A Raman spectroscopic study of H/D isotopically substituted hydrous aluminosilicate glasses

We have obtained high quality Raman spectra for two H/D isotopically substituted hydrous aluminosilicate glasses with compositions along the NaAlSi₃O₈-SiO₂ join. Consistent with the results of previous studies, the isotope shift for the band near 900 cm^–1, whose intensity grows with increasing water content, is extremely small: v _h /v _d = 1.004 ± 0.004. The lack of a definite H/D isotope shift for this band does not, however, preclude its association with a vibration of a hydrous species in the glass, because of likely strong coupling between different vibrational modes of hydrated framework species. The 900 cm^–1 band could well be due to a T — OH (T = Si, Al) stretching or bending vibration in the hydrous glass, as required by the presence of a combination band near 4500 cm^–1 in near-infrared spectra.     

中国重要生态保护区域人类干扰时空变化特征分析

构建人类干扰指数,从时间和空间双重角度,评估中国重要生态保护区域人类干扰变化特征。研究表明：① 总体来说,2018年中国重要生态保护区域人类干扰低于全国平均水平,1980―2018年,和全国平均水平相比,中国重要生态保护区域人类干扰增加幅度小、增长趋势慢,定量说明中国重要生态保护区域人类活动整体管控成效好;② 1980―2018年,3类重要生态保护区域（国家级自然保护区、生物多样性优先区、重点生态功能区）人类干扰指数均呈逐步增加趋势。以“胡焕庸线”为界,重要生态保护区域以西、以北人类干扰总体较小,增加相对缓慢;以东、以南人类干扰相对明显,增加也相对明显,今后对这些区域要重点加强管控;③ 国家级自然保护区人类干扰指数在5个监测年份均最低,增加趋势最平缓、增幅最小,人类活动实际管控成效最好;重点生态功能区和生物多样性优先区人类干扰相对较大,管控成效有待显现,结果反映中国对重要生态保护区域分类管控力度和梯度的差异;④ 重要生态保护区域内部人类干扰指数及增幅均低于外部未受保护区域,构建重要生态保护区域有效降低人类干扰。     

红树林单宁的研究进展

植物单宁(vegetable tannin)，又称植物多酚(plant polyphenol)是一类广泛存在于植物体内的多元酚化合物，在维管植物中的含量仅次于纤维素、半纤维素和木质素，主要存在于植物的皮、根、叶、果中，含量可达20％。作为皮革的一种传统鞣剂，单宁一般指的是相对分子质量为500～3000的多酚。Haslam提出了植物多酚这一术语，它包括了单宁及相关化合物(如单宁的前体化合物和单宁的聚合物)。根据化学结构的不同，     

A comparison of the photospheric and interplanetary magnetic fields during the flight of Mariner IV

The polarity of the interplanetary magnetic field observed by the Mariner IV spacecraft is compared to the polarity of the photospheric magnetic field observed with the solar magnetograph at Mt. Wilson Observatory. Unlike the results obtained from observations during the flight of IMP-I, these polarities are not well correlated when the photospheric polarity is determined from data along a narrow latitudinal strip. It is suggested that the structure of the interplanetary field is often related to major features in the photospheric field that are observed over a broad range of solar latitudes.     

Modelling atmospheric and hydrologic processes for assessment of meadow restoration impact on flow and sediment in a sparsely gauged California watershed

The restoration of meadowland using the pond and plug technique of gully elimination was performed in a 9‐mile segment along Last Chance Creek, Feather River Basin, California, in order to rehabilitate floodplain functions such as mitigating floods, retaining groundwater, and reducing sediment yield associated with bank erosion and to significantly alter the hydrologic regime. However, because the atmospheric and hydrological conditions have evolved over the restoration period, it was difficult to obtain a comprehensible evaluation of the impact of restoration activities by means of field measurements. In this paper, a new use of physically based models for environmental assessment is described. The atmospheric conditions over the sparsely gauged Last Chance Creek watershed (which does not have any precipitation or weather stations) during the combined historical critical dry and wet period (1982–1993) were reconstructed over the whole watershed using the atmospheric fifth‐generation mesoscale model driven with the US National Center for Atmospheric Research and US National Center for Environmental Prediction reanalysis data. Using the downscaled atmospheric data as its input, the watershed environmental hydrology (WEHY) model was applied to this watershed. All physical parameters of the WEHY model were derived from the existing geographic information system and satellite‐driven data sets. By comparing the prerestoration and postrestoration simulation results under the identical atmospheric conditions, a more complete environmental assessment of the restoration project was made. Model results indicate that the flood peak may be reduced by 10–20% during the wet year and the baseflow may be enhanced by 10–20% during the following dry seasons (summer to fall) in the postrestoration condition. The model results also showed that the hydrologic impact of the land management associated with the restoration mitigates bank erosion and sediment discharge during winter storm events. Copyright © 2013 John Wiley & Sons, Ltd.     

