全固态钠离子电池硫系化合物电解质

全固态钠离子电池具有资源丰富、安全性高等优势,作为未来大规模储能的重要选择而成为近年来先进二次电池前沿研究热点。钠离子硫系化合物电解质室温离子电导率高、弹性模量高、容易冷压成型,能增强电极/电解质界面接触、减小界面阻抗、缓冲电极材料在充放电过程中的应力/应变,是全固态钠离子电池的研究重点。本文对钠离子硫系化合物固态电解质的结构及性质进行了总结,讨论了硫系化合物电解质的本征特性、与电极的界面稳定性,并介绍了硫系化合物全固态钠离子电池的研究现状,最后分析了硫系化合物电解质面临的挑战及今后的发展方向。     

Synthesis of two A-B-C type conjugated amphiphilic triblock fullerene derivatives and their application in organic solar cells

Two A-B-C type conjugated amphiphilic triblock fullerene derivatives C60-2 HMTPB and C60-2 EHTPB were obtained in multi steps synthesis with three different blocks,and the amphiphilic diblock molecular C60-4 TPB was also preferred as a reference.When as modifying layer on zinc oxide(ZnO),the three fullerene derivatives can all reduce the work function of ZnO via modulation of the interfacial dipoles and lead a better electrical coupling.As introducing treatment of toluene,the obvious self-assembly of fullerene derivatives were observed,which were supported by X-ray diffraction and contact angle of water measurement.Base on PTB7-Th:PC71 BM system,the inverted organic solar cells devices with structure of ITO/ZnO/fullerene derivatives/PTB7-Th:PC71BM/Mo03/Al got power conversion efficiencies of 8.62%,8.83%and 9.00%for C60-4 TPB,C60-2 HMTPB and C60-2 EHTPB,respectively,compared 8.13%of devices with bare ZnO.The result of conjugated amphiphilic triblock fullerene derivatives provides a straightforward approaching by simultaneously modulating the morphology and interfacial work function of ZnO,which can also lead high performance in optoelectronic devices.     

Boosting Photocatalytic Oxygen Evolution: Purposely Constructing Direct Z-Scheme Photoanode by Modulating the Interface Electric Field

Ti-Fe₂O₃ photoanode has received widespread attention in photoelectrochemical(PEC) water spilling because of its optimized oxidative and reductive capability of composites catalyst. However, its low efficiency could limit its development. Herein, in order to improve the efficiency of PEC water spilling, the all-solid-state direct Z-scheme Ti-ZnFe₂O₄/Ti-Fe₂O₃(TZFO/Ti-Fe₂O₃) nanorod arrays composited with the ideal energy band structure are synthesized by modulating the Fermi level of TZFO for PEC water splitting. The photophysical methods in this work, including the Kelvin probe measurement and transient photovoltage spectroscopy(TPV) measurement, are applied to explore the migration behavior of electric charges at the enhanced interface electric field. Finally, the Z-scheme charge transfer mechanism of TZFO/Ti-Fe₂O₃ photoanode is proved successfully. Benefiting from the desirable charge transfer at interface electric field, the TZFO/Ti-Fe₂O₃ exhibits the outstanding photocatalytic oxygen evolution reaction(OER) performance, and the photocurrent of 60TZFO/Ti-Fe₂O₃ photoanode reaches 2.16 mA/cm² at 1.23 V vs. reversible hydrogen electrode(RHE), which is three times higher than that of pure Ti-Fe₂O₃ photoanode. This work provides a facile approach of modulating interface electric field to optimize the Z-scheme charge-transfer process.     

Particles in composite polymer electrolyte for solid-state lithium batteries: A review

Solid-state lithium batteries (SSLBs) have been identified as one kind of the most promising energy conversion and storage devices because of their safety, high energy density, and long cycling life. The development of solid-state electrolyte is vital to commercialize SSLBs. Composite polymer electrolyte (CPE), derived by compositing inorganic particles into solid polymer electrolyte has become the most practical species for SSLBs because it inherits the advantages of polymer electrolyte and simultaneously achieves enhanced ionic conductivity and mechanical properties. The characteristics of inorganic particles and their interaction with polymers strongly impact the performance of CPE, improving its ionic conductivity, mechanical properties, thermal and electrochemical stability, as well as interface compatibility with both electrodes. In this review, the effects of particle characteristics including its species, size, proportion, morphology on the ionic conductivity and mechanical properties of CPE are reviewed. Meanwhile, some novel composite strategies are also introduced including surface modification, hybridization, and alignment of particles in polymer matrices, as well as some new preparation methods of CPE. The interactions between particles and other components in CPE including polymer matrices or lithium salt are particularly focused herein to reveal the lithium conductive mechanism. Finally, a perspective on the direction of future CPE development for SSLBs is presented.     

