Pt-WO₃ nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method. The morphology, composition, nanostructure, electrochemical characteristics and electrocatalytic activity were characterized, and the formation mechanism was investigated. The average particle size was 2.3 nm, the same as that of Pt/C catalyst. The W/Pt atomic ratio was 1/20, much lower than the design of 1/3. The deposition of WO₃·xH₂O nanoparticles on Vulcan XC-72R carbon black was found to be very difficult by TEM. From XPS and XRD, the Pt nanoparticles were formed in the colloidal solution of Na₂WO₄, the EG insoluble Na₂WO₄ resulted in the decreased relative crystallinity and increased crystalline lattice constant compared with those of Pt/C catalyst and, subsequently, the higher specific electrocatalytic activity as determined by CV. The Pt-mass and Pt-electrochemically-active-specific-surface-area based anodic peak current densities for ethanol oxidation were 422.2 mA·mg⁻¹Pt and 0.43 mA·cm⁻²Pt, 1.2 and 1.1 times higher than those of Pt/C catalyst, respectively.

One-dimensional and quasi-one-dimensional nanostructure materials are promising building blocks for electromagnetic devices and nanosystems. In this work, the composite Ni_0.5Zn_0.5Fe₂O₄(NZFO)/Pb(Zr_0.52Ti_0.48)O₃(PZT) nanofibers with average diameters about 65 nm are prepared by electrospinning from poly(vinyl pyrrolidone) (PVP) and metal salts. The precursor composite NZFO/PZT/PVP nanofibers and the subsequent calcined NZFO/PZT nanofibers are investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM).The magnetic properties for nanofibers are measured by vibrating sample magnetometer(VSM). The NZFO/PZT nanofibers obtained at calcination temperature of 900 °C for 2 h consist of the ferromagnetic spinel NZFO and ferroelectric perovskite PZT phases, which are constructed from about 37 nm NZFO and 17 nm PZT grains. The saturation magnetization of these NZFO/PZT nanofibers increases with increasing calcination temperature and contents of NZFO in the composite.

High transparent and conductive thin films of zinc doped tin oxide (ZTO) were deposited on quartz substrates by the radio-frequency (RF) magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO₂ ceramic target. The effect of substrate temperature on the structural, electrical and optical performances of ZTO films has been studied. X-ray diffraction (XRD) results show that ZTO films possess tetragonal rutile structure with the preferred orientation of (101). The surface morphology and roughness of the films was investigated by the atomic force microscope (AFM). The electrical characteristic (including carrier concentration, Hall mobility and resistivity) and optical transmittance were studied by the Hall tester and UVVIS, respectively. The highest carrier concentration of −1.144×10²⁰ cm⁻³ and the Hall mobility of 7.018 cm²(V · sec)⁻¹ for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10⁻² Ω·cm were obtained when the ZTO films deposited at 250 °C.

Oxyfluoride glasses were developed with composition 60GeO₂·10AlF₃·25BaF₂·(1.95−x) GdF₃· 3YbF₃·0.05TmF₃·xErF₃ (x = 0.02, 0.05, 0.08, 0.11, 0.14, 0.17) in mole percent. Intense blue (476 nm), green (524 and 546 nm) and red (658 nm) emissions which identified from the ¹ G ₄→³ H ₆ transition of Tm³⁺ and the (² H _11/2, ⁴ S _3/2) → ⁴ I _15/2, ⁴ F _9/2→⁴ I _15/2 transitions of Er³⁺, respectively, were simultaneously observed under 980 nm excitation at room temperature. The results show that multicolor luminescence including white light can be adjustably tuned by changing doping concentrations of Er³⁺ ion or the excitation power. In addition, the energy transfer processes among Tm³⁺, Er³⁺ and Yb³⁺ ions, and up-conversion mechanisms are discussed.

