钛粉质量鉴定新方法试验研究

钛粉质量鉴定一直是用化学分析测定全钛含量，而不能确定单质态的钛含量，实验表明用Ｘ射线衍射分析鉴定钛粉质量效果较好，避名了化学分析的缺点，是一种值得推广的鉴定方法。     

Copper Oxide – Graphite Composite Electrodes: Application to Nitrite Sensing

A simple method for the modification of carbon powder with copper oxides is presented. Carbon powder is impregnated with copper(II) nitrate by stirring carbon powder in copper(II) nitrate solution for 1 hour and subsequently thermally treated at 823 K. The modified carbon powder was characterized using electrochemical and spectroscopic techniques. The existence of both copper(I) and copper(II) oxides have been established. The copper oxide modified carbon powder was used for preparation of composite electrodes, and the electrochemical and electrocatalytic behavior of the resulting composite electrodes was studied. The copper oxide modified carbon powder – epoxy composite electrodes showed a high electrocatalytic activity for the nitrite detection in aqueous media, with the detection limit comparable or lower than detection limits obtained with other electrochemical sensors.     

玉米芯粉对中性红的吸附脱色研究

本文研究了玉米芯粉对染料的吸附脱色情况,结果表明,玉米芯粉能有效吸附阳离子染料。以阳离子染料中性红为模型,考察了吸附剂用量、溶液浓度、溶液p H以及温度等对吸附平衡的影响,结果表明玉米芯粉吸附中性红符合拟二级动力学方程;不同温度下,该吸附过程符合Langmuir方程和Freundlich方程,qmax、KF受温度影响小;D-R等温方程拟合结果表明该吸附是以化学吸附为主;热力学参数计算结果表明玉米芯粉吸附中性红是一个熵减的自发放热过程。其他电解质的存在不利于吸附反应的进行。     

用热重分析与X-射线衍射法探究中国花鲈耳石的微结构

为表征中国花鲈耳石的微结构,应用数码照相机、热重分析仪与X-射线衍射仪对中国花鲈耳石的外观形貌、化学组成与晶体结构进行记录及表征。结果显示:中国花鲈耳石为较厚的宽叶形,表面有不同大小的晶状突,边缘有叶形晶状突,内弯面有中央突,弯曲背面有嵴突及几乎贯穿整个耳石的主凹槽;TGA曲线分为晶体间隙水的挥发,有机质和无机盐的灰化与分解,碳酸钙热分解为氧化钙等三个平台,化学组成中碳酸钙含量为97.92%,水、有机质和其它无机盐含量为2.08%;XRD晶体结构属于稳定性较差的含很少量第二相的霰石。组成与结构的表征有助于鱼类耳石的化学生物学分类数据库的建立,也丰富了耳石的研究内涵。     

Preparation,spectroscopic, thermal and powder X‐ray diffraction characterization,and antimicrobial activities of mixed bis(O,O′‐diisopropyldithiophosphato‐S,S′)antimony(III) derivatives with some oxygen and sulfur donor ligands

Newly synthesized mixed bis(O,O′‐diisopropyldithiophosphato‐S,S′)antimony(III) derivatives have been characterized using physicochemical, spectral, thermal and powder X‐ray diffraction studies, and their antimicrobial activities were investigated. These derivatives have nanometric crystallite size (11.39–14.67 nm) with unit cell volume (4968.47 and 5079.79 ų) and lower symmetry (monoclinic) crystal system. After thermal decomposition in inert atmosphere, these derivatives give antimony sulfide as a final decomposition product which has many potential applications, and they exhibit enhanced antimicrobial activities (greater zone of inhibition) as compared to the free ligands and standard drugs (chloroamphenicol and terbinafine were used as standard antibacterial and antifungal drugs, respectively) due to the nanometric size of the complexes.     

Flow properties and inter-particle forces in fuel powders

This work studied the mechanical properties of a series of industrial fuel powders: bituminite, lignite, and petroleum coke. Sieved cuts of these powders were assessed and the flow properties of each sample were used to calculate tensile strengths as functions of consolidation stress. In addition, BET surface areas and dispersive surface energies were estimated from surface energy analysis. To analyze the bulk flow properties of these fuel powders in terms of micro-contact mechanics, the fundamentals of fuel powder adhesion and consolidation were reconsidered based on the “stiff particles with soft contacts” model proposed by Tomas. In the present work, a multi-contact concept was introduced to account for the irregular shapes of actual particles. This modified model was based on elastic–plastic contact deformation theory and was employed to describe the contact between rough particles and to estimate the associated inter-particle forces. The results were used in conjunction with the Rumpf approach to relate the isostatic tensile strength to the degree of consolidation. Applying average values for the powder compressibility parameters allowed the model to be used for predictive purposes, and an acceptable level of agreement was found between predicted and measured tensile strengths.     

Extraction of humic acid from biological matrix – dry cow dung powder

Abstract

The increased local and global concern, for alarming environmental pollution, offers incentives to explore new green and clean materials and methods for safeguarding the environment. The generation of benign alternate routes for any step in chemical processes, is the need for today and tomorrow. In the present work, humic acid (HA) has been extracted from a green source, “dry cow dung powder”, using simple, cost effective, and eco-friendly methods. HA has been extracted, isolated, and characterized by employing different spectroscopic methods. The process investigated herein imparts a boost to “Green Chemistry”, a promising solution to many global environmental problems.     

Synthesis and characterization of thiosalicylic acid stabilized gold nanoparticles

We report the synthesis of photoluminescent Au nanoparticles of varying sizes stabilized with a carboxylate group terminated aromatic thiol, thiosalicylic acid. The formation of Au nanoparticles and its stabilization with the thiol has been characterized by different spectroscopic and thermal methods. The water solubility, along with the low degree of aggregation and photoluminescence, enhances their suitability for biological applications. The photoluminescence may be due to charge transfer of the Au core with the stabilizing ligand.