辽宁岫岩叶蛇纹石热处理产物的矿物学特征

对辽宁岫岩叶蛇纹石进行了热活化处理 ,通过差热 热重分析 (DTA TG)、X射线粉晶衍射分析 (XRD)、红外光谱分析 (IR)和扫描电镜分析 (SEM) ,发现热活化温度达到 5 0 0℃时 ,叶蛇纹石八面体片中的羟基开始显著脱失 ,并出现镁橄榄石新物相 ,但仍然保持层的结构 ;当温度达到 5 5 0℃时 ,叶蛇纹石的层状结构被完全破坏 ;温度升高到 65 0℃时 ,镁橄榄石结晶度增高 ,并出现顽火辉石新物相 ;当温度达到 1 0 5 0℃时 ,镁橄榄石的含量略有减少 ,并出现较多的晶质顽火辉石物相。

天然和热活化蛇纹石对土壤镉赋存形态的影响

以天然蛇纹石粉为原料,应用马弗炉制备不同温度（550℃和700℃）的热活化蛇纹石,通过室内培养试验,探究不同剂量（分别为土重的1%,3%,5%）的天然和热活化处理的蛇纹石对外源镉污染土壤中镉赋存形态的影响。结果表明,土壤pH值随蛇纹石用量增加而增加,随培养时间延长呈现先降低后趋于稳定的趋势,但均显著高于对照。高剂量700℃热活化蛇纹石对土壤pH值影响最大,培养60d时与对照相比提升了1.98个单位。添加天然蛇纹石、550℃和700℃热活化蛇纹石均能降低土壤可交换态镉的含量,与对照相比分别降低了17.42%-28.32%,28.99%-39.63%,33.11%-53.72%。相关性分析表明,各培养时期土壤可交换态镉的含量与土壤pH值呈现极显著负相关关系。各处理对土壤镉各形态含量的影响差异不同,显著降低了土壤可交换态镉的含量,不同程度地提高了碳酸盐结合态、铁锰氧化物结合态和残渣态镉的含量,对有机物结合态镉的影响并不明显。总的来说,蛇纹石添加入土壤后能够提高土壤pH值,促使可交换态镉向其他生物可利用性较低的镉形态转变,且不同剂量、不同热活化温度间存在显著差异。

Electrical conductivity of (Na_3AlF_6-40%K_3AlF_6)-AlF_3-Al_2O_3 melts

The effects of contents of AlF3 and Al2O3, and temperature on electrical conductivity of （Na3AlF6-40%K3AlF6）- AlF3-Al2O3 were studied by continuously varying cell censtant （CVCC） technique. The results show that the conductivities of melts increase with the increase of temperature, but by different extents. Every increasing 10 ℃ results in an increase of 1.85 × 10^-2, 1.86× 10^-2, 1.89 × 10^-2 and 2.20 × 10^-2 S/cm in conductivity for the （Na3AlF6-40%K3AlF6）-AlF3 melts containing 0%, 20%, 24%, and 30% AlF3, respectively. An increase of every 10 ℃ in temperature results an increase about 1.89× 10^-2, 1.94 × 10^-2, 1.95 × 10^-2, 1.99× 10^-2 and 2.10× 10^-2 S/cm for （Na3AlF6-40%K3AlF6）-AlF3-Al2O3 melts containing 0%, 1%, 2%, 3% and 4% Al2O3, respectively. The activation energy of conductance was calculated based on Arrhenius equation. Every increasing 1% of AlF3 results in a decrease of 0.019 and 0.020 S/cm in conductivity for （Na3AlF6-40%K3AlF6）-AlF3 melts at 900 and 1 000 ℃, respectively. Every increase of 1% Al2O3 results in a decrease of 0.07 S/cm in conductivity for （Na3AlF6-40%K3AlF6）-AlF3-Al2O3 melts. The activation energy of conductance increases with the increase in content of AlF3 and Al2O3.

Vanadium oxide nanotubes for selective catalytic reduction of NO_x with NH_3

Vanadium oxide （VOx） nanostructures, synthesized by hydrothermal treatment using dodecylamine as template, were evaluated for the selective catalytic reduction of NOx with ammonia （NH3-SCR）, The effect of solvent type in the reaction mixture （EtOH/（EtOH ＋ H20）） and time of hydrolysis was studied. The obtained materials were characterized by XRD, SEM, TEM and BET, The VOx nanorods （80-120 nm diameter and 1-4 μm length） were synthesized in 25 vol% EtOH/（EtOH ＋ H20） and the open-ended multiwalled VOx nanotube （50-100 nm inner diameter, 110-180 nm outer diameter and 0,5-2 pm length） synthesized in 50 vol% EtOH/（EtOH ＋ H20）. VOx nanotuhes performed the superior NH3-SCR activity under a gas hourly space velocity of 12,000 h-1 at low temperature of 250 ~C （NOx conversion of 893g ＆ N2 selectivity of 100%）, while most of the developed Vanadia base catalysts are active at high temperature （〉350 ℃）. The superior NH3-SCR activity ofVOx nanotubes at low tem- perature is related to nanocrystalline structure, special nanotube morphology as well as high specific surface area.

Intergranular Corrosion of UNS S31803 Heat Treated at 800 ℃ Varying Range Times

The aim of this work is evaluate the intergranular corrosion on UNS S31803 steel, with heat treatments at 800 ℃, varying treatment times of 30 mins, 360 mins and 1,440 mins. The results confirm the formation of o phases and secondary austenite （γ2）. For the analysis of the influence of o and γ2 phases, metallographic analysis were conducted through optical microscopy, potentiokinetic reactivation electrochemical techniques and potentiodynamic polarization in NaCI 3.5% solution. Microstructural analysis has shown a formation of γ2 and o phase in heat treatment, due to diffusion of chromium and molybdenum from δ phase to y phase, precipitating on δ/γ and δ/δ interfaces. The DL-EPR （Double loop electrochemical potentiokinetic reactivation） results have shown an increase of the DOS （degree of sensitization） for long periods of time on heat treatment. The results of potentiodynamic polarization showed a reduction of the corrosion and pitting potentials, followed by an increase of the current density when the UNS S31830 steel is heat treated during long periods of time.

Gasification of Municipal Solid Waste for Power Generation in Brazil, a Review of Available Technologies and Their Environmental Benefits

This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristics and removal mechanisms currently employed, in the same way, available technologies for the thermochemical treatment of MSW with an emphasis on gasification and clean technology are evaluated, highlighting the current technical and reported in the literature in order to identify indicators of efficiency and flexibility of the technology. From the review it is concluded that gasification is a technically feasible option for the thermochemical conversion of municipal solid waste and subsequent power generation, besides being a technology that meets the applicable emission limits. Some of the main advantages of gasification of municipal solid waste are： （a） the sharp reduction in the waste mass （about 70-80%） and volume （approximately 80-90%）; （b） the drastic reduction in land use, 1：3000; （c） destruction of organic pollutants and other halogenated hydrocarbons; （d） concentration and immobilisation of inorganic contaminants so that they can be used effectively and safely removed; （e） use recyclables, such as ferrous metals, ferrous ash and slag materials; （f） reducing emissions of greenhouse gases by anaerobic decomposition of organic waste and （g） power generation.