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排序方式: 共有411条查询结果,搜索用时 31 毫秒
1.
高耐蚀性Zn—Co合金镀层钝化工艺的研究   总被引:1,自引:0,他引:1  
研究了电镀Zn-Co合金镀层的钝化液的组成及工艺条件,溶液各成分及工艺条件对钝化膜质量的影响,通过几种腐蚀试验方法,测量了钝化膜的耐蚀性,结果表明,研究的钝化工艺可以得到耐蚀性良好的钝化膜。  相似文献   
2.
The passivation and pitting corrosion of tin-nickel alloy (34% Ni-66% Sn) in NaCl solution was studied using potentiodynamic, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques complemented by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of concentration of the chloride ion, the switching potential, scans rate and pH on the electrochemical behavior of Sn-Ni alloy is discussed. The data indicate that the corrosion rate and the pitting corrosion of Sn-Ni alloy increases by the increasing of chloride ion concentration. The observed corrosion resistance of electrodeposited Sn-Ni alloy is due to the formation of a thin passive film from tin and nickel oxides.  相似文献   
3.
探索了氨合成催化剂还原后的温度对钝化操作与产品质量的影响,确定了最佳的钝化温度。  相似文献   
4.
表面钝化与涂装工艺相结合可显著提高铜及其合金的防腐性能.采用电化学工作站对涂层腐蚀电流进行定量测量,其结果显示,常规的涂装试样,在3% NaCl盐水溶液中浸泡1天,测得腐蚀电阻(Rc)为3.56×105Ω.钝化处理后再涂装的试样测试结果为无穷大.盐水浸泡5天后,前者95%表面受到不同程度的腐蚀,后者仍然正常.后者浸泡15天的腐蚀电阻为2.31×106Ω,仍高于前者浸泡1天的数据.钝化涂装工艺可用于室外及抗腐蚀性能要求较高的铜及其合金制品的表面防护装饰.  相似文献   
5.
In this paper, Zr, Cr and V were selected as the partial substitution elements for Ti to form Mg35Ti5M5Ni55 quaternary alloys prepared by means of mechanical alloying on the basis of the ternary Mg35Ti10Ni55 electrode alloy previously studied by the authors. It is found that all the three quaternary alloys possess an amorphous main phase and exhibit improved cycling stability than the original ternary Mg35Ti10Ni55. The Zr-substituted alloy has also a higher discharge capacity. X-ray photoelectron spectroscopy (XPS) surface analysis reveals that on the surface of each alloy a multi-component oxide composite film is formed, which is more compact and corrosion resistant than the Mg(OH)2 film and the (TiO2)x(NiO)y(Mg(OH)2)z composite films reported previously. Auger electron spectroscopy (AES) analysis shows that the substituting elements tend to reduce the thickness of the passivation films. The thickness of composite oxide film on the alloys is in the following order: Mg35Ti10Ni55>Mg35Ti5V5Ni55>Mg35Ti5Zr5Ni55>Mg35Ti5Cr5Ni55. The result agrees well with that of the polarization resistances (RP) values obtained from the electrochemical impedance spectroscopy (EIS) Nyquist diagrams. It demonstrates that the thicker the passivation film is, the higher the RP is and the more difficultly the charge transfer reaction proceeds. Anodic polarization curves indicate that the addition of Cr and Zr decreases effectively the corrosion current. However, the corrosion of the electrode alloys in the electrolyte is still high and proceeds constantly as the corrosion current remains almost constant during further cycles.  相似文献   
6.
J.H. Lee 《Thin solid films》2006,515(3):917-921
SiOxNy thin films were deposited by inductively coupled plasma enhanced chemical vapor deposition (ICP-PECVD) using hexamethyldisilazane (HMDS, 99.9%)/NH3/O2/Ar at a low temperature, and examined for use as a water vapor diffusion barrier. The film characteristics were investigated as a function of the O2:NH3 ratio. An increase in the O2:NH3 ratio decreased the level of impurities such as -CHx, N-H in the film through a reaction with oxygen. Thereby, a more transparent and harder film was obtained. In addition, an increase in the O2:NH3 ratio decreased the nitrogen content in the film resulting in a more SiO2-like SiOxNy film. Using SiOxNy fabricated with an O2:NH3 ratio of 1:1, a multilayer thin film consisting of multiple layers of SiOxNy/parylene layers was formed on a polyethersulfone (PES, 200 μm) substrate, and its water vapor transmittance rate (WVTR) was investigated. A WVTR < 0.005 g/(m2 day) applicable to organic thin film transistors or organic light emitting diodes was obtained using a multilayer composed of SiOxNy (260 nm)/parylene (< 1.2 μm) on the PES.  相似文献   
7.
