Rainbows and glories in the angular scattering of the state-to-state F + H2 reaction at E(trans)=0.04088 eV

State-of-the-art differential cross sections (DCSs) have been reported by Wang et al. [Proc. Nat. Acad. Sci. (U.S.), 2008, 105, 6227] for the state-to-state F + H(2)→ FH + H reaction using fully quantum-state-selected crossed molecular beams. We theoretically analyze the angular scattering of this reaction, in order to quantitatively understand the physical content of structure in the DCSs. Three transitions are studied, v(i)=0, j(i)=0, m(i)=0 → v(f)=3, j(f)=0, 1, 2, m(f)=0 at a translational energy of 0.04088 eV, where v, j, m are the vibrational, rotational and helicity quantum numbers respectively for the initial and final states. The input to our analyses consists of accurate quantum scattering (S) matrix elements computed for the Fu-Xu-Zhang potential energy surface, as used by Wang et al. in a computational simulation of their experimental DCSs. We prove that the pronounced peak at forward angles observed in the experimental and simulated DCSs for all three transitions is a glory. At larger angles, it is demonstrated that the 000 → 300 and 000 → 310 DCSs both possess a broad farside rainbow, which is accompanied by diffraction oscillations. We confirm the conjecture of Wang et al. that these diffraction oscillations arise from nearside-farside (NF) interference. We find that the reaction is N dominant for all three transitions. The theoretical techniques used to analyze the angular scattering include uniform semiclassical theories of glory and of rainbow scattering. We also make the first application of a semiclassical formula that is uniform for both glory + rainbow scattering. In addition, structure in the DCSs is analyzed using NF theory and local angular momentum theory, in both cases with three resummations of the partial wave series for the scattering amplitude. We make the first explicit application of the Thiele rational interpolation formula to extract the position and residue of the leading Regge pole from a set of S matrix elements, thereby making contact with complex angular momentum theories of DCSs, which interpret the angular scattering in terms of Regge resonances. Our calculations complement the exit-valley vibrationally-adiabatic analysis of Wang et al.     

Local angular momentum-local impact parameter analysis: derivation and properties of the fundamental identity, with applications to the F+H2, H+D2, and Cl+HCl chemical reactions

The technique of local angular momentum-local impact parameter (LAM-LIP) analysis has recently been shown to provide valuable dynamical information on the angular scattering of chemical reactions under semiclassical conditions. The LAM-LIP technique exploits a nearside-farside (NF) decomposition of the scattering amplitude, which is assumed to be a Legendre partial wave series. In this paper, we derive the "fundamental NF LAM identity," which relates the full LAM to the NF LAMs (there is a similar identity for the LIP case). Two derivations are presented. The first uses complex variable techniques, while the second exploits an analogy between the motion of the scattering amplitude in the Argand plane with changing angle and the classical mechanical motion of a particle in a plane with changing time. Alternative forms of the fundamental LAM-LIP identity are described, one of which gives rise to a CLAM-CLIP plot, where CLAM denotes (Cross section) x LAM and CLIP denotes (Cross section) x LIP. Applications of the NF LAM theory, together with CLAM plots, are reported for state-to-state transitions of the benchmark reactions F+H2-->FH+H, H+D2-->HD+D, and Cl+HCl-->ClH+Cl, using as input both numerical and parametrized scattering matrix elements. We use the fundamental LAM identity to explain the important empirical observation that a NF cross section analysis and a NF LAM analysis provide consistent (and complementary) information on the dynamics of chemical reactions.     

有机硅/蒙脱土复合改性聚氨酯弹性体的制备和性能

采用先将聚醚三元醇N330与有机蒙脱土(OMMT)研磨,制得N330/OMMT复合物,再将其与有机硅改性聚氨酯的预聚体混合的方法,以二甲硫基甲苯二胺(DMTDA)为固化剂,制备了有机硅/蒙脱土复合改性聚氨酯弹性体,并用FTIR对产物结构进行了表征.XRD和TEM表明,蒙脱土片层被撑开,并分散在基体中;SEM显示,加入蒙脱土后,有机硅与聚氨酯之间的相容性提高;TGA表明,有机硅和OMMT共同改性聚氨酯后,其耐热性比有机硅单一改性聚氨酯有所提高,并在OMMT含量为5 wt％时提高最大;DSC数据表明,在OMMT含量为5 wt％时,有机硅/蒙脱土复合改性聚氨酯弹性体的Tg明显升高.复合改性材料具有良好的表面性能和力学性能,其拉伸强度、断裂伸长率和硬度在OMMT含量为3 wt％时达到最大值.     

