分解炉内气固两相流场不同模型模拟结果分析

针对某高性能水泥分解炉的实际尺寸，分别采用Eulerian模型、mixture模型和离散相模型模拟了炉内气固两相三维流场，结果显示Eulerian(mixture)模型模拟所得炉内速度、压力、温度场以及固相体积分数梯度结果整体上优于其它模型，其流动趋势和规律与该分解炉的优质性能定性符合．     

分解炉内三维湍流流场数值模拟

针对某大型高性能分解炉的实际尺寸，用Realizable(带旋流修正的)k-ε模型，采用SIMPLE算法，二阶迎风差分格式，模拟了炉内三维湍流流场．计算所得的速度、压力分布与该炉热工标定的结果以及其实际运行的性能符合较好．     

不同分解方法对聚乙烯分解行为的影响

综述了有关聚乙烯(PE)热分解和超临界水分解的研究情况，对PE的两种分解过程进行了对比。考察了分解产物的分子量、油转化率、催化剂的作用、反应机理等内容。对比结果表明，超临界水分解时不使用催化剂、反应温和、具有较高的油转化率，同时，产物分子量分布宽，组成复杂。超临界水分解对于热分解过程中产生的炭化现象有很好的抑制作用，因而具有广阔的工业应用前景。     

局部特征尺度分解方法及其分解能力研究

在研究内禀时间尺度分解(Intrinsic Time-Scale Decomposition,ITD)方法的基础上提出了一种新的自适应时频分析方法——局部特征尺度分解(Local Characteristic-scale Decomposition,LCD)方法,该方法可以自适应地将一个复杂的多分量信号分解为若干个瞬时频率具有物理意义的内禀尺度分量(Intrinsic Scale Component,ISC)之和.对LCD方法的基本原理进行了阐述,通过建立分解能力研究模型分别研究了分量信号的频率比、幅值比和初相位差以及单个分量迭代次数对LCD方法分解能力的影响,并给出了多分量信号可由LCD方法分解的大致条件.     

DDF型分解炉中NO_x减排的数值模拟

为研究选择性非催化还原法对分解炉中NO_x减排效果的影响,采用计算流体力学方法对DDF型分解炉进行数值模拟。以尿素为还原剂设计选择性非催化还原脱硝方案,对比分析各操作参数对NO_x减排效果的影响。结果表明,还原剂喷射高度、喷嘴伸入距离、喷嘴数量等操作参数对NO_x减排效果的影响较大,还原剂喷射速度对NO_x减排效果的影响较小,且喷射高度为17 m,喷嘴伸入距离为0~0.6 m,喷嘴数量为4~8个,还原剂喷射速度为50~70 m/s时,分解炉中NO_x减排效果较好。     

全序格上Fuzzy关系的最大分解及其分解唯一性

本文在完备的全序格上引入广义正规Ｆｕｚｚｙ集及其不可达Ｆｕｚｚｙ集的概念，得到了可分解Ｆｕｚｚｙ关系有最大分解及其分解唯一等两个充要条件。     

聚丙烯的热分解与超临界水分解对比实验研究

为了寻求一种更为有效的聚合物分解回收方法，采用热分解和超临界水分解方式对聚丙烯(PP)的分解行为和分解产物进行了对比实验研究，并利用红外光谱、热分析仪等分析手段对反应残留物进行分析，用气相色谱和质谱对液相成分进行表征．结果表明：在反应温度为420℃的条件下，PP经热分解全部转化成液体油状物，而超临界水分解只有63％的分解率，反应较热分解进程缓慢；超临界水分解时，压力越高，PP分解率越低；压力的存在对于某些小分子分解产物的生成有一定的抑制作用。     

磁石能分解液体

磁石分解液体分子与电解水是同一个道理，都是用来对两极对液体进行分解。磁石分解液体对磁石有一定要求；磁石不能过于太硬，太脆和磁石磁性太强，这些都很难制出能分解液体的磁石。磁石分解液体需要用硬物体对磁石进行撞击，使磁石受撞击裂出小口对液体进行分解。撞击磁石所用的力有一定的要求，撞击磁石的力不能太大，也不能太小，由于磁石裂开就会形成两个相反的极相互排斥；一旦把磁石撞裂，力大一点就会使磁石两半，就不能对液体进行分解。太小不会把磁石撞裂。在裂开的地方是磁石磁性最强的地方，用这个地方可以对液体进行分解。磁石会分解一会儿便不分解了，这是因为磁石过多接触水受潮，需要热来烤干，热也是维持磁石分解液体需要守恒的能量。磁石分解液体主要分解水，获得新能源氢气代替石油，分解处理掉污水。以及用公式计算这些量之间的转换。     

