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通过对山顶上高38.5m的三钢管钢塔架的设计,比较风荷载取值在新旧规范中的差异,阐述了高耸结构风荷载下的受力特点,并给出其内力差别。 相似文献
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The time-dependent formation of one-dimensional two-photon screening-photovoltaic(PV) grey spatial solitons under low-amplitude conditions is presented theoretically.The time-dependent propagation equation of two-photon screeningphotovoltaic solitons is obtained by the numerical method.The results indicate that as the time evolves,the intensity width of grey screening-photovoltaic spatial solitons decreases monotonously to a minimum value towards the steady state.The higher the ratio of soliton peak intensity to the dark irradiation intensity,the narrower the width of grey solitons within the propagation time. 相似文献
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SHF—1型保安防盗报警器是采用进口集成电路及晶体管研制组装而成。产品性能稳定,灵敏度高,全方位监视,不受角度限制,且探测器及引线还具有防破坏功能,即使犯罪分子将探测器及引线破坏,仍能照常报警。该报警器广泛适用于机关、仓库、银行、门市部、果园、鱼塘、家庭住宅等需要保安防盗之场所。工作原理:图1是探测器电路,晶体管BG_1等元件组成的振荡电路产生的超高频微波信号,由天线发射出去在周围产生电磁波,当有物体在电磁波覆盖的范围内移动时,则会产生多普勒效应,即探测器发射出 相似文献
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