不锈钢氩氧脱碳精炼过程的物理和数学模型

The available studies in the literature on physical and mathematical modeling of the argon-oxygen decarburization(AOD) process of stainless ssteel have briefly been reviewed.The latest advances made by the author with his research group have been summarized.Water modeling was used to investigate the fluid flow and mixing characteristics in the bath of an 18t AOD vessel,as well as the “back-attack” action of gas jfets and its effects on the erosion and wear of the refractory lining,with sufficiently full kinematic similarity.The non-rotating and rotating gas jets blown through two annular tuyeres,respectively of straight-tube and spiral-flat tube type.Were employed in the experiments.The geometric similarity ratio between the model and its prototype(including the straighttube type tuyeres)was 1:3 ,The influences of the gas flow rate,the angle included between the two tuyeres and other operating parameters,and the suitability of the spiral tuyere as a practical application,were examined.These latest studies have clearly and successfully brought to light the fluid flow and mixing characteristics in the bath and the overall features of the back-attack phenomena of gas jfets during the blowing.nd have offered a better understanding of the refining process.Besides,mathematical modeling for the refining process of stainless steel was carried out and a new mathematical model of the process was proposed and developed.The model performs the rate calculations of the refining and the mass and heat balances of the system.Also,the effects of the operating factors,including adding the salg materials.crop ends,and scrap,and alloy agents;the non-isothermal conditions;the changes in the amounts of metal and slag materials,crop ends,and scrap,and alloy agents;the non-isothermal conditions;the changes in the amounts of metal and slag during the refining;and other factors were all considered.The model was used to deal with and analyze the austenitic stainless steel making (including ultra-low carbon steel) and was tested on data of 32 heats obtained in producing 304 grade steel in an 18t AOD vessel.The changes in the bath compostion and temperature during the refining process with time can be accurately predicted using this model.The model can provide some very useful information and a reliable basis for optimizing the process practice of the refining of stainless steel and control of the process in real-time and online.     

Specifications of OCLC CJK Bibliographic Records And the Adoption of CJK Records from Asia

OCLC Online Computer Library Center, the largest library automation network in the world, links nearly 20,000 libraries in the Uaited States and 60 other countries and territories. Introducing a library automatian network of Chinese, Japanese, and Korean(CJK) characters in 1986, OCLC operates the largest CJK library network in the world in terms of the member of online CAK institutional asers. As of January 1, 1995, OCLC had 40 CJK users in the United States, Aastralia, Hong Kang and Taiwan. As of October 1, 1994, there were nearly 850, 000 unique CJK bibliographic records in the OCLC database. OCLC is interested in sharing the CJK bibliographic records, especially in loading CJK records created in Asia into the OCLC database. To this end, OCLC has entered into an agreement with the National Central Library, Taiwan; the National Library of China, and Waseda University, Japan, and is in negotiation to load the Japan-MARC records. Sharing of CJK bibliographic records between libraries in Asia and those in the United States is a complex task as the CJK records created in Asia and those created in the United States are not compatible. This paper explains the specifieatioas of the OCLC CJK records, and lists eight areas where the incompatibility exists. The following five areas of incompatibility are due to different cataloging practices: 1. AACR2; 2. name and subject authorities;3.romantzation; 4.subject headings; and 5.ctassification schemes. Three additional areas of incompatibility are technical in nature; 6.MARC format; 7.character set; and 8.internal code.     

Symmetric alteration of four knots of B-spline and NURBS surfaces

INTRODUCTION Modification of knots of a B-spline curve changes the shape of the curve. In some recent pub-lications (Juhász and Hoffmann, 2001; 2003; Hoff-mann and Juhász, 2004; Li and Wang, 2005), the authors studied the effect of the alteration of a single knot on the shape of the curve. Hoffmann (2004) and Li & Wang (2006) applied these theories into the constrained shape modification of B-spline and NURBS curves. Juhász (2001) and Hoffmann & Ju-hász (2005) studied the effe…     

Association between mandibular posterior alveolar morphology and growth pattern in a Chinese population with normal occlusion

Objective:To investigate the relationship between growth patterns and mandibular posterior tooth-alveolar bone complex morphology in a Chinese population with normal occlusion.Methods:Forty-five patients with normal occlusion(23 males,22 females) were included in this study.Among these patients,20 displayed the vertical growth pattern,and 20 had the horizontal growth pattern,while the remaining patients displayed the average growth pattern.All of the patients underwent dental cone beam computed tomography(CBCT),which included the region of the mandibular posterior teeth and the alveolar.A linear regression analysis and a correlation analysis between the facial height index(FHI) and the alveolar bone morphology were performed.Results:The inclination of the molars,the thickness of the cortical bone,and the height of the mandibular bone differed significantly between patients with the horizontal growth pattern and those with the vertical growth pattern(P<0.05).Significant positive correlations were found between:the FHI and the inclination of the molars;the FHI and the thickness of the cortical bone;and the FHI and the height of the mandibular bone.Conclusions:The mandibular posterior tooth-alveolar bone complex morphology may be affected by growth patterns.     

