Quantitative Investigation on Structural Evolution of Co-continuous Phase under Shear Flow

Components of co-continuous phase can form an interpenetrating network structure, which has great potential to synergistically improve the mechanical properties of the blends, and to impart the functional blends superior electrical conductivity and permeability. In this work, the effects of shear rates (50–5000 s^?1) at different temperatures on the phase morphology, phase size and lamellar crystallites of biodegradable co-continuous polybutylene terephthalate (PBAT)/polybutylene succinate (PBS) blend are quantitatively investigated. The results show that the above features of the PBAT/PBS have a strong dependence on the shear flow and thermal field. The co-continuous phase of the blend is well maintained at 130 °C. Interestingly, this phase structure transforms into a “sea-island” structure at 160 °C, which gradually recovers to a co-continuous phase when the shear rate increases from 1000 s^?1 to 5000 s^?1. The phase size decreases with the increase of shear rate both at 130 °C and 160 °C due to the refinement and deformation of phase structures caused by strong shear stress. Unexpectedly, a unique phenomenon is observed that the shear-induced lamellar crystallites are oriented perpendicular to shear direction in the range of 500–5000 s^?1 at 130 °C, while the orientation of lamellar crystallites at 160 °C is along the shear direction within the whole range of shear rates. The degree of orientation for the PBAT/PBS blend crystals increases first and then decreases at both temperatures above. In addition, the range of shear rate has reached the level in the industrial processing. Therefore, this work has important guiding significance for the regulation of the co-continuous phase structure and the performance for the blend in the practical processing.

     

一个富路易斯碱位配合物的合成、结构及对痕量Ag+的荧光检测

通过溶剂热方法合成了一个由氢键拓展的携带路易斯碱位的三维超分子配位聚合物：{[Cd（HTZ-IP）（HPYTZ）（H₂O）₂]·5H₂O}_n（HTZ-H₂IP=5-（5-四氮唑基）间苯二甲酸;HPYTZ=3,5-（4-吡啶基）-1,2,4-三唑]。X射线单晶衍射结果表明,中心镉离子由含氮杂环羧酸配体和富氮辅助配体连接成"有悬挂手臂"的一维链,而链间则凭借配位水和2个配体的氢键作用拓展成三维超分子化合物。有趣的是配合物存在大量裸露的未配位的N原子,此N原子具有路易斯碱性质,能与路易斯酸性质的Ag⁺有效结合,从而引起配合物的荧光猝灭。该性质能在无色溶液中有效检测10^-4~10^-6 mol·L^-1范围内的痕量Ag⁺离子。     

类氖钛X射线激光实验研究

在“星光”装置上采用预脉冲技术和透-反射线聚焦系统成功地进行了类氛钛x射线激光实验.测量了TiXⅢ,3s-3p,J=0～1激光线的增益系数.首次实验研究了预脉冲能量不同时,激光线强度随泵浦激光能量的变化及其发散角和偏转角.     

Quantum Entanglement Creating and Evolving in Two Charge Qubits Coupling to a Nanomechanical Resonator System

We investigate the coupling of two superconducting quantum interference devices (SQUIDs) via a metallic nanomechanical resonator (NAMR), and bring out the effective interaction between the two SQUIDs. By constructing the evolution operator, we also study the evolvement of entanglement in this composed system.     

基于同步光解的OH自由基标定方法

OH自由基是大气中最重要的氧化剂,准确测量对流层OH自由基的浓度是厘清我国二次污染形成机理的关键.本文介绍了一种基于同步光解的OH自由基便携式标定方法,使用汞灯的185 nm线辐射处于层流状态下的具有一定水汽浓度的合成空气,光解HO2和O2定量产生确定浓度的OH, HO2自由基和O3.开展了臭氧浓度及廓线分布因子P和氧气吸收截面等影响因素的准确测量,降低该标定方法的不确定度.进一步构建便携式标定装置,建立应用于实际外场标定的OH自由基浓度快速获取方法.开展基于激光诱导荧光技术OH自由基(LIF-OH)探测系统的准确标定测试,准确产生3×10^8-2.8×10^9 cm^-3浓度的OH自由基, LIF-OH探测系统的荧光信号与自由基浓度具有非常好的相关性.在综合外场观测(STORM)的应用中该标定装置的不确定度为13.0%,具有良好的稳定性和准确性,可以用于复杂外场环境下LIF-OH系统的快速标定.     