A series of Eu_0.5Tb_0.5(TTA)₃Phen/PMMA (TTA=thenoyltrifluoroacetone, Phen=phenanthroline) and Eu_0.5Tb_0.5(TTA)₃Dipy/PMMA (Dipy=2,2′-dipyridyl) were prepared by in-situ polymerization. The structures of the composites were characterized by IR spectra and electron spectrum. Photoluminescence properties were investigated by UV-Vis spectra and fluorescence spectra. Meanwhile, the energy transfer models were set up. The results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent materials. Eu_0.5Tb_0.5(TTA)₃Phen/PMMA and Eu_0.5Tb_0.5(TTA)₃Dipy/PMMA emitted mostly characteristic fluorescence of europium ion and intense red fluorescence with peak wavelength at 611.8 nm and bandwidth of 10.4 nm under UV excitation at 365 nm. Fluorescence intensity of Eu_0.5Tb_0.5(TTA)₃Phen/PMMA was found to be influenced with the content of MMA. The fluorescence emission of europium ions was greatly sensitized by terbium ions and the enhancement of red emission was most likely due to the energy transfer enhancement from Tb³⁺ to Eu³⁺.

Five kinds of heating treatment processing were chosen according to the experiment result of differential scanning calorimeter to prepare SiO₂-Al₂O₃-MgO-K₂O-F glass ceramics samples. The effects of heat treatment processing on the crystallization of these samples were explored by X-ray diffraction and scanning electron microscopy techniques. The results indicate that phase separations can occur in the bulk regions of the glass sample when holding at 670 °C for 3 h. The phase separation can accelerate the precipitation of the crystallization phase: when the temperature directly rises to 950 °C after the phase separation, there are mainly interlocked plate-shapes mica phases; If holding at 860 °C for 3 h first after the phase separation, the star-shape cordierite phases form; Thereby, elevating temperature to 950 °C and holding for 1 h will bring plate-shapes mica phases growing at inter-phases of the star-shape cordierite and finally the homogeneously distributed micacordierite composites form. However, if heating at 950 °C directly without holding at 670 °C, there is a small quantity of phase separation appearing at 670 °C and a little crystallization phases precipitating at last.

A series of composites as electrode materials for supercapacitors were prepared via incipient wetness impregnation method utilizing ordered mesoporous carbon (OMC) and tin (IV) oxide (SnO₂) with different ratio. The structure and electrochemical properties of the OMC/SnO₂ composites were characterized by XRD, TEM and cyclic voltammetry (CV). Pore characteristics were measured by nitrogen adsorption and desorption isotherms. The results show that the structure and electrochemical properties of the composites depend mainly on the loading amount of SnO₂ in the ordered mesoporous carbon. The optimum amount of SnCl₄ added is found to be 40 % (1.54 g ethanol-based SnCl₄·5H₂O added to 1 g OMC) of the saturated solution. The specific capacitance of the composite of optimum amount of SnCl₄ (200 F g⁻¹) is nearly three times of that of the pristine SnO₂ (72 F g⁻¹) at the scan rate of 5 mV s⁻¹, and its specific capacitance is almost equal to that of the ordered mesoporous carbon (126 F g⁻¹) at the scan rate of 200 mV s⁻¹. Meanwhile, it has better specific volumetric energy density than OMC due to its higher density. Besides, in the potential range of 0–0.9 V the composite electrode material exhibits a stable cycle life after 500 cycles.

MoS₂/Zr composite films were deposited on the cemented carbide YT14 (WC+14%TiC+6%Co) by medium-frequency magnetron sputtered and coupled with multi-arc ion plated techniques. The influence of negative bias voltage on the composite film properties, including adhesion strength, micro-hardness, thickness and tribological properties were investigated. The results showed that proper negative bias voltage could significantly improve the mechanical and tribological properties of composite films. The effects of negative bias voltage on film properties were also put forward. The optimal negative bias voltage was −200 V under this experiment conditions. The obtained composite films were dense, the adhesion strength was about 60 N, the thickness was about 2.4 μm, and the micro-hardness was about 9.0 GPa. The friction coefficient and wear rate was 0.12 and 2.1×10⁻⁷ cm³/N·m respectively after 60 m sliding operation against hardened steel under a load of 20 N and a sliding speed of 200 rev·min⁻¹.

