Modulated Terahertz Transmission through Sub-Wavelength Cu Grating by Liquid Water

Submerging the sub-wavelength Cu wire grating in liquid water, we prove that the transmission ration can be changed pronouncedly from 0.1THz to 1.7THz. The modulation of terahertz responses by liquid water is explained by the increasing effective electron mass in the plasmon picture. Due to this response, we extract the index of liquid water, and our results provide a potential application of using metal grating to detect real solvated condition biomaterials in the THz frequency range.     

Theoretical mechanistic study on the radical-molecule reaction of CH2Br/CHBrCl with NO2

The radical-molecule reaction mechanisms of CH₂Br and CHBrCl with NO₂ have been explored theoretically at the UB3LYP/6-311G(d, p) level. The single-point energies were calculated using UCCSD(T) and UQCISD(T) methods. The results show that the title reactions are more favorable on the singlet potential energy surface than on the triplet one. For the singlet potential energy surface of CH₂Br + NO₂ reaction, the association of CH₂Br with NO₂ is found to be a barrierless carbon-to-oxygen attack forming the adduct IM1 (H₂BrCONO-trans), which can isomerize to IM2 (H₂BrCNO₂), and IM3 (H₂BrCONO-cis), respectively. The most feasible pathway is the 1, 3-Br shift with C–Br and O–N bonds cleavage along with the N–Br bond formation of IM1 lead to the product P1 (CH₂O + BrNO) which can further dissociate to give P4 (CH₂O + Br + NO). The competitive pathway is the 1, 3-H-shift associated with O–N bond rupture of IM1 to form P2 (CHBrO + HNO). For the singlet potential energy surface of CHBrCl + NO₂ reaction, there are three important reaction pathways, all of which may have comparable contribution to the reaction of CHBrCl with NO₂. The theoretically obtained major products CH₂O and CHClO for CH₂Br + NO₂ and CHBrCl + NO₂ reactions, respectively, are in good agreement with the kinetic detection in experiment.     

Mechanistic and dual-level direct dynamics studies on the reaction Cl + CH2FCl

Theoretical investigations are carried out on the reaction Cl + CH₂FCl by means of direct dynamics method. The minimum energy path (MEP) is obtained at the MP2/6-311G(d, p) level. The energetic information is further improved by single-point energy calculations using QCISD(T)/6-311++G(d, p) method. The kinetics of this reaction are calculated by canonical variational transition state theory incorporating with the small-curvature tunneling correction over a wide temperature range of 220–3,000 K, and rate constant expression are found to be k(T) = 1.48 × 10^?17 T ^2.04exp(?913.91/T). For the title reaction, H-abstraction reaction channel is the major channel at the lower temperatures. At higher temperatures, the contribution of Cl-abstraction reaction channel should be taken into account.     

Syntheses, Crystal Structures and Fluorescent Properties of Two New Imidazolidino Schiff Base Compounds

Two new imidazolidino Schiff base compounds, （E）-N-（（quinoxalin-2-yl）methylene）- 2-（2-（quinoxalin-3-yl）imidazolidin-1-yl）ethanamine 1 and 2-（1-（2-（2-（quinoxalin-3-yl）imidazolidin- 1-yl）ethyl）imidazolidin-2-yl）quinoxaline 2, have been synthesized and characterized by elemental analysis, ^1H NMR, IR, MS and single-crystal X-ray diffraction. Crystallographic data for 1： C22H21N7, Mr = 383.46, monoclinic, space group P21, a = 7.0036（14）, b = 6.9151（14）, c = 19.701（4）A, β = 96.57（3）°, Z = 2, V = 947.9（3）A^3, Dc = 1.344 g/cm^3, F（000） = 404, μ = 0.085 mm^-1, Flack parameter = 0（2）, R = 0.0464 and wR = 0.1055; and those for 2： C24H26N8, Mr = 426.53, triclinic, space group PI, a = 9.6680（19）, b = 10.334（2）, c = 11.389（2）A, α= 104.12（3）, β = 102.95（3）, γ= 100.48（3）°, Z= 2, V = 1041.2（4）A3, Dc= 1.361 g/cm^3, F（000） = 452, μ = 0.086 mm^-1, R = 0.0373 and wR = 0.1155. For the two compounds, the five-membered imidazolidine rings all adopt envelope conformation. Moreover, the title compounds show one-dimensional layered and three-dimensional supramolecular chainlike structures, respectively. Fluorescent properties of the two compounds have been investigated in the solid state at room temperature. Compound 1 exhibits strong fluorescence and thus may serve as excellent candidates of green fluorescent materials.     

