全文获取类型
收费全文 | 1276篇 |
免费 | 43篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 93篇 |
综合类 | 4篇 |
化学工业 | 375篇 |
金属工艺 | 47篇 |
机械仪表 | 41篇 |
建筑科学 | 37篇 |
能源动力 | 56篇 |
轻工业 | 106篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 76篇 |
一般工业技术 | 259篇 |
冶金工业 | 72篇 |
原子能技术 | 32篇 |
自动化技术 | 123篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 32篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 27篇 |
2017年 | 17篇 |
2016年 | 30篇 |
2015年 | 27篇 |
2014年 | 48篇 |
2013年 | 77篇 |
2012年 | 71篇 |
2011年 | 110篇 |
2010年 | 53篇 |
2009年 | 71篇 |
2008年 | 83篇 |
2007年 | 71篇 |
2006年 | 48篇 |
2005年 | 57篇 |
2004年 | 55篇 |
2003年 | 43篇 |
2002年 | 31篇 |
2001年 | 37篇 |
2000年 | 18篇 |
1999年 | 21篇 |
1998年 | 21篇 |
1997年 | 20篇 |
1996年 | 17篇 |
1995年 | 14篇 |
1994年 | 24篇 |
1993年 | 21篇 |
1992年 | 8篇 |
1991年 | 16篇 |
1990年 | 12篇 |
1989年 | 18篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有1328条查询结果,搜索用时 46 毫秒
231.
Hiroko Ohuchi-Yoshida Yuji Hatano Yasushi Kino Yasuhiro Kondo 《Fusion Engineering and Design》2012,87(5-6):423-426
A method to detect tritium non-destructively in regions deeper than the escape depth of beta rays is being developed using bremsstrahlung induced by beta rays with an imaging plate (IP). An IP made of europium-doped BaFBr(I), a photostimulated luminescence (PSL) material, is a two-dimensional radiation sensor. The bremsstrahlung energy spectrum is a continuum with photon energies, varying based on the atomic number and thickness of the target (or absorbing) material. When tritium migrates into matter, the bremsstrahlung energy spectrum distribution would change. The PSL intensity of the IP is affected by this energy spectrum variation. In order to quantify the amount of tritium in deeper regions with the IP technique, a tritium depth profile is required.In this study, a new method of obtaining a tritium depth profileusing the combined technique of the IP and thin absorbers is presented. 相似文献
232.
Serum uric acid concentration due to Gnetum gnemon chip supplementation and quality changes analyses based on its chemical constituents in post‐frying process
下载免费PDF全文
![点击此处可从《Journal of Food Processing and Preservation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
233.
Toshiisa Konishi Shuhei Takahashi Zhi Zhuang Kohei Nagata Minori Mizumoto Michiyo Honda Yasuhiro Takeuchi Hitomi Matsunari Hiroshi Nagashima Mamoru Aizawa 《Journal of materials science. Materials in medicine》2013,24(6):1383-1394
Novel biodegradable β-tricalcium phosphate (β-TCP) cements with anti-washout properties were created on the basis of chelate-setting mechanism of inositol phosphate (IP6) using β-TCP powders. The β-TCP powders were ball-milled using ZrO2 beads for 0–6 h in the IP6 solutions with concentrations from 0 to 10,000 ppm. The chelate-setting β-TCP cement with anti-washout property was successfully fabricated by mixing the β-TCP powder ball-milled in 3,000 ppm IP6 solution for 3 h and 2.5 mass% Na2HPO4 solution, and compressive strength of the cement was 13.4 ± 0.8 MPa. An in vivo study revealed that the above cement was directly in contact with host and newly formed bones without fibrous tissue layers, and was resorbed by osteoclast-like cells on the surface of the cement. The chelate-setting β-TCP cement with anti-washout property is promising for application as a novel injectable artificial bone with both biodegradability and osteoconductivity. 相似文献
234.