Reflective Consciousness of Teaching and Learning on English Curriculum in Higher Vocational Colleges

In English classroom of higher vocational colleges,there exist two essential factors:teachers’reflective consciousness and students’reflective consciousness.The former is teachers’awareness of learning activities and effect,and it contains the teacher’s reflections on the classroom practice,the presentation of learning tasks,the participation of students and the interaction between teachers and students in the classroom.The latter refers to students’awareness of self-improvement and the growing process.It focuses on the self-realization of students and their professional ability,method ability and social ability.The two factors are interactive to each other;in the interaction,the former is dominated,and the latter is strongly influenced;through the interaction,a harmonious classroom is constructed so as to achieve the effective teaching.     

论商务英语中同义词重复问题(英文)

Discussed and has analyzed in the commercial English, shrank the abbreviation and identical words and expressions redundant and the synonym compound use; Ancient substantive; Expression precise and fuzziness; The active voice sentence and so on several language phenomena is opposite with passive voice sentence in takes the ordinary English which in the daily life uses, commercial English belongs to one dedicated application English, its linguistic environment are many and the finance, the economics and trade, the public relations, the management, the marketing and so on foreign work is related, specialized knowledgeable is strong. Compares with the ordinary English, commercial English in aspects and so on topical glossary, sentence type characteristic, issue document structure, turn of expression often displays and the ordinary English different individuality.     

Teaching and learning how to write proofs in Concepts of Geometry

This paper concerns my experience teaching Concepts of Geometry, an inquiry-based course that emphasizes discovery learning, analytical thinking, and individual creativity. The author discusses how to guide the students to recognize the connections among different mathematical ideas; to select the types of reasoning and methods of proof that apply to the problem; to organize their mathematical thinking through communication; to make their own mathematical conjectures; and to analyze and evaluate each other＇s mathematical arguments and proofs. In particular, the comments and the feedback from students are included.     

Deformation mechanism of high-stress and broken-expansion surrounding rock and supporting optimization based on the gray correlation theory

Aiming at the large deformation and support problems of high-stress and broken-expansion surrounding rock, and taking 1 000 m level roadway of Mine II in Jinchuan as the research object, an investigation on the deformation and damage of roadway surrounding rock and an analysis of its mechanism were carried out. The gray correlation theory was used in support scheme optimization design. First, causes and mechanism of deformation of the 1 000 m horizontal transport channel were analyzed through field investigation, laboratory test and data processing methods. We arguued that poor engineering geological conditions and deep pressure increases were the main factors, and the deformation mechanism was mainly the ground deformation pressure. Second, the gray correlation theory was used to construct supporting optimization decision method in the deep roadway. This method more comprehensively considers various factors, including construction, costs, and supporting material functions. The combined support with pre-stressed anchor cables, shotcrete layer, bolt and metal net was put forward according to the actual roadway engineering characteristics. Finally, 4 support schemes were put forward for new roadways. The gray relational theory was applied to optimizing the supporting method, undertaking technical and economic comparison to obtain the correlation degree, and accordingly the schemes were evaluated. It was concluded as follows： the best was the flexible retaining scheme using the steel strand anchor; the second best was the one using plate anchors on the top and rigid common screw steel bolt on the two sides; the ttiird was; the rigid common screw steel bolt in full section of roadway; and the worst is the planished steel rigid support. The optimized scheme was applied to the 1000 m level of new excavation roadway. The results show that the roadway surrounding rock can reach a stable state after 5 to 6 months monitoring, with a convergence rate less than 1 mm/d.     

Copyright Highway—Photocopying as Fair Use —Williams& Wilkins Co. v. United States

Fair use doctrine is easily controversial and difficult to judge,and owning to the coming of the new age,fair use doctrine becomes more troublesome.This paper will hold the balance between the right of reproduction of library and the publisher interests by approaching a case under these four elements:the requirement for the Purpose and character of the use;The nature of the copyrighted work;The amount and substantiality of the works used in relation to the copyrighted work as a whole;The effect of the use upon the potential market for and value of the copyrighted work.     

Theory and Practice of Teachers＇ Team Construction of Non-government University in China

The paper is to explore the regularity of teachers＇ team construction of non-government university. In the paper, the author analyzed the instability of the teachers＇ structure and their thoughts; summarize the experience which the non-government university has accumulated over 13 years and put forward the measures to construct non-government university teachers＇ team. That is, to organize the teacher to study the laws and regulations, guide them to dispel the psychological obstacles; pay attention to the emotional fostering with the thought of encourage excellent; carry out the strategy of ＂keep people by emotion, welfare, atmosphere, ideal and good management＂; open new thinking of encouraging excellent. So as to build a comparatively stable, well educated and high-quality team that combines old and young teachers, taking young and the middle aged teachers as the leading factors, not only respects their work but also looks for the truth.     

