乌鲁木齐市1955—2007年日照特征变化分析

利用乌鲁木齐市1955—2007年逐月日照时数以及与日照变化相关的≥0．1mm降水日数、雾日数等实测资料,运用一元线性回归、Mann—Kendall等方法分析了乌鲁木齐市日照的变化特征及影响日照减少的可能气象因素。结果发现：乌鲁木齐市日照呈减少趋势,其中秋季日照时数减少比较显著,突变检验的结果表明年日照时数在1976年发生了突变,之后年日照时数逐渐减少。日照时数和≥0．1mm降水日数、雾日数具有很好相关性,说明日照时数减少可能受降水日数、雾日数的影响。     

义乌市降水变化特征分析

根据历史和实测资料的统计分析,得到义乌市的降水变化特征。结果表明：丰水期义乌市的涝年偏多,旱年偏少,而枯水期则旱年偏多,涝年偏少。厄尔尼诺事件的当年或翌年,义乌市的降水显著偏多,而拉尼娜事件的当年或翌年,义乌市的降水则显著偏少。丰水期平均入梅日偏早,平均出梅日偏晚,平均梅雨日数偏长,平均梅雨量偏多,而在枯水期则反之。义乌市6月6—15日入梅的可能性最大,出梅日期的时间分布相对比较分散,其集中期的发生规律不如入梅集中期明显。厄尔尼诺事件的当年或翌年,义乌市的出梅日偏晚,而拉尼娜事件的当年或翌年,义乌市的出梅日偏早。研究结果可为水库源区雨季的人工增雨作业提供科学依据。     

热带太平洋地区风场异常和与El Ni?o有关的年际变化

利用1964～1993年NCEP/NCAR再分析风应力资料和中国科学院大气物理研究所发展的14层热带太平洋环流模式(OGCM),对热带太平洋与El Ni?o有关的年际变化进行了研究.首先,分析了西太平洋暖池次表层海温异常(SOTA)与Ni?o3区海表温度异常(SSTA)的年际变化关系,发现在El Ni?o事件之前,暖池的次表层海温都有明显正异常出现,它的东传导致了El Ni?o的发生,并且SOTA的传播随纬度变化,沿赤道东传,在赤道外西传.然后,选取了20世纪70年代和80年代两次最强的El Ni?o事件讨论了引起这种机制的可能原因--西风异常的作用.最后,对1964～1993所有的El Ni?o年的风场、次表层海温和海表温度的异常进行了综合分析.     

NCEP FNL全球分析资料的解码及其图形显示

美国环境预报中心（NCEP）的FNL资料分辨率较高且融合了大量的观测资料及卫星反演资料,被广泛用于数值模式及天气、气候的诊断分析研究中。本文对该类资料的解码程序及绘图时所需控制文件、索引文件生成方法进行介绍,通过一系列批处理命令,可以进行大量FNL资料的解码及绘图处理,为科研工作者在资料内容提取和图形显示等方面的工作提供一定的参考。     

从钻井测温曲线看地下水流方向及油气储藏条件——以川东南地区丁山1井为例

实测丁山1井测温曲线显示:温度向井底持续升高,井口温度25℃左右,井底温度107.5℃。温度曲线在1 000～3 000 m深度范围内出现"上凸"的扰动现象。现今平均地温梯度纵向上分段明显:三叠系及二叠系地层平均地温梯度为23.94℃/km;志留系和奥陶系地层平均地温梯度较大,为37.27℃/km;寒武系地层平均地温梯度较低,为16.65℃/100m。根据地温梯度分段性特征与地层热导率、地层岩性的相关性分析认为地下流体垂向上升运动造成了温度曲线扰动。进而推断出下奥陶统—中寒武统的地层具有较高的孔隙度和渗透率,而中奥陶统—志留系的地层则具有良好的封堵性,而这种上盖下储的地层组合,对油气成藏较为有利,反映了川东南地区下组合良好的油气储藏条件。     

Morphological patterns of Aptian Lithocodium–Bacinella geobodies: relation to environment and scale

