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Escherichia coli O157: H7 (E. coli O157: H7) is a foodborne pathogenic bacterium which can cause fever, diarrhoea and vomiting in humans. Thus, a rapid, simple, and specific bioprobe for pathogen detection in contaminated foods has been attracted more and more attention. In this work, the strong fluorescent amino-functionalized graphene quantum dots (af-GQDs) were prepared by hydrothermal method. The microtopographic height, surface morphology and spectroscopic properties of af-GQDs are characterized by the high resolution transmission electron microscope (HRTEM), atomic force microscope (AFM), UV-vis, fluorescence, Raman spectroscopic techniques. All the results showed that the af-GQDs can be effectively applied in the preparation of biocompatible immunofluorescence probe and in the detection of E. coli O157: H7. The minimum detection limit is 100 cfu/mL. It is a simple, rapid, sensitive, low-cost and easy to be popularized method, which provides a feasible way to monitor E. coli O157: H7 in food safety.

Metal matrix syntactic foams are consisting of metal matrix and hollow spheres in closely or randomly packed, which own multifunctional properties with lightweight, damping, heat insulation, energy absorption and have a vast application prospect. Steel matrix can extend the potential of syntactic foams as a materials class to several new fields of application. In this paper, the hollow alumina spheres were introduced into the steel matrix by infiltration casting, the minimum diameter of hollow spheres for infiltration is analyzed in theory, the steel matrix syntactic foams were successfully prepared, which contain two different sphere types with average diameter sizes 3.97mm and 4.72mm, and the average densities of syntactic foams were calculated to be 4.39 (spheres occupy 43.7% of the volume) and 3.74 g/cm3 (spheres occupy 52.1% of the volume), respectively. The microstructure characteristics of the steel matrix syntactic foam were analyzed by means of scanning electron microscopy and energy spectrum.

As a new type composite material, steel-based porous materials presented the higher stiffness, strength and higher temperature resistance in comparison with the nonferrous metals. In order to realize the free-design of pore structure and free-control of porosity of steel-based porous material, indirect 3D printing technology combined with the investment casting process has been used to fabricate the steel-based porous materials. The finite element method has been carried out to study the relationship between the porosity and the mechanical properties by quasi-static compression simulation, which is consistent with compression test. The modified Gibson-Ashby formula is used to establish the quantitative relationship between porosity and elastic modulus and yield strength of steel-based porous materials based on Kelvin structure.

In order to prepare the bone repair scaffold materials that could employ the sources of the injured bone, the bioactive HA and BMP-2 were added into the biomaterial PLLA. The four scaffold materials, PLLA, PLLA/HA, PLLA/BMP-2 and PLLA/HA/BMP-2 were prepared by electrospinning. The SEM results revealed that the morphology of the 7wt% PLLA fibers was better than the 5wt% PLLA fibers, and the HA nanoparticles were distributed uniformly in fibers. The calculated surface energy of the PLLA/HA/BMP-2 scaffold was higher compared with other three scaffolds, this result fit well with the result of MTT assay of the four scaffold materials, and the MTT assay showed that the MG63 cells on the PLLA/HA/BMP-2 scaffold material proliferated faster compared with the PLLA/HA or PLLA/BMP-2. It is logical to assume that PLLA/HA/BMP-2 scaffold material is a promising material for bony tissue repair.

Based on the classical Mayer-arc model, this paper establishes the equivalent circuit of traction network for AC25kV electric railway from the essence of contact loss discharge. The voltage waves of contact loss arc at different moments are obtained by MATLAB/simulink. Through the analysis, it can be confirmed that the EMI (electromagnetic interference) with broad band and high amplitude will appear at the moment the contact loss between pantograph and catenary happens. Finally, relevant measures are given to avoid the probability event of contact loss.

Based on the transmission line theory, this paper applies the mode theory to predict the MTL(multi-conductor transmission line) crosstalk by selecting voltage as the research object, thus establish the model of estimating MTL crosstalk in inhomogeneous medium. Then make numerical calculation in MATLAB for the estimate model established in this paper, and also compare the calculated values with the simulated values in EMC studio. The compared results show that the calculated results of this model is highly consistent with the practical simulated values, verifying the correctness and feasibility of mode theory in MTL crosstalk prediction.

