Determination of five sesquiterpenoids in Xingnaojing injection by quantitative analysis of multiple components with a single marker

A quantitative analysis of multiple components with a single‐marker method was established for the simultaneous determination of five sesqutiterpenoids in Xingnaojing injection. This method was established with Xingnaojing injection determined by high‐performance liquid chromatography coupled with diode array detection. The durability and system suitability of the established method were evaluated, and the reliable relative correction factors were obtained with curdione selected as an internal reference. The contents of the five components in all Xingnaojing injections were determined by external standard method and the contents of curcumenone, curcumenol, curzerenone, and germacrone were also calculated with the obtained relative correction factors. Then, relative error was investigated to estimate the difference of the two methods. As a result, the established new method possesses good adaptability, and there is no significant difference between the two methods, except for the content of curzerenone in eight samples. To put the established method into practice, the limits of quantitation of the established method of the five components were proposed and defined. Thus, the developed methodology can also be utilized to the quality evaluation of Xingnaojing injection, in spite of the difference found in the content of curzerenone between the external standard method and the newly established method.     

Self‐Assembled Colloidal Particle Clusters from In Situ Pickering‐Like Emulsion Polymerization via Single Electron Transfer Mechanism

A simple route is reported to synthesize colloidal particle clusters (CPCs) from self‐assembly of in situ poly(vinylidene fluoride)/poly(styrene‐co‐tert‐butyl acrylate) [PVDF/P(St‐co‐tBA)] Janus particles through one‐pot seeded emulsion single electron transfer radical polymerization. In the in situ Pickering‐like emulsion polymerization, the tBA/St/PVDF feed ratio and polymerization temperature are important for the formation of well‐defined CPCs. When the tBA/St/PVDF feed ratio is 0.75 g/2.5 g/0.5 g and the reaction temperature is 35 °C, relatively uniform raspberry‐like CPCs are obtained. The hydrophobicity of the P(St‐co‐tBA) domains and the affinity of PVDF to the aqueous environment are considered to be the driving force for the self‐assembly of the in situ formed PVDF/P(St‐co‐tBA) Janus particles. The resultant raspberry‐like CPCs with PVDF particles protruding outward may be promising for superhydrophobic smart coatings.

     

波长校准用低压石英汞灯驱动电源的研制

研制波长校准用低压石英汞灯电源,用于驱动汞灯起辉并维持稳态发光。电路由EMI滤波电路、桥式整流电路、LCC半桥谐振逆变电路、控制电路和保护电路5部分组成。采用系统建模与仿真验证电路的可行性并计算电路参数理论值,利用示波器和功率表验证电源输出参数,功率输出稳定性不大于0.03 W。根据紫外可见近红外分光光度计国防最高计量标准对研制的电源驱动汞灯的工作效果进行评价。结果表明,汞灯能够输出系列特征谱线,谱线相对强度稳定性不大于5.16%;汞灯工作3 h后,灯管外壳表面温度为43℃。该驱动电源的性能参数满足JJG112–2015《低压石英汞灯波长标准器检定规程》的要求。     

微波消解–石墨炉原子吸收光谱法测定空气中碲

建立微波消解–石墨炉原子吸收光谱法测定空气中的碲。采用微孔滤膜收集样品,以硝酸–双氧水混合体系微波消解滤膜,氯化钯为基体改进剂,在优化的仪器工作条件下测定。碲的质量浓度在0~15μg/L范围内与吸光度线性关系良好,相关系数为0.999 5,方法检出限为0.14μg/L。样品加标回收率在95.6%~104.0%之间,测定结果的相对标准偏差为1.15~1.37%(n=7)。该方法操作简单、灵敏度高,适用于空气中微量碲的测定。     

Thickness difference induced pore structure variations in cellulosic separators for lithium-ion batteries

The pore structure of the separator is crucial to the performance of a lithium-battery as it affects the cell resistance. Herein, a straightforward approach to vary the pore structure of Cladophora cellulose (CC) separators is presented. It is demonstrated that the pore size and porosity of the CC separator can be increased merely by decreasing the thickness of the CC separator by using less CC in the manufacturing of the separator. As the pore size and porosity of the CC separator are increased, the mass transport through the separator is increased which decreases the electrolyte resistance in the pores of the separator. This enhances the battery performance, particularly at higher cycling rates, as is demonstrated for LiFePO₄/Li half-cells. A specific capacity of around 100 mAh g^?1 was hence obtained at a cycling rate of 2 C with a 10 µm thick CC separator while specific capacities of 40 and close to 0 mAh g^?1 were obtained for separators with thicknesses of 20 and 40 µm, respectively. As the results also showed that a higher ionic conductivity was obtained for the 10 µm thick CC separator than for the 20 and 40 µm thick CC separators, it is clear that the different pore structure of the separators was an important factor affecting the battery performance in addition to the separator thickness. The present straightforward, yet efficient, strategy for altering the pore structure hence holds significant promise for the manufacturing of separators with improved performance, as well as for fundamental studies of the influence of the properties of the separator on the performance of lithium-ion cells.     

