小孔法测量Cr-Ni奥氏体不锈钢焊接残余应力的适用性研究

应变释放系数Ａ、Ｂ 的标定试验发现,直到单轴拉伸应力达到０．７３σｓ 时,孔边屈服产生的塑性变形才发生,对Ｃｒ － Ｎｉ 奥氏体不锈钢小孔法测量残余应力的影响小。同时经过小孔法和全释放法测量实际焊接残余应力及其分布的对比发现,只要选择恰当的应变片,使之与小孔孔径匹配,小孔法测量高残余应力,特别是焊接残余应力仍有较好的适用性。ＳＵＳ３２１ 不锈钢的对接接头的纵向焊接残余应力最大值为５４０ＭＰａ,大大超过母材屈服强度     

特定条件下电阻应变测量—不可加卸载的静态工作：应力的小孔法测量

提出了一种测量不可加卸载静态工作应力的简便电阻应变测量方法－小孔法，并简要介绍了该测量方法的基本原理，认为小孔法测量工作应力的精度比测量接残余应力的精度高。     

基于Lagrange二次插值理论的光纤纵差保护数据同步的研究

文章首先介绍了光纤纵差保护所存在的数据同步问题及相关解决方法.并对采样数据修正法进行了介绍,分析了现存方法的不足之处.在此基础上,本文针对数据修正法误差较大不能实现较高同步精度的问题,提出了基于二次插值理论的改进算法,并对误差进行了理论和仿真分析.结果表明,二次插值同步算法可以有效提高同步的精度,波形中各分量能够满足幅值和相位误差的要求.     

中和法测定工业二氧化硒中SeO_2的含量

:SeO2 溶于水生成亚硒酸 ,属中等二元强酸。采用中和法测定SeO2 含量 ,分析流程短 ,操作简便。测定结果的RSD为 0 11%。利用误差修正法对测定值进行修正 ,可获得准确的结果。     

Cr－Ni奥氏体不锈钢焊接残余应力小孔法测量技术

根据Ｃｒ－Ｎｉ奥氏体不锈钢的特点，对其焊接残余应力小孔法测量技术要点——电阻应变片粘贴前的表面准备、应变片尺寸、钻孔直径等项进行了试验与分析。指出Ｃｒ－Ｎｉ奥氏体不锈钢焊接残余应力的小孔法测量是可行的     

旋光仪旋光度示值误差的测量不确定度评定

依据JJG 536—2015及JJF 1059—2012,介绍了旋光仪旋光度示值误差测量结果的不确定度评定方法,建立了评定旋光度示值误差不确定度的数学模型,给出了方差和灵敏系数的计算方法,详细分析了各标准不确定度分量,并计算了测量结果的扩展不确定度。通过不确定度的评定,增强了测量结果之间的可比性,为实验的科学性和准确度提供了保证。     

中和法测定工业二氧化硒中SeO2的含量

SeO2溶于水生成亚硒酸，属中等二元强酸。采用中和法测定SeO2含量，分析流程短，操作简便。测定结构的RSD为0．11％。利用误差修正法对 测定值进行修正，可获得准确的结果。     

激光多普勒准静态法测量磁致伸缩系数

提出了一种利用激光多普勒测量磁致伸缩系数的方法,理论分析了激光多普勒测量磁致伸缩系数的工作原理,设计了铁镓合金棒材的测试系统.对铁镓合金棒(Galfenol)的准静态磁致伸缩系数进行测量.结果显示,该方法所获得应变与出厂数据符合较好,在10 Hz驱动电流下获得铁镓合金棒的动态变化曲线.该测量方法具有以下优势:(1)能够实现非接触测量;(2)可以测量铁镓合金棒端面任意点的应变情况;(3)测量结果准确度较高;(4)测量操作简单.      

