紫苏叶促进大鼠肠胃消化吸收作用的研究

研究紫苏叶促进肠蠕动与健胃消食的作用。实验分成两大组（A组,B组）。A组SD大鼠68只,随机分8组：阴性对照组、阳性对照组（1．4g／kg）、紫苏叶石油醚提取物低剂量组（15g／kg）、中剂量组（30g／kg）、高剂量组（60g／kg）,乙醇提取物低剂量组（10g／kg）、中剂量组（20g／kg）、高剂量组（30g／kg）。连续给药10d,测大鼠小肠碳末推进百分率。B组SD大鼠56只,随机分7组：阴性对照组、紫苏叶石油醚提取物及乙醇提取物大、中、小剂量组。连续给药8d,测大鼠胃部总酸度和总酸排出量。结果表明：与阴性对照组相比,各剂量组大鼠小肠碳末推进百分率与总酸排出量均增高（P〈0．05,P〈0．01）。紫苏叶的石油醚提取物及乙醇提取物具有促进肠胃消化吸收的作用。     

Adaptive interpolation scheme for NURBS curves with the integration of machining dynamics

This paper develops a comprehensive interpolation scheme for non-uniform rational B-spline (NURBS) curves, which does not only simultaneously meet the requirements of both constant feedrate and chord accuracy, but also real-time integrates machining dynamics in the interpolation stage. Although the existing work in this regard has realized the importance to simultaneously consider chord error and machining dynamics, none has really incorporated these in one complete interpolation scheme. In this paper, machining dynamics is considered for three aspects: sharp corners or feedrate sensitive corners on the curves, components with high frequencies or frequencies matching machine natural ones and high jerks. A look-ahead module was developed for detecting and adaptively adjusting the feedrate at the sharp corners. By Fast Fourier Transform (FFT) analysis with a moving window in the interpolation stage identified were some special frequency components such as those containing high frequencies or with frequencies matching machine natural ones. Then, the notch filtering or time spacing method was used to eliminate these components. To more completely reduce feedrate and acceleration fluctuations, the jerk-limited algorithm was also developed. Finally, the interpolated feedrate was further smoothened with B-spline fitting method and the NURBS curves were re-interpolated with the smoothened feedrate. During the interpolation, the chord error was repeatedly checked and confined in the prescribed tolerance. Two NURBS curves were used as examples to test the feasibility of the developed interpolation scheme.     

高精度管材拉拔过程计算机模拟研究

高精度管材是一种内表面质量要求很高,内径尺寸允许偏差很小的管材。研究了高精度管材拉拔模具形式对管材生产的影响。开发了一种新型芯棒,利用MSC.MARC有限元仿真软件,模拟高精度管材的拉拔过程,分析了新型芯棒对高精度管材尺寸精度的影响规律,为研究和生产提供有效的帮助。     

根据涡流检查技术对传热管堵管进行完整性评价

主要介绍蒸汽发生器传热管通过涡流检查发现缺陷后堵管准则的确定方法,并以田湾核电站卧式蒸汽发生器为例说明堵管准则的计算流程。     

新型TC21钛合金热处理工艺参数与显微组织演变的关系研究

TC21钛合金是新型的高强韧损伤容限型钛合金，其模锻件为网篮组织，锻后热处理工艺采用双重退火工艺。本研究采用金相法、SEM等方法系统研究了TC21钛合金模锻件的锻后热处理工艺和显微组织演变规律。试验分析了TC21钛合金模锻件锻后第1次退火加热温度、第2次退火加热温度和保温时间等工艺参数条件下的初生α相数量、形状以及网篮组织形貌特征的变化规律，为TC21钛合金模锻件获得高强、高韧和损伤容限优良综合性能奠定基础。     

Conditional diagnosability and strong diagnosability of shuffle-cubes under the comparison model

The growing size of multiprocessor systems increases the vulnerability to component failures. It is crucial to locate and replace faulty processors to maintain the system's high reliability. Processor fault diagnosis is essential to the reliability of a multiprocessor system and the diagnosabilities of many well-known networks (such as hierarchical hypercubes and crossed cubes [S. Zhou, L. Lin and J.-M. Xu, Conditional fault diagnosis of hierarchical hypercubes, Int. J. Comput. Math. 89(16) (2012), pp. 2152–2164 and S. Zhou, The conditional diagnosability of crossed cubes under the comparison model, Int. J. Comput. Math. 87(15) (2010), pp. 3387–3396]) have been investigated in the literature. A system is t-diagnosable if all faulty nodes can be identified without replacement when the number of faults does not exceed t, where t is some positive integer. Furthermore, a system is strongly t-diagnosable if it is t-diagnosable and can achieve (t+1)-diagnosability except for the case where a node's neighbours are all faulty. In addition, conditional diagnosability has been widely accepted as a new measure of diagnosability by assuming that any fault-set cannot contain all neighbours of any node in a multiprocessor system. In this paper, we determine the conditional diagnosability and strong diagnosability of an n-dimensional shuffle-cube SQ_n, a variant of hypercube for multiprocessor systems, under the comparison model. We show that the conditional diagnosability of shuffle-cube SQ_n (n=4k+2 and k≥2) is 3n?9, and SQ_n is strongly n-diagnosable under the comparison model.     

Strong matching preclusion for two-dimensional torus networks

The torus network is one of the most popular interconnection networks for massively parallel computing systems. The strong matching preclusion number of a graph is the minimum number of vertices and edges whose deletion results in a graph that has neither perfect matchings nor almost perfect matchings. In this paper, we establish the strong matching preclusion number and classify all optimal solutions for the two-dimensional torus network with an odd number of vertices.     

Fault tolerant approach for biosignal-based robot control

This paper proposes a fault tolerant framework for biosignal-based robot control with multiple sensor electrodes. In this approach, to cope with sensor faults, a reliable joint torque estimation model is selected from a group of estimation models based on sensor failure classifiers. The correlation among the electromyography (EMG) signal streams is used as input feature vectors for fault detection. To validate our proposed method, we artificially disconnect an EMG electrode or detach one side of an EMG probe from the skin surface during elbow-joint torque estimation experiments with five participants. When one EMG sensor electrode experiences one of the problems, the experimental results show that the joint torque can be estimated with significantly fewer errors using our proposed approach than a joint torque estimation method without sensor fault detection or than a method with a conventional sensor fault detection algorithm. Furthermore, we controlled a mannequin-arm-attached one-DOF exoskeleton based on the estimated torque profiles by generating movements with the estimated torque derived from the selected model.     

一种改进的实时嵌入式系统容错优化方法

容错技术中硬件冗余会产生较高的设计和生产成本.针对该问题,提出一种改进的实时嵌入式系统容错优化方法,基于检查点容错技术综合分析系统故障性能、硬实时任务时间约束和软实时任务的效用函数值.以设计的容错模型为基础,计算系统故障概率保证其在故障最大概率值内,给出硬任务截止时间确定可调度性,并应用改进的禁忌搜索算法获得软任务效用函数最佳值,算法有2种简单的邻节点结构,其禁忌准则遵循邻节点方法禁忌,优化效率明显改善.实验结果表明,该方法可进行故障分析等综合分析,并能迅速获得最大效用函数值.