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891.
Hiroshi Koyama Masayuki Fujimoto Tomoya Ohno Hisao Suzuki Junzo Tanaka 《Journal of the American Ceramic Society》2006,89(11):3536-3540
We investigated the structural and optical properties of microporous titanium oxide (TiO2 ) fabricated by the sol–gel method using templates of colloidal crystals with polystyrene spheres when the annealing temperature was changed between 600° and 1000°C. From X-ray diffraction patterns and SEM images, the rutile TiO2 annealed at a high temperature did not form periodic porous bodies, while the anatase TiO2 annealed at lower than 800°C formed periodic porous bodies. The porous TiO2 obtained acts as an air-sphere/TiO2 photonic crystal with an FCC structure. It is suggested that TiO2 sol annealed at a lower temperature do not lead to phase transition from the anatase phase to the rutile phase to obtain the air-sphere/TiO2 photonic crystal by the sol–gel method using templates of colloidal crystals. 相似文献
892.
893.
Multirobot exploration for search and rescue missions: A report on map building in RoboCupRescue 2009 总被引:1,自引:0,他引:1
Keiji Nagatani Yoshito Okada Naoki Tokunaga Seiga Kiribayashi Kazuya Yoshida Kazunori Ohno Eijiro Takeuchi Satoshi Tadokoro Hidehisa Akiyama Itsuki Noda Tomoaki Yoshida Eiji Koyanagi 《野外机器人技术杂志》2011,28(3):373-387
In the future, mobile robots may be able to assist rescue crews in search and rescue missions that take place in the dangerous environments that result from natural or man‐made disasters. In 2006, we launched a research project to develop mobile robots that can rapidly collect information in the initial stages of a disaster. One of our important objectives is three‐dimensional (3D) mapping, which can be a very useful tool for assisting rescue crews in strategizing rescue missions. To realize this 3D mapping, we identified five issues that we needed to address: (1) autonomous traversal of uneven terrain, (2) development of a system for the continuous acquisition of 3D data of the environment, (3) coverage path planning, (4) centralization of map data obtained by multiple robots, and (5) fusion of map data obtained by multiple robots. We solved each problem through our joint research. Each research institute in our group took charge of solving one of the above issues according to its area of expertise. We integrated these solutions to perform 3D mapping using our tracked vehicle, Kenaf. To validate our integrated autonomous 3D mapping system, we participated in RoboCupRescue 2009 and demonstrated our system using multiple robots on the RoboCupRescue field. In this paper, we introduce our mapping system and report the mapping results obtained at the RoboCupRescue event. © 2011 Wiley Periodicals, Inc. 相似文献
894.
895.
Naoki Igawa Takanori Nagasaki Yoshinobu Ishii Kenji Noda Hideo Ohno Yukio Morii Jaime A. Fernandez-Baca 《Journal of Materials Science》1998,33(19):4747-4758
The rate of the transformation from the metastable tetragonal to the monoclinic phase of ZrO2 was measured in air from 850°C to 1000°C by neutron diffraction. This rate was found to be temperature dependent, and its measured values were considerably lower then those reported previously. The kinetics of this phase transformation is discussed in terms of a modified crystallite growth-martensitic transformation model' that includes the distribution of crystallite sizes. 相似文献
896.
Summary Zwitterion bearing highly dissociable imide anion (EIm5csI) was used as major component for stable polymer electrolytes. A
polymerization of methyl acrylate in the presence of EIm5csI/LiTFSI mixture gave a flexible film with the ionic conductivity
of 9.3×10-6 Scm-1 at 50 °C. Mixing of poly(lithium acrylate) and EIm5csI/LiTFSI mixture improved ionic conductivity (3.3×10-5 Scm-1 at room temperature), lithium transference number (0.44), and thermal stability. 相似文献
897.
