文章介绍了基于工业以太网的新兴现场总线Ethernet Power Link的系统组成,以及基本原理出发,对基于Ethernet Power Link总线系统的德国克朗斯无菌饮料灌装机控制系统的硬件组成和软件设计作了较为详细的阐述,并从应用上表明了Ethernet P...文章介绍了基于工业以太网的新兴现场总线Ethernet Power Link的系统组成,以及基本原理出发,对基于Ethernet Power Link总线系统的德国克朗斯无菌饮料灌装机控制系统的硬件组成和软件设计作了较为详细的阐述,并从应用上表明了Ethernet Power Link现场总线控制的系统优势。展开更多
为了满足硬币的精确定位包装和整理,研究并设计了一种基于热熔胶固封的新型硬币包装设备系统。首先利用Solid W orks建立了该系统的3D模型。设计了硬币进币机构、硬币包装机构、硬币收集机构,最后,利用激光计数器记录硬币数量,当硬币数...为了满足硬币的精确定位包装和整理,研究并设计了一种基于热熔胶固封的新型硬币包装设备系统。首先利用Solid W orks建立了该系统的3D模型。设计了硬币进币机构、硬币包装机构、硬币收集机构,最后,利用激光计数器记录硬币数量,当硬币数达到设定数值时采用热熔胶对其进行固封,整个设备系统采用单片机完成。通过对设备不断完善和通过大量的实验,其结果验证了新型包装设备系统的可行性,并进行了改进。展开更多
A three degree-of-freedom (DOF) planar changeable parallel mechanism is designed by means of control of different drive parameters. This mechanism possesses the characteristics of two kinds of parallel mechanism. Base...A three degree-of-freedom (DOF) planar changeable parallel mechanism is designed by means of control of different drive parameters. This mechanism possesses the characteristics of two kinds of parallel mechanism. Based on its topologic structure, a coordinate system for position analysis is set-up and the forward kinematic solutions are analyzed. It was found that the parallel mechanism is partially decoupled. The relationship between original errors and position-stance error of moving platform is built according to the complete differential-coefficient theory. Then we present a special example with theory values and errors to evaluate the error model, and numerical error solutions are gained. The investigations concentrating on mechanism errors and actuator errors show that the mechanism errors have more influences on the position-stance of the moving platform. It is demonstrated that improving manufacturing and assembly techniques can greatly reduce the moving platform error. The small change in position-stance error in different kinematic positions proves that the error-compensation of software can improve considerably the precision of parallel mechanism.展开更多
AIM: Hepatic fibrogenesis has close relation with hepatic stellate cells (HSC)and tissue inhibitors of metalloproteinase (TIMP). Oxymatrine (OM) is a kind of Chinese herb that is found to have some effects on liver fi...AIM: Hepatic fibrogenesis has close relation with hepatic stellate cells (HSC)and tissue inhibitors of metalloproteinase (TIMP). Oxymatrine (OM) is a kind of Chinese herb that is found to have some effects on liver fibrosis. We aimed to determine the effects of OM on hepatic fibrosis and explore the possible mechanism. METHODS: Thirty-two rats were randomly divided into four groups; 16 were used to develop hepatic fibrosis by carbon tetrachloride (CCI4) and treated with or without OM, and 16 were used as controls. The expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and α-smooth muscle actin (α-SMA) in the livers of rats was detected by immunohisto-chemical assay. Liver pathology was determined by H&E staining and reticulum staining. RESULTS: In CCl4-injured rats, the normal structure of lobules was destroyed, and pseudolobules were formed. Hyperplasia of fibers was observed surrounding the lobules. While the degree of fibrogenesis in liver tissues was significantly decreased in those rats with OM-treatment compared with those without OM treatment. The pseudolobules were surrounded by strong, multi-layer reticular fibers, which netted into pseudolobules in CCl4-injured rats, however, there was a significant decrease in reticular fibers in OM-treated rats. The expression of TIMP-1 in hepatic cells was weak in control groups, but strong in CCl4-injured groups, however, the expression of TIMP-1 was significantly inhibited by OM (F = 52.93, P<0.05). There was no significant change in the expression of α-SMA between CCl4-injured rats with or without OM treatment (F= 8.99, P>0.05). CONCLUSION: OM effectively inhibits CCl4-induced fibrogenesis in rat liver tissues, probably by reducing the expression level of TIMP-1.展开更多
Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan coolin...Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan cooling system (ECHDFCS). The system was applied to a 50-wheel loader. We carried out the coolant temperature simulation using fluid modeling software FLOWMASTER, followed by laboratory experiments and road tests. The results show that ECHDFCS can adjust the cooling capability of the system automatically based on machine heat dissipation requirements. The coolant temperature is consequently remained within an appropriate range. The simulation results are consistent with the experiment results when the experiment is performed on the plain, but are different from the road tests in some investigated parameters on the plateau.展开更多
