Kinetic theory of traveling wave gyro-peniotron

Using an equilibrium distribution function f_o=f_o(p, p, p_g), where R_g is the radial position of electron guiding center, this paper presents a kinetic theory of TW gyro-peniotron. The dispersion equation obtained in this paper can be used to describe both gyrotron and gyro-peniotron. The influence of beam position is discussed.     

Tuning topological and dimensional versatility from 1D to 3D of Zn/Cd luminescent biphenyl-3,5-dicarboxylate coordination polymers by ancillary ligand

The present study reports application of biphenyl-3,5-dicarboxylic acid (H₂L) as a versatile building block for synthesis of d¹⁰ metal coordination polymers (CPs). Five Cd(II) and Zn(II)-containing CPs based on N,N-donor ancillary ligands, [Cd₂(μ₃-L)₂(μ₂-4,4′-tmbpy)(MeOH)]_∞ (1), [Cd(μ₂-L)(2,2′-bpy)(H₂O)]_∞·n(MeOH) (2), [Cd(μ₂-L)(dipt)]_∞ (3), [Cd(μ₃-L)(phen)]_∞·nH₂O (4), and [Zn(μ₂-L)(μ₂-4,4′-tmbpy)]_∞·nH₂O (5) {4,4′-tmbpy = 4,4′-trimethylenedipyridine, 2,2′-bpy = 2,2′-bipyridine, dipt = 2,9-dimethyl-1,10-phenanthroline, phen = 1,10-phenanthroline} have been prepared under solvothermal conditions. 1–5 have been characterized by single crystal X-ray diffraction, elemental analysis, infrared (IR) spectra, and powder X-ray diffraction (PXRD). Complex 1 exhibits a three-dimensional (3-D) framework with a rare fsc-3,4-I41/amd topology. Complexes 2–4 show one-dimensional (1-D) structures. Complex 5 features a two-dimensional (2-D) layer structure with a sql topology. The structural and topological diversity of 1–5 are mainly attributed to the effect of the N,N-donor ancillary ligand. Solid-state luminescent properties and thermal stabilities of the obtained products have been investigated.     

Synthesis,characterization and luminescent properties of three-coordinate copper(I) halide complexes containing 2-(diphenylphosphino)biphenyl

Highly emissive three-coordinate copper halide complexes with a bidentate phosphine ligand have attracted attention. Here, a series of three-coordinate mono- and dinuclear copper halide complexes, [CuI(dpbp)₂] (1) and [CuX(dpbp)]₂ (dpbp = 2-(diphenylphosphino)biphenyl, X = Br (2), Cl (3)), were synthesized, and their molecular structures and photophysical properties were investigated. In the solid state, these complexes exhibit green photoluminescence with microsecond lifetimes (λ_max = 515–538 nm; τ = 11.8–19.1 μs) at 298 K. The emission of the complexes originates from the (σ + X) → π* transition. All three complexes displayed good thermal stability.     

三个基于1,5-二(2-乙基苯并咪唑基)-戊烷柔性配体的镉配合物

通过设计柔性配体1,5-二（2-乙基苯并咪唑基）戊烷（bep）,在二羧酸辅助配体的调控下成功制备了3个配位聚合物[Cd（bep）（sba）]_n（1）,[Cd（bep）（bda）]_n（2）,and{[Cd₂（bep）（ada）₂]·H₂O}_n（3）（H₂sba=4,4’-磺酰基二苯甲酸,H₂bda=4,4’-联苯二甲酸,H₂ada=1,3-金刚烷二乙酸）。配合物均呈现二维层状结构。配合物1由交替的Cd（Ⅱ）/bep/sba^2-螺旋链构成。配合物2由Cd/bda^2-单元构成二维结构,bep作为单齿配体与Cd（Ⅱ）配位。配合物3的二维层通过Cd/ada^2-/H₂O氢键螺旋链拓展成三维超分子。此外,对配合物1~3的粉末X射线衍射、热稳定性以及荧光性质进行了研究。     

基于一个四羧酸配体构筑的具有(4,8)-连接的镧系金属有机框架材料及对小分子的检测试验

以3,3’,5,5’-四-(羧基苯基)联苯为配体(H₄L),与镧系金属Ln(Ⅲ)盐反应,自组装形成了5个具有三维孔洞结构的镧系金属-有机框架材料：{[Ln₃L₂(H₂O)₇]·(OH)·10DMA}_n(Ln=Gd(1a);Ln=Ho(2a),{[Ln₃L₂(H₂O)3]·(OH)·mDMA}_n(Ln=Er,m=10(1b);Ln=Yb,m=9(2b);Ln=Lu,m=10(3b))。单晶X射线衍射分析表明,这些MOFs属于2种系列的类质同晶化合物,分别属于正交晶系Ccca空间群和单斜晶系C2/c空间群。有机小分子溶剂交换荧光研究发现,2b对小分子二氯甲烷和甲苯荧光有增强效应,表现出良好的荧光探测功能。     

Imaging oersted field around current flowing wire based on a diamond scanning magnetometer

We demonstrate imaging current flow in a transport device by measuring the current-induced Oersted field. A diamond scanning magnetometer that hosts a single nitrogen-vacancy (NV) center at the tip apex is used to obtain the image. We fabricate a U-shape of Pt wire and study evolution of the Oersted field as the current continuously changes its direction along the wire. We find a good agreement between the obtained results and the simulated images based on the Biot-Savart law. In order to show the capability of imaging different field components, we perform the same experiment but with two different axes of the NV center. This work provides a novel imaging method of the current profile and can be applied to various transport experiments.     

Staffing call centers under arrival-rate uncertainty with Bayesian updates

We consider the problem of staffing service centers with quality-of-service constraints. We focus on the case where the arrival rates are uncertain. We introduce formulations that handle staffing decisions made over two decision periods, minimizing the staffing costs over the stages while satisfying a service quality constraint on the second stage operation. A Bayesian update is used to obtain the second-stage arrival-rate distribution based on the first stage prior arrival-rate distribution and the observations in the first stage.     

Ln3+‐Mediated Self‐Assembly of a Collagen Peptide into Luminescent Banded Helical Nanoropes

Design of biomimetic peptides to achieve the desired properties of natural collagen has much potential to build functional biomaterials. A collagen‐peptide/Ln³⁺ system has been constructed and self‐assembled to form helical nanoropes with a distinct periodic banding pattern characteristic of natural collagen. The fully reversible self‐assembly is specifically mediated by lanthanide ions, but not by other commonly used divalent metal ions. Lanthanide ions not only provide an external biocompatible stimulus of the assembly, but also play as a functional unit to endow the assembled materials with easily tunable photoluminescence. To our knowledge, this is the first report of collagen‐peptide‐based materials with exquisite nanorope structure and excellent photoluminescent features. These novel luminescent nanomaterials may have great potential in cell imaging, medical diagnostics, and luminescent scaffolds for cell cultivation.     

基于 Eu~(3 +)还原制备 Eu~(3 +)-Eu~(2 +)共存发光材料的研究进展

稀土Eu元素因其优良的光学特性常被作为激活离子广泛应用于无机发光材料中。激活离子的发光性质由自身的价态决定,同时受基质晶体结构影响。不同价态的Eu离子呈现不同的光学特性,当二者共存时有可能得到单一基质的白光。本文主要综述近几年Eu~(3+)-Eu~(2+)共存于铝酸盐、磷酸盐、硅酸盐及硼酸盐基质中的荧光性能、Eu~(3+)的还原条件及还原机理。