氘代DMSO试剂中残留~1H的检测

本文提出一种利用尿素作为内标物质,通过加入不同量的尿素测量它与氘代DMSO中溶剂残留信号峰面积比变化的方法。结果表明,尿素和DMSO溶剂峰的1H共振峰面积比与它们之间摩尔比之间有很强的线性关系,进而可以计算DMSO溶剂的氘代率。该方法简单、快速,所需试剂较少,低毒,可在实验室准确测试DMSO试剂的氘代率,也可以将此方法推广到其他氘代试剂的检测。     

超高效液相色谱法检测湿巾中苄索氯铵含量

建立湿巾产品中苄索氯铵的超高效液相色谱检测方法。湿巾样品以甲醇-水溶液(1∶1)超声提取,振荡离心过滤后,用Phenomenex C18液相色谱柱分离,以二极管阵列检测器于220 nm波长处检测进行定性、定量。苄索氯铵的质量浓度在1~200 mg/L范围内与色谱峰面积线性良好,相关系数(r2)为0.9999。苄索氯铵的检出限为0.50 mg/L,色谱峰面积的相对标准偏差为2.17%(n=9),苄索氯铵的加标回收率为91.28%~98.65%。该方法样品处理简便快捷,测定结果准确可靠。     

A low cost composite quasi-solid electrolyte of LATP,TEGDME,and LiTFSI for rechargeable lithium batteries

The composite quasi solid state electrolytes(CQSE) is firstly synthesized with quasi solid state electrolytes(QSE) and lithium-ion-conducting material Li_(1.4)Al_(0.4)Ti_(1.6)(PO_4)_3(LATP), and the QSE consists of [LiG4][TFSI] with fumed silica nanoparticles. Compared with LATP, CQSE greatly improves the interface conductance of solid electrolytes. In addition,it has lower liquid volume relative to QSE. Although the liquid volume fraction of CQSE is droped to 60%, its conductivity can also reach 1.39 × 10~(-4)S/cm at 20℃. Linear sweep voltammetry(LSV) is conducted on each composite electrolyte.The results show the possibility that CQSE has superior electrochemical stability up to 5.0 V versus Li/Li+. TG curves also show that composite electrolytes have higher thermal stability. In addition, the performance of Li/QSE/Li Mn_2O_4 and Li/CQSE/Li Mn_2O_4 batteries is evaluated and shows good electrochemical characteristics at 60℃.     

一种改进的冲量测试装置及其数据处理方法

对摆锤式片炸药比冲量测试装置及其数据处理方法进行了改进。首先,在对机械结构进行了改进设计的基础上,利用光栅测试系统测量摆动角度,并解决了测试时波形失真的问题,提高了装置的精密性和稳定性。然后,采用该装置研究了阻尼随摆动幅度的变化规律,并用实测数据进行了验证;提出了片炸药比冲量测试时的最大摆角修正方法,并进行了试验对比研究。结果表明:改进后的装置及其数据处理方法能够更加准确地测量片炸药的比冲量。     

锂电池中的凝胶聚合物电解质

锂电池目前在人们生活中已经得到广泛应用,但是传统的液体电解质沸点低且易泄漏,容易引起锂枝晶生长和安全问题。凝胶聚合物电解质(GPEs)的状态介于液态电解质和固态电解质之间,不仅可以作为电解质,还可以作为隔膜,这样可以减少液体电解质的泄漏以及改善固体电解质的界面电阻。本文综述了锂电池中制备不同类型的GPEs的方法,如溶液浇铸法、相转化法、原位聚合法、UV(紫外)固化法和静电纺丝法等,重点总结了不同纤维基的GPEs(聚(偏二氟乙烯)(PVDF)、聚(偏二氟乙烯-共六氟丙烯)(PVDF- HFP)、聚甲基丙烯酸甲酯(PMMA)、聚丙烯腈(PAN)和聚间亚苯基间苯二甲酰胺(PMIA))在锂电池中的运用,并通过对不同基质的改性来改善电解质的离子电导率,阻碍锂枝晶的生长。最后,本文对锂电池中GPEs的未来发展前景进行了展望,讨论和提出的策略将为今后高性能锂电池的实际应用提供更多的途径。     

Forming solid electrolyte interphase in situ in an ionic conducting Li_(1.5)Al_(0.5)Ge_(1.5)(PO_4)_3-polypropylene(PP) based separator for Li-ion batteries

A new concept of forming solid electrolyte interphases(SEI) in situ in an ionic conducting Li_(1.5)Al_(0.5)Ge_(1.5)(PO_4)_3-polypropylene(LAGP-PP) based separator during charging and discharging is proposed and demonstrated. This unique structure shows a high ionic conductivity, low interface resistance with electrode, and can suppress the growth of lithium dendrite. The features of forming the SEI in situ are investigated by scanning electron microscopy(SEM) and x-ray photoelectron spectroscopy(XPS). The results confirm that SEI films mainly consist of lithium fluoride and carbonates with various alkyl contents. The cell assembled by using the LAGP-coated separator demonstrates a good cycling performance even at high charging rates, and the lithium dendrites were not observed on the lithium metal electrode. Therefore, the SEI-LAGP-PP separator can be used as a promising flexible solid electrolyte for solid state lithium batteries.     

量子点室温磷光法检测生物体液中尿酸

在水相中合成了3-巯基丙酸包覆的Mn掺杂ZnS量子点,基于Mn掺杂ZnS量子点的室温磷光特性,利用尿酸中的强吸电子基羰基通过电子转移能够有效猝灭量子点磷光,构建了一种检测尿酸的方法,该法无需预处理过程。结果表明,在pH 7.4的磷酸盐缓冲溶液中,尿酸对Mn掺杂ZnS量子点的猝灭程度呈线性变化,线性范围为2~70μmol/L,相关系数为0.99,检出限为0.31μmol/L。用于尿样中加标回收,加标回收率为97.5%~100.3%。方法适用于人体液中痕量尿酸的检测。     

二氧化钼-碳复合涂层的电化学性能研究

应用简单的刮涂法以及真空煅烧可制备出承载在铜箔表面的二氧化钼-碳（MoO₂-C）复合涂层,并对样品的形貌、成分、结构和电化学性能进行分析.结果表明,该复合涂层由单斜结构的MoO₂纳米粒子和无定形碳组成.一些MoO₂纳米粒子承载在碳基体表面,其尺寸为5~30nm;一些MoO₂纳米粒子包覆在碳基体内部,其尺寸约为5nm. MoO₂-C复合涂层为多孔结构,其孔隙尺寸为1~3nm.该复合涂层与铜箔结合紧密,界面处没有裂纹.承载在铜箔表面的MoO₂-C复合涂层的比容量高、循环和倍率性能良好.在100mA·g^-1电流密度下,该负极经过100次循环后的比容量为814mAh·g^-1,在循环过程中没有出现明显的容量衰减,即使在5000mA·g^-1的高电流密度下,其比容量仍有188mAh·g^-1.