Effect of different oxygen species originating from the dissociation of O2, N2O and NO on the selectivity of the Pt-catalysed NH3 oxidation

An effect of oxygen species formed from O₂, N₂O and NO on the selectivity of the catalytic oxidation of ammonia was studied over a polycrystalline Pt catalyst using the temporal analysis of products (TAP) reactor. The transient experiments were performed in the temperature range between 773 and 1073 K in a sequential pulse mode with a time interval of 0.2 s between the pulses of the oxidant (O₂, N₂O and NO) and NH₃. In contrast to adsorbed oxygen species formed from NO, those from O₂ and N₂O reacted with ammonia yielding NO. It is suggested that the difference between these oxidising agents may be related to the different active sites for dissociation of O₂, N₂O and NO, where oxygen species of various Pt-O strength are formed. Weaker bound oxygen species, which are active for NO formation, originate from O₂ and N₂O rather than from NO. These species may be of bi-atomic nature.     

石灰石矿最佳爆破参数的确定及其应用

针对卡布其石灰石矿的实际情况，研究和确定了以提高块矿率、改善爆破质量为目的的最佳爆破参数，并在生产实际中加以应用，取得了良好的爆破效果和经济效益。     

控制爆破拆除危桥的实践

介绍了运用控制爆破技术,对悬臂钢筋混凝土斜拉桥爆破拆除方法,指出了布孔、装药、防护等方面的技术问题.     

硐室爆破技术在鹅头厂铁矿的应用

说明了鹅头厂铁矿露天采场延深采用硐室爆破的理由,分析了爆破参数选择、硐室爆破参数计算、边坡安全的要求、导硐及药室布置、药室堵塞及起爆网路等,并对爆破效果进行了评价。     

Experiments and reaction characteristics of liquid phase simultaneous removal of SO<Subscript>2</Subscript> and NO

Experiments of simultaneous removal of SO₂ and NO from simulated flue gas, using NaClO₂ solution as the absorbent, were carried out in a self-designed bubble reactor, and high simultaneous removal efficiencies of SO₂ and NO were obtained under the optimal experimental conditions. The mechanism of simultaneous removal based on NaClO₂ acid solutions was proposed by analyzing the removal products. Possibility and limitation of the desulfurization and denitrification using NaClO₂ acid solutions were calculated by thermodynamic methods. Experimental results of reaction kinetics for simultaneous desulfurization and denitrification indicated that the oxidation-absorption processes of SO₂ and NO were divided into two zones, namely the fast and slow reaction zones. In the slow reaction zones both were zero order reactions, and in the fast reaction zones, the reaction order, rate constant and activation energy of SO₂ reaction with absorbent were 1.4, 1.22 (mol·L⁻¹)^−0.4·s⁻¹ and 66.25 kJ·mol⁻¹, respectively, and 2, 3.15×10³ (mol·L⁻¹) ⁻¹·s⁻¹, and 42.50 kJ·mol⁻¹ for NO reaction, respectively. Supported by the National High-Tech Research and Development Program of China (“863” Project) (Grant No. 2007AA061803)     

一种新的InSAR基线估计方法

针对InSAR技术中基线估计误差对DEM精度的影响,从传统的基线估计方法入手,提出了一种新的估计基线参数的方法,并用仿真实验做了论证.结果表明,该方法比以往传统的方法得到的基线参数的精度更高,运算速度更快,应用范围更加广泛.     

大型地下洞室上层爆破开挖对下层围岩振动特性的影响

某地下实验厅采用上、下层同时爆破开挖,最后进行贯通的开挖施工方案。采用现场爆破试验监测的手段,研究了上层水平钻孔爆破开挖时下层围岩的质点峰值振动速度及频率特性,分析了上层爆破开挖对下层围岩动力稳定的影响。研究结果表明,大型地下洞室上层水平钻孔爆破开挖时,爆炸地震波能量主要向下层岩体传播,致使下层洞室顶拱处的振动速度大于上层底板相同距离处的振动速度;爆破振动主要以剪切波(SV波)的形式向下层岩体传播,下层洞室围岩在平行于炮孔纵轴向(实验厅纵轴向)方向上的振动速度最大;由于上层的爆破振动以体波的形式在岩体内向下层传播,下层围岩的振动频率更高。     

Rock-breaking mechanism and experimental analysis of confined blasting of borehole surrounding rock

The rock-breaking mechanism and effect of confined blasting were analysed by blasting and impact dynamic mechanics, fluid dynamic mechanics, fracture mechanics as well as blasting experiment. The results showed that the fracturing of surrounding rock in confined blasting condition is the result of coaction of rock pre-cracking by shock wave and stress wave and the continuing expanding crackenhancement of confined medium, and the model of crack development of borehole surrounding rock in confined blasting condition was established. This study acquired the damage range of surrounding rock under the action of shock wave and stress wave, as well as the crack development characteristics of surrounding rock after the wedge-in confined medium into the crack space. Deep-hole confined blasting experiment on large rock showed that the high-efficient utilisation of in-hole explosive was achieved and the safety of rock blasting operation was ensured. Safe static rock-breaking under the action of high-efficient explosive blasting was achieved as well as the unification of super dynamic load of explosive blasting and static rock-breaking of water medium.     

乌都河洞口水电站新建厂房开挖控制爆破施工效果分析

乌都河洞口水电站新建厂房与原厂房间的水平距离小,开挖位置狭窄,施工条件受限、施工干扰较大,预固结灌浆后再控制爆破是厂房基础开挖施工技术关键。文章结合工程地质条件,按“自上而下,先坡后河床”的开挖方式,提出了预开挖边坡固结灌浆超前处理、分区分期梯度爆破为主辅以光面爆破和预裂爆破的开挖爆破施工技术方案,经爆破后验证,爆破效果良好,达到了预期效果,确保了工程工期质量和施工安全,节约了工程投资。     

某工程爆破及机车振动作用下房屋响应的研究

工程爆破及震动对地表建筑物会造成一定程度的损伤.以临合高速公路为背景,对该工程隧道爆破及机车震动的强震动实时测试和分析,并对附近房屋的损伤程度进行了宏观调查,分析得出地表震动特性、震动影响范围和程度,及其对房屋结构的影响.为类似工程爆破及震动的设计及施工安全管理提供参考和依据.