Coherent spectroscopy of a strongly driven triple quantum dot molecule

Based on a calculation model, we study the interference phenomena of serially coupled V-type and Λ-type triple quantum dots (CTQDs) driven simultaneously by a strong driving field and a weak probe field. Strongly depending on the configuration of the three-level CTQD, the probe absorption spectra, which are shown in the tunneling current, exhibit various quantum coherence properties. In the case where the two pairs of transitions of the CTQD have a small eigenfrequency difference Δω, the double-coupling effect of the driving field results in two Autler-Townes doublets and one weak Mollow triplet in one spectrum. With the value of Δω increasing, only one Autler-Townes splitting remains due to the single-coupling of the field. We also find that the effect of spontaneous emission of phonons may lead to an obvious background current, which can be used to distinguish which transition is driven by the driving field in experiment. The interesting quantum property of a CTQD revealed in our results suggests its potential applications in quantum modulators and quantum logic devices.     

川东南长宁地区地震活动及b值演化特征

利用全国统一目录和流动台站目录,研究了四川盆地东南部长宁地区的地震活动特征和b值的空间分布特征.研究结果显示,长宁地区的地震活动在时间上呈现明显的分段特征,地震活动在2015年后明显增强;在空间上,长宁地区的地震活动主要集中在以28.3°N为界限的南、北2个地区,对于这2个区域的b值演化,计算结果显示出不同的分段特征....     

西藏斯弄多地区晚白垩世埃达克岩:岩石成因及成矿潜力指示

西藏冈底斯带广泛分布晚白垩世埃达克质岩,其岩石成因一直存在争论,并且对于成矿潜力的研究也十分有限.为此对谢通门县斯弄多-加多捕地区具铜矿化的黑云母二长花岗岩开展了锆石U-Pb定年、全岩地球化学以及锆石微量元素地球化学特征的研究,以探明岩石成因及成矿潜力.结果表明黑云母二长花岗岩侵位时间为晚白垩世(83.1± 1.6 M...     

中国滑雪场可达性及市场潜力测度

利用可达性分析方法与潜力模型对中国滑雪场空间分布格局与市场潜力进行了系统分析,全面认识了滑雪场在交通可达性方面的优劣势,并针对不同区域提出了相应的发展或改进方向.研究表明:中国滑雪场距离城市中心的平均最短旅行时间为1.24 h,南方可达性普遍较差,北方同一城市内部差异较大.全国各城市到达某一滑雪场的最短时间呈圈层式分布...     

山西交城断裂带西张探槽全新世古地震研究

西张探槽①位于山西太原市西北10km,沿交城断裂带北段NNW方向高4.6m的低陡坎前缘开挖。探槽长108m,宽8m,深10m,揭露18层地层。探槽上部地层为亚砂土,探槽内断层下降盘的上部地层为一套砾石层,下部地层为一套褐色垆土与亚砂土互层,断层的上升盘地层以亚砂土为主夹砾石层。探槽揭露出3条断面,断面的上断点距地表1.5m,断错的最新地层距今(3.74±0.06)ka。探槽揭示出断面、地层断错、崩积楔、地层倾斜等现象。由探槽揭露出的地层与断层的关系可知早全新世以来交城断裂带曾发生3次断层活动事件,其时间分别为距今(3.74±0.06)～(3.06±0.26)ka、(8.35±0.09)～(3.74±0.06)ka与(10.66±0.85)～(8.35±0.09)ka,具有2.6～3.6ka的强震重复间隔;3次同事件最小垂直位移分别为3.0m、2.5m及3.2m。西张探槽的意义在于揭示了历史上未有强震记载的晋中盆地几千年前有过多次强震活动。西张探槽获得的交城断裂带全新世古地震活动的依据,对评价太原市未来的强震危险性具有重要意义     

Study on inelastic displacement ratio spectra for near-fault pulse-type ground motions

In displacement-based seismic design, inelastic displacement ratio spectra (IDRS) are particularly useful for estimating the maximum lateral inelastic displacement demand of a nonlinear SDOF system from the maximum elastic displacement demand of its counterpart linear elastic SDOF system. In this study, the characteristics of IDRS for near-fault pulse-type ground motions are investigated based on a great number of earthquake ground motions. The in? uence of site conditions, ratio of peak ground velocity (PGV) to peak ground acceleration (PGA), the PGV, and the maximum incremental velocity (MIV) on IDRS are also evaluated. The results indicate that the effect of near-fault ground motions on IDRS are signifi cant only at periods between 0.2 s - 1.5 s, where the amplifi cation can approach 20%. The PGV/PGA ratio has the most signifi cant in? uence on IDRS among the parameters considered. It is also found that site conditions only slightly affect the IDRS.     

基于小波分析的场地波速测量方法

在场地波速测量中,由于噪声等因素的影响很难准确识别P、S波的初至时刻,致使波速结果存在很大的误差。本文给出了一种基于小波变换的波速测量的新方法。该方法利用波动信号的小波变换与弹性波群速度的关系准确识别弹性波初至时刻。弹性波小波变换的峰值时刻代表着以群速度传播的弹性波的初至时刻,使P波、S波的初至时刻的确定具有明确的物理意义,波速的结果准确、可靠、稳定。此外,波动信号的小波多尺度分析还可以确定地层中传播的弹性波的频散特性。最后,该方法在场地波速测量的实测信号的应用表明该方法可准确确定P、S波速。     

赵九章先生对推进我国地震科学事业的贡献

赵九章先生是一位开拓性的科学家,眼光看得远,只要国家需要就干。他的领导艺术和组织才能也是众所周知的。1950年4月6日,中国科学院建立地球物理研究所,任命赵九章为所长,下属气象、地磁、地震和物探4个组。在赵九章所长领导下,4个组都得到了重大发展,以致分别发展为大气物理、     

ON SOME KEY SEDIMENTATION PROBLEMS OF THREE GORGES PROJECT (TGP)

I. INTRODUCTIONThe Three Gorges Project (TGP) being planned is to be located on the Yangtze River at Sandouplug, 44 km upstream of Yichang (Fig. l). A scheme studied in the feasibility stage has the crest ofthe dam placed at 185 m with a maximums height o…     

云南地区地热基本特征

本文从实测26口井的地热数据中取得14个大地热流值,认为云南地区地热场具有西高东低,并自西往东呈波浪式逐渐变低的趋势,该区具有高地热特征的地质发展历史。由于该区地处世界两大地震带的过渡地区,具有岛弧型的高地热特征,也具有岛弧地带地震活跃的特点,强震多发生在深大断裂带上。该区不同构造单元中的地热场存在的明显不均一性,影响着地震的孕育和地震的发生,地热场、温泉和地震的分布呈良好的对应关系