全文获取类型
收费全文 | 1924篇 |
免费 | 311篇 |
国内免费 | 225篇 |
专业分类
2460篇 |
出版年
2024年 | 10篇 |
2023年 | 50篇 |
2022年 | 62篇 |
2021年 | 48篇 |
2020年 | 108篇 |
2019年 | 97篇 |
2018年 | 89篇 |
2017年 | 107篇 |
2016年 | 106篇 |
2015年 | 65篇 |
2014年 | 88篇 |
2013年 | 285篇 |
2012年 | 71篇 |
2011年 | 75篇 |
2010年 | 55篇 |
2009年 | 60篇 |
2008年 | 69篇 |
2007年 | 73篇 |
2006年 | 100篇 |
2005年 | 114篇 |
2004年 | 80篇 |
2003年 | 69篇 |
2002年 | 78篇 |
2001年 | 82篇 |
2000年 | 45篇 |
1999年 | 59篇 |
1998年 | 53篇 |
1997年 | 53篇 |
1996年 | 47篇 |
1995年 | 39篇 |
1994年 | 34篇 |
1993年 | 10篇 |
1992年 | 17篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1975年 | 2篇 |
排序方式: 共有2460条查询结果,搜索用时 7 毫秒
241.
HaiYing Wu YaHong Chen XinFang Su ChengRong Deng Zi-Jiang Liu 《Philosophical Magazine Letters》2013,93(4):198-204
A phase transition of MgS under high pressure is investigated using a first-principles method. It is found from energy-volume calculations that the rock-salt (B1) phase of MgS transforms into a FeSi-type (B28) phase at 143?GPa. The calculated ground-state parameters in the B1 phase are in excellent agreement with available experimental and theoretical data. Ab initio phonon calculations are also performed to investigate the structural behaviour of MgS under high pressure. An unstable transverse acoustic mode and a phase transition from B1 to B28 phase at ~143.7?GPa driven by this soft mode are predicted. The B28 structure of MgS is stable up to 350?GPa according to lattice dynamics calculations. 相似文献
242.
The effect of a high magnetic field on the morphology of the MnBi primary phase during the directional solidification has been investigated experimentally and the results show that an application of a high magnetic field has enhanced the faceted growth and the coarsening of the MnBi primary phase. This may be attributed to the effect of a high magnetic field on the diffusion of the solute Mn and the growth anisotropy of the MnBi crystal. 相似文献
243.
Savaş Sönmezoğlu Yakup Ulusu Fatma Gedikli Özlem Ateş Sönmezoğlu İsa Gökçe 《Philosophical Magazine Letters》2013,93(5):211-216
We have fabricated a molecular organic light-emitting device comprising indium–tin oxide/a molecular organic layer/aluminum in which the organic layer is a green fluorescent protein. The device exhibits peak external quantum and power efficiencies of 8?±?0.2% and 13?±?0.7?lm?W???1 at a current of J?=?1.5?A?m?2, respectively. In addition, the turn-on voltage is 2.5?V for 1?cd?m?2 and the maximum luminance achieved is 1275?cd?m?2. This good performance can be explained by the presence of singlet-excited states, leading to a high internal efficiency. 相似文献
244.
Romi Zäske Verena G. Skuk Jürgen M. Kaufmann Stefan R. Schweinberger 《Acta psychologica》2013,144(3):583-593
Aftereffects of adaptation have revealed both independent and interactive coding of facial signals including identity and expression or gender and age. By contrast, interactive processing of non-linguistic features in voices has rarely been investigated. Here we studied bidirectional cross-categorical aftereffects of adaptation to vocal age and gender. Prolonged exposure to young (~ 20 yrs) or old (~ 70 yrs) male or female voices biased perception of subsequent test voices away from the adapting age (Exp. 1) and the adapting gender (Exp. 2). Relative to gender-congruent adaptor-test pairings, vocal age aftereffects (VAAEs) were reduced but remained significant when voice gender changed between adaptation and test. This suggests that the VAAE relies on both gender-specific and gender-independent age representations for male and female voices. By contrast, voice gender aftereffects (VGAEs) were not modulated by age-congruency of adaptor and test voices (Exp. 2). Instead, young voice adaptors generally induced larger VGAEs than old voice adaptors. This suggests that young voices are particularly efficient gender adaptors, likely reflecting more pronounced sexual dimorphism in these voices. In sum, our findings demonstrate how high-level processing of vocal age and gender is partially intertwined. 相似文献
245.
246.
This study explored adjustment and adaptation in families living with Autism Spectrum Disorder (ASD). Data on family resilience were collected from 19 biological mothers of children with ADS. The data were analysed qualitatively and quantitatively to yield information on factors that enable these families to bounce back from the diagnosis and accompanying challenges with regard to ADS. The findings from the qualitative analysis indicate that social support, the spousal relationship, and family time, togetherness and routines are the most important resilience-promoting factors with ASD. Family hardiness, family problem-solving communication, and family time and routines were significant resilience resources. 相似文献
247.
Deployment may lead the soldiers to dichotomise their profession and their family life, resulting in unwanted effects on family or career. Effects on reintegration and functioning within family are considered. Reunions may be characterized by perceived negative reception and consequences could spill over to children as parents attempt to equivocate their differences. Risks exist for fragmentation of the family system or divorce. Social support may serve to buffer families with members on deployment. 相似文献
248.
Simin Jodeyr 《Psychodynamic Practice》2013,19(2):205-214
Abstract There is little research and literature available in the United Kingdom which addresses the issues for black and ethnic minority families who have dealings with the family court system. Therefore, this article is based largely on the personal views and experiences of the author. In it I shall be commenting on the functioning of the court in terms of private law concerning children. 相似文献
249.
《Journal of couple & relationship therapy》2013,12(1-2):45-56
Abstract Therapies for alcoholism, substance abuse, and other addictions traditionally focus on characteristics of individuals such as behaviors, thoughts, and emotions. These kinds of programs tend to target problems inside the abusing person rather than a relational system. Treatments that are more recent locate the problems within systems of people. Regardless of the locus or cause of the abuse or addiction, seen as arising from disease processes, systemic dynamics, or other mechanisms that lead to unfortunate habits and behaviors, utilizing the individual's partner or family in therapy has become an important part of successful treatment. This article reviews models of couple treatment for alcoholics and substance abusers in terms of initiation into treatment, primary treatment, and relapse prevention. 相似文献
250.
《Journal Of Applied School Psychology》2013,29(1):67-89
Many people are equipped, through crisis intervention strategies and plans, to handle the immediate ramifications of a death within a particular school or community system. However, after the crisis has passed the question generally surfaces as to how one can help the children who have been greatly impacted by the death and are in the midst of the grieving process. The grieving child has often been invisible to adult caregivers like counselors, teachers, and school psychologist. The means of helping a child who has experienced a death in his family can be greatly enhanced by the developmcnt of grief support groups. Through the use of support groups children can learn to share their feelings, discover that they are not alone, and move through the grieve process. 相似文献