降低气体悬浮焙烧炉焙烧过程中Al_2O_3粒度破损的措施

为了降低气体悬浮焙烧炉焙烧过程中Al_2O_3粒度的破损,对气体悬浮焙烧炉焙烧过程中氧化铝粒度的影响因素进行了分析,提出了降低粒度破损的一些措施。     

Quality assurance

BACKGROUND: The treatment of pediatric empyemas remains controversial. While thoracentesis and tube thoracostomy appear adequate for relatively benign organisms, virulent bacteria cause thick fibrinous pleural peels entrapping the lung. Open thoracotomies have been effectively used for decortication but are painful. METHODS: We report the use of minimally invasive thoracoscopic decortication in 12 patients (mean age 5 years). All failed conventional management with persistent fever, increasing oxygen requirement, recurrent effusion, and pleural consolidation; 5- and 10-mm trocars were used and complete decortication was accomplished. RESULTS: Ten of 12 patients were afebrile by 72 h and discharged 4-12 days after surgery. Eleven of 12 patients had clear chest x-rays by 1 month. CONCLUSION: Thoracoscopic decortication is a safe and effective means of treating pediatric empyemas.     

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

Ｈｉｇｈ ｓｐｅｅｄｓｔｅｅｌ (ＨＳＳ) ,ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅｘ ｃｅｌｌｅｎｔｈａｒｄｎｅｓｓ ,ｗｅａｒｒｅｓｉｓｔａｎｃｅ ,ａｎｄ ｇｏｏｄｒｅｄｈａｒｄｎｅｓｓ .Ｒｅｃｅｎｔｌｙ ,ＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｈｏｔｒｏｌｌｉｎｇｒｏｌｌｓｔｏｐｒｏｄｕｃｅｓｔｒｉｐｓｏｆｇｏｏｄｓｈａｐｅａｎｄｓｍａｌｌｃｒｏｗｎｗｉｔｈｅｘｔｅｎｄｅｄｒｏｌｌｓｅｒｖｉｃｅｌｉｆｅ[1,2 ] .ＴｈｅＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｒｏｌｌｃｏｌｌａｒｆｏｒ…     

Variations in Spectral Slope in Lake Taihu,a Large Subtropical Shallow Lake in China

Spectral slope (S), describing the exponential decrease of the absorption spectrum over a given wavelength range, is an important parameter in the study of of chromophoric dissolved organic matter (CDOM) dynamics, and also an essential input parameter in remote sensing models. Furthermore, S is often used as a proxy for CDOM composition, including the ratio of fulvic to humic acids and molecular weight. The relative broad range in S values reported in the literature can be explained by the different spectral ranges and fitting methods used. A single exponential model is used to fit the S values for 17 investigations involving 458 samples in Lake Taihu from January to October in 2004. The average S value was 15.18 ± 1.39 μm⁻¹ for the range of 280–500 nm, which fell within the range reported in the literature. The frequency distribution of S value basically obeyed a normal distribution. Significant differences in S values between summer and other seasons showed that phytoplankton degradation was one of the important sources of CDOM in summer, whereas CDOM mainly came from the river input in other seasons. Furthermore, the estimated S value decreased with increasing wavelength range used in regression. The maximum and minimum values derived from the regression were 17.89 ± 1.25 μm⁻¹ and 13.62 ± 2.11 μm⁻¹ for the wavelength ranges of 280–380 nm and 400–500 nm, respectively, a decrease of 23.9%. S values significantly decreased with the increase of CDOM absorption coefficients. CDOM absorption coefficients could be more appropriately estimated from exponential model introducing the variation of S with absorption coefficients, making them useful for a remote sensing bio-optical model of Lake Taihu. DOC-specific absorption coefficient a*(λ) and the parameter M describing molecular size of the humic molecules could also be used as a proxy for the sources and types of CDOM. A general relationship was found between S and a*(λ), and M values. S increased with the decrease of DOC-specific absorption coefficient and the increase of M corresponding to the decrease of molecular weight.     

Matlab在“计算机辅助电路分析”中的应用

"计算机辅助电路分析"课程,是通过计算机仿真实验来训练学生分析和解决电路问题的能力.实践证明,将Matlab软件,特别是其中的Simulink仿真模块作为电路分析工具,引入到计算机辅助电路分析课程教学中,收到了良好的教学效果.本文以二阶电路阶跃响应问题的求解为例,介绍了辅以Matlab的五种求解方法,并对这五种方法的特点进行了比较,说明了Matlab在电路分析方面的优越性.     

In situ polymerization and characterization of polyester‐based polyurethane/nano‐silica composites

Polyester‐based polyurethane/nano‐silica composites were obtained via in situ polymerization and investigated by Fourier‐transform infrared spectroscopy (FTIR), or FTIR coupled with attenuated total reflectance (FTIR‐ATR), Transmission electron microscopy (TEM), atomic force microscopy (AFM), an Instron testing machine, dynamic mechanical analysis (DMA) and ultraviolet‐visible spectrophotometry (UV‐vis). FTIR analysis showed that in situ polymerization provoked some chemical reactions between polyester molecules and nano‐silica particles. FTIR‐ATR, TEM and AFM analyses showed that both surface and interface contained nano‐silica particles. Instron testing and DMA data showed that introducing nano‐silica particles into polyurethane enhanced the hardness, glass temperature and adhesion strength of polyurethane to the substrate, but also increased the resin viscosity. UV‐vis spectrophotometry showed that nano‐silica obtained by the fumed method did not shield UV radiation in polyurethane films. Copyright © 2003 Society of Chemical Industry     

从印刷技术的发展看印刷业的重新定位

近20年以来的技术革命使印刷业发生了脱胎换骨的变化，曾经被认为是技术含量低、员工文化素质低、劳动密集型的印刷业已今非昔比。世界上最先进的电子技术、激光技术、计算机技术及网络技术在印刷领域广泛地应用与发展，改变了人们对印刷的传统思维和行为。在信息时代的今天。印刷业已经成为信息社会的先行行业。在新的形势下，印刷业的经营既离不开生产又离不开增值服务，全面解决方案的推行使印刷业的外延扩大到了第三产业。     

基于拓扑法的多关节机械手无碰路径规划

本文提出了一种基于拓扑法的多关节机械手无碰路径规划方法,文中重点讨论了三关节机械手路径规划时如何划分状态空间、判别各连通块之间的连通性以及路径搜索等问题,最后我们给出了一个实验结果以示该方法的有效性。