红红火火过大年

玉兔呈祥春来早,红红火火过大年。看,在都市,在乡村,在中州大地的各个地方,到处都是欢乐的人流,到处是爽朗的笑声。就让这一组组珍贵的的镜头,留住这些幸福快乐的瞬间吧!     

论制冷系统冷凝器管道设计

制冷系统冷凝器的任务是将压缩机排出的高温过热蒸汽给予冷却、冷凝，也就是使过热蒸汽流经冷凝器的放热面而凝结为高压液体，所放出的热量就被冷却介质吸收后排至周围环境中，同时为了保证冷凝器液体能及时排出，以免制冷剂液体在冷凝器内占据一定的容积，相应的减少冷凝器的放热面积，而使冷凝压力升高，影响制冷效能。因此，在冷凝器后，还设置一个贮液器，     

浅析过钻头测井面临的挑战及应对策略

本文研究了时下热门的过钻头测井技术。过钻头测井技术是21世纪以来新兴的测井方式,不同于以往的电缆测井和随钻测井。过钻头测井主要是在水平井、大斜度井段实施测量,自该技术开发以来,解决了多种技术难题。同时,过钻头测井技术也暴露出各种问题,主要就体现在(1)抗温抗压性能;(2)垂向分辨率和测量精度;(3)测量项目。本文着重介绍了这三个方面的认识与看法,提出了一些解决方案,并简要叙述了过钻头测井技术的发展方向。     

辽东三家子地区晚侏罗世花岗岩SHRIMP U-Pb年龄、Hf同位素特征及地质意义

辽东岫岩三家子矿化集中区位于青城子矿化集中区以西三家子一带,属于青城子矿化带西延部分。矿区内发育以洼岭二长花岗岩为代表的晚侏罗世侵入岩,应与本地区矿化作用有密切的关系。岩体锆石SHRIMP U-Pb年龄加权平均值为162.4±1.9Ma,代表岩浆结晶年龄,应为燕山期岩浆活动产物,是华北东部侏罗世花岗岩的一部分。全岩岩石化学分析结果显示,洼岭二长花岗岩为高钾钙碱性岩浆系列,其中SiO2(72.28%~75.61%)≥56%,Al2O3(14.37%~15.06%)≥15%(极少数低于此值),MgO小于3%制,A/CNK值1.035~1.083,均大于1,具有铝过饱和型特征。微量元素数据显示亏损重稀土元素,(La/Yb)N为18.06~22.66,Eu无负异常。具有高Sr(497×10-6~574×10-6),低Y(4.56×10-6~5.61×10-6)和Yb(0.47×10-6~0.62×10-6)特征,表现为具有埃达克质亲和性的I型花岗岩。岩体εHf(0)为负值,εHf(t)为负值(-28.9~-17.5),说明洼岭岩体形成时壳源物质成分占主导地位,单阶段Hf模式年龄(TDM)平均为1714Ma,两阶段Hf模式年龄(TDMC)平均为3704Ma。综上,洼岭岩体可能形成于从中侏罗世(160Ma)开始的多板块向东亚汇聚的构造背景,可能为加厚下地壳熔融的产物,同时是埃达克岩与铜成矿有密切关系的又一佐证。     

龙门山推覆构造带新生代热演化历史研究及其对青藏高原东缘隆升机制的约束

龙门山作为青藏高原的东边界,是一个从青藏高原到四川盆地的陡直的过渡地带,其新生代的造山运动受到约50 Ma年前印度板块和欧亚板块碰撞的影响.2008汶川地震及其后续的研究证明了其晚更新世以来的活跃性,但是对于龙门山推覆构造带及其邻近地区的新生代的演化过程的认识还较缺乏.     

http://www.sciencedirect.com/science/article/pii/S167498711200148X

The Earth was born from a giant impact at 4.56 Ga. It is generally thought that the Earth subsequently cooled, and hence shrunk, over geologic time. However, if the Earth's convection was double-layered, there must have been a peak of expansion during uni-directional cooling. We computed the expansion-contraction effect using first principles mineral physics data. The result shows a radius about 120 km larger than that of the present Earth immediately after the consolidation of the magma-ocean on the surface, and subsequent shrinkage of about 110 km in radius within about 10 m.y., followed by gradual expansion of 11 km in radius due to radiogenic heating in the lower mantle in spite of cooling in the upper mantle in the Archean. This was due to double-layered convection in the Archean with final collapse of overturn with contraction of about 8 km in radius, presumably by the end of the Archean. Since then, the Earth has gradually cooled down to reduce its radius by around 12 km. Geologic evidence supports the late Archean mantle overturn ca. 2.6 Ga, such as the global distribution of super-liquidus flood basalts on nearly all cratonic fragments (>35 examples). If our inference is correct, the surface environment of the Earth must have undergone extensive volcanism and emergence of local landmasses, because of the thin ocean cover (3–5 km thickness). Global unconformity appeared in cratonic fragments with stromatolite back to 2.9 Ga with a peak at 2.6 Ga. The global magmatism brought extensive crustal melting to yield explosive felsic volcanism to transport volcanic ash into the stratosphere during the catastrophic mantle overturn. This event seems to be recorded by sulfur mass-independent fractionation (SMIF) at 2.6 Ga. During the mantle overturn, a number of mantle plumes penetrated into the upper mantle and caused local upward doming of by ca. 2–3 km which raised local landmasses above sea-level. The consequent increase of atmospheric oxygen enabled life evolution from prokaryotes to eukaryotes by 2.1 Ga, or even earlier in the Earth history.     

新闻速递

发现首颗地球大小岩质外星行星 一个天文学家团队在太阳系之外首次发现了一颗有着与地球类似岩质成分且大小与地球相当的行星。这颗行星被称为开普勒-78b,绕其宿主恒星公转的周期约为8．5小时。这使得其温度过高,无法承载生命。     

太阳耀斑光谱诊断和辐射动力学过程研究

太阳耀斑是太阳大气中最为剧烈的活动现象之一,涉及到很多复杂的物理过程,包括快速的能量释放、等离子体的不稳定性、高能粒子的加速和传播、耀斑大气辐射和动力学变化、物质的运动和抛射现象等.     

月球车图像超分辨率重建算法

为了更好地满足嫦娥探月工程二期中月球车导航和探测规划任务对图像数据的要求,提出了一种基于压缩感知的超分辨率图像重建方法,利用经过模糊处理并加入噪声的低分辨率图像重建原始的高分辨率图像,实现了月球车图像的超分辨率重建。算法采用局部Sparse-Land模型,从美国阿波罗计划获取的月面图像、嫦娥二期工程实验中获取的图像以及随机选取的自然图像中提取了大量训练图块,采用K-SVD算法完成了高、低分辨率过完备字典Ah和Al的学习,在对待重建图像进行有效分割的基础上,通过求解优化问题获得待处理低分辨率图块的稀疏表示,并将表示系数用于Ah以生成对应的高分辨率图块。最后,运用最小二乘算法,得到满足重构约束的高分辨率图像。实验结果表明,此算法在视觉效果及PSNR指标上均优于插值方法和Yang的方法。