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排序方式: 共有903条查询结果,搜索用时 31 毫秒
111.
Application of Highly Functional Ti-Oxide-Based Photocatalysts in Clean Technologies 总被引:1,自引:0,他引:1
Masato Takeuchi Shirou Sakai Afshin Ebrahimi Masaya Matsuoka Masakazu Anpo 《Topics in Catalysis》2009,52(12):1651-1659
Various Ti-oxide based photocatalysts such as the highly dispersed Ti-oxide species within zeolite frameworks, TiO2 nano-particles hybridized with hydrophobic zeolite adsorbents as well as visible light responsive TiO2 thin films have been successfully prepared. Characterization studies at the molecular level, such as X-ray absorption fine
structure (XAFS) and photoluminescence (PL), revealed that the highly dispersed Ti-oxide species within the nano-spaces of
zeolites possess a tetrahedral coordination and that they demonstrate unique and high performance for the photocatalytic decomposition
of NOx and the photocatalytic reduction of CO2 with H2O. A high photocatalytic reactivity for the TiO2 semiconducting photocatalysts could be achieved by blending them with hydrophobic siliceous zeolites which was equal to the
performance of TiO2 deposited with expensive Pt particles. The role of the siliceous zeolites can be described as a so-called “catch and release
effect of organic compounds”, i.e., (i) the condensation of the reactants within the hydrophobic cavities of zeolites and;
(ii) the efficient diffusion of the reactant onto the TiO2 photocatalytic sites. Furthermore, a novel photocatalytic system which can convert abundant solar energy into renewable H2 energy by the decomposition of H2O into H2 and O2 can also be achieved by using visible light responsive TiO2 thin film photocatalysts prepared by a RF-magnetron sputtering deposition method. The conversion efficiency of solar energy
into H2 energy may be estimated at ca. 0.1% from the initial rate of H2 evolution. 相似文献
112.
Takashi Kubo Masato Takeuchi Masaya Matsuoka Masakazu Anpo Atsushi Nakahira 《Catalysis Letters》2009,130(1-2):28-36
Morphologic control of Pt supported titanate nanotubes was attempted by the hydrothermal hot-pressing (HHP) technique in order to improve the handleability as a photocatalyst. The bulk of Pt-nanocrystal supported titanate nanotubes was successfully fabricated without the H2 reduction process by applying the HHP technique. The bulky Pt-nanocrystal supported titanate nanotubes possessed dense microstructures, significantly sharp distributions of mesopores, and high Brunauer–Emmett–Teller (BET) surface area. Furthermore, the bulky Pt-nanocrystal supported titanate nanotubes showed the photocatalytic degradation activities of 2-propanol aqueous solution under UV-light irradiation. 相似文献
113.
We prepared ultrafine Fe–Pt alloy nanoparticle colloids by UV laser solution photolysis (KrF excimer laser of 248 nm wavelength)
using precursors of methanol solutions into which iron and platinum complexes were dissolved together with PVP dispersant
to prevent aggregations. From TEM observations, the Fe–Pt nanoparticles were found to be composed of disordered FCC A1 phase
with average diameters of 0.5–3 nm regardless of the preparation conditions. Higher iron compositions of nanoparticles require
irradiations of higher laser pulse energies typically more than 350 mJ, which is considered to be due to the difficulty in
dissociation of Fe(III) acetylacetonate compared with Pt(II) acetylacetonate. Au colloid preparation by the same method was
also attempted, resulting in Au nanoparticle colloids with over 10 times larger diameters than the Fe–Pt nanoparticles and
UV–visible absorption peaks around 530 nm that originate from the surface plasmon resonance. Differences between the Fe–Pt
and Au nanoparticles prepared by the KrF excimer laser solution photolysis are also discussed. 相似文献
114.
Masato Takeuchi Junichi Deguchi Manabu Hidaka Shiro Sakai Kyoungja Woo Pyuck-Pa Choi Jong-Ku Park Masakazu Anpo 《Applied catalysis. B, Environmental》2009,89(3-4):406-410
The photocatalytic oxidation of gaseous acetaldehyde with O2 on commercial TiO2 nano-particles could be successfully enhanced by a simple mechanical blending with a high-silica mordenite (MOR) zeolite, the surface of which showed high hydrophobic properties. When the TiO2 nano-particles of ca. 5–20 wt% were mixed with the MOR zeolite powders in an agate mortar for only 5 min, the blended TiO2/MOR samples showed higher photocatalytic reactivity as compared to the pure TiO2 nano-particles. Since the high-silica zeolite powders are highly transparent in UV light regions, the incident UV light is effectively irradiated onto the whole part of the TiO2 nano-particles without any loss of light intensity. Furthermore, the siliceous MOR zeolite powders effectively adsorb the gaseous acetaldehyde molecules and supply them onto the surfaces of the blended TiO2 nano-particles, resulting in an enhancement of the photocatalytic reactivity. 相似文献
115.
