全文获取类型
收费全文 | 498篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
综合类 | 2篇 |
化学工业 | 180篇 |
金属工艺 | 13篇 |
机械仪表 | 7篇 |
建筑科学 | 17篇 |
能源动力 | 41篇 |
轻工业 | 26篇 |
无线电 | 29篇 |
一般工业技术 | 83篇 |
冶金工业 | 33篇 |
原子能技术 | 18篇 |
自动化技术 | 45篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 11篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 10篇 |
2013年 | 19篇 |
2012年 | 20篇 |
2011年 | 32篇 |
2010年 | 23篇 |
2009年 | 30篇 |
2008年 | 31篇 |
2007年 | 21篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 19篇 |
2002年 | 13篇 |
2001年 | 13篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 24篇 |
1997年 | 17篇 |
1996年 | 12篇 |
1995年 | 15篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 4篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有503条查询结果,搜索用时 46 毫秒
481.
Hirokazu Ikeda Takeshi Matsuda Yutaka Saitoh Tadao Akamine Masahiro Inoue Junko Yamanaka Masaaki Mandai Hitoshi Takeuchi Shin-ichi Miyahara Masaaki Kamiya 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1997,400(2-3):367-378
We explored wide-pitch ohmic-side structures for the BELLE SVD, where we proposed a field-plate structure combined with narrow p-barriers in between the readout electrodes of 90, 113, 180, and 226 μm-pitch detectors. The effect of the p-barriers was studied with a numerical model to trace the carrier trajectories. The charge collection and sharing properties were examined in practice for prototype small-size detectors with an IR pulse shining from either the junction side or the ohmic side. The channel separation capabilities were also shown to be appropriate under nominal operation conditions. 相似文献
482.
Taro Matsumoto Toshihiro Akihisa Shin-ichi Soma Michio Takido Shushichi Takahashi Sakae Yamanouchi 《Journal of the American Oil Chemists' Society》1986,63(4):544-546
The composition of the unsaponifiable lipid, which consisted of squalene, squalene-2,3-oxide, triterpene alcohols, 4α-methyl-sterols,
and sterols, of the seed oils ofPanax ginseng andP. quiquefolium, was determined. Squalene was the most abundant component (54%) of the unsaponifiable lipid fromP. ginseng, whereas sterols constituted the principal components of unsaponifiable lipid fromP. quiquefolium. Both ginseng seed oils showed specific features in sterol composition, i.e., 28-isofucosterol (40%) and 24-ethyl-22E-dehydrocholesterol
(66%) constituted the most predominant components of the sterol fractions fromP. ginseng andP. quiquefolium seed oils, respectively. 相似文献
483.
根据拉伸试验(TT)得到的应力-应变曲线和通过声音脉冲方法(APM)得到的声速,计算并比较了烧结钢的弹性模量(E)和泊松比(v).Err和vTT的值分别小于EAPM和vAPM,这是因为在烧结钢的应力-应变中不仅包含了弹性应变,而且也包含了塑性应变.利用由EAPM和vAPM的值计算得到的纵向和横向弹性应变,从纵向和横向应力-应变中分离出纵向和横向的塑性应变.在小应变时烧结钢没有显示线性应力-应变的情况下,可以很简单地由纵向塑性应力表中求出弹性极限或0.2%的屈服强度.对于同样的应力,每个样品的弹性应变和塑性应变的不同,可以由基于孔隙特征(孔隙的大小、形状、相互连接及微观结构的不同)的模型来解释. 相似文献
484.
Wataru Sakamoto Yu-ki Mizutani Naoya Iizawa Toshinobu Yogo Takashi Hayashi Shin-ichi Hirano 《Journal of Electroceramics》2006,17(2-4):293-297
Ferroelectric Si-doped (Bi,Nd)4Ti3O12 thin films have been prepared on Pt/TiOx/SiO2/Si substrates through metal-organic compounds by the chemical solution deposition. The Bi3.25Nd0.75Ti2.9Si0.1O12 (BNTS) precursor films were found to crystallize into the Bi-layered perovskite Bi4Ti3O12 single-phase above 600∘C. The synthesized BNTS films revealed a random orientation having a strong 117 reflection. The BNTS thin films prepared between
600∘C and 700∘C showed well-saturated P-E hysteresis loops with P
r of 13–14 μ C/cm2 and E
c of 100–110 kV/cm at an applied voltage of 5 V. The surface roughness of the BNTS thin films was improved by Si doping compared
with that of undoped Bi3.35Nd0.75Ti3O12 films. 相似文献
485.
