全文获取类型
收费全文 | 4241篇 |
免费 | 188篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 21篇 |
综合类 | 8篇 |
化学工业 | 1051篇 |
金属工艺 | 44篇 |
机械仪表 | 46篇 |
建筑科学 | 186篇 |
矿业工程 | 13篇 |
能源动力 | 67篇 |
轻工业 | 727篇 |
水利工程 | 27篇 |
石油天然气 | 9篇 |
无线电 | 125篇 |
一般工业技术 | 485篇 |
冶金工业 | 1086篇 |
原子能技术 | 24篇 |
自动化技术 | 515篇 |
出版年
2023年 | 20篇 |
2022年 | 60篇 |
2021年 | 201篇 |
2020年 | 82篇 |
2019年 | 98篇 |
2018年 | 108篇 |
2017年 | 84篇 |
2016年 | 100篇 |
2015年 | 94篇 |
2014年 | 134篇 |
2013年 | 259篇 |
2012年 | 173篇 |
2011年 | 225篇 |
2010年 | 190篇 |
2009年 | 156篇 |
2008年 | 212篇 |
2007年 | 192篇 |
2006年 | 149篇 |
2005年 | 134篇 |
2004年 | 119篇 |
2003年 | 96篇 |
2002年 | 120篇 |
2001年 | 72篇 |
2000年 | 66篇 |
1999年 | 88篇 |
1998年 | 79篇 |
1997年 | 53篇 |
1996年 | 73篇 |
1995年 | 50篇 |
1994年 | 55篇 |
1993年 | 54篇 |
1992年 | 61篇 |
1990年 | 49篇 |
1989年 | 69篇 |
1988年 | 45篇 |
1987年 | 51篇 |
1986年 | 55篇 |
1985年 | 53篇 |
1984年 | 58篇 |
1983年 | 45篇 |
1982年 | 30篇 |
1981年 | 46篇 |
1980年 | 26篇 |
1979年 | 23篇 |
1978年 | 22篇 |
1977年 | 22篇 |
1976年 | 30篇 |
1975年 | 26篇 |
1973年 | 16篇 |
1970年 | 17篇 |
排序方式: 共有4434条查询结果,搜索用时 31 毫秒
101.
Hindson Barbara; Byrne Brian; Fielding-Barnsley Ruth; Newman Cara; Hine Donald W.; Shankweiler Donald 《Canadian Metallurgical Quarterly》2005,97(4):687
Preschool children at familial risk for reading disability were assessed on cognitive and linguistic variables and compared with preschoolers without familial risk. Risk children displayed performance profiles resembling those of older children with reading disability. Each group received intensive instruction in phonemic awareness and structured book reading. Instructed risk children made somewhat smaller gains than the nonrisk and required more teaching sessions to reach criterion. Rhyme and phoneme awareness predicted instruction outcome levels, and vocabulary and verbal short-term memory predicted number of teaching sessions to criterion. In kindergarten, the nonrisk group outperformed the risk group on reading and spelling, although the risk group reached grade-appropriate levels. At-risk children can be helped by appropriate preschool instruction, but they require more sustained teaching than nonrisk preschoolers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
102.
Golden-Kreutz Deanna M.; Thornton Lisa M.; Wells-Di Gregorio Sharla; Frierson Georita M.; Jim Heather S.; Carpenter Kristen M.; Shelby Rebecca A.; Andersen Barbara L. 《Canadian Metallurgical Quarterly》2005,24(3):288
The authors investigated the relationship between stress at initial cancer diagnosis and treatment and subsequent quality of life (QoL). Women (n = 112) randomized to the assessment-only arm of a clinical trial were initially assessed after breast cancer diagnosis and surgery and then reassessed at 4 months (during adjuvant treatment) and 12 months (postadjuvant treatment). There were 3 types of stress measured: number of stressful life events (K. A. Matthews et al., 1997), cancer-related traumatic stress symptoms (M. J. Horowitz, N. Wilner, & W. Alvarez, 1979), and perceived global stress (S. Cohen, T. Kamarck, & R. Mermelstein, 1983). Using hierarchical multiple regressions, the authors found that stress predicted both psychological and physical QoL (J. E. Ware, K. K. Snow, & M. Kosinski, 2000) at the follow-ups (all ps 相似文献
103.
Michael L. Bernard Barbara S. Chaparro Melissa M. Mills Charles G. Halcomb 《International journal of human-computer studies》2003,59(6):823-835
Times New Roman and Arial typefaces in 10- and 12-point, dot-matrix and anti-aliased format conditions were compared for readability (accuracy, reading speed, and accuracy/reading speed), as well as perceptions of typeface legibility, sharpness, ease of reading, and general preference. In assessing readability, the 10-point anti-aliased Arial typeface was read slower than the other type conditions. Examining perceptions of typeface legibility, sharpness, and ease of reading detected significant effects for typeface, size, and format. Overall, the 12-point dot-matrix Arial typeface was preferred to the other typefaces. Recommendations for appropriate typeface combinations for computer-displayed text are discussed. 相似文献
104.
