全文获取类型
| 收费全文 | 93篇 |
| 免费 | 3篇 |
| 国内免费 | 1篇 |
专业分类
| 电工技术 | 1篇 |
| 综合类 | 5篇 |
| 化学工业 | 6篇 |
| 金属工艺 | 21篇 |
| 机械仪表 | 13篇 |
| 矿业工程 | 1篇 |
| 能源动力 | 19篇 |
| 武器工业 | 1篇 |
| 无线电 | 1篇 |
| 一般工业技术 | 19篇 |
| 冶金工业 | 3篇 |
| 自动化技术 | 7篇 |
出版年
| 2024年 | 4篇 |
| 2023年 | 20篇 |
| 2022年 | 4篇 |
| 2021年 | 6篇 |
| 2020年 | 7篇 |
| 2019年 | 3篇 |
| 2017年 | 2篇 |
| 2016年 | 3篇 |
| 2015年 | 4篇 |
| 2014年 | 5篇 |
| 2013年 | 5篇 |
| 2012年 | 5篇 |
| 2011年 | 5篇 |
| 2010年 | 2篇 |
| 2009年 | 3篇 |
| 2007年 | 1篇 |
| 2006年 | 1篇 |
| 2002年 | 1篇 |
| 2001年 | 2篇 |
| 1999年 | 2篇 |
| 1998年 | 1篇 |
| 1994年 | 1篇 |
| 1992年 | 2篇 |
| 1990年 | 1篇 |
| 1988年 | 3篇 |
| 1986年 | 2篇 |
| 1981年 | 1篇 |
| 1972年 | 1篇 |
排序方式： 共有97条查询结果，搜索用时 15 毫秒
71.
《International Journal of Machine Tool Design and Research》1986,26(4):415-429
In this paper, it is shown how the receptance of a modified system can be described in terms of the receptance of the unmodified system. Furthermore, a receptance sensitivity analysis is introduced to show the effects of design changes on the dynamic performance of vibrating structures. The spindle-bearing system is chosen as a good target for investigation with respect to machine tool's performance. The sensitivity analysis carried out shows the effect of concentrated mass inserrts on its dynamic behaviour.The concept of modal flexibility sharing is chosen as a good measure of modal balance of the vibrating structure. Therefore, a technique is introduced based on the aforementioned method to achieve such state of modal balance by means of some mass inserts. The results obtained lead one to think that such a procedure can be employed to optimise the vibration behaviour of structures in general and machine tools in particular. 相似文献
72.
Magnetic leakage distribution results from linear defects of oil–gas pipelines in a weak magnetic field, which is modeled by the magnetic dipole theory. The analysis is useful for the identification of defects located either inside or outside the pipelines. The results indicate that the radial signals of inside–outside defects can be clearly distinguished, and the axial signals are basically the same in a weak magnetic field. The theoretical and the experimental results are very consistent. 相似文献
73.
The effects of Co and Ti additions on the microstructures and compressive strength of the Ni-based superalloy Udiemt710 (U710) were investigated. The preliminary results showed that the Ni3Ti-type (η) phase was observed in the alloys with low Co and Ti content; while a (NixCo1?x)3Ti phase with a hexagonal structure was detected in the alloys with high Co and Ti content. The γ′ → η → (NixCo1?x)3Ti phase transformation was discussed in terms of Co and Ti contents. The γ′ morphology changed from spherical to cuboidal with increasing Co and Ti content. Compressive tests showed that the alloys with Co and Ti addition possessed higher yield strength than the base alloy, U710. The strength increase could be ascribed to solid–solution strengthening of the γ and γ′ phases as a result of the Co and Ti additions, and the higher volume fraction of γ′ in the new alloys. 相似文献
74.
《Wear》2002,252(5-6):518-527
The impregnation of inorganic fullerene-like nanoparticles of WS2 (IF) allows to improve effectively the tribological properties of powdered materials in comparison to the impregnation of oil or commercially available layered WS2 (2H) particles. The main goal of this work was to determine the dominant lubrication regimes under friction of the bronze, iron, and iron–nickel porous matrixes impregnated with 2H and IF solid lubricants. The tribological tests were performed at laboratory atmosphere (humidity ∼50%) using a ring-on-block tester at the sliding speed of V=1 m/s, and the loads of 150–1000 N. The wear of the metal bodies was measured by an eddy current probe system and by weighting of the samples before and after the test. In order to evaluate the radial clearance, the profiles of wear blocks were analyzed by profile projector. Than these data were used in the calculation of the Sommerfeld reciprocal values. Friction and wear results were presented as the Stribeck curves. The critical Sommerfeld reciprocals were evaluated from these curves. The Stribeck curves were compared with the Morgan’s curves for different ranges of non-dimensional permeability, Ψ. These results are used then in calculation of the permeability, Φ. Three lubrication regimes as: quasi-hydrodynamic, boundary or mixed, and dry friction were revealed under friction of porous samples in the load-range studied. It was found that the impregnation of IF nanoparticles provides the regime of quasi-hydrodynamic lubrication in the widest range of loads in comparison to the reference sample and the sample impregnated with 2H–WS2. Fe–Ni samples exhibited the highest wear resistance and provided the widest range of quasi-hydrodynamic lubrication in comparison to bronze and iron powdered composites. The effect of IF on the regimes of lubrication is explained on the base of the third-body model. It is expected that the sliding/rolling of the IF nanoparticles in the boundary of the first bodies and in between the wear particles (third-body) facilitate the shear of the lubrication film and thus provide the quasi-hydrodynamic regime of friction. It is supposed that the roll shape of IF nanoparticles allows to release the IF from the pores to contact surfaces. 相似文献
75.
