烧成及热处理工艺对钛酸锶铅基热敏材料性能及显微结构的影响

研究了烧成及热处理工艺对钛酸锶铅基热敏材料的阻温特性及显微结构的影响。通过扫描电镜（ＳＥＭ）和能量分散仪（ＥＤＡＸ）分析了材料的显微结构及不同形貌晶粒的成份。通过对组成、烧成及热处理工艺的控制，可得到具有Ｖ型ＰＴＣＲ特性的热敏材料。     

Effect of Bi and Sr concentrations on the formation of the 2223 phase in Bi-Pb-Sb-Sr-Ca-Cu-O materials, obtained under different conditions of thermal treatment

The superconducting properties and the phase and chemical composition of Bi _x Pb_0.3Sb_0.1Sr _y Ca₂Cu₃O_z (x=1.5, 1.6, and 1.7;y=1.9, 2.0, and 2.1) materials synthesized by one-step and multistep thermal treatments have been investigated. The multistep annealing between 825–875°C promotes the 2223 phase. The change of Bi concentration has little effect on the 2223 phase formation, regardless of the kind of thermal treatment used, but increasing the Sr concentration (y> 2) strongly inhibits this phase. It has also been established that the loss of Pb after synthesis depends on the initial Bi concentration. The loss of Pb decreases when the initial Bi content is lower.     

火电仿真技术研究

在电力行业中，计算机仿真一直是不可缺少的工具，它在减少损失、节约经费、提高效率、确保安全经济运行等方面发挥了巨大作用。主要介绍了计算机仿真技术在660MW火电站中的具体应用情况。以邯峰发电厂^#1机为对象，采用STAR-90仿真支撑系统，建立起660MW火电机组1：1仿真机，并在机组投产前建成，取得了良好的培训效果。论述了火电站仿真机未来的发展趋势，包括开发高精度机理性仿真数学模型以及真实的DCS仿真模型、进行性能计算与故障诊断、应用于热工人员培训及机组调试等。     

Effects of the International Temperature Scale of 1990 (ITS-90) on CIE Documentary Standards for Radiometry,Photometry, and Colorimetry

The differences between ITS-90 and IPTS-68 above 1235 K are described. It is shown that none of the following CIE definitions or recommendations require revision because of the introduction of the ITS-90: International Lighting Vocabulary definitions; CIE Standard Illuminants A, D₆₅, other illuminants; and sources for realizing CIE Illuminants. The effect of the ITS-90 on previously calibrated sources for realizing CIE illuminants is negligibly small.²     

Experimental investigation and thermodynamic modeling of the Mg–Sn–Sr ternary system

The isothermal sections of the Mg–Sn–Sr ternary system in the Mg-rich region at 415 and 350 °C have been determined using the scanning electron microscopy (SEM) equipped with energy dispersive X-Ray spectrometry (EDS). The existence of the MgSnSr ternary compound was confirmed in these two isothermal sections. Two new compounds, named Mg₅Sn₃Sr and Mg₂₅Sn₂₄Sr_14, were found in the present work based on the SEM/EDS results. Thermodynamic optimization of the Sn–Sr binary and Mg–Sn–Sr ternary systems were carried out using the CALPHAD (CALculation of PHAse Diagrams) technique. The Modified quasi-chemical model (MQM) was used for the liquid solution which exhibits a high degree of short-range ordering behavior. The solid phases were described with the Compound energy formalism (CEF). Finally, a self-consistent thermodynamic databases for the Mg–Sn–Sr ternary system has been constructed in the present work, which can be an efficient and convenient guidance to investigate and develop the Mg-based alloys.     

infi90控制系统在钢管加热炉上的应用

介绍了用于钢管加热炉双交叉限幅燃烧控制的ｉｎｆｉ９０控制系统的构成和通讯网络，基本控制模件ＣＬＣ０４指令回路控制器的硬件结构，软件功能等。     

DISACCOMMODATION OF INITIAL SUSCEPTIBILITY IN AMORPHOUS Fe_(90-x)Ni_xZr_(10) ALLOYS

The disaccommodation(DA)measurements of initial susceptibility were performed inamorphous Fe_(90-x)Ni_xZr_(10)(x=10,20,30)alloys.The DA was measured for two differentamorphous states:as-quenched and pretreated at 537 K for 45 min.For all the as-quenched samples,in the isochronal spectra of DA a well defined relaxation peak around350 K is accompanied by a samll but distinct peak near the Curie temperature ofFe_(90)Zr_(10) phase(T_c=230 K).The reversibility and annealing effect on DA are analyzedwithin the framework of two-level model.The fits of the theory to the experimentaldata of reversible relaxation processes gave a spectrum,of activation energies and pre-exponential factor.     

Oxygen transport in ferrite-based ceramic membranes: Effects of alumina sintering aid

Moderate additions of Al₂O₃ to strontium ferrite-based mixed conductors, such as SrFe_0.7Al_0.3O_3−δ and La_0.2Sr_0.8Fe_0.8Ga_0.2O_3−δ with the composition close to the solid solution formation limits, make it possible to improve ceramics sinterability, to increase oxygen permeability and to decrease thermal expansion. These effects are associated with the segregation of alumina-rich phases, primarily SrAl₂O₄, and the formation of A-site cation-deficient perovskite. The improved properties of the SrFe_0.7Al_0.3O₃-based material were used to fabricate high-quality tubular membranes for methane conversion reactors. Similar enhancement in sinterability is also observed for another promising parent material of mixed-conducting membranes, La_0.5Sr_0.5FeO_3−δ. However, extensive dissolution of Al³⁺ cations in the iron sublattice, creation of A-site vacancies and changing the La:Sr concentration ratio all lead to decreasing ionic transport in La_0.5Sr_0.5FeO_3−δ. As a result, additions of either Al₂O₃ or SrAl₂O₄ have a deteriorating influence on the oxygen permeation fluxes through La_0.5Sr_0.5FeO₃-based ceramics.     

Posture variation among office workers when using different information and communication technologies at work and away from work

Office workers perform tasks using different information and communication technologies (ICT) involving various postures. Adequate variation in postures and muscle activity is generally believed to protect against musculoskeletal complaints, but insufficient information exists regarding the effect on postural variation of using different ICT. Thus, this study among office workers aimed to determine and compare postures and postural variation associated with using distinct types of ICT. Upper arm, head and trunk postures of 24 office workers were measured with the Physiometer® over a whole day in their natural work and away-from-work environments. Postural variation was quantified using two indices: APDF_(90-10) and EVA_(sd). Various ICT had different postural means and variation. Paper-based tasks had more non-neutral, yet also more variable postures. Electronics-based tasks had more neutral postures, with less postural variability. Tasks simultaneously using paper- and electronics-based ICT had least neutral and least variable postures. Tasks without ICT usually had the most posture variability. Interspersing tasks involving different ICT could increase overall exposure variation among office workers and may thus contribute to musculoskeletal risk reduction.     

Protein design to understand peptide ligand recognition by tetratricopeptide repeat proteins

Protein design aims to understand the fundamentals of protein structure by creating novel proteins with pre-specified folds. An equally important goal is to understand protein function by creating novel proteins with pre-specified activities. Here we describe the design and characterization of a tetratricopeptide (TPR) protein, which binds to the C-terminal peptide of the eukaryotic chaperone Hsp90. The design emphasizes the importance of both direct, short-range protein-peptide interactions and of long-range electrostatic optimization. We demonstrate that the designed protein binds specifically to the desired peptide and discriminates between it and the similar C-terminal peptide of Hsp70.