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31.
Numerical investigation on broadband mid-infrared supercontinuum generation in chalcogenide suspended-core fibers 下载免费PDF全文
As_2S_3 and As_2Se_3 chalcogenide 3-bridges suspended-core fibers(SCFs) are designed with shifted zero-dispersion wavelengths(ZDWs) at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schr ¨odinger equation is used to numerically compare supercontinuum(SC) generation in these SCFs pumped at an anomalous dispersion region nearby their ZDWs. Evolutions of the long-wavelength edge(LWE), the power proportion in the long-wavelength region(PPL), and spectral flatness(SF) are calculated and analyzed. Meanwhile, the optimal pump parameters and fiber length are given with LWE, PPL, and SF taken into account. For As_2S_3 SCFs, SC from a 14 mm-long fiber with a ZDW of 2825 nm pumped at 2870 nm can achieve the longest LWE of ~ 13 μm and PPL up to ~72%. For As_2Se_3 SCFs, the LWE of 15.5 μm and the highest PPL of ~ 87% can be achieved in a 10 mm-long fiber with ZDW of 1982 nm pumped at 2000 nm. Although the As_2Se_3 SCFs can achieve much longer LWE than the As_2S_3 SCFs, the core diameter of As_2Se_3 SCFs will be much smaller to obtain a similar ZDW, leading to lower damage threshold and output power. Finally, the optimal parameters for generating SC spanning over different mid-IR windows are given. 相似文献
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Effect of micro-dimple patterns on capillary pull-off force and friction force of silicon surface 下载免费PDF全文
A microtribometer is used to measure and compare pull-off forces and
friction forces exerted on (a) micro-dimpled silicon surfaces, (b)
bare silicon surfaces, and (c) octadecyltrichlorosilane (OTS)
treated silicon surfaces at different relative humidity (RH) levels
separately. It is found that above a critical RH level, the
capillary pull-off force increases abruptly and that the
micro-dimple textured surface has a lower critical RH value as well
as a higher pull-off force value than the other two surfaces. A
micro topography parameter, namely sidewall area ratio, is found to
play a major role in controlling the capillary pull-off force.
Furthermore, micro-dimpled silicon surface is also proved to be not
sensitive to variation in RH level, and can realize a stable and
decreased friction coefficient compared with un-textured silicon
surfaces. The reservoir-like function of micro dimples is considered
to weaken or avoid the breakage effect of liquid bridges at
different RH levels, thereby maintaining a stable frictional
behaviour. 相似文献
35.
用网络分析仪对HL-2A装置LHCD天线阵列子波导间的相位差,子波导间的相对功率和各主波导的电压驻波比等参数进行了测量。用测量值代入程序计算得到的波谱与理论计算的结果进行比较,表明天线发射的波谱与数值计算基本一致,能满足将要在HL-2A进行的LHCD实验。 相似文献
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A novel reverse-conducting insulated-gate bipolar transistor(RC-IGBT) featuring a floating P-plug is proposed. The P-plug is embedded in the n-buffer layer to obstruct the electron current from flowing directly to the n-collector, which achieves the hole emission from the p-collector at a small collector size and suppresses the snapback effectively. Moreover, the current is uniformly distributed in the whole wafer at both IGBT mode and diode mode, which ensures the high temperature reliability of the RC-IGBT. Additionally, the P-plug acts as the base of the N-buffer/P-float/N-buffer transistor, which can be activated to extract the excessive carriers at the turn-off process. As the the simulation results show, for the proposed RC-IGBT, it achieves almost snapback-free output characteristics with a uniform current density and a uniform temperature distribution, which can greatly increase the reliability of the device. 相似文献
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分子束注入(MBI)是一种新的托卡马克加料方法,其已成功地在HL-1M装置上开发,并应用于HL-2A装置。分子束注入在改善等离子体约束性能方面具有很多优点,如形成密度峰化,提高能量约束时间等。在过去的分子束注入实验中,发现了一些很有物理意义的现象。但是到目前为止,分子束注入的机制还不是很清楚。 相似文献