浅析X荧光成份分析仪在水泥生产过程中的应用

阐述了X荧光成份分析仪在水泥生产过程运行的现状及其测量原理,结合现代新型干法大规模生产线对产品质量的控制要求,对X荧光成份分析仪在水泥生产过程应用的必要性进行了说明。     

白光LEDs用(Ba/Sr/Ca)2.9Ce(PO4)3:0.1Eu2+的发光特性

采用高温固相法制备了(Ba/Sr/Ca)_2.9Ce(PO₄)₃:0.1Eu²⁺系列荧光粉,研究了材料的发光特性。在400 nm光激发下,增大x值,Ba_2.9-xSr_xCe(PO₄)₃:0.1Eu²⁺的主发射峰由515 nm红移至540 nm,色坐标从(0.312,0.607)变到(0.376,0.580);随着y值的增大,Ba_2.9-yCa_yCe(PO₄)₃:0.1Eu²⁺的主发射峰由515 nm红移到553 nm,色坐标从(0.312,0.607)变到(0.427,0.535),随z值的增大,Sr_2.9-zCa_zCe(PO₄)₃:0.1Eu²⁺的主发射峰值由540 nm红移...     

高密度聚乙烯DSC原位加速热老化特性研究

利用DSC原位加速热老化方法,研究了高密度聚乙烯(HDPE)热老化特性,分析了热老化温度对HDPE熔融特性、结晶度和微观结构的影响,通过主成分分析法(PCA)探究了参数变化的相关关系,建立并评估了HDPE在热老化条件下的老化综合评价指标。结果表明,在较低热老化温度条件下,交联作用占主导,随着老化温度的升高,断链与支化作用加强,氧化产物生成变多,由于非结晶区分子链断裂,增强了分子链的活动性导致结晶度先上升后下降。峰值温度和终止温度与亚乙烯基、支化程度、断链程度和羰基指数协同相关程度高,峰值温度、终止温度与亚乙烯基、支化程度互为强抵抗相关。老化综合评价指标整体上Z值呈现两段式的变化趋势。     

聚丙烯酰胺澄清果汁工艺研究——澄清过程主要成分的变化

本文研究了聚丙烯酰胺澄清苹果汁时的主要成分变化。结果表明:澄清后果汁的透光率在98％以上;主要果汁成分的保存率均在95％以上。这一结果与果胶酶澄清法和超滤澄清法有所不同。这种差异是由于澄清机理不同所致。     

Parallel algorithms for image enhancement and segmentation by region growing, with an experimental study

This paper presents efficient and portable implementations of a powerful image enhancement process, the Symmetric Neighborhood Filter (SNF), and an image segmentation technique that makes use of the SNF and a variant of the conventional connected components algorithm which we call -Connected Components. We use efficient techniques for distributing and coalescing data as well as efficient combinations of task and data parallelism. The image segmentation algorithm makes use of an efficient connected components algorithm based on a novel approach for parallel merging. The algorithms have been coded in Split-C and run on a variety of platforms, including the Thinking Machines CM-5, IBM SP-1 and SP-2, Cray Research T3D, Meiko Scientific CS-2, Intel Paragon, and workstation clusters. Our experimental results are consistent with the theoretical analysis (and provide the best known execution times for segmentation, even when compared with machine-specific implementations). Our test data include difficult images from the Landsat Thematic Mapper (TM) satellite data.Also affiliated with the Department of Electrical Engineering.Also affiliated with the Department of Computer Science and the Center for Automation Research.     

家用无线智能燃气表的三防防护

城市进程的加快同时也对燃气行业提出了更高的要求,如何有效地降低运行故障率成为行业内有待解决的问题。文章主要讲述了如何通过加强燃气表的三防防护工作,有效降低控制部分的运行故障率。其中通过列举一款智能表的材料优选、工艺防护和结构防护三方面进行的具体三防防护处理措施,以及投入市场使用后所取得的效果,从而验证了经过三防处理的燃气表在恶劣环境下稳定运行的寿命可以得到很大的提高。     

高校信息化平台遗留系统的重用设计与实现

目前,随着国家推进国民教育资源的优化组合,许多高校进行扩建和合并,增设了院系,新建或接收了新校区,信息系统规模不断扩大。新增院系和校区的信息系统与主校区的信息系统无法有效融合,大量需要共享的关键信息被封闭在相对独立的系统里。如何对现有遗留系统进行统一规划,封装成可重用的Web服务组件,从而集成各个孤立的信息系统,消除信息孤岛现象,实现遗留系统的重用设计,是高校信息一体化平台建设中的亟待解决的问题。     

Helicopter maintenance error analysis: Beyond the third order of the HFACS-ME

In this paper a statistical analysis of a sample of 58 helicopter maintenance-induced safety occurrences is conducted to study helicopter accidents and incidents’ survivability and the severity distribution of such occurrences. Analysis is also carried out to identify helicopter main and sub-systems mostly exposed to maintenance errors and to determine various types of such errors. Expected inherent relations between rotorcraft components affected and types of associated maintenance errors are investigated. Human factors-based triggers of these accidents and severe incidents are explored. The concept of Specific Failures (SFs) that immediately precede each of such occurrences is introduced for more detailed representation of the last breached individual and organizational safety barriers. Root causes of these safety occurrences were then sought utilizing the Human Factors Analysis and Classification System-Maintenance Extension (HFACS-ME) taxonomy with a refined focus on its third order categories’ list. The rotorcraft characteristics influencing individuals and organizational behaviours within Maintenance, Repair and Overhaul organizations (MROs) are discussed in the light of the root cause investigation results.

Relevance to industry

The study of human reliability within helicopter maintenance industry is waited to emphasise the understanding of causes and propagation mechanisms of maintainers' errors and their consequences on the overall aviation safety. Previous works often investigated maintenance errors and their roles in promoting aviation accidents of fixed-wing aircraft; this research is investigating the case of rotorcraft.     

Shape optimized design of microwave dielectric resonators by level‐set and topology gradient methods

The finite element method is coupled with the topology gradient (TG) and level‐set (LS) methods for optimizing the shape of microwave components using a computer‐aided design model. On the one hand, the LS approach is based on the classical shape derivative; while on the other hand, the TG method is precisely designed for introducing new perturbations in the optimization domain. These two approaches, which consist in minimizing a cost function related to the component behavior, are first described. Regarding given electrical specifications, these techniques are applied to optimize the distribution of ceramic parts of a dual‐mode resonator in order to improve its behavior. The optimized dielectric resonators result in a wide spurious‐free stop band. A comparison between classical and optimized dual mode resonator is presented. Theoretical results are then validated by careful measurements. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE 2010.