Synthesis and Characterization of Triphenylethylene Derivatives with Aggregation-Induced Emission Characteristics

New aggregation-induced emission (AIE) compounds derived from triphenylethylene were synthesized. The thermal, photophysical, electrochemical and aggregation-induced emissive properties were investigated. All the compounds had strong blue light emission capability and good thermal stability. Their maximum fluorescence emission wavelengths were between 443 to 461 nm in solid states, while their glass transition temperatures ranged from 86 to 129 °C. The decomposition temperatures of the synthesized compounds were in the range of 432–534 °C. The synthesized compounds possessed aggregation-induced emission properties, namely exhibited enhanced fluorescence emission in aggregated states. The highest occupied molecular orbital (HOMO) energy levels estimated from the oxidation potentials were between 5.61 and 5.66 eV and the lowest unoccupied molecular orbital/highest occupied molecular orbital (LUMO/HOMO) energy gap values were found to be in the range of 3.18–3.22 eV. The compounds 4-(4-(2,2-bis(4-(naphthalen-1-yl)phenyl)vinyl)phenyl) dibenzothiophene [(BN)₂Bt] and 4-(4-(2,2-di(biphenyl-4-yl)vinyl)phenyl) dibenzothiophene [(BB)₂Bt] exhibited vibronic fine-structure photoluminescence spectra when the water fraction was less than 70%.     

碳包覆改性制备高倍率性能的锂离子电池正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2

采用碳酸盐共沉淀-高温固相法制备了一系列表面碳包覆改性(w=1.0%,2.0%,3.0%)的LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料,借助X射线衍射(XRD)分析、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电流充放电测试等表征手段对材料的晶体结构、微观形貌和电化学性能进行了较系统的研究。结果表明,碳成功地包覆在了材料颗粒的表面,碳包覆改性后的材料具有良好的α-Na Fe O2结构(空间群:R3m),且随着包碳量的增加,一次颗粒平均尺寸逐渐增大(从177 nm增至209 nm)。表面的无定形碳层可以提高材料的电子导电率,减少电极材料与电解液的副反应,故而碳包覆材料的电化学性能都有了一定程度提升。包覆碳量为2.0%的样品高倍率和长循环性能最好,在2.7~4.3 V,1C下循环100次后,容量保持率为93%;在0.1C、0.2C、0.5C、1C、3C、5C、10C和20C时的放电比容量分别为:155、148、145、138、127、116、104和96 m Ah·g-1。在超高倍率50C(9 A·g-1)时,其放电比容量还能达到62 m Ah·g-1(原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料仅为30 m Ah·g-1),倍率性能十分优异。     

铸铁的价电子结构及元素石墨化行为的判据

计算了常用合金元素在铸铁相中的价电子结构.取相结构中最强共价键的键能为结构形成因子“S”,揭示了合金元素原子的电子结构与平衡凝固、非平衡凝固及石墨化的关系.以石墨的结构形成因子及渗碳体最强共价键上的n_A为临界值,提出了合金元素石墨化行为的判据.将此判据用于常用的合金元素,发现理论与实际符合得极好.     

A Facile Strategy for Non-fluorinated Intrinsic Low-k and Low-loss Dielectric Polymers: Valid Exploitation of Secondary Relaxation Behaviors

High-performance low-k and low-loss circuit materials are urgently needed in the field of microelectronics due to the upcoming FifthGeneration Mobile Communications Technology(5 G Technology).Herein,a facile design strategy for non-fluorinated intrinsic low-k and low-loss polyimides is reported by fully considering the secondary relaxation behaviors of the polymer chains.A new amorphous non-fluorinated polymer(TmBPPA)with a k value of 2.23 and a loss tangent lower than 3.94×10^-3 at 104 Hz has been designed and synthesized,which to the best of our knowledge is the lowest value amongst the non-fluorinated and non-porous polymers reported in literature.Meanwhile,TmBPPA exhibits excellent overall properties,such as excellent thermostability,good mechanical properties,low moisture absorption,and high bonding strength.As high-performance flexible circuit materials,all these characteristics are highly expected to meet the present and future demands for high density,high speed,and high frequency electronic circuit used in 5 G wireless networks.     

A Single-Longitudinal-Mode Dual-Wavelength cw Tm,Ho:GdVO4 Microchip Laser

A liquid nitrogen cooled dual-wavelength Tm,Ho：GdVO4 microchip laser is reported. The output dual wavelengths axe at 2038.9nm and 2050.1 nm. At each wavelength, the laser has a single longitudinal mode. The threshold power is nearly 20mW and the slope efficiency is 18.7%. The single longitudinal mode output power reaches 98mW, and the ratio of power is about 60% （2038.9nm） and 40% （2050.1 nm）.     

100MeV强流回旋加速器射频数字低电平系统研制

介绍了100MeV射频低电平控制系统的设计及其桌面实验的组成. 通过实测, 验证了他激模式下幅度控制环路和相位控制环路中实现数字式控制的可行性. 初步测试数据及调试过程均表明数字式控制可用于100MeV回旋加速器的射频低电平控制系统.     

