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81.
Summary
Copolymerization of vinyl chloride (VC) and ethylene with Cp*Ti( OCH3)3/MAO catalyst was investigated. The Cp*Ti( OCH3)3/MAO catalyst initiated the copolymerization of VC with ethylene, although the copolymer yields were low. In the 13C NMR spectra of the copolymers, the peaks based on junction part between VC and ethylene was observed, but the signals were
small. From DSC measurement of the copolymers, only one glass transition temperature was observed. Thus, it is clear that
the copolymerization with Cp*Ti( OCH3)3/MAO catalysts gave the copolymer, and the copolymer consisting of block sequence rather than random copolymer.
Received: 13 November 2002/Revised: 6 January 2003/Accepted: 10 January 2003
Correspondence to Kiyoshi Endo 相似文献
82.
Terminal chromosome associations ("satellite associations") in ASG-banded preparations have been used to determine the number and location of staellites in the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus). Five pairs of satellites are found in the former and four in the latter. Nucleolar organizing regions (NORs) were visualized with the Ag-AS silver precipitation technique, and their number and position corresponded exactly with the number and position of satellites in Phodopus, where positive chromosome identification can be made in the absence of banding. Numerical agreement is exact in Mesocricetus as well, and the morphology of the silver-tagged NOR-bearing chromosomes strongly suggests that corrrespondence also occurs in this species. 相似文献
83.
Laser-produced plasma is expected to fulfill the strict requirement as an extreme ultraviolet (EUV) light source for the next-generation lithography with 115-W average power at the intermediate focus, in terms of stability, minimum contamination, and cost of ownership. A liquid xenon micro jet is employed in our experimental facility to confirm the scalability up to the 115-W clean output power. The present experimental device is composed of a 1-kW 10-kHz 6-ns Nd:YAG laser with a xenon jet of up to 50-/spl mu/m diameter of 35 m/s speed inside a vacuum chamber, combined with a xenon recirculation system. The observed EUV power is 4 W at 13.5 nm (2% bandwidth, 2/spl pi/sr) from the plasma source with 0.5% stability (1 /spl sigma/, 50-pulse moving average). Debris mitigation and contamination control is now studied for fast ions by time-of-flight measurements, and confinement and exhaust by a magnetic field is shown to be effective. Xe/sup +/ to Xe/sup 13+/ ions were observed with Xe/sup 2+/ being the main charged state. Experimental study is presented on these subjects and further parametric study on the laser wavelength and pulsewidth is reported, discussing the scalability toward the realization of a 115-W system. 相似文献
84.
Etsuro Shibata Takashi Nakamura Takeshi Nishida Mitsunori Endo Hideyuki Itou Tomio Takasu 《国际钢铁研究》2004,75(5):308-313
The flux of the CaO‐Al203‐BaO‐CeO2‐MgO system as a desulphurization flux containing no fluorine for the secondary metallurgy process was evaluated in this study. The flux composition was designed using the eutectic compositions of the binary systems. The melting and desulphurization abilities of the fluxes were evaluated by measuring their liquidus temperatures and the distribution ratios of sulphur between the fluxes and the carbon‐saturated iron or stainless steel. The lowest liquidus temperature of 1325°C was obtained by adding 5.7 mass% MgO to the 80mass%A‐20mass%B flux. (A: 12CaO‐7Al2O3, B: BaCeO3+12mass%Al2O3). The distribution ratios of sulphur and sulphide capacities of the fluxes in this study were higher than those of the commercial product of calcium aluminate flux. This means that the CaO‐Al2O3‐BaO‐CeO2‐MgO fluxes developed in this study have higher desulphurization and melting abilities compared with the commercial product of calcium aluminate flux. 相似文献
85.
Yu Hua Wang Tadashi Endo Xuan Guo Yukio Murakami Mizumoto Ushirozawa 《Journal of the Society for Information Display》2004,12(4):495-499
Abstract— The broad bands at around 155 nm for GdAl3(BO3)4:Eu, at 184 nm for Ca4GdO(BO3)3:Eu, at 183 nm for Gd2SiO5:Eu, and at 170 nm for GdAlO3:Eu were observed. These bands were assigned to the charge‐transfer (CT) transition of Gd3+‐O2?. In the excitation spectrum of (Gd,Y)BO3:Eu, a broadened excitation band was observed in VUV region. It could be considered that this band was composed of two bands at about 160 and 166 nm. The preceding band was assigned to the BO3 group absorption. The later one at about 166 nm could be assigned to the CT transition of Gd3+‐O2?, according to the result of GdAl3(BO3)4:Eu, Ca4GdO(BO3)3:Eu, Gd2SiO5:Eu, and GdAlO3:Eu. The excitation spectra overlapped between the CT transition of Gd3+‐O2? and BO3 groups absorption. It caused the emission of Eu3+ to take place effectively in the trivalent europium‐doped (Gd,Y)BO3 host lattice under 147‐nm excitation. 相似文献
86.
