水处理系统的分段优化设计方法

采用分段设计法研究水处理过程.根据给水浓度和产水浓度要求的不同,以年费用最小为目标,将水处理过程作为超结构模型,进而优化设计段数和每段的工艺参数.研究表明,当进水浓度为5 000 ppm～35 000 ppm时,制备生活用水采用反渗透法处理费用最低,而制备纯水采用反渗透+离子交换联合法处理费用最低;当进水浓度为500 ppm～5 000 ppm时,前者采用电渗析法处理费用最低,而后者采用电渗析+离子交换联合法处理费用最低;当进水浓度小于500 ppm时,制备纯水采用离子交换法费用最低.     

基于TMS320F2812的液晶显示模块接口设计

为适应工业应用现场以及智能化仪器仪表前端显示的需要,阐述了TMS320F2812DSP和QH2001液晶显示模块的原理及特性,提出了一种基于高速DSP处理器控制低速液晶显示模块的接口设计方案,并对该方案的硬件接口电路和软件驱动程序进行了设计,同时给出了软、硬件实现的相应电路图、程序流程图以及具体程序段;实验调试表明,设计方案结构简单、成本低、抗干扰能力强、显示性能稳定可靠,达到设计要求,能够有效解决高速DSP对低速LCD的驱动及显示问题,并取得了良好的显示效果,对其它便携式系统显示终端的设计也具有一定参考价值。     

A piecewise analysis method to stability analysis of linear continuous/discrete systems with time‐varying delay

The delay‐dependent stability problem of linear continuous/discrete systems with time‐varying delay is investigated based on a piecewise analysis method (PAM). In the method, the variation interval of the time delay is firstly divided into several subintervals. By checking the variation of the Lyapunov functional in every subinterval, some new delay‐dependent stability criteria are derived. Several numerical examples show that our method can lead to much less conservative results than those in the existing references. Moreover, when the number of the divided subintervals increases, the corresponding criteria can provide an improvement on the results. Copyright © 2008 John Wiley & Sons, Ltd.     

新形势下对设计教育方法的思考

在信息化社会里,设计专业与社会需求之间有着非常紧密的联系,为了使学生在大量信息面前,对所学习的专业知识与技能,展开独立的思考,多向思维、多种角度去认识同一事物,并能根据自己的需要进行分类和整理,培养学生捕捉信息的敏锐感受和理解的能力,要求教师积极主动调整知识结构、增加新的教育方法来改善我们的设计教育,使每一个学生的潜能都能得到充分发展,并获得更直接、更实际的专业知识。     

如何设定品牌标志的设计标准

品牌设计师通过知觉联想可以将文字语言转化为直接、可见的视觉图形传达给社会大众,这种语言上的转换是设计师发掘人们想象不到或想象不全面的一种表现方式,是艺术创造。同时,在没有限制,具有广泛可能性的创意、设计中,要把企业理念和目标等文字语言浓缩、整合出适合创意、设计的关键语,这一个个关键语就是品牌标志设计的依据和标准。有了这样的设计标准就会提高设计效率和准确性,减少在标志设计过程中的矛盾与摩擦,起到指引方向和检验最终方案的作用。     

Web Services技术在气象产品发布中的应用

根据气象产品发布现状,结合统一的Web Service对象封装技术,提出了一种跨平台、无缝集成的方案;采用Web Service技术发布气象产品,实现了跨平台和不同语言的应用集成,并能够使气象产品的发布速度更快、效率更高。     

Diffractive-phase-element design that implements several optical functions

A scheme for the design of diffractive phase elements (DPE's) that integrates several optical functions is presented in a consistent sense based on the general theory of amplitude-phase retrieval and the Yang-Gu algorithm [Appl. Opt. 33, 209 (1994)]. We extend the original Yang-Gu algorithm to treat a system illuminated by a beam of incident light whose components are at different wavelengths, and a set of equations for determining the phase distribution of the DPE is derived. The profile of a surface-relief DPE can be designed with an iterative algorithm. Numerical simulations are carried out for the design of one-dimensional DPE's capable of both demultiplexing different wavelength components and focusing each partial wave at predetermined positions. The influence of the extension of sampling points in the DPE's from ideal geometric points to physical spots on design results is also investigated. The numerical simulation results show that the new algorithm can be used successfully to design the desired DPE's. It is therefore expected to be useful in the design of DPE's for micro-optical systems.     

Lightweight deep learning methods for panoramic dental X-ray image segmentation

Neural Computing and Applications - Dental X-ray image segmentation is helpful for assisting clinicians to examine tooth conditions and identify dental diseases. Fast and lightweight segmentation...     

Application potential of bone marrow mesenchymal stem cell (BMSCs) based tissue-engineering for spinal cord defect repair in rat fetuses with spina bifida aperta

Spina bifida aperta are complex congenital malformations resulting from failure of fusion in the spinal neural tube during embryogenesis. Despite surgical repair of the defect, most patients who survive with spina bifida aperta have a multiple system handicap due to neuron deficiency of the defective spinal cord. Tissue engineering has emerged as a novel treatment for replacement of lost tissue. This study evaluated the prenatal surgical approach of transplanting a chitosan–gelatin scaffold seeded with bone marrow mesenchymal stem cells (BMSCs) in the healing the defective spinal cord of rat fetuses with retinoic acid induced spina bifida aperta. Scaffold characterisation revealed the porous structure, organic and amorphous content. This biomaterial promoted the adhesion, spreading and in vitro viability of the BMSCs. After transplantation of the scaffold combined with BMSCs, the defective region of spinal cord in rat fetuses with spina bifida aperta at E20 decreased obviously under stereomicroscopy, and the skin defect almost closed in many fetuses. The transplanted BMSCs in chitosan–gelatin scaffold survived, grew and expressed markers of neural stem cells and neurons in the defective spinal cord. In addition, the biomaterial presented high biocompatibility and slow biodegradation in vivo. In conclusion, prenatal transplantation of the scaffold combined with BMSCs could treat spinal cord defect in fetuses with spina bifida aperta by the regeneration of neurons and repairmen of defective region.