全文获取类型
收费全文 | 17910篇 |
免费 | 1382篇 |
专业分类
各国政治 | 634篇 |
工人农民 | 599篇 |
世界政治 | 1300篇 |
外交国际关系 | 490篇 |
法律 | 13068篇 |
中国共产党 | 1篇 |
中国政治 | 126篇 |
政治理论 | 2966篇 |
综合类 | 108篇 |
出版年
2020年 | 398篇 |
2019年 | 431篇 |
2018年 | 490篇 |
2017年 | 577篇 |
2016年 | 601篇 |
2015年 | 511篇 |
2014年 | 546篇 |
2013年 | 1770篇 |
2012年 | 421篇 |
2011年 | 523篇 |
2010年 | 649篇 |
2009年 | 608篇 |
2008年 | 438篇 |
2007年 | 444篇 |
2006年 | 541篇 |
2005年 | 401篇 |
2004年 | 386篇 |
2003年 | 411篇 |
2002年 | 354篇 |
2001年 | 706篇 |
2000年 | 595篇 |
1999年 | 486篇 |
1998年 | 224篇 |
1997年 | 193篇 |
1996年 | 174篇 |
1995年 | 193篇 |
1994年 | 207篇 |
1993年 | 172篇 |
1992年 | 340篇 |
1991年 | 357篇 |
1990年 | 336篇 |
1989年 | 371篇 |
1988年 | 327篇 |
1987年 | 313篇 |
1986年 | 320篇 |
1985年 | 346篇 |
1984年 | 317篇 |
1983年 | 310篇 |
1982年 | 231篇 |
1981年 | 210篇 |
1980年 | 186篇 |
1979年 | 235篇 |
1978年 | 162篇 |
1977年 | 141篇 |
1976年 | 119篇 |
1975年 | 112篇 |
1974年 | 131篇 |
1973年 | 120篇 |
1972年 | 93篇 |
1971年 | 103篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
21.
Minji Lee M.S. Ju Yeon Jung M.S. Sungsoo Choi M.S. Ilung Seol Ph.D. Seohyun Moon Ph.D. In Kwan Hwang Ph.D. 《Journal of forensic sciences》2020,65(6):2117-2120
Lophophora is a member of the Cactaceae family, which contains two species: Lophophora williamsii and L. diffusa. Lophophora williamsii is an illegal plant containing mescaline, a hallucinogenic alkaloid. In this study, a novel method based on a single nucleotide polymorphism (SNP) assay was developed for identifying L. williamsii; this assay reliably detects SNPs within chloroplast DNA (rbcL, matK, and trnL-trnF IGS) and was validated for identifying Lophophora and L. williamsii simultaneously. The chloroplast DNA sequences from four L. williamsii and three L. diffusa plants were obtained and compared using DNA sequence data from approximately 300 other Cactaceae species available in GenBank. From this sequence data, a total of seven SNPs were determined to be suitable for identifying L. williamsii. A multiplex assay was constructed using the ABI PRISM® SNaPshot™ Multiplex Kit (Applied Biosystems, Forster City, CA) to analyze species-specific SNPs. Using this multiplex assay, we clearly distinguished the Lophophora among 19 species in the Cactaceae family. Additionally, L. williamsii was distinguished from L. diffusa. These results suggest that the newly developed assay may help resolve crimes related to illegal distribution and use. This multiplex assay will be useful for the genetic identification of L. williamsii and can complement conventional methods of detecting mescaline. 相似文献
22.
Sabrina Zorbo M.S. Patrick P. J. M. H. Jeuniaux Ph.D. 《Journal of forensic sciences》2020,65(2):641-648
In the case of suspicious deaths, the technique of 1:1 taping is often used in Belgium. It consists of affixing a large number of adhesive tapes to the body of the victim. It is conventionally aimed at obtaining microtraces (e.g., fibers, hair) and is usually not used for DNA analysis. However, in some cases, DNA analysis of certain areas of interest identified on the 1:1 taping material can offer a last resort solution. The four-step method that is described in this article involves the selection of areas of interest on the body (Step 1), the selection of the corresponding tapes (Step 2), the decontamination of the tapes (Step 3), the selection of areas of interest on the tapes, for DNA sampling (Step 4). The method is illustrated by its successful application in four murder cases. In each case, DNA profiles of good quality could be identified, including profiles of persons different from the victim. 相似文献
23.
