THE ROLE OF ARC-PLASMA IN METALLURGY

Abstract

Arc-plasma is introduced by a comparison with conventional heat sources. The mechanism and requirements of arc-plasma devices and equipment are then considered. An arc-plasma materials-deposition unit for automatic operation in an atmosphere of controlled composition and pressure is described. Photographs of objects plasma-spray-formed in tungsten are shown, together with microstructures of plasma-sprayed refractory deposits.

Metallurgical applications of arc-plasma technology are considered under four headings:

Plasma as a user: the requirements of powders for arc-plasma purposes are discussed.

Plasma as a producer: extractive metallurgy, production of ultrafine–and spherical–particles, powders of intermetallic compounds and alloys.

Plasma as a fabricator: consideration of spraying, spray-welding, spray-forming, cutting, and arc-plasma furnaces, including King’s rotating-plasma furnace.

Plasma as a tester: pla,sma for the analyst, application to thermal endurance, ablation, and thermal-shock testing.     

THE EFFECT OF THE TEST FLUID AND TEST METHOD IN THE MEASUREMENT OF THE PERMEABILITY OF POROUS METAL BEARINGS

Abstract

Previous work on the determination of the fluid permeability of porous materials is reviewed, and methods for the measurement of the gas and liquid permeability coefficients of porous metal bearings are described. It is shown that the liquid permeability in porous metal is not independent of time and pressure as is the gas permeability. By the use of relatively simple experimental methods, the influence of surface-active additives in the mineral oil on the liquid permeability can be studied. By a complete understanding of the interactions between the lubricating oil and the metal surfaces of the porosity, an improvement in the performance prediction of porous metal bearings is to be expected.     

添加复合粘结剂的球团试验

对复合粘结剂与无机膨润土粘结剂进行了球团对比试验。试验结果表明，复合粘结剂的成球性能远远优于无机膨润土的，可大幅度降低粘结剂配比(由2．5％降低至0．6％～1．0％)，提高球团矿品位(球团矿品位上升0．8％～1．0％)。配加复合粘结剂的生球爆裂温度和成品球强度指标均有下降，但这些指标都能满足球团生产和高炉冶炼要求。     

氮在非调质钢中的作用

介绍了氮在非调质钢中的有益作用。非调质钢中增氮,改变了钒在相间的分布,促进Ｖ（Ｃ,Ｎ）析出,使析出相的颗粒尺寸明显减小,从而增强了钒的沉淀强化作用、大幅度提高钢的强度。氮通过促进Ｖ（Ｃ〉Ｎ）析出,有效地钉扎奥氏体－－铁素体昌细化了铁素体晶粒。增氮还可促进晶内铁素体的形成,进一步细化了铁素体组织。对微钛处理非调质钢,增氮提高了ＴｉＮ颗粒的稳定性,更有效地阻止奥氏体晶粒长大,充分利用廉价的氮元素,在保     

JH-3型烧结复合粘结剂的工业试验

介绍了枝花钢铁公司采用JH－3型烧结复合粘结剂的工业生产实践及高炉使用该烧结矿后的冶炼效果。     

THE ROLE OF THE BEHAVIORAL SCIENTIST IN THE CIVIL RIGHTS MOVEMENT.

IT IS MAINTAINED THAT BEHAVIORAL SCIENTISTS HAVE NOT CONTRIBUTED SIGNIFICANTLY TO THE CIVIL RIGHTS MOVEMENT. 3 AREAS WHERE ASSISTANCE FROM SOCIAL SCIENTISTS IS URGENTLY NEEDED ARE THE PROBLEMS OF NEGRO LEADERSHIP, POLITICAL ACTION BY THE NEGRO, AND PSYCHOLOGICAL AND IDEOLOGICAL CHANGES IN NEGROES. SOCIAL SCIENCE AND SOCIAL SCIENTISTS ARE NEEDED TO EXPLAIN NEW DEVELOPMENTS IN BOTH THE WHITE AND BLACK COMMUNITY, AND HOW SUCH DEVELOPMENTS WILL LEAD TO THE PROMOTION OF A NONRACIST DEMOCRATIC SOCIETY OR GREATER RACIAL ISOLATION. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

战略采购在企业物资采购中的重要作用

随着经济的发展和市场竞争的激烈,企业的低成本运行越显重要。目前,大部分企业都在开展降本增效,加强采购供应管理,降低采购成本已成为企业价值链的重要环节,对提升企业核心竞争力具有十分重要的意义。战略采购在采购中发挥重要作用,对降低采购成本至关重要。     

THE ROLE OF SPEECH RESPONSES IN SHORT-TERM MEMORY.

