全文获取类型
收费全文 | 197篇 |
免费 | 6篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 28篇 |
金属工艺 | 22篇 |
机械仪表 | 18篇 |
建筑科学 | 1篇 |
能源动力 | 2篇 |
轻工业 | 5篇 |
石油天然气 | 1篇 |
无线电 | 9篇 |
一般工业技术 | 63篇 |
冶金工业 | 34篇 |
原子能技术 | 1篇 |
自动化技术 | 17篇 |
出版年
2021年 | 6篇 |
2020年 | 3篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 1篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有203条查询结果,搜索用时 9 毫秒
1.
2.
3.
4.
A new discontinuous robust control law for a rigid manipulator with bounded parameter uncertainties to track a desired trajectory, is presented. Global exponential stability is proved by the use of a natural Lyapunov function based on a transformation of the manipulator's differential equation due to Slotine and Li [2]. Convergence is to a sliding mode along which the tracking error is reduced at an arbitrary exponential rate. It is also shown how adaptation of bounds on uncertainties, and parameter adaptation, can be incorporated. For a continuous approximation of the discontinuous control law,practical stability (essentially, global uniform ultimate boundedness) of the tracking error is proved. Simulation results for the continuous control law exhibit excellent robust tracking. 相似文献
5.
6.
A systematic study was carried out aimed at evaluating the environmental effects of H2S containing environment on the creep-fatigue failure of coated undirectionally solidified MM-002 nickel-base superalloy at high temperature. The cyclic loading conditions were constant and consisted of creep tension and plastic compression following the CP-mode of the strain range partitioning method. The results obtained have shown that although the pack cementation coating used showed adequate resistance under the combination of cyclic loading and oxidizing environments, this resistance was not evident under the H2S containing atmosphere. In fact, it was found that even an amount as little as 0.05% H2S had an extremely detrimental effect on the creep-fatigue life of the coated superalloy at 650 °C. The crack initiation and propagation in the H2S environment was controlled by an aggressive sulphidation attack ahead of the crack tip. This was demonstrated by the formation of low melting eutectic sulfides at the plastic zone ahead of the crack tip, causing an accelerated transdendritic cracking and premature failure. 相似文献
7.
Ya. Unigovski A. Eliezer E. Abramov Y. Snir E. M. Gutman 《Materials Science and Engineering: A》2003,360(1-2):132-139
Corrosion fatigue tests were carried out on extruded AZ31 (3% Al, 1% Zn, 0.3% Mn, Mg—the rest), AM50 (5% Al, 0.4% Mn, Mg—the rest) and ZK60 (5% Zn, 0.5% Zr, Mg—the rest) Mg alloys in air, NaCl-based and borate solutions. Nsol/Nair ratios (the relative fatigue life) were used for the analysis of the corrosion fatigue behavior of Mg alloys in various environments, where Nsol and Nair are the numbers of cycles to failure in the solution and in air, respectively. Extruded ZK60 alloy reveals very high fatigue and corrosion fatigue properties in comparison with other alloys. However, it has the lowest relative fatigue life (Nsol/Nair 10−3–10−2) or the highest sensitivity to the action of NaCl-based solutions in comparison with that of AM50 and AZ31 alloys (Nsol/Nair 10−2–10−1). Under the same stress, the corrosion fatigue life of extruded alloys is significantly longer than that of die-cast alloys (Nsol for extruded AM50 in NaCl is two to three times longer than that of die-cast AM50). 相似文献
8.
D. Eliezer 《Journal of Materials Science》1981,16(4):1008-1012
A comparative study was carried out on the effect of the methods of preparation on the Mössbauer spectrum of the -Fe5Ge3 phase. The disagreements between the various reported spectra for the -phase can be attributed to variations in the stochiometry of the final product. Sintering seems to be the best way to prepare the -phase, while melting of the iron-germanium powders resulted in evaporation and considerable loss of germanium. The various methods of preparation were subjected to chemical analysis and X-ray diffraction. 相似文献
9.
With the ever-increasing use of pharmaceuticals and the relatively high risk of developing drug allergies, particularly for patients in hospitals and for ambulatory patients with a history of drug allergy, the need to develop in vitro assays for drug allergy is great. In the early 1970's a mast cell technique was developed for diagnosis of drug allergies. A PRIST inhibition assay has also recently been developed to detect IgE antibodies to drug allergens. This test has also been referred to as the Total IgE Inhibition Test by Specific Drug Allergen, and is a variant of the in vitro RAST Test. In vitro mast cell and IgE inhibition tests are applied for identification of drug and chemical allergens and for their cautious clinical trial to prevent future drug and chemical reactions. Over the last eight years, over 1,300 patients were examined utilizing the mast cell technique. Over 100 drugs were tested, with penicillin, barbiturates, "caine" derivatives and sulfonamides most frequently employed. Of 270 patients with well-defined drug reactions, 190 (70 per cent) gave a positive response to the mast cell test. Eighty-five per cent of sera tested with Type I reactions gave a mast cell response. Of these, a group of 30 patients was studied with PRIST inhibition as well. Procedures for comparative testing of necessary drugs and/or chemicals in cases of high anaphylaxis risk of reaction in the clinical setting, hospital or office are included in the study as well as individual case reports. Mast cell assay coupled with IgE inhibition has been successfully used to diagnose drug and chemical allergic reactions. The incidence of positivity is high when the offending drug causes a Type I allergic reaction. The cases reported indicate that both the Mast Cell and the PRIST inhibition assays are useful for diagnosing and setting the clinical treatment and clinical course of the patient. The mast cell assay would be potentially employed for patient use in hospitals where the incidence of drug allergy is highest and for occupational health in the chemical industry. The greatest potential would be in outpatient care applied to patients with multiple drug allergies in the selection of safe drugs (test negative by both methods, and other clinical studies) for future drug usage. 相似文献
10.