The low surface energy fluorocarbon polymer from the synthesized fluoro-acrylic resins was developed. Then the molecule orientation principle of nonpolar and polar functional groups in the polymers was analyzed. And the contact angles of pure water drops on the surfaces of various fluoro-monomer homopolymers and interpolymers were measured. So the relation of polymers’ fluoro-content with the surface energy was determined. The distribution of fluoric functional groups in the polymers was investigated. And the test results show that though the total fluorine content of the fluorocarbon polymers is relative few, their surface energy is really low due to the enrichment of fluoro-chains on the polymers surface.
Based on the needs of green motor oil, and in order to improve the antioxidation properties of green lubricating oil, the effect of tocopherol antioxidation properties of rapeseed oil was studied. Experiments of high temperature oxidation, antiwear and infra-red spectrum analysis were accomplished, the results show that the rapeseed oil including tocopherol can still keeps steady structure after high temperature oxidation, with a small variety of acid number, whose antioxygenic properties are improved evidently. Meanwhile, both thiocarbamate and vitamin C play an assistant role in tocopherol, which can make rapeseed oil to have better oxidation stability and keep excellent antiwear properties after high temperature oxidation.
Hydroxyapatite (HA) coatings on pyrolytic carbon were produced via electrophoretic deposition (EPD) using glycol and ethanol as dispersion medium respectively. The effect of the solubility of HA in the dispersion medium on crack occurrence and adherence of the coating was investigated by means of scanning electronic microscope (SEM) and atomic absorption spectrometer (AAS). The results show that the solubility of HA in glycol is higher than that in ethanol. The usage of glycol as a dispersion medium can reduce the possibility of crack formation and enhance the adhesive strength between the coating and the carbon substrate. The green coatings can be sintered under vacuum at 1 000 °C whether the coatings are obtained using ethanol or glycol as dispersion medium. No HA decomposition was observed up to 1 000 °C by vacuum sintering by X-ray diffraction (XRD) analysis.
The longitudinal mechanical behavior of shape memory alloy (SMA) composite lamina subjected to longitudinally strain or stress controlled cyclic loading is investigated. The SMA is under pseudo-elastic condition and the fibers are embedded (bonded) to the host material. The influences of temperature, volume fraction of SMA and longitudinal modulus of the host material on the stress-strain relation and energy dissipation of the SMA hybrid composite lamina are discussed. The results indicate that the stress-strain curve of the lamina per cycle shows a hysteresis loop. The hysteresis damping decreases with increasing temperature and with decreasing volume fractions of SMA. In addition, the hysteresis damping is nearly independent of the longitudinal modulus of the host material under strain controlled loading. However, it depends dramatically on the longitudinal modulus of the host material under stress controlled loading, which shows the SMA composite lamina has high pseudo-elastic hysteresis damping when the longitudinal modulus of the host material is low.
To investigate the durability, especially the long-term stability of cement-based materials with very low w/b, the air permeability test, carbonation test, capillary absorption rate test and dilation potential test were adopted under long-term heat treatment condition. Microstructure of these materials is also analyzed by scanning electronic microscopy (SEM) and mercury intrusion porosimeter (MIP) in order to further unveil its mechanism and interrelation between microstructure and its properties. The results indicate that in the area investigated, cement-based material with w/b 0.17, like RPC, possesses low porosity and excellent durability. Moreover, its porosity will further decrease under long-term heat treatment compared with normal heat treatment. Its long-term durability is much superior to that of other cement-based materials with w/b 0.25 or 0.35 as high strength concrete(HSC).
Nanosized ZrO2 powder was prepared by evaporative decomposition of solution(EDS). The particle size is from 50 nm to 200 nm. This process has such advantages as high purity, precise compositional control, simple procedure and successive auto-operating. In this process, mixed solution of zirconium acetate and yttrium nitrate was atomized to from a fine mist and blown into the hot zone from the bottom of furnace. The solution was rapidly decomposed at 900°C and the powder was collected by a filter system. The powder characteristics can be controlled by adjusting the concentration, droplet volume and decomposition temperature of the solution.
