准噶尔盆地中部永进地区走滑断裂发育特征及成因物理模拟

永进地区位于准噶尔盆地中部,最近发现了多个与走滑断层相关的含油气构造,但关于走滑断层的发育特征及成因机制研究程度不够深入。本文通过三维地震资料精细解释,在研究区三叠系—侏罗系内识别出近东西向、北西西向以及北东东向的三组走滑断裂体系,平面上呈“网格状”展布,剖面上具有不同深度几何学形态差异展布特征。在此基础上基于相似性原理设计四组砂箱模拟对比实验,重现研究区构造演化过程。模拟结果表明,这类走滑断裂的形成与基底先存断层的发育位置有关,是受先存构造和地层属性双重控制的广布式走滑断裂系统,从而建立了研究区的断裂系统成因模式。研究成果对具有相似地质背景地区的走滑断裂成因解释具有借鉴意义。     

辽宁省霾天气季节变化特征及其主导因子分析

利用辽宁省51个地面气象观测站的能见度、均一化相对湿度和天气现象资料,采用最优距离法和固定比例法对能见度资料进行一致性处理,重建了1961—2020年的辽宁省逐日霾资料,并利用该资料对辽宁省年和四季霾日时空变化特征和主导因子进行分析。结果表明,1961—2020年辽宁省平均年霾日呈显著增加趋势[2.1 d·(10 a)^-1],但2015年以来霾日显著减少;空间上,年和四季霾日呈现一致的分布特征,均存在1个高值中心(沈阳)和2个副高值中心(北票和锦州),年平均霾日分别为139、52、46 d,辽东和辽西山区为霾日低发区,年平均霾日在20 d以内。风向和风速是霾日形成的重要气象因子,西南偏南风增加带来的暖湿气流对春季、夏季和秋季霾日的形成贡献较大,北风的减少则对冬季霾日的形成贡献较大。霾发生时辽宁省春季、夏季和秋季发生西南偏南风的频率分别由11.4%、12.1%和8.0%增加至15.8%、19.8%和13.5%,冬季则表现为北风发生频率的减少和静风发生频率的增加;霾发生时四季风速均较平均状况偏小,说明小风有利于霾的形成。辽宁省霾长期演变受到污染物排放、风力因子和环境政...     

高速铁路和城市蔓延对雾霾污染的异质性影响

为了探寻高铁开通能否抑制雾霾污染以及这种抑制作用在不同城市空间形态下是否存在异质性,本文首先分析了高铁和城市蔓延对雾霾污染的作用机制,在利用LandScan数据测算2003-2016年中国281个地级市城市蔓延指标的基础上,采用动态空间面板模型检验了城市蔓延与雾霾污染的空间动态关系.借助双重差分(DID)模型验证了高铁...     

NOAA WP-3D instrumentation and flight operations on AGASP-II

The second Arctic Gas and Aerosol Sampling Program (AGASP-II) was conducted across the non-Soviet Arctic in March and April 1986, to study the aerosol, gaseous, chemical, and optical properties of Arctic haze. One component of the program was supported with an instrumented NOAA WP-3D atmospheric research aircraft. Measurements of wind, temperature, ozone, water vapor, condensation nucleus concentration, and aerosol scattering extinction coefficient were used to determine the locations and properties of haze layers. The first three NOAA WP-3D research flights were conducted north of Barrow, Alaska, and over the Beaufort Sea northeast of Barter Island, Alaska. The next three sampled conditions in the high Arctic near Alert, Northwest Territories, Canada. All basic meteorological, gas, and aerosol systems are described. The WP-3D flight tracks and operations are presented.     

Arctic hazes in summer over Greenland and the North American Arctic: II. Nature and concentrations of accumulation-mode and giant particles

Airborne measurements made during August 1985 over Greenland and its environs show that both accumulation-mode (0.1 m D2.0 m) and giant (D2 m) particles were present in relatively high concentrations in arctic haze layers and that the accumulation-mode particles dominated light scattering. Particles with diameters (D) between 1 and 4 m consisted predominately of mixed materials, small and dense inclusions, and probably organic compounds containing sulfur. Many of the particles from 0.1 to 1 m in diameter were also of mixed composition, with sulfuric acid, ammonium sulfate and organics probably the dominant constituents.     