广义经验模态分解性能分析与应用

针对经验模态分解（empirical mode decomposition,EMD）的均值曲线采用三次样条拟合而容易引起包络过冲和不足等缺陷,相关学者提出了许多改进均值曲线的变种EMD方法,取得了一定的效果。广义经验模态分解（generalized EMD,GEMD）方法综合了多种改进EMD方法,通过定义不同的均值曲线对信号进行逐阶筛分,从得到的每一阶分量中选取最优作为最终的广义内禀模态函数（generalized intrinsic mode function,GIMF）,由于每一阶的GIMF分量都是最优的,因此相较于EMD等单一均值曲线筛分方法,GEMD分解结果也是最优的。论文对GIMF分量准则进行了改进以及对GEMD性能进行了分析,并将GEMD应用于仿真和实测信号的分析,结论表明GEMD分解是完备的和正交的,有比EMD更强的分解能力,而且适合机械振动信号的处理和故障诊断。     

基于神经网络的动态测量误差分解研究

在讨论神经网络方法的基础上，尝试将其应用于动态测量误差分解理论。建立了一个简单的动态测试仿真系统，分别用小波变换方法和神经网络方法对系统输出的总误差进行分解，并对两种方法的处理结果作了比较，指出了神经网络方法在动态误差分解中的实用性和优越性。     

Simulations on pressurized oxy-coal combustion and gasification by molecular dynamics method with ReaxFF

Pressurized oxy-fuel combustion (POFC) is recognized to have the potential to effectively capture CO₂ with low cost and high efficiency. To investigate the chemical mechanism of oxy-fuel combustion and the effects of different operating parameters on combustion characteristics, a gasification reaction model and the pressurized oxy-fuel combustion model were constructed. A series of reactive molecular dynamics (MD) simulations were conducted on the POFC model using ReaxFF force field under the pressure of 0.2, 0.3 and 0.5 MPa, and with the temperature at 1600, 1800 and 2000 K, respectively. The activation energy for atmospheric oxy-fuel combustion was firstly calculated, in agreement with reported experimental results, which verified the accuracy of ReaxFF MD method. The results of gasification and combustion showed that both temperature and pressure positively affect coal decomposition and the combustion reaction rate. The conversion mechanism of C in coal to CO₂ is a process with dehydrogenation, coal decomposition and oxidation reaction. Compared with atmospheric oxy-fuel combustion, the increase of pressure/density would accelerate the dehydrogenation reaction and the decomposition of coal structure, and improve the performance of coal combustion and promote the decomposition of coal molecule into smaller fragments, and further promote the releasing of CO₂ and small fragments.     

碳酸钙制备小孔径中等孔隙率类球形孔泡沫铝及其合金

与传统的Ca增黏与TiH2发泡的泡沫铝熔体发泡制备方法不同,CaCO3在铝熔体中可同时用作增黏剂和发泡剂.现有TiH2泡沫铝制备技术在制备小孔径类球形孔泡沫铝及合金方面存在困难,以轻质Ca-CO3颗粒为基础研制的新型泡沫铝增黏发泡剂,其热分解特性平缓,通过理论与实验确定了CaCO3在制备过程中的使用比例,分析了孔结构并讨论了CaCO3在铝熔体中的分解热力学问题,稳定制备出小孔径(0.4-1.1mm)、中等孔隙率(40-79%)的类球形孔泡沫铝及其合金.     

Effects of calcium-based sorbents on PCDD/F formation from pentachlorophenol combustion process

Calcium-based sorbents are widely employed to reduce the acidic gases emission from combustion processes, and also have effects on trace organic pollutants formation and emission. Batch experiments were conducted to investigate the effects of calcium-based sorbents on pentachlorophenol (PCP) forming PCDDs/Fs during high temperature combustion processes. The results indicated that highly chlorinated PCDD/F homologues were the predominant dioxin products from PCP thermo decomposition, and only minor increasing of PCDDs happened when Ca/Cl ratio was lower than 1, while a major jump occurred when Ca/Cl ratio increased from 1 to 2. The CaO addition clearly promoted the production of all chlorinated dibenzo-p-dioxins homologue and 4-7DFs homologue. Comparison of total PCDD/F emission and its I-TEQ for three different calcium-based sorbents addition (CaO, CaCO3, basic fly ash) indicated that CaO and fly ash containing CaO had almost the same promotion effects on PCDDs/Fs originated from PCP, while CaCO3 inhibit PCDD/F formation greatly with inhibition efficiency up to 70%. Such effects may be partly proved by the observed clearly different micro-surface structures of their reaction residues. The mechanism of CaO on condensation and dechlorination reactions for PCP forming PCDDs and acid-base interaction were proposed to speculate the promotion effects of CaO, and the reaction precedence was used to speculate the inhibition effects of CaCO3 on PCDDs/Fs originated from PCP. The results of the present paper might be useful for the industrial application of calcium-based sorbents to control PCDD/F emission.     

CaCO3纳米线的制备及表征

以碳酸钙(CaCO₃)为原料利用溶胶-凝胶法与热分解法合成了CaCO₃纳米线,纳米线的制备分为两个步骤,首先利用溶胶-凝胶法合成线状含Ca中间体,这种含Ca中间体是一维线状纳米结构;然后通过含Ca中间体热分解制得CaCO₃纳米线,直径为50-80nm,长度达5μm以上,所得CaCO₃纳米线为三方晶系,由纳米晶粒组装而成.     

