超细碳酸钙的制备与表征

分别以硅酸钠和硫酸锌为晶型控制添加剂，通过石灰乳碳化工艺制备超细CaCO3粉体。研究了添加剂用量对CaCO3颗粒尺寸的影响，并用TEM，XRD和TG－DTA对CaCO3粉体进行了表征。结果表明，添加0．7％－1．5％硅酸钠和0．5％－1．2％硫酸锌可分别制得颗粒尺寸为40－50m和40－60nm的球形和立方形超细CaCO3粉体。     

CaCO3填充母料产品开发及性能研究

填充母料是将片各种填充剂直接加入树脂中,然后混合、塑炼、挤出造粒。采用填充母料,可得到各组分均匀的制品,成型工艺稳定,生产效率高本文在PP或ABS中加入无机填料碳酸钙,以及钛酸酯偶联剂、液体石蜡、硬脂酸等其他助剂经过挤出合成了CaCO3填充母料,产品以熔体流动速率（MFR）和断裂伸长率以及拉仲强度等指标进行表征,得到了性能较好的产品配方。     

气液法制备文石型碳酸钙晶须及影响条件研究

研究了在MgCl2-Ca（OH）2--CO2体系中,气液法制备碳酸钙晶须的形貌和影响条件．结果显示,在此条件下制备的是具有较好形貌和高长径比,且分布均一的文石型碳酸钙晶须,并利用扫描电镜（SEM）、X-射线粉末衍射（PXRD）和傅里叶转换红外（FT—IR）光谱图等手段对其进行了表征．其最佳制备工艺为：反应温度为80℃,CO2的流量为5mL／min,搅拌速度为250r／min,MgCl2溶液浓度为0．4mol／L．     

Development of lanthanum strontium cobalt ferrite composite cathodes for intermediate- to low-temperature solid oxide fuel cells

Solid oxide fuel cells(SOFCs) offer high energy conversion,low noise,low pollutant emission,and low processing cost.Despite many advantages,SOFCs face a major challenge in competing with other types of fuel cells because of their high operating temperature.The necessity to reduce the operational temperature of SOFCs has led to the development of research into the materials and fabrication technology of fuel cells.The use of composite cathodes significantly reduces the cathode polarization resistance and expands the triple phase boundary area available for oxygen reduction.Powder preparation and composite cathode fabrication also affect the overall performance of composite cathodes and fuel cells.Among many types of cathode materials,lanthanum-based materials such as lanthanum strontium cobalt ferrite(La1-xSrxCo1-yFeyO3- have recently been discovered to offer great compatibility with ceria-based electrolytes in performing as composite cathode materials for intermediate-to low-temperature SOFCs(IT-LTSOFCs).This paper reviews various ceria-based composite cathodes for IT-LTSOFCs and focuses on the aspects of progress and challenges in materials technology.     

When Glass and Metal Corrode Together,VI: Chalconatronite

ABSTRACT

Chalconatronite, Na₂[Cu(CO₃)]₂·3H₂O, is formed as a corrosion product when copper alloys are exposed to sodium carbonate solutions in the air. This also happens when metals come into contact with corroding soda glass which forms alkaline surface films in reaction with humidity from clean air. More often, substantial amounts of formaldehyde are present indoors which react to formate via the Cannizzarro reaction and accumulate over time in the films. Twenty cases of chalconatronite (including two mentioned in the literature) are reported as occurring on heritage objects with glass in contact with copper alloys: Baroque reliquaries with set glass gems, enamel on metal (sixteenth century and a modern replica of intentionally unstable composition), Christmas tree glass baubles with wires, glass buttons with metal shanks, a glass figure with a wire support, miners’ lamps, and a glass framed daguerreotype. These confirmed identifications might help conservators in investigating similar cases to shed more light on the formation conditions.     

Diversity of Terrestrial Cyanobacteria Colonizing Selected Stone Monuments in Serbia

The presence of biofilms on stone monuments can lead to biodeterioration processes that significantly lower not only the aesthetic value of cultural heritage sites but also cause considerable physical and chemical damage to stone surfaces. In terrestrial environments, cyanobacteria have a significant role in biofilm formation on a variety of natural and artificial stone substrata, including granite, sandstone, limestone, lime mortar, etc. Studies on cyanobacterial diversity and estimation of biodeteriorative activity on stone cultural heritage objects can be very important for conservators and restorers, and cyanobacteria removal from stone monuments is currently a great challenge for conservation science. In that sense, the diversity of terrestrial cyanobacteria was investigated at six localities in Serbia. Samples for cyanobacterial analyses were taken from surface biofilms covering different substrata: granite and lime mortar (The Monument to the Unknown Hero), sandstone (Branko's Bridge, Eiffel’s Lock) and carbonate rock (Medieval tombstones from Mramorje and Rasti?te, Gradac Monastery). A total of 18 cyanobacterial taxa were identified. The highest diversity was found on carbonate rock, followed by sandstone. Cyanobacteria were also recorded on an artificial substratum – lime mortar, while cyanobacteria were not found on granite. All detected cyanobacteria seriously impaired the structural and aesthetic integrity of the studied monuments via mechanical and chemical actions, so their presence must not be overlooked.     

钙离子对原子荧光测定锡的干扰

原子荧光测定锡的方法有许多文献都有记载,但对钙离子对测定锡的干扰在现有文献上还没有相关的记载。在实践中发现碳酸盐中测定锡时如不进行处理则有严重的负误差,在熔矿时加入一定量的EDTA可以消除这种干扰。     

CaF2-doped ZrO2： A base catalyst for synthesis of dimethyl carbonate

The effect of CaF2-doped ZrO2 catalyst for the synthesis of dimethyl carbonate （DMC） was studied by X-ray diffraction （XRD）, CO2-temperature programmed desorption （TPD）, Raman spectra, and X-ray photoelectron spectroscopy （XPS）. Catalytic performance was evaluated in the bath and distillation reactors. Results showed that the CaF2/ZrO2 catalysts had activity and stability for DMC synthesis.     

头孢替安盐酸盐合成方法研究

目的：研究头孢替安盐酸盐合成工艺。方法：以7-氨基头孢霉烷酸为原料,通过三氟化硼催化法制得头孢替安三位中间体,再与氨噻唑乙酰氯反应制得头孢替安盐酸盐。结果：本方法制备简便,适于工业化生产。     

Advance on Molten Carbonate Fuel Cell and Research on Some Key Problems

1 IntroductionIn the late nineteen cenny chemists were seekingfor a way to convex chemical ~ of coal directlyinto electrical energy by means of electrochemisnyThey could not make a rapid progress on it anvil 1970's,when the molten carbonate fuel cell (MCFC) wasPresent. It is well-kllown that in tradihonal electricitygeneration, such as firepower electricity-generation,chemical energy is cotlvthed intO heat energy, then intomechanical energy, at last into electrical energy, and theconversion …