高架污染绕建筑对流扩散风洞实验与数值仿真

采用激光衍射瞬时浓度场测量系统和图像处理系统,对不同高架与周围建筑高度比下污染点源绕建筑对流扩散进行了风洞实验.Fluent双相耦合模型与实验进行了相互校核,得到了建筑的各个高度层面污染分布、不同高度比下的污染扩散及污染分布随时间变化的规律.不同高度比对污染对流扩散具有明显的影响,建筑各高度层面污染浓度分布也存在明显差别.当高度比较小时,污染将堆积在建筑物底层.污染分布随时间变化有助于了解污染对流扩散的时间效应.结果可以为高架与周围建筑规划提供参考与依据.     

CO2-CO分子间等效作用势与液态CO冲击压缩特性研究

二氧化碳(CO2)和一氧化碳(CO)是高含碳凝聚态炸药爆轰混合产物中两种重要成分,因此,在研究爆轰反应平衡问题以及爆轰产物状态方程时,必然要涉及到CO2-CO分子间等效作用势的确定问题.本文从反应体系化学平衡的角度,采用分子流体的微扰变分理论(MCR)以及分子混合物的范德瓦耳斯单相流体模型(vdW-1f),对过去和最近发表的液态CO的冲击压缩实验数据进行了详细分析,重新优化了CO2-CO分子间exp-6型势函数中的参数值.讨论了本文确定的CO2-CO分子间等效作用势与过去所采用的势函数之间存在的差别.     

CO2地质封存中突破压力梯度的孔隙尺度数值模拟

以CO2捕集与封存为研究背景,开展了二氧化碳盐水层封存条件下超临界二氧化碳在多孔结构中的流动规律研究.通过基于孔隙尺度的数值模拟方法,研究了超临界CO2注入储层多孔结构时突破压力梯度和流动时间以及CO2饱和度的关系,分析了压力、温度、颗粒直径、接触角和表面张力系数对突破压力梯度的影响规律.研究表明,对于孔隙率以及颗粒分...     

感应耦合非热等离子体催化转化二氧化碳

射频感应耦合等离子体能够在室温条件下选择活化并分解二氧化碳,本文通过调控等离子体放电条件(气体流量、放电频率等)获得了较高的一氧化碳产率. 研究发现网状金属催化剂在二氧化碳等离子体中能促进氧原子的复合反应,从而有效抑制其与目标产物一氧化碳的逆反应,提升反应整体效率. 本文为实时转化过剩的可再生电能(来自太阳能、风能、潮汐能等)为高附加值一氧化碳中的化学能提供了一个可行的方案.     

感应耦合非热等离子体催化转化二氧化碳（英文）

射频感应耦合等离子体能够在审温条件下选择活化并分解二氧化碳,本文通过调控等离子体放电条件(气体流量、放电频率等)获得了较高的一氧化碳产率.研究发现网状金属催化剂在二氧化碳等离子体中能促进氧原子的复合反应,从而有效抑制其与目标产物一氧化碳的逆反应,提升反应整体效率.本文为实时转化过剩的可再生电能(来自太阳能、风能、潮汐能等)为高附加值一氧化碳中的化学能提供了一个可行的方案.     

用Cadna/A软件预测桥梁交通噪声及应用分析

城市环境噪声的主要声源是车辆交通噪声，而城市高架道路经过区域的声环境影响比较复杂。城市高架桥路段两侧交通噪声排放主要在地面辅道和桥梁高架段，地面辅道交通噪声对临路第一排居民影响最大，而高架道路交通噪声对高层及后排居民的影响较大，范围更广。如何有效单独分析地面辅道交通噪声和桥梁高架交通噪声对周围环境的影响程度，将对交通噪声源的治理和对道路两侧不同范围内声功能区域建筑物的降噪措施提供理论依据。下面以上海沪闵路一沪杭公路地方越江大桥为例，分析了大桥的地面辅道和高架桥段敏感点的声环境现状，运用Cadna／A软件预测和分析越江大桥运营后地面辅道和桥梁高架段交通噪声各自对周围环境的影响，研究相关敏感地区的可能环境噪声状况，以及交通噪声影响的程度特征。     

带电球面和带电球体电场强度和电势分布求解探讨

在大学物理静电场的教学中, 与球形有关的问题很典型, 比如带电球面和带电球体周围空间的电场强 度和电势分布问题, 不同电荷密度分布带电球体周围空间的电场强度和电势分布的求解问题, 本文对这些球形带电 体系进行分析探讨, 分别根据定义式求解和高斯定理求解, 并找出了其规律式和特点     

冷却条件下管内超临界压力CO2对流换热研究

本文用数值计算和实验测量结合的实验方法对冷却条件下超临界压力二氧化碳在细圆管内(Din=2 mm)的局部对流换热进行了实验研究.结果表明,冷却条件下超临界二氧化碳局部对流换热系数在流体温度略高于准临界温度时达到峰值.本文还对该过程进行了数值模拟,比较了不同湍流模型的计算结果,根据数值模拟提供的信息分析了影响冷却条件下超临界压力二氧化碳换热的主要因素和物性变化对换热的影响.     

