全文获取类型
收费全文 | 3316篇 |
免费 | 50篇 |
专业分类
各国政治 | 166篇 |
工人农民 | 18篇 |
世界政治 | 459篇 |
外交国际关系 | 456篇 |
法律 | 1715篇 |
中国共产党 | 75篇 |
中国政治 | 228篇 |
政治理论 | 168篇 |
综合类 | 81篇 |
出版年
2021年 | 25篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 20篇 |
2014年 | 110篇 |
2013年 | 29篇 |
2012年 | 176篇 |
2011年 | 173篇 |
2010年 | 95篇 |
2009年 | 97篇 |
2008年 | 171篇 |
2007年 | 206篇 |
2006年 | 234篇 |
2005年 | 201篇 |
2004年 | 194篇 |
2003年 | 156篇 |
2002年 | 147篇 |
2001年 | 130篇 |
2000年 | 115篇 |
1999年 | 60篇 |
1998年 | 25篇 |
1997年 | 15篇 |
1996年 | 17篇 |
1995年 | 24篇 |
1994年 | 51篇 |
1993年 | 24篇 |
1992年 | 22篇 |
1991年 | 32篇 |
1990年 | 22篇 |
1989年 | 22篇 |
1988年 | 107篇 |
1987年 | 25篇 |
1986年 | 28篇 |
1985年 | 28篇 |
1984年 | 26篇 |
1983年 | 27篇 |
1982年 | 17篇 |
1981年 | 37篇 |
1980年 | 40篇 |
1979年 | 40篇 |
1978年 | 16篇 |
1977年 | 43篇 |
1976年 | 31篇 |
1964年 | 27篇 |
1963年 | 24篇 |
1962年 | 42篇 |
1961年 | 19篇 |
1960年 | 22篇 |
1959年 | 30篇 |
排序方式: 共有3366条查询结果,搜索用时 31 毫秒
821.
This paper is focused on the preparation of samples for laser microdissection (LM) in forensic casework. In forensic genetics, it is essential to preserve and separate cellular traces during sample preparation, as they are usually gathered in very small amounts and are often contaminated with undesired cells. This is made possible by laser microdissection, a technique developed to cut cells or tissue of a certain type from a microscopical specimen by UV laser and catapult them directly into a PCR reactor. This method minimizes the risk of getting inconclusive, mixed DNA profiles due to contamination by foreign DNA and also supplies information about the cellular origin of a DNA profile. A method for optimized fixation and staining of spermatozoa for laser microdissection was established. Four different fixation methods combined with two staining methods were tested on two different microscope slides. Moreover, the effect of a blocker pen to contain the specimen on the slide was investigated. 相似文献
822.
Filograna L Bolliger SA Kneubuehl B Jackowski C Hatch GM Thali MJ 《Journal of forensic sciences》2012,57(5):1329-1335
We investigated the feasibility of postmortem percutaneous needle biopsy (PNB) for obtaining pulmonary samples adequate for the study of pulmonary fat embolism (PFE). Samples of both lungs were obtained from 26 cadavers via two different methods: (i) PNB and (ii) the double-edged knife technique, the gold standard at our institute. After water storage and Sudan III staining, six forensic pathologists independently examined all samples for the presence and severity of PFE. The results were compared and analyzed in each case regarding the vitality of the PFE and its relationship to the cause of death. The results showed that PFE was almost identically diagnosed and graded on the samples obtained via both methods. The discrepancies between the two techniques did not affect the diagnoses of vitality or cause of death related to PFE. This study demonstrates the feasibility of the PNB sampling method for the diagnosis and interpretation of PFE in the postmortem setting. 相似文献
823.
Poroscopy is the term applied to a specialized study of pore structure found on papillary ridges of skin as a means of identification. It comes under level 3 detail of identification and hence is more reliable and accurate. The goal of this study is to estimate the importance of poroscopy for identification of individuals and to determine the gender based on frequency, type, and shape of pores. Left plain thumb prints of 200 individuals (100 men and 100 women) aged between 18 and 60 belonging to South Indian population were observed. The results have shown that women tend to have a significantly higher frequency of pores than men. Number of pores ≤ 8 pores/25 mm(2) is more likely to be of male origin and ≥9 pores/25 mm(2) is more likely to be of female origin. There was no significant sex difference based on type and shape of pores. 相似文献
824.
