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81.
M. G. Burke M. Watanabe D. B. Williams J. M. Hyde 《Journal of Materials Science》2006,41(14):4512-4522
The characterization of the solute-enriched features (clusters or nanoprecipitates in irradiated low-alloy steels) requires extremely high spatial and elemental resolution, previously necessitating analysis using atom probe field-ion microscopy. In this investigation, field-emission gun-scanning transmission electron microscope (FEG-STEM) quantitative energy dispersive X-ray (EDX) microanalysis (spectrum imaging) has been applied to the characterization of the irradiation-induced nanoprecipitates in a low-alloy forging steel. Refinements in the EDX data have been possible via the application of multivariate statistical analysis (MSA) to the spectrum images, resulting in significantly reduced noise in the images. Most importantly, MSA permitted the clear identification of other elements in these Ni-enriched nanoprecipitates—including Mn and Cu. The processed X-ray spectrum images also provided direct evidence of the preferential formation of these irradiation-induced features along pre-existing dislocations within the steel, as well as the formation of intragranular nanoprecipitates. This research has provided the first direct X-ray spectrum images of irradiation-induced nanoprecipitates in high Ni A508 Gr4N forging steel, and has demonstrated the significant improvements attainable though the application of MSA techniques to the spectrum images. These results independently confirmed the analyses of the Ni-enriched nanoprecipitates previously conducted by 3D-APFIM, with the performance of the FEG-STEM/EDX technique shown to be comparable to that of the 3D-APFIM technique. 相似文献
82.
Comparisons of computed mobile phone induced SAR in the SAM phantom to that in anatomically correct models of the human head 总被引:1,自引:0,他引:1
Beard B.B. Kainz W. Onishi T. Iyama T. Watanabe S. Fujiwara O. Jianqing Wang Bit-Babik G. Faraone A. Wiart J. Christ A. Kuster N. Ae-Kyoung Lee Kroeze H. Siegbahn M. Keshvari J. Abrishamkar H. Simon W. Manteuffel D. Nikoloski N. 《Electromagnetic Compatibility, IEEE Transactions on》2006,48(2):397-407
The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, Sub-Committee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position. 相似文献
83.
Zuogui Zhang Yoshimi Watanabe Icksoo Kim Xiangfa Liu 《Metallurgical and Materials Transactions A》2005,36(13):837-844
Refining experiments were conducted to evaluate the grain refining performance of an Al−5Ti−0.25C refiner before and after
equal-channel angular pressing (ECAP) with the use of a high-purity Al. The results show that the Al−5Ti−0.25C refiner has
remarkable and stable grain refining performance when the holding times are within 5 to 30 minutes and the melt temperatures
are within 1003 to 1073 K. Furthermore, some Al−5Ti−0.25C refiner samples were subjected to severe plastic deformation by
using the ECAP technique at 298 K. It was found that Al3Ti and TiC particles were significantly fragmented and their mean sizes were decreased to 10 and 1.08 μm, respectively, and
the Al−5Ti−0.25C refiner appeared to have a double grain refining effect in comparison with that of before ECAP. It is also
testified that the Vickers microhardness (Hv) value of the pure Al samples refined by the Al−5Ti−0.25C refiner after ECAP
processing has a significant increment than that of before ECAP processing. It is concluded that the Al−5Ti−0.25C refiner
with ECAP technique has a very useful practical application in refining industrial Al alloys.
ZUOGUI ZHANG, formerly Master's Student, the Key Laboratory of Liquid Structure and Heredity of Material, Ministry of Education,
Shandong University, Jinan 250061, People's Republic of China 相似文献
84.
H. Ohyama K. Takakura T. Watanabe K. Nishiyama K. Shigaki T. Kudou M. Nakabayashi S. Kuboyama S. Matsuda C. Kamezawa E. Simoen C. Claey 《Journal of Materials Science: Materials in Electronics》2005,16(7):455-458
The impact of radiation damage on the device performance of 4H-SiC Schottky diodes, which are irradiated at room temperature with 2-MeV electrons is studied. After irradiation the reverse current increases, while the forward current and the capacitance decrease with barrier height and carrier density. The decrease of the barrier height is mainly responsible for the increase of the reverse current, while the decrease of the forward current for a high fluence is caused by the increase of the resistance in the bulk of the crystal. Although no electron capture levels are observed before irradiation, three electron capture levels (E1, E2, and E3) are induced after irradiation. It is noted that the decrease in carrier density is partly caused by the contribution of non-observed electron capture level in the DLT spectrum, which compensates the free carriers. 相似文献
85.
Sayaka Yanagida Yoshikazu Kameshima Toshiya Watanabe 《Materials Research Bulletin》2005,40(8):1335-1344
TiO2 (anatase) coating was prepared on stainless mesh by electrophoretic (EPD) process utilizing an isopropyl alcohol (IPA)-based suspension with submicron TiO2 powder. When the deposition time was 30 s, a smooth thin coating was obtained. It remained crack-free even after sintering. Coating surface morphology was roughened by UV pre-illumination of the suspension. Photocatalytic decomposition of IPA to acetone and resultant electrochemical reaction at cathode during EPD provides heterogeneous deposition. 相似文献
86.
