全文获取类型
收费全文 | 3016篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 14篇 |
综合类 | 2篇 |
化学工业 | 115篇 |
金属工艺 | 36篇 |
机械仪表 | 24篇 |
建筑科学 | 23篇 |
矿业工程 | 9篇 |
能源动力 | 20篇 |
轻工业 | 49篇 |
水利工程 | 12篇 |
石油天然气 | 7篇 |
无线电 | 77篇 |
一般工业技术 | 119篇 |
冶金工业 | 2417篇 |
原子能技术 | 17篇 |
自动化技术 | 84篇 |
出版年
2021年 | 18篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2016年 | 8篇 |
2014年 | 11篇 |
2013年 | 30篇 |
2012年 | 18篇 |
2011年 | 26篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 27篇 |
2007年 | 32篇 |
2006年 | 19篇 |
2005年 | 32篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 25篇 |
2001年 | 21篇 |
2000年 | 18篇 |
1999年 | 75篇 |
1998年 | 700篇 |
1997年 | 409篇 |
1996年 | 255篇 |
1995年 | 161篇 |
1994年 | 125篇 |
1993年 | 134篇 |
1992年 | 49篇 |
1991年 | 38篇 |
1990年 | 55篇 |
1989年 | 43篇 |
1988年 | 39篇 |
1987年 | 43篇 |
1986年 | 44篇 |
1985年 | 41篇 |
1984年 | 15篇 |
1983年 | 17篇 |
1982年 | 22篇 |
1981年 | 28篇 |
1980年 | 27篇 |
1979年 | 11篇 |
1978年 | 13篇 |
1977年 | 67篇 |
1976年 | 144篇 |
1975年 | 10篇 |
1974年 | 9篇 |
1973年 | 8篇 |
1972年 | 11篇 |
1971年 | 5篇 |
1970年 | 5篇 |
排序方式: 共有3025条查询结果,搜索用时 0 毫秒
61.
Content analyses of research published in the 1982 volumes of the Journal of Personality and Social Psychology indicate that social psychologists have largely failed to study subjects drawn from meaningfully defined social groups, to consider social structural variables, to study genuine social interaction, to observe social influences on psychological functioning, or to ask Ss about social issues. It is maintained that with few exceptions, personality researchers have failed to study groups other than college students, to use biographical materials or personal documents, to devise appropriate experimental treatments, to study persons over time, or even to retain the individual as a unit of analysis. Currently, the 2 fields of social and personality psychological research appear to be linked mainly by their deficiencies and appear to have little content worth sharing. Reexamination of each field's traditions and priorities is urgently needed. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
62.
Hypervolemia with hypertension often occurs 36-72 hours following massive blood and fluid replacement for hypovolemic shock. This syndrome of "fluid overload" has been attributed to the rapid intravascular flux of previously sequestered fluid in patients with impaired diuresis. This hypothesis was tested in 35 injured patients who received a mean of 9.3 L of blood and 17.4 L of salt during resucitation. The renal parameters measured soon after resuscitation included: 1) renal clearance of inulin (GFR), para-amino hippurate (ERPF), milliosmoles, sodium, and free water; 2) inulin space, renal vascular resistance (RVR), O2 consumption, renin, renal blood flow (RBF), and response to furosemide. Eighteen patients developed hypertension, hypervolemia, and respiratory insufficiency. When compared to the 17 normovolemic, non-hypertensive patients, the 18 hypervolemic patients had significantly increased RVR, with a significant decrease in RBF despite an increase in plasma volume and cardiac output. Furosemide produced less diuresis and natriuresis in the hypertensive patients. The balance between hypovolemia and "fluid overload" seemed percarious in the hypertensive patients. Peripheral renin and catecholamine levels were normal in both groups. Patients with post-traumatic "fluid overload" appear to have a combination of hypervolemia, respiratory insufficiency, hypertension, increased cardiac output, decreased extracellular fluid space, and decreased renal perfusion. These findings suggest that decreased interstitial fluid space compliance rather than "fluid overload" is the underlying factor leading to respiratory insufficiency. The therapeutic aspects of these findings are discussed. 相似文献
63.
CE McMahon 《Canadian Metallurgical Quarterly》1976,2(3):112-115
Despite its impressive rate of growth in the past decades, an increasing amount if dissatisfaction with the area of psychosomatic medicine is reflected in recent literature. The discipline's failures relate to concepts of pathogenesis and therapeutic application of research findings. These failures are explained as a necessary consequence of the philosophical tenet of mind-body dualism which underlies medical theory. It is urged that advocates of psychosomatic medicine give the concept of "holism" meaning at the most fundamental level by establishing a rational basis for theory, or else forsake this line of research for others which yield causal relationships conductive to effective therapy. 相似文献
64.