Mechanism,kinetics, and environmental assessment of OH-initiated transformation of CTDE in the atmosphere

The transformation mechanism and kinetics of 2-chloro-1,1,2-trifluoroethyl-difluoromethyl-ether (CTDE, CHF₂OCF₂CHFCl) triggered by OH radicals are studied by density-functional theory methods and canonical variational transition state theory. The computational rate constant including small-curvature tunneling correction is found to be in commendable agreement with the experimental data. Two hydrogen abstraction channels to form the alkyl radicals of C·F₂OCF₂CHFCl and CHF₂OCF₂C·FCl are observed, and the formation of CHF₂OCF₂C·FCl is found to be more favorable than C·F₂OCF₂CHFCl kinetically and thermodynamically. Subsequent evolution of CHF₂OCF₂C·FCl in the presence of NO and O₂ indicates that the organic nitrate (CHF₂OCF₂CONO₂FCl) is the stable product. The dechlorinate of alkoxy radical (CHF₂OCF₂C(O·)FCl) is the most favorable degradation channel, and the estimated ozone depletion potential for CTDE relative to chlorofluorocarbon-11 is 0.0204, which could lead to ozone depletion as a consequence. The computed atmospheric lifetime for CTDE is found to be 3.69 years by considering the combined contributions from OH radicals and Cl atoms. The total radiative forcing and global warming potential of CTDE are, respectively, 0.547 W m⁻² ppbv and 628.58 (100 years) at 298 K, suggesting that the contribution of CTDE to the greenhouse effect is moderate.     

Geometric Phase of Double Quantum Dot Qubits System with Coulomb Interaction

In quantum computing the geometric phase is a valuable tool to achieve fault tolerant. And quantum dot system is a candidate for constructing quantum processor. In this paper we investigate the geometric phase of a double qubits system interaction with a quantum point contact device. The qubits were constructed by two coupled double quantum dots systems. The coulomb interaction between the two subsystem have been considered. By using the definition which introduced by Tong, we calculate the geometric phases of each double quantum dots subsystem.     

Syntheses,structures and magnetic properties of three cobalt(II) coordination polymers based on flexible itaconic acid ligands

Transition Metal Chemistry - Three Co(II) coordination polymers, namely [Co(ia)(bpe)0.5(H2O)]n (1), {[Co(ia)(bib)(H2O)]·H2O}n (2) and {[Co(ia)(btmb)(H2O)]·H2O}n (3)...     

基于柔性的高酞酸和双咪唑型配体的Ni(Ⅱ)/Cd(Ⅱ)/Zn(Ⅱ)配位聚合物的合成、结构和性质（英文）

基于柔性的高酞酸(H2hmph)和双咪唑型配体,通过溶剂热法合成了3种新的配位聚合物:{[Ni2(hmph)2(bib)2(H2O)2]·3H2O}n(1)、[Cd(hmph)(bib)]n(2)和{[Zn(hmph)(bip)]·H2O}n(3),其中bib=1,4-双(1-咪唑基)苯、bip=3,5-双(1-咪唑基)吡啶。配合物1是由Ni-羧酸链之间通过bib配体桥联而成的二维单层结构;配合物2为Cd-羧酸双股链之间通过bib配体拓展而成的二维双层结构,并含有由羧基连接的双核单元;配合物3是由羧酸连接而成的双核Zn单元通过bip配体拓展形成的双股链。3个配合物都具有较高的热稳定性。磁性分析表明在配合物1中存在铁磁性交换偶合作用。另外,配合物2和3的荧光性质与相应的配体相比都表现出明显的蓝移。