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991.
Modeling of potassium sorbate diffusion through chitosan films 总被引:1,自引:0,他引:1
The mechanism of potassium sorbate (K-sorbate) release from chitosan films was studied as a function of immersion time in aqueous solution. Fick's law was applied to calculate the diffusion coefficient and the power law defining the type of diffusion mechanism. The novelty in this study is the compound diffusion mechanisms comparison through chitosan film (CF) and chitosan emulsion film. Initially, the lipid was selected to obtain the emulsion films. The evaluation was based on the water vapor permeability (WVP). The lower WVP (32.45% less than chitosan film) was found using 0.5 g/100 g of palmitic acid for 2.0 g/100 g of chitosan. Then, active chitosan films (ACF) were obtained incorporating K-sorbate on CF at 0.1 and 0.5 g/100 g of K-sorbate. Also, active palmitic acid-chitosan films (APEF) were obtained, incorporating 0.1 g/100 g of K-sorbate. The mechanisms of K-sorbate diffusion through ACF and APEF were mainly non-Fickian. However, the K-sorbate diffusion coefficient did not reduced in lipid presence. 相似文献
992.
Recently, a new nitriding process was proposed to produce the aluminum nitride on an aluminum surface using a barrel. After barrel nitriding, AlN nitride layer is formed on the aluminum surface and the surface hardness can be improved remarkably. In this study, barrel nitriding was performed to investigate the interface between aluminum substrate, with SUS304 austenitic stainless steel used for a physical catalyst. The barrel nitriding was carried out at 893 K for 18 ks, 25.2 ks and 36 ks, respectively with aluminum and aluminum–magnesium alloy powder. After barrel nitriding, aluminum nitride layer and Fe–Al intermetallic compound layers were formed at the interface between pure aluminum and austenitic stainless steel at the same time. The thickness of the aluminum nitride layer and intermetallic layer was increased by increasing the treatment time. 相似文献
993.
Synthesis and gas permeability of ABA‐type triblock copolymers derived from fluorine‐containing polyimide with polyhedral oligomeric silsesquioxane 下载免费PDF全文
Tsubasa Suzuki Akihiro Yoshida Shota Ando Kazukiyo Nagai 《Polymer International》2015,64(9):1209-1218
ABA‐type triblock copolymers derived from 4,4'‐(hexafluoroisopropylidene)diphthalicanhydride‐2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (6FDA‐TeMPD) and methacryl phenyl polyhedral oligomeric silsesquioxane (MPPOSS) were synthesized by atom transfer radical polymerization. The chemical structure of the synthesized ABA‐type triblock copolymer was confirmed by 1H NMR, 13C NMR, 29Si NMR and Fourier transform infrared analyses. The ratios of 6FDA‐TeMPD and MPPOSS determined by TGA were 94/6, 85/15, 77/23, 68/32, 57/43 and 31/69. The film density of the ABA‐type triblock copolymer films did not conform to the mixing rule because of polyimide (PI) chain aggregation. Based on contact angle and water uptake analyses, the hydrophobicity of the ABA‐type triblock copolymer film was determined to be higher than the theoretical value because of POSS cage effects and PI chain aggregation. The gas permeability coefficient of the ABA‐type triblock copolymer decreased compared with that of PI because of aggregation of PI chains and inhibition of solubility decreases by substitutes with high affinity. ABA‐type triblock copolymer CO2/H2 separation performance increased compared with that of PI. The ABA‐type triblock copolymer derived from PI and MPPOSS can be described as a polymer material with higher hydrophobicity and higher CO2/H2 selectivity than PI. © 2015 Society of Chemical Industry 相似文献
994.
Fernando Fresno Tomoaki Yoshida Nobuyuki Gokon Rocío Fernández-Saavedra Tatsuya Kodama 《International Journal of Hydrogen Energy》2010
In this work, we compare the activity of unsupported and monoclinic zirconia – supported nickel ferrites, calcined at two different temperatures, for solar hydrogen production by two-step water-splitting thermochemical cycles at low thermal reduction temperature. Commercial nickel ferrite, both as-received and calcined in the laboratory, as well as laboratory made supported NiFe2O4, are employed for this purpose. The samples leading to higher hydrogen yields, averaged over three cycles, are those calcined at 700 °C in each group (supported and unsupported) of materials. The comparison of the two groups shows that higher chemical yields are obtained with the supported ferrites due to better utilisation of the active material. Therefore, the highest activity is obtained with ZrO2-supported NiFe2O4 calcined at 700 °C. 相似文献
995.
