大口径空间相机反射镜高反膜研究进展

大口径反射镜高反膜是大口径空间相机光学系统中的重要光学元件。为了观测到更多的目标、获取更多的地球以及空间观测信息,对大口径空间相机的反向射膜提出了更高要求,即要求有更宽的工作谱段和更高的反射率,还要提升基底光学性能,降低空间环境对高反膜性能的影响以及降低薄膜应力等等。对近年国内外天基大口径空间相机反射镜高反膜研究进行了综述,概述了针对以上要求所取得的成果。尽管高反膜的设计制造仍面临许多困难,但随着研究的深入与新方法的提出,这几方面难点已基本找到解决的途径。     

An improved U-Net for cell confluence estimation

Cell confluence is an important metric to determine the growth and the best harvest time of adherent cells. At present, the evaluation of cell confluence mainly relies on experienced labor, and thus it is not conducive to the automated cell culture. In this paper, we proposed an improved U-Net algorithm (called DU-Net) for the segmentation of adherent cells. First, the general convolution was replaced by the dilated convolution to expand the receptive fields for feature extraction. Then, the convolutional layers were combined with the batch normalization layers to reduce the dependence of the network on initialization. As a result, the segmentation accuracy and F1-score of the proposed DU-Net for adherent cells with low confluence (<50%) reached 96.94% and 93.87%, respectively, and for those with high confluence (≥50%), they reached 98.63% and 98.98%, respectively. Further, the paired t-test results showed that the proposed DU-Net was statistically superior to the traditional U-Net algorithm.     

基于子空间投影的复杂水下环境运动小目标检测前跟踪方法

针对复杂水下环境运动小目标检测中存在的目标信号强度弱、信杂比低等问题,该文提出基于子空间投影的检测前跟踪(TBD)算法:对原始图像数据截取序列片段,将3维时空片段中的短时运动航迹投影到2维子空间平面;利用2维投影图中平面航迹的形态特征进行初步筛选,提取目标的有效运动区域;将2维平面中的目标短时航迹在局部区域重建3维时序,在3维航迹回溯过程中利用目标运动特征再次筛选目标短时航迹.通过上述分级检测机制,可实现快速高精度的目标短时航迹检测.结合前景检测以及基于层次凝聚聚类(HAC)的长时航迹检测算法,构建了针对运动小目标的完整检测前跟踪方法.最后使用实测声呐图像数据验证了算法的检测精度和检测速度.     

A Novel Photoproduct of 1, 3-Dimethyluracil in Phosphate Buffered-saline

1, 3-Dimethyluracil （DMU） in phosphate buffered-saline （PBS, pH=8） was irradiated by a medium pressure mercury lamp （MPML） and produced a novel compound C6H9N2O6P. The composition and structure of the compound has been identified by elemental analysis, EIMS, UV, IR, ^1H and ^31P-NMR.     

微胶囊固定化过氧化氢酶

以乙基纤维素为膜材，用液中干燥法将过氧化氢酶微胶囊化，研究了温度和ｐＨ值对酶活性的影响及过氧化氢和尿素对固定化酶的抑制作用，由于乙基纤维素膜的保护，明胶对ｐＨ值的缓冲作用及明胶与尿素的反应，明显地扩大了酶对温度和ｐＨ值的适应性，降低了酶活性抑制剂的影响。     

双核镍(Ⅱ)配合物的合成、晶体结构和磁性质

合成了通过N-N键桥联的不对称的N₂O₃席夫碱配体(H₃L)的镍(Ⅱ)配合物[Ni₂(HL)₂]₂(DMF)₈(H₂O)₂ (1)。配合物晶体属于三斜晶系，空间群为P1，a=1.273 5(2) nm，b=1.360 4(3) nm，c=1.427 6(3) nm，α=85.358(4)°，β=63.513(3)°，γ=79.545(4)°，V=2.176 8(7) nm³，Z=1，F(000)=980，R₁=0.073 6。配合物1的不对称单元中含有两个双核结构Ni₂(HL)₂(DMF)₂(H₂O)₂ (Ⅰ)和Ni₂(HL)₂(DMF)₄ (Ⅱ)以及两个DMF溶剂分子。通过酚基氧原子桥联的镍-镍距离分别为：Ni(1)-Ni(1A)，0.308 4 nm；Ni(2)-Ni(2B)，0.310 3 nm(对称操作：A：1-x，2-y，-z；B：1-x，1-y，1-z)。金属镍(Ⅱ)离子采取扭曲的八面体配位构型，一个配体的NO₂三齿配位单元和另一个配体的酚基氧原子位于赤道面位置，两个溶剂分子占据轴向位置。晶体中存在着分子内以及分子与溶剂分子间的两种氢键作用。配合物1的变温磁化率测定表明，Ni(Ⅱ)离子之间的反铁磁耦合作用在它的磁性质中起主导作用。     

Studies on the refolding of the reduced-denatured insulin with size exclusion chromatography

The refolding of the reduced-denatured insulin from bovine pancreas was investigated with the size exclusion chromatography (SEC). It was shown that the reduced-denatured insulin originally denatured with 7.0 mol·L-1 guanidine hydrochloride (GuHCI) or 8.0 mol·L-1 urea could not be refolded with a non-oxidized mobile phase. Although the oxidized and reduced glutathione (GSSG and GSH) were employed in the oxidized mobile phase, the reduced-denatured insulin still could not be renatured. However, in the presence of 2.0 mol·L-1 urea in the oxidized mobile phase employed, the reduced-denatured insulin can be refolded with SEC, and the aggregation of denatured insulin can be diminished by urea. In addition, the disul-fide exchange of reduced-denatured insulin also can be accelerated with GSSG/GSH in the oxidized mobile phase. The three disulfide bridges of insulin were formed correctly and the reduced-unfolded insulin can be renatured completely. The results were further tested with re-versed-phase liquid chromatography (RPLC) and hydrophobic interaction chromatography (HIC).     

维生素B12缺乏致神经损害临床分析

维生素B12缺乏多继发于胃肠道外科手术后、贫血及其它内科疾病，其引起的神经系统损害临床表现多样，主要为周围神经损害及亚急性联合变性。测定维生素B1：值、查肌电图等可明确诊断。补充维生素B12治疗有效。     

含羟基芳基或氨基芳基的磷酰胺酯衍生物的合成

采用均相反应的方法合成了6个含羟基芳基或氨基芳基的磷酰胺酯衍生物:[(ClCH_2CH_2)_2NP(O)(OPh)(XArY)](X:O,NH;Y:m或p-OH或NH_2).用元素分析、红外光谱、氢核磁共振谱及质谱证实了它们的组成及结构.