全文获取类型
收费全文 | 1192篇 |
免费 | 36篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 99篇 |
综合类 | 2篇 |
化学工业 | 296篇 |
金属工艺 | 43篇 |
机械仪表 | 32篇 |
建筑科学 | 26篇 |
矿业工程 | 1篇 |
能源动力 | 96篇 |
轻工业 | 64篇 |
水利工程 | 6篇 |
石油天然气 | 6篇 |
无线电 | 97篇 |
一般工业技术 | 283篇 |
冶金工业 | 21篇 |
原子能技术 | 64篇 |
自动化技术 | 101篇 |
出版年
2022年 | 14篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 16篇 |
2018年 | 18篇 |
2017年 | 12篇 |
2016年 | 30篇 |
2015年 | 15篇 |
2014年 | 25篇 |
2013年 | 59篇 |
2012年 | 55篇 |
2011年 | 61篇 |
2010年 | 57篇 |
2009年 | 58篇 |
2008年 | 55篇 |
2007年 | 55篇 |
2006年 | 46篇 |
2005年 | 40篇 |
2004年 | 47篇 |
2003年 | 38篇 |
2002年 | 46篇 |
2001年 | 32篇 |
2000年 | 44篇 |
1999年 | 31篇 |
1998年 | 28篇 |
1997年 | 17篇 |
1996年 | 25篇 |
1995年 | 22篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 13篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 21篇 |
1983年 | 18篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1971年 | 2篇 |
排序方式: 共有1237条查询结果,搜索用时 31 毫秒
31.
Takashi Noji Yoji Koike Hideo Iwasaki Masatsune Kato Norio Kobayashi Yoshitami Saito 《Journal of Superconductivity and Novel Magnetism》1996,9(1):65-71
Anisotropie properties of the single crystal Pb2Sr2Ho0.5Ca0.5Cu3O8 have been investigated by measuring the electrical resistivity in theab-planeρ ab (H, θ,T), which depends on the angleθ between theab-plane and the magnetic-field direction, in various constant fieldsH perpendicular to the current direction. All the angle-dependent values ofρ ab (H, θ,T) at a constant temperature are scaled to be on one curve as a function of reduced field. The anisotropic parameter γ≡(m c * /m ab * )1/2 is estimated as 12–13, which is larger than that of YBa2Cu3O7 and much smaller than that of Bi2Sr2CaCu2O8. It has been concluded that the anisotropy does not always depend on the thickness of the blocking layer but seems to depend on the overlap of the electronic wave functions along thec-axis. Anisotropy in the pinning potential has also been discussed from the resistive tail in the temperature dependence ofρ ab (H,θ,T). 相似文献
32.
33.
Kikuta K Tochigi N Saito S Shimoda T Morioka H Toyama Y Hosono A Suehara Y Beppu Y Kawai A Hirohashi S Kondo T 《Proteomics. Clinical applications》2010,4(5):560-567
Purpose : We aimed to identify novel chemotherapy responsiveness biomarkers for osteosarcoma (OS) by investigating the global protein expression profile of 12 biopsy samples from OS patients. Experimental design : Six patients were classified as good responders and six as poor responders, according to the Huvos grading system. The protein expression profiles obtained by 2‐D DIGE consisted of 2250 protein spots. Results : Among them, we identified 55 protein spots whose intensity was significantly different (Bonferroni adjusted p‐value<0.01) between the two patient groups. Mass spectrometric protein identification demonstrated that the 55 spots corresponded to 38 distinct gene products including peroxiredoxin 2 (PRDX 2). Use of a specific antibody against PRDX 2 confirmed the differential expression of PRDX 2 between good and poor responders, while PRDX 2 levels as measured by Western blotting correlated highly with their corresponding 2‐D DIGE values. The predictive value of PRDX 2 expression was further confirmed by examining an additional four OS cases using Western blotting. Conclusions and clinical relevance : These results establish PRDX 2 as a candidate for chemotherapy responsiveness marker in OS. Measuring PRDX 2 in biopsy samples before treatment may contribute to more effective management of OS. 相似文献
34.
Takashi Ijiri Kenshi Takayama Hideo Yokota Takeo Igarashi 《Computer Graphics Forum》2009,28(7):1821-1828
Animations of characters with flexible bodies such as jellyfish, snails, and, hearts are difficult to design using traditional skeleton‐based approaches. A standard approach is keyframing, but adjusting the shape of the flexible body for each key frame is tedious. In addition, the character cannot dynamically adjust its motion to respond to the environment or user input. This paper introduces a new procedural deformation framework (ProcDef) for designing and driving animations of such flexible objects. Our approach is to synthesize global motions procedurally by integrating local deformations. ProcDef provides an efficient design scheme for local deformation patterns; the user can control the orientation and magnitude of local deformations as well as the propagation of deformation signals by specifying line charts and volumetric fields. We also present a fast and robust deformation algorithm based on shape‐matching dynamics and show some example animations to illustrate the feasibility of our framework. 相似文献
35.
