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排序方式: 共有1337条查询结果,搜索用时 31 毫秒
181.
本文从地质力学观点阐述白竹磷矿的构造控矿特征,分析保康磷矿的古构造、古地理环境,以及构造的复合关系,预测隐伏矿体的存在远景。 相似文献
182.
A. K. Chu M. J. Chuang K. Y. Hsieh H. L. Huang Y. C. Yu C. W. Wang E. K. Lin 《Journal of Electronic Materials》1999,28(12):1457-1460
The connection between the chemical corrosion resistance and the microstructure of the Ta2O5 thin films prepared at room temperature by a RF magnetron sputtering technique on Si substrates has been investigated. We
find that the microstructure of the films changes with different RF sputtering power, and is responsible for the degradation
of the corrosion resistance in HF solutions. The deposited films are amorphous and porous when the RF power is low. A preferred
orientation toward (200) β-Ta2O5 can be observed when the RF power is increased to 150 W. In addition, the films deposited under this condition are dense
and are consequently more resistant to the attack of chemicals. AT an RF power of 300 W the corrosion resistance of the films
declines due to an increase of the exposed pore surface to the HF solution. 相似文献
183.
Hai-Uk Nam Jong-Hyun Lee Young-O Kim Young-Gyu Kim Tae-Joo Park 《Korean Journal of Chemical Engineering》1998,15(4):429-433
In order to remove nitrogen and phosphorus simultaneously and to develop a compact process for retrofitting a conventional
activated sludge system, a new fixed-biofilm reactor was designed and tested employing an operation strategy with three and
two reaction phases : anaerobic/anoxic/aerobic (Run-1) and anoxic/aerobic (Run-2). Four kinds of HRT (4, 6, 8 and 10 h) were
varied to investigate the effect of nitrification and denitrification in each reactor. The results of the experiments are
summarized as follows. All removal rates of COD, T-N and T-P in the water treated in Run-1 were higher than those of Run-2.
The average values of COD, T-N and T-P in the treated water were reduced to 5.0 mg/L, 5.6 mg/L and 3.1 mg/L in case of Run-1.
The COD and T-N removal efficiencies of Run-1 were higher than that of Run-2, but the difference between Run 1 and Run 2 was
almost negligible. More than 60 % T-P removal efficiency could be achieved when the HRT was above 8 hour, but the efficiency
was sharply decreased to 36% as the HRT was decreased to 4 hour in case of Run-1. Although the removal efficiency of T-P in
Run-2 decreased by 56 % compared with that of Run-1, the fixed biofilm reactor using SAC media reduced the volume of reactor,
and high-level COD and T-N removal from domestic wastewater was performed ; stable effluent quality was thereby achieved.
The performance of Run 2 with no anaerobic reactor was mostly similar to that of Run 1 with an anaerobic reactor, except for
T-P removal. Hence, according to these results, anoxic and aerobic processes using SAC media could be possible for removing
organics and nutrients from municipal wastewater, in case phosphorus removal is not considered for municipal wastewater with
low concentration of phosphorus. 相似文献
184.
贵州经济发展的支柱之一——磷及磷化工产业 总被引:3,自引:3,他引:0
对贵州磷化工产业优势、发展现状、市场前景及存在问题进行了分析,说明磷有磷化工是贵州经济发展的支柱之一,并说明将贵州磷及磷化工开发作为新的增长点的必要性和可行性,结合贵州实际提出相应的对策和规划建议。 相似文献
185.
P2O5-BaO-Nb2O5三元系统玻璃的形成及性能的研究 总被引:7,自引:0,他引:7
研究P2O5-BaO-Nb2O5三元系统的玻璃形成区,给出了该三元系统玻璃形成范围。结果发现该系统在网络形成体P2O5的摩尔分数仅为20%,Nb2O5的摩尔分数为30%,BaO的摩尔分数为50%的成分点仍成玻璃。讨论了Nb2O5在系数中的作用以及部分玻璃的着色问题。熔制了BaO的摩尔分数恒定为50%的(50-x)P2O5-xNb2O5-50BaO(x=0,1,10,25,30)和Nb2O5的摩尔分数恒定为10%的yP2O5-10Nb2O5-(90-y)BaO(y=40,50,60,70)玻璃。测定了其折射率、Abbe数、非线性折射率、转变温度、析晶温度、熔化温度、氧原子摩尔体积及密度和组成之间的关系,并从红外吸收光谱的结果初步探讨该玻璃结构。认为在该系统中Nb2O5的作用介于网络形成体和中间体之间。玻璃着色的原因是Nb^5 被还原。 相似文献
186.
187.
188.
Fatma Z. Tepehan Ferhad E. Ghodsi Nilgun Ozer Galip G. Tepehan 《Solar Energy Materials & Solar Cells》1999,59(3):147
Amorphous Ta2O5 films were prepared by sol–gel dip process on different substrates. The dip-coating technique was used to prepare amorphous Ta2O5 films by hydrolysis and condensation of tantalum ethoxide, Ta(OC2H5)5, precursor. Stable coating solutions were prepared using acetic acid as a chelating ligand and catalyzer. Single layer and multi-layered Ta2O5 films were fabricated at a dipping rate of 107 mm/min. The microstructure, stoichiometry and optical properties of these films were investigated as a function of the film thickness. Room temperature CV measurements clearly revealed a protonic conductor behavior for Ta2O5 films. Optical properties such as refractive index, extinction coefficient and optical band gap value of the Ta2O5 films were calculated from optical transmittance measurements. It was found that the refractive index and extinction coefficient values were affected by the thickness of the coatings. The refractive index at a wavelength of 550 nm increased from 1.70 to 1.72 with increasing film thickness. The optical band gap value (3.75±0.12 eV) of the coating was unaffected by the film thickness. These results indicate that sol–gel-deposited Ta2O5 films have a promising application as proton conductors in electrochromic devices. 相似文献
189.
食用油脂物理精炼和化学精炼诸多因素的比较 总被引:1,自引:1,他引:0
目前,在我国具有一定规模的禽用油脂精炼工厂(车间)中,以物理精炼或化学精炼的方法加工着不同品种的植物油脂,或以此两种不同的方法加工着同一品种的油脂。这两种方法的优缺点已成为多年来争议的焦点之一。列举了物理精炼和化学精炼中的许多因素,并加以对照、比较,以期对它们有更好的了解。 相似文献
190.