共查询到19条相似文献,搜索用时 420 毫秒
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微波场中甲烷部分氧化制合成气 Ⅱ.Co/ZrO_2催化剂在微波场中的升温行为及催化活性 总被引:4,自引:0,他引:4
近年来,甲烷部分氧化制合成气(POM)的研究一直十分活跃[1,2].前文报道了用于甲烷部分氧化制合成气的镍基催化剂(Ni/La2O3)在微波场中的升温行为和催化活性[3],发现在达到相同的CH4转化率时,微波活化方式下的催化剂床层温度比常规加热低得多... 相似文献
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现场测定了溶液在微波场和非微波场中的电导率~温度函数,结果表明在微波场与非微波场中溶液的电导率(Lw)随温度的变化可分别用方程Lw=a′+b′T+c′T2和Ln=a+bT+cT2表述,类似于非微波场中的溶液电导率,而Lw和Ln两者的关系则可表示为lnLw=A+BLn+CL2n。以上a,b,c,…A,B,C等皆为经验系数。 相似文献
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微波频率下氯化钠溶液电导率的非线性特性 总被引:1,自引:0,他引:1
在微波频段研究了电磁场对氯化钠溶液电导率的影响. 运用不对称周期双阱势函数和Langvin方程描述了恒温条件下氯化钠溶液团簇结构中平均氢键的动力学行为, 由Bertolini公式建立团簇的平均氢键形成的概率变化与电导率变化的关系. 计算结果表明, 在恒温条件下, 当微波场的场强达到10 kV·m-1 时, 微波能会部分转化为团簇里分子间势能, 使得氯化钠溶液的电导率与电场强度有关, 这一结果与实验结果符合. 这种微波与氯化钠溶液的相互作用表现出强烈的非线性变化, 应该属于微波的非热效应范畴. 相似文献
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循环伏安法研究表明2,2′-联吡啶催化Co(Ⅱ)通过水/硝基苯界面的相转移伴有化学反应发生。水相或有机相的伴随化学反应直接影响Co(Ⅱ)与2,2′-联吡啶逐级配合物的相转移的循环伏安行为,并观察到类似于金属电极/电解质溶液界面出现的不可逆渡,不同的配合物,相转移机制不同。 相似文献
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循环伏安法研究表明2,2′-联吡啶催化Co(Ⅱ)通过水/硝基苯界面的相转移伴有化学反应发生。水相或有机相的伴随化学反应直接影响Co(Ⅱ)与2,2′-联吡啶逐级配合物的相转移的循环伏安行为,并观察到类似于金属电极/电解质溶液界面出现的不可逆渡,不同的配合物,相转移机制不同。 相似文献
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微波场下非贵金属氧化物的升温行为和烹饪油烟的催化净化性能研究 总被引:3,自引:0,他引:3
在考察了多种金属氧化物在微波场下升温性能的基础上,制备了用于烹饪油烟催化净化的非贵金属催化剂.实验表明,VB族、V族、B族和B族元素氧化物在微波中升温效果明显,其中Co、Ni和V三种元素氧化物的升温效果最好.涂覆氧化铝的蜂窝堇青石负载V2O5的催化剂具有较稳定的吸波升温性和高油烟催化净化活性.添加La2O3后负载型V2O5催化剂活性明显增加,在微波条件下,含有1%La2O3的负载型V2O5催化剂在150℃可使油烟净化率达到88%以上. 相似文献
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Y. Fukui T. Sato M. Ushirokawa T. Asada S. Onogi 《Journal of Polymer Science.Polymer Physics》1970,8(7):1195-1209
The strain-optical coefficient and relaxation modulus were simultaneously measured for high-density polyethylene at various temperatures ranging from 12 to 100°C. Not only horizontal but also vertical shifts were necessary to obtain smooth master curves by the application of time–temperature superposition. However, the relaxation modulus decreases with rising temperature while the strain-optical coefficient increases. This behavior indicates that the variation of the relaxation modulus and the strain-optical coefficient with time can not be explained by a decrease in crystallinity with rising temperature since a decrease in crystallinity usually causes a decrease in the strain-optical coefficient with time can not be explained by a decrease in crystallinity with rising temperature since a decrease in crystallinity usually causes a decrease in the strain-optical coefficient. It was emphasized that another explanation should be sought for the vertical shift in the time–temperature superposition of the time-dependence curves of the relaxation modulus and the strain-optical coefficient at various temperatures. The master curve of the strain-optical coefficient at various temperatures. The master curve of the strain-optical coefficient or the optical distribution function of relaxation times determined from it serve to distinguish the type and thermal history of the polyethylene. 相似文献
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NdFeB合金吸氢过程的研究 总被引:1,自引:1,他引:1
