The fatigue property of AZ31 magnesium alloy and its TIG welded joints were investigated. The ultrasonic peening treatment （UPT） was used to improve the fatigue property of the TIG welded joints, which was treated a...
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The fatigue property of AZ31 magnesium alloy and its TIG welded joints were investigated. The ultrasonic peening treatment （UPT） was used to improve the fatigue property of the TIG welded joints, which was treated at the weld toe by the UPT process. The test results show that the fatigue strength of the base metal of AZ31 magnesium alloys is 57.8 MPa, and those of the fillet joint and the transverse cross joint are respectively 20. 0 MPa and 17.2 MPa at 2 × 10^6 cycles. The fatigue strengths of two kinds of welded joints treated by the UPT are respectively 30. 3 MPa and 24. 7 MPa, which have been improved by 51.5% and 43.6%, respectively. The fatigue life of the fillet joint specimens is prolonged by about 2. 74 times and the fatigue life of the transverse cross joint specimens is prolonged by about 1.05 times when the stress range is at 40. 0 MPa.
Herein a higher purity 8-hydroxyquinoline organic metal complex, GaMq2Cl, was synthesized and purified by vacuum sublimation. Its structure, thermal stability and energy band structure were investigated by 1HNMR, elem...
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Herein a higher purity 8-hydroxyquinoline organic metal complex, GaMq2Cl, was synthesized and purified by vacuum sublimation. Its structure, thermal stability and energy band structure were investigated by 1HNMR, elemental analysis, TG analysis, UV-vis absorption spectra, fluorescent emission spectra and PL spectra. Experimental results show that the complex was a thermally stable material, with decomposition temperature being 348°C. GaMq2Cl consists of two 2-methyl-8-hydroxyquinoline ligands and one chlorin atom as well as one aluminum atom. Its UV absorption bands were at about 265 and 361 nm, its DMSO solution emitted intensive blue-green fluorescence at peak wavelength of 511 nm. The absorption band at about 265 nm can be assigned to π-π* of phenyl ring. Its optical gap was about 3.09 eV, as determined by intrinsic absorption band edge of the complex in DMSO solution. Under UV excitation at 365 nm, the complex in film emitted blue-green fluorescence with the maximum emission peak at 511 nm in PL spectra.
In general,a microemuision consists of oil,water,surfactant(s)and possibly cosurfactant(s).In this paper,a novel surfactant-free microemulsion(SFME)is reported,which is composed of furaldehyde(oil phase),water and eth...
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In general,a microemuision consists of oil,water,surfactant(s)and possibly cosurfactant(s).In this paper,a novel surfactant-free microemulsion(SFME)is reported,which is composed of furaldehyde(oil phase),water and ethanol without a traditional surfactant of the amphiphilic molecular *** phase behavior of this ternary system was studied finding that there is a single-phase microemulsion region and a two-phase region in the ternary *** electrical conductivity measurement was undertaken to investigate the microregion of the single-phase microemulsion *** the basis of the percolation theory,the single-phase microemulsion region was subdi-vided into three different microregions:furaldehyde-in-water(O/W),bicontinuous region and water-in-furaldehyde(W/O),which were confirmed by freeze-fracture transmission electron microscopy(FF-TEM)*** sizes of the microemulsion droplets are in the range of 30-80 *** surfactant-free emulsions(SFE)reported are O/W type and turbid,the significant apparent characteristic of SFME reported here is transparent,different from the *** stability change of the SFME was not evidently observed after storage at room temperature for 22 months up to now.
Polymerization reactions in vesicles are known to fix the vesicular structure to provide stabilized hollow colloidal nanoparticles used as biological membrane models, drug delivery vehicles, or templates for the synth...
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Polymerization reactions in vesicles are known to fix the vesicular structure to provide stabilized hollow colloidal nanoparticles used as biological membrane models, drug delivery vehicles, or templates for the synthesis of nanostructures. As a precursive work of polymerization directly from vesicles, a polymerizable surfactant, allyl dodecyl dimethylammonium bromide (ADDB) was synthesized, and spontaneous stable vesicles were formed from aqueous solutions of ADDB and sodium dodecyl sulfonate (SDS) in equimolar composition. The aqueous mixture of ADDB/SDS could form homogeneous solutions even at a high surfactant or sodium bromide (NaBr) concentration. Before polymerization, salt effect on the polymerizable vesicles was investigated by using dynamic light scattering (DLS) and freeze-fracture transmission electron microscopy (FF-TEM) measurements. It was interestingly revealed by the DLS method that the vesicle size increased from 83 nm in a salt-free solution to 250 nm with increasing the salt concentration to 250 mmol/L, but decreased from 250 to 180 nm with increasing the salt concentration to 1000 mmol/L. The same meaningful trend was disclosed by the FF-TEM measurements that when NaBr concentration was below 150 mmol/L the dispersed individual vesicle size was about 70 nm but it decreased to 20 nm while the NaBr concentration was above 400 mmol/L. The causation of increment of average aggregate radius can be attributed to the fusion and flocculation of vesicles observed clearly under a TEM imagine. The decrease of vesicle size results from the fact that, at a high salt concentration, electrolyte screens the interaction between the charged head groups, thus entropic increase drives big vesicles to decrease to small ones.
