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961.
962.
963.
介绍了最大后验概率(MAP)复原超分辨力算法发展现状,然后着重介绍了基于Markov随机场的泊松最大后验概率复原算法(MPMAP)和小波滤波方法。以MPMAP算法为基础,提出了基于后端小波滤波处理和Markov分布的最大后验概率算法(PWMPMAP),试验证明这种算法具有很强的抑制噪声和振铃现象的能力,与MPMAP算法相比,复原效果明显提高,对红外热图像等低信噪比图像尤为有效,以30 dB的红外“建筑物”图像为例,相对MPMAP算法,峰值信噪比(PSNR)可以提高0.4 dB左右。 相似文献
964.
965.
Xi Xing Beth Reed Mi Kyung Bahng Peng Wang Hin Koo Woo Sun Jong Baek Chee Shing Lam Cheuk Yiu Ng¤ 《化学物理学报(中文版)》2008,21(3):193-201
We show that by scanning the frequency of a single mode infrared (IR) optical parametric oscillator (IR-OPO) laser to excite the molecular species of interest and fixing the frequency of a vacuum ultraviolet (VUV) laser to photoionize the IR excited species, high-resolution IR spectra of polyatomic neutrals can be obtained with high sensitivity. The fact that this IR-VUV-photoion (IR-VUV-PI) method is based on VUV photoionization probe, and thus, allows the identification of the neutral IR absorber, makes it applicable for IR spectroscopy measurements of isotopemers, radicals, and clusters, which usually exist as impure samples. The highly resolved IR-VUV-PI measurements achieved using the single mode IR-OPO laser have made possible the selection of single rovibrational states of CH3X (X=Br and I), C2H4, and C3H4 for VUV-pulsed field ionization-photoelectron (VUV-PFI-PE) measurements, resulting in rovibrationally resolved photoelectron spectra for these polyatomic molecules. These experiments show that the signal-to-noise ratios of the IR-VUV-PI and IR-VUV-PFI-PE spectra obtained by employing the high-resolution IR-OPO laser are significantly higher than those observed in previous IR-VUV-PI and IR-VUV-PFI-PE studies using a low-resolution IR-OPO laser. Further improvement in sensitivity of IR-VUV-PI and IR-VUV-PFI-PE measurements by using the collinear arrangement of IR-VUV lasers and molecular beam is discussed. 相似文献
966.
《Wave Motion》2020
Material topologies in phononic crystals take the key role in wave controlling. A genetic algorithm with a plane wave expansion method was adopted to optimize the three-phase phononic crystal for a larger relative band gap in both out-of-plane and in-plane wave modes. Fourier displacement property was used to calculate the structure function in the plane wave expansion. The mutation and crossover rates were calculated based on the adaptive GA method. Results indicate that the volume fraction and the symmetry are two key factors for the design of topological configurations. The relations between the key factors and the different topologies are correlated. 相似文献
967.
Coal and gangue (black-gray solid wastes in coal) recognition is vital to avoid waste of resources and pollution of the environment during the coal production. Considering their color/temperature is very close to each other, the traditional visible image and infrared image analyzing method is hard to obtain satisfied recognition efficiency. Therefore, a new idea of the ‘liquid intervention + infrared monitoring’ method was proposed to improve the recognition efficiency. In this article, the coal/gangue recognition experiments with different water temperatures were conducted, and the infrared thermal imager was used to record temperature variation after water intervention. The results show that when the water temperature is lower than the ambient temperature, the temperature difference between coal and gangue reaches the maximum value within 10 s, which is five times that without water intervention. The mean value of temperature difference between coal and gangue shows an approximate linear downward trend with the increasing of water temperature. The results indicate that under the condition of water intervention, it is recommended to choose water with a temperature below the ambient air, which may be a new approach to improve the coal/gangue recognition efficiency under different complex environments in underground coal mines. 相似文献
968.
The process of filament-to-filament adhesion during polymer extrusion additive manufacturing (AM) is critically influenced by temperature distribution around the filament. Direct measurement of temperature distribution around the filament being deposited is, therefore, important for fully understanding this critical process. While past papers have reported side-view (x-z) temperature measurement using infrared (IR) thermography, this paper presents measurement of the in-plane (x-y) temperature field on the build plate during printing of the first layer by infrared thermography. This measurement is carried out from under the build plate. A small part of the build plate is replaced by an infrared-transparent window. In conjunction with an infrared right-angle prism mirror positioned underneath, direct measurement of in-plane temperature distribution is carried out with an infrared camera. With a thin graphite coating on the build plate, in-plane temperature field on the build plate is obtained, whereas experiments without the graphite coating result in direct measurement of the filament temperature distribution. Bottom-view measurements are shown to agree well with side-view measurements. Temperature fields on the build plate are measured as functions of time for single-line and multi-line printing. A few key features revealed by measurements include symmetrical and asymmetrical temperature distributions for single and multi-line printing, respectively, and the thermal influence between lines being limited only to the adjacent line. The in-plane temperature measurement approach complements past side-view measurements, and improves upon our understanding of thermal phenomena during polymer AM. 相似文献
969.
电子计算机辅助红外断层摄影技术进展 总被引:4,自引:3,他引:1
电子计算机辅助红外断层摄影技术,是一项把红外测试技术应用于加热设备内壁热场分布检测的高新技术。加热设备内部热场的变化,由于热传导必然反映到设备外部,用热像仪可测出表面温度分布热图,已知表面温度值求解系统的几何形状,是热传导问题的一种反运算。本文详细地介绍了应用电子计算机求解这类反问题的一种通用解法,最后简述了提高计算精度的途径。 相似文献
970.
Robert W. Haas Dennis Brest Harry Mueggenburg Lee Lang Dave Heimlich 《International Journal of Infrared and Millimeter Waves》1993,14(11):2289-2294
Future spaceborne millimeter and sub-millimeter wave sensing systems will require the sensitivity and resolution only achievable with large focal plane array receiving systems. A technique has been developed for the low cost fabrication of large arrays of millimeter and sub-millimeter wave corrugated feed horns. These arrayed horns exhibit high efficiency and symmetrical receiving patterns and are compatible with integrated receivers. W-band test results of a 3×3 array are presented. 相似文献