Online Soft-measurement for Thermal Efficiency of Circulating Fluidized Bed Boilers

提出循环流化床(Cfb)锅炉热效率的在线软测量方法,该方法将效率分为煤燃烧效率和传热效率两部分,根据Cfb锅炉动态机理模型在线计算锅炉未燃烧碳量,在此基础上计算煤燃烧效率,再通过反平衡法和正平衡法计算锅炉传热效率,最后得到锅炉热效率.应用该方法对某440T/H循环流化床锅炉热效率进行了计算,分析了影响该锅炉热效率的主要因素.结果表明:影响锅炉热效率的最主要因素是烟气中的飞灰含量;该软测量方法适用于Cfb锅炉,能有效指导锅炉调控,从而提高锅炉热效率.An online soft-measuring method for thermal efficiency of the circulating fluidized bed boiler(CFB)is being proposed.The method divides the efficiency into two parts,coal combustion efficiency and heat transfer efficiency.On-line calculation for the unburned carbon content of the boiler is carried out according to the dynamic mechanism model of the CFB boiler,after that combustion efficiency of the coal is calculated.Then heat transfer efficiency is calculated by indirect heat balance and direct heat balance,finally the boiler thermal efficiency is obtained.The thermal efficiency of certain 440 t/h CFB was calculated by the method,and the main factors which influence the thermal efficiency of the boiler were analyzed.Results show that the main factor which influences the thermal efficiency of the boiler is the content of fly ash in the flue gas.The soft-measuring method is suitable for CFB boiler,which can effectively direct the control of the boiler,thus improving the thermal efficiency of the boiler.福建省科技基金资助项目(2007J0165

Two-dimensional Model Predictive Iterative Learning Control Scheme Based on a Two-dimensional Performance Model

将迭代学习控制(ITErATIVE lEArnIng COnTrOl,IlC)系统看作一类具有2维动态特性的控制系统,根据模型预测控制(MOdEl PrEdICTIVE COnTrOl,MPC)和性能参考模型控制思想,提出了一种基于2维性能参考模型的2维模型预测迭代学习控制系统设计方案.在该控制系统设计方案中,可以通过选择适当的2维性能参考模型来构造2维动态变化的设定值信号和预测控制信号,从而引导迭代学习控制系统收敛到合理的控制性能,并有效避免系统性能收敛过程中控制输入可能发生的剧烈波动.通过对控制系统的结构分析可知,所得的迭代学习控制器本质上是由沿时间指标的参考模型预测控制器和沿周期指标的迭代学习控制器组成,闭环系统的收敛性等价于一个2维滤波系统的稳定性.数值仿真结果证明了该设计方案的有效性和鲁棒性.By representing an iterative learning control(ILC) system as a two-dimensional system and using the philosophy of model predictive control(MPC) and performance model reference control,a two-dimensional performance model based model predictive iterative learning control scheme is proposed in this paper.Through the design of two-dimensional dynamics of the performance model to generate more proper reference trajectories and predictive control signals for each cycle,the convergence pattern of the iterative learning control system can be guided to avoid the issue of possibly violent oscillation of input signal.The structure analysis indicates that the resulted control is composed of the time-wise performance model based model predictive control and cycle-wise iterative learning control,and that the convergence of the closed loop control system is equivalent to the stability of a two-dimensional filter.Numerical simulations illustrate the effectiveness and robustness of the proposed control scheme.国家自然科学基金(61174093)资助~

Steady-state simulation of fixed bed for coal gasification using ASPEN PLUS

用ASPEn PluS软件对固定床煤气化过程进行模拟,采用带fOrTrAn气化动力学子程序的串联全混流反应器来代替gIbbS反应器,能够更好地反映气化炉的真实反应情况,结果表明该模型与实际固定床煤气化的反应结果吻合较好。利用该模型研究了串联釜数对碳转化率及出口温度的影响,研究表明:随着釜数的增加,碳转化率和出口温度更加接近于实际数据;在保证模拟精度的前提下,较少的釜数有利于减少计算量。ASPEN PLUS is used to simulate the fixed bed for coal gasification process.The gasification reaction kinetics is expressed by FORTRAN subroutine in RCSTRs,and then the RSCTRS in series are used to substitute the Gibbs reactor.So the reaction condition of the gasifier can be described more accurate in the simulation and the results of the simulation are in agreement with the actual fixed bed of the coal gasification process.The proposed model was applied to study the effect of the number of RCSTRs on carbon conversion and outlet temperature.The results show that carbon conversion and outlet temperature are closer to the actual data with the number increase of RCSTRs.However,less number of RCSTRs helps to reduce the computation time.With consideration of the accuracy and computation time of the simulation for coal gasification,it is suitable to use 6 RCSTRs in series to describe the fixed bed according to the results of the simulation.中央高校基本科研业务费专项资金资助项目(2010121047

Modeling and Simulation for Sterilization Process of Canned Food

食品加工业中的罐头食品蒸汽灭菌过程是一种典型的多阶段间歇式生产过程。针对该过程,从物质守恒和能量守恒两方面,建立起通过热传递而相互关联的灭菌锅系统模型和罐头系统模型,而两者又构成了灭菌系统完整的数学模型。在此模型基础上进行了整个过程的仿真计算。通过对仿真结果与实验数据的对比,验证了所建模型的有效性。该模型为研究该类生产过程的优化控制策略提供了一个有效的模拟和测试平台。In the food industry,the sterilization of canned food is a typical multi-stage batch process.The mathematical models of the retort system and the can system were proposed on the basis of mass and energy conservation.The dynamical model of sterilization process was composed of these two subsystems which were connected by heat transfer.With the simulation of whole model,not only the accuracy of the mathematical model was demonstrated,but also an effective platform for testing was provided for the optimization and controller design for such production processes.国家自然科学基金(61174093); 中央高校基本科研业务费专项资金(2010121047