M Arai H Imai T Koumura M Yoshida K Emoto M Umeda N Chiba Y Nakagawa 《Canadian Metallurgical Quarterly》1999,274(8):4924-4933
Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is synthesized as a long form (L-form; 23 kDa) and a short form (S-form; 20 kDa). The L-form contains a leader sequence that is required for transport to mitochondria, whereas the S-form lacks the leader sequence. A construct encoding the leader sequence of PHGPx tagged with green fluorescent protein was used to transfect RBL-2H3 cells, and the fusion protein was transported to mitochondria. The L-form of PHGPx was identified as the mitochondrial form of PHGPx and the S-form as the non-mitochondrial form of PHGPx since preferential enrichment of mitochondria for PHGPx was detected in M15 cells that overexpressed the L-form of PHGPx, whereas no similar enrichment was detected in L9 cells that overexpressed the S-form. Cell death caused by mitochondrial injury due to potassium cyanide (KCN) or rotenone (chemical hypoxia) was considerably suppressed in the M15 cells, whereas the L9 cells and control RBL-2H3 cells (S1 cells, transfected with the vector alone) succumbed to the cytotoxic effects of KCN. Flow cytometric analysis showed that mitochondrial PHGPx suppressed the generation of hydroperoxide, the loss of mitochondrial membrane potential, and the loss of plasma membrane integrity that are induced by KCN. Mitochondrial PHGPx might prevent changes in mitochondrial functions and cell death by reducing intracellular hydroperoxides. Mitochondrial PHGPx failed to protect M15 cells from mitochondrial injury by carbonyl cyanide m-chlorophenylhydrazone, which directly reduces membrane potential without the generation of hydroperoxides. M15 cells were more resistant than L9 cells to cell death caused by direct damage to mitochondria and to extracellular oxidative stress. L9 cells were more resistant to tert-butylhydroperoxide than S1 cells, whereas resistance to t-butylhydroperoxide was even more pronounced in M15 cells than in L9 cells. These results suggest that mitochondria might be a target for intracellular and extracellular oxidative stress and that mitochondrial PHGPx, as distinct form non-mitochondrial PHGPx, might play a primary role in protecting cells from oxidative stress. 相似文献
996.
Design method for a new control system for an autonomous underwater vehicle using linear matrix inequalities 总被引:1,自引:0,他引:1
Yohei Nasuno Etsuro Shimizu Masanori Ito Ikuo Yamamoto Satoshi Tsukioka Hiroshi Yoshida Tadahiro Hyakudome Shojiro Ishibashi Taro Aoki 《Artificial Life and Robotics》2007,11(2):149-152
The independent administrative corporation Japan Agency for Marine–Earth Science and Technology (JAMSTEC) has developed a
small light autonomous underwater vehicle (AUV) named marine robot experimental 1 (MR-X1).1 The motion control of MR-X1 is considered in this article. Since the dynamics of MR-X1 mainly depends on its own speed, the motion control is a nonlinear control system. We propose a new controller design method
for this system using linear matrix inequalities (LMIs). This algorithm gives a solution as a linear matrix inequality, and
can be adapted to solve many LMIs simultaneously. LMIs can be obtained by substituting several speeds into the dynamics of
the MR-X1. The proposed controller, which can be derived from the solution of the LMIs, was adapted to MR-X1 and showed good performance in experiments.
This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January
23–25, 2006 相似文献
997.
In this study, we investigate an inter-industrial and inter-regional recycling system for industrial waste by the cement industry in Japan. We develop a linear programming model that represents cement production processes and waste transportation of all cement factories in Japan. We simulate cost and CO2-minimizing systems. The result implies that making waste transportation more efficient in cost is an effective means for CO2 reduction. 相似文献
998.
Toshiaki Koike Hidekazu Murata Susumu Yoshida 《Wireless Personal Communications》2005,35(1-2):213-225
A trellis-coded multiple-input multiple-output (MIMO) transmission technique, which exploits multiple-antenna elements at
both transmitter and receiver sides and employs trellis-coded modulations (TCMs), has potential to significantly increase
spectral efficiency in wireless communications. At the receiver, an adaptive equalizer based on maximum-likelihood sequence
estimation (MLSE) deals with intersymbol interference (ISI) incurred in wideband transmissions and jointly decodes multiplexed
TCM signals. Recently, a sphere-constrained maximum-likelihood detection, so-called sphere decoding, has drawn much attention
for reducing the computational burden in MIMO transmission systems. This paper describes the super-trellis structured Viterbi
algorithm applying per-survivor sphere decoding, and evaluates the effect of the complexity reduction in branch metric computations.
