全文获取类型
收费全文 | 266篇 |
免费 | 9篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 68篇 |
金属工艺 | 1篇 |
机械仪表 | 2篇 |
建筑科学 | 25篇 |
矿业工程 | 6篇 |
能源动力 | 2篇 |
轻工业 | 20篇 |
水利工程 | 5篇 |
无线电 | 17篇 |
一般工业技术 | 40篇 |
冶金工业 | 41篇 |
原子能技术 | 1篇 |
自动化技术 | 42篇 |
出版年
2023年 | 2篇 |
2022年 | 18篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 22篇 |
2011年 | 22篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 25篇 |
2007年 | 15篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 15 毫秒
261.
私有户外空间在建筑林立的都市里是很稀缺的商品。若是需要在狭小的地方待上一小时,为何不尽量创造机会来享受自己的绿色空间?维也纳的交通规则让人人享有平等使用街道系统的权利,人们只须要付费就有权使用短暂停留地区中适合的停车位。"短暂休憩"是一张车位大小的人工草皮,配有一个存放口袋。平时放在停放车辆的地方,为你营建一片临时私人绿地。不需要时,可以把它卷起来,放到小公寓里。它占用面积不大,携带方便。打开时,一片车位大小的绿地就呈现在眼前。通过它,所有者就能明显地标示出他或她的小型绿色王国。从晨操到园艺,从午餐会到在折叠椅上享受闲适时光 相似文献
262.
263.
We study the performance of an adaptive optics (AO) system with four laser guide stars (LGSs) and a natural guide star (NGS). The residual cone effect with four LGSs is obtained by a numerical simulation. This method allows the adaptive optics system to be extended toward the visible part of the spectrum without tomographic reconstruction of three-dimensional atmospheric perturbations, resolving the cone effect in the visible. Diffraction-limited images are obtained with 17-arc ms precision in median atmospheric conditions at wavelengths longer than 600 nm. The gain achievable with such a system operated on an existing AO system is studied. For comparison, performance in terms of achievable Strehl ratio is also computed for a reasonable system composed of a 40 x 40 Shack-Hartmann wave-front sensor optimized for the I band. Typical errors of a NGS wave front are computed by use of analytical formulas. With the NGS errors and the cone effect, the Strehl ratio can reach 0.45 at 1.25 microm under good-seeing conditions with the Nasmyth Adaptive Optics System (NAOS; a 14 x 14 subpupil wave-front sensor) at the Very Large Telescope and 0.8 with a 40 x 40 Shack-Hartmann wave-front sensor. 相似文献
264.
Uhlig PN Brown J Nason AK Camelio A Kendall E 《The Joint Commission journal on quality improvement》2002,28(12):666-672
BACKGROUND: The Cardiac Surgery Program at Concord Hospital (Concord, NH) restructured clinical teamwork for improved safety and effectiveness on the basis of theory and practice from human factors science, aviation safety, and high-reliability organization theory. A team-based, collaborative rounds process--the Concord Collaborative Care Model--that involved use of a structured communications protocol was conducted daily at each patient's bedside. METHODS: The entire care team agreed to meet at the same time each day (8:45 AM to 9:30 AM) to share information and develop a plan of care for each patient, with patient and family members as active participants. The cardiac surgery team developed a structured communications protocol adapted from human factors science. To provide a forum for discussion of team goals and progress and to address system-level concerns, a biweekly system rounds process was established. RESULTS: Following implementation of collaborative rounds, mortality of Concord Hospital's cardiac surgery patients declined significantly from expected rates. Satisfaction rates of open heart patients scores were consistently in the 97th-99th percentile nationally. A quality of work life survey indicated that in every category, providers expressed greater satisfaction with the collaborative care process than with the traditional rounds process. Practice patterns in the Cardiac Surgery Program at Concord Hospital have changed to a much more collaborative and participatory process, with improved outcomes, happier patients, and more satisfied practitioners. A culture of continuous program improvement has been implemented that continues to evolve and produce benefits. 相似文献
265.
Telch Christy F.; Agras W. Stewart; Rossiter Elise M.; Wilfley Denise; Kenardy Justin 《Canadian Metallurgical Quarterly》1990,58(5):629
This study tested the initial effects of cognitive-behavioral therapy for binge eating in Ss who do not purge. Forty-four female binge eaters were randomized to either cognitive-behavioral treatment (CB) or a waiting-list (WL) control. Treatment was administered in small groups that met for 10 weekly sessions. At posttreatment a significant difference was found, with 79% of CB Ss reporting abstinence from binge eating and a 94% decrease in binge eating compared with a nonsignificant reduction (9%) in binge eating and zero abstinence rate in WL Ss. Following the posttest assessment, WL Ss were treated and evidenced an 85% reduction in binge episodes and a 73% abstinence rate. Binge eating significantly increased at 10-week follow-up for initially treated Ss; however, the frequency remained significantly improved compared with baseline levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
266.
Examined individual play interactions of 14 pairs of parents with their preschool-aged boys and girls (2.6–4.11 yrs old) to determine the ways mothers and fathers provided and elicited lexical information about the names and functions of the parts of a complex toy car. Parents' and children's speech was analyzed for utterances that provided or requested the name (label) or purpose (function) of a car part and for nonlabeling utterances that mentioned the part (term). Analyses revealed significant contrasts between fathers and mothers in their interactive styles and in the amounts and kinds of lexical information they provided and elicited. Fathers' speech contained more different terms than did mothers', and more fathers than mothers described the functions of the car parts. Fathers were also more cognitively and linguistically demanding: More fathers than mothers requested labels and functions from their children. Children, in turn, produced more total vocabulary to fathers than to mothers. These parent–child interaction patterns suggest that fathers and mothers may exert an active influence on children's language development. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
267.
