Abstract: Zinc oxide nanopowder was prepared by sol-gel method using oxalic acid and zinc acetate as starting material for the first time. And Rhodamine B as the target material to study the different levels of ionic liquids on the photocatalytic performance of nano-ZnO. ZnO powder was determined by SEM and XRD for introduction of ionic liquids derived from nano-ZnO surface morphology and crystal before and after. The results show that nano-ZnO catalyst surface pores increased and grain refinement by adding ionic liquid which is conducive to nano-ZnO on the photocatalytic degradation of Rhodamine B.
Abstract: The welding between Fe-Al intermetallic compound and high-strength steel was done via SPS technology. Microstructure, elements concentration and micro-hardness of welding joint were examined. The results indicated that there was no obvious welding heat-affected zone in both Fe-Al intermetallic compound and high-strength steel. The HAZ microstructures of high-strength steel were mainly martensite. In Fe-Al intermetallic compound, the grain size of heat-affected zone was larger than that of base metal and the density of heat-affected zone was lower than that of base metal. Besides, the grains of base metal had deformation phenomena. The welding joint had steady performance and the connection was reliable. Under the influence of chemical potential differences, unidirectional impulses discharge current and axial pressure, elements diffused perfectly in a short period of time.
Abstract: Microstructures, morphologies and energy spectrums of oxidized films and their cross sections of plasma sprayed alloy coating Co-02 with Co-base, Co-04 whose matrix is nickel partially instead of cobalt and NDCo-02 with Ni-base substituting for Co-base were investigated. The result indicates that the coatings of these three kinds of alloys are white austenite base and Cr7C3 and Cr7(C, B)3 eutectic; Co-02 produces Cr2O3 oxidation protection film, and there were distinct areas with shortage of chromium in Co-04 and NDCo-02 coatings where CoCr2O4 and NiCr2O4 oxidation protection films were produced with spinel structure, these efficiently improved oxidation resistance; these three kinds of alloys have super oxidation resistance which increases according to NDCo-02,Co-04 and Co-02 orderly. The level of oxidation resistance was assessed.
Abstract: Prepared lead dioxide（PbO2） coating on a Ti substrate by pulse current technique. The effect of the pulse current density, pulse time and relaxation time on the morphology and electrochemistry properties of the coating was studied by means of scanning electron microscopy and electrochemistry station. Compared with lead dioxide fabricate by common electroplate technique, lead dioxide coating prepared by pulse current technique is more dense, without hole, better corrosion resisting property and more stable electrochemistry properties.
Abstract: The Bi3.25La0.75O12 films were prepared on the Pt/TiO2/SiO2/Si substrate using RF-magnetron sputtering method. The effects of sputtering conditions, including sputtering pressure, oxygen partial pressure and substrate temperature on microstructure, ferroelectric properties were investigated. When deposited at low substrate temperature (room temperature), the BLT thin film exhibits preferentially c-axis oriented. With the increasing of substrate temperature, the (117) diffraction peak become stronger, indicating the changing of the microstructure in the BLT films. The BLT film samples deposited at 4.5-6Pa exhibit desired bismuth-layered structure, with no any preferred orientation. However, when BLT films were deposited above 5 Pa, some weak pyrochlore diffraction peaks appear in the X-ray diffraction pattern. The Pr is a maximum for the BLT film deposited at 5 Pa with O2/Ar ratio 1/5 and decreases with both decreasing and increasing deposition pressure.
Abstract: Elastic modulus of the pipe mill is one of the most important figures, which decides the character of the mechanics of materials. It is usually gained by experiments or finite element analysis. Combining computing formula of ring stiffness of buried pipeline and test results of ring stiffness of new straight buried thermal pipe (steel-plastic composite pre-insulated pipe), this article uses moment of inertia and equivalent section method to calculate elastic modulus of this pipe catalogue. By comparing with practical test results, the article testifies that this method could be probably used in directly buried installation.
Abstract: Cu-12.1 at.% Al-4.1 at.% Zn alloys with stacking fault energy (SFE) of 7 mJ/m2 were rolled in liquid nitrogen. Further annealing treatment has been conducted to the cryorolled samples at different temperatures. Compared to cryorolled samples, it is found that the microhardness of the annealed ones has increased at the temperature of 200°C. The reason for the hardening phenomenon is briefly discussed in the paper.
Abstract: The spinel Mg-doped LiMn2-xMgxO4（0≤x≤0.10）lithium ion cathode material was prepared by LiNO3, Mn(Ac)2.4H2O and Mg(Ac)2.4H2O by a low-temperature flameless solution combustion at 400°C, and HNO3 was used as oxidant. The results showed that the crystallinity of prepared material was superior to the pure LiMn2O4, and this method was better than traditional solid-state method. The particle sizes of the Mg-doped spinel LiMn2-xMgxO4 decreased with the increase of Mg doping, and the particle sizes were 50 to 90 nm; the crystal lattice interface was clear. The original capacities of Mg-doped were lower than that of undoped LiMn2O4 (109.2 mAh/g) excepts for x(Mg)=0.04, original capacity of which was 128mAh/g. However, the rentions of all the doped spinels were higher than that of undoped spinel.
Abstract: Hydrogen is widely used to prepare tungsten from tungsten oxides. Such a gas is combustible and strict measures must be taken. However, assisted by Mg or Li3N, tungsten can be prepared through the ball milling at room temperature. The reduction of WO3 by Al powder is investigated thermodynamically. Simulations on the loss of Gibbs energy of these hypothetic reactions reveal that the reduction of WO3 and WO2(OH)2 (or H2WO4) is feasible when Al powder is used; and it is more difficult to generate the intermediate tungsten oxides such as WO2, WO2.72 and WO2.9. In addition, it is better to prepare tungsten powder in vacuum containers in view of economy.
Abstract: The foamed composites could be completely biodegradable which was mainly prepared by corn starch and PVA as matrixes, reinforced by bamboo fiber, separately foamed by water, NH4HCO3 and AC/ZnO, plasticized by the mixed plasticizer of glycerol/urea and other adjuvants using extrusion foaming method. They were respectively called as WPS, NPS, APS. Then, the foamed composites’ apparent density, expansion ratio, water absorbtion, rebound rate, thermostability and cell morphology were discussed and compared with. The results showed that the apparent density decreased with increasing foamer content, then increasing; The apparent density of WPS、NPS and APS was respectively 0.24 g.cm-3, 0.27 g.cm-3, 0.15 g.cm-3; The expansion ratio increased with increasing foamer content, then decreasing; The expansion ratio of WPS, NPS and APS was respectively 63.8%、69.3%、75.4%; The water absorption increased with increasing foamer content, then decreasing; The water absorption of WPS, NPS and APS was respectively 71.3%, 64.4%, 73.4%; The rebound rate increased with increasing foamer content, then decreasing; The reboundrate of WPS, NPS and APS was respectively 54.3%, 46.8%, 58.3%; The thermostability of NPS was the best, and APS was the second, and WPS was the third. The number of cells was firstly increased with increasing foamer content, then decreasing and the side of cells became smaller with increasing content of foamer, then becoming larger.