全文获取类型
收费全文 | 456篇 |
免费 | 23篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 39篇 |
综合类 | 2篇 |
化学工业 | 140篇 |
金属工艺 | 24篇 |
机械仪表 | 19篇 |
建筑科学 | 10篇 |
能源动力 | 18篇 |
轻工业 | 31篇 |
水利工程 | 1篇 |
无线电 | 25篇 |
一般工业技术 | 113篇 |
冶金工业 | 9篇 |
原子能技术 | 13篇 |
自动化技术 | 41篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 17篇 |
2015年 | 8篇 |
2014年 | 17篇 |
2013年 | 33篇 |
2012年 | 11篇 |
2011年 | 26篇 |
2010年 | 15篇 |
2009年 | 32篇 |
2008年 | 29篇 |
2007年 | 17篇 |
2006年 | 25篇 |
2005年 | 26篇 |
2004年 | 18篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 5篇 |
2000年 | 15篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有485条查询结果,搜索用时 31 毫秒
81.
Electrospray pyrolysis, i.e. combination of electrospray and in-flight thermal treatment, has attracted much attention as a preparation method of functional ceramic particles. In this paper, we report the processing detail of spherical TiO2 nano- and microparticles by the electrospray pyrolysis method as well as their photocatalytic activity for hydrogen evolution. Titanium(IV) bis(ammonium lactato)dihydroxide aqueous solutions (TALH aq., 0.2–20 wt%) were injected into a capillary nozzle by a syringe pump (0.15–0.59 mL/min), and were electrosprayed by using DC 4 kV voltage, followed by the pyrolysis at 300–500 °C. Spherical TiO2 nano- and microparticles were successfully obtained. Effects of precursor-liquid concentration, liquid flow-rate, and pyrolysis temperature on the particle size, microstructure and functions were discussed. 相似文献
82.
Hiroki Takahashi Takahiro Tomita Hiroyuki Takahashi Yoshikazu Mizuguchi Yoshihiko Takano Satoshi Nakano Kazuyuki Matsubayashi Yoshiya Uwatoko 《Science and Technology of Advanced Materials》2012,13(5)
The superconducting transition temperature, Tc, in iron-based solids can be enhanced by applied pressure: Tc increases from 8 to 37 K for the 11-type FeSe when the pressure is raised from 0 to 4 GPa. High-pressure studies can elucidate the mechanism of superconductivity in such novel materials. In this paper, we present a high-pressure study of Fe(Se1−xTex) and Fe(Se1−xSx). In the case of Fe(Se1−xTex), the maximum Tc under high pressure did not exceed the Tc of FeSe, which can be attributed to the structural transition to the monoclinic phase. For Fe(Se1−xSx) (0 < x < 0.3), Tc exhibited a significant increase with pressure; however, the maximum Tc under high pressure did not exceed the Tc of FeSe. This may be due to the disorder induced by substituting S for Se, which is similar to the pressure effect on Tc for the 1111-type superconductor Ca(Fe1−xCox)AsF. The Tc of Fe(Se1−xSx) showed a complex behavior below 1 GPa, first decreasing and then increasing with increasing pressure. From high-pressure x-ray diffraction measurements, the Tc (P) curve was correlated with the local structural parameter. 相似文献
83.
Takahiro Kozawa Hideya Hattori Shuhei Ogo Yusuke Ide Yoshikazu Suzuki 《Journal of Materials Science》2013,48(22):7969-7973
A simple and mild synthetic route via a hydrothermal treatment of Mg2TiO4 has been developed to prepare brookite-type TiO2. The hydrothermal conversion of Mg2TiO4 to brookite proceeded in 1 M HCl solution even at 100 °C. The converted brookite grains were composed of the angular particles covered on the textured surface, leaving the original morphology of Mg2TiO4 grains. Compared with the commercially available TiO2 catalysts (rutile, anatase, and P25), the brookite obtained in this study showed a good photocatalytic activity toward the oxidation of benzyl alcohol to benzaldehyde under a simulated sunlight irradiation. 相似文献
84.
85.