24.
John P. Crank 《Crime, Law and Social Change》2003,39(1):39-67
This concept paper presents a theory of environmental scarcity developed byHomer-Dixon. Homer-Dixon developed a model to describe the consequences of scarcity for sub-national violence in third world countries. This paper hasfour interrelated purposes. First, it presents the model of scarcity developedby Thomas Homer-Dixon in 1999. Second, it assesses the way in which the scarcity model contextualizes criminal justice and criminology research, andby extension, how research in crime and justice processes can broaden the scarcity model. Third, it applies elements of the model to the United States,a goal that represents a generalization of the model from third-world to first-world settings. Fourth, it presents a particular case, the migrationof African-Americans from the rural South to urban centers in the 1950s and1960s and consequent inner-city violence in the 1960s, that displays manyelements of the environmental scarcity model. 相似文献
25.
In 1991 the FCC implemented a price cap plan for local exchange carriers' interstate access service designed to deal with the regulatory boundaries problem arising from the breakup of AT&T in 1984. The experience with the price cap plan demonstrates the difficulty of predicting productivity growth accurately and makes clear that regulators cannot depend upon a pure price cap plan to keep prices within a reasonable range of costs. With periodic reviews to readjust plan parameters, however, a price cap plan can maintain the rate-of-return close to the target rate-of-return without diminishing the price cap plan's incentives for efficient production. A simple method of recalculating the X-factor based on the rate-of-return over the previous three years worked well in simulations. If this procedure had been used over the price cap period 1991 to 2000, prices would have been 20 percent lower and expenditures on LECs' telecommunications service subject to a price cap would have been $3.8 billion lower. 相似文献
26.
The adjustment problems associated with sexual abuse, physical abuse, psychological maltreatment, neglect, and witnessing family violence during childhood were examined in three studies. Study 1 demonstrated significant overlap between maltreatment types in parent reports (N = 50) of maltreatment experiences of their child aged 5–12 years. Parental sexual punitiveness, traditionality, family adaptability and family cohesion significantly predicted scores on 4 maltreatment scales and children's externalizing behavior problems. Level of maltreatment predicted internalizing, externalizing, and sexual behavior problems. In Study 2, significant overlap was found between adults' retrospective reports (N = 138) of all 5 types of maltreating behaviors. Parental sexual punitiveness, traditionality, family adaptability, and family cohesion during childhood predicted the level of maltreatment and current psychopathology. Although child maltreatment scores predicted psychopathology, childhood family variables were better predictors of adjustment. Study 3 demonstrated that child maltreatment scores predicted positive aspects of adult adaptive functioning (N = 95). 相似文献
27.
While the concepts of race and ethnicity have been abused historically, they are potentially invaluable in epidemiology and public health. Epidemiology relies upon variables that help differentiate populations by health status, thereby refining public health and health care policy, and offering insights for medical science. Race and ethnicity are powerful tools for doing this. The prerequisite for their responsible use is a society committed to reducing inequalities and inequities in health status. When this condition is met, it is irresponsible not to utilize these concepts. 相似文献
28.
Ellen K. Marshall Ph.D. 《Journal of Police and Criminal Psychology》2006,21(1):62-71
The present study measured the existence of traumatic stress symptomatology as reported by certified law enforcement officers
within the State of Delaware. A questionnaire was devised which documented age, sex, race, education, years of service, marital
status, children, rank, position, and shift work. The questionnaire was divided into parts which assessed the exposure and
the frequency of specific traumatic incidents experienced in the line of duty, and the frequency of experienced traumatic
symptomatology criteria: re-experiencing, numbing, and arousal. 相似文献
29.
30.
Acute myoglobinuria as a fatal complication of heroin addiction 总被引:3,自引:0,他引:3
Y F Chan P K Wong T C Chow 《The American journal of forensic medicine and pathology》1990,11(2):160-164
A fatal case of myoglobinuria complicating heroin addiction is described. Clinically the patient had no overt symptoms of rhabdomyolysis. Pathologists should be alerted to this rare complication in heroin addicts who die of no apparent cause. The antimyoglobin immunoperoxidase technique is useful in confirming the diagnosis. 相似文献