1.5μm处CO2与CO高温线强的实验分析与理论计算

本文在采用乘积近似方法计算二氧化碳、一氧化碳分子总的配分函数(其中分子的振动配分函数采用谐振子近似, 转动配分函数采用非刚性转子模型, 并考虑了离心扭曲修正)的基础上, 利用所得配分函数和振动跃迁矩平方的实验值以及Herman-Wallis系数, 计算了1.5 μm 附近二氧化碳30012–00001跃迁带和一氧化碳3–0跃迁带在300–6000 K温度范围内部分温度下的吸收线强; 为验证计算方法和结果的准确性, 在基于可调谐二极管激光吸收光谱技术搭建的高温测量系统中, 对300–800 K温度范围内部分谱线线强进行了测量, 并把计算结果、测量结果及HITRAN数据库中对应数据进行了对比, 发现相对偏差小于3%, 证明了本方法的有效性, 同时计算及测量所得高温线强数据可对HITRAN数据库进行有效的校正和补充.     

HTc SQUID磁强计用无磁液氮玻璃钢杜瓦的真空性能研究

提出当对无磁液氮玻璃钢杜瓦抽真空时 ,向无磁液氮玻璃钢杜瓦的真空夹层充注微量的二氧化碳气体 ,所充入的二氧化碳气体就会和玻璃钢表面的氢气、一氧化碳、二氧化碳、甲烷等气体发生协同交换反应 ,使玻璃钢表面的氢气、一氧化碳、二氧化碳、甲烷等气体的脱附速度大大增加 ,减少了抽真空时间。由于无磁液氮玻璃钢杜瓦内使用的活性炭吸附剂对二氧化碳的吸附性能远远大于对玻璃钢材料所放出的氢气、一氧化碳和甲烷等主要气体的吸附性能 ,从而使得抽好真空的无磁液氮玻璃钢杜瓦的真空保持时间大大增加 ,延长了无磁液氮玻璃钢杜瓦的使用寿命     

Computational studies of CO and CO: Density functional theory and time-dependent density functional theory

Potential energy curves, equilibrium interatomic distances, term energies and harmonic vibration frequencies for the 16 lowest states of neutral carbon monoxide and the six lowest states of singly ionized carbon monoxide are calculated by density functional theory (DFT) and linear-response time-dependent density functional (LR-TDDFT) theory. The results are compared with experimental data. The two theories, DFT and LR-TDDFT, are described briefly.     

CO adsorption energies on metals with correction for high coordination adsorption sites - A density functional study

We investigate the accuracy of carbon monoxide adsorption energies and site preferences for the metals Ag, Al, Au, Co, Cu, Fe, Ir, Mo, Ni, Pd, Pt, Re, Rh, Ru, W, and Zn using the RPBE functional with a recently suggested empirical adsorption energy correction for carbon monoxide based on the internal CO stretch vibrational frequency. We find that when including the correction, the adsorption site preference for six of the metals changes, and all adsorption site predictions become accurate. We also collect a large number of experimental studies for comparison with our calculated adsorption energies. The mean absolute deviation including the correction is found to be less than 0.2 eV, showing that the RPBE functional gives a much better quantitative agreement between experiments and calculations than the PW91 functional.     

一氧化碳的太赫兹时域光谱研究

以飞秒激光为基础的太赫兹时域光谱技术是一种新型的相干远红外光谱测量技术。文章首次利用太赫兹时域光谱技术测量了一氧化碳气体在0.2～2.5太赫兹频谱范围内的吸收光谱。实验结果表明,一氧化碳在此波段有明显的特征吸收峰,峰值位置与理论计算得到的结果有很好的一致性。随着压强的减小,吸收峰变尖锐。研究一氧化碳的太赫兹吸收光谱特性,对于快速、准确检测环境中有害气体以及排除安全隐患具有重要意义。     