Lithocodium aggregatum and Bacinella irregularis are now extinct, shallow marine life forms of unknown taxonomic origin. Forming part of the tropical platform biota during much of the Mesozoic, these organisms experienced bloom periods and temporarily replaced rudist–coral assemblages during parts of the Early Aptian. Within the limitations of time resolution, this ‘out‐of‐balance’ facies is coeval with the Oceanic Anoxic Event 1a‐related black shale deposition in oceanic basins but the triggering factors remain poorly understood. Here, a platform‐wide comparison of Lithocodium–Bacinella geobodies and morphotypes from the Sultanate of Oman is presented and placed in its environmental, bathymetric and physiographic context. Lithocodium–Bacinella geobodies reach from kilometre‐scale ‘superstructures’ to delicate centimetre‐sized growth forms. Clearly, scale matters and care must be taken when drawing conclusions based on spatially limited observational data. Whilst the factors that cause Lithocodium–Bacinella expansion should probably be considered in a global context, regional to local factors affected growth patterns in a more predictable manner. Here, the unresolved taxonomic relationship remains the main obstacle in any attempt to unravel the response of Lithocodium–Bacinella to specific or interlinked environmental parameters as different organisms respond differently to changing environment. Acknowledging these limitations, the following tentative patterns are observed: (i) Lithocodium–Bacinella tolerated a wide range of hydrodynamic levels and responded to differences in energy level or physiographic settings (margin, intrashelf basin, inner platform) by obtaining characteristic growth forms. (ii) Lithocodium–Bacinella favoured low‐sediment input but had the ability to react to higher sedimentation rates by enhanced upward growth; a feature perhaps pointing to a phototrophic metabolism. Circumstantial evidence for continuous growth within the upper‐sediment column is debated. (iii) The availability of accommodation space had a direct influence on the maximum size of geobodies formed. (iv) Fluctuating nutrient levels and sea water alkalinity may have affected the growth potential of Lithocodium–Bacinella. Understanding the relationship between Lithocodium–Bacinella morphogenesis on a wide range of scales and local environmental parameters allows for better prediction of the spatial distribution of reservoir properties and also results in an improved interpretation of palaeoenvironments. This study might represent a useful first step in this direction.     

黄骅坳陷古近系沙一段下部碳酸盐岩成岩作用

黄骅坳陷古近系沙河街组沙一段下部发育一套厚20～60m的湖相碳酸盐岩,并在生物灰岩、鲕粒灰(云)岩和泥晶白云岩中显示丰富的油气,具有良好的勘探前景。通过对研究区沙一段下部10余口钻井岩心、薄片的宏观及微观观察,结合地球化学特征,对成岩作用类型及特征进行较详细的研究,探讨了成岩作用与储集空间演化的关系。研究发现区内沙一段下部碳酸盐岩的成岩演化过程复杂,各种成岩作用发育,储层质量的好坏受成岩作用影响明显。压实压溶作用、多期方解石和白云石的胶结作用导致粒间孔、生物体腔孔和格架孔大幅度减少;混合水白云石化作用、同生期-准同生期和埋藏期溶解作用是优质储层形成的关键,形成了大量的晶间孔、晶间溶孔、粒内溶孔、铸模孔、生物体腔孔、粒间溶孔和溶蚀缝,成为现今该层段的主要储集空间。     

P/2008 T1 (Boattini): Another comet under transition from Saturn to Jupiter

The newly discovered periodic comet P/2008 T1 (Boattini) is found to have experienced a recent capture into its present orbit, following a close approach to Saturn in 1995 to within 0.17 AU. This orbital change transferred the comet into an orbit tangent to that of Jupiter, which lead to an even closer passage within 0.02 AU with that planet in 2003 decoupling it from the influence of Saturn (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Chang’E-1 gamma ray spectrometer and preliminary radioactive results on the lunar surface

The Chang’E-1(CE-1) spacecraft took a gamma-ray spectrometer (hereafter, CGRS) to detect the element distributions on the lunar surface in a circular, 200 km altitude, polar orbit with approximately 2 h periodicity. CGRS consists of two large CsI(Tl) crystals as the main and anticoincidence detectors. The large CsI crystal of CGRS has a higher detector effective area than other lunar gamma ray spectrometers. For its 1-year mission, gamma ray spectra including many peaks of major elements and trace elements on the lunar surface have been measured by CGRS. Global measurement within 0.55-0.75 MeV is given here to describe the distribution of radioactive composition (e.g., uranium and thorium) on the lunar surface. Although CGRS has a lower energy resolution that cannot separate the uranium peak from others in this energy region, 609 keV uranium gamma ray line dominates the shape of the spectrum in this energy region. Therefore, the radioactive map can indirectly describe the uranium distribution on the lunar surface. The radioactive map shows that the higher radiation is concentrated in the Procellarum KREEP Terrene (PKT) on the nearside with an oval shape. The secondary high-radiation is located in South Pole-Aitken (SPA) basin. Lunar highlands have lower concentration. The relationship between radiation and topography displays different linear correlations for lunar highlands and SPA basin, which imply the different processes for these two regions.