激光多普勒效应地震波实时测量技术的研究

传统的磁电式地震检波器易于受到电磁干扰、存在非线性 ;提出一种应用激光多普勒技术的地震波检测方法 ,采用优化设计的差动光路结构方案、信号处理单元的适宜带宽。通过F/V转换可以实时地得到被测速度、位移、加速度和频率。实现线性测量的频率范围 1 0～ 1 0 0 0Hz ,动态范围 1 0 0dB。     

Visible photocatalytic activity and photoelectrochemical behavior of TiO2 nanoparticles modified with metal porphyrins containing hydroxyl group

TiO₂ nanoparticles modified with 5-(p-hydroxylphenyl)-10,15,20-triphenylporphyrin (HTPP), 5-(p-hydroxylphenyl)-10,15,20-triphenylporphyrin zinc (ZnHTPP) and trans-dichloro-5-(p-hydroxylphenyl)-10,15,20-triphenylporphyrin tin (SnHTPP) were prepared in order to improve the visible photocatalytic activity of TiO₂ nanoparticles. The photocatalytic activity of the modified TiO₂ nanoparticles was investigated by carrying out the photodegradation of methyl orange in aqueous solution under visible light irradiation. The TiO₂ nanoparticles modified with SnHTPP show the highest visible photocatalytic activity with a degradation ratio of 86% of methyl orange after 180 min irradiation among three catalysts. This result indicates that the central metal ions in porphyrins can significantly influence the sensitization efficiency of porphyrins. In addition, the photoelectrochemical behavior of the modified TiO₂ nanoparticles was examined and related to their photocatalytic activity. Finally, the photocatalytic mechanism was discussed preliminarily.     

基于线程池技术DHCP服务器的设计与实现

DHCP服务器在IP地址的集中管理和计算机网络参数的配置方面发挥着重要作用。但是,DHCP服务器效率问题影响其在大型网络管理中的应用。文中提出了基于线程池技术DHCP服务器的设计思想,提出了动态调整线程池大小的可行算法。测试结果显示,基于线程池技术DHCP服务器的服务效率有了明显改善。     

基于神经网络逆系统方法的链式STATCOM线性化解耦控制

针对链式STATCOM补偿负载无功电流以及稳定电网电压的控制问题,建立了链式STATCOM动态数学模型,得出了双变量δ、M(移相角与调制比)和电流的关系式,提出了一种基于神经网络逆系统控制方法,通过对该链式STATCOM系统可逆的验证、神经网络的构建以及控制系统的设计,实现了链式STATCOM输出的有功-无功电流的线性化解耦控制。仿真结果表明,在感性负载与容性负载进行切换以时,该控制策略取得了良好的动态效果以及稳态效果,使得装置具有较好的抗参数变化、抗负载扰动性能,从而验证了该控制策略的有效性及可行性。     

中国绿色照明工程进展及展望——祝贺《照明工程学报》创刊20周年

中国政府高度重视照明节电工作,1996年启动实施绿色照明工程,先后将其列入"九五"、"十五"重点节能领域和"十一五"、"十二五"重点节能工程。本文总结和回顾了中国绿色照明工程走过的十几年历程,在此基础上对中国绿色照明工程的未来发展进行了展望。     

乳酸菌发酵对青稞β-葡聚糖加工特性及其耐缺氧和抗疲劳作用影响

该文研究植物乳杆菌(Lactobacillus plantarum,LP)、保加利亚乳杆菌(Lactobacillus bulgaricus,LB)、鼠李糖乳杆菌(Lactobacillus rhamnosus,LR)发酵对青稞β-葡聚糖加工特性及其耐缺氧、抗疲劳作用的影响。结果表明,LB发酵制备青稞β-葡聚糖的含量高于LP和LR,达到(5.14±0.22)%。保加利亚乳杆菌发酵后得到的β-葡聚糖(Lactobacillus bulgaricus β-glucan,LBG)中多糖均一性较高,起泡能力和溶解性均显著高于植物乳杆菌发酵后得到的β-葡聚糖(Lactobacillus plantarum β-glucan,LPG)、鼠李糖发酵后得到的β-葡聚糖(Lactobacillus rhamnosus β-glucan,LRG)和未发酵得到的β-葡聚糖(no fermentation β-glucan,NFG)起泡稳定性显著高于LPG、LBG和NFG。LPG、LBG、LRG与NFG相比,密闭缺氧存活时间延长了26.6%、42.3%和36.4%,游泳存活时间延长了22.6%、40.3%和4...     