486.
487.
Isamu Sato Koji Maeda Mitsuo Suto Masahiko Osaka Toshiyuki Usuki Shin-ichi Koyama 《Journal of Nuclear Science and Technology》2013,50(4):580-587
Penetration behavior of radionuclides such as 137Cs into dried concrete material, dried mortar material and epoxy paint for a few dozen days was observed using a solution containing fission products extracted from irradiated fuels to obtain fundamental information on the radionuclide penetration rate and depth. Hardly any radionuclides could penetrate into the epoxy paint. The radionuclide solution penetrated into concrete and mortar materials to a depth of a few millimeters for a few dozen days. The penetration behavior observed near the surface of concrete and mortar materials was similar to the diffusion of nuclides in media such as water-saturated concrete, bentonite and cement materials. 相似文献
488.
Nakakita S Sumiyoshi W Miyanishi N Natsuka S Hase S Hirabayashi J 《Analytical chemistry》2007,79(7):2674-2679
Pyridylamination is a versatile method for fluorescence labeling of oligosaccharides. The technique affords sensitive detection of saccharides with reducing termini and high-resolution separation by high-performance liquid chromatography. The conventional method, based on a liquid-phase reaction, has been extensively used in various aspects of glycobiology and glycotechnology. Unfortunately, the necessity for removing excess 2-aminopyridine makes the technique both laborious and time-consuming. Furthermore, removal of excess reagent can result in a significant loss of short saccharide components. In the present paper, we report an alternative methodology based on a "gas-phase" reaction, in which dried saccharides are reacted with vaporized 2-aminopyridine. The resultant Schiff base was also reduced in the gas phase within the same reaction microtube using a purpose-built device. The newly developed procedure was applied to both monosaccharide (GlcNAc) and oligosaccharides (isomalto-oligosaccharides) at quantitative yields with no requirement to remove excess reagent. The acid-labile sialyl linkages of alpha2-6-disialobiantennary oligosaccharides proved to be fully stable during the procedure. The developed method was also successfully applied to profiling N-linked oligosaccharides liberated from glycoproteins by hydrazinolysis and, thus, should contribute to various fields of glycomics. 相似文献
489.
Laser emission, consisting of three primary colors, is generated by frequency conversions of the second-harmonic emission of a picosecond (120 ps) Nd:YAG laser by means of stimulated Raman scattering and subsequent four-wave Raman mixing in molecular deuterium. In the double-pass configuration, the fundamental beam (532 nm, 14.16 mJ, 100%) is converted to blue (459 nm, 1.71 mJ, 12.1%), green (532 nm, 7.04 mJ, 49.7%), and red (632 nm, 4.90 mJ, 34.6%), resulting in a total conversion efficiency of 96.4%. 相似文献
490.
Kazunari Imaide Shin-ichi Nishimura Toshifumi Shibata Takayuki Shuku Akira Murakami Kazunori Fujisawa 《Soils and Foundations》2019,59(6):1758-1771
A method for evaluating the liquefaction probability of an earth-fill dam over the next 50 years is presented through the use of a geostatistical method for the measured values from cone penetration tests (CPTs). In particular, this paper discusses a new procedure for evaluating the liquefaction probability based on CPTs. Although the fines content, Fc, and the N-value are required in the Japanese standards to evaluate the liquefaction risk, the number of test data is not enough for the statistical modeling. Herein, Fc and the N-value are derived directly from CPTs. The statistical modeling procedure for Fc and the N-value is the unique point of this study. Since CPTs can be conducted with short intervals, especially in the horizontal direction, the geostatistical parameters can be determined, and the geostatistical simulation method is applicable for evaluating the liquefaction probability. In addition, since the frequency of the seismic load at the studied site will affect the liquefaction probability, the seismic hazard should be evaluated properly. An illustrative example, assessing the liquefaction probability of an earth-fill dam in Japan, is presented to demonstrate the capability of the proposed method. Finally, the spatial average of the liquefaction probability of the dam over the next 50 years is calculated. The proposed procedure is confirmed to work well for actual design problems. 相似文献