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141.
基于Bitaper-LPFG-Bitaper结构的全光纤Mach-Zehnder干涉仪的温度传感特性 总被引:1,自引:1,他引:0
提出并制作出一种基于锥体光纤-长周期光纤光栅-锥体光纤结构的全光纤Mach-Zehnder(M-Z)干涉仪传感器,并对其温度传感特性进行了研究.实验结果表明,固定光纤锥体和长周期光纤光栅的结构,仅改变两个光纤锥体之间的距离,对应不同的M-Z干涉谐振峰呈现出不同的温度传感特性:随着两个光纤锥体之间的距离增加,位于短波长处的谐振峰,传感器的温度灵敏度减小,而位于长波长处的谐振峰,传感器的温度灵敏度增加.当传感器长度为16.5 cm时,在1 680 nm附近的温度灵敏度达到0.102 06 nm/℃.实验结果对于锥体光纤-长周期光纤光栅组合型温度传感器的优化设计具有重要参考价值. 相似文献
142.
143.
提出了一种利用二维窗口傅里叶变换从径向剪切干涉条纹中准确得到波前的重建技术。首先对剪切干涉条纹做二维窗口傅里叶变换,设置阈值和频率积分范围后,进行二维窗口傅里叶逆变换,然后对包裹相位做去载频和相位展开处理得到相位差分布,最后使用波前迭代算法从相位差中复原实际波前。模拟计算表明,使用该方法最大相位复原误差为0.82%,均方根值为0.020 9 rad,实验结果验证了该方法的有效性。同时也对窗口傅里叶变换的关键参数,如窗函数的选择、窗口大小的确定以及阈值的选取等进行了简要讨论。与传统傅里叶变换法(FFT)相比,基于窗口傅里叶变换的剪切干涉波前检测法有更高的精度和稳定性,为波前检测提供一种新的处理方法。 相似文献
144.
根据薄膜干涉原理分析了迈克耳孙干涉仪实验中的等倾干涉现象,得到了接收屏上的光强分布与入射角的关系.采用计算机模拟的方法,用Matlab编写程序,运行后得到了迈克耳孙干涉仪等倾干涉环的图样. 相似文献
145.
Novel optical orthogonally modulation scheme for superimposing DPSK signals on dark RZ signals 总被引:1,自引:0,他引:1
Yufeng Shao Yaoqiang Xiao Lili Cheng Huiwen Xu Yazhi Pi 《Optics Communications》2008,281(14):3658-3667
A configuration of transmitter for superimposing DPSK signals on dark RZ signals was proposed. The transmitter comprises two optical phase modulators and a delayed line Mach-Zehnder interferometer. A new orthogonally modulation format with tunable duty cycle and extinction ratio in the optical domain was generated and discussed. The results show that the proposed modulation format offers significant advantages in offering high spectral efficiency values, high extinction ratio, and requiring electronics with reduced bandwidth. 相似文献
146.
S. Kourtev N. Minkovski L. Canova O. Albert A. Jullien J. Etchepare S.M. Saltiel 《Optics Communications》2008,281(12):3375-3380
Novel χ(3)-based nonlinear polarization interferometer is theoretically and experimentally investigated. It enables efficient spatial and temporal filtering of femtosecond pulses via generation of cross-polarized wave. By changing the interferometer parameters different beam shapes can be obtained. 相似文献
147.
This study develops a high-precision, non-destructive measurement technique based on a laser interferometer for determining the alcohol concentration of a liquid solution from its refractive index. The optical metrology system is employed to measure the refractive indexes of samples with known alcohol concentrations ranging from 5% to 95%. By applying regressional analysis to the experimental results, an analytical expression is derived to describe the quadratic relationship between the refractive index and the alcohol concentration. An excellent agreement is observed between the experimentally determined values of the alcohol concentration and the analytically predicted results. For an assumed laser interferometer resolution of 1 nm, the measurement resolution of the proposed metrology system is found to be at least F = 0.0025%, which is significantly better than that of typical stereometry methods (approximately 1.0%) Furthermore, it is shown that the measurement resolution improves as the alcohol concentration reduces. 相似文献
148.
Hao Tian Zhongxiang Zhou Minghui Zhang Dajun Liu Lei Li 《Optics Communications》2008,281(21):5420-5422
The Kerr (quadratic electro-optic) property of K0.95Li0.05Ta0.60Nb0.40O3 was measured by using an automated scanning Mach–Zehnder interferometer. K0.95Li0.05Ta0.60Nb0.40O3 has large Kerr effect with R11 = 7.2 × 10−16 m2/V2 and R12 = −1.2 × 10−16 m2/V2 at 632.8 nm near its phase-transition temperature. The dielectric and Kerr properties as function of temperature were also investigated, thus the quadratic polarization-optic coefficients were calculated. The values of g11 and g12 are 0.083 m4/C2 and −0.014 m4/C2, respectively, and do not depend on temperature within the measurement accuracy of 5%. 相似文献
149.
给出了一种基于均方误差估计的非本征光纤法布里-珀罗(EFPI)传感器的腔长解调算法。在参量估计方面, 均方误差将估计子的方差和偏差结合在一起, 具有更高的估计精度和准确度。如果给出某一个真值的一系列估计子, 则具有最小均方误差的估计子比其他估计子更为有效。在非本征光纤法-珀传感器的腔长解调方面, 则实际腔长对应于腔长均方误差估计取最小值时的腔长估计子。对一个非本征光纤法-珀压力传感器的测试结果表明, 腔长解调分辨率为0.18 nm, 对应的压力分辨率可达2.99 kPa。与传统的解调算法相比, 通过该算法可在较宽的动态范围内获得高的解调分辨率, 并实现绝对腔长的解调。 相似文献
150.
The curious dual nature of the neutron, sometimes a particle, sometimes a wave, is wonderfully manifested in the various non-local
interference and quantum contextuality effects observed in neutron interferometry. Non-classical states may become useful
for novel fundamental and solid state research. Here we discuss unavoidable quantum losses as they appear in neutron phase-echo
and spin rotation experiments and we show how entanglement effects in a single particle system demonstrate quantum contextuality.
In all cases of interactions, parasitic beams are produced which cannot be recombined completely with the original beam. This
means that a complete reconstruction of the original state would, in principle, be impossible which causes a kind of intrinsic
irreversibility. Even small interaction potentials can have huge effects when they are applied in quantum Zeno-like experiments.
Recently, it has been shown that an entanglement between external and internal degrees of freedom exists even in single particle
systems. This contextuality phenomenon also shows that a quantum system carries much more information than usually extracted.
The path towards advanced neutron quantum optics will be discussed.
相似文献