An experiment study of the guided bone regeneration

BMP is one of important factors in the pathophysiology of bone regeneration. Fifteen New Zealand rabbits were used in this experiment. We studied the distribution and effectiveness of endogenic BMP on a 10 mm bone defect of radius, by utilizing immunohistochemistry of BMP and quantitative computer imaging system. On the 3rd day, death of osteocytes and BMP positive blood clot were observed. The mesenchymal cells from periosteum and endoosteum, and osteoblast were also BMP positive. By quantitative study, we found there was a gradient distribution of BMP in bone defect, i.e, the value of BMP decreased gradually along the distance from the fracture ends. The maximal value of BMP was noted at the 1st week postoperation. In conclusion, two sources of endogenic BMP were found, one was from the absorption of necrotic tissue of fracture ends, the other was from the secretion of osteogenic mesenchymal cells during the process of bone regeneration. Nonunion of bone defect was caused in part by the gradient distribution of BMP. Accordingly, the concept of effective quantity of endogenic BMP was drawn rosen. It might be a new method in the treatment of bone defect by increasing the concentration of endogenic BMP and improving its distribution.     

28Cr2Mo1VA钢变速冷却转变动力学研究

用膨胀法对28Cr2Mo1VA钢测定了变速冷却过冷奥氏体转变动力学曲线,结果表明,先慢冷后快冷,珠光体、贝氏体转变滞后;反之,转变超前。并提出用图解计算法求转变点,结果与实验相符合。     

COIL中BHP浓度对发生O_2(~1△)的影响

本文实验研究了BHP的浓度对产生O2（1△）的影响。实验结果表明：当BHP浓度大于3.5M时，Cl2利用率以及O2（1△）的产率将不依赖于BHP浓度的变化而变化，同时，实验结果表明，使用低浓度的BHP对COIL的操作是可行的。     

一例风机高噪声及轴瓦烧毁的原因剖析

阐述了西林钢厂 Ｃ４００──２．１５型电动鼓风机组发生的一起高噪声及轴瓦烧毁事故、经过、现象及原因分析，并提出了对策。     

我的家

我生于东京的银座,那是个靠近传统花街柳巷、歌舞升平的地方,在童年的记忆里那里随时随地都是一片华美景象。而在这些景象的背后有一排排美丽的临街二层长屋建筑,大都是料亭,还有颇有风致的砖结构剧场。那时父母在这里经营着咖啡馆,街上的行人总是把店里挤得满满的。数年前父亲     

石家庄市室内氡及其子体浓度

本文报道了用双滤膜法对石家庄市室内空气中氡及其子体浓度的调查结果。47个房间室内氡年平均浓度为17.0Bq·m~(-3),氡子体平均浓度是7.14Bq·m~(-3)。氡及其子体浓度的日变化是清晨4—8时出现峰值。季节变化是夏秋季低,冬季高,全年的最低值出现在8月,最高值出现在11月。     

Localized audio watermarking technique robust against time-scale modification

Synchronization attacks like random cropping and time-scale modification are very challenging problems to audio watermarking techniques. To combat these attacks, a novel content-dependent localized robust audio watermarking scheme is proposed. The basic idea is to first select steady high-energy local regions that represent music edges like note attacks, transitions or drum sounds by using different methods, then embed the watermark in these regions. Such regions are of great importance to the understanding of music and will not be changed much for maintaining high auditory quality. In this way, the embedded watermark has the potential to escape all kinds of distortions. Experimental results show strong robustness against common audio signal processing, time-domain synchronization attacks, and most distortions introduced in Stirmark for Audio.     

A wavelet-based procedure for process fault detection

To detect faults in a time-dependent process, we apply a discrete wavelet transform (DWT) to several independently replicated data sets generated by that process. The DWT can capture irregular data patterns such as sharp "jumps" better than the Fourier transform and standard statistical procedures without adding much computational complexity. Our wavelet coefficient selection method effectively balances model parsimony against data reconstruction error. The few selected wavelet coefficients serve as the "reduced-size" data set to facilitate an efficient decision-making method in situations with potentially large-volume data sets. We develop a general procedure to detect process faults based on differences between the reduced-size data sets obtained from the nominal (in-control) process and from a new instance of the target process that must be tested for an out-of-control condition. The distribution of the test statistic is constructed first using normal distribution theory and then with a new resampling procedure called "reversed jackknifing" that does not require any restrictive distributional assumptions. A Monte Carlo study demonstrates the effectiveness of these procedures. Our methods successfully detect process faults for quadrupole mass spectrometry samples collected from a rapid thermal chemical vapor deposition process