Sulfonated polyether ether ketone (SPEEK) based composite membranes for direct methanol fuel cell (DMFC) application were prepared by sol-gel reaction of tetraethoxysilane (TEOS) in the SPEEK matrix and the incorporation of phosphotungstic acid (PWA). The conductivity of the developed membranes was determined by impedance spectroscopy and the methanol permeability through the membranes was obtained from diffuseness experiments. The SEM images show that the addition of SiO₂ and the covalent cross-linking structure lead to fine PWA particles and more uniformly dispersion. The swelling of composite membranes remains in the range of 5%–8% at 30–90 °C and the effusion of PWA reduces significantly. The composite membranes show a good balance in higher proton conductivity and lower methanol permeation. The cell with composite membrane has higher open circuit voltage(0.728 V) and higher peak power density(45 mW/cm²) than that with Nafion117.

Based on the study of a new type of conducting polymer poly (3, 4-ethylenedioxythiophene) (PEDOT), we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method. Moreover, we deeply investigated the optical, electrical and the thermal stability of PEDOT nanoparticles. The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods, such as ultraviolet/visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) spectrum, scanning electron microscopy(SEM) and so on. The results show that the amount of oxidizer, ultrasonic treatment, polymerizing temperature and doping degree can influent morphology, electrical ability and gas sensitivity of PEDOT nanoparticles. The Bragg peaks of nanoparticles at 6.7°, 12.7°, 25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid, which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.

Titanium nitride (TiN) nanoparticles were prepared from a novel refluxing-derived precursor. The organic/inorganic hybrid precursor was prepared by a two-stage refluxing method using hydrous TiO₂ as titania source and n-dodecane as carbon source. The precursor was heat-treated to 1 200 °C in flowing ammonia (NH₃) to get TiN nanoparticles. The phase and chemical compositions were investigated by means of XRD, Raman spectroscopy and XPS. Samples microstructure was studied by means of SEM, TEM and SEAD. XRD pattern indicated that the product was face-centered cubic TiN with a lattice constant a = 4.236 Å and average crystallite sizes of 35.2 nm. Raman spectra indicated that long time refluxing results in Alkane dehydrogenation and the formation of coke on TiO₂ nanoparticles. Oxygen presence in TiN lattice was confirmed by XPS investigation. The particle size that was showed by Electron microscopy photographs ranged from 20 to 60 nm.

γ-LiAlO₂:Eu³⁺(Eu³⁺:LAO) phosphor was obtained by gel combustion method using LiNO₃, Al(NO₃)₃·9H₂O, Eu(NO₃)₃·6H₂O and citric acid as raw materials. The structure, morphology and luminescence were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL). The results demonstrated that the phosphor was pure-phase of flaky tetragonal crystal system with a mean size of around 1 μm. The strongest excitation peak was at 254 nm, belonging to the broadband excitation and the maximum emission peak was at 613 nm, corresponding to the ⁵ D ₀→⁷ F ₂ transition of Eu³⁺. Luminous intensity is closely related to the calcination temperature and doping concentration of Eu³⁺.

A procedure was developed for the determination of residual monomers in polycarboxylate superplasticizer (PCs) by reversed-phase high performance liquid chromatography (RP-HPLC). Four kinds of residual monomers were well separated and determined on a SinoChrom ODS-BP (C18) column with mobile phases composed of acetonitrile and phosphate buffer solution. The monomers were detected by UV detector at 205 nm and quantitatively analyzed with an external standard method. For those residual monomers, the linear response ranged from 4.0×10⁻⁶ mol·L⁻¹ to 2.0×10⁻³ mol·L⁻¹. The determination limit of acrylic acid, sodium methylallyl sulfonate and 2-Acrylamido-2-methylpropane sulfonic acid was 0.02×10⁻⁵ mol·L⁻¹, while that of methoxy-polyethylene glycol monoacrylate was 0.1×10⁻⁵ mol·L⁻¹. The relative standard deviation (RSD) of high concentration samples was less than 1%, while that of the low concentration samples was between 1%–4%. The standard (additional) recovery ratio was 97.4%–104.2%.

