全文获取类型
收费全文 | 1748篇 |
免费 | 41篇 |
国内免费 | 4篇 |
学科分类
工业技术 | 1793篇 |
出版年
2021年 | 23篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2017年 | 20篇 |
2016年 | 30篇 |
2015年 | 19篇 |
2014年 | 52篇 |
2013年 | 96篇 |
2012年 | 61篇 |
2011年 | 79篇 |
2010年 | 64篇 |
2009年 | 65篇 |
2008年 | 86篇 |
2007年 | 73篇 |
2006年 | 59篇 |
2005年 | 54篇 |
2004年 | 55篇 |
2003年 | 66篇 |
2002年 | 47篇 |
2001年 | 43篇 |
2000年 | 31篇 |
1999年 | 54篇 |
1998年 | 92篇 |
1997年 | 82篇 |
1996年 | 42篇 |
1995年 | 36篇 |
1994年 | 40篇 |
1993年 | 36篇 |
1992年 | 16篇 |
1991年 | 23篇 |
1990年 | 18篇 |
1989年 | 15篇 |
1988年 | 12篇 |
1987年 | 24篇 |
1986年 | 18篇 |
1985年 | 17篇 |
1984年 | 24篇 |
1983年 | 15篇 |
1982年 | 21篇 |
1981年 | 14篇 |
1980年 | 22篇 |
1979年 | 11篇 |
1978年 | 16篇 |
1977年 | 12篇 |
1976年 | 16篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1970年 | 8篇 |
1969年 | 5篇 |
排序方式: 共有1793条查询结果,搜索用时 515 毫秒
101.
Wakasugi K. Naru-Fumi Kishi Matsuo M. 《Geoscience and Remote Sensing, IEEE Transactions on》1986,(5):732-737
An analytic model of the ocean surface SAR images with a three-dimensional framework is developed following the formalism presented by Swift and Wilson (1979); a trochoidal swell propagates through a uniform field of Bragg-type distributed scatterers. Two- dimensional SAR images are calculated for the interpretation and prediction of actual SAR images of the ocean surface as a function of ocean wave amplitude, wave frequency, propagation direction, and radar frequency, off-nadir angle of the antenna, and spatial resolutions. 相似文献
102.
K Tsuji N Konishi GW Spears T Ogino K Nakamura T Tojo T Ochi F Shimojo H Senoh M Matsuo 《Canadian Metallurgical Quarterly》1997,45(9):1475-1481
A series of novel 1,5-diphenylpyrazole derivatives bearing hydrophilic substituents was prepared. The anti-inflammatory and analgesic activities of these compounds were evaluated by using the adjuvant arthritis and Randall-Selitto assays in rats, and the structure-activity relationships were studied. The optimal compound was 3-(difluoromethyl)-1-(4-methoxyphenyl)-5-[4-(methylsulfinyl)phenyl]pyraz ole (10) with oral ED50 values of 0.31 and 2.6 mg/kg on adjuvant-induced arthritis and carrageenin-induced foot edema, respectively. Compound 10 showed analgesic activities not only toward inflamed paw but also toward normal paw (ED30 = 0.55 and 1.8 mg/kg, respectively) in the Randall-Selitto assay, and moreover, 10 was effective in the tail-pinch assay (ED50 = 21 mg/kg) similarly to morphine. The asymmetric synthesis and pharmacological properties of the enantiomers of 10 are also reported. 相似文献
103.
Yoshihiko Nakata Satoshi Ninomiya Chikage Imada Masafumi Nagai Takaaki Aoki Jiro Matsuo Nobutsugu Imanishi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2005,230(1-4):489-494
We have measured both secondary neutral and ionized particles from an InSb target under 3.0 MeV Si ion bombardment. Measurements of both ions and neutrals have not been carried out so far in the MeV-energy range. The mass spectra and axial emission energy distributions of secondary particles were investigated. Secondary ions were measured with a linear- and a reflective-type time-of-flight technique, whereas secondary neutral particles were photo-ionized by a UV pulsed laser (ArF: 193 nm) and measured with a reflective-type time-of-flight technique. Different results were obtained for neutral particles in comparison with ionized particles. The mean energy of neutral Sb atoms was much lower than that of neutral In atoms, whereas the mean energies of secondary In and Sb ions were nearly equal. 相似文献
104.