Cr—Ni奥氏体不锈钢焊接残余应力小孔法测量技术

根据Ｃｒ－Ｎｉ奥氏体不锈钢的特点，对其焊接残余应力小孔法测量技术要点－电阻应变片粘贴前的表面准备、应变片尺寸、钻孔直径等项进行了试验与分析，指出Ｃｒ－Ｎｉ奥氏体不锈钢焊接残余应力的小孔法测量是可行的。     

蒸汽流量检测自动补偿

根据对蒸汽流量产生误差的分析,阐明了流量系数,流体膨胀系数以及蒸汽密度、温度、压力关键要素,对流量测量的影响。根据对饱和蒸汽、过热蒸汽流量测量的特点,分析减少流量测量误差所采取的修正方法,并推导出饱和蒸汽压力补偿,过热蒸汽压力、温度补偿的数学模型。介绍了微机流量测量及自动补偿在我厂的实际应用效果。     

爆破一次成井技术在漂塘钨矿的应用实践

介绍了爆破一次成井技术在漂塘钨矿的应用实践,提出了爆破一次成井的掏槽方式,爆破参数的设计计算方法和炮孔的施工要求。     

复式桶形直眼掏槽中深孔爆破法掘进实验

针对井下气腿式钻机凿岩、浅孔爆破掘进方式存在的工作效率低、循环进尺短和掘进单位成本高等问题,提出等直径空孔复式桶形直眼掏槽中深孔爆破法掘进技术,并设计相应的爆破参数。通过分别采用YT-24型气腿式凿岩机钻孔、等直径空孔复式桶形直眼掏槽浅孔爆破,DF20-2BD型凿岩台车钻孔、等直径空孔复式桶形直眼掏槽浅孔爆破以及DF20-2BD型凿岩台车钻孔、等直径空孔复式桶形直眼掏槽中深孔爆破法在掘进相同长度（30 m）条件下进行现场试验,得出在3种不同的凿岩爆破方式下各钻孔单位耗时、钻爆单位成本和平均循环进尺等指标。结果表明,采用DF20-2BD型凿岩台车钻孔、等直径空孔复式桶形直眼掏槽中深孔爆破法掘进不仅可降低钻爆单位成本,而且能有效提高平均循环进尺。     

Hole Expansion of Dual‐phase and Complex‐phase AHS Steels ‐ Effect of Edge Conditions

Hole expansion is one of the most important properties describing the formability of steel sheets, especially those used in automotive industry. In order to determine and emphasize the influence of hole edge conditions and hole surface quality on the results of standardized hole expansion tests, different hole preparation methods such as hole punching, hole drilling and wire cutting were applied to the industrially produced dual–phase and complex–phase steel grades DP800 and CP800. Results of hole expansion testing were discussed with respect to the impact of deformation introduced into the material during the hole preparation and to the material microstructure and mechanical properties. The damage characteristics of every method as well as the fracture surfaces were investigated in detail via light optical microscopy (LOM) as well as scanning electron microscopy (SEM). Qualitative and quantitative analyses of microstructure combined with microhardness measurements were used for the interpretation of the results and are correlated with the mechanical properties and the formability characteristics of the investigated steel grades.     

Correcting for measurement error in the analysis of case-control data with repeated measurements of exposure

The authors present a technique for correcting for exposure measurement error in the analysis of case-control data when subjects have a variable number of repeated measurements, and the average is used as the subject's measure of exposure. The true exposure as well as the measurement error are assumed to be normally distributed. The method transforms each subject's observed average by a factor which is a function of the measurement error parameters, prior to fitting the logistic regression model. The resulting logistic regression coefficient estimate based on the transformed average is corrected for error. A bootstrap method for obtaining confidence intervals for the true regression coefficient, which takes into account the variability due to estimation of the measurement error parameters, is also described. The method is applied to data from a nested case-control study of hormones and breast cancer.     

