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排序方式: 共有1784条查询结果,搜索用时 15 毫秒
91.
92.
Moon Gi Cho Kyung Wook Paik Hyuck Mo Lee Seong Woon Booh Tae-Gyu Kim 《Journal of Electronic Materials》2006,35(1):35-40
The interfacial reaction between 42Sn-58Bi solder (in wt.% unless specified otherwise) and electroless Ni-P/immersion Au was
investigated before and after thermal aging, with a focus on the formation and growth of an intermetallic compound layer,
consumption of under bump metallurgy (UBM), and bump shear strength. The immersion Au layer with thicknesses of 0 μm (bare
Ni), 0.1 μm, and 1 μm was plated on a 5-μm-thick layer of electroless Ni-P (with 14–15 at.% P). The 42Sn-58Bi solder balls
were then fabricated on three different UBM structures by using screen printing and pre-reflow. A Ni3Sn4 layer formed at the joint interface after the pre-reflow for all three UBM structures. On aging at 125°C, a quaternary phase,
identified as Sn77Ni15Bi6Au2, was observed above the Ni3Sn4 layer in the UBM structures that contain Au. The thick Sn77Ni15Bi6Au2 layer degraded the integrity of the solder joint, and the shear strength of the solder bump was about 40% less than the nonaged
joints. 相似文献
93.
The intermetallic compounds formed in Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder BGA packages with Ag/Cu pads are investigated.
After reflow, scallop-shaped η-Cu6Sn5 and continuous planar η-(cu0.9Ni0.1)6Sn5 intermetallics appear at the interfaces of the Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder joints, respectively. In the
case of the Sn3Ag0.5Cu specimens, an additional ε-Cu3Sn intermetallic layer is formed at the interface between the η-Cu6Sn5 and Cu pads after aging at 150°C, while the same type of intermetallic formation is inhibited in the Sn3Ag0.5Cu0.06Ni0.01Ge
packages. In addition, the coarsening of Ag3Sn precipitates also abates in the solder matrix of the Sn3Ag0.5Cu0.06Ni0.01Ge packages, which results in a slightly higher
ball shear strength for the specimens. 相似文献
94.
TAN Yong-wen XIE Xue-bing Jack Zhou XU Tian-wei YANG Wei-guo YANG Hai 《半导体光子学与技术》2007,13(4):272-275,288
The damage properties of Focused Ion Beam(FIB) milling Si3N4 thin film are investigated by the detailed analyzing images of nanoholes and simulation of Monte Carlo. The damage depth in the Si3N4 thin film for two different ion species(Gallium and Arsenic) under various parameters(ion energy, angle of incidence) are investigated by Monte Carlo method. The simulations show the damage depth increases with the increasing ion energy, the damage depth is dependent on the angle of incident ion, the curves of the damage depth for Ga ion and As ion at 30 keV nearly superpose, while the damage depth for Ga with 90 keV ion is more than that for As ion with the same energy. 相似文献
95.
M.E. Williams K.-W. Moon W.J. Boettinger D. Josell A.D. Deal 《Journal of Electronic Materials》2007,36(3):214-219
Intermetallic compound (IMC) formation at the interface between the tin (Sn) plating and the copper (Cu) substrate of electronic
components has been thought to produce compressive stress in Sn electrodeposits and cause the growth of Sn whiskers. To determine
if interfacial IMC is a requirement for whisker growth, bright Sn and a Sn-Cu alloy were electroplated on a tungsten (W) substrate
that does not form interfacial IMC with the Sn or Cu. At room temperature, conical Sn hillocks grew on the pure Sn deposits
and Sn whiskers grew from the Sn-Cu alloy electrodeposits. These results demonstrate that interfacial IMC is not required
for initial whisker growth. 相似文献
96.
Investigation of the ion dose non-uniformity caused by sheath-lens focusing effect on silicon wafers
The ion dose non-uniformity induced on the wafer surface by modal and discrete focusing effects is investigated for different plasma densities and implantation parameters. Measured impact radius agrees well with values obtained by simulation. The optical pattern observed on the wafer surface is correlated with the ion dose by FT-IR measurements. The applicability of a previously proposed vertical ring is demonstrated, the ring being able to considerably improve the ion flux uniformity by shifting the discrete focusing effect out of the wafer surface and reducing the modal focusing. Experiments are performed in an inductively coupled plasma produced in hydrogen. 相似文献
97.
PCB技术的革新与进步 总被引:2,自引:0,他引:2
文章概述了近几年来在PCB工业中生产技术的革新与进步情况,特别是直流电镀(镀层均匀性、填孔镀等)、表面涂(镀)覆(化学镀镍/钯浸金和直接浸金等)技术的革新与进步,推动了PCB工艺技术的发展。 相似文献
98.
通过分析矿粉和水泥在沥青混合料中的作用机理,分别以不同比例的水泥代替矿粉,对沥青胶浆做延度、软化点、DSR、BBR等试验;同时,以AK-16和SAC-16为例,用不同比例的水泥代替矿粉,分别做浸水马歇尔试验、单轴压缩试验、动稳定度等试验,分析水泥代替矿粉后对沥青混合料的高、低温性能和水稳性等性能变化。试验结果表明,以一定比例的水泥代替矿粉可以有效的改善沥青混合料的性能。 相似文献
99.
水平阵聚焦波束形成声图定位算法研究 总被引:8,自引:1,他引:8
为解决一些特定情况下需要的近场高精度定位问题提出了聚焦波束形成声图定位法.该方法根据测量区内不同位置对各阵元接收信号进行球面波补偿,获得目标声源的分布.根据声图来给出目标方位,距离进行定位.为了减少计算量,先测量目标方位,然后只对该方位附近小角度进行扫描.利用分频段综合的方法抑制由阵型引起的声干涉.经研究表明,该算法能够给出水下目标声源的二维声图并对近场目标进行高精度定位. 相似文献
100.
Controlled Drug Release and Chemotherapy Response in a Novel Acoustofluidic 3D Tumor Platform
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Ioannis K. Zervantonakis Costas D. Arvanitis 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(19):2616-2626
Overcoming transport barriers to delivery of therapeutic agents in tumors remains a major challenge. Focused ultrasound (FUS), in combination with modern nanomedicine drug formulations, offers the ability to maximize drug transport to tumor tissue while minimizing toxicity to normal tissue. This potential remains unfulfilled due to the limitations of current approaches in accurately assessing and quantifying how FUS modulates drug transport in solid tumors. A novel acoustofluidic platform is developed by integrating a physiologically relevant 3D microfluidic device and a FUS system with a closed‐loop controller to study drug transport and assess the response of cancer cells to chemotherapy in real time using live cell microscopy. FUS‐induced heating triggers local release of the chemotherapeutic agent doxorubicin from a liposomal carrier and results in higher cellular drug uptake in the FUS focal region. This differential drug uptake induces locally confined DNA damage and glioblastoma cell death in the 3D environment. The capabilities of acoustofluidics for accurate control of drug release and monitoring of localized cell response are demonstrated in a 3D in vitro tumor mode. This has important implications for developing novel strategies to deliver therapeutic agents directly to the tumor tissue while sparing healthy tissue. 相似文献