Clogging of venting slots in injection molds is a common maintenance problem caused by the degradation and the accumulation of gaseous and volatiles by-products of polymer melting. In this work, the effect of laser-induced periodic surface structures on the self-cleaning properties of venting slots is investigated. The degradation of poly(ethylene terephthalate) (PET) over different surfaces is characterized by reproducing the mechanisms that occurs in mold cavities when the air is pushed through the venting channel. An imaging technique is developed for the quantification of the sediment that deposits on sample surfaces due to condensation of by-products of PET melting. The experimental results indicate that the use of a multiscale texture minimizes the deposition of residues on the vent surface reducing it from 17.2 to 3.1%. A linear dependency between contact angle and clogging ratio indicates the efficacy of the model that explains vent self-cleaning properties considering their wetting properties. 相似文献
116.
Sensitivity of charged particle activation analysis for long-lived radioactive nuclide determination
Masumi Oshima Yurie Yamaguchi Masato Asai Kazuaki Tsukada Jun Goto Shigeru Bamba 《Journal of Nuclear Science and Technology》2019,56(9-10):866-872
ABSTRACTCharged Particle Activation Analysis (CPAA) utilizing an 8-MeV proton beam has been studied for determination of 35 long-lived radioactive nuclides. We accumulated the reaction cross section and nuclear decay data by referring to nuclear database supplied by National Nuclear Data Center in Brookhaven National Laboratory. We also calculated the reaction cross sections by using statistical model code ALICE. By using the nuclear data, we have derived determination sensitivity of the radioactive nuclides relative to unit weight and specific radioactivity. The result indicates that several hardly measurable nuclides with long half-lives such as 135Cs, 244Pu, 129I, 126Sn, 93Mo, 107Pd, 236U, 248Cm, and 237Np have high sensitivity. It may be concluded that CPAA can be applied to determination of several long-lived nuclei and will provide a quick and non-destructive analysis method. 相似文献
117.
118.
Saito Ken Inoue Chikara Ikegawa Jin Yamazaki Kazuhiko Goto Sota Takamura Masato Mihara Shunsuke Suzuki Shinsuke 《Metallurgical and Materials Transactions A》2020,51(9):4499-4510
Metallurgical and Materials Transactions A - In this study, we investigated the effects of the size and distribution of spheroidized cementite on the characteristics of a punched surface as well as... 相似文献
119.
Zijing Wang Fen Wang Angga Hermawan Yusuke Asakura Takuya Hasegawa Hiromu Kumagai Hideki Kato Masato Kakihana Jianfeng Zhu Shu Yin 《材料科学技术学报》2021,73(14):128-138
Acetone,as widely used reagents in industry and laboratories,are extremely harmful to the human.So the detection of acetone gas concentrations and leaks in special environments at room temperature is essential.Herein,the nanocomposite combining SnO-SnO2 (p-n junction) and Ti3C2Tx MXene was successfully synthesized by a one-step hydrothermal method.Because of the existence of a small amount of oxygen during the hydrothermal conditions,part of the p-type SnO was oxidized to n-type SnO2,forming in-situ p-n junctions on the surface of SnO.The hamburger-like SnO-SnO2/Ti3C2Tx sensor exhibited improved acetone gas sensing response of 12.1 (Rg/Ra) at room temperature,which were nearly 11 and 4 times higher than those of pristine Ti3C2Tx and pristine SnO-SnO2,respectively.Moreover,it expressed a short recovery time (9 s) and outstanding reproducibility.Because of the different work functions,the Schottky barrier was formed between the SnO and the Ti3C2Tx nanosheets,acting as a hole accumulation layer (HALs) between Ti3C2Tx and tin oxides.Herein,the sensing mechanism based on the formation of hetero-junctions and high conductivity of the metallic phase of Ti3C2Tx MXene in SnO-SnO2/Ti3C2Tx sensors was discussed in detail. 相似文献
120.
Taehwan Jun Junghwan Kim Masato Sasase Hideo Hosono 《Advanced materials (Deerfield Beach, Fla.)》2018,30(12)
Transparent amorphous semiconductors (TAS) that can be fabricated at low temperature are key materials in the practical application of transparent flexible electronics. Although various n‐type TAS materials with excellent performance, such as amorphous In‐Ga‐Zn‐O (a‐IGZO), are already known, no complementary p‐type TAS has been realized to date. Here, a material design concept for p‐type TAS materials is proposed utilizing the pseudo s‐orbital nature of spatially spreading iodine 5p orbitals and amorphous Sn‐containing CuI (a‐CuSnI) thin film is reported as an example. The resulting a‐CuSnI thin films fabricated by spin coating at low temperature (140 °C) have a smooth surface. The Hall mobility increases with the hole concentration and the largest mobility of ≈9 cm2 V?1 s?1 is obtained, which is comparable with that of conventional n‐type TAS. 相似文献