秦岭—大别东段应力状态研究

本文首先通过Snoke发展的利用P波、 SV波和SH波的初动和振幅比方法计算秦岭—大别东段2008年以来83次M_L≥2.5地震的震源机制解, 然后通过FMSI方法反演得到平均应力场的方向特征: 近东西向的水平挤压和近南北向的水平拉张作用, 与参数统计结果一致; 进而通过震源机制的一致性参数分析应力场方向的变化信息。 分析表明震源机制解呈现了由变化紊乱、 偏离平均应力场到变化一致、 趋于平均应力场再到变化紊乱、 偏离平均应力场的变化过程, 在显著地震前, 研究区整体的震源机制一致性参数处于持续低值状态; 计算了2008年以来93次M_L≥2.5地震的视应力, 拟合视应力与震级的关系, 分析扣除震级影响的差视应力随时间变化特征, 近似反映研究区应力大小的变化。 分析表明显著地震前研究区的差视应力值呈现出明显的先上升后下降的变化过程, 在下降过程中发生地震; 最后利用震源机制一致性参数和差视应力综合分析研究区的应力状态, 均表明显著地震前震源区的构造应力场增强。 目前研究区的震源机制一致性参数较高、 差视应力较低, 研究区的应力水平较低。     

The geometry and petrogenesis of hydrothermal dolomites at Navan, Ireland

The dolomites at Navan, Ireland, formed in Courceyan peritidal and shallow-shelf limestones. The dolomite body has a plume-like geometry, cross-cutting both lithological boundaries and diagenetic barriers generated by sea-floor cementation and emergence. The dolomitizing fluids rose parallel to major faults to diffuse laterally through the succession, controlled by variations in permeability that reflect both facies variation on deposition and pre-dolomitization diagenesis. Cathodoluminescent zones reveal three principal stages of dolomite emplacement, separated by dissolution surfaces, with each stage reflecting several changes in the character of dolomitizing solutions. The predominance of dull zones indicates burial rather than surface conditions. The dolomites formed some time after burial in response to an areally limited hydrothermally-driven flow. Isotope values (σ¹⁸O of — 6σ6 to — 10.4%_δ and σ¹³C of — 0σ2 to +2σ5%_δ PDB), and fluid inclusion data, suggest that these fluids had compositions similar to those of Carboniferous seawater. However, these became hotter with time, with temperature increasing from 60 to 160δC. The Navan dolomites are closely associated with Europe's largest zinc-lead deposit. The distribution of the ores follows the same trend as that of the dolomites and paragenetic relationships indicate that dolomitization and mineralization were temporally and genetically related.     

The co-production of land use and livelihoods change: Implications for development interventions

In a previous paper [McCusker, B., Carr, E.R., 2006. The co-production of livelihoods and land use change: Case studies from South Africa and Ghana. Geoforum 37 (5), 790–804], we argued that land use and livelihoods could best be understood as co-produced, where land use and livelihoods are not separate objects of knowledge related to one another through abstract processes, but different manifestations of social processes through which individuals and groups come to understand the challenges facing their everyday lives, the various resources available to them to negotiate these challenges, and the strategies by which they can conduct that negotiation. In this paper, we examine the theoretical basis for “co-production” with the goal of using this approach to inform development interventions.     

白银厂的火山碎悄岩岩石学与古海相火山作用

应用古火山地质学和岩石地球化学对白银厂中酸性火山穹隆内的凝灰岩、昌屑凝灰岩、中酸性枕状、绳状熔岩和具有特殊构造的补丁岩等火山碎屑碉进行了较快速度沉降并堆积成岩,产于火山喷口附近。海底成矿热液蚀变作用使其ＳｉＯ２、ＦｅＯ、ＭｇＯ、ＣＯ２等化学成分发生变化。凝灰质千枚岩则是细火山灰在海吕中经缓慢的沉降后形成于远离火山口的火山斜坡上的火山－沉积变质岩。根据“０补丁”的成分可将补丁岩分为两种类型：绿泥石质