三维随机矩阵置乱变换的周期及其应用

 为了适合数字多媒体特性,实施多媒体加密与信息隐藏,生成充分大的密钥空间,使用了数论、近世代数、算法分析等工具,对高维随机矩阵置乱变换的精确周期进行了研究。给出三维随机整数矩阵A决定的置乱变换在任意模N下,其周期T(A,N)的精确表达式及上界估计,构造了求周期的快速算法,仅耗费O(log₂ N)² 次模N乘法便可得到T(A,N)。大量的算例和应用范例与理论结果相吻合。结论可用于建立数字多媒体的新型密码体制,实施高效率的加密。     

大型同步电动机励磁装置的改造

制氧车间使用的3号氧压机、2号氮压机励磁装置,为前苏联产品,投入运行了近十五年,设备故障不断发生。动力厂采用中国核工业部电机运行技术开发公司生产的BKL-501H型励磁装置,取代原前苏联励磁系统,取得了较好效果。     

Brief Analysis on Sexism in English Language

English language,to some extent,reflects a sexist society.Linguistic directions of degrading and devaluing female can be located everywhere.This paper tries to investigate linguistic sexism against women in English words.The purpose is to disclose some of the features of English language that suggest cultural biases and socially unjust attitudes towards women.The study will help us to have a better understanding of the relationship between language and society.     

Efficient transformation and expression of gfp gene in the edible mushroom Pleurotus nebrodensis

An efficient transformation method mediated by PEG-protoplasts was developed for the newly commercial edible mushroom Pleurotus nebrodensis. Two plasmids were used to co-transform protoplasts of P. nebrodensis. One plasmid is pAN7-1 containing a positive selectable marker gene hph conferring hygromycin B resistance. Another plasmid is pBlue-GFP containing a reporter gene gfp conferring green fluorescent protein. PCR and Southern blot analysis showed that hph gene or/and gfp gene were integrated into the genome of P. nebrodensis transformants. The transformation efficiency of the positive selectable marker gene hph was 3 transformants per microgram of plasmid pAN7-1 DNA, which was about 30 times higher than that previously reported in thoroughly studied Pleurotus species such as Pleurotus ostreatus. The transformation efficiency of the reporter gene gfp was 9 transformants per microgram of plasmid pBlu-GFP DNA. The co-transformation efficiency was 23.68%. This is the first report that a ＂reporter＂ gene, green fluorescent protein gene can be successfully stably exoressed in this Pleurotus species.     

污水土地处理系统污染物迁移转化的模拟研究

综合考虑污染物在土壤中的生物吸收作用、机械吸收作用、化学吸收作用、土壤胶体的吸收作用和代换性吸收作用,建立了污染物在土壤中的迁移转化模型,模拟计算土壤中各种污染物在迁移转化过程中的浓度变化,为污水土地处理的管理和控制提供了定量化依据．     

改进的灰色模型及其实例分析

目的针对农民人均纯收入增长趋势的特点,建立我国1996～2003年农村居民家庭人均纯收入的3种灰色预测模型。方法应用函数变换理论和灰色系统建模理论,同时运用遗传算法计算变换函数中的参数。结果引入了3种变换函数,建立了以平均相对误差最小为目标的改进的灰色预测模型;建立农民家庭人均纯收入的3种改进灰色预测模型。结论计算和分析结果表明,经线性函数f=px^（0）（k）＋q变换、复合函数f=p√x^（0）（k）＋q和f=√px^（0）（k）＋q的变换建立的3种改进的灰色预测模型的拟合效果和预测精度均优于传统GM（1,1）的模型,可以在实际中加以推广应用。     

一种简化计算的Bent函数判定方法

为讨论Bent函数性质的需要,在研究了线性函数与Bent函数关系及e-偏导数的密码学性质的基础上,本文提出了一种判断布尔函数是否为Bent函数较容易的算法.同时,也讨论了Bent函数旋转变换生成的函数性质.     

Constraint on the late Mesozoic regional angular unconformity in West Liaoning--North Hebei by LA-ICP-MS dating

The angular unconformity between the Tuchengzi Formation and the Zhangjiakou Formation in the Chengde area is commonly regarded as the direct evidence of boundary between Jurassic and Cretaceous systems, and as the evidence of tectonic transformation interfaces in Mesozoic Era in the West Liaoning-North Hebei. Moreover, the lower boundary age of the Zhangjiakou Formation in the Chengde was to be thought about 135 Myr in the past. Based on the detailed study and systematic sampling in Yixian-Beipiao, Lingy- uan, Chengde and Luanping areas in the field, the authors obtained the following isotopic ages by means of LA-ICP-MS dating： In the Lingyuan area, the Zhangjiakou Formation and the Yixian Formation are in angular unconformable contact; the age range of the Zhangjiakou Formation volcanic rock is from 133 to 130 Myr （seven samples）, and that of the Yixian Formation volcanic rock is from 126 to 121 Myr （eleven samples）. In the Luotuoshan of Chengde, the Tuchengzi Formation and the Zhangjiakou Formation are in angu- lar unconformable contact; the age at the lower Zhangjiakou Formation is about 124 Myr （one sample）, which reflects that the age range of the lower Zhangjiakou Formation is from 129 to 124 Myr combined with the previous study. In the Luanping basin, there is the larg- est sediment gap in upper Mesozoic, whose lower boundary age is confined in 131 to 130 Myr. In the Yixian-Beipiao area, the second Member of the Yixian Formation, making up more than 3/4 thickness of the Yixian Formation, was formed in 126 to 119 Myr, and the age of the Yixian Formation at the bottom is about 132 Myr. Moreover, the upper boundary age of the Tuchengzi Formation is about 136 Myr in the West Liaoning-North Hebei region. Based on the above isotopic data combined with the geological characteristics in the field in the West Liaoning-North Hebei region, it reflects that there was a widespread tectonic event in the period of 136 to 126 Myr （mainly in 130-126 Myr） in the West Liaoning-North Hebei, and it formed th     

近液相线半连续铸造中凝固组织的多尺度模拟

建立了描述连续铸造过程的温度场模型及相变模型,通过固相率变化将宏观和介观尺度上的模拟耦合起来.利用外推边界条件对Al-Cu合金在近液相线半连续铸造过程的稳态温度场进行了计算;根据连续铸造特点,提出了用液/固相变区域中元胞的平均过冷度作为形核计算的基本参数,避免了铸件中心区域的多余形核问题.对Al-(3.5~10)%Cu合金、铸造速度为2.0 mm/s的液相线铸造的凝固组织进行了模拟,并且ZL201合金的模拟结果与实验吻合.计算表明:合金成分对半固态合金组织的形成有较大影响,当合金质量分数在(8~10)%时可获得晶粒大小和分布良好的合金组织.     

浅谈小水电站的改造——以沁水县曲堤水电站技改增容为例

以沁水县曲堤水电站技改增容为例,介绍了小水电站的改造过程,并对改造后的小水电站效益进行了分析。