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91.
氮化钛微粉增强镍磷化学复合镀层的组织及其摩擦磨损性能研究 总被引:1,自引:0,他引:1
利用自蔓延高温合成法得到的氮化钛微粉制备了Ni-P-TiN化学复合镀层,采用X射线衍射仪,扫描电子显微镜和电子探针分析了镀层的组织和结构,并在球-块摩擦磨损试验机上对镀层的摩擦学特性进行了研究,结果表明,TiN微粉可使Ni-P化学镀层的组织明显细化,且能提高镀层的最佳时效硬化温度随着Ni-P-TiN化学复合镀层中TiN共析量的增摩擦系数逐渐降低并趋于稳定,耐磨性则存在的一个最佳TiN含量;TiN微 相似文献
92.
93.
Nano-WC/PTFE-Ni复合电刷镀层的磨损性能研究 总被引:1,自引:1,他引:1
采用电刷镀技术在Q235钢基材上制备含纳米WC和PTFE的镍基复合镀层,采用S-2700型扫描电子显微镜观察镀层表面形貌及其显微组织,采用HX-1型显微硬度计测定镀层的显微硬度,采用WS-2005型涂层附着力自动划痕仪测定镀层与基体的结合强度,采用HT-500型销-盘高温摩擦磨损试验机测量镀层的滑动磨损性能.结果表明:镀液中同时加入纳米WC和PTFE可以得到表面形貌平整、纳米粒子分布均匀的纳米复合镍镀层;复合镀层的硬度随WC含量的增加而增大,随PTFE含量的增加而减小;含有2种纳米粒子的复合镍镀层的耐磨性比镍镀层和含单一WC或PTFE的镍镀层的耐磨性优良;当镀液中WC和PTFE含量分别为3.0 g/L和7.5 mL/L时,复合镍镀层的显微硬度较镍镀层提高约30%,耐磨性较镍镀层提高7倍. 相似文献
94.
Electroless Pd and Ag deposition kinetics of the composite Pd and Pd/Ag membranes synthesized from agitated plating baths 总被引:1,自引:0,他引:1
The atomic absorption spectroscopy (AAS) has been successfully utilized for the measurement of the Pd and Ag ion concentrations in the plating baths and to elucidate the effects of temperature, initial metal ion and reducing agent concentrations and agitation on the electroless plating kinetics of Pd and Ag metals. The initial metal ion concentrations for Pd and Ag were varied over a range of 8.2–24.5 mM and 3.1–12.5 mM, respectively. The plating reactions were conducted in a constant temperature electroless plating bath over a temperature range of 20–60 °C and an initial hydrazine concentration range of 1.8–5.4 mM. It was found that the electroless plating of both Pd and Ag were strongly affected by the external mass transfer in the absence of bath agitation. The external mass transfer limitations for both Pd and Ag deposition have been minimized at or above an agitation rate of 400 rpm, resulting in a maximum conversion of the plating reaction at 60 °C and dramatically shortened plating times with the added advantage of uniform deposition morphology. The derivation of the differential rate laws and the estimation of the reaction orders and the activation energies for the electroless Pd and Ag kinetics were conducted via non-linear regression analysis based on the method of initial rates. For a constant-volume batch reactor, the integrated rate law was solved to calculate the conversion and the reactant concentrations as a function of plating time. The model fits were in good agreement with the experimental data. Furthermore, the bath agitation and the plating conditions used in the kinetics study were adopted for the synthesis of 16–20 μm thick composite Pd/Ag membranes (10–12 wt% Ag) and a pure-Pd membrane with a hydrogen selective dense Pd layer as thin as 4.7 μm. While hydrogen permeance of the Pd/Ag membranes A and B at 450 °C were 28 and 32 m3/m2-h-atm0.5, the H2 permeance for the 4.7 μm thick pure-Pd membrane at 400 °C was as high as 63 m3/m2-h-atm0.5. The long-term permeance testing of all the membranes synthesized from agitated plating baths resulted in a relatively slow leak growth due primarily to the improved morphology obtained via the bath agitation and modified plating conditions. 相似文献
95.
