全文获取类型
收费全文 | 498篇 |
免费 | 11篇 |
专业分类
电工技术 | 12篇 |
综合类 | 1篇 |
化学工业 | 152篇 |
金属工艺 | 4篇 |
机械仪表 | 8篇 |
建筑科学 | 5篇 |
能源动力 | 16篇 |
轻工业 | 113篇 |
水利工程 | 2篇 |
无线电 | 43篇 |
一般工业技术 | 62篇 |
冶金工业 | 57篇 |
原子能技术 | 11篇 |
自动化技术 | 23篇 |
出版年
2023年 | 4篇 |
2022年 | 13篇 |
2021年 | 16篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 17篇 |
2015年 | 6篇 |
2014年 | 18篇 |
2013年 | 17篇 |
2012年 | 29篇 |
2011年 | 26篇 |
2010年 | 15篇 |
2009年 | 20篇 |
2008年 | 30篇 |
2007年 | 18篇 |
2006年 | 14篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 10篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 22篇 |
1997年 | 21篇 |
1996年 | 12篇 |
1995年 | 6篇 |
1994年 | 14篇 |
1993年 | 13篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 9篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 5篇 |
排序方式: 共有509条查询结果,搜索用时 15 毫秒
71.
H. Ohtsuka M. Sakamoto K. Tsutsui Y. Yazawa 《Progress in Photovoltaics: Research and Applications》2000,8(4):385-390
We introduced a triode structure with p–n junctions on both sides into single‐crystalline bifacial silicon solar cells in order to improve solar cell performance. These fabricated bifacial silicon solar cells have an energy conversion efficiency of 21·3% under front 1 sun illumination (the standard 1 kW/m2 AM 1·5 global spectrum at 25°C) and 19·8% under rear 1 sun illumination tested at the Japan Quality Assurance Organization. The total of the front and rear conversion efficiencies is the highest ever reported for bifacial silicon solar cells. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
72.
Hiroko Uchida 《Color research and application》1998,23(4):202-209
With the advent of fluorescent whitening agents, the general idea of whiteness has changed. Numerous whiteness formulas by which we evaluate whiteness of white materials have been proposed, but these formulas (including the CIE whiteness formula) were found not to correlate well to visual estimation. In this article, a modified CIE whiteness formula dealing with the tint and the excitation purity is proposed. There is a significant correlation between this formula and the visual estimation of whiteness. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23, 202–209, 1998 相似文献
73.
74.
Takuya Tsutsui Masahiko Natsuhara Kaoru Yamada Yoshiaki Tanizawa 《Journal of surfactants and detergents》2007,10(1):53-59
The cooking of oil-containing food products at high temperatures results in an insoluble, unsightly, greasy layer of grime
on appliance surfaces in residential and commercial kitchens. Over time, adsorbed grime becomes difficult to remove using
normal dishwashing detergents. A number of studies have focused on the deterioration and oxidation of oils and the harmful
effects that volatile compounds associated with such processes have on human health. Little attention, however, has been paid
to kitchen grime. The present study examined grime obtained from the surfaces of appliances such as sirocco fans, filters,
and range hoods in residential kitchens in Tokyo. The grime was characterized by X-ray fluorescence spectroscopy (XRF), Fourier-transform
infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), thermal hydrolysis methylation–gas chromatography–mass
spectroscopy (THM–GCMS), and nuclear magnetic resonance (NMR) techniques. The chemical composition and structure of the grime
differed from those of the edible oils. The grime consisted mainly of polymerized and oxidized triacylglycerols. Bridging
between unsaturated acyl groups of triglycerols occurred through thermal oxidation and aging in air, yielding their dimers,
trimers, and highly polymerized products while also transforming unsaturated acyl groups into saturated ones. Cross-linking
reactions involving dibasic acids also caused polymerization. Those polymerized products strongly adhered to the hard surfaces
of the appliances. Small amounts of cellulose fibers from air or towel may also play a role in mechanically stabilizing the
dirt structure.
相似文献
Yoshiaki TanizawaEmail: |
75.