Enhancement of SrTiO<Subscript>3</Subscript>/BiPO<Subscript>4</Subscript> heterostructure for simulated organic wastewater degradation under UV light irradiation

A novel SrTiO₃/BiPO₄ heterostructure with different amounts of SrTiO₃ have been successfully prepared through the hydrothermal process. The photocatalysts were characterized by X-ray powder diffraction, UV–Vis diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic performance was evaluated by degrading the methylene blue dye solution under UV light. Results showed that the samples displayed excellent photocatalytic degradation efficiency due to the highly efficient suppression of the recombination of electron–hole pairs. A possible mechanism of SrTiO₃/BiPO₄ heterojunctions was discussed. The research indicated that the as-prepared SrTiO₃/BiPO₄ heterogeneous photocatalyst can be used as an effective material for degrading industrial organic wastewater.     

含铵根离子等规聚丙烯离聚体的合成及性能研究

合成了一系列高分子量、窄分子量分布且高等规度,含有不同―NR_3~+X~-离子基团含量的聚丙烯离聚体(iPP-NR_3~+X~-).以PP/IUD共聚物作为反应中间体,与三乙胺或N-甲基咪唑氨化得到聚丙烯离聚体.通过离子交换反应制备不同反离子的N-甲基咪唑聚丙烯离聚体,包括双三氟甲基磺酰亚胺根离子(Tf_2N~-)、四氟硼酸根离子(BF_4~-)和六氟磷酸根离子(PF_6~-).热重分析结果发现N-甲基咪唑聚丙烯离聚体的热稳定性明显优于三乙胺聚丙烯离聚体,表明不含β-H的N-甲基咪唑聚丙烯离聚体具有较高的热稳定性.同时,聚丙烯离聚体的表面亲水性得到明显改善.并且,聚丙烯离聚体的断裂伸长率也得到显著提高,最高达到900%.比较不同反离子聚丙烯离聚体的屈服强度和断裂强度发现I~-聚丙烯离聚体具有最优的力学性能.     

无模板法水热合成CoTe及其可见光光催化还原CO_2性能

本文利用无模版水热法合成了碲化钴(CoTe)纳米催化剂。为了避免引入残炭,所有的反应物均为无机化合物。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见(UV-Vis)吸收光谱和X射线光电子能谱(XPS)等技术对所制备的CoTe纳米材料进行了表征。结果表明,所得产物为具有六方结构的海绵状CoTe,且具有可见光(λ420 nm)光催化活性。当以N,N-二甲基乙酰胺(DMA)或纯水为溶剂时,二氧化碳(CO_2)均可被光催化还原为甲烷(CH_4),但产率较低。而在催化体系中加入牺牲剂三乙醇胺(TEOA)后,产物由CH_4变为一氧化碳(CO)。这些实验结果表明,溶剂和牺牲剂的引入均可影响CoTe纳米催化剂对CO_2的光催化还原性能。     

尺寸效应对二硫化钼量子点光学性能的影响

通过油溶法成功地制备出不同粒径大小的二硫化钼,并探究了单层二硫化钼尺寸效应对荧光性质的影响。其中反应时间为3 h制备出的二硫化钼量子点为单层结构,3种尺寸的二硫化钼的荧光光谱和拉曼光谱研究表明,当粒径或激发波长增大时,荧光谱图中峰位发生红移。     

Crystal structures and enhanced luminescence of Zn(II) and Cd(II) complexes containing conjugated organic ligands

By self-assembly of delocalized organic ligands (L¹ and L²) with Cd(SCN)₂, ZnI₂ and Zn(NCS)₂, three luminescent complexes ZnI₂(L¹)₂ (I), [Cd(L¹)₂(μ_1,3-SCN)₂] _n (II) and Zn(NCS)₂(L²)₂ (III) were obtained (L¹ = 2-{5,5-dimethyl-3-[2-(pyridine-4-yl)ethenyl]cyclohex-2-enylidene}propanedinitrile and L² = 2-{5,5-dimethyl-3-[2-(pyridine-3-yl)ethenyl]cyclohex-2-enylidene}propanedinitrile). The structures of the complexes were determined by single crystal X-ray diffraction analysis (CIF files CCDC nos. 1406116 (I), 1406115 (II), and 1400360 (III)). In complex I, Zn(II) is coordinated by two functional organic ligands and two I^– ions, to form a I₂N₂ distorted tetrahedral geometry. In 1D coordination polymer II, the Cd(II) centers show six-coordinated geometries, two organic ligands and four SCN^– ions involve in coordination with each Cd(II) center. The thiocyanate groups show μ_1,3-SCN bridging coordination modes and the adjacent Cd(II) ions are bridged by double μ_1,3-SCN ions to form an infinite chain. In complex III, Zn(II) is coordinated by two functional organic ligands and two NCS^– groups, to form a N₄ distorted tetrahedral geometry. Compared with the free ligands, the complexes show superior luminescent property with red-shift and enhancement of fluorescence intensity.