To evaluate the effect of targeting to hepatoma treated by magnetic biliary stent combining with magnetic nanoparticle containing 5-fluorouracil (5-FU), thirty-two nude mice modes with transplanted hepatoma were divided equally into four groups randomly. Experimental group received magnetic biliary stent and magnetic nanoparticles containing 5-FU. The tumor volume and pathomorphology of all groups was measured. The tumor control rate of the experimental group provided magnetic biliary stent wires and magnetic nanoparticles containing 5-FU is remarkably higher than three other control groups, showing significant curative effect. More apoptosis of tumor cells could be detected easily in experimental group. There are more apoptotic bodies and phagotrophic magnetic particle in apoptosis cells of experimental group under electron microscope. Magnetic biliary stent combining with magnetic nanoparticle containing 5-FU could inhibit the growth of hepatoma, and its curative effect is more remarkable than the traditional methods based on external magnetic fields.
Polyaniline was obtained by chemical oxidation in the microemulsion system consisting of aniline, emulsifier, assistant emulsifier and water in magnetic field (0 T, 0.2 T, 0.4 T, 0.6 T). The effect of magnetic field on the polymerization rate and the inherent viscosity of polyaniline were studied. The molecular structure of polyaniline was characterized by IR spectra and the thermal degradation behavior was assessed using TG techniques. The results show that the polymerization rate, molecular weight, thermal stability and conductivity of the synthesized polyaniline enhanced and no effect on the basic structural units of polyaniline was observed in magnetic field. Within the range of the intensity of magnetic field studied, the magnetic field of 0.4 T exerts the largest influence on polymerization of aniline.
An electrostrictive uniaxial ultrasonic levitation reaction system was designed to perform TiC synthesis reaction by suspending graphite powder in Al-3Ti melt and an Al-3Ti-0.15C grain refiner alloy was obtained. The results show that sound pressure node in which graphite suspends is formed in the melt between radiation block and reflecting board by ultrasonic and TiAl3 particles congregate around C powder Meanwhile, due to ultrasonic cavitation, dissolved TiAl3 provides better surface condition for the synthesis reaction of TiC. The reaction route is that C and dissolved Ti react to form TiC. Ultrasonic cavitation has a thermal activation effect on TiC particles and Al-3Ti-0.15C refiner has excellent microstructural refining effect on α-Al.
By means of testing the shear strength with single lap joint, measuring electrical resistivity for cured products and the curing strain with strain gauges, the effect of cure parameters on the properties of HT1012 conductive adhesive filled with copper powder was investigated, and the residual stress in the conductive adhesives was also estimated. The experimental results show that the properties such as shear strength of the adhesives, electrical resistivity of products as well as the residual stress of cured HT1012 copper-filled conductive adhesive were evidently affected by curing temperature and time. The diagrams of scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) were also used to determine the properties. The higher mechanical property was achieved under the condition of curing the adhesive 3 h at 60 °C as the density of the hydrogen links or linkages existed in the adhesive was relatively higher and the lower electrical resistivity occurred at 80 °C.
The influence of each factor on the reaction of geopolymers material was investigated by using the orthogonal experimental design method, which got the optimal condition of reaction. Based on this results the performances of geopolymers were investigated. The results are as follows: (1) The effect of each factor on the compressive strength of geopolymers was different; (2) For paste the optimal condition of reaction is that the modulus and the concentration of sodium silicate solution are 1.2 and 40%, the calcined temperature and calcined time of kaolin are 800 °C and 2 h, and the liquid-solid ratio is 1.25; (3) When the pH value of solution is higher than 1, the compressive strength of Geopolymers will not decrease as that in the water; (4) As the calcined temperature of samples were lower than 700 °C the heat-resistant of geopolymers was good;(5) Geopolymers is unlikely to react with the active aggregate.
The adsorption mechanism of Na+, Cl− and other impurities on the surface of basic nickel carbonate was clarified by electric double layer model. Based on the mechanism, a new purification method was studied. The method can be described as washing-drying-rewashing-drying. The experimental results indicate that the process is very efficient to remove impurities adsorbed by the precipitate when using NiCl2 and Na2CO3 as the raw materials. The finished product’s contents of sodium and chlorine are both less than 0.01 wt%.
A liquid-solid metathetical reaction method (LSMRM) of synthesizing AlN nanocrystallines is presented. AlN nanocrystallines made through LSMRM are characterized by X-ray diffractions (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier transformation infrared (FT-IR) spectroscopy, and Raman spectroscopy. The results show that the samples are single hexagonal-phase AlN and the size of the AlN samples is about tens of nanometer.
