Resonance-enhanced multiphoton ionisation photoelectron spectroscopy of the ClO radical: the C 2 sigma- state

A (2 + 1) one-colour resonance-enhanced multiphoton ionisation study is carried out on the C 2 sigma- state of the ClO radical in the one-photon energy range 29,500-31,250 cm-1. The ClO radical is produced by one-photon photolysis of ClO2 employing 359.2 nm photons derived from a separate laser. In this way a significant concentration of vibrationally excited ClO in its spin-orbit split X 2 pi omega (omega = 3/2 or 1/2) electronic ground state is produced. In addition to mass-resolved excitation spectra, kinetic-energy resolved photoelectron spectra for the X 3 sigma-(v+)<--C 2 sigma-(v' = 3-5) transitions are measured. These transitions are not completely Frank-Condon diagonal, and indicate a decrease in bond length on removal of the Rydberg electron from the C 2 sigma- state. In addition to an unambiguous assignment of the C 2 sigma- state, valuable information is obtained on the degree of vibrational excitation with which the nascent ClO radical is formed in the photolysis of ClO2. Analysis of the photoelectron spectra is supported by Franck-Condon calculations based on potential energy curves either from experimental spectroscopic parameters, or obtained by theoretical ab initio methods.     

Structural Modulation in Lanthanide Tetracyanoplatinates Incorporating Terpyridine: Synthesis and Structures of Four Distinct One-Dimensional Variants

Abstract  

The synthesis of four different lanthanide tetracyanoplatinates all incorporating 2,2′:6′,2″-terpyridine have been carried out in acetonitrile/water mixtures by reaction of an appropriate Ln³⁺ salt with 2,2′:6′,2″-terpyridine and potassium tetracyanoplatinate. The use of different Ln³⁺ salts as reactants results in the isolation of {La(tpy)(H₂O)₃}₂[Pt(CN)₄]₃·2CH₃CN·2H₂O (La-1) space group P[`1] P\bar{1} , a = 9.3862(15) ?, b = 12.186(1) ?, c = 13.493(1) ?, α = 88.082(7)°, β = 80.22(1)°, γ = 74.88(1)°, {Pr(tpy)(H<sub>2</sub>O)<sub>3</sub>}<sub>2</sub>[Pt(CN)<sub>4</sub>]<sub>3</sub>·2H<sub>2</sub>O (Pr-2) space group P[`1] P\bar{1} , a = 9.2458(15) ?, b = 10.8068(9) ?, c = 13.6178(14) ?, α = 84.554(8)°, β = 74.905(10)°, γ = 79.490(9)°, Ho(tpy)(H₂O)₂(NO₃)[Pt(CN)₄] · CH₃CN (Ho-3) space group P2₁/c, a = 12.867(1) ?, b = 15.1046(15) ?, c = 13.651(4) ?, β = 105.39(1)°, or Yb(tpy)(H₂O)₂(NO₃)[Pt(CN)₄]·0.5CH₃CN·1.5H₂O (Yb-4) space group Pbcn, a = 13.226(7) ?, b = 15.870(2) ?, c = 24.276(3) ? under quite similar reaction conditions. All four of these compounds have been isolated as single crystals and X-ray diffraction has been used to investigate their structural features. None of these compounds are isostructural with one another, but all contain one-dimensional, polymeric structures that contain tris chelation of the Ln³⁺ cations by terpyridine and bridging of the Ln³⁺ ions by tetracyanoplatinate. La-1 and Pr-2 contain both cis- and trans-bridging of Ln³⁺ cations by tetracyanoplatinate resulting in double chains with a ladder-type structure. Ho-3 and Yb-4 are similar in that they contain chelation of Ln³⁺ by both terpyridine and a nitrate anion and both structure types only contain cis-bridging by tetracyanoplatinate. All four structures contain Pt–Pt interactions in the form of dimeric units.     

PARALLEL AUXILIARY SPACE AMG FOR H（curl） PROBLEMS

In this paper we review a number of auxiliary space based preconditioners for the second order definite and semi-definite Maxwell problems discretized with the lowest order Nedelec finite elements. We discuss the parallel implementation of the most promising of these methods, the ones derived from the recent Hiptmair-Xu （HX） auxiliary space decomposition [Hiptmair and Xu, SIAM J. Numer. Anal., 45 （2007）, pp. 2483-2509]. An extensive set of numerical experiments demonstrate the scalability of our implementation on large-scale H（curl） problems.     

