高效集水仿生超浸润材料的研究进展

有效地收集空气中的雾气是缓解缺水危机的一种方法.近年来,可雾水收集的仿生超浸润材料受到了广泛的关注.通过进一步研究雾水收集过程中的液滴动态运输行为,为设计并构筑多功能仿生超浸润材料提供指导.本综述详细地总结了自然界典型的雾水收集现象,并对液滴在不同润湿性材料表面的动态运输行为进行了分类.从单一仿生到多重仿生出发,系统介...     

地基水平运动时高桥墩的动力屈曲

考虑大变形的影响,建立了高桥墩在地震波冲击下引起的地基水平运动时的非线性动力学基本方程式;通过位移形函数假设,采用伽辽金积分方法得到了时间变率的动力学控制方程;对时间变率的非线性微分方程进行数值求解,给出了同一地震波不同强度下高桥墩的位移响应曲线以及从产生横向振动到失稳的全过程;得到了地震波冲击时高桥墩失稳的临界地震加速度acr和失稳时刻。通过数值算例比较了地震波幅值、高桥墩柔度、桥面质量大小对位移幅值响应、临界地震加速度、失稳时刻等参数的影响。算例表明当发生7.5级以上地震时,桥墩会有较大程度的破坏。     

The chaotic property in the autoionization of Rydberg lithium atom

This paper presents theoretical computations of the ionization rate of Rydberg lithium atom above the classical ionization threshold using semiclassical approximation. The yielded random pulse trains of the escape electrons are recorded as a function of emission time such that they can be related to the terms of the recurrence periods of the photoabsorption. This fact illustrates that it is ionic core scattering processes which give rise to chaos in autoionization dynamics and this is verified by comparison of our results with the hydrogen atom situation. In order to reveal the chaotic properties in detail, the sensitive dependence of the ionization rate upon the scaled energy is discussed for different scaled energies. This approach provides a simple explanation for the chaotic character in autoionization decay of Rydberg alkali-metal atoms.     

Correspondence between classical dynamics and recurrence spectra of Rydberg hydrogen atom near a metal surface

The chaotic behaviours of the Rydberg hydrogen atom near a metal surface are presented. A numerical comparison of Poincare surfaces of section with recurrence spectra for a few selected scaled energies indicates the correspondence between classical motion and quantum properties of an excited electron. Both results demonstrate that the scaled energy dominates sensitively the dynamical properties of system. There exists a critical scaled energy εc, for ε 〈 εc, the system is near-integrable, and as the decrease of ε the spectrum is gradually rendered regular and finally turns into a pure Coulomb field situation. On the contrary, if ε 〉 εc, with the increase of ε, the system tends to be non-integrable, the ergodic motion in phase space presages that chaotic motion appears, and more and more electrons are adsorbed on the metal surface, thus the spectrum becomes gradually simple.     

Photovoltaic and Electroluminescence Characters in Hybrid ZnO and Conjugated Polymer Bulk Heterojunction Devices

We report electroluminescence in hybrid ZnO and conjugated polymer poly[2-methoxy-5-（3′, 7′-dimethyloctyloxy）- 1,4-phenylenevinylene] （MDMO-PPV） bulk heterojunction photovoltaic cells. Photoluminescence quenching experimental results indicate that the ultrafast photoinduced electron transfer occurs from MDMO-PPV to ZnO under illumination. The ultrafast photoinduced electron transfer effect is induced because ZnO has an electron affinity a bout 1.2 e V greater than that of MDMO-PP V. Electron ＇back transfer＇ can occur if the interfacial barrier between ZnO and MDMO-PPV can be overcome by applying a substantial electric field. Therefore, electrolumi- nescence action due to the fact that the back transfer effect can be observed in the ZnO：MDMO-PPV devices since a forward bias is applied. The photovoltaic and electroluminescence actions in the same ZnO：MDMO-PPV device can be induced by different injection ways： photoinjection and electrical injection. The devices are expected to provide an opportunity for dual functionality devices with photovoltaic effect and electroluminescence character.     

