梅钢40 t板坯中间包的工业试验与仿真分析

梅山钢铁公司炼钢厂有2座150t的LD转炉,配40t板坯连铸中间包.为了了解和掌握中间包内部过程的基本特征,在实际中间包内对流动控制装置、钢水停留时间分布及熔池内温度分布情况进行了现场测试,并结合数学和物理模拟方法进行分析.研究结果表明钢包与中间包内钢水的温差对中间包内钢水的流动状态有很大影响,进而影响着中间包内许多冶金过程;实际中间包熔池内温度分布不均,即使没有任何流动控制装置,熔池内上部温度也高于下部温度,现场测定的停留时间曲线与传统的等温水模型实验结果相差较大;在大多数生产条件下,中间包内的流动是非等温流动,以等温条件为前提的挡板设计、控制参数可能与实际情况不符,应该重新鉴别.     

水平连铸中间包流动特性的模拟研究

浇注过程中钢水在中间包内的流动特性对中间包的设计、工艺操作和铸坯质量都有重要影响。本文结合马钢水平连铸7.5t中间包,模拟研究了中间包内液体流动行为和平均停留时间分布规律。在生产中应用结果证明对夹杂物的去除有明显的效果。     

连铸中间包分流挡渣实验研究

在中间包流场分布分析的基础上，借助水模拟试验研究了6流小方坯连铸中间包内钢水流动规律。通过设置分流挡渣墙改进中间包内的钢水流动，分离钢水和炉渣，提高钢中夹杂物的上浮率，达到了预期的效果，并应用于生产实践．     

连铸中间包内钢液流动及其控制

对连铸中间包内钢液流动现象进行了水模拟研究和速度分布测量。研究表明,注入的钢流下降时吸收周围液体,形成扩张角10°～12°的射流,是中间包内流动的动量源。挡墙设置能改变钢液流动方向,是控制钢液流动的有效手段。对不同类型的挡墙设置方案。用示踪剂分布方法测量了流动特点及夹杂物的去除率,探讨了合理的挡墙设置位置。     

底吹中间包内钢液及夹杂物运动特性的数模研究

根据某厂实际中间包的操作工艺参数，采用欧拉两流体模型和拉格郎日随机轨道模型，模拟计算采用湍流控制器和气幕挡墙技术的中间包内的钢液流动特性及钢水中夹杂物的运动行为，研究结果表明，中间包底部吹气过程可以有效地改善钢液的流动状态，消除短路流，起到中间包档墙的作用，并且增大夹杂物在中间包内上浮排出率，大大提高了钢水的清洁度．     

中间包——一种典型的非等温反应器

温度差对中间包内流动的影响将直接影响中间包内许多冶金过程·在许多水模和数模研究中,中间包被看为一种等温反应器·研究发现,中间包内流动过程对温差十分敏感·物理模型实验、数学模拟和现场直接测定对温差的影响作了定性和定量研究·提出了鉴别温差影响的中间包准数,并给出临界值·     

连铸中间包控流装置优化的水模实验

通过对某厂板坯连铸中间包进行控流装置优化的水模实验，发现原中间包结构造成钢水在中间包内的最小停留时间过短，死区体积大；合理结构的挡墙和湍流控制器能够明显改善中间包内的流体流动特性，可以使钢包长水口注流区上方的液面更加平稳。     

连铸中间包分流挡渣实验研究

在中间包流场分布分析的基础上,借助水模拟试验研究了6流小方坯连铸中间包内钢水流动规律,通过设置分流挡渣墙改进中间包内的钢水流动,分离钢水和炉渣,提高钢中夹杂物的上浮率,达到了预期的效果,并应用于生产实践.     

H型中间包与T型中间包的水模对比研究

进行了H型中间包的挡墙和坝的水模拟优化试验,确定出挡墙和坝的最佳设计方案。结合H型中间包的优点,与普遍使用的T型中间包进行了水模实验对比研究。研究表明：H型中间包内流动比T型中间包内更加稳定;当挡墙间距为130 mm、上挡墙高为87.5 mm、下挡墙高为52.5 mm时,H型中间包内液体的流动状态最好,死区体积比T型中间包小;符合工艺参数条件下增大中间包容积有利于停留时间的延长。     

中间包内非等温流现象研究

在专门设计的二维模型上对非等温流现象的形成条件进行了实验研究,定义了衡量非等温流动出现的准数,并给出了临界值,以用来判断中间包内温度差对钢水流动的影响程度.对中间包非等温流动的形成过程进行了数值模拟,并在40t中间包上做了生产现场的直接测量.结果表明,在正常生产条件下,中间包内流体流动是一个典型的非等温过程.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the