Changes in the potential and vibrational energies upon the formation of vacancies in the oxygen-alloyed cores of crystallite-conjugation regions of polycrystalline Cr, Cu, and Ir

The changes in the potential and vibrational energies upon the formation of vacancies in the oxygen-alloyed (OA) cores of crystallite-conjugation regions (CCRs) in polycrystals of d transition metals Cr, Cu, and Ir have been determined. The potential energy increases upon the formation of vacancies (upon the formation of complexes of vacancies with oxygen atoms) in the OA cores of CCRs in the polycrystalline Cr, Cu, and Ir. However, the vibrational energy decreases upon the formation of vacancies in the OA cores of CCRs in these polycrystals, as in the OA cores of CCRs in polycrystals of the 4d and 5d transition bcc metals Mo, Ta, and W. The volume of the OA cores of CCRs in polycrystals of Cr, Cu, and Ir decreases upon the formation of vacancies. The changes in the interatomic interactions and dynamic properties in the regions of vacancy localization in the OA cores of CCRs coincide with analogous changes introduced into the lattices of metals by split interstitials.     

Two decades of change in graduate education in metallurgy/materials—A perspective

It is now almost a decade since the introduction of massive federal support to universities for graduate education and research in the materials field. Accordingly, it is appropriate to examine the changes in the nature and activity of the field which have occurred during this period, both in the universities themselves, and in professional practice in industry and government, and also the implications of such changes for graduate education in metallurgy and materials science in the future.The present paper examines the growth of relevant university activities in the field over the past 10 years in comparison with that during the preceding decade and with the growth of engineering, science and advanced education in general in the United States, i.e., the question of the supply of new personnel with advanced training in the materials field. While it is appreciated that the nature and quality of education must be of prime importance, this paper deals principally with the numerical aspects of graduate education in materials, rather than with the philosophy, as a necessary first step in the broader study which is advocated.     

高通量方法在钎焊领域的应用现状

高通量方法作为"材料基因组技术"三大核心要素之一,在材料成分设计、组织分析、性能优化、过程模拟等方面起着关键性作用.钎焊技术作为焊接与连接领域的重要分支之一,是现代制造业中材料连接应用最广的方式.首先对高通量方法在钎焊领域的应用研究进行概述,其次主要对近5年有关高通量制备钎料、软钎焊和硬钎焊领域高通量计算方面的最新研究...     

水钢100 t转炉出钢过程回磷分析与实践

转炉出钢过程常伴有钢水回磷现象,导致钢水磷含量上升甚至出格,影响钢材成品质量和经济技术指标。为有效控制转炉出钢过程回磷,通过现场取样、数据采集、模拟试验及FactSage软件分析了出钢过程钢水回磷机理,研究探讨了渣中FeO、SiO₂、出钢温度、钢包渣碱度对回磷的影响。研究结果表明,出钢过程下渣,渣中FeO含量与出钢温度过高,钢包渣SiO₂含量与碱度不在合适范围均会增大钢水回磷率,最高达41%。结合水钢生产实践,出钢温度控制为1 625~1 640 ℃、转炉终渣FeO质量分数为15%、钢包渣碱度为3.6~4.1、控制含硅合金加入、控制出钢过程下渣量的条件下,可高效调节出钢过程回磷,将回磷率降低至15%以下。通过控制出钢温度、终渣FeO、碱度等,可有效降低因下渣导致的回磷。     

非对称通道内亲疏水结构影响下的纳米气泡滑移效应

目的 研究非对称性通道中亲疏水表面结构影响下纳米气泡特征与边界滑移之间的关系,以实现良好的流体减阻效果.方法 采用二元体系分子动力学方法,研究纳米气泡在通道流动中产生的滑移减阻效应.首先建立上下壁面非对称微通道模型,通过考虑微通道流动传热过程,探究纳米气泡影响下的微通道界面速度滑移现象.结果 保持亲水下壁面高度以及上下...     

