安阳南断裂带土壤H2、Rn地球化学特征

为研究安阳南断裂带土壤气体地球化学特征及构造地球化学背景,采用野外流动测量的方法对安阳南断裂带宗村段开展2期土壤H₂和Rn的重复观测。结果表明,第1期H₂和Rn的浓度范围分别为（0.66~58.56）×10^-6 和15~123 kBq/m³,背景值分别为6.87×10^-6和52.49 kBq/m³;第2期H₂和Rn的浓度范围分别为（0.36~29.73）×10^-6和28.2~103 kBq/m³,背景值分别为0.89×10^-6和47.49 kBq/m³。2期H2和Rn的测量结果均显示,在距测量起点210~300 m处气体浓度出现高值异常,气体在断裂带附近较为富集,对断层位置有一定的指示作用,利用断层气H2和Rn探测隐伏断裂的浅层位置在该区具有可行性。     

温州双溪-焦溪垟断裂土壤Rn和H2地球化学特征

利用断层土壤气探测方法,在珊溪水库地区双溪-焦溪垟断裂上3个不同位置进行土壤Rn和H2的测量,发现断裂带上的土壤Rn和H2测值在靠近断层破碎带或岩脉出露位置明显升高。结合断层气探测方法在探测隐伏断裂方面的应用,确定双溪-焦溪垟断裂在包山垟村附近具体经过位置。发震断裂上的土壤Rn和H2测值明显高于非发震断裂,说明珊溪水库地区土壤Rn和H2与地震活动性关系密切。     

基于遥感数据和XGBoost算法的31个城市NO2、CO2浓度比率变化特征

研究城市二氧化氮(NO₂)与二氧化碳(CO₂)的共同排放水平对于实现城市减污降碳协同增效具有重要意义。NO₂与CO₂的人为排放具有同源性,二者的浓度比率可以体现城市的大气污染物和碳排放综合水平。基于XGBoost算法,利用对流层星载监测仪(TROPOMI)、轨道碳观测2号(OCO-2)和3号(OCO-3)卫星的遥感数据以及相关环境协变量,重构全国2019～2020年NO₂垂直柱浓度(X_NO2)和CO₂垂直柱浓度(X_CO2)的高分辨率数据集,并分析31个城市的X_NO2年均值与ΔX_CO2(X_CO2观测值与背景值之差)的比率(X_NO2/ΔX_CO2)变化情况。结...     

砂岩含水层CO2封存中考虑盐沉淀反馈作用的数值模拟:以鄂尔多斯盆地为例

盐沉淀是含水层CO₂封存中需要关注的问题。当前,大多数数值模拟没有考虑盐沉淀引起的地层孔隙度和渗透率变化对流体流动的反馈作用。以鄂尔多斯盆地刘家沟组地层为例,利用TOUGH2软件建立了一个二维模型。通过修改程序源代码,使得模型能考虑盐沉淀对流体流动的反馈作用。模拟结果表明,刘家沟组地层在CO₂注入20 a时,盐沉淀的反馈作用使得注入井附近地层压力提升达到了0.87MPa,储层注入性损失7.17%。地层水盐度对盐沉淀及其反馈作用的影响最大,CO₂注入速度的影响次之,地层渗透率的影响最小。在地层水盐度较高时,固体盐饱和度显著增加,从而造成地层渗透率明显下降。当地层水盐度为0.24时,盐沉淀造成注入性损失45.32%,引起的地层压力提升达到了12.14MPa。因此,需要特别关注高盐度地层水引起的盐沉淀及其反馈作用。     

岩浆硫化物熔体中成矿金属元素的富集及迁移过程研究综述

近年来,有关岩浆热液矿床源区硫化物熔体的熔离过程及其对成矿的贡献已引起相当的重视。在系统地介绍热液矿床
岩浆源区原生硫化物熔体分离机制,以及其对成矿金属元素的初始富集行为基础上,重点综述了岩浆硫化物熔体破坏分解并参与
到成矿流体的具体过程和实例。同时对该领域的关键技术方法LA-ICPMS原位微区成分测试的进展进行了概述,并提出了一些
研究展望,尤其是深部岩浆演化中成矿金属元素的富集迁移过程。      