This note aims to present new denoising method based on thin-plate splines (TPS). The proposed approach is based on the general TPS denoising Berman [2], however, its unfavorable smoothing of edges and details is suppressed by introduction of a weighting approach applied locally. The performance of the method is shown and compared to the original TPS denoising. 相似文献
105.
This paper describes the design, development, implementation, and assessment of a multimedia‐based learning module focused on biomechanics. The module is comprised of three challenges and is based on a model of learning and instruction known as the How People Learn (HPL) framework. Classroom assessment of the first challenge was undertaken to test the hypothesis that the HPL approach increases adaptive expertise in movement biomechanics. Student achievement was quantified using pre‐ and post‐test questionnaires designed to measure changes in three facets of adaptive expertise: factual and conceptual knowledge and transfer. The results showed that the HPL approach increased students' conceptual knowledge as well as their ability to transfer knowledge to new situations. These findings indicate that challenge‐based instruction, when combined with an intellectually engaging curriculum and principled instructional design, can accelerate the trajectory of novice to expert development in bioengineering education. 相似文献
106.
McCrady Barbara S.; Epstein Elizabeth E.; Kahler Christopher W. 《Canadian Metallurgical Quarterly》2004,72(5):870
Ninety men with alcohol problems and their female partners were randomly assigned to 1 of 3 outpatient conjoint treatments: alcohol behavioral couples therapy (ABCT), ABCT with relapse prevention techniques (RP/ABCT), or ABCT with interventions encouraging Alcoholics Anonymous (AA) involvement (AA/ABCT). Couples were followed for 18 months after treatment. Across the 3 treatments, drinkers who provided follow-up data maintained abstinence on almost 80% of days during follow-up, with no differences in drinking or marital happiness outcomes between groups. AA/ABCT participants attended AA meetings more often than ABCT or RP/ABCT participants, and their drinking outcomes were more strongly related to concurrent AA attendance. For the entire sample, AA attendance was positively related to abstinence during follow-up in both concurrent and time-lagged analyses. In the RP/ABCT treatment, attendance at posttreatment booster sessions was related to posttreatment abstinence. Across treatment conditions, marital happiness was related positively to abstinence in concurrent but not time-lagged analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
The use of pointers presents serious problems for software productivity tools for software understanding, restructuring, and testing. Pointers enable indirect memory accesses through pointer dereferences, as well as indirect procedure calls (e.g., through function pointers in C). Such indirect accesses and calls can be disambiguated with pointer analysis. In this paper we evaluate the precision of one specific pointer analysis (the FA pointer analysis by Zhang et al.) for the purposes of call graph construction for C programs with function pointers. The analysis is incorporated in a production-strength code-browsing tool from Siemens Corporate Research in which the program call graph is used as a primary tool for code understanding.The FA pointer analysis uses an inexpensive, almost-linear, flow- and context-insensitive algorithm. To measure analysis precision, we compare the call graph constructed by this analysis with the most precise call graph obtainable by a large category of existing pointer analyses. Surprisingly, for all our data programs the FA analysis achieves the best possible precision. This result indicates that for the purposes of call graph construction, inexpensive pointer analyses may provide precision comparable to the precision of expensive pointer analyses. 相似文献
108.
109.
This study explores the relational and affective aspects of personal ties of cultural mediators by means of in-depth interviews with Dutch book publishers. Through examining the affective side of publishers' personal networks, we contribute to understanding the role of cultural mediators—those in-between artists and consumers—and how they deal with the tensions between and the integration of culture and commerce in increasingly concentrated markets. Informal networking is not primarily based on sociality ties and mutual exchange, as is often assumed; instead, publishers use informal contacts to keep an eye on each other, they share communalities with authors in more private settings and they exchange specific content in more formal ways. Personal ties involve different loyalties and motives which elevate or increase tensions between career and conglomerate and between culture and commerce. We critically employ Grabher's typology to get more understanding of how cultural mediators deal with these tensions and the integration of culture and commerce and the creation of value. By moving beyond dichotomies of emotion–business and culture–commerce, we aim to contribute to a more nuanced understanding of the role of both networks and place in cultural industries. 相似文献
110.
Faming Zhang Arne Weidmann J. Barbara Nebe Eberhard Burkel 《Materials science & engineering. C, Materials for biological applications》2012,32(5):1057-1061
In order to investigate the interaction of cells with modified multi-walled carbon nanotubes (MWCNTs) for their potential biomedical applications, the MWCNTs were chemically modified with carboxylic acid groups (–COOH), polyvinyl alcohol (PVA) polymer and biomimetic apatite on their surfaces. Additionally, human osteoblast MG-63 cells were cultured in the presence of the surface-modified MWCNTs. The metabolic activities of osteoblastic cells, cell proliferation properties, as well as cell morphology were studied. The surface modification of MWCNTs with biomimetic apatite exhibited a significant increase in the cell viability of osteoblasts, up to 67.23%. In the proliferation phases, there were many more cells in the biomimetic apatite-modified MWCNT samples than in the MWCNTs–COOH. There were no obvious changes in cell morphology in osteoblastic MG-63 cells cultured in the presence of these chemically-modified MWCNTs. The surface modification of MWCNTs with apatite achieves an effective enhancement of their biocompatibility. 相似文献