Insight into the Alkali Resistance Mechanism of CoMnHPMo Catalyst for NH_(3) Selective Catalytic Reduction of NO

The existence of alkali metals in fl ue gases originating from stationary sources can result in catalyst deactivation in the low-temperature selective catalytic reduction(SCR)of nitrogen oxides(NO_(x)).It is widely accepted that alkali metal poisoning causes damage to the acidic sites of catalysts.Therefore,in this study,a series of CoMn catalysts doped with heteropolyacids(HPAs)were prepared using the coprecipitation method.Among these,CoMnHPMo exhibited superior catalytic performance for SCR and over 95%NO_(x) conversion at 150-300.Moreover,it exhibited excellent catalytic activity and stability after alkali poisoning,demonstrating outstanding alkali metal resistance.The characterization indicated that HPMo increased the specifi c surface area of the catalyst,which provided abundant adsorption sites for NO_(x) and NH_(3).Comparing catalysts before and after poisoning,CoMnHPMo enhanced its alkali metal resistance by sacrifi cing Brønsted acid sites to protect its Lewis acid sites.In situ DRIFTS was used to study the reaction pathways of the catalysts.The results showed that CoMnHPMo maintained high NH_(3) adsorption capacity after K poisoning and then reacted rapidly with NO intermediates to ensure that the active sites were not covered.Consequently,SCR performance was ensured even after alkali metal poisoning.In sum-mary,this research proposed a simple method for the design of an alkali-resistant NH_(3)-SCR catalyst with high activity at low temperatures.

Pitting corrosion resistance of a novel duplex alloy steel in alkali-activated slag extract in the presence of chloride ions

In this study, two types of reinforcing steels(conventional low-carbon steel and a novel duplex alloy steel with Cr and Mo) were exposed to chloride-contaminated extract solutions(ordinary Portland cement(OPC) extract and alkali-activated slag(AAS) extract) to investigate their pitting corrosion resistance. The results confirm that the pitting corrosion resistance of the alloy steel is much higher than that of the low-carbon steel in both extract solutions with various Na Cl concentrations. Moreover, for each type of steel, the AAS extract contributes to a higher pitting corrosion resistance compared with the OPC extract in the presence of chloride ions, likely because of the formation of flocculent precipitates on the steel surface.

Influence of TiO_2 on the Alkali Resistance and Structure of Invert Glass

Through measuring the alkali resistance of the invert glass and the quantity of SiO 2 and TiO 2 migrating fron the glass into the solution,the influence of TiO 2 on the alkali resistance of the glass is discussed and its structure is also analyzed by infrared spectroscopy.It is concluded that TiO 2 has double functions for the alkali resistance of the invert glass.On the one hand ,both TiO 2 polarizing the secondary ions in glass and TiO 2 isomorphism replacement of SiO 2 make the alkali resistance of the glass decrease.On the ther hand,TiO 2 patching network and anti erosion covering help to increase the alkali resistance.

Research on Alkali Resistance of Alumina-rich MgAl2O4 Spinel for Alkali Recovery Furnace

Chrame containing refractories are a kind of traditional material for the lining of alkali recovery furnaces, but the formation of hexavalent chrome compounds will give rise to detrimental effect on environment and human＇s health. With the gradual awakening of people＇s comciousness about environment protection, it is urgent to prepare environmental-friendly materials for alkali recovery jurnaces with high quality and long life. In this paper, alumina-rich MgAl2O4 spinel （ AR90 ） was used to replace chromite. The physical properties of dried （110 ℃ for 24 h） or fired （1 300 ℃ for 3 h） AR90 and chromite were studied, respectively. The alkali vapor method was used to determine the alkali resistance of the two materials. The results show that： （1） after drying at 110 ℃ for 24 h, AR90 specimens show higher apparent porosity and slightly lower bulk density than chromite specimens; after firing at 1 300 ℃ for 3 h, AR90 has significantly higher apparent porosity as well as higher bulk density; （2） after the alkali attack, the AR90 specimens sintered at 1 300 ℃ exhibit smaller strength change and much higher compressive strength than the chromite specimens; meanwhile, the permeability degree of alkali salt in chromite specimens is more serious than that in AR90 specimens, which indicates that AR90 possesses better alkali resistance.