Koliya Pulasinghe Keigo Watanabe Kiyotaka Izumi Kazuo Kiguchi 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2004,34(1):293-302
We present a methodology of controlling machines using spoken language commands. The two major problems relating to the speech interfaces for machines, namely, the interpretation of words with fuzzy implications and the out-of-vocabulary (OOV) words in natural conversation, are investigated. The system proposed in this paper is designed to overcome the above two problems in controlling machines using spoken language commands. The present system consists of a hidden Markov model (HMM) based automatic speech recognizer (ASR), with a keyword spotting system to capture the machine sensitive words from the running utterances and a fuzzy-neural network (FNN) based controller to represent the words with fuzzy implications in spoken language commands. Significance of the words, i.e., the contextual meaning of the words according to the machine's current state, is introduced to the system to obtain more realistic output equivalent to users' desire. Modularity of the system is also considered to provide a generalization of the methodology for systems having heterogeneous functions without diminishing the performance of the system. The proposed system is experimentally tested by navigating a mobile robot in real time using spoken language commands. 相似文献
87.
Recently, various control methods represented by proportional-integral-derivative (PID) control are used for robotic control.To cope with the requirements for high response and precision, advanced feedforward controllers such as gravity compensator,Coriolis/centrifugal force compensator and friction compensators have been built in the controller.Generally, it causes heavy computational load when calculating the compensating value within a short sampling period.In this paper, integrated recurrent neural networks are applied as a feedforward controller for PUMA560 manipulator.The feedforward controller works instead of gravity and Coriolis/centrifugal force compcusators.In the learning process of the neural network by using back propagation algorithm, the learning coefficient and gain of sigmoid function are tuned intuitively and empirically according to teaching signals.The tuning is complicated because it is being conducted by trial and error.Especially, when the scale of teaching signal is large, the problem becomes crucial.To cope with the problcm which concerns the learning performance, a simple and adaptive learning technique for large scale teaching signals is proposed.The learning techniques and control effectiveness are evaluated through simulations using the dynamic model of PUMA560 manipulator. 相似文献
88.
Y Kawano Y Takaue P Law T Watanabe T Abe Y Okamoto A Makimoto J Sato R Nakagawa T Kajiume A Hirao A Watanabe Y Kuroda 《Canadian Metallurgical Quarterly》1998,22(10):1011-1017
The quality of population-based cancer registries has been measured by the indices of the proportion of total incident cases (DCO%) registered by death certificate only (DCO), and the ratio of incidence to mortality (I/D ratio). Recently it has been recommended that DCO% should be used as an index for the reliability of diagnosing cancers and that the proportion of cases first notified via death certificate (DCN, DCN%) be used as an index for the completeness of registration. Parkin introduced a method to estimate the registration rate, the estimated proportion of the "true incidence" that are registered in population-based registries. We recommend a modified method for estimating the registration rate for cancer registries where DCN% is relatively high, as it is in Japan, as Parkin's method may overestimate the registration rate. The method is as follows: the registration rate = (1-DCN% x 1/D ratio)/(1-DCN%). The registration rates at the Osaka Cancer Registry between 1966 and 1992 were estimated using our method. During this period, the yearly registration rate was 74.6-78.4% for males and 69.1-73.3% for females. When the cancer cases were looked at according to site, the yearly registration rate was 74.2-81.6% for stomach cancer, 81.2-89.3% for lung cancer, and 71.3-76.9% for uterine cancer. These results show that the registration rate is high for cancers that have an unfavorable prognosis and low for cancers that have a favorable prognosis. We recommend that all cancer registries in Japan calculate the completeness of registration by utilizing DCN defined as the sum of DCO plus cases not reported as cancer but with supportive clinical information of such obtained through survey of the registry for DCN. 相似文献
89.
Uniform temperature cooling power measurements of a superfluid Stirling refrigerator are presented for3He-4He molar concentrations of 5.9%, 17% and 36% and for temperatures between 0.37 K and 1.4 K. The results are compared to an ideal Fermi gas model and to a more general thermodynamic model. The Fermi model agrees well with the 5.9% concentration data; however, the more elaborate model is needed for higher concentration mixtures. 相似文献
90.
Wei Zhang Kazuki Tainaka Seongyool Ahn Hiroaki Watanabe Toshiaki Kitagawa 《Advanced Powder Technology》2018,29(10):2322-2330
In this study, an experimental and a numerical investigations are performed to investigate the effect of particle’s shape and size distribution on its dispersion behavior. Firstly, particle dispersion of pulverized coal and spherical polymer particles is observed by Particle Image Velocimetry (PIV) technique in the experiment. Secondly, a simulation is performed to analyze the particle dispersion in detail. Spherical and spheroidal motion models are applied to particle’s movement to investigate the shape effect. Furthermore, monodisperse and polydisperse for particles are applied to investigate the size distribution effect on the dispersion. Experimental results show that in the jet turbulence flow, pulverized coal particles, which have complex shapes and various sizes, have quite different dispersion behavior compared to spherical particles. In terms of the results of the simulation, this difference is mainly caused by the size distribution effect. Although particle’s shape affects the dispersity, it is weakened by the size distribution effect. 相似文献