Corrosion Inhibition Mechanism with Spilt Cell Technique of Rare Earth Metal on LC4 Al Alloy

A new method of studying the corrosion inhibition mechanism of rare earth metal(REM) on LC4 Al alloy with the spilt cell technique was studied. The principle and experimental method of the spilt cell technique were analyzed. By measuring the change of net-electric current between the two electrodes caused by the change of the amount of oxygen in the solution and the addition of CeCl₃, the influence of corrosive performance of CeCl₃ on LC4 super-power aluminum alloy in the 0.1 mol·L⁻¹ NaCl solution was investigated. Meanwhile, the conditional changes of pH values, CeCl₃ solution, additire and time of performance were also studied. Finally, the features of electrode surface were revealed by using SEM and X-ray energy-dispersive spectrometry (EDS). By combining these with other electric chemical techniques, such as potential-time curve, polarization curve et al.     

寻找非构造油气藏的新思路

目前,一种新的理论体系和研究方法已经形成,并正在发展和逐步完善。那就是层序地层学和油气成藏系统理论的诞生和发展;以及由计算机的快速发展带动起来的地震测井资料的采集、处理、显示和各种地质问题的计算机模拟技术,使得地质学和石油地质学都在朝着从定性到定量,从推测到更科学的预测方向发展。在今后的5～10年中,中国的石油地质家们不仅要注意方法和技术方面的进步,还应当重视在陆相层序地层学和陆相层序中油气成藏机制等基本理论方面的研究。     

科技期刊编辑专业化和学者化是保证期刊学术质量的关键

一般科技期刊刊载的论文内容都具有很强的专业性,这就要求科技期刊编辑必须具有丰富的专业知识和较高的学术水平才能胜任编辑工作.从编辑过程的选题组稿、论文初审、选择审稿专家和编辑加工四个方面对此进行了阐述,指出了提高科技期刊编辑的相关专业知识和学术水平的措施.     

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

Ｈｉｇｈ ｓｐｅｅｄｓｔｅｅｌ (ＨＳＳ) ,ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅｘ ｃｅｌｌｅｎｔｈａｒｄｎｅｓｓ ,ｗｅａｒｒｅｓｉｓｔａｎｃｅ ,ａｎｄ ｇｏｏｄｒｅｄｈａｒｄｎｅｓｓ .Ｒｅｃｅｎｔｌｙ ,ＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｈｏｔｒｏｌｌｉｎｇｒｏｌｌｓｔｏｐｒｏｄｕｃｅｓｔｒｉｐｓｏｆｇｏｏｄｓｈａｐｅａｎｄｓｍａｌｌｃｒｏｗｎｗｉｔｈｅｘｔｅｎｄｅｄｒｏｌｌｓｅｒｖｉｃｅｌｉｆｅ[1,2 ] .ＴｈｅＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｒｏｌｌｃｏｌｌａｒｆｏｒ…     

Squeeze-film effects in MEMS devices with perforated plates for small amplitude vibration

Squeeze-film effects of perforated plates for small amplitude vibration are analyzed through modified Reynolds equation (MRE). The analytical analysis reckons in most important influential factors: compressibility of the air, border effects, and the resistance caused by vertical air flow passing through perforated holes. It is found that consideration of air compressibility is necessary for high operating frequency and small ratio of the plate width to the attenuation length. The analytical results presented in this paper agree with ANSYS simulation results better than that under the air incompressibility assumption. The analytical analysis can be used to estimate the squeeze-film effects causing damping and stiffness added to the system. Since the value of Reynolds number involved in this paper is low (< 1), inertial effects are neglected.     

Langmuir–Blodgett films of physical and chemical polyimide mixtures from linear and network precursors

Physical and chemical mixture Langmuir–Blodgett polyimide films were obtained by reacting mellitic acid hexamethyl ester with pyromellitic anhydride and 4,4′-diaminodiphenyl ether followed by formation of polyamic acid salts with octadecyl amine. The additions of mellitic acid hexamethyl ester provided more reinforcement to the copolymers than the blends because of the more evenly distributed linear and network segments as observed from the Π-A isotherms. The alkyl chains randomly tilted to the normal of the substrate at an angle about 20° while the tilt angels increased with the increase of the amount of mellitic acid hexamethyl ester. The ordered chain packing pattern along the dipping direction was disrupted and even disappeared if more mellitic acid hexamethyl ester was added as shown from the atomic force microscopy images. Accordingly, the X-ray diffraction results showed that the crystallinity decreased with the increase of the amount of mellitic acid hexamethyl ester. The branched component, the mellitic acid hexamethyl ester, had much more effects both in structure and morphology on the copolymers than on the blends.     

A Study of the Specific Heats of the Compounds in the Sm_2O_3-BaO-CuO System

By means of X-ray diffraction and adiabatic scanning calorimeter,the specific heatsof five compounds in the Sm_2O_3-BaO--CuO system,such as Sm_2BaO_4,Sm_2CuO_4,BaCuO_4,Sm_2BaCuO_5,SmBa_2Cu_3O_(7-x),from -150℃ to 800℃ have been measured.It is found that the specific heats ofthese compounds increase smoothly with the increase of temperature.     

粉末冶金铁基烧结炉的现状与展望

评述了国内外粉末冶金铁基烧结炉的发展动向和具体改进装备。即功能带设计、脱蜡装置,烧结带气氛控制,淬火带的设想,加热元件配置及新型可塑性耐火材料。     

Interfacial reaction between CO2-CO gas and molten iron oxide containing P2O5

The interfacial reaction between CO₂-CO gas and molten iron oxide containing P₂O₅ was investigated by the ¹³CO₂-CO isotope exchange technique at 1773 K with CO₂/CO=1.0. The apparent rate constant rapidly decreased with the addition of P₂O₅ up to 2.86 mol pct PO_2.5 and the Fe³⁺/Fe²⁺ ratio kept constant at approximately 0.2. By the classic site blockage model, in which the reaction only occurs on the vacant sites, and the modified site blockage model, in which the reaction occurs on the vacant sites and the sites occupied by phosphorus simultaneously, the effect of the addition of P₂O₅ was analyzed and the reaction mechanism of CO₂ dissociation was discussed. It may be concluded that the dissociation of the adsorbed CO₂ molecule is reasonable as a rate-determining step and that the effect of phosphorus on the interfacial reaction is caused by the decrease in the number of active sites with the increase of phosphorus content as a surface active element in molten iron oxide.     

用高梯度磁场净化轧钢废水

通过用高梯度磁场处理热轧厂废水的试验,得到了在试验条件下浊度(水中不溶物的含量)和铁的去除率,确定了最佳净化条件.在此条件下,能够有效去除废水中的不溶物和铁,经过处理的水质达到了工艺循环水的水质标准.