全文获取类型
收费全文 | 892篇 |
免费 | 27篇 |
专业分类
各国政治 | 61篇 |
工人农民 | 62篇 |
世界政治 | 75篇 |
外交国际关系 | 39篇 |
法律 | 424篇 |
中国政治 | 51篇 |
政治理论 | 201篇 |
综合类 | 6篇 |
出版年
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 35篇 |
2017年 | 33篇 |
2016年 | 37篇 |
2015年 | 17篇 |
2014年 | 23篇 |
2013年 | 158篇 |
2012年 | 23篇 |
2011年 | 21篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 27篇 |
2007年 | 23篇 |
2006年 | 19篇 |
2005年 | 19篇 |
2004年 | 17篇 |
2003年 | 19篇 |
2002年 | 25篇 |
2001年 | 8篇 |
2000年 | 19篇 |
1999年 | 14篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 17篇 |
1994年 | 14篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 17篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 16篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 10篇 |
1975年 | 5篇 |
1972年 | 4篇 |
1968年 | 4篇 |
排序方式: 共有919条查询结果,搜索用时 9 毫秒
871.
Due to their high polarity and low vapor pressure, most amine salts of amphetamine-type drugs are not directly amenable to headspace recovery using solid-phase microextraction (SPME). Described in this article is a simple vapor-phase procedure for the conversion of solid drug salt samples into their free bases by the use of triethylamine. This process can be conducted simultaneously with headspace SPME, the outcome being that solid drug salts can be sampled directly for GC-MS without the need for dissolution and chemical processing. Potential applications for this methodology include the noninvasive recovery of drug traces from objects such as banknotes and garments. This new process for recovery of amphetamine-type drugs has been combined with on-fiber derivatization using alkylchloroformates. This extra step was included to improve the chromatographic performance of analytes and allow for the resolution of drug enantiomers. 相似文献
872.
Brown R Killian E Evans WP 《International journal of offender therapy and comparative criminology》2003,47(5):529-541
Youths transitioning out of detention are particularly in need of support systems that can divert them from recidivism. This article examines the relationship between incarcerated youths' sense of their families' functioning and their perceived likelihood for postdetention success. Despite the control of background variables, results reveal that delinquents who indicated stronger familial functioning also reported a greater likelihood of future success. Although interventions that focus on improving the supportive capacity of families have shown great promise, treatment drop-out rates remain high. To explore incarcerated youths' view of family focused interventions, respondents rated the potential utility of family and nonfamily focused intervention options. A majority of respondents reported that family focused interventions would be helpful. A group of respondents, overrepresented by adolescents with low family functioning, reported that this type of intervention would not be helpful. These results are discussed in terms of their impact on offering family focused interventions for juveniles. 相似文献
873.
874.
Turner WD Brown RE Kelliher TP Tu PH Taister MA Miller KW 《Forensic science international》2005,154(2-3):149-158
Modern forensic facial reconstruction techniques are based on an understanding of skeletal variation and tissue depths. These techniques rely upon a skilled practitioner interpreting limited data. To (i) increase the amount of data available and (ii) lessen the subjective interpretation, we use medical imaging and statistical techniques. We introduce a software tool, reality enhancement/facial approximation by computational estimation (RE/FACE) for computer-based forensic facial reconstruction. The tool applies innovative computer-based techniques to a database of human head computed tomography (CT) scans in order to derive a statistical approximation of the soft tissue structure of a questioned skull. A core component of this tool is an algorithm for removing the variation in facial structure due to skeletal variation. This method uses models derived from the CT scans and does not require manual measurement or placement of landmarks. It does not require tissue-depth tables, can be tailored to specific racial categories by adding CT scans, and removes much of the subjectivity of manual reconstructions. 相似文献
875.
The professional and legal regulation of assisted reproductive technologies (ART) in Australia is a vast maze of intersecting laws and guidelines which place restrictions on the provision of services such as infertility treatment, surrogacy, sex selection for social reasons, donor insemination, pre-implantation diagnosis and human embryo research. This study investigated the application of these restrictions on clinical practice in New South Wales, a relatively unregulated State, and Victoria, a relatively highly regulated State. The results of the survey indicate that the range of ART services in Victorian clinics was far more limited than in New South Wales clinics. The Victorian clinics uniformly restricted access of single and lesbian women and did not offer social sex selection procedures. The New South Wales clinics adopted different polices regarding these services. It was found that restrictive laws governing "social" issues have a significant impact on the availability of ART services and some respondents seemed unclear about the nature of restrictions and laws relevant to their work. It was also found that "reproductive tourism" is prevalent and restrictions were circumnavigated by patients with assistance from clinics. It was concluded that more evidence is required to evaluate regulation in this field of medicine. 相似文献
876.
