全文获取类型
收费全文 | 381篇 |
免费 | 2篇 |
专业分类
综合类 | 2篇 |
化学工业 | 6篇 |
金属工艺 | 1篇 |
机械仪表 | 5篇 |
建筑科学 | 3篇 |
能源动力 | 2篇 |
轻工业 | 13篇 |
无线电 | 6篇 |
一般工业技术 | 7篇 |
冶金工业 | 335篇 |
自动化技术 | 3篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 9篇 |
1998年 | 104篇 |
1997年 | 57篇 |
1996年 | 41篇 |
1995年 | 34篇 |
1994年 | 19篇 |
1993年 | 15篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 14篇 |
1976年 | 26篇 |
1975年 | 1篇 |
1955年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有383条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
We have studied the efficacy of two extradural infusions (10 ml h-1) in 50 patients in active labour. Patients in the diamorphine group (n = 25) received 0.0625% plain bupivacaine 6.25 mg h-1 mixed with 0.005% diamorphine 0.5 mg h-1 and those in the control group (n = 25) received 0.125% plain bupivacaine 12.5 mg h-1. Both groups received intermittent "top-ups" of 0.25% bupivacaine 10 ml when indicated. Although median pain scores during the infusion were similar in both groups, patients in the diamorphine group indicated greater satisfaction with the infusion (88% very satisfied, compared with 52% in the control group (P < 0.02)). There were no differences in the incidence of hypotension, instrumental vaginal delivery, number of "top-ups", duration of the second stage or extent of motor block. However, patients in the diamorphine group had a high incidence of pruritus (44%, compared with 0% in the control group (P < 0.01)). 相似文献
6.
7.
BACKGROUND: Like other areas of health care, critical care faces increasing pressure to improve the quality while reducing the cost of care. Strategies drawn from the literature and the authors' experiences are presented. STRATEGIES AND OPPORTUNITIES FOR IMPROVEMENTS: Ten process- or structure-related areas are targeted as strategically important focuses of improvement: (1) restructuring administrative lines to better suit key processes; (2) physician leadership in critical care units; (3) management training for critical care managers; (4) triage; (5) multidisciplinary critical care; (6) standardization of care; (7) developing alternatives to critical care units; (8) timeliness of care delivery; (9) appropriate use of critical care resources; and (10) tracking quality improvement. TIMELINESS OF CARE DELIVERY: Whatever the root cause(s) of unnecessary delays, the result is inefficient use of critical care resources-and ultimately either a need for more resources or longer wait times. Innovations designed to reduce wait times and waste, such as the establishment of a microchemistry stat laboratory, may prove valuable. APPROPRIATE USE OF CRITICAL CARE RESOURCES: Possible strategies for the appropriate use of critical care resources include better selection of well-informed patients who undergo procedures. Reduction in variation among physicians and organizations in providing therapies will also likely lead to a reduction in some high-risk procedures offering little or no benefit, and therefore a reduction in need for critical care services. Better preparation of patients and families should also make end-of-life decisions easier when questions of "futility" arise. Better information on outcomes and cost-effectiveness and consensus on withdrawal of critical care treatments represent two additional strategies. 相似文献
8.
With a growing emphasis on human identification, iris recognition has recently received increasing attention. Iris recognition includes eye imaging, iris segmentation, verification, and so on. In this letter, we propose a novel and efficient iris recognition method which employs a cumulative‐sum‐based grey change analysis. Experimental results demonstrate that the proposed method can be used for human identification in efficient manner. 相似文献
9.
JASNA DEBICKI-POSPIIL TOMISLAV LOVRI NENAD TRINAJSTI ALEKSANDAR SABLJI 《Journal of food science》1983,48(2):411-416
The influence of furfural (F) and 5-hydroxymethylfurfural (HMF) on degradation of cyanidin-3-glucoside (CG) was investigated in blackberry juice and in a citrate buffer model solution (pH 3,45) at 24°, 50° and 70°C. Presence of 0.012 M F or HMF accelerated pigment degradation. The acceleration was directly temperature-dependent, more pronounced in fruit juice, and considerably decreased in nitrogen. CG and HMF disappearance – but not the interaction between these compounds – followed the first-order reaction kinetics. The influence of formaldehyde (Fa) acetaldehyde (Aa) and benzaldehyde (Ba) on the stability of CG was investigated in blackberry juice. CG degradation effect of non-furane aldehydes (0.012 M) was Fa < Aa < Ba. CG and cyanidine (C) reactivities were studied by condensation with F and examination of molecular electrone properties (cyanidine, keto-pseudobase, anhydrobase, chalcone). Furfural did not react with CG but it did react with C. Electron charge distribution points to anhydrobase as the tautomeric form of C most reactive to F. Possible mechanisms of C decomposition in presence of F are proposed and discussed. 相似文献
10.