This special issue, entitled "Evidence-Based Parent and Family Interventions in School Psychology," examines the data that support the use of interventions as methods for changing children's school-related behavior and learning problems. Taken together, the articles reflect the work of the Parent and Family Intervention domain of the Evidence-Based Interventions in School Psychology Task Force. Across the articles in this special issue, the categories of coding criteria in the Manual were used to organize the presentation of results. Six review articles on the evidence base for parent and family intervention appear next; these are followed by commentary from distinguished scholars and a brief reflective comment from the special issue editors. Parent intervention is the exclusive focus of the reviews of parent education and parent consultation. Two reviews focus on the home-school relationship including the articles on parent involvement and home-school collaboration. Two reviews include both parent and family treatments: early childhood family-focused interventions and parent training and family systems interventions. Commentary was sought from the current co-chairs of the Task Force, an expert in evidence-based practice in child clinical psychology, a researcher in family-school linkages and parent consultation, and a methodologist. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
65.
Michael Yvonne L.; Carlson Nichole E.; Bowen Deborah J.; Ritenbaugh Cheryl 《Canadian Metallurgical Quarterly》2011,30(3):375
[Correction Notice: An erratum for this article was reported in Vol 30(4) of Health Psychology (see record 2011-13978-001). The letter was missing the doi. The correct doi is 10.1037/a0022737. The online version of this article has been corrected.] Responds to the comments by J. C. Coyne and C. Johansen (see record 2011-09497-016) on the current author's original article, "Influence of stressors on breast cancer incidence in the Women's Health Initiative" (see record 2009-03297-001). Coyne and Johansen (2011) took issue with the study conducted by the current authors' group (Michael et al., 2009), which analyzed the interaction between stressful life events and social support on breast cancer risk among 83,334 postmenopausal women enrolled in the Women’s Health Initiative (WHI). While the current authors agree with the Coyne and Johansen that too often null results are difficult to publish due to confirmatory bias that privileges results that support an alternative hypothesis, they strongly disagree with the assertion that their group selectively reported findings, inaccurately reported findings, or provided selective and uncritical reference to the existing literature. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
66.
Himes C. Carlson E. Ricchiuti R. J. Otis B. P. Parviz B. A. 《Nanotechnology, IEEE Transactions on》2010,9(1):2-5
67.
Erika K.Carlson 《工程(英文)》2021,7(3):275-276
Over the past year or so,wireless companies have begun to roll out fifth-generation (5G),the latest generation wireless network[1].For today's consumers,moving ... 相似文献
68.
69.
A. Chaudhry R. Kleiman K. D. Carlson 《Journal of the American Oil Chemists' Society》1990,67(11):863-866
Routine analysis of fatty ester fractions ofLesquerella fendleri oil suggested the presence of epoxy compounds and other minor components. By a combination of open silica column and high
performance liquid chromatography (HPLC) fractionations of the methyl esters prepared from the oil, these constitutents were
isolated and then characterized by thin-layer chromatography-mass spectrometry (GC-MS—electron ionization, EI, and chemical
ionization, CI) and nuclear magnetic resonance (NMR—1H and13C). Three epoxy acids, 15,16-epoxy-9,12-octadecadienoic, 9,10-epoxy-12-octadecenoic and 9,10-epoxy-octadecanoic, were found.
Hydroxy acids present included a C-22 homologue of lesquerolic acid (16-hydroxy-12-docosenoic acid) and 14,15-dihydroxy-tricosanoic
acid. Other minor ocmponents included four sterols, brassicasterol, campesterol, β-sitosterol and stigmasterol, and a series
of saturated and unsaturated fatty acids up to C30.
Visiting postdoctoral scientist sponsored by the government of India. 相似文献
70.
Tianhao Wang Harpreet Sidhar Yuri Hovanski Piyush Upadhyay Blair Carlson 《Science & Technology of Welding & Joining》2018,23(3):249-255
Friction stir scribe technology, a derivative of friction stir welding, was applied for the dissimilar lap welding of an aluminium alloy and galvanised mild steel sheets. During the process, the rotating tool with a cobalt steel scribe first penetrated the top material – aluminium – and then the scribe cuts the bottom material – steel. The steel was displaced into the upper material to produce a characteristic hook feature. Lap welds were shear tested, and their fracture paths were studied. Welding parameters affected the welding features, including hook height, which turned out to be highly related to fracture position. Therefore, in this paper, the relationships among welding parameters, hook height, joint strength and fracture position are presented. In addition, the influence of zinc coating on joint strength was also studied. 相似文献