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261.
Dr. Kyohei Muguruma Rento Osawa Akane Fukuda Naoto Ishikawa Konomi Fujita Dr. Akihiro Taguchi Dr. Kentaro Takayama Dr. Atsuhiko Taniguchi Prof. Yuji Ito Prof. Yoshio Hayashi 《ChemMedChem》2021,16(11):1814-1821
Immunoglobulin G (IgG)-binding peptides such as 15-IgBP are convenient tools for the site-specific modification of antibodies and the preparation of homogeneous antibody–drug conjugates. A peptide such as 15-IgBP can be selectively crosslinked to the fragment crystallizable region of human IgG in an affinity-dependent manner via the ϵ-amino group of Lys8. Previously, we found that the peptide 15-Lys8Leu has a high affinity (Kd=8.19 nM) due to the presence of the γ-dimethyl group in Leu8. The primary amino group required for the crosslinking to the antibodies has, however, been lost. Here, we report the design and synthesis of a novel unnatural amino acid, 4-(2-aminoethylcarbamoyl)leucine (Aecl), which possesses both the γ-dimethyl fragment and a primary amino group. A peptide containing Aecl8 (15-Lys8Aecl) was synthesized and showed a binding affinity ten times higher (Kd=24.3 nM) than that of 15-IgBP (Kd=267 nM). Fluorescein isothiocyanate (FITC)-labeled 15-Lys8Aecl with an N-hydroxy succinimide ester at the side chain of Aecl8 (FITC-15-Lys8Aecl(OSu)) successfully labeled an antibody (trastuzumab, Herceptin®) with the fluorophore. This peptide scaffold has both strong binding affinity and crosslinking capability, and could be a useful tool for the selective chemical modification of antibodies with molecules of interest such as drugs. 相似文献
262.
Takehisa Mochizuki Takeshi Hara Naoto Koizumi Muneyoshi Yamada 《Catalysis Letters》2007,113(3-4):165-169
Co/SiO2 catalysts were prepared by the incipient wetness method using the aqueous Co nitrate solution modified with various organic
acids and/or chelating agents followed by drying and calcination. After H2 reduction at 773 K, the catalyst prepared with nitrilotriacetic acid (NTA) showed Fischer-Tropsch synthesis (FTS) activity
ca. 3 times higher than the catalyst without additives under mild reaction conditions (503 K, 1.1 MPa). 相似文献
263.
The structures of ultra‐thin films of vinylidene fluoride and trifluoroethylene copolymer were characterized using Fourier transform infrared reflection absorption spectroscopy (FTIR‐RAS), FTIR transmission spectroscopy (FTIR‐TRS), atomic force microscopy, and wide‐angle X‐ray diffraction. The ferro‐electricity was determined from polarization charge (a displacement (D)–electric field (E) hysteresis). FTIR‐RAS and FTIR‐TRS measurements showed that the molecular chains of polymers (crystal c‐axis) near the substrate tended to align parallel to the substrate. However, thermal annealing of the sample films at temperatures above 145 °C caused a marked change in molecular alignment of the polymer chains (crystal c‐axis) from parallel to normal to the substrate, and, further, caused a conformation change from trans to partially gauche forms. Copyright © 2007 Society of Chemical Industry 相似文献
264.
As a novel partial substitution and surface modification process, we focused on a step-by-step (double-step) supersonic-wave treatment in a Zn-containing aqueous solution without any heat-treatments, and performed the treatment on LiMn2O4 powder. From XRD measurements, it was demonstrated that the lattice constant of LiMn2O4 decreased slightly by the treatments, indicating a partial substitution of Zn for Mn. It was also suggested by SEM–EDX and XPS that Zn was well dispersed in/on the samples and their surfaces were modified by Zn compounds. Such a partial substitution and surface modification was supported by crystal structure analysis based on the Rietveld method using neutron diffraction. Cycle performance of LiMn2O4 was significantly improved by the step-by-step supersonic-wave treatments. In the processes, it was especially effective for the improvement to apply lower and higher frequencies at the first and second steps, respectively, keeping the power higher. The cathode property improvement was considered due to the partial substitution and the surface coating caused by the step-by-step supersonic-wave treatments. From the investigation on the cathodes and electrolytes after the cycle tests, it was suggested that the crystal structure of LiMn2O4 was stabilized by the treatments. 相似文献
265.
H. Yamaguchi I. Saito Y. Kudo T. Masuzawa T. Yamada M. Kudo Y. Takakuwa K. Okano 《Diamond and Related Materials》2008,17(2):162-166
Clarification of the electron emission mechanism of diamond has been one challenging topic in the field of vacuum nanoelectronics. Electric field of less than 5 V/µm is enough to extract electrons from diamond, which is orders of magnitude lower than the value required for electron emission from metal emitter in general. There have been number of studies on the clarification of electron emission mechanism, however, unified model has not been proposed. The difficulty largely lies in determining the origin of emitted electrons. In this study, we succeeded in clarifying the electron emission mechanism of hydrogenated natural type IIb diamond (111) surface by using combined x-ray photoemission spectroscopy/ultraviolet photoemission spectroscopy/field emission spectroscopy (XPS/UPS/FES) system. Obtained spectra clearly defined the origin of emitted electrons at the valence band maximum (VBM). As applied voltage was increased, the number of emitted electrons increased, however, the origin remained at VBM independent of the applied voltage. 相似文献
266.