REPORTS 3 EXPERIMENTS IN WHICH SS SAW LISTS OF LETTERS FOR IMMEDIATE RECALL, BUT HAD TO SAY A NEUTRAL SOUND AS THEY PERCEIVED EACH LETTER. IN EXP. I THIS TECHNIQUE SUBSTANTIALLY REDUCED RECALL OF LETTERS, SPOKEN AS CAPITALS, AS COMPARED WITH THAT FOR NORMALLY VOICED LISTS, BUT NO DIFFERENCE BETWEEN "SUPPRESSION" AND VOICING EMERGED IF THE LETTERS WERE PRONOUNCED IN ALTERED FASHION. IN EXP. II SS GAVE A SOUND WHICH COINCIDED WITH THE DOMINANT SOUND OF THE PRESENTED LIST. THIS LED TO SLIGHTLY POORER RECALL THAN DID THE SAYING OF NONCOINCIDENT SOUNDS AT PRESENTATION. EXP. III SHOWED THAT THE MAIN ADVANTAGES FOR RECALL OF ARTICULATION CONSISTED IN RAISING THE RECALL PARTICULARLY OF LISTS OF LOW ACOUSTIC SIMILARITY, REDUCING ORDER ERRORS, AND RASING THE RECALL PARTICULARLY OF THE EARLY AND MIDDLE ITEMS OF LISTS. IT IS CONCLUDED THAT THE ADVANTAGE OF ARTICULATION AT PRESENTATION INCREASES AS THE ACOUSTIC SIMILARITY OF THE ITEMS DECREASES. IMPLICATIONS FOR SHORT-TERM MEMORY ARE CONSIDERED. (FRENCH SUMMARY) (26 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PSYCHOPATHOLOGY AND MARITAL ROLE DISTURBANCE: A TEST OF THE THARP-OTIS DESCRIPTIVE HYPOTHESIS.

R. G. THARP AND G. D. OTIS (SEE 40:12) HAVE PROPOSED A THEORY AND TECHNIQUE FOR THERAPEUTIC INTERVENTION IN FAMILIES WHICH ATTRIBUTES "PSYCHOPATHOLOGY" TO A SOCIAL SYSTEM DISORDER, CHARACTERIZED BY DISTURBANCES IN FAMILY ROLES. IT WAS HYPOTHESIZED THAT INDIVIDUAL PSYCHIATRIC PATIENTS AND THEIR SPOUSES EXPERIENCE MARITAL ROLE DISTURBANCE TO A GREATER DEGREE THAN THE AVERAGE NONCLINICAL POPULATION. KELLY-THARP MARRIAGE ROLE QUESTIONNAIRES WERE ADMINISTERED TO 35 PSYCHIATRIC PATIENTS, THEIR SPOUSES, AND TO NORMAL SS AND THEIR SPOUSES. DISCREPANCIES BETWEEN ROLE EXPECTATIONS AND ROLE ENACTMENTS OF THE GROUPS WERE SIGNIFICANT IN THE HYPOTHESIZED DIRECTION FOR 4 OF THE 5 AREAS OF ROLE FUNCTIONING. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

信息资源共享的内在机制——利益平衡

利益平衡机制是合作者之间的利益调节方式，它对信息资源共享具有促进作用，这种作用表现在信息资源共享涉及的利益平衡关系以及平衡方式上。运用利益平衡机制促进信息资源共享，采取利益协调、利益补偿和利益引导的策略与措施是最为有效的途径。     

论信息资源在社会可持续发展中的能动作用

信息资源与物质、能源一起构成现代社会三大资源造福人类。信息资源是一种可再生性资源，可以反复地为人类所利用，可以使社会效益增值。信息资源在社会可持续发展中发挥着能动作用。     

焦炭热反应性试验误差的分析

通过对焦炭反应性和反应后强度试验数据以及常见现象的分析，结果表明；通过控制焦炭粒度、密度、反应温度、时间和CO2流速等因素，可以使试验结果更准确。     

THE CHANGING ROLE OF PSYCHOLOGICAL ABSTRACTS IN SCIENTIFIC COMMUNICATION.

