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121.
122.
I Turkevych V Ryukhtin V Garamus S Kato T Takamasu G Kido M Kondo 《Nanotechnology》2012,23(32):325606
We performed studies of the self-organization processes in nanoporous alumina membranes at initial and late stages of aluminum anodization by using scanning electron microscopy (SEM) and small-angle neutron scattering (SANS). SEM observations indicated three stages in the self-organization of nanopores in alumina: (1) nucleation of random nanopores with a broad radius distribution, (2) narrowing the radius distribution and (3) slow evolution of the nanoporous structure towards ordering of nanopores into large domains. SANS studies revealed orientational correlation between ordered domains of nanopores, which is characterized by a small misorientation angle. For the samples with high aspect ratios of nanopores, the SANS patterns showed azimuthal smearing, which was attributed to the redistribution of nanopores between the domains during their growth. 相似文献
123.
Daisuke Yokoyama Ken‐ichi Nakayama Toshiya Otani Junji Kido 《Advanced materials (Deerfield Beach, Fla.)》2012,24(47):6386-6386
124.
Gold nano-rod array membranes (Au-NRM) were prepared by modification of the template method. A simple two-electrode device was assembled by holding an electrolyte solution between the Au-NRM and a transparent electrode. Small reflectance changes (less than 2%) in the visible band were induced on the Au-NRM surface by applying a DC voltage to the device. These changes could be visually observed. It was found based on a further evaluation that the reflectance changes responded very fast (less than 100 ms) to the DC voltage application, and were stable during the switching repetition (over 5000 times). When the cyclic scanning of the applied voltage to the device was carried out between -1.5 V and +1.5 V, the reflectance changes were increased over +1.0 V (-1.0 V). It was suggested from these experimental results that the reflectance changes were attributed to the surface oxidation and the deformation or mechanical motion of the Au nano-rod. 相似文献
125.
Kenji TakadaYuta Ishigami Junji Inukai Yuzo NagumoHiroshi Takano Hiroyuki Nishide 《Journal of power sources》2011,196(5):2635-2639
Visualization inside polymer electrolyte fuel cells (PEFCs) is important for elucidating reaction distributions to improve the performance and durability of the cells. An O2-sensitive porphyrin luminescent dye film was used to visualize oxygen partial pressures and water blockages simultaneously in triple-serpentine gas flow channels in an operating PEFC. Water droplets formed near the exit of a gas-flow channel lowered the oxygen partial pressure noticeably over the channel by blocking air flow near the entrance. Meanwhile, air was continuously supplied from the other channels through the gas diffusion layer, thus allowing power to be generated in the blocked channel. With water blockages, however, the catalyst layer under the channel became flooded by the water produced during the reaction, and the flooded state continued to exist in the catalyst and/or porous layers, even after blowing the water droplet out, so that the power generation was lowered along the channel. 相似文献
126.
A fullerene/expanded graphite composite, in which fullerene crystals were incorporated into the expanded graphite interspaces,
was prepared by chemical and thermal treatments and its lubricating properties in commercial grease were investigated. Expanded
graphite, which was synthesized from graphite by oxidizing by KMnO4 in 98% H2SO4 containing NaNO3 and by heating at 400 °C for 3 min, and fullerene were placed in a stainless steel tube, and were heated in a furnace under
vacuum at 600 °C for 2 weeks. The fullerene/expanded graphite composite obtained was characterized by X-ray diffraction analysis
(XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). XRD and FT-IR analyses showed
that crystalline fullerene was present in the material and SEM images confirmed that it existed in the expanded graphite interspaces.
The composite was blended with a commercial grease, and its lubricating properties were investigated using a four-ball lubricant
tester. These properties were evaluated by measuring the wear scar diameter and wear volume loss of the test ball. The combination
of composite and grease provided a better lubricating performance than that of pure graphite and grease. 相似文献
127.
For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P(t) was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in this paper. From the measured dynamic surface tension of aqueous surfactant sodium dodecyl sulfate (SDS) solutions at 25 ℃, the adsorption kinetics of SDS at air/solution interface was studied. It was proved that for both of the short and long time limits, the adsorption process of SDS was controlled by diffusion. 相似文献
128.
Gentoku Kido Mikihiro Takasaki Kimitaka Minami Hisashi Tanaka Hiroshi Ogawa Tohru Kawamoto 《Journal of Nuclear Science and Technology》2017,54(11):1157-1162
Ash-washing technology is a crucially important technology for removing radioactive Cs from contaminated ash. For that technology, Cs+ removal from the ash-washing solution by the adsorbent is necessary. This study was conducted to establish rapid preparation of appropriate adsorption columns for Cs+ uptake. A one-site model was not used for analysis because the model cannot accommodate sites with different adsorption speed. Results demonstrated that the adsorption behavior of the column filled with the granules of potassium copper hexacyanoferrate was well reproduced by a two-site adsorption model with parameters chosen through analysis of batch adsorption test results. 相似文献
129.
Junji Matsunaga Kan Sakamoto Hiroaki Muta Shinsuke Yamanaka 《Journal of Nuclear Science and Technology》2013,50(10):1231-1240
Since the formation of helium bubbles degrades swelling property and thermal conductivity of minor actinide-containing mixed oxide (MA-MOX) fuel, it is essential to understand the conditions of the bubble formation. In order to examine the dependence of vacancy concentration on morphology of helium bubbles, helium was infused into (Zr,Fe)O2?x. The oxygen vacancy concentration was controlled by addition of solute Fe3+ into ZrO2. Helium was infused by hot isostatic pressing. The helium-infused specimens were observed by field emission scanning electron microscopy (FE-SEM) and field emission transmission electron microscopy (FE-TEM). In addition, X-ray fluorescence, X-ray diffraction analysis, conversion electron yield–X-ray absorption near-edge structure and FE-SEM/EDX (energy dispersive X-ray) analyses were also made to interpret the results of microstructure observations. As a result of the helium infusion treatment, numerous 0.5–10 nm bubbles were observed and its number density clearly depended on oxygen vacancy concentration. On the other hand, sizes of the helium nano-bubbles in all specimens were almost constant. 相似文献
130.