全文获取类型
收费全文 | 890篇 |
免费 | 50篇 |
专业分类
各国政治 | 81篇 |
工人农民 | 89篇 |
世界政治 | 82篇 |
外交国际关系 | 48篇 |
法律 | 450篇 |
中国共产党 | 1篇 |
中国政治 | 6篇 |
政治理论 | 181篇 |
综合类 | 2篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 31篇 |
2019年 | 38篇 |
2018年 | 53篇 |
2017年 | 56篇 |
2016年 | 57篇 |
2015年 | 29篇 |
2014年 | 49篇 |
2013年 | 149篇 |
2012年 | 34篇 |
2011年 | 42篇 |
2010年 | 35篇 |
2009年 | 33篇 |
2008年 | 26篇 |
2007年 | 30篇 |
2006年 | 24篇 |
2005年 | 35篇 |
2004年 | 26篇 |
2003年 | 36篇 |
2002年 | 27篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 4篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有940条查询结果,搜索用时 0 毫秒
231.
Maria Papadakis 《Journal of policy analysis and management》1994,13(1):1-20
Much policymaking in the 1980s at the federal, state, and local levels tried to redress the U.S. competitiveness crisis. A guiding presumption was that there was a sudden and profound inability of the United States to compete in manufactured goods. However, there has been little systematic analysis of American competitive performance disaggregated for the entire manufacturing sector. Data analyzed here for the years 1970–1990 and for the 24 major two-and three-digit ISIC industries reveals that there was a competitiveness crisis in the 1980s, but it was not endemic to all industries. Market share, trade balance, and revealed comparative advantage indicators suggest the crisis was characterized by intensified competitive decline for the auto, textiles, and electronics, industries, and by competitive reversals for the electrical machinery and office and computing machine industries. While many other major American industries appear to be in competitive health, the cumulative effect of macroeconomic imbalances is likely to cause future competitive stress in the capital goods and high-technology sectors. 相似文献
232.
Griffith Michael A. Dubow Eric F. Ippolito Maria F. 《Journal of youth and adolescence》2000,29(2):183-204
In this study, we investigated developmental and cross-situational differences in strategies adolescents use to cope with family, school, and peer stressors. We also examined the relation between adolescents' use of coping strategies and two indices of adjustment (self perceptions of their adjustment as a result of coping with the specific stressor and state anxiety). The sample included 148 seventh graders, 124 ninth graders, and 103 twelfth graders (n = 375). Approach coping increased across the three grade levels, especially in relation to family and peer stressors. Adolescents used more avoidance than approach coping strategies for family stressors, and more approach than avoidance strategies for school and peer stressors. Across stressors, approach coping predicted more favorable outcomes and avoidance coping predicted less favorable outcomes. Coping strategies in response to a specific stressor were more strongly predictive of stressor-specific adjustment than state anxiety, suggesting the need to include both stressor-specific and global measures of adjustment in assessing the relation between coping and adjustment. 相似文献
233.
Firrao D Matteis P Scavino G Ubertalli G Ienco MG Pellati G Piccardo P Pinasco MR Stagno E Costanza G Montanari R Tata ME Brandimarte G Petralia S 《Journal of forensic sciences》2006,51(3):520-531
Evidence of exposure of a metal component to a small charge explosion can be detected by observing microstructural modifications; they may be present even if the piece does not show noticeable overall plastic deformations. Particularly, if an austenitic stainless steel (or another metal having a face-centered cubic structure and a low stacking fault energy) is exposed to an explosive shock wave, high-speed deformation induces primarily mechanical twinning, whereas, in nonexplosive events, a lower velocity plastic deformation first induces slip. The occurrence of mechanical twins can be detected even if the surface is damaged or oxidized in successive events. In the present research, optical metallography (OM) and scanning electron microscopy (SEM), and scanning tunneling microscopy (STM) were used to detect microstructural modifications caused on AISI 304Cu steel disks by small-charge explosions. Spherical charges of 54.5 or 109 g TNT equivalent mass were used at explosive-to-target distances from 6.5 to 81.5 cm, achieving peak pressures from 160 to 0.5 MPa. Explosions induced limited or no macro-deformation. Two alloy grain sizes were tested. Surface OM and SEM evidenced partial surface melting, zones with recrystallization phenomena, and intense mechanical twinning, which was also detected by STM and X-ray diffraction. In the samples' interior, only twins were seen, up to some distance from the explosion impinged surface and again, at the shortest charge-to-sample distances, in a thin layer around the reflecting surface. For forensic science locating purposes after explosions, the maximum charge-to-target distance at which the phenomena disappear was singled out for each charge or grain size and related to the critical resolved shear stress for twinning. 相似文献
234.
235.
The postmortem diagnosis of shaken baby syndrome, a severe form of child abuse, may be difficult, especially when no other visible signs of significant trauma are obvious. An important finding in shaken baby syndrome is subdural haemorrhage, typically originating from ruptured cerebral bridging veins. Since these are difficult to detect at autopsy, we have developed a special postmortem computed tomographic (PMCT) method to demonstrate the intracranial vein system in infants. This method is minimally invasive and can be carried out conveniently and quickly on clinical computed tomography (CT) systems. Firstly, a precontrast CT is made of the infant's head, to document the original state. Secondly, contrast fluid is injected manually via fontanel puncture into the superior sagittal sinus, followed by a repeat CT scan. This allows the depiction of even very small vessels of the deep and superficial cerebral veins, especially the bridging veins, without damaging them. Ruptures appear as extravasation of contrast medium, which helps to locate them at autopsy and examine them histologically, whenever necessary. 相似文献
236.