In the research of 2D flexible tactile sensor matrix, pressure-sensitive conductive rubber was developed and tested in which carbon black was used as its conductive phase and silicon rubber as its matrix layer. Experiments were undertaken and the resultant data were used for its piezoresistive characteristics investigation for two kinds of electrode connection configurations, the surface directive connection and embedded connection. It is found that due to the rather strong nonlinearity of the piezoresistive characteristic curves obtained, a higher correlation relationship can be obtained by means of quadratic polynomial fitting. It also showed that the embedded electrode assembling has higher fitting accuracy while the surface directive connection has better mechanical sensitivity.

A low-cost rout for modification the polyacrylontrile(PAN) precursor fibers was developed. The approach involved pretreatment PAN precursor fibers with UV irradiation for various periods of time before the fibers were stabilized. The effect of UV irradiation on the chemical structure, orientation factor, density, crystallite size and morphology of the fibers in the process of stabilization was characterized by use of fourier transform infrared spectroscopy(FTIR), float-sink procedure, X-ray diffraction(XRD), scanning electron microscope(SEM), respectively. The results showed that UV irradiation could increase the density of the fibers in stabilization process. FTIR analysis indicated that the cyclization of nitrile groups was initiated at room temperature by UV irradiation. The transformation of C≡N groups to C=N ones was accelerated in the process of stabilization. The orientation factor of irradiated fibers was also increased. The crystallite size was decreased at first and increased later, and the better irradiation time of UV was 3 min according to the XRD test. SEM analysis indicated that irradiation could decrease the internal and surface defects of the stabilized fibers treated at 300 °C.

A new carbonaceous catalyst with sulfonic acid group (-SO₃H) was prepared by incomplete carbonization of β-cyclodextrin followed by sulfonation. The sulfonated amorphous carbon was characterized by IR, elemental analysis, DSC-TGA and PXRD, and the catalytic activity was investigated to be an efficient catalyst for the esterification reactions with maximum yield of 87%. The sulfonated carbonaceous catalyst was readily separated from the reaction solution and keeps approximately equal catalytic activity. The results confirm that the active centre is the hydrophilic sulfonic acid functional group in the esterification reactions.

3D evaluation method of cutting surface topography for C/Ph composites was established. The cutting surface was measured by Talyscan 150, using 3D non-contact measurement. Through the results of 2D and 3D roughness evaluating for C/Ph composite and Duralumin, the 2D evaluation method of the cutting surface topography of C/Ph composite loses a lot of information, the characteristics of the surface topography of C/Ph composite can be comprehensively and authentically evaluated only by 3D evaluation method. Furthermore, 3D amplitude and spatial parameters were adopted to evaluate the surface. The results show that: the topography of the C/Ph composite is anisotropic, there are more valleys in the machined surface of C/Ph than that of duralumin, and there are not obvious feeding textures for C/Ph, which indicates the machining mechanism is different from the metal. In conclusion, the topography of the C/Ph composite cutting surface is anisotropic; the cutting surface of C/Ph composite needs 3D evaluation method.

A numerical model of thermoelectric module (TEM) is created by academic analysis, and the impacts of the resistance ratio and thermoelement size on the output power and thermoelectric efficiency of the TEM are analyzed by the MATLAB numerical calculation. The numerical model is validated by the ANSYS thermal, electrical, and structural coupling simulation. The effects of the variable physical property parameters and contact effect on the output power and thermoelectric efficiency are evaluated, and the concept of aspect ratio optimal domain is proposed, which provides a new design approach for the TEM.

The electrochemical behaviours of titanium alloy Ti-10V-2Fe-3Al after electropolishing in a self-developed electrolyte in comparison with conventional grinding were studied by electrochemical impedance spectroscopy (EIS). Optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the surface characteristics of the alloy. It was found from the EIS experiments that the polarization resistance (R _p) was increased, the double layer capacitance (Q _c) was decreased and the electrochemical impedance of the alloy was enhanced by electropolishing. The electropolished surface was flat, smooth and bright and its roughness was 3.310 nm. To underline the advantage of electropolishing process against grinding to provide the anodic oxidation process with a higher quality substrate, the ground and electropolished titanium alloys were anodized in parallel under the same conditions. The corrosion behaviours of the two kinds of anodized titanium alloys were compared. It was revealed that electropolishing generated a high quality substrate and improved the corrosion resistance of anodic oxide film formed on titanium alloy Ti-10V-2Fe-3Al. Furthermore, the mechanism of electropolishing improving the corrosion resistance of the anodic oxide film was proposed.