The self-cementing mechanism at early ages of circulating fluidized bed combustion (CFBC) coal ashes was studied by X-ray diffraction (XRD), infrared (IR) spectroscopy and chemical method. The results indicate that the amorphous phase is predominant in CFBC coal ashes. The polymerization degree of [SiO4] and [AlO6] of CFBC desulphurization coal ashes is lower than that of those without desulphurization. The contents of the components with fast hydration rate of CFBC desulphurization coal ashes are significantly greater than those of the ashes without desulphurization. This work confirms that the amorphous minerals with high chemical activity are the main causes of the self-cementing property of CFBC desulphurization coal ashes at early ages.
The thermodynamic analysis of the formation of in-situ reinforced phases in (TiB2+Al3Ti)/Al-4.5Cu composites prepared by mixed salts reaction was conducted, and heat changes of mixed salts system were analyzed by differential thermal analysis(DTA).The results show that although TiB2 possesses the strongest formation ability in Al-Ti-B ternary system, [Ti] is relatively excessive in the in-situ reaction and it combines with Al to form Al3Ti phase. The reinforced phases are TiB2 and Al3Ti in the produced composites due to the reaction taking place to form reinforced phase with the addition of mixed salts into Al-4.5Cu melt between 900 °C and 1 032 °C.
A novel environmental friendly catalyst, H3PW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of n-butyl methacrylate catalyzed by H3PW12O40/MCM-48 was studied with methacrylic acid and n-butyl alcohol as reactants. H3PW12O40/MCM-48 is an excellent catalyst for synthesizing n-butyl methacrylate and Keggin structure of H3PW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n(methacrylic acid):n(n-butyl alcohol), catalyst dosage, cyclohexane(water-stripped reagent) and reaction time on yields of the product were investigated. The optimum conditions have been found, that is, molar ratio of acid to alcohol is 1:1.6, mass ratio of catalyst used to the reactants is 0.5% and reaction time is 2.0 h. Under these conditions, the yield of n-butyl methacrylate can reach 93.7%.
Composites consisting of strontium stabilized bismuth oxide (Bi1.14Sr0.43O2.14, SSB) and silver were investigated as cathodes for intermediate-temperature solid oxide fuel cells with doped ceria electrolyte. There were no chemical reactions between the two components. The microstructure of the interfaces between composite cathodes and Ce0.8Sm0.2O1.9 (SDC) electrolytes was examined by scanning electron microscopy (SEM). Impedance spectroscopy measurements show that the performance of cathode fired at 700 °C is the best. When the content of Ag2O is 70 wt%, polarization resistance values for the SSB-Ag cathodes are as low as 0.2 Ωcm2 at 700 °C and 0.29 Ωcm2 at 650 °C. These results are much smaller than some of other reported composite cathodes on doped ceria electrolyte and indicate that SSB-Ag composite is a potential cathode material for intermediate temperature SOFCs.
Nano-SiO2/polypropylene composite was prepared by melt-blending process. The nano-SiO2 particles were organized by wet process surface treatment with silane coupling agent KH-570. The effect of mass fraction of nano-SiO2 particles and dosage of KH-570 on the toughening and strengthening of PP matrix were investigated based on the fractography of impact notch and the analysis of crystal structure by X-ray and dispersive structure of nano-SiO2 by TEM. Results show that the impact and flexural strength and modulus of the composite are improved obviously with low loading of nano-SiO2 (3 wt%–5 wt%), and the izod impact strength of PP increases twice with 4 wt% nano-SiO2. The nano-SiO2 particles treated can disperse into the matrix resin, which has evident heterogeneous nucleation effects on the crystallization of PP. The optimal toughening and strengthening effects of PP matrix can be obtained when the content of nano-SiO2 and KH-570 are 4 wt% and 3 wt%, respectively.
The Mo-N surface modified layer on Ti6Al4V alloy was obtained by the plasma surface alloying technique. The structure and composition of the Mo-N modified Ti6Al4V alloy were investigated by X-ray diffraction (XRD) and glow discharge optical emission spectroscopy (GDOES). The Mo-N modified layer contains Mo-N coating on subsurface and diffusion layers between the subsurface and substrate. The X-ray diffraction analysis of the Mo-N modified Ti6Al4V alloy reveals that the outmost surface of the Mo-N modified Ti6Al4V alloy is composed of phase Mo2N (fcc) and Mo2N (tetr). The electrochemical corrosion performance of the Mo-N modified Ti6Al4V alloy in 0.5 mol/L HCl solution was investigated and compared with that of Ti6Al4V alloy. The chemical corrosion performance of the Mo-N modified Ti6Al4V alloy in boiling 37% HCl solution was investigated and compared with that of Ti6Al4V alloy. Results indicate that self-corroding electric potentials and corrosion-rate of the Mo-N modified Ti6Al4V alloy are higher than that of Ti6Al4V alloy in 0.5 mol/L HCl solution. The corrosion-rate of the Mo-N modified Ti6Al4V alloy is lower than that of Ti6Al4V alloy in boiling 37% HCl solution.
