小麦粉中偶氮甲酰胺含量测量的不确定度评定

分析了高效液相色谱法测定小麦粉中偶氮甲酰胺含量不确定度的各分量,对其测量不确定度进行合理的评定,结果表明:小麦粉样品中偶氮甲酰胺的含量为43.1mg/kg时,其扩展不确定度为2.6 mg/kg(k=2),不确定度主要是最小二乘法拟合标准工作曲线求得样品浓度过程引入的。     

POSS在涂料领域的应用研究进展

本文简要介绍了POSS及POSS在聚合物中的应用特点,并回顾了近年来国内外有关POSS改性丙烯酸树脂,聚氨酯树脂,环氧树脂以及POSS在涂料领域的应用研究现状,并对未来POSS在涂料领域的应用和研究进行了展望。     

大米中镉含量的测量不确定度评定

分析了石墨炉原子吸收光谱法测定大米中镉含量不确定度的各分量,对其测量不确定度进行合理的评定,结果表明:大米样品中镉的含量为0.18 mg/kg时,其扩展不确定度为0.01 mg/kg(k=2),不确定度主要是最小二乘法拟合标准工作曲线求得样品浓度过程和测试过程随机效应引入的。     

陶瓷超塑性的研究进展

本文综述了氧化锆及其复相陶瓷超塑性的研究现状，论述了陶瓷超塑性的变形机理，微观特征和断裂特性。同时，分析和对比了陶瓷超塑性与金属超塑性的特点。目前，对于正确理解超塑性陶瓷的变形机理，还需进行大量工作。     

Use of adhesives in repair of cracks in ship structures

Abstract

The structures of modern warships frequently contain significant quantities of aluminium alloy: a material especially prone to fatigue induced cracking. The satisfactory repair of such cracks is often vital if the fighting efficiency of a warship is to be maintained properly and would usually be carried out by welding. The welding of aluminium and its alloys is often difficult and onboard is further complicated by the necessity to remove inflammable linings, cables, and items of equipment to reduce the fire risk and provide access for the repair. Consequently, repair welds are often carried out from the most accessible side and are seldom full penetration. The finished weld is invariably little more than a sealant with a fatigue life inferior to that of the original plate. Initiation of further cracking in the repair weld can be prevented by adhesively bonding a reinforcement across the weld to provide a strength at least as good as that of the original plate and a stiffness sufficient to prevent the onset of further cracking. The use of adhesively bonded steel and carbon fibre patches in typical ship applications are described and the factors governing patch design, methods of surface preparation to ensure good bond durability in a marine environment, and choice of adhesives are discussed.

MST/834     

超支化聚合物在树脂改性中的应用研究进展

超支化聚合物因其独特的结构和性能特点,已在众多领域得到应用,特别是在树脂改性中的研究发展迅速。综述了超支化聚合物作为树脂改性剂在聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、聚碳酸酯、尼龙6等热塑性树脂和环氧树脂、不饱和聚酯树脂、乙烯基酯树脂等热固性树脂中的应用研究进展,超支化聚合物可作为热塑性树脂的加工助剂、流变学改性剂、增容剂或增强剂以及热固性树脂的增韧剂。同时对超支化聚合物在树脂改性中的应用研究方向做出了展望。     

电风扇噪声测量的不确定度评定

根据测量不确定度评定规范,对电风扇噪声测量进行测量不确定度的评定和分析。     

Compression of ice in freezing of supercooled water in capillaries

When supercooled water is crystallized in a capillary, the ice is found to be strongly compressed A theory of maximum possible compression is discussed for a rigid cylindrical capillary and its experimental verification is presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 17, No. 5, pp. 936–943, November, 1969.     

氧化镁真空碳热还原过程焦煤的热解行为研究

焦煤的热解经历干燥阶段、胶质体阶段和焦炭生成三个阶段,第二阶段焦煤失重较多。常压条件下焦煤热解时固定炭损失较多,孔隙度随温度和时间的增加而增加,500℃热解30 min后胶质体数量较少,物料内部变化不大;真空条件下煤热解时固定炭不损失,孔隙度随温度的升高而降低,且随着时间的延长升高,60 min后降低,500℃热解30 min可生成较多数量的胶质体,碳元素和镁元素分布趋于均匀。用焦煤做还原剂进行氧化镁真空碳热还原可以得到较纯净的金属镁,没有发生喷料现象。焦煤具有良好的黏结性和结焦性,适于做还原剂。     

Relaxation of stresses in steels in tempering

Strength of Materials -     

液态奶中三聚氰胺含量的测量不确定度评定

依据国标GB/T 22388-2008规定,采用高效液相色谱法对液态奶中三聚氰胺的含量进行了检测。建立数学模型,分析确定检测液态奶中三聚氰胺含量的不确定度来源,并对测量过程中的不确定度分量进行逐层分析与合成,得到合成标准不确定度和扩展不确定度分别为0.054 mg/kg和0.11 mg/kg。计算结果显示由样品溶液测量重复性、标准溶液测量重复性、标准溶液配制过程引入的不确定度分量对合成标准不确定度贡献较大,是不确定度的主要来源;由样品称量、定容引入的不确定度相对来说较小。     