McCormick Robert L. Alptekin Gokhan O. Williamson D.L. Ohno T.R. 《Topics in Catalysis》2000,10(1-2):115-122
Selective oxidation of methane to methanol and formaldehyde at atmospheric pressure was studied over a series of silicasupported FePO4 catalysts, with iron phosphate content ranging from 2 to 16 wt%. Performance was evaluated over the range T=773–963 K, GHSV=25,000–65,000 h–1, and CH4 : O2=1. The main products were formaldehyde, carbon monoxide and carbon dioxide. Small, but quantifiable amounts of methanol were also observed. Catalytic activity exhibited a clear dependence on the iron phosphate content. The highest selectivity and space time yield (STY) to formaldehyde and methanol were observed for 2 wt% FePO4 on silica (STY of 622 and 25 g/kgcat h, respectively). The selectivity–conversion pattern suggests that methane is oxidized directly to methanol and formaldehyde, and sequentially to carbon oxides. Characterization was performed by Xray powder diffraction, Xray photoelectron spectroscopy, and Mössbauer spectroscopy. Crystalline FePO4 is observed at all loading levels, however, a significant fraction of the iron (58% at 2 wt% FePO4) is present in an Xray amorphous phase. Mössbauer spectra suggest that this phase contains iron in fivefold coordination, and with a higher electron density relative to bulk FePO4. The amount of this fivecoordinate phase present is roughly 1 wt% Fe, independent of total iron loading. XPS confirms the lower effective oxidation state of iron, and indicates that at low loading the surface is enriched in phosphorus relative to bulk FePO4. It is proposed that iron in fivefold coordinate sites, isolated by phosphate groups, more selectively activates methane than crystalline FePO4. As loading increases, so does the amount of crystalline FePO4, which is proposed to more rapidly catalyze sequential oxidation of the selective products. 相似文献
898.
Kenichi Ohno Shinobu Ohya Masaaki Tanaka 《Journal of Superconductivity and Novel Magnetism》2007,20(6):417-420
The authors have investigated the magnetic properties of heavily Mn-doped ferromagnetic semiconductor Ga1−x
Mn
x
As thin film with the Mn concentration x of 15.2% grown by molecular-beam epitaxy at relatively high growth temperature of 250 °C. Magnetic circular dichroism and
the anomalous Hall effect measurements indicate that this thin film holds the intrinsic ferromagnetic semiconductor features.
By low-temperature annealing, the resistivity was significantly decreased and the Curie temperature was largely enhanced from
95 K to 172.5 K. 相似文献
899.
900.
K Ishikawa S Mochida S Mashiba M Inao A Matsui H Ikeda A Ohno M Shibuya K Fujiwara 《Canadian Metallurgical Quarterly》1999,254(3):587-593
Vascular endothelial growth factor (VEGF) can induce proliferation of sinusoidal endothelial cells. Its mRNA expression was increased in proliferating rat hepatocytes in primary culture. To clarify a role of VEGF in liver after necrosis, expressions of VEGF and its receptors were measured in the liver or liver cells isolated from rats after carbon tetrachloride intoxication. Hepatic VEGF mRNA expression increased later than 24 h after the intoxication and became prominent at 168 h when liver necrosis disappeared, while hepatic mRNA expressions of its receptors increased between 24 and 72 h. VEGF mRNA expression was increased in Kupffer cells, hepatic macrophages and stellate cells isolated from rats between 24 and 72 h after the intoxication and in hepatocytes at 168 h compared to those cells from normal rats. Immunohistochemical VEGF stains were comparable to such results. Vascular endothelial cells existed abundantly in the necrotic areas, and sinusoidal endothelial cells appeared following disappearance of the necrotic areas. VEGF mRNA expression in hepatocytes isolated from 70% resected liver was increased at 12 h after the operation and became marked between 72 and 168 h. Similar increase of hepatic VEGF expression was immunohistochemically seen. In conclusion, VEGF derives from nonparenchymal as well as parenchymal cells in rat liver after necrosis. The former might contribute to vascular endothelial cell proliferation and the latter to sinusoidal endothelial cell regeneration. 相似文献