国内外摆动辗压技术的研究和发展

介绍了摆动辗压成形技术在美国、英国、波兰、前苏联、瑞士、日本和德国等工业发达国家的研制和生产概况。综述了我国科技工作者在摆动辗压机的机身设计计算与制造、摆头的设计计算、摆动辗压的运动轨迹以及摆动辗压成形过程中坯料与摆头之间的接触情况等;在摆动辗压成形过程中的应力、应变分布的实验研究与数值模拟分析,缺陷形成机理分析,以及摆辗变形力的工程计算等;热摆动辗压成形工艺、温摆辗成形工艺和冷摆辗成形工艺在汽车、摩托车、五金工具和兵器工业等加工制造业的工程应用等方面所作的成形机理、数值模拟、设备和工艺研究情况。     

DISTRIBUTION OF SULFUR IN HIGH TEMPERATURE PHASES OF CAST IRON

The distribution of subversive element sulfur in high temperature phases during solidificationof cast iron was investigated by means of liquid quenching method and autoradiography.Theresults show that in grey cast iron,sulfur is concentrated in the liquid,flake graphite and in theperipherial area of D-type supercooled graphite eutectic cells,but less sulfur is in austenite.Besides,the content of sulfur in A-type graphite is higher than that in D-type graphite,andsulfur content in eutectic austenite is a little higher than that in primary austenite.While,innodular graphite cast iron less sulfur is in liquid and austenite,but more in nodular graphite.The blackness of the spots on the emulsion film corresponds to the atomic percentage ofradioactive substances located on the surface of the specimen.     

切题知识原则简论

本文第一部分简论知识的切题性及语境、总体性属性、多维度属性与复杂性等影响认知的因素;第二部分简论一般性智能及二十世纪高等教育中学科专业化对切题性知识的肢解;第三部分分析二十世纪(高等)教育中影响切题知识获取的三个基本问题:知识分割与封闭式专业化、还原与分离、虚假合理性。     

丹酚酸对大鼠骨骼肌缺血再灌注损伤的保护

目的：分析丹酚酸通过AKT/mTOR/p70S6K信号通路对骨骼肌缺血再灌注损伤小鼠细胞自噬及凋亡的影响。方法：选取SPF级雄性大鼠45只,随机数字表法分为假手术组、模型组、丹酚酸组,模型组、丹酚酸组制备骨骼肌缺血再灌注损伤模型,丹酚酸组分别在开始实验前72 h、48 h、24 h及再灌注前15 min,腹腔注射剂量为30 mg/kg的丹酚酸溶液1 mL,假手术组和模型组大鼠腹腔注射生理盐水1 mL。观察各组大鼠腓肠肌组织病理形态,血清肌酸激酶（CK）、乳酸脱氢酶（LDH）含量,腓肠肌组织Akt、p-Akt、p70S6K、p-p70S6K、mTOR及p-mTOR蛋白表达及腓肠肌组织内Bcl-2、Bax表达。结果： 再灌注0 h、4 h及24 h时模型组大鼠腓肠肌湿/干重（W/D）比值较假手术组升高,丹酚酸组腓肠肌W/D比值较模型组降低,差异有统计学意义（P<0.05）;再灌注0 h、4 h及24 h时模型组大鼠血清LDH、CK含量较假手术组升高,丹酚酸组大鼠血清LDH、CK含量较模型组降低,差异有统计学意义（P<0.05）;模型组大鼠腓肠肌Akt蛋白表达较假手术组降低,p-Akt蛋白表达较假手术组升高;丹酚酸组大鼠Akt、p-Akt、p70S6K、p-p70S6K、mTOR及p-mTOR蛋白表达较模型组升高,差异有统计学意义（P<0.05）;光密度值（IOD）量化腓肠肌细胞内Bax、Bcl-2蛋白表达,模型组Bcl-2 IOD数值、Bcl-2/Bax比值较假手术组降低,Bax IOD数值较假手术组增加;丹酚酸组Bcl-2 IOD数值、Bcl-2/Bax比值较模型组升高,Bax IOD数值较模型组降低,差异有统计学意义（P<0.05）。结论：丹酚酸可维持骨骼肌缺血再灌注损伤大鼠骨骼细胞Bax与Bcl-2动态平衡,抑制细胞凋亡,其作用机制可能和激活AKT/mTOR/p70S6K信号通路有关。     

