甘氨酸钙络合物的熔融法合成及表征

以甘氨酸和氢氧化钙为原料,采用熔融法合成了甘氨酸钙络合物,最佳合成条件为:原料摩尔比n甘氨酸:nCa(OH)2=2:1,在熔融状态下,反应温度150℃左右,反应时间40min,并通过元素分析、红外光谱、X-射线粉末衍射、差热-热重等实验手段对该络合物进行了表征,确定其化学式为Ca(NH2CH2COO)2,所得产品的产率达94.1%.     

DEPENDENCE OF PHASE TRANSITION ON THE MASS NUMBER OF HOT NUCLEI

The dependence of phase transition,associated with the disassembly of hot nuclei,on the mass number of hot nuclei is investigated.By studying six hot nuclei ranging from ⁵⁶Ni* to ²³⁸U*,we find that in the curves of excitation energy of hot nuclei vs.Thermodynamic temperature T(E*) of ⁶³Cu* and heavier ones there are always two temperature plateaus,but in T(E*) of ⁵⁶Ni the first temperature plateau (at lower excitation energy) shrinks into a kink.     

IMPROVEMENT OF THERMODYNAMICAL MONTE CARLO SIMULATION IN SU(2) PURE GAUGE FIELD THEORY ——AN APPROACH TO CONTINUUM PHYSICS LIMIT

The thermodynamical quantities of SU(2) pure lattice gauge field have been simulated first time on the asymmetric lattice (ξ>1).The finite size effect and continuum physics limits have also been studied.The results show that the use of asymmetric lattice is of benefit to calculate the thermodynamical quantities and study the behavior of continuum physics limits.In addition,it is explained that the efficiency of the whole Monte Carlo simulation and the calculation of heat capacity will be improved quite a lot by using bias sampling technique.     

Ω Production and Corresponding Ratio of Antiparticle to Particle in Relativistic Nucleus-Nucleus

We use the event generator LUClAE to analyze the WA85 data of ratio of Ω^- to Ω^- in reaction (200A GeV/c)S + W. The result indicates that the reproduction of WA85 data might be achieved in hadronic rescattering regime of LUCIAE and might need not to rely on the formation of QGP.     

Infrared multiple photon dissociation in the quadrupole ion trap via a multipass optical arrangement

The design of a novel multipass optical arrangement for use with infrared multiple photon dissociation (IRMPD) in the quadrupole ion trap is presented. This design circumvents previous problems of limited IR laser power, small IR absorption cross sections for many molecules, and the limited ion statistics of trapping and detection of ions for IRMPD in the quadrupole ion trap. In contrast to previous designs that utilized the quadrupole ion store, the quadrupole ion trap was operated in the mass selective instability mode with concurrent resonance ejection. The instrumental design consisted of a modified ring electrode with three spherical concave mirrors mounted on the inner surface of the ring. This modified design allowed for eight laser passes across the radial plane of the ring electrode. IRMPD of protonated bis(2-methoxyethyl)ether (diglyme) was used to characterize the performance of the multipass ring electrode. Two consecutive reactions for the IRMPD of protonated diglyme were observed with a lower energy channel predominant at less than 0.6 J (irradiation times from 1 to 30 ms) and a second channel predominant at energies greater than 0.6 J (irradiation times > 30 ms). Other studies presented include a discussion of the dissociation kinetics of protonated diglyme, the use of a pulsed valve for increased trapping efficiency of parent ion populations, and the effects of laser wavelength and of ion residence time in the radial plane of the ring electrode on photodissociation efficiency.     

Probing trapped ion energies via ion-molecule reaction kinetics: Quadrupole ion trap mass spectrometry

We present a detailed study of the energies of the ions stored in a quadrupole ion trap mass spectrometer (QITMS). Previous studies have shown that the rate constant, k, for the charge exchange reaction Ar⁺ N⁺ ₂ →, N⁺ ₂+Ar increases with increasing ion-molecule center-of-mass kinetic energy (K.E._cm). Thus, we have determined k for this chemical “thermometer” reaction at a variety of Ar and N₂ pressures and have assigned K.E._cm values as a function of the q₂ of the Ar⁺ ion both with and without He buffer gas present in the trap. The K.E._cm energies are found to lie within the range 0.11–0.34 eV over the variety of experimental conditions investigated. Quantitative “cooling” effects due to the presence of He buffer gas are reported, as are increases in K.E._cm due to an increase in the q₂ of the Ar⁺ ion. “Effective” temperatures of the Ar⁺ ions in He buffer are determined based on a Maxwell-Boltzmann distribution of ion energies. The resulting temperatures are found to lie within the range ≈ 1700–3300 K. We have also examined the K.E._cm, values arising from the chemical thermometer reaction of O⁺ ₂ with CH₄, as previous assignments of effective ion temperatures based on this reaction have been called into question.     

高压密封微波消解-等离子体发射光谱法测定5种蒙药中镁、钙、锰、铁、钴、镍、铜和锶

高压密封微波消解-等离子体发射光谱法测定5种蒙药中8种金属元素.实验结果表明:其中铁、锶、锰的含量较高.测定方法简便、快速、省时、稳定性好、回收率均在97.5%-105.5%.测试方法具有较好的精密度和准确度.     

Absorbing boundary technique for open channel flows

An absorbing boundary condition is formulated and applied to the one‐dimensional open channel flow equations in conjunction with an explicit MacCormack scheme. The physical flow domain has been truncated by introducing an artificial pseudo‐boundary. By using an appropriate boundary condition on a truncated domain, it is shown that, for flow containing shocks, the solution can be accelerated to its stationary profile with no loss of accuracy. Copyright © 2000 John Wiley & Sons, Ltd.     

Stability of Runge-Kutta methods for delay differential systems with multiple delays

The stability of Runge-Kutta methods for systems of delay differentialequations (DDEs) with multiple delays is considered. The stabilityregions of explicit and implicit Runge-Kutta methods are discussedwhen they are applied to asymptotically stable linear DDEs withmultiple delays. A simple estimate on the stability regionsof explicit Runge-Kutta methods is presented. It is shown thatthe stable step-size for numerical integration of DDEs withmultiple delays can be easily selected by means of the estimate.     

Flux‐corrected transport technique for open channel flow

In modeling flow in open channels, the traditional finite difference/finite volume schemes become inefficient and warrant special numerical treatment in the presence of shocks and discontinuities. The numerical oscillations that arise by making use of a second‐ and higher‐order schemes require some additional smoothing mechanism. A characteristic feature of high‐resolution schemes lies in smooth capturing of the shock fronts. This paper provides a general formulation for a flux‐corrected transport algorithm to the one‐dimensional open channel flow equations. The preliminary results presented show that the present algorithm is an efficient, conservative and robust tool that can be easily coded. To demonstrate the robustness of the present formulation, results are compared with other published numerical results, experimental data and analytical solutions when available. In particular, a comprehensive study on the effect of the source term, dry bed, variable width channel, steep sloping channel and flow with mixed flow conditions (as in a hydraulic jump) has been carried out to test the efficacy of the present algorithm. Copyright © 1999 John Wiley & Sons, Ltd.