To obtain high-performance alumina powder for high-tech application, a comparative study was carried out for the spheroidization of two types of alumina powder using radio-frequency argon-oxygen thermal plasma. The morphology, crystallography, and particle size distribution of spheroidized alumina powder were analyzed. The effect of feed rate on the spheroidization efficiency was investigated. The results show that when the powder flow rate was 35 g/min, the spheroidization efficiency reached up to 100%, and the alumina powder had perfect sphericity, while the spheroidization efficiency decreased with increasing powder flow rate. The X-ray diffraction analysis reveals that the spheroidized alumina powder had mixed crystal structures with a stable α phase and a part of metastable phase. The particle size distribution analysis shows that the particle size of the spheroidized alumina powder did not change obviously. These results will help us to better understand the process engineering of the spheroidization of ceramic powder using radio-frequency argon-oxygen thermal plasma, and provide simultaneously technical assistance for industrialization.

The paper establishes signal correlation processing mathematical model according to Ordinary differential equations with boundary value, which is introduced into the analysis on basketball virtual simulation sliding technique, and it designs the signal autocorrelation computer processing system. In order to verify the reliability and practicality of the system in the basketball technology analysis, this paper extracts the temperature signal using the FLUENT software, it obtains the isotherm diagram and temperature distribution cloud picture, verifies the effectiveness of the system. Finally, it verifies the practicality system in basketball technology analysis, taking analysis of back gliding speed rhythm of basketball as an example, and it gets the basketball shuffle rhythm control 3D signal response curves, which provides technical reference for basketball players.

Analyze of university-industry-research cooperation’s characteristics which the university is the main target, and each case has been specifically addressed, characteristics of the cooperation were discussed, and detailed analysis of the relationship between the characteristics of the main features of each. From the perspective of their own cooperation feature, further discusses the characteristics of cooperation.

Convert Inhomogeneous media space into infinite homogeneous medium space with method of image charges, obtain the relations between Inhomogeneous media wire bound charge and free charge rely on electromagnetic theory and deduced analytical the model of parasitic capacitance per unit length of Inhomogeneous dielectric wire in insulation in automotive cable harness. Taking a car harness for example, analytical formulas and Ansys Q3D Extractor software were used to calculation and analysis harness unit length parameter matrix. Among them, the algorithm of Ansys Q3D Extractor software to calculate the parasitic of automotive cable harness is two-dimensional static finite element method, numerical methods belong.

Coolant for gundrill under MQL is impermissible to be high pressure, large quantity, or direct emission on the interface. These restricts would be seriously unfavorable to lubrication. Experiments reveal that poor lubricating always appear on the hole periphery with dark burns on the hole wall. A prospective solution is to regulate the pressure distribution by modifying the dub-off structure. Its derivation is detailed in this paper. Its validity is demonstrated by practical experiments.

Customers’ individual and rapid product customization demands for 2K-V series reducers are taken as the study background. The rapid modeling method of the product skeleton and the parametric design method of the product level are studied. Products’ assembly models and templates of products’ skeleton models for series products are created on the basis of analyzing the structure similarity. Through changing parameters’ values of the skeleton template the product’s assembly model can be updated automatically and this template is rapidly transformed to the product instance so as to realize the rapid variant design. The above method not only is effective to 2K-V series reducers but also has reference value to others series products’ design.

The design load plays an important role in research on structural analysis of surface warship. The methods for the design loads have been proposed by many famous classification societies rules. In this paper the methods of the design loads from the native existing classification societies rules and foreign rules were studied, and based on these rules, the design loads of a warship were obtained. Meanwhile, segment model self propulsion tests of this ship were performed in heading waves in the seakeeping tank to confirm the design values. Comparisons of calculation of classification societies rules with experimental data were also conducted and results were summarized in this paper. It is concluded that the evaluation methods from the rules don’t take full account of the importance of slamming，the slamming moments from rules are fewer and wave moments are too large while those from BV rules give relatively conservative design values for the surface warship.