浅孔留矿法在斗南锰矿试验应用

通过斗南锰矿戛科矿区急倾斜薄矿体采矿方法试验,详细介绍了浅孔留矿法的矿块布置,采场结构参数以及回采顺序、凿岩爆破、采场通风、底部放矿及顶板管理等工艺过程。试验结果表明,对于矿体厚度>0.6m,且顶板中等稳固的条件,采用浅孔留矿法是合适的。     

钻孔测斜在帷幕工程中的质量保证

钻孔弯曲测量（俗称测斜）是保证工程质量的重要手段之一。本文介绍了钻孔弯曲测量的意义、要求、原理和方法，并通过测斜资料对测斜结果和钻控工程质量进行了评述。     

钻孔测斜在帷幕工程中的质量保证

钻孔弯曲测量（俗称测斜）是保证工程质量的重要手段之一。本文介绍了钻孔弯曲测量的意义、要求、原理和方法，并通过测斜资料对测斜结果和钻探工程质量进行了评述。     

Constitutive Model of Warm Deformation Behavior of Medium Carbon Steel

The compressive behaviors of medium carbon steel specimens were investigated over a wide range of tem-peratures and strain rates using a Gleeble-3500 thermo-simulation machine.The results show that the flow stress in-creased with strain at first,and then gradually decreased after reaching a peak value.The flow stress softening rate at a high strain rate was larger than that at a low strain rate.The effects of deformation heating and friction on flow stress were analyzed.A new friction correction method,wherein the effect of strain on frictional coefficient was con-sidered,was established here.The stresses revised by the new method deviated from the measured stresses with in-creasing strain.Meanwhile,the apparent frictional coefficient variation law with strain was obtained.The frictional coefficient increased as the strain increased and then slightly decreased after maintaining a constant value.The stress was corrected by considering deformation heating.The accuracy of the temperature correction method was verified using a special experiment.The results of the verification experiment show that the temperature correction method exhibited a good accuracy in calculating the variation of stress caused by deformation heating.A constitutive model considering strain was proposed here to describe the deformation behaviors.Compared with experimental data,the modified constitutive model exhibited a good accuracy as to constitutive correlation.     

中型热轧圆钢直径在线检测的研究

本文简述了中型热轧圆钢直径的在线测量方法。作者研究了自然对流和受迫对流状态下热轧圆钢周围温度场的分布及其所引起的测量误差,并建立了误差列表函数。提出了水平、垂直两个方向的双光路CCD测量系统和浮动切割电平二值化信号处理方法。通过计算机误差修正技术,提高了热轧圆钢直径的测量精度。对φ60至φ130 mm的中型热轧圆钢在线检测,仪器检测的分辨力为0.02 mm,检测精度优于0.1 mm。     

掏槽孔超深深度对爆破效果的影响

煤矿岩巷钻爆施工中,速度的关键在于掏槽.随着岩巷掘进工程量不断增大,虽然炮孔深度逐渐增大,但是掏槽孔超出普通孔的长度并没有改变,基本保持在200 mm及以下.针对掏槽孔超深与炮孔利用率这一问题,本文在超深系数η的基础上,引入裂隙区重合度φ的概念,利用数学建模方法,分析了不同超深深度爆破时的岩石应力状态,建立了超深深度及岩石碎胀系数之间的关系,并确定了掏槽槽腔主要参数的计算公式及取值范围,发现存在最优掏槽孔超深系数η和裂隙区重合度φ,使得炮眼利用率最高.利用LS-DYNA数值模拟分析了掏槽孔超深爆破时爆炸应力波的传播规律和孔底岩石的受力特征,并比较了200、300、400和500 mm不同超深深度的应力波强度变化特征并应用于岩巷掘进现场,对比了超深爆破方案和普通爆破方案的单循环进尺、炮孔利用率、眼痕率及大块率等爆破效果指标.结果表明,当超深深度为400 mm时,炸药爆破能量充分用于破岩,能量利用率最高,爆破后形成重叠的裂隙区,增大了后续爆破的自由面,提高了爆破破岩的效率,对岩巷钻爆法施工的参数优化有一定的指导意义.