氧化铝真空碳热还原氯化歧化过程中二氯化铝行为研究

对氧化铝真空碳热还原氯化歧化过程中AlCl_2的相关反应进行热力学计算,结果表明在1760 K,60 Pa的条件下,Al_2O与C、Al_4C_3与Al_2O_3、Al_4O_4C与C均可发生氯化反应,AlCl_2的歧化反应在冷凝区也可以进行。采用基于密度泛函(DFT)框架下的第一性原理平面波赝势法,并用从头算分子动力学的方法对Al_2O与C的氯化反应和AlCl_2的歧化反应进行了结构优化和动力学模拟。结果表明碳热还原-氯化-歧化过程中的确有AlCl_2生成,吸附态的AlCl_2将进一步与Al_2O和C反应生成吸附态的AlCl分子,在C和AlCl_3(或AlCl_2)存在的条件下,Al_2O气体具有氯化活性,自由态的AlCl_2将在冷凝区歧解为AlCl分子。     

Differences in coagulation in clotting of vascular access in hemodialysis patients

Arteriovenous graft (AVG) thrombosis is a frequent cause of graft failure. We evaluated coagulation protein concentrations, platelet function, and viscoelasticity factors in 20 hemodialysis (HD) patients with AVGs. The goal was to determine whether significant differences in protein concentrations, platelet function, and viscoelasticity factors exist among dialysis patients requiring frequent AVG declot procedures vs. those who do not. Twenty HD patients were enrolled: 10 frequent clotters (>3 declots in the previous year) and 10 were nonclotters. Patients on antiplatelets or chronic anticoagulation were excluded. Laboratories were drawn pretreatment and heparinase was added to counteract any potential heparin effect. Coagulation protein concentrations including tissue factor (TF), thrombin/antithrombin III complex (TAT), and prothrombin fragment 1 + 2 (F₁₊₂) were assayed. The time to clot onset was measured by force onset time (FOT). Platelet contractile force (PCF) measured the force produced by platelets during clot retraction, whereas clot rigidity was measured as clot elastic modulus (CEM). FOT, CEM, and PCF were measured by Hemodyne. Both groups had upregulation of the TF pathway, as TF, TAT, and F₁₊₂ levels were similarly increased over baseline levels. Hemodialysis patients with frequent AVG clotting had higher levels of both PCF and CEM compared with nonclotters. Additionally, the frequent clotters had a lower FOT relative to nonclotters, although both were considered in the normal range. Our study suggests that HD patients with recurrent AVG thrombotic events form clots with higher tensile strength compared with HD patients without recurrent graft thrombosis.     

SHS技术在空间科学实验中,特别是在空间制备材料中的应用

论述了自蔓延高温合成（SHS）技术在空间制备材料中的应用,着重讨论了该技术的应用现状、存在问题和解决途径。     

Assurance of accuracy in determinations of contents of micro components in samples of very pure substances and in environmental specimens

We propose an approach allowing us to use preliminary enrichment (concentration) in accordance with the characteristic features of the method for taking into account the resulting systematic error based on the relationship between the systematic error of the analysis results and the determined content. This allows us to avoid a number of difficulties specific to quantitative determination of very low contents with substantial improvement in the accuracy of the final analysis result.Translated from Izmeritel'naya Tekhnika, No. 2, pp. 58–60, February, 1995.     

爆破技术在分解水中漂浮物的应用

针对山东汛期暴雨天气多,汛情紧急的情况,为能够使群众安全、高效、有序地撤离受灾区域,省防洪防汛指挥部决定在日照市仕阳水库组织应急防洪、防汛演练,即对泄洪闸附近大量的漂浮物进行爆破清障疏通。在漂浮物爆破分解中采用长药包串联网路及装药防水技术,精准传爆,一次成功,周边建筑物设施及人员均未受到任何影响和伤害,泄洪疏通效果比较理想。对推广爆破技术在汛期大中型水库应急疏通领域中的应用,提高应急救援施工能力,具有一定的指导意义和积极的社会效益。     

Comparison of designs in presence of a possible correlation in observations

We often assume the standard linear model with uncorrelated observations for comparison of designs without realizing a possible presence of correlation in observations. In this paper we present several change of variance functions including the one given in Zhou (2001) for comparing designs in presence of possible correlation in observations. We find a design by minimizing one of our proposed change of variance functions in a simple response surface setup. We then compare its performance with all variance design, all bias design, and the design making the average variance equal to the average squared bias. We also compare a second order rotatable design with a non-rotatable design. The rotatable design is better than the non-rotatable design with respect to A-, D-, and E- optimality criterion functions under the standard linear model with uncorrelated observations. We observe that the rotatable design may not perform better than the non-rotatable design with respect to the change of variance functions. We present some important properties of the change of variance functions. We find that the A-optimum designs may perform poorly with respect to a change of variance function.     

Pharmacokinetics of Rifampin in the Presence of Dipyrone in Leprosy Patients

Some pharmacokinetic parameters such as elimination rate, half-life, AUC etc., of rifampin following p.o. administration of rifampin 600 mg. alone and 600 mg. rifampin in combination with 1000 mg. dipyrone were determined in untreated patients of leprosy. Statistical comparison of the mean values of the parameters suggests that the pharmacokinetic behaviour as well as the bioavailability of rifampin are not statistically affected in the presence of dipyrone.