瞬态电子碰撞激发类氖锗19.6nm X射线激光的理论研究

近来，许多实验室仅采用一个脉宽为几个ps的短脉冲就得到了强放大的软X射线激光.这表明瞬态是来得及电离的.为此，在类氖锗的瞬态电子碰撞激发19.6nm 波长X射线激光研究中，提出了采用低预脉冲产生低电离度的预等离子体，后续一个ps级短脉冲既电离又加热等离子体的驱动方式.并用系列程序进行了模拟.模拟结果表明，这种驱动方式也可以得到高增益. 关键词： X射线激光 等离子体 增益系数 瞬态电子碰撞激发     

10-6-10-4m2/s黏度液体中靶受力学作用的测试与分析

通过自行研制的光纤传感器对不同黏度液体中材料靶后的力学作用进行研究,获得了液体黏度变化对等离子体烧蚀力、射流冲击力及空泡生存周期的影响. 实验结果表明:液体黏度相同时,靶材所受冲击力幅值随作用激光能量的增加单调上升;液体黏度增加时,靶材所受的冲击力减小,靶材的空化空蚀程度亦减小;受液体黏度增大的影响,空泡膨胀或收缩过程减缓,相应的生存周期也增大. 此外,对空泡溃灭周期公式进行修正,结果表明修正后的理论估算值与实验值的一致性较好.     

海藻异枝麒麟菜多糖抑制尿石盐草酸钙晶体生长的研究

采用扫描电子显微镜(SEM)、 红外光谱(FTIR)和X射线衍射(XRD)方法研究了从海藻异枝麒麟菜中提取的硫酸多糖(ESPS)对草酸钙(CaOxa)晶体生长的影响. 结果表明, 添加ESPS能抑制一水草酸钙(COM)的生长, 同时诱导二水草酸钙(COD)晶体的形成. 随着ESPS的质量浓度从0增加到0.03和0.50 mg/mL, COD的质量分数从0分别增加到10%和55%; COM的(1 01)晶面加强, (020)晶面减弱直至消失, 并从三维晶体转变为棱角圆顿的四角形片状晶体; COM和COD的尺寸均明显变小. 这些结果表明, ESPS是抑制CaOxa结石形成的一种潜在药物.     

Theoretical investigations on electronic structures and photophysical properties of N-heteroaryl carbazole derivatives as host materials

The carbazole-endcapped host molecules with tailoring different heteroaryl core and meta-position linkage mode have great potential on phosphorescent organic light-emitting diodes. To provide a profound view on structure?Cproperty relationships, new linear-shaped counterparts have been designed based on the existing molecular composition and the linkage at para-position (p-type molecules). A series of studies about the influence of the linkage mode on optical and electronic properties of these carbazole derivatives have carried out via density functional theory and time-dependent density functional theory calculations. The geometric and the electronic structure of these molecules in the ground states, ions states, and lowest triplet states have been calculated especially focusing on the analysis of highest occupied molecular orbitals, lowest unoccupied molecular orbitals, energy gaps, triplet energies, ionization potentials, electron affinities, reorganization energies, triplet exciton-formation fraction, and absorption spectra. These optoelectronic properties can be effectively tuned by the chemical modifications of different linkage pattern. The good coordination between our calculated results and the available experimental data has been observed. The study reveals that the designed p-type molecules show great promise as new high-performance red host materials with large triplet energy, narrow energy gap, good electron and hole-transport properties, and high triplet exciton-formation fraction.     

两个由双咪唑基配体构筑的锰、镉配合物的合成及晶体结构

通过水热法合成了2个金属-有机配位聚合物[Mn（dipha）（1,3-bix）]_n·nH₂O（1）和[Cd₂（NIPH）₂（bimb）_2.5（H₂O）]_n·3nH₂O（2）（H₂dipha=2,2’-联苯二甲酸,1,3-bix=1,3-双（咪唑基-1-甲基）-苯,H₂NIPH=5-硝基间苯二甲酸,bimb=1,4-双（咪唑基-1-甲基）-丁烷）。并对其进行了元素分析、红外光谱、热重和X-射线单晶衍射测定。这2个配合物通过氢键和π-π相互作用形成了超分子网状结构。此外还研究了配合物2的荧光性质。     

三维超分子锌/锰配合物的合成、晶体结构及理论计算

通过水热法合成了2个新的三维超分子配合物{[Zn₂（pzdc）（L）₂（H₂O）]·H₂O}_n（1）和[Mn（μ₂-O）（H₂O）₂（HL）]·NIPH（2）（H₂pzdc=吡嗪-2,3-二甲酸,H₂NIPH=5-硝基间苯二甲酸,HL=3-（2-吡啶基）吡唑））。并对其进行了元素分析、红外光谱、紫外光谱、热重、荧光光谱、X射线单晶和粉末衍射测定。配合物1是二维网状结构,配合物2为零维结构,这2个配合物通过氢键和π-π相互作用形成了三维超分子网状结构。此外,还用高斯09程序PBE0/LANL2DZ方法对配合物1和2进行了自然键轨道（NBO）分析,计算结果表明配位原子与Zn、Mn离子之间存在着共价作用。