Alkali Resistant Bricks for Cement Kiln

This standard specifies the classification, techni- cal requirements, test methods, inspection rules, marking, packing, transportation and storage of alkali resistant bricks.

An Alkali Activated Binder for High Chemical Resistant Self-Leveling Mortar

This paper reports the development of an Alkali Activated Binder (AAB) with an emphasis on the performance and the durability of the AAB-matrix. For the development of the matrix, the reactive components granulated slag and coal fly ash were used, which were alkali activated with a mixture of sodium hydroxide (2 - 10 mol/l) and aqueous sodium silicate solution (SiO2/Na2O molar ratio: 2.1) at ambient temperature. A sodium hydroxide concentration of 5.5 mol/l revealed the best compromise between setting time and mechanical strengths of the AAB. With this sodium hydroxide concentration, the compressive and the 3-point bending tensile strength of the hardened AAB were 53.4 and 5.5 MPa respectively after 14 days. As a result of the investigation of the acid resistance, the AAB-matrix showed a very high acid resistance in comparison to ordinary Portland cement concrete. In addition, the AAB had a high frost resistance, which had been validated by the capillary suction, internal damage and freeze thaw test with a relative dynamic E-Modulus of 93% and a total amount of scaled material of 30 g/m2 after 28 freeze-thaw cycles (exposure class: XF3).

Damage Action of Alkali-resistant Glass Fiber in Cement-based Material

The compressive strength and flexural strength with the same strength class cement mortar of the alkali-resistant glass fiber cement mortar were tested in standard and hot-water curing condition, and the damage mechanism of alkali-resistant glass fiber was studied. The interaction mechanisms of the chemical erosion and physical injury in different curing conditions were studied in order to summarize the damage mechanism of alkali-resistant glass fiber in cement-based materials, and chloride diffusivity coefficient and porosity of cement mortar were tested in the different curing conditions. The experimental results are that the strength of cement based materials and fiber cement slurry interface zone were closely related, and heat curing could accelerate the hydration of cement, but inevitably enlarge the defect.

Isolation and Identification of Alkali-Resistant 1,3-Propanediol Producing Strain

1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described here the isolation of strain ZH-1, which has the ability of high production with 1,3-propanediol, from Fenhe River in China. It was classified as a member of K. pneumoniae after the study of phenotypic, physio-logical, biochemical and phylogenetic (16S rDNA). The initial glycerol concentration, fermentation time and pH value of strain ZH-1 were determined to be 50 g·L-1, 36 h and 8.0. Under these conditions, the practical yield of 1,3-PD was 18.53 g·L-1 and a molar yield (mol1,3-PD molGlycerol-1 of 1,3-propanediol to glycerol of 0.497. In addition, we found that for the strain ZH-1, the optimum grown pH was 9.0, so we can deter-mine that it is a new member of alkali-resistant strains.

盐碱胁迫对植物的影响及抗性机制研究进展

盐碱胁迫是仅次于干旱胁迫抑制植物生长发育的主要非生物胁迫之一,不仅影响植物的生长发育,而且对农业生产和生态环境造成严重威胁。研究植物的耐盐碱机制,对耐盐碱作物选育及盐碱地的开发利用具有重要的现实意义。结合近年来国内外的相关研究总结性阐述了盐碱胁迫对植物代谢的伤害(包括离子伤害、膜系统伤害、诱导渗透伤害等)机制,并从膜系统保护以及诱导基因表达方面综述了植物对盐碱胁迫的缓解机制,进而提出外源物质的导入、生物技术手段、耐盐碱品种培育是解决植物抗盐碱的主要手段。最后就植物适应盐碱胁迫方面的研究进行了展望,指出了当前研究者需要解决的问题和突破口,旨在为提高植物耐盐碱能力、增加作物产量提供一定的理论依据。