Soil Carbon,Nitrogen and Phosphorus Concentrations and Stoichiometries Across a Chronosequence of Restored Inland Soda Saline-Alkali Wetlands,Western Songnen Plain,Northeast China

Soil carbon(C), nitrogen(N) and phosphorus(P) concentrations and stoichiometries can be used to evaluate the success indicators to the effects of wetland restoration and reflect ecosystem function. Restoration of inland soda saline-alkali wetlands is widespread, however, the soil nutrition changes that follow restoration are unclear. We quantified the recovery trajectories of soil physicochemical properties, including soil organic carbon(SOC), total nitrogen(TN), and total phosphorus(TP) pools, for a chronosequence of three restored wetlands(7 yr, 12 yr and 21 yr) and compared these properties to those of degraded and natural wetlands in the western Songnen Plain, Northeast China. Wetland degradation lead to the loss of soil nutrients. Relative to natural wetlands, the mean reductions of in SOC, TN, and TP concentrations were 89.6%, 65.5% and 52.5%, respectively. Nutrients recovered as years passed after restoration. The SOC, TN, and TP concentrations increased by 2.36 times, 1.15 times, and 0.83 times, respectively in degraded wetlands that had been restored for 21 yr, but remained 29.2%, 17.3%, and 12.8% lower, respectively, than those in natural wetlands. The soil C∶N(RC N), C∶P(R CP), and N∶P(R NP) ratios increased from 5.92 to 8.81, 45.36 to 79.19, and 7.67 to 8.71, respectively in the wetland that had been restored for 12 yr. These results were similar to those from the natural wetland and the wetland that had been restored for 21 yr(P 0.05). Soil nutrients changes occurred mainly in the upper layers(≤ 30 cm), and no significant differences were found in deeper soils( 30 cm). Based on this, we inferred that it would take at least 34 yr for SOC, TN, and TP concentrations and 12 yr for RC N, R CP, and RN P in the top soils of degraded wetlands to recover to levels of natural wetlands. Soil salinity negatively influenced SOC(r =-0.704, P 0.01), TN(r =-0.722, P 0.01), and TP(r =-0.882, P 0.01) concentrations during wetland restoration, which indicates that reducing salinity is beneficial to SOC, TN, and TP recovery. Moreover, plants were an important source of soil nutrients and vegetation restoration was conducive to soil nutrient accumulation. In brief, wetland restoration increased the accumulation of soil biogenic elements, which indicated that positive ecosystem functions changes had occurred.     

The Effects of Land Use and Landscape Position on Labile Organic Carbon and Carbon Management Index in Red Soil Hilly Region,Southern China

Labile organic carbon(LOC) and carbon management index(CMI), which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of LOC and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands(pine forest(PF) on slope land, barren hill(BH) on slope land, citrus orchard(CO) on terrace land and Cinnarnornum Camphora(CC) on terrace land) at a sampling depth of 20 cm. Soil nutrients, soil organic carbon(SOC), LOC and CMI were measured. Results showed that the LOC and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC PF CO BH at the upperslope, while CO CC BH PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order: upper-slope down-slope midslope. As whole, the mean values of LOC and CMI in different lands followed the order CC CO PF BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a highquality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.     

Effects of Reclamation on Soil Carbon and Nitrogen in Coastal Wetlands of Liaohe River Delta,China

To evaluate the influence of wetland reclamation on vertical distribution of carbon and nitrogen in coastal wetland soils, we measured the soil organic carbon(SOC), soil total nitrogen(STN) and selected soil properties at five sampling plots(reed marsh, paddy field, corn field, forest land and oil-polluted wetland) in the Liaohe River estuary in September 2013. The results showed that reclamation significantly changed the contents of SOC and STN in the Liaohe River estuary(P 0.001). The SOC concentrations were in the order: oil-polluted wetland corn field paddy field forest land reed marsh, with mean values of 52.17, 13.14, 11.46, 6.44 and 6.16 g/kg, respectively. STN followed a similar order as SOC, with mean values of 1351.14, 741.04, 632.32, 496.17 and 390.90 mg/kg, respectively. Interaction of reclamation types and soil depth had significant effects on SOC and STN, while soil depth had significant effects on SOC, but not on STN. The contents of SOC and STN were negatively correlated with pH and redox potential(Eh) in reed marsh and corn field, while the SOC and STN in paddy field had positive correlations with electrical conductivity(EC). Dissolved organic carbon(DOC), ammonium nitrogen(NH_4~+-N) and nitrate nitrogen(NO_3~–-N) were also significantly changed by human activities. NH_4~+-N and NO_3~–-N increased to different degrees, and forest land had the highest NO_3~–-N concentration and lowest DOC concentration, which could have been caused by differences in soil aeration and fertilization. Overall, the results indicate that reed harvest increased soil carbon and nitrogen release in the Liaohe River Estuary, while oil pollution significantly increased the SOC and STN; however, these cannot be used as indicators of soil fertility and quality because of the serious oil pollution.     

