Local and global bifurcations in magnetic resonance force microscopy

Nonlinear Dynamics - The focus of this paper is on the investigation of local and global bifurcations in a continuum mechanics-based resonator model proposed for measurement of electron spin via...     

In situ determination of refractive index and size of Bacillus spores by light transmission

Light-extinction measurements in the wavelength range of 400 to 1000 nm are performed in situ on Bacillus subtilis endospores during heat-shock-induced activation. Simultaneous information on particle size and refractive indices during activation is calculated from the transmission spectra by use of the Gaussian ray approximation of anomalous diffraction theory. During activation the refractive index of the core decreases from 1.51 to 1.39, and the size increases from 0.38 to 0.6 microm.     

The rotational spectrum and geometrical structure of thiozone, S3

The rotational spectrum of thiozone, S3, has been observed for the first time. From the rotational constants of the normal and 34S isotopic species, a precise geometrical structure has been derived: S3 is a bent chain with a bond to the apex S of length 1.917(1) A and an apex angle of 117.36(6) degrees . The derived structural parameters indicate substantial double-bonding character in S3 and sp2 hybridization of the central sulfur atom. Thiozone is an excellent candidate for astronomical detection in the atmosphere of Io, the innermost Galilean moon of Jupiter, and in rich interstellar sources.     

NUCLEAR CHARGE DISPERSION OF FRAGMENTS IN HIGH ENERGY PROTON-NUCLEUS COLLISION

The charge dispersion of fragments in high energy p+Cu,Kr and Xe reactions are calculated by statistical model and Monte Carlo technique.The corresponding data are reproduced quite well.It is shown that the charge dispersions are all nearly gaussian.The mass dependence of the most probable fragment charge reflects the rest target memory effect.     

Charged Multiplicity Density and Number of Participant Nucleons in Relativistic Nuclear Collisions

The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclearcollisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic p+p experimental dataand the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework ofJPCIAE model and without retuning the model parameters. The predictions for Pb + Pb collisions at the LHC energywere also given. We computed the participant nucleon distributions using different methods. It was found that thenumber of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may beinappropriate to use the charged particle pseudorapidity density per participant pair .as a function of the number ofparticipant nucleons for distinguishing various theoretical models.     

多光子过程中相位退相干时两原子布局数反转

利用全量子理论的方法,研究了存在相位退相干时多光子T-C模型中两个二能级原子与二项式光场相互作用系统中两原子的布居数反转。讨论了相位退相干系数、二项式光场系数、最大光子数、跃迁光子数对原子布居数反转的影响。结果表明：相位退相干减少了原子布居数反转的振幅、破坏了原子的量子特性。改变跃迁光子数,可以改变原子间布居数反转演化周期及演化强度。当二项式光场的最大光子数增大时,原子布居差的崩塌-回复现象就会逐渐消失。相位退相干因子不变时, 二项式光场从相干态过渡到数态过程中,原子布居的振荡频率由大变小,周期性的崩塌与回复现象逐渐消失。     

Investigation of fluid dynamics within a miniature mixed flow blood pump

An oil dot flow visualization method was utilized in conjunction with a traditional light sheet particle tracer method to investigate internal flow dynamics of a miniature mixed-flow blood pump. The effects of the operating condition and impeller design on the internal fluid dynamics and hydrodynamic performance were studied. The oil dot method enabled analysis of separated and disturbed flow within the highly wrapped rotating-blade passages – previously imperceptible with light sheet methods. The blade wrap was found to be critical to providing a favorable fluid dynamics for blood pumping over a range of off-design conditions. The low flow operating conditions were found to have a detrimental effect on blood flow. Received: 13 september 2000 / Accepted: 3 April 2001     

Simple instrument for titrimetry without visual indicators. Gasometric titrations: Dichromatometry

Even ions which do not release gases with a certain titrant can be determined by direct gasometric titration. To achive this end, a substance which liberates a gas with the titrant, must be added to the sample solution. The end-point of the main reaction can be read from the gasometric titration curve of this indicator substance.This principle is applied in the present paper to the titration of ferrous and stannous ions by potassium dichromate. Hydrazine sulfate serves as indicator. The results are comparable in precision and accuracy to the values obtained by the conventional visual end-point titrations.