全文获取类型
收费全文 | 1016篇 |
免费 | 37篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 22篇 |
综合类 | 2篇 |
化学工业 | 218篇 |
金属工艺 | 27篇 |
机械仪表 | 25篇 |
建筑科学 | 7篇 |
能源动力 | 20篇 |
轻工业 | 55篇 |
无线电 | 89篇 |
一般工业技术 | 191篇 |
冶金工业 | 317篇 |
原子能技术 | 25篇 |
自动化技术 | 57篇 |
出版年
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 15篇 |
2014年 | 18篇 |
2013年 | 51篇 |
2012年 | 24篇 |
2011年 | 30篇 |
2010年 | 24篇 |
2009年 | 35篇 |
2008年 | 32篇 |
2007年 | 22篇 |
2006年 | 24篇 |
2005年 | 28篇 |
2004年 | 19篇 |
2003年 | 20篇 |
2002年 | 21篇 |
2001年 | 22篇 |
2000年 | 26篇 |
1999年 | 35篇 |
1998年 | 133篇 |
1997年 | 74篇 |
1996年 | 39篇 |
1995年 | 34篇 |
1994年 | 28篇 |
1993年 | 35篇 |
1992年 | 17篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 18篇 |
1981年 | 18篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 16篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1972年 | 5篇 |
排序方式: 共有1055条查询结果,搜索用时 0 毫秒
11.
S. Watanabe S. Nakasato S. Hayano H. Kuwamura T. Nagai M. Negishi Y. Sasamoto H. Seino S. Shiraishi 《Journal of the American Oil Chemists' Society》1973,50(9):360-363
In this study known mixtures of four or five fatty acid methyl esters were analyzed collaboratively by gas chromatography
with flame ionization detectors. The experimental data was treated statistically to examine inter- and intralaboratory scattering.
More-over the effect of the use of correction factors was investigated. Even if only the specific analytical values that scattered
a little were chosen, the averages of such values did not always approach the actual values. In some laboratories a sort of
regularity was observed in the deviation of analytical values from real values throughout the analyses of four samples. The
application of correction factors to the analytical values obtained by these laboratories resulted in a considerable decrease
of interlaboratory scattering and deviation from the real values. When a constant amount of sample was injected, intralaboratory
scattering was decreased, whereas interlaboratory scattering was not. Injection of large sample sizes caused deviation. From
this collaborative study it was recommended that 0.5–1.0 μl of 20% solution be injected.
Presented at the JOCS-AOCS Joint Meeting, Los Angeles, April 1972. 相似文献
12.
1 INTRODUCTION Since Cu-ZSM-5 was reported as an effective catalyst for the selective catalytic reduction (SCR) of NO by hydrocarbons in the presence of excess oxygen, the SCR of NOx has received much attention as a kind of potential technology for cleaning NOx in various oxygen-rich exhausts of diesel engine, lean burning gasoline engine and gas engine. Although a number of catalysts have been tested, to date, it still seems to be difficult to find a catalyst that is completely suit… 相似文献
13.
14.
We developed equipment and methods for measuring quantitatively the local Young's modulus of solids. It consists of an electrodeless langasite oscillator and line antennas, and oscillator vibrations are generated and detected contactlessly. A constant biasing force results from oscillator mass and is independent of surface roughness. The effect of material anisotropy on the measured stiffness is theoretically discussed for studying the limitation of the quantitative measurement. The microscopy has been applied to polycrystalline copper, and the measured modulus is compared to calculations based on electron-backscatter-diffraction measurements. Also, we applied it to a duplex stainless steel and an embedded silicon-carbide fiber. The results reveal textured regions, defects with high sensitivity, and even stiffness distribution in a single grain. 相似文献
15.
M. Nakao Y. Hatamura T. Sato K. Koyano K. Ichiki H. Sangu M. Hatakeyama T. Kobata K. Nagai 《Microsystem Technologies》1995,1(3):124-128
In order to make micro 3-D structures, we are designing a table-sized factory, namely Nano Manufacturing World (NMW). In NMW, we challenged to use a new process fused by semiconductor process for preciseness and machine process for 3-dimensionality. In order to realize the new process, we designed three new mechanisms in this paper: multi-face shape making beam, co-focus rotational robot and micro mechanical tools. Through an evaluation to actually make a micro Gojunoto with the mechanisms, we confirmed their validities for functions of integration of 3-D shape construction and assembly. 相似文献
16.
When BALB/c mice were treated with a Kampo (Japanese herbal) medicine "Sho-seiryu-to (SST)" (1 g/kg, 10 times) orally from 7 days before to 5 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34 by nasal-site restricted infection, SST caused increment of the influenza virus hemagglutinin-specific IgA antibody secreting cells in nasal lymphocyte but not in Peyer's patch lymphocyte at 6 days after infection in comparison with water-treated mice. Oral administration of SST also augmented IL-2 receptor beta chain+ (activated) T-cell in Peyer's patch lymphocyte, but not in the nasal lymphocyte. We previously reported that SST showed potent anti-influenza virus activity through augmentation of the antiviral IgA antibody titer in the nasal and broncho-alveolar cavities of the mice (T. Nagai and H. Yamada, 1994, Int. J. Immunopharmacol. 16, 605-613). These results suggest that oral administration of SST shows anti-influenza virus activity in the nasal cavity by activation of T-cell in Peyer's patch lymphocyte and stimulation of production of anti-influenza virus IgA antibody in nasal lymphocyte. When ovalbumin-sensitized allergic pulmonary inflammation model mice were administered orally with SST (1 g/kg) from 8 days before (11 times) or from 2 h after (4 times) to 4 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34, replications of the virus in the both nasal and broncho-alveolar cavities or only nasal cavity were significantly inhibited at 5 days after infection in comparison with water-treated control by augmenting antiviral IgA antibody, respectively. These results suggest that SST is useful for both prophylaxis and treatment of influenza virus infection on patients with allergic pulmonary inflammation, such as bronchial asthma. 相似文献
17.
