Synthesis, Crystal Structure and Luminescence of a Novel One-dimensional Silver(I)Sulfonate Complex with Pyrazine Ligand

The title complex,[Ag2(L1)2(Pyr)·2.5H20]1(L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1,with a=7.339(5),b=13.105(5),c=14.097(5)(A),α=84.377(5),β=76.921(5),γ=79.628(5)°,V= 1296.7(11)(A°)3,C48H50Ag4N8O17S4,Mr =1570.68,Z=1,Dc=2.011 g/cm3,/μ= 1.732 mm-1,F(000)=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections(I＞20(I)).Compound 1 shows a rare one- dimensional(1D)double chain, and the chains are further connected through secondary bonding,hydrogen bonds, and π-π interactions to generate a three-dimensional(3D)supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture.     

Si(111)分子束外延生长时RHEED强度振荡的观察

本文报道用反射式高能电子衍射的强度振荡测量来观察Si(111)衬底上分子束外延的生长行为,观察到了双原子层的振荡模式。振荡的衰减和恢复特性不同于Si(100)衬底上的生长行为,而同GaAs分子束外延时的特性非常相似。 关键词：     

用RHEED强度振荡锁相外延控制Ge/Si超晶格的生长

观察了Ge,Ge/Si交替外延时的反射式高能电子衍射(RHEED)强度振荡现象,并由此研究了Si(100)和Si(111)衬底上分子束外延Ge,Ge/Si超薄叠层的生长行为和生长特性。利用RHEED强度振荡,锁相控制生长了Ge(2ML)/Si(2ML),Ge(4ML)/Si(4ML)超薄超晶格。 关键词：     

Synthesis and structure of fused ring containing phosphorus compound—pyridinium 8, 9, 16,-17-tetradehydro-6,14-dithiono-7,8,15,16-tetraza-5,13-dioxa-6,14-diphospha-dibenzo [a,h] tetradecahydroanthracene-6,14-dithiolate and its derivatives

The syntheses of pyridinium of 8,9,16,-17-tetradehydro-6,14-dithiono-7,8,15,16-tetraza-5,13-dioxa-6,14-diphospha-dibenzo [a,h] tetradecahydroanthracene-6,14-dithiolate and its eleven derivatives were described. The crystal and molecular structures of the pyridinium compound and its several derivatives were also determined.     

五种中药中微量元素及重金属元素的含量分析

用微波消解-原子吸收分光光度法对巴戟天、大黄、陈皮、板蓝根、茯苓等5种中药材中的7种金属微量元素进行了含量分析。结果表明,该法的线性良好,重现性在3.3%~11%之间,精密度在2.6%以内,回收率满足定量分析要求;5种药材中铅均未超标,茯苓中镉超出国家标准;5种药材里的铜含量均有超标,其中,巴戟天超标最严重;铁在5种药材中的含量最高,其中以巴戟天含量最为丰富,达到了746.750 mg/kg,其次是锌和锰,铬的含量最少。结论:对5种药材中铜均出现超标,虽然在边缘位置,但应该予以重视;巴戟天中丰富的铁元素,可能在防止癌变发生和发展中起到一定功效。     

Observation of the crystallization and supersaturation of mixed component NaNO3-Na2SO4 droplets by FTIR-ATR and Raman spectroscopy

We present here a study of the phase behavior of mixed component NaNO(3)-Na(2)SO(4) (SNS) droplets with NaNO(3) to Na(2)SO(4) molar ratios of 1:1, 3:1, and 10:1, comparing observations with thermodynamic predictions. Measurements are made by Fourier transform infrared attenuated total reflection and micro-Raman spectroscopy for SNS droplets deposited on ZnSe and quartz substrates, respectively. The conventional deliquescence/efflorescence hysteresis in phase behavior is observed. On drying, heterogeneous crystallization leads to phase behavior that is consistent with bulk solution thermodynamics, with the formation of the mixed salt NaNO(3)·Na(2)SO(4)·H(2)O, Na(2)SO(4) (s), and NaNO(3) (s) all observed to form at relative humidities that coincide with predictions by the aerosol inorganics model. However, conditioning of the droplet at high relative humidity prior to drying is observed to lead to quantitative differences between the fractions of different salts formed. When substrate effects do not influence the crystallization process, supersaturated solutions are formed, and this leads to the observation of contact ion pairs. Such measurements of the phase behavior of mixed component droplets are important for testing the reliability of thermodynamic models.     

Boron-doped Covalent Triazine Framework for Efficient CO2 Electroreduction

Converting CO₂ into chemicals with electricity generated by renewable energy is a promising way to achieve the goal of carbon neutrality. Carbon-based materials have the advantages of low cost, wide sources and environmental friendliness. In this work, we prepared a series of boron-doped covalent triazine frameworks and found that boron doping can significantly improve the CO selectivity up to 91.2% in the CO₂ electroreduction reactions(CO₂RR). The effect of different doping ratios on the activity by adjusting the proportion of doped atoms was systematically investigated. This work proves that the doping modification of non-metallic materials is a very effective way to improve their activity, and also lays a foundation for the study of other element doping in the coming future.     

含硫醚结构均苯型聚酰亚胺的合成及表征

以4,4′-二氨基二苯硫醚(SDA)和均苯四酸酐(PMDA)为原料,通过溶液缩聚法-热酰亚胺/化学酰亚胺化的方法制备了一种含硫醚结构均苯型聚酰亚胺.利用高级旋转流变仪建立了在线跟踪反应进程的方法,采用热失重分析仪研究反应条件对热酰亚胺化及化学酰亚胺化法的影响,这些方法的建立为进一步制备高性能的聚酰亚胺提供有效的实验手段.采用小角激光光散射法、红外光谱、元素分析、接触角仪、DSC等方法对聚合物的结构与性能进行表征.结果显示,硫醚结构的引入,可有效改善聚合物薄膜的表面性能,其与铜箔之间的粘附功明显大于传统聚酰亚胺,在无胶挠性线路板应用方面显示出较好的应用前景.所获聚合物的Mw为(6.7±1.6)×104,分解温度均高于560℃;DSC的结果显示所制备的两种酰亚胺化聚合物均具有较高的玻璃化转变温度,相比之下,化学酰亚胺化更有利于获得高酰亚胺化程度的聚合物,产物的玻璃化转变温度也更高.     

ICP-AES测定向日葵花盘中13种金属元素

向日葵花盘经湿法消解,采用ICP-AES对其中钾、钙、钠、钡、铝、铬、铜、镁、铁、锰、镍、锶、锌13种元素进行测定.对光谱仪的工作条件及分析谱线等测定条件进行了选择,并进行了方法的回收率及精密度试验,其回收率在95％-122％之间.