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1.
A new on-line titration method and device based on a new technique-continuous flow titration is described.By the means of electronically controlled switching of a solenoid valve,the main component of the system,the equivalent point of the titration is easily determined.Several kinds of mixing tools were examined.whereby a self-made mixing chamer with minimum volume gave best results and was therefore used in the dveice,The error of the titration is within 0.2% and the relative standard deviation(RSD) is below 1.2%,The results show no difference compared with a commercial device,meanwhile the new on-line titration system is cheaper and fully automated and thus easy to hand and less slovent consumption.  相似文献   
2.
A theoretical treatment of simulating the morphology and content of SnO2 film coated on ultrafine Al2O3 particles in fluidized bed by chemical vapor deposition (CVD) was developed. The present model accounted for chemical reaction, coagulation, film coating, nucleation coating and gas entrainment of the coating process, which made it possible to predict the quality and quantity of the film coated. By means of Tenanor's method, the model was calculated numerically. Part of the numerical results were compared with the experimental data.  相似文献   
3.
The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification such as Soxhlet extraction, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and zeta potential (ζ). The results of FT-IR and TG-DSC show that the desired reaction chains have been covalently bonded on the surface of ZnO nanoparticles. Zetasizer results reveal that themaximal absolute value of ζ of the modified ZnO particles in acetone medium was 67.0 mV, which was much higher than that of the unmodified ZnO particles. So the surface of nanosized ZnO changed from hydrophilicity to hydrophobicity and the dispersity of ZnO nanoparticles were improved simultaneously. Finally, the mechanism of graft modification was discussed.  相似文献   
4.
The modification of the traditional interior wall paint was carried out by means of adding nano-TiO2 as a functional pigment. By regulating the dosage of dispersant, the nano-particles can be dispersed in paint homogeneously. With two aspects of experiments: dosage of nano-TiO2 and pigment volume concentration (PVC), the paint formulation can be optimized and its properties~ such as hardness, scrub resistance, storage stability, contrast ratio and gloss can be improved. Finally an interior wall paint with high performance and air purification was prepared. Its character of formaldehyde degradation would be discussed in the next article.  相似文献   
5.
Fluidized chemical vapor deposition (FCVD) technology was developed for coating SnO2 thin film on ultrafine Al2O3 particles.Transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM) analyses demonstrated that SnO2 films with different structures were deposited through controlling the coating temperature, reactant concentration, etc.. Nanocrystalline SnO2 film was formed at 572.15K by gas phase reaction of SnCl4 and H2O.Electron probe microanalyser (EPMA) and energy dispersive spectrometer (EDS) analyses indicated that the distribution of nanocrystalline SnO2 over inner and outer part of the Al2O3 agglomerates was homogeneous.  相似文献   
6.
1IntroductionThesynthesisofultrafineparticles(UFPs)isofincreasingscientificandtechnicalinterest.Thesmallsizeofthesepal-tidesendowsthemwithunusualstlvctural,electronic,optical,magneticandchemicalproperties,leadingtomanyimportalapplicationssuchascatalysts,e…  相似文献   
7.
Multi-walled carbon nanombes with homogeneous diameters (40 - 60 nm), produced by chemical vapor deposition of hydrocarbon gas, are purified by nitric acids. Infrared and Raman studies indicate that oxygen containing surface groups, which are predominately carboxylic, phenolic and lactonic groups, are introduced into purified carbon nanotubes. Then three kinds of block-form porous tablets of carbon nanotubes are fabricated as electrodes in electrochemical double-layer capacitors. Using mounded mixture comprising carbon nanotubes and binder powders provides these tablets. Comparison of the effect of different processing on the structural performance of the capacitors is specifically investigated. Using chemically treated electrodes, electrochemical double-layer capacitors with a specific capacitance of about 33 F/g are obtained with 38 wt % H2SO4 as the electrolyte.  相似文献   
8.
1 Introduction Thesmallsize(diameter<100nm)ofultrafineparticlesendowsthemwithunusualstructure,electronic,optical,magneticandchemicalproperties,leadingtomanyimportantapplicationssuchascatalysts,electroopticaldevicesandfineceramics[1].Asoneofspecialf…  相似文献   
9.
目标管理作为一种现代科学管理理论在企业中已得到广泛应用并已取得显著实效,国内部分著名高校和许多科研院所已经将目标管理融入日常管理工作当中.但是高校科学研究工作与科研院所不同,具有其自身的特殊性.如何在高校科研管理工作中推行目标管理,是一个从科研人员意识培养到科研环境建设的系统工程.本文结合上海大学试行全系统目标管理的具体案例,对如何在高校科研管理工作中进行目标管理体系建设的若干问题进行了探讨.  相似文献   
10.
In this study, the barite nanoparticles were successfully modified with stearate and the influence of stearate addition on the performance of barite nanoparticles was systematically investigated. The products were characterized by activating factor analysis, contact angle test, surface energy calculation, sedimentation rate calculation, rheological measurement, and FT-IR analysis, etc. As the quantity of added stearate increased, both the activating factor and contact angle of barite nanoparticles increased first then decreased. When the stearate content was 5% of the mass of barite nanoparticles, the activating factor and water contact angle of modified particles reached maximum value, 97% and 126° respectively. At this time, the sedimentation rate reached minimum, and so did the surface energy. The rheological test reveals that the viscosity of modified barite nanoparticles/petronol system decreases greatly, indicating the surface performance of barite nanoparticles has changed from hydrophilicity to lipophilicity after modification. C=O and COO stretching vibration peaks were found in the FT-IR spectra, which proves that the stearate has combined onto the surface of barite nanoparticles. Finally, according to the zeta potential result of unmodified barite, the possible modification mechanism was provided. Project supported by the International Corporation Project (Grant No.07SU07001), and the Science Foundation of Science and Technology Commission of Shanghai Municipality (Grant No.0552nm011)  相似文献   
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