全文获取类型
收费全文 | 993篇 |
免费 | 57篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
综合类 | 1篇 |
化学工业 | 190篇 |
金属工艺 | 15篇 |
机械仪表 | 14篇 |
建筑科学 | 55篇 |
矿业工程 | 3篇 |
能源动力 | 24篇 |
轻工业 | 163篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 63篇 |
一般工业技术 | 191篇 |
冶金工业 | 197篇 |
原子能技术 | 7篇 |
自动化技术 | 106篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 6篇 |
2021年 | 39篇 |
2020年 | 24篇 |
2019年 | 29篇 |
2018年 | 34篇 |
2017年 | 25篇 |
2016年 | 30篇 |
2015年 | 36篇 |
2014年 | 18篇 |
2013年 | 38篇 |
2012年 | 45篇 |
2011年 | 66篇 |
2010年 | 40篇 |
2009年 | 26篇 |
2008年 | 52篇 |
2007年 | 46篇 |
2006年 | 35篇 |
2005年 | 35篇 |
2004年 | 28篇 |
2003年 | 37篇 |
2002年 | 26篇 |
2001年 | 34篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 52篇 |
1997年 | 44篇 |
1996年 | 32篇 |
1995年 | 22篇 |
1994年 | 17篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有1051条查询结果,搜索用时 546 毫秒
1.
Deniz Caylioglu Rieke Johanna Meyer Dana Hellmold Carolin Kubelt Michael Synowitz Janka Held-Feindt 《International journal of molecular sciences》2021,22(7)
Glioblastoma (GBM) is a barely treatable disease due to its profound chemoresistance. A distinct inter- and intratumoral heterogeneity reflected by specialized microenvironmental niches and different tumor cell subpopulations allows GBMs to evade therapy regimens. Thus, there is an urgent need to develop alternative treatment strategies. A promising candidate for the treatment of GBMs is AT101, the R(-) enantiomer of gossypol. The present study evaluates the effects of AT101, alone or in combination with temozolomide (TMZ), in a microenvironmental glioma stem cell niche model of two GBM cell lines (U251MG and U87MG). AT101 was found to induce strong cytotoxic effects on U251MG and U87MG stem-like cells in comparison to the respective native cells. Moreover, a higher sensitivity against treatment with AT101 was observed upon incubation of native cells with a stem-like cell-conditioned medium. This higher sensitivity was reflected by a specific inhibitory influence on the p-p42/44 signaling pathway. Further, the expression of CXCR7 and the interleukin-6 receptor was significantly regulated upon these stimulatory conditions. Since tumor stem-like cells are known to mediate the development of tumor recurrences and were observed to strongly respond to the AT101 treatment, this might represent a promising approach to prevent the development of GBM recurrences. 相似文献
2.
3.
Iris Bakker Theo van der Voordt Peter Vink Jan de Boon Conne Bazley 《Color research and application》2015,40(1):62-71
Studies on color preferences are dependent on the topic and the relationships with personal characteristics, particularly personality, but these are seldom studied in one population. Therefore a questionnaire was collected from 1095 Dutch people asking for color preferences about different topics and relating them to personal characteristics. Color preferences regarding different topics show different patterns and significant differences were found between gender, age, education and personality such as being technical, being emotional or being a team player. Also, different colors were mentioned when asked for colors that stimulate to be quiet, energetic, and able to focus or creative. Probably, due to unconsciousness of contexts, many people had no color preference, a result that in the literature seldom is mentioned. Blue was the overall favorite color; however, most males chose for blue (25%) while most females had no color preference (18%). Black was the overall favorite color for clothing, mainly chosen by females (40%), while males primarily chose blue (27%). For building interiors subjects preferred white. For moods, subjects preferred white for being quiet or being able to focus, red for being energetic and had no color preference for being creative. It is concluded that color preferences are dependent upon the topic, and personal characteristics. The findings are important for architects, interior designers, fashion designers and product designers to have a basic idea of preferred colors for different objects by different types of people. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 62–71, 2015 相似文献
4.
Within the realm of oncology nursing, research has been an integral part in its development as a specialty practice. Yet despite the growing volume of published nursing research studies, little is known about how nurses working in oncology care settings perceive research. Therefore, the purposes of this study were to examine clinical oncology nurses' perceptions of research and to determine factors influencing their perceptions. Two hundred and eighty-three registered nurses providing cancer care to patients in 40 health care agencies across northern Ontario participated in the survey. Data were collected using a questionnaire developed by Alcock and colleagues (1990) which addressed nurses' perceived value of research, their role, interest and experience in research as well as the research climate of the agency. The findings showed that respondents valued nursing research and perceived a research role for staff nurses. However, the respondents did not perceive strong administrative or collegial support for nurses' involvement in research activities. In addition, the study results indicated that the clinical oncology nurses' perceptions of research were influenced by educational preparation. 相似文献
5.
