稀土配合物红色有机电致发光器件的研究

以TTA为配体合成了新的共掺杂稀土配合物Tb0.5Eu0.5(TTA)3Dipy,通过与PVK的掺杂,制备了以PVK:Tb0.5Eu0.5(TTA)3 Dipy为发光层的结构为:ITO/PVK:Tb0.5Eu0.5(TTA)3Dipy/BCP/Al的发光器件,在直流电压的驱动下,发现了铕在612 nm处的特征发射,和PVK在410 nm处的发光.此外,还观察到了位于490 nm处的新的发光峰,通过分析研究,认为新的发光来自于稀土配合物的配体和BCP之间相互作用形成的电致激基复合物.用PBD代替了BCP作为电子传输层,制备了结构为:ITO/PVK:Tb0.5Eu0.5(TTA)3DiPy/PBD/Al的发光器件,得到了纯的红色发光.     

An Improved Approach for Practical Synthesis of 5-Hydroxymethyl-2′-deoxycytidine (5hmdC) Phosphoramidite and Triphosphate

5-Hydroxymethyl-2′-deoxycytidine (5hmdC) phosphoramidite and triphosphate are important building blocks in 5hmdC-containing DNA synthesis for epigenetic studies. However, efficient and practical methods for the synthesis of these compounds are still limited. The current research provides an intensively improved synthetic method that enables the preparation of commercially available cyanoethyl-protected 5hmdC phosphoramidite with an overall yield of 39% on 5 g scale. On the basis of facile and efficient accesses to cyanoethyl protected-5hmdU and 5hmdC intermediates, two efficient synthetic routes for 5hmdC triphosphate were also developed.     

Discovery of an NAD+ analogue with enhanced specificity for PARP1

Among various protein posttranslational modifiers, poly-ADP-ribose polymerase 1 (PARP1) is a key player for regulating numerous cellular processes and events through enzymatic attachments of target proteins with ADP-ribose units donated by nicotinamide adenine dinucleotide (NAD⁺). Human PARP1 is involved in the pathogenesis and progression of many diseases. PARP1 inhibitors have received approvals for cancer treatment. Despite these successes, our understanding about PARP1 remains limited, partially due to the presence of various ADP-ribosylation reactions catalyzed by other PARPs and their overlapped cellular functions. Here we report a synthetic NAD⁺ featuring an adenosyl 3′-azido substitution. Acting as an ADP-ribose donor with high activity and specificity for human PARP1, this compound enables labelling and profiling of possible protein substrates of endogenous PARP1. It provides a unique and valuable tool for studying PARP1 in biology and pathology and may shed light on the development of PARP isoform-specific modulators.

An analogue of nicotinamide adenine dinucleotide (NAD⁺) featuring an azido group at 3′-OH of adenosine moiety is found to possess high specificity for human PARP1-catalyzed protein poly-ADP-ribosylation.     

硫脲掺杂金刚石的高温高压合成及FT-IR光谱研究

利用温度梯度法,在6.5 GPa、1 300～1 350℃的高温高压极端物理条件下,通过在FeNiCo-C合成体系中添加硫脲(CH4N2S)成功合成了金刚石,所合成的晶体呈现出黄色且具有六-八面体形貌.利用扫描电镜(SEM)对所合成金刚石的表面形貌进行了表征,测试结果表明,随着合成体系中CH4N2S添加量的逐渐增加,所合成金刚石的表面变得逐渐粗糙.借助傅里叶红外(FT-IR)光谱对金刚石样品内部的氮、氢缺陷以及化学键结构进行了测试分析,结果表明,金刚石中的氢元素以-CH3,-CH2-,C-H形式存在,而其内部的氮杂质以C心、A心形式存在.此外,在3 300～3 600 cm-1观察到NH的吸收带.     