Yasuhiro Yamada Hajime Yasuda Kazumasa Murota Masashi Nakamura Toshiaki Sodesawa Satoshi Sato 《Journal of Materials Science》2013,48(23):8171-8198
X-ray photoelectron spectroscopy (XPS) is among the most powerful methods to determine the surface chemical properties of carbon materials. Because heat-treated graphite oxide includes various defects, analyses of the structure by XPS help us understand the structures of various carbon materials. Thus, XPS spectra of graphene-related materials containing various functional groups and other defects on edges and in the basal plane were simulated and full width at half maximums (FWHMs) and peak shifts were obtained by density functional theory calculation. Shifts of whole C1s spectra were influenced by the electron-withdrawing functional groups such as C=O-containing functional groups. FWHMs of the main peak of C1s spectra were influenced by mainly electron-withdrawing functional groups in addition to defects such as vacancy, pentagons, and heptagons. Analyses using only XPS provide us limited information, even though the peak tops and FHWMs of simulated XPS spectra are used for assignment. Combination use of peak shifts and FWHMs of XPS spectra, infrared spectroscopy, and density functional theory calculation provided more reliable assignments of defects including oxygen-containing functional groups of carbon materials than commonly used methods using only peak shifts of XPS spectra. 相似文献
235.
236.
237.
There have been several studies on biopolymer synthesis under hydrothermal conditions. The conventional hydrothermal methods
make it possible to synthesize only a dipeptide and short oligopeptides as well as cyclo-dimer, from amino acids. As these
studies that were applied with various quenching methods suggested the importance of quenching rate from hydrothermal conditions,
rapid quenching could avoid hydrolysis of the oligomers that had already been synthesized under hydrothermal conditions. In
this study, therefore, we designed a novel hydrothermal flow reactor adopted with adiabatic expansion cooling system from
the reason that it was thought to be one of the most rapid quenching methods. It mimics geysers, fumaroles, hot springs, and
volcanic eruptions. Once aqueous solutions of monomers were treated at high temperature and pressure, the solutions were released
into the atmosphere through an orifice to be depressurized and cooled down simultaneously with the Joule–Thomson effect. We
demonstrated oligomerization of glycine up to decamer (Gly10) by using the flow reactor, which had never been yielded with any other quenching methods. This suggests that rapid quenching
methods under non-equilibrium conditions such as adiabatic expansion cooling is an efficient way to produce long oligomers
connected by covalent bonds via dehydration condensation. 相似文献
238.
Oxygen-impurity boron-doped hydrogenated microcrystalline silicon (p-μc-Si:Ox:H) films have been deposited using catalytic chemical vapor deposition (Cat-CVD). Pure silane (SiH4), hydrogen (H2), oxygen (O2), and diluted diborane (B2H6) gases were used. The tungsten catalyst temperature (Tfil) was varied from 1900 to 2100 °C and films were deposited on glass substrates at temperatures of 100 to 300 °C. Different catalyst-to-substrate distances were employed and single- or double-coiled filaments were used. In addition to p-μc-Si:Ox:H deposition, we have also deposited conventional p-type microcrystalline silicon (p-μc-Si:H) in order to compare their electrical and optical properties to p-μc-Si:Ox:H. 相似文献
239.
ABSTRACT: Anodic aluminum oxide (AAO) templates are used to fabricate arrays of poly(3-hexylthiophene) (P3HT) pillars. This technique makes it possible to control the dimensions of the pillars, namely their diameters, intervals, and heights, on a tens-of-nanometer scale. These features are essential for enhancing carrier processes such as carrier generation, exciton diffusion, and carrier dissociation and transport. An interdigitated p-n junction between P3HT pillars and fullerene (C60) exhibits a photovoltaic effect. Although the device properties are still preliminary, the experimental results indicate that an AAO template is an effective tool with which to develop organic solar cells because highly regulated nanostructures can be produced on large areas exceeding 100 mm2. 相似文献
240.
Yoshiyuki Mizushina Yoshihiro Takahashi Yoshihiro Sato Yasuhiro Yamaguchi Toshifumi Takeuchi Isoko Kuriyama Fumio Sugawara Hiromi Yoshida 《Food chemistry》2012
During the screening of selective DNA polymerase (pol) inhibitors, we isolated two glucosyl compounds, a cerebroside (glucosyl ceramide, AS-1-4, compound 1) and a steroidal glycoside (eleutheroside A, compound 2) from soybean (Glycine max L.). Compounds 1 and 2 selectively inhibited the activity of eukaryotic pol λ in vitro, with IC50 values of 12.2 and 9.1 μM, respectively. These compounds did not influence the activities of other eukaryotic pols including those from the A-family (pol γ), B-family (pols α, δ and ε), and Y-family (pols η, ι and κ), and also showed no effect on the activity of pol β which is of the same family (X) as pol λ. The tendency for in vitro pol λ inhibition by these compounds showed a positive correlation with the in vivo suppression of TPA (12-O-tetradecanoylphorbol-13-acetate)-induced inflammation in mouse ear. These results suggest that these glucosyl compounds from soybean may be useful for their anti-inflammatory properties. 相似文献