Advanced Materials Research Vols. 430-432

Abstract: Na-doped ZnO thin films were deposited on microscope glass substrates by sol-gel spin coating method, the Na/Zn ratio were 0at.%, 5at.%, 7.5at.%, 10at.%, 15at.%. The crystal structures, surface morphology, and optical properties were analyzed by X-ray diffraction, scanning electron microscopy, ultraviolet–visible spectrophotometer, respectively. The results show that all the films are preferentially oriented along the c-axis perpendicular to the substrate surface. With the increase of the doping concentration, the roughness of the surfaces decrease and grain size grows from 17.1nm to 21.7nm, the sample with 10at.% Na exhibits best crystallinity and has lowest strain along the c-axis. The average optical transparency of the samples is higher than 70%, optical band gaps are between 3.213eV and 3.289eV.

Abstract: The crystal structure and luminescent properties of synthesized SrSi2O2N2: Yb2+ phosphors have been investigated to seek for convention phosphor for white light-emitting diode applications. The Sr1-xYbxSi2O2N2 phosphors have yellow-red luminescence under the exciting of blue light, which is attributed to the 4fn↔4fn-15d transitions of Yb2+. Although the chemical compositions for Sr1-xYbxSi2O2N2 materials are different, no shifts are observed from the excitation and emission spectra.

Abstract: Corrosion fatigue damage is the main reason of influencing cement concrete durability performance. With the loading test equipment of fatigue corrosion designed specially. Laboratory experiments are made on the cement concrete under fatigue load and sulfate solution in this paper. The related factors water-cement ratio affecting the performance of cement concrete under corrosion are also studied. Test results show the damage of cement concrete under corrosion is much more than the mathematical summation of each participating single action by alternating stresses and corrosion agents. Reducing water–cement ratio in reasonable range can improve the ability to resist the coupled action of alternating stresses and corrosion agents.

Abstract: With the development of digital reproduce technology for traditional Chinese painting, the current demand for high quality “digital xuan paper” and the requirements for its quality is increasing. Handmade xuan paper as the most basic and important material in traditional Chinese painting works, its unique brush pattern and click texture is not available in the “digital xuan paper” dedicated to the digital copy. Therefore, in the reproduction process for traditional Chinese painting, in addition to the rigorous reproduce process, the most important condition to obtain high-fidelity replication products is choosing a type of paper that meet the characteristics of traditional Chinese painting. Based on the digital inkjet technology in this paper, handmade xuan paper chose as the object was modified to obtain the technical requirements of digital reproduce by surface sizing process. Through the study process of different composition sizing agent and different sizing technology, find not only the Influence law of sizing technology and formula on tone level, clarity and color aspects of handmade xuan paper, but also the sizing technology and formula required for modifying handmade xuan paper to comply with part of Index in digital inkjet reproduce process. Through this thesis can provide a reference for handmade xuan paper in the field of digital reproduce technology.

Abstract: The pH and electric responsive composite hydrogels were prepared by in situ polymerization in the presence of graphene oxide (GO). Their structure and properties were characterized by scanning electron microscopy, Raman microscopy and mechanical testing. The results indicate that the GO is evenly dispersed in the composite hydrogels and the mechanical properties of the GO based composite hydrogels are significantly improved. Most importantly, the composite hydrogels were responsive to external stimuli such as pH and electric field.

Abstract: Carbon fiber-reinforced polymer (CFRP) sheets have recently become popular for use as repair or rehabilitation material for deteriorated carbon fiber reinforced concrete structures. Carbon fiber reinforced concrete beams were analyzed by finite element software ANASYS. Through the finite element analysis, the results showed that using bonded CFRP to strengthen R. C. beams can significantly increase their load carrying capacity. However, the beams with prestressed CFRP can withstand larger ultimate loads than beams with bonded CFRP. Using bonded CFRP to strengthen R. C. beams can obviously reduce the ultimate deflection.

Abstract: Thermodynamics software on inclusions prediction in 430 stainless steel was developed with Matlab and VC++. The inclusions’ composition could be predicted by composition of molten steel input, and equilibrium phase diagrams of MgO•Al2O3, 2MgO•SiO2, 3Al2O3•2SiO2 and 2Al2O3•2MgO•5SiO2 were displayed on the main interface simultaneously. The following predicted results by inputing experiments data at 1873 K can be gained that When Si content is 3.9×10-3and Al content is 3.5×10-4, MgO•Al2O3 spinel inclusions is unformed in case of Mg content with larger than 1.71×10-5; while MgO•Al2O3 spinel inclusions transformed into 2Al2O3•2MgO•5SiO2 inclusions in case of Mg content being less than 2.9×10-8. The predicted results of software fit well with the experiment results, Therefore, the software can provide some results for controlling the composition of inclusions in molten steel.

Abstract: In order to investigate the safety performance of welding structure of 10CrNi3MoV hull steel, with the application of FAD method provided by SINTAP, this paper made safety assessment for 2 joints with the same yield stress under-matching ratio but different weld toughness. Based on tensile test and CTOD test results, assessment was carried out. Several different sizes (2a) of weld central crack were given. Then the crack size tolerance for each joint can be found. Through relative analysis, a few conclusions were gained. As long as the assessment level is selected, FAD shape changed little. Weld toughness influenced weakly on a joint’s resistance to plastic instability, but significantly on its anti-brittle capacity. The higher weld toughness is, the more likely assessment point located within failure assessment curve, i.e. the safety performance is correspondingly better.

Abstract: In this paper, we introduced the method of preparing cationic copolymer clay stabilizer PDA and something about its laboratory study. Dimethyl diallyl ammonium chloride (DMDAAC) and acrylamide (AM) were the reaction materials, and potassium persulfate was the initiating agent, which was used to synthesize the cationic copolymer clay stabilizer PDA. Through laboratory experiments, the performance of clay stabilizer PDA was evaluated, and the results were as follows: the anti-swelling performance of PDA was better than that of KCl solution and another cationic copolymer clay stabilizer PTE. The swelling ratio of 1.0% PDA clay stabilizer was only 15.3% and anti-swelling ratio was more than 72.0%. Under the temperature of 25°C to 150°C, the anti-swelling performance was still stable. Furthermore, clay stabilizer PDA performed well in resisting salt and calcium at normal temperature, and the average damage ratio of natural cores was less than 17.5%.

Abstract: The graphite was exfoliated by concentrated acid treatment, strong oxidants oxidation, high temperature rapid thermal shock process. Investigated in detail that the kind of oxidants, concentrated acid ratio, oxidation time affected on the graphite expansion rate. Experimental results (expansion, micro-structure observation and chemical structure analysis of graphite) showed that the optimum volume ratio of concentrated sulfuric acid and concentrated nitric acid was 4:1; the expansion rate was better that added oxidant KMnO₄ than added oxidant K₂Cr₂O₇; The best oxidation time (concentrated acid treatment time) was 30~60 min.