全文获取类型
收费全文 | 2975篇 |
免费 | 319篇 |
国内免费 | 717篇 |
出版年
2024年 | 10篇 |
2023年 | 42篇 |
2022年 | 54篇 |
2021年 | 91篇 |
2020年 | 136篇 |
2019年 | 84篇 |
2018年 | 102篇 |
2017年 | 135篇 |
2016年 | 100篇 |
2015年 | 98篇 |
2014年 | 99篇 |
2013年 | 289篇 |
2012年 | 181篇 |
2011年 | 226篇 |
2010年 | 207篇 |
2009年 | 220篇 |
2008年 | 219篇 |
2007年 | 299篇 |
2006年 | 286篇 |
2005年 | 246篇 |
2004年 | 163篇 |
2003年 | 119篇 |
2002年 | 74篇 |
2001年 | 58篇 |
2000年 | 50篇 |
1999年 | 65篇 |
1998年 | 35篇 |
1997年 | 34篇 |
1996年 | 35篇 |
1995年 | 32篇 |
1994年 | 24篇 |
1993年 | 25篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 17篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 11篇 |
1986年 | 17篇 |
1985年 | 9篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1946年 | 1篇 |
排序方式: 共有4011条查询结果,搜索用时 15 毫秒
21.
不同时相日光下颜色的恒常性 总被引:1,自引:0,他引:1
一、前言 在光源光谱成份改变的条件下,我们周围物体的颜色在眼睛看来保持相对不变,称为颜色恒常性。1807年Thomas Young首先描述了颜色恒常性现象,他指出室内不管是由蜡烛的黄光或火焰的红光来照明的,书页纸仍然看来是白色的。Young认为,外界某一表面的颜色外观,并不完全决定于网膜的红、绿、蓝三种感受器的吸收特性,而也依赖于周围其它物体射入眼睛的光通量。此后,E.Hering对颜色恒常性做了实验表演。一般认为颜色恒常性是对环境照明感受性的降低。视觉通道只传递由物体表面所反射的光谱成 相似文献
22.
23.
本实验采用四种不同显色特性的光源分别作为两种类型视标的照明。在同一照度上对各照明条件下的视觉敏度予以测定和计算。结果表明:增加光源显色指数对于颜色背景上黑色视标的辨认能力有所提高;而对于中灰色背景上颜色视标的辨认能力则有所下降。这种效果主要是由于在不同光源照明下,视标与背景的亮度对比变化所致。结果还表明:使用中灰背景颜色视标在辨认效果上优于颜色背景黑视标。对前一类型视标采用高压钠灯照明有助于提高视觉辨别力。这对推广应用这种显色指数较低,但光效率较高的新光源有实际意义。 相似文献
24.
Research has demonstrated that on the path from a creative idea to a creative outcome, high creativity motivation and self-efficacy do not necessarily lead to creative behavior. The present study proposed and examined the notion that daily creativity planning could promote creative behavior and contribute to the cultivation of creativity. A total of 77 middle school students (39 students in the experimental group and 38 in the control group) participated in this study, for which a quasi-experimental design was administered. The experimental group conducted a two-week daily planning for creative activities, while the control group did not conduct any intervention. The results showed that students' creativity motivation and creative self-efficacy were at relatively high levels overall and were positively and moderately correlated with creative behavior. Daily planning could effectively facilitate students' creative behavior. These findings point to a promising and simple creativity enhancement strategy for cultivating students to develop the habit of making creative plans in their daily lives. 相似文献
25.
