一个典型的寒武系油藏:塔里木盆地塔中62井油藏成因分析

塔里木盆地志留系沥青砂岩广泛发育,主要原因是来源于寒武系的原油在进入志留系储层后区域性的抬升剥蚀使油藏遭到严重破坏,但到目前为止,究竟是寒武系烃源岩还是中上奥陶统烃源岩或是两者都对现今的志留系沥青砂岩中的有机质有贡献还不清楚.对塔中62井原油的化学组成和油源的分析表明,其甾萜类组成具有寒武系烃源岩的组成特征,反映该油藏原油主要来源于寒武系.另一方面,塔中62井砂岩透镜体被泥岩圈闭,油藏具有较好的保存条件,且后期中上奥陶统生成的烃类难以充注进入油藏.塔中62井志留系油藏破坏作用较弱、保存较好,是塔里木盆地在志留系发现的第一例来源于寒武系的油藏.     

Analytical Model of Roll Vortices in the Convective Boundary Layer

Analytical solutions of convective waves in the convective boundary layer (CBL) were obtained with two-layer linearized atmospheric equations including Rayleigh friction, which represents the turbulent viscosity in the lower CBL. The analytical model shows that the interaction between the convection in the lower layer and gravity waves in the upper layer is one of the causes for the formation of convective bands. The flow and temperature fields obtained by the analytical model present the main characteristics of convective bands found in field observations. We have also investigated the influences of atmospheric conditions on the characteristics of the bands. Results accord with previous knowledge about these phenomena.     

VORTEX MOTIONS IN THE ATMOSPHERIC CONVECTIVE BOUNDARY LAYER

Large vortices with scales ranging from hundreds meters to tens of kilometers are generallyfound in the atmospheric convective boundary layer(CBL).These vortices play important roles in the vertical transport of momentum,heat,water vaporand other tracers in the boundary layer.On the basis of the view of interaction between theconvection in CBL and the gravity waves in the upper stable layer the authors developed aconvection-wave theory on the formation of large vortices.According to the theory thewavenumber spectrum of the large vortices mainly depends on the atmospheric conditions in bothof the upper and lower layers,such as wind speed,wind direction shear,stratification as well astemperature jump.In the present paper satellite image and weather data in a case of cold air outbreak over warmocean are analyzed to study every stage of the convective processes,such as cloud street,convective cell as well as their transformation.According to the theory the wavenumbercompositions for cloud street and convective cell are calculated,respectively,on the basis of theatmospheric conditions at every stage.The distributions of vertical motions,convergent band anddisturbed interface are obtained and compared with the cloud patterns in the convective processes.Thus the study seems to offer a likely explanation for the origin of large vortices in CBL.     

银川市太阳总辐射对气候变化的影响分析

对银川市1961~2004年的实测太阳总辐射资料分析表明,银川市的太阳总辐射40年来呈逐渐减少的趋势。方差分析表明,银川市的太阳总辐射突变点出现在1980年,此前银川处于相对偏多的时段,此后虽然在20世纪80年代后期有一次明显波动,但总体上呈下降趋势,银川处于相对偏少的时段,突变后比突变前平均年总辐射量减少了295.41 MJ/(m2.a)。银川市各月总辐射减少幅度不同,9月减少幅度最大,4月减少幅度最小。日照时数的变化趋势与太阳总辐射的变化趋势一致。分析其对气候的影响可知,银川市总辐射和年平均气温、夏季降水量呈负相关,与年蒸发量呈正相关,呈线性趋势。若总辐射减少100 MJ/(m2.a),年平均气温将升高0.15℃,5~9月降水量将增加6 mm,蒸发量将减少18 mm。     

白天谷地逆温层生消过程的数值模拟

本文用二维数值模式模拟了谷地白天边界层的发展过程.通过求解大气动力.热力学方程组.模拟出了谷地上空的温度场、流场以及在两种不同层结条件下的湍流动能q~2的分布特征.从而对白天谷地上稳定层结(或逆温层)的生消机制进行了初步探讨.模拟出的温度分布廓线等与有关实测资料基本一致.     

