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101.
Ordinary quartz tuning fork resonators, operated at about 30 or 200 kHz frequency, couple to acoustic first and second sound resonances in helium fluids under certain conditions. We have studied acoustic resonances in supercritical 4He, normal and superfluid 4He, and in isotopic mixtures of helium. Suggestive temperature, pressure, and concentration dependences are given. Furthermore, we propose a thermometric reference point device based on second sound resonances in helium mixtures, and indicate possible differences in the nature of second sound resonances in superfluid 4He and helium mixtures. 相似文献
102.
Rahela Kulčar Mojca Friškovec Marta Klanjšek Gunde Nina Knešaurek 《Coloration Technology》2011,127(6):411-417
Leuco dye‐based thermochromic inks reversibly change from the coloured to the discoloured state in a defined, comparatively wide temperature region. Inside this region, the colour of a sample depends on the temperature and thermal history, which is known as the hysteresis effect. The colour of such a sample as a function of temperature has the shape of a hysteresis loop. Commercially available thermochromic inks have different loops, narrow or broad, and their shapes range from approximately symmetric to highly asymmetric. These properties are also important in mixtures of inks. The hysteresis loop of a mixture reveals its binary nature if the individual pure inks have well‐separated hysteresis. When inks with close‐separated loops, i.e. with similar activation temperatures, are mixed together, the loop of the mixture fuses together into an apparently single loop. Our research shows that some of their dynamic colour properties could be predicted in advance. However, optic and colorimetric properties of mixtures are not additive. 相似文献
103.
Tomasz Patyk Perttu Salmela Teemu Pitkänen Pekka Jääskeläinen Jarmo Takala 《Journal of Signal Processing Systems》2011,65(2):245-259
Field programmable gate array (FPGA) is a flexible solution for offloading part of the computations from a processor. In particular,
it can be used to accelerate an execution of a computationally heavy part of the software application, e.g., in DSP, where
small kernels are repeated often. Since an application code for a processor is a software, a design methodology is needed
to convert the code into a hardware implementation, applicable to the FPGA. In this paper, we propose a design method, which
uses the Transport Triggered Architecture (TTA) processor template and the TTA-based Co-design Environment toolset to automate
the design process. With software as a starting point, we generate a RTL implementation of an application-specific TTA processor
together with the hardware/software interfaces required to offload computations from the system main processor. To exemplify
how the integration of the customized TTA with a new platform could look like, we describe a process of developing required
interfaces from a scratch. Finally, we present how to take advantage of the scalability of the TTA processor to target platform
and application-specific requirements. 相似文献
104.
The heat of wetting for very fine iron powder and its composites with Ag, Pt, Au, Cu, and Zn prepared by a thermochemical method is measured. It is established that their surface is hydrophilic. This makes it possible to modify the surface of powders with different substances and create new materials intended for medicine and technics.
相似文献105.
106.
A new classification of ternary reciprocal systems is proposed taking into account the number of thermal effects in the thermograms
of complete conversion points. The classification is useful for general evaluation of the liquid surface of the systems. 相似文献
107.
Identity and overall acceptance of two types of sour rye bread 总被引:1,自引:0,他引:1
Raija-Liisa Heiniö Nina Urala Jukka Vainionpää Kaisa Poutanen & Hely Tuorila 《International Journal of Food Science & Technology》1997,32(2):169-178
Response surface methodology was employed to study the influence of four recipe variables (wheat: rye flour ratio, bread acidity, ash content of rye flour and sodium chloride content) on the identity and overall acceptance of two rye bread types (soft and crisp rye bread). The subjects ( n = 79) rated attribute intensities, the extent to which the salient sensory properties and the overall sample corresponded to their expectations of rye bread, and the overall acceptance (pleasantness and purchase intentions). The acidity and ash content contributed the most to the extent to which a sample met subjects' expectations. The NaCl content was not critical. Consumer acceptance was affected by ash content, and by the interactions, NaCl content × acidity and wheat:rye ratio × ash content. The non-significance of NaCl content should encourage the baking industry to put low-salt rye products on the market. 相似文献
108.
A compact, internally heated, catalytic reactor is demonstrated for the low-temperature oxidation of carbon monoxide. Carbon
nanofibres were grown on carbon felt and used as a support material for Au/TiO2 catalysts. The carbon composite plays two roles; as a support material for the catalyst and for providing heat to the reaction
by the Joule effect. The internal heating offers a stable reactor system with quick temperature response at relatively low
energy input. Comparison between external and internal heating shows higher conversion of CO in the low-temperature range
when using internal heating. The Au/TiO2 catalyst supported on the carbon-carbon composite shows good stability at 250°C. 相似文献
109.
110.
David Rafaja Milan Dopita Magsud Masimov Volker Klemm Nina Wendt Walter Lengauer 《International Journal of Refractory Metals and Hard Materials》2008,26(3):263-275
Combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used for investigation of local composition gradients in the hard-phases of cermets. XRD revealed distribution of lattice parameters in hard-phase grains, from which the composition gradients in the hard-phases were estimated using an appropriate microstructure model. This microstructure model was build with the aid of SEM micrographs, which were taken with back-scattered electrons (BSE) and completed by the registration of the electron back-scatter diffraction (EBSD) patterns and characteristic X-ray spectra. SEM/BSE yielded the first information about the spatial distribution of elements in individual hard-phase grains, SEM/EBSD about the morphology, the size and the size distribution of these grains. The final interpretation of the distribution of lattice parameters, which was obtained from the X-ray line profile analysis, was done with the aid of the local elemental analysis that was performed using SEM with the energy dispersive analysis of the characteristic X-ray spectra (EDX) and the known dependence of the lattice parameters on concentration. 相似文献