Isotope and hydrochemical study of seawater intrusion in Laizhou Bay, Shandong Province

Seawater intrusion on the northern coast of Laizhou City is featured by "three sources and three dimensions". Modern sea water, ancient saline water and brine contained both in the Quaternary aquifer and in the bedrock fissures or crevice have been identified as possible sources. The ratio of γSO4/γCI is used to distinguish the origin of the different types of saline water. The correlation between 3H and y SO4/γ Cl provides a quantitative differentiation on the origin of the saline water, which makes it possible to take counter protection measures in different areas affected by sea water intrusion.     

理论物理类CAI电子教程功能要求初探

探讨理论物理类CAI教程的基本要求和特色功能,说明理论物理类CAI教程不仅应具有符合大纲的完整内容、丰富的教学资料和友好的界面,还应具备开放性和灵活方便的检索功能.提出定量动画的概念,它是研制此类CAI教程的一个值得注意和可发展的空间.     

Fabrication and magnetic properties of Sm_3(Fe,Ti)_(29)N_x/α-Fe dual-phase nanocomposite permanent magnetic material

Sm3(Fe,Ti)29Nx/α-Fe dual-phase nanometer magnetic material was fabricated through rapid solidification, crystallization and nitridation of Sm-Fe (Ti) alloy. The effect of combination of rapid solidification and Ti alloy addition on the phase for- mation and microstructure of the Sm-Fe alloy is investigated in this paper. The mi- crostructure of amorphous phase and dual-phase nano-grain crystals before and after crystallization annealing were observed using a high-resolution transmission electron microscope (HREM). The dual-phase nano-grains after annealing were compacted together with a clear interface with the direct exchange-coupling mechanism. Different annealing processes were used to examine the melt-spun alloy. Comparison of the images of SEM showed that annealing at 750 ℃ for 10 min was most suitable to get homogeneous and nano-grains. No obvious kink was de- tected in the second quadrant of the hysteresis loop like a single hard magnet, and strong exchange coupling was found between hard magnets and soft magnets.     

INVESTIGATION ON SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS OF TiAl INTERMETALLIC COMPOUND

The self-propagating high-temperature syn-thesis method was used to synthesize the TiAl intermetalliccompound,and two kinds of synthesis modes were studied inthis paper.The results show that the thermal explosion modeis suitable for the synthesis of TiAI,the pre-heating tempera-ture has a great influence on the synthesis.Microstructurestudy show that the density of the sample fabricated by thermal explosion mode is higher than that fabricated by propa-gating mode.     

改进的对称分布期望估计量的性质

本文证明了改进后的对称分布期望估计量W_p在一定条件下具有无偏性和强相合性,并给出了方差的上界,其中:W_p.=1/n-2[np] sum from a-[ap] to i=[ap]+1 X_(j),0≤p<1/2     

用moire技术测量平板玻璃折射率

本文描述了使用moire技术测量平板玻璃折射率的理论并进行了实验论证。测量方法简单且快捷。可精确测量任何透明材料的折射率。测量精确度可达10~(-5)。     

居民心理——城市空间扩展的另一个重要因素

本文从分析当前城市空间扩展与城市居民心理之间的冲突出发,探讨了城市空间利用的主客体之间的关系。作者特别分析了在当前形势下城市居民的心理行为表现,指出城市居民心理行为也是城市空间扩展决策的一个重要依据。     

聚醚固体电解质锂电池放电性能研究

利用氧亚甲基连接的聚氧乙烯-聚氧丙烯多嵌段共聚物或氧亚甲基连接的聚氧乙烯多嵌段共聚物与高氯酸锂的络合物作电池的电解质,锂片作负极,几种含钒的化合物作正极,组装了全固态二次锂电池.研究了不同正极材料、不同电解质和不同温度对电池短路放电性能的影响以及电池的重复短路放电性能.研究表明,正极材料V_6O_(13)的性能优于Na_(1+x)V_3O_8;电解质(PEO)_n·LiClO_4的性能优于(PEO-PPO)_n·LiClO_4,这与它们的电导率分别为3.2×10~(-3)S·cm~(-1)和2.2×10~(-3)S·cm~(-1)是一致的.     

会计职业道德对提高会计信息质量的影响

会计信息质量与环境、会计系统等诸多因素有关,同时会计职业道德也是一个非常重要的因素。它作为一种引导和制约会计行为的社会规范,与会计信息的质量息息相关。我国会计信息质量的现状不容乐观,重整我国会计职业道德,将对我国会计信息质量的提高起到积极的推动作用。文中分析了会计职业道德的特征和现状,提出了重整会计职业道德的几点思考.     

基于熵、能量函数的BP网改进算法

为了增强ＢＰ网隐层的归纳能力，文［１］提出了调整权重的熵方法，我们在文［２］中给出了基于能量函数的改进算法，本文把文［１］算法与文［２］算法结合在一起给出了新算法，实验证明此算法既能大大加快收敛速度，又可增强网的归纳能力。