多功能电缆路径探测技术研究

文章介绍了一种多功能电缆路径探测技术。该技术通过调整发射机的工作方式,采用组合线圈接收机的方式可以实现埋地电缆路径的探测。     

硝酸尾气治理工艺探讨

分析了抚顺石化公司腈纶化工厂腈纶纺丝组件清洗工序原有的硝酸尾气治理工艺方案,认为存在着较严重的硝酸损失及废气污染问题。根据试验方案,决定采用冷却器将硝酸蒸气从85℃冷却至35℃以下,再经过滤器使气液分离,回收硝酸,分离后的气体与各集气罩引出的气体一同进行碱洗、水洗,可以提高硝酸尾气回收率,改善工作环境。     

6Cr/SiO_2催化剂上CO_2氧化乙烷脱氢制乙烯反应的研究

在常压固定床微反反应器上 ,对CO2 氧化乙烷脱氢制乙烯反应催化剂进行了评价。通过对载体及活性组份的筛选 ,发现 6Cr/SiO2 催化剂具有较佳的催化反应性能。温度在 82 3～ 92 3K之间 ,该催化剂的乙烷转化率和乙烯选择性分别为1 2 1 %～ 3 2 1 %和 85 2 %～ 77 3 %。增加V(CO2 ) /V(C2 H6 ) ,有利于提高乙烷转化率和乙烯产率 ,随V(CO2 ) /V(C2 H6 )从1 0增加到 4 0 ,乙烷转化率从 3 1 2 %增加到 49 1 % ,乙烯产率从 2 4 8%增加到 3 5 1 %。另外 ,考察了Cr担载在不同载体上CO2 对乙烷脱氢的作用。对于 6Cr/SiO2 和 6Cr/AC催化剂 ,CO2 对乙烷脱氢起促进作用 ,而对于 6Cr/MCM41和 6Cr/Al2 O3催化剂 ,CO2 对乙烷脱氢却起抑制作用。对 6Cr/SiO2 催化剂上CO2 氧化乙烷脱氢制乙烯反应的再生实验也进行了探讨。结果表明 ,在 92 3K下反应后的催化剂用O2 可完全再生 ,而用CO2 则不能完全再生。     

Cr系催化剂上二氧化碳氧化乙烷脱氢制乙烯反应的研究

考察了SiO2、活性炭(AC)担载金属氧化物催化剂上二氧化碳氧化乙烷脱氢制乙烯的反应性能,表明Cr2O3是最佳的金属活性组分,具有较好的二氧化碳氧化乙烷脱氢制乙烯反应性能.在823～923K温度下,6Cr/SiO2和6Cr/AC催化剂的乙烷转化率分别为12.0%～32.1%和8.5%～29.2%,乙烯选择性分别为85.2%～77.3%和87.5%～69.6%.考察6Cr/SiO2和6Cr/AC催化剂表面CO2对乙烷脱氢的作用表明,CO2在参与乙烷脱氢反应过程中,有利于提高乙烷转化率和乙烯产率,同时对反应过程中产生的积炭具有抑制作用.     

高职毕业生择业困惑与对策

本文针对高职毕业生择业心态现状进行分析并展开论述。指出高职毕业生因对市场缺乏了解、自主择业意识不够、不能合理定位、急功近利和不堪压力等原因,导致不良择业心态;并从加强教育与疏导,创设良好的择业环境,着力“特色”培养、增强其适应能力,鼓励自主创业四个方面入手,论述了如何帮助高职毕业生减轻择业压力,调整择业心态,摆脱择业困惑,以实现顺利就业。     

智能建筑系统集成的实施

系统集成是楼宇智能化的核心技术,文中介绍了系统集成的特点及其提供的功能,并介绍了系统的软件构成和工作原理,本系统在技术上可行,经济上合理,并为业主的管理提供方便。     

Microstructure and Electrochemical Characteristics of Melt-Spinning Alloy Ml(NiCoMnAl)_5

Microstructure and Electrochemical Characteristics of Melt-Spinning Alloy Ml(NiCoMnAl)_5     

Effect of processing parameters on formability,microstructure, and micro-hardness of a novel laser additive manufactured Ti-6.38Al-3.87V-2.43Mo alloy

