Cross-Correlation of Tenerife Data with Galactic Templates-Evidence for Spinning Dust?

The recent discovery of dust-correlated diffuse microwave emission has prompted two rival explanations: free-free emission and spinning dust grains. We present new detections of this component at 10 and 15 GHz by the switched-beam Tenerife experiment. The data show a turnover in the spectrum and thereby support the spinning dust hypothesis. We also present a significant detection of synchrotron radiation at 10 GHz, which is useful for normalizing foreground contamination of cosmic microwave background experiments at high galactic latitudes.     

黑海西南陆架(土耳其)全新世沉积物矿物学及其与物源、海平面和海流状态的关系

岩心中沉积物颗粒大小和矿物成分用来研究不同大陆和海洋环境的影响。在全新世,黑海西南陆架地区都处于这种环境。附近沿海腹地主要沉积类型是硅质碎屑泥质夹少量砂质和砾石。陆架边缘、伊斯坦布尔海峡和杜鲁湖(古河口)沉积物为大量生物成因和陆源砂质和砾石。数量不等的文石、10A-云母、石英、长石、方解石、白云石构成主要的非黏土矿物。<2μm的黏土矿物组合为蒙脱石、伊利石、高岭土、绿泥石。文石和方解石主要来自底栖聚集物,而长石(主要是斜长石)和蒙脱石反映其岩浆和火山物源区。10A-云母和绿泥石的分布与附近的变质岩源区相关。然而…     

南越大陆架基岩中油,气藏的热液成因

在南越大陆架结晶基底的断层附近发现了油饱和花岗岩、这些花岗岩具有特征的热液交代作用和淋滤晕矿物共生组合。自然银、重晶石、含锌、铜和铁的氯化物的存在表明，矿化流体为深部成因。这些热蚀变花岗岩是一种可能的新型油，气储集层，这将会大为拓宽油，气勘探的领域。     

Distribution and ecological relevance of fine sediments in organic-enriched lagoons: the case study of the Cabras lagoon (Sardinia, Italy)

In organic-enriched sedimentary systems, like many Mediterranean coastal lagoons, a detailed analysis of sediment grain size composition and partitioning within the muds is crucial to investigate sedimentological trends related to both hydrodynamic energy and basin morphology. In these systems, sediment dynamics are particularly important because the partitioning and transport of fine sediments can strongly influence the redistribution and accumulation of large amounts of organic matter, and consequently the distribution of benthic assemblages and the trophic status and functioning of a lagoon. Nevertheless, studies on benthic-sediment relationships have been based mainly on a rather coarse analysis of sediment grain size features. In muddy systems, however, this approach may impede a proper evaluation of the relationships and effects of the distribution of fine sediment and organic matter on the biotic benthic components. Here we show that the distribution of sedimentary organic matter (OM) and total organic carbon (TOC) in the Cabras lagoon (Sardinia, Italy) can be explained (i.e., predicted) as a function of a nonlinear increase in the amount of the cohesive fraction of sediments (< or = 8 microm grain size particles) and that this fraction strongly influences the structure, composition and distribution of macrobenthic assemblages. Even in such a homogeneously muddy system, characterized by "naturally" occurring impoverished communities, impaired benthic assemblages were found at < or = 8 microm, OM, TOC contents of about 77%, 11% and 3.5%, respectively. A review of studies conducted in Mediterranean coastal lagoons highlighted a lack of direct integrated analysis of sediment features and the biotic components. We suggest that, especially in organic-enriched coastal lagoons, monitoring programs should primarily investigate and consider the cohesive fraction of sediments in order to allow a better assessment of benthic-sediment relationships and ecological quality of the system.     

Spatiotemporal Differences and Classification Regulation of Urbanization Impact on Agricultural Development in Shrinking Areas: A Case Study of 15 Shrinking Cities in Three Provinces of Northeast China

Studying the impact of urbanization on agricultural development in shrinking areas is important for maintaining food security and promoted agricultural development in China. Based on the measurement results of the shrinking cities in the three provinces of Northeast China, this paper selects 15 shrinking cities as the research object, and constructs a multi-dimensional index system to explore the impact of the urbanization level of the shrinking areas on the agricultural development in the regio...     

