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基于GPRS的高速公路智能收费系统设计 总被引:2,自引:0,他引:2
以AT89S8252为核心,结合nRF2401和GR47设计一套高速公路智能收费系统.采用无线通信方式,实现车辆与收费站之间收费的无人化操作;收费信息借助GPRS网络传输到网络银行,再进行相应的代收费.GPRS模块和GPRS网络的应用,增强系统的可靠性、收费的便捷性,降低成本.系统给智能收费系统的实现提供新方案,具有良好的市场前景. 相似文献
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以可溶性淀粉为原料,通过反相悬浮聚合法,合成了一种交联淀粉微球(CSM)。研究了CSM对羟基苯甲醚的吸附行为,分析了其吸附动力学特性和热力学性质,并利用扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)和X射线衍射仪对淀粉微球及其吸附产物进行了表征,探讨其吸附机理。结果表明:在研究范围内,CSM对对羟基苯甲醚的吸附行为同时符合Langmuir和Freundlich等温吸附方程;在不同温度下,CSM吸附对羟基苯甲醚的吸附焓变(ΔH)、吸附熵变(ΔS)、吸附自由能变(ΔG)均为负值,吸附是一个自发、放热过程。 相似文献
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Inthe 1990s ,newaluminatelongafterglowphos phorswerereported ,theluminescenceintensityandtheafterglowpersistencearemuchhigherthanthatofthetraditionalsulfide .Moreover ,theydonotcontainradiativeelementandhasgoodstructuralstability .Therehasbeenincreasinginterestonthenewphos phorsovertheworld .Thewideanddeepresearchonthisnewmaterialhasbeenmadeinrecentyears[1~ 3] .Nowadays ,thegreenandbluephosphorescencephos phorscanbesuccessfullypreparedwhichlastsmorethan 30and 12hrespectively[4 ] .Ithasalread… 相似文献
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汪波黄赤黄志雄张景洁 《材料研究学报》2016,(3):209-219
以不同种类的偶联剂对空心玻璃微球表面改性,改性后的微球填充酚醛树脂制备了酚醛复合泡沫塑料。研究了空心微球改性前后的表面性能和酚醛复合泡沫塑料的弯曲强度、断裂韧性以及动态力学性能的变化。结果表明:经过偶联剂处理后的空心微球,降低了空心微球之间的团聚,增加了表面疏水性,改善了与基体间的相容性和界面性能,提高了复合材料的各项性能。不同种类偶联剂中,钛酸酯偶联剂以物理缠结的方式同酚醛基体聚合物链连接,硅氧烷偶联剂除部分与甲阶酚醛中的羟甲基有化学键合作用,大部分仍以物理缠结为主,戊二醛和硅氧烷协同改性通过形成缩醛结构将微球与基体连接起来,因此,在酚醛基复合材料中以戊二醛和硅氧烷偶联剂协同改性的效果最为明显。 相似文献
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Preparation and Long Persistence Red Luminescence of M0.2Ca0.8TiO3 : Pr^3+ (M = Mg^2+ , Sr^2+ , Ba^2+ , Zn^2+) 总被引:2,自引:0,他引:2
M0.2Ca0.8TiO3 : Pr^3 (M = Mg^2 , Sr^2 , Ba^2 , Zn^2 ) long persistence red phosphors were prepared by solid state reaction. The influence of the partially replacing Ca^2 in CaTiO3 with Mg^2 , Sr^2 , Ba^2 , Zn^2 on the excitation spectra, the emission spectra and the long persistence properties were studied. The results suggest that certain quantity of Mg^2 , Sr^2 , Ba^2 , Zn^2 which partially replace Ca^2 can enhance the luminescent intensity and prolong the afterglow persistence of the samples. The intensity of Mg0.2Ca0.8TiO3: Pr^3 is above all of the samples. Take Mg0.2Ca0.8TiO3:Pr^3 as the basic sample, the influence of Pr^3 concentrations (C (Pr^3 )) on the long afterglow properties were also studied.The results suggest that when the C (Pr^3 ) is 0.10% (tool fraction) the intensity of the sample is the highest. The excitation spectra of all these samples show broad band spectra ranging from 300 - 500 nm peaking at about 342 nm. The emission spectra also exhibit a broad band peaking at 613 nm (CaTiO3: Pr^3 is 612 nm). XRD research indicates that the crystalline phases change due to the replacement of divalent metal ions. The research on the thermoluminescence spectra of Mg0.2Ca0.8TiO3:Pr^3 indicates that the peak is at 107.35℃ and the depth of the trap energy is about 0.852 eV. 相似文献