Influence of the Gaussian colored noise and electromagnetic radiation on the propagation of subthreshold signals in feedforward neural networks

Science China Technological Sciences - Iterative methods are used to simulate the in vitro feedforward neural networks in physiological experiments. Emissivity can be propagated to a minimum of ten...     

Evaluation the quality characteristics of wheat flour and shelf-life of fresh noodles as affected by ozone treatment

In this study, the effects of ozone treatment on the microorganism mortality in wheat flour and shelf-life of fresh noodles were investigated, as well as the physicochemical properties of wheat flour and textural qualities of cooked noodles. Results showed that the total plate count (TPC) can be largely reduced in wheat flour exposed to ozone gas for 30 min and 60 min. Whiteness of flour and noodle sheet, dough stability, and peak viscosity of wheat starch were all increased by ozone treatment. Free cysteine content in wheat flour was shown to decrease significantly (P < 0.05) as the treatment time increased and remarkable protein aggregates were observed in both reduced and non-reduced SDS–PAGE patterns. In addition, ozone treated noodles were generally higher in firmness, springiness, and chewiness, while lower in adhesiveness. Microbial growth and darkening rate of fresh noodles made from ozone treated flour were delayed significantly.     

基于压力传感器的负压波法泄漏检测

着重讨论了采用负压波技术进行管道泄漏检测和定位技术,从理论上探讨了在管道泄漏情况下的管道运行状态,采用两个压力检测点对管道进行泄漏检测和定位.     

基于MEMS传感器的胎儿心率检测仪

对胎儿心率的监护,能够监测出胎儿在母体的突发情况,并及时进行救治,可有效预防围产期胎儿死亡.本文运用一种新型MEMS加速度传感器,设计制作出一个小型化、便携式的胎儿心率监护仪.据有体积小、重量轻、功耗低的特点,便于在日常生活中随身携带,方便实用.     

一种快速的防伪起始码处理方法

伪起始码在AVS视频编码标准中起着关键作用.出现伪起始码将使图像的头信息发生错误,导致后续信息发生错位.因此,在完成熵编码输出前,必须进行伪起始码检测.分析了传统的和AVS标准中采用的防伪起码方法,在此基础上,提出了一种采用整字节检测的快速防伪起始码方法.实验结果表明,相对于原有方法,在有无伪起始码时,处理速度均可提高20倍以上.     

含周期性分布导电夹杂压电陶瓷的力电损伤分析

采用胞元法,分析含周期性分布球形/椭球形导电夹杂的压电陶瓷的力电损伤.首先,选取一个代表性材料胞元,通过三维有限元分析获得材料有效弹性、压电和介电系数,然后根据压电连续损伤力学模型中力电损伤变量与材料有效系数的关系,确定力电损伤大小,从而获得力电损伤与夹杂弹性模量、体积和形状参数等的定量关系.结果表明,夹杂体积对力电损伤的影响都很显著,而夹杂弹性模量和形状分别只对力损伤和电损伤有显著影响.     

Experimental investigation on the cracking behavior of 3D printed kinked fissure

Uniaxial compression tests were carried out for 3D printed samples having various types of kinked fissures by using the rock mechanics servo-controlled testing system. Photo-elastic technique is adopted to characterize and visualize the stress distribution and evolution of 3D printed models subjected to vertical compression. The stress field in the loading process can clearly be captured via a high-speed camera. The results showed that fringes around the kinked fissure tips formed a central symmetrical interference fringe pattern, and failure firstly occurred at interference fringe of highest order. Two failure types i.e. tip-cracking and non-tip-cracking are categorized on the basis of crack propagation pattern of 3D printed samples. Tensile crack propagation of wing cracks is the main form of failure of the antisymmetric kinked fissures, but the inclination of the branch fissures also played a key role on the location of initial fracture. The finite element method was applied to numerically simulate the process of crack propagation. The isochromatic fringe patterns are in good agreement with the experimental investigation. The current work gives an insight for implication of advanced technique to quantify and visualize the distribution of stress field, and provides further understanding of kinked fissure behavior at failure.     

铝铸件凝固过程枝晶生长的相场方法模拟

简介了相场方法,利用相场法对纯铝进行了数值模拟。研究了噪声和各向异性等参数对晶粒形貌的影响。计算结果表明:噪声的加入会促进二次枝晶的生长;各向异性系数对枝晶的生长有重要作用。模拟结果与实验结果基本吻合。     

大型异步电机结构振动特性的研究

精确计算电机的固有频率和响应,对于预测电机的振动和噪声是至关重要的.文中利用三维有限元分析研究大型感应电机定子的振动模态和固有频率,并分析绕组、端盖、连接筋及安装方式对电机定子固有频率和振动模态的影响;研究表明,对于大型异步电机,定子绕组对固有频率和振动模态有显著的影响,安装端盖和机座固定使定子固有频率上升,通过改变机座及端盖结构可改变定子固有频率,避免发生共振,采用弹性连接筋,可有效减小定子振动的传播.实验验证部分计算结果.     

基于大数据的电网设备供应链溯源管理评价研究

为了加强电网设备质量源头治理,解决设备质量可追溯性问题,实现贯穿设备全寿命周期的全程质量管控。本文从大数据理念出发,首先建立了基于大数据的电网设备供应链溯源管理评价框架模型,指明了电网设备供应链溯源管理评价的技术路线,其次设计采用网络爬虫技术对散落的海量数据进行爬取和处理,从而提取电力设备供应商的信息,然后构建了包含5个一级指标、8个二级指标和两个维度的三级指标的电力物资供应商评价指标体系,分析了指标间的相互关系,最后对如何合理配指标权重进行了探索,对主观赋权法、客观赋权法和模糊综合评价三种权重确定方法进行了对比分析,从而搭建了具有追溯性的电网设备供应链溯源管理评价模型,为电网企业进行供应商的评价优化提供借鉴。