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991.
CIGRE Study Committee A3 established WG A3.22 ‘Technical requirements for substation equipment exceeding 800 kV’ to review the state-of-the-art technical specifications for substation equipment exceeding 800kV in accordance with a request from IEC SC 17A. WG A3.22 conducted the initial surveys and submitted the first Technical Brochure on technical specifications for substation equipment such as gas circuit breaker (GCB), disconnecting switches (DS), earthing switches (ES), high-speed grounding switches (HSGS) and metal oxide surge arrester (MOSA) applied to 800 kV and 1100/1200 kV networks. The investigations include the insulation level, first-pole-to-clear factor, DC time constants, transient recovery voltage (TRV), line surge impedance and secondary arc extinction time. WG A3.22 will provide the technical background of all aspects of the available specifications with the intention of identifying the best practice for ultra high voltage (UHV) transmission systems. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
992.
Yuichi Kim Eiichi Nishikawa Toshihide Kioka 《IEEJ Transactions on Electrical and Electronic Engineering》2009,4(4):578-580
We succeeded in producing carbon nanotubes (CNTs) on scanning tunneling microscope (STM) probes using the simple arc discharge method. We used STM probes with a diameter of 200 µm (500 nm in diameter at the tip), and placed them in a position 5 mm from a set of carbon electrodes between which a direct current discharge of 30 V/20 A was applied. The results of scanning electron microscopy observation confirmed that the fine particles generated included high-purity CNTs on the STM probe surface. Specifically, CNTs were generated directly on the surface of the STM probe. This study indicates that the technique is suitable for nano-analysis application in the field of nanotechnology. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
993.
Mitsuru Wakamatsu Nobuyuki Takeuchi Hiroki Nagai Shingo Ishida 《Journal of the American Ceramic Society》1989,72(1):16-19
R — O , N — R , and O — R firing operations produce copper red glazes resulting from the formations of Cu2 O, metallic copper, and both Cu2 O and metallic copper, respectively. The symbols O , N , and R denote oxidizing, neutral, and reducing atmospheres, respectively, and in the set of symbols, the former corresponds to the heating atmosphere and the latter to the successive cooling atmosphere. All other firing operations such as R — R and R — N fail to produce red glazes. The formation mechanisms of metallic copper and Cu2 O are postulated from a microscopic viewpoint. 相似文献
994.
Fuminori Arai Hiroki Takeshita Masako Dobashi Katsuhiko Takenaka Masamitsu Miya Tomoo Shiomi 《Polymer》2012,53(3):851-856
To analyze the interplay between crystallization and liquid–liquid phase separation (LLPS), isothermal crystallization behavior of poly(ethylene glycol) (PEG) in blends with isotactic poly(methyl methacrylate) (i-PMMA) was investigated by differential scanning calorimetry (DSC). The blend system had an upper critical solution temperature (UCST) type phase diagram. When the crystallization occurred simultaneously with LLPS, the overall crystallization rate was enhanced at high crystallization temperatures Tc, relatively compared with that of neat PEG. This behavior was interpreted by the combination of the effects of spinodal quench depth ?Ts and usual supercooling degree ?Tc, according to the theory of Mitra and Muthukumar, namely, the crystallization rate is enhanced by the concentration fluctuation-assisted nucleation at high Tc. In the crystallization after LLPS proceeded, on the other hand, the overall crystallization rate was slow and less dependent on the blend composition. In addition, it was revealed by small-angle X-ray scattering measurements that amorphous i-PMMA was excluded from the interlamellar region of PEG crystals in SQ as well as WQ. 相似文献
995.
Adsorptive separation of arsenate and arsenite anions from aqueous medium by using orange waste 总被引:7,自引:0,他引:7
Cellulose and orange waste were chemically modified by means of phosphorylation. The chemically modified gels were further loaded with iron(III) in order to create a suitable chelating environment for arsenate and arsenite removal. The loading capacity for iron(III) on the gel prepared from orange waste (POW) was 1.21 mmol g−1 compared with 0.96 mmol g−1 for the gel prepared from cellulose (PC). Removal tests of arsenic with the iron(III)-loaded gel were carried out batchwise and by using a column. Arsenite removal was favored under alkaline condition for both PC and POW gels, however, the POW gel showed some removal capability even at neutral pH. On contrary, arsenate removal took place under acidic conditions at pH=2–3 and 2–6 for the PC and POW gels, respectively. Since iron(III) loading is higher on the POW gel than on the PC gel greater arsenic removal has been achieved by the POW gel compared with the PC gel. It can be concluded that the POW gel can be used for the removal and recovery of both arsenite and arsenate from arsenic contaminated wastewater. 相似文献
996.
