Fractal sets determined by dilation-stable processes

Let be a dilation-stable process on . We determine a Hausdorff measure function (a) such that the fractal set X[0,1]={X(t):0t1} has positive finite -measure. We also investigate the packing measure of X[0,1].     

保费收取过程是随机过程的双险种风险模型

研究保费收取过程是一个随机过程的双险种风险模型,得出了Lundberg上界、最终破产概率、不破产所满足的微积分方程、索赔服从指数分布的不破产概率、有限时间不破产所满足的微积分方程.     

水／离子液体两相体系中出芽短梗霉催化4-氯-乙酰乙酸乙酯不对称还原合成（S）-4-氯-3-羟基-丁酸乙酯

考察了水/离子液体两相体系中出芽短梗霉(Aureobasidium pullulansCGMCC1244)催化4-氯乙酰乙酸乙酯(COBE)不对称还原生成光学活性(S)-4-氯-3-羟基丁酸乙酯((S)-CHBE)的性能,并对反应条件如摇床转速、相体积比、温度、初始底物浓度和pH值等进行了优化.结果表明,在水/1-丁基-3-甲基咪唑六氟磷酸盐体系中,出芽短梗霉催化COBE不对称还原生成(S)-CHBE,在30℃,pH6·6,摇床转速180r/min和不对称反应8h条件下,反应物的转化率、产物ee值和浓度分别达到95·6%,98·5%和47·1g/L.在控制pH值为6·6的情况下,通过分添加底物可有效提高产物(S)-CHBE浓度至75·1g/L.     

1986年哈雷彗星的分裂

1986年3月25日在新西兰John 山天文台拍摄的9张照片,显示出哈雷彗星的彗核分裂成相隔甚远的两个分立彗核。投影在天空切平面上的分离距离约为5×10³km。主核和小伴核都呈现有它们自身的彗发。伴核有一个高达几千公里的突出喷流,而且伴核必定在数天以内即消失不见。结合陈培生等的光电观测结果,看来分裂与一个爆发事件相关。并对有些照片作了数字成像增强处理。     

非局部源耦合抛物方程组中的奇性传播

讨论一个经由非局部源耦合的非线性抛物组的解的奇性传播. 给出解的4种可能的blow-up速率及相应的边界层估计. 还得到此非线性抛物组的临界指标.     

Experimental Study of Four-Wave Mixing in Semiconductor Laser Amplifier and its Application to Dispersion Compensation in Mid-Span Spectral Inversion System

Properties of four-wave mixing (FWM) in the semiconductor laser amplifier are studied experimentally in this paper. The optical phase conjugation of the mixing wave is applied to compensate the chromatic dispersion of transmission fiber. It is presented experimental results of the transmission of short optical pulses with 12-ps width over 204 km standard single mode fiber. The results confirm that mid-span spectral inversion (MSSI) employing FWM in a semiconductor laser amplifier is one of potential dispersion compensation techniques for optical transmission over standard single mode fiber with bit rate beyond 40Gb/s.     

苦参提取液中黄酮类化合物的抑菌作用

为探讨苦参中黄酮类化合物体外抑菌活性,采用乙醇回流法从苦参中提取含黄酮类化合物并用分光光度法在510 nm处测定黄酮含量.同时,采用琼脂扩散法研究了苦参黄酮类化合物对2种细菌和3种真菌的抗菌性能,测定了其最小抑菌浓度.结果表明:浓度为0.556 g/L的苦参黄酮类化合物对金黄色葡萄球菌、大肠杆菌抑菌圈直径分别为11,8 mm,对啤酒酵母菌、黑曲霉和产黄青霉的抑菌圈直径分别为11,9,9 mm;苦参黄酮类化合物对金黄色葡萄球菌、大肠杆菌、啤酒酵母菌、产黄青霉、黑曲霉的最小抑菌浓度分别为5.6×10-3,0.56,0.28,0.56,0.56 g/L.由此得出结论,苦参中黄酮类化合物对细菌和真菌都有抑制作用,对革兰氏阳性菌的作用强于革兰氏阴性菌,对单细胞真菌作用强于丝状真菌.     

The Influence of the Renormalization Condition to the Equation of State of the Nuclear Matter

In the relativistic σ-ω model, the influences of the parameters b, c, d in the potential U(σ) = (1/2!)bo2 - -(1/3!)cσ3 (1/4!)dσ4 to the incompressibility, effective mass and binding energy of the nuclear matter are studied in detail.The calculation of equation of state of nuclear matter shows that the values of b, c, d depend on the renormalization condition, we also find that a soft equation of state of nuclear matter can be obtained in a suitable renormalization condition, and the experimental incompressibility coefficient can be reproduced. These results are also used to study the thermal properties of hot A-resonant nuclear matter.self-interaction of σ meson, renormalization, hot and dense hadronic matter ``