有机半导体薄膜的有序化及其器件应用

近些年来,有机薄膜场效应晶体管(OTFTs)得到了快速的发展,但是载流子在薄膜中的传输机理以及如何有效地通过控制有机半导体层的形貌来构筑高性能的有机薄膜晶体管器件仍然是当前研究的难点.本文从有机共轭小分子半导体材料出发概述了通过不同的加工方式来优化和改善其薄膜的有序性,从而进一步提高载流子在半导体层的传输特性及其场效应性能,为制备高性能的有机半导体薄膜器件提供了新的视角和途径.     

Space qualification mechanical tests of HTS filters for satellite application

High performance high-temperature superconducting （HTS） filters have been designed and constructed for satellite application. The filters are actually a superconducting integration of an 8-pole band-pass filter with an adjustable band-stop filter onto a single piece of LaAIO3 substrate （with dimension of 0.5x45x20 mm3）. Typical results of the filters, i.e., Filters A （made by YBCO） ＆ B （made by TBCCO） will be reported. The measured responses of Filter A showed excellent specifications, e.g., an insertion loss less than 0.1 dB, a return loss better than -22.5 dB in pass-band, band-edge steepness greater than 12 dB/MHz and out-of-band rejection at a certain band deeper than -110 dB. To satisfy the requirement of rocket launch and space operation, three filters of the above design have undergone mechanical environmental simulation tests for space qualification. Detailed analysis of the response curves of Filter B measured before and after the tests showed that no noticeable change in the performance can be found. All the filters passed the rigorous ground simulation tests, which is the first time in China for HTS devices and provided a solid foundation for satellite applications of high-temperature superconductors in the near future.     

蜡酯合成酶的研究进展及其应用

蜡酯合成酶（WS）是生物体内蜡酯合成的关键酶，存在于多种动植物和微生物中，该酶可催化生成一系列结构各异、功用不同的酯类化合物。随着对WS的深入研究，人们发现不同物种的WS在功能与活性上有较大的差异，这些差异导致了其合成产物及用途的多样性。本文系统论述了不同生物体内蜡酯的合成途径、WS的生化特性与酶工程改造及其在各种酯类化合物生产中的应用，为WS的进一步研究提供参考依据。     

Synthesis of MxHyTi3O7 nanotubes by simple ion-exchanged process and their adsorption property

The MxHyTi3O7 (M=K, Fe, Zn, Co, Na, Ag) nanotubes were prepared by ion-exchange reactions, in which H2Ti3O7 nanotube reacted with salts of K2SO4, Na2SO4, Fe(NO3)3, ZnSO4, Co(NO3)2 and AgNO3 in solution respectively. The properties of products were characterized by SEM, TEM, XRD and EDX. Synthesis of MxHyTi3O7 nanotubes by ion-exchanged process was proved by our experimental results. The adsorp- tion properties of MxHyTi3O7 nanotube for methylene blue in aqueous solution were studied.     

基于多巴胺的杂化膜界面优化及其气体分离性能强化

采用仿生黏合剂多巴胺改性二氧化硅纳米颗粒（PDA@SiO₂）并与聚乙烯醇（PVA）高分子基质共混，再将获得的PVA-PDA@SiO₂杂化材料涂覆到聚砜（PSf）中空纤维支撑层表面制备中空纤维复合膜用于丙烯气体除湿，研究了杂化膜的微观形貌、晶态结构、高分子链运动性、自由体积特性等物理化学性质。实验结果表明，当填充剂PDA@SiO₂含量（质量分数，下同）为1%时，在298 K、原料气水含量为0.5%的条件下，PVA-PDA@SiO₂/PSf膜分离因子为24 837，是PVA/PSf膜的12.7倍，渗透系数为904 GPU[1 GPU=7.501×10^-10 cm³/（cm²·s·Pa）]，是PVA/PSf膜的3.6倍。仿生黏合剂多巴胺的多重相互作用可改善PVA与填充剂SiO₂的界面相容性，进而提升杂化膜的分离性能。     

持续参与世界最大综合孔径望远镜SKA国际合作

平方公里阵SKA（Square Kilometre Array）是计划建造的世界最大综合孔径射电望远镜,致力于回答宇宙起源和基本力等问题.自1993年概念提出,全球已有20个国家67个科研机构的天文学家和工程师参与SKA预研究.中国在SKA发起、选址、工程概念及技术研发等方面起到了重要推进作用.目前SKA已进入建设准备阶段,包括中国在内的许多国家正在进行先导天线、相位阵馈源等SKA关键技术试验研究.中国持续参与SKA国际合作,组建团队探索有限科学目标、致力于高精度轻型天线设计与工艺研究、宽频带大视场接收机技术研究,将跨越式提升我国天文学和技术水平、我国工程和制造业水平,实现国际重大科学工程的＂中国创造＂里程碑.其可行性已通过多方分析和论证,SKA是中国参与21世纪国际重大科学工程千载难逢的机遇.     

The RAG2 C terminus suppresses genomic instability and lymphomagenesis

Misrepair of DNA double-strand breaks produced by the V(D)J recombinase (the RAG1/RAG2 proteins) at immunoglobulin (Ig) and T cell receptor (Tcr) loci has been implicated in pathogenesis of lymphoid malignancies in humans and in mice. Defects in DNA damage response factors such as ataxia telangiectasia mutated (ATM) protein and combined deficiencies in classical non-homologous end joining and p53 predispose to RAG-initiated genomic rearrangements and lymphomagenesis. Although we showed previously that RAG1/RAG2 shepherd the broken DNA ends to classical non-homologous end joining for proper repair, roles for the RAG proteins in preserving genomic stability remain poorly defined. Here we show that the RAG2 carboxy (C) terminus, although dispensable for recombination, is critical for maintaining genomic stability. Thymocytes from 'core' Rag2 homozygotes (Rag2(c/c) mice) show dramatic disruption of Tcrα/δ locus integrity. Furthermore, all Rag2(c/c) p53(-/-) mice, unlike Rag1(c/c) p53(-/-) and p53(-/-) animals, rapidly develop thymic lymphomas bearing complex chromosomal translocations, amplifications and deletions involving the Tcrα/δ and Igh loci. We also find these features in lymphomas from Atm(-/-) mice. We show that, like ATM-deficiency, core RAG2 severely destabilizes the RAG post-cleavage complex. These results reveal a novel genome guardian role for RAG2 and suggest that similar 'end release/end persistence' mechanisms underlie genomic instability and lymphomagenesis in Rag2(c/c) p53(-/-) and Atm(-/-) mice.