XRF法快速测定铝土矿火车样

采用压样法，使用国产便携式Ｘ射线光分析仪快速测定铝土矿火车样中的铝、硅、磷、硫、钾、钙、铁、钛８个元素。文章对标样的采集、制样、仪器某些性能的改进，各种影响因素的校正（如基体效应、谱叠加干扰等）、数学模型的研究开发等作了简要说明，提出了解决问题的基本原则，在小型仪器上攻克了铝土矿火车样工业分析的难题。该技术具有准确、快速、成本低的优点。     

基于极限平衡法和有限元法的边坡协同式可靠度分析

极限平衡法和有限元法是两种常用的边坡稳定分析方法。基于极限平衡法的边坡可靠度分析计算效率较高,但需要假定失效模式,从而导致计算结果不准;与之相反,基于有限元法的边坡可靠度分析更为严格,但计算效率较低。为此,提出了一种新的基于随机模拟的边坡可靠度分析方法——边坡协同式可靠度分析方法。该方法包括初步可靠度分析和精细可靠度分析两步,可以同时利用极限平衡法和有限元法的优势,实现既高效又准确的边坡可靠度分析。通过一个考虑空间变异性的两层土坡算例验证了该方法的有效性,结果表明:协同式可靠度分析方法与基于有限元法的蒙特卡洛模拟或子集模拟相比,不仅具有一致的可靠度分析结果,而且显著提高了小概率水平下的计算效率,促进了基于有限元法的边坡可靠度分析在实际工程中的应用。该方法可以将基于极限平衡法的边坡可靠度分析成果合理纳入到基于有限元法的边坡可靠度分析中,从而获得大量的失效样本,以制定合理的边坡防治措施。该方法非常适用于高维可靠度问题,如考虑空间变异性的边坡可靠度问题。     

Phase‐shifting differential interference contrast microscope with Savart shear prism and rotatable analyser

A novel differential interference contrast microscope (DICM) is proposed in this research. It is constituted by inserting a Savart shear prism between the objective and sample of a polarising microscope having a rotatable analyser as the phase‐shifter, and it is with the ability to enhance image contrast using the principle of shearing interferometry. This letter is to introduce the configuration, interpret the interference patterns and present the experimental setup of the DICM. In addition, this letter is to display the experimental results from the uses of the setup; the results demonstrate the validity and ability of the DICM.     

Application of principal components analysis and signal-to-noise ratio for calibration of spectrophotometric analysers of food

Spectrophotometric analysers of food, being instruments for determination of the composition of food products and ingredients, are today of growing importance for food industry, as well as for food distributors and consumers. Their metrological performance significantly depends on the numerical performance of available means for spectrophotometric data processing; in particular – the means for calibration of analysers. In this paper, a new algorithm for this purpose is proposed, viz. the algorithm using principal components analysis. It is almost as efficient as partial least squares algorithms of calibration, but much simpler. It is fully automatic, viz. the selection of the most informative components is based on the signal-to-noise ratio characterising processed measurement data. The practical effectiveness of the proposed algorithm is demonstrated on a test problem consisting in determination of the concentrations of components of trinary oil mixtures.     

A modified support vector regression: Integrated selection of training subset and model

In recent years, support vector regression (SVR) has become an emerging and popular forecasting technique in the field of machine learning. However, it is subjected to the model selection and learning complexity O(K * N³), especially for a massive data set (N is the size of training dataset, and K is the number of search). How to simultaneously reduce K and N can give us insight and inspiration on designing an effective and accurate selection algorithm. To this end, this paper tries to integrate the selection of training subset and model for SVR, and proposes a nested particle swarm optimization (NPSO) by inheriting the model selection of the existing training subset based SVR (TS-SVR). This nested algorithm is achieved by adaptively and periodically estimating the search region of the optimal parameter setting for TS-SVR. Complex SVR, involving large-scale training data, can be seen as extensions of TS-SVRs, yielding a nested sequence of TS-SVRs with increasing sample size. The uniform design idea is transplanted to the above modeling process, and the convergence for the proposed model is proofed. By using two artificial regression problems, Boston housing and electric load in New South Wales as empirical data, the proposed approach is compared with the standard ones, the APSO-OTS-SVR, and other existing approaches. Empirical results show that the proposed approach not only can select proper training subset and parameter, but also has better generalization performance and fewer processing time.     

