Penetration Depth of Torpedo Anchor in Two-Layered Cohesive Soil Bed by Free Fall

The penetration depth of torpedo anchor in two-layered soil bed was experimentally investigated. A total of 177 experimental data were obtained in laboratory by varying the undrained shear strength of the two-layered soil and the thickness of the top soil layer. The geometric parameters of the anchor and the soil properties (the liquid limit, plastic limit, specific gravity, undrained shear strength, density, and water content) were measured. Based on the energy analysis and present test data, an empirical formula to predict the penetration depth of torpedo anchor in two-layered soil bed was proposed. The proposed formula was extensively validated by laboratory and field data of previous researchers. The results were in good agreement with those obtained for two-layered and single-layered soil bed. Finally, a sensitivity analysis on the parameters in the formula was performed.     

Unconventional geometric phase gate and multiqubit entanglement for hot ions with a frequency-modulated field

We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and preparing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all ions. Selecting the index of modulation yields selective mechanisms for coupling and decoupling between the internal and the external states of the ions. By the selective mechanisms, we obtain the unconventional geometric two-qubit phase gate, multiparticle Greenberger--Horne--Zeilinger states and highly entangled cluster states. Our scheme is insensitive to the thermal motion of the ions.     

Early Cretaceous Metasomatized Lithospheric Mantle beneath the Central Jiangnan Orogen in South China: Geochemical and Sr-Nd Isotope Evidence from the Tuanshanbei Dolerite

It is well established that Cretaceous magmatism in the South China Block (SCB) is related to the Paleo-Pacific subduction. However, the starting time and the associated deep crust-mantle processes are still debatable. Mafic dike swarms carry important information on the deep earth (including mantle) geodynamics and geochemical evolution. In the Jiangnan Orogen (South China), there is no information on whether the Mesozoic magmatic activities in this region are also directly related to the Pacific subduction or not. In this study, we present detailed zircon U-Pb geochronological, whole-rock element and Sr-Nd isotope data for Early Cretaceous Tuanshanbei dolerite dikes, and provide new constraints on the condition of the lithospheric mantle and mantle dynamics of the SCB during that time. LA-ICP-MS zircon U-Pb dating suggests that this dolerite erupted in the Early Cretaceous (~145 Ma). All samples have alkaline geochemical affinities with K2O + Na2O = 3.11–4.04 wt%, K2O/Na2O = 0.50–0.72, and Mg# = 62.24–65.13. They are enriched in LILE but depleted in HFSE with higher initial 87Sr/86Sr ratio (0.706896–0.714743) and lower εNd(t) (?2.61 to ?1.67). They have high Nb/U, Nb/La, La/Sm and Rb/Sr, and low La/Nb, La/Ta, Ce/Pb, Ba/Rb, Tb/Yb and Gd/Yb ratios. Such geochemical signatures suggest that the fractional crystallization is obvious but crustal contamination play a negligible role during magmatic evolution. Tuanshanbei dolerite were most likely derived from low-degree (2%–5%) partial melting of a phlogopite-bearing mantle material consisted of ~85% spinel peridotite and ~15% garnet peridotite previously metasomatized by asthenosphere-derived fluids/melts with minor subduction-derived fluids/melts. Slab-rollback generally lead to the upwelling of the hot asthenosphere. The upwelling of asthenosphere consuming the lithospheric mantle by thermo-mechanical-chemical erosion. The lithospheric mantle may have partially melted due to the heating by the upwelling asthenosphere and lithospheric extension. It is inferred that the Tuanshanbei dolerite might be associated with the initial slab rollback and corresponding lithospheric extension occurred potentially at ca. 145 Ma.     

1958-2017年太湖蒸发量年际变化趋势及主控因子

湖泊蒸发对气候变化非常敏感,是水文循环响应气候变化的指示因子,因此研究湖泊蒸发的控制因素,对于理解区域水文循环有重要意义.本文利用太湖中尺度涡度通量网避风港站观测数据校正JRA-55再分析资料,驱动CLM4.0-LISSS模型,并利用2012-2017年涡度相关通量数据和湖表面温度数据检验模型模拟蒸发结果,验证了该模型在太湖的适用性;估算了1958-2017年间太湖的湖面蒸发量,并利用Manner-Kendall趋势检验分析了湖面蒸发的变化趋势,寻找太湖实际蒸发的年际变化的主控因子.结果如下:校正后的JRA-55再分析资料模拟的太湖蒸发与观测值之间存在季节偏差,但是季节偏差在年尺度上相互抵消,再分析资料可用于年际尺度太湖蒸发变化的模拟;1958-2017年间太湖蒸发量以1977年为界,先下降(-3.6 mm/a),后增加(2.3 mm/a);多元逐步回归结果表明,向下的短波辐射是太湖1958-2017年间太湖蒸发变化的主控因子,向下的长波辐射、气温、比湿也对湖泊蒸发年际变化有一定影响,但是风速对蒸发量的年际变化影响不大.     

空间GPS无线电掩星反演大气参数方法及其应用

给出了空间无线电掩星反演大气参数的原理及其误差估计方法,介绍了国内外在该领域的研究进展。并针对该技术的一些特点,指出了若干尚需解决的问题。     

利用小半径粉晶相机测定钙镁碳酸盐矿物的含镁量

白云石和方解石是分布很普遍的造岩矿物,尤其在沉积地层中更属常见。镁方解石是现代碳酸盐沉积物和某些海洋生物介壳的一种常见矿物。一般说来,区分白云石与方解石是比较容易做到的。但是,要确切地回答一块白云岩样品是由典型的白云石(Ca/Mg克分子比值接近于1)还是由富钙白云石矿物(Ca/Mg克分子比值大于1)构成的,则比较困难。     

岩溶地下水集中开采区水质系统预测研究

在岩溶地区，地下水的超强度开采与工业“三废”及生活废弃物不合理的排放，造成了地下水较严重的污染。用动态系统方法建立的地下水污染时间序列递推预测模型，在岩溶地下水环境质量预测与管理方面都具有指导意义。     

华北地区早更新世生物-气候事件--以哺乳动物化石为例

讨论了华北地区几个早析世洞穴地点哺乳动物群的生态环境、气候变迁和动物迁移。龙牙洞、第１８地点、贾家山以及东洞动物群都是喜冷型动物群,反映的气候干冷或干凉,植被为稀树草原、森林－草原或干冷草原。在气候方面,它们可与黄土层堆积时气候对比。第１２地点显示炎热湿润气候,东洋界动物向北迁移,森林茂密,是我国北方一次重要的温暖事件,相当黄土剖面中的古土壤层（Ｓ２４－Ｓ２５）的气候。第９地点和西洞动物群批示气候     

高活性粉煤灰注浆材料在实际工程中的应用

高活性粉煤灰是一种新型注浆材料,本文结合工程实际,系统介绍了高活性粉煤灰作为注浆材料的性能,并与水泥浆材料进行了多方面的应用比较。得出了高活性粉煤灰的成本低、渗透性好等优点,值得推广应用。     

模糊聚类分析在岩溶水化学分类中的应用

模糊聚类分析方法是一种用样本之间的相似程度来代替某种单一传统分类指标的较新分类法。本文利用天津蓟县地区岩溶水系统的３９个代表性水点及１０个指标构成的样本集,进行了水化学模糊聚类分析。结果表明该方法比传统的一些分类方法更能系统地、全面地反映地下水的各种属性,对确定水点的地球化学环境、系统边界的性质及含水层之间的水力联系有实际意义,是一种理论上合理、应用上灵活的有效分类法。