《Carbon》2013
We report on the modification of graphene oxide (GO) with poly(vinyl alcohol) (PVA) leading to the mechanical improvement of GO based materials. First, GO was covalently functionalised with PVA by esterification of carboxylic groups on GO with hydroxyl groups of PVA resulting in functionalised f-(PVA)GO. This was carried out for PVA of six different molecular weights. This functionalised graphene oxide could be formed into a paper-like material by vacuum filtration. Papers prepared from f-(PVA)GO showed significant increases in mechanical properties compared to those prepared with GO or with simple mixtures of GO and PVA. The best performance was achieved for PVA functional groups with molecular weights between 50 and 150 kg/mol. Improvements in Young’s moduli of 60% and tensile strength of 400% were observed relative to GO-only paper. The improved mechanical properties are attributed to enhanced inter-flake stress transfer due to the covalently bonded PVA. Second, functionalised f-(PVA)GO was used as filler in PVA-based composites. The application of a pre-selection method allowed the use of only the largest functionalised f-(PVA)GO flakes. This resulted in substantially reinforced PVA–f-(PVA)GO composites. Both modulus and strength increased by 40% relative to the pure polymer for f-(PVA)GO loadings below 0.3 vol.%. 相似文献
76.
77.
78.
HVOF喷涂Co基WC涂层的耐锌腐蚀行为 总被引：2，自引：0，他引：2
为了提高热镀锌用辊件的耐腐蚀性,试验采用超音速火焰喷涂方法制备WC-12Co涂层,研究了涂层在450 ℃锌液中的耐腐蚀性能以及失效机制.将316L/WC-12Co涂层进行液锌腐蚀,以扫描电镜能谱分析、x-射线衍射方式分析对比了未经过腐蚀试件、腐蚀5天试件、腐蚀10天试件的组织变化和相组成,结果显示涂层基体Co受液锌腐蚀生成Co与Zn化合物,引发横向裂纹,导致涂层剥落.涂层全部剥落后保护失效,使母材被液锌直接严重腐蚀,最终生成锌渣FeZn13. 相似文献
79.
《International Journal of Hydrogen Energy》2017,42(40):25608-25618
In this study, the effects of TiO2 and TiOSO4 on the precipitation of the positive electrolyte of vanadium redox battery (VRB) systems were investigated. TiO2 and TiOSO4 were used as anti-precipitating agents for V(V) ions at 40 and 60 °C. The optimum amounts and electrochemical properties of additives were determined by electrochemical methods such as cyclic voltammetry and electrochemical impedance spectroscopy. The optimum amount of additives was identified as wt% 0.004 and 0.003 for TiO2 and TiOSO4, respectively. The structural features and composition of electrodes were investigated by scanning electron microscopic and energy-dispersive X-ray analysis. A plausible reaction mechanism was also proposed for redox reaction occurring on the positive electrode of a VRB. The concentration of V(V) ions in the additive including electrolyte were higher than that of blank solution at the end of the thermal precipitation tests. According to thermal and electrochemical studies, TiO2 and TiOSO4 can be useful additives for the positive electrolyte of a VRB. 相似文献
80.
Z. Oksiuta J.R. Dabrowski A. Olszyna 《Journal of Materials Processing Technology》2009,209(2):978-985
The powder metallurgy (PM) technology was used to produce a porous Co–Cr–Mo-based composite material with the bioactive glass (S2) addition of 5 wt.%, 10 wt.% and 15 wt.%. The results show that the addition of bioglass to the matrix of Co–Cr–Mo alloy, as well as rotary cold repressing and heat treatment of sintered specimens can cause significant changes in the microstructure, mechanical and corrosion properties of composite materials in comparison with the pure porous Co–Cr–Mo alloy. A significant increase in the hardness, yield strength and corrosion resistance of the composites was observed with increasing the bioglass volume fraction. Although all PM samples are in a passive state, the higher corrosion resistances were obtained in the case of the composites with bioglass additions. Superior mechanical properties were achieved in the case of composite with 10 wt.% of bioglass. 相似文献