不同热处理的Cu-0.8Cr-0.05Y合金形变时效行为

对铸造Cu-0.8Cr-0．05Y合金采用了两种处理工艺：铸态＋固溶处理＋冷轧＋时效（工艺A）；铸态＋冷轧＋时效（工艺B）。通过对显微组织观察、硬度和导电率的分析，研究了经上述工艺处理后该合金的形变时效行为。结果表明，经工艺B处理的试样在时效过程中由于第二相析出、长大先于再结晶进行，因而具有更好、更稳定的综合性能，经90％冷轧变形，在480℃时效3min后，显微硬度可达150HV，导电率达90％IACS。     

Three dimensional micromachining on aluminum surface by electrochemical wet stamping technique

We proposed an up–down working mode of electrochemical wet stamping technique (EC-WETS) for three dimensional (3D) micromachining on aluminum (Al) surface. 3D microstructures on a Si mold were transferred on to an agarose hydrogel containing 15% NaNO₃, 2% MgF₂, 1% NaOH and 5% glycerin, which acted as the quasi-solid electrolyte for the electrochemical micromachining. The transferred 3D microstructures on agarose hydrogel were then duplicated onto Al surface through anodic dissolution. The micromachining quality was improved by pulse-potential method dramatically with a machining tolerance lower than 200 nm and an average removal rate of 210 nm min^− 1 in the Z direction. This method was proved to be a highly efficient, low cost and green method for 3D micromachining on active metal surface, which would be valuable for the manufacture of microelectromechanical system (MEMS).     

一维高精度离散GDQ方法

GDQ method is a kind of high order accurate numerical methods developed several years ago, which have been successfully used to simulate the solution of smooth engineering problems such as structure mechanics and incompressible fluid dynamics. In this paper, extending the traditional GDQ method, we develop a new kind of discontinuous GDQ methods to solve compressible flow problems of which solutions may be discontinuous. In order to capture the local features of fluid flows, firstly, the computational domain is divided into many small pieces of subdomains. Then, in each small subdomain, the GDQ method is implementedand some kinds of numerical flux limitation conditions will be required to keep the correct flow direction. At the boundary interface between subdomains, we also use some kind of flux conditions according to the flow direction. The numerical method obtained by the above steps has the advantages of high order accuracy and easy to treat boundary conditions. It can simulate perfectly nonlinear waves such as shock, rarefaction wave and contact discontinuity. Finally, the numerical experiments on one dimensional Burgers equation and Euler equations are given.The numerical results verify the validation of the method.     

Diffraction from angular multiplexing slanted volume hologram gratings

The diffraction characteristics of the volume holographic gratings made by multiexposures with angular multiplexing during its construction is investigated. Because of the reflection by the interface between the emulsion and the substrate or the air there is an extra unslanted periodic structure inside a slanted grating, it will affect properties of the slanted volume holographic gratings. When the angle between the surface of the substrate and the grating plane of the slanted grating is less than a certain value, an extra peak accompanying the main peak will appear in the diffraction spectrum. But, when the angle is larger than the certain value, one designed and expected main peak will disappeared while the extra peak is kept and observed. This phenomenon limits the capacity of the volume hologram for the application in wavelength-division multiplexing (WDM).     

DIAGNOSTICS OF ARC PLASMA BY MOIRE DEFLECTOMETRY

This paper presents a new method to diagnose the welding arc temperaturefield on the basis of plasma physics,Talbot effect and Moire techniques.This method hasadvantages of immunity to mechanical shock and vibration,tunable sensitivity and conside-rable simple optical system.     

Time-spreading wavelength-hopping 2D-OCDMA system with optical hard limiter

The performance of time-spreading wavelength-hopping two-dimensional optical division multiple access (2D-OCDMA) system with optical hard limiter was analyzed firstly. Prime/OOC codes are employed as address codes. By dividing other codes into three groups according to the sum of shift cross-correlations and analyzing the probability distribution of the interference patterns, the bit error rate (BER) of the system was obtained.     

TiO2-CeO2介孔复合氧化物的合成及应用

以氯化十六烷基吡啶(C16PyCl)为模板剂, 在室温、中性条件下合成了TiO2-CeO2介孔复合氧化物, 分别用红外光谱(FT-IR)、X射线粉末衍射(XRD)和BET 比表面测定等技术对介孔TiO2的结构、晶相和比表面积进行了表征. 结果表明, Ce4+的引入能稳定介孔结构. 负载活性组分Ru 后, Ru 颗粒与介孔复合载体发生相互作用, 尽管可能会部分堵塞孔道, 但对于甲醇分解为CO 和H2, Ru/m-TiO2-CeO2的催化活性依然远高于Ru/m-TiO2. Ru 和CeO2之间的相互作用对甲醇分解反应表现出协同效应.     

Poly(vinylidene fluoride)-graft-poly(N-vinyl-2-pyrrolidone) copolymers prepared via a RAFT-mediated process and their use in antifouling and antibacterial membranes

PNVP-g-PVDF copolymers were synthesized and used to produce microfiltration membranes. The pore size and distribution varied with the grafting concentration and the density of graft points. A significant decrease of the amounts of adsorbed BSA indicated improved antifouling properties of PVDF. The MF membranes were further functionalized via surface-initiated block copolymerization with DMAEMA to obtain (PVDF-g-PNVP)-b-PDMAEMA MF membranes. Quaternization of the tertiary amine groups of the PDMAEMA brushes gave rise to a high concentration of quaternary ammonium salt on the membrane surfaces. The bactericidal effect of the QAS-functionalized membranes on E. coli was also demonstrated and discussed.     

藜蒿中黄酮类化合物的微波辅助萃取研究

应用密闭微波萃取装置，分别对藜蒿茎和藜蒿叶中黄酮类化合物进行微波萃取研究。采用正交试验方法得到微波提取藜蒿中黄酮类化合物的最佳条件。微波提取藜蒿茎的最佳条件为乙醇体积分数70％，微波功率800W，提取温度80℃和料液比1：20；微波提取藜蒿叶的最佳条件为乙醇体积分数70％，微波功率600W，照射时间12min，提取温度70℃和料液比1：20；在最佳条件下，藜蒿茎和叶中总黄酮提取率分别为6．43％和7．01％。并将微波萃取与乙醇回流提取进行了比较。     

掺杂铁酸盐的制备、结构及其催化分解CO2成C的性能

采用混合离子共沉淀法制备掺杂铁酸盐,采用XRD,TGA和H2-TPR等手段对其结构进行了表征,并考察了其直接催化分解CO2成C的性能.研究结果表明,用混合离子共沉淀法能够制备出纳米级晶粒、且为单一尖晶石结构的Cr3+掺杂的NiFe2O4.所掺杂的Cr3+进入NiFe2O4的晶格B位,极大地促进了NiFe2O4在还原氧化过程中结构的稳定性,分解CO2反应后,NiFe2O4的结构易恢复,从而明显地提高了其分解CO2成C反应的循环寿命(35次以上)和积炭量(25.3%).