尾矿土中解磷细菌的筛选及对镉的耐受研究

为了筛选出具有较好的有解磷效果的细菌,以尾矿土为材料进行筛选,分离纯化具有高效解磷作用和高耐受重金属的细菌菌株,并对其进行分子鉴定。分离得到136株细菌,筛选出4株解磷效果较好的菌株。对这4株细菌进行分子鉴定,通过16S rRNA测序分析,4株细菌属于芽孢杆菌属(Bacillus)。从4株细菌中进一步优化,筛选出解磷效果最好的菌株WDN-5,分析WDN-5菌株对重金属镉的耐受性。研究结果表明:WDN-5在发酵第五天的解磷效果最好,溶磷量达到77.14μg/mL;WND-5对镉的致死浓度为300mg/L,对镉的耐受性较高;在50—300 mg/L的镉胁迫下,随着镉浓度增加,WDN-5的溶磷量逐渐降低。

高钒铁合金渣作为耐火材料的可行性研究与应用

对用攀钢生产的高钒铁合金渣作为耐火材料的可行性进行了研究，并在攀钢耐材公司生产的炉外精炼用耐火材料中得到了应用．结果表明：该合金渣的主要化学成分为Ａｌ２Ｏ３（含量为９０％左右），主要矿物相为刚王，耐火度＞１７９０℃，体积密度＞３．６ｇ／ｃｍ３，可代替特级钒土骨料用于不定形耐火材料的生产。

混杂复合材料胶结机理的探讨

叙述了混杂复合材料聚合物水泥混凝土的制备方法 ,重点研究了混杂复合材料中的无机胶凝和有机聚合凝结机理 .水泥和砂石胶结成无机的刚性骨架 ,有机聚合物不仅填充了混凝土中的孔隙 ,而且在无机物团块周围包裹了一层有机网膜 ,使混凝土的强度、抗冻性。

Soil vanadium pollution and microbial response characteristics from stone coal smelting district

A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed that the contents of soil V ranged from 168 to 1538 mg/kg, which exceeded the maximum permissible value of Canadian soil quality for V. The mean soil V content from wasteland area reached 1421 mg/kg, and those from the areas related with slag heap, ore pile and smelting center were 380, 260 and 225 mg/kg, respectively. Based on the results of the modified BCR sequential extraction procedure, V contents in the mobile fractions varied from 19.2 to 637 mg/kg accounting for 7.4%-42.3% of total V, and those of V(+5) species were between 21.9 and 534.0 mg/kg. Soil enzyme activity and microbial basal respiration were adversely affected by high level of soil V. More attention should be paid to soil V pollution and potential hazardous surrounding the stone coal smelting district.

小型四冲程发动机适用的催化剂配方的开发

介绍适用于小型多用途四冲程化油器发动机的耐用型含钯催化剂的开发。根据催化剂涂层的总体结构(即采用的储氧材料)评估催化剂的催化活性。利用合成气体试验台上的点火试验,对所有被研究的新鲜催化剂配方和热老化催化剂配方的基本参数进行评定。此外,还在发动机试验台上进行催化剂样品试验,以证实其在实际使用条件下的催化活性。最后,按美国环境保护署G1排放法规,对1组颇具前景的催化剂配方进行125.0h的耐久性试验运行[1]。

