Promotional effect for SCR of NO with CO over MnOx-doped Fe3O4 nanoparticles derived from metal-organic frameworks

MnO_x-Fe₃O₄ nanomaterials were fabricated by using the innovative scheme of pyrolyzing manganese-doped iron-based metal organic framework in inert atmosphere and exhibited extraordinary performance of NO reduction by CO (CO-SCR). Multi-technology characterizations were conducted to ascertain the properties of fabricated materials (e.g., TGA, XRD, SEM, FT-IR, XPS, BET, H₂-TPR and O₂-TPD). Moreover, the interaction between reactants and catalysts was ascertained by in situ FT-IR. Experimental results demonstrated that Mn was an ideal promoter for iron oxides, resulting in decrease of crystallite size, improve reducibility property, enhance the mobility and the amount of lattice O^2- species, as well as strength the adsorption ability of active NO and CO to form multiple species (e.g., nitrate and carbonate). The unprecedented enhancement of CO-SCR activity over Mn-Fe nanomaterials follows the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) reaction pathway.     

赤泥协同CuMn/CeZr催化剂对含NOx工业尾气的综合治理

"以废治废"方式对含NOx工业尾气的连续性综合治理方案,一方面是对NO的催化氧化处理,另一方面是赤泥对NOx的吸收,为工业化应用提供可行性方向指导和技术性数据支持.将经过催化氧化处理的尾气通入装有赤泥的吸收装置后,尾气中NOx吸收率达80％.当增加尾气湿度时,可以最大程度地延长赤泥对NOx的吸收寿命.当NO2/NO浓度...     

价格系统的混沌行为研究

本文首先研究了价格系统的混沌行为,然后建立并分析了一个具有混沌行为的价格系统模型,从而在价格系统混沌行为的研究方面取得了进展。     

预应变和超载对低合金钢疲劳性能的影响

本文总结了微量预应变和超载对低合金高强度钢疲劳性能影响的实验结果.实验结果表明,微量预应变和超载的影响与试件几何有关,对光滑试件产生负效应,而对切口试件产生零效应.对超载效应的机制作了实验研究与分析.讨论了Miner定则适用性及应考虑的因素.     

基于"互联网+"模式的大学计算机基础教学诊断与改进

依据云南省教育厅计算机基础教指委对大学计算机基础教学要求的"3+X"模式设计,对云南省36所高校计算机基础教学状况进行调研,以教学环节的操作系统部分、办公软件部分、附加教学平台、教学辅助软件、组织教学模式几大教学模块为主要内容,对各高校教材与教学模式情况进行逐项调查,分析、找出传统教学模式在"互联网+计算机基础教育"新要求下存在的问题.以"互联网+计算机基础教育"包容、共享、开放、互动的内涵建设为指导思想,从教材内容、教学手段、教学组织实施方案3个方面,提出诊断意见和改进措施.     

Microstructure and Mechanical Properties of AZ31 Alloys Processed by Residual Heat Rolling

To produce high strength and ductility Mg alloys with high productivity and low energy consumption,the residual heat rolling (RHR) process was initially proposed.The microstucture and mechanical properties of AZ31 processed by RHR were investigated by optical micrscopy (OM),electron backscatter diffraction (EBSD),and electron universal testing machine.The yield strength (YS),ultimate tensile strength (UTS),and elongation to failure of RHRed AZ31 sheet were 194 MPa,311 MPa,and 22%,respectively.Th...     

分子筛辅助人参须根粉快速制备人参皂苷Rg5的工艺研究

利用多功能改进型索氏提取器为提取工具,以人参须根粉为原料,盐酸为催化剂,分子筛辅助下高效制备了稀有人参皂苷Rg5,并通过单因素实验优化了工艺条件。实验结果表明：当以30 mL的甲醇为溶剂、加入0.3 g 4 A分子筛、于65 ℃提取4 h时,人参总皂苷的提取率达到10.2%,稀有人参皂苷Rg5的得率达到3.20%,与传统索氏提取器相比可以显著提高人参皂苷Rg5的制备效率。分子筛辅助下利用多功能改进型索氏提取器从人参须根粉提取制备稀有人参皂苷Rg5,不仅得率较高,而且操作简单快捷,是一种快速制备人参皂苷Rg5的工艺方法。     

Structural Topology Optimization by Combining BESO with Reinforcement Learning

结合BESO与强化学习的结构拓扑优化

孙鸿博, 马岭

（深海载人装备国家重点实验室,中国船舶科学研究中心,江苏 无锡 214033）

摘要：

本文将双向进化结构优化法(Bi-direction evolutionary structural optimization, BESO)与强化学习(Reinforcement learning, RL)结合,提出一种新算法,用于求解结构拓扑优化问题。与传统算法仅生成一个确定的近优解不同,该算法的目标是向设计者提供若干个近优解,类似于生成式设计(generative design)。该算法主要包含两部分：1） 除灵敏度外,根据蒙特卡洛强化学习更新的值函数也被用于衡量各结构单元的重要性,以使结果更加收敛并向最优值靠近;2） -贪心策略在主搜索方向上添加了一个随机扰动,以扩展算法的搜索能力。最后,通过控制结构柔度值以及交并比(Intersection-over-Union, IoU),来保证解的质量及多样性。本文将该算法用于一些二维和三维结构最小应变能问题,包括一个几何非线性算例,结果表明,该算法在可接受的时间内,能够生成一组“好而不同”的解,以满足实际工程中可能存在的多种需求。

关键词：结构拓扑优化;双向进化结构优化法;强化学习;首次访问蒙特卡洛法;-贪心策略;生成式设计

     

一种面向弱纹理图像的特征点描述子

现有的大多数特征点提取算法适用于处理纹理丰富的图像,而对于弱纹理图像则无法提取有效的特征点. 对此,提出了多邻域结构张量特征(MNSTF)算法. 基于一系列固定的邻域和图像结构张量,通过表达局部图像的结构和纹理信息,解决了弱纹理和无纹理场景下特征点提取和匹配等相关问题;同时,通过计算邻域之间的相对方向,实现了MNSTF算法特征描述子的旋转不变性. 实验结果表明,MNSTF算法在经过旋转的弱纹理图像测试集上的特征点匹配准确率达到了99.9%以上,验证了其良好的适用性、旋转不变性和鲁棒性.     

Fast realization of the LADT ECG data compression method

The system clock in the authors' Intel 80c31-based Holter recorder is 12 MHz, and thus it takes tens of milliseconds to obtain the d_k at instant k. Therefore, it is impossible to apply the original linear approximation distance thresholding (LADT) algorithm in real time. With the authors' improved algorithm it takes about one ms to calculate |a_adm|=σ·(1+(a/t)²)^1/2 . Though it is much faster to fulfill a linear segment approximation by the improved algorithm than by the original one, it is still difficult directly to apply the improved algorithm in a real-time system. However, it takes only two microseconds to get |a_adm| by look-up in the error threshold table. In this way, about one millisecond is needed to complete a linear segment approximating (about 50 points). It can be seen that the fast realization scheme using the error threshold table not only preserves the high compression ratio and low distortion advantages of the LADT algorithm, but also makes possible the application of the LADT algorithm in real-time