Independent component analysis is an efficient way to solve blind source separation, which has been broadly used in many fields, such as speech recognition, image processing, wireless communication system, biomedical signal processing etc. Independent component analysis for the traditional ways to solve the blind source separation problem only considers the non-Gaussian signal, without taking into account the time structure of the signal information. Proposed based on generalized self-related and non-Gaussian source separation method, the full account of the non-Gaussian signal and time structure information, to solve the blind source separation problem in the time structure of the signal. Finally, this simulation method is validated, the simulation results show that the method is effective and worthy of promotion.

The purpose of this investigation is to examine the machining behavior of cemented carbide tools in dry hard milling of cellular aluminium alloy (6N01) by experiments and finite-element analysis. From the machining point of view, Cellular aluminium alloy are often considered as poor machinability materials. Milling tests were carried out by using a three-head milling machine and a milling force measuring device. For this purpose, both microscopic and microstructural aspects of the tools were taken into consideration. Meanwhile, the cutting forces and the noise intensity are also considered in the experiment. Results show that cutting forces vary greatly with the experimental cutting parameters. Additionally, the noise field intensity increased greatly as the feed rate increased. Analysis indicated that the major tool wear mechanisms observed in the machining tests involve adhesive wear and abrasion wear.

The block copolymer solutions were prepared by dissolving polyethylene glycol/polybutylene terephthalate (PEG-b-PBT) with different intrinsic viscosities in chloroform. The composite ultrafine nanofibers of PEG-b-PBT and PEG-b-PBT-HA(hydroxyapatite) were obtained by gas-electrospun, and were characterized by scanning electron microscopy (SEM), horizontal attenuated total reflectance for Fourier transform infrared spectrometer (HATR-FTIR), dynamic contact angle measuring apparatus and differential scanning calorimetry (DSC). The gas-electrospun fibrous membranes, which were made of ultrafine fibers with average diameter 180-1200nm and well-interconnected pores, were possessed with high surface-to-volume ratio and excellent hydrophilicity. The above results strongly suggest that fibrous membranes combine advantages of synthetic biodegradable polymers and nanometer-scale dimension for mimicking the natural ECM, and may represent an ideal tissue engineering scaffold, particularly for soft tissue, such as skin and cartilage tissue engineering scaffold.

In this work, the composite nanofibers of polybutylene terephthalate/polyethylene glycol (PEG/PBT) with difference intrinsic viscosity and different ratio of the hard-segment to the soft-segment were obtained by gas-electrospun. The PEG/PBT-HA composite nanofibers were also obtained by gas-electrospun. PEG/PBT and PEG/PBT-HA composite nanofibers were characterized using scanning electron microscopy (SEM), horizontal attenuated total reflectance for Fourier transformation infra-red spectrometer (HATR-FTIR), dynamic contact angle measurement and differential scanning calorimetry (DSC). The results strongly suggest that this synthetic matrix combines with the advantages of synthetic biodegradable polymers, nanometer-scale dimension mimicking the natural ECM, may represent an ideal tissue engineering scaffold, especially for soft tissue, such as skin and cartilage tissue engineering scaffold.

An ECMP slurry screening protocol is proposed based on inhibition efficiency of inhibitor in copper static corrosion test, aiming at enhancing the planarization efficiency of copper ECMP slurries. The elctrochemical properties of copper in electrolytes including H3PO4 and BTA with different concentrations are studied basing on Linear Sweep Voltammetry (LSV) and chronoamperometry under static corrosion states. According to analysis of the anodic current, material removal rate (MRR) and inhibition efficiency of BTA, an electrolyte formula of 30 wt% H3PO4+0.01M BTA is sort out and the anodic potential on copper should be set below 0.5 V.

Nanocomposite tool materials are developing very fast in engineering field for their highlighted advantage in mechanical properties and stability under high temperature. However, there are lots of puzzles to be discussed in the materials design theory and the fabrication processing due to the difference between the traditional materials and the nanocomposite. Therefore, in this paper, a new nanocomposite tool materials design method has been proposed based on the interface strengthening theory. The sintering temperature and the soaking time could be optimized based on the interface strengthening theory and the relative density of the tool materials. Meanwhile, a series of experiments were carried out to fabricate the nanocomposite tool materials under the guider of the interface strengthening theory. Results showed that experimental data agreed well with the calculation and the model was proved to be correct.

