基于CA3070的相干检波在无线电罗盘中的应用     

李杰  张菊  魏书生 《湖南农机》2015,(2):47-48

文章简要介绍调制解调原理,结合无线电罗盘的检波电路,分析了罗盘的调幅检波。文中围绕器件CA3070着重叙述相干解调的原理及过程,同时使用仿真软件Multisim对解调的电路进行仿真。  相似文献   

Evaluation of electrical nerve stimulation to confirm sacrococcygeal epidural needle placement in dogs     

Natali Verdier  Fernando Martinez-Taboada  Pablo E. Otero  José Ignacio Redondo García  Andrea S. Zaccagnini  Alejo A. Costoya  Lisa Tarragona  Diego A. Portela 《Veterinary anaesthesia and analgesia》2021,48(4):612-616

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带状渐变非均匀介质中波的传播     

罗松南周正平  熊慧而 《湖南农业大学学报(自然科学版)》2004,31(2)

对弹性波在带状渐变非均匀介质中的传播进行了研究，建立了非均匀介质中波动方程的一般形式；利用走时变换，考虑边界条件、辐射条件和非均匀带两端的连续条件对变系数偏微分方程式进行求解。对3种不同的具有二次变化的带状非均匀介质中波的传播得出了解析解，并进行了实例计算。在非均匀介质区域中的弹性模量不同变化情况下，得到了不同区域长度与接收波波幅之间的变化规律曲线，讨论了弹性波在非均匀介质中传播的一般性质，这些均为无损检测或波动反分析提供依据。  相似文献   

Salidroside increases release of intracellular free Ca²⁺ from sarcoplasmic reticulum in cultured rat cardiomyocytes     

PANG Yong-jun  SUN Li  XIE Wen-juan  MO Shu-rong 《园艺学报》2011,27(10):2021

AIM: To observe the effects of salidroside on intracellular free Ca²⁺ concentration in cultured rat cardiomyocytes. METHODS: Primarily cultured cardiomyocytes of neonatal rats were divided into control group, different concentrations of salidroside groups and verapamil pretreatment+different concentrations of salidroside groups. The fluorescent intensity of intercellular free calcium concentration ([Ca²⁺]_i) in cultured cardiomyocytes of newborn rats loaded with fluo-3/AM(5 μmol/L) was measured by laser scanning confocal microscopy. RESULTS: Salidroside at concentrations of 15 mg/L, 30 mg/L and 60 mg/L elevated [Ca²⁺]_i in cultured rat cardiomyocytes with the peak values of 574.08±4.65, 591.86±3.64 and 618.66±4.27, respectively (all P<0.01), indicating that the effect of salidroside on the level of [Ca²⁺]_i was dose-dependent. In the presence of verapamil in D-Hanks solution, salidroside also elevated the fluorescent intensity of [Ca²⁺]_i in cardiomyocytes from 357.74±3.13, 387.17±2.37 and 391.43±1.34 to 480.86±3.98, 496.70±3.08 and 522.18±3.19, respectively (all P<0.01). CONCLUSION: Salidroside increases the release of [Ca²⁺]_i from sarcoplasmic reticulum in cultured rat cardiomyocytes.  相似文献   

动力作用下块体式基础竖向振幅的计算研究          下载免费PDF全文

赵荣飞  把多铎  高微 《西北农林科技大学学报(自然科学版)》2006,34(1):162-164

考虑阻尼比和频比对动力作用下块体式基础竖向振幅计算的影响,对质-弹-阻计算模式和质-弹计算模式在设定的阻尼比和频比下进行计算分析,提出了在采用2种模式动力作用下块体式基础竖向振幅计算时的阻尼比和频比范围。  相似文献   

机液伺服振动台系统稳定的分析与研究     

谢拥群  江青秀 《福建林学院学报》1994,14(1):16-22

本文通过对系统中存在的各非线性环节对系统稳定性影响的理论分析与实验研究，揭示了机液伺服振动台的系统稳定区域与系统各参数之间的关系．从而为该类振动台的实际应用，打下了坚实的理论基础．也为同类型振动台的设计、研制提供了有益的依据．  相似文献   

