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101.
A stochastic local limited one-dimensional rice-pile model is numerically investigated. The distributions for avalanche sizes have a clear power-law behavior and it displays a simple finite size scaling. We obtain the avalanche exponents
τs=1.54±0.10,
βs=2.17±0.10 and
τT=1.80±0.10,
βT=1.46±0.10.
This self-organized critical model belongs to the same universality
class with the Oslo rice-pile model studied by K. Christensen et al.
[Phys. Rev. Lett. 77 (1996) 107], a rice-pile model studied by L.A.N. Amaral et al. [Phys. Rev. E 54 (1996) 4512], and a simple deterministic self-organized critical model studied by
M.S. Vieira [Phys. Rev. E 61 (2000) 6056]. 相似文献
102.
The thermodynamical behaviors of E′ centers in 8 quartz samples from core XJ33-2-1 recovered in the Zhujiang Mouth Basin were measured by electron spin resonance (ESR) technique. The E′ ESR spectral intensity of samples before any laboratory treatment was measured and expressed asI 1. The samples were then annealed at 300°C or 350°C for 60 min. The E′ ESR spectral intensity measured after this procedure is expressed asI 2. The ratios ofI 1, toI 2 for the samples increase with the sample depth (from 320 to 3972 m), showing that there is a correlation between this ratio and the storage temperature of samples. Therefore the ratio ofI 1/I 2 can be used as an ESR paleothermometer. Besides the temperature, we must take into account the period of time for which the samples have been buried since their deposition, because we find that the ratiosI 1/I 2 (from 0.293 to 0.941) are closely related to the sediment ages (from 1.5 to 27.5 Ma), with a correlation coefficient of 0.98 or 0.99 obtained by linear or exponential regression, respectively. This relation can be explained by the increase of E′ center concentration in quartz samples with the sedimentation age. 相似文献
103.
Chang Ying ZHU* Xiao Di KOU Zhi Qiang ZHANG Ying Cai YOU Diao Hu Xin Department of chemistry Nankai University Department of Micro-organism Nankai University Tianjin 《中国化学快报》2001,(7)
With the increasing use of one-off plastic products, the environmental pollution resulted from the plastic waste has become more and more serious. So many scientists have focused their attention on developing biodegradable polymers to substitute the traditional unbiodegradable polymers in the manufacture of disposable products. Thus the plastic waste can be treated by landfill or composting technique. It has been found that aliphatic polyesters possess better biodegradability compared with oth… 相似文献
104.
105.
106.
Stilling basin with a negative step is an important structure in hydraulic systems, because it can avoid atomization and decrease scouring problems. Although stilling basins with a negative step have attracted much attention from researchers, few researchers have focused on the wave characteristics. In this research, an experimental study on the wave characteristics of stilling basins with a negative step was carried out. The wave height, average period, wave probability density and power spectrum along the flow direction of different stilling basins with a negative step were described based on the wave theory, and the results indicate discharge and step height have a significant effect on the wave characteristics. The relationships between the different characteristic wave heights, and the empirical formula for the relative characteristic wave height are obtained. Finally, the dimensionless standard deviation at the end of the stilling basin with a negative step is linearly related to the flow-energy ratio and the relative step height under B-jump. 相似文献
107.
运用美国宾州大学发展的AMPS程序模拟分析了n-型纳米硅(n+-nc-Si:H)/p-型晶体硅(p-c-Si)异质结太阳电池的光伏特性.分析表明,界面缺陷态是决定电池性能的关键因素,显著影响电池的开路电压(VOC)和填充因子(FF),而电池的光谱响应或短路电流密度(JSC)对缓冲层的厚度较为敏感.对不同能带补偿(bandgap offset)的情况所进行的模拟分析表明,随着ΔEc的增大,由于界面态所带来的开路电压和填充因子的减小逐渐被消除,当ΔEc达到05eV左右时界面态的影响几乎完全被掩盖.界面层的其他能带结构特征对器件性能的影响还有待进一步研究.最后计算得到了这种电池理想情况下(无界面态、有背面场、正背面反射率分别为0和1)的理论极限效率ηmax=3117% (AM15,100mW/cm2,040—110μm波段). 相似文献
108.
109.
Zhiyuan Chang Lijun Diao Songsheng Jiang Anli Li Min Zhao 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(1):61-68
Vezetéknév
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
110.
硒对慢性活动性肝炎的影响 总被引:2,自引:0,他引:2
50例慢性活动性肝炎(慢活肝)随机分为治疗组和对照组。25例治疗组接受12周补硒治疗,结果显示,治疗组与对照组比较,血清ALT显著下降,谷胱甘肽过氧化物酶活力明显升高,提示补硒能防治自由基引起的肝损伤,防止慢性肝病的发展。 相似文献