A novel all‐polymer light modulator with a gel‐in‐gel system was developed. The gel‐in‐gel system was constructed with colored gel particles responsive to stimuli held independently in another stimuli‐nonresponsive gel matrix. Well‐known thermoresponsive N‐isopropylacrylamide (NIPAM) gel particles containing a pigment were dispersed and fixed in an outer stimuli‐nonresponsive gel matrix. When poly(vinyl alcohol)–styrylpyridinium (PVA–SbQ) was used for the outer gel matrix, the light modulator showed excellent color‐changing properties because the PVA–SbQ matrix was selectively formed around the NIPAM gel particles and the particles exhibited a large volume change in the matrix. The temperature when the outer gel matrix was formed affected the haze of the light modulator. When the outer gel matrix was formed in the swollen state of the NIPAM gels, the haze of a light modulator increased with heating. On the contrary, the haze of a light modulator prepared in the shrunken state of the NIPAM gels decreased with heating. The response time of the color change was less than 1 s. The gel‐in‐gel system made a very fast macroscopic color change, taking advantage of the fast response of the micrometer‐sized gel particles. We believe that a light modulator with a gel‐in‐gel system may find various applications in optical devices. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2295–2303, 2007 相似文献
76.
Thin-films and organic field-effect transistors fabricated from a solution-processable precursor of zinc tetrabenzoporphyrin (ZnTBP) are reported. Amorphous, insulating precursor films were deposited by spin-casting and thermally converted into polycrystalline, semiconducting thin-films comprising grains on the order of 5 μm in diameter. Thin-film X-ray diffraction indicates a monoclinic unit cell with molecules arranged in a herringbone pattern, which in conjunction with optical and atomic force microscopy indicate a thin-film with grains comprised of randomly oriented ZnTBP aggregates. Optical absorption measurements display broad absorption with bands characteristic of a D4h symmetric porphyrin molecule. Organic field-effect transistors displayed field-effect mobilities on the order of 10− 2 cm2/V s and ON-/OFF-current ratios exceeding 102. 相似文献
77.
78.
79.
Tsuruoka T Kawasaki H Nawafune H Akamatsu K 《ACS applied materials & interfaces》2011,3(10):3788-3791
We report a novel approach for synthesizing inorganic nanoparticle/metal-organic frameworks (MOFs) heterostructured nanocomposites by self-assembly of MOFs on nanoparticles. This approach involves the synthesis of Au nanoparticles and preferential growth of [Cu(3)(btc)(2)](n) frameworks consisting of Cu(2+) ions and benzene-1,3,5-tricarboxylate (btc) on nanoparticles. Aggregates consisting of 11-mercaptoundecanoic acid (MUA)-stabilized Au nanoparticles linked by Cu(2+) ions were necessary for preferential self-assembly of [Cu(3)(btc)(2)](n) frameworks on the aggregates, resulting in the formation of Au nanoparticles/[Cu(3)(btc)(2)](n) nanocomposites. The present approach was confirmed to be applicable for other hybrids consisting of Au nanoparticles and tetragonal [Cu(2)(ndc)(2)(dabco)](n) frameworks. 相似文献
80.
Y. Iwata S. Yamada T. Fujimoto H. Ogawa K. Yamamoto Y. Sakamoto T. Takeuchi H. Tsutsui T. Ueda 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2008,266(10):2150-2156
A compact injector for a heavy-ion medical-accelerator complex was developed. It consists of an electron-cyclotron-resonance ion-source (ECRIS) and two linacs, which are a radio-frequency-quadrupole (RFQ) linac and an Interdigital H-mode drift-tube-linac (IH-DTL). Beam acceleration tests of the compact injector were performed, and the designed beam quality was verified by the measured results, as reported earlier. Because the method of alternating-phase-focusing (APF) was used for beam focusing of the IH-DTL, the motion of beam ions would be sensitive to gap-voltage errors, caused during tuning of the gap-voltage distribution and by automatic-frequency tuning in actual operation. To study the effects of voltage errors to beam quality, further measurements were performed during acceleration tests. In this report, the effects of voltage errors for the APF IH-DTL are discussed. 相似文献