The properties of biogenic magnetite (Fe₃O₄) nanoparticles in chiton acanthochiton rubrolineatus lischke were characterized by selected electron diffractometry, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, Mössbauer spectroscopy and magnetization measurements. Results showed that the magnetite nanoparticles presented crystalline appearance, exhibiting strong absorptions at 595, 1 463, 3 467 cm⁻¹ and weak adsorptions at 1 697, 1 113, 1 048, 848, 445 cm⁻¹ in FT-IR, two partially overlapping sextets in Mössbauer spectrum, and the area ratio of the sextets was 1.08. Also, the particles exhibited ferromagnetic behavior, and had 82 A·m²/kg saturation magnetization, 1.4×10⁴ A/m coercive force and 4.0 A·m²/kg remnant magnetization, respectively. The investigation indicates that the biogenic magnetite nanoparticles mineralized in the chiton are impure in composition and non-stoichiometric.

The unmodified rectorite (REC), a kind of layered silicate, was incorporated into polyurethane (PU) as matrix by the process of one-pot synthesizing polyurethane in situ, and hence produced a series of nanocomposite materials with enhanced strength and elongation. It is worth noting that the nanocomposite containing 2 wt% REC had the maximum elongation (1 449%) and strength (32.66 MPa) as ca. 2.7- and 1.4-fold over those of neat PU film, respectively. Meanwhile, the unexfoliated agglomerates and exfoliated nanoplatelets of REC co-existed in PU matrix. By virtue of strong interfacial interaction on the surface of REC lamella, the stress facilely transferred to the rigid RECs and hence contributed to the enhancement of strength in spite that the original structure and interaction in the PU matrix were partly cleaved. Moreover, the intertwisting of polymer chains in PU matrix with REC as well as the gliding among the REC lamellae might produce greater strain. Nevertheless, excess unexfoliated REC agglomerates under high loading level inhibited the enhancement of mechanical performances, which verified the key role of exfoliated REC nanoplatelet in improving mechanical performances. As a result, this work submitted a simple method to develop a polyurethane-based nanocomposite with high mechanical performances without any modification of layered silicates and the complicated treatment for exfoliation and dispersion.

Based on the lowest melting point and Schroeder’s theoretical calculation formula, nanomodified organic composite phase change materials (PCMs) were prepared. The phase transition temperature and the latent heat of the materials were 24 °c and 172 J/g, respectively. A new shape-stabilized phase change materials were prepared, using high density polyethylene as supporting material. The PCM kept the shape when temperature was higher than melting point. Thus, it can directly contact with heat transfer media. The structure, morphology and thermal behavior of PCM were analyzed by FTIR, SEM and DSC.

C, N-codoped TiO₂ films have been deposited onto stainless steel substrates using plasma surface alloying and thermal oxidation duplex process. Composition analysis shows that the films shield the substrates entirely. The TiO₂ films are anatase in structure as characterized by X-ray diffraction. The electrochemical measurements show that the equilibrium corrosion potential positively shifts from −0.275 eV for bare stainless steel to −0.267 eV for C, N-codoped TiO₂ coated stainless steel, and the corrosion current density decreases from 1.3×10⁻⁵ A/cm² to 4.1×10⁻⁶ A/cm². The corrosion resistance obtained by electrochemistry noise also reveals that the C, N-codoped TiO₂ films provide good protection for stainless steel against corrosion in stimulated body fluid. The above results indicate that C, N-codoped TiO₂ films deposited by plasma surface alloying and thermal oxidation duplex process are effective in protecting stainless steel from corrosion.