基于内毒素血症探讨皂术茵陈方对非酒精性脂肪性肝炎大鼠的影响

目的 基于内毒素血症探讨皂术茵陈方防治非酒精性脂肪性肝炎(NASH)大鼠的影响及其作用机制。方法 采用随机数字表法将40只大鼠分为5组,即正常组、模型组、皂术茵陈方组、盐酸吡格列酮组及培菲康组,每组8只。除正常组外,其余32只大鼠采用高脂饮食16周建立大鼠NASH模型,在造模第9周开始,皂术茵陈方组给予皂术茵陈方水提液60 mg/(kg·d)灌胃,盐酸吡格列酮组给予盐酸吡格列酮10 mg/(kg·d)灌胃,培菲康组给予培菲康210 mg/(kg·d)灌胃,正常组及模型组均给予双蒸水10 mL/(kg·d)灌胃,共治疗8周。第16周末经腹主动脉取血,生化法检测肝组织甘油三酯(TG)水平,苏木精—伊红(HE)染色观察肝组织病理学变化。终点显色法检测血浆内毒素(LPS)含量。ELISA法检测肝组织肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-6等炎症因子的表达水平。结果 与正常组比较,模型组大鼠肝组织显示出典型的NASH组织学特征,出现重度脂肪变性,不同程度的炎细胞浸润和坏死灶。大鼠肝湿重、肝指数、肝脏TG含量、血浆LPS水平、肝组织TNF-α、IL-1β、IL-6等炎症因..

第十八届美国理论与应用力学大会总结

1会议概况2018年6月5—9日,第18届美国理论与应用力学大会(18th U.S. National Congress of Theoretical and Applied Mechanics, USNCTAM2018)在美国芝加哥召开.本次大会由美国力学国家委员会和中国力学学会联合主办,旨在探讨和交流近四年世界范围内在理论和应用力学领域的基础研究、创新技术的最新进展,吸引了来自世界各地的近千名专家学

改良分子信标-双重实时荧光PCR快速检测SARS病毒

目的建立改良分子信标-双重实时荧光PCR检测SARS病毒的方法,用于SARS的早期诊断和动物溯源。方法利用改良分子信标技术、装甲RNA和双片段双色荧光技术,根据GenBank公布的SARS病毒聚合酶基因1b的阅读开放框架结构的保守序列,自行设计一对引物和探针,以部分临床标本的酶联吸附实验结果和传统细胞培养方法作为对照,建立分子信标检测SARS病毒的方法。对368份临床标本(咽漱液、血液、粪便、尿液)、52份细胞培养液和50份动物标本进行荧光PCR扩增。结果分子信标检测SARS病毒的方法灵敏度为10～100个拷贝ml,与流感病毒等呼吸道病毒无交叉反应。分子信标检测368份临床标本,20份阳性。其中确诊病例阳性率为21.27%(1047),确诊病例的咽漱液阳性率为43.48%,还分别从粪便和血清中检测到SARS病毒。52份细胞培养液,29份阳性,阳性率为55.77%。50份动物标本,23份阳性,阳性率为46%。结论改良分子信标-双重实时荧光PCR检测SARS病毒方法灵敏度高、特异性强,可用于SARS的临床早期诊断和动物溯源

Stabilization of anti-aromatic and strained five-membered rings with a transition metal

1981年诺贝尔化学奖获得者、美国康奈尔大学RoaldHoffmann教授评价该项工作说：'The　paper is an excellent one--it's　quite a mazing that the parent Os　system,molecule 1,chooses to give the osmapentalyne'。德国化学家Uwe Rosenthal教授等在同期《自然—化学》杂志的《News and Views》栏目以《Breaking the rules》为题撰文评述了这一研究成果。全文地址：http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.1702.pdfAnti-aromatic compounds, as well as small cyclic alkynes or carbynes, are particularly challenging synthetic goals. The combination of their destabilizing features hinders attempts to prepare molecules such as pentalyne, an 8π-electron anti-aromatic bicycle with extremely high ring strain. Here we describe the facile synthesis of osmapentalyne derivatives that are thermally viable, despite containing the smallest angles observed so far at a carbyne carbon. The compounds are characterized using X-ray crystallography, and their computed energies and magnetic properties reveal aromatic character. Hence, the incorporation of the osmium centre not only reduces the ring strain of the parent pentalyne, but also converts its Hückel anti-aromaticity into Craig-type Möbius aromaticity in the metallapentalynes. The concept of aromaticity is thus extended to five-membered rings containing a metal–carbon triple bond. Moreover, these metal–aromatic compounds exhibit unusual optical effects such as near-infrared photoluminescence with particularly large Stokes shifts, long lifetimes and aggregation enhancement

Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25

阿尔茨海默病（Alzheimer’s disease, AD）是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征（Down’s syndrome, DS）是早发型阿尔茨海默病的一个重要风险因素，作为最常见的智力障碍遗传疾病，厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点，并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能，缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成，厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作，王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持，清华大学董晨教授提供了Usp25基因敲除小鼠，厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao). 该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持