分子光谱法研究漆黄素与DNA的相互作用

利用多种光谱技术及伏安技术研究了漆黄素与DNA之间的相互作用.由荧光光谱法可知,DNA对漆黄素的猝灭过程是静态猝灭,计算得到不同温度下二者的结合常数及结合位点数.ΔH,ΔS,ΔG的计算结果表明漆黄素与DNA的作用力为范德华力或氢键作用.循环伏安法进一步表明了DNA的加入使漆黄素的峰电位发生了移动,二者产生了有效结合.离子强度实验、黏度法、紫外光谱法、圆二色光谱法、DNA熔解温度实验和单双链DNA对比实验的结果均表明漆黄素与DNA的结合是嵌插结合模式.     

官能化苯并菲盘状液晶的合成及不饱柔链对介晶性的影响

合成了12个含不饱和软链的苯并菲盘状液晶化合物,C18H6（OC5H11）6-x（OR）x（x=1,2,3）,R=-C3H6CH=CH2（a）,-C3H6C≡CH（b）,-C2H4OCH=CH2（c）.化合物结构通过核磁共振氢谱和高分辨质谱表征.化合物热致液晶性通过偏光显微镜（POM）,差视扫描热量法（DSC）,和X射线衍射（XRD）进行了研究.结果显示目标化合物呈现有序的六方柱状介晶相.端炔基链化合物b系列熔点最高.乙烯氧基柔链化合物c系列有最高的清亮点和最宽的介晶性温度范围,且随着不饱和醚链数的增多,清亮点明显升高.对称苯并菲化合物sym-C18H6（OC5H11）3（OR）3比不对称化合物asym-C18H6（OC5H11）3（OR）3具有更高的熔点和清亮点.乙烯氧基柔链可极化的偶极相互作用对液晶稳定性有较大贡献.     

Semiclassical Calculations of Autoionization Rate for Lithium Atoms in Parallel Electric and Magnetic Fields

By using a semiclassical method, we present theoretical computations of the ionization rate of Rydberg lithium atoms in parallel electric and magnetic fields with different scaled energies above the classical saddle point. The yielded irregular pulse trains of the escape electrons are recorded as a function of emission time, which allows for relating themselves to the terms of the recurrence periods of the photoabsorption. This fact turns to illustrate the dynamic mechanism how the electron pulses are stochastically generated. Comparing our computations with previous investigation results, we can deduce that the complicated chaos under consideration here consists of two kinds of seff-similar fractal structures which correspond to the contributions of the applied magnetic feld and the core scattering events. Furthermore, the effect of the magnetic field plays a major role in the profile of the autoionization rate curves, while the contribution of the core scattering is critical for specifying the positions of the pulse peaks.     

g-C3N4/Fe3O4/BiOI磁性材料的制备及其可见光助芬顿催化性能

采用共沉淀-回流法制成g-C₃N₄/Fe₃O₄/BiOI磁性复合材料作为异相光助芬顿(Fenton)催化剂。运用扫描电镜(SEM)、透射电镜(TEM)、X-射线衍射(XRD)、振动样品磁强计(VSM)和N₂吸附-脱附等手段分别对催化剂的形貌、结构、组成、磁性和比表面积等进行了表征，并以罗丹明B(RhB)为模型污染物考察了材料的可见光催化性能。实验结果表明，当BiOI的负载质量为50%时，在可见光照射下，复合材料具有最好的光催化性能，180 min内对RhB的降解效率可达到99.20%。较高的光催化性能归因于所制备材料对RhB较强的吸附、强烈的可见光响应以及异质结构促进了光生载流子的分离。进一步在光催化体系中加入适量的H₂O₂后，可极大提高三元复合材料可见光助Fenton降解RhB的效率，30 min内即可达到98.44%,这得益于体系中发生Fenton反应产生较多具有强氧化性的羟基自由基，同时光生电子可加速Fe³⁺     

可反应表面修饰银纳米颗粒的制备与结构表征

Surface reactable modified silver nanoparticles were prepared by NaBH4 reduced silver ion in the aquenous solvent, in the presence of the double group modifying agent, O,O′-di(11-bromic undecane)dithiophosphonic acid. The morphology and structure of the product were characterized using Transmission Electron Microscope(TEM), UV-Visible Absorption(UV-Vis) spectra, Fourier Transform Infrared(FTIR) spectra. The result indicate that the products are spherical shape and no aggregation, C-Br functional groups are on the outermost portion of the silver nanoparticles. The nanoparticles were well dispersed in organic solution, such as chloroform, petroleum ether, toluene etc. The analysis of the sample which reacted with trimethylamine by X-ray photoelectron spectra(XPS) shows the silver nanoparticles can undergo many reactions.