Magnesium research and applications: Past, present and future

As the lightest structural metal and one of the most abundant metallic elements on earth, magnesium(Mg) has been used as an "industrial metal" for lightweighting in the transportation and electronics industries, in addition to other traditional applications in aluminum alloying,steel desulfurization and protective anodes. In recent years, research has shown significant potential for Mg to become a "technology metal"in a variety of new applications from energy storage/battery to biomedical products. However, global Mg production has shown steady but moderate growth in the last three decades. Mg applications as an industry metal are still limited due to some sustainability concerns of primary Mg production, as well as a number of technical issues related to the structural and corrosion performance of commercial Mg alloys.New Mg applications as an industrial or technology metal face tremendous technical challenges, which have been reflected in the intensified global research efforts in the last twenty years. This paper will review some past and present applications, and discuss future opportunities and challenges for Mg research and applications for the global Mg community.

Development and prospects of degradable magnesium alloys for structural and functional applications in the fields of environment and energy

Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is important, such as in the aerospace and automotive industries.However, their practical applications are still limited because of their poor corrosion resistance, low high temperature strength and ambient formability. Based on such their property shortcomings, recently degradable magnesium alloys were developed for broadening their potential applications. Considering the degradable Mg alloys for medical applications were well reviewed, the present review put an emphasis on such degradable magnesium alloys for structural and functional applications, especially the applications in the environmental and energy fields. Their applications as fracture ball in fossil energy, sacrificial anode, washing ball, and as battery anodes, transient electronics, were summarized. The roles of alloying elements in magnesium and the design concept of such degradable magnesium alloys were discussed. The existing challenges for extending their future applications are explored.

Curriculum Reform of“Woven Fabric Structure Design and Application”in Higher Vocational College Based on Industry-College Partnerships

The curriculum“Woven Fabric Structure Design and Application”is the core curriculum of textile majors in higher vocational colleges,which plays a very important role in the cultivation of students’vocational ability and professional quality.The curriculum reform of“Woven Fabric Structure Design and Application”through the deep cooperation of industry-college partnerships,the comprehensive analysis of the major training objectives and graduation requirements,the redesign of the curriculum teaching content,the improvement of the teaching method and the examination method,has achieved good results.

Structural Applications of NiAl

Alloys based on NiAl offer significant payoffs as structural materials in gas turbine applications due to a unique range of physical and mechanical properties These properties include high melting temperature. low density. high thermal conductivity. and excellent environmental resistance Very significant improvements in the strength and ductility of NiAl single crystals have been achieved through alloying. Tensile strength and stress rupture properties which compete with current Ni-base Superalloys have been achieved through precipitation of an ordered L21 Heusler phase in NiAl single crystals Room temperature tensile ductility as high as 6% has been produced in NiAl single crystals containing less than 0.5% (atomic) of Fe. Ga or Mo. However. a single alloy with both room temperature ductility and sufficient high temperature strength has not yet been developed. While activity to develop on alloy with both high temperature strength and room temperature ductility continues. the Current approach also emphasizes design and test methodologies which can accept a material with limited ductility and damage tolerance More work is required on measuring and understanding strain rate sensitivity and impact behaviour While several significant challenges still remain. excellent progress has been made in many areas, and the prognosis for using NiAl alloys as high temperature structural materials is promising

Microstructure studies of air-plasma-spray-deposited CoNiCrAlY coatings before and after thermal cyclic loading for high-temperature application

In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying（APS） techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, X-ray diffraction（XRD）, and atomic force microscopy（AFM） were used to investigate the phases and microstructure of the as-sprayed, APS-deposited Co Ni Cr Al Y bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ′-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in Co Ni Cr Al Y bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.

APPLICATION OF WAXD AND SAXS TO STRUCTURAL ANALYSIS OF PA1010+BMI

WAXD and SAXS for PA1010+BMI system have been measured. The results obtained with the help of Ruland and ID EDCF. showed that Wc1x1, the long period L and the thickness of the crystal lamellae do decreased with BMI content at PA10101+BMI system. Comparing both experimental and calculated densitl c values indicated thst the values were of better conformity. Adding BHI into PA1010 caused an increase in distortion.The results from SAXS analysis have also led to the conclusion that a crystal-amorphous interphase could exist in lamellae of Semicrystalline polymers and a three-phase model instead of traditional two-phase model should be used.

APPLICATION OF 2D-NMR TECHNIQUES IN THE STRUCTURE DETERMINATION OF HYPODEMATINE

An alkaloid with a novel structure,named Hypodematine,was isolated from Hypodematium sinense Iwatsuki(belonging to Thelypterdaceae).Its structure was elucidated by means of the ~1H-~1H COSY' ~1H-^(13)C COSY and long-range ~1H-^(13)C COSY spectroscopy to have the skeleton of benzo-aza-cyclooctatetraene with a phenyl substituent.Such basic structure has not been found in the na- tural product before.

MOCVD growth of AlGaInP/GaInP quantum well laser diode with asymmetric cladding structure for high power applications

In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode （LD）, we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by metal organic chemical vapor deposition （MOCVD）. For the devices with 100-ttm-wide stripe and 1000-/zm-long cavity under continuous-wave （CW） operation condition, the typical threshold current is 190 mA, the slope efficiency is 1.31 W/A, the wall-plug efficiency reaches 63%, and the maximum output power reaches higher than 7 W. And the internal absorption value decreases to 1.5 cm^-1.

Nonlinear optical and optical limiting properties of new structures of organic nonlinear optical materials for photonic applications

The nonlinear optical （NLO） and optical limiting （OL） properties of three new structures of organic NLO guest host Poly（N-vinylcarbozole）/disperse orange 3 （PVK/DO3）, PVK/disperse orange 13 （PVK/DO13）. and PVK/disperse orange 25 （PVK/DO25） as a solution at different concentrations and as a thin-film sample are studied using continuous wave z-scan system at 532 nm. The open-aperture z-scan data of the NLO materials in the solution and thin-film samples displayed two-photon and saturable absorptions, respectively. The PVK/DO13 exhibites the largest and best values of the nonlinearities, such as n2, β, X（3） compared with those of PVK/DO3 and PVK/DO25. This nonlinearity increases as the concentration increases. Tile results indicate that these NLO materials are good candidates for optical switching and OL devices.

Periodic structural defects in Bragg gratings and their application in multiwavelength devices

In this paper, we present the finding that periodic structural defects(PSDs) along a Bragg grating can shift the Bragg wavelength. This effect is theoretically analyzed and confirmed by numerical calculation. We find that the Bragg wavelength shift is determined by the defect size and the period of the defects. The Bragg wavelength can be well tuned by properly designing the PSDs, and this may provide an alternative method to fabricate grating-based multiwavelength devices, including optical filter arrays and laser arrays. In regards to wavelength precision, the proposed method has an advantage over the traditional methods, where the Bragg wavelengths are changed directly by changing the grating period. In addition, the proposed method can maintain grating strength when tuning the wavelength since only the period of defects is changed. This will be a benefit for devices such as arrays.