Results 91 to 100 of about 3,931 (161)

Study on the influence of porosity of blocking air-leakage material on gas migration in goaf of cutting roof and retaining roadway [PDF]

open access: yes
In order to study the influence of the porosity of blocking air-leakage material on the O2, CH4 gas migration and the coupling disaster of coal spontaneous combustion and gas in the goaf of working face Y-type ventilation cutting roof and retaining ...
Jie LIU   +6 more
core   +1 more source

SF6替代气体与空气混合的绝缘性能研究

open access: yesGaoya dianqi, 2018
CF3I和c-C4F8作为目前研究最多的SF6替代气体,需要与缓冲气体混合以降低液化温度。为了评估使用空气作为SF6替代气体缓冲气体的可能性,通过求解两项近似的Boltzmann方程,计算了CF3I/空气、c-C4F8/空气混合气体的电子崩参数。首先,分别计算了CF3I/空气、c-C4F8/空气混合气体的约化电离系数、约化附着系数、约化有效电离系数、约化临界场强,以及表征对不均匀电场敏感程度的c值(约化有效电离系数关于约化电场的关系曲线中零点附近的斜率值)。然后 ...
林启明, 邓云坤, 赵谡, 肖登明
doaj  

NaA型分子筛膜的合成及分离性能的研究 [PDF]

open access: yes, 2000
在自制的片状多孔陶瓷载体上 ,通过多次原位水热晶化合成出NaA型分子筛膜 .通过扫描电子显微镜观测 ,发现在某些区域 ,小颗粒的NaA型分子筛以非常紧密的形式畸晶孪生在一起 ,其致密度远好于由分子筛晶粒松散无规律堆积而形成的膜排列方式 .此类膜生长形式可能是获取致密无缺陷型分子筛膜的一种途径 .单组分及双组分气体渗透测试结果表明 ,在所合成的分子筛膜上 ,晶粒间隙孔可能是主要的膜扩散通道 ...
万惠霖   +3 more
core  

Visible-light deep reduction of low concentration CO2 over composite catalyst Ru/CoAl-LDH and the performance enhancement mechanism [PDF]

open access: yes
Under the dual-carbon goal, the resource utilization of CO2 driven by clean and renewable solar energy has become an important research topic. However, the previous reports have mostly used high-purity CO2 as the research object, while the CO2 ...
Chongchong LENG   +5 more
core   +1 more source

C4F7N-air混合气体在稍不均匀和极不均匀电场中的工频绝缘特性分析

open access: yesGaoya dianqi
近年来,作为SF6有效替代气体之一,七氟异丁腈(C4F7N)因其优异的电气性能和物化特性而受到关注与讨论,然而由于C4F7N的液化温度较高,需要与低液化温度的缓冲气体并用。选择空气作为缓冲气体,在稍不均匀电场与极不均匀电场下,通过工频击穿实验研究气压、混合占比和电极间隙对C4F7N-air混合气体工频击穿电压的影响。结果发现:C4F7N-air混合气体在两个电场下的工频击穿电压随着电极间隙的增大而近似线性增加,在极不均匀电场下,出现明显“驼峰”效应,混合比为8%~16%的C4F7N ...
陈曦   +4 more
doaj  

基于Boltzmann方程对C3F8/CF3I/CO2三元环保型混合气体的绝缘性能研究

open access: yesGaoya dianqi
为研究一种新型SF6替代环保绝缘气体介质,采用密度泛函理论(DFT)从微观结构层面上深入地分析C3F8作为一种SF6替代环保绝缘气体的可行性,利用两项近似的Boltzmann方程对300 K下C3F8/CF3I/CO2三元环保混合绝缘气体介质的绝缘特性进行了分析,计算三元环保混合气体的电子能量分布函数、电子群参数和协同效应系数等多种微观参数,分析了这些参数随C3F8混合气体比例的变化情况,并与同比例下的c-C4F8/CF3I/CO2三元混合气体的微观参数进行了对比和分析。在约化电场强度E/N低于418 ...
钟蕊霜   +4 more
doaj  

Process Simulation and Analysis for Methanation of Synthetic Natural Gas from Coal [PDF]

open access: yes, 2013
我国是一个“富煤贫油少气”的国家,但目前我国煤炭的使用效率低,环境污染大。受环境压力和能源结构的调整需求,迫切需要将煤炭进行清洁化利用。煤制取合成天然气因其能源转化效率高,单位热值耗水量少而成为我国煤炭清洁利用的一大热点。虽然国外有相对成熟的煤制取合成天然气技术,但仅美国大平原煤制天然气能经长周期考验,因此开发拥有自主知识产权的甲烷化技术,以满足我国煤化工工业需求,意义重大。本文以合成气甲烷化为对象进行热力学分析、建立绝热固定床反应器模型 ...
蔡运安
core  

Radiative properties of flue gas under high-altitude sub-atmospheric pressure [PDF]

open access: yes
The special geography of the plateau area leads to a series of problems in boiler operation. In this study, the absorption coefficients and total emissivity of flue gas were determined under different air pressures during air combustion using the Line-By-
Defu CHE   +6 more
core   +1 more source

Ignition mechanism of methane by 5G electromagnetic waves and power safety thresholds in underground coal mines [PDF]

open access: yes
5G technology, with its advantages of high bandwidth, low latency, and extensive connectivity, has shown great potential in driving the intelligent transformation of the coal mining industry.
Haijian CHEN   +6 more
core   +1 more source

高气压下氮氧混合气体的工频击穿特性

open access: yesGaoya dianqi
文中通过工频击穿实验研究了不同电场均匀度、配比、气压下氮氧混合气体的工频绝缘特性。实验发现:板—板电极下,配比对氮氧混合气体的击穿电压影响较小,氮氧混合气体的击穿电压随充气压力的提高均呈增长趋势;棒—板电极下氮氧混合气体的击穿电压明显降低;针—板电极下氮氧混合气体的击穿电压在0.6~0.9 MPa出现“驼峰”效应,随着针—板电极间距增大,“驼峰”效应越发显著,较高气压下绝缘强度出现饱和。综合分析表明,在不同电场均匀度下,0.8 MPa时80%N2/20%O2与SF6在0.4 MPa时80%的绝缘强度相当。
陈凯   +4 more
doaj  

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