全文获取类型
收费全文 | 3007篇 |
免费 | 131篇 |
国内免费 | 191篇 |
学科分类
工业技术 | 3329篇 |
出版年
2024年 | 2篇 |
2023年 | 26篇 |
2022年 | 47篇 |
2021年 | 109篇 |
2020年 | 69篇 |
2019年 | 43篇 |
2018年 | 51篇 |
2017年 | 53篇 |
2016年 | 47篇 |
2015年 | 64篇 |
2014年 | 87篇 |
2013年 | 88篇 |
2012年 | 126篇 |
2011年 | 235篇 |
2010年 | 203篇 |
2009年 | 199篇 |
2008年 | 181篇 |
2007年 | 230篇 |
2006年 | 240篇 |
2005年 | 217篇 |
2004年 | 166篇 |
2003年 | 211篇 |
2002年 | 154篇 |
2001年 | 134篇 |
2000年 | 64篇 |
1999年 | 46篇 |
1998年 | 44篇 |
1997年 | 30篇 |
1996年 | 35篇 |
1995年 | 28篇 |
1994年 | 19篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1964年 | 7篇 |
1963年 | 1篇 |
1956年 | 1篇 |
1955年 | 2篇 |
排序方式: 共有3329条查询结果,搜索用时 15 毫秒
991.
Silton Rebecca Levin; Heller Wendy; Engels Anna S.; Towers David N.; Spielberg Jeffrey M.; Edgar J. Christopher; Sass Sarah M.; Stewart Jennifer L.; Sutton Bradley P.; Banich Marie T.; Miller Gregory A. 《Canadian Metallurgical Quarterly》2011,120(2):272
A network consisting of left dorsolateral prefrontal cortex (LDLPFC) and dorsal anterior cingulate cortex (dACC) has been implicated in top-down attentional control. Few studies have systematically investigated how this network is altered in psychopathology, despite evidence that depression and anxiety are associated with attentional control impairments. Functional MRI and dense-array event-related brain potential (ERP) data were collected in separate sessions from 100 participants during a color–word Stroop task. Functional MRI results guided ERP source modeling to characterize the time course of activity in LDLPFC (300–440 ms) and dACC (520–680 ms). At low levels of depression, LDLPFC activity was indirectly related to Stroop interference and only via dACC activity. In contrast, at high levels of depression, dACC did not play an intervening role, and increased LDLPFC activity was directly related to decreased Stroop interference. Specific to high levels of anxious apprehension, higher dACC activity was related to more Stroop interference. Results indicate that depression and anxious apprehension modulate temporally and functionally distinct aspects of the frontocingulate network involved in top-down attention control. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
992.
Professional psychologists can be profoundly affected by their patients and must know how to take care of themselves physically and emotionally while delivering effective treatment. In this paper, I examine the effects of one patient on my personal and professional lives. Over the course of 2 years, the patient experienced numerous losses and became deeply depressed. Her symptoms included suicidal urges and self-harm (cutting). I describe the impact of the patient's life events on the therapy and on me as the therapist. I enumerate self-care strategies that preserved my ability to treat the patient without becoming distressed or impaired by the demands of the case. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
993.
Kwag Kyung Hwa; Jang Yuri; Rhew Sung Han; Chiriboga David A. 《Canadian Metallurgical Quarterly》2011,2(2):91
This study explored how the physical and mental health of Korean American older adults were influenced by neighborhood characteristics (i.e., proportion of individuals living below the poverty level, proportion of individuals 65 years of age and older, and proportion of racial/ethnic minorities in the census block groups where each respondent lived). Health perceptions (i.e., the subjective appraisal of one's own health) and depressive symptoms were used as indicators of physical and mental health. Multilevel analyses were performed with 567 individuals (at Level 1) nested within 233 census block groups (at Level 2). After controlling for individual demographic and health characteristics, we found that neighborhood poverty predicted health perceptions. The results add to the growing literature on the influence of the social environment and suggest that neighborhood characteristics should be taken into consideration in developing community-based policies for racially/ethnically diverse populations. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
994.
995.
Tanofsky-Kraff Marian; Shomaker Lauren B.; Olsen Cara; Roza Caroline A.; Wolkoff Laura E.; Columbo Kelli M.; Raciti Gina; Zocca Jaclyn M.; Wilfley Denise E.; Yanovski Susan Z.; Yanovski Jack A. 《Canadian Metallurgical Quarterly》2011,120(1):108
Loss of control (LOC) eating in youth is associated cross-sectionally with eating-related and psychosocial distress and is predictive of excessive weight gain. However, few longitudinal studies have examined the psychological impact and persistence of pediatric LOC eating. We administered the Eating Disorder Examination and self-reported measures of depressive and anxiety symptoms to 195 boys and girls (mean age = 10.4 years, SD = 1.5) at baseline and again 4.7 years (SD = 1.2) later to 118 of these youth. Missing data were imputed. Baseline report of LOC was associated with the development of partial- or full-syndrome binge eating disorder (p = .03), even after accounting for the contribution of sex, race, baseline characteristics (age, disordered eating attitudes, and mood symptoms), body mass index growth between baseline and follow-up, and years in study. Half (52.2%; 95% CI [1.15, 6.22]) of children who endorsed experiencing LOC at baseline reported persistence of LOC at follow-up (p = .02). Compared with children who never reported LOC eating or reported LOC only at baseline, those with persistent LOC experienced significantly greater increases in disordered eating attitudes (ps p = .027) over time. These data suggest that LOC eating in children is a problematic behavior that frequently persists into adolescence and that persistent LOC eating is associated with worsening of emotional distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
Marsh Herbert W.; Nagengast Benjamin; Morin Alexandre J. S.; Parada Roberto H.; Craven Rhonda G.; Hamilton Linda R. 《Canadian Metallurgical Quarterly》2011,103(3):701
Existing research posits multiple dimensions of bullying and victimization but has not identified well-differentiated facets of these constructs that meet standards of good measurement: goodness of fit, measurement invariance, lack of differential item functioning, and well-differentiated factors that are not so highly correlated as to detract from their discriminant validity and substantive usefulness in school settings. Here we demonstrate exploratory structural equation modeling, an integration of confirmatory factor analysis and exploratory factor analysis. On the basis of responses to the 6-factor Adolescent Peer Relations Instrument (verbal, social, physical facets of bullying and victimization), we tested invariance of factor loadings, factor variances–covariances, item uniquenesses, item intercepts (a lack of differential item functioning), and latent means across gender, year in school, and time. Using a combination of relations with student characteristics and a multitrait–multimethod analysis, we showed that the 6 bully/victim factors have discriminant validity over time and in relation to gender, year in school, and relevant psychosocial correlates (e.g., depression, 11 components of academic and nonacademic self-concept, locus of control, attitudes toward bullies and victims). However, bullies and victims are similar in many ways, and longitudinal panel models of the positive correlations between bully and victim factors suggest reciprocal effects such that each is a cause and an effect of the other. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
997.