Impact of Vanadium on Enzyme Activity and Microbial Biomass in Soils

[Objective] This study aimed to investigate the impact of vanadium at dif- ferent concentration on enzyme activity and microbial biomass in soils. [Method] Us- ing pot experiments in the growth cabinet, we would like to investigate the changes of the soil enzyme activity and microbial biomass at different growing stages of rape （Brassica juncea L.） at different soil vanadium concentrations （soil background value was 147 mg/kg, spiked with 0, 50, 100, 150, 250 and 500 mg/kg of exogenous vanadium）. [Result] Among all enzymes examined, polyphenol oxidase was most sensitive to soil vanadium. Addition of 50 mg/kg vanadium decreased its activity up to 56% of the control probably due to the vanadium toxicity. In comparison, the ac- tivities of sucrase, urease and catalase was less affected by soil vanadium. Surpris- ingly, the activity of sucrase, urease and catalase at the rape seedling stage differed significantly from at the maturity stage, highlighting the potential impact of plant growth on the vanadium-soil enzyme interaction. Different soil vanadium concentra- tions led to increases of microbial biomass to different extents. However, the corre- lation between soil microbial biomass carbon and phosphorus with vanadium con- centrations was insignificant. This revealed that the presence of additional factors （eg. plant） affected soil microbial biomass carbon and phosphorus aside from soil vanadium. [Conclusion] Polyphenol oxidase may be considered as an indicator of soil vanadium contamination. Due to the highly complicated interaction between vanadium and soil biological activities during plant growth, more investigations are required to reveal the mechanisms beyond our findings here.

esearch and Application of Burned Microporous High Alumian—Graphite（Al／C） Brick in Blast Furnace

This paper inroduces the research background,technology,product property and application of burned microporous high alumina-graphite brick (Al2O3-C brick) used in blast furnace,The difference of property between Al2O3-C brick and other blast furnace refractories is discussed .The results of simulative tests show that ,Al2O3-C brick has good alkali resistance,slag resistance,thermal shock resistance,oxidation resistance,high thermal conductivity,low permeability and low solubility in molten iron,The brick with micropores of average radius less than 1μm has been successively applied to fourteen blast furnaces, the lining life of the brick is almost as long as that of Si3N4 bonded SiC brick Al2O3-C brick will be widely used in lower stack ,belly,bosh and hearth in the future.

Kinetics study and analysis of zeolite Y destruction

A series of zeolites,including USY zeolites without sodium,Na-USY at different Na contents,La-USY with different rare earth（RE） contents and La-Na-USY with RE and Na were prepared by an ion exchange method.They were investigated to understand the activation barriers for the destruction of Y zeolite structure under hydrothermal treatment and the effect of V using the solid-state kinetic model.The results showed that the pathways for Y zeolite destruction were dealumination,desiliconization and the disappearance of La-O bonds.Zeolites were destroyed by steam through acid hydrolysis,which was accelerated by V.In addition,Na and V exerted a synergistic effect on the framework destruction,and the formation of NaOH was the rate-determining step.The presence of RE elements decreased hydrolysis and stabilized the structure of the zeolites.The interaction between V and RE destroyed zeolite structure by eliminating the stabilizing La-O[RE-OH-RE]^（5＋）bridges in the sodalite cages.

Resistance to SO_2 poisoning of V_2O_5/TiO_2-PILC catalyst for the selective catalytic reduction of NO by NH_3

A titania pillared interlayered clay（Ti-PILC） supported vanadia catalyst（V2O5/TiO2-PILC） was prepared by wet impregnation for the selective catalytic reduction（SCR） of NO with ammonia. Compared to the traditional V2O5/TiO2 and V2O5-MoO3/TiO2 catalysts, the V2O5/TiO2-PILC catalyst exhibited a higher activity and better SO2 and H2O resistance in the NH3-SCR reaction. Characterization using TPD, in situ DRIFT and XPS showed that surface sulfate and/or sulfite species and ionic SO4^（2-）species were formed on the catalyst in the presence of SO2. The ionic SO4^（2-） species on the catalyst surface was one reason for deactivation of the catalyst in SCR. The formation of the ionic SO4^（2-） species was correlated with the amount of surface adsorbed oxygen species. Less adsorbed oxygen species gave less ionic SO4^（2-） species on the catalyst.