A novel Ti-6.38Al-3.87V-2.43Mo alloy was designed with a cluster formula of 12[Al-Ti12](V0.75Mo0.25Ti2)+4[Al-Ti12](Al3)by replacing Ti with Mo/V on the basis of the Ti-Al congruent alloy.The effects of laser power and scanning speed on the molten pool size,surface roughness,relative density,microstructure,and micro-hardness of single-track and bulk Ti-6.38Al-3.87V-2.43Mo samples prepared via laser additive manufacturing(LAM)were investigated.The results show that processing parameters significantly affect the formability,microstructure,and micro-hardness of the alloy.With decreasing laser power from 1,900 W to 1,000 W,the relative density is decreased from 99.86%to 90.91%due to the increase of lack-of-fusion;however,with increasing scanning speed,the relative density does not change significantly,but exceeds 99%.In particular,Ti-6.38Al-3.87V-2.43Mo samples of single-track and bulk exhibit a good formability under an input laser power of 1,900 W and a scanning speed of 8 mm·s_-1,and display the lowest surface roughness(Ra=13.33μm)and the highest relative density(99.86%).Besides,the microstructure of LAM Ti-6.38Al-3.87V-2.43Mo alloy coarsens with increasing laser power or decreasing scanning speed due to the greater input energy reducing the cooling rate.The coarsening of the microstructure decreases the microhardness of the alloy.     

Hydrous ferric oxide incorporated diatomite for remediation of arsenic contaminated groundwater

Two reactive media [zerovalent iron (ZVI, Fisher Fe0) and amorphous hydrous ferric oxide (HFO)-incorporated porous, naturally occurring aluminum silicate diatomite [designated as Fe (25%)-diatomite]], were tested for batch kinetic, pH-controlled differential column batch reactors (DCBRs), in small- and large-scale column tests (about 50 and 900 mL of bed volume) with groundwater from a hazardous waste site containing high concentrations of arsenic (both organic and inorganic species), as well as other toxic or carcinogenic volatile and semivolatile organic compounds (VOC/SVOCs). Granular activated carbon (GAC) was also included as a reactive media since a permeable reactive barrier (PRB) at the subject site would need to address the hazardous VOC/SVOC contamination as well as arsenic. The groundwater contained an extremely high arsenic concentration (341 mg L(-1)) and the results of ion chromatography and inductively coupled plasma mass spectrometry (IC-ICP-MS) analysis showed that the dominant arsenic species were arsenite (45.1%) and monomethyl arsenic acid (MMAA, 22.7%), while dimethyl arsenic acid (DMAA) and arsenate were only 2.4 and 1.3%, respectively. Based on these proportions of arsenic species and the initial As-to-Fe molar ratio (0.15 molAs mole(-1)), batch kinetic tests revealed that the sorption density (0.076 molAs molFe(-1)) for Fe (25%)-diatomite seems to be less than the expected value (0.086 molAs molFe(-1) calculated from the sorption density data reported by Lafferty and Loeppert (Environ. Sci. Technol. 2005, 39, 2120-2127), implying that natural organic matters (NOMs) might play a significant role in reducing arsenic removal efficiency. The results of pH-controlled DCBR tests using different synthetic species of arsenic solution showed that the humic acid inhibited the MMAA removal of Fe (25%)-diatomite more than arsenite. The mixed system of GAC and Fe (25%)-diatomite increased the arsenic sorption speed to more than that of either individual media alone. This increase might be deduced by the fact that the addition of GAC could enhance arsenic removal performance of Fe (25%)-diatomite through removing comparably high portions of NOMs. Small- and large-scale column studies demonstrated that the empty bed contact time (EBCT) significantly affected sorpton capacities at breakthrough (C = 0.5 C0) forthe Fe0/sand (50/50, w/w) mixture, but notfor GAC preloaded Fe (25%)-diatomite. In the large-scale column tests with actual groundwater conditions, the GAC preloaded Fe (25%)-diatomite effectively reduced arsenic to below 50 microg L(-1) for 44 days; additionally, most species of VOC/SVOCs were also simultaneously attenuated to levels below detection.