Teleportation and thermal entanglement in two-qubit Heisenberg XYZ spin chain with the Dzyaloshinski—Moriya interaction and the inhomogeneous magnetic field

This paper studies the average fidelity of teleportation and thermal entanglement for a two-qubit Heisenberg XYZ chain in the presence of both an inhomogeneous magnetic field and a Dzyaloshinski--Moriya interaction. It shows that for a fixed D_z, the increase of b_z will broaden the critical temperature at the cost of decreasing the thermal entanglement. And it can modulate the inhomogeneous magnetic field and the Dzyaloshinski--Moriya interaction for the average fidelity of teleportation to be optimal.     

Detrital apatite fission track constraints on Cenozoic tectonic evolution of the northeastern Qinghai-Tibet Plateau,China: Evidence from Cenozoic strata in Lulehe section,Northern Qaidam Basin

The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due to compressional deformation during the Indo-Asian collision. In this paper, we used detrital apatite fission-track thermochronology, including 4 sandstones and 2 conglomerates samples from the Lulehe section, to reveal the Cenozoic evolution of the northern Qaidam Basin. Fission-track dating indicated the source region of the Lulehe section has experienced important cooling and uplifting in the Late Cretaceous (at ~85.1 Ma and ~65 Ma) and the Eocene (~52 Ma), respectively. The AFT age distribution on the section suggested that the provenance of Lulehe section sediments were mainly derived from the south Qilian Shan (Qilian Mountains) and Altun Shan (Altun Mountains), and two significantly provenance changes may occur at 43.4-46.1 Ma and ~37.8 Ma, respectively. The results may have strong constrains on the Cenozoic deformation and tectonic evolution of the northern Qaidam Basin and Qinghai-Tibet Plateau.     

湖北永兴洞降水对2015年厄尔尼诺的响应

通过对湖北永兴洞为期3年（2013年6月至2016年7月）的地表降水δ¹⁸O观测,发现该地点降水δ¹⁸O在2015夏季显著偏正。利用HYSPLIT后向轨迹方法对永兴洞降水水汽来源进行分析,结果表明在厄尔尼诺事件的影响下2015年夏季来自远源印度洋的水汽显著减少,而近源太平洋水汽相对增多,即降水δ¹⁸O因"环流效应"而偏正。本研究提供的观测证据表明永兴洞石笋δ¹⁸O记录在重建ENSO主导下的亚洲季风大气环流方面具有重要潜力。

     

Assessment of global meteorological,hydrological and agricultural drought under future warming based on CMIP6

在全球变暖背景下,分析和预测干旱的变化趋势和传播规律对于区域生态环境安全和灾害管理具有重要意义.本文基于第六次国际耦合模式比较计划(CMIP6),分析了SSP2-4.5和SSP5-8.5两种变暖情景下的气象(标准化降水指数SPI和标准化降水蒸发指数SPED,水文(标准化径流指数SRI)和农业(标准化土壤水分指数SSI)...     

新疆尼勒克、巩留交界6.0级地震灾害损失评估与房屋震害特征

新疆尼勒克、巩留交界6.0级地震震中烈度为Ⅶ度,地震没有造成人员伤亡,但个别民宅倒塌,大量村镇居民房屋遭受中等以上破坏,一些教育、卫生等公房遭破坏;交通和水利设施有一定程度破坏,经及时抢修,未对灾区生产生活产生明显影响。通过实地抽样调查和统计计算,评估出本次地震造成的直接经济损失为67 846万元,需恢复重建的经费120 349万元。     

中西太平洋金枪鱼围网高产渔区年间变化及其原因分析

金枪鱼类是中西太平洋海域重要的经济鱼种,其中鲣产量约占到总产量的50%。本研究利用1995-2010年16年的中西太平洋（20°S~20°N,120°E~155°W）鲣围网生产统计数据和Niño3.4海区（5°S~5°N,120°~170°W）海表温度异常数据,对这16年鲣产量最高的十大渔区（5°×5°）进行时空格局分析,讨论渔场分布差异及CPUE与ENSO指数的关系。结果表明:16年间十大作业渔区主要分布在5°S~5°N、130°~175°E区域,这十大渔区产量占总产量的比重达47.5%,其中5°S~0°、155°~160°E,0°~5°N、130°~135°E,0°~5°N、135°~140°E及5°S~0°、160°~165°E等4个渔区产量占高产渔区产量的比重均超过10%,是中西太平洋重要的鲣产区。高产渔区的分布受海表温度影响较大,在厄尔尼诺时期,高产渔区分布明显偏东,主要分布在155°~180°E海域;在拉尼娜时期,高产渔区分布明显偏西,主要分布在130°~160°E海域。     

Geochemistry of the high-Mg andesites at Zhangwu, western Liaoning: Implication for delamination of newly formed lower crust