Removal of137Cs from an intermediate level liquid waste by using various ion-exchange media

An intermediate level liquid waste (ILLW or Category III waste) stream was treated for the removal of radioactive Cs in pilot scale experiments, using three different ion exchange media. Results indicated that the polyacrylic fibre coated with cupric ferric hexacyanoferrate (CuFeHCF-fibre composite) was the most efficient, followed by cupric hexacyanoferrate loaded ion exchange resin (CuHCF-resin) and mixed zeolites (AR-1, 4A and 13X in the ratio 6:1:1). The mixed zeolites column and the CuFeHCF-fibre column were used in series in order to get a high total decontamination factor (DF). Leaching studies on the CuFeHCF-fibre composite loaded with¹³⁷Cs, in demineralised (DM) water, tap water and ground water media indicated a release of about 19.3%, 25.5% and 41.3% of¹³⁷Cs, respectively, in a period of about 8 months. XPS studies with CuFeHCF-fibre composite indicated some chemical interaction between the CuFeHCF precipitate and the polyacrylic fibre. Some of the possible disposal options for the CuFeHCF-fibre composite have also been discussed.     

Ultra-Low-Power,High-Accuracy 434 MHz Indoor Positioning System for Smart Homes Leveraging Machine Learning Models

Global navigation satellite systems have been used for reliable location-based services in outdoor environments. However, satellite-based systems are not suitable for indoor positioning due to low signal power inside buildings and low accuracy of 5 m. Future smart homes demand low-cost, high-accuracy and low-power indoor positioning systems that can provide accuracy of less than 5 m and enable battery operation for mobility and long-term use. We propose and implement an intelligent, highly accurate and low-power indoor positioning system for smart homes leveraging Gaussian Process Regression (GPR) model using information-theoretic gain based on reduction in differential entropy. The system is based on Time Difference of Arrival (TDOA) and uses ultra-low-power radio transceivers working at 434 MHz. The system has been deployed and tested using indoor measurements for two-dimensional (2D) positioning. In addition, the proposed system provides dual functionality with the same wireless links used for receiving telemetry data, with configurable data rates of up to 600 Kbauds. The implemented system integrates the time difference pulses obtained from the differential circuitry to determine the radio frequency (RF) transmitter node positions. The implemented system provides a high positioning accuracy of 0.68 m and 1.08 m for outdoor and indoor localization, respectively, when using GPR machine learning models, and provides telemetry data reception of 250 Kbauds. The system enables low-power battery operation with consumption of <200 mW power with ultra-low-power CC1101 radio transceivers and additional circuits with a differential amplifier. The proposed system provides low-cost, low-power and high-accuracy indoor localization and is an essential element of public well-being in future smart homes.     

YBa2Cu3Ox超导体的光谱研究

能带是决定固体特性的头等重要的因素。我们用光谱方法对单相YBa₂Cu₂O_x高T。超导体进行了研究,测量了样品的反射-吸收谱、Raman光谱和荧光光谱.其350和500nm吸收带以及390nm,560nm荧光峰来自晶格中Cu⁺发光中心,是跃迁过程¹A_1g(3d¹⁰)-¹E_g和~3E_g(3d⁹4s¹)。其720nm和860nm荧光峰来自Cu²⁺发光中心,是由于自由离子光谱项²D在八面体晶场、正交晶系晶场中分裂为5个能级之间的跃迁。此外,还有一些光谱可能来自晶格中Cu³⁺发光中心,其481cm^-1和551cm^-1声子对说明了312cm^-1处声子对与电子系统是强耦合。     

相对论性核与乳胶(Ag)碰撞中灰粒子的系统研究 *

用描写相对论性核 核碰撞的LUCIAE模型和相应的事件产生器系统地研究了 1 4.6 ,6 0和 2 0 0AGeV的O核、2 0 0AGeV的Si和S核以及 1 1 .6AGeV的Au核与乳胶 (Ag)碰撞中灰粒子产生的平均多重数、多重数分布以及角分布 3个物理量同入射能量、射弹质量及碰撞中心度间的关系 ,还研究了再散射在灰粒子产生机制中的作用 .LUCIAE的这些研究结果与相应的EMU0 1乳胶实验结果都相一致 .     

算术级数中的陈景润定理 *

设N为一充分大的偶数且q≥ 1 ,(l_i,q) =1 (i=1 ,2 ) ,l₁+l₂ ≡N(modq) .证明了方程N =p+P₂ ,p≡l1(modq) ,P₂ ≡l₂ (modq)对区间 1 ,N^1/37中除了ON^1/37log^-5 N个例外的整数q ,都有无穷多解 ,其中p是素数 ,P₂ 为一至多有2个素因子的殆素数 .     

涡旋成对分布和对二元速度关联函数的影响

本文考虑了涡旋之间相互作用的影响,假定均匀各向同性湍流场是由涡旋对在整个空间等几率分布而成,这样计算出的二元速度关联函数f(γ/λ)在远处略有提高,这个结果是与Bennett和Corrsin的实验结果和其他实验结果相合的。