We fabricated the indium-gallium-zinc oxide (IGZO) thin film transistor (TFT) with reactive sputtered SiOx as passivation layer, and investigated the role of the SiOx passivation layer in the IGZO-TFT under gate bias stress. The bias stability of IGZO-TFT with passivation layer is much better than that of IGZO-TFT without passivation layer. After applying positive bias stress of 20 V for 10000s, the device without passivation layer shows a larger positive Vth shift of 7.3 V. However, the device with passivation layer exhibits a much smaller Vth shift of 1.3 V. It suggests that Vth instability is attributed to the interaction between the exposed IGZO back surface and oxygen in ambient atmosphere during the positive gate voltage stress. The results indicate that reactive sputtered SiOx passivation layer can effectively improve the bias stability of IGZO-TFT.  相似文献   
8.
Reduced graphene oxide (rGO) sheets have received great attention as a key element for thin barrier films that block the permeation of water vapor and other gases. However, it remains a challenge to prepare the rGO-based barrier films on plastic substrates through a chemically benign and low temperature fabrication route. Toxic chemicals or high temperature thermal treatments that are widely used for preparing rGO need to be avoided because they can damage the underlying plastic substrates. In this study, we report the fabrication of rGO/TiO2 composite films via an eco-friendly and low temperature ultraviolet (UV) photoreduction process and demonstrate their enhanced gas barrier properties by measuring water vapor transmission rates (WVTRs). When photocatalytic TiO2 nanoparticles are employed, UV exposure reduces the GO/TiO2 composite solution to form rGO/TiO2, which is subsequently deposited on plastic substrates. The rGO/TiO2 composites become resistant to water absorption because the UV photoreduction of GO/TiO2 effectively removes most polar groups on the GO sheets. We confirmed that rGO/TiO2 composites were successfully deposited onto the plastic substrate through a solution process and the barrier films led to a substantial reduction in WVTRs of the substrate. Our strategy for preparing graphene-based thin barrier films by using a UV photoreduction process enables the fabrication of solution-processed graphene-based encapsulation layers on plastic substrates with an eco-friendly and low temperature fabrication method.  相似文献   
9.
以Ti-35421(Ti-3Al-5Mo-4Cr-2Zr-1Fe)合金为研究对象,采用自制的钝化膜损伤修复原位电化学测试装置研究了模拟深海静水压力对Ti-35421合金经过Al2O3陶瓷刀划伤后钝化膜破裂损伤和自修复的原位电化学行为。Ti-35421合金在3.5%NaCl溶液中的钝化平台为-0.27~0.01 V。在-0.13 V钝化电压条件下极化并进行划痕实验,无压应力作用时破损钝化膜发生快速修复。压应力增大导致原子间结合力降低,金属溶解速度增加,再钝化减缓,在原位电化学上表现为电流上升,电流回复时间增长,自修复能力减弱。再钝化过程中的暂态阶段钝化膜生长符合线性高场模型。观察划痕形貌发现压应力下划痕槽中出现微裂纹,说明较高压应力损伤作用下在划痕槽近表面产生应力集中,对合金产生的伤害部分不可修复。钝化膜破损加剧和自修复能力减弱是残余应力与环境腐蚀共同作用的结果。  相似文献   
10.
Polyaniline–polyvinyl alcohol (PANI–PVA) composite has been electrodeposited on stainless steel surface from aqueous sulfuric acid solution of aniline monomer in presence of soluble PVA at different concentrations. The PVA increased the rate of electropolymerization where 4 g/L PVA formed a composite of 37 wt% PANI and 63 wt% PVA composition. The composite layer exhibited more adhesion to the steel surface in comparison with PANI layer but with less thermal stability. It has higher protection role for the stainless steel (SS) against general and pitting corrosion. It enhanced the passivation of the SS surface by increasing the thickness of oxide film and improving the composition.  相似文献   
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