基于B-P神经网络的环境空气质量预测模型

B-P神经网络是一种刻画非线性现象的强有力工具,可以将它应用到环境空气质量预测中。B-P神经网络针对不同的监测项目,根据不同的气象特征因子,将污染源排放数据为输入因子,监测点位监测数据作为输出因子,形成多组训练样本,进行学习训练,建立起不同的预测网络。然后用空气污染源排放监测数据输入相同气象条件的、已调整好权值的B-P神经网络系统,即可输出该项污染物的监测点位预测监测值。实验证明B-P神经网络预测模型取得了较好的结果,比现有预测模型具有更大的优势。     

Graphene–sulfur–Ni(OH)2 sandwich foam composites as free-standing cathodes for high-performance Li–S batteries

Lithium–sulfur (Li–S) batteries are considered as a next-generation energy storage solution thanks to the dramatic increase in their energy density and the accompanying low fabrication cost. Nonetheless, their practical applications have been hampered by critical challenges such as cycling instability, low sulfur utilisation and efficiency. Here, the interfacial growth of Ni(OH)₂-encapsulated sulfur nanoparticles in a reduced graphene oxide free-standing matrix as Li–S cathodes has been highlighted, along with a detailed application investigation of the sandwich foam structure in Li–S batteries. Compared to sulfur composites based solely on a graphene host (S@rGO), this composite foam cathode could provide significant improvements in specific capacity and long-cycle stability with the effective confinement and promoted conversion of lithium polysulfides. Moreover, the sandwich foam composite cathode exhibits a high specific capacity of 1189 mA h g⁻¹ (0.1 C), better rating performance (691 mA h g⁻¹ at 2 C) and remarkable cycling stability, retaining 81% of the initial capacity after 200 cycles of charge–discharge at 0.2 C. Furthermore, Ni(OH)₂ wrapping at the cathode–electrolyte interface offers vastly improved polysulfide shuttle suppression, which provides a new cathode encapsulation method for further developments of advanced Li–S cathodes.     

考虑负载均衡的无线传感器网络数据汇集算法

基于最小生成树策略的数据汇集算法使得数据传输效率高,但是树的构造使得转发节点负载过高,能量消耗过大,还会造成无线传感器网络的负载不均衡。针对这种情况,提出一种考虑负载均衡的数据汇集算法,该算法基于最小代价树的建立策略,在构造树的过程中避开剩余能量小的节点,最大化无线传感器网络的生存时间。     

MANET中“虫洞”攻击的位置检测算法设计与仿真

着重研究了移动Ad hoc网络中一种严重的恶意攻击——“虫洞”攻击,针对其提出一种简洁高效的位置检测算法,并采用OMNeT++仿真器进行仿真实验,根据实验分析移动网络中的各种因素对位置检测算法执行的影响,证明了算法的有效性。     

粗规律F-分解与规律识别

函数S-粗集具有规律特性、动态特性;利用函数S-粗集和基于函数S-粗集的粗规律生成方法,给出f-分解规律,F-分解粗规律,属性f-扰动度,属性F-下扰动度,属性F-上扰动度等概念; 利用这些概念,提出规律f-分解定理,属性f-扰动度定理,粗规律F-扰动度定理,给出粗规律F-分解识别的基本原理,并给出应用实例。     

Preparation of dense β-CaSiO3 ceramic with high mechanical strength and HAp formation ability in simulated body fluid

In present study, dense CaSiO₃ (CS) ceramics have been fabricated through spark plasma sintering (SPS) technique using β-CS powder prepared by chemical precipitation method. The β-CS ceramic sintered at 950 °C has a relative density of about 95% and shows a fine microstructure with an average grain size of 0.6 μm, thus expresses good bending strength of about 294 MPa. The simulated body fluid (SBF) immersion tests show that the dense β-CS ceramic has a high hydroxyapatite (HAp) formation rate on its surface. The HAp layer formed on the CS ceramic surface has a granular structure consisting of silkworm-like HAp grains, and the thickness of HAp and Si-rich layer are 70 and 120 μm, respectively.     

Determination method of water gushing runoff zones in the open pit mining area

Bulletin of Engineering Geology and the Environment - Taking the Hejing limestone mining area of Guangxi Huarun Cement (Pingnan) Company as the research background, the method for water gushing...     

基于PSO的Markov随机场在医学图像分割中的应用

研究了应用粒子群优化算法（PSO）优化Markov随机场方法对磁共振图像进行分割的算法。建立了基于马尔可夫随机场的图像分割模型,针对马尔可夫随机场图像模型的局部相关特性和最大后验概率估计,将粒子群优化算法应用于该模型,快速获得图像分割目标的全局最优解。实验数据表明该方法的高效性。     

基材信息在线检测及喷码系统设计

基材是汽车内饰件的重要组成部分,长久以来其质量检测依靠人工抽检,效率低,精度差.本文针对基材质量检测过程中的1问题,开发在线检测及喷码系统.系统采用激光位移传感器实现两路厚度测量,PLC采集厚度数据并控制报警装置,皮带秤和称重仪表PT650D实现重量采集,上位机软件通过串口与下位机通信,实现数据处理,保存,查询,统计及其他数据库管理.为了便于质量追踪,系统给每块基材设置并喷印一个编号,并且可以打印厚度,重量等不规则信息,实现了信息实时喷印.     

An experimental investigation of the influence of cutting parameters on cutting temperature in milling Ti6Al4V by applying semi-artificial thermocouple

An investigation was reported on the cutting temperature in milling Ti6Al4V by applying semi-artificial thermocouple. ANOVA was conducted on the experimental results, and regression models were obtained. Analysis results showed that the tool temperature and workpiece temperature performed a similar rising trend with the increase of cutting parameters, including cutting speed, feed rate, radial feed, and axial feed. And their influence degrees decreased successively. The cutting force with different cutting parameters was also measured, and the relationship between cutting temperature and cutting force was discussed. It was found that cutting temperature and cutting force obtained in the experiment had the same fluctuation feature. Therefore, the cutting force and cutting temperature could complement each other for monitoring and analysis of the cutting process.