全文获取类型
收费全文 | 311篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 44篇 |
综合类 | 2篇 |
化学工业 | 58篇 |
金属工艺 | 22篇 |
机械仪表 | 7篇 |
建筑科学 | 6篇 |
能源动力 | 9篇 |
轻工业 | 35篇 |
石油天然气 | 1篇 |
无线电 | 14篇 |
一般工业技术 | 68篇 |
冶金工业 | 33篇 |
原子能技术 | 2篇 |
自动化技术 | 21篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 7篇 |
2011年 | 21篇 |
2010年 | 11篇 |
2009年 | 15篇 |
2008年 | 13篇 |
2007年 | 20篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 10篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有322条查询结果,搜索用时 31 毫秒
1.
Masatsune Kato Takaaki Aoki Takashi Noji Yasuhiro Ono Yoji Koike Tomoyuki Hikita Yoshitami Saito 《Journal of Superconductivity and Novel Magnetism》1994,7(1):37-38
We have investigated the relation between the crystal structure and superconductivity in La1.9Bi0.1CuO4+δ , in which the phase separation observed in La2CuO4+δ is suppressed. A phase diagram in theT?δ plane is given for La1.9Bi0.1CuO4+δ with excess oxygen. For very smallδ values, the crystal structure is orthorhombic, and an orthorhombic-tetragonal phase transition occurs markedly atδ ~ 0.03 in the measured temperature range between 13 and 293 K. Superconductivity is observed in the range of 0.04<δ<0.11. This is clear evidence thathigh-T c superconductivity also appears in the tetragonal phase. 相似文献
2.
Koichi Itagaki Md. Mortuza Ali Hiroshi Kitamura Takeo Maruyama 《Electrical Engineering in Japan》1992,112(2):1-10
Several sealed-off triggered vacuum gaps are connected in series to improve hold-off voltage. The characteristics of impulse breakdown voltage of these series-connected gaps are investigated experimentally. The sum hold-off voltage of series-connected gaps decreases to a unit hold-off voltage when the maximum value of voltage division ratio across the gaps increases to unity. Self-breakdown probability of the series-connected gaps is always higher than that of a single gap under the same conditions. Hence, stage efficiency of the multistage gap decreases with increasing number of stages. Its value is 90 percent with 2-stage gap and 75 percent with 5-stage gap, respectively, under the same voltage division ratio and the same gap length (2.0 mm) in each stage. Triggered breakdown voltage of 2- or 3- stage gap is several hundred volts when all gaps are triggered simultaneously at the peak of the main impulse wave and a working voltage range is nearly 100 percent in this case. The working voltage range decreases with number of stages. Its value is 45 percent with 3-stage gap and 15 percent with 5-stage gap, respectively, when one triggered gap is fired for switching. 相似文献
3.
4.
A Kuniyasu K Itagaki T Shibano M Iino G Kraft A Schwartz H Nakayama 《Canadian Metallurgical Quarterly》1998,273(8):4635-4641
To identify the binding domain of a new Ca2+ antagonist semotiadil on L-type Ca2+ channels from skeletal muscle, photolabeling was carried out by using an azidophenyl derivative of [3H]semotiadil. Photoincorporation was observed in several polypeptides of membrane triad preparations; the only specific photoincorporation was in the alpha1 subunit of the Ca2+ channel. After solubilization and purification, the photolabeled alpha1 subunit was subjected to proteolytic and CNBr cleavage followed by antibody mapping. Specific labeling was associated solely with the region of transmembrane segment S6 in repeat IV. Quantitative immunoprecipitation was found in the tryptic and the Lys-C/Glu-C fragments of 6.6 and 6.1 kDa, respectively. Further CNBr cleavage of the Lys-C digests produced two smaller fragments of 3.4 and 1.8 kDa that were included in the tryptic and Lys-C/Glu-C fragments. The smallest labeled fragments were: Tyr1350-Met1366 and Leu1367-Met1381 containing IVS6, a possible pore-forming region. The data suggest that semotiadil binds to a region that is overlapped with but not identical to those for phenylalkylamines, dihydropyridines and benzothiazepines. The present study also provides evidence that region IV represents an important component of a binding pocket for Ca2+ antagonists. 相似文献
5.