Sood Johanna R.; Cisek Edward; Zimmerman Joan; Zaleski Ellen H.; Fillmore Herbert H. 《Canadian Metallurgical Quarterly》2003,48(1):44
Objective: To replicate and extend P. A. Lichtenberg and colleagues' (1996) cross-disciplinary intervention to improve physical and mental health among older adults. Participants: 14 depressed older adults (6 treatment, 8 control). Setting: The short-term rehabilitation unit of an urban nursing home. Intervention: Occupational therapists were trained to treat depression using pleasant events and cognitive-behavioral therapies. Outcome Measures: Geriatric Depression Scale, the Short Form-12, and the Multi-Level Assessment Instrument: Activities of Daily Living. Results: No significant group differences were found in physical or mental health. However, more control group members (75%) than treatment group members (33%) were depressed at study completion. Conclusions: The treatment of depressive symptoms can be integrated with a nonmental health treatment modality. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
6.
Gorgievski-Duijvesteijn Marjan J.; Bakker Arnold B.; Schaufeli Wilmar B.; van der Heijden Peter G. M. 《Canadian Metallurgical Quarterly》2005,10(3):210
This study of 513 Dutch farmers tested a dynamic equilibrium model of resources (an extension of the conservation of resources theory; S. E. Hobfoll, 1989, 1998, 2001). With structural equation modeling, the advantages of a 3-wave longitudinal design were comprehensively used, such as addressing bidirectional causal effects and within-individual vs. between-individual change. This allowed for a careful analysis of the management function of resources in the stress process. Results showed that well-being had stronger within-person stability than finances. Increased levels of financial problems temporarily increased psychological distress but not self-reported illness. Conversely, farmers with higher stable baselines of psychological distress also had higher baselines of self-reported illness and experienced more negative changes in their financial situation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
W J Stut J P de Valk H W Didden A R Bakker B M ter Haar Romeny 《Computer methods and programs in biomedicine》1989,28(1):63-70
Since the construction of picture archiving and communication systems (PACS) appears to be extremely difficult, computer modelling and simulation are used as decision support tools. The package MIRACLES (Medical Image Representation, Archiving and Communication Learned from Extensive Simulation) has been developed at BAZIS in order to support the construction of simulation models of image information systems. This article discusses the application of MIRACLES to a prototypical PACS as being installed in a clinical environment. Attention is focussed to the required system analysis and difficulties which arose during the construction of the simulation model. The emphasis is on the presentation of the results of the simulation study, which show that simulation can be fruitfully used to predict, to analyse and to assist in solving performance problems. The simulation study confirmed assumptions and suppositions concerning both the system performance itself and strategies to improve the performance. The study also resulted in a number of concrete recommendations which might be useful for the set-up of the prototypical PACS. 相似文献
8.
9.
T Peelen M van Vliet A Petrij-Bosch R Mieremet C Szabo AM van den Ouweland F Hogervorst R Brohet MJ Ligtenberg E Teugels R van der Luijt AH van der Hout JJ Gille G Pals I Jedema R Olmer I van Leeuwen B Newman M Plandsoen M van der Est G Brink S Hageman PJ Arts MM Bakker P Devilee 《Canadian Metallurgical Quarterly》1997,60(5):1041-1049
We have identified 79 mutations in BRCA1 in a set of 643 Dutch and 23 Belgian hereditary breast and ovarian cancer families collected either for research or for clinical diagnostic purposes. Twenty-eight distinct mutations have been observed, 18 of them not previously reported and 12 of them occurring more than once. Most conspicuously, a 2804delAA mutation has been found 19 times and has never been reported outside the Netherlands. A common haplotype spanning > or = 375 kb could be identified for each of the nine examined recurrent mutations, indicating the presence of multiple BRCA1 founder mutations in the Dutch population. The 2804delAA mutation has been estimated to have originated approximately 32 generations ago. No specific breast or ovarian cancer phenotype could be assigned to any of the common mutations, and the ovarian cancer incidence among 18 families with the 2804delAA mutation was heterogeneous. 相似文献
10.
J. J. M. Franse K. Bakker N. H. van Dijk A. A. Menovsky A. de Visser 《Journal of Low Temperature Physics》1994,95(1-2):177-190
The transition to the superconducting state of UPt3 has been studied in specific-heat experiments on polycrystalline and single-crystalline samples in dependence of heat treatment, purity of starting materials and deviations from stoichiometry, as well as on substituted compounds. The concepts behind the splitting of the transition in two anomalies that are 60 mK apart are critically reviewed. The superconducting phase diagram in the B-T plane has been studied with the use of a sensitive dilatometric technique. The three superconducting phases meet at a tetracritical point and all four phase lines are of second order. From the length anomalies at the phase boundaries the pressure derivatives of the phase lines have been determined and the most stable phase under uniaxial pressure along the c-axis has been identified. 相似文献