含软弱夹层的某公路边坡开挖支护数值模拟分析

基于某含有软弱夹层的公路边坡工程,利用有限元软件对其开挖支护过程进行数值模拟分析,计算考虑了2种不同的开挖工况：1）只开挖不支护;2）开挖并及时支护。研究表明：在开挖未支护时,边坡开挖完成后安全系数小于1,边坡整体都发生很大位移,将沿着软弱夹层带发生破坏;在开挖并及时支护时,边坡位移明显减小,软弱夹层附近塑形变形区得到了有效控制,且开挖完成后安全系数为1．87,满足设计要求。     

Fabrication of phytic acid embellished kaolinite and its effect on the flame retardancy and thermal stability of ethylene vinyl acetate composites

A modified kaolinite by grafting with phytic acid (PA-g-Kaol) is fabricated, and it was introduced into ethylene vinyl acetate (EVA) with intumescent flame retardancy (IFR) together to improve the flame retardancy of EVA composites. The results show the limiting oxygen index value of EVA/ (18.0 wt% IFR)/ (2.0 wt% PA-g-Kaol) is 30.8%. Meanwhile, there is only one dripping produced in the vertical burning test. What's more, the flame-retardant mechanism is demonstrated by TG-IR, real-time-IR and GC–MS analysis. The results indicate that some pyrolytic products of IFR and PA-g-Kaol, like ammonia and phosphoric acid, catalyze the crosslinking of EVA and flame retardant, the resultant compact char protects the substrate from further burning.     

高岭石脱水反应的非等温热重法研究

在系统分析非等温固相反应特点的基础上,建立了非等温脱水反应速率方程.采用非等温热重法、通过计算机辅助计算,对高岭石脱水反应动力学规律进行了研究.结果表明:由于高岭石晶体结构中内、外羟基脱除的顺序不同,其脱水反应机制在反应分数(α)为0.7左右时发生改变.在反应前期(0＜α＜0.7)时,脱水反应遵循二维扩散控制规律,脱水反应表观活化能为159.682 kJ/mol、表观频率因子为1.007×10 10/min.     

微波对制备高岭石插层作用的研究

为了明确微波对制备高岭石插层的作用,采用乙酰胺对高岭石的微波熔融插层和油浴熔融插层进行了对比实验.借助于XRD、FTIR等分析测试手段,通过对比不同时间段2种插层环境下的插层率,分析了微波对插层反应的影响,进而探讨了微波对插层反应的作用机理.研究发现在反应初期微波对插层反应起促进作用,但随着时间的延长这种促进作用减弱,并呈现出一定的阻碍作用,认为是微波对乙酰胺的热作用和极化作用综合作用的结果.     

Study on Adsorption of Rare Earth Elements by Kaolinite

Rareearthelements (REEs)werewidelyappliedtotracingthesourcesofmaterialsandtostudyingtheirevolutionprocessesinmanyfieldsofearthscienceinconsiderationoftheirsimilarityandsystematicdiffer enceinchemicalproperties .Furthermore ,lanthanidesarebothimportantprod…     

Reaction Activity of Kaolinite Surfaces：Quantum Chemistry Calculations

The anion-kaolinite surface infractions and AuS - adsorption onto the surfaces of kaolinite were studied using the self-consistent-field discrete variation ( SCF - Xα - DV) method. Electronic structure and energies of the system of anion AuS- adsorbed on an atomic cluster of kaolinite were calculated. The results show that the systems with lower total energy are those AuS- adsorbed on the edge surfaces, which indicates that the systems of adsorption of AuS- on the edges are more stable relative to those adsorbed on the basal plane. On the other hand, bond order data suggest that significant shifting of atomic charge and the overlapping of electronic cloud between Au ( Ⅰ ) of the AuS- and the surface ions of kaolinite would take place in the systems with AuS - being adsorbed on the edges, especially at the she near A1 octahedra. Therqrore, it can be concluded that edge sites will dominate the complexation reactions of the surfaces of kaolinite, with negligible contributions from other fimctional groups on the basal plane, which are dominated by either siloxane sites in silica layers or aluminol sites in gibbsite layers.     

A novel nonmetal intercalated high crystalline g-C3N4 photocatalyst for efficiency enhanced H2 evolution

Introducing nickel foam as assistant, a novel nonmetal intercalated high crystalline graphitic carbon nitride (g-C₃N₄) catalyst was successfully fabricated by β-cyclodextrin (β-CD) pretreated melamine with one step thermal polymerization process. The final results show that 0.3-NCCN presented a remarkably visible-light (λ > 400 nm) photocatalytic H₂ evolution reaching 9297  μmol g^?1 h^?1, and the reaction process follows the zero-order kinetic model. The increase in crystallization of 0.3-NCCN implies a higher-ordered arrangement of tris-s-triazine. The nonmetal interlayer formed by oxygen-contained graphitized carbon can extend the π-conjugated system. Both above significantly benefit the rapid migration and separation of charge-carrier. Moreover, the narrowed band gap provides a stronger thermodynamic driving force for improving the photocatalytic water splitting efficiency. Our work paved a new method to construct high performance photocatalyst for water splitting.     

煤系高岭土生产流程中除铁装置的设计探讨

为了提高煤系高岭土产品质量和扩大煤系高岭岩资源的利用,在高岭土生产工艺流程中设计配置了一种和现有磁分离设备结构原理不同的叶轮式除铁装置．该装置采用稀土永磁磁源,借助生产流程中粉状物料下落的能量,驱动分离机构转动,因而设备不新增能耗,对试验高岭岩粉料中的铁质除净率可达75％,并具有使用可靠的特点．