The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors. The material for investigation was non-metallic friction material synergistically reinforced with aramid fibre and CaSO₄ whisker, which was developed for hoisting applications in coal mine. The response surface method (RSM) was employed to analyze the material performances affected by the independent and interactive effect of the factors under the normal working condition and severe working condition, respectively. Results showed that under the normal working condition, the newly developed material exhibited stable tribological properties which were insensitive to the test conditions. While under the severe working condition, the sliding velocity was the most dominant factor affecting the friction coefficient. Additionally, compared to the commercially available material, the modified material showed superior wear resistance and thermal stability.

Two ingots were produced by centrifugal casting at mould rotational speeds of 600 rpm and 800 rpm using 20 vol% SiC_p/AlSi9Mg composite melt, respectively. The microstructure along the radial direction of cross-sectional sample of ingots was presented. SiC particles migrated towards the external circumference of the tube, and the distribution of SiC particles became uniform under centrifugal force. Voids in 20 vol% SiC_p/AlSi9Mg composite melt migrated towards the inner circumference of the tube. The quantitative analysis results indicated that not only SiC particles but also primary α phases segregated greatly in centrifugal casting resulting from the transportation behavior of constitutions with different densities in the SiC_p/AlSi9Mg composite melt. In addition, the eutectic Si was broken owing to the motion of SiC_p/AlSi9Mg composite melt during centrifugal casting.

Optical and micro-infrared microscope were used to observe the internal structure and mineral composition of high and low quality Chinese seawater and freshwater cultured pearls. Results clearly reveal that aragonite and calcite are found in seawater cultured pearls, but vaterite is not found. In contrast, vaterite and aragonite are found in freshwater cultured pearls, but calcite is not found. Based on our analysis and observations of the internal structure of high and low quality cultured pearls, a modified integrated model of the internal structure of Chinese cultured pearls was established. Our revisions to the previous model focus on significant differences within the prismatic layer of Chinese cultured pearls.

Mesoporous materials with the highest surface area were synthesized by hydrothermal treatment from coal-measure kaolin using cetyltrimethylammonium bromide (CTAB) as template. The effect of several factors on surface area of products also had been discussed. The products were characterized by FTIR, HRTEM and N₂ adsorption and desorption isotherm plot methods. There was typical structure as Si-O, Si-OH and Si-O-Si of mesoporous materials in the framework of synthesized materials; the pore size distributions of the products showed a sharp peak at 3.82 nm. The effect of hydrothermal treatment time and the amount of template on the specific surface area of mesoporous materials was important, when the Surf/Si = 0.135, and hydrothermal time = 12 h, and the surface area of the product reached up to 1 070 m²/g, which was higher than other products.

Xonotlite-type insulation material was prepared by hydrothermal synthesis technology using industrial zirconium waste residue in this paper, and the phase analysis together with the observation of micro-morphology were also carried out by XRD, SEM and TEM. The density and thermal conductivity were measured finally. The results indicate, chlorine ion impurity contained in zirconium waste residue can be removed effectively via water washed process, and the reactive activity of silicon dioxide is almost not affected, which make it be a good substitution of silicon material for the preparation of calcium silicate insulation material by hydrothermal synthesis technique. The density and thermal conductivity of xonotlite-type calcium silicate insulation material obtained by hydrothermal synthesis technique can reach 159 kg/m³, 0.049 W/(m·° C), respectively, meeting with National Standard well, when synthesis conditions are selected as follows: Ca/Si molar ratio equal to 1, synthesis temperature at 210 °C and kept for 8 hrs. It provides a new approach to realize lightweight and low thermal conductivity of calcium silicate insulation material.

The thermal decomposition processes of Wangjiatan siderite samples were studied in nitrogen by thermogravimetric(TG) analysis. The mechanism of thermal decomposition of the siderite obeyed an F _n kinetic law and the n-order was between 1.16 and 1.29. The results from non-isothermal experiments show that the size of particles has an obvious effect on the logarithm of pre-exponential factor in kinetics parameter of the thermal decomposition of Wangjiatan siderite. A linear relationship is shown between the size of particles and the logarithm of pre-exponential factor. An F₁ kinetic model containing size factor describes the thermal decomposition of Wangjiatan siderite well.