Akira Kariyasaki Yoshikazu Yamasaki Masazumi Kagawa Tohru Nagashima Akiharu Ousaka Shigeharu Morooka 《传热工程》2013,34(1-2):28-36
A technique was developed and tested to measure the local thickness of a droplet or a liquid film on a surface of an opaque or thick single transparent plate by an interference fringe pattern that was easily formed by reflecting laser lights. Monochromatic epi-illumination through an objective lens of a conventional microscope was provided by a 5 mW or 300 mW laser and a filter to remove the noise caused by laser speckle. The incremental height difference of the liquid layer between neighboring maxima or minima of fringes was evaluated from the wavelength of the laser light and the refractive index of the liquid. Estimation error of a local inclination angle was discussed using ray tracing under parallel illumination approximation. Droplet profiles evaluated from the interferogram that were obtained by the present fringe method agreed well with those by Laser Focus Displacement Meter. Measurement was made to ensure the usefulness of the present technique. It was made clear that the contact angle of a liquid droplet could be obtained precisely and swiftly, even in small size or small contact angle, and that instantaneous three-dimensional profile of a liquid film on a bubble moving in a microchannel could be measured. The fringe method had sufficient potential to obtain more detailed information about three-dimensional characteristics of liquid film in flows such as the generation, breakdown, and growth of waves and the liquid film on a bubble at the beginning of movement. 相似文献
86.
87.
Formation of high performance ice slurry by W/O emulsion in ice storage (effective method to propagate supercooling dissolution) 总被引:1,自引:1,他引:0
Koji Matsumoto Kazuki Sakae Hirofumi Yamauchi Yoshikazu Teraoka 《International Journal of Refrigeration》2008,31(5):832-840
This study focused ice slurry formation in an ice storage system using W/O emulsions with 70 and 80% water contents. Emulsions consisted of a silicone oil–water mixture with a small amount of amino-group-modified silicone oil additive. Ice slurry was formed by cooling the emulsion without ice adhesion to the cooling wall, as water in the emulsion did not directly contact the cooling wall. As the structure of W/O emulsion slowed the propagation rate of supercooling dissolution, voltage and ultrasonic wave were applied to the W/O emulsion to propagate dissolution more quickly and decrease maximum supercooling degree, respectively. Thus, the effects of voltage and ultrasonic wave applications on propagation rate were clarified. 相似文献
88.
Hiromasa Yagyu Yoshikazu Hirai Akio Uesugi Yoshihide Makino Koji Sugano Toshiyuki Tsuchiya Osamu Tabata 《Polymer》2012,53(21):4834-4842
The mechanical properties of an epoxy-based chemically amplified resists with various cross-linking ratios were simulated using a newly developed coarse-grained molecular dynamics simulation that employs a bead–spring model. Models with the different cross-linking ratios were created in the molecular dynamics calculation step and uniaxial elongation simulations were performed. The results reveal that the simulated elastic modulus of the resist modeled by the Kremer–Grest model with an extended angle bending potential depends on the cross-linking ratio, its dependency exhibits good agreement with that determined by nanoindentation tests. 相似文献
89.
90.
Kurauchi K Nakaguchi Y Tsutsumi M Hori H Kurihara R Hashimoto S Ohnuma R Yamamoto Y Matsuoka S Kawai S Hirata T Kinoshita M 《Environmental science & technology》2005,39(8):2762-2768
Detection of endocrine disrupting chemicals, in particular, environmental estrogens with living organisms, has many advantages if compared to chemical analysis. The screening of novel pollutants with meaningful endpoints, the integration of uptake, bioconcentration, and excretion as well as the evaluation of endocrine disrupting effects with respect to toxicity require in vivo biotests for estrogen-like substances (ELSs). Critical disadvantages of whole organism biotests are their low sensitivity and the need for laborious and time-consuming work. To overcome these problems, we have developed a transgenic medaka strain harboring the green fluorescence protein (GFP) gene driven by choriogenin H gene regulatory elements. Choriogenin H is an egg envelope protein induced by estrogens in the liver. With yolk sac larvae of this strain, GFP induction in liver was observed 24 h after onset of aqueous exposure to 0.63 nM 17beta-estradiol (E2), 0.34 nM ethynylestradiol, or 14.8 nM estrone. Furthermore, concentrated sewage treatment effluent induced GFP expression. Comparison of E2 equivalents estimated by GFP-induction in transgenic medaka, a YES assay, and GC/MS showed detection limits in the same order of magnitude. These results indicated that the sensitivity of the transgenic medaka strain was sufficient for application as an alternative model in monitoring environmental water samples for ELSs. 相似文献