全文获取类型
收费全文 | 2516篇 |
免费 | 99篇 |
国内免费 | 3篇 |
出版年
2023年 | 21篇 |
2022年 | 14篇 |
2021年 | 24篇 |
2020年 | 49篇 |
2019年 | 61篇 |
2018年 | 88篇 |
2017年 | 71篇 |
2016年 | 70篇 |
2015年 | 67篇 |
2014年 | 58篇 |
2013年 | 264篇 |
2012年 | 99篇 |
2011年 | 99篇 |
2010年 | 72篇 |
2009年 | 57篇 |
2008年 | 84篇 |
2007年 | 94篇 |
2006年 | 82篇 |
2005年 | 52篇 |
2004年 | 72篇 |
2003年 | 43篇 |
2002年 | 48篇 |
2001年 | 121篇 |
2000年 | 117篇 |
1999年 | 75篇 |
1998年 | 17篇 |
1997年 | 29篇 |
1996年 | 23篇 |
1994年 | 18篇 |
1992年 | 40篇 |
1991年 | 55篇 |
1990年 | 39篇 |
1989年 | 42篇 |
1988年 | 42篇 |
1987年 | 29篇 |
1986年 | 18篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 19篇 |
1981年 | 15篇 |
1979年 | 20篇 |
1976年 | 15篇 |
1974年 | 17篇 |
1973年 | 16篇 |
1971年 | 17篇 |
1970年 | 14篇 |
1969年 | 15篇 |
1968年 | 16篇 |
1967年 | 17篇 |
1966年 | 13篇 |
排序方式: 共有2618条查询结果,搜索用时 31 毫秒
841.
842.
A sample containing single-wall carbon nanotubes (SWCNTs) has been annealed at 900°C and then irradiated by high-energy electrons in an ultrahigh-vacuum transmission electron microscope. Sequential high-resolution images showed that the structures of SWCNT bundles and individual SWCNT segments first collapsed into disordered and fullerene-like carbon materials and then reorganized into graphitic particles under continuous electron irradiation. The speed of structural evolution is dependent on the flux density of the electron irradiation. 相似文献
843.
The microstructures of Al–1.8 to 92.5?at.% Cu thin films prepared by radiofrequency (13.56?MHz) cathodic magnetron sputtering have been investigated by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). A phase separation occurs in films of nominal Al–66.64?at.% Cu composition, consisting of a fcc Al solid solution phase, a fcc Cu solid solution phase and an unexpected sc Cu3Al ordered phase with a Cu3Au structure and a lattice parameter of about 0.36?nm. 相似文献
844.
Abstract The microstructure of long-range-ordered vanadium carbides based on V6C5 has been analysed by means of high-resolution electron microscopy (HREM). Lattice images have been produced by including in the objective-aperture superlattice spots associated with the ordered distribution of vacancies in the interstitial carbon sublattice of these substoichiometric compounds: ‘perfectly’ ordered structures have been imaged, and a direct discussion of the experimental micrographs is made in terms of positions of the vacancy-containing columns. This HREM study will soon be extended to theinvestigation of various kinds of planar defects within differently annealed specimens. 相似文献
845.
846.
Younus Y. Mirza 《Islam & Christian-Muslim Relations》2013,24(3):277-298
This article examines how Ibn Taymiyya and Ibn Kathīr shift the Islamic exegetical tradition towards accepting Ishmael as Abraham's intended sacrifice. Earlier exegetes, such as al-?abarī, maintained that Isaac was the intended sacrifice through a philological analysis of the qur'anic text. Contrary to expectations, Ibn Taymiyya and Ibn Kathīr do not only use Prophetic reports (Hadith) to make their case but also employ biblical and philological arguments. The modern dominance of Ibn Taymiyya's qur'anic hermeneutic and the popularity of Ibn Kathīr's qur'anic exegesis have influenced Islamic orthodoxy to hold that Ishmael was the sacrificial son and to be more skeptical of biblical sources. 相似文献
847.
Positive and negative perfectionism (measured by the Positive and Negative Perfectionism Scale; PANPS) are found to have differential roles in predicting eating problems. This study translated and back-translated the PANPS into Chinese and then examined whether its factor structure was comparable to the original PANPS. The relationships between positive and negative perfectionism (using Chinese PANPS) and eating problems were also evaluated. Malaysian Chinese (N = 205) adults completed the Chinese PANPS, Eating Disorder Inventory (EDI) and Marlowe-Crowne Social Desirability Scale. Principal Component Analysis showed the two-factor solution of the Chinese PANPS accounted for 33.42% of the total variance, which was comparable to previous studies. Hierarchical multiple regressions revealed that negative perfectionism significantly predicted all eating disorder symptoms for females, but not drive for thinness and body dissatisfaction for males. Conversely, positive perfectionism significantly predicted lower total EDI scores, lower ineffectiveness and lower interpersonal distrust, but only predicted lower body dissatisfaction among females. In conclusion, negative perfectionism was consistently associated with eating problems whereas positive perfectionism might be a potentially adaptive factor, confirming the distinctive roles each played in the development of eating problems, even in a non-Western population. 相似文献
848.
Meagan C. Alder W. Justin Dyer Jonathan G. Sandberg Stephanie Y. Davis Julianne Holt-Lunstad 《The American journal of family therapy》2013,41(5):541-555
AbstractDecades of research have shown that depression can have deleterious effects on couple relationships. Emotionally-focused therapy (EFT; Johnson, 2004) is an empirically validated form of couple therapy, which has shown effectiveness in reducing depressive symptoms in couples where the wife has depression. The aim of the current pilot study was to examine the extent to which EFT and the comparison treatment as usual (TAU) therapy group decrease depressive symptoms in distressed couples. Results show that both groups were effective in decreasing depressive symptoms, with EFT showing a clinically significant reduction. Clinical implications and future research are discussed. 相似文献
849.
Emotions are for action, but action styles in emotional episodes may vary across cultural contexts. Based on culturally different models of agency, we expected that those who engage in European-American contexts will use more influence in emotional situations, while those who engage in East-Asian contexts will use more adjustment. European-American (N=60) and Asian-American (N=44) college students reported their action style during emotional episodes four times a day during a week. Asian Americans adjusted more than European Americans, whereas both used influence to a similar extent. These cultural differences in action style varied across types of emotion experienced. Moreover, influencing was associated with life satisfaction for European Americans, but not for Asian Americans. 相似文献
850.
Anneke D. M. Haddad Mengran Xu Sophie Raeder Jennifer Y. F. Lau 《Cognition & emotion》2013,27(5):914-922
Common and persistent fears may emerge through learning mechanisms such as fear conditioning and generalisation. Although there have been extensive studies of these learning processes in healthy but also psychiatric samples, many of the tasks used to produce conditioning and assess generalisation either use painful and aversive stimuli as the unconditioned stimuli (UCS), or suffer from poor belongingness between the conditioned stimuli and the UCS. Here, we present novel data from a paradigm designed to examine fear conditioning and generalisation in healthy individuals. Two female faces served as conditioned threat cue (CS+) and conditioned safety cue (CS?) respectively. The CS+ was paired repeatedly with a fearful, screaming face (unconditioned stimulus). Generalisation included intermediate faces which varied in their similarity to the CS+ and CS?. We measured eyeblink startle reflex and self-reported ratings. Acquired fear of the CS+ generalised to intermediate stimuli in proportion to their perceptual similarity to the CS+. Our findings demonstrate how fears of new individuals may develop based on resemblance to others with whom an individual has had negative experiences. The paradigm offers new opportunities for probing the role of generalisation in the emergence of common and persistent fears. 相似文献