A long time immersion experiment of mortar specimens is carried out to investigate their degradation mechanism by sulfuric acid. Water-cement ratios of mortar are ranging from 0.5 to 0.7 and the pH value of sulfuric acid is 3.5 and 4.0 respectively. The pH meter is used to monitor the soak solution and the titration sulfuric acid with given concentration is added to maintain original pH value, through which the acid consumption of mortar is recorded. A theoretical reaction rate model is also proposed based on concentration boundary layer model. The results show that theoretical model fits the experimental results well and the corrosion mechanism can be modeled by a diffusion process accompanied with an irreversible chemical reaction when pH value of soak solution is no less than 3.5.

Properties and mechanism were investigated on flexural fatigue of concrete containing polypropylene fibers and ground granulated blast furnace slag(GGBFS). Four polypropylene fibers’ volume fractions and five slag proportions were considered. An experiment was conducted to obtain the fatigue lives at three stress levels in 20 Hz frequency and at a constant stress level of 0.59 in four frequency respectively. Mechanism and evaluation were investigated based on the experimental data. Fatigue life span models were established. The results show that the addition of polypropylene fibers improves the flexural fatigue cumulative strength and fatigue life span. It is proposed that the slag particles and hydrated products improve Interfacial Transition Zone (ITZ) structure and benefit flexural fatigue performance. A composite reinforce effect is found with the incorporation of slag and polypropylene fibers. The optimum mixture contents 55% slag with 0.6% polypropylene fiber for the cumulative fatigue stress. Fatigue properties are decreased as the stress level increasing, the higher frequency reduces the fatigue strength more than lower frequency at a constant stress level.

In order to monitor the basic mechanical properties and interior damage of concrete structures, the piezoelectric actuator/sensor based wave propagation method was investigated experimentally in the laboratory using a specifically designed test setup. The energy attenuation of stress waves was measured by the relative index between the output voltage of sensors and the excitation voltage at the actuator. Based on the experimental results of concrete cube and cylinder specimens, the effect of excitation frequencies, excitation amplitude, wave propagation paths and the curing age on the output signals of sensors are evaluated. The results show that the relative voltage attenuation coefficient RVAC is an effective indicator for measuring the attenuation of stress waves through the interior of concrete.

A new hydraulic cementitious binder was developed by mainly utilizing industrial byproducts phosphogypsum (PG) and ground granulated blast furnace slag (GGBFS) with small addition of ordinary portland cement (OPC). The hydration process and microstructure were studied by X-ray diffraction (XRD) and scanning electronic microscopy (SEM). OPC hydrated first at early age to form primarily C-S-H gel, ettringite and calcium hydroxide (CH). GGBFS activated by CH and sulfate ions hydrated continuously at later age, producing more and more hydration products, C-S-H gel and ettringite. Thus the paste developed a denser microstructure and its strength increased. The 28 d compressive strength of the mixture of 50% PG, 46% GGBFS and 4% OPC exceeded 45 MPa. The setting time was faster and 3 d and 7 d strength were higher when the proportion of OPC increased. But the 28 d strength decreased when OPC exceeded 4% due to large amount of ettringite formed at late hydration age which damaged the microstructure.

The structure characteristics of hydrated calcium silicate synthesized by solution reaction method with the existing of water soluble polymer polyvinyl alcohol (PVA) are investigated. Using Na₂SO₃ and Ca(NO₃)₂ as the main raw materials, in the condition of 2%(in weight) addition of PVA and the water to solid ratio of 20, hydrated calcium silicate samples (Ca/Si=1.0 and 1.5) were prepared with 60 °C water bath. IR, BET, XRD and SEM methods were used to study the microstructure of the hydration products. The results showed that the addition of water soluble PVA did not alter obviously the amorphous structure characteristic of hydrated calcium silicate, but it had effects on the polymerization status of Si-O chain and the pore structure. The effects are somewhat obvious in the samples with the Ca/Si of 1.0.

