Aspects of microstructure in low carbon steels produced by the CSP process

The solidification structure, microstructure evolution during rolling and precipitates with nanometers in dimension of the low carbon steels produced by CSP process with thin slabs have been studied in recent years. Important differences in microstructure and mechanical properties between the CSP products and the conventional one were observed. These differences may arise from the much rapider solidification rate and cooling rate after casting of the thin slabs. Some aspects of the microstructure for the low carbon steels of the CSP thin slabs are summarized and compared with the conventional one.     

常规变电站无人值班改造的几项关键技术

常规变电站正在无人值班改造，但在进行过程中，由于理解的不同，往往产生各种认部分和措施上的差异，使已改造的变电站运行并不理想，本文针对常规变电站在进行无人值班改造的几个关键技术进行分析，并提出相应的解决方法。     

混凝土结构剩余使用寿命的评估

主要就混凝土结构剩余使用寿命的评估的最新发展情况及实用方法做详细论述,并提出了自己的见解.     

团结水库大坝渗流状态分析

对四川省三台县团结水库自1993年7月至2000 年的大坝观测资料进行了 分析，并建立了用来预报和检验测点水位的多因子统计模型，此模型基本反映了大坝的实际 渗流状态。     

TXP分散控制系统在660MW发电机组中的应用

根据TXP分散控制系统在邯峰电厂 6 6 0MW发电机组上实际应用 ,介绍了TXP分散控制系统的系统配置和实现功能 ,其中重点介绍了OM 6 5 0过程控制和管理系统的构成、功能、组态的内容、组态途径、过程监视画面、报表和性能计算 ;详细介绍了自动系统AS6 2 0的控制范围及其功能 ,如 :DAS、SCS、CCS、FSSS、DEH、MEH、BPS。同时 ,结合本人在邯峰电厂调试中发现的问题 ,给出了相应问题的处理方法     

具有动态的(t,n)共享验证的认证加密方案

给出了一种新的 (t,n)共享验证的认证加密方案 ,其安全性基于大数的因式分解和离散对数问题 .本方案改进了现有的 (t,n)秘密共享方案 ,系统每个用户都可担任信息处理者和验证者 ,信息处理者可根据信息的安全需求设置不同的 t值 ,这些动态的操作都不需系统重新设置系统参数和各用户密钥 ;并能有效地检测和识别多种欺骗行为 ,因而有较高的安全性和实用性     

内燃机车主整流柜均流随车检测初探

本文针对内燃机车硅整流装置的故障问题,介绍了新的随车检测方案,可实现对整流柜均流值的实时检测.在分析整流装置及整流元件电流的基础上,提出了均流系数检测的不同方法,论述了检测过程中的关键技术问题,设计了整套软硬件方案.     

Grain refinement of low carbon steel produced by CSP process

In comparison with conventional production for hot strips, compact strip production (CSP) brings about some new micro-structural phenomena. Investigations were carried out to clarify the grain refinement mechanism of low carbon steel strips produced by the EAF-CSP process. Samples, obtained from the same rolling stock during continuous rolling, were examined through SEM,TEM and XEDS. Thin slabs have a dominant columnar structure and the spacing of the secondary dendrite arms ranges from 90 to ～125 μm. The average grain sizes for the central area of the samples from the 1st to 6th pass are 41.6, 25.2, 21.4, 20.2, 13.1, 6.7 μm,respectively. Large number of nanometer oxide and sulfide have been found in the low carbon steel produced by the CSP process.The grain refinement mechanism can be summarized as follows: finer solidification structure of the thin slab; austenite recrystalliza-tion at higher temperature and stain accumulation at lower temperature caused by the great reduction of single rolling pass during continuous rolling; nano-scaled precipitates of sulfide and oxide which drag grain boundaries of austenite or ferrite to prevent the grain coarsening.     

Droplet Deformation and 2-D/3-D Marangoni Flow Phenomena in Droplets Levitated by Electric Fields

An integrated numerical model is presented for free surface phenomena and Marangoni fluid flows in electrically levitated droplets under both terrestrial and microgravity conditions. The model development is based on the boundary element solution of the Maxwell equations simplified for electrostatic levitation applications and the free surface deformation that is primarily caused from the surface Maxwell stresses resulting from the applied electric fields. The electric and free surface model is further integrated with a finite element model for the surface-tension-induced fluid flows in the levitated droplets. Both 2-D and 3-D fluid flow structures may be developed in the electrically levitated droplets depending on the applied laser heating sources. The integrated model is applied to study the electric field distribution, free surface deformation, and 2-D and 3-D internal fluid flow structures in normal and microgravity for single, symmetric two-beam, four-beam, and six-beam laser heating arrangements. Among these arrangements, the six-beam arrangement with equal heating intensity gives the smallest temperature difference and the smallest maximum velocity.     

Stimulated Collision-induced Fluorescence in XeCl-laser-pumped Barium Vapour at High Buffer-gas Pressures

Abstract

New stimulated collision-induced fluorescence lines at 551·9, 606·3 and 611·1 nm were observed in XeCl-laser-pumped barium vapour at high buffer-gas pressures. They correspond to barium 6s6d ³D₂-6s6p ³P₁ and 5d6p ³P_{2, 1}-6s5d ³D_{3, 2} transitions, following a preceding spin-forbidden transition 6s7p ¹P₁-6s6d ³D₂. A similarity was found to exist between this 6s7p ¹P₁-6s6d ³D₂ transition and the well studied 6s6p ¹P₁-6s5d ³D₂ transition.