β基Ni52Ga28Fe20-xCox合金的马氏体相变和磁性转变

利用金相和SEM，XRD，DSC和VSM研究了Co含量x对Ni52Ga28Fe20-xCox合金马氏体相变和铁磁性的影响。结果表明：x≤6％时（原子分数，下同），Co代替Fe显著提高合金的马氏体相变温度，每1％Co可以使马氏体相变温度提高50K～60K，但对Curie点的影响不大。淬火温度从1423K降低到773K对马氏体相变温度的影响不大，但使Curie点提高20K-30K，其原因是母相的B2→L21转变导致的有序化程度提高。粉末试样X射线衍射发现1423K和773K2种温度处理后都只出现L10（2M）晶体结构类型的马氏体，并且合金粉末化后降低了马氏体相变温度和增加了γ相的析出，但块状Ni52Ga28Fe17Co3合金773K淬火后为14M型马氏体。     

Phase equilibria and phase transformation of Co−Ni−Ga ferromagnetic shape memory alloy system

Phase equilibria and martensitic and magnetic phase transformations of the β phase in the Co−Ni−Ga system have been investigated. It has been shown that the β phase is in equilibrium with the α-phase over a wide range compositions at 600–1100°C. The β phase exhibits both a paramagnetic-ferromagnetic transition and a thermoelastic martensitic transition from B2 to L1₀ structure. The Curie temperature T _C increases with decreases with decreasing Ni content and with increasing Ga content. The composition region of the β phase exhibiting the thermoelatstic martensitic transformation from ferromagnetic austenite is located near the α+β two-phase region. T _C and M _s of α+β two-phase alloys increase with increasing annealing temperature. This paper was presented at the International Symposium on User Aspects of Phase Diagrams, Materials Solutions Conference and Exposition. Columbus, Ohio, 18–20 October, 2004.     

Fabrication of multilayered Au/silica/gadolinium compound core–shell particles and their imaging properties

The present work proposes a preparation method for multilayered Au nanoparticle/silica/gadolinium compound core–shell (Au/SiO₂/GdC) particles. Silica-coated Au core–shell (Au/SiO₂) particles with a size of 38.0?nm were prepared by a sol-gel reaction in the presence of the Au nanoparticles with a size of 15.5?nm. Multilayered Au/SiO₂/GdC particles with sizes of ca. 35–52?nm were prepared by a homogeneous precipitation reaction in the presence of Au/SiO₂ particles. The computed tomography (CT) value of the Au/SiO₂/GdC colloid solution containing 4.3?×?10^?2?M Au was 344.1?HU: Its converted CT value (CT divided by Au concentration) was as large as 8.0?×?10³?HU/M. The r₁ value of the Au/SiO₂/GdC colloid solution was as large as 3.5?mM^?1?s^?1.     

13.3‐inch 8k4k 664‐ppi foldable OLED display using crystalline oxide semiconductor FETs

A prototype 13.3‐inch 8k4k 664‐ppi high‐resolution foldable organic light emitting diode display is constructed. C‐axis aligned a‐b‐plane‐anchored crystal In–Ga–Zn oxide field effect transistors designed using a 1.5‐µm rule process are used in the backplane. Each pixel circuit has three transistors and one capacitor, and an external circuit is used to correct pixel current.     

The consequences of engineering an extra disulfide bond in the Penicillium camembertii mono-and diglyceride specific lipase

The extracellular lipase from Penicillium camembertii has uniquesubstrate specificity restricted to mono- and diglycerides.The enzyme is a member of a homologous family of lipases fromfilamentous fungi. Four of these proteins, from the fungi Rhizomucormiehei, Humicola lanuginosa, Rhizopus delemar and P.camembertii,have had their structures elucidated by X-ray crystallography.In spite of pronounced sequence similarities the enzymes exhibitsignificant differences. For example, the thermo-stability ofthe P.camembertii lipase is considerably lower than that ofthe H.lanuginosa enzyme. Since only the P.camembertii enzymelacks the characteristic long disulfide bridge, correspondingto Cys22–Cys268 in the H.lanuginosa lipase, we have engineeredthis disulfide into the former enzyme in the hope of obtaininga significantly more stable fold. The properties of the doublemutant (Y22C and G269C) were assessed by a variety of biophysicaltechniques. The extra disulfide link was found to increase themelting temperature of the protein from 51 to 63°C. However,no difference is observed under reducing conditions, indicatingan intrinsic instability of the new disulfide. The optimal temperaturefor catalytic activity decreased by 10°C and the optimumpH was shifted by 0.7 units to more acidic.     