Comparison of taxon calibrations,modern analogue techniques,and forest-stand simulation models for the quantitative reconstruction of past vegetation: A critique

Taxon calibrations based on eastern North America or on the southeastern United States alone suggest a different forest composition from that based on Wisconsin/Michigan, which is argued as preferable. Questions are raised about how well comparison with modern analogues distinguishes forest characteristics. The simulation model used by Delcourt and Delcourt is thought to be inappropriate, partly because it is constrained by faulty climatic data. Models are seen as complementary to other techniques rather than as an alternative methodology.     

利用铀矿床进行天然类似物研究

天然类似物研究是国际上新兴起的一门边缘科学。本文结合我国实际情况，综述研究的意义以及我国开展这项研究的有利条件、课题优选和具体开发内容。     

1980～～2014年中国中东部持续性霾天气的多尺度变化特征

对1980～2014年中国中东部地区324个台站的持续性霾天气的时空变化和相关气象影响因子进行分析，结果表明:中东部地区年平均持续性霾事件和其在所有霾事件的贡献比例逐年增加，增长率分别为0.79 (10 a)-1和2.7% (10 a)-1。主要表现为3个大值区:华北平原地区（包括山西省、京津冀地区）、长江三角洲和四川盆地东部，增加最显著的区域位于黄淮地区，增长率分别为6.3 (10 a)-1、13.95 d (10 a)-1。1月是持续性霾事件的高发月，月均2.56 d。夏季和秋季持续性霾事件增加最为明显，增长率分别为0.38 (10 a)-1和0.46 (10 a)-1。不利的气象条件，如静风日数的增加，风速和大风日数的减少，以及不利的环流形势，如东亚冬季风的减弱，都可能造成持续性霾天气的增加和异常维持。     

North-south transfer zones and paleo-morphological reconstruction of the Xylokastro area (Corinth Gulf, Greece)

A large number of studies have documented the structural and sedimentary architecture of the Corinth Gulf, especially the major E–W trending normal faults important in accommodating the main extensional strain and associated growth of the Gilbert fan deltas. However, the role of several N–S oriented structures that crop out at the surface and are detectable at depth by seismic reflection and gravity surveys are not clearly understood. Based on new geological data, collected near Xylokastro, we describe the N–S oriented tectonic activity of this area. The mapped inland faults correspond to off-shore structures identified in re-interpreted seismic lines and appear to have acted as a major transfer zone during the opening of the Corinth Gulf. Reconstruction of the paleo-topography based on sedimentary facies and the environment of clay mineral formation suggest these transfer zones played an important role in controlling both local structural relief and depositional conditions of the Gilbert fan deltas.     

Effect of Atmospheric Haze on the Deterioration of Visibility over the Pearl River Delta

The studies on the effect of atmospheric aerosol on climate and environment are hot issues in the current circle of international science and technology. In recent years the pollution of aerosol is getting worse and worse over the Pearl River Delta. The clouds of aerosol occur all year round, with heavy pollution area located at the western side at the mouth of Pearl River. The haze weather mainly occurs from October to April next year, resulting in visibility deterioration. From the beginning of 1980s, visibility dramatically deteriorated, obviously increasing haze weather, in which there are three big fluctuations, showing the periods of pollutions of dust, sulphate and dust, fine particle from photochemical process and sulphate and dust accompanying with the development of economy respectively. The long-term tendency of visibility caused by fog and light fog does not show a tendency due to human activities or economic development, which mainly shows the interannual and interdecadal variation of climate. The deterioration of visibility has close relation to the fine particles over Pearl River Delta, with half of PM10 overpass the limited value set by national second graded standard (150μg m-3), meanwhile, all values of PM2.5 overpass the day-mean limited value of American national standard (65μg m-3), especially from October to January next year, monthly mean values of PM2.5 almost reach two times of standard value, indicating the fine particle concentration is very high. The ratio of PM2.5 to PM10 is also very high, reaching 58%-77%, higher especially in dry season than in rainy season. Thus it is the fine particle pollution in aerosol pollution over the Pearl River Delta. Compared with the data of 15 years ago, the ratio of fine particle to aerosol has obviously increased.