Verdeli Helen; Baily Charles; Vousoura Eleni; Belser Alexander; Singla Daisy; Manos Gail 《Canadian Metallurgical Quarterly》2011,25(4):488
The increased operational tempo associated with current deployments to Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) is placing considerable strain on military families. Among other sequelae of OIF and OEF deployment, findings from recent studies suggest high rates of depression in spouses of service members. This review presents a rationale for targeting depression among military spouses. It examines how stressors relating to the deployment cycle may contribute to depression in spouses and outlines the effects of spousal depression on the mental health of service members and their children. Mental health services currently available to military spouses as well as barriers to their care are also described. Considerations for the adaptation of treatment to their unique circumstances and needs are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
998.
Lindwall Magnus; Larsman Pernilla; Hagger Martin S. 《Canadian Metallurgical Quarterly》2011,30(4):453
Objective: The aim of this prospective study was to investigate the reciprocal nature of the physical activity-depressive symptoms relationship in 17,593 older adults from 11 European countries older adults (M age = 64.07, SD = 9.58) across two-year follow-up. Also, gender and age were examined as potential moderators of this relation. Method: A two-wave cross-lagged panel design and latent change score models with structural equation modeling was used to analyze data. Depressive symptoms were measured at baseline (T1) and follow-up (T2) using the EURO-D scale, capturing the two factors of affective suffering and motivation. Physical activity was measured at T1 and T2 as frequency of moderate physical activity and vigorous physical activity. Results: Cross-sectional latent variable analyses revealed that higher levels of physical activity at T1 and T2 were associated with lower levels of affective suffering and motivation at T1 and T2. Physical activity at T1 was significantly associated with affective suffering and motivation at T2. The relations of depressive symptoms at T1 with physical activity at T2 were not significant. However, a cross-lagged model showed best model fit, supporting a reciprocal prospective relationship between physical activity and depressive symptoms in older adults. Latent change in depressive symptoms factors was related to latent change in physical activity indicating complex and dynamic associations across time. Conclusions: Regular physical activity may be a valuable tool in the prevention of future depressive symptoms in older adults, and depressive symptoms may also prevent older adults from engaging in regular physical activity. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
999.
Kamila Pucha?owicz Maciej Tarnowski Irena Baranowska-Bosiacka Dariusz Chlubek Violetta Dziedziejko 《International journal of molecular sciences》2014,15(12):23672-23704
Purinergic signalling plays a crucial role in proper functioning of the nervous system. Mechanisms depending on extracellular nucleotides and their P2 receptors also underlie a number of nervous system dysfunctions. This review aims to present the role of purinergic signalling, with particular focus devoted to role of P2 family receptors, in epilepsy, depression, neuropathic pain, nervous system neoplasms, such as glioma and neuroblastoma, neurodegenerative diseases like Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. The above-mentioned conditions are associated with changes in expression of extracellular ectonucleotidases, P2X and P2Y receptors in neurons and glial cells, as well as releasing considerable amounts of nucleotides from activated or damaged nervous tissue cells into the extracellular space, which contributes to disturbance in purinergic signalling. The numerous studies indicate a potential possibility of using synthetic agonists/antagonists of P2 receptors in treatment of selected nervous system diseases. This is of particular significance, since numerous available agents reveal a low effectiveness and often produce side effects. 相似文献
1000.
Hiroshi Mitoma Shinji Kakei Kazuhiko Yamaguchi Mario Manto 《International journal of molecular sciences》2021,22(9)
The cerebellum is endowed with the capacity for compensation and restoration after pathological injury, a property known as cerebellar reserve. Such capacity is attributed to two unique morphological and physiological features of the cerebellum. First, mossy fibers that convey peripheral and central information run mediolaterally over a wide area of the cerebellum, resulting in the innervation of multiple microzones, commonly known as cerebellar functional units. Thus, a single microzone receives redundant information that can be used in pathological conditions. Secondly, the circuitry is characterized by a co-operative interplay among various forms of synaptic plasticity. Recent progress in understanding the mechanisms of redundant information and synaptic plasticity has allowed outlining therapeutic strategies potentiating these neural substrates to enhance the cerebellar reserve, taking advantage of the unique physiological properties of the cerebellum which appears as a modular and potentially reconfiguring brain structure. 相似文献