Regularity for 3-D MHD Equations in Lorentz Space L^(3,∞)

.The regularity for 3-D MHD equations is considered in this paper,it is proved that the solutions(v,B,p)are Holder continuous if the velocity field v∈L^(∞)(0,T;L^(3,∞)_(x)(R^(3))with local small condition r^(-3)|{x∈B_(r)(x_(0):|v(x,t_(0))|>εr^(-1)}|≤ε and the magnetic field B∈L^(∞)(0,T;VMO^(-1)(R^(3)).

Efficient air water harvesting of TpPa-1 COFs@LiCl composite driven by solar energy

Adsorbent-assisted air water harvesting(AWH)may help alleviate the current global freshwater scarcity crisis.However,the weak sorption capacity of various adsorbents and the high energy required to release water are two long-standing problems.Herein,we propose a class of green and clean adsorbent,TpPa-1@LiCl composite,whose sorption capacity is greatly improved to 0.37 and 0.80 g g^(-1)under 30%and 90%relative humidity(RH),respectively,and which has excellent stability,showing only a slight decrease(0.79%)after 10 sorp-tion–desorption cycles(1400 min).This TpPa-1@LiCl composite can reach equilibrium within 2 h and undergo complete desorption in 30 min under air mass 1.5 G irradiation.A corresponding solar-driven AWH device can complete up to 4 sorption–desorption cycles per day,with each cycle capable of collecting 0.34 g g^(-1)water without additional energy input,which implies TpPa-1@LiCl composite has the potential for achieving sorption-assisted AWH with high efficiency and rapid cycling.

High ammonia sensitive ability of novel Cu12Sb4S13 quantum dots@reduced graphene oxide nanosheet composites at room temperature

In the work,rGO nanosheet is synthesized using the typical Hummer’s method,then Cu12Sb4 S13 quantum dots@rGO composites are prepared by solvent thermal method,and Cu12Sb4 S13 quantum dots with the average size of 5 nm are densely distributed on the surface of rGO sheet.NH3 gas response of Cu12Sb4 S13quantum dots@rGO nanosheet composites at room te mperature of 25℃is enhanced compared with the pure Cu12Sb4 S13 quantum dots and rGO nanosheet,and the composites possess an excellent stability during the humidity range of 45%-80%with a low detection limit of 1 ppm,which is related with the intrinsic hydrophobicity characteristic of Cu12Sb4 S13 quantum dots.It also proves that Cu12Sb4 S13quantum dots@rGO nanosheet composites have a quite high selectivity towards ammonia compared with ethanol,methanol,acetone,toluene,hydrogen sulfide and nitrogen dioxide at room temperature.The gas sensing mechanism of the composites is discussed primarily.

具有尺寸依赖性的全无机Cu12Sb4S13量子点的阻变存储性能

全无机零维Cu12Sb4S13量子点因其优异的光学性能、带隙可调性和载流子迁移率而受到广泛关注.本文首次报道了Cu12Sb4S13量子点的阻变存储特性,构建的FTO/Cu12Sb4S13QDs/Au阻变存储器具有良好的可再现性和可靠的双极性电阻开关特性.量子点的写入/擦除电压具有尺寸依赖性,通过控制Cu12Sb4S13量子点的尺寸调控其能带结构进而调控写入/擦除电压,实现了器件的写入/擦除电压的有效调控.同时,器件具有较大开/关比(大于104),优异的保持性和耐久性.在保持1.4×10^6s和经过104次快速读取后,阻变性能变化率小于0.1%.性能稳定性的提升也得益于更加均一的量子点尺寸,因此可通过制备尺寸均匀的量子点来提升器件稳定性.理论计算表明Cu12Sb4S13量子点的阻变机理由空间电荷限制电流机制占主导,在电场作用下,Cu 3d、Cu 3p和S 3p作为电子自俘获中心进行电子的俘获与去俘获,从而改变了Cu12Sb4S13量子点的阻值.结果表明,Cu12Sb4S13量子点可作为一种新型的阻性开关材料,在数据存储器件中具有巨大的应用潜力,有望促进下一代非易失性存储器的发展与应用.