Local dimming light‐guiding plate type backlight system using alignment‐controlled polymer‐dispersed liquid crystals 下载免费PDF全文
Eri Uchida Takahiro Ishinabe Hideo Fujikake 《Journal of the Society for Information Display》2017,25(4):258-265
A new technology which enables a local brightness control according to the displayed images has been expected in the thin and lightweight backlight systems to improve a contrast ratio and power consumption of the liquid crystal displays (LCDs). In this paper, we have proposed a novel local‐dimming backlight system using alignment‐controlled polymer‐dispersed liquid crystals as a light‐guiding plate and investigated the forming conditions of polymer‐dispersed liquid crystals to achieve both a high‐luminance ratio and a fast response speed. As a result, we found that a luminance ratio and response speed of the backlight system can be improved by using bifunctional LC monomer materials and forming fine and rigid polymer network in the LCs, and achieved high luminance ratio of 16:1 and fast response time less than 0.5 ms. In addition, we fabricated the twisted nematic‐mode LCD using the local dimming light‐guiding plate‐type backlight based on this design, and successfully realized eight times higher contrast ratio than that of the traditional twisted nematic‐mode LCD. 相似文献
36.
Since a pairwise comparison matrix in the Analytic Hierarchy Process (AHP) is based on human intuition, the given matrix will always include inconsistent elements violating the transitivity property. We propose the Interval AHP by which interval weights can be obtained. The widths of the estimated interval weights represent inconsistency in judging data. Since interval weights can be obtained from inconsistent data, the proposed Interval AHP is more appropriate to human judgment. Assuming crisp values in a pairwise comparison matrix, the interval comparisons including the given crisp comparisons can be obtained by applying the Linear Programming (LP) approach. Using an interval preference relation, the Interval AHP for crisp data can be extended to an approach for interval data allowing to express the uncertainty of human judgment in pairwise comparisons. 相似文献
37.
Hideo Yoshioka 《Journal of Low Temperature Physics》2006,142(3-4):507-510
The magnetic susceptibility χ(T) in normal states of the quasi-one-dimensional (Q1D) superconductor is calculated by using
the N-chain renormalization group technique developed newly. For temperatures above T
cross
being of the order of the interchain hopping t┴, χ(T) of QID system agrees with that of one-dimensional systems. For temperatures
below T
cross
where the Fermi liquid state is expected, it is found that dχ(T)/dT>0 in contrast to the case of the normal Fermi liquid, i.e., dχ(T)/dT=0. The origin of such a “pseudo-gap like” behavior is discussed in terms of antiferromagnetic spin fluctuations. 相似文献
38.
Applying the concept of materials design for transparent conductive oxides to layered oxychalcogenides, several p-type and n-type layered oxychalcogenides were proposed as wide-gap semiconductors and their basic optical and electrical properties were examined. The layered oxychalcogenides are composed of ionic oxide layers and covalent chalcogenide layers, which bring wide-gap and conductive properties to these materials, respectively. The electronic structures of the materials were examined by normal/inverse photoemission spectroscopy and energy band calculations. The results of the examinations suggested that these materials possess unique features more than simple wide-gap semiconductors. Namely, the layered oxychalcogenides are considered to be extremely thin quantum wells composed of the oxide and chalcogenide layers or 2D chalcogenide crystals/molecules embedded in an oxide matrix. Observation of step-like absorption edges, large band gap energy and large exciton binding energy demonstrated these features originating from 2D density of states and quantum size effects in these layered materials. 相似文献
39.
Youichi Ogo Kenji Nomura Hiromichi Ohta Masahiro Hirano Hideo Hosono 《Thin solid films》2006,496(1):64-69
A reactive solid-phase epitaxy (R-SPE) method combines deposition of a thick amorphous or polycrystalline layer with a desired chemical composition and post-deposition solid-phase epitaxial growth. The solid-phase epitaxial growth is invoked by thermal annealing with an assistance of a sacrificial layer working as an epitaxial template. Thereby it enables us to grow high-quality epitaxial films of complex oxides whose epitaxial films are not grown by conventional high-temperature growth techniques. It was reported that 2-nm-thick ZnO layers worked as template for growing InGaO3(ZnO)m (m = integer) epitaxial films. The present study extended the R-SPE technique to growth of various complex oxides with chemical compositions of RAO3(MO)m and to use of various epitaxial template layers. We found that mono oxide epitaxial layers such as In2O3 and Ga2O3 work as template layers as well. Alternatively, a ZnO epitaxial layer is also applicable to ZnO-free compounds. The films obtained were grown heteroepitaxially on YSZ(111) and single-crystalline when the fabrication conditions are optimized. 相似文献
40.
The generalization ability of feedforward neural networks (NNs) depends on the size of training set and the feature of the training patterns. Theoretically the best classification property is obtained if all possible patterns are used to train the network, which is practically impossible. In this paper a new noise injection technique is proposed, that is noise injection into the hidden neurons at the summation level. Assuming that the test patterns are drawn from the same population used to generate the training set, we show that noise injection into hidden neurons is equivalent to training with noisy input patterns (i.e., larger training set). The simulation results indicate that the networks trained with the proposed technique and the networks trained with noisy input patterns have almost the same generalization and fault tolerance abilities. The learning time required by the proposed method is considerably less than that required by the training with noisy input patterns, and it is almost the same as that required by the standard backpropagation using normal input patterns. 相似文献