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1.
用热重TG和DSC对—叔丁基杯[6]的热分解过程进行了研究,用“DSC—TG”结合法推断出了对—叔丁基杯[6]热分解的可能过程,求出了其热分解反应动力学方程及热分析动力学参数;其最概然机理函数为21号,为一级反应过程。表观活化能为101.79 KJ.mol-1,指前因子的对数为51.64 S-1。 相似文献
2.
对-叔丁基杯[6]热力学及热分析动力学研究 总被引：1，自引：0，他引：1
用热重TG和DSC对对-叔丁基杯[6]的热分解过程进行了研究,用"DSC-TG"结合法推断出了对-叔丁基杯[6]热分解的可能过程,求出了其热分解反应动力学方程及热分析动力学参数;其热分解的过程为四号机理函数,为球型三维扩散过程.其动力学方程为:f(a)=3/2[(1-a)1/3-1],活化能为168.7KJ.mol-1,指前因子为8.54×1037S-1. 相似文献
3.
The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000℃ at a heating rate of 10 oC/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results. 相似文献
4.
使用粉煤灰作为催化剂,对聚丙烯进行热解处理,并用程序升温的热重法(TG)和恒温法两种模型方法对热解反应进行研究。结果表明,这两种方法都适用于聚丙烯的催化降解,且粉煤灰含量为2%时,恒温模型计算得到的反应活化能为196kJ/mol,TG模型计算的结果是233kJ/mol(反应级数为1)。从两种模型计算的计算结果与实验结果的拟合情况来看,恒温法得到的结果与实验结果更加吻合。 相似文献
5.
Erythromycinis a mixture of macrolide antibiotics pro-duced bystreptomyces erythreus.Treatment withthis antibi-otic drugin humanand veterinary practiceis still verycom-mon because of the highactivityagainst gram-positive and afewgram-negative strains[1]. … 相似文献
6.
曹承平 《淮南职业技术学院学报》2008,8(3):1-3
通过对影响煤炭自燃因素的分析,建立了采空区内遗煤自燃过程数学模型,可随时预测不同漏风强度和不同推进速度条件下,采空区遗煤自然发火的危险性,对丁集煤矿1262（1）首采面采空区遗煤自燃过程中,氧化时间、工作面推进速度对煤温的影响进行了计算机模拟,成功预报了在回采过程中采空区遗煤不自燃,确保了该工作面安全回采。 相似文献
7.
IN REEENT YEARS，MUEH ATTENTION HAS BEEN PAID TO DIARYL一SUBSTITUTED HETEROEYELES THAT ARE ASSOEIATED WITH HIGH BIOLOGIEAL AETIVITIES AS SELEETIVE COX一2 INHIBI- TORS[L〕AND ANRITUMOR AGENTS[21.A NEW EOM卯UND， NAMELY4一{5一[3，4一DIMETHYL一5一(3，4，5一T 相似文献
8.
用TG-DTG(热重-微分热重)联用技术研究了氨茶碱片剂在氮气气氛中的热分解行为。首先运用普适法Kissinger和Ozawa法计算了氨茶碱片剂的表观活化能E和指前因子lnA,然后运用一般积分法Coats-Redfern法和Satava-Sestak法推测了主分解阶段的最佳热分解机理,推测出热分解机理为相边界反应,求出了热分解反应的表观活化能和指前因子。几种方法求得的表观活化能和指前因子的平均值分别为113.933KJ/mol,lnA为22.101(1/min).用malek法对所得结果进行了验证,进一步证明所得动力学参数和机理函数的正确性。 相似文献
9.
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion. 相似文献
10.
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion. 相似文献
11.
为了研究甲烷掺氢后的燃烧特性,采用定容燃烧弹实验系统和OpenFOAM软件,将实验测试与数值模拟相结合,系统地分析了掺氢比、指前因子、活化能等参数对甲烷燃烧特性参数的影响。研究结果表明,掺氢后可使混合气燃烧速度加快,燃烧温度提高;指前因子对燃烧性能参数影响不明显;活化能增加,导致燃烧反应速率对混合气初始温度变化的敏感性提高。 相似文献
12.
采用热重法(TG)和微分热重法(DTG)对合成的磺胺增效剂三甲氧苄二氨嘧啶(TMP)进行了热稳定性研究.研究结果表明:在25℃～700℃范围内有一次失重过程.运用Kissinger和Ozawa等方法计算了其活化能,并运用Satava-Sestak积分方程得到了TMP的热解动力学参数,其中热分解积分函数采用[-ln(1-a)]1/n的形式.求得的热解反应活化能Ea=70.2276 kJ/mol,反应级数n=2.02298.得到的热解动力学方程为:dα/dt=3.3576×106exp(-7.0228×104/RT)(1-α)[-ln(1-α)]0.4967 相似文献
13.