Measurement and Scaling of Mercury on Soil and Air in a Historical Artisanal Gold Mining Area in Northeastern China

The Jiapigou gold mine area, located in the upper reaches of the Songhua River, was the first and largest artisanal gold mine once in China, and it used to be prominent in two marking years(1870 and 1974). Jiapigou area had a gold mining history of more than 190 years, which was first opened in 1820. Gold extraction with algamation was applied as the dominant method of excavation from 1940 to 2008, and a total of more than 100 t of gold were extracted from the mine using this method and it was estimated that 100–200 t Hg were released, thus causing severe mercury environmental pollution in the mining area. In the experimental campaigns of this study, in situ air and soil Hg concentrations and air-soil Hg fluxes were measured from April 2009 to December 2011. The results showed that in the study area the total gaseous mercury(TGM) concentration exhibited remarkable spatial and temporal distribution patterns, i.e. the TGM gradually decreased following the increase in distance to gold mining sites in space, and the values in spring, summer and autumn were elevated by 1–2 orders of magnitude in comparison with those in winter. Furthermore, at other sampling sites the total soil mercury(TSM) concentration in spring was higher than that in autumn, except for the contrary laws demonstrated at the Erdaogou mining site. However, in spring and winter the Hg flux between air and soil was under the control of different environmental factors, and the characteristics were clear and distinct. In spring the Hg flux between air and soil was directly under the control of solar irradiation, and the releasing process was predominant with a remarkable positive correlation to solar irradiation. Nevertheless, in winter the Hg fluxes were indirectly under the control of solar irradiation, which caused thermal inversion due to the thick snow cover. The depositing process was predominant and the correlations between Hg flux and air temperature was remarkably negative, and there was a positive correlation between Hg flux and solar irradiation.     

湖北清江岩溶洞穴现代土壤有机碳同位素与生物标志物指标变化规律

为进一步理解中国南方岩溶区现代土壤生物有机地球化学演化规律,对采自湖北清江流域典型岩溶洞穴上覆土壤开展了
系统的分析。分别采用稳定同位素质谱仪(MAT-251)与气相色谱质谱仪(GC-MS)测试了样品中的有机碳同位素与生物标志物指标。
其中有机碳同位素值(δ13C_org)在-28.3‰~-27.4‰之间变化,并随深度的增大呈逐渐正偏的趋势,指示了当地的植被类型自土壤
层形成以来主要为C3 植物。而可抽提有机质的总量、正构烷烃高碳数奇偶优势(CPIh 值)、高碳数与低碳数含量比值(Rh/l值)、平均
链长(ACL 值)以及脂肪酸C16:1/C16:0等指标随土壤剖面深度的增大呈现逐渐降低的趋势,与土壤有机碳同位素的变化趋势基本一
致,说明岩溶地区表层土壤中有机碳同位素和生物标志物均与土壤层内微生物活动的强弱密切相关。另一方面,也暗示了有机碳源
是制约岩溶地区土壤微生物活动的重要因素之一。为进一步深入理解湖北清江和尚洞洞穴石笋记录提供了新的思路。      

Carbon biomass,carbon-to-chlorophyll a ratio and the growth rate of phytoplankton in Jiaozhou Bay,China