Thermally stable and biodegradable composites from poly (propylene carbonate) (PPC), poly (ethylene-co-vinyl alcohol) (EVOH), starch and CaCO3 were fabricated by melt blending. Differential scanning calorimetry (DSC), differential thermal analysis/thermal gravimetric analysis (DTA/TGA), tensile test and scanning electron microscope (SEM) were performed to investigate the miscibility, thermal behavior and tensile properties of the PPC/EVOH/Starch/CaCO3 composites. DSC results indicate that the introduction of EVOH could improve the compatibility between PPC and starch to some extent because of the interfacial interaction between PPC and EVOH, leading to an increase in tensile strength. The tensile strength began to decrease when more starch was added due to the aggregation of starch particles. SEM examination showed the good interfacial bonding between the fillers and polymeric components. The incorporation of both EVOH and fillers can greatly increase the thermal stability of PPC matrix. The PPC/EVOH/Starch/CaCO3 composites can be melt processed and can be used as a common biodegradable material for a wide application.
Two new photochromic inorganic-organic hybrid materials formed from Keggin-type polyoxometalates(POMs) and metronidazole (C6H9N3O3, MNZ), formulated as H3PMo12O40·3MNZ·3H2O(1) and H3PW12O40·3MNZ·3H2O(2), were synthesized and characterized by elemental analysis, IR spectra, electronic spectra, electron spin resonance (ESR) spectra and thermogravi-metry-differential thermal analysis (TG-DTA). Reflectance spectra show the presence of weak intermolecular charge transfer between the organic and inorganic moieties in the solid state. The photochromic properties were studied by solid diffuse reflectance spectra and ESR spectra, and the photochromic reactions were found to exhibit first-order kinetics. TG-DTA showed that two hybrid materials have similar thermal behavior.
The preparation of granulated adsorption material of water-quenched slag/rectorite composite and the treatment of Cu (II)-containing copper smelter wastewater with the adsorption material were studied. The experimental results showed that under the conditions with the mass ratio of water-quenched slag to rectorite of 1:1, 10% additive of industrial starch (IS), and 50% water, and a calcination temperature of 400 °C, the granulated adsorption material prepared had a density of 1.06 kg/m3, a porosity of 62.29%, water absorption rate of 58.82%, and compressive strength of 2.22 MPa. The efficiency of wastewater treatment was the best, whereas the rate of spallation loss was low. Under the conditions of natural pH, with the addition of the granulated adsorption material of 0.05 g/mL, a reaction time of 40 minutes, and temperature of 25 °C, the efficiency of the granulated adsorption material for the removal of Cu (II) ions from the copper smelter wastewater attained 98.2%, and the quality indexes of the wastewater after treatment conformed with the first level of integrated wastewater discharge standard (GB8978-1996). The reclamation of the used granulated adsorption material was carried out by de-sorption of the Cu (II) ions from the surface with 1 mol/L sodium chloride solution. The de-sorption rate was 96.4%, and the adsorption material can be reused many times to treat copper smelter wastewater.
On the base of the influence rule of silica fume, slag and fl y ash on alkali-silica reaction under the condition of 70 °C, the mechanism of the effect of mineral admixtures on alkali-silica reaction is studied further in the paper. The results show that the effects of mineral admixtures on alkali-silica reaction are mainly chemistry effect and surface physichemistry effect. Under suitable condition, the chemistry effect may make alkali-silica reaction to be inhibited effectively, but the physichemistry effect only make alkali-silica reaction to be delayed. The chemistry effect and the physichemistry effect of minerals admixture are relative to the content of Ca(OH)2 in system. Under the condition that there is a large quantity of Ca(OH)2, mineral admixture cannot inhibit alkali-silica reaction effectively. Only when Ca(OH)2 in the system is very less, it is possible that mineral admixture inhibits alkali-silica reaction effectively.