Motoshima K Hiwasa Y Yoshikawa M Fujimoto K Tai A Kakuta H Sasaki K 《ChemMedChem》2007,2(10):1527-1532
Malaria is one of the three major serious infectious diseases in the world. As the area affected by malaria includes a large proportion of developing countries, there is a need for new antimalarials that can be synthesized and supplied inexpensively. To generate low-cost antimalarials, the MAP series 6-10, bis-cation dimers, synthesized by amidating the carboxyl group of isonicotinic acid (11) with various amines and by cationizing the nitrogen atoms of the pyridine ring with the corresponding alkyl bromides, were designed. This design enabled expansion of the structural variations of bis-cation-type antimalarial compounds. The compounds bearing alkyl or phenyl groups in the amide moieties showed remarkable antimalarial activities in vitro. Moreover, 1,1'-(1,12-dodecanediyl)bis[4-[(buthylamino)carbonyl]pyridinium bromide], MAP-412 (6 d), exhibited a potent antimalarial activity (ED(50)=8.2 mg kg(-1)). Being prepared at low cost, our bis-cation-type antimalarial compounds may be useful as lead compounds for inexpensive antimalarials. 相似文献
997.
Seicho Makihira Yuichi Mine Hiroki Nikawa Takahiro Shuto Eduardo Kosaka Masaru Sugiyama Ryuji Hosokawa 《Journal of materials science. Materials in medicine》2010,21(2):647-653
The purpose of the present study was to examine the effect of osteoprotegerin (OPG)-Fc fusion protein immobilized on a titanium surface on the initial differentiation of osteoclast precursor RAW264.7 cells. These cells were cultured on titanium specimens over which OPG-Fc was immobilized. The enhancement of tartrate-resistant acid phosphatase (TRAP) and cathepsin K mRNA expression in RAW264.7 cells exposed to receptor activator of NF-κB ligand (RANKL) stimulation on OPG-Fc-coated titanium was significantly lower than that in RAW264.7 cells exposed to RANKL on titanium specimens without immobilized OPG-Fc (ANOVA, P < 0.01). Preincubation of OPG-Fc-coated titanium, in a medium supplemented with 10% fetal bovine serum at 37°C for two days before the cells were seeded, had no significant effect on the decrease in mRNA expression (ANOVA, P < 0.01). Taken together, these results indicate that OPG-Fc immobilized on a titanium surface blocks the differentiation of RAW264.7 cells induced by RANKL stimulation. 相似文献
998.
Hiroki Maenami Osamu Watanabe Hideki Ishida Takeshi Mitsuda 《Journal of the American Ceramic Society》2000,83(7):1739-1744
The strength development of hydrothermally solidified kaolinite–quartz–lime systems with kaolinite as the aluminum source was studied. The starting materials were mixed so that the Ca/(Si + Al) atomic ratio was in the range 0.23 to 0.25, and the Al/(Si + Al) ratio was between 0 to 0.50. Specimens were formed by uniaxial pressing and hydrothermal treatment under saturated steam pressure at 200°C for 2 to 20 h. For quartz-rich systems with Al/(Si + Al) = 0 and 0.05, strength development by the formation of calcium silicate hydrates, such as C–S–H and tobermorite (Ca5 (Si6 O18 H2 )·(4H2 O), was observed. On the other hand, in the case of kaolinite-rich systems with Al/(Si + Al) = 0.24 to 0.50, strength development by the formation of hydrogarnet (Ca3 Al2 (SiO4 )(OH)8 ) was recognized, resulting in flexural strengths between 15 to 20 MPa. It is proposed that strength development is related to the formation of mesopores (∼0.04 μm) that accompanied formation of the hydrogarnet. 相似文献
999.
1000.