Production of aromatics by catalytic fast pyrolysis of cellulose in a bubbling fluidized bed reactor

Catalytic fast pyrolysis of cellulose was studied at 500°C using a ZSM‐5 catalyst in a bubbling fluidized bed reactor constructed from a 4.92‐cm ID pipe. Inert gas was fed from below through the distributor plate and from above through a vertical feed tube along with cellulose. Flowing 34% of the total fluidization gas through the feed tube led to the optimal mixing of the pyrolysis vapors into the catalyst bed, which experimentally corresponded to 29.5% carbon aromatic yield. Aromatic yield reached a maximum of 31.6% carbon with increasing gas residence time by changing the catalyst bed height. Increasing the hole‐spacing in the distributor plate was shown to have negligible effect on average bubble diameter and hence did not change the product distribution. Aromatic yields of up to 39.5% carbon were obtained when all studied parameters were optimized. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1320–1335, 2014     

缸套珩磨网纹模拟及流动特性分析

目的 研究缸套珩磨网纹表面计算机模拟方法,对比缸套网纹表面确定性分析流量因子与Patir & Cheng高斯分布流量因子差异。方法 采用快速傅里叶变换技术(FFT)及坐标变换,对高斯分布平台表面及具有任意方向的各向异性沟槽表面进行了计算机模拟,并叠加合成满足要求Rpq、Rvq及珩磨角度参数的双高斯缸套珩磨网纹表面。通过表面概率支承率曲线分析,验证该方法的精度。在此基础上,进行给定边界条件下网纹表面的流动分析,对比确定性分析流量因子与Patir & Cheng高斯分布流量因子差异。结果 调整表面高度标准差、珩磨角度及自相关长度,可实现不同参数珩磨网纹的建模,生成的珩磨网纹表面参数与给定输入参数偏差较小。相比Patir & Cheng高斯分布流量因子,珩磨网纹确定性分析压力流量因子能更好地反映珩磨角度对不同方向流量的影响。同时,珩磨网纹沟槽对小间隙下剪切流量的影响更加明显。结论 网纹表面的确定性分析流量因子与Patir & Cheng高斯分布流量因子存在较大差异,缸套网纹表面建模及流动特性分析可更好地反映表面粗糙度对表面润滑性能的影响,为进一步开展缸套-活塞环多尺度摩擦学分析及珩磨网纹参数优化奠定了基础。     

Rapid Total Synthesis of DARPin pE59 and Barnase

We report the convergent total synthesis of two proteins: DARPin pE59 and Bacillus amyloliquefaciens RNase (Barnase). Leveraging our recently developed fast‐flow peptide‐synthesis platform, we rapidly explored numerous conditions for the assembly of long polypeptides, and were able to mitigate common side reactions, including deletion and aspartimide products. We report general strategies for improving the synthetic quality of difficult peptide sequences with our system. High‐quality protein fragments produced under optimal synthetic conditions were subjected to convergent native chemical ligation, which afforded native full‐length proteins after a final desulfurization step. Both DARPin and Barnase were folded and found to be as active as their recombinant analogues.     

750kV GIS用变压器端部的快速暂态过电压的研究

GIS内开关操作产生的快速暂态过电压(VFTO)对系统的变压器构成了很大的威胁,对于超高压GIS更是如此。参考多个GIS变电站,建立了750kVGIS系统,并确定了断路器、隔离开关、接地开关及电抗器的计算模型可简化为等值对地电容或入口电容,其参数分别为276pF、240pF、240pF和5000pF。利用EMTP计算了不同操作过程在变压器端部出现的VFTO。分析了系统运行方式、开关操作顺序、变压器入口电容以及变压器与GIS的连接方式对变压器端部VFTO的影响。研究了断路器、隔离开关的并联电阻以及MOA对变压器的保护效果。     

大城市快速交通对周边小城镇发展规划的影响--以武汉市横店街规划为例

交通问题源于人类克服空间障碍的实践.管子云:山川涸落,天气上,地气下,万事交通.交通的发展促进着社会的进步和发展,交通的发展水平往往成为一个国家或地区进步的标志.快速干道作为现代交通建设不可或缺的重要组成部分,在城市和区域发展中越来越凸显其不可忽略的指导性作用.在带动大城市地区周边小城镇发展的同时也对其规划发展形成难以逾越的障碍.进而进一步影响大城市的扩张.     

基于统计学的上海城市快速路自由流车速确定

以上海城市快速路交通数据采集系统采集的大量实测交通数据为分析对象,提出了一种基于统计学原理的自由流车速确定方法。介绍了自由流车速的定义,基于统计学原理的自由流车速确定方法、步骤。对计算结果进行正态分布检验和稳定性分析。这一车速确定方法得到的城市快速路自由流车速可为进一步研究城市快速路的有关问题提供很好的基础。     

快速城市化地区城乡统筹规划所面临的问题和建议--以嘉兴地区为例

以嘉兴为例,分析了快速城市化地区统筹城乡规划所面临的主要问题,剖析了产生这些问题的主要原因,并以此为基础指出．加快建立“规划一张图,城乡全覆盖”的规划法规体系和技术规范体系,建立公平的区域合作成本补偿和利益分配机制,建议编制省、市、县域城乡统筹发展总体规划,以协调区域发展。     

现代园林中的艺术课堂--苏州工艺美术职业技术学院石湖新校区规划设计

以苏州工艺美术职业技术学院石湖新校区规划设计方案为例，从艺术、园林、校园、课堂、手工艺等元素出发提出校园规划设计新模式，从分析项目的关键词入手，通过关键词的提出、关键词的展开与整合，强调个性化在校园规划设计和校园文化建设中的重要性。提出个性化是今后校园规划设计的一个注重点并归纳出校园个性化设计的理论方法。     

Adaptive Noise Cancellation Method Used for Wheel Speed Signal of Integrate ABS/ASR System

The anti-lock braking system (ABS) and anti-slip regulation system(ASR) are the very i mportantparts of active safety systems used for modern vehi-cles . This two systems make up of commonintegratesystem ABS/ASR[1 ,2]. At present ,the main controlmethodin ABS/ASRis the logic threshold method.When getting the wheel speed signal ,ECUcomputesand applies control after comparing current signalwith the threshold[3 -5].Because of many reasons ,the wheel speed sig-nals sampled in ABS/ASRalw…