基于广播加密的文件保密分发系统

对已有的广播加密方案进行了改进,在子集差分广播加密方案(Subset Difference Method)的基础上引入主密钥机制(Master Key)。与SD方案相比较,新的方案在确保安全性的前提下减少了用户存储的密钥量。利用改进方案的层次特性,实现了一个企业文件保密分发系统,可高效灵活地进行解密权限的控制。     

激光在线测氧仪与电捕焦油器联锁控制的开发与应用

介绍激光在线测氧仪、电捕焦油器的选型与应用,以及在集散控制系统中实现氧含量的实时检测、电捕焦油器远程控制、与氧含量信号的联锁控制。     

红霉素对解脲支原体肺炎的疗效及对细胞亚群和肝功能的影响

目的: 探讨红霉素对解脲支原体肺炎的疗效及对细胞亚群、肝功能的影响。方法: 收集我院2016年5月至2017年5月收治的41例解脲支原体肺炎患儿作为试验组,静脉滴注10 mg/kg红霉素与适量5%葡萄糖注射液,每天2次,疗程7～10 d,同期选取41例健康体检儿童,比较健康组与试验组治疗前后细胞亚群及肝功能,并分析试验组疗效及安全性。结果: 治疗前,试验组CD4+、CD4+/CD8+分别为（41.95±5.71）%、1.26±0.18,低于健康组的（48.13±7.21）%、1.79±0.20,试验组CD8+为（35.10±4.41）%,高于健康组的（26.56±3.13）%,试验组谷丙转氨酶、乳酸脱氢酶、总胆汁酸、胆红素、总胆固醇、甘油三酯、谷草转氨酶、谷丙转氨酶/谷草转氨酶分别为（136.71±17.20）U/L、（439.67±54.45）U/L、（28.39±3.72）U/L、（68.05±8.95）μmol/L、（7.82±0.95）mmol/L、（1.70±0.24）mmol/L、（113.37±14.25）U/L、1.24±0.14,高于健康组的（45.26±4.88）U/L、（397.98±47.20）U/L、（22.24±2.66）U/L、（36.71±4.83）μmol/L、（4.26±0.46）mmol/L、（1.24±0.17）mmol/L、（62.51±9.19）U/L、0.77±0.12;治疗后,试验组CD4+、CD4+/CD8+显著上升,CD8+、谷丙转氨酶、乳酸脱氢酶、总胆汁酸、胆红素、总胆固醇、甘油三酯、谷草转氨酶、谷丙转氨酶/谷草转氨酶显著下降,且两组比较无统计学差异（P>0.05）。结论: 红霉素对解脲支原体肺炎的疗效肯定,能够利于细胞亚群及肝功能的缓解。     

Displacement Discontinuity or Complex Shape of Sample: Assessment of Accuracy and Adaptation of Local DIC Approach

In this paper, we study the impact of a complex shape of sample and the appearance of a displacement discontinuity on performances of measurement by local Digital Image Correlation (DIC). Both cases are modelled from synthetic images into two parts: one with a speckle field and another part without speckle or two parts with similar speckle fields but with different kinematics. The accuracy of displacement measurements assessed for DIC subsets crossing the boundary between the two parts is lower than the one obtained without discontinuity and justifies adapting DIC method. A new local DIC process is presented in detail. It is an alternative way able to take into account any shape of sample and several curved lines of discontinuity in the same subset. Two experimental examples are presented: displacement and strain fields obtained by DIC and adapted DIC are compared. We can conclude that it is possible to lead a mechanical analysis until the limits of the sample and even during the appearance and the propagation of a crack.     

Handling properties of cereal materials in the presence of moisture and oil

A powder flow analyzer attached to a Texture Analyser (Stable Micro Systems, UK) was used to compare the flow behaviour of four cereals systems: maize and wheat (in both starch and flour forms), as functions of particle size and distribution, water content and the addition of different types of oil. It was expected that the smaller the particle size the higher the tendency to stick (because of less free volume between the particles), but that was not the case. The results showed that wheat starch used, with bigger particle size than maize starch, had higher cohesion properties and as water content increases the cohesion increases by the same magnitude. This was attributed to the differences in granular shape as well as protein quantity and quality. Caking strength for both starches was influenced by the water content; in particular at 30% water content (w/w), neither cohesion nor caking indices could be measured for wheat starch because of the high stickiness of the particles.Although the two flours had particles of very similar sizes, with differences in the distributions only, maize showed higher cohesion indices compared to wheat flour. These values decreased with increasing water content. The caking property for maize was not significantly affected by water content with values of approximately 100 ± 5. The caking strength increased for wheat flour from 8 to 500 as moisture increased from 12.5 to 30%. This was ascribed to the differences in hydration properties of the two flours. For wheat flour and as the water content increased, gluten started to form and would require more than 30% to form a homogenous, visco-elastic mass.Generally, cohesivity and cake forming ability were affected by water content as well as the physical state of the oil i.e. by the solid/liquid ratios. As water content increases, wheat starch showed the greatest packing and cohesive behaviour, with and without the oil, while maize flour exhibited the weakest packing and cohesive properties.