隧道掘进爆破振动对围岩影响的HHT分析

为了探究隧道掘进爆破振动信号在围岩等级改变处的传播衰减特性,以新建铁路北京至沈阳客运专线（辽宁段）TJ-1标三棱山隧道为工程背景,采用理论分析与现场试验相结合的方法,基于TC-4850监测试验数据,对爆破质点振速时程曲线进行EMD分解和Hilbert变换。依据测点3个方向的边际谱和瞬时能量谱,分析爆破振动能量在时域和频域的分布规律,进而可以得出各频带的能量百分比以及总能量与距离的关系曲线。通过分析地震波信号沿隧道围岩传播衰减性质可以得出:爆破振动能量在频域上分布具有各向异性,而且在垂直方向上具有数量比例高、所占频带低的特点;隧道掘进爆破振动总能量在围岩等级改变处出现“断崖式”衰减,且在Ⅳ级围岩中相对衰减率更高,衰减更为迅速。     

杭钢电炉厂除尘器改造探索

分析了杭钢电炉厂除尘器运行中出现的问题,对原设计进行了改造,并达到了改造效果。     

沧炼曝气池串联改造的应用

论述了沧炼曝气池由原来的并联运行改造为串联运行的原理，特点，并经过运行证明，改造后的曝气池运行方式更加灵活，且其耐冲击能力，处理效果等有较大幅度的提高。     

Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O

Absorption spectroscopy, which is widely used for concentration measurements of tropospheric and stratospheric compounds, requires precise values of the absorption cross-sections of the measured species. NO₂, O₂ and its collision-induced absorption spectrum, and H₂O absorption cross-sections have been measured at temperature and pressure conditions prevailing in the Earth’s atmosphere. Corrections to the generally accepted analysis procedures used to resolve the convolution problem are also proposed.     

Evaluation of the antifungal effects of bio-oil prepared with lignocellulosic biomass using fast pyrolysis technology

This study was performed to investigate the utility of bio-oil, produced via a fast pyrolysis process, as an antifungal agent against wood-rot fungi. Bio-oil solutions (25-100 wt.%) were prepared by diluting the bio-oil with EtOH. Wood block samples (yellow poplar and pitch pine) were treated with diluted bio-oil solutions and then subjected to a leaching process under hot water (70 °C) for 72 h. After the wood block samples were thoroughly dried, they were subjected to a soil block test using Tyromyces palustris and Trametes versicolor. The antifungal effect of the 75% and 100% bio-oil solutions was the highest for both wood blocks. Scanning electron microscopy analysis indicated that some chemical components in the bio-oil solution could agglomerate together to form clusters in the inner part of the wood during the drying process, which could act as a wood preservative against fungal growth. According to GC/MS analysis, the components of the agglomerate were mainly phenolic compounds derived from lignin polymers.     

Synthesis of calcium phosphate hydrogel from waste incineration fly ash and its application to fuel cell

Waste incineration fly ash was successfully recycled to calcium phosphate hydrogel, a type of fast proton conductor. The crystallized hydrogel from incineration fly ash had a lower electric conductivity and a lower crystallinity than that from calcium carbonate reagent. However, the difference in electric conductivity between these crystallized hydrogels decreases with temperature. This was due to the presence of potassium in the incineration fly ash. The fuel cell with a membrane electrode assembly (MEA) using the calcium phosphate hydrogel membrane prepared from incineration fly ash was observed to generate electricity. The performance of this fuel cell was almost equal to that of a mixture of K₂CO₃ and CaCO₃ reagents; further, the performance of the former was superior to the fuel cell with a perfluorosulfonic polymer membrane at temperatures greater than approximately 85 °C.     

近似Rayleigh地震波作用下地下综合管廊响应分析

地下综合管廊是一种重要的生命线基础设施,目前对其抗震性能的研究还处于起步阶段。由于属于浅埋地下结构,故地震波中的面波、尤其是Rayleigh波可能会成为地下综合管廊破坏的控制因素。本文根据简谐Rayleigh波的特点,提出了近似Rayleigh地震波的概念,并在假定已知Rayleigh波水平分量的情况下,利用傅里叶变换求得近似Rayleigh地震波场。采用三维有限元模型,对地下管廊结构进行了地震响应分析。分析结果表明:本文建议方法可以有效地模拟波动的传播过程;地下综合管廊结构的变形以整体弯曲变形为主;结构顶面应变约为对应底面位置应变的两倍,与Rayleigh波沿深度衰减的规律相类似。     

滇池优势挺水植物茭草和芦苇降解过程中DOM释放特征研究

利用室内分解模拟实验,研究了滇池外海优势挺水植物茭草和芦苇(成熟期)的叶在水环境中降解过程,分析了其释放于水体中水溶性有机质(DOM)浓度和化学结构变化特征.结果表明,植物分解可造成上覆水pH值升高,茭草和芦苇分解过程中上覆水中DOM浓度的变化趋势基本一致.两种植物上覆水中水溶性有机碳(DOC)和水溶性有机氮(DON)的浓度均在8h达到最大值,水溶性有机磷(DOP)的浓度在24 h达到最大值.同时,茭草和芦苇残体内DOM释放强度和速率的变化趋势也基本一致.两种植物DOC、DON和DOP的释放强度和速率都在8 h达到最大,且8 h的释放强度、释放速率、释放比例依次为DOC>DON>DOP.另外,茭草和芦苇分解过程中DOM结构变化分析表明上覆水紫外吸收光谱中SUVA254值先升高再降低,傅里叶红外光谱中—OH特征峰消失,三维荧光光谱中类腐殖酸单位有机碳荧光强度增强.     

利用宽频带速度记录的频域特征研究台风

利用福建省地震台网宽频带速度记录,以1h为移动窗长,研究了台风生成、发展、消亡整个过程的波谱特征,提出了以Fourier波谱的卓越周期作为刻画台风特征的一种尺度,并以台风“海棠”和“泰利”为例,统计了在登陆台湾之前,其卓越周期与台风参数的对应关系。研究表明,在台风初始形成阶段,其卓越周期由平常噪声的2～4s跃升为7～8s,随着台风向陆地的移动,卓越周期缓慢降低,经过台湾海峡时卓越周期显著降低,随着台风登陆,卓越周期又逐步恢复为噪声水平。     

Thermogravimetric coupled with Fourier transform infrared analysis study on thermal treatment of monopotassium phosphate residue

In China, safe disposal of hazardous waste is more and more a necessity, urged by rapid economic development. The pyrolysis and combustion characteristics of a residue from producing monopotassium phosphate (monopotassium phosphate residue), considered as a hazardous waste, were studied using a thermogravimetric, coupled with Fourier transform infrared analyzer (TG-FTIR). Both pyrolysis and combustion runs can be subdivided into three stages: drying, thermal decomposition, and final devolatilization. The average weight loss rate during fast thermal decomposition stage in pyrolysis is higher than combustion. Acetic acid, methane, pentane, (acetyl) cyclopropane, 2,4,6-trichlorophenol, CO, and CO₂ were distinguished in the pyrolysis process, while CO₂ was the dominant combustion product.