用DSC法研究混入煤粉的铵油炸药相容性

为了研究混入煤粉的铵油炸药的相容性以及煤粉与铵油炸药之间的相互作用,采用差示扫描量热仪(DSC)研究了铵油炸药、混入煤粉的铵油炸药、硝酸铵和混入煤粉的硝酸铵的热分解特性。用Kissinger方程求解了铵油炸药和混入煤粉的铵油炸药的表观活化能(E_a),考察了煤粉与铵油炸药的化学相容性。研究结果表明:在常压氮气氛围的环境中,铵油炸药和硝酸铵的DSC曲线中的热分解均为吸热峰;当煤粉和硝酸铵混合后,煤粉与硝酸铵会在硝酸铵的热分解温度之前发生化学反应,随着煤粉含量的提高,硝酸铵的热分解逐渐转变为放热峰,说明煤粉能极大地降低硝酸铵的热稳定性;使用DSC法研究混入煤粉的铵油炸药相容性等级为4级,煤粉与铵油炸药的相容性差。     

超重力反应结晶法制备纳米碳酸钙颗粒研究

以Ca（OH）2悬浊液和CO2气体在起重力反应器（旋转填充床反应器）中进行碳化反应制备纳米立方形碳酸钙为研究对象，实验研究了超重力加速度gr，液体循环量L，气体流量G，Ca（OH）2初始浓度等操作条件对产物粒度及其分布、碳化反应时间的影响。结果表明：利用超重力反应结晶法可以制备出平均粒度为15～40nm、分布较窄的CaCO3，碳化反应时间较传统方法缩短约4～10倍。     

表面TiO2包膜对制备CaCO3／TiO2复合材料颜料性能的影响

采用机械力化学方法，通过对碳酸钙进行表面TiO2包膜制备了CaCO3／TiO2复合材料，对CaCO3／TiO2复合材料的颜料性能、CaCO3和TiO2的结合形态与反应机理进行了研究。结果表明：CaCO3／TiO2复合材料形成了具有类似钛白粉的颜料性质，遮盖力为钛白粉的90％，吸油量和紫外线吸收功能与钛白粉相同；CaCO3／TiO2复合材料中TiO2在CaCO3颗粒表面形成均匀包覆和二者通过各自表面羟基形成化学结合是导致其呈现钛白粉颜料性质的内在机制。     

自石灰石矿粉中直接提取CaCO3晶须的碳化-分解法研究

提出一种自石灰石矿粉中直接提取CaCO_3晶须的碳化-分解方法。该方法能够以天然石灰石矿粉为原料,通过水溶性碳酸的作用溶解出Ca(HCO_3)_2,进而在升温条件下通过Ca(HCO_3)_2的分解反应得到形貌规整的棱锥状CaCO_3晶须。扫描电镜观测与X射线衍射分析显示,Ca(HCO_3)_2分解温度对CaCO_3晶须微观形貌的影响显著,晶须长度与长径比随分解温度的升高均呈上升趋势,但分解温度超过80℃会导致文石晶相向方解石晶相转化。实验结果表明,80℃、2h条件下,Ca(HCO_3)_2分解产物中文石晶相含量较高,晶须几何形貌更为合理,其平均长度为14.61 μm、长径比为8.10。     

Effects of intrinsic properties,particle size and specific surface area on WOP and spontaneous combustion susceptibility of coal

This study examines the effects of intrinsic properties, particle size, and specific surface area (SSA) of coal on spontaneous combustion. Moreover, it analyzes the underlying mechanism of spontaneous combustion from particle size, SSA and gas adsorption perspectives. The susceptibility of coal to spontaneous combustion is studied by wet-oxidation potential (WOP) method. Coal residues left after the WOP experiment are analyzed for change in structural and compositional behaviour. The study revealed an inverse relationship between the particle size and SSA of coal. Spontaneous combustion susceptibility increased with increase in volatile matter and decreased with increase in fixed carbon content of coal. The optimum moisture content of coal resulting maximum spontaneous combustion tendency is determined 6%. Decrease in particle size and increase in SSA augmented the spontaneous combustion propensity of coal. With decrease in coal particle size from 425 to 850 to < 38 µm, the mean D₅₀ value decreased by 27 times, the mean SSA increased by 42 times and coal spontaneous combustion susceptibility increased almost by 2 times. Critical coal particle size is determined 38–74 µm (D₅₀ = 50.56 µm), below which no appreciable change in oxidation rate is observed. Moreover, two models are developed to predict the spontaneous combustion susceptibility of coal based on particle size (D₅₀) and SSA.     

滑石粉/碳酸钙增强增韧高密度聚乙烯的研究

采用熔融共混法制备HDPE复合材料,研究了talc和(或)CaCO3的添加量对HDPE复合材料力学性能的影响。结果表明,将滑石粉和碳酸钙共复合时,可以同时发挥片状滑石粉的增强作用和近球状碳酸钙的增韧作用;当无机粉体的添加量为30%时,HDPE/talc/CaCO3共混复合体系的拉伸强度提高了29.9%,冲击强度提高了56.1%,弯曲强度提高了40%。