Generally, a microemulsion consists of oil, water, surfactant and sometimes cosurfactant. Herein, for the first time to our knowledge, a novel surfactant-free microemulsion (SFME), consisting of furaldehyde (oil phase...
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Generally, a microemulsion consists of oil, water, surfactant and sometimes cosurfactant. Herein, for the first time to our knowledge, a novel surfactant-free microemulsion (SFME), consisting of furaldehyde (oil phase), water and N,N-dimethyl formamide (DMF) without the amphiphilic molecular structure of traditional surfactant is re-ported. The phase behavior of the ternary system was investigated, finding that a single-phase microemulsion region and a two-phase region were formed. The electrical conductivity measurement was employed to investigate the sin-gle-phase microemulsion region. On the basis of the percolation theory, the single-phase microemulsion region was identified to consist of three different microregions: furaldehyde-in-water (O/W), bicontinuous region and water-in-furaldehyde (W/O), which were further proved by freeze-fracture transmission electron microscopy (FF-TEM) observations. The diameter of the microemulsion spherical droplets is in the range of 40-70 nm.
Onion-like fullerenes (OLFs) were synthesized by arc discharge in benzene using graphite as electrode and ferrocene as catalyst. The effect of ferrocene on the morphologies and structures of the OLFs was investigated ...
Onion-like fullerenes (OLFs) were synthesized by arc discharge in benzene using graphite as electrode and ferrocene as catalyst. The effect of ferrocene on the morphologies and structures of the OLFs was investigated by HRTEM and XRD. Results show that ferrocene directly influenced the morphology and yield of OLFs: The degree of graphitization is better. The diameters of the OLFs can be controlled in the range between 10 and 30 nm The method described here suggests a novel and promising route to synthesize OLFs in large scales.
The ternary hybrid films consisting of chitosan (CS), polyethylene glycol (PEG) and nano-sized silica which was surface-modified by amino groups (RNSA) were prepared. The structures of the blend membranes were charact...
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A pure blue light emitting material bis-2-(2-hydroxyphenyl) benzimidazole zinc has been synthesized. Its structure, energy band, photoluminescent property, film-forming ability, and thermal properties were charaterize...
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A pure blue light emitting material bis-2-(2-hydroxyphenyl) benzimidazole zinc has been synthesized. Its structure, energy band, photoluminescent property, film-forming ability, and thermal properties were charaterized by elemental analysis,1H-NMR, IR, UV-vis absorption, cyclic voltammetry, photoluminescent spectra, atomic force microscopy, and TG-DTG technique. The results show that the complex had a good thermal stability. UV-vis absorption bands of Zn (pbm)2were located at about 299, 334, 357. Its optical gap, HOMO energy and LUMO energy were 3.03, -5.72 and -2.69 eV, respectively. Zn (pbm)2formed dense film by vacuum vapor deposition. The maximum emitting wavelength of Zn (pbm)2was 445 nm, with FWHM being 81 nm and color purity being 0.8599, which indicates that this complex is an excellent blue-emitting material. The complexe was expected to find applications in organic electroluminescence diodes through appropriate device design.
Onion-like Fullerenes (OLFs) were synthsized by arc discharge in benzene and ferrocene using graphite as electrode. The effect of ferrocene on synthesis of OLFs was discussed. High resolution transmission electron mic...
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Onion-like Fullerenes (OLFs) were synthsized by arc discharge in benzene and ferrocene using graphite as electrode. The effect of ferrocene on synthesis of OLFs was discussed. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) technique were used to characterize morphology and structure of the products. The results show that the yield of OLFs might be improved if ferrocene is used as catalyst. The degree of graphitization is higher. The diameters of OLFs are in the range from 10 to 30 nm.
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