全文获取类型
收费全文 | 1399篇 |
免费 | 30篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 120篇 |
综合类 | 2篇 |
化学工业 | 228篇 |
金属工艺 | 38篇 |
机械仪表 | 31篇 |
建筑科学 | 32篇 |
能源动力 | 38篇 |
轻工业 | 116篇 |
水利工程 | 1篇 |
石油天然气 | 6篇 |
无线电 | 148篇 |
一般工业技术 | 189篇 |
冶金工业 | 313篇 |
原子能技术 | 27篇 |
自动化技术 | 143篇 |
出版年
2022年 | 9篇 |
2021年 | 23篇 |
2020年 | 5篇 |
2019年 | 12篇 |
2018年 | 22篇 |
2017年 | 16篇 |
2016年 | 28篇 |
2015年 | 19篇 |
2014年 | 29篇 |
2013年 | 59篇 |
2012年 | 48篇 |
2011年 | 49篇 |
2010年 | 50篇 |
2009年 | 47篇 |
2008年 | 52篇 |
2007年 | 45篇 |
2006年 | 46篇 |
2005年 | 50篇 |
2004年 | 35篇 |
2003年 | 40篇 |
2002年 | 29篇 |
2001年 | 34篇 |
2000年 | 32篇 |
1999年 | 47篇 |
1998年 | 130篇 |
1997年 | 80篇 |
1996年 | 39篇 |
1995年 | 50篇 |
1994年 | 34篇 |
1993年 | 24篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 20篇 |
1988年 | 15篇 |
1987年 | 7篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 14篇 |
1983年 | 17篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 20篇 |
1979年 | 9篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1970年 | 4篇 |
排序方式: 共有1432条查询结果,搜索用时 562 毫秒
61.
Yuta Nakamura Ryoichi Hara Hiroyuki Kita Kiyotaka Takeda 《Electrical Engineering in Japan》2019,207(3):23-34
Recent growth of renewable energy generations with natural variability, such as photovoltaic generation and wind turbine generation, would make the demand and supply control in a whole power system more difficult, and therefore, alternatives for demand and supply regulation resources would be required. The authors focus on cogeneration system (CGS) as one of regulation resources. In order to procure adequate volume of regulation capability, an aggregator coordinates a number of CGSs efficiently and flexibly considering the wide variety of electricity/thermal demands of CGS owners. This paper proposes a novel optimal operation strategy of CGS coordinated by the aggregator considering the energy balance and operation cost of individual CGS owner. This paper also demonstrates the availability of CGSs for regulation capability by numerical case studies in which the actual consumption profile is employed. 相似文献
62.
Metallic colors have a unique appearance of glossiness with features such as highlights, contrast, and reflections on their surface, and therefore, metallic objects are very attractive to humans. Especially, gold, silver, and copper colors are familiar metals used as decorative materials, coins, and other furnishings. However, the mechanism and condition of metallic perception have not been fully investigated. There are a few studies for investigating metallic perception using rendered patches or images, but there is no study using real‐world objects. In our previous study, we developed a simple representation technique that made real objects appear to be made of gold by projecting a solid color onto a target nonmetallic object. By using the representation technique, in this study, we have further investigated the perception of metallic appearance such as gold, silver, and copper using real‐world materials, and analyzed the difference between these metallic perceptions. Our results indicate that the perception of the metallic object is different for gold, silver, and copper. Our new findings are as follows: the glitter required for the perception of gold and silver becomes an obstacle to the perception of copper; the metallic perception reveals that learning experience might be strongly affecting; and luminance adjustment is sensitive to the perception of metallic objects. 相似文献
63.
Operation Assist by Vibration Suppression Control Using Impulse‐Shaped Signals for Power Assist Conveyance System
下载免费PDF全文
![点击此处可从《Electrical Engineering in Japan》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yuichi Yamamoto Masaki Uchida Yoshifumi Morita Susumu Hara 《Electrical Engineering in Japan》2014,186(2):31-39
This paper presents an assist control method for a flexible parts conveyance task using a power assist conveyance system. The assist control method should be designed so as not only to suppress vibration but also to reduce the degradation of operating feel. For this purpose, multiple impulse‐shaped signals are used as feedforward signals in order to reduce the vibration of flexible parts during conveyance. In addition, the adjustment time is introduced to adjust the input timing of the impulse‐shaped signal and to suppress vibration. In order to improve the degradation of operating feel, the smaller amplitudes of the three impulse‐shaped signals are used and input repeatedly. The effectiveness of the proposed system was verified experimentally. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(2): 31–39, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22476 相似文献
64.
Midori Takasaki Kentaro Hara Yutaka Ohkoshi Takayuki Fujii Hiroyasu Shimizu Masaharu Saito 《Polymer Engineering and Science》2014,54(11):2605-2609
Thermoplastic polyurethane fiber webs were prepared using a laser‐heated electrospinning process combined with air blowing. The effect of spinning conditions such as air flow rate and air temperature on fiber diameter and molecular weight was investigated. Although the average fiber diameter decreased with increased air flow rate at each air temperature, the diameter increased when the air flow rate was >15 NL min?1. In addition, the fiber was comparatively thicker with an increase in the air temperature. The variation in the fiber diameter tends to increase with the air flow rate, and a reduction in the molecular weight of the fiber by thermal degradation was suppressed. The thinnest and most uniform fiber with a diameter of 0.9 µm and a diameter coefficient variation of 15% was obtained at an air temperature of 25°C under an air flow rate of 15 NL min?1. This fiber also had a minimum of decreased molecular weight. POLYM. ENG. SCI., 54:2605–2609, 2014. © 2013 Society of Plastics Engineers 相似文献
65.