To understand the thermal distribution in a complex structure and high quality linkage casting, a mathematical model of temperature and stress field was established. Numerical simulation techniques was applied by using Procast software in the temperature and stress fields of solidification process, and the foundry defect such as old lap, misrun, shrinkage and dispersed shrinkage was predicted. The stress distribution and deformation in cooling process of casting were analyzed. The simulation results can supply a scientific foundation for foundry technology.

Nanocomposite tool materials are very important in engineering field for their advantage in mechanical properties and have a good foreground in the coming years. However, there are lots of puzzles in the materials design theory. So in this paper, a new nanocomposite tool materials design method is proposed based on the interface debonding theory. The wild phase content can be fixed by calculating the debonding interface rate and the strength requirement of the tool materials. Therefore, an experiment is carried out to fabricate WC based nanocomposite tool materials under the guider of the interface debonding theory. Results show that the experimental data is in accordance well with the calculation and the model is proved to be correct.

Wear behavior of WC based nanocomposite cutting tool when high speed cutting ductile cast iron was investigated. Orthogonal cutting tests were carried out on a CA6140 lathe using three speeds, namely, 100, 215 and 287m min-1. The WC based nanocomposite tool is found to be superior to cemented carbide tools (YG8). The tool life is prolonged 60% as compared to cemented carbide, as the width of the wear land (VB), which was monitored at selected time intervals. Meanwhile, the topography of worn surfaces was scanned by a profilemeter. Wear characterization of the rake face and the flank surfaces as well as of the collected chips was conducted using a scanning electron microscopy (SEM). Results showed that distinctive traces of single abrasive tool wear event were found on the rake face of the tool, additionally, the adhesion wear is the main wear mechanism in the flank face of the tool. However, the extent of improvement in tool life depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates.

The purpose of this investigation is to recognize the wear mechanisms of cemented carbide tools in dry hard turning of stainless steel (1Cr18Ni9Ti). From the view point of machining, stainless steels are often considered as poor machinability materials. Turning tests were carried out by using a CA6140 lathe and a cutting force measuring device. For this purpose, both microscopic and microstructural aspects of the tools were taken into consideration. Meanwhile, the cutting forces are also measured in the experiment. The chips were analyzed by scanning electron microscopy. The machinability of 1Cr18Ni9Ti austenitic stainless steels is examined in terms of tool life and cutting parameter presented in this paper. Results show that cutting forces vary greatly with the experimental cutting parameters. Analysis indicated that tool wear mechanisms observed in the machining tests involve abrasion wear, thermal and fatigue shock wear and adhesive wear.

Formula uniform design method was adopted to study the performance of iron-based matrix with high content of phosphorus and boron. Two forms of regression models on matrix hardness and wear resistance and the optimum matrix formulae were obtained respectively by regression analysis and constrained nonlinear programming using MATLAB. Regression analyses indicate that matrix hardness was mainly affected by the factor of Ni, Co and Fe; matrix hardness and brittleness increased with the increment of P-Fe alloy, but decreased with the increase of 663-Cu. These results can be used as a rough guide for design of highly adaptive diamond bits for different rock formations. After the indoor experiments, diamond bit based on 3# matrix formula was made to perform field drilling tests. The results were that the penetration rate was 1.91m/h and the average diamond bit life was 67.37m.

A new WC matrix nanocomposite cermet was prepared by hot-press sintering. In the composite, certain amounts of VC is added to the composite as grain growth inhibitors. The consolidation is carried out under pressure 30～35Mpa and sintering temperature 1610°C for soaking 30min sintering. Microstructure of the nanocomposite cermet is scanned by SEM and mechanical properties are measured. It is detected that microstructure and fracture morphology is dissimilar to different particle sizes. Experimental results show that particle size of WC is important to the composite. Results show that relative density and hardness have the similar trend in growth. Meanwhile, the function of Al2O3 addition is also investigated in this paper.