莫来石-刚玉-镁铝尖晶石复相材料的抗碱侵蚀性能研究

为了提高莫来石-刚玉质匣钵的抗碱侵蚀性能,以煤矸石、工业氧化铝和工业氧化镁为原料,采用二步煅烧法制备了莫来石-刚玉-镁铝尖晶石复相材料,研究了工业氧化镁加入量(加入质量分数分别为1%、2%、3%、4%和5%)对试样物相组成、显微结构及物理性能的影响,并探究了试样抗钠离子电池正极材料的侵蚀机制。结果表明:1)氧化镁可促进莫来石晶体生长和试样烧结致密化,且由于莫来石晶体直接结合及微晶镁铝尖晶石颗粒增韧,所有试样均具有高的常温耐压强度,≥248 MPa;2)以不同形态分布于试样中的镁铝尖晶石可形成物理屏障,阻止Na^(+)渗透,阻隔其与莫来石和刚玉反应,提高试样的抗碱侵蚀性能;3)综合试样的物理性能和抗碱侵蚀性能,工业氧化镁的最佳加入量为4%(w)。

间位芳纶的结构与耐酸碱性能研究

通过X射线衍射仪和红外光谱仪分别对间位芳纶的晶体聚集态结构和大分子结构进行表征,利用场发射扫描电镜观察其表面形貌,使用热重/差示扫描量热同步热分析仪测试其热学性能,并对酸碱处理后的纤维力学性能进行表征。结果表明:间位芳纶的结晶度为46.24%,晶区轴取向指数为0.8494;间位芳纶表面粗糙,内部大分子链中存在苯环结构;间位芳纶具有良好的耐热性能,在292℃的高温内无任何损伤;间位芳纶具有一定的耐强酸强碱腐蚀能力,在85℃下分别经体积分数小于等于20%的硫酸溶液及质量分数小于等于20%的氢氧化钠溶液处理,处理后其断裂强度均保持在原来的90%以上。

36份藜麦种质资源苗期耐盐碱性评价与筛选

为探究不同藜麦种质苗期耐盐碱性差异,本研究对36份藜麦种质苗期用150 mmol/L盐碱浓度(NaCl∶NaHCO_(3)=4∶1)进行胁迫处理,对株高、叶面积和叶片相对含水量等11个指标进行了测定,采用主成分分析等多种统计方法,筛选出适宜山西地区生长的藜麦种质。结果表明,盐碱胁迫下,藜麦种质各类指标相互之间均存在一定程度的关联;本试验中共提取5个主成分因子,方差累积贡献率为74.947%,可以代替11个指标的绝大部分信息,显示盐碱胁迫下藜麦苗期的抗盐碱特性,并且计算出耐盐碱性综合评价D值,并基于D值进行聚类分析,将36份种质资源分为四个大类,包括高耐盐碱种质5份、耐盐碱种质14份、弱耐盐种质11份、盐碱敏感种质共6份。

含生活垃圾焚烧炉渣的碱矿渣水泥耐高温机理

为探究生活垃圾焚烧炉渣(MSWI-BA)对碱矿渣净浆耐高温性能的影响机理,将6%的矿渣等质量替换为MSWI-BA,制备碱矿渣水泥净浆(AASBp),研究不同温度对AASBp的质量损失率、干燥收缩率和强度的影响.以普通硅酸盐水泥净浆作为对照组,结合多种微观手段,揭示AASBp的耐高温机理,并与未掺MSWI-BA的碱矿渣水泥(AASp)进行对比.结果表明:随着温度的升高,AASBp中水化硅铝酸钙的钙硅比(C/S)先降低后升高;在400℃时,水化硅铝酸钙的聚合度最高,C/S最低;Al—O键在600℃断裂,而Si—O键在1000℃断裂;MSWI-BA可提高基体孔隙的连通性,高温处理后孔隙压力得到释放,因此AASBp比AASp具有更高的归一化抗压强度和耐高温性能.

