二维耗散准地转方程在Lorentz空间的正则性准则

考虑二维耗散准地转方程解的正则性.通过在Lorentz空间上推广一个改进的Gronwall型引理,同时借助于Lorentz空间的插值,并结合二维耗散准地转方程解的能量估计,得到了其在时空型Lorentz空间的新爆破准则,精炼了之前的相关结果.     

两步沉积法制备Br或Cl掺杂的有机-无机杂化钙钛矿太阳电池

采用控制前驱体浓度的两步沉积法和插入PbI₂层的DMSO分子（PbI₂（DMSO）复合体）分别与MAX（MA=CH₃NH₃,X=I,Br）或MAX（X=I,Cl）进行的分子内交换法,实现了Br或Cl的掺杂并合成了厚度为300nm左右的混合卤化物钙钛矿MAPbI_3-xBr_x和MAPbI_3-xCl_x膜。MAX前驱体溶液中含5%（摩尔分数,下同）MABr或15% MACl所生成的Br或Cl掺杂钙钛矿膜能提高钙钛矿太阳电池的光伏性能,进一步提高MABr或MACl的含量并不会明显改变掺杂量,但会形成小的白色颗粒或者针孔,这些将对电池的性能产生不利影响。前驱体溶液含5% MABr的MAPbI_3-xBr_x钙钛矿太阳电池所获得的能量转换效率（PCE）为13.2%,含15% MACl的MAPbI_3-xCl_x钙钛矿太阳电池获得了最高13.5%的PCE。     

ON CONTINUATION CRITERIA FOR THE FULL COMPRESSIBLE NAVIER-STOKES EQUATIONS IN LORENTZ SPACES

In this paper,we derive several new sufficient conditions of the non-breakdown of strong solutions for both the 3 D heat-conducting compressible Navier-Stokes system and nonhomogeneous incompressible Navier-Stokes equations.First,it is shown that there exists a positive constant ε such that the solution（ρ,u,θ） to the full compressible Navier-Stokes equations can be extended beyond t=T provided that one of the following two conditions holds:■To the best of our knowledge,this is the first continua...     

420nm thick CH_3NH_3PbI_(3-x)Br_x capping layers for efficient TiO_2 nanorod array perovskite solar cells

The rutile TiO_2 nanorod arrays with 240 nm in length, 30 nm in diameter, and 420 μm~(-2) in areal density were prepared by the hydrothermal method to replace the typical 200-300 nm thick mesoporous TiO_2 thin films in perovskite solar cells. The CH_3NH_3PbI_3-xBrx capping layers with different thicknesses were obtained on the TiO_2 nanorod arrays using different concentration PbI_2·DMSO complex precursor solutions in DMF and the photovoltaic performances of the corresponding solar cells were compared. The perovskite solar cells based on 240 nm long TiO_2 nanorod arrays and 420 nm thick CH_3NH_3PbI_(3-x)Br_x capping layers showed the best photoelectric conversion efficiency(PCE) of 15.56%and the average PCE of 14.93 ± 0.63% at the relative humidity of 50%-54% under the illumination of simulated AM 1.5 sunlight(100 mW·cm~(-2)).     

基于核心素养的初中数学教学的思考——以《平面直角坐标系》为例

本文从对数学学科素养的思考出发,以平面直角坐标系为例,站在学科思想方法的高度启发引导学生,开展教学实践,采用初高中一致的函数教学逻辑,培养和训练学生的思维,发展学生的数学核心素养.