Franck Cheillan Huguette Lafont Elise Termine Yolande Hamann Guy Lesgards 《Lipids》1989,24(3):224-228
A method combining enzymatic and electrochemical detection of cholesterol in biological fluids was compared with conventional
detection methods: two chromatographic methods—gas chromatography or high performance liquid chromatography—and two enzymatic
methods with colorimetric detection either by kinetic measurement or at the end of the reaction. For serum, enzymatic determination
is accurate with both colorimetric detection methods; but for bile, colorimetric detection is difficult to perform due to
interference from bile pigments. Enzymatic cholesterol determination, combined with electrochemical detection, is simpler
and gives results in good agreement with those of chromatographic methods. 相似文献
268.
Gilles Nalbone Jeannie Leonardi Elise Termine Henri Portugal Paulette Lechene Anne-Marie Pauli Huguette Lafonf 《Lipids》1989,24(3):179-186
In this study, we investigated the effect of various types of fats on heart lipid peroxidation status and on blood lipid parameters.
Rats were fed either a low-fat diet (2.2% lard plus 2.2% corn oil), a corn oil diet (17%), a salmon oil diet (12.5%) supplemented
with 4.5% corn oil, or a lard diet (15%) supplemented with 2% corn oil. All diets were supplemented with 1% cholesterol. Rats
were fed for eight weeks. When compared with the low-fat diet, the salmon oil-diet intake resulted in a lower blood cholesterol,
triglyceride and phospholipid concentrations (−50, −56 and −30%, respectively). Corn oil only tended to lower blood lipids;
this decrease was significant for triglycerides only (−40%). The hypocholesterolemic effect of salmon oil diet is even more
pronounced, if blood cholesterol values are compared with those of rats fed the lard diet. Heart lipid composition was not
affected by dietary manipulations. Fatty acid composition of cardiac phosphatidylcholines and phosphatidylethanolamines, however,
were altered by high-fat diets. In phosphatidylcholine, salmon oil induced a twelvefold decrease in the n−6/n−3 ratio and
a 26% increase in the unsaturation index. For phosphatidylethanolamine, the n−6/n−3 ratio decreased 7.7-fold and the unsaturation
index increased by 13%. A 50% decrease of the n−6/n−3 ratio was observed in animals fed the lard diet. Ultramicroscopic examination
of ventricles revealed that those of the salmon oil group significantly accumulated lipofuscin-like or ceroid material, whereas
this accumulation was barely detectable in hearts of the other groups. Seleniumdependent glutathione peroxidase activity tended
to be the highest in hearts of rats fed the salmon oil diet; this increase is significant (+36% and +54% for total and specific
activities, respectively), if values are compared with those of the rats fed the lard diet. Liver glutathione peroxidase and
heart glutathione S-transferases activities remained unchanged. These results indicate that fish oil did not lower the selenium
involved in glutathione peroxidase activity. This rules out that a deficiency in this enzyme was at the origin of heart lipofuscinosis.
Also, it is concluded that the n−6/n−3 ratio of the diet is likely more determinant in the alteration of heart lipid peroxidation
status than is the polyunsaturated/saturated ratio.
Part of this work was presented at the International Congress: “Selenium in Medicine and Biology,” Avoriaz, France, March,
15–18, 1988. 相似文献
269.
Collision analysis indicates that many car accidents occur when negotiating a bend. Excessive speed and steering wheel errors are often given by way of explanation. Nevertheless, the underlying origin of these dramatic errors could be, at least in part, a poor estimation of bend curvature. The aim of this study was to investigate both the assessment of bend curvature by drivers and the impact of symbolic road signs that indicate a hazardous bend on this assessment. Thus, participants first viewed a video recording showing approaching bends of different curvature before being asked to assess the curvature of these bends. This assessment could either be a verbal (symbolic control) estimation of the bend's curvature and risk, or a sensorimotor (subsymbolic control) estimation of the bend's curvature (participants were asked to turn a steering wheel to mimic the position that would be necessary to accurately negotiate the bend). Results show that very severe bends (with a radius of less than 80 m) were actually underestimated. This was associated with an underestimation of risk corresponding to these bends and a poor sensorimotor anticipation of bend curvature. Road signs, which indicate risk significantly improve bend assessment, but this was of no use for sensorimotor anticipation. Thus, other indicators need to be envisaged in order to also improve this level of control. 相似文献
270.
The possibility of performing FT-IR spectromicroscopy experiments on individual living cells is the focus of considerable attention. Among the applications of interest, the obtainment of structural information in rapid measurements, with a time resolution of the minute or better, is a prized goal. In this work, we show that the use of synchrotron FT-IR spectromicroscopy allows one to extract weak spectral changes, of less than 10(-3) au per minute, in the absorption spectrum of single rod cells following photostimulation. We also show that absorption changes are accompanied by other optical effects due to changes in the real part of the refractive index of the cell. The use of two-dimensional correlation spectroscopy allows us to assign bands to specific molecular chromophores and to extract weak spectral variations in the presence of a noisy background. 相似文献