A SUBSCRIBER SURVEY AND OTHER SURVEYS HAVE PROVIDED DATA ON THE USE OF PSYCHOLOGICAL ABSTRACTS (PA). A LONG-RANGE PLAN FOR PA PROMISES TO PROVIDE A WIDE VARIETY OF IMPROVED SERVICES TO SUBSCRIBERS AND TO ESTABLISH AN EFFECTIVE SYSTEM FOR SCIENTIFIC INFORMATION DISSEMINATION. DESCRIPTIONS AND DIAGRAMS OF THE EARLIER AND THE CURRENT OPERATIONS OF PA ARE PRESENTED. "BEGINNING WITH THE JANUARY 1966 ISSUE, PA SHIFTED TO A COMPUTERIZED SYSTEM OF PRINTING. THIS CHANGE WAS THE 1ST OF THE MAJOR REVISIONS PLANNED FOR PA'S OPERATION AND IS A CRITICAL FEATURE IN THE NEW SYSTEM. THE PRINTING PROCESS . . . IS DISTINCTIVE IN THAT INFORMATION IS ENCODED ON THE COMPUTER TAPE ACCORDING TO FUNCTION RATHER THAN ACCORDING TO STYLE." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE ROLE OF SURFACE ENERGY AND POWDER GEOMETRY IN POWDER COMPACTION

Abstract

The factors governing the strength of cold-pressed metal powder compacts have been investigated. It is concluded that the most important parameters are freedom from oxidation and the plastic properties of the powder particles. These determine the roles played by surface energy and powder geometry in powder compaction.     

THE INFLUENCE OF TOOLING METHODS ON THE DENSITY DISTRIBUTION IN COMPLEX METAL-POWDER PARTS

Abstract

The theoretical movements required for the various moving tool elements during the pressing cycle are examined for several typical component sections. These theoretical movements are then compared with the actual movements of the moving tool elements in various types of tooling. The conclusion is reached that the conventional tool designs vary greatly from the ideal in many ways, permitting uncontrolled lateral powder movement during pressing and causing excessive density variation in the pressed compact.

Three major problems are apparent:

(1) The use of a solid die for pressing compacts with varying section thicknesses results in an “average” die movement that is always too great for the thicker section and too small for the thinner section.

(2) The double function of the floating punch, which takes vertical pressure on its horizontal face while its vertical face acts as a die, presents a very difficult problem. The floating punch movement, controlled by its horizontal face, is always greater than the correct movement required to give minimum density variation in the portion of the compact formed by the vertical surface of the punch.

(3) The various types of support used for floating punches rarely provide the correct timing, sufficient maximum load, or progressively increasing resistance essential to ensure equal density distribution within the powder during the pressing operation.

Suggestions for tooling, designed to solve some of these problems, are discussed.     

粉末冶金在国民经济和国防建设中的作用(Ⅰ)

本文首先阐明了现代粉末冶金发展的特点;作为一系列相关产业发展的重要支柱,综述了粉末冶金在航天,汽车制造,机械制造,电子电器,核子等部门的作用;作为当代材料科学发展的前沿,分析了粉末冶金在发展一系列高技术新材料方面的重大作用;指出了发展现代粉末冶金的战略意义。     

网络环境下参考咨询馆员角色转换

根据网络环境下传统参考咨询向网络信息咨询转变的必然趋势，指出传统参考咨询馆员要向网络信息咨询员的角色转换，探讨了网络信息咨询员角色内涵，提出传统参考咨询员向网络信息咨询员转换的几项措施。     

铌在Nd-Fe-B合金中的作用研究

熔炼是制备粉末冶金烧结Nd-Fe-B永磁体的关键技术之一，直接影响到磁体最终磁性能的好坏。本文采用传统熔炼技术制备了成分为Nd15Fe78-xNbxB7的系列合金铸锭，通过对不同含铌量合金铸锭的显微结构及成分分析得出：随着铌含量的增加，合金铸锭中的显微结构由片状晶和枝状晶向颗粒状晶粒转变，同时也改变了α-Fe的晶粒形貌，使富钕相分布更加均匀，从而改善了磁体的磁性能。     

粉末冶金在国民经济和国防建设中的作用(Ⅱ)

本文首先阐明了现代粉末冶金发展的特点;作为一系列相关产业发展的重要支柱,综述了粉末冶金在航天、汽车制造、机械制造、电子电器、核子等部门的作用;作为当代材料科学发展的前沿,分析了粉末冶金在发展一系列高技术新材料方面的重大作用;指出了发展现代粉末冶金的战略意义。     

我国土工离心模型试验技术发展综述

小尺寸物理模型试验是岩土力学与岩土工程研究的重要手段.常规小比尺模型由于其自重产生的应力远低于原型,以及原型材料明显的非线性,因而不能再现原型的特性.解决这一问题的唯一途径是提高模型的自重,使之与原型等效.提高模型的自重应力水平、增大材料自重的最简便的方法就是用离心机.本文在总结回顾大量文献资料的基础上,根据离心模型试验技术的研究深度和应用范围,将我国土工离心模型试验技术的发展历史分为3个阶段,并分别阐述了各阶段土工离心模型试验技术在我国的应用类型及研究状况,介绍了试验设备、试验技术、数据采集等几个方面的发展历程.最后,总结指出了目前离心模型试验技术研究存在的问题,并对今后的研究和工作做了展望.