废液晶玻璃再生制备低膨胀硼硅玻璃及其理化性能研究

基于废液晶玻璃的高值化再生利用,以废液晶玻璃作为主要原料,石英砂、硼酸、纯碱为辅助原料,制备了低膨胀硼硅玻璃。通过浮力法、压痕法、石英膨胀法和重量试验法,探究了废液晶玻璃和辅助原料(Na_(2)O和B_(2)O_(3))掺量对玻璃理化性能的影响。结果表明:随着废液晶玻璃掺量增加,玻璃密度、线热膨胀系数和耐酸质量损失增大,维氏硬度和耐碱质量损失减小;随着辅助原料中Na_(2)O含量增大,玻璃密度、线热膨胀系数、耐酸质量损失和耐碱质量损失增大,维氏硬度减小;随着辅助原料中B_(2)O_(3)含量增大,玻璃密度和维氏硬度减小,线热膨胀系数和耐酸耐碱质量损失增大;当废液晶玻璃、辅助原料中Na_(2)O和B_(2)O_(3)质量分数分别为60.00%、1.00%和14.72%时,玻璃维氏硬度最大、密度和线热膨胀系数最小,分别为7.1430 GPa、2.3097 g·cm^(-3)和3.5317×10^(-6)℃^(-1);当废液晶玻璃、辅助原料中Na2O和B2O3质量分数为60.00%、3.00%、9.72%时,玻璃耐酸质量损失最小,为0.6140 mg·cm^(-2);当废液晶玻璃、辅助原料中Na2O和B2O3质量分数为70.00%、2.00%、11.67%时,玻璃耐碱质量损失最小,为1.2140 mg·cm^(-2)。

耐火材料的抗碱侵蚀性研究进展

碱侵蚀是高炉、回转窑、匣钵等高温装置重要部位损毁的主要原因,不同于熔渣导致的溶解侵蚀和物理冲刷导致的蚀损,碱侵蚀有着其特殊的作用机制。本文首先介绍了碱的物理性质并计算了其与耐火氧化物反应的吉布斯自由能和体积效应,以此为出发点综述了碱对典型高温装置关键部位的侵蚀过程及机制,并概述了碱性耐火材料、铝硅系耐火材料、非氧化物耐火材料、新型合成材料抗碱侵蚀的研究与应用新进展,同时对比了几种国内外抗碱侵蚀标准或方法,最后对耐火材料抗碱侵蚀性研究提出了几点建议。

三维大隔距机织间隔织物柔性复合材料的服役性能研究

为了探究陆基充气天线用三维大隔距机织间隔织物柔性复合材料的服役性能影响因素,分别对裁剪拼接造成的拼接强力、在酸碱工作环境中的材料强力、经折叠-展开-再折叠的耐折叠性能三大方面进行了研究。结果表明:拼接宽度为30 mm,选用胶黏剂聚氨酯A584,拼接方向夹网布经向,得到的拼接强力效果最佳,能达到反射面本体材料的断裂强力;在耐酸碱试验中,聚氨酯A584和TPU热熔胶膜均未脱胶,且表现出较好的耐腐蚀性能,表明构成反射面的各部分材料能适应天线的各种工作环境;充气反射面材料表现出较好的折叠性,其折叠性能与折叠次数、拼接宽度具有一定相关性,而与拼接用胶关系不大,拼接材料的宽度增加,折叠次数对其作用越小,折痕回复性能较好。

Penetrative and migratory behavior of alkali metal in different binder based TiB_2-C composite cathodes

In electrolyte melts containing K at low temperature, the penetrative and migratory path of alkali metals （K and Na） in pitch, furan, phenolic aldehyde and epoxy based TiB2-C composite cathodes during the electrolysis process were studied by EDS and self-made modified Rapoport apparatus. The electrolysis expansion rates, the diffusion coefficients of the alkali metals and the corrosion rates of the composite cathode were also calculated and discussed. The results show that no matter what kind of binder is used, alkali metals have the same penetrative path in composite cathodes：firstly in pore, then in binder and finally in carbonaceous aggregates. K and Na penetrate into both binder and carbonaceous aggregates, which leads to the expansion of composite cathodes, and K has stronger penetration ability than Na. Electrolysis expansion rate of resin based composite cathode is smaller than that of pitch based composite cathodes, and so do the diffusion coefficient and corrosion rate. Resin based composite cathode has better resistance ability to the penetration of alkali metals than pith based composite cathode, and phenolic aldehyde based composite cathode exhibits the strongest resistance ability. The penetration rate, the diffusion coefficient of alkali metals in phenolic aldehyde based TiB2-C composite cathode and the corresponding corrosion rate are 4.72 mm/h, 2.24×10^-5 cm^2/s and 2.31 mm/a, respectively.