The combustion of sewage sludge and coal was studied by thermogravimetric analysis. Both differential scanning calorimetric analysis and derivative thermogravimetric profiles showed differences between combustion of sewage sludge and coal, and non-isothermal kinetics analysis method was applied to evaluate the combustion process. Based on Coats-Redfern integral method, some reaction models were tested, the mechanism and kinetics of the combustion reaction were discussed. The results show that the combustion of sewage sludge is mainly in the low temperature stage, meanwhile the ignition temperature and Arrhenius activation energy are lower than that of coal. The combustion of sewage sludge has the advantage over coal in some aspects, thus sewage sludge can partly replace coal used as cement industry fuel.

Thaumasite form of sulfate attack (TSA) is a major concern in evaluating durability of concrete structures subjected to sulfate and carbonate ions. By means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrum (EDS) as well as Raman spectra of erosion substances, effect of fly ash on TSA resistance of Portland cement-based material were investigated. Immersed in magnesium sulfate solution with 33 800 ppm mass concentration of SO₄ ²⁻ at 5±2 °C for 15 weeks, ratio of compressive strength loss decreased as binder replacement ratio of fly ash increased. Furthermore, when binder replacement of fly ash was 60%, compressive strength increased. When thaumasite came into being in samples with 0, 15% binder replacement ratio of fly ash, ettringite and gypsum appeared in those with 30%, 45%, 60% binder replacement ratio of fly ash. Results mentioned above showed that fly ash can restrain formation of thaumasite and improve TSA resistance of Portland cement-based material sufficiently.

By analyzing the fine aggregate gradation scales from standards, fine aggregate in the asphalt mixture is regarded as a whole research object and fractal dimensions X of the samples were obtained by linear regression and (AC-13) is 2.43–2.56, Sup-13 is 2.28–2.54, SMA-13 is 2.66–2.88 and SAC-13 is 2.54–2.73. In the dense gradation mixture, there are little different between fractal dimensions of coarse and fine aggregates but it makes sense for skeleton asphalt mixture. For a given coarse aggregate gradation and the same percentage of coarse aggregates, the compressive strengths and splitting strengths of the asphalt mixture are studied when the fractal dimensions are selected as 2.60, 2.65 and 2.70, respectively. When asphalt-stone ratio is less than optimal asphalt-stone ratio, the higher compressive strength is, the bigger X can be gotten. When asphalt-stone ratio is larger than optimal asphalt-stone ratio, little difference of compressive strength can be observed under these three conditions. The largest splitting strength can be got when X is 2.65, and larger splitting strength can be observed with the ascending of the asphalt-stone ratio.

Based on the assumptions validated by the experiments, an analytical method to detect the coupling actions of bending fatigue and temperature on concrete was proposed. To this purpose, a coefficient denoted by f _D(T) with the strain distributions caused by these two actions was defined. In terms of the known parameters and the fitted functions of strain, the explicit expression for f _D(T) which develops in the way same as the law of temperature change in the body of specimens was obtained. Our experimental results indicate that the weigh fraction of temperature stress decreases in the coupling damage field with the fading temperature gradient, and consequently disclose the mutual influence between these two types of actions in the loading history.

Optimization of the content of tricalcium silicate (C₃S) of high cementing clinker was investigated. The content of free-CaO(f-CaO), mineral composite, the content of C₃S in the clinker and the hydration product were analyzed by chemical analysis and X-ray diffraction (XRD). “K Value” method of QXRD was selected as a quantitative analysis way to measure the content of C₃S, and the strength of cement paste was determined. The results show that at a water cement ratio of 0.29, the strength of cement paste with 73% C₃S can be up to 97.5 MPa at 28 days age. The strength at 28 d of cement with 73% C₃S is 16% higher than that with 78% C₃S at water requirement for normal consistency. The relationship between the strength of high cementing Portland cement and the content of C₃S in the clinker is nonlinear. According to the strength of cement paste, the optimal content of C₃S in cement clinker is around 73% in this paper.

Using object mathematical model of traditional control theory can not solve the forecasting problem of the chemical components of sintered ore. In order to control complicated chemical components in the manufacturing process of sintered ore, some key techniques for intelligent forecasting of the chemical components of sintered ore are studied in this paper. A new intelligent forecasting system based on SVM is proposed and realized. The results show that the accuracy of predictive value of every component is more than 90%. The application of our system in related companies is for more than one year and has shown satisfactory results.

Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.