Numerical modeling the role of rubber dams on groundwater recharge and phreatic evaporation loss in riparian zones

Rubber dams have been widely built for their advantages in increase of flooding resources utilization in the north arid and semiarid plain regions of China. Rise in river water stage by the dams, particularly during the drought periods, increases lateral seepage of river water into groundwater, and thus groundwater table and phreatic evaporation loss in the riparian zones. In this study, a riparian area of the Baihe River in Nanyang of Henan Province, China was selected for investigation of influences of the river dams on the groundwater recharge and evaporation loss. A hydraulic model, HEC-RAS, was used for simulation of the river stage variations along the Baihe River, and a numerical groundwater model, MODFLOW, was applied for simulation of groundwater dynamics and estimation of river flow seepage into aquifer and evaporation loss. The results show that the dams increase river stages of 2–3 m during January 2000–December 2002. The increase in the captured groundwater recharge was 7.15–34.06 million m³/a and the increased phreatic evaporation loss occupies 10% of the increased recharge when four rubber dams were built.     

Numerical modeling of the morphological change in Lhok Nga, west Banda Aceh, during the 2004 Indian Ocean tsunami: understanding tsunami deposits using a forward modeling method

A coupled hydrostatic and morph-dynamic model COMCOT-SED was used to investigate the morphological change in Lhok Nga bay during the 2004 Indian Ocean tsunami, and the coupled model predicted the thickness of tsunami deposits in agreement with the measured ones. The relationship between the characteristics of tsunami deposit and flow hydrodynamics was discussed in details. Phenomena such as landward thinning in deposit thickness, landward fining in grain size, and fining upwards in grain size are commonly used to identify tsunami deposits and were examined in this case study. We also discussed the effects of sediment supplies and the constraints that can be put on the earthquake parameters using the information derived from tsunami deposits. This study shows that the model presented in this paper is capable of simulating extreme tsunami events (tsunami wave height ~30?m) in a large domain and that forward models of tsunami sediment transport can be a promising tool to help tsunami geologists understand tsunami deposits.     

农业活动对岩溶作用碳汇的影响:以重庆青木关地下河流域为例

以受农业活动影响强烈的重庆青木关地下河流域为研究对象,利用CTDP300多参数水质自动记录仪、WGZ-1型光电数字水位计、HOBO小型气象站在线自动监测电导率、水位以及降雨等数据,并获取流域耕地面积数据,于2010年分月采集地下水样,分析常规水化学和地下水溶解无机碳δ13C,初步探讨流域农业活动对岩溶作用过程和碳汇的影响,发现农业活动对岩溶作用过程产生明显的影响,进而影响到岩溶地质碳汇。地下水水化学以及地下水δ13CDIC值证实了流域地下水DIC是碳酸、硝酸和硫酸共同溶蚀碳酸盐岩的产物;每月碳酸溶蚀碳酸盐岩产生DIC占地下水中总DIC的比例在55.53%～81.25%之间,雨季(62.98%)普遍低于旱季(74.86%);碳酸溶蚀碳酸盐岩产生的DIC的量为14.67×106mol/a,其中岩溶作用产生的净CO2汇量为7.335×106mol/a,而硝酸和硫酸溶蚀碳酸盐岩产生的DIC总量为7.48×106mol/a,约占地下水中总DIC的33.8%,单位面积耕地上硝酸和硫酸溶蚀碳酸盐岩产生DIC的强度为1.89×106mol/(km2.a)。人类活动引入的硝酸和硫酸参与碳酸盐岩的溶解并改变了区域碳循环。     

Ultrasound‐Assisted Emulsification–Microextraction Combined with Graphite Furnace Atomic Absorption Spectrometry for the Determination of Trace Lead in Water

The ultrasound‐assisted emulsification–microextraction (USAEME) method was combined with graphite furnace atomic absorption spectrometry (GFAAS) for the determination of trace Pb using dithizone (H²DZ) as chelating reagent. Some effective parameters influenced the detection and microextraction, such as ashing temperature and atomization temperature, pH, extraction solvent, sample volume, extraction time, and extraction temperature were selected and optimized. After extraction, the calibration curves for Pb was in the concentration range of 0.1–10 ng mL^?1, and the linear equation was y = 0.097 x + 0.023 (R = 0.99). Under the optimized conditions, the detection limit of the method was 20 pg mL^?1 with an enrichment factor of 70 and the relative standards deviation (RSD) for seven determinations of 1 ng mL^?1 Pb was 11%. The proposed method was successfully applied to determine trace Pb in Yueya Lake water, pond water, and spiked samples. Furthermore, a certified reference material of Environment Water (GBW08607) was analyzed and the determined value was in good agreement with the certified value, which showed the accuracy, recovery, and applicability of the reported method.     

