火电厂SCR烟气脱硝反应器前设置灰斗及增加烟道截面的探讨

阐述了飞灰对火电厂脱硝催化剂的磨损和堵塞机理.通过分析国内燃煤电厂飞灰的特性,说明飞灰对催化剂的磨损作用是较强的.探讨了通过在选择性催化还原烟气脱硝反应器前设置灰斗和增加烟道截面的方式,来提高大颗粒飞灰的去除效率,有效减少飞灰对催化剂的磨损和阻塞,延长催化剂寿命的可行性.     

Polyfluorene Derivatives are High‐Performance Organic Hole‐Transporting Materials for Inorganic−Organic Hybrid Perovskite Solar Cells

Photovoltaics based on organic?inorganic perovskites offer new promise to address the contemporary energy and environmental issues. These solar cells have so far largely relied on small‐molecule hole transport materials such as spiro‐OMeTAD, which commonly suffer from high cost and low mobility. In principle, polyfluorene copolymers can be an ideal alternative to spiro‐OMeTAD, given their low price, high hole mobility and good processability, but this potential has not been explored. Herein, polyfluorene derived polymers‐TFB and PFB, which contain fluorine and arylamine groups, are demonstrated and can indeed rival or even outperform spiro‐OMeTAD as efficient hole‐conducting materials for perovskite solar cells. In particular, under the one‐step perovskite deposition condition, TFB achieves a 10.92% power conversion efficiency that is considerably higher than that with spiro‐OMeTAD (9.78%), while using the two‐step perovskite deposition method, about 13% efficient solar cells with TFB (12.80%) and spiro‐OMeTAD (13.58%) are delivered. Photo­luminescence reveals the efficient hole extraction and diffusion at the interface between CH₃NH₃PbI₃ and the hole conducting polymer. Impedance spectroscopy uncovers the higher electrical conductivity and lower series resistance than spiro‐OMeTAD, accounting for the significantly higher fill factor, photocurrent and open‐circuit voltage of the TFB‐derived cells than with spiro‐MeOTAD.     

Propagation and transformation of flat-topped multi-Gaussian beams in a general nonsymmetrical apertured double-lens system

On the basis of expanding a hard-edged aperture function as a finite sum of complex Gaussian functions, an approximate analytical expression for the propagation of an input complex amplitude distribution passing through a general nonsymmetrical apertured double-lens system is derived. Then, the propagation result for two-dimensional flat-topped multi-Gaussian beams is given. It is shown that the apertured Lohmann's symmetrical double-lens system for fractional Fourier transform is a special case of the general apertured double-lens system. The numerical calculation, graphical illustration, and some discussions for the transformation of the two-dimensional flat-topped multi-Gaussian beam in apertured Lohmann's symmetrical double-lens systems are also presented.     

新集风井坚硬岩石爆破技术

分析和探讨了立井掘进深孔爆破中的掏槽形式和掏槽参数、周边光面爆破参数和光爆装药结构等技术问题,提出了一些较为切合实际的技术观点.     

1000MW在装超超临界汽轮机组节能降耗措施的应用

针对在装1 000MW汽轮机组的结构特点,提出了节能降耗的一些改进措施,并在机组安装及调试过程中实施。该机组试运后与已投运的同类型机组相比,节能效果显著,仅高、中压缸效率分别提高1.5%和0.2%。     

找回我们的根脉--关于义乌城市特色塑造的若干思考

塑造城市特色,是处于转型期的义乌的一项肾迫的工作。对现代化的片面理解,对自己传统的轻率抛弃,是“欧陆风”盛行的重要原因。义乌的传统建筑文化品位极高,经历了几千年的发展演进,形成了开放性、包容性、与时俱进、与自然融为一体、粉墙黛瓦等突出特点义鸟应该找回自己的根脉,传承、弘扬优秀传统。     

Stability‐aware multi‐metric clustering in mobile ad hoc networks with group mobility

Clustering can help aggregate the topology information and reduce the size of routing tables in a mobile ad hoc network (MANET). The maintenance of the cluster structure should be as stable as possible to reduce overhead and make the network topology less dynamic. Hence, stability measures the goodness of clustering. However, for a complex system like MANET, one clustering metric is far from reflecting the network dynamics. Some prior works have considered multiple metrics by combining them into one weighted sum, which suffers from intrinsic drawbacks as a scalar objective function to provide solution for multi‐objective optimization. In this paper, we propose a stability‐aware multi‐metric clustering algorithm, which can (1) achieve stable cluster structure by exploiting group mobility and (2) optimize multiple metrics with the help of a multi‐objective evolutionary algorithm (MOEA). Performance evaluation shows that our algorithm can generate a stable clustered topology and also achieve optimal solutions in small‐scale networks. For large‐scale networks, it outperforms the well‐known weighted clustering algorithm (WCA) that uses a weighted sum of multiple metrics. Copyright © 2008 John Wiley & Sons, Ltd.     

Waveband Grooming based on Layered Auxiliary Graph in multi-domain optical networks

With the number of wavelengths on fibers keeps increasing, the size and the cost of Optical Cross-Connect (OXC) are greatly enhanced and then the control and management of optical switches become more and more complicated. Therefore, the technique called waveband switching is proposed to reduce the size and the cost of OXC; that is, to save the All-Optical (OOO) switching ports in OXC. However, the existing waveband switching algorithms are all limited in single-domain optical networks. Actually, with the scale of optical backbone keeps enlarging, the network is divided to multiple independent domains to perform the hierarchy routing for achieving the scalability. In order to reduce the size and the cost of OXC meanwhile to achieve the scalability in multi-domains, in this paper we propose a new heuristic algorithm called Waveband Grooming with Layered Auxiliary Graph (WGLAG) since the waveband grooming problem is the NP-hard to perform the inter-domain routing based on the virtual topology of multi-domain network and the intra-domain routing based on the physical topology of single-domain network. In intra-domain routing with waveband grooming of each single-domain, we propose the Layered Auxiliary Graph (LAG) that includes one virtual topology layer and multiple waveband-plane layers to compute a single-hop, or multi-hop or hybrid waveband route for each connection request based on the sub-path waveband grooming scheme. Simulation results show that, WGLAG not only can effectively save more switching ports to reduce the cost of OXC but also can obtain lower blocking probability than other algorithm.     

高分子材料的一种应力松弛试验方法

介绍了一种利用DDV-Ш-EA型动态粘弹谱仪研究高分子材料应力松弛试验的方法.采用该方法考察了聚砜(PSU)在不同温度点下的应力松弛过程,根据时温等效原理,拟合出PSU的叠合曲线.对于研究高分子材料在工程中的实际应用、预估高分子材料在一定形变下的使用寿命具有重要的价值.     

某铜硫选厂铜粗精矿再磨工艺优化研究

某铜硫矿选矿厂为提高铜矿物单体解离度,在原生产工艺中增加了铜粗精矿再磨工艺,但因再磨工艺的各项参数不佳,铜回收指标未达到预期目标.针对铜粗精矿再磨工艺存在的问题,对旋流器给矿压力、给矿浓度、立磨机装球量等工艺参数进行了优化.与优化前相比,铜粗精矿再磨工艺的磨矿技术效率提高14.47%,旋流器溢流与铜粗精矿中合格粒级铜金属占有率的差值提高1.57%.对铜品位0.70%的原矿,铜精矿Cu品位和回收率分别提高1.40%,2.51%.