全文获取类型
收费全文 | 210篇 |
免费 | 34篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 42篇 |
金属工艺 | 1篇 |
机械仪表 | 2篇 |
建筑科学 | 10篇 |
能源动力 | 4篇 |
轻工业 | 23篇 |
水利工程 | 8篇 |
无线电 | 28篇 |
一般工业技术 | 54篇 |
冶金工业 | 52篇 |
自动化技术 | 19篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 15篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 11篇 |
2015年 | 14篇 |
2014年 | 9篇 |
2013年 | 8篇 |
2012年 | 10篇 |
2011年 | 10篇 |
2010年 | 17篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 7篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有244条查询结果,搜索用时 15 毫秒
81.
Purpose: This study examined the relationship between level of treatment engagement through completion of homework on treatment outcomes within nonpharmacological interventions for participants with ME/CFS. Method: A sample of 82 participants with ME/CFS was randomly assigned to one of four nonpharmacological interventions. Each intervention involved 13 sessions over the course of 6 months. Change scores were computed for self-report measures taken at baseline and 12-month follow-up. Homework compliance was calculated as the percentage of completed assignments across the total number of sessions and grouped into three categories: minimum (0–25%), moderate (25.1–75%), or maximum (75.1–100%). Results: Findings revealed that after controlling for treatment condition, those who completed a maximum amount of homework had greater improvement on a number of self-report outcome measures involving role, social, and mental health functioning. There were no differential improvements in physical and fatigue functioning based on level of homework compliance. Implications: Findings from this study suggest homework compliance can have a positive influence on some aspects of physical, social, and mental health functioning in participants with ME/CFS. It should be emphasized that these interventions do not cure this illness. The lack of significant changes in physical functioning and fatigue levels suggests a need for more multidisciplinary treatment approaches that can elicit improvement in these areas. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
82.
Jack D. Kartez Molly P. Casto 《Journal of the American Planning Association. American Planning Association》2013,79(4):467-495
From the Reviews Editors Above and Beyond: Visualizing Change in Small Towns and Urban Areas Julie Campoli, Elizabeth Humstone, and Alex MacLean. APA Planners Press, Chicago, 2002. 210 pages. $54.95 (paperback). The Boulevard Book: History, Evolution, Design of Multiway Boulevards Allen B. Jacobs, Elizabeth Macdonald, and Yodan Rofé. MIT Press, Cambridge, MA, 2001. 257 pages. $39.95. The Homevoter Hypothesis: How Home Values Influence Local Government Taxation, School Finance, and Land-Use Policies William A. Fischel. Harvard University Press, Cambridge, MA, 2001. 329 pp. $45. Planning the New Suburbia: Flexibility by Design Avi Friedman. UBC Press, Vancouver, 2002. 194 pages. $85. You Don't Always Get What You Pay For: The Economics of Privatization Elliott D. Sclar. Cornell University Press, Ithaca, NY, 2000. 184 pages. $29.95, $17.95 (paperback). Digital Places: Building Our City of Bits Thomas A. Horan. Urban Land Institute, Washington, DC, 2000. 143 pages. $26.95. Urban Transport, Environment and Equity Eduardo Vasconcellos. Earthscan, Sterling, VA, 2001. 333 pages. $85. Informal Transport in the Developing World Robert Cervero. United Nations Centre for Human Settlements (Habitat), Nairobi, 2000. 288 pages. $25. St. Louis: The Evolution of an American Urban Landscape Eric Todd Sandweiss. Temple University Press, Philadelphia, 2001. 282 pages. $74.50, $24.95 (paperback). Israeli Planners and Designers: Profiles of Community Builders John Forester, Raphael Fischler, and Deborah Shmueli, editors. State University of New York Press, Albany, 2001. 382 pages. $27.95 (paperback). Planning Canadian Regions Gerald Hodge and Ira M. Robinson. UBC Press, Vancouver, 2001. 486 pages. $85. The Civic Culture of Local Economic Development Laura Reese and Raymond Rosenfeld. Sage Publications, Thousand Oaks, CA, 2002. 240 pages. $92.95, $37.95 (paperback). Introduction to Zoning, 2nd Edition David Owens. Institute of Government, University of North Carolina at Chapel Hill, Chapel Hill, NC, 2001. 184 pages. $20 (paperback). Cultures, Communities, Identities: Cultural Strategies for Participation and Empowerment Marjorie Mayo. Houndmills &; Basingstoke, Hampshire, UK, 2000. 232 pages. $67.50. Urban Future 21: A Global Agenda for Twenty-first Century Cities Peter Hall and Ulrich Pfeiffer. E&;FN Spon, New York, 2000. 364 pages. $32.99 (paperback). Environmental Problems in an Urbanizing World Jorge E. Hardoy, Diane Mitlin, and David Satterthwaite. Earthscan, London, 2001. 448 pages. $69.95, $27.50 (paperback). The Community Economic Development Movement: Law, Business &; the New Social Policy William H. Simon. Duke University Press, Durham, NC, 2001. 230 pages. $18.95 (paperback). America Becoming: Racial Trends and their Consequences, Volumes I and II Neil J. Smelser, William Julius Wilson, and Faith Mitchell, editors. National Research Council, National Academy Press, Washington, DC, 2001. Volume I, 530 pages. $24.95 (paperback). Volume II, 491 pages. $24.95 (paperback). Geographic Information Systems for Transportation: Principles and Applications Harvey J. Miller and Shih-Lung Shaw. Oxford University Press, New York, 2001. 458 pages. $60. Landscape Modeling: Digital Techniques for Landscape Visualization Stephen Ervin and Hope Hasbrouck. McGraw Hill, New York, 2002. 290 pages, with CD-ROM. $59.95. Hands on the Land: A History of the Vermont Landscape Jan Albers. MIT Press, Cambridge, MA, 2002. 351 pages. $19.95 (paperback). Visions of Heaven and Hell: Information Technology and the Future Mark Harrison and Leanne Klein, producers. 1995. Films for the Humanities and Sciences. $395.95 (series). Selling the Future 52 minutes. $149.95. Welcome to the Jungle 52 minutes. $149.95. The Virtual Wasteland 52 minutes. $149.95. 相似文献
