ICP-OES法测定钽中钙、铝、镁、铌、硅和钨

用ICP-OES光谱仪对钽中钙、铝、镁、铌、硅和钨的测定进行了研究和探讨.对样品中元素的分析谱线,仪器分析参数,准确度和精密度进行了研究,确定了最佳实验条件.相对标准偏差不大于6.41％.方法具有良好的精密度和准确度,操作简单、快捷.     

ICP-AES法测定低铬、中铬合金中Si、P、Mn的含量

利用全谱直读分析技术,通过对试样溶解方法、试验仪器、分析参数等因素进行研究,综合确定了最佳试验条件.实验结果表明,该方法测定低铬、中铬合金中的Si、P、Mn,其分析误差符合冶金类合金中的误差要求,可用于普通材质的检验.     

发射光谱法同时测定铁镍基合金中铅、铋、锡、锑、砷、铜

本文采用加入载体方法,实验了铁镍基合金中杂质元素的测定.实验表明试样加入载体能使样品中的待测元素改善蒸发条件,激发稳定,抑制了铁的干扰,降低了背景,提高了分析灵敏度和精度,各元素在测定范围内含量与谱线黑度成线性关系.一、主要试剂与仪器铅、铋、锡、锑、砷标准溶液:准确称     

FAAS法测定焊锡中的锑、铋、铜、铁、银

用FAAS法在盐酸介质中测定焊锡中的锑、铋、铜、铁、银.基体锡对锑、铋有背景吸收,用氘灯扣背景技术扣除.或用与试液相当的锡标准溶液调零抵消背景干扰.对四种牌号的焊锡标准样进行了精度试验和分析结果对照,实验值与标样推荐吻合.测定精度能满足焊锡生产要求.本方法具有简便、快速、经济、准确的特点.     

电感耦合等离子体质谱法测定钕铁硼中铝、钴、铜、镓、锆、铽、钛、铌

建立了电感耦和等离子体质谱法测定钕铁硼中微量元素的方法。通过实验选择了测定质量数,测定Nb、Zr时,选择了氢氟酸加入量,并进行了测定酸度和基体效应实验。考察了以Rh、In、Cs和Tl为内标元素对仪器信号漂移和基体效应的校正,根据实验结果选择Cs为最佳校正内标。各元素测定下限为0.095～0.56 ng/mL,回收率为（n=20）为96%~108%。用电感耦合等离子体发射光谱（ICP-AES）进行样品对照分析,结果一致。实际样品测定的RSD在2.7%～7.3%之间。     

铌铁、钽铁精矿中锡量测定方法

采用碘量法测定铌铁、钽铁精矿中锡量.对滴定的酸度,碘酸钾与碘化钾的比例,还原剂的选择进行了实验,选取了最佳的滴定条件.并进行了干扰元素的实验,采取了较简便的方法分离了干扰元素.     

ICP-MS法测定氧化钆中铅、镉、汞、砷等有害元素

研究了ICP-MS法测定氧化钆中铅、镉、汞、砷等有害元素的分析方法.研究了基体效应,选择了合适的测定同位素和校正内标,确定了最佳分析条件.在优化的实验条件下,测得方法的回收率在90.6%～113%、精密度RSD<5%和定量限<1μg/g.方法简便、快速、准确.     

ICP-MS法测定稀土铌钽矿中稀土、钍量

研究了等离子体质谱法测定稀土铌钽矿中稀土、钍量.选择了最佳溶样方法.确定了仪器最佳工作条件.通过测定标准样品及考察干扰情况确定了被测元素的质量数.进行了不同内标元素校正结果实验,确定铊为校正内标元素.进行了精密度实验,结果对照实验,结果令人满意.     

"快乐足球"对中年男性健身、健心作用的研究

目的:通过一段时间的快乐足球训练,利用血压、心率和体重等指标的实验前后对比,来探讨快乐足球对中年男性健身、健心的作用.方法:查阅相关文献资料,对皖北地区中年男性足球爱好者进行访谈和12周的快乐足球训练实验,将实验前后受试者身体成分的测试结果进行比较分析.结果:1.中年男性足球爱好者对快乐足球有着自己的看法和理解.2.快乐足球运动能帮助中年男性很好的进行身体锻炼.3.快乐足球运动能帮助中年男性乐观向上、热爱生活,具有很好的健心作用.     

2010全国大学生数学建模竞赛C题2、3问的几何画板解法探析

本文对2010全国大学生数学建模竞赛C题"输油管的布置"中2、3问所建立的模型进行了分析,探讨了利用"几何画板"进行求解这一巧妙的数学实验方法,并对这种方法的优缺点进行了分析.     

Thorndike, Hunter, and the delayed reaction experiment.

"In his account of his life in Volume III of the History of Psychology in Autobiography, E. L. Thorndike states '… the idea of the delayed-reaction experiment (which has proved the most valuable of my methods of studying animal mentality) came to me after two years work with animals' (p. 269). This is a surprising statement, since it challenges the priority of Hunter, who uniformly is credited with the first published research employing the delayed-response method." Facts are cited which suggest that "… Thorndike does not seem to have been justified in referring in 1936, to the delayed-reaction experiment as 'the most valuable of my methods of studying animal mentality.' " (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cheilognathopalatoschisis: its embryology, epidemiology, etiology, clinical picture and therapy. The experience of a division of pediatrics]