Toshihiro Takaine Mutsumi Tashiro Takahiko Shiina Toshihiro Noda Akira Asaoka 《Soils and Foundations》2010,50(2):245-260
The continuous behaviour of a ground-embankment system from the stage of deformation up to failure was predicted with respect to an actual test embankment that had been constructed in stages on a soft ground made up of peat and calcareous soil. The behaviour prediction was carried out by employing soil-water coupled finite deformation analysis, which also included simulation of the embankment construction process. The information used in the analysis was limited to such things as the results of soil tests on soil materials (peat and calcareous soil) sampled from the ground, including their sensitivity ratios, and the embankment's construction history. The SYS Cam-clay model was used in the constitutive equations of the soils to determine the material constants of the soils and the initial conditions of the ground, and the computations were performed under plane strain conditions. As a result, the computed profiles of W-type ground settlement and of slip surfaces running through the embankment were found to be in good overall agreement with the actual profiles measured at the site. Furthermore, we found that this slippage is attributable to the undrained shear response of the soil elements in the calcareous soil layer, where slippage begins to occur during embankment loading. In other words, the slippage is caused by the rapid softening behaviour caused by the degradation of structure after the effective stress ratio reaches the vicinity of the critical state line. 相似文献
66.
We review our recent work on spatial inhomogeneity of the electronic states in the strongly correlated molecular conductors κ-(BEDT-TTF)2X. Spatial mapping of infrared spectra (SMIS) is used for imaging the distribution of the local electronic states. In molecular materials, the infrared response of the specific molecular vibration mode with a strong electron–molecular vibration coupling can reflect the electronic states via the change in the vibration frequency. By spatially mapping the frequency shift of the molecular vibration mode, an electronic phase separation has been visualized near the first-order Mott transition in the bandwidth-controlled organic conductor κ-(BEDT-TTF)2Cu[N(CN)2]Br. In addition to reviewing SMIS of the phase separation, we briefly mention the electronic and optical properties of κ-(BEDT-TTF)2X. 相似文献
67.
We evaluated the effects of seven mushroom extracts (Grifola frondosa, Pholiota nameko, Panellus serotinus, Hypsizygus marmoreus, Pleurotus cornucopiae, Armillaria mellea, and Flammulina velutipes) on cytotoxic activity and cytokine production of lamina propria leukocytes (LPLs) isolated from rat small (S) and large (L) intestinal mucosa. Boiling water extracts from seven species of mushrooms showed no direct cytotoxicity against the YAC-1 target cells. However, prominent increases of cytotoxicity were observed in S- and L-LPLs co-cultured with P. serotinus extract. Cytokine production (TNFα, IFNγ, IL-12 p70, and IL-4) of S- and L-LPLs was stimulated in response to P. cornucopiae extract. Mushroom extracts contributed to target cell adhesion and/or cytokine production in the effector cells. The promotion of cytotoxic activity in S- and L-LPLs was not necessarily related to β-glucan content of the mushroom. 相似文献
68.
Ming Zhou Hidetaka Hara Yifan Dai Lisha Mou David K. C. Cooper Changyou Wu Zhiming Cai 《International journal of molecular sciences》2016,17(8)
Different cell types possess different miRNA expression profiles, and cell/tissue/organ-specific miRNAs (or profiles) indicate different diseases. Circulating miRNA is either actively secreted by living cells or passively released during cell death. Circulating cell/tissue/organ-specific miRNA may serve as a non-invasive biomarker for allo- or xeno-transplantation to monitor organ survival and immune rejection. In this review, we summarize the proof of concept that circulating organ-specific miRNAs serve as non-invasive biomarkers for a wide spectrum of clinical organ-specific manifestations such as liver-related disease, heart-related disease, kidney-related disease, and lung-related disease. Furthermore, we summarize how circulating organ-specific miRNAs may have advantages over conventional methods for monitoring immune rejection in organ transplantation. Finally, we discuss the implications and challenges of applying miRNA to monitor organ survival and immune rejection in allo- or xeno-transplantation. 相似文献
69.
70.
Mina Han Ikue Abe Jihun Oh Jaehoon Jung Young Ji Son Jaegeun Noh Mitsuo Hara Takahiro Seki 《International journal of molecular sciences》2022,23(2)
Fluorescent molecular assembly systems provide an exciting platform for creating stimuli-responsive nano- and microstructured materials with optical, electronic, and sensing functions. To understand the relationship between (i) the plausible molecular structures preferentially adopted depending on the solvent polarity (such as N,N-dimethylformamide [DMF], tetrahydrofuran [THF], and toluene), (ii) the resulting spectroscopic features, and (iii) self-assembled nano-, micro-, and macrostructures, we chose a sterically crowded triangular azo dye (3Bu) composed of a polar molecular core and three peripheral biphenyl wings. The chromophore changed the solution color from yellow to pink-red depending on the solvent polarity. In a yellow DMF solution, a considerable amount of the twisted azo form could be kept stable with the help of favorable intermolecular interactions with the solvent molecules. By varying the concentration of the DMF solution, the morphology of self-assembled structures was transformed from nanoparticles to micrometer-sized one-dimensional (1D) structures such as sticks and fibers. In a pink-red toluene solution, the periphery of the central ring became more planar. The resulting significant amount of the keto-hydrazone tautomer grew into micro- and millimeter-sized 1D structures. Interestingly, when THF-H2O (1:1) mixtures were stored at a low temperature, elongated fibers were stacked sideways and eventually developed into anisotropic two-dimensional (2D) sheets. Notably, subsequent exposure of visible-light-irradiated sphere samples to solvent vapor resulted in reversible fluorescence off↔on switching accompanied by morphological restoration. These findings suggest that rational selection of organic dyes, solvents, and light is important for developing reusable fluorescent materials. 相似文献