FTIR spectroscopy of the 2v3 overtone band for different BrCN isotopomers: an improved evaluation of the anharmonic force field of cyanogen bromide

The 2v₃ overtone band of six different isotopomers of cyanogen bromide has been recorded in the range from 4200 to 4400 cm^?1 with a resolution of 0.02 cm^?1 using a Fourier transform infrared (FTIR) spectrometer. This allowed us to achieve complete knowledge of the energies for all levels corresponding to double vibrational excitation. An improved evaluation of the quartic force field of cyanogen bromide has been performed using the new data obtained together with those already known from previous works. Theoretical values derived from a recent ab initio calculation have been used to constrain the potential terms which cannot be determined with sufficient precision by the least-squares analysis of the available experimental data.     

MULTISPECIES EXPLOITATION WITH EVOLUTIONARY SWITCHING OF HARVESTING STRATEGIES

In this paper, we propose a bioeconomic model which describes a fishery in which each of two noninteracting species is harvested by a given group of fishers during a defined time period. Then the Fishing Regulatory Authority allows each fisher to reconsider the harvesting decision at fixed (discrete) periods of time. The model derives from an Italian fisheries management experience in the Northern Adriatic Sea, where this kind of “self‐adjusting” fishing policy has been proposed to regulate harvesting of two shellfish species. The proposed dynamic model assumes the form of a hybrid system, as the natural growth functions of the two species (in continuous time) are coupled with a discrete time adaptive system that regulates how agents switch from one harvesting strategy to the other period by period according to an evolutionary mechanism based on profit comparison. In order to obtain some insights into the basic mechanisms of the system, some relevant benchmark cases are analyzed before tackling (mainly numerically) the complete hybrid model. Our results suggest that, for proper sets of parameters, this kind of myopic and adaptive self‐regulation may ensure a virtuous trade‐off between profit maximization and resource conservation, driven by cost externalities and market pressure.     

用触针下分布电阻的光电导相位法测量半导体中非平衡载流子寿命

本文提出一种测量半导体中非平衡载流子寿命的新方法。这方法是测量触针下分布电阻的光电导相位移,在不同的表面情况和不同的激发光光谱成分下,导得各种结果表达式,文中对通常所使用的测量条件即粗磨表面和长波激发条件给出数值计算的结果。同时,对这些结果进行较为详细的分析和讨论,这个方法具有一系列的优点。例如:1)可以在锭状晶体上测量;2)表面处理十分简单;3)在样品上不需制作固定电极;4)测量仪器简单,操作方便;5)有一定准确度。这个方法可以检验不均匀材料,可供科研机关作研究用,更适合于工厂检验单晶材料用。用这方法在锗和硅样品上进行测量,测得寿命值基本上与其它方法的结果一致。