Release of Sulfur and Chlorine During Cofiring Rdf and Coal In An Internally Circulating Fluidized Bed

An internally circulating fluidized bed (ICFB) was applied to investigate the behavior of chlorine and sulfur during cofiring RDF and coal. The pollutant emissions in the flue gas were measured by Fourier transform infrared (FTIR) spectrometry (Gasmet DX-3000). In the tests, the concentrations of the species CO, CO2, HCl, and SO2 were measured online. Results indicated when cofiring RDF and char, due to the higher content of chlorine in RDF, the formation of HCl significantly increases. The concentration Of SO2 is relatively low because alkaline metal in the fuel ash can absorb SO2. The concentration of CO emission during firing pure RDF is relatively higher and fluctuates sharply. With the CaO addition, the sulfur absorption by calcium quickly increases, and the desulfuration ratio is bigger than the dechlorination ratio. The chemical equilibrium method is applied to predict the behavior of chlorine. Results show that gaseous HCl emission increases with increasing RDF fraction, and gaseous KCl and NaCl formation might occur.

Optimization of Air Staging In A 1 Mw Tangentially Fired Pulverized Coal Furnace

This paper deals with an experimental study of air staging in a 1 MW (heat input power) tangentially fired pulverized coal furnace. The influences of several variables associated with air staging on NOx reduction efficiency and unburned carbon in fly ash were investigated, and these variables included the air stoichiometric ratio of primary combustion zone (SR1), the locations of over-fire air nozzles along furnace height, and the ratio of coal concentration of the fuel-rich stream to that of the fuel-lean one (RRL) in primary air nozzle. The experimental results indicate that SR1 and RRL have optimum values for NOx reduction, and the two optimum values are 0.85 and 3:1, respectively. NO, reduction efficiency monotonically increases with the increase of OFA nozzle location along furnace height. On the optimized operating conditions of air staging, NOx reduction efficiency can attain 47%. Although air staging can effectively reduce NOx emission, the increase of unburned carbon in fly ash should be noticed. (C) 2008 Elsevier B.V. All rights reserved.

Effect of coal-over-coal reburn on furnace temperature and heat flux distributions in 1 MW tangentially fired furnace

The furnace temperature and heat flux distributions of 1 MW tangentially fired furnace were studied during coal-over-coal reburn, and the influences of the position of reburn nozzle and reburn fuel fraction on furnace temperature and heat flux distributions were investigated. Compared with the baseline, the flue gas temperature is 70–90 C lower in primary combustion and 130–150 C higher at furnace exit, and the variations of the flue gas temperature distributions along furnace height are slower. The temperature distribution along the width of furnace wall decreases with the increase of the relative furnace height. In the primary combustion zone and the reburn zone, the temperature and heat flux distributions of furnace wall are much non-uniform and asymmetric along the width of furnace wall, those of furnace wall in the burnout zone are relatively uniform, and the temperature non-uniformity coefficients of the primary combustion zone, the reburn zone and the burnout zone are 0.290, 0.100 and 0.031, respectively.

山西煤核中辉木植物二个新种的研究--山西枝蕨和山西始莲座蕨

辉木植物是莲座蕨目在晚古生代最重要的成员，广泛分布于当时处于热带－亚热带气候条件下的晚石炭世－二叠纪欧美植物区和华夏植物区。目前欧美植物区晚石炭世的辉木植物已经研究得非常深入和全面，但相对来说二叠纪的辉木植物的研究，尤其是关于其非茎器官的研究要薄弱得多。中国山西太原西山煤田早二叠世早期太原组7号煤层煤核中产有丰富的辉木植物各种器官化石，这就为深入了解二叠纪辉木植物的形态、解剖以及辉木植物的系统发育与演化提供了重要的化石材料。本论文利用国际上研究煤核时广泛采用的揭膜法，深入研究了山西煤核中2种分散保存的辉木植物器官：羽轴－山西枝蕨（新种）和生殖羽片－山西始莲座蕨（新种）。由于目前尚无有关二叠纪具解剖构造的辉木植物羽轴的详细研究的报道，因此，山西枝蕨（新种）是国内外目前为止第一种研究得最详细的二叠纪具解剖构造的辉木植物羽轴，它与欧美植物区枝蕨属已有的几个种（均为晚石炭世）的主要区别在于：前者为背腹扁状，后者则为两侧扁状;前者具较发育的鳞片，后者一般没有;前者的表皮下方有一条含有较大的单宁质细胞的薄壁组织带，后者没有;前者的内维管束呈“C”形，较大，位于正中央，后者的内维管束一般呈“W”形，较小，位于一侧。山西始莲座蕨（新种）是目前为止国内第一种（世界第二种）详细研究的二叠纪具解剖构造的两侧对称形的辉木植物聚合囊，同时也是目前国内发现的时代最早的华夏植物区两侧对称形的莲座蕨目聚合囊（包括印痕－压型化石和具解剖构造的矿化化石），它与欧美植物区始莲座蕨属已有的2个种（均为晚石炭世）的主要区别在于：前者的聚合囊囊托维管化，后者的囊托中无维管组织存在;前者的孢子囊侧壁细胞在近顶端呈明显的径向伸长状，后者的孢子囊侧壁细胞的形状和大小在孢子囊的上下没有很明显的变化;前者的孢子很小，数量多，纹饰简单，后者的孢子大，数量少，纹饰复杂。总的来说，本文所研究的二个新种与欧美植物区同属其它种之间的区别要大于后者彼此之间的区别，这可能是由于处于不同的植物地理区，经过长期地理隔绝和平行演化的结果。本研究成果不仅丰富了我们对二叠纪辉木植物非茎器官解剖构造的认识，而且对今后开展华夏植物区二叠纪辉木植物的分类、系统发育和演化以及整体植物的研究，都具有重要的作用和意义。