复方甘草酸苷对PPD患者抗菌肽LL-37的表达及临床预后的影响

目的:观察复方甘草酸苷对着色紫癜性皮肤病（pigmented purpuric dermatosis,PPD）患者抗菌肽LL-37的表达及其对患者临床预后的影响。方法:选取本院2015年4月到2018年4月间收治的54例PPD患者为研究对象,随机抽签将其分为观察组和对照组,每组27例,另外选取30例正常受试者作为正常组。对照组口服甲泼尼龙片、皮损处涂抹氟芬那酸丁酯软膏进行治疗;观察组在此基础上给予口服复方甘草酸苷片治疗;正常组不做任何治疗处理,1个月后进行观察评价。比较观察组和对照组患者的疗效、不良反应发生率及复发率,比较三组血清中LL-37水平与皮损处LL-37水平以及三组血清TNF-α、IL-6、IL-17炎性因子水平。结果:治疗前,观察组和对照组患者血清LL-37水平、皮损处LL-37水平以及血清TNF-α、IL-6、IL-17水平比较无明显差异（P>0.05）,治疗后,两组患者血清LL-37水平、皮损处LL-37水平与血清TNF-α、IL-6、IL-17水平均显著降低（P<0.05）,且观察组血清LL-37水平、皮损处LL-37水平与血清TNF-α、IL-6、IL-17水平均明显低于对照组（P<0.05）。观察组治疗有效率为70.37%,显著高于对照组51.85%（P<0.05）;观察组不良反应发生率为18.52%,略低于对照组33.33%,但差异无统计学意义（P>0.05）;观察组复发率为11.11%,略低于对照组18.52%,但差异无统计学意义（P>0.05）。结论:复方甘草酸苷能够降低PPD患者体内抗菌肽LL-37的表达水平,减轻炎性反应,同时不良反应发生率和复发率更低,疗效及安全性更佳,值得临床推广。     

面向制冷行业在线应用的铝铝感应钎焊

铝管由于其熔点低,在焊接的过程中很容易烧破,致使管壁减薄或管路泄漏。所以,制冷行业的铝铝管路基本采用洛克环进行连接,洛克环连接的成本较高,并且洛克环在本质上不属于焊接,在安装工艺不成熟时也会存在较大比例的焊漏率;铝铝感应钎焊在工艺成熟的前提下可以实现铝管的低成本连接,并且焊接效果稳定,降低焊漏率。针对铝铝管的感应钎焊进行研究,并探究铝铝感应钎焊的在线应用条件,推动感应钎焊在制冷行业铝铝管路连接中的应用和发展。     

素质教育新视野

立足21世纪时代背景，以全新视角界定素质教育内涵。素质教育是一种全新的教育理念和教育思想。全面实施素质教育，标志教育理念深刻变革，教育思想的飞跃。素质教育的灵魂是道德教育，素质教育的核心是创新教育，素质教育的基础是人文教育，素质教育的方向是通才教育。     