83.
J. P. Molly 《e & i Elektrotechnik und Informationstechnik》2003,120(10):317-321
Ohne Zusammenfassung
Kurzfassung eines Vortrags der 41. Fachtagung der ?sterreichischen Gesellschaft für Energietechnik (OGE) im OVE, die am 5.
und 6. November 2003 in Salzburg stattfindet. 相似文献
84.
Three experiments evaluated an imputed pitch velocity model of the auditory kappa effect. Listeners heard 3-tone sequences and judged the timing of the middle (target) tone relative to the timing of the 1st and 3rd (bounding) tones. Experiment 1 held pitch constant but varied the time (T) interval between bounding tones (T = 728, 1,000, or 1,600 ms) in order to establish baseline performance levels for the 3 values of T. Experiments 2 and 3 combined the values of T tested in Experiment 1 with a pitch manipulation in order to create fast (8 semitones/728 ms), medium (8 semitones/1,000 ms), and slow (8 semitones/1,600 ms) velocity conditions. Consistent with an auditory motion hypothesis, distortions in perceived timing were larger for fast than for slow velocity conditions for both ascending sequences (Experiment 2) and descending sequences (Experiment 3). Overall, results supported the proposed imputed pitch velocity model of the auditory kappa effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
85.
Causal attributions of hyperactive children: Implications for teaching strategies and self-control. 总被引:1,自引:0,他引:1
The combined influence of attribution and self-control training on the short- and long-term maintenance of strategic behavior, impulsivity, and beliefs about self-efficacy was assessed in 77 underachieving, hyperactive children. During 4 sessions, children in a self-control condition received self-management training and instructions in the use of interrogative and clustering rehearsal strategies. Children in a self-control plus attribution condition received the same instructions plus training designed to enhance general and program-specific beliefs about the importance of effort in improving performance. Children in a control condition were given strategy training but received no self-control or attribution instructions. Analysis of short-term treatment effects showed that children who received attribution training used more complex strategies, demonstrated higher personal causality scores endorsing effort, and displayed reduced impulsivity. Ten months following training, children in the self-control plus attribution condition persisted in their use of acquired strategies, maintained beliefs about the importance of effort, and displayed more mature memory knowledge. Severely hyperactive children, who had received the attributional boost, showed decreased hyperactivity in the classroom and improved self-control. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
Brunk Molly A.; Henggeler Scott W.; Whelan James P. 《Canadian Metallurgical Quarterly》1987,55(2):171
This study evaluated the relative efficacy of two promising treatments of child abuse and child neglect: parent training and multisystemic therapy. Subjects included 18 abusive families and 15 neglectful families who were randomly assigned to the treatment conditions. Self-report and observational measures were used to evaluate the effects of treatment at three levels that have been associated with child maltreatment: individual functioning, family relations, and stress/social support. Statistical analyses revealed that families who received either treatment showed decreased parental psychiatric symptomology, reduced overall stress, and a reduction in the severity of identified problems. Analyses of sequential observational measures revealed that multisystemic therapy was more effective than parent training at restructuring parent–child relations. Parent training was more effective than multisystemic therapy at reducing identified social problems. The differential influences of the two treatments were probably associated with differences in their respective treatment contexts and epistemologies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
JR Moffett T Els MG Espey SA Walter WJ Streit MA Namboodiri 《Canadian Metallurgical Quarterly》1997,144(2):287-301
