FoxBASE应用程序的2000年问题解决方法

论述了FaxBASE应用程序中存在的2000年问题，并提出解决的方法。     

CN—23换热转化催化剂工业应用

本文介绍用于换热转化工艺的ＣＮ－２３催化剂的设计，研究和工业应用情况，该催化剂具有出色的活性及稳定性，其抗析碳性能优良，即使在低水碳比下运转也不会发生炭沉积，同时有足够长的寿命，新开发的ＣＮ－２３催化剂完全有满足工艺要求。     

板件粉末涂装产生“缩孔”原因的理论研究（续）

重点论述了设备接地因素对粉末涂装产生“缩孔”的影响。     

Using EIS to analyse samples of Al–Mg alloy AA5083 treated by thermal activation in cerium salt baths

This paper describes a study undertaken of the morphological and anticorrosive characteristics of surface layers formed on the Al–Mg alloy AA5083 from solutions of Ce(III), by means of various heat treatments while immersed in baths of cerium salts. SEM/EDS studies have demonstrated the existence of a heterogeneous layer formed by a film of aluminium oxide/hydroxide on the matrix and a series of dispersed islands of cerium deposited on the cathodic intermetallics. With the object of evaluating the degree of protection provided by the layers formed and of characterising the particular contribution of the electrochemical response of the system in NaCl, the results obtained by means of EIS are presented and discussed.     

土方路基压实不够的原因及防治措施

分析了土方路基压实度不够的原因，提出了防治措施。     

An IR study of thermally stable V2O5-WO3 -TiO2 SCR catalysts modified with silica and rare-earths (Ce, Tb, Er)

The catalytic activity of silica-free and silica-modified rare earth (Ce, Tb, Er) containing V₂O₅-WO₃ -TiO₂ catalysts in the selective catalytic reduction of NO by ammonia has been investigated as a function of ageing temperatures. The adsorption of ammonia on the catalysts and the behavior of their surface hydroxy groups and of bulk vibrations has also been studied by IR spectroscopy. Rare earths slightly decrease the catalytic activity of catalysts in a fresh state, and this has been attributed to the perturbation, observed by IR, of the vanadyl groups with a likely lowering of their Lewis acidity. However, rare earths (in particular Tb and Er) increase strongly the catalytic activity of catalysts after ageing. Silica only does not seem to have a positive effect on thermal stability and activity when vanadium is present. It has been concluded that rare earths strongly increase the thermal resistance of the catalysts and inhibit rutilization and surface area loss because they do not penetrate the anatase bulk while tend to cover the external surface. In addition the negative action of free vanadium on phase stability is decreased due to formation of rare earth vanadates.     

Synthesis and luminescence properties of rare earth ternary complexes consisting of Tb(III), β-diketones and 1,10-phenanthroline (phen)

In order to study the luminescent properties of ternary rare earth complexes with β-diketone ligand, three new β-diketone ligands, 1-phenyl-3-(p-phenylethynylphenyl)-1,3-propanedione(HPPP), 1-(2-thienyl)-3-(p-phenylethynylphenyl)-1,3-propanedione (HTPP) and 1-(2-furyl)-3-(p-phenylethynylphenyl)-1,3-propanedione (HFPP), were synthesized by Sonogashira coupling reaction and Claisen condensation. Three new ternary rare earth complexes, TbL₃phen (L = PPP, TPP, or FPP), were synthesized by the reaction of rare earth chloride TbCl₃,1,10-phenanthroline (phen) with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Tb(III) complexes only emit the weak fluorescence of the Tb(III) ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb³⁺ ion.     

Influence of La and Dy on the properties of the long afterglow phosphor CaAl2O4: Eu, Nd

The long afterglow phosphor CaAl₂O₄:Eu²⁺,Nd³⁺ was prepared by the high temperature solid-state reaction method, and the influence of La³⁺ and Dy³⁺ on the properties of the long afterglow phosphor was studied by X-ray diffraction (XRD), photoluminescence (PL), and thermoluminescence (TL). The XRD pattern shows the host phase of CaAl₂O₄ is produced and no impurity phase appears. The peak wavelength of the phosphor does not vary with La³⁺ and Dy³⁺ doping. It implies that the crystal field, which affects the 5d electron states of Eu²⁺, is not changed dramatically after doping of La³⁺ and Dy³⁺. The TL spectra indicate that the phosphor doped with La³⁺ or Dy³⁺ produces different depths of trap energy level. In the mechanism of long afterglow luminescence, it is considered that La³⁺ or Dy³⁺ works as trap energy level. The decay time lies on the number of electrons in the trap energy level and the rate of the electrons returning to the excitation level.     

Recovery of oxalate from scrubbing solution containing rare earths and iron produced during uranium recovery from phosphoric acid

A solution containing oxalate complexes of rare earths, yttrium and iron (III) is obtained during the processing of wet process phosphoric acid for uranium recovery by solvent extraction. A process is described to recover oxalic acid from such a solution. The process is based on the conversion of iron (III) oxalate into calcium oxalate by calcium chloride followed by the metathesis of calcium oxalate with sulphuric acid to produce calcium sulphate and free oxalic acid. Data is presented to illustrate the influence of various parameters such as pH, temperature, digestion time and amount of calcium chloride on effective conversion of calcium oxalate. Under optimized conditions of pH 1, digestion time 2 h, twice the stoichiometric ratio of calcium chloride at ambient temperature (30±1°C) the recovery of calcium oxalate was found to be >94%. An overall schematic material balance flow -sheet for treating the oxalate solution of rare earths, yttrium and iron (III) to oxalic acid recovery has been presented. An improvement in the second cycle of patented process flow-sheet based on 1.5 M D2EHPA + 0.2 M TBP incorporating oxalic acid scrubbing / recycle for uranium recovery from phosphoric acid has been tested and found to be simple in terms of operations and capable of meeting product specifications..     

Phase relations in the Al–Pr–Sb system at 773 K

The isothermal section of the phase diagram of the Al–Pr–Sb ternary system at 773 K over the whole concentration region has been investigated mainly by powder X-ray diffraction (XRD) with the aid of scanning electron microscopy (SEM). A new ternary compound Al₁₁Pr₂₄Sb₆₅ has been found.