准东博格达山山前带二叠系芦草沟组重油的发育特征及其指示意义

二叠系芦草沟组是准噶尔盆地东部地区最重要的烃源岩层系和勘探目的层系之一。2013年中国地质调查局油气资源调查中心在准噶尔盆地南缘博格达山山前带实施的油页岩调查井JZK1井钻探过程中,发现二叠系芦草沟组重油。通过对JZK1重油和岩心样品有机地球化学的测试数据研究表明:二叠系重油原油演化程度适中,主要赋存于岩石裂缝中,且经历过后期生物降解作用;油源对比指示,原油来自于芦草沟组本身,属自生自储型油藏。据此推测西起乌鲁木齐市雅玛里克山,东至奇台的白杨沟,断续延长136 km,宽2~10 km,分布面积约2×10⁴ km²的芦草沟组均为下步油气勘探的有利区。基于钻井和过井地震测线的解释结果,指出存在推覆体上盘和推覆体下盘两个勘探领域,且推覆体下盘的原生油藏领域埋藏深、规模大,是下步勘探重点领域。     

闪锌矿流体包裹体显微红外测温及其矿床成因意义——以云南会泽超大型富锗银铅锌矿床为例

显微红外测温是利用红外显微镜研究不透明半透明矿物的流体包裹体丰度和分布特征,并与冷热台相结合进行流体包裹体显微测温分析的一种有效的新技术。云南会泽超大型富锗银铅锌矿床是分布于川滇黔接壤区典型的会泽型(HZT)铅锌矿床。本文以该矿床的闪锌矿、方解石流体包裹体为例,应用显微红外测温技术发现闪锌矿中发育大量流体包裹体,按其相态可分为6类:纯气相(V)、富液相气液两相(L+V)、富气相气液两相(L+V)、纯液相(L)、含子矿物三相(L+V+S)、含CO₂三相(L_CO2+L_H2O+V_CO2)包裹体,而在热液方解石中仅发现富液相气液两相(L+V)、纯液相(L)包裹体。闪锌矿中的流体包裹体均一温度集中在2个区间:150~221℃和320~364℃;而盐度变化范围较大,主要集中于3个区间:12.0%~18.0%、5.0%~11.0%、1.1%~5.0%。不同世代闪锌矿流体包裹体均一温度大致反映成矿流体演化的全过程,而方解石流体包裹体均一温度主要反映成矿流体演化的中晚阶段,而且与脉石矿物(方解石)共生的闪锌矿流体包裹体均一温度也高于方解石包裹体均一温度;反映了闪锌矿流体包裹体较方解石更能反映成矿流体的信息,进一步揭示从早成矿阶段到晚成矿阶段,成矿流体大致经历了中高温-中盐度→中低温-中盐度→中低温-中低盐度的演化过程。通过压力校正后的流体包裹体捕获温度反映了早成矿阶段成矿流体呈中高温,进一步证实了该矿床并非低温矿床。通过矿床对比研究,不仅反映了该矿床明显不同于典型的MVT铅锌矿床,而且表明了显微红外测温技术为该类矿床成矿流体p-T-x条件及矿床成因的研究提供了新方法与途径,并将在金属矿床成矿流体的研究领域发挥重要作用。     

Identifying scale-location specific control on vegetation distribution in mountain-hill region

The scale-location specific control on vegetation distribution was investigated through continuous wavelet transforms approaches in subtropical mountain-hill region, Fujian, China. The Normalized Difference Vegetation Index (NDVI) was calculated as an indicator of vegetation greenness using Chinese Environmental Disaster Reduction Satellite images along latitudinal and longitudinal transects. Four scales of variations were identified from the local wavelet spectrum of NDVI, with much stronger wavelet variances observed at larger scales. The characteristic scale of vegetation distribution within mountainous and hilly regions in Southeast China was around 20 km. Significantly strong wavelet coherency was generally examined in regions with very diverse topography, typically characterized as small mountains and hills fractured by rivers and residents. The continuous wavelet based approaches provided valuable insight on the hierarchical structure and its corresponding characteristic scales of ecosystems, which might be applied in defining proper levels in multilevel models and optimal bandwidths in Geographically Weighted Regression.     

