Grain boundary segregation of minor arsenic and nitrogen at elevated temperatures in a microalloyed steel

Auger electron spectroscopy (AES) was used to investigate the grain boundary segregation of arsenic and nitrogen in a kind of microalloyed steel produced by a compact strip production (CSP) technology at 950 to 1100℃, which are similar to the hot working temperature of the steel on a CSP production line. It was discovered that arsenic segregated on grain boundaries when the steel was annealed at 950℃ for 2 h. When the annealing temperature increased to 1100℃, arsenic was also found to have segregated on grain boundaries in the early annealing stage, for instance, within the first 5 min annealing time. However, if the holding time of the steel at this temperature increased to 2 h, arsenic diffused away from grain boundaries into the matrix again. Nitrogen was not found to have segregated on grain boundaries when the steel was annealed at a relatively low temperature, such as 950℃. But when the annealing temperature increased to 1100℃, nitrogen was detected to have segregated at grain boundaries in the steel.     

整合资源专业服务--天长市科技兴农再谱新曲

近年来,天长市以"三个代表"重要思想为指导,努力整合农业科技资源,集成专业服务优势,紧紧围绕"促进农村经济结构全面提升、农业综合效益切实提高、农民科技水平整体攀升"这一目标,积极实施科技项目,大力培育示范基地,充分整合农业人才资源,科技兴农再上新台阶.     

高原环境下可碳化固体可燃物表面火蔓延特性研究

为了揭示可碳化固体可燃物在高原地区的火蔓延特性, 实验选取了质地较为均匀的白木为研究对象, 分别在海拔3658 m的拉萨和50 m的合肥进行了一系列实验, 通过测量不同宽度、倾斜角度下白木表面火焰高度、火蔓延速度、火焰温度、试样表面温度等参数, 定量分析了高原环境下可碳化固体表面火蔓延的特性. 结果表明, 在高原低氧浓度和低压力条件下, 火焰高度和表面火蔓延速度都有所降低, 但火焰温度却略有升高; 当试样宽度增大时, 合肥与拉萨的火蔓延相对速度差值越来越小.     

变风量空调系统运行调节实验的设计

本文以中原工学院楼宇自动化实验室为基础,对变风量空调系统运行调节实验设计进行讨论。通过该实验,可以让学生更好地了解和掌握变风量空调系统运行过程及基本控制原理,对提高学生的专业知识水平和综合素质具有重要作用。     

2-乙酰基-乙酰甲氧基苯胺与铕(Ⅲ)和铽(Ⅲ)配合物的合成及荧光性质研究

合成了一个新型β-二酮型配体,以及它与铕(Ⅲ)和铽(Ⅲ)形成的配合物。配体和配合物分别用元素分析、红外光谱1、HNMR、质谱、荧光光谱进行了表征。分别在DMF、乙醇、丙酮、氯仿及甲醇溶液中研究了配合物的荧光性质,并讨论了溶剂效应对配合物荧光强度的影响。     

在机械设计课程中培养学生的创新思维能力

提出了机械设计课程教学中培养创新思维能力方法和手段,并对如何通过课堂教学和实训教学,培养学生的创新思维能力进行了探讨。     

电化学方法快速测定尿酸的应用研究

采用恒电位沉积方法制备了EDTA修饰玻碳电极,并考察了尿酸(UA)在修饰电极上的电化学行为。在优化的实验条件下,UA在修饰电极上的氧化峰电流显著增强,UA在8.0×10~(-7)～8.0×10~(-5)mol·L~(-1)浓度范围内与其氧化峰电流成良好的线性关系。该电极制备简单,响应快,使用方便,用于尿样中UA的检测,效果良好。     

Evolution of carbides and carbon content in matrix of an ultra-high carbon sintered steel during heat treatment process

DTA, thermal expansion, XRD, and SEM were used to evaluate the effect of quenching temperature on the mechanical properties and microstructure of a novel sintered steel Fe-6Co-1Ni-5Cr-5Mo-1C. Lattice parameters and the mass fraction of carbon dissolved in the matrix of the steel quenched were investigated. It is discovered that the hardness of the steel increases with quenching temperature in the range of 840-900℃ and remains constant in the range of 900 to 1100℃. It decreases rapidly when the temperature is higher than 1100℃. The mass fraction of carbon dissolved in the matrix of the steel quenched at 840℃ is 0.38, but when the quenching temperature is increased to 1150℃, it increases to 0.98. The carbides formed during sintering are still present at grain boundaries and in the matrix of the steel quenched at low quenching temperatures, such as 840℃. When the quenching temperature is increased to 1150℃, most of the carbides at grain boundaries are dissolved with just a small amount of spherical M₂₃C₆ existing in the matrix of the quenched steel.     

循证护理在妇科肿瘤中的应用分析

目的探讨循证护理在妇科肿瘤患者中的应用效果,为肿瘤患者制定科学合理的护理方案提供参考.方法选择盐城市肿瘤医院妇产科2009年9月—2012年1月收治的80例妇科肿瘤患者作为观察对象,将其分为循证护理组和常规护理组,各40例.循证护理组患者采用循证护理的方法,发现问题,查阅文献,将证据与患者实际情况综合比较后,筛选出最佳证据,进行针对性的护理;常规护理组进行常规护理.对两组患者的护理效果进行比较.结果循证护理组有2例患者发生压疮,未有患者发生深静脉血栓,压疮发病率与深静脉血栓发病率显著降低.治疗前两组患者的SCL-90,SAS,SDS评分差异均无统计学意义(P>0.05).治疗后两组患者的SCL-90,SAS,SDS评分均得到了显著的改善,差异有统计学意义(P<0.05).循证护理组的SCL-90,SAS,SDS评分显著低于常规护理组.循证护理组患者有8例患者为完全缓解,25例患者为部分缓解,其疼痛缓解情况显著优于对照组.结论妇科肿瘤患者手术及化疗过程中的护理是十分重要的.循证护理基于科学的基础,审慎地对护理文献进行系统评价,根据每位妇科肿瘤患者制定了个性化的护理方案,护理效果优于常规护理,值得临床上重视和推广使用.     

嵌入误分类代价和拒识代价的二元分类算法

传统分类算法隐含的假设(每个样本的误差都具有相同的代价,且接受每个样本的分类结果)并不适用于医疗诊断、故障诊断、欺诈检测等领域的实际需求。在定义拒识代价的基础上,本文提出一种嵌入非对称误分类代价和非对称拒识代价的二元分类算法(CSVM-CM C2RC),包括以下4个步骤:学习代价敏感支持向量机、估计每个样本的后验概率、计算每个样本的分类可靠性、确定每类样本的最优拒识阈值。基于标准数据集的试验研究表明,CSVM-CM C2RC能有效地降低误分类率和平均代价,提高分类结果的可靠性。