全文获取类型
收费全文 | 271篇 |
免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 8篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 33篇 |
矿业工程 | 1篇 |
轻工业 | 10篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 2篇 |
一般工业技术 | 21篇 |
冶金工业 | 181篇 |
自动化技术 | 3篇 |
出版年
2024年 | 2篇 |
2022年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 14篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 63篇 |
1997年 | 28篇 |
1996年 | 25篇 |
1995年 | 17篇 |
1994年 | 13篇 |
1993年 | 8篇 |
1992年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有272条查询结果,搜索用时 707 毫秒
1.
2.
J. Wright V. Adams J. Hykin P. Gowland B. Issa P. Boulby P. Tokarczuk D. Evans R. Spiller P. Mansfield 《Magma (New York, N.Y.)》1994,2(3):467-469
Echo-planar imaging (EPI) can be used to produce snapshot images of the human stomach and antro-pyloro-duodenal segment in real time as an alternative technique to intubation and exposure to ionizing radiation. The method has been further developed to monitor simultaneous gastric motility and gastric emptying of liquid and solid meals. The model has been utilized to study the effects of pharmacological agents on gastric function.Eight normal subjects were imaged in a 0.5-T superconducting magnet for up to 6 h following ingestion of 800 ml tap water, followed by 500 ml porridge test meal + 500 ml tap water. A rapid multislice technique was adopted to image adjacent transverse slices (10 mm thick) through the gastric region. In addition, three subjects were orally dosed with 20 mg of the prokinetic agent Cisapride. Gastric volumes for each slice were calculated and summed to produce a measure of total gastric volume and gastric emptying. Contractile activity at the level of the antro-pyloric segment was detected using sequential 128 ms images at 3 s intervals. Alternate measurements of gastric volume and motility were made for the duration of the study.Gastric emptyingT
1/2's (times to empty 50% of the gastric contents) of 12.9 min for water and 116 min for porridge were in agreement with results obtained by the traditional techniques of gamma scintigraphy and impedance imaging. The frequency of gastric contractions increased from 2.4 contractions per minute (cpm) to 3.2 cpm following water and from 2.9 to 3.2 cpm following porridge. The prokinetic effect of enhanced coordination of antroduodenal contractions was also observed. These studies have demonstrated that EPI can be used to detect and image gastroduodenal function in man, totally noninvasively, and can be used to study the effects of drugs acting on the gastrointestinal tract. 相似文献
3.
ShSh Eliava IuM Filatov OB Sazonova AIu Lubnin IN Rudnev AS Khe?reddin 《Canadian Metallurgical Quarterly》1996,41(4):3-6
Internal carotid aneurysms in the ophthalmic area presents a challenge in cerebrovascular neurosurgery. The study was undertaken to provide evidence for the application of intravascular aspiration during direct surgical interventions and to outline their variants used at the N. N. Burdenko Institute of Neurosurgery. The study included 4 (3 females and 1 male) patients with large and giant internal carotid aneurysms of parasphenoidal site who were treated at the Institute. Clipping of the aneurysmal neck was made by employing intravascular blood aspiration from the aneurysm. The technique proved to be effective in proximal monitoring the carotid artery at surgery. It substantially reduced aneurysmal blood flow and wall tension, thus favouring aneurysmal dissection to make clipping. 相似文献
4.
Using total quality management principles within a shared governance framework, this case study discusses how to design and implement a plan to achieve independent nursing practice when an employee has unique needs. This experience demonstrates the importance of looking at root causes, separating ability and compliance issues, using all available resources creatively, and planning for success. 相似文献
5.
6.
7.