醇盐水解法制备钛酸铅微粉的机理研究

采用ＴＧ－ＤＴＡ、ＸＲＤ、ＩＲ等手段研究了醇盐水解法制备的钛酸铅微粉的晶化行为，并用化学分析方法对微粉中可溶铅含量做了研究。结果表明，未昌化微粉中Ｐｂ以无定形ＰｂＴｉＯ３和无定形ＰｂＯ两种形式存在，当热处理温度达到晶化温度区间（４３０￣４７０℃）时，无定形ＰｂＴｉＯ３向结晶型ＰｂＴｉＯ３的转化和无定形ＰｂＯ与ＴｉＯ２间的反应同时发生。     

氨蒸发诱导法制备纳米结构LiNi1/3Co1/3Mn1/3O2及其作为高功率型锂离子电池正极材料的性能

采用氨蒸发诱导法成功制备出纳米结构LiNi_1/3Co_1/3Mn_1/3O₂正极材料,借助X射线衍射（XRD）分析、扫描电镜（SEM）、透射电镜（TEM）、高分辨率透射电镜（HRTEM）、能量分散谱（EDS）和比表面测试等表征手段及恒电流充放电测试研究了其晶体结构、微观形貌和电化学性能. 研究表明该方法制备出的材料具有良好的α-NaFeO₂层状结构,阳离子混排程度低. 纳米片交错堆积而成核桃仁状形貌,片与片之间形成许多纳米孔,而且纳米片的侧面属于{010}活性面,能够提供较多的锂离子的脱嵌通道. 在室温下及3.0-4.6 V充放电范围内,该材料在电流密度为0.5C、1C、3C、5C和10C时放电比容量分别为172.90、153.95、147.09、142.16 和131.23mAh·g^-1. 说明其具有优异的电化学性能,非常有潜力用于动力汽车等高功率密度锂离子电池中.     

混合反胶束的电导与微结构研究

反胶束是两亲分子在非极性溶剂中形成的一种有序组合体，在医药、化工、采油、胶束催化及酶催化等领域中有重要应用．与胶束溶液相比，人们对反胶束的形成与结构的了解至今仍不充分．特别是对于由混合表面活性剂形成的反胶束的研究几乎无人涉及．本文采用动态光散射、电导及荧光光谱等手段对阴离子表面活性剂AOT与非离子表面活性剂形成的混合反胶束进行了研究，旨在探讨利用表面活性剂的复配来调节和控制反胶束的结构和性能．亚实验部分二异辛基磺化琉璃酸钠（AOT，Sigma公司）；Brij30为含4个氧乙烯基（EO基）的十二碳醇（AcrosOrgani…     

Construction of Ag/1,2,4-triazole/polyoxometalates hybrid family varying from diverse supramolecular assemblies to 3-d Rod-packing framework

Eight members of the Ag/1,2,4-triazole/polyoxometalates (POMs) hybrid supramolecular family, namely, [Ag4(dmtrz)4][Mo8O26] (dmtrz=3,5-dimethyl-1,2,4-triazole, 1), [Ag6(3atrz)6][PMo12O40]2.H2O (3atrz=3-amino-1,2,4-triazole, 2), [Ag2(3atrz)2]2[HPMoVI10MoV2O40] (3), [Ag2(dmtrz)2]2[HPMoVI10MoV2O40] (4), [Ag2(trz)2]2[Mo8O26] (trz=1,2,4-triazole, 5), [Ag2(3atrz)2][Ag2(3atrz)2(Mo8O26)] (6), [Ag4(4atrz)2Cl][Ag(Mo8O26)] (4atrz=4-amino-1,2,4-triazole, 7), and [Ag5(trz)4]2[Ag2(Mo8O26)].4H2O (8), were synthesized through hydrothermal reactions of 1,2,4-triazole or its derivatives with appropriate silver salts and molybdates. Crystal structure analysis reveals that the POM-dependent Ag-1,2,4-triazolate units in these hybrid compounds form a novel tetranuclear cluster (1), a unique double calix[3]arene-shaped hexamer (2), zigzag chains (5 and 6), helix chains (3, 4, and 8), and an interesting looped chain (7). A series of hydrogen bonding-based supramolecular assemblies varying among the 0-D+0-D (1 and 2), 0-D+1-D (3 and 4), 1-D+1-D (5 and 7), and 1-D+2-D (6) modes between the organomatic cations and POM anions were observed in these structures. Moreover, the inorganic chain [Ag(Mo8O26)]n3n- in 7 constructed by the building block [Mo8O26]4- linked only via single Ag+ ion is unprecedented. Compound 8 is the first high-dimensional framework constructed from the [Ag2(Mo8O26)]n2n- rod-shaped subunits. These hybrid supramolecular compounds present interesting photochemical properties. The spectroscopic experiments show that they not only are potential semiconductor materials but also have interesting photoluminescence phenomena, including O-->Mo [LMCT] and intraligand [pi-pi*] emissions generated by internal heavy metal effect.