PCB孔金属化几种制作工艺的分析 总被引:1,自引:0,他引:1
本文主要阐述了PCB孔金属化过程中化学沉薄铜、化学沉中铜、化学沉厚铜及直接电镀等几种工艺的使用及其优劣性。 相似文献
97.
The electroless nickel plating on an aluminum input/output (I/O) pad was investigated. The aluminum pad was pretreated in
a zincate solution prior to electroless nickel plating. Zinc particles on the aluminum pad gave a good adherent nickel layer.
The adhesion and uniformity of zinc on the aluminum is the key factor in under-bump metallurgy (UBM). The electrode potential
changes with and without zinc ions in the bath were measured to analyze the sequence of two competing reactions: zinc deposit
and hydrogen evolution. The relationship between aluminum dissolution and the ratio of zinc and NaOH was investigated. The
electroless nickel deposition rate was dependent on bath composition. The effects of complexing ligand and additive on the
nickel deposit were analyzed. Electrode potential changes were measured with time to confirm nucleation and grain growth.
Adhesion of the UBM was related to zinc-particle dissolution and nickel nucleation. The uniform nickel UBM was fabricated
on a real Al I/O pad. 相似文献
98.
The capability of a cobalt-phosphorous [Co(P)] layer, which was grown via the electroless plating process, to serve as the
diffusion barrier of lead-tin (PbSn) solder was investigated in this work. The Auger electron spectroscopy (AES) and energy
dispersive spectrometry (EDX) indicated that the phosphorous contents in Co(P) films decrease with increasing film thickness
and that the average contents are no less than 8.7 at.% for the specimens prepared in this work. X-ray diffraction in conjunction
with composition analyses revealed that the electroless Co(P) layer was a mixture of amorphous and nanocrystalline structures;
however, the AES depth profile and subsequent analyses indicated that the first-formed Co(P) layer should be amorphous because
it contains as much as 18 at.% P. This implied a good barrier capability for electroless Co(P) because, as revealed by EDX
line scan, the Sn and Cu atoms could not penetrate the Co(P) layer after the PbSn/Cu/Co(P)/Cu/Ti/Si sample was subjected to
annealing at 250°C in a forming gas ambient for 24 h. The fact that Sn and Cu underlayers could not penetrate the Co layer
after such a liquid-state annealing step was evidence that the Co(P) layer may simultaneously serve as a diffusion-barrier
interlayer dielectric and as an under-bump metallization for flip-chip copper (Cu) ICs. 相似文献
99.
谈电子产品中铝制件预处理工艺配方 总被引:1,自引:0,他引:1
随着电子技术的发展,电子产品中铝制件电镀愈来愈多。铝制件电镀质量的好坏,预处理是关键。就浸锌酸盐和浸锌镍合金两种预处理工艺配方在本厂生产中的实际应用情况作以比较。 相似文献
100.
为了揭示激光淬火预处理钢基体细化镀铬层界面晶粒的电镀机理,采用理论和试验相结合的方法进行了理论分析和试验验证。用化学腐蚀法制备了铬层/激光离散预处理基体界面的两侧(铬层界面与基体界面),利用扫描电镜研究了铬层界面晶粒形貌,利用激光粗糙度仪测量了基体界面粗糙度;借助电镀理论构建了以过电位为中间变量的铬层界面晶粒尺寸和基体界面粗糙度关系分析模型;取得了粗糙度与晶粒尺寸呈正比的试验结果和粗糙度与晶粒尺寸呈正比的理论关系,得到了淬火预处理钢基体细化镀铬层界面晶粒的电镀机理。结果表明,激光淬火预处理钢基体得到的较小粗糙度可以提高过电位,过电位的提高减小了铬层界面晶粒尺寸。这一结果对进一步解释激光淬火预处理可以提高基体/铬层界面结合强度是有帮助的。 相似文献