乌鲁木齐市SO2浓度的分布及其可能原因

根据乌鲁木齐市 1994～ 1997年 SO2 浓度和气象监测资料 ,分析了 SO2 浓度的时空分布特征及其可能原因 ,并对各监测点 SO2 污染等级作出了评价。     

High-resolution 3-μm spectra of Jupiter: Latitudinal spectral variations influenced by molecules, clouds, and haze

We present latitudinally-resolved high-resolution (R = 37,000) pole-to-pole spectra of Jupiter in various narrow longitudinal ranges, in spectral intervals covering roughly half of the spectral range 2.86-3.53 μm. We have analyzed the data with the aid of synthetic spectra generated from a model jovian atmosphere that included lines of CH₄, CH₃D, NH₃, C₂H₂, C₂H₆, PH₃, and HCN, as well as clouds and haze. Numerous spectral features of many of these molecular species are present and are individually identified for the first time, as are many lines of and a few unidentified spectral features. In both polar regions the 2.86-3.10-μm continuum is more than 10 times weaker than in spectra at lower latitudes, implying that in this wavelength range the single-scattering albedos of polar haze particles are very low. In contrast, the 3.24-3.53 μm the weak polar and equatorial continua are of comparable intensity. We derive vertical distributions of NH₃, C₂H₂ and C₂H₆, and find that the mixing ratios of NH₃ and C₂H₆ show little variation between equatorial and polar regions. However, the mixing ratios of C₂H₂ in the northern and southern polar regions are ∼6 and ∼3 times, respectively, less than those in the equatorial regions. The derived mixing ratio curves of C₂H₂ and C₂H₆ extend up to the 10⁻⁶ bar level, a significantly higher altitude than most previous results in the literature. Further ground-based observations covering other longitudes are needed to test if these mixing ratios are representative values for the equatorial and polar regions.     

Exploring urban commuting imbalance by jobs and gender

Previous findings support that distance matters for job access. Typically, long distances act negatively on job access either due to the lack of information about the opportunities or the cost (time, transportation, etc.). Disparities in job access are explained with the workers’ demographic and socioeconomic characteristics and their spatial condition. Nevertheless, job access was not fully explored in multi-dimensional ways because of data and computational limitations. Recently, the wealth of commuting data, combined with the growing capacity of computation and methodological development, enables us to examine more commuting pattern details than what existing data provide at an aggregate level. This study uses a disaggregate journey-to-work model on 2000 Census Transportation Planning Package (CTPP) commuting data to investigate access to job by gender and occupation, in a more localized context. To explore this varying degree of job access and associated explanation, we analyzed disaggregate commuting flows and ran a regression model on them. This study has three main objectives: (1) to disaggregate journey-to-work flows by gender and occupation to estimate the number of commute trips between census tracts, (2) to explore the variations in job access by gender and occupation, and (3) to draw relationships between job access and various worker’s situations. The results show the details of commuting patterns, suggesting that some occupations have more gender imbalance than others. Further, the findings indicate that the same demographic, socioeconomic and spatial conditions have different effects on workers, and the effect is related to the workers’ demographic-socioeconomic status in complex ways. Unlike conventional research in which a particular worker group is compared to a control group of opposite characteristics, our methodology makes it possible to examine an overview of all the job and gender groups, providing advantages in 2-way comparisons between gender and occupation groups beyond a conventional comparison between two groups. Therefore, our study adds an additional dimension to the conventional comparison.     

石羊河流域中下游地区地下水位动态特征及变化趋势

依据石羊河流域中下游地区64个观测点30年（1978-2007）的地下水位观测资料,定量分析了地下水位的季节性动态特征和多年变化规律及其分布地带,将季节性动态划分为径流、开采、灌溉一开采、蒸发4种类型,多年动态划分为快速下降、缓慢下降和基本稳定3种类型。采用灰色理论建立了所有观测点地下水位的灰色残差修JEGM（1,1）预报模型并进行了预报。预报至2010年,石河河流域中下游地区的地下水位仍将处于不断下降过程,但下降幅度较1978-2007年有所减缓,部分地带地下水位可能趋于稳定。预报结果对于改善流域特别是下游民勤绿洲的生态与环境将起到积极的影响。     

基于概率神经网络的遥感影像分类方法

在对数据进行归一化处理的基础上,将概率神经网络用于遥感影像分类,并探讨样本区的选择和高斯基函数标准差对分类精度的影响。用西藏波密地区1999年的TM遥感影像进行分类试验,并将分类结果和经典的最大似然法进行比较。结果表明：概率神经网络的总体分类精度和Kappa系数分别为94.5%和0.934,取得了较为理想的识别和分类效果。