四大在线音乐网站大比拼

相信大家都知道前段时间在山东发生的火车相撞事故了。记得泡泡鱼是早晨上班，看到的快讯，当时还没有任何细节呢。泡泡鱼也没想到事情会如此严重。车祸、矿难、山洪、冻灾，这些天灾、人祸无时无刻都在发生。中国有十三亿人口，总也觉得跟自己没什么关系。这次事故一共有400多个伤者，71个生命消逝，与自己有联系的概率太小，然而当自己真真切切地与事故联系起来，才感觉到生命是如此脆弱…… ——泡泡鱼     

巧用心机 扩展QQ空间新思路

QQ已经成为国内众多网络用户们相互沟通的工具，相信大多数网络用户也都有自己的QQ帐号，而QQ所带来的一些衍生产品，也是深受年轻朋友们的欢迎。随着博客的兴盛，QQ空间也以自己独特的博客风格，以及与QQ帐号的关联，迅速在年轻的QQ用户中风靡开来。     

碳钢组织遗传性的研究

本文作以30钢为例,,研究了碳钢过热预淬马氏体非平衡组织的粗大晶粒及粗断口在随后热处理时的遗传规律。研究表明,30钢的奥氏体粗晶于慢速加热时也能得到遗传,但在中速,快速甚至超快速加热时原粗晶均得到细化。研究还表明碳钢中不存在断口遗传。最后讨论了碳钢出现晶粒遗传的原因。     

Room temperature synthesis of highly hemocompatible hydroxyapatite, study of their physical properties and spectroscopic correlation of particle size

Needle shaped nanoparticles of hydroxyapatite (HA) have been synthesized at room temperature using orthophosphoric acid as the source of (PO4)3- ions, while calcium chloride, the calcium source, is suitably complexed with citric acid/tartaric acid/acetic acid. The presence of ligands inhibits the growth along [001] and [100] directions of the crystal and thus, helps in formation of needle shaped nanoparticles. The chemical compositions of the samples have been established through AAS and FTIR spectroscopy, while the crystallinity has been assessed through XRD and by the spectral changes in the υ1 and υ3 frequencies of the phosphate group in the respective FTIR spectra. The particle sizes of the samples have been determined from line broadening studies and correlations have been established between the curve fitted percentage area of FTIR and full width half height (FWHH) of the XRD peaks. TEM studies revealed the particle to be needle-shaped with a length and diameter in the range of 20-65 nm and 4-11 nm respectively. Changes in the surface charge of the water dispersed HA samples have been determined at different pH and the isoelectric point for the samples have been found in the range of 3.1-3.4. Finally, the morphology, surface area and hemocompatibility characteristics of the HA samples, prepared by using different complexing agents, have been compared.