Hui-Li Li Rong-Jun Xie Naoto Hirosaki Berjamin Dierre Takashi Sekiguchi Yoshiyoki Yajima 《Journal of the American Ceramic Society》2008,91(5):1711-1714
In this paper, undoped, Mg- and Zn-doped gallium nitride powders were prepared by direct nitridation of Ga2 O3 under a flowing NH3 gas. The phase purity, morphology and cathodoluminescence spectra were presented. The Ga2 O3 powders can be completely nitridized to GaN at 1000°C. The resultant GaN powders agglomerated together with submicron-sized polyhedral crystals. At room temperature, the Mg- and Zn-doped powders exhibit bright blue-violet emission at around 3.05 and 2.81 eV, respectively. This provides clear evidence that magnesium or zinc is incorporated into the GaN powders as an acceptor and suggests that the luminescent materials are promising candidates for optoelectronic applications. 相似文献
267.
Xin Xu Toshiyuki Nishimura Naoto Hirosaki Rong-Jun Xie Hidehiko Tanaka 《Journal of the American Ceramic Society》2007,90(4):1058-1062
A nano-Si3 N4 /5 wt% nano-C composite was successfully fabricated for the first time via high-energy ball milling, followed by spark plasma sintering. The milling promoted the amorphization of the starting powders; most of the carbon particles were transformed into nano-size and embedded in the amorphous phase. This, combined with a low sintering temperature and a rapid densification rate, prevented the reactions between carbon and the other starting powders, leading to a uniform nano/nano-composite microstructure. Nano-sized carbon grains with an average diameter of about 10 nm were homogeneously dispersed in nano-sized (about 70 nm) Si3 N4 grain boundaries. The hardness of the obtained nano-ceramics is comparable with that of conventional Si3 N4 , whereas Young's modulus is significantly decreased. 相似文献
268.
The hold-up of molten pig iron and slag melt in the coke packed bed of blast furnace (BF) causes a decrease of void between coke lumps and inhibits gas permeability. Smooth dripping of those liquids in the coke bed is desirable to keep the productivity of BF. Herein, the conditions for smooth flowing of molten iron on coke surface are calrified, and the falling angles of Fe-C and actual pig iron droplets on coke and graphite are measured at high temperature. It is found that Fe-C droplet easily slids down on coke because of small falling angle, and the falling angle of actual pig iron is even smaller, while those droplets adhere to a graphite substrate. The carbon in iron has only a small effect on the static contact angle with coke, but has a great influence on the falling angle. From the viewpoint of the roughness of coke surface, the variation of static contact angle and falling angle is discussed. 相似文献
269.
Naoto Yorino Tsutomu Fujimura Hiroshi Sasaki Hiroaki Sugihara Yosuke Nakanishi 《Electrical Engineering in Japan》1998,124(4):1-9
The dynamic behaviors of the TCUL controls are investigated from the viewpoint of the effect of control actions on voltage stability as well as on voltage regulations, taking into account the interference among the multiple control actions of TCULS. The Liapunov stability theorem is applied to a system having nonlinear voltage-dependent loads to derive conditions for stability. We define the term “reverse control action for multiple TCULS” to indicate undesirable tap operations, where multiple controls as a whole cause the decrease in voltages of specific nodes, leading to voltage collapse, in spite of normal individual operations. A criterion to detect the phenomena is derived and then a new control strategy based on this criterion is demonstrated. In this demonstration, unsuitably acting TCULs are individually deactivated at their most effective timings to improve voltage stability. The effectiveness of the proposed criterion and its application to the deactivation control have successfully been confirmed through numerical simulations in a radial network with three cascaded TCUL transformers, where a specific area of a real system is reduced to form the example system. 相似文献
270.
Yakata M Kuramitsu R Kai S Kudo H Yamoto R Matsuo S 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2012,53(1):45-51
An analytical method of ethephon in feeds by GC-FPD was developed. Ethephon was extracted with ethyl acetate-hydrochloric acid (100 : 1) from feed samples. The extract was treated with added trimethylsilyldiazomethane in acetone-acetic acid (99 : 1) and this methylation procedure was repeated three times. Methylated ethephon was cleaned up on a graphitized carbon mini-column and a silicagel mini-column, and determined by GC-FPD. A method performance study in 7 laboratories was conducted with three kinds of samples spiked with ethephon at 10 mg/kg, 1 mg/kg and 0.5 mg/kg. The recovery of ethephon ranged from 81.8% to 90.8% (the reproducibility standard deviation (RSDr) were within 11%) and HorRat values were 0.58 to 0.94. The limit of detection (S/N≧3) and the limit of quantitation (S/N≧10) of ethephon in samples except hay were 0.02 mg/kg and 0.05 mg/kg, respectively. In the case of hay, the corresponding values were 0.2 mg/kg and 0.5 mg/kg, respectively. 相似文献