Remote Measurement of Motorcycle Exhaust Using Fourier Transform Infrared System

Abstract

We have explored the basic theory and quantitative methods for the measurement of motorcycle exhaust using a Fourier transform infrared interferometer system. Remote sensing direct measurements were made and the species carbon monoxide, carbon dioxide, nonmethane paraffinic carbon(CH^x) and unburned additional harmful species in motorcycle exhaust were determined. Typical concentrations observed in absorption for carbon monoxide, carbon dioxide and nonmethane paraffinic carbon were about 1.11%, 1.91%, 0.54% respectively. Furthemore, this paper describes the remote sensing Fourier transform infrared spectrometer system. The system covers the infrared spectral region from 700 to 6000 cin^?1 at a maxim resolution of 0.06 cm^?1 for beamsplitter of gerrniuiirun coated zinc selenide and receiver telescope with zinc selriide leis. For air multipollutant monitoring the analytica1 methods have the potential and become important. The remote measurements usirig the Fourier transform inf raid spectroscopy could become niore practical.     

液氮中单管加注二氧化碳气体的实验研究

向饱和液氮中加注常温二氧化碳气体时,为形成细小而分散的固体二氧化碳颗粒以及充分且均匀的固液混合物,通过实验分别采用不锈钢盘管、大管径塑料管以及金属毛细管往液氮中加注一定流量下的常温二氧化碳气体,研究固液混合过程、凝固颗粒大小以及管路的堵塞状况。结果表明,不管是否经过预冷,大直径管道加注时,经过一段时间后管道必定发生堵塞;而毛细管加注则不会堵塞,但是气体流量会发生脉冲性变化。     

A study of the gasification of carbon black with molten salt of Li2CO3 and K2CO3 for application in the external anode media of a direct carbon fuel cell

The characteristics of gasification reactions for carbon–carbonate mixtures were experimentally investigated at high temperatures up to 900 °C, considering the application of the mixtures to the external anode media of a direct carbon fuel cell. A thermo-gravimetric analysis (TGA) was conducted in either a nitrogen or carbon dioxide ambient environment for Li₂CO₃, K₂CO₃ and a mixture of these two substances with carbon black. Changes in the exit gas composition were also monitored during the heating process. It was shown that gasification in the mixture media occurs much more rapidly than carbonate decomposition at elevated temperatures, even for low concentrations of CO₂. It was also shown that the loading of carbonates to carbon significantly affects the global gasification reaction; it increased the reaction rate by an order of magnitude and decreased its activation energy. Based on the experimental observations, a simplified reaction model of gasification was suggested for the anode media of a DCFC, regarding carbonate-catalysed and metal-catalysed pathways of Boudouard reactions.     

Electrochemical conversion of carbon dioxide in a solid oxide electrolysis cell

Carbon dioxide is one of the greatest concerns worldwide, since it is not only a major greenhouse gas but also expected to be an important, sustainable resource for fuels and chemicals. The electrochemical conversion of carbon dioxide, based on solid electrolyte membrane reactors, has the promise to overcome the limitations of the conventional catalytic reactors such as the limited conversion and kinetics, relatively low selectivity and high energy consumption. In this review, electrocatalysts and solid oxide electrolytes, both proton and oxide ion conductors as core materials in an electrochemical ceramic membrane reactor have been reviewed and particular emphasis is placed on their application to synthesize carbon monoxide and hydrogen.     

Interaction of carbon monoxide and oxygen at the surface of inverse titania/Au model catalyst

Interaction of carbon monoxide and oxygen on the surface of titania/Au(1 1 1) inverse model catalyst held at 200 K has been studied by reflection absorption infrared spectroscopy. It was found that CO adsorbs on the oxide/Au perimeter interface, whereas no or very weak adsorption was observed on Au(1 1 1) or titania surface, respectively. Exposing of such species to oxygen results in their decay possibly due to carbon dioxide formation. Efficiency of this effect is higher at lower CO initial concentration which points at the importance of free surface sites for the reaction process.     

On the mechanism of the sensitization of PADC (poly(allyl diglycol carbonate)) track detectors by carbon dioxide treatment

The sensitization effect of carbon dioxide treatments with 0.6 MPa on poly(allyl diglycol carbonate) (PADC) etched track detectors is confirmed for protons and He, C, and Fe ions, where the stopping powers range from 10 to 600 keV/μm. Based on the FT-IR study for the PADC films that were maintained at room temperature and at elevated temperatures, the diffusion coefficient of carbon dioxide, is determined as D = 14,670exp(−9030/T(K)) cm²/s. The sensitivity is enhanced when carbon dioxide is released toward the chemical etching solution that passes through the detector surface. Segmented PADC polymer chains are washed away by the flow of carbon dioxide along the latent tracks in PADC, which results in a higher track etch rate.