基于ANSYS和ADAMS的煤矿胶轮车前轮静壳静力及振动分析

基于ANSYS和ADAMS仿真平台,对所设计的静壳最大变形和最大应力的分布做了分析,判定静壳强度是否满足设计要求;分析了静壳固有频率和振型变化情况,为评价静壳动态特性提供理论依据;研究了刹车过程中静壳质心轨迹情况,为评价其刹车性能提供依据。

提高EPS轻骨料混凝土强度的研究

利用废旧聚苯乙烯(EPS)泡沫塑料颗粒作为轻骨料,以硅酸盐水泥为胶凝材料,制作轻骨料混凝土。采用不同外加剂增强材料,搅拌过程中采用"造壳"法,并对"造壳静停"法进行研究,EPS轻骨料混凝土最终的强度由水泥浆体强度决定。

Fabrication IL-1Ra loaded galactosylated chitosan nanoparticles for liver targeting

Galactosylated chitosan （GC） is synthesized and used to prepare IL-1Ra loaded GC nanoparticles by an electrospraying technique. Polyethylene oxide （PEO） is mixed with GC to enhance the electrospraying ability. The effect of the spraying solution properties on particle formation is investigated. The IL-1Ra loaded nanoparticles with an average diameter of 530 nm and a regularly spherical shape are observed by the scanning electron microscopy （SEM）. The amount of the IL-1Ra is measured by the enzyme-linked immunosorbent assay （ELISA） kit. The loading capacity of the nanoparticle is （1.52± 0.04）% （n = 3） and the encapsulation efficiency reaches （90. 36 ± 3.46） % （n = 3）. For the evaluation of GC nanoparticles＇ hepatocytes targeting efficacy, hepatocytes and mesenchymal stem cells （MSCs） are incubated with FITC-labeled GC nanoparticles for 24 h as the experimental and control groups. Results of the fluorescence microscope show that the fluorescence signals observed in hepatocytes are significantly higher than in the MSCs, indicating that the developed GC nanoparticles have an obvious liver targeting property.

Preparation of dual-shell Si/TiO_(2)/CFs composite and its lithium storage performance

A dual-shell Si/TiO2/CFs composite was synthesized through a simple method to deal with the intrinsic drawbacks of silicon-based anode,in terms of huge volume change,unstable SEI films,and low electronic and ionic conductivity.The inner rigid TiO2 shell alleviates the huge volume expansion of the nano silicon,and the outer resilient carbon fiber,which is porous and staggered,is beneficial to the rapid transport of electrons and ions.The as-prepared Si/TiO2/CFs composite displays a superior reversible specific capacity of 583.4 mA·h/g,high rate capability and decent cycling performance.The dual-shell encapsulation method provides a guideline for other anode materials with huge volume expansion during the cycling process.

Parametric Modeling of Static Three-Dimensional Problem of Buried Pipeline through the Coupling between a Finite Cylindrical Shell Element and Special Boundary Elements

This work deals with an application in parametric modeling of problems regarding pipelines buried in static system, written in C＋＋ using ObjectARX functions. The application is fully integrated with AutoCAD through saproms.dll and saproms.arx libraries where the stages of pre-processing, processing and post-processing are done in AutoCAD sotlware environment itself without having to export data to another processing environment. The analysis processing is done by functions whose algorithms are based on the solution of the coupling between the FEM （finite element method） and the BEM （boundary element method）. The representation of the homogeneous pipeline is made by the FEM using a finite element in the form of a cylindrical panel called CYS （cylindrical shell）, developed from the homogeneous isotropic model proposed initially by Djoudi Bahai, who uses the philosophy of the assumed deformation model （assumed strain based model）. The soil is taken to be a continuum infinite or semi-infinite elastic solid patterned by BEM where special boundary elements are proposed with curved surface or curved edges to represent the soil-structure interaction mainly in the areas of contact with the pipeline.

Static and Buckling Analysis of Concrete Spherical Shells

A finite element analysis, including static and buckling analysis is presented for several notable concrete spherical shells around the world. Also, the structural optimization study of these shells was performed for thickness distribution and structure shape to reduce overall tensile stress, deflection and reinforcements. The finite element analysis using Sofistik software shows that a distributed concrete thickness reduces shell stresses, deflections and reinforcements. A geometrically non-linear analysis of these structures with and without imperfections was also performed. To take into account the possible plastification of the material an analysis with non-linear material was performed simultaneously with the geometrically non-linear analysis. This helps in developing an understanding of the structural behaviour and helps to identify all potential failure causes using failure analysis.