流-固界面波的激光激发与光偏转检测

基于光偏转原理,研制了可用于流-固界面波探测的光纤传感装置.在此基础上,建立了以调Q Nd∶YAG激光为流-固界面波激发光源的实验系统.实验上探测了激光在空气-铝、水-铝和酒精-铝等界面上激发的界面波波形.根据实验波形,算得在这三种界面上的泄漏Rayleigh波和Scholte波的速度分别为2889 m/s和339 m/s、2916 m/s和1512 m/s、2872 m/s和1184 m/s,此实验值与理论计算值相比,偏差小于5％.     

Interface trap-induced negative differential resistance in nMOSFET with floating source

Interface trap can act as the generation center in device to induce a very weak generation current. We observed the negative differential resistance NDR of this generation current I_D in nMOSFET with the floating source. It originates from that the generation function of interface trap is enabled and then is shut down in turn as increasing the drain voltage. This change relies on the interaction among the interface trap energy-level and the electron's Fermi-levels of drain and source under the floating source condition. It is found that the peak-to-valley ratio of I_D is beyond 30.     

Wettability and surface energy of parylene F deposited on PDMS

For the first time, the wettability and surface energy of parylene F were investigated. The results showed that parylene F had a hydrophobic surface with an eigen water contact angle of 104.7 ± 0.6°. We found that 3.5 μl probe liquid was an optimal value for the contact angle measurement of parylene F. Moreover, we found that the Lifshitz–van der Waals/acid–base approach was unsuitable for determining the surface energy of parylene F, whereas the Owens–Wendt–Kaelble approach and the limitless liquid–solid interface wetting system were compatible. The surface energy of parylene F was estimated to be 27.06 mJ/m² (Owens–Wendt–Kaelble) and 40.41 mJ/m² (Limitless liquid-solid interface wetting system). Furthermore, this investigation also provided a reference for the applications of empirical and physics-based semi-empirical approaches for the estimation of surface energy.     

液/液界面生长法制备一维纳米硒

采用均相反应界面生长法制备了一维结构的纳米硒。在制备过程中,初始硒纳米粒子首先在均相反应液中生成,然后加入与该反应液不互溶的溶剂,使其形成液液界面,硒纳米粒子聚集在界面上生长为一维结构。用扫描电镜、透射电镜、X射线粉末衍射等测试技术对样品进行了表征,并讨论了界面生长的机理及其影响因素。     

Secondary succession and its effects on soil moisture and nutrition in abandoned old-fields of hilly region of Loess Plateau, China

Floristic composition, community structure and soil moisture and nutrient contents in abandoned fields of different ages were analyzed to clarify the regenerative aspects of succession as a tool for vegetation restoration. The results indicated that secondary succession in this region can be interpreted as an auto-succession: there are main changes in species-relative abundance and species turnover. Annual or biennial species (e.g. Artemisia scoparia), acted as pioneers and strongly dominated the early stages. Then, they underwent a progressive decline, while forbs (e.g. Artemisia sacrorum) and grasses (e.g. Xanthium sibiricum) had their peak abundance at intermediate stages. Dwarf shrubs (e.g. Lespedeza dahurica) and short rhizome grass (e.g. Bothriochloa ischaemum) appeared at mid-succession stage and gradually increased in abundance during succession, becoming dominant at late stages. The first axis of detrended correspondence canonical analysis arranged the sites according to their fallow time, indicating a successional sere. The second axis, associated with diverging pathways of regeneration, correlated with topographic factors and soil moisture and nutrition. Structural divergence between plots increased as succession went on, attained the highest at the mid-succession stage, decreased at the late stage.

Soil moisture and available phosphorus content decreased steadily with field age after their abandonment, whereas pools of organic matter, total and available nitrogen, potassium and total phosphorus increased with field age. The pace and direction of recovery of native vegetation and natural soil properties in these abandoned fields resembled classic old-field succession, which is a form of secondary succession that often serves as a template for guiding restoration efforts. Interface between the abandoned field soil and plant system was crucial to the above process. Our current study supported the generally accepted hypothesis in the succession literature.     

单碱基多样性的非测序检测

单碱基多样性（SNP）是最常见的基因突变形式之一,经研究证明与很多疾病相关。虽然测序是检测SNP的重要方法,但其需要检测仪器,且检测时间较长,限制了其临床应用。本文综述了SNP的常见非测序分析方法。首先讨论了检测的热力学问题,并归纳了主要的检测策略：基于杂交的检测,基于链取代反应的检测和酶介导的检测。在三维均相检测方法中,主要介绍了不同信号开关策略,如荧光开关、酶识别开关和场效应开关。三维原位检测不仅能检测SNP,还能提供其细胞定位信息,在细胞异质性较高时更具优势。二维界面检测的识别反应速率和杂交效率受到一定影响,但界面检测能进一步减小干扰,亦便于实现高通量检测。以DNA正四面体探针界面为代表的改良界面具有优良的灵敏度和特异性。同时本文亦讨论了现有方法的局限性,并对SNP非测序检测研究进行展望。