Carbon biomass,carbon-to-chlorophyll a ratio(C:Chl a),and the growth rate of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou B ay,China.Water samples were collected from 12 stations,and phytoplankton carbon biomass(phyto-C) was estimated from microscopemeasured cell volumes.The phyto-C ranged from 5.05 to 78.52 μg C/L in the bay,and it constituted a mean of 38.16% of the total particulate organic carbon in the bay.High phyto-C values appeared mostly in the northern or northeastern bay.Diatom carbon was predominant during all four cruises.Dinoflagellate carbon contributed much less(30%) to the total phyto-C,and high values appeared often in the outer bay.The C:Chl a of phytoplankton cells varied from 11.50 to 61.45(mean 3 1.66),and high values appeared in the outer bay during all four seasons.The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay,and phytoplankton growth rates ranged from 0.56 to 1.96/d;the rate was highest in summer(mean 1.79/d),followed by that in fall(mean 1.24/d) and spring(mean 1.17/d),and the rate was lowest in winter(mean 0.77/d).Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay.To our knowledge,this study is the first report on phytoplankton carbon biomass and C:Chl a based on water samples in Jiaozhou B ay,and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.     

Soil Organic Carbon Contents and Stocks in Coastal Salt Marshes with Spartina alterniflora Following an Invasion Chronosequence in the Yellow River Delta,China

Plant invasion alters the fundamental structure and function of native ecosystems by affecting the biogeochemical pools and fluxes of materials and energy. Native(Suaeda salsa) and invasive(Spartina alterniflora) salt marshes were selected to study the effects of Spartina alterniflora invasion on soil organic carbon(SOC) contents and stocks in the Yellow River Delta. Results showed that the SOC contents(g/kg) and stocks(kg/m~2) were significantly increased(P 0.05) after Spartina alterniflora invasion of seven years, especially for the surface soil layer(0–20 cm). The SOC contents exhibited an even distribution along the soil profiles in native salt marshes, while the SOC contents were gradually decreased with depth after Spartina alterniflora invasion of seven years. The natural ln response ratios(Ln RR) were applied to identify the effects of short-term Spartina alterniflora invasion on the SOC stocks. We also found that Spartina alterniflora invasion might cause soil organic carbon losses in a short-term phase(2–4 years in this study) due to the negative Ln RR values, especially for 20–60 cm depth. And the SOCD in surface layer(0–20 cm) do not increase linearly with the invasive age. Spearman correlation analysis revealed that silt + clay content was exponentially related with SOC in surface layer(Adjusted R~2 = 0.43, P 0.001), suggesting that soil texture could play a key role in SOC sequestration of coastal salt marshes.     

Soil Cellulase Activity and Fungal Community Responses to Wetland Degradation in the Zoige Plateau,China

Four soil types(peat, marsh, meadow, and sandy) in the Zoige Plateau of China are associated with the severity of wetland degradation. The effects of wetland degradation on the structure and abundance of fungal communities and cellulase activity were assessed in these 4 soil types at 3 depths using DGGE(Denatured Gradient Gel Electrophoresis), q PCR(Quantitative Real-time PCR),and 3,5-dinitrosalicylic acid assays. Cellulase activity and abundance of the fungal community declined in parallel to the level of wetland degradation(from least to most disturbed). DGGE analysis indicated a major shift in composition of fungal communities among the4 soil types consistent with the level of degradation.Water content(WC), organic carbon(OC), total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were strongly correlated with cellulase activity and the structure and abundance of the fungal community.The results indicate that soil physicochemical properties(WC, OC, TN, TP, AN, and AP), cellulase activity, and diversity and abundance of fungal communities are sensitive indicators of the relative level of wetland degradation. WC was the major factorinvolved in Zoige wetland degradation and lower WC levels contributed to declines in the abundance and diversity of the fungal community and reduction in cellulase activity.     

星载GPS实时定轨中重力场模型阶次的最优确定方法

分析重力场模型的截断误差及其影响因素,并用多颗不同轨道高度的低轨卫星GPS实测数据进行实时定轨仿真分析,提出实时定轨精度能够达到1.0 m(伪距法实时定轨)和0.5 m(相位法实时定轨)的重力场模型阶次的最优确定方法。使用CHAMP和TerraSAR-X 2颗卫星实测数据,验证了重力场模型阶次的最优确定方法的可行性和有效性。该方法不仅避免了传统经验法确定重力场模型阶次不准确的问题,而且不需要借助精密轨道进行精度评估,便于实时定轨系统的工程应用。