Thermodynamic analysis on the direct preparation of metallic vanadium from NaVO_3 by molten salt electrolysis

A novel and environmentally friendly route to directly prepare metallic vanadium from NaV03 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaV03 to metallic vanadi- um is analyzed based on the thermodynamic calculations and experimental verifications. The theoretical decomposition voltage of NaV03 to metallic vanadium is only 0.47 V at 800 ℃ and much lower than that of the alkali and alkali earth metal chloride salts. The value is slightly higher than that of low-valence vanadium oxides such as V203, V305 and VO. However, the low-valence vanadium oxides can he further electro-reduced to metallic vanadium thermodynamically. The thermodynamic analysis is verified by the experimental results. The direct preparation of metallic vanadium from NaV03 by molten salt electrolysis is feasible.

Effect of iron transformation on Acidithiobacillus ferrooxidans bio-leaching of clay vanadium residue

The acid bio-leaching process of vanadium extraction from clay vanadium water-leached residue was studied and the effect of the performance of iron transformation was investigated.Acidithiobacillus ferrooxidans affects the dissolution of vanadium through the catalytic effect on Fe^3+/Fe^2+couple and material exchange.The passivation of iron settling correlates with ferrous ion content in bio-leaching solution.In medium containing A.ferrooxidans and Fe(Ⅲ),the increment in Fe(Ⅱ)concentration leads to the formation of jarosite,generating a decline in vanadium extraction efficiency.Analysis of cyclic voltammetry shows that Fe(Ⅱ)ion is apt to be oxidized and translated into precipitate by A.ferrooxidans,which strongly adsorbed to the surface of the residue.Fe(Ⅲ)ion promotes the vanadium extraction due to its oxidizing activity.Admixing A.ferrooxidans to Fe(Ⅲ)medium elevates the reduction of low valence state vanadium and facilitates the exchange of substance between minerals and solution.This motivates 3.8%and 21.8%increments in recovery ratio and leaching rate of vanadium compared to the Fe(Ⅲ)exclusive use,respectively.Moreover,Fe(Ⅱ)ion impacts vanadium extraction slightly in sterile medium but negatively influences vanadium leaching in the presence of bacteria.

Defects in Tm^(3+)/Yb^(3+)-doped YVO_4 Crystals

The microscopic defects have been investigated for crystal Tm3+/Yb3+:YVO4. These defects mainly include the inclusions (solid inclusions, bubbles and inclusions of the liquid phase), dendrites and growth stripes. They are caused by in-pure raw materials, unstable growth conditions, super-cooling component and so on. Tm3+/Yb3+:YVO4 crystals of large size and excellent optical quality are grown by improving the growth conditions to eliminate these defects.

Synthesis of gold/rare-earth-vanadate core/shell nanorods for integrating plasmon resonance and fluorescence

The nanoscale core/shell heterostructure is a particularly efficient motif to combine the promising properties of plasmonic materials and rare-earth compounds; however, there remain significant challenges in the synthetic control due to the large interfacial energy between these two intrinsically unmatched materials. Herein, we report a synthetic route to grow rare-earth-vanadate shells on gold nanorod （AuNR） cores. After modifying the AuNR surface with oleate through a surfactant exchange, well-packaged rare-earth oxide （e.g., Gd2O3：Eu） shells are grown on AuNRs as a result of the multiple roles of oleate. Furthermore, the composition of the shell has been altered from oxide to vanadate （GdVO4：Eu） using an anion exchange method. Owing to the carefully designed strategy, the AuNR cores maintain the morphology during the synthesis process; thus, the final Au/GdVO4： Eu core/shell NRs exhibit strong absorption bands and high photothermal efficiency. In addition, the Au/GdVO4：Eu NRs exhibit bright Eu^3＋ fluorescence with quantum yield as high as -17%; bright Sm^3＋ and Dy^3＋ fluorescence can also be obtained by changing the lanthanide doping in the oxide formation. Owing to the attractive integration of the plasmonic and fluorescence properties, such core/shell heterostructures will find particular applications in a wide array of areas, from biomedicine to energy.