Camptotheca acuminata decne residue after camptothecin extract as a substrate to produce mushroom spawn

Currently in China,no technically and economically viable methods exist to handle large quantities of Camptotheca acuminata Decne residue(CA residue) after camptothecin extract while there is a great demand for low cost alternatives to replace the cottonseed hull-based materials used in commercial mushroom culture.Hence,it is of importance for camptothecin extract factories and mushroom producers to explore the utilization of CA residue in mushroom industry.We conducted a research to study how partially or completely substituting traditional mushroom substrate by CA residue would influence the mycelial growth in mushroom spawn production.5 mushroom strains from 4 species were used in the test,i.e.,oyster mushroom(Pleurotus ostreatu) strains,Zayou No.1 and Xide 33,needle mushroom(Flammulina velutipes) strain Chuanjin No.3,hairy wood ear(Auricularia polytricha) strain Huang Er No.10,and shiitake(Lentinula edodes) strain Wuxiang.The nutrient element composition and heavy metal contents of CA residue were determined to ensure its safety and to determine its appropriate component in the substrate formulation for mushroom spawn production.The four substrate formulations(one control-CK,and three treatments,named,T1,T2,T3,) contained 0%,40%,79%,and 100% CA residue,respectively,to allow comparison of the fungal mycelial growth.The control(CK) was the popularly used formulation in Chinese commercial mushroom production,comprising of 73% cottonseed hulls,10% sawdust,15% wheat bran,1% lime,1% white sugar(percentage by weight).All mushroom spawns of the five strains in the four treatments were incubated under the same conditions.The results showed that mycelia of the five mushroom strains grew significantly faster on the substrates containing CA residue than on the substrate with no CA residue(CK).There were no significant differences in the mycelial growth rate among treatments containing CA residue for the two oyster mushrooms and the needle mushroom,but mycelial growth rate in treatments T2 and T3 was significantly higher than in treatment T1 for hairy wood ear and shiitake.The results suggest that CA residue can be used to culture oyster mushroom,needle mushroom,hairy wood ear,and shiitake spawn,and the medium containing CA residue can stimulate their mycelial growth.The commercial production of mushroom spawn using CA residue not only brings better economical benefits including lower cost to mushroom producers,but also reduces environmental pollution by providing a means to reduce dumping and piling of CA residue.     

基于X-CT 技术的韩城示范区煤储层精细描述

X射线层析扫描(X-CT)技术具有无损分析岩石内部结构特征的优点。应用该项技术,重构了韩城示范区煤样内部孔隙、裂隙和矿物的空间分布格架与形态。结果表明,煤样的CT像素频数存在两个峰值区间,分别表征孔隙-裂隙和矿物的发育特征。当孔隙、裂隙发育较好时,该峰左偏;矿物含量较高时,矿物峰右偏或峰值区间变宽。CT孔隙度、矿物含量与CT数有较好的相关性,CT孔隙度与氦气孔隙度显著正相关。通过煤样三维重构的三维表面蒙皮和三维立体模型,可以清楚地识别煤中孔隙、裂隙及矿物的空间形态特征和连通性。     

Does the Amati Relation depend on the Luminosity of the GRB＇s Host Galaxy？

In order to test the systematics of the Amati relation, 24 long-duration GRBs with available Eγ,iso, and Ep are separated into two subgroups according to the B-band luminosity of their host galaxies. The Amati relations in the two subgroups are found to be in agreement with each other within the uncertainties. Taking into account of the well established luminosity-metallicity relation of galaxies, no strong evolution of the Amati relation with the GRB's environmental metallicity is implied in this study.