掏槽爆破掘进效率的装药研究

通过对掏槽爆破的实验研究,利用火药和猛炸药的联合装药方式,改变了以往的单一装药结构．模拟实验的结果表明,联合协同装药结构与单一装药结构的掏槽效果有着显著的区别．前者的掏槽效果要优于后者;同时通过炸药水下的测试结果表明,改进以后的装药结构的冲击波峰值压力的持续时间明显提高,即联合装药的爆炸生成气体量要大于单一装药,为爆破工程上快速高效的掘进提供了理论依据。     

高职学生患者致病菌耐药性分析

目的：了解高职学生患者常见致病菌的种类及耐药情况,为临床抗感染治疗提供参考依据。方法：对来自高职学生患者的68株致病菌进行菌种鉴定和药敏试验,并对结果进行统计分析。结果：高职学生患者致病菌种的前三位分别是金黄色葡萄球菌（36．76％）、铜缘假单胞菌（17．65％）、大肠埃希氏菌（16．18％）;药敏试验结果显示,金黄色葡萄球菌对万古霉素、利奈唑胺和达福普汀的敏感率较高保持为100％,但对青霉素G的耐药率很高,达到97．5％,铜绿假单胞菌对各类抗生素的耐药性均较强。结论：金黄色葡萄球菌对多种抗生素耐药率提高,临床上应重视药敏试验,根据药敏试验结果合理选用抗菌药。     

Modeling of polishing process for electric stainless-steel kettle

The market of stainless electric steel kettles is growing significantly, but the main mechanism for polishing kettles via traditional handwork operations limits the growth of electric kettle manufacturing. Based on the successful multi-tool automatic polishing system for electric stainless steel kettles, regression analysis and orthogonal tests were employed to construct a polishing process model, with a purpose to improve the automatic polishing technology for electric stainless steel kettles. The model reveals the relationship between the surface roughness and processing parameters including gringding depth, abrasive tangent speed, workpiece rotating speed and axial feeding speed. Simulation and experimental results are in agreement,which shows that this modeling method is feasible in practice, and it can also be used as a guidance for planning automatic polishing process of electric stainless-steel kettles.     

On Sample-Size Calculations for Precise Contrast Analysis in ANCOVA

The analysis of covariance (ANCOVA) is a useful statistical procedure that incorporates covariate features into the adjustment of treatment effects. The consequences of omitted prognostic covariates on the statistical inferences of ANCOVA are well documented in the literature. However, the corresponding influence on sample-size calculations for precise interval estimation has not been fully evaluated. This article aims to explicate the deficiency of approximate methods for ignoring the stochastic nature of covariate variables and to present exact approaches for precise interval estimation of treatment contrasts under the assumption that the covariate variables have a joint multinormal distribution. The desired precision of a confidence interval is assessed with respect to the control of expected half-width and to the assurance probability of interval half-width within a designated value. Numerical appraisals show that the suggested approaches outperform the approximate formulas for the two precision considerations.     

不稳定液位的检测

对液位测量现有方案作了阐述及其优缺点比较,针对现有液位测量方法不能较好地测量不稳定液位的问题,提出了利用CYG13固态压阻式压力传感器进行不稳定液位测量的方法,并对其进行了验证,实验结果表明方案有效。     

数字集成电路参数测试仪的设计

针对现有集成电路测试设备结构复杂,功能单一的缺点,本文利用FPGA核心板、D／A模块、A／D模块、电流转换电压电路等器件,采用SOPC技术,设计了一个中小规模通用数字集成电路测试系统,在逻辑功能测试的基础上。实现了74系列中小规模数字集成电路直流性能参数的测试。通过实验,将测试结果与标准的反相器参数进行比较,数据结果一致。表明参数测试仪符合设计要求,设计方案具有一定的参考价值。     

碳基复合材料有效性能的细观力学研究

作为一种多相体材料,碳基复合材料的力学性能和损伤破坏规律与其组元材料的弹性常数、体积含量以及细观结构密切相关。独创了组元材料试样加工与拉伸试验方法,获得了石墨基体和碳纤维的拉伸模量、强度和断裂应变率,在此基础上利用细观力学中Eshelby等效夹杂理论和Mori-Tanaka方法,建立了预报材料弹性常数的细观力学模型,并将理论预报结果与试验结果进行了比较,分析了误差产生的原因。结果表明：理论预报值与试验值之间的误差在10%以内,说明计算模型合理,计算结果可信。     

某空腹式双曲拱桥承载力现场测试与分析

为检验在役双曲拱桥的承载能力与动力特性,对某净跨为36 m空腹式双曲拱桥进行了静载试验、动载试验及空间有限元分析。测试结构的静态应变、动态应变、挠度、自振频率、振型及加速度等结构反应,计算得出冲击系数。将实测结果与有限元结果进行对比分析,结果表明:应变校验系数为0.5~0.9,结构具有较好承载力。实测的各阶频率及相应振型与有限元计算结果比较吻合,桥梁整体竖向刚度较好。     

产业集聚对出口贸易的影响研究——基于湖南省冶金及金属制品产业的实证分析

产业集聚作为一种空间地理特征,对于一国或地区的对外贸易与经济增长具有重要影响。以湖南省冶金及金属制品产业出口贸易与产业集聚的状况为例,实证分析产业集聚对出口贸易的影响,研究结果表明,从长期来看,湖南省冶金及金属制品产业出口贸易与产业集聚之间存在着长期稳定的关系,产业集聚有效促进了出口贸易的增长,且集聚规模每增长1%,出口规模增长0.41%。     

面试型口语考试中考官提示语的量对考生话语流利性的影响

考官的问语是面试型口语考试中的重要组成部分,对考试的顺利进行和考生口语能力的表现具有至关重要的影响.面试是国内唯一的汉语作为第二语言的面试型口语考试,通过对实用汉语水平考试(C.test)的口语考试实测录像的观察发现,在不同场次的考试中,考官提示语的量是不同的.本文通过对20份C.test考试录像转写的文本材料进行研究,考察了面试型口语考试中考官提示语的量对考试话语流利性是否造成影响,从而验证考试中考官的提示语量的差异会不会给考试造成不公平.