On the Nonrepresentability of Functions of Several Variables by Quadratures

The paper completes the construction of a multidimensional topological version of differential Galois theory. We construct a rich class of germs of functions of several variables which is closed under superpositions and other natural operations. The main theorem describes the behavior of the monodromy groups of such germs under the natural operations. As a result, we obtain topological obstructions to the representability of functions by quadratures, which give the strongest known statements about unsolvability of equations in closed form.     

Study of 19Na at SPIRAL

The excitation function for the elastic-scattering reaction p( ¹⁸Ne, p) ¹⁸Ne was measured with the first radioactive beam from the SPIRAL facility at the GANIL laboratory and with a solid cryogenic hydrogen target. Several broad resonances have been observed, corresponding to new excited states in the unbound nucleus ¹⁹Na. In addition, two-proton emission events have been identified and are discussed.     

Study of the conditions for the effective energy transfer in a process of acceleration and collision of the thin metal disks with the massive target

Efficiency studies of laser driven thin metal disks acceleration using the first harmonic (λ₁=1.315 μm) of the Prague Asterix Laser System (PALS) and subsequent craters creation produced by collisions of these disks with massive targets are presented. Several different disks made of aluminium and copper foils with diameters of 300 μm and 600 μm and thicknesses of 11 μm (Al) and 3.6 μ m (Cu) were employed. Disks were placed at the distance of either 100 μ m or 300 μm in front of aluminium massive targets. The following irradiation conditions were used: the laser beam energy of 120 J, the focal spot diameter of 200 μm, and the pulse duration of 0.4 ns (FWHM). A three-frame interferometric system was employed to determine electron density distributions in plasma corona. Shape and volume of craters were obtained by crater replica technology and microscopy measurements. The aim of these investigations was to analyse conditions leading to the most effective energy transfer in the process of collision of the accelerated disks with solid targets. The overall efficiency of these processes was characterized by the volume of craters produced in such targets.     

Proton-neutron structure of collective excitations in 94Mo

Due to the recent development of radioactive beam production, various direct reaction studies in reversed kinematics have been made to investigate the behavior of the N = 20 shell closure in the neutron-rich region. Coulomb excitation, proton inelastic scattering, and fragmentation of unstable nuclei have been studied with γ-ray detection. Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002 RID="a" ID="a"e-mail: motobaya@rikkyo.ne.jp     

二个强飞秒延时激光脉冲的相对相位对Na2+光解离的影响

报道了Na₂⁺离子的三个低激发态1Σu、2Σg、2Σu在二个光脉冲作用下的解离动量谱,激光波长为680nm,各脉冲功率为1×10¹²W/cm²,脉宽50fs,从研究结果可见,其单光子、双光子、三光子激发的对应的解离峰及峰值随相对相位而变,并且这种影响随延时增大而减小.     

High pressure treatment of pharmaceutical drug delivery and related systems

Abstract

Solids like layer silicates (kaolinite and montmorillonite) as well as ZnO are in use in pharmacy. They are pressure treated and subsequently analyzed by means of ESR spectroscopy. The structural changes indicated by Fe³⁺ ions and paramagnetic defects are reponsible for the enhanced chemical activity of the pressurized systems.

Especially active Fe-O-species are formed which can react with intercacalated organic molecules. The most probable first step of such reactions will be a solid state single electron transfer. Spin probes and spin traps were used to prove this statements. The activation of the drug delivery systems by mechanical treatments is of importance for the stability of the drugs incorporated.     

高光谱成像技术检测高温障碍胁迫下番茄叶片色差的研究

提出了利用可见/近红外高光谱成像技术检测高温障碍胁迫下番茄叶片色差的方法。首先采集380~1 023 nm波段范围内60个高温障碍胁迫和60个健康番茄叶片的高光谱图像,同时获取全部叶片的色差值(L*, a*和b*),然后提取所有样本的高光谱图像中感兴趣区域(region of interest, ROI)的光谱反射率值。基于不同预处理方法建立偏最小二乘(partial least squares, PLS)预测模型,再利用连续投影算法(successive projections algorithm, SPA)提取特征波长并建立SPA-PLS预测模型。最后分别基于全波段和特征波段建立偏最小二乘-判别分析(partial least squares-discriminant analysis, PLS-DA)模型。结果显示,全波段中基于原始光谱信息建立的模型效果最好,3个色差值的预测集决定系数(determination coefficient, R2)分别是0.818,0.109和0.896;基于特征波长建立的模型预测集R2分别是0.591,0.244和0.673;所有模型预测集的总体识别率均大于77.50%。结果表明,可见/近红外高光谱成像技术检测番茄叶片色差值(L*和b*)和识别高温障碍样本是可行的。     

Studies on convergence and scaling law of Thomson backscattering spectra in strong fields

With the saddle point analysis method for the Bessel function structure and property, the convergence problem and the scaling laws of Thomson backscattering spectra are solved and studied in both cases that are for the plane wave laser field without and with applied external constant magnetic field. Some unclear points appeared in previous work are clarified. The extension of the method to a general situation for the laser field with an arbitrary polarization is discussed. We also make a simple analysis and discussion about the optimal spectra dependence of field parameters and its implication to practical applications.     

Decay of proton-rich nuclei between 39Ti and 49Ni

Decay studies of very neutron-deficient nuclei ranging from ³⁹Ti to ⁴⁹Ni have been performed during a projectile fragmentation experiment at the GANIL/LISE3 separator. For all nuclei studied in this work, ^{39, 40}Ti, ^{42, 43}Cr, ⁴⁶Mn, ^{45, 46, 47}Fe and ⁴⁹Ni, half-lives and decay spectra have been measured. In a few cases, γ coincidence measurements helped to successfully identify the initial and final states of transitions. In these cases, partial decay scheme are proposed. For the most exotic isotopes, ³⁹Ti, ⁴²Cr, ⁴⁵Fe and ⁴⁹Ni, which are candidates for two-proton radioactivity from the ground state, no clear evidence of this process is seen in our spectra and we conclude rather on a delayed particle decay. Received: 26 July 2000 / Accepted: 20 December 2000