Toshiaki Koike received the B.S. degree in electrical and electronics engineering and M.S. degree in communications and computer engineering
from Kyoto University, Kyoto, Japan, in 2002 and 2003, respectively. Since 2003, he has been working towards the Ph.D. degree
in communications and computer engineering, Kyoto University. His current research interest includes digital signal processing
for multiple-antenna systems and multi-user communications. He has been a Research Fellow of the JSPS since 2004.
Hidekazu Murata received B.S., M.S., and Ph.D. degrees in electronic engineering from Kyoto University, Kyoto, Japan, in 1991, 1993, and
2000, respectively. In 1993, he joined the Faculty of Engineering, Kyoto University. Since 2002, he has been an associate
professor of Tokyo Institute of Technology, Tokyo, Japan. His current research interests include signal processing and its
hardware implementation, with particular application to multihop radio networks. He received the Young Researcher's Award
from the IEICE of Japan in 1997 and the Ericsson Young Scientist Award in 2000. He is a member of the IEEE and SITA.
Susumu Yoshida received the B.E., M.E. and Ph.D. degrees in electrical engineering from Kyoto University, Kyoto, Japan in 1971, 1973 and
1978, respectively. Since 1973, he has been with the Faculty of Engineering, Kyoto University and currently he is a full professor
of the Graduate School of Informatics, Kyoto University. During the last two decades, he has been mainly engaged in the research
of wireless personal communications. His current research interest includes wireless transmission technologies beyond IMT-2000
and wireless ad hoc networks. During 1990–1991, he was a visiting scholar at WINLAB, Rutgers University, U.S.A. and Carleton
University in Canada. He served as an Executive Committee Chairperson of PIMRC'99, Osaka and also as a Technical Program Committee
Chairperson of IEEE VTC 2000-Spring, Tokyo. He was a guest editor of IEEE J-SAC on Wireless Local Communications published
in April and May 1996. He was a Director, Journal and Transactions of IEICE during 2002–2004 and has been a Fellow of the
IEICE since 2004. He was awarded the Young Researcher's Award in 1978 and the Achievement Award in 1993 both from the IEICE. 相似文献
999.
1000.
Nanbu K. Ozawa S. Yoshida K. Saijo K. Suga T. 《Components and Packaging Technologies, IEEE Transactions on》2005,28(4):760-764
A new cladding process has been developed using the surface activated bonding (SAB) method. In this process, the surfaces of materials to be bonded are cleaned, activated by Ar ion sputter etching, and immediately rolled together with low distortion at room temperature in a vacuum chamber . This process is applicable not only to cladding metals but also to laminating polymer film on metal without adhesives. We focused on laminating liquid crystal polymer (LCP) on copper (Cu) foil using the SAB method , which is different from other conventional methods . We also investigated the chemical state at the interface between the Cu foil and LCP film before and after heat treatment (up to 300/spl deg/C), by comparing with that on raw LCP film. All laminated materials were etched and cropped out, and the LCP surfaces were analyzed with X-ray photoelectron spectrometer (XPS). After the heat treatment, the ratio of C=O increased with increasing heat treatment temperature. It indicated that, under the high temperature of the heat treatment, the oxidation occurs not only at the Cu foil/sputtered Cu but also the LCP surfaces. We reported previously that the peel strength of laminated material made by the SAB method was improved by using Cu sputtering on the LCP film , . But after a heat-resistance test, the peel strength significantly decreased. This decrease resulted from the oxidation around the interface between the Cu foil/sputtered Cu and the LCP film due to gas permeation through the LCP film, and the softening of the Cu foil by its recrystallization due to high temperature. To prevent this loss of peel strength, we used Cu-0.02%Zr alloy foil with a higher recrystallization temperature and sputter Cu-Ni alloy or Ni-Cr alloy on the LCP film instead of Cu. It is also shown that the Cu/LCP materials produced by the SAB method have excellent electrical properties and etching ability. 相似文献