全文获取类型
收费全文 | 138篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
化学工业 | 18篇 |
金属工艺 | 28篇 |
机械仪表 | 10篇 |
能源动力 | 6篇 |
轻工业 | 4篇 |
水利工程 | 1篇 |
无线电 | 5篇 |
一般工业技术 | 4篇 |
冶金工业 | 54篇 |
自动化技术 | 12篇 |
出版年
2021年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 9篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 12篇 |
1997年 | 19篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1961年 | 2篇 |
1959年 | 1篇 |
1935年 | 2篇 |
1931年 | 1篇 |
排序方式: 共有142条查询结果,搜索用时 15 毫秒
1.
A preliminary report presenting the results of fibular strut grafting in the severely resorbed mandibular and maxillary region is presented. Thirteen patients were treated due to severe resorption of alveolar and basilar bone of 49 segments of the mandible and the maxilla. Two patients additionally had pathological fractures of the mandible. In 10 cases the strut graft was harvested by means of a new minimally invasive technique. After modelling the fibular bone it was fixed to the recipient site by miniscrews or implants. After a mean follow-up period of 20 months (max. 31, min. 11 months) a retrospective analysis of clinical and radiological findings was carried out. It showed that a mean augmentation of 16 mm was achieved. Compared to other studies the fibular strut graft was resorbed less, and due to the primary stability it could be used for the treatment of fractures of the mandible. No more than natural resorption was observed when the patients received their prostheses fixed to dental implants. 相似文献
2.
A sensitive electrochemical technique has been used to examine the passive state of titanium-based materials in Ringer's physiological solution. At ambient temperature, the alloy Ti-6Al-4V shows transient microscopic breakdown of the passive state induced by the presence of chloride ions, and enhanced by increased acidity. These breakdown events involve highly localized depassivation of the passive surface followed by repassivation. Under similar experimental conditions no breakdown of passive titanium was detected. 相似文献
3.
4.
The inhibition of pitting corrosion of stainless steels by chromate and molybdate ions 总被引:2,自引:0,他引:2
The inhibitive effects of chromate and molybdate on pitting corrosion in stainless steel AISI 304 and AISI 316 were studied in acidified chloride solution. The results presented show that these known inhibitors affect both the nucleation of pitting and metastable pitting by reducing the numbers and sizes of these events. This makes attainment of stable pit growth more difficult. 相似文献
5.
The generation of surface roughness during slurry erosion-corrosion and its effect on the pitting potential 总被引:1,自引:0,他引:1
Results of experiments performed to isolate the effect of surface roughness generated during slurry erosion-corrosion of 304L stainless steel are presented. Surfaces prepared by grinding to different finishes show that increasing the roughness lowers the pitting potential in chloride solution. Subsequent erosion by an aqueous sand slurry then alters this pitting potential (Ep), as measured in the solution phase alone, in a manner dependent on the initial surface roughness. Surfaces which were initially rougher show a pronounced rise in p after erosion, while those with an initially smoother finish show a fall in Ep after erosion. Measurement of Ep during erosion-corrosion does not fit either process, with values of Ep lower than those predicted from the surface roughness alone. 相似文献
6.
The behaviour of freshly generated electrode surfaces of Ni, Ni-30Cu, Ni-50Cu and Ni-70Cu in 1.0 M H2SO4 has been investigated. At low potentials all metals grow a monolayer of film designated as MOH when M is Cu+ or Ni+. The kinetics of formation of this monolayer follows Tafel's equation. At higher potentials passivation of the metals occurs by film growth under high electric field, with two different sets of high field parameters for different film thicknesses. The rate of film growth for all metals is controlled largely by the nickel oxide component of the film. 相似文献
7.
Potentiostatic scratching experiments have been carried out on copper and 70-30 brass electrodes in acid and neutral electrolytes. The results are compared with published measurements of stress corrosion crack velocities in α-brass in neutral ammoniacal solutions. The plateau crack velocity at low strain-rates can be accounted for by stoichiometric bare surface oxidation of the alloy components, but at high strain-rates it is necessary to invoke rapid bare surface dezincification. Charge analysis shows that zinc dissolution can occur from several alloy layers at > 5 A cm?2 without appreciable anodic reaction of copper. Some features of the bare surface electrochemistry of copper are discussed. 相似文献
8.
9.
This study describes and evaluates twoessay-based discourse analysis systems thatidentify thesis and conclusion statements fromstudent essays written on six different essaytopics. Essays used to train and evaluate thesystems were annotated by two human judges,according to a discourse annotation protocol. Using a machine learning approach, a number ofdiscourse-related features were automaticallyextracted from a set of annotated trainingdata. Using these features, two discourseanalysis models were built using C5.0 withboosting: a topic-dependent and atopic-independent model. Both systemsoutperformed a positional algorithm. While thetopic-dependent system showed somewhat higherperformance, the topic-independent systemshowed similar results, indicating that asystem can generalize to unseen data – thatis, essay responses on topics that the systemhas not seen in training. 相似文献
10.
O. Berkh H. Ragones D. Schreiber L. Burstein Y. Shacham-Diamand 《Journal of Applied Electrochemistry》2012,42(7):491-499
The behavior of gold electrodes for the detection of dissolved oxygen was studied by the method of cyclic voltammetry in a phosphate-buffered solution with physiological pH. Surface modification with electropolymerized poly (o-phenylenediamine) film was performed to improve electrode antifouling properties. The voltammetric signature of oxygen was considered in terms of film electropolymerization conditions and post-deposition conditioning of the electrodes. The changes in the chemical structure of the poly (o-phenylenediamine) films as a result of these factors were confirmed by X-ray photoelectron spectroscopy analysis. Following long post-deposition conditioning in a phosphate-buffered solution, the modified electrodes exhibited stable voltammetric signatures in repeated tests and during storage as well as in the presence of a dense population of Escherichia coli (characterized by negligible metabolic activity) in the buffer. The results are indicative of the improved electrode antifouling properties. 相似文献