Montcalm C Grabner RF Hudyma RM Schmidt MA Spiller E Walton CC Wedowski M Folta JA 《Applied optics》2002,41(16):3262-3269
We present our results of coating a first set of optical elements for an extreme-ultraviolet (EUV) lithography system. The optics were coated with Mo-Si multilayer mirrors by dc magnetron sputtering and characterized by synchrotron radiation. Near-normal incidence reflectances above 65% were achieved at 13.35 nm. The run-to-run reproducibility of the reflectance peak wavelength was maintained to within 0.4%, and the thickness uniformity (or gradient) was controlled to within +/-0.05% peak to valley, exceeding the prescribed specification. The deposition technique used for this study is an enabling technology for EUV lithography, making it possible to fabricate multilayer-coated optics to accuracies commensurate with atomic dimensions. 相似文献
8.
9.
Tracey Hollowood Sara Bayarri Luca Marciani Johanneke Busch Susan Francis Robin Spiller Andrew Taylor Joanne Hort 《European Food Research and Technology》2008,227(2):537-545
Model emulsion samples, prepared subject to a d-optimal response surface design, were used to investigate the effect of rapeseed
oil, sugar and hydroxypropyl methyl cellulose thickener (HPMC) on perceived sweetness, textural attributes (thickness, stickiness,
mouth-coating, dispersing), instrumental measures of apparent viscosity 50 s−1 and Kokini oral shear stress. An increase in oil, sugar and HPMC resulted in an increase in perceived thickness, stickiness
and mouth-coating, and a decrease in dispersion; sweetness was enhanced by the addition of both sugar and oil but suppressed
by the addition of HPMC. Viscosity and Kokini oral shear stress were well correlated with oral thickness (r
2 > 0.9). Validated multiple linear regression models highlighted several 2-factor interactions between ingredients. Model
statistics indicated that the variation in data was well explained; the models were predictive and could be used to navigate
the design space. Samples predicted to be iso-thick and iso-sweet could not be discriminated (P > 0.10) in a 3-alternative forced choice (3-AFC) test using 35 panellists. 相似文献
10.
J Fernandez C Chen G Anolik OB Brdlik GW Laub WA Anderson LB McGrath 《Canadian Metallurgical Quarterly》1997,11(6):1133-1140
OBJECTIVE: Demographic changes, associated with increased demands for open heart surgery in the elderly, place increased burden on financial resources. To evaluate perioperative risk factors affecting incidence of hospital events and estimation of hospital charges, 2577 patients > or = 65 years (range 65-91), operated on from January 1991 to December 1994, were compared with a concurrent cohort of 2642 younger patients. METHODS: Statistical analysis, by surgical procedure, focused on hospital mortality, key postoperative complications affecting length of hospital stay and hospital charges. RESULTS: Overall hospital mortality was 4.7%, 3.5% in younger patients versus 6.1% in the older group (P < 0.01). Mortality was significantly lower in patients less than 65 years undergoing coronary artery bypass grafting (3% versus 5%, P < 0.01) and valve replacement (4% versus 9%, P = 0.01). Significant risk factors for hospital death in the elderly: diabetes (P < 0.01), hypertension (P < 0.01), myocardial infarction (P < 0.01) and congestive heart failure (P < 0.01). Significant postoperative events, more common in older patients, included prolonged ventilation (P < 0.01), congestive heart failure (P < 0.01), infection (P < 0.01), cerebrovascular accident (P < 0.01), and intra aortic balloon pump (P < 0.01). Incremental risk factors for morbidity in the elderly were: higher New York Heart Association class, congestive heart failure, emergent operation, and female gender. Mean length of hospital stay for the < 65 group was 15.3 versus > 19.5 days for the > 65 group (P < 0.01). Length of stay over 18 days positively correlated with increased morbidity in both age groups. For patients > or = 65 years of age, the average hospital charge for open heart surgery was 172% higher for patients with a length of stay greater than 18 days compared with 165% for patients less than 65 years of age. CONCLUSIONS: Higher operative mortality and longer length of stay in elderly patients, resulting in increased health care costs, was associated with more co-morbidities. These results suggest interventions designed to reduce congestive heart failure and other co-morbidities may improve patient's recovery and reduce costs. 相似文献