Juveniles' competency to participate in delinquency proceedings has received increased attention in recent years. Developmental incompetence, whereby juveniles' incompetency is based upon their immaturity, as opposed to a mental disorder or developmental disability, is an evolving and important aspect of this area of law. The following paper reviews theories used to support the notion of developmental incompetence, as well as the extant empirical research on juveniles' competency-related abilities. Using a LexisNexis search, statutory and case laws pertaining to juvenile competency were identified across the 50 states and the District of Columbia. Only six states clearly allow developmental incompetence, whereas 17 have laws that do not include developmental immaturity as an acceptable basis of incompetence in juvenile courts. Developmental incompetence is likely to affect a relatively small proportion of juvenile cases, but has important implications for juvenile forensic practice. Recommendations are offered for forensic practitioners conducting this type of evaluation. 相似文献
825.
Musshoff F Kirschbaum KM Graumann K Herzfeld C Sachs H Madea B 《Forensic science international》2012,215(1-3):60-63
A preliminary initial enzyme-linked immunosorbent assay (LUCIO-Direct ELISA kit) and a preliminary DRI enzyme immunoassay were evaluated for drug detection in head hair with respect to lowered cutoff values recommended in Germany for the control of abstinence in cases of re-granting of drivers' licences. Following drug classes were included: cannabinoids, opiates, cocaine like substances, amphetamine, methamphetamine (and methylenedioxyamphetamines), methadone, and benzodiazepines. 759 analyses were performed using LUCIO-Direct ELISA kits and 936 analyses using DRI enzyme immunoassay tests. Sample size for each drug group and immunoassay test reached from 74 to 178. The LUCIO-Direct ELISA kit revealed a sensitivity of 91% for amphetamine up to 98% for methadone (methamphetamine 92%, cocaine 94%, opiates 94%, benzodiazepines 96%) and values of specificity of 72% for methadone up to 89% for amphetamine and benzodiazepines. The test was not useful for a preliminary screening for tetrahydrocannabinol (sensitivity of 65%) in consideration of a suggested cutoff of 0.02 ng/mg. The DRI enzyme immunoassay test was only useful for morphine and cocaine testing at low recommended new cutoff values (0.1 ng/mg) revealing sensitivities of 94% and 99%, respectively. 相似文献
826.
Błachut D Wojtasiewicz K Krawczyk K Maurin J Szawkało J Czarnocki Z 《Forensic science international》2012,216(1-3):108-120
The synthesis of the designer drug 4-methylthioamphetamine (4-MTA) has been carried out using the well-known Leuckart reaction in four versions. The treatment of 4-methylthiophenylacetone with formamide, mixture of formamide/formic acid, ammonium formate, and mixture of ammonium formate and formic acid followed by acid hydrolysis brought about the formation of 4-MTA contaminated with a number of impurities. The gas chromatography mass-spectrometry (GC-MS) analysis of the reaction mixtures allowed identification of the most prominent impurities, such as diasteromers of N,N-di-[β-(4-methylthiophenyl)isopropyl]amine, N,N-di-[β-(4-methylthiophenyl)isopropyl]methylamine, N,N-di-[β-(4-methylthiophenyl)isopropyl]formamide, the Schiff bases derived from 4-MTA and 4-methylbenzaldehyde (benzaldimine) and 4-methylthiophenylacetone (ketimine) as well as some heterocycles: 4-methyl-5-(4'-methylthiophenyl)pyrimidine, 4-(4'-methylthiobenzyl)pyrimidine, 2,6-dimethyl-3,5-di-(4'-methylthiophenyl)pyridine, 2,4-dimethyl-3,5-di-(4'-methylthiophenyl)pyridine. The correctness of identification was confirmed by independent synthesis of these compounds. Each synthesized reference compound was characterized by means of MS, (1)H and (13)C NMR, and IR methods. The stereochemistry of (RR/SS) diasteromer of N,N-di-[β-(4-methylthiophenyl)isopropyl]amine was confirmed by a crystallographic method. 相似文献
827.