Summary The rate constants for intramolecular excimer formation, kDM, of poly(α-methylstyrene) with different molecular weight were determined by using picosecond pulse radiolysis. Values of
kDM for poly(α-methylstyrene) are a little smaller than those for polystyrene with nearly same molecular weight. It appears to
be mainly due to steric hindrance by methyl substituent of main chain. 相似文献
6.
Makoto Ishiguro Katsufumi Ohmuro Yukito Saitoh Yuuta Takahashi Jun Watanabe Tsutomu Arai Yoji Ito Keiji Mihayashi 《Journal of the Society for Information Display》2012,20(11):598-603
We have successfully developed a quarter‐wave retardation film (QWF) for wide viewing angle 3D liquid crystal displays (3D‐LCDs) that provides high luminance, low crosstalk, low color change, and low head‐tilt‐angle dependency. It was found that the out‐of‐plane retardation (Rth) of the QWF in the LCD needs to be close to 0 nm in order to improve the 3D display properties at an off‐axis position and that the in‐plane retardation (Re) needs to be adjusted from 120 to 130 nm to achieve low color change with head tilting. We adopted a coating process for making our QWF because of its potential for retardation control. 3D‐LCDs with this QWF whose Rth was nearly zero had high performance and allowed off‐axis other than on‐axis. 相似文献
7.
Hajime Arai Masayuki Tsuda Masahiko Hayashi Hideaki Ohtsuka Yoji Sakurai 《Electrochimica acta》2005,50(9):1821-1828
Several polymorphs of layered nickel dioxide were prepared by using the chemical insertion of alkaline ions into Li0.10NiO2. We used aqueous AOH (A = Li, Na, K) solutions as reducing agents. Sodium and potassium insertion resulted in hydrated layered compounds that can be classified as γ-NiOOH with high crystallinity, while lithium insertion occurred without hydration. We discuss the coordination environment around the A+ ions for these inserted compounds. The thermal behavior, analyzed using high temperature (HT) X-ray diffraction (XRD) and thermogravimetric (TG) measurements, indicated that heating the hydrate at 150 °C yielded its dehydrate. The electrode performance of the nickelate was studied in lithium cells. We discuss the effect of interlayer water on cell rechargeability and the similarity between these nickelate and hydrated manganese dioxide (birnessite). 相似文献
8.
Masatsune Kato Takaaki Aoki Takashi Noji Yasuhiro Ono Yoji Koike Tomoyuki Hikita Yoshitami Saito 《Journal of Superconductivity》1994,7(1):37-38
We have investigated the relation between the crystal structure and superconductivity in La1.9Bi0.1CuO4+
, in which the phase separation observed in La2CuO4+
is suppressed. A phase diagram in theT– plane is given for La1.9Bi0.1CuO4+
with excess oxygen. For very small values, the crystal structure is orthorhombic, and an orthorhombic-tetragonal phase transition occurs markedly at 0.03 in the measured temperature range between 13 and 293 K. Superconductivity is observed in the range of 0.04<<0.11. This is clear evidence thathigh-T
c
superconductivity also appears in the tetragonal phase. 相似文献
9.
Correlation between Chemical Dopants and Topological Defects in Catalytically Active Nanoporous Graphene
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
10.
Takashi Noji Yoji Koike Hideo Iwasaki Masatsune Kato Norio Kobayashi Yoshitami Saito 《Journal of Superconductivity and Novel Magnetism》1996,9(1):65-71
Anisotropie properties of the single crystal Pb2Sr2Ho0.5Ca0.5Cu3O8 have been investigated by measuring the electrical resistivity in theab-planeρ ab (H, θ,T), which depends on the angleθ between theab-plane and the magnetic-field direction, in various constant fieldsH perpendicular to the current direction. All the angle-dependent values ofρ ab (H, θ,T) at a constant temperature are scaled to be on one curve as a function of reduced field. The anisotropic parameter γ≡(m c * /m ab * )1/2 is estimated as 12–13, which is larger than that of YBa2Cu3O7 and much smaller than that of Bi2Sr2CaCu2O8. It has been concluded that the anisotropy does not always depend on the thickness of the blocking layer but seems to depend on the overlap of the electronic wave functions along thec-axis. Anisotropy in the pinning potential has also been discussed from the resistive tail in the temperature dependence ofρ ab (H,θ,T). 相似文献