Testa M 《Journal of interpersonal violence》2004,19(12):1494-1505
Literature addressing the relationship between substance use and physical and sexual violence against women is reviewed briefly. There is substantial evidence of a relationship between men's substance use and perpetration of physical violence, some evidence of a relationship between women's substance use and experiences of sexual aggression, but weak evidence that men's substance use contributes to sexual aggression or that women's substance use contributes to their physical victimization. Understanding the mechanisms underlying the relationship between substance use and violence relationship will be facilitated by narrowing the scope of research questions to identify for whom there is a relationship and under what circumstances. 相似文献
237.
This paper evaluates the use of climate-based information in drought mitigation in Ceará, Northeast Brazil. It examines two policies – a seed-distribution program (Hora de Plantar) and the Emergency Drought-Relief Program – that use climate information produced by FUNCEME (Cearás Foundation for Meteorological and Hydrological Resources) to implement drought planning. It argues that, in politically charged policy-making environments, the use of climate forecast information may go beyond its problem-solving function to influence broader issues of accountability and democratization. In Cearás politically charged environment, technocrats rely on scientific information about climate to insulate policy-making from both political meddling and public accountability. However, insulation afforded by the use of climate information has played different roles in the policy areas examined in this study. While in drought emergency-relief planning the use of climate information critically contributed to the democratization of policy implementation, in agricultural planning, it worked towards further insulating decision-making from public accountability and client participation. Thus, the use of climate information is context-dependent, that is, the distribution of costs and benefits associated with information use in policymaking depends on the social, political, and cultural context in which information producers and users work. Moreover, climate information can be used in ways – positive or negative – significantly different from the use that information producers intended. 相似文献
238.
Bezerra de Menezes LM Volpato MC Rosalen PL Cury JA 《Forensic science international》2003,137(2-3):209-214
The use of bone as a biomarker for chronic and acute exposure to fluoride salts has been suggested, but there are no data published about its use to evaluate lethal intoxication. One hundred and sixty rats were divided into eight groups that received a single oral intubation dose from 0 (control) to 90 mg F/kg as NaF. The animals' time of death was recorded and their femurs were removed for fluoride analysis. Acid-soluble fluoride was determined in the whole bone and on the surface (periosteal), using an ion specific electrode. The data showed a statistically significant relationship between fluoride dose and the number of deaths (P<0.0001). A statistically significant relationship was also found between fluoride dose and fluoride concentration ([F]) in either the whole femur (P<0.0017), on the surface (P<0.0001) or for the ratio periosteal [F]/whole [F] (P<0.0001). However, the [F] on the femur surface was more closely correlated with mortality than that in the whole bone, showing statistically significant differences among the lethal doses and control (P<0.05). The data suggest that the ratio [F] periosteal bone/[F] whole bone, is a biomarker for acute fluoride toxicity. 相似文献
239.
Sánchez-Diz P Gusmão L Beleza S Benítez-Páez A Castro A García O Solla LP Geada H Martín P Martínez-Jarreta B de Fátima Pinheiro M Raimondi E Silva de la Fuente SM Vide MC Whittle MR Zarrabeitia MT Carracedo A Amorim A;GEP-ISFG 《Forensic science international》2003,135(2):158-162
A collaborative exercise was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) in order to evaluate the performance of two Y-chromosome STR PCR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The participating laboratories were asked to type three samples for the eight markers, using a specific amplification protocol. In addition, two control samples, with known haplotypes, were provided. The results obtained by the 13 different participating laboratories were identical, except for two laboratories that failed to type correctly the same two samples for GATA C4. By sequence analyses, two different GATA C4 allele structures were found. One control sample (allele 21) and two questioned samples (allele 22, correctly typed by all the laboratories, and allele 25) presented the following repeat structure: (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)n, but different from the one found for allele 26 in one sample included in this exercise, as well as in the second control sample (allele 23), namely (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)2(TGTA)2(TCTA)n. The collaborative exercise results proved that both Y-tetraplexes produce good amplification results, with the advantage of being efficiently typed using different separation and detection methodologies. However, since GATA C4 repeat presents a complex structure, with alleles differing in sequence structure, efficient denaturing conditions should be followed in order to avoid typing errors due to sizing problems. 相似文献
240.
Calacal GC De Ungria MC Delfin FC Lara MC Magtanong DL Fortun R 《The American journal of forensic medicine and pathology》2003,24(2):148-152
We describe here our collaborative efforts in identifying 2 fatalities of a fire disaster by using a variety of identification techniques. Postmortem findings in both cases were reinforced using Short Tandem Repeat (STR) DNA technology to establish with a high degree of certainty the identities of 2 child victims. STR markers used in the present study include HUMAMEL, HUMCSFIPO, HUMTHO1, HUMvWA, HUMFES/FPS, HUMF13A01, HUMFOLP23, D8S3O6, HUMFGA, and HUMTPOX. Unambiguous identification was made possible through matching DNA profiles generated from skeletal remains with those from umbilical tissues. These tissues were kept by their mothers in accordance with a Philippine tradition and were submitted for DNA analysis. Of the DNA profiles generated from exhumed bone samples of 21 child victims, comparison with the genetic profiles of children A and B obtained from umbilical tissues showed consistent DNA matches with remains 1756 and 1758, respectively. 相似文献