This study examines Merton's Classical Strain Theory (1938) as a causative factor in intimate partner violence among college students. We theorize that college students experience general life strain and cumulative strain as they pursue the goal of a college degree. We test this strain on the likelihood of using intimate partner violence. Strain due to unrealistic expectations of intimate partnership and economic strain are also examined. The analysis examines the following causative factors representing strain: 1) the College Undergraduate Stress Scale (Renner & Mackin, 1998); 2) cumulative academic strain measured by college classification; 3) cumulative intimate partner strain measured as the length of time in the relationship; 4) academic strain measured by number of hours studied weekly, and 5) economic strain measured by number of hours worked weekly. Additionally, we examine the extent to which gender and race/ethnicity differentially affect intimate partner in the context of these measures of strain. The Conflict Tactics Scales II (Straus et al, 1996) are used to measure dating violence and include indicators for sexual coercion, physical aggression, injury, and psychological aggression. Data were collected from 142 students in lower-division classes from Texas Tech University. Results show that general strain and cumulative intimate partner strain increase the use of dating violence among college students. The longer dating partners are in a relationship, the higher the chances of psychological aggression, physical assault, and sexual coercion. Converse to our expectations, time spent working reduces psychological aggression due to reducing time spent together rather than reflecting economic strain. 相似文献
828.
Research that attempts to identify characteristic features of multiple perpetrator sexual assault (MPSA) is limited. This study compared demographic and assault related characteristics of 135 cases of MPSA with 139 cases of single perpetrator sexual assault (SPSA) reported to the Haven sexual assault referral centre, Camberwell, London, over a 4-year period, and aimed to identify any unique features of MPSA victims, perpetrators and assault type. Victims of MPSA were younger, less likely to be White, more likely to report previous self-harm and more likely to sustain injuries than victims of SPSA. Multiple perpetrators were younger, less likely to be White and more likely to be strangers to the victim than single perpetrators. The nature of the assault was different in single and multiple perpetrator cases; in MPSA, there were more completed rapes and more multiple rapes, and perpetrators were more likely to meet the victim in an outside location before carrying out the assault in a place of residence that was not the victim's. These findings add to a scant but growing evidence base. 相似文献
829.
离婚后扶养、净益补偿和养老金补偿是德国离婚财产法补偿制度的三大支柱。近年来,这三大制度都经历了不同程度的修订和改革。这些改革在净益和养老金补偿方面产生了对离婚以后的经济负担合理分配的结果,但是在扶养法领域改革却发生了相反的影响,照顾子女的妇女所遭受的不利益没有得到足够的补偿。2010年2月4日签署的德法协定提供了一个适用于德法跨国婚姻的统一夫妻财产制规则。这一跨国的统一实体法规则可能为未来欧洲统一婚姻法提供了蓝本。 相似文献
830.
In the third quarter of last century, Malaga experienced a period of important residential growth that produced the construction of great commuter suburbs, in promotions of collective housing in opened block, forming an urban aggregate without any other relation than the juxtaposition of independent pieces. The population that initially occupied these districts came from the countryside, as time went by, this population has been improving economically, notwithstanding this was not reflected in the improvement of the urban surroundings. The architectonic and city-planning characteristics of its conception: precarious constructions without improvement due to the disadvantages of the horizontal property, a public space wrongly defined and invaded by the parking area, deficit of equipment. This situation has favored the departure of a part of the original population and the arrival of another one with greater economic difficulties and important social differences in relation to the first. In some cities, this situation has caused important problems of marginalization and confrontation. Apart from the economic and cultural problems, the total deterioration of the housing, the bad quality of the urban space and the lack of consideration of the new necessities of the residents are factors that have negatively affected these districts. 相似文献