Hydrothermal Synthesis of Magnesium Aluminate Platelets

Magnesium aluminate (MgAl₂O₄) platelets were first synthesized by hydrothermal treatment of γ-AlO(OH) in a magnesium nitrate aqueous solution at 400°C. The platelets are 100–200 nm in width and 25 nm in thickness. The influence of temperature, the anions of the magnesium salt, the amount of magnesium salt, and precursor pH on the formation of such structure was investigated. The experimental results indicated that the anions of the magnesium salt and precursor pH could have a significant influence on the growth of MgAl₂O₄. MgAl₂O₄ formation followed the in situ transformation mechanism, which was the reason why the MgAl₂O₄ crystallites had a platelet morphology.     

Effects of tube rupture modeling and the parameters on the analysis of multiple steam generator tube rupture event progression in APR1400

A multiple steam generator tube rupture (MSGTR) event in APR1400 has been investigated using the best estimate thermal hydraulic system code, MARS1.4. The effects of the parameters such as the number of ruptured tubes, rupture location, affected steam generator on the analysis of the MSGTR event in APR1400 are examined. In particular, tube rupture modeling methods, single tube modeling (STM) and double tube modeling (DTM), are compared. The APR1400 is found to have the capability of allowing more than 30 min to operators for the MSGTR event of five tubes. The effects of rupture location on the MSSV lift time is not significant in the case of STM, but the MSSV lift time for tube-top rupture is found to be 25.3% larger than that for rupture at the hot-leg side tube sheet in the case of DTM. The MSSV lift time for the cases that both steam generators are affected (4C5x, 4C23x) are found to be larger than that of the single steam generator cases (4A5x, 4B5x) due to a bifurcation of the primary leak flow. The discharge coefficient of Cd is found to affect the MSSV lift time only for a smaller value of 0.5. It is found that the most dominant parameter governing the MSSV lift time is the leak flow rate. Whether any modeling method is used, it gives the similar MSSV lift time if the leak flow rate is close, except in the case where both steam generators are affected. Therefore, the system performance and the MSSV lift time of the APR1400 are strongly dependent on the break flow model used in the best estimate system code.     

三氯乙酰氯的合成与应用

综述了三氯乙酰氯的合成方法及其在农药、医药等领域中的应用。     

Al2O3对唐钢高炉炉渣性能的影响

针对唐钢近2年提高进口矿配比后，Al2O3含量升高对炉渣流动性带来的不利影响，对唐钢高炉的炉渣性能进行了试验研究。并结合国内同行业的生产实践经验，从理论上分析了炉渣中Al2O3及MgO的适宜含量范围，着重论述了唐钢所处冀东矿区条件下降低Al2O3的主要途径及适应高Al2O3炉渣的具体措施。     

An anti-plane crack perpendicular to the weak/micro-discontinuous interface in a bi-FGM structure with exponential and linear non-homogeneities

Treated was an anti-plane crack perpendicular to the interface of an exponential-type FGM strip bonded to another linear-type FGM substrate with infinite thickness. Through Fourier integral transform, the problem was reduced as a Cauchy singular integral equation, which was further solved numerically by the Lobatto–Chebyshev collocation method. Based on the numerical solution, the effects of the geometrical and physical parameters on the stress intensity factor (SIF) were analyzed and the following conclusions were obtained: (a) A notable discrepancy between the interface-perpendicular crack and the interfacial one is that, to reduce the weak-discontinuity of interface or to make the interface micro-discontinuous will not necessarily decrease the SIF of the former, but will surely decrease that of the latter. (b) When a crack tip is situated very near to the interface (or free surface), its SIF will be high and totally dominated by the interface (or free surface). (c) To increase the stiffness of the FGM on one side of the interface is beneficial to preventing the crack on the other side from growing toward the interface. Besides, some practical suggestions were further given for material design in the field of composites.     

外浮顶油罐的液位检测仪表选型及安装

音叉式液位开关和外贴超声波液位开关具有多种优点，近年来逐步取代浮球液位开关，成为大型储罐液位检测的重要仪表。本文通过详细介绍这两种液位开关在外浮顶油罐的设计选型和具体安装，通过阐述检测原理，比较各种安装方式的优缺点，分析产生缺陷的原因以及提出解决方法，为设计施工人员进行仪表选型和安装提供重要参考意见。     

超低渗广谱油层保护技术在板深51区块的应用

板深51区块存在压力敏感地层，在非目的层井段存在大段高渗低压砂岩，而目的层又属于高压低渗地层，属于难采油气田。室内进行的砂床滤失量、砂床封堵带承压能力、岩心封堵带的承压能力及油气层保护效果实验表明，在超低渗钻井液中增加固相含量，能够提高超低渗透膜结构强度，提高地层承压能力，降低砂床侵入深度，增强保护油气层效果，而且有选择性地增加有用固相效果更佳。基于这一理论，研究成功了超低渗广谱屏蔽暂堵油层保护技术，并在板深51区块长22—15井和长23—17K井进行了试验应用。该技术的关键是依据地层特性确定复配暂堵剂。长22-15井和长23-17K井射孔后未经过压裂、酸化、排液处理，获自喷高产，尤其是长22-15井形成自喷油流，创油田单井试采产量最高记录。应用结果表明，超低渗广谱保护油气层钻井液技术封堵隔层的承压能力强，很大程度地提高了漏失层的承压能力和破裂压力，较好地解决了含多套压力层系长裸眼段钻井过程中发生的漏失、井喷、卡钻、油气层保护等技术难题。     

Design of the ECRH/ECCD Launcher System for HL-2A Tokamak

An ECRH/ECCD system with two 68GHz/500kW/1S gyrotrons will be built up in HL-2A tokamak. The location of the Gaussian beam waist is 580 mm away from the center of the plasmas and the beam radius is 37 mm at the center of the plasmas. Compared to the minor plasma radius （420 mm）, it is small enough for localized control. The launcher system covers a wide toroidal and poloidal steering range by the two steering plane mirrors. Therefore it is possible to explore the on- and off-axis heating over half of the plasma minor cross section and the co-current drive.     

小纸层析法快速测定^99mTc—HMPAO放射化学纯度

采用小纸层析系统１：１的氯仿／四氢呋喃展开剂分析＾９９ｍＴｃ－ＨＭＰＡＯ的放射化学纯度，并与两个薄层析系统和一个纸层析系统的方法作比较。配对ｔ检验结果表明两种方法测定的放射化学纯度无显著差异；放射化学纯度在７４．２％－９６．４％，小纸层析法与薄层／纸层析法紧密相关，回归公式ｙ＝１．００６ｘ－０．３２３。