In order to investigate the microstructural evolution during self-propagating high-temperature synthesis (SHS) of Ti-Al powder mixture with an atomic ratio of Ti: Al=1:1, a combustion front quenching method (CFQM) was used for extinguishing the propagating combustion wave, and the microstructures on the quenched sample were observed with scanning electron microscope (SEM) and analyzed with energy dispersive spectrometry (EDS). In addition, the combustion temperature of the reaction was measured, and the phase constituent of the synthesized product was inspected by X-ray diffraction (XRD). The results showed that the combustion reaction started from melting of the Al particles, and the melting resulted in dissolving of the Ti particles and forming of Al3Ti grains. As the Al liquid was depleted, the combustion reaction proceeded through solid-state diffusion between the solid Al3Ti and the solid Ti. This led to the forming of TiAl and Ti3Al diffusing layers. In addition, the combustion reaction is incomplete besides TiAl, there are a large amount of Ti3Al and TiAl3 and a small amount of Ti in the final product. This incompleteness chiefly results from the using of coarser Ti powder.
Ln0.6Sr0.4Co0.8Fe0.2O3 (Ln=La, Pr, Nd, Sm) perovskite-type complex oxides were synthesized using a glycine-nitrate process, and the structure, electrical conducting and thermal expansion properties of the resulting ceramics were examined with regard to the nature of the lanthanide cations. The results indicated that the La, Pr and Nd specimens had a rhombohedral symmetry, while an orthorhombic structure was determined for the Sm specimen. The pseudo-cubic lattice constant decreased with smaller lanthanide cations. It was found that the electrical conducting properties declined with decreasing lanthanide cation size. Fortunately, all the compositions remained rather high electrical conductivities exceeding 650 Ω−1·cm−1 in the intermediate temperature range (600–800 °C). An appreciable thermal expansion increase at high temperatures was detected for all the compositions. Decreasing the size of the lanthanide cations resulted in an increase of thermal expansion. With respect to the high electrical conductivities, the Ln0.6Sr0.4Co0.8Fe0.2O3 oxides are considered to be acceptable as mixed conducting component in composite cathode designs together with doped ceria electrolytes.
The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated. Results indicate that the porous concrete with a cement dosage only 150 kg/m3 has high strength and satisfying permeability when the aggregate has a passing percentage of 4.75 mm around 10% to 15%, with the increase of the maximum size of the aggregate, the strength of the porous concrete decreases and the permeability increases. When the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate is about 20%, there are no interference among the particles by Weymouth theory, the strength of the pervious porous concrete reaches the peak value. The optimum continues gradation limit of the aggregate for porous concrete pervious road base material is recommended according to the theoretical calculation and experimental results.
Hydroxyapatite whiskers are used as reinforcement for biomaterials because of their needlelike morphology and strong strength of single crystal. HAP nanoparitcles are used in drug delivery system, protein separation and anticancer drug besides their implant applications. Many new properties arise from nanoeffects while nanoeffects come from specialty of nanostructure. The Ca(NO3)2·4H2O and (NH4)2HPO4 were used as starting reagents for preparation of HAP whiskers and nanoparticles. The whiskers are 100–200 μm long while nanoparticles are 30–80 nm in size. XRD is applied to characterize the lattice parameter difference of whisker and nanoparticle. Compared with those of HAP whiskers, the a-axis and b-axis of HAP nanocrystals are shortened while the c-axis is elongated. That makes nanoparticles capable of their non-needle-like morphology, higher reaction activity and special bioeffects
W-15Cu composite powders prepared by mechanical alloying (MA) of raw powders were consolidated by spark plasma sintering (SPS) process at temperature ranged 1 230–1 300 °C for 10 min and under a pressure of 30 MPa. By using high energy milling, particles containing very fine tungsten grains embedded in copper, called composite particles, could be produced. The W grains were homogeneously dispersed in copper phase, which was very important to obtain W-Cu alloy with high mechanical properties, fine and homogeneous microstructure. The microstructure and properties of W-15Cu alloys prepared by SPS processes at different temperature were researched. The results show that W-15Cu alloys consolidated by SPS can reach 99.6 % relative density, and transverse rupture strength (TRS) is 1 400.9 MPa, Rockwell C hardness (HRC) is 45.2, the thermal conductivity is 196 W/m·K at room temperature, the average grain size is less than 2 μm, and W-15Cu alloy with excellent properties, homogeneous and fine microstructure is obtained.
