拉伸试验中测量的不确定度评定

介绍拉伸试验中测量结果的不确定度评定方法。依据测量不确定度的七个评定步骤，按不同的试样形状、尺寸，试验人员、尺寸测量器具、试验机等级、引伸计等级、拉伸速度等影响因素分别给出拉伸试验中的强度指标RP、ReH、ReL、Rt、Rm，与塑性指标A、Z测量结果的不确定度评定。此次给出的拉伸试验中测量结果的不确定度评定适用于本部门拉伸试验，可按试验时所用的试样形状、尺寸、测量器具、试验机、引伸计等条件选用不确定度的评定结果。     

基于线结构光阵列的铸坯切割熔渣尺寸在线测量方法

在连铸连轧产线上，铸坯火焰切割产生的熔渣会对成品和设备造成损害，目前工业现场主要由人工主观地对熔渣的尺寸进行判断。针对铸坯切割熔渣尺寸在线测量问题，研究了基于线结构光阵列的熔渣尺寸在线测量方法，通过线结构光阵列倾斜投射多条线结构光至铸坯表面，多个面阵相机组成的视场覆盖铸坯上下表面整个宽度方向，利用产线上铸坯的自身运动完成铸坯上下表面的扫描，最后利用基于三角测量原理实现铸坯切割熔渣尺寸的在线测量，并给出测量范围和测量精度的调整方法。通过搭建熔渣尺寸在线测量系统，现场试验证明，系统熔渣尺寸测量响应时间为0.144 s,满足实时性测量的需求。通过对算法的理论分析和实际测量结果数据比对表明，熔渣尺寸理论测量精度和实际测量误差标准差可达0.1 mm,熔渣检出正确率达到100%。     

金属材料室温拉伸试验影响因素分析

金属材料室温拉伸试验是获取材料力学性能指标的常用方法。为提高金属材料室温拉伸试验结果的准确性,从试样制作、尺寸测量、试验设备、试样夹持方法、拉伸速率、环境因素的影响进行分析。     

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     

利用数字图像处理技术测量几何尺寸

针对传统接触式尺寸测量方法的缺点,探讨利用数字图像处理技术进行几何尺寸测量的方法,为产品的尺寸测量提供实时、快速、有效、经济的测量途径.给出了利用数字图像处理技术进行非接触式尺寸测量的方法,它包括图像的预处理,二值化,图像分割,轮廓线条的提取、拟合、光滑,系统的标定,尺寸的计算等.并从理论和实践上证明该方法的可行性和正确性.     

抗拉强度不确定度的评定与分析

通过使用不同量具测量同一组拉伸样品尺寸进行拉伸试验,对抗拉强度进行了不确定度评定,对各不确定度量进行了分析.     

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。     

试样几何因素对r值n值试验结果的影响

试验目的考核试样宽度、平行长度、过渡弧半径、标距等几何因素对r值n值试验结果的影响。试验条件 1)试验基本尺寸,如图1所示。2)尺寸测量工具标距一比长仪(分度值0.001mm)引伸计(最大应变示值误差≤0 .001) 3)测量方法 r值n值在同一试样上测定,所有结果均为3片试徉的平均值。r值用卸载结果计算,n值用不卸载结果根据拟合法计算。应     

车用铜铝合金发动机轴承尺寸测量标准分析

现代化工业生产对于车内零部件产品的要求逐步提高的大形势下,针对质量管控中传统尺寸测量标准分析方法存在精度低的缺陷,提出了一种车用铜铝合金发动机轴承尺寸测量标准分析方法的设计。通过提取滤波处理后轴承尺寸标准数据集,采用三点均匀测量的方式,计算轴承边缘标准尺寸允许误差,选择轴承中心检测方法,修正轴承尺寸测量标定范围,修正轴承尺寸测量标定范围。设计对比实验,验证提出方法在实际应用中,降低了测量误差,提高了监测工作效率,有力支持了质量检验工作。     

论非接触测量技术应用在机械检测上的必要性

文章通过对非接触测量技术基本概念,方法及原理的介绍,表述该技术在机械制造业中较之传统机械检测特别是对于微小机械尺寸、大型机械尺寸、复杂机械的结构尺寸和异形机械曲面尺寸检测中具有明显的优点,阐明了非接触测量技术在机械零件检测上应用的可行性和必要性。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.