Modeling and analysis of wet clutch engagement characteristics

A mathematical model was developed to analyze the characteristics of the wet clutch during engagement. The lubricant squeeze action was simulated with Patir and Cheng average flow model in which the permeability of friction material is taken into account, and the asperity load is calculated according to the Greenwood and Tripp approach. In this model, effects of friction material permeability, applied load and driving velocity on the engagement characteristics of the wet clutch were studied. The results show that friction material with high permeability reduces the film thickness rapidly and increases the torque peak; the applied load increases the asperity contact pressure and the friction torque, and reduces the engagement time; the driving velocity mainly increases the engagement time. The theoretical torque and relative velocity curves agree qualitatively with the experimental ones, which verifies the wet clutch engagement model.     

卖火柴的小姑娘

It was terribly cold and nearly dark on the last evening of the old year, and the snow was falling fast. In the cold and the darkness, a poor little girl, with bare; head and naked feet, roamed through the streets. It is true she had . on a pair of slippers     

The Comparison of Tasked-based Teaching Method and Situation Teaching Method in Lexical Learning in Senior High Language Teaching

there are many teaching methods in current teaching procedures,such as the whole language teaching method;communicative teaching method;cooperation teaching method;situation teaching method;tasked-based teaching method;content-based teaching method;competence-based teaching method multiple intelligence teaching method and other teaching methods.This article depicts the usage and comparison of the tasked-based teaching methods and situation teaching method in lexical learning in senior high language leaching.This article first talks about the definition and feature of these two teaching methods.Then through observing the students using different methods,I aim to compare these two methods in order to find out the similarities and differences between them when students are learning vocabulary.Making further study on the teaching methods,I would like to take good advantage of them in lexical learning in senior high classes in hope that we teachers can inspire students'thinking,arouse their desire,active the atmosphere and help them have a better and simpler command of the vocabulary they obtained in the class.     

Reliability-based research for failure risks of ship hull girder

In order to find a simple and programmed method to analyze the reliability of hull beams when fatigue and corrosion act on ships, the stress of ships is to be calculated in compliance with the longitudinal bending and cross-section modulus of ship beams. The calculation value of stress is to be compared with the allowable stress in order to gain the actual ship load and margin of safety, and then assess the reliability and failure probability of ship beams. The longitudinal bending moment is a random variable; the fatigue and cauterization are also random variables; and as the ship is influenced by cumulative damage of fatigue and cauterization, the cross-section modulus is a time-varying random variable. The reliability and failure probabilities can be actually reflected through the reliability analysis method. The analysis results indicate that in the service time of ships, as the age of ship increases and the fatigue and corrosion effects accumulate, the reliability of ship beams decreases and the failure probability increases, especially after 15 to 20 years.     

Residential environment index system and evaluation model established by subjective and objective methods

In this research, the residential environment index system and evaluation model were established by means of subjective and objective methods. The methodology for establishing the evaluation system for residential environment was first analyzed; then the subjective evaluation data-base was established by questionnaire survey; and at the same time, the objective evaluation data-base was constructed by Geographic Information System (GIS); and then the related equation system between subjective and objective system was developed by multiple regression analysis. This research could benefit evaluation of the residential environment quality for various purposes, and also provide important rudimentary data-base for the development and improvement of residential environment for officials. Furthermore, the index system and evaluation model established in this research could construct a strong relation between subjective evaluation and objective data; and thus could provide a comprehensive, efficient and effectiv     

Moral crisis in higher institutions and the dress code phenomenon

This article reviewed the case of indecent dressing among the youth of today especially on the universities campuses, which has forced the authorities of those institutions to enact dress codes to stem the tide and restore high moral standards, integrity and decency. Whether this bid was successful or not was another thing which was a function of many factors namely： （1） absence of procedural and legal structures for enforcement and sanctions; （2） weak moral backgrounds from home; （3） lip-service paid to the issue of dress code by the authorities; （4） negative influence of foreign cultures through the moral pollution of the mass media; and （5） the corrupt nature of the society iner-alia. In the view of the fact that this phenomenon portends serious danger to realizing the sincere goals of training reliable, decent-minded, well mannered workforce and leaders for the future, the study recommended that： （1） all hands be put on deck by all the stake holders within and outside campuses to stem the dangerous tide; （2） well designed structures be laid down for enforcing the rules and penalizing non-compliance; and （3） regular counselling programmes be mounted all over the campuses and in the communities utilizing agencies like the parents, the teachers, the religious bodies and the media most especially.     

“The Poetics” as Apology for Poetry and Poets

Plato and Aristotle are both great philosophers in Greek,and Plato is the teacher of Aristotle.But their attitudes to the philosophy and art are quite different from each other.In Plato’s point of view,all poets should be rebelled out of his republic as they will lead the ordinary people to a wrong way;but to Aristotle,poets and the poetry they write should be admired because they will make good effects on the people and the society.This paper is going to discuss about their different attitudes to the so cial function of the poetry in three aspects:the content and the effect of the poetry;the nature of poetry.