Rho激酶抑制剂对脓毒症肝损伤的影响

目的：探讨Rho激酶抑制剂Y-27632对脓毒症急性肝损伤的作用。方法：健康成年雄性SD大鼠32只,随机分为假手术组（Sham组）、假手术＋Y-27632组（Sham+Y组）,盲肠结扎穿孔组（CLP组）和CLP+Y-27632组（CLP+Y组）,每组8只。采用CLP方法制备大鼠脓毒症模型,造模24 h心脏采血后安乐死大鼠,收集血清及肝脏组织。苏木精-伊红（HE）染色观察各组大鼠肝组织病理学变化;蛋白质免疫印迹（Western blot）检测各组大鼠肝组织ROCK1和下游NF-κB蛋白的表达情况;免疫组织化学法（ICH）检测大鼠肝脏组织ROCK1蛋白表达;酶联免疫吸附（ELISA）法检测各组大鼠血清肝功能指标ALT、AST水平及肝组织匀浆IL-18、IL-10和谷胱甘肽（GSH）含量变化。结果：与Sham组相比,Sham+Y组肝脏组织病理学无明显变化,CLP组肝细胞排列紊乱,有大量炎症细胞浸润,CLP+Y组炎症细胞浸润较少,肝细胞条索逐渐恢复。与Sham组相比,CLP和CLP+Y组ROCK1蛋白表达增加（P<0.05）;与CLP组相比,CLP+Y组ROCK1蛋白表达减少（P<0.05）。与Sham组相比,CLP和CLP+Y组NF-κB蛋白表达增加（P<0.05）;与CLP组相比,CLP+Y组NF-κB蛋白表达减少（P<0.05）;ICH检测到Sham组肝脏ROCK1少量表达,CLP组和CLP+Y组大量表达;与Sham组相比,CLP和CLP+Y组血清ALT、AST水平升高（P<0.05）,与CLP组相比,CLP+Y组ALT、AST水平降低（P<0.05）。与Sham组相比,CLP和CLP+Y组肝组织匀浆IL-18含量升高（P<0.05）,CLP组肝组织匀浆IL-10和GSH含量降低（P<0.05）,CLP+Y组IL-10和GSH的变化相近（P>0.05）;与CLP组相比,CLP+Y组IL-18含量降低（P<0.05）,IL-10和GSH含量升高（P<0.05）。 结论：Rho激酶抑制剂可以减轻脓毒症大鼠急性肝损伤,可能与抑制Rho/ROCK/NF-κB信号通路及其下游的炎症因子,减轻肝脏炎症反应,同时降低肝脏氧化应激水平有关。     

高磷鲕状赤铁矿添加脱磷剂还原焙烧脱磷机理(英文)

高磷鲕状赤铁矿是一种典型的难处理铁矿石,采用常规的选矿方法难以得到较好的提铁降磷指标。采用添加脱磷剂还原焙烧,然后对焙烧产物进行两段磨矿磁选来处理此类矿石,获得了较好的选别指标。实验结果表明,铁的品位从43.65%(原矿)提高到90.23%(磁选精矿),磷含量从0.82%(原矿)降低到0.06%(磁选精矿),铁的回收率达到87%。采用XRD、SEM、EPMA等分析方法对焙烧产物进行脱磷机理研究。结果表明,在还原焙烧过程中,原矿中有20%的磷灰石生成单质磷随气体挥发,80%的磷灰石没有参与生成单质磷的反应,仍以磷灰石的物相存在于焙烧产物中,而通过磨矿磁选被脱除到尾矿中。磁选精矿中少量的磷以磷灰石的形态存在。在焙烧过程中,加入的脱磷剂与原矿中的脉石矿物(SiO2、Al2O3)反应生成铝硅酸钠,此反应部分破坏原矿的鲕状结构,充分改善焙烧产物中矿物的单体解离程度,有利于后续的磨矿磁选。     

稀土Ce含量对4Cr5MoSiV1钢中夹杂物的变质作用

为探究Ce元素对热作模具钢中夹杂物的影响及其作用机理,用场发射扫描电镜(SEM/EDS)和附带的夹杂物自动分析系统对不同Ce含量的4Cr5MoSiV1钢中夹杂物的类型、形貌、数量、尺寸及其分布进行观察和统计分析。结果表明,不含Ce的试样中夹杂物不仅数量多、平均尺寸较大且形状不规则,主要类型为Mg-Al-O类、MnS和Mg-Al-O外覆盖MnS的夹杂物;随Ce含量的增加,试样中的夹杂物有数量和平均尺寸减小、并变质为球形稀土硫氧化物的趋势。当钢中Ce含量为0.0070%时,夹杂物的数量最少,平均尺寸最小;继续增加稀土Ce含量到0.0120%时,会形成更多的硫氧化物夹杂,且夹杂物有数量增多、平均尺寸增大的趋势。随着凝固过程的进行,Ce主要以稀土硫氧化物形式存在试验钢中,60%以上的夹杂物会被凝固前沿推动,且最终留在晶界附近。     

