全文获取类型
收费全文 | 480篇 |
免费 | 30篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 13篇 |
综合类 | 1篇 |
化学工业 | 118篇 |
金属工艺 | 19篇 |
机械仪表 | 11篇 |
建筑科学 | 13篇 |
矿业工程 | 2篇 |
能源动力 | 14篇 |
轻工业 | 51篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
无线电 | 63篇 |
一般工业技术 | 93篇 |
冶金工业 | 35篇 |
原子能技术 | 4篇 |
自动化技术 | 73篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 19篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 16篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 30篇 |
2012年 | 29篇 |
2011年 | 29篇 |
2010年 | 24篇 |
2009年 | 23篇 |
2008年 | 17篇 |
2007年 | 32篇 |
2006年 | 21篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 4篇 |
1996年 | 10篇 |
1995年 | 13篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有515条查询结果,搜索用时 15 毫秒
1.
Francois P.-L. Monerie M. Vassallo C. Durteste Y. Alard F.R. 《Lightwave Technology, Journal of》1989,7(3):500-513
Depending on the spectal width of the source illuminating an interferometer, measurement procedures can utilize either the whole interferogram, or only the fringe envelope, or only the fringe quick oscillations. With an ultraband spectrum source, a simplified adaptation of the methods of Fourier transform spectroscopy yields the variations of the test-fiber propagation constant over the whole wavelength-interval of the source. Chromatic dispersion can then be computed from a single interferogram. With narrower spectrum sources, only the fringe envelopes are utilized and yield measurements of mode delay, with application to chromatic and polarization mode dispersion. In this case, however, interferograms at several wavelengths are necessary. With even narrower spectrum sources, the fringe quick oscillations provide measurements of phase shifts, related to changes in the mode propagation constant, when outside perturbations are applied to the test fiber. A direct method for measuring the third-order nonlinear susceptibilities is discussed. In this case the outside perturbation is an intense pump laser field 相似文献
2.
3.
The cooling power of aqueous solutions of ethylene oxide-propylene oxide copolymers are studied with a silver standard sample by using two apparatuses quench with injection and quench with agitation. For temperature T>400°C, the viscosity plays the predominant role; for T<400°C, the cooling is controlled by the polymer precipitation and the cooling rate decreases by lowering the cloud point of the polymer solution. This work demonstrates the possibility of adjusting the cooling curves by taking into account the thermodynamical properties of the polymer. 相似文献
4.
Electrical conductivity, thermoelectrical power and thermal conductivity measurements on boron carbide samples show that the electrical conductivity follows the small polaron hopping theory and that thermal conductivity occurs by phonon diffusion. The evolution of these properties with carbon content illustrates the particular role played by the 13.3 at% C compound in the phase homogeneity range B10.5C to B4C. The value of the figure of merit (0.85×10–3 K at 1250 K) proves that this particular boron carbide compound could be a very interesting candidate material for high-temperature thermoelectrical conversion. 相似文献
5.
The concept of volume averaging is used to theoretically study the mechanisms of mass dispersion, adsorption, and dead-space volume. These mechanisms are important to the understanding of miscible surfactant flooding. After simpiffication based on order-of-magnitude scaling, a linear core model is solved using state variable finite-difference techniques. Mass dispersion and adsorption are shown to be important model parameters while dead-space volume is a rather insensitive model parameter. 相似文献
6.
子午线轮胎出现不久,就采用钢丝带束层代替了纤维带束层,这对于实现子午线轮胎提高使用寿命和改善操纵性能的潜能是必要的。 相似文献
7.
Intelligent Service Robotics - Multi-robot path finding and coordination is one of the key performance-affecting subsystems of the overall robotic order fulfilment process for use in warehouse... 相似文献
8.
A. Littner M. Francois B. Malaman J. Steinmetz M. Vilasi E. Elkaim 《Intermetallics》2003,11(11-12):1223
Efforts to improve the high temperature behavior of MoSi2 in oxidizing environments led to the investigation of the Mo–Ru–Si phase diagram. The isothermal section at 1673 K was determined by X-ray diffraction, optical and scanning electron microscopies and EPMA. Five new silicides were identified and their crystallographic structure was characterized using conventional and synchrotron X-ray as well as neutron powder diffraction. Mo15Ru35Si50, denoted α-phase, is of FeSi-type structure, space group P213, a=4.7535 (5) Å, Dx=7.90 g. cm−3, Bragg R=7.13. Mo60Ru30Si10 is the ordered extension of the Mo70Ru30 σ-phase with space group P42/mnm, a=9.45940(8) Å, c=4.94273(5) Å, Dx=6.14 g. cm−3, Bragg R=5.75. 相似文献
9.
High Figure of Merit (FOM) of Bragg Modes in Au‐Coated Nanodisk Arrays for Plasmonic Sensing 下载免费PDF全文
Maxime Couture Thibault Brulé Stacey Laing Wenli Cui Mitradeep Sarkar Benjamin Charron Karen Faulds Wei Peng Michael Canva Jean‐Francois Masson 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(38)
Gold‐coated nanodisk arrays of nearly micron periodicity are reported that have high figure of merit (FOM) and sensitivity necessary for plasmonic refractometric sensing, with the added benefit of suitability for surface‐enhanced Raman scattering (SERS), large‐scale microfabrication using standard photolithographic techniques and a simple instrumental setup. Gold nanodisk arrays are covered with a gold layer to excite the Bragg modes (BM), which are the propagative surface plasmons localized by the diffraction from the disk array. This generates surface‐guided modes, localized as standing waves, leading to highly confined fields confirmed by a mapping of the SERS intensity and numerical simulations with 3D finite element method. The optimal gold‐coated nanodisk arrays are applied for refractometric sensing in transmission spectroscopy with better performance than nanohole arrays and they are integrated to a 96‐well plate reader for detection of IgY proteins in the nanometer range in PBS. The potential for sensing in biofluids is assessed with IgG detection in 1:1 diluted urine. The structure exhibits a high FOM of up to 46, exceeding the FOM of structures supporting surface plasmon polaritons and comparable to more complex nanostructures, demonstrating that subwavelength features are not necessary for high‐performance plasmonic sensing. 相似文献
10.
Ulrich Schmatz Catherine Dubourdieu Oleg Lebedev Gerard Delabouglise Francois Weiss Jean-Pierre Senateur 《Journal of Low Temperature Physics》1996,105(5-6):1301-1306
Thin and thick YBCO Films have been grown by Aerosol Assisted as well as by thermal MOCVD. The Aerosol Assisted MOCVD technique allows the growth of YBCO films from a single liquid source at deposition rates of up to 10m/h.Transport measurements (I-V) on etched microbridges using a single pulse technique have been performed. The angular magnetic field dependence Jc() of the critical current density from Tc down to 50 K has been measured. Transport properties are reported and discussed with respect to the microstructural features as determined by X-ray diffraction and electron microscopy. 相似文献