Synthesis and surface properties of submicron barium sulfate particles

Barium sulfate particles were synthesized in the presence of EDTA at room temperature. X-ray diffractometry (XRD), Fourier transform infrared resonance (FTIR) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of BaSO₄ particles. The effect of the preparation parameters on the particle size distribution and morphology was investigated. The conditional formation constants of Ba-EDTA at different pH values were calculated. The results show that the size and morphology of BaSO₄ particles can be effectively controlled by adding EDTA in the precipitation process. Among all the operation conditions, the pH value has significant effect on the particle size. The obtained barium sulfate particles are spherical and well dispersed at pH = 9-10. Zeta potentials of BaSO₄ were measured at different pH. The isoelectric point (IEP) of barium sulfate colloid appears at pH 6.92. The model of the solid-solution interface at a particle of BaSO₄ was presented. The FTIR result indicates that the surface of the prepared BaSO₄ absorbs the functional groups of EDTA, which lower the IEP of the barium sulfate particles.     

磁性纳米TiO_2/Fe_3O_4的制备及其光催化性能

采用特殊液相沉淀法分两步制备了壳核结构的磁性纳米TiO2/Fe3O4,并讨论了TiO2/Fe3O4比例对其磁性的影响。利用XRD、TEM和VSM对其进行了表征,用它做催化剂,甲基橙溶液为降解目标,在日光作用下对其光催化活性进行了研究,并测出了其回收率。结果表明,在本实验条件下制备的磁性纳米TiO2/Fe3O4表现为超顺磁性,具有较强的光催化活性和较高的回收率。当TiO2∶Fe3O4为4∶1,在450℃焙烧30min条件下得到的催化剂,对20mg/L的甲基橙溶液在60min内降解率高达91.5%,明显高于纯TiO2的催化活性,在外加强磁场的作用下,此催化剂很快从溶液中分离出来,测得其回收率为88.2%。     

基于气象因子的烟粉虱发生预测

利用冬季温度和春季寒潮可以预测烟粉虱的越冬虫源数量,利用扩散期间的风向、风力、持续时间可以预测烟粉虱的扩散方向和在田间的分布区域;利用6-9月份的温度可以预测大田烟粉虱的发生量。应用该方法,作者根据11月至翌年4月的温度、降水和日照,对2007年江苏东台市大田烟粉虱的发生进行了成功预测。     

The effect of calcium cations on the precipitation of barium sulfate 2: calcium ions in the presence of organic additives

Calcium ions have been implicated in changing the precipitation of barium sulfate when organic additives are present, although whether it inhibits or promotes nucleation and/or growth has been disputed in the literature. We conducted a thorough investigation into the effect of calcium when additives are present and show that calcium cations do indeed promote nucleation of barium sulfate particles when compared to the appropriate control. This result is independent of the analytical method (conductivity or turbidity) used to assess precipitation. The nucleation promotion produces no change in the crystal morphology, thus morphology is not always a good indicator of nucleation or growth behavior. The extent of nucleation promotion depends on the functional group of the additive.     

Effect of Ni Precipitation Method on CO Methanation over Ni/TiO2 Catalysts

A Ni/TiO₂(TBT) catalyst was prepared through in situ precipitation, using tetrabutyl titanate(TBT) as the TiO₂ precursor, and was studied in CO methanation. A Ni catalyst supported on commercial TiO₂ was also prepared through post precipitation and studied to compare the influence of Ni precipitation conditions on the catalyst's performance. To gain insight on their structure and physicochemical properties, the catalysts were characterized with N₂-adsorption, X-ray diffraction, transimission electron microscopy, H₂ temperature programmed reduction and temperature programmed desorption. The results showed that the in situ precipitation method was beneficial to the dispersion of Ni and the formation of more active sites on the Ni/TiO₂ catalyst. In addition, the density of the metal-support boundary and its interaction with the active component were also increased. These characteristics of Ni/TiO₂(TBT) led to a lower light-off temperature and a suppression of Ni sintering during CO methanation. As a consequence, the Ni/TiO₂(TBT) exhibited better catalytic behavior, with a CO conversion of 99.4% and CH₄ selecti-vity of 90.4% under the following conditions:p=1 MPa, t=320℃, n(H₂)/n(CO)=3, gas hour space velocity (GHSV)=2×10⁴ mL·g^-1·h^-1. The life test results of the two catalysts showed that Ni/TiO₂(TBT) was more stable and the catalytic activity remained at its initial level after being used for 30 h.     

沉淀聚合制备磺酸掺杂的聚苯胺

以二丁基萘磺酸(DBNSA)或十二烷基苯磺酸(DBSA)为有机酸,水为主要反应介质的条件下进行沉淀聚合直接制备有机酸掺杂的聚苯胺(PAn).讨论了酸度、温度和氧化剂用量等反应条件对产物的影响。2L规模扩大实验的产率约为75%～80%,所得PAn具有高电导率(3.0S·cm^-1),并易溶于普通有机溶剂。其中PAn-DBNSA在各方面较具优势。     

Ag3PO4/PBN复合材料的制备及可见光催化性能研究

在空气氛围下,900℃热解硼酸-三聚氰胺前驱体制备多孔氮化硼(PBN),然后通过原位沉淀法制备出Ag₃PO₄/PBN复合光催化剂。利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)、紫外-可见漫反射光谱(UV-Vis DRS)、荧光分光光度计(PL)等方法对复合物的结构和形貌进行分析。以罗丹明B(RhB)为降解底物,对光催化性能进行评价。使用异丙醇(PA)、乙二胺四乙酸二钠(EDTA-2Na)、对苯醌(BQ)和AgNO₃捕获.OH、h₊^、.O_2-^和e_-^,对光催化机理进行研究。结果表明, Ag₃PO₄/PBN在PBN含量为70mg时催化效果最好,在可见光照射10min后,0.03g复合光催化剂对RhB溶液(50ml,30mg/L)降解率达到99.6%,具有优良的降解性能;3次重复实验后,催化剂的催化性能几乎没有发生变化,.OH、h₊^和.O_2-^在Ag₃PO₄/PBN光催化降解过程中起主要作用。     

Development and Verification of a Diagnostic Technology for Waste Battery Deterioration Factors

We defined four major deterioration factors (electrolyte loss (EL), lithium loss (LL), lithium precipitation (LP), and compound deterioration (CD)). Then, we derived eleven key performance indicators (KPIs) for comparative analysis. After that, we fabricated three deteriorated cells for each of three deterioration factors (EL, LL, and LP) and one cell with CD (for verification) with four individual (dis)charging experiment manuals. The two major contributions of this study are the performance of 1) trend analysis to determine a suitable diagnostic metric by inspecting the eleven KPIs and 2) comparison analysis of and to verify the effectiveness of utilizing as a real-time deterioration diagnostic factor using a concept of model-in-the-loop simulation. The results show that 1) has the most conspicuous trendline tendency among the eleven comparison targets for all four major deterioration factors, and 2) the angle difference between the two trends of and lies within a minimum of 9° and a maximum of 43° (with a sscale on the x-axis and a scale on the y-axis for a clear trend line analysis). From this, we can conclude that the trendline-based real-time deterioration analysis employing may be practically applicable to a limited extent.