Katherine A. Hirchak PhD MHPA Melanie Nadeau PhD MPH Angel Vasquez PhD Alexandra Hernandez-Vallant MS Kyle Smith Cuong Pham MD Karen Anderson Oliver PhD Paulette Baukol BS Karen Lizzy CDP Racquel Shaffer CPC Jalene Herron MS Aimee N. C. Campbell PhD Kamilla L. Venner PhD The CTN- Collaborative Board 《American journal of community psychology》2023,71(1-2):174-183
American Indian/Alaska Native (AI/AN) communities are disproportionally impacted by the opioid overdose epidemic. There remains a dearth of research evaluating methods for effectively implementing treatments for opioid use disorder (OUD) within these communities. We describe proceedings from a 2-day Collaborative Board (CB) meeting tasked with developing an implementation intervention for AI/AN clinical programs to improve the delivery of medications to treat OUD (MOUD). The CB was comprised of Elders, cultural leaders, providers, individuals with lived experience with OUD, and researchers from over 25 communities, organizations, and academic institutions. Conversations were audio-recorded, transcribed, and coded by two academic researchers with interpretation oversight provided by the CB. These proceedings provided a foundation for ongoing CB work and a frame for developing the program-level implementation intervention using a strength-based and holistic model of OUD recovery and wellbeing. Topics of discussion posed to the CB included engagement and recovery strategies, integration of extended family traditions, and addressing stigma and building trust with providers and clients. Integration of traditional healing practices, ceremonies, and other cultural practices was recommended. The importance of centering AI/AN culture and involving family were highlighted as priorities for the intervention. 相似文献
26.
Food stealing is often a serious behavioral problem among children with diagnoses of autism and other developmental disorders. Very few empirical studies concerning this behavioral challenge have been reported. We applied a correspondence training procedure to teach self-control as replacement behavior to four children with autism and developmental disorders who displayed food stealing in the community. A changing criterion design embedded within a nonconcurrent multiple-probe across participants design was used. The treatment succeeded for all four participants by increasing latency to eating highly preferred food to a predetermined criterion and reducing occurrences of food stealing to zero. Three participants generalized the replacement behavior to natural settings and maintained the behavior for 2 weeks, 1 month, 2 months, 3 months, and 4 months. One participant without expressive language was taught successfully during treatment trials but failed to maintain and generalize the behavior. A functional relation between delaying food eating and Say-Do correspondence training was demonstrated. 相似文献
27.
Xin Sun Rebecca A. Marks Kehui Zhang Chi-Lin Yu Rachel L. Eggleston Nia Nickerson Tai-Li Chou Xiao-Su Hu Twila Tardif Teresa Satterfield Ioulia Kovelman 《Developmental science》2023,26(1):e13251
How do early bilingual experiences influence children's neural architecture for word processing? Dual language acquisition can yield common influences that may be shared across different bilingual groups, as well as language-specific influences stemming from a given language pairing. To investigate these effects, we examined bilingual English speakers of Chinese or Spanish, and English monolinguals, all raised in the US (N = 152, ages 5–10). Children completed an English morphological word processing task during fNIRS neuroimaging. The findings revealed both language-specific and shared bilingual effects. The language-specific effects were that Chinese and Spanish bilinguals showed principled differences in their neural organization for English lexical morphology. The common bilingual effects shared by the two groups were that in both bilingual groups, increased home language proficiency was associated with stronger left superior temporal gyrus (STG) activation when processing the English word structures that are most dissimilar from the home language. The findings inform theories of language and brain development during the key periods of neural reorganization for learning to read by illuminating experience-based plasticity in linguistically diverse learners. 相似文献
28.
Yin Dake Yu Jiangping Jin Jiangping Shen Chao Zhang Li Li Xudong Zhang Keqin Wang Haitao 《Animal cognition》2023,26(4):1423-1430
Animal Cognition - Birds have the ability to assess the risk of predation in their environment and adjust their antipredation strategies based on this risk information. However, whether nest site... 相似文献
29.
Shareable digital coupons have emerged as a new marketing strategy. Prior literature on shareable coupons assumes that shareable coupons can play a role only after they have been shared with others. Surprisingly, we theorize that shareable coupons can come into play as early as when consumers merely possess them, even before consumers share them with others, an effect that precedes the effect of the actual coupon sharing. In this research, we show that the mere possession of shareable digital coupons (not necessarily the actual sharing) is able to induce anticipated self-enhancement among consumers. Hence shareable digital coupons are more effective than non-shareable digital coupons, and the effect is most pronounced among consumers with high image concerns. The higher coupon effectiveness of shareable digital coupons is reflected in consumers' greater urge/intention to acquire the coupon, intention to revisit, willingness to spend, as well as in firm's sales increase when products are promoted with shareable instead of non-shareable digital coupons. Our work contributes to the literature on shareable coupons, the mere possession effects, anticipated self-enhancement, and other-rewarding promotions, and is of important managerial value given the ease with which the shareability feature can be added to coupons. 相似文献
30.