波在局部损伤混凝土介质中的传播     

罗松南  程红梅 《湖南农业大学学报(自然科学版)》2002,29(2)

对弹性波在损伤介质中的传播理论进行研究 .利用弹性动力学基本原理和损伤力学模型建立了损伤介质中的波动方程 .求得了波动方程的基本解 ,并进行了实例计算分析 .由于损伤的存在 ,结构的波动响应在波形、波幅、传播时间等各方面都产生了明显的变化 .为进一步的波动反分析和无损检测的研究提供依据  相似文献   

芦荟胶囊通便作用的实验研究     

王英军  孙英莲  唐炜  徐宏  许荔新 《特产研究》2007,29(2):36-38

目的研究芦荟胶囊润肠通便的作用。方法通过结扎大鼠回肠模型,观察动物肠道水分的分泌及家兔在体肠肌收缩幅度及频率。结果芦荟胶囊可明显促进大鼠肠道水分的分泌,增强家兔在体肠肌收缩幅度及频率。结论芦荟胶囊具有很好的润肠功能及排便功能。  相似文献   

不同昼夜温差对赤霞珠葡萄果实香气的影响及转录组分析     

张乐  张亚红  乔振羽  王亚楠  陈璐  周娟  黄嘉俊 《核农学报》2023,37(4):865-878

为探究不同昼夜温差对酿酒葡萄果实成熟期间挥发性香气合成的影响,以酿酒葡萄赤霞珠为试验材料,通过调控夜间温度改变昼夜温差,设置T_-2.6℃(夜间平均温度为17.0℃,温差为15.1℃)、T_0.5℃(夜间平均温度为20.1℃,温差为12.0℃)、T_3.5℃(夜间平均温度为23.1℃,温差为9.0℃)和CK(夜间平均温度为19.6℃,温差为12.5℃)4组处理,测定分析果实中挥发性香气组分和含量的变化,并进行挥发性香气合成机制的生物信息学分析。结果表明,昼夜温差与可溶性固形物、可溶性糖和可滴定酸含量呈正比;T_-2.6℃和T_0.5℃处理提高了赤霞珠果实中的花香和果香,后续在酿酒过程中可提高葡萄酒一类香气的含量,在酿造干红的同时,也宜于酿造起泡桃红类葡萄酒;T_3.5℃处理提高了果实中的烟草香,为后续酿造葡萄酒提供了更多的三类香气,即陈酿香,在较小温差环境下生长的葡萄酿酒后更适宜储存较长时间,以更好地形成陈酿香。共检测到5 111个差异表达基因,其中T_-2....  相似文献   

Growth and oxygen consumption of the juvenile sea cucumber Apostichopus japonicus (Selenka) at constant and fluctuating water temperatures   总被引：3，自引：0，他引：3  

Yunwei Dong  & Shuanglin Dong 《Aquaculture Research》2006,37(13):1327-1333

The effects of thermal amplitudes of diel fluctuating temperature on growth and oxygen consumption of the juvenile sea cucumber Apostichopus japonicus (Selenka) were studied at the average temperatures of 15 and 18°C with three diel different fluctuating amplitudes of ±2, ±4 and ±6°C. The optimum thermal amplitudes for growth of the juvenile sea cucumber at the sizes of this experiment, at average temperatures of 15 and 18°C, were estimated to be ±1.38 and ±1.67°C respectively. In the constant temperature regimes, the growth rate at 15°C was higher than that at 18°C. However, the growth rate at 18±2°C was higher than that at 15±2°C. The results from this study suggested that fluctuating temperatures enhanced the optimum temperature for the growth of sea cucumbers compared with that at constant temperatures. Therefore, accurate predictions of the optimum temperature of sea cucumbers in the natural environment, in which water temperatures fluctuate daily and seasonally, should be made from data obtained at fluctuating temperatures.  相似文献