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淳安县林业可持续发展能力的评价和分析 被引量:9
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作者 郭仁鉴 陈法荣 朱铨 《浙江林学院学报》 CAS CSCD 北大核心 2001年第4期337-344,共8页
以浙江省淳安县县级行政单位为研究对象 ,用县域林业可持续发展理论研究中所提出的基本原理和指标体系 ,根据淳安县近年来的自然—社会复合系统以及林业系统的变化发展趋势 ,定量测度了该县可持续发展能力的指标值 :资源丰富度为 0 5 ... 以浙江省淳安县县级行政单位为研究对象 ,用县域林业可持续发展理论研究中所提出的基本原理和指标体系 ,根据淳安县近年来的自然—社会复合系统以及林业系统的变化发展趋势 ,定量测度了该县可持续发展能力的指标值 :资源丰富度为 0 5 4 ,系统稳定度为 0 69,经济富强度为 0 49,管理力度为 0 38。对各指标作等权处理 ,求得淳安县目前可持续发展度为 0 5 3。当项目指标值为 1时 ,可持续发展度为 0 70 ,可以认为可持续发展度大于等于0 70时为可持续状态 ,淳安县尚未达到此标准。在评价和分析淳安县林业可持续发展能力的基础上 ,从总体上探讨了该县走可持续发展道路的具体措施。表 5参 展开更多
关键词 林业可持续发展度 评价 淳安县 资源丰富度 系统稳定度 经济富强度 管理力度
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汽轮机裂纹转子升速过程非线性振动数字仿真及分析 被引量:3
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作者 何青 彭慧春 +1 位作者 翟鹏程 甄亚欣 《热力发电》 CAS 北大核心 2016年第11期5-12,24,共9页
基于应力强度因子为零法,建立了汽轮机转子升速过程中开裂纹转子和呼吸型裂纹转子的振动模型,并采用Runge-Kutta法对模型进行数值积分,实现升速过程中2种转子的稳态响应数字仿真及稳定性量化分析。结果表明:开裂纹转子和呼吸型裂纹转子... 基于应力强度因子为零法,建立了汽轮机转子升速过程中开裂纹转子和呼吸型裂纹转子的振动模型,并采用Runge-Kutta法对模型进行数值积分,实现升速过程中2种转子的稳态响应数字仿真及稳定性量化分析。结果表明:开裂纹转子和呼吸型裂纹转子在升速过程中均存在明显的1/3阶和1/2阶超谐共振;在超临界转速区,开裂纹转子和呼吸型裂纹转子均在转速比p=ω/ω0=2.10、2.20、2.55处出现了亚谐共振,该现象可作为判断转子裂纹故障是否存在的依据;在不同转速区,呼吸型裂纹转子与开裂纹转子的表现各不相同,尤其在超临界转速区,质量偏心e进一步抵消裂纹引起的非线性失稳,呼吸型裂纹转子出现局部渐进稳定区域,特别是在0.8<e<1.6时,质量偏心会进一步抑制非线性失稳运动,这一现象可为裂纹转子非线性运动失稳控制提供理论依据。 展开更多
关键词 非线性振动 裂纹转子系统 汽轮机 升速过程 转子动力学 非自治系统稳定度 质量偏心
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System reliability analysis of seismic pseudo-static stability of rock wedge based on nonlinear Barton–Bandis criterion 被引量:4
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作者 ZHAO Lian-heng JIAO Kang-fu +1 位作者 LI De-jian ZUO Shi 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第11期3450-3463,共14页
Based on the nonlinear Barton–Bandis(B–B)failure criterion,this study considers the system reliability of rock wedge stability under the pseudo-static seismic load.The failure probability(Pf)of the system is calcula... Based on the nonlinear Barton–Bandis(B–B)failure criterion,this study considers the system reliability of rock wedge stability under the pseudo-static seismic load.The failure probability(Pf)of the system is calculated based on the Monte−Carlo method when considering parameter correlation and variability.Parameter analysis and sensitivity analysis are carried out to explore the influence of parameters on reliability.The relationships among the failure probability,safety factor(Fs),and variation coefficient are explored,and then stability probability curves of the rock wedge under the pseudo-static seismic load are drawn.The results show that the parameter correlation of the B–B failure criterion has a significant influence on the failure probability,but correlation increases system reliability or decreases system reliability affected by other parameters.Under the pseudo-static seismic action,sliding on both planes is the main failure mode of wedge system.In addition,the parameters with relatively high sensitivity are two angles related to the joint dip.When the coefficient of variation is consistent,the probability of system failure is a function of the safety factor. 展开更多
关键词 3D rock wedge seismic pseudo-static stability nonlinear Barton–Bandis failure criterion system reliability sensitivity analysis stability probability curves
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Stability analysis and stabilization of wireless networked control systems based on deadband control scheduling 被引量:4
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作者 刘英英 褚云凯 +1 位作者 车伟伟 刘意杨 《Journal of Central South University》 SCIE EI CAS 2014年第11期4228-4235,共8页
The stability analysis and stabilization problems of the wireless networked control systems(WNCSs) with signal transmission deadbands were considered. The deadbands were respectively set up at the sensor to the contro... The stability analysis and stabilization problems of the wireless networked control systems(WNCSs) with signal transmission deadbands were considered. The deadbands were respectively set up at the sensor to the controller and the controller to the actor sides in the WNCS, which were used to reduce data transmission, furthermore, to decrease the network collision and node energy consumption. Under the consideration of time-varying delays and signal transmission deadbands, the model for the WNCS was presented. A novel Lyapunov functional which took full advantages of the network factors was exploited. Meanwhile, new stability analysis and stabilization conditions for the WNCS were proposed, which described the relationship of the delay bounds, the transmission deadband bounds and the system stability. Two examples were used to demonstrate the effectiveness of the proposed methods. The results show that the proposed approach can guarantee asymptotical stability of the system and reduce the data transmission effectively. 展开更多
关键词 wireless networked control system transmission deadband time-varying delay stability analysis stabilization
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