类氢氖在高温高密度等离子体中的光谱漂移

 采用离子球模型,通过自洽求解Poisson方程和Dirac方程,得到氖的类氢离子低能级组态的能级能量随等离子体电子温度和电子密度的变化关系,进一步研究了等离子体电子温度和电子密度对光谱漂移的影响。结果表明：光谱漂移随着等离子体电子密度的增大而增大,随着电子温度的升高而减小;谱线精细结构分裂随着电子密度的增大而减小,随着电子温度的升高而增大。等离子体对束缚电子的屏蔽是决定光谱漂移的主要原因。这些变化规律不仅对等离子体光谱模拟结果产生影响,而且使实验上观测光谱的相对或绝对漂移成为可能,从而为高密度等离子体诊断的新方法提供了理论依据。     

发动机机油滤清器虑层强度分析及优化

针对机油滤清器工作工况下进出口压差、机油滤层强度及导流桩高度等问题, 通过试验测试与仿真相结合, 对滤清器初步设计进行了评估及优化, 以确保滤清器在工作工况下进出口压降及滤层强度能满足要求. 首先进行滤层性能试验, 得到滤层的惯性阻力系数和黏性阻力系数; 再通过滤层多孔介质CFD分析, 对滤清器进出口压降进行分析计算. 结果表明: 在-18℃、25℃和70℃的工况下, 进出口压降都小于10kPa, 满足相关要求. 针对滤层的最大主应力超过其抗拉强度的问题, 通过CAE仿真分析, 优化滤层与导流桩间隙, 将滤层最大主应力由110.1MPa降至36.99MPa, 小于其抗拉强度42.8MPa.     

Copper (50 MeV) and Oxygen (84 MeV) Ion Irradiation Probed Thermal,Structural and Optical Behavior of Polyethylene Terephthalate

Polyethylene terephthalate (PET) films of 50?μm thickness were exposed to swift-heavy 50?MeV copper and 84?MeV oxygen ions, with fluence varying from 1?×?10¹¹ to 1?×?10¹³ ions cm^?2. Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) and UV-visible spectroscopic techniques were used to characterize the irradiated samples. The XRD and DSC analysis indicated the loss of crystallinity during/after the irradiation. The FTIR spectra revealed the formation of alkyne end groups, C═C groups and structural deformation with increase of ion fluence. Considerable reduction in the value of the optical bandgap was inferred from the study of the UV-visible absorption curves.     

Hillock formation on ion-irradiated graphite surfaces

Abstract

Scanning probe microscopy experiments show that ion irradiation of (0001) graphite results in the formation of isolated defects comprising of a few tens of atoms. We use molecular dynamics simulations and density-functional theory calculations to study the formation probabilities of these defects. We identify different defect structures which correspond to experimentally observed hillocks on graphite surfaces. We find that the predominant source of defects are vacancies and interlayer interstitials, and identify a three-atom carbon ring defect on the graphite surface.     

Development of a prototype high-current low-energy ion implanter

A high current-low energy implant system for the processing of semiconductor devices at medium-high dopant levels is described. Criteria for selection and design of ion beam components such as ion beam optics, vacuum requirements and reliability are discussed. Variations in wafer uniformities for within wafer, wafer-to-wafer and run-to-run are presented.     

Resistivity control of sputtered amorphous-silicon by ion-implantation

The resistivity of a hydrogenated sputtered amorphous-silicon is controlled by using room temperature implantation of P⁺. It is found that the defects produced by implantation can be minimized by annealing at 300°C in an H₂ atmosphere, and also found that there is a threshold implanted dose, beyond which the resistivity begins to be controlled by changing the dose.     

Radiation damage and annealing in Sb implanted diamond

The predicted, but as yet unobserved, intradonor absorption spectrum of the hydrogenic-like donors in CdF₂ crystals is presented. The role of phonon coupling in these spectra is discussed. From the data on the insulator-semiconductor transition in CdPbF₂ it is concluded that the dominant factor in convertibility of CdF₂ to a semiconducting state is its electron affinity, the largest among the fluorites (x≈4 eV).     

Synthesis Of 2-Acyltetrahydro-β-Carbolines By An Intramolecular α-Amidoalkylation Reaction

2-Acyltetrahydro-β-carbolines 7 have been obtained by cyclization of adducts 5 from imines 3 of tryptamine 1 and aldehydes 2 with acyl chlorides 4 as a result of an intramolecular a-amidoalkylation reaction in the presence of bases as N,N-dimethylaniline or Et₃N.     

Synthesis,characterisation and ion exchange properties of hybrid organic–inorganic composite material: polyacrylamide zirconium (IV) iodosulphosalicylate

ABSTRACT

Contamination of groundwater by heavy metal is one of the most emerging and serious environmental problems. There are so many methods which are available to overcome these problems. Among various available methods, hybrid organic–inorganic ion exchange resin has become more popular due to certain advantages over other available conventional methods; hence, in the present proposed work, we synthesised a hybrid organic–inorganic composite material polyacrylamide zirconium (IV) iodosulphosalicylate by using the sol-gel technique. Synthesised resin was characterised by various methods like Infrared spectroscopy and Thermogravimetric analysis-Differential thermal analysis. Various samples of this ion exchange resin are prepared by changing the condition of synthesis, i.e. concentration of acrylamide to rationalise the ion exchange capacity of the synthesise hybrid organic–inorganic ion exchange resins. A mixture of 0.1 M potassium iodate, 0.1 M sulphosalicylic acid and 0.1 M acrylamide was added dropwise to 0.4 M zirconium oxychloride accompanied by constant stirring for 8 h using magnetic stirrer at 70°C to yield polyacrylamide zirconium (IV) iodosulphosalicylate with maximum ion exchange capacity. Ion exchange capacity of synthesised resin was determined by column method and the maximum ion exchange capacity was found for Pb(II). Determination of k_d values shows that the resin was highly selective for Pb (II).The selectivity for Pb was also evaluated by using certain binary mixture separation such as Ni (II)-Pb(II), Cu(II)-Pb(II), Cd(II)-Pb(II), Sr(II)-Pb(II), Ba(II)-Pb(II),Zn(II)-Pb(II) and Mg(II)-Pb(II).     

On a new FeOF polymorph: Synthesis and stability

A new polymorph of FeOF (up to now only known in its rutile type structure) was prepared by using a new synthesis approach formally based on anionic exchange using the well-known layered FeOCl as precursor. The synthesis was achieved using [CH₃C(CH₂O–)₂(COO–)B] to vehicle fluorine through the formation of soluble (CH₃)₄N⁺ [CH₃C(CH₂O–)₂(COO–)BF]⁻ and using N,N-dimethylformamide (DMF) as the reacting medium. The XRD pattern of layered FeOF can be indexed with an orthorhombic cell which doubles along the b axis (which is the direction perpendicular to the layers) with respect to that of pristine FeOCl (a = 3.792(1) Å, b = 12.699(1) Å, c = 3.321(1) Å). Both thermal analysis and diffraction indicate similar stability for the layered and rutile polymorphs. Such findings are rationalized through Density Functional Theory calculations. It is found that the energy difference between the more stable rutile and layered polymorphs is practically nul. The origin of the similar stability lies in the fact that although the number of Fe–F and Fe–O bonds is different in the two structures, the strength of both the total number of Fe–O as well as Fe–F bonds are found to be almost identical. Even if the crystal and electronic structures are considerably different, the total bonding and thus, the stability of the two polymorphs, is comparable. The stability of different FeOF rutile type structures is also analyzed.