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71.
The electrocardiogram (ECG) signal is a recording of the electrical activity on the body surface generated by the heart frequency of which is weak and low. Many researchers devote themselves to get more perfect ECG in many ways. This article introduces the characterize of an ECG signal , then discusses the requirements for the sampling circuit of an ECG. Since there are some shortcoming in common design means, the authors give an effective circuit. The system is composed of a low-cost , low-power and high-performance MCU C8051F020 , amplifier AD620 , right-leg drive circuit ,communication circuit and power management circuit. Then software design is given which is used to sampling and filtering ECG signal. Levkov filter arithmetic and smooth filter arithmetics are used in this design. In the end , the authors advance a distributing and networking ECG monitor system. 相似文献
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基于DEM的水文模型在沮河流域的应用 总被引:2,自引:0,他引:2
基于DEM的流域水文模型是近年来水文模型的热点,而干旱半干旱地区的水文模型一直是水文研究的一个难题。分析了干旱地区的降雨产流特性,建立了符合该产流特性的数字高程模型和陕北模型相结合的水文模型,并将其应用到沮河流域桃曲坡水库的洪水预报中,计算结果证明该水文模型在干旱地区是切实可行的。 相似文献
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钢丝绳隔振器驾驶座减振性能研究 总被引:2,自引:0,他引:2
介绍了拖拉机非线性驾驶座动态特性分析和随机振动试验技术。该技术是在大量试验的基础上,根据振动理论和数值分析方法,建立起来的非线性驾驶座振动特性分析和仿真技术。将此技术运用到自行研制的复合阻尼钢丝绳隔振器驾驶座的研制和分析上,取得了良好的效果。 相似文献
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ZHANG Qiong WAN Chang-wu YU Yan-ni XIA-Bing LIU Jiang-jin ZHANG Qiao-jun LI Zhu WANG Cheng-fei DAI Jia-lin WANG Jie 《园艺学报》2021,36(12):2133-2138
AIM To explore the possible mechanism of cathepsin C (CTSC) and tumor necrosis factor-α (TNF-α) in coronary heart disease (CHD) by detecting the protein expression of CTSC and TNF-α in human coronary artery tissue. METHODS The coronary artery tissues from 52 cases of CHD and 25 cases of accidental death without any heart disease in the Forensic Judicial Expertise Center of Guizhou Medical University from October 2018 to December 2019 were collected as CHD group and control group, respectively. The coronary artery stenosis and intimal plaque formation were examined by histopathology, the protein expression of CTSC and TNF-α was determined by Western blot, and the intracellular expression of CTSC and TNF-α was analyzed by immunohistochemical staining. RESULTS The results of HE staining showed that the intima of coronary artery in control group was smooth, and no thickening or stenosis was observed. In CHD group, the intima thickened irregularly, atherosclerotic plaques formed, the intima became thinner and the lumen showed eccentric stenosis in varying degrees (P <0.05). The results of Western blot showed that the expression of CTSC and TNF-α in CHD group was significantly higher than that in control group (P <0.05). Immunohistochemical staining showed that both CTSC and TNF-α were expressed in the cytoplasm of foam cells, and their positive expression was significantly higher than that in control group (P <0.05). The results of Pearson moment correlation analysis showed that there was positive correlation between the expression of CTSC and TNF-α in CHD (r2 =0.743, P <0.05). CONCLUSION The up-regulated expression of CTSC in coronary artery tissue may promote the expression of TNF-α and affect the occurrence and development of CHD. 相似文献
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基于灰色关联分析的区域保险差异影响因素分析 总被引:1,自引:0,他引:1
蒋才芳 《湖南农业大学学报(自然科学版)》2010,27(4):22-26
研究了经济学中广泛应用的决策模糊理论中模糊集覆盖系数的性质,并据此提出了无须通过繁杂的统计实验就能够计算覆盖系数的实用方法,进而提出了模糊集交并运算算子. 用两个算例说明了该方法和算子与实际情形相符,具有可行性. 相似文献