全文获取类型
收费全文 | 2308篇 |
免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 179篇 |
金属工艺 | 58篇 |
机械仪表 | 3篇 |
建筑科学 | 2篇 |
矿业工程 | 8篇 |
能源动力 | 1篇 |
轻工业 | 15篇 |
水利工程 | 1篇 |
石油天然气 | 3篇 |
无线电 | 20篇 |
一般工业技术 | 57篇 |
冶金工业 | 1924篇 |
原子能技术 | 4篇 |
自动化技术 | 30篇 |
出版年
2013年 | 17篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2003年 | 8篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 10篇 |
1999年 | 47篇 |
1998年 | 567篇 |
1997年 | 293篇 |
1996年 | 220篇 |
1995年 | 120篇 |
1994年 | 99篇 |
1993年 | 113篇 |
1992年 | 23篇 |
1991年 | 34篇 |
1990年 | 30篇 |
1989年 | 43篇 |
1988年 | 41篇 |
1987年 | 36篇 |
1986年 | 42篇 |
1985年 | 24篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 29篇 |
1979年 | 7篇 |
1978年 | 14篇 |
1977年 | 70篇 |
1976年 | 150篇 |
1975年 | 15篇 |
1974年 | 17篇 |
1973年 | 21篇 |
1972年 | 15篇 |
1971年 | 14篇 |
1970年 | 7篇 |
1969年 | 7篇 |
1968年 | 6篇 |
1967年 | 6篇 |
1966年 | 5篇 |
1964年 | 3篇 |
1963年 | 3篇 |
1926年 | 3篇 |
1921年 | 5篇 |
排序方式: 共有2309条查询结果,搜索用时 171 毫秒
41.
TS Bocanegra AL Weaver EA Tindall DH Sikes JA Ball CB Wallemark GS Geis JG Fort 《Canadian Metallurgical Quarterly》1998,25(8):1602-1611
42.
OBJECTIVES: To compare gastric tonometry (pHi) with estimates of pHi in ill injured patients, and to correlate pHi with haemodynamic variables. DESIGN: Prospective, non-interventional study. SETTING: ICU of Level I trauma centre, USA. MAIN OUTCOME MEASURES: 154 gastric tonometry measurements were compared with physicians' estimates of adequacy of resuscitation. Resuscitation was categorised as inadequate (pHi < 7.35) or adequate (pHi> or = 7.35). Measured and estimated pHi were also compared with oxygen delivery, oxygen consumption, cardiac index, mixed venous O2 saturation, and critical illness scores. RESULTS: Estimated pHi was often higher than measured pHi in the judgement of all four surgical intensive care physicians. Measured pHi correlated positively with mixed venous O2 tension (r = 0.21). There were significant negative correlations between measured pHi and both oxygen delivery (r = -0.25) and oxygen consumption (r = 0.28). Estimated pHi correlated positively with mean arterial pressure (r = 0.21) and hospital day (r = 0.26); it correlated negatively with pulmonary arterial elastance (r = -0.35). CONCLUSION: Experienced intensive care physicians tended to overestimate visceral perfusion, which suggests that gastric tonometry adds useful information over and above routine haemodynamic indices. Arterial blood pressure and mixed venous oxygen saturation correlated better with measured pHi than with other indices of perfusion. 相似文献
43.
44.
45.
SC Shim DH Yoo JK Lee HK Koh SR Lee SH Oh SY Kim 《Canadian Metallurgical Quarterly》1998,25(12):2464-2468
Ankylosing spondylitis (AS) results in disease-specific inflammation at the site of ligamentous insertion into the bone. Atlantoaxial joint subluxation and vertical subluxation of the axis may occur as a consequence of instability resulting from the inflammatory process. Spontaneous anterior atlantoaxial subluxation is a well recognized complication in about 2% of patients with AS, and presents with or without signs of spinal cord compression. Vertical subluxation may follow anterior or posterior subluxation. It was noted in 3-8% of patients with rheumatoid arthritis, but is an exceedingly rare complication of AS. Moreover, it has never been reported that multiple cerebellar infarction and bulbar symptoms developed spontaneously due to atlanto-occipital subluxation and vertical subluxation in a patient with a long [corrected] history of AS. We describe a man with AS who developed multiple cerebellar infarction due to vertebral artery obstruction and bulbar symptoms associated with atlanto-occipital subluxation and vertical subluxation. 相似文献
46.
47.
48.
A. L. Geller A. V. Kharchenko E. D. Kachura S. V. Kovalenko V. T. Alekseenko 《Metal Science and Heat Treatment》1995,37(5):187-191
Large-sin parts are usually produced from steels with high hardenability. Intermediate-carbon improved chromium-nickel steels containing 1–3% Ni are used successfully for this purpose in Ukraine and in foreign countries. However, nickel is an expensive and scarce alloying element. The present work is devoted to steels with different compositions with the aim of choosing the most suitable one for large-size parts. The effect of alloying elements on the hardenability and mechanical properties of steels is investigated. A mathematical model is obtained.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 13–17, May, 1995. 相似文献
49.
DV Beard PL Molina KE Muller KM Denelsbeck BM Hemminger JR Perry MP Braeuning DH Glueck WD Bidgood M Mauro 《Canadian Metallurgical Quarterly》1995,197(3):753-758
PURPOSE: Interpretation time of serial staging chest CT cases, which each contained current and previous examinations, with a simple prototype workstation called filmstack was experimentally compared with interpretation time with a film alternator. MATERIALS AND METHODS: The filmstack displayed a "stack" of sections for each examination; user controls allowed rapid selection of preset attenuation windows and both synchronized and unsynchronized scrolling. Eight radiologists were timed as they used the filmstack and the film alternator to interpret four ergonomically complex serial CT cases. RESULTS: All reports dictated on the basis of findings with filmstack and film were of acceptable clinical accuracy. The time to examine a case with filmstack was significantly faster than the time with film, including the time to load and unload the alternator (99% confidence [P = .01]). There was no statistically significant difference in interpretation time between filmstack and prehung film. CONCLUSION: Use of a low-cost stacked CT workstation with a single 1,024 x 1,024 monitor is an effective means of interpreting cases that require comparison of multiple CT examinations. 相似文献
50.