中国西南地区晚二叠世莲座蕨目植物研究

本论文应用揭膜方法（Peeling Method）对产于我国西南地区滇东黔西一带晚二叠世地层中的保存有解剖构造的莲座蕨目化石进行了较为深入的研究，包括3 种茎和一种生殖器官。3 种茎中有二种为本文首次研究，均归入辉木属Psaronius Cotta，建立了二个新种：盘县辉木P. panxianensis 和老屋基辉木P. laowujiensis；另外一个种－田氏辉木P. tianii Li（MS）为前人所建立，但未正式发表，本文做了重新研究，新发现了一些特征，并对一些已有特征做了修订。讨论了这3 个种一些重要特征的分类和系统演化意义，这些特征包括：叶迹最后分出时的维管构型、维管束鞘和边缘茎维管束内侧的厚壁组织束。通过对不同地区和不同时代辉木属已有种的特征分析，对辉木属属下分类做了尝试，根据维管束是否结成环状、叶迹维管构型、是否具维管束鞘、边缘茎维管束内侧的厚壁组织束的发育与否、边缘茎维管束是否分叉等特征将辉木属已有种（包括本文所研究的3 个种）分为5 个组：1. Blicklei 组，代表种为Psaronius blicklei Morgan，包括欧美植物区目前已知各种，可能还包括华夏植物区的一些种。它们的主要特征是：不具维管束鞘；边缘茎维管束内侧的厚壁组织束不发育。2．Panxianensis 组，代表种为盘县辉木Psaronius panxianensis He，Wang，Hilton,Tian et Zhou，包括王氏辉木、老屋基辉木、江苏辉木，可能还有八角辉木和六角辉木。最主要特征是：具维管束鞘，简单，仅由薄壁细胞构成；边缘茎维管束内侧具树枝状和伞状或锚状厚壁组织束；叶迹由3 根维管束构成。该组目前仅发现于华南地区二叠系。3. Tianii 组，以田氏辉木Psaronius tianii Li（MS）为代表，目前只有这一个种。该组的主要特征：具维管束鞘，复杂，可分为两层；边缘茎维管束内侧具菊花状厚壁组织束，且每两环维管束之间具两条厚壁组织束，其中一条连续，另一条不连续；叶迹呈歪斜的弓形或M 形；叶迹维管束与茎维管束等粗；边缘茎维管束可分叉。该组目前仅发现于华南地区二叠系。4. Brasiliensis 组，以巴西辉木Psaronius brasiliensis Brongniart 为代表，除巴西辉木外，可能还包括P. sp. Herbst。该组的最主要特征就是其维管束的一端内卷并与主体部分连接形成一个封闭的环状构造；茎中央的维管束小，形态多变，而且排列十分不规则。该组目前仅发现于南美地区二叠系。5. Sinuosus 组，以P. sinuosus Herbst 为代表，目前也只有此一个种。其最主要的特征就是叶迹具多个维管束，且排列无规则；茎维管束非常长，呈盘绕状。该组目前仅发现于南美地区二叠系。生殖器官归入虫囊蕨属Scolecopteris（Zenker）Millay，建立一新种：贵州虫囊蕨。该种仅保存有聚合囊和分散的孢子囊，生殖小羽片不明。孢子囊面向外的壁较厚，但分化，自内向外可分为三部分；孢子具三缝，较大，直径55-60μm。由于该种同时拥有Millay 认为的原始特征（大的孢子）和进化特征（即分化的孢子囊面向外的壁）。很可能Millay 的观点仅仅反映了欧美植物区虫囊蕨属的演化规律。

Effects of damming on population sustainability of Chinese sturgeon, Acipenser sinensis: evaluation of optimal conservation measures

The numbers of spawning sites for Chinese sturgeon have been drastically reduced since the construction of the Gezhouba Dam across the Yangtze River. This dam has blocked migration of Chinese sturgeon to their historic spawning ground causing a significant decline of the Chinese sturgeon population. We conducted a VORTEX population viability analysis to estimate the sustainability of the population and to quantify the efficiency of current and alternative conservation procedures. The model predicted the observed decline of Chinese sturgeon, resulting from the effect of the Gezhouba Dam. These simulations demonstrated the potential interest of two conservation measures: increasing spawning area and reducing predation on sturgeon eggs. The simulations also demonstrated that the actual restocking program is not sufficient to sustain sturgeon population as the artificial reproduction program induce the loss of more wild mature adults that the recruitment expected by the artificial reproduction.

Detecting a set of entanglement measures in an unknown tripartite quantum state by local operations and classical communication

We propose a more general method for detecting a set of entanglement measures, i.e., negativities, in an arbitrary tripartite quantum state by local operations and classical communication. To accomplish the detection task using this method, three observers do not need to perform partial transposition maps by the structural physical approximation; instead, they only need to collectively measure some functions via three local networks supplemented by a classical communication. With these functions, they are able to determine the set of negativities related to the tripartite quantum state.