CuAPTPP-TDI-TiO2光催化微球的合成及其光催化性能 (cited: 1)

采用Adler法合成了5-(4-氨基苯基)-10,15,20-三苯基卟啉铜配合物(CuAPTPP),通过甲苯二异氰酸酯(TDI)的桥联作用对TiO₂微球进行表面修饰,使TDI分子中的两个活性TDI基团分别与TiO₂表面的羟基和CuAPTPP的氨基反应,将CuAPTPP敏化剂分子以化学键合的方式固定在TiO₂表面,形成光催化微球CuAPTPP-TDI-TiO₂．通过FT-IR、XRD、SEM、EA、UV-Vis和DRS等测试手段对CuAPTPP-TDI-TiO₂进行结构表征．讨论了桥联分子TDI修饰量对光催化微球性能的影响,确定了TDI与TiO₂的最佳摩尔比．以亚甲基蓝(MB)为降解对象,考察了CuAPTPP-TDI-TiO₂微球的可见光催化性能．结果表明,桥联分子TDI在CuAPTPP与TiO₂微球表面形成了牢固的化学键,复合微球在150 W氙灯辐照下降解10 mg/LMB溶液,120 min降解率可达98.7%,其降解率过程服从一级动力学规律,测得降解速率常数为5.1×10^-2 min^-1,半衰期为11.3 min．催化微球在回收4次的条件下,对MB的降解率仍保持在90%以上．     

(TiO2)n(n=3—6)团簇吸附水分子的理论研究

给出了优化小分子在团簇表面吸附结构的遗传算法.结合经验势函数,搜寻了水分子在(TiO₂)_n(n=3—6)团簇上可能的吸附方式;利用B3LYP/6-31G^**方法对各种吸附结构进行了优化.结果表明水分子主要通过O原子以非解离方式吸附到团簇中配位数较低或位置比较凸出的Ti原子上.分子轨道分析表明,水分子与团簇之间的成键主要来自吸附位Ti原子3s3p轨道的贡献,水分子的轨道保持了气相水分子中的基本特征,但离域化程度增大 关键词： 2团簇')" href="#">TiO₂团簇 2O吸附')" href="#">H₂O吸附 遗传算法 DFT     

Adsorption-controlled transition of the electrical properties realized in Hematite（alpha-Fe2O3） nanorods ethanol sensing

Alpha-Fe2O3 nanorods are synthesized through a hydrothermal method with no surfactant introduced and ethanol sensors are fabricated from these nanorods.The device can respond to ethanol vapour in a concentration range from 1 to 1500 parts per million and shows both p-type and n-type responding characteristics during the investigation of the ethanol sensing.The sensor displays a p-type characteristic when the ethanol concentration is low and converted into an n-type characteristic as the concentration exceeds a certain value.Such a phenomenon is attributed to the chemisorbed oxygen,which leads to different modifications of the energy band at the surface,namely,depletion layer or inversion layer.     

强阻尼非线性热弹耦合杆系统的全局吸引子

本文主要以算子半群理论为依据,证明了一类强阻尼非线性热弹耦合杆方程组在初边值条件下,全局吸引子的存在性,并且对吸引子维数做了估计. 关键词： 热弹耦合杆系统 强阻尼 非线性 全局吸引子     

Spectral feature with sub-natural linewidth due to quantum interference in a four-level system

This paper studies the narrow spectral feature appearing in a four-level system coupled by two strong coherent fields and probed by a weak laser field. The linewidth is examined as a function of the Rabi frequencies of coupling fields, and the result is explained by using the dressed-state formalism.     

An oxide/silicon core/shell nanowire metal-oxide semiconductor field-effect transistor

This paper studies an oxide/silicon core/shell nanowire MOSFET(OS-CSNM).Through three-dimensional device simulations,we have demonstrated that the OS-CSNM has a lower leakage current and higher I on /I off ratio after introducing the oxide core into a traditional nanowire MOSFET(TNM).The oxide/silicon OS-CSNM structure suppresses threshold voltage roll-off,drain induced barrier lowering and subthreshold swing degradation.Smaller intrinsic device delay is also observed in OS-CSNM in comparison with that of TNM.     

High-Tc planar SQUID gradiometer for eddy current non-destructive evaluation

This paper reports the fabrication and test of a high-Tc SQUID planar gradiometer which is patterned from YBCO thin film deposited on a SrTiO3 bicrystal substrate. The measurement of noise spectrum at 77K shows that the white noise at 200 Hz is about 1×10^-4 φ0/√Hz. The minimal magnetic gradient is measured and the results suggest that the minimal magnetic gradient is 94 pT/m. The planar gradiometer is used in non-destructive evaluation （NDE） experiments to detect the artifacts in conducting aluminium plates by performing eddy current testing in an unshielded environment. The effect of the exciting coil dimension on the NDE results is investigated. By mapping out the induced field distribution, flaws about 10mm below the plate surface can be clearly identified.     

Bi2ZnOB2O6单晶偏振拉曼光谱

本文通过分析不同几何配置下的偏振拉曼光谱对非线性光学晶体的晶格振动模式进行了研究. 首先根据因子群分析,将晶体的振动模按晶体对称群的不可约表示进行分类,其次测量了晶体在10–1600 cm^-1范围内,不同几何配置下的偏振拉曼光谱,并在此基础上指认了晶体的晶格振动模式. 300 cm^-1以下的振动峰,归结为晶体的外振动,来自[BiO₆],[ZnO₄],[BO₄]和[BO₃]原子基团的平动和转动;300cm^-1以上为晶体的内振动,主要与Bi-O,和Zn-O键振动有关. 晶体拉曼光谱中最高振动频率达到1407 cm^-1,被指认为[BO₃]三角形中B-O键的伸缩振动,体现了[BO₃]基团中高的电子非局域化程度. 关键词： 2ZnOB₂O₆单晶')" href="#">Bi₂ZnOB₂O₆单晶 偏振拉曼光谱 振动模式     

True spin and pseudo spin entanglement around Dirac Points in graphene with Rashba spin–orbit interaction

We analytically obtained the Schmidt decomposition of the entangled state between the pseudo spin and the true spin in graphene with Rashba spin–orbit coupling. The entangled state has the standard form of the Bell state, where the SU(2) spin symmetry is broken. These states can be explicitly expressed as the superposition of two nonorthogonal, but mirror symmetrical spin states entangled with the pseudo spin states. Because of the closely locking between the pseudo spin and the true spin, it is found that the orbit curve in the spin-polarization parameter space for the fixed equi-energy contour around Dirac points has the same shape as the $\delta \overrightarrow{k}$-contour. Due to the spin–orbit coupling that cause the topological transition in the local geometry of the dispersion relation, the new equi-energy contours around the new emergent Dirac Points can be obtained by squeezing the one around the original Dirac point. The spin texture in the momentum space around the Dirac points is analyzed under the Rashba spin–orbit interaction and it is found that the orientation of the spin polarization at each crystal momentum $\overrightarrow{k}$ is independent of the Rashba coupling strength.