Probing the improved stability for high nickel cathode via dual-element modification in lithium-ion

One of the major hurdles of nickel-rich cathode materials for lithium-ion batteries is the low cycling stability, especially at high temperature and high voltage, originating from severe structural degradation, which makes this class of cathode less practical. Herein, we compared the effect of single and dual ions on electrochemical performance of high nickel (LiNi_0.88Mn_0.03Co_0.09O₂, NMC) cathode material in different temperatures and voltage ranges. The addition of a few amounts of tantalum (0.2 wt%) and boron (0.05 wt%) lead to improved electrochemical performance. The co-modified LiNi_0.88Mn_0.03Co_0.09O₂ displays an initial discharge capacity of 234.9 mAh/g at 0.1 C and retained 208 mAh/g at 1 C after 100 cycles at 45 ℃, which corresponds to a capacity retention of 88.5%, compared to the initial discharge capacity of 234.1 mAh/g and retained capacity of 200.5 mAh/g (85.6%). The enhanced capacity retention is attributed to the synergetic effect of foreign elements by acting as a surface structural stabilizer without sacrificing specific capacity.     

Proximity effects in topological insulator heterostructures

Topological insulators （Tls） are bulk insulators that possess robust helical conducting states along their interfaces with conventional insulators. A tremendous research effort has recently been devoted to TI-based heterostructures, in which con- ventional proximity effects give rise to a series of exotic physical phenomena. This paper reviews our recent studies on the potential existence of topological proximity effects at the interface between a topological insulator and a normal insu- lator or other topologically trivial systems. Using first-principles approaches, we have realized the tunability of the vertical location of the topological helical state via intriguing dual-proximity effects. To further elucidate the control parameters of this effect, we have used the graphene-based heterostructures as prototypical systems to reveal a more complete phase diagram. On the application side of the topological helical states, we have presented a catalysis example, where the topo- logical helical state plays an essential role in facilitating surface reactions by serving as an effective electron bath, These discoveries lay the foundation for accurate manipulation of the real space properties of the topological helical state in TI- based heterostructures and pave the way for realization of the salient functionality of topological insulators in future device applications.     

PBX-9404炸药高压反应速率方程的研究

研究了ＰＢＸ ９４０４ 炸药在高幅值冲击波加载下的化学反应速率方程。将所得高压反应速率方程与Ｊｏｈｎｓｏｎ 等的经验热点模型的低压项结合,得到ＰＢＸ ９４０４ 炸药的冲击波起爆反应速率模型。利用一维特征线程序模拟该炸药的冲击波起爆过程和爆轰波传播过程。     

一种基于碳酸锶纳米材料的催化发光乙醛气体传感器研究

研制了一种使用碳酸锶纳米材料作为敏感材料,用来检测空气中痕量乙醛气体的催化发光传感器。该传感器在342℃对乙醛有高灵敏度和选择性,在波长425nm处进行定量分析,催化发光强度与乙醛浓度的线性范围为6～6000mL／m^3(r=0．9995,n=8);检出限为2mL／m^3(信噪比=3)。外来物质如环己烷、四氯化碳、氨、苯、氯仿、甲苯、甲醇、乙醇及甲醛气体通过传感器时,除了乙醇和甲醛分别引起42．5％和12．5％的干扰外,其它气体不干扰测定。20000mL／m^3的水蒸气不干扰200mL／m^3乙醛气体的测定。连续1130h通过乙醛气体测试了传感器的稳定性。对含有乙醛、甲醛和苯的人工合成样品进行了分析。     

多语言编程技术在软件开发中的应用

在地球物理资料综合处理解释系统的开发过程中，如何利用多种语言混合编程技术解决用不同编程语言开发的程序的相互联接问题，并简述了AFORTRN语言与C＋＋语言的部分联接过程。     

伊红探针可视化检测牛奶中环丙沙星残留

基于伊红和环丙沙星离子缔合形成二元复合物后,溶液颜色由琥珀色转变成玫红色,构建了以伊红为探针的环丙沙星定量可视化检测体系。对缔合物的组成比进行了确认,对溶液pH、伊红用量进行了优化。在最优实验条件下,体系在540 nm,环丙沙星浓度在5～17μmol/L范围内与吸光度呈良好线性关系,检出限为3.57μmol/L,裸眼观察的检出限为2μmol/L。方法应用于实际样品牛奶中环丙沙星检测时,回收率在91.5%～97.0%之间,相对标准偏差(RSD)小于5.4%。方法适用于动物源性食品中环丙沙星的快速筛查。     

固相微萃取技术在法庭科学领域中的应用

综述国内外固相微萃取技术在法庭科学领域中毒物、毒品和微量物证(炸药残留物、助燃剂残留物、人体气味)样品前处理及分析中的应用,以及在火场助燃剂残留物及人体气味鉴别方面的应用;对固相微萃取技术在法庭科学领域中的发展方向进行了展望。可以对法庭科学领域毒物毒品、微量物的相关研究和侦查办案提供参考。     

任意非亏损系统特征灵敏度分析的直接摄动法

本文发展了一种任意非亏损系统特征灵敏度分析的二阶段摄动法，将未摄动的问题的解作为零阶近似，把摄动影响作为摄动后问题的高阶修正，经过严格的数学推导，得到了支配高阶修正量的完全方程组。本方法无损知道摄问题的全部特征向量，仅需知被摄模态的特征对。本方法可处理被摄问题具有重特征值，甚至具有等导重特征值这一高度退化极难处理的情况。算例显示了本方法的正确性。