实现均匀照度光伏聚光镜设计

为满足聚光光伏系统的聚光需求,解决传统点聚焦式聚光光伏系统中聚焦光斑不均匀、径长比过大和聚光比较小的缺点,在不增加二次匀光器件的前提下,设计了径长比小、聚焦光斑相对均匀、聚光比高的聚光光伏系统。根据几何光学柯勒照明原理、等光程原理和反射定律,通过数值求解等光程方程组获得聚光镜各个面型的轮廓曲线。利用TracePro软件对所设计的聚光系统进行光线追迹模拟,结果表明:在聚光比为725的情况下,聚焦光斑最大照度仅为太阳照度的2300倍,是点聚焦情况下的1/10左右,系统的径长比为0.3,接收角为0.72°。系统设计实现了结构紧凑,聚光性能高的设计目标,为高倍聚光光伏系统的小型化,简单化提供了一种有效的解决途径。     

颜色可区分的氰桥五边形带经亲铜作用聚集的异金属多形体

水热条件下,环境友好的K₂[Ni(CN)₄]能缓慢水解形成cis-[Ni(CN)₂(H₂O)₄]单元和氰基配体,并进一步与金属铜(Ⅰ)原子组装形成异金属的五边形带。这些五边形带通过亲铜聚集作用形成二维有色的超分子多形体[(CuCN)₂Ni(CN)₂(H₂O)₄](1和2)。研究发现,低温条件下形成了密集态的深蓝色的化合物1,然而高温反应条件形成疏松态的紫色化合物2,这一现象与高温高压的反应条件形成密集态的物质这一规律相违背。结构的进一步分析发现五边形环尺寸的微小改变和二维超分子层间距离的差异是引起这一反常的原因。除此之外,这两个新的化合物也是少见的由亲铜性聚集作用诱导的着色异常的多形体的例子,显示了从深蓝色到紫色的颜色改变。磁性研究证实了平面正方形的[Ni(CN)₄]^2-中的金属镍(Ⅱ)转换成了有着基态自旋S=1的八面体配位几何中心。     

超高强度钢（35CrNi3Mo）化学成分标准物质研制

采用与超高强度钢,台炼过程相同的工艺制备了35CrNi3Mo化学成分标准物质。对标准物质的制备技术、均匀性检验、稳定性考察进行了分析。研制的35CrNi3Mo化学成分标准物质具有良好的均匀性和稳定性。采用8家实验室进行协作定值,对定值结果的不确定度进行评定,各组分定值结果的相对扩展不确定度小于13％。     

多羧基小分子化合物诱导阳离子囊泡聚集的研究

研究了由阳离子型肽脂质溴化N,N-二-十六烷基-Na-6-三甲胺基己酰基-L-丙氨酰胺(N+C5Ala2C16)形成的阳离子囊泡,在加入含羧基小分子化合物后形成的聚集。考察了乙二胺四乙酸(EDTA)加入到囊泡中后吸光值随时间的变化。结果表明:当EDTA增加到一定浓度时可以引起由阳离子囊泡的聚集;在加入Ca2+后,阳离子囊泡聚集体得到分散;借助电子显微镜观察到了囊泡的聚集和分散。超滤后,用高效液相色谱法确定了囊泡结合的EDTA量。考察了不同pH条件下EDTA对囊泡聚集的影响,当EDTA等含多羧基小分子化合物羧基解离数为三个或以上时能够引起囊泡的聚集,而少于三个时囊泡不能发生聚集。     

二苯乙烯基蒽衍生物:聚集诱导发光性质、机理及应用

与传统的发光分子相比,具有聚集诱导发光(AIE)性质的分子,在聚集态或固态条件下,由于独特的分子结构和聚集态结构,表现出显著增强的荧光发射,因而在光电器件、生物化学检测等领域展现出广阔的应用前景。本文总结了二苯乙烯基蒽(DSA)及其衍生物的AIE性质,分析了DSA类分子AIE现象的机理,如分子内转动受限、扭曲的分子结构及分子间聚集结构等,同时介绍了此类分子在固态发光、刺激-响应材料,以及生物检测和生物成像等方面的应用。     

平衡均匀水平试验确定挥发性有机化合物测量方法的精密度

挥发性有机化合物通常使用吹扫捕集色谱法检测。在7家协作实验室进行平衡均匀水平试验,测定了水中氯乙烯、1,1-二氯乙烯、二氯甲烷、反-1,2-二氯乙烯、1,1-二氯乙烷、氯仿、1,1,1-三氯乙烷等24种挥发性有机化合物。测量结果经一致性和离群值检验后,计算得重复性标准差范围为0.085～5.350μg/L,再现性标准差范围为0.096～7.737μg/L。对标准差和平均值拟合函数关系,得到精密度最终值。     

支化侧链偶氮无规共聚物中空和类囊泡聚集体研究

研究了支化侧链型偶氮无规共聚物(PMAPB6P-AA)在THF/H2O混合溶液中的自组装行为.研究发现,通过缓慢增加体系的水含量,可以制备出具有中空结构的非球形聚集体.调节聚合物的初始浓度,可以得到不同粒径的聚集体.聚集体中偶氮生色团的光致异构化速率与异构化程度随聚合物初始浓度的增大而减小.在此基础上,采用更加缓慢的增加水含量的方法,使聚合物分子进行充分的疏水聚集与H-聚集,制备出类囊泡状聚集体.在紫外光照射条件下,观察到类囊泡聚集体发生了光致解聚集.     

