全文获取类型
收费全文 | 171篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 43篇 |
金属工艺 | 5篇 |
机械仪表 | 3篇 |
建筑科学 | 3篇 |
能源动力 | 7篇 |
轻工业 | 11篇 |
水利工程 | 1篇 |
无线电 | 29篇 |
一般工业技术 | 27篇 |
冶金工业 | 22篇 |
原子能技术 | 5篇 |
自动化技术 | 16篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 10篇 |
2013年 | 4篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 13篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1976年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有181条查询结果,搜索用时 15 毫秒
11.
Satoshi Horikoshi Takashi Miura Masatsugu Kajitani Natsuko Horikoshi Nick Serpone 《Applied catalysis. B, Environmental》2008,84(3-4):797-802
The photoassisted degradation (HPLC-UV absorption), dehalogenation (HPLC-IC) and mineralization (TOC decay) of the flame retardants tetrabromobisphenol-A (TBBPA) and tetrachlorobisphenol-A (TCBPA) were examined in UV-irradiated alkaline aqueous TiO2 dispersions (pH 12), and for comparison the parent bisphenol-A (BPA, an endocrine disruptor) in pH 4–12 aqueous media to assess which factor impact most on the photodegradative process. Complete degradation (2.7–2.8 × 10−2 min−1) and dehalogenation (1.8 × 10−2 min−1) of TBBPA and TCBPA occurred within 2 h of UV irradiation, whereas only 45–60% mineralization (2.3–2.7 × 10−3 min−1) was complete within 5 h for the flame retardants at pH 12 and ca. 80% for the parent BPA. Factors examined in the pH range 4–12 that impact the degradation of BPA were the point of zero charge of TiO2 particles (pHpzc; electrophoretic method), particle or aggregate sizes of TiO2 (light scattering), and the relative number of OH radicals (as DMPO–OH adducts; ESR spectroscopy) produced in the UV-irradiated dispersion. Dynamics of BPA degradation (2.0–2.4 × 10−2 min−1) were pH-independent and independent of particle/aggregate size, but did correlate with the number of OH radicals, at least at pHs 4 to 8–9, after which the rates decreased somewhat at pH > 9 with decreasing adsorption owing to Coulombic repulsive forces between the very negative TiO2 surface and the anionic forms of BPA (pKas ca. 9.6–11.3), even though the number of OH radicals continued to increase at the higher pHs. 相似文献
12.
Flow-through electrolysis for copper electrowinning from cuprous ammine complex was studied in order to develop a hydrometallurgical copper recycling process using an ammoniacal chloride solution, focusing on the anodic oxidation of cuprous to cupric ammine complexes. The current efficiency of this anodic oxidation was 96% at a current density of 200 A m−2 under a batch condition. In a flow-through electrolysis using a sub-liter cell and a carbon felt anode, the anodic current efficiency increased with the flow rate and was typically higher than 97%. This tendency was explained by the backward flow of the cupric ammine complex, which was formed on the anode, through the diaphragm. The anodic overpotential was lower than 0.3 V even at an apparent current density of 1500 A m−2. A similar current efficiency and overpotential were also achieved in a liter scale cell, which indicates the scale flexibility of this electrolysis. The power consumption requirements for copper electrowinning in this cell were 460 and 770 kWh t−1 at the current densities of 250 and 500 A m−2, respectively, which were much lower than that of the conventional copper electrowinning despite the longer interpolar distance. 相似文献
13.
Shioiri S Ito S Sakurai K Yaguchi H 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(11):2169-2179
We measured the lowest velocity (velocity threshold) for discriminating motion direction in relative and uniform motion stimuli, varying the contrast and the spatial frequency of the stimulus gratings. The results showed significant differences in the effects of contrast and spatial frequency on the threshold, as well as on the absolute threshold level between the two motion conditions, except when the contrast was 1% or lower. Little effect of spatial frequency was found for uniform motion, whereas a bandpass property with a peak at approximately 5 cycles per degree was found for relative motion. It was also found that contrast had little effect on uniform motion, whereas the threshold decreased with increases in contrast up to 85% for relative motion. These differences cannot be attributed to possible differences in eye movements between the relative and the uniform motion conditions, because the spatial-frequency characteristics differed in the two conditions even when the presentation duration was short enough to prevent eye movements. The differences also cannot be attributed to detecting positional changes, because the velocity threshold was not determined by the total distance of the stimulus movements. These results suggest that there are two different motion pathways: one that specializes in relative motion and one that specializes in uniform or global motion. A simulation showed that the difference in the response functions of the two possible pathways accounts for the differences in the spatial-frequency and contrast dependency of the velocity threshold. 相似文献
14.
15.
Kamino T Yaguchi T Kuroda Y Ohnishi T Ishitani T Miyahara Y Horita Z 《Journal of electron microscopy》2004,53(5):459-463
Transmission electron microscopy (TEM) samples of an Mg-Al alloy has been prepared using a Ga-focused ion beam (FIB) milling at two different operating voltages of 10 kV and 40 kV to investigate the influence of the FIB energy on the sample quality. The fine structures of the samples have been studied using a high resolution TEM, and the concentration of the implanted Ga was analysed using an energy dispersive X-ray (EDX) analysis. The result of the TEM observation revealed that point defects were introduced to the sample finally milled at 40 kV but not at 10 kV. However, crystal lattice images and electron diffraction patterns were clearly observed on both the samples. The typical influence of the FIB energy was indicated in the elemental analysis. The relative Ga concentration in the thin sample finally milled at 10 kV was 1.0-2.0 at% that is less than half of 4.0-6.0 at% of the Ga concentration in the sample finally milled at 40 kV. A comparison between the experimental results of the Ga concentration measurement with simulation was also discussed. 相似文献
16.
Guoqing Guan Katsuki Kusakabe Haruka Ozono Masatsugu Taneda Masato Uehara Hideaki Maeda 《Journal of Materials Science》2007,42(24):10196-10202
Three-dimensionally (3D) well-ordered carbon microparticle assemblies with different particle morphologies were fabricated
by infiltration of phenolic resin solution into SiO2 inverse opal structures and subsequent carbonization. The effect of the phenolic resin solution concentration and the carbonization
temperature on the morphology of the fabricated carbon microparticles was investigated. At a carbonization temperature of
1000 °C, carbon microparticles with interlocked bridges were obtained when the concentration of phenolic resin solution is
40 wt% and hollow carbon microparticles with opened window channels were obtained at a concentration of 30–35 wt%. When the
carbonization temperature was decreased to 500 °C, carbon microparticles with interlocked bridges also were observed, even
when the phenolic resin concentration was 30 wt%. The structures and properties of the carbon microparticles and their assemblies
were characterized using SEM, XRD, and N2 adsorption. 相似文献
17.
Printed Electronics: Room‐Temperature Printing of Organic Thin‐Film Transistors with π‐Junction Gold Nanoparticles (Adv. Funct. Mater. 31/2014) 下载免费PDF全文
18.
19.
The purpose of this study is to clarify damage process of “Type IV cracking” in weldment of a 2.25Cr-1Mo steel and to propose a micro damage prediction method. From continuous observation under a creep-fatigue test, it was found that spherical shape voids initiated and grew on grain boundaries in fine grain region and these voids grow continuously by changing their shape to crack-like. Both spherical and crack-like void growth rate equations were derived from the proposed void growth model. It was indicated that measured void growth rate under the creep-fatigue loading was well predicted by the growth rate equations. 相似文献