A new customization approach based on support vector regression (SVR) is proposed to obtain individual headrelated
impulse response (HRIR) without complex measurement and special equipment. Principal component analysis (PCA) is
first applied to obtain a few principal components and corresponding weight vectors correlated with individual anthropometric
parameters. Then the weight vectors act as output of the nonlinear regression model. Some measured anthropometric
parameters are selected as input of the model according to the correlation coefficients between the parameters and the weight
vectors. After the regression model is learned from the training data, the individual HRIR can be predicted based on the
measured anthropometric parameters. Compared with a back-propagation neural network (BPNN) for nonlinear regression,
better generalization and prediction performance for small training samples can be obtained using the proposed PCA-SVR
algorithm. 相似文献
impulse response (HRIR) without complex measurement and special equipment. Principal component analysis (PCA) is
first applied to obtain a few principal components and corresponding weight vectors correlated with individual anthropometric
parameters. Then the weight vectors act as output of the nonlinear regression model. Some measured anthropometric
parameters are selected as input of the model according to the correlation coefficients between the parameters and the weight
vectors. After the regression model is learned from the training data, the individual HRIR can be predicted based on the
measured anthropometric parameters. Compared with a back-propagation neural network (BPNN) for nonlinear regression,
better generalization and prediction performance for small training samples can be obtained using the proposed PCA-SVR
algorithm. 相似文献
14.
INTRODUCTIONTherearefewofquantitativethermalanalysis(TA)investigations (Mulokozi,1992 )ofthegoverningrelationsbetweentheparametersofsolidphasereactionkineticsandtheaveragedi ametersofultrafinecalciumcarbonateandtheeffectsoffineparticlesontheirsolidphasere… 相似文献
15.
朱克强 《淮南职业技术学院学报》2013,13(2):12-15
火电机组的锅炉燃烧效率及标准煤耗与煤质、发电负荷率、机组环境温度有着直接的联系,供电煤耗与煤炭发热量在一定范围内呈正相关关系;而煤炭销售收入与煤质、价格、原煤到商品煤的洗选深度即资源回收率有着直接的关联;煤炭的可售资源量与煤质又是负相关,单方追求效益的最大化都会导致整体效益的下降。 相似文献
16.
基于设计的试验方案,对常见的生活垃圾如木筷、垃圾袋、棉布及其混合组分进行燃烧试验研究,得出了各组分燃烧特性曲线以及各组分的平均活化能;在此基础上根据各组分燃烧时的平均活化能建立了用于计算各种不同配比混合垃圾活化能的经验公式;通过生活垃圾活化能的试验进行验证,该计算公式简便实用,可运用公式计算混合生活垃圾的活化能。 相似文献
17.
反应类过渡态理论，是以过渡态理论为基础，对于与主反应同一类的其它反应的热力学速率常数仅从它们的势垒差和反应能中就可有效的预测出发，这种理论已应用于许多氢提取反应，在复杂反应的基本动力学模型设计中预测热力学速率常数将是非常有用的。 相似文献
18.
Application of neural network in the study of combustion rate of natural gas/diesel dual fuel engine
In order to predict and improve the performance of natural gas/diesel dual fuel engine (DFE), a combustion rate model based
on forward neural network was built to study the combustion process of the DFE. The effect of the operating parameters on
combustion rate was also studied by means of this model. The study showed that the predicted results were good agreement with
the experimental data. It was proved that the developed combustion rate model could be used to successfully predict and optimize
the combustion process of dual fuel engine.
Project supported by National Lab. for Automotive Engine and Safety, Tsinghua University, China 相似文献
19.
Kathleen Moritz Rudasill 《Early childhood research quarterly》2011,26(2):147
The quality of children's relationships with teachers in early elementary grades has implications for their academic and behavioral outcomes in later grades (e.g., Hamre & Pianta, 2001). The current study uses data from the NICHD SECCYD to extend work from a recent study of first grade (Rudasill & Rimm-Kaufman, 2009) by examining connections between child shyness, effortful control, and gender and teacher-child relationship quality in third grade directly and indirectly through the frequency of teacher- and child-initiated interactions in third grade, and teacher-child relationship quality in first grade. Path analyses using structural equation models were used to test two different models, one for conflict and one for closeness. Findings reveal five main points: (a) Children's characteristics (i.e., shyness and effortful control) were related to the frequency of interactions they initiated with their third grade teachers; (b) The number of teacher-initiated interactions with a child in third grade was positively related to teacher perception of conflict, but not closeness, with that child; (c) Teachers’ perceptions of relationship quality and the number of teacher-initiated interactions in first grade predicted teachers’ perceptions of relationship quality and the number of teacher-initiated interactions in third grade; (d) Children's gender predicted the number of teacher-initiated interactions and teachers’ perceptions of relationship quality in third grade; (e) Teacher-child relationship quality in first grade, and the number of teacher and child-initiated interactions in third grade, mediated associations between children's characteristics and teacher-child relationship quality in third grade. Findings have implications for future research and training for preservice and practicing teachers. 相似文献
20.
基于煤自燃氧化特性测试系统,推导煤自燃过程中的平均耗氧速率和标准耗氧速率计算式,求解各温度点煤体的平均氧浓度数值以及氧浓度和耗氧速率分布函数,确定煤自燃氧化动力学参数表达式。采用模拟实验对此系统的耗氧规律进行分析,结果表明,煤自燃过程中随着温度升高,反应体平均氧浓度点逐渐沿气体流动方向远离流动距离中心点,各温度点煤体氧浓度及耗氧速率沿流动路径呈负指数分布,当温度较低时可近似作线性处理。此外,分析表明,若以平均耗氧速率作为煤自燃氧化反应速率,可更全面、直观地对煤自燃氧化阶段进行划分。 相似文献