酰胺功能化修饰琼脂糖/硅胶复合材料的制备及吸附性能研究

采用溶胶-凝胶法,以氧化琼脂糖和四甲氧基硅烷为前驱体,通过水解、缩聚反应制得琼脂糖/硅胶复合材料,进一步利用开环、"巯-烯"点击和酰胺化反应对复合材料实现酰胺基团功能化修饰.借助红外光谱(FT-IR)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)对所制备复合材料进行结构、组成和微观形貌表征.以制备的酰胺功能化修饰琼脂糖/硅胶复合材料为吸附剂,探讨其对莱克多巴胺的吸附过程,实验考察了溶剂、吸附时间、莱克多巴胺的初始浓度等对吸附的影响.结果表明:经过修饰反应酰胺基团成功接枝到琼脂糖/硅胶复合材料,该材料颗粒呈球形,粒径在2～3μm之间;复合材料对莱克多巴胺表现出良好的吸附性能,吸附过程50 min达到平衡,适合准二级动力学特征,属化学吸附,吸附等温线符合Freundlich模型;复合材料经过6次吸附解析,再生后对莱克多巴胺的吸附率仅有小幅下降,表明具有较好的循环再生吸附能力.     

基于近似解析法的超导储能磁体设计

降低超导储能磁体的研制成本一直是控制超导磁储能系统(Superconducting Magnetic Energy Storage, SMES) 总成本的重要手段之一. 本文考虑在一定磁体结构参数范围内, 磁体产生的最大磁场值可以采用级数进行 表示, 磁体的电感值可以采用线性函数表示, 给出了超导储能磁体磁场能量的近似解析表达式, 提出了一种基于近 似解析法的超导储能磁体设计方法. 该方法以储能磁体的线材用量最小作为设计目标, 在给定超导线材参数和临界电流特性曲线, 以及磁体储能总量要求的情况下, 依据此方法可快速的得到成本最优时所对应的磁体结构参数.将近似解析法优化和采用传统的有限元软件 Ansys 仿真优化进行对比分析, 结果表明采用近似解析法进行磁体优化更加方便快捷, 节省了大量计算时间.     

紫外熔石英元件高精度低缺陷控形控性制造技术研究进展

传统的紫外熔石英元件加工方法本身会引入各类制造缺陷,需要后期加工来消除前期加工带来的缺陷,限制了熔石英元件的加工质量和加工效率。针对这些问题,课题组提出了采用磁流变、离子束、保形光顺和流体动压抛光等可控柔体加工技术提升熔石英元件的加工效果,并开展了相关研究。主要介绍了课题组在关键技术上取得的重要进展,包括亚纳米精度表面控形制造技术、纳米精度本征表面控性生成方法、熔石英元件高精度低缺陷组合工艺与设备等一系列关键技术。通过探讨关键技术及其发展现状,为未来紫外熔石英元件高精度低缺陷制造技术的发展提供参考。     

非齐次动力学方程的一种精细积分单步方法

针对非齐次动力学方程■,结合精细积分法和微分求积法,利用同阶的显式龙格-库塔法对计算过程中待求的v_(k+i/s)(i=1,2,…,s)进行预估,提出了一种避免状态矩阵求逆的高效精细积分单步方法。该方法采用精细积分法计算e~(Ht),而Duhamel积分项采用s级s阶的时域微分求积法,计算格式统一且易于编程,可灵活实现变阶变步长。仿真结果表明,与其他单步法及预估校正-辛时间子域法进行数值比较,该方法具有高精度、高效率及良好的稳定性,在求解大规模动力系统时间响应问题中具有较大的优势。     

Giant Asymmetric Transmission and Circular Dichroism with Angular Tunability in Chiral Terahertz Metamaterials

Inspired by the chiral structure from mode interaction, a chiral terahertz metamaterial and its complementary structure with the coexistence of asymmetric transmission and circular dichroism response are designed. The asymmetric transmission happens in the presence of electric and magnetic modes perpendicular to each other, resulting from intrinsic chirality under normal incidence. Circular dichroism exists in the presence of electric and magnetic modes parallel to each other under oblique incidence because of extrinsic chirality. Both asymmetric transmission and circular dichroism are enhanced by complementary structures, benefitting from the coupling between adjacent units. The maximum of chiral parameter κ can achieve 450, which is one hundred times higher than previously reported. The chiral response can be tuned by the incident angle and is sensitive to the environmental refractive index. The results highlight the potential applications of these metamaterials in chiral sensing and polarization transformation devices.     

正电子冲击下氦电离三重微分截面的理论计算

我们发展了一种正电子碰撞原子电离的畸变波Born近似方法, 在这个方法中,正负电子偶素通道通过一个ab initio的光学势附加到入射粒子和靶的相互作用势上,且通道对电离作用被第一次被考虑在正电子碰撞原子电离的过程中. 应用这个方法计算了在50 eV入射能量范围氦的电离的三重微分截面,计算结果和实验数据很好的符合.