A kind of PEG-MAH maleic anhydride to modify polyethylene glycol) crystalline polymer whose melting point was approximately 64 °C was synthesized, and its thickening traits to LPMC were also investigated. The analysis of rheological properties indicates that the dosage and adding methods of crystalline polymer have a direct effect on the viscosity of LPMC, and that the thickening method of using melting dispersal and freezing is propitious to the thickening process of SMC. Additionally, it is also shown that SMC’s viscosity decreases along with the elevation of temperature, and that it reduces rapidly at the medium range of temperature, which is propitious to the dispersal of SMC in mould, and to its low pressure molding as well.
The compound of diphosphopentamolybdate {[Cu(en)(Hen)]2[P2Mo5O23]}·3H2O [en=ethylenediamine] had been obtained from the hydrothermal method and characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, and thermogravimetric analysis. The structure consist of [P2Mo5O23]6− clusters anions, complex [Cu(en)(Hen)]3+ cations and crystallization water molecules, which are held together to a two-dimensional framework. The most interesting feature of the compound is that two nitrogen atoms are both coordinated with Cu(II) in one ethylenediamine molecule, for the other ethylenediamine molecule, only one nitrogen atom is towards Cu(II) and the other nitrogen atom is protonated and formed Hen+.
Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.
Skutterudite CoAs3 is a potentially important thermoelectric material. Morse potential is employed here to carry out molecular dynamics simulations of nanobulk CoAs3 at the temperature of 0 K. The stress-strain relationships under uniaxial tensile and/or compressive strain are obtained. The elastic modulus, extreme strength and deformation mechanism are studied. The simulation results indicate that nanobulk CoAs3 abruptly ruptures at much higher strain level under tension than conventional bulk CoAs3. Both the extreme stresses under tension and compression are much higher than those of conventional bulk CoAs3.
The IR spectra of R2O-RO-B2O3-SiO2 and R2O-RO-B2O3-Al2O3-SiO2 glasses were tested for the study of coordination state of B, Al and their content. The results show that no matter Na2O/B2O3>1, =1, or<1, both [BO3] and destroyed Si-O bond exist in glass structure; the addition of Al2O3 to borosilicate glass reduced both the number of non-bridging oxygen in the silicate network and the number of [BO4] units.
The synthesis, structure and properties of a new A5B4O15-type cation-deficient perovskite Ba3La2Ti2Ta2O15 were discribed. The compound was prepared by the conventional solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The results reveal that the compound is successfully synthesized. The compound crystallizes in the trigonal system with unit cell parameter a=5.6730(2) Å, c=11.6511(2) Å, V=324.93(1) Å3 and Z=1. The microwave dielectric properties of the ceramic are studied using a network analyzer, and it shows a high dielectric constant of 45.1, a high quality factors with Q×f of 21 029 GHz, and a positive τ f of 5.3 ppm°C−1.
CdS hollow structures were built up by using the one pot method and using carbon disulfide (CS2) and ethylenediamine as starting materials. CS2 is insoluble in water and could form metastable oil droplets in the water at a moderate temperature. The oil droplets formed chains in the circumvolving water. CdS crystals grew and mineralized on the surfaces of the CS2 droplet chains, forming CdS shells around the unreacted CS2 cores. After the surrounding temperature was raised above the boiling point of CS2, the unreacted CS2 cores vaporized, leaving the CdS shelled hollow structures. The CdS hollow structures were characterized by using a transmission electron microscope, an X-ray diffractometer, a UV-Visible spectrophotometer and a fluorescence spectrophotometer. The CdS hollow structures were mainly tubes with closed ends. The exterior diameter and the interior diameter of tubes were about 50 nm and about 15 nm, respectively. Compared with the absorption onset wavelength of the bulk CdS, the CdS hollow structures exhibited a blue shift of about 57 nm. While excited at 213 nm, the CdS hollow structures emitted greenish blue light centered at 470 nm.
The effect of oxidizing-heat-treatment conditions on the electricity performance of doped SrTiO3 ceramic is analyzed by using the theory of grey neural network. Based on the number of main parameters, the model of GNNM (1,1), GNNM (1,2), GNNM (1,3) is used to analyze and construct the corresponding model of GNNM (2,1) gray neural network. It can reach the required precision by calculating.