Multi-channel neural mass modelling and analyzing

Multi-channel neural signals generated by a computational model can help understand the mechanism of EEG rhythms, analyze brain functional connectivity and evaluate neural signal processing methods. In this study, a two-kinetics lumped-parameter neural mass model is extended to a multi-kinetics and multi-channel coupled model. This new model can effectively simulate the coupled dynamics activities between different areas in the brain. The simulation results show that the proposed model can generate neural s...     

一种改进的BIRCH分层聚类算法

由于传统的BIRCH算法是用直径来控制聚类的边界,因此如果簇不是球形,它就不能很好地工作,而且传统的BIRCH算法只适用于单表.针对BIRCH的这些缺点,本文提出了一种改进的BIRCH-IBIRCH算法,该算法首先通过ID传播把多个表联系起来,使得BIRCH算法可以适用于多表的情况,再通过计算共享最近邻密度,可以发现任意形状的簇.实验表明,该算法不仅具有较强的可伸缩性,还可以得到较高精确的聚类结果.     

稳压器下封头成形工艺的研究

介绍了一重集团公司生产的工程稳压器下封头锻件的研制，利用成形分析软件，对稳压器下封头板坯尺寸参数进行了优化，提出了整体封头的成形工艺，使封头各方面的指标达到了技术条件要求，从而验证了这种封头成形新工艺是可行的。     

Isothermal Aging Kinetics in CuZnAl Shape Memory Alloy

Isothermal aging behaviours of a CuZnAl shape memory alloy have been investigated by means ofdilatometry.The length of the specimens during isothermal aging from 190 to 280℃ increases withthe aging time at each temperature.The isothermal aging kinetics fits in Avrami equation and thetime exponent n decreases with the increase in aging temperature.The apparent activation energyfor the isothermal aging process was measured to be 109.0kJ/mol,which is about equal to that of arelaxation internal friction peak at about 200℃ (f≈1 Hz) in the alloy.     

热处理对冷加工奥氏体不锈钢晶粒度的影响

本文研究了热处理对冷加工奥氏体不锈钢组织的影响，试验结果表明利用形变马氏体的逆转变可获得超细化不锈钢晶粒。     

新预处理ILUCG法求解稀疏病态线性方程组

大型稀疏病态线性方程组的高效求解在科学计算和工程应用中起着十分重要的作用.对于一般非对称正定的非奇异线性代数方程组,首先介绍常用的不完全LU分解预处理矩阵构造技术;然后给出SSOR预处理分解及其改进分解,并基于ILUCG思想提出新预处理ILUCG法同时给出收敛性分析;最后进行数值模拟仿真试验,数值结果表明该算法是有效可行的,且较之一般的预处理ILUCG方法该法在求解稀疏病态方程组方面具有优越性.     

冷带轧机两侧压下位置系统鲁棒动态输出反馈同步控制

冷带轧机操作侧和传动侧位置子系统的内部参数和外界负载不一致, 并且均存在一定的不确定性, 这会造成两侧压下位置系统动静态性能不同和压下位置的不同步, 从而影响被轧带材两侧的厚度和板形质量. 为了解决这一问题, 需要在轧机两侧位置控制系统中增加同步闭环控制器. 本文在考虑两侧位置子系统存在参数不确定性和外部负载扰动不确定性的情况下, 设计了压下位置鲁棒动态输出反馈同步控制器, 并从理论上验证了所设计控制系统的稳定性. 仿真和实验研究结果证明了所设计同步控制器的有效性.     

13.56MHz RFID读卡器天线的设计

简要介绍了由13.56 MHz射频芯片MFRC500设计的RFID读卡器,重点论述该读卡器天线的设计与实现.经实践证明,该天线具有良好的性能,使用该天线的阅读器工作稳定.     

Hot deformation behavior of a Cr-containing low carbon steel in the ferrite range

A low carbon steel with Cr addition of 0.46wt% combined with trace elements of Mn and Ti was studied.The apparent activation energy of deformation and the hot deformation equation of the steel in the ferritic range were determined by means of single hot compression tests.The hot-rolled strip of 3 mm in thickness rolled in the ferritic range was obtained using a laboratory hot rolling mill.The mechanical properties show that the values of yield strength and ultimate tensile strength are 230 and 330 MPa,respe...