Katsuhiko Nagai 《Journal of Low Temperature Physics》1977,28(1-2):139-149
The dynamical susceptibility of the B phase of superfluid He-3 in the presence of dipolar coupling is calculated in the collisionless regime. Two poles of the susceptibility that correspond to the spin wave and the mode with energy gap (2/5)1/2 2 are found. The result agrees with that of Tewordt and Einzel qualitatively and contradicts the recent work by Maki. The residue of the high-frequency mode becomes remarkable near the transition temperature. The dispersion relations of these modes atT=0 K and near the transition temperature are given in the most general form. 相似文献
18.
Masatsugu Nagai Yozo Fujino Hiroki Yamaguchi Eiji Iwasaki 《Canadian Metallurgical Quarterly》2004,9(5):444-452
This paper describes the feasibility of 1,400 m steel cable-stayed bridges from both structural and economic viewpoints. Because the weight of a steel girder strongly affects the total cost of the bridge, the writers present a procedure to obtain a minimum weight for a girder that ensures safety against static and dynamic instabilities. For static instability, elastoplastic, finite-displacement analysis under in-plane load and elastic, finite-displacement analysis under displacement-dependent wind load are conducted; for dynamic instability, multimodal flutter analysis is carried out. It is shown that static critical wind velocity of lateral torsional buckling governs the dimension of the girder. Finally, the writers briefly compare a cable-stayed bridge with suspension bridge alternatives. 相似文献
19.
Yuta Uenoyama Atsushi Matsuda Kazune Ohashi Koji Ueda Misaki Yokoyama Takuya Kyoutou Kouji Kishi Youichi Takahama Masaaki Nagai Takaaki Ohbayashi Osamu Hotta Hideki Matsuzaki 《International journal of molecular sciences》2022,23(9)
Aberrant glycosylation of IgA1 is involved in the development of IgA nephropathy (IgAN). There are many reports of IgAN markers focusing on the glycoform of IgA1. None have been clinically applied as a routine test. In this study, we established an automated sandwich immunoassay system for detecting aberrant glycosylated IgA1, using Wisteria floribunda agglutinin (WFA) and anti-IgA1 monoclonal antibody. The diagnostic performance as an IgAN marker was evaluated. The usefulness of WFA for immunoassays was investigated by lectin microarray. A reliable standard for quantitative immunoassay measurements was designed by modifying a purified IgA1 substrate. A validation study using multiple serum specimens was performed using the established WFA-antibody sandwich automated immunoassay. Lectin microarray results showed that WFA specifically recognized N-glycans of agglutinated IgA1 in IgAN patients. The constructed IgA1 standard exhibited a wide dynamic range and high reactivity. In the validation study, serum WFA-reactive IgA1 (WFA+-IgA1) differed significantly between healthy control subjects and IgAN patients. The findings indicate that WFA is a suitable lectin that specifically targets abnormal agglutinated IgA1 in serum. We also describe an automated immunoassay system for detecting WFA+-IgA1, focusing on N-glycans. 相似文献
20.
Development of biobased microwave absorbing composites with various magnetic metals and carbons 下载免费PDF全文
Shinji Kanehashi Hiroki Oyagi Toraki Iwamaru Shota Ando Kazukiyo Nagai Shinichiro Uekusa Tetsuo Miyakoshi 《应用聚合物科学杂志》2016,133(44)
The preparation and characterization of a biobased electromagnetic absorbing composites derived from natural lacquer as a renewable resource with microwave‐absorption fillers, including Ni–Zn ferrite and carbonyl iron (CI) as magnetic metals and soot and carbon nanotube (CNT) as carbon materials, were investigated in terms of the gel content, hardness, drying properties, and electromagnetic absorption properties. Interestingly, composites with ferrite and CI contained up to 320 and 550 wt %, respectively, of these compounds. This quite high loading capacity of the metal fillers in a natural‐lacquer base could have been due to the high compatibility between the filler and the natural lacquer; this indicated that the natural lacquer worked as a binder for these metals. The morphology of the biobased composite was characterized by scanning electron microscopy. The electromagnetic absorption properties of composites were characterized in the frequency range from 0.05 and 20 GHz by the reflection loss (RL) measurement method in terms of the kind of fillers and filler loading. The natural lacquer did not affect the absorption properties of the fillers. Biobased composites showed over 99% electromagnetic absorption in the frequency range 3.0–4.0 GHz for 280 wt % ferrite and 8.9–9.7 GHz for 200 wt % CI. Conversely, 10 and 20 wt % soot exhibited good performance (RL < ?20 dB) between 16.5 and 17.3 and between 8.8 and 9.2 GHz, respectively. The areas with RL values of less than ?20 dB of the CNT composites were 10.4–11.0 GHz for 5 wt % and 14.6–15.2 GHz for 10 wt %. Hence, natural lacquer can be used as a binder material for electromagnetic absorption composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44131. 相似文献