关于模N的逆的分布问题

本文稿研究摸ｎ逆的分布性质，并给出的一个较强的渐近公式．     

An Application of Genetic Algorithm in Positioning Bricks

This note deals with how to position bricks so that m aximizing the numbers of whole brick in a given area. A method by genetic algori thm is given to solve this problem. By this method, the numbers of whole brick a nd their position are gained when given areas are convex polygon and brick is re ctangular, and you can easily design a CAD soft to optimize the scheme of positi oning bricks. It is huge advantage by this method when given areas are nonregula r. Some rules of parameter‘s influence to algorithm ...     

阿勒泰马鹿标准化饲养与增茸措施及效果分析

依据阿勒泰马鹿在一年内不同生产时期的生理特点，分成冬季恢复期、生茸前期、生茸期。生茸结束期、发倩控制期等五个生产周期，提出不同时期的标准化饲料程序及日粮配合要点，并分析了增茸措施及效果。     

钠在铝液中的活度

以纯钠为参比电极,以含硅的铝-钠合金为待测电极,以Naβ-Al_2O_3固体材料为Na~ 离子导电的电解质,组成无迁移浓差电池,测量电池电动势后计算钠在电极合金中的活度。实验温度为1000K,钠在铝-钠合金中的含量从零至过饱和(约0.26wt-%Na)。结果表明,当钠含量极低时(1.04%Na以下),溶液的性质符合亨利定律,钠的活度系数略小于1;钠含量超过上述范围时,钠的活度系数即迅速增大,溶液呈强烈正偏差;当钠含量达到饱和时,钠的活度即为恒定。     

ZnO-Al_2O_3-SiO_2:Eu~(3+),Bi~(3+)的溶胶→凝胶→材料转变及其发光特性的研究

在实验室中,采用溶胶-凝胶法,在较低的温度下,合成出组成为:2.686ZnO-1.6Al_2O_3-5SiO_2:0.05Eu~(3+),0.007Bi~(3+)发光材料.利用X射线小角散射、红外光谱、X射线粉末衍射谱、热重及差热分析,研究了由溶胶→凝胶→发光晶体的转变.采用日本岛津RF-540荧光分光光度计,测量了发光体的激发光谱和发光光谱.讨论了发光体的发光特性及Bi~(3+)对Eu~(3+)的敏化作用.     

熔模铸件凝固收缩流动过程的数值模拟

本文在考虑了由于凝固收缩而引起的液相流动后针对回转体类熔模铸件的凝固过程进行了数值模拟研究,探讨了熔模铸件的凝固界面、空单元界面的移动和凝固过程中的流速场,并直接模拟求得了熔模铸件内部的孔隙率分布。     

关于重要极限lim from (n→∞) ((1+1/n)~n=e)的若干问题

分析了重要极限limn→∞(1+1/n)n=e的特征,归纳了此类极限的一般性解法。针对学生对此极限所提出的几个疑难问题,给出通俗易懂的解答。     

Vegetation evolution and millennial-scale climatic fluctuations since Last Glacial Maximum in pollen record from northern South China Sea

A large number of paleoclimate records reveal subMilankovitch climatic fluctuations on the millennial-scalesuperimposing on the Earth orbital cycles[1], such as theHeinrich ice draft events in the Atlantic (each intervalabout 7000–10000 a)[2,3], the Dansgaard/Oeschger (D-O)events (millennial-scale) in Greenland Ice Cores and theBond cycle composed of a Heinrcih event after severalD-O events[4]. At present, most recent work on millennial-scale climatic fluctuations focuses on the high lat…     

Meso-Cenozoic uplifting and exhumation on Yunkaidashan： Evidence from fission track thermochronology

Yunkaidashan, located at the southern South China block (SCB) and closely adjacent to the Indochina block, is an ideal region for better understanding the temporal and spatial framework of tectonothermal overprinting at the southern SCB since Mesozoic. Apatite and zircon fission track thermochronology of various-type rocks from Yunkaidashan is presented in this paper. The results show, no matter what rocks are, the apparent ages of zircon fission track range from 97.4 to 133.0 Ma, and those of apatite fission track from 43.2 to 68.4 Ma. The length of apatite fission track yields an average confined track length of -13 μm andshows normal distribution of unimodal frequency. It is inferred that the uplifting amplitude has been more than 5 km in Yunkaidashan since late Mesozoic. The difference of fission track apparent ages at different locations in Yunkaidashan suggests a paleophysiognomic scenario of the heterogeneous uplift/denudation. These data of the fission track thermochronology provide new constraints for better understanding the tectonophysiognomic pattern of the SCB sincelate Mesozoic.     

海藻酸钠吸附铜离子的研究

研究了用海藻酸钠作为吸附剂去除水相中的Cu2 ,以及吸附过程中试验条件对吸附效果的影响·结果表明:吸附过程在10min左右就达到了平衡;在pH=6时吸附效果达到最佳;吸附温度以30℃左右为宜;海藻酸钠对Cu2 吸附的最大负载量为144～150mg/g·铜离子去除率的大小与水相中铜离子的初始质量浓度有关,对含铜量较高的水样(如铜离子质量浓度为800mg/L),海藻酸钠对溶液中Cu2 的去除率最高达81%,对含铜量较低的水样(如铜离子质量浓度为40mg/L),Cu2 的去除率达99 5%;因此采用海藻酸钠进行二次吸附,溶液中的Cu2 的残余质量浓度低于国家污水综合排放标准中铜离子的最高允许排放质量浓度·