焊接与连接领域科学基金资助浅析与发展趋势

介绍了焊接与连接领域国家自然科学基金2018年度的申请情况,并分析了该领域近三年的资助情况和资助项目成果情况及热点研究方向. 对焊接新方法、新技术与新原理、界面冶金行为与调控机制、焊接结构设计与可靠性评估、电弧增材制造形性调控机制等方向的基础科学问题进行了梳理,探讨了未来重点发展方向.     

On the Thermodynamic Aspect of Interaction Between Dislocations and Highly Mobile Interstitial Solute:With Special Focus on Recent Progress in Pd–H System:A Review

It is well known that, in kinetics, the interaction between dislocations and interstitial solute normally exerts strong solute drag effect on dislocations, leading to strong solution hardening of the metals. However, due to the low mobility of interstitial solute in many metals, thermodynamic aspect of the interaction between dislocations and interstitial solute is often unobservable and omitted. It will be shown in this article by reviewing the H-induced behaviors in metal–H systems, especially the recent progress in Pd–H system that, when the interstitial solute atoms are highly mobile and able to collect in the vicinity of mobile dislocations easily, the scenario will be remarkably different. The interaction between dislocations and these highly mobile interstitial solute atoms, in thermodynamics, will reduce the line energy of dislocations and will facilitate the generation of dislocations, leading to an increase in dislocation density and an enhanced strain hardening of metals upon plastic deformation.     

ECSC research into weldability carried out in the last ten years

Abstract

The paper illustrates the research carried out with ECSC financial support in the decade 1976–86 by various laboratories and institutes in countries belonging to the European Community, in the field of the welding and weldability of different steels.

The industrial impact of the research is underlined, particularly with regard to the possibility of making greater use of the characteristics of modern steels, in order to achieve improved quality, productivity and economy in welded constructions.

The importance of each piece of research for the study of heat affected zones (HAZs) and of fusion zone behaviour in welded joints is illustrated, and further research now in progress is also mentioned.

Finally, attention is drawn to the need to promote, through the appropriate development of European standards and regulations and by the drawing up of suitable guidelines for designers, users and manufacturers, knowledge of the possibilities of new steels in order to achieve further development and competitiveness in welded steel constructions.     

Microstructural Features of Scales and Their Likely Influence on Creep Behaviour

The microstructural features of scales as formed during the high temperature corrosion of metals can vary considerably. Apart from the obvious differences between scales derived from different metals, even with a given metal the microstructure of the scale is affected by factors such as metal purity and the conditions of exposure, namely the duration and temperature of oxidation and the partial pressure of the oxidant in the atmosphere. In particular variations in grain size and morphology, and in the degree and morphology, and in the degree and nature of porosity can occur; in addition in some systems precipitation of a second phase of variable morphology can take place. Some of these differing structural features in scales are discussed and illustrated. It is suggested that such variations in microstructure will considerably affect the mechanical properties of the scales in which they occur. In general few data concerning mechanical properties, in particular plastic deformation characteristics of scales have been published; furthermore little attempt has been made to assess the possible role of such variations in structure. Rather more information is, however, available from the field of ceramics, and this knowledge is critically reviewed. The usefulness and limitations of such information in relation to the interpretation of the creep behaviour of cobalt monoxide scales is illustrated.     

依靠科技进步 节能降耗 开发品种 在市场竞争中创造更好的经济效益──在1997年轧钢工作会议上的讲话

综述了近年来轧钢行业在提高产品产量和质量、改善品种结构等方面取得的成绩，在轧钢工艺、技术、装备方面取得的进步；同时指出目前存在着产品竞争力不强等诸多问题，为此，提出轧钢行业要抓好品种、质量、成本、环保工作，并且，今后应以板带和专用钢管为重点，广泛做好节能降耗工作，在技术改造中注意分层次，在国产化工作中注意技术创新。