Some Engineering Properties of Sunflower Seed and Its Kernel

Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels （3-14% d.b.） for three size categories （large, medium and small）. With increase of moisture content from 3 to 14% d.b., all the main dimensions （length, width and thickness）, geometric mean diameter, porosity, true density, terminal velocity and static coefficient of friction increased while bulk density and rupture force for both sunflower seed and its kernel decreased for all size categories. The results showed that the highest value of static coefficient of friction for both seed and kernel was on the rubber surface, followed by plywood, polyethylene, galvanized iron, and finally aluminium surfaces. The seeds required less compressive force to dehull when loaded under the horizontal as compared to the vertical orientation. But for kernels, the trend was the opposite. Also, the compressive forces needed to initiate rupture of sunflower seed hulls were higher （47.1-94.72 N） than those required to rupture the kernel （8.5-13.4 N） in both orientations.

Preparation and Characterization of Core-Shell MoSi_(2)@Nb Materials Sintered by SPS

Core-shell MoSi_(2)@Nb powder was prepared by electrostatic layer self-assembly method.The surfactants SDS(CHSO_(4)Na)and CTAB(C_(19)H_(42)BrN)were used to modify the surface of the two particles to make them charged,and the Zeta potential of the suspension was tested by the Zeta potentiometer.Scanning electron microscope,transmission electron microscope and energy dispersive spectrometer were used to characterize the phase,morphology,microstructure and element distribution of synthetic materials.The results show that when the SDS concentration is 2 mmol/L,the CTAB concentration is 3mmol/L and the pH value of Nb suspension is 5,the coating effect is better after secondary cladding.NbSi_(2)phase is found at the interface between Nb and MoSi_(2)after calcination at 200℃ for 2 h in Ar atmosphere,indicating that Nb is highly active and reacts with Si.Core-shell structure is still retained in MoSi_(2)@Nb material after spark plasma sintering at 1450℃ for 2 h under uniaxial pressure of 40 MPa.However,it is found that Nb reacts strongly with MoSi_(2),and most of the Nb phase is reacted.This issue needs to be addressed in subsequent studies.The fracture toughness(K_(IC))of MoSi_(2)@Nb material is significantly improved to 5.75 MPa·m^(0.5)compared with that of MoSi_(2)material(3.32 MPa·m^(0.5)).

Ultrahigh Resolution Fiber-Optic Quasi-Static Strain Sensors for Geophysical Research

A review of our recent work on ultrahigh resolution optical fiber sensors in the quasi-static region is presented, and their applications in crustal deformation measurement are introduced. Geophysical research such as studies on earthquake and volcano requires monitoring the earth＇s crustal deformation continuously with a strain resolution on the order of nano-strains （ne） in static to low frequency region. Optical fiber sensors are very attractive due to their unique advantages such as low cost, small size, and easy deployment. However, the resolution of conventional optical fiber strain sensors is far from satisfactory in the quasi-static domain. In this paper, several types of recently developed fiber-optic sensors with ultrahigh resolution in the quasi-static domain are introduced, including a fiber Bragg grating （FBG） sensor interrogated with a narrow linewidth tunable laser, an FBG based fiber Fabry-Perot interferometer （FFPI） sensor by using a phase modulation technique, and an FFPI sensor with a sideband interrogation technique. Quantificational analyses and field experimental results demonstrated that the FBG sensor can provide nano-order strain resolution. The sub-nano strain resolution was also achieved by the FFPI sensors in laboratory. Above achievements provide the basis to develop powerful fiber-optic tools for geophysical research on crustal deformation monitoring.

Node shift method for stiffness-based optimization of single-layer reticulated shells

This paper presents a node shift method to find the optimal distribution of nodes in single-layer reticulated shells. The optimization process searches for the minimum strain energy configuration and this leads to reduced sensitivity in initial imper- fections. Strain energy sensitivity numbers are derived for free shift and restricted shift where nodes can move freely in the 3D space or have to move within a predefmed surface respectively. Numerical examples demonstrate the efficiency of the proposed approach. It was found that optimized structures achieve higher ultimate load and are less sensitive to imperfections than the initial structure. The configuration of the final structure is closely related to factors like the initial structural configuration, spatial conditions, etc. Based on different initial conditions, architects can be provided with diverse reasonable structures. Furthermore, by amending the defined shapes and nodal distributions, it is possible to improve the mechanical behavior of the structures.

Sorption of norfloxacin from aqueous solutions by activated carbon developed from Trapa natans husk

The low-cost activated carbon was prepared from a renewable aquatic plant residue,Trapa natans husk,and tested for its ability to remove norfloxacin (NOR) from aqueous solutions. Physical and chemical properties of the Trapa natans husk activated carbon (TAC) were characterized. TAC has a large surface area of 1274 m2/g and mesoporous structure. Carboxylic and hydroxyl groups contributed to the sorption of NOR onto TAC but they were not the most important factors in the sorption process. The rates of adsorption followed the pseudo-second-order kinetics and the overall rate of NOR uptake was controlled by both external mass transfer and intro particle diffusion during the entire adsorption period. The equilibrium data fitted well with the Freundlich and Tempkin models and the sorption was found to be a favorable process. The adsorption of NOR by TAC was strongly dependent on the solution pH. Electrostatic interaction and hydrophobic interaction were proposed to be the principal NOR sorption mechanism.