Detecting rupture precursors and determining the main fracture spread direction of rock with dynamic rock resistivity change anisotropy

In the past, domestic and abroad scientific workers have done a large number of experiment researches on a great number of researches of experiment for the relationship between electrical resistivity change and the load stress on rock (Geoelectric Testing Group, Department of Geophysics, Peking University and Research Division, Seismological Brigade of Lanzhou, 1978; Zhang, 1981; Chen, et al, 1983; Zhao, et al, 1983; Zhang, Lu, 1983; Zhang, et al, 1985; Brace, Orange, 1968; Kurite, 1986; Teisseyre, 1989), such as imitating dynamic fracture of rock, frictional sliding course, and observing its resistivity change shape with a lot of experimental workssuch as simulating the dynamic course of crustal rocks fracturing and frictional slipping along the fracture surface, and observing its resistivity change shape with experiment. They found that, in the fracture process of rock under loading, not only its resistivity shape change notably, and its direction changes also very clearly, and therefore many scientific workers have shown strong interest in anisotropy of resistivity change, and have done some researches onfor it.     

Simulated Sensitivity of Ozone Generation to Precursors in Beijing during a High O3 Episode

This study uses the WRF-Chem model combined with the empirical kinetic modeling method (EKMA curve) to study the compound pollution event in Beijing that happened in 13-23 May 2017. Sensitivity tests are conducted to analyze ozone sensitivity to its precursors, and to develop emission reduction measures. The results suggest that the model can accurately simulate the compound pollution process of photochemistry and haze. When VOCs and NOx were reduced by the same proportion, the effect of O3 reduction at peak time was more obvious, and the effect during daytime was more significant than at night. The degree of change in ozone was peak time > daytime average. When reducing or increasing the ratio of precursors by 25％ at the same time, the effect of reducing 25％ VOCs on the average ozone concentration reduction was most significant. The degree of change in ozone decreased with increasing altitude, the location of the ozone maximum change shifted westward, and its range narrowed. As the altitude increases, the VOCs-limited zone decreases, VOCs sensitivity decreases, NOx sensitivity increases. The controlled area changed from near-surface VOCs-limited to high-altitude NOx-limited. Upon examining the EKMA curve, we have found that suburban and urban are sensitive to VOCs. The sensitivity tests indicate that when VOCs in suburban are reduced about 60％, the O3-1h concentration could reach the standard, and when VOCs of the urban decreased by about 50％, the O3-1h concentration could reach the standard. Thus, these findings could provide references for the control of compound air pollution in Beijing.     

Time dependent calibration of a sediment extraction scheme

Sediment extraction methods to quantify metal concentration in aquatic sediments usually present limitations in accuracy and reproducibility because metal concentration in the supernatant is controlled to a large extent by the physico-chemical properties of the sediment that result in a complex interplay between the solid and the solution phase. It is suggested here that standardization of sediment extraction methods using pure mineral phases or reference material is futile and instead the extraction processes should be calibrated using site-specific sediments before their application. For calibration, time dependent release of metals should be observed for each leachate to ascertain the appropriate time for a given extraction step. Although such an approach is tedious and time consuming, using iron extraction as an example, it is shown here that apart from quantitative data such an approach provides additional information on factors that play an intricate role in metal dynamics in the environment. Single step ascorbate, HCl, oxalate and dithionite extractions were used for targeting specific iron phases from saltmarsh sediments and their response was observed over time in order to calibrate the extraction times for each extractant later to be used in a sequential extraction. For surficial sediments, an extraction time of 24 h, 1 h, 2 h and 3 h was ascertained for ascorbate, HCl, oxalate and dithionite extractions, respectively. Fluctuations in iron concentration in the supernatant over time were ubiquitous. The adsorption-desorption behavior is possibly controlled by the sediment organic matter, formation or consumption of active exchange sites during extraction and the crystallinity of iron mineral phase present in the sediments.