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991.
Homotopy methods are globally convergent under weak conditions and robust; however, the efficiency of a homotopy method is closely related with the construction of the homotopy map and the path tracing algorithm. Different homotopies may behave very different in performance even though they are all theoretically convergent. In this paper, a spline smoothing homotopy method for nonconvex nonlinear programming is developed using cubic spline to smooth the max function of the constraints of nonlinear programming. Some properties of spline smoothing function are discussed and the global convergence of spline smoothing homotopy under the weak normal cone condition is proven. The spline smoothing technique uses a smooth constraint instead of m constraints and acts also as an active set technique. So the spline smoothing homotopy method is more efficient than previous homotopy methods like combined homotopy interior point method, aggregate constraint homotopy method and other probability one homotopy methods. Numerical tests with the comparisons to some other methods show that the new method is very efficient for nonlinear programming with large number of complicated constraints. 相似文献
992.
993.
994.
根据爱因斯坦方程和Marcus电荷传输模型, 使用密度泛函理论B3lyp/6-31g**理论水平计算6 个吐昔烯衍生物分子的结构和电荷传输性质. 结果显示: 6个吐昔烯的衍生物分子的空穴迁移速率为0.018–0.062 cm2·V-1·s-1, 电子迁移率为0.055–0.070 cm2·V-1·s-1, 其中3, 8, 13-辛烷氧基吐昔烯衍生物分子适合作为双极性传输材料. 三条烷氧基链的吐昔烯衍生物分子上引入三个甲氧基或羟基, 均使空穴和电子传输率降低. 引入给电子基团或共轭性基团可减小吐昔烯衍生物分子的能隙, 达到有机半导体的能隙要求.
关键词:
吐昔烯衍生物
空穴传输
电子传输
有机半导体 相似文献
995.
本文研究了Au/SrTiO3/Au三明治结构中的双极电阻翻转效应, 观察到高、低阻态的电阻弛豫现象. 低频噪声测量表明高、低阻态的电阻涨落表现出1/f行为. 对比试验表明, 高阻态的低频噪声来源于反向偏置肖特基势垒和氧空位的迁移, 强度较大, 低阻态的噪声则源于类欧姆接触底电极区域的氧空位迁移导致的载流子涨落, 强度较低. 同时, 界面上氧空位浓度的弛豫导致了高、低阻态的弛豫过程.
关键词:
电阻翻转效应
低频噪声
氧空位 相似文献
996.
《物理学报》2013年第62卷第6期第068701页《质子束治疗中非均匀组织的等效水厚度修正研究》一文中,因作者疏忽导致几处错误,特此更正,并诚挚地向读者致歉.期刊网上此文的电子版已做相应的更正.将3.1节中三个公式做如下更正:将(1)式:"WET=R介质/R水×b"改成:"WET=R水/R介质×b"将(2)式:"WET=R1/R水×d1+R2/R水×d2+···+Rn/R水×dn"改成:"WET=R水/R1×d1+R水/R2×d2+···+R水/Rn×dn" 相似文献
997.
In this paper, we summarize the existing methods of solving the evolution equation of the leading-twist \begin{document}$B$\end{document} ![]()
![]()
-meson LCDA. Then, in the Mellin space, we derive a factorization formula with next-to-leading-logarithmic (NLL) resummation for the form factors \begin{document}$F_{A,V}$\end{document} ![]()
![]()
in the \begin{document}$B \to \gamma \ell\nu$\end{document} ![]()
![]()
decay at leading power in \begin{document}$\Lambda/m_b$\end{document} ![]()
![]()
. Furthermore, we investigate the power suppressed local contributions, factorizable non-local contributions (which are suppressed by \begin{document}$1/E_\gamma$\end{document} ![]()
![]()
and \begin{document}$1/m_b$\end{document} ![]()
![]()
), and soft contributions to the form factors. In the numerical analysis, which employs the two-loop-level hard function and the jet function, we find that both the resummation effect and the power corrections can sizably decrease the form factors. Finally, the integrated branching ratios are also calculated for comparison with future experimental data. 相似文献
998.
In order to protect the vulnerable turbine components from extreme high temperature, coolant flow is introduced from the compressor to the disk cavity, inevitably interacting with the main flow. This paper describes an experimental investigation of the interaction between the main flow and the purge flow in a low-speed turbine cascade with three purge flow rates, Cm = 0, Cm = 1%, and Cm = 2%. In order to study the effect of the interaction between the main flow and the purge flow on the secondary flows, a Rortex method developed by Liu Chaoquan is introduced to identify the vortex in the flow field. In the meantime, a method to calculate the mean entropy production rate based on the particle image velocimetry (PIV) result is adopted to investigate the flow loss. The PIV result indicates that the purge flow has a prominent impact on the flow field of the cascade passage, changing the velocity distribution that induces a local blockage area. The results of vortex identification show that the purge flow promotes the generation of the passage vortex near the suction side. In addition, the purge flow makes the passage vortex migrate to the tip wall direction, enlarging the region affected by the secondary flow. The mean entropy production (MEP) result shows that the flow loss is mainly caused by the passage vortex. The coincidence of the high-MEP region and the location of the passage vortex indicates that the purge flow increases the secondary flow loss by affecting the formation and the migration of the passage vortex. 相似文献
999.
1引言我们知道,一个可生成L2(R)中的多分辩分析的尺度函数(x)满足双尺度差分方程(1)式的Fourier变换为其中(ω)是函数(x)的Fourier变换,而叫做小波的共轭滤波器(简称滤波器),它满足若将滤波器H(ω)设成则条件(3)成为可形式地写出Daubechies[1]给出了(6)式无穷乘积收敛的条件.她还针对F(z)为多项式情形(此时称滤波器为多项式滤波器),给出了产生紧支小波的方法并给出了正则阶估计[2].在[3]中,作者给出了小波分式滤波器的定义(即(4)式中F(z))是实系数有理… 相似文献
1000.
Zheng Chenglong Li Jie Li Jitao Yue Zhen Wang Silei Li Mengyao Zhao Hongliang Hao Xuanruo Zang Huaping Zhang Yating Yao Jianquan 《中国科学:物理学 力学 天文学(英文版)》2021,64(11):1-12
The usage of full-color imaging in digital pathology produces significant results. Compared with a grayscale image or a pseudocolor image containing contrast information, a full-color image can identify and detect the target object better with color texture information. Fourier ptychographic microscopy(FPM) is a high-throughput computational imaging technique that breaks the tradeoff between high resolution(HR) and a large field of view. It also eliminates the artifacts of scanning and stitching in digital pathology and improves its imaging efficiency. However, the conventional full-color digital pathology based on FPM is still time-consuming because of the repeated experiments with tri-wavelengths. A color transfer FPM approach termed "CFPM" was reported. The color texture information of a low-resolution full-color pathologic image is directly transferred to the HR grayscale FPM image captured by only a single wavelength. Both of the color space of FPM based on the standard CIE-XYZ color model and the display based on the standard RGB color space were established. Different FPM colorization schemes were analyzed and compared with 30 biological samples. Three types of evaluation approaches were provided, including the root-mean-square error(RMSE), the difference maps, and the image histogram cosine similarity. The average RMSE values of the conventional method and CFPM compared with the ground truth were 5.3% and 5.7%, respectively. Therefore, the reconstruction time is significantly reduced by 2/3 with the sacrifice of precision of only 0.4%. The CFPM method is also compatible with advanced fast FPM approaches to further reduce computation time. 相似文献