Experimental tumors of the central nervous system were investigated with antibodies to quinolinate to assess the cellular distribution of this endogenous neurotoxin. In advanced F98 and RG-2 glioblastomas and E367 neuroblastomas in the striatum of rats, variable numbers of quinolinate immunoreactive cells were observed in and around the tumors, with the majority being present within tumors, rather than brain parenchyma. The stained cells were morphologically variable, including round, complex, rod-shaped, and sparsely dendritic cells. Neuroblastoma and glioma cells were unstained, as were neurons, astrocytes, oligodendrocytes, ependymal cells, endothelial cells, and cells of the choroid plexus and leptomeninges. Glial fibrillary acidic protein immunoreactivity was strongly elevated in astrocytes surrounding the tumors. Dual labeling immunohistochemistry with antibodies to quinolinate and glial fibrillary acidic protein demonstrated that astrocytes and the cells containing quinolinate immunoreactivity were morphologically disparate and preferentially distributed external and internal to the tumors, respectively, and no dual labeled cells were observed. Lectin histochemistry with Griffonia simplicifolia B4 isolectin and Lycopersicon esculentum lectin demonstrated numerous phagocytic macrophages and reactive microglia in and around the tumors whose distribution was similar to that of quinolinate immunoreactive cells, albeit much more numerous. Dual labeling studies with antibodies to quinolinate and the lectins demonstrated partial codistribution of these markers, with most double-labeled cells having the morphology of phagocytes. The present findings suggest the possibility that quinolinate may serve a functional role in a select population of inflammatory cell infiltrates during the immune response to brain neoplasms. 相似文献
88.
Here we report a new technique, Correlative Light-Ion Microscopy (CLIM), to correlate SEM-like micrographs with fluorescence images. This technique presents significant advantages over conventional methods in enabling topographical and biochemical information to be correlated with nanoscale resolution without destroying the fluorescence signal. We demonstrate the utility of CLIM for a variety of investigations of cell substrate interactions validating its potential to become a routine procedure in biomedical research. 相似文献
89.
C Aeppli CA Carmichael RK Nelson KL Lemkau WM Graham MC Redmond DL Valentine CM Reddy 《Environmental science & technology》2012,46(16):8799-8807
Following the Deepwater Horizon disaster, the effect of weathering on surface slicks, oil-soaked sands, and oil-covered rocks and boulders was studied for 18 months. With time, oxygen content increased in the hydrocarbon residues. Furthermore, a weathering-dependent increase of an operationally defined oxygenated fraction relative to the saturated and aromatic fractions was observed. This oxygenated fraction made up >50% of the mass of weathered samples, had an average carbon oxidation state of -1.0, and an average molecular formula of (C(5)H(7)O)(n). These oxygenated hydrocarbon residues were devoid of natural radiocarbon, confirming a fossil source and excluding contributions from recent photosynthate. The incorporation of oxygen into the oil's hydrocarbons, which we refer to as oxyhydrocarbons, was confirmed from the detection of hydroxyl and carbonyl functional groups and the identification of long chain (C(10)-C(32)) carboxylic acids as well as alcohols. On the basis of the diagnostic ratios of alkanes and polycyclic aromatic hydrocarbons, and the context within which these samples were collected, we hypothesize that biodegradation and photooxidation share responsibility for the accumulation of oxygen in the oil residues. These results reveal that molecular-level transformations of petroleum hydrocarbons lead to increasing amounts of, apparently recalcitrant, oxyhydrocarbons that dominate the solvent-extractable material from oiled samples. 相似文献
90.
Declining global per capita agricultural production and warming oceans threaten food security 总被引:1,自引:0,他引:1
Despite accelerating globalization, most people still eat food that is grown locally. Developing countries with weak purchasing
power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices
or production declines. Local agricultural production, therefore, is critical to both food security and economic development
among the rural poor. The level of local agricultural production, in turn, will be determined by the amount and quality of
arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related
technology, practices and policies. This paper discusses several emerging threats to global and regional food security, including
declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian Ocean and
its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia and Central
and Southern America will experience substantial declines in per capita cereal production. Global per capita cereal production
will potentially decline by 14% between 2008 and 2030. Climate change is likely to further affect food production, particularly
in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and
Pacific Oceans, may also reduce 21st century food availability in some countries by disrupting moisture transports and bringing
down dry air over crop growing areas. The impacts of these circulation changes over Asia remain uncertain. For Africa, however,
Indian Ocean warming appears to have already reduced rainfall during the main growing season along the eastern edge of tropical
Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling
of food balances and an examination of climate change, this study presents an analysis of emerging threats to global food
security. 相似文献