A game model for information dissemination in live streaming e-commerce environment

As a new form of social e-commerce, live streaming e-commerce is becoming increasingly popular among Chinese consumers. Live streaming brings huge opportunities, and we can take measures to further expand the dissemination of live streaming information. A live streaming information dissemination game model based on social evolutionary game theory is presented to simulate multiple complex live streaming e-commerce networks. The introduction of incentive mechanism in the model further quantifies the internal relation between rewards and live streaming information dissemination to a certain extent and predicts the ratings of live streaming in networks with different update frequency of social relationships. The simulation results indicate that the reputation environment in social networks, adjusting frequency of relationship, pre-broadcast rewards to post-broadcast rewards ratio all have certain ranges of impact on information dissemination in live streaming e-commerce environment and then affect the live streaming ratings. These findings offer insights into the dissemination of live streaming information in social networks.     

变面积式电涡流传感器线圈阻抗理论计算模型

变面积式电涡流传感器相比于传统的变距式传电涡流感器具有线性度好和量程易扩展等优点。介绍了变面积式电涡流传感器的基本测量原理和理论模型的建立方法。该模型利用二阶矢量位结合截取边界法建立了相关电磁场方程组,在此基础上推导并建立了传感器的理论模型并给出了传感器线圈阻抗计算以及相关场量的闭合解析表达式。实验结果证明了此模型的有效性和正确性,该计算模型与传统的数值仿真运算相比,不仅物理意义明晰,而且极大缩短了运算时间。     

鞍钢鲅鱼圈3.8m中板厂房优化设计

针对鞍钢3.8 m中厚板生产线厂房跨度大、吊车吨位大、工艺布局要求严等难点,通过厂房方案比较、结构选型、材料选择、设计参数选优,工艺、土建、机电等专业会商进行设计优化。东北寒冷地区保温厂房含钢量通常约210 kg/m2,设计优化后降至165 kg/m2,降低约20%。此含钢量为目前同类厂房最低,取得较好的技术经济效果,可供同类厂房设计参考。     

A system for destination and future route prediction based on trajectory mining

Location is a key context ingredient and many existing pervasive applications rely on the current locations of their users. However, with the ability to predict the future location and movement behavior of a user, the usability of these applications can be greatly improved. In this paper, we propose an approach to predict both the intended destination and the future route of a person. Rather than predicting the destination and future route separately, we have focused on making prediction in an integrated way by exploiting personal movement data (i.e. trajectories) collected by GPS. Since trajectories contain daily whereabouts information of a person, the proposed approach first detects the significant places where the person may depart from or go to using a clustering-based algorithm called FBM (Forward–Backward Matching), then abstracts the trajectories based on a space partitioning method, and finally extracts movement patterns from the abstracted trajectories using an extended CRPM (Continuous Route Pattern Mining) algorithm. Extracted movement patterns are organized in terms of origin–destination couples. The prediction is made based on a pattern tree built from these movement patterns. With the real personal movement data of 14 participants, we conducted a number of experiments to evaluate the performance of our system. The results show that our approach can achieve approximately 80% and 60% accuracy in destination prediction and 1-step prediction, respectively, and result in an average deviation of approximately 60 m in continuous future route prediction. Finally, based on the proposed approach, we implemented a prototype running on mobile phones, which can extract patterns from a user’s historical movement data and predict the destination and future route.