共查询到19条相似文献,搜索用时 67 毫秒
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目的 研究M胆碱能受体阻滞剂东莨菪碱对猕猴吗啡静脉自身给药及反应恢复行为的影响。方法 建立猕猴吗啡静脉自身给药模型(固定比率1,给药期4h)以及反应恢复模型。观察不同浓度东莨菪碱急性处理对吗啡静脉自身给药模式、踏板反应率、吗啡用药量以及自由活动度的影响。同时观察慢性和急性东莨菪碱处理对静脉自身给药行为淬灭后反应恢复行为的影响。结果 东莨菪碱急性处理(0.025,0.075,0.25,0.75mg/kg)可以减弱FR1程序控制下吗啡静脉自身给药行为,不仅表现为总用药量和反应速率的降低,而且还可延迟自身给药行为的起动,同时对自身给药行为模式有较大的影响,小剂量东莨菪碱可使急促的用药行为变为缓慢,大剂量时几乎可完全阻断动物的踏板反应。反应恢复实验结果显示,东莨菪碱急性处理可延迟淬灭后踏板反应的恢复,而慢性处理可降低动物的踏板反应率及总的强化次数。结论 提示东莨菪碱对复吸行为可能有一定的治疗作用。 相似文献
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《中国有色金属学会会刊》2019,(4)
基于热物理实验研究Cu-6wt.%Ag合金在温度为973~1123 K、应变速率为0.01~10 s-1条件下的热变形行为。研究发现,当真应变较小时,应力随应变的增加迅速增加直至达到最大值,随后在加工硬化、动态回复和再结晶的共同作用下应力变化缓慢并趋于稳定;常规Arrhenius本构模型中材料参数在不同变形条件下仅与应变相关,预测误差较大,无法准确表征材料的热流变行为。为了准确描述合金的热变形行为,本文作者建立考虑变形温度、应变速率和应变三者协同影响的修正本构模型。结果表明,修正模型的相关系数和平均相对误差分别为0.993和4.2%,能较准确地描述Cu-6wt.%Ag合金的热变形行为。 相似文献
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提出了一种连铸结晶器内氩气/钢液两相非稳态湍流流动的大涡模拟模型,采用非齐次Euler-Euler双流体模型描述氩气/钢液两相流运动方程,采用大涡模拟模型对湍流黏性力进行求解.利用板坯探伤缺陷检测结果间接地验证了氩气/钢液两相非稳态湍流运动特征,利用水模型实验结果验证了两相的非对称流动特征.结果表明,氩气泡的行为将直接影响结晶器内钢液的流动行为.气泡在结晶器内的运动行为主要受吹Ar量和钢流量的影响,其平均直径随着吹Ar量的增大而增大,随着钢流量的增大而减小.结晶器内的不对称流场具有不稳定性,偏流是绝对的,对称是暂时的、偶然的,偏流的周期性不明显.结晶器二冷区弯曲段的弧形形状对结晶器内部流场的影响较大,偏流发生在弯曲段附近. 相似文献
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基于OV模型,考虑驾驶员性格对交通流影响,提出了一个新的跟驰模型.首先分析了模型的稳定性能,并获得交通系统保持稳定的条件,并用mKDV方程描述交通波的传播过程.结果表明:考虑驾驶员的性格对交通流的稳定性具有重要的作用. 相似文献
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为加强车辆管理设计了汽车电子牌照管理系统。本系统以安装Windows 2000 AdvancedServer的计算机为服务器;以安装了Windows 2000 Professional的计算机为客户端;以Microsoft SQL Server2000企业版作为开发数据库平台;以Delphi6作为前端开发工具,构建了网络开发环境,完成了汽车电子牌照管理系统的不停车收费、停车场管理、在逃车辆追踪、交通流监控、报表打印等基本功能。本系统实现了汽车牌照的有机管理,提高了交通运输效率和管理水平。 相似文献
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Deng-Kui Zhang Guo-Qing Wang Ai-Ping Wu Ji-Guo Shan Yue Zhao Tian-Yi Zhao Dan-Yang Meng Jian-Ling Song Zhong-Ping Zhang 《金属学报(英文版)》2019,32(6):684-694
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone. 相似文献
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After nearly two years'tense construction the first phase of industrialized base of Shenyang Research Institute of Foundry 《中国铸造》2008,5(1):63-64
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation. 相似文献
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Z. Sun S.L. Zheng Y. Zhang 《金属学报(英文版)》2007,20(3):187-192
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process. 相似文献
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R. González-Martínez 《金属学报(英文版)》2007,20(4):235-240
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke. 相似文献