氢破碎工艺作为烧结钕铁硼永磁体制作过程中铸锭粗破碎的新工艺, 具有使主相破碎成单晶的独特优点. 为了优化氢破碎工艺, 主要研究了铸锭表面积、温度和钕含量对钕铁硼铸锭发生破碎的吸氢孕育期、平均吸氢量和吸氢速度的影响. 结果发现, 表面积增大, 吸氢孕育期缩短. 温度提高, 孕育期缩短, 吸氢速度加快, 平均吸氢量稍有变化, 这主要是因为温度的提高, 增加氢扩散速度所致. 而提高钕含量, 孕育期同样缩短, 吸氢速度加快, 平均吸氢量增大, 这与富钕相的增多有关. 并且, 可以通过吸氢量来计算铸锭中富钕相的含量. 相似文献
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In order to study the surface temperature change and distribution during charging and discharging and in the simulation working
condition of LiFePO4/C power battery at normal temperature, the surface temperature is tested by placing the battery in the incubator and fixing
10 temperature probes on the battery surface. Results show that the temperature of the upper part is higher, and the temperature
at the bottom is the lowest, while around the positive electrode is the highest during charging and discharging. The maximum
temperature rising rate is reached at the moment of constant current charging transforming to the constant voltage charging
during charging, and at the end moment during discharging. During charging in a certain range and discharging, the relations
between the maximum temperature, the average temperature rising rate, and the maximum temperature difference of all the measurement
points at the same time and the current are approximately linear, respectively. In the simulation working condition, the moment
of the maximum temperature is consistent with the large current discharging instantaneous in each stage. 相似文献
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建立测定磷酸三甲苯酯临、间、对位异构体含量的气相色谱方法。通过优化色谱分析条件,如降低初始柱箱温度和程序升温速度,可较好分离开TCP的10种同分异构体。选用弱极性的AB–5MS色谱柱,设置柱箱初始温度为120℃,升温速度为3℃/min,终温为300℃。使用相应的纯物质,对其中的临-临-临,间-间-间,对-对-对进行了定量分析。三种异构体在各自的线性范围内均呈良好的线性,线性相关系数大于0.999,检出限为0.162 7~0.168 8 mg/L,测定结果的相对标准偏差小于5%(n=6)。该方法检出限低,重现性好,适合于磷酸三甲苯酯异构体含量的检测。 相似文献
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采用分光光度法对铝制炊具溶出铝量及影响因素展开了研究。结果表明,铝制炊具溶出的铝量随温度升高明显增加;且在一定温度下,使用家用调味品也会增加铝制品溶出的铝量。 相似文献
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Proposed methods that yield information about mechanisms of atom formation, utilize the shapes of analytical signals that lie either under the rising or under the constant part of the temperature curve. We have evaluated both types of methods by use of a versatile data acquisition system, by which temperature and corresponding absorbance values were simultaneously sampled and stored. The stored data were subsequently used for calculations referring to arbitrary parts of the analytical signal, thus permitting accurate evaluations.Results obtained from “constant temperature methods” were found to be influenced by factors like sample amount, type of graphite surface and inner gas flow-rate. Meaningful results were only obtained for sample amounts larger than those used during normal working conditions.Results obtained from “rising temperature methods” were in rough agreement with each other. However, they all showed large standard deviations, indicating that several mechanisms are acting during atom formation. This makes it difficult to extract useful information from energy values obtained with these methods. 相似文献
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在前文研究天然Stilbite沸石(CXN沸石)水热稳定性影响因素的基础上, 以27Al与29Si MAS NMR, NH3-TPD和低温氮吸附等详细研究了铵型CXN沸石骨架铝配位状态和硅配位状态, 表面酸性与孔性质等与水蒸汽处理温度的关系. 随温度升高, 沸石骨架硅铝比逐渐提高, 并伴随硅羟基缺陷增多. 经750 ℃水蒸汽处理3 h后沸石骨架硅铝比可达到21.3. 沸石总酸量随水蒸汽处理温度的提高而降低, 沸石骨架铝脱除造成沸石孔道部分被堵塞, 但同时形成有利于分子扩散的介孔. 相似文献