Chen Xiaoming Zhou Zhiwei Gao Zuying Wu Wei Takashi Nakagawa Satoko Matsuo 《Reliability Engineering & System Safety》2005,87(1):476
A nuclear power plant (NPP) is a complex system but requires high reliability. The human–machine interface (HMI) design plays very important role in reactor safety. This paper describes an assessment on HMI design of a Chinese NPP, using a software system named Dynamic Interaction Analysis Support (DIAS). DIAS can give not only quantitative indices for dynamically assessing the HMI design, but also allow modify the values of these indices by taking into account human error probability during specified emergent operation procedures. The operation procedures dealing with postulated accidents and transients recorded from a full-scale plant simulator in the training center of a Chinese NPP were selected as references. According to the results of simulation and analysis, the potential problems in the HMI design and the operation procedures were detected. Suggestions to improve the HMI design and the operation procedures were addressed. 相似文献
105.
We have investigated the microstructure of the poly(vinyl alcohol) (PVA) films using small- and wide-angle X-ray scattering (SAXS and WAXS, respectively) techniques. The samples were uniaxially drawn in water or KI/I2 aqueous solution and then dried in an air-oven at 333 K for 1 h prior to SAXS and WAXS measurements. It was found that for the films drawn in KI/I2 solution PVA chains in the microfibrillar structure are more extended upon the film drawing compared to the case of the films drawn in pure water, which is resulted from the correlation function analysis on the SAXS data. Adsorbed iodines into the film were anticipated to act as junction points between the microfibrils via the formation of the PVA-iodine complexes. 相似文献
106.
Ruwan Gallage Atsushi Matsuo Takeshi Fujiwara Tomoaki Watanabe Nobuhiro Matsushita Masahiro Yoshimura 《Journal of the American Ceramic Society》2008,91(7):2083-2087
Crystalline CeO2 films and patterns have been successfully fabricated in a "single-step process" at moderate temperature. In this process, the combination of the ink-jet technique and depositing the precursor on a hot substrate (≤300°C) gave crystalline CeO2 without further heat treatment. X-ray diffraction analysis revealed that the phase formed was crystallized ceria with nanosized (<10 nm) crystallites. The film thickness was several hundred nanometers and the pattern width was about 150 μm. Scanning electron microscopy analysis showed that the films and patterns were free of cracks and adhered to the substrate. This is the first report about the direct patterning of crystalline CeO2 without postfiring or posttreatments like masking, etching, etc. 相似文献
107.
The response of the structure subjected to nonstationary random vibration such as earthquake excitation is nonstationary random vibration. Calculating method for statistical characteristics of such a response is complicated. Mean square value of the response is usually used to evaluate random response. Integral of mean square value of the response corresponds to total energy of the response. In this paper, a simplified calculation method to obtain integral of mean square value of the response is proposed. As input excitation, nonstationary white noise and nonstationary filtered white noise are used. Integrals of mean square value of the response are calculated for various values of parameters. It is found that the proposed method gives exact value of integral of mean square value of the response. 相似文献
108.
K. Matsuo Y. Gosho T. Toyoda Y. Sonoda K. Muraoka M. Akazaki 《Journal of Infrared, Millimeter and Terahertz Waves》1985,6(10):1051-1059
This paper is concerned with systematic developments of the Fraunhofer-diffraction method for studies of plasma density fluctuations in high-temperature plasmas using infrared lasers, namely (i) development of the general theory of the Fraunhofer-diffraction method, (ii) measurements of fluctuations propagating in an azimuthal direction, (iii) measurements of fluctuation intensities, and (iv) application in measurements on high-temperature plasmas. 相似文献
109.
110.
Shigeru Okada Toetsu Shishido Takao Mori Kiyokata Iizumi Kunio Kudou Kazuo Nakajima 《Journal of Alloys and Compounds》2008,458(1-2):297-301
LEAlB14 (orthorhombic, Imam) (LE = Li, Mg) crystals were grown using metal salts (Li2CO3, LiF, LiI, MgO, MgF2, MgI2) and crystalline boron from a high-temperature aluminium metal flux. The growth conditions for growing LEAlB14 were established using the starting mixtures of B/LE = 2.0, and Al metal was added to each mixture at a mass ratio of 1:15–20. LEAlB14 crystals from the Al-self flux using metal salts could be obtained from all the different salts. The maximum dimensions of LiAlB14 and MgAlB14 crystals were approximately 18 and 12 mm for the crystals obtained from LiF and MgF2. The unit-cell parameters of as-grown LEAlB14 are as follows: for LiAlB14, obtained from LiF, a = 0.5846 (2) nm, b = 0.8144 (2) nm, c = 1.0355 (3) nm, V = 0.4930 (2) nm3: for MgAlB14, obtained from MgF2, a = 0.5845 (2) nm, b = 0.8114 (2) nm, c = 1.0330 (3) nm, V = 0.4899 (3) nm3. Microhardness, oxidation resistance and magnetic susceptibility of these materials are described in detail. 相似文献