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81.
《印度化学会志》2023,100(3):100933
The electrochemical machining is a non-conventional machining process based on the electrolysis principle. It is used to machine various features on conducting engineering materials with the required accuracy and precision. So an attempt has been made to machine micro-holes on a 300 μm thick copper plate as an anode and a hollow stainless steel tool electrode of 250 μm diameter as the cathode. The machining operation is performed on the in-house developed micro-ECM experimental setup with controlled machining parameters voltage, concentration, and duty factor varied in three levels. A full factorial experimental plan is used to study the output responses material removal rate (MRR), radial overcut (ROC), circularity, and taper angle (TA). Later an adaptive neuro-fuzzy inference system (ANFIS) model has been developed and shown the effectiveness of the developed model in the paper. The Sugeno fuzzy model has been used in ANFIS to generate the fuzzy rules required for the model. Out of 27 experiments, 22 machining data are used for training the model, and the remaining 5 machining data are used for testing the developed model. The average error observed between the ANFIS predicted values and experimental values of MRR is 12.56%, circularity is 43.09%, ROC is 13%, and TA is 27.53%, respectively. 相似文献
82.
83.
The microstructural changes and phase transformation of an ultra-precision machined Zn-Al based alloy were examined using X-ray diffraction and back-scattered electron microscopy techniques. Decomposition of the Zn-rich η phase and the related changes in crystal orientation was detected at the surface of the ultra-precision machined alloy specimen. The effects of the machining parameters, such as cutting speed and depth of cut, on the phase decomposition were discussed in comparison with the tensile and rolling induced microstrucutural changes and phase decomposition. 相似文献
84.
Microthermal machining using scanning thermal microscopy (SThM) has been performed on polymethylmethacrylate (PMMA) materials, which are a soft polymer and suitable for microthermal machining. The probe of the SThM is heated and used as a machining tool on the PMMA material. Adjustment of the resistance can control the probe’s temperature. To obtain good machining quality, the probe temperature must be continuously controlled. The temperature of the machined area of the sample’s surface must be higher than the melting point of the PMMA material. However, a lower machined quality occurs when the probe temperature is too high. Furthermore, the adhesive phenomenon is very apparent when the contact mode is used in SThM machining. The microthermal machining of PMMA materials using SThM in semi-contact mode at a probe temperature of 400 °C has the best results. The technique can be used to process a complicated pattern and applied for use of high-density data storage. 相似文献
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86.
Huaqiong Li Yee Shan Wong Feng Wen Kee Woei Ng Gary Ka Lai Ng Subbu S. Venkatraman Freddy Yin Chiang Boey Lay Poh Tan 《Macromolecular bioscience》2013,13(3):299-310
Direct laser machining and electrospinning are utilized to obtain a bi‐layered hybrid scaffold with hierarchical topographical features to mimic extracellular matrix‐like microenvironment of cells. Adult bone marrow derived human mesenchymal stem cells (hMSCs) are cultured in vitro in these hybrid scaffolds, and cell orientation, proliferation, viability, and differentiation are evaluated. The results show that this novel hybrid scaffold not only supports cell growth like traditional scaffolds, but also elicits positive responses from the cells, like lineage commitment and alignment, which are essential features of future scaffolds.
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88.
Ching-Yuan Bai Jeou-Long LeeTse-Min Wen Kung-Hsu Hou Min-Sheng WuMing-Der Ger 《Applied Surface Science》2011,257(8):3529-3537
A uniform and continuous chromized coating on AISI 1020 steel is produced by low-temperature pack chromization (LTPC) with electrical discharge machining and Ni electroplating pretreatments. The anticorrosive performance of the chromized steels is investigated in a 0.5 M H2SO4 solution at room temperature. The testing results indicate that the chromized specimen with electrical discharge machining and Ni electroplating pretreatments exhibits the lowest corrosion current density, 2.16 × 10−8 A cm−2, among the tested specimens. The corrosion resistance of all tested specimens are in the order of bare 1020 < 1020-Cr(700-2) < 1020-Ni-Cr(700-2) < 1020-EDM-Ni-Cr(700-2). Moreover, the 1020-Ni-Cr(700-2) specimen have the best conductivity as a result of the less amount of oxides in the superficial coating. 相似文献
89.
在光学加工领域,采用功率谱密度(power spectral density,PSD)对误差频谱方面信息进行表征,但是功率谱密度是表面误差统计信息,不如峰谷值(peak-valley,PV)和均方根值(root mean square,RMS)直观。为了分析功率谱密度与工艺参数之间的关系,该文从PSD定义出发,分析了随机面形轮廓不同参数对光学PSD的影响规律,总结了PSD控制的要点,在平面玻璃上对数控抛光典型路径下加工的PSD曲线进行分析。分析结果表明:PSD与随机轮廓幅值、频率分布有关,相位对它几乎无影响;在RMS接近情况下,PSD线性拟合斜率和RMS Slope随随机轮廓的自相关长度增加而下降;短程加工路径相较于长程有序路径能够有效抑制PSD曲线峰值,使得光学元件符合频谱抑制要求。 相似文献
90.
Molecular dynamics (MD) simulations of diffusion couple tests were conducted between carbon (diamond/graphite) and iron at three different temperatures (300, 800 and 1600 K) and contact times (0, 40 and 80 ps) to investigate the chemical interaction between carbon and iron. Two different carbon structures, namely, diamond (cubic) and graphite (hexagonal), were considered. Diffusion of carbon into iron was observed only when a graphite interlayer was added to the diamond surface. When diamond alone was used, no diffusion was observed. This result provides corroborating evidence that diamond tool wear in the machining of iron occurs via a mechanism that involves an initial graphitization of diamond followed by diffusion of the newly formed graphite into the iron workpiece. 相似文献