文摘文章介绍了基于工业以太网的新兴现场总线Ethernet Power Link的系统组成,以及基本原理出发,对基于Ethernet Power Link总线系统的德国克朗斯无菌饮料灌装机控制系统的硬件组成和软件设计作了较为详细的阐述,并从应用上表明了Ethernet Power Link现场总线控制的系统优势。
文摘为了满足硬币的精确定位包装和整理,研究并设计了一种基于热熔胶固封的新型硬币包装设备系统。首先利用Solid W orks建立了该系统的3D模型。设计了硬币进币机构、硬币包装机构、硬币收集机构,最后,利用激光计数器记录硬币数量,当硬币数达到设定数值时采用热熔胶对其进行固封,整个设备系统采用单片机完成。通过对设备不断完善和通过大量的实验,其结果验证了新型包装设备系统的可行性,并进行了改进。
基金Preject 50225519 supported by the National Outstanding Youth Science Foundation of China
文摘A three degree-of-freedom (DOF) planar changeable parallel mechanism is designed by means of control of different drive parameters. This mechanism possesses the characteristics of two kinds of parallel mechanism. Based on its topologic structure, a coordinate system for position analysis is set-up and the forward kinematic solutions are analyzed. It was found that the parallel mechanism is partially decoupled. The relationship between original errors and position-stance error of moving platform is built according to the complete differential-coefficient theory. Then we present a special example with theory values and errors to evaluate the error model, and numerical error solutions are gained. The investigations concentrating on mechanism errors and actuator errors show that the mechanism errors have more influences on the position-stance of the moving platform. It is demonstrated that improving manufacturing and assembly techniques can greatly reduce the moving platform error. The small change in position-stance error in different kinematic positions proves that the error-compensation of software can improve considerably the precision of parallel mechanism.
基金Supported by Foundation of "Bai Ren Ji Hua" of Shanghai Health Bureau, No. 98BR32
文摘AIM: Hepatic fibrogenesis has close relation with hepatic stellate cells (HSC)and tissue inhibitors of metalloproteinase (TIMP). Oxymatrine (OM) is a kind of Chinese herb that is found to have some effects on liver fibrosis. We aimed to determine the effects of OM on hepatic fibrosis and explore the possible mechanism. METHODS: Thirty-two rats were randomly divided into four groups; 16 were used to develop hepatic fibrosis by carbon tetrachloride (CCI4) and treated with or without OM, and 16 were used as controls. The expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and α-smooth muscle actin (α-SMA) in the livers of rats was detected by immunohisto-chemical assay. Liver pathology was determined by H&E staining and reticulum staining. RESULTS: In CCl4-injured rats, the normal structure of lobules was destroyed, and pseudolobules were formed. Hyperplasia of fibers was observed surrounding the lobules. While the degree of fibrogenesis in liver tissues was significantly decreased in those rats with OM-treatment compared with those without OM treatment. The pseudolobules were surrounded by strong, multi-layer reticular fibers, which netted into pseudolobules in CCl4-injured rats, however, there was a significant decrease in reticular fibers in OM-treated rats. The expression of TIMP-1 in hepatic cells was weak in control groups, but strong in CCl4-injured groups, however, the expression of TIMP-1 was significantly inhibited by OM (F = 52.93, P<0.05). There was no significant change in the expression of α-SMA between CCl4-injured rats with or without OM treatment (F= 8.99, P>0.05). CONCLUSION: OM effectively inhibits CCl4-induced fibrogenesis in rat liver tissues, probably by reducing the expression level of TIMP-1.
基金Funded by the Innovation Foundation of Guangzhou, P. R. China (No. 2005V42C0021)
文摘Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan cooling system (ECHDFCS). The system was applied to a 50-wheel loader. We carried out the coolant temperature simulation using fluid modeling software FLOWMASTER, followed by laboratory experiments and road tests. The results show that ECHDFCS can adjust the cooling capability of the system automatically based on machine heat dissipation requirements. The coolant temperature is consequently remained within an appropriate range. The simulation results are consistent with the experiment results when the experiment is performed on the plain, but are different from the road tests in some investigated parameters on the plateau.