In this paper, the models of multilayer absorbing coating and hollow ball are studied. For the former model, a computer program is made to simulate absorbing results with the electromagnetic transmission line theory. The results show that there is a relevant absorbing peak at different frequencies for different dielectric constant (ε) and the apex’s height and position change with ε and thickness of the multilayer coatings. This program can predict the coating’s absorbing property efficiently. With the latter model, it is found that SiC hollow micro-balls whose porosity is about 0.89 make the best absorbing effect.

MgO nanowires combined with C nanotubes have been prepared through method of high-temperature catalytic reaction. The nanostructures consist of nanowires that have right-angled zigzag manner to elongate in three dimensions. Structural characterization and elemental composition analysis identified that the nanowires were made of MgO nanowires combined with C nanotubes. A growth mechanism based on the vapor-liquid-solid (VLS) process is proposed for the formation of the combined nanostructures. With the aid of XRD, SEM, HRTEM and EDS, the morphology, structure and growth mechanism were investigated.

Fully transparent polycrystalline spinel(MgAl2O4)has been prepared by combined vacuum sintering and hot isostatic pressing. This paper investigated transparent polycrystalline spinel optical properties sintered in different atmospheres and discussed the effect of sintered processing parameters on the development of the microstructure and transmission properties. The optical transmittance of the specimen sintered at 1500°C following HIPed at 1800°C was nearly the same as that of single crystal spinel. The transmission properties of spinel can be improved with the increase of temperature and pressure of sintered/HIPed spinel. Specimens sintered in vacuum following HIP have higher transmittance than those sintered in air or in hydrogen.

Mullite powders of stoichiometric composition were synthesized by sol-gel process with TEOS and Al(NO3)3·9H2O as silicon and aluminum source. Homogeneous mullite powders were used as the starting materials to prepare the porous mullite coating on the porous silicon carbide support by repeated dip-coating method. XRD analysis revealed that the mullite precursor gels almost completely transformed to orthorhombic crystalline mullite at 1200°C. The average pore diameter and porosity of the porous mullite coating were about 4.5µm and 52.3%, respectively.

In this paper, NiCo2O4 spinel oxide was synthesized by the oxidation of Ni-Co alloy. The variables that affect the formation of spinel oxide include the Ni-Co ratio in the alloy, the oxidation temperature and time. 350°C is the upper oxidation temperature limit. And longer oxidation time is helpful. Surface roughness analysis shows that with the formation of NiCo2O4, the surface shows rougher.

Mesoporous carbon with high surface area and ordered structure was synthesized via a nanocasting process using mesoprous MCM-41 silica as a template and sucrose as a carbon precursor. Sample was characterized by XRD, SEM, TEM and nitrogen adsorption. The results show that the templated carbon has a BTE surface area ∼1200 m2/g, a pore volume ∼1.0 cm3/g, and a bimodal porosity centered at around 4 nm and 46 nm.

A membrane support provides mechanical strength to a membrane top layer to withstand the stress induced by the pressure difference applied over the entire membrane and must simultaneously have a low resistance to the filtrate flow. Due to their low thermal-expansion coefficient and good thermal-shock resistance as well as excellent mechanical and chemical stability at elevated temperatures, porous SiC ceramics have been widely used as catalyst supports and hot-gas or molten-metal filters. In this work, the influence of the particle size, sintering time and sintering temperature on the porosity and permeability of supports made by dry-pressing of micron-sized SiC powders is investigated. The present work presents a comparison of properties and performance data for samples made with different particle size. The effects of sintering time and temperature were analyzed in view of overall porosity and permeability. From calculations it becomes clear that optimum values exist for the material properties of the support.

Nanotube-shaped powders had been synthesized successfully from commercial anatasetype titanium dioxide powder by ion exchange approach. All nanotubes were open-ended with 3~5 nm in inner diameter, 8~12 nm in outside diameter and 200~400 nm in length. EDS result revealed that the nanotube was only composed of Ti and O. XPS analysis showed that two peaks located at 458.5 and 464.2 eV were assigned to Ti4+ in titanium dioxide. The formation mechanism of titanium dioxide nanotubes was also discussed in this paper.