R. M. J. Janssen A. Endo J. J. A. Baselmans P. J. de Visser R. Barends T. M. Klapwijk 《Journal of Low Temperature Physics》2012,167(3-4):354-359
The sensitivity of microwave kinetic inductance detectors (MKIDs) based on coplanar waveguides (CPWs) needs to be improved by at least an order of magnitude to satisfy the requirements for space-based terahertz astronomy. Our aim is to investigate if this can be achieved by reducing the width of the CPW to much below what has typically been made using optical lithography (>1?μm). CPW resonators with a central line width as narrow as 300?nm were made in NbTiN using electron beam lithography and reactive ion etching. In a systematic study of quarter-wave CPW resonators with varying widths it is shown that the behavior of responsivity, noise and power handling as a function of width continues down to 300?nm. This encourages the development of narrow KIDs using Al in order to improve their sensitivity. 相似文献
87.
In this study, both naturally occurring and artificial amino acids were successfully transformed into the corresponding urethane derivatives using diphenyl carbonate. The urethanes thus prepared could be efficiently cyclized into amino acid N‐carboxyanhydrides (NCAs) without the requirement of phosgene. In addition, the presence of primary amines converted the urethane derivatives into NCAs and initiated the ring‐opening polymerization of the in situ formed NCAs, allowing for the well‐defined synthesis of polypeptides. These polypeptides contained initiating ends functionalized by an amine‐derived residue and propagating ends bearing the reactive amino group. By precise control of the structures of the polypeptides, various polypeptide conjugates such as block copolymers and graft copolymers were successfully synthesized as designed, and their applications in antifouling coatings against proteins, drug delivery systems and biosensors were demonstrated. © 2019 Society of Chemical Industry 相似文献
88.
Thermal Spray Using a High-Frequency Pulse Detonation Combustor Operated in the Liquid-Purge Mode 总被引:1,自引:0,他引:1
T. Endo R. Obayashi T. Tajiri K. Kimura Y. Morohashi T. Johzaki K. Matsuoka T. Hanafusa S. Mizunari 《Journal of Thermal Spray Technology》2016,25(3):494-508
Experiments on thermal spray by pulsed detonations at 150 Hz were conducted. Two types of pulse detonation combustors were used, one operated in the inert gas purge (GAP) mode and the other in the liquid-purge (LIP) mode. In both modes, all gases were supplied in the valveless mode. The GAP mode is free of moving components, although the explosive mixture is unavoidably diluted with the inert gas used for the purge of the hot burned gas. In the LIP mode, pure fuel-oxygen combustion can be realized, although a liquid-droplet injector must be actuated cyclically. The objective of this work was to demonstrate a higher spraying temperature in the LIP mode. First, the temperature of CoNiCrAlY particles heated by pulsed detonations was measured. As a result, the spraying temperature in the LIP mode was higher than that in the GAP mode by about 1000 K. Second, the temperature of yttria-stabilized zirconia (YSZ) particles, whose melting point was almost 2800 °C, heated by pulsed detonations in the LIP mode was measured. As a result, the YSZ particles were heated up to about 2500 °C. Finally, a thermal spray experiment using YSZ particles was conducted, and a coating with low porosity was successfully deposited. 相似文献
89.
Thermodynamic Properties of Ionic Semiclathrate Hydrate Formed with Tetrabutylammonium Propionate 下载免费PDF全文
The phase equilibrium temperature and dissociation heat of tetrabutylammonium propionate (TBAPr) hydrate are reported. TBAPr hydrate is a type of ionic semiclathrate hydrates and also could potentially be used as thermal energy storage material. The temperature‐composition phase diagram of the TBAPr hydrate was determined in a defined range of mass fractions. Considering the dissociation heat of differential scanning calorimetry (DSC) measurements, multiple peaks of heat flow were observed in the TBAPr‐water system at the TBAPr mass fraction lower than 0.35, and there was a single peak at the mass fraction higher than 0.37. 相似文献
90.
Cationic polymerization behavior of β‐methylglycidyl ether derivatives and physical properties of their cationically cured materials 下载免费PDF全文
β‐Methylglycidyl ethers have been applied to Electrical and Electronic adhesives. However, there is no report about the detailed polymerization behavior and physical properties of their cured products. Hence, we investigated cationic polymerization behavior of bisphenol A di(β‐methylglycidyl) ether (Me‐BADGE) and physical properties of the cured products containing Me‐BADGE. DSC analysis suggested that Me‐BADGE could be cured completely at lower temperature than bisphenol A diglycidyl ether (BADGE). Physical properties were analyzed by dynamic viscoelastic analysis. Glass transition temperature (Tg) of BADGE homopolymer was 194°C. In contrast, the copolymer of BADGE (50 wt %) with Me‐BADGE (50 wt %) showed Tg at 124°C. According to the data of E’ and tan δ, crosslink density of the cured products decreased with increasing the Me‐BADGE content. The analysis of cationic polymerization of monofunctional β‐methylglycidyl ether suggested that the cationic polymerization proceeded not only through oxonium cation but also through carbocation formed by ring‐opening reaction of oxonium cation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42377. 相似文献