Diversity of lanthanide(iii)-2,5-dihydroxy-1,4-benzenedicarboxylate extended frameworks: syntheses, structures, and magnetic properties

Six lanthanide(iii)-2,5-dihydroxy-1,4-benzenedicarboxylate frameworks, namely, [Ln(H(2)-DHBDC)(1.5)(H(2)O)(2)](n) (Ln = La (1) and Pr (2); H(4)-DHBDC = 2,5-dihydroxy-1,4-benzenedicarboxylic acid), {[Nd(H(2)-DHBDC)(1.5)(H(2)O)(3)](H(2)O)}(n) (3), {[Eu(H(2)-DHBDC)(NO(3))(H(2)O)(4)](H(2)O)(2)}(n) (4), and {[Ln(2)(H(2)-DHBDC)(2)(DHBDC)(0.5)(H(2)O)(3)](H(2)O)(4)}(n) (Ln = Gd (5) and Dy (6)), with four different structural types ranging from 1D chain, 2D layer to 3D networks have been synthesized and structurally characterized. Compounds La (1) and Pr (2) are isomorphous and exhibit 3D frameworks with the unique 1D tubular channels. Compounds Nd (3) and Eu (4) are 2D layer and 1D zigzag chain, respectively, which are further extended to 3D supramolecular frameworks through extensive hydrogen bonds. Isomorphous compounds of Gd (5) and Dy (6) are 3D frameworks constructed from secondary infinite rod-shaped metal-carboxylate/hydroxyl building blocks. While the hydroxyl groups as secondary functional groups in the 1D chain of Eu (4) and 2D layer of Nd (3) are not bonded to the lanthanide centers, the hydroxyl groups in the 3D frameworks of La (1), Pr (2), Gd (5), and Dy (6) participate in coordinating to lanthanide centers and thus modify the structural types of theses compounds. The magnetic data of compounds Pr (2), Nd (3), Gd (5), and Dy (6) have been investigated in detail. In addition, elemental analysis, IR spectra, powder X-ray diffraction (PXRD) patterns and thermogravimetric analysis of these compounds are described.     

基于ADS的2.25GHz低噪声放大器的设计与制作

首先介绍用ADS软件仿真设计S波段低噪声放大器的方法,在仿真过程中,采用带封装模型的原理图-版图联合仿真的方法;然后对制作出的放大器在工作频段2.15—2.35GHz内测试,测试结果和电路仿真结果基本一致:输入输出驻波比均小于1.2,增益达到25dB,且带内增益波动为±0.4dB,噪声为0.7dB;最后对放大器进行了低温(液氮环境)测试,结果表明该放大器在低温下也能正常工作。     

Syntheses,Structures, and Photoluminescence of Two Three‐dimensional Cadmium Coordination Polymers with Benzene­dicarboxylate Ligands

Two cadmium(II) coordination polymers, namely, [Cd₃(m‐phth)₂(atz)₂]_n ( 1 ) (m‐phth = m‐phthalate and atz = 3‐amino‐1,2,4‐triazolate) and [Cd(atphth)(H₂O)]_n ( 2 ) (atphth = 2‐aminoterephthalate), were synthesized and structurally characterized. Compound 1 features a three‐dimensional (3D) pillared framework based on two‐dimensional (2D) cadmium‐benzenedicarboxylate ladders pillared by the triazolate ligands. Compound 2 has a 3D framework constructed from 2D cadmium‐benzenedicarboxylate layers, which are further linked by Cd–N bonds between the cadmium ions and amino groups of the atphth^2– ligands of the adjacent layers to form the final 3D structure. Compounds 1 and 2 exhibit solid‐state photoluminescence with emission maxima at 448 and 470 nm, respectively.     

同位素稀释质谱法测定U3O8中痕量Sm,Eu,Gd和Dy

建立了分析U_3O_8中痕量Sm、Eu、Gd和Dy的IDMS法。在一条灯丝上一次涂样完成4个相对含量10~(-8)的元素测定。方法较简便,测定含Sm、Eu、Gd和Dy分别为8.90×10~(-8)、9.07×10~(-8)、8.65×10~(-8)和8.47×10~(-8)的U_3O_8试样,方法精密度分别为±4.2%、±3.5%、±4.8%和±4.1%。本法与其他方法相比结果相符。测Gd,~(176)〔~(160)Dy~(16)O〕~+与~(176)〔~(160)Gd~(16)O〕~+有叠加。通过测定~(160)Dy~+峰高计算出~(176)〔~(160)Dy~(16)O〕~+峰高,从而校正~(176)〔~(160)Gd~(16)O〕~+峰高。     

高温超导双工器综合与设计

介绍了一种高温超导双工器的设计方法.双工器包含一个公共节点和两个带通滤波器.作者使用开环半波长谐振器作为公共节点用于合并两信道滤波器,同时作为消纳网络消除滤波器之间的影响.各信道滤波器均包含了六个带折叠耦合线的发卡型谐振器,利用跨线引入交叉耦合.该高温超导双工器工作在c波段,仿真结果与理论计算结果相一致,说明了该设计方...