TiO2 nanocrystalline films were prepared by electrophoretic deposition (EPD) under a pulseperiodic electric field. The EPD behavior of TiO2 nanocrystalline suspension was investigated. The uniform 9.2-μm-thick TiO2 film was obtained by reasonably controlling the EPD condition. A dye-sensitized solar cell, with the EPD TiO2 film as the photoanode, obtained about 4.1% of photon-to-electron conversion efficiency (η). Its Jsc, Voc and fill factor (ff) are 11.6 mA/cm2, 0.65 V and 0.55, respectively. The effect of TiCl4 modification on the photovoltaic property of the solar cell was also discussed.

The effects of rare earth oxides (Lu2O3 and La2O3) on the property, microstructure and oxidation behavior of hot-pressing sintered Si3N4 ceramics were investigated. The silicon nitride ceramics with Lu2O3 and La2O3 as addition have been fabricated by hot-pressed at 1800°C for 1h under a pressure of 25MPa. Oxidation test was carried out at 1400°C in air for 100 hours. Mechanical properties, SEM and XRD were measured before and after oxidation. The results showed that Si3N4 ceramics doped Lu2O3 had good microstructure and mechanical properties than those doped La2O3. Oxidation test showed a parabolic weight gain with oxidation time at 1400°C in air and the oxidation products of the ceramics were SiO2, Re2Si2O7 and Re2SiO5 confirmed by XRD and EDS. The rate-controlling step was the diffusion of ion. The samples doped Lu2O3 showed superior oxidation resistance to those doped La2O3.

A series of BN-SiO2 composite ceramics with high relative densities have been fabricated by hot pressing of a mixture of hexagonal boron nitride powder and silica sol. X-ray diffraction (XRD) results show that silica are distributed in the BN matrix as noncrystalline state. Microstructure of as-sintered composite ceramics is observed by scanning electron microscopy (SEM). The influence of the secondary phase on the mechanical properties is studied by varying the silica content from 10 wt% up to 40 wt%. Dielectric properties of composite ceramics are also measured from 1 MHz to 2.0 GHz.

Silicon nitride ceramics were fabricated with Yb2O3 as the sintering additive. The effects of the amount of Yb2O3 on the microstructure and the mechanical properties such as the flexural strength and the fracture toughness were investigated. Almost fully densified Si3N4 was obtained when only 4 wt% Yb2O3 was added. Both the flexural strength and the fracture toughness increased steadily with the Yb2O3 content. The transgranular fracture mode was observed in the specimen containing 4 wt% Yb2O3, however, the intergranular fracture mode was observed in the specimen containing 10 wt% Yb2O3.

Wollastonite powder was selected as a starting material with carbonate as pore-forming agent and binder added. The porous ceramics were prepared at different temperature by sintering method. The process includes batching, granulating, pressing molding, drying and sintering. It is discussed the influence of sintering temperature, dosage of binder, dosage of pore-forming agent, pressure of molding and holding time on the performance of porous ceramics. According to the principle of particles stack, the porous wollastonite ceramics for filtration with various diameters, shapes and porosity were fabricated by serial experiments. These products have 1 to 10 microns in pore size, 30.04 to 66.15% in porosity, 2.82 m2/g in specific surface area.

In this article, the spinel NiCo2O4 nanosheets with diameters of 100-200 nm were prepared by calcinations of co-precipitates, which were obtained by co-precipitation method. Different kinds of precipitants, including NaOH, KOH, Na2CO3 and ethanedioic acid aqueous solutions were investigated, and regular hexagonal nanosheets are synthesized only when the precipitant is strong KOH or NaOH solution. The morphology and structure of the hexagonal precursor particles and nanosheets were investigated, and the mechanism of the formation of hexagonal nanosheets is discussed.

In this paper, firstly, titanate nanotubes was synthesized by hydrothermal method with commercial antase-type TiO2 powder as the raw material. TiO2 nanotubes (TNTs) can be obtained by heat-treating the as-prepared titanate nanotubes at 400 °C. Secondly, an electrode with 30 % TNTs and 70% nanocrystalline TiO2 was designed and prepared successfully. By using the nano-electrode as the photoanode of DSC, the light-to-energy conversion efficiency of 5.42 % was obtained. In addition, the effect of hydrothermal temperature on the crystal growth of nanotubes and the effect of tert-butyl pyridine (TBP) on the photoelectric performance of the DSC were also discussed.