Ten volcanic samples at Zhangwu,western Liaoning Province,North China were selected for a sys-tematic geochemical,mineralogical and geochronological study,which provides an opportunity to ex-plore the interaction between the continental crust and mantle beneath the north margin of the North China craton.Except one basalt sample(SiO2= 50.23%),the other nine samples are andesitic with SiO2 contents ranging from 53% to 59%.They have relatively high MgO(3.4%―6.1%,Mg#=50―64) and Ni and Cr contents(Ni 27×10?6―197×10?6,Cr 51×10?6―478×10?6).Other geochemical characteristics of Zhangwu high-Mg andesites(HMAs) include strong fractionation of light rare earth elements(LREE) from heavy rare earth elements(HREE),and Sr from Y,with La/Yb greater than 15,and high Sr/Y(34― 115).Zircons of andesite YX270 yield three age groups with no Precambrian age,which precludes ori-gin of the Zhangwu HMAs from the partial melting of the Precambrian crust.The oldest age group peaking at 253 Ma is interpreted to represent the collision of the Siberia block and the North China block,resulting in formation of the Central Asian orogenic belt by closure of the Mongol-Okhotsk Ocean.The intermediate age group corresponds to the basalt underplating which caused the wide-spread coeval granitoids in the North China craton with a peak 206Pb/238U age of 172 Ma.The youngest age group gives a 206Pb/238U age of 126±2 Ma,which is interpreted as the eruption age of the Zhangwu HMAs.The high 87Sr/86Sri(126 Ma)>0.706 and low εNd(t)= ?6.36―?13.99 of the Zhangwu HMAs are distinct from slab melts.The common presence of reversely zoned clinopyroxene phenocrysts in the Zhangwu HMAs argues against the origin of the Zhangwu HMAs either from melting of the water saturated mantle or melting of the lower crust.In light of the evidence mentioned above,the envisaged scenario for the formation of the Zhangwu HMAs is related to the basaltic underplating at the base of the crust,which led to the thickening of the lower crust and formation of lower crustal eclogite,followed by foundering of the eclogitic lower crust into the asthenosphere.The foundered eclogite then melted and the resul-tant melts interacted with surrounding peridotite during their upward transport,which finally produced the high-Mg andesites.This well explains the high-Mg adakitic characters and absence of ancient in-herited zircon in the Zhangwu lavas.     

塔河油田海西早期岩溶古水系识别方法及其特征

塔河油田海西早期形成了复杂的碳酸盐岩岩溶缝洞系统,其发育规模在东部地区和西部地区表现出显著的差异性。岩溶水作为岩溶发育的关键因素,在不同地质背景下表现出的水文学特征及水动力作用与岩溶缝洞系统的发育密切相关。为了深入认识和阐述岩溶储层发育机制,基于三维地震资料,通过地震属性技术结合现代岩溶理论成果恢复了塔河油田埋深5 000m以下的古水文网络,精细描述了水系发育特征。研究结果表明:东部地区地表水系统具有较大汇水量,水系以强烈的垂向侵蚀作用为主,发育了完整的地表-地下双重水系型水文网络系统;西部地区地表水以水平溶蚀作用为主,地貌较为平缓,尚未产生大型地下水系网络系统,属于地表水系型水文网络系统。东、西部地区地表、地下水文系统动力学机制的不同,为这2个地区岩溶储层发育的差异性提供了合理解释。     

从构造塌陷的角度解释唐山地震的一些趋势异常现象

构造塌陷,是指构造运动造成的地壳岩层塌陷。根据唐山地震前的跨地震主断裂的水准测量结果,可以认为,伴随1970年5月25日的丰南地震,在主断裂下降盘内出现了大规模的侧向张破裂。这以后出现的地下水位和重力等震前趋势异常,都可以用地下水向破裂区的迁移来解释     

基于Landsat 8 OLI数据与面向对象分类的昆嵛山地区土地覆盖信息提取

利用2015年Landsat 8 OLI遥感影像和DEM作为分类数据源,结合野外调查数据,采用面向对象的分类方法对昆嵛山地区土地覆盖信息进行提取,并对分类结果进行精度评价与比较分析。研究表明：面向对象分类方法提取的各地类连续且边界清晰,分类效果与实际情况基本吻合。昆嵛山地区占主导地位的土地覆盖类型是针叶林,面积为1 546.81 km²。研究区土地覆盖分类的总体精度和Kappa系数分别为91.5%和0.88,其中针叶林、草地、水体和建设用地的生产者精度均达到87%以上。相对于监督分类方法,本研究提出的土地覆盖信息提取方法的总体分类精度和Kappa系数分别提高14.7%和0.17。基于面向对象的中分辨率遥感影像,能够获取较高精度的土地覆盖信息,为大范围土地覆盖分类研究提供方法参考。