排序方式: 共有22条查询结果,搜索用时 171 毫秒
11.
采用基于802.15.4/ZigBee的无线传感器网络技术及ARM嵌入式技术,结合简单网络管理协议在传统网络管理上的优势,将无线传感器网络集成到现有网络中来,设计并实现对ZigBee无线传感器网络的管理.实验结果表明,基于简单网络管理协议的无线传感器网络管理方案可以有效地对无线网络终端的数据进行实时采集和监控,达到对无... 相似文献
12.
The stability characteristics of an ultra-thin layer of a viscous liquid flowing down a cylindrical fibre are investigated
by a linear theory. The film with the thickness less than 100 nm is driven by an external force and under the influence of
the van der Waals forces. The results show that, when the relative film thickness decreases, the curvature of the fibre depresses
the development of the linear perturbations, whereas the van der Waals forces promote the instabilities. This competition
results in a non-monotonous dependence of the growth rate on the relative film thickness. The critical curves are also obtained
to describe the transition from the absolute instability to the convective instability, indicating that the van der Waals
forces can enlarge the absolutely unstable region. Furthermore, the surface tension can cause the development of the absolute
instability, whereas the external force has an opposite effect. 相似文献
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研究了时标上三阶非线性ρ-Laplacian三点边值问题[φp(p(t)u△▽(t))]▽+a(t)f(t,u(t))=0,t∈[O,T],βu(0)-γu△(0)=0,u△(T)=αu(η),u△▽(0)=0借助于锥上的五泛函不动点定理,得到了边值问题至少有三个正解的一些新的结果,同时给出了例子验证了主要结果. 相似文献
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研究了时标上三阶非线性p-Laplacian三点边值问题[Φp(p(t)u Δ8710; (t))]Δ+a(t)f(t,u(t))=0,t∈[0,T],βu(0)-γuΔ(0)=0,uΔ(T)=αu(η),u Δ8710;(0)=0借助于锥上的五泛函不动点定理,得到了边值问题至少有三个正解的一些新的结果,同时给出了例子验证了主要结果。 相似文献
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研究了时标上三阶非线性p-Lap lac ian三点边值问题[φp(p(t)uΔ(t))]+a(t)f(t,u(t))=0,t∈[0,T],βu(0)-γuΔ(0)=0,uΔ(T)=αu(η),uΔ(0)=0借助于锥上的五泛函不动点定理,得到了边值问题至少有三个正解的一些新的结果,同时给出了例子验证了主要结果。 相似文献
18.
研究了一类奇异奇摄动系统边值问题.通过几何奇摄动理论构造了系统的奇异轨道,并用交换引理证明了解的存在性.最后用该方法研究了一个经典半导体模型. 相似文献
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为揭示深水湖库沉积物磷的分布特征,运用沉积物磷形态标准分析法SMT,于2011年10月至2012年7月对长潭水库库区5个采样点沉积物中的TP和各形态磷含量进行了分析。结果表明:长潭水库沉积物处于还原状态,有利于Fe/Al-P的还原溶解,其中中下游还原性比上游强,夏季还原性最强。沉积物含水率和TOC质量比上游较低,中下游较高;春季和夏季沉积物中TOC质量比较高。长潭水库TP质量比平均值在0.56~0.79mg/g之间,其空间分布特征是中游较高,上游和下游较低。其中,Fe/Al-P在TP中占27%~48%,平均为41%,Ca-P在TP中占16%~25%,平均为19%,OP在TP中占35%~52%,平均为40%。可见,各形态磷中Fe/Al-P所占百分比最大,有利于水体中藻类吸收利用。长潭水库沉积物磷污染主要来源为上覆水体中磷的沉降。 相似文献
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Numerical investigation on properties of attack angle for an opposing jet thermal protection system
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The three-dimensional Navier-Stokes equation and the k-ε viscous model are used to simulate the attack angle characteristics of a hemisphere nose-tip with an opposing jet thermal protection system in supersonic flow conditions.The numerical method is validated by the relevant experiment.The flow field parameters,aerodynamic forces,and surface heat flux distributions for attack angles of 0°,2°,5°,7°,and 10° are obtained.The detailed numerical results show that the cruise attack angle has a great influence on the flow field parameters,aerodynamic force,and surface heat flux distribution of the supersonic vehicle nose-tip with an opposing jet thermal protection system.When the attack angle reaches 10°,the heat flux on the windward generatrix is close to the maximal heat flux on the wall surface of the nose-tip without thermal protection system,thus the thermal protection has failed. 相似文献