Moretti TR Baumstark AL Defenbaugh DA Keys KM Brown AL Budowle B 《Journal of forensic sciences》2001,46(3):661-676
With the use of capillary electrophoresis (CE), high-resolution electrophoretic separation of short tandem repeat (STR) loci can be achieved in a semiautomated fashion. Laser-induced detection of fluorescently labeled PCR products and multicolor analysis enable the rapid generation of multilocus DNA profiles. In this study, conditions for typing PCR-amplified STR loci by capillary electrophoresis were investigated using the ABI Prism 310 Genetic Analyzer (Applied Biosystems). An internal size standard was used with each run to effectively normalize mobility differences among injections. Alleles were designated by comparison to allelic ladders that were run with each sample set. Multiple runs of allelic ladders and of amplified samples demonstrate that allele sizes were reproducible, with standard deviations typically less than 0.12 bases for fragments up to 317 bases in length (largest allele analyzed) separated in a 47 cm capillary. Therefore, 99.7% of all alleles that are the same length should fall within the measurement error window of +/- 0.36 bases. Microvariants of the tetranucleotide repeats were also accurately typed by the analytical software. Alleles differing in size by one base could be resolved in two-donor DNA mixtures in which the minor component comprised > or = 5% of the total DNA. Furthermore, the quantitative data format (i.e., peak amplitude) can in some instances assist in determining individual STR profiles in mixed samples. DNA samples from previously typed cases (typed for RFLP, AmpliType PM+DQA1, and/or D1S80) were amplified using AmpFlSTR Profiler Plus and COfiler and were evaluated using the ABI Prism 310. Most samples yielded typable results. Compared with previously determined results for other loci, there were no discrepancies as to the inclusion or exclusion of suspects or victims. CE thus provides efficient separation, resolution, sensitivity and precision, and the analytical software provides reliable genotyping of STR loci. The analytical conditions described are suitable for typing samples such as reference and evidentiary samples from forensic casework. 相似文献
877.
Non-fatal injuries due to interpersonal violence in Johannesburg-Soweto: incidence, determinants and consequences. 总被引:1,自引:0,他引:1
A prospective, hospital based sampling procedure conducted between June 8th, 1989 and August 24th, 1990 identified 1592 victims of interpersonal violence in six state and five private hospitals serving the Johannesburg magisterial district (which includes Soweto). For the 1282 victims resident in the area, this corresponded to crude annualised incidence rates per 100,000 population of 3821 for coloureds, 1527 for blacks, 467 for whites, 433 for asians and 1380 for all residents. Males, most of whom were aged 20-24 years, constituted 83.9% of all victims and were most often attacked on the streets. The majority of females were attacked at home by a spouse or lover, and most incidents occurred between dusk and midnight on weekends. Sharp violence was the most frequent type, involving 52.2% of the male and 51.4% of the female victims. Analysis by racial classification of the overall findings for mechanism of injury and relationship to aggressor showed dramatic differences. Limitations of the findings are discussed. After comparison with similar data for two United States cities and Copenhagen, Denmark, it is hypothesised that the racial differences in the present findings reflect the interplay of universal structural determinants and a specific colonial factor rooted in the sociology and psychology of oppression. Some implications of these findings and hypothesised determinants for violence prevention initiatives are mentioned. 相似文献
878.
During first semester 1980, 96 first and last year male police students and 166 law students were surveyed about their drug use patterns and attitudes towards alcohol. Of these students, 69.3 percent drank at least once a month, 80.7 percent used coffee or tea, 23.6 percent analgesics, 3 percent antihistamines and marijuana and less than 1 percent sedatives, tranquilizers, stimulants, hallucinogens, cocaine or opiates once a month or more. Law students used caffeine and marijuana significantly more frequently than police students. On the whole, there were more similarities than differences between the two groups in terms of drug consumption. In terms of attitudes, police students felt significantly more than law students that alcoholism was caused by moral weakness and medical illness as shown in the Attitude Towards Alcoholism questionnaire. But significantly more police students (82 percent) than law students (37 percent) felt that it was important to have drug and alcohol education as part of their course of study. Also significantly more police students (58 percent) than law students (24 percent) felt that they were prepared to manage drug or alcohol problems professionally. 相似文献
879.
880.