低压下酞菁裂解法制备定向碳纳米管阵列

在低压条件下以酞菁铁为原料, 采用独立双温控加热系统在石英玻璃基底上气相沉积制备了大面积准直性好和管径均匀的碳纳米管. 利用扫描电子显微镜(SEM/FESEM)和透射电子显微镜(TEM)研究了定向碳纳米管的生长形态和结构. 详细讨论了系统真空度、反应温度、气体流速及氢气和氩气的体积比例等参数对碳纳米管生长的影响, 并测试了该碳纳米管的场发射性能及超电容性能.     

Self-Compacting Alkali-Activated Materials: Progress and Perspectives

Alkali-activated materials (AAMs) are considered to be alternative cementitious materials for civil infrastructures. Nowadays, efforts have been made in developing AAMs with self-compacting ability. The obtained self-compacting AAMs (SCAAMs) accomplish superior passing and filling properties as well as excellent mechanical and environmental advantages. This work critically revisits recent progresses in SCAAMs including mixture proportions, fresh properties, mechanical strength, microstructure, acid and sulfate resistance, high temperature behaviors, impact resistance and interface shear strength. To facilitate direct comparison and interpretation of data from different publications, mixture proportions were normalized in terms of the content of key reactive components from precursors and activators, and correlation with mechanical behaviors was made. Moreover, special attention was paid to current research challenges and perspectives to promote further investigation and field application of SCAAMs as advanced construction material.     

Synthesis and relaxivity of polyamide paramagnetic metal complexes for magnetic resonance imaging

A new class of paramagnetic macromolecular magnetic resonance imaging contrast agents has been developed. Eight new polyamide ligands were synthesized by copolymerization of ethylenediaminetetraacetic acid dianhydride or diethylenetriaminepentaacetic acid dianhydride and diamine monomers. Their gadolinium(III), manganese(II) and iron(III) complexes were also synthesized. All polyamide ligands and metal complexes were characterized by ¹H nuclear magnetic resonance, infrared spectra and elemental analyses. Relaxivity studies showed that the polyamide paramagnetic metal complexes had obviously higher relaxation effectiveness as compared to corresponding simple monomeric paramagnetic metal complexes.     

质谱技术研究儿茶素及儿茶素-锗多聚体特性

采用HPLC-ESI-Q-TOF和MALD I-TOF质谱技术分析儿茶素组成与结构,发现儿茶素中的表没食子儿茶素没食子酸酯(EGCG)具有多聚体特性。有机化学法合成EGCG-Ge4 化合物,并经HPLC进一步分离纯化。红外光谱和质谱技术分析并证实EGCG不仅能形成多聚体,而且还能络合金属锗(包括其他金属离子),成为EGCG-Ge4 和EGCG-Ge4 多聚体。EGCG-Ge4 抑制肺癌细胞生长速率明显高于EGCG,其提高幅度约为30%~40%左右。     

取压方式对微通道内单相摩擦阻力特性的影响

本文以去离子水和氮气为工质,在水平圆形微通道(dh=0．336 mm)中采用两种直接取压方式-缝隙取压和小孔取压,对单相摩擦阻力特性进行了实验研究,并通过改变缝隙宽度,研究缝隙宽度对压降测量偏差的影响．     

Recent Progress and Perspectives of Sodium Metal Anodes for Rechargeable Batteries

Sodium metal anodes have attracted significant attention due to their high specific capacity,low redox potential and abundant resources.However,the dendrites and unstable solid electrolyte interphase(SEI)of sodium anodes restrict the development of sodium metal batteries.This review includes the recent progress on the Na anode protection in sodium metal batteries.The strategies are summarized as modified three-dimensional current collectors,artificial solid electrolyte interphases,and electrolyte modifications.Conclusions and perspectives are envisaged for the further understanding and development of Na metal anodes.     

Highly efficient perovskite solar cells by tuning electronic structures of thienothiophene-based as hole transport materials

The atomic substitutions were used to study the hole transport materials (HTM) properties of six thiophenothiophene molecules (HTM1-HTM6) to reveal the relationship between their core structures and photoelectric properties. To better investigate the difference between experimentally original and designed molecules, we calculated the hole mobility and some parameters (such as energy levels, stability, and optical properties, etc). The results showed that the molecular orbital levels of the original and designed molecules have well matched with perovskite and Ag electrode to ensure hole transport and inhibit the electron reflux. Among the designed HTMs, HTM5 has the smallest energy gap that results in the red-shifted absorption spectra. Furthermore, there is an obviously increased charge transfer integral V due to the introduction of the Si atom, which greatly improved the hole mobility. Therefore, atom substitution by introducing Si atoms (HTM5) will improve the energy levels and charge transport ability, and molecular design by means of atom substitution can be a potential way to tunable HTM performance in solar cells.     

利用可见-近红外-中红外超快光谱揭示离子交换法制备的少层MoS2中缺陷介导的载流子动力学

本文结合可见-近红外-中红外瞬态吸收光谱技术对离子交换法制备的少层MoS₂中缺陷介导的载流子动力学进行了详细的解析. 在近红外瞬态吸收光谱中观察到的宽带漂白信号表明少层MoS₂纳米片带隙中分布着大量的缺陷态. 实验结果明确揭示了载流子被缺陷态的快速捕获以及进一步的复合过程,证明带隙中的缺陷态对MoS₂光生载流子动力学过程起着至关重要的作用. 在中红外瞬态吸收光谱中观察到的正信号到负信号的转变进一步证实了在导带下小于0.24 eV处存在被载流子占据的缺陷态. 这些在少层MoS₂纳米片中存在的缺陷态可以作为有效的载流子捕获中心来辅助光生载流子在皮秒时间尺度内完成非辐射复合过程.     

Identity-Based Quantum Designated Verifier Signature

International Journal of Theoretical Physics - Designated verifier signatures are very useful in the applications such as e-voting and auction. In this paper, an identity-based quantum designated...     

端羧基聚丁二烯及端羧基聚（丁二烯－co－丙烯腈）离聚体的合成及表征

用溶液法由液体端羧基聚丁二烯（ＣＴＰＢ）及液体端羧基聚（ＣＴＢＮ）合成了Ｌｉ＾＋、Ｎａ＾＋、Ｋ＾＋、Ｍｇ＾２＋、Ｚｎ＾２＋、Ａｌ＾３＋的遥爪型离聚体，考察了反应条件对离聚体形成的影响及离聚体稀溶液的性质。并用红外光谱，透射电子显微镜、动态粘弹谱仪研究和表征了部分ＣＴＰＢ、ＣＴＢＮ遥爪型离聚体。