
847.
848.
Heungchong Kim 《Asia Europe Journal》2003,1(4):503-509
The North Korean nuclear standoff has escalated since North Korea let slip that it was developing nuclear weapons while James Kelly, U.S. Assistant Secretary of East Asian and Pacific Affairs, was visiting Pyongyang in October 2002. The Bush administration has acknowledged that the United States will not discount a preemptive military strike on the suspected nuclear development facilities, and North Korea has stood firm against any pressure to halt its nuclear development from the international community. Dialogue and meetings for international cooperation among the major countries concerned, including Korea, the U.S., Japan and China, have been activated to resolve the nuclear crisis in the Korean Peninsula, especially after the U.S. pronounced an end to its war against Iraq in early May of this year. In the middle of the rapidly changing situation on the Korean peninsula, the inter-Korean reconciliation and cooperation initiated by the Sunshine Policy of the Kim Dae Jung administration and followed by the Roh Moo-hyun administrations Policy of Peace and Prosperity are not separable from the nuclear situation. This paper follows recent developments of inter-Korean relations, illustrates South Koreas stance on the issue and suggests the EUs role on the nuclear issue.
This is a revised version of the paper presented at the Asia-EU Journalists Seminar organized by the Asia Europe Foundation and the Korea Press Foundation (KPF), held in Brussels, Belgium, May 22 2003. Financial support from the KPF is gratefully acknowledged. 相似文献
849.
One in five Aboriginal people enrolled in a Vancouver study of people who inject drugs became HIV-positive over a five-year period ending in May 2001. This is twice the rate among non-Aboriginal people in the study. 相似文献
850.
Many burn injuries are mistakenly referred to as "accidents" because they occur suddenly and seem unpredictable and uncontrollable; however, injuries often occur in predictable patterns. We reviewed all pediatric forensic cases referred to the Medical University of South Carolina Forensic Pathology Section over a 28-year period from January 1975 to December 2002. There were 124 cases with 121 fire-related fatalities and three scald fatalities. Ninety of the burn victims were in the 0-5-year age group. The manner of deaths showed 108 accidents and 12 homicides (four undetermined). Eleven of 12 burn-related homicides occurred at the home with all of the victims in the 1-8-year age group. The perpetrator of the home fire homicides was the mother in five cases and the sister in one case (two undetermined). Homicide involved a vehicle fire in one case in which the father caused an explosion with an accelerant. The three scald death perpetrators were the father, mother's boyfriend, and an aunt.This retrospective study and review of the literature may reveal patterns useful for evaluation of manner of death. By recognizing scene characteristics, potential perpetrators, and children at risk, we can better classify pediatric burn-related fatalities. 相似文献