On assumptions associated with ΔKeff and their implications on FCG predictions

In this paper, an assessment of commonly used assumptions associated with ΔK_eff and their implications on FCG predictions in light of existing experimental and numerical data is presented. In particular, the following assumptions are examined: (1). ΔK_eff fully describes cyclic stresses and strains at the crack-tip vicinity. (2). K_op can be determined experimentally or numerically with certain accuracy. (3). Overload alters K_op but not K_max and associated σ_max at the crack-tip ‘process zone’. (4). Contact of crack faces curtails the crack driving force in terms of ΔK_eff.The analysis indicates that there is insufficient support to justify the above assumptions. In contrary, the analysis demonstrates that a two-parameter fatigue crack driving force in terms of ΔK and K_max, which accounts for both applied and the internal stresses should be used in FCG analyses and predictions.     

毛细管区带电泳的紫外可见光吸收检测

利用紫外可见光吸收方法完成毛细管区带电泳的检测工作，本文就实验装置，实验结果进行了讨论。     

辊套材料对铸轧区磁感应强度影响的实验研究

电磁场快速铸轧技术要求辊套材料不仅具有高导热系数、高承载能力和高抗疲劳能力，而且要具有磁场控制能力，保证铸轧区足够的磁感应强度，达到细化晶粒、改善板坯组织性能的目的．本文主要从介质对电磁场的集肤效应、涡流效应、磁场衰减以及屏蔽效应的角度，研究辊套对铸轧区电磁场的影响．     

东乡铜矿区构造特征与成矿的关系

本文针对东乡铜矿区构造特征的分析,尤其是对矿区北东向断层,含矿破碎带及横跨褶皱的深入探讨,结合地史背景阐明构造的产生、演化及对成矿的关系,并指出其找矿意义。     

对提升成都高新西区产业聚群外部规模性的建议

针对成都高新西区的聚群经济仍处在低级阶段,西区企业缺乏核心竞争力,急待升华的现实,建议政府要调整开发区布局,要促成产业聚群经济;要与西区周边各大学互动发展。     

金针菇冻结规律及品质变化研究

研究了金针菇在不同低温条件下的冻结规律及品质变化,探讨了多酚氧化酶和感官品质等指标变化,实验表明,金针菇在-37℃以上的温度达不到速冻要求,金针菇适宜的冻结条件为-37～-40℃。     

Effect of deteriorated microstructures on stress corrosion cracking of X70 pipeline steel in acidic soil environment

In order to investigate stress corrosion cracking (SCC) of X70 pipeline steel and its weld joint area in acidic soil environ-ment in China, two simulating methods were used: one was to obtain bad microstructures in heat affected zone by annealing at 1300°C for 10 min and then, quenching in water; the other was to get different simulating solutions of acidic soil in Yingtan in south-east China. The SCC susceptibilities of X70 pipeline steel before and after quenching in the simulating solutions were analyzed...     

区域熔炼法制备高纯锌的研究

采用区域熔炼法对高纯锌的制备进行了研究.估算了锌中主要杂质在锌熔点附近的平衡分配系数,分别为k(0,Fe)=474,K(0,Cu)=1.12,K(0,Cd)=0.15,K(0,Pb)=1.17×10(-2).通过参考Spim数学模型,分析了在区熔提纯中熔区长度对区熔提纯效率的影响,获得每次通过时的最优熔区长度,并考察了区熔次数、熔区长度对提纯效率的影响.通过辉光放电质谱仪对杂质进行分析,结果表明:在高纯氩气流动保护下,控制熔区移动速率为3 cm·h(-1),熔区长度为50 mm,区熔20次后,杂质总量从1.006μg·g(-1)降低到0.303μg·g(-1),纯度达到6N7(99.99997%).采用第1～6次为70～80mm,第7～10次为50～60mm,第11～20次为30～40mm的变化熔区长度,杂质总量可降低到0.216 μg·g(-1),即采用变化熔区比不变熔区的提纯效果好,产品锌的纯度为6N8(99.99998%),满足了半导体和光电材料的应用要求.     

内蒙古翁牛特旗二台营子银多金属矿成矿地质特征及找矿标志

二台营子银多金属矿位于内蒙古大兴安岭成矿省,突泉-林西海西、燕山期铁(锡)、铜、铅、锌、银、铌(钽)Ⅲ级成矿带之次级成矿带的结合部位。区内岩浆活动频繁,褶皱、断裂发育,具有良好的形成银、金多金属矿床的成矿条件,但多年来一直没有投入系统的勘查工作,限制了本区的找矿突破。本文通过调查研究,论述了二台营子银多金属矿床的主要成矿地质特征,分析了其找矿标志,为本区开展进一步找矿工作提供了参考。     

Advanced HSLA Steels for Automotive Use

Characteristic HSLA steels for automotive use are introduced in which both of precipitation and microstructure is controlled to obtain suitable mechanical properties.For outer panels such as fender,the combination of low yield strength,high tensile strength and deep-drawability were realized by controlling the distribution of NbC and precipitation free zone.The other steel,developed for chassis parts such as lower arm,utilizes extremely fine interphase precipitation to obtain high yield strength and excellent hole expansionability.Both steels have contributed to the reduction of weight in car body.