Poly(p-substituted phenylacetylene) with perfluoroalkyloxydimethylsilyl side groups for oxygen and ethanol permselective membrane

Summary p-(1H,1H,2H,2H-perfluorodecyloxydimethylsilyl)phenylacetylene(ACf8) and p-(1H,1H,2H,2H-Perfluorohexyloxydimethylsilyl)phenylacetylene(ACf4) were synthesized and copolymerized with p-trimethylsilylphenylacetylene(ASi). The resulting copolymers, copoly(ACf8/ASi) and copoly(ACf4/ASi), were fabricated to tough membranes showing high oxygen permeabilities(Po ₂) of 10^-8 cc(STP)·cm/cm²·s·cmHg and high oxygen permselectivities(=Po ₂/Pn ₂) of more than 2.7. In particular, a copoly(ACf4/ASi) containing 15.1 mol% of ACf4 unit showed the best result: Po ₂=3.51x10^-8 cc(STP)·cm/cm²·s·cmHg and =3.04. The values were in a top level and very close to those of upper bound line in an -Po ₂ plot of data in the literature. In addition, copoly(ACfn/ASi) membranes were ethanol permselective owing to water repellency of the perfluoroalkyl groups. Copoly(ACf4/ASi) membranes showed better oxygen and ethanol permselectivity than copoly(ACf8/ASi) membranes.     

ESR study of radiation-induced polymerization of styrene adsorbed on silica gel

The effect of the specific surface area of silica gels on the radiation-induced polymerization of styrene adsorbed on silica gel was studied by ESR. The same radicals were generated on the silica gels regardless of the specific surface area, but the stability of the radicals at room temperature depended on the specific surface area. This means that the decay of the radicals proceeded mainly on the surface of the silica gel. Almost all the radicals generated by irradiation were initially in the bulk of the silica gel and migrated from the interior to the surface of the gel. When styrene monomer was adsorbed on the surface of the silica gel, the silica gel radicals interacted with the monomer and initiated polymerization and then generated polymer. The rate of migration of the silica gel radical was rather fast in the case of silica gel with a large specific surface area. Thus, the polymerization behavior of styrene adsorbed on silica gel greatly depended on the specific surface area of the gel.     

Satellite-driven estimation of terrestrial carbon flux over Far East Asia with 1-km grid resolution

The terrestrial carbon cycle is strongly affected by natural phenomena, terrain heterogeneity, and human-induced activities that alter carbon exchange via vegetation and soil activities. In order to accurately understand terrestrial carbon cycle mechanisms, it is necessary to estimate spatial and temporal variations in carbon flux and storage using process-based models with the highest possible resolution. We estimated terrestrial carbon fluxes using a biosphere model integrating eco-physiological and mechanistic approaches based on satellite data (BEAMS) and observations with 1-km grid resolution. The study area is the central Far East Asia region, which lies between 30° and 50° north latitude and 125° and 150° east longitude. Aiming to simulate terrestrial carbon exchanges under realistic land surface conditions, we used as many satellite-observation datasets as possible, such as the standard MODIS, TRMM, and SRTM high-level land products. Validated using gross primary productivity (GPP), net ecosystem production (NEP), net radiation and latent heat with ground measurements at six flux sites, the model estimations showed reasonable seasonal and annual patterns. In extensive analysis, the total GPP and NPP were determined to be 2.1 and 0.9 PgC/year, respectively. The total NEP estimation was + 5.6 TgC/year, meaning that the land area played a role as a carbon sink from 2001 to 2006. In analyses of areas with complicated topography, the 1-km grid estimation could prove to be effective in evaluating the effect of landscape on the terrestrial carbon cycle. The method presented here is an appropriate approach for gaining a better understanding of terrestrial carbon exchange, both spatially and temporally.