The local lymph node assay is an alternative method for the prospective identification of chemicals that have the potential to cause skin sensitization. Activity in the assay is measured as a function of proliferative responses by draining lymph node cells induced by topical exposure of mice to the test chemical. Positive responses are defined as those where a test chemical, at one or more application concentrations, is able to induce a stimulation index of 3 or greater compared with concurrent vehicle-treated control values. Although the method has been evaluated extensively, the stability over time of responses induced in the local lymph node assay has not previously been addressed formally. It was the purpose of the investigations described here to consider this issue and, to this end, responses provoked in the local lymph node assay by hexyl cinnamic aldehyde (HCA)--a skin sensitizing chemical of moderate potency--were assessed in five separate experiments conducted in a single laboratory over a 10-month period. In each case, HCA elicited a positive response. Although some significant inter-experimental variation was recorded, this was attributable entirely to the stimulation by HCA of slightly more vigorous responses in one of the five experiments. When the results of this experiment were excluded from the data set, significant variations were lost. Finally, for each experiment an EC3 value was derived, this being the estimated concentration of test chemical required to induce a stimulation index of 3. Similar EC3 values were derived in each experiment. These data demonstrate the relative stability over time of activity in the local lymph node assay.     

连铸坯三段曲线矫直法的试验研究

用长１６００ｍｍ、宽５５ｍｍ、高３０ｍｍ的铅坯模拟高温连铸坯，在自制的模拟实验装置上用三段曲线矫直法对铅坯做弯曲和矫直试验，实测了铅坯的矫直应奕和矫直反力，实测结果与理论分析一致，证明了三段曲线矫直法的正确性与优越性。     

均匀设计在烧结试验中的应用

烧结试验是指导烧结厂设计和生产工艺条件优化的基础,也是烧结研究的重要组成部分。烧结试验过程环节多,工作量大,为缩短试验周期,节约试验成本,有时人为削减试验因子数与水平数,但这对试验效果影响很大。以处理多因素多水平试验设计见长的均匀设计法目前已在各个领域广泛应用。且成效显著。本文介绍了均匀设计的基本原理与使用规则,对于均匀设计在烧结试验设计中的应用问题进行了探讨,重点讨论了如何使用均匀设计表来设计试验方案,以期通过这种新的试验设计法来提高烧结试验的效率与质量。     

新型片式散热器试验

完成了4组变压器新型片式散热器与普通片式散热器的散热能力对比试验。通过研究阻力特性、模拟变压器及散热器温度场、循环流量等因素的改变,对新型散热器的总传热系数和循环流量进行了简单分析计算。试验和计算表明,新型片式散热器的总传热系数有所提高。     

多孔介质换热元件的流动特性研究

对几种非均匀孔隙的多孔介质换热元件进行了冷态实验，得到流动阻力与流速的经验关系式，基于冷态实验，建立多孔介质系统的能量平衡模型，通过数值模拟，得到系统内部压力曲线；将冷态实验的结果推广到了非等温系统，并讨论了流量，温度场，组成多孔介质物质的形状，流通长度等因素对阻力损失的影响。     

运用均匀设计实施烧结试验与参数寻优

烧结试验是指导烧结设计、生产工艺条件优化的基础,也是烧结研究的重要组成部分。烧结试验过程环节多,工作量大,为缩短试验周期,节约试验成本,只有削减试验因子数与水平数,对试验效果影响很大。以处理多因素多水平试验设计见长的均匀设计法目前已在各个领域广泛使用且成效显著。介绍了均匀设计的基本原理与使用规则,对于均匀设计在烧结试验设计中应用问题展开了详细探讨,重点讨论如何使用均匀设计表设计试验方案,旨在推广均匀设计在烧结试验中的应用,提高烧结试验效率与质量。     

运用均匀设计试验优化不同褐铁矿烧结性能与工艺参数

由于褐铁矿烧结影响因素多,烧结性能差,技术经济指标恶化.本试验考察褐铁矿配比、料层、水份、燃料配比4个关键因素,运用混合水平均匀设计法,试验次数少代表性强.采用"6水平3因素+4水平1因素"仅试验12次,通过对试验结果直观择优与建模寻优,找出了4个参数的最优组合,对指导现实生产具有重要意义.使用褐铁矿后烧结矿强度与利用系数下降,固体燃耗上升,综合评价三种褐铁矿烧结性能相差不是很大.验证性试验表明与不使用褐铁矿对比的满意程度达到94%以上.配加褐铁矿后,烧结矿的矿物组成变好,软熔性能变差,低温还原粉化性恶化,但还原性改善.     

Effects of a solid lubricant and technological parameters on the friction, wear, and mechanical properties of a composite based on polytetrafluoroethylene powder

Mathematical experiment planning methods have been applied to the effects of solid molybdenum disulfide lubricant content and those of technological parameters (content of special carbon fiber, preliminary size reduction time, and composite mixing time) on the antifriction and other mechanical properties of composite materials based on polytetrafluoroethylene and carbon fiber. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 21–32, May–June, 2006.     

The measurement of solid-liquid surface energies in the Al-Cu,Al-Si and Pb-Sn systems

A technique has been developed to routinely measure solid-liquid surface energies in eutectic systems. The shape of grain boundary cusps were measured after annealing in a temperature gradient. A numerical model was developed to calculate the temperature around the cusp in alloys which have different thermal conductivities in the two phases. Values for the solid-liquid surface energy and the Gibbs-Thomson constant have been obtained for solid Al in Al-Cu solution, solid Al in Al-Si solution, solid CuAl₂ in Al-Cu solution, solid Si in Al-Si solution, solid Sn in Pb-Sn solution and solid Pb in Pb-Sn solution. Grain boundary measurements were also made for the same materials. During the experiment accurate measurements were made of the thermal conductivities for different alloys in the Al-Cu, Al-Si and Pb-Sn systems.