不同品种马铃薯幼苗对NaHCO_(3)胁迫的响应及耐碱能力指标筛选

[目的]探究不同马铃薯品种对NaHCO_(3)胁迫的响应机制,为选育耐碱性较强的马铃薯品种提供理论依据。[方法]以V_(7)、后旗红、克新1号、兴佳2号、荷兰15号、康尼贝克6个品种马铃薯为研究对象,以1/2霍格兰(Hoagland)营养液为母液进行了水培试验。营养液设置6个NaHCO_(3)浓度,分别为0、10、20、30、40、50 mmol/L,选择出苗后7天的马铃薯幼苗,缓苗3天后进行碱胁迫处理。胁迫处理7天后,调查马铃薯幼苗株高、茎粗、主根长,分析叶片含氮量和叶绿素相对含量,分析根系脯氨酸含量、过氧化物酶(POD)活性、过氧化物歧化酶(SOD)活性以及过氧化氢酶(CAT)活性等11项生理指标。[结果]随着碱胁迫浓度的增加,各品种马铃薯幼苗生长受到不同程度的影响,在碱浓度30、40、50 mmol/L胁迫处理下,V_(7)根长较0 mmol/L处理分别增加了54.37%、46.04%、25.58%,其余5个品种根长均显著低于0 mmol/L。50 mmol/L胁迫处理下,各品种株高、茎粗均显著低于碱浓度0 mmol/L处理。各品种叶片含氮量、叶绿素相对含量随胁迫浓度增加呈现不同的变化趋势,V_(7)、后旗红、克新1号叶片含氮量均在40 mmol/L处理下达到峰值,兴佳2号叶绿素相对含量在50mmol/L处理下达到峰值,而荷兰15号、康尼贝克叶片含氮量、叶绿素相对含量均在50mmol/L处理达到最小值。各品种幼苗根系活力呈先增后降的趋势,碱浓度40 mmol/L胁迫处理下,V_(7)、后旗红根系活力显著高于0mmol/L,而荷兰15号的降幅达80%以上。各品种幼苗根系中丙二醛含量随胁迫程度加剧而增加,但V_(7)的丙二醛含量始终低于其他品种。各品种幼苗根系CAT活性、SOD活性均呈先升后降变化趋势,其中V_(7)、后旗红、克新1号、兴佳2号的CAT活性、SOD活性高于康尼贝克和荷兰15号。利用主成分分析计算得到5个特征值>1的归一化指标,其对碱胁迫抗性的累积贡献率达80.07%,符合主成分分析要求,因此将11个指标转化为7项生理指标,包括:株高、茎粗、叶片含氮量、叶绿素相对含量、脯氨酸含量、POD活性、CAT活性。[结论]株高、茎粗、叶片含氮量、叶绿素相对含量、脯氨酸含量、POD活性、CAT活性这7项生理指标可作为马铃薯耐碱性能力强弱的评价指标。综合各项指标筛选出耐碱能力较强的品种为V_(7),后旗红、克新1号、兴佳2号耐碱能力中等,康尼贝克与荷兰15号耐碱性较弱。

张掖耐盐碱亚麻品种筛选与示范研究

为筛选生育期适宜、丰产性好、出麻率高、纤维产量高的亚麻品种,高效开发利用张掖盐碱地;以8个亚麻品种为试验材料,以张掖市龙纺麻业提供的山丹为对照,在山丹县位奇镇进行试验;对不同品种原茎产量、种子产量以及其他农艺性状进行田间鉴定;结果表明:8个参试品种的原茎、纤维产量均较当地对照品种山丹大幅度增产,其中华亚5号产量居首,中亚麻3号稍逊,二者原茎较当地对照品种山丹分别增产94.83%和80.85%,达极显著水平;纤维较当地对照品种增产164.74%和147.32%,达极显著水平;华亚5号、中亚麻3号等2个品种(系)在张掖试点综合经济性状、丰产性表现较好,适应性及抗逆性相对较强,可在张掖作为纤维用亚麻品种示范推广.