胆碱酯酶抑制剂萘酰亚胺衍生物的合成与聚集诱导发光性质

阿尔茨海默症(Alzheimer’s disease, AD)是一种神经退行性疾病,严重影响老年人的生活质量,目前治疗AD的药物主要是胆碱酯酶抑制剂,如多奈哌齐、卡巴拉汀等.本文基于多奈哌齐结构,设计合成了一系列新的萘酰亚胺衍生物并进行了活性评价.结果表明,所合成的化合物均对乙酰胆碱酯酶(AChE)有选择性抑制,其中2-((1-(3-甲氧基苄基)哌啶-4-基)甲基)-1H-苯并异喹啉-1,3(2H)-二酮(4k)的抑制活性最强,IC₅₀值为4.43μmol·L^-1,优于对照药物卡巴拉汀.酶动力学及分子对接表明4k能够同时作用于ACh E的催化活性位点和外周结合位点,并且4k对SH-SY5Y和PC12细胞毒性较低.此外,这些化合物均显示出典型的聚集诱导发光(AIE)性质,可能与萘酰亚胺分子内旋转受阻机制有关.     

双萘酰亚胺衍生物用于检测水溶液中的苦味酸

设计合成了一个新的双1,8-萘酰亚胺衍生物(Bis-Nph), 并通过核磁共振波谱和高分辨质谱鉴定了其结构. Bis-Nph呈现出典型的分子内电荷转移(ICT)和聚集诱导增强发射(AIEE). 该化合物可以作为荧光探针检测水溶液中的苦味酸(2,4,6-三硝基苯酚, TNP), 检出限为5.8×10^-7 mol/L. 作用机制为TNP的质子转移到Bis-Nph, 有效地阻断了其ICT发射, 使荧光发生显著猝灭. 另外, Bis-Nph的细胞毒性较低, 可做成试纸进行TNP的快速检测.     

表面限域掺杂提升高比能正极材料稳定性

Lithium ion batteries (LIBs) have broad applications in a wide variety of a fields pertaining to energy storage devices. In line with the increasing demand in emerging areas such as long-range electric vehicles and smart grids, there is a continuous effort to achieve high energy by maximizing the reversible capacity of electrode materials, particularly cathode materials. However, in recent years, with the continuous enhancement of battery energy density, safety issues have increasingly attracted the attention of researchers, becoming a non-negligible factor in determining whether the electric vehicle industry has a foothold. The key issue in the development of battery systems with high specific energies is the intrinsic instability of the cathode, with the accompanying question of safety. The failure mechanism and stability of high-specific-capacity cathode materials for the next generation of LIBs, including nickel-rich cathodes, high-voltage spinel cathodes, and lithium-rich layered cathodes, have attracted extensive research attention. Systematic studies related to the intrinsic physical and chemical properties of different cathodes are crucial to elucidate the instability mechanisms of positive active materials. Factors that these studies must address include the stability under extended electrochemical cycles with respect to dissolution of metal ions in LiPF₆-based electrolytes due to HF corrosion of the electrode; cation mixing due to the similarity in radius between Li⁺ and Ni²⁺; oxygen evolution when the cathode is charged to a high voltage; the origin of cracks generated during repeated charge/discharge processes arising from the anisotropy of the cell parameters; and electrolyte decomposition when traces of water are present. Regulating the surface nanostructure and bulk crystal lattice of electrode materials is an effective way to meet the demand for cathode materials with high energy density and outstanding stability. Surface modification treatment of positive active materials can slow side reactions and the loss of active material, thereby extending the life of the cathode material and improving the safety of the battery. This review is targeted at the failure mechanisms related to the electrochemical cycle, and a synthetic strategy to ameliorate the properties of cathode surface locations, with the electrochemical performance optimized by accurate surface control. From the perspective of the main stability and safety issues of high-energy cathode materials during the electrochemical cycle, a detailed discussion is presented on the current understanding of the mechanism of performance failure. It is crucial to seek out favorable strategies in response to the failures. Considering the surface structure of the cathode in relation to the stability issue, a newly developed protocol, known as surface-localized doping, which can exist in different states to modify the surface properties of high-energy cathodes, is discussed as a means of ensuring significantly improved stability and safety. Finally, we envision the future challenges and possible research directions related to the stability control of next-generation high-energy cathode materials.