Weiwoboidae fam.nov.of 'Higher' Fulgoroidea (Hemiptera:Fulgoromorpha) from the Eocene Deposits of Yunnan,China     

Lin Qibin  Jacek Szwedo  Huang Diying  Adam Stroiński 《《地质学报》英文版》2010,84(4):751-755

<正>A new family of so-called‘higher' planthoppers,Weiwoboidae fam.nov.,from the Lower Eocene of Yunnan is described.A new monotypic genus,Weiwoboa gen.nov.,with Weiwoboa meridiana sp.nov.is also described and illustrated.The characters of tegmen venation of the new family,its evolution,and supposed relationships are briefly discussed.  相似文献   

Characteristics and Drivers of Methane Fluxes from a Rice Paddy Based on the Flux Measurement     

Chaoqing Song  Wei Liu  Haibo Lu  Wenping Yuan 《地球科学进展》2019,34(11):1141-1151

Rice paddies are an important anthropogenic source of methane (CH₄) to the atmosphere, which aggravate the global warming greatly. CH₄ fluxes from a rice paddy in Central China were continuously measured with the eddy covariance method in 2018. The characteristics, dynamics and drivers of the observed CH₄ fluxes from this paddy field were subsequently analyzed. The results indicated that \mathrm{①} a distinct seasonal variation of daily CH₄ fluxes was found over the whole observed period. Daily CH₄ fluxes were the highest in the vegetative period, then decreased gradually, and became the lowest in the fallow period; \mathrm{②} observed CH₄ fluxes had a clear single-peak diurnal pattern during the vegetative and reproductive periods, and reached daily peaks at about 14:00-16:00. However, no obvious diurnal variation in CH₄ fluxes was observed during the fallow period; \mathrm{③} air temperature was the most important drivers that controlled the seasonal variation of CH₄ fluxes from this paddy field, and Vapor Pressure Deficit (VPD) was also found related to the CH₄ emissions; \mathrm{④} the largest daily CH₄ flux was 0.69 μmol/(m²·s), occurred in the late of vegetative period, and the total amount of CH₄ emissions over the whole observed period was about 28 g C/m².  相似文献   

Study on Dynamic Transformation,Application and Comparison of Aviation Carbon Emission Environmental Damage Assessment Methods     

Ruiling Han  Zi Lu  Haifang Yao 《地球科学进展》2019,34(7):688-696

The contradiction between the rapid development of aviation market and supply of airspace resources has increased the environmental damages of aviation carbon emission. The conversion and application of environmental damage assessment method of aviation carbon emission were summarized, and the characteristics of the assessment methods for air and ground transportation were compared. We found out the followings: \mathrm{①} The evaluation method has been transformed from static assessment to dynamic evaluation, and focused on four key problems, average and total carbon emissions, airspace resource utilization, LTO stage emission, and reduction practice; \mathrm{②} Airport terminal area as well as LTO are becoming the focus in the study of aviation carbon emission assessment method, while the former is the main area and the latter is the main stage of aviation carbon emission. The practice of emission reduction is mainly reflected in the optimization of emission reduction measures in economic field; \mathrm{③} Based on the situation and total assessment methods, environmental damage assessment and comparative advantage of aviation carbon emission and ground transportation carbon emission are reflected in the distance by using distance factor and energy consumption; \mathrm{④} Improving the smoothness of airspace resource traffic network, optimizing flight schedule structure and airspace resource allocation are more conducive to promoting aviation emission reduction.  相似文献   

Raman Quantitative Measurements for Carbon Isotopic Composition in CO2-Rich Fluid Inclusion: A Preliminary Study     

Yao Ying  Sun Qiang 《地球科学进展》2016,31(10):1032-1040

Carbon dioxide is a common and important component in fluid inclusions. Because carbon isotopic ratio of CO₂ in fluid inclusion can provide geochemical characteristics of source rocks, many works have been conducted to measure the carbon isotopic ratio (¹³C/¹²C) of CO₂. In general, carbon isotopic composition (¹³C/¹²C) of CO₂ fluid inclusions are measured by mass spectroscopy. However, mass spectroscopy is a destructive analytical technique, and can not be applied to measure single inclusion. Raman spectroscopy is an efficient non-contact and non-destructive method, and has been widely employed in many research fields. In fact, due to the difference of carbon atom mass, the Femi resonance of ¹³CO₂ is lower than that of ¹²CO₂, so they can be identified in Raman spectrum. In principle, the carbon isotopic composition (¹³CO₂/¹²CO₂) in CO₂ is closely related to the Raman intensity ratio between ¹³CO₂ and ¹²CO₂ (I+13/I+12). Therefore, Raman spectroscopy can theoretically be utilized to measure the carbon isotopic composition (¹³CO₂/¹²CO₂) of CO₂. However, this method is seriously hampered by the poor measurement accuracy and precision. In this study, based on the theoretical analysis, and in combination with previous Raman studies on carbon isotopic composition in CO₂, a preliminary research on Raman quantitative measurement for carbon isotopic composition in CO₂ was carried out.  相似文献   

Application of Glycerol Dialkyl Glycerol Tetraether Lipids in Paleoenvironment Reconstruction of Loess Deposits: A Review of Recent Progresses     

Shaohua Tian  Guoqiao Xiao  Huan Yang 《地球科学进展》2020,35(5):465-477

The Glycerol Dialkyl Glycerol Tetraethers (GDGTs) occur ubiquitously in a wide range of environments, such as loess, peat, lake, soil, and ocean, which vary compositionally in response to environmental changes, and provide a series of biomarker proxies for paleoenvironmental reconstruction. This paper introduced the structures and biological sources of GDGTs, and reviewed the recent progresses of the application of the GDGTs proxies in the paleoenvironmental reconstruction of loess deposits. The main progresses include: \mathrm{①} The GDGTs proxies have been widely used in reconstructing the climate changes in loess deposits, and have established the temperature changes of last 800 ka for the Chinese Loess Plateau; \mathrm{②}Temperature variations in Chinese Loess Plateau displayed significant correlation with the Northern Hemisphere insolation, which may be also regulated by the surface vegetation conditions; and \mathrm{③} In the Chinese Loess Plateau, the increase in monsoon precipitation during the last deglaciation significantly lagged behind the rise of temperature. However, problems still exist in the current studies. For instance, the GDGTs-based temperature is likely overestimated, probably reflecting the temperature of warm season, and relationships between GDGT indices and climate factors are still unclear. In the future, the development of new proxies and more accurate regional calibrations based on the separation of 6- methyl GDGTs are expected to provide more reliable paleoenvironmental information, and will provide essential evidence for the evolution of hydrothermal pattern and mechanisms behind climate changes in different regions.  相似文献   

Research and Application Progress of DRAINMOD Model     

Jiake Li  Zhouli Liu  Bei Zhang 《地球科学进展》2019,34(7):679-687

Establishing an effective hydrological model is important for guiding the design of small-scale drainage systems. The simulation principle and the sensitivity of key parameters of DRAINMOD model were summarized from four aspects:Hydrological characteristics, nitrogen transport, salt transport and model cooperation. The research application progresses of DRAINMOD model and its coupled model at home and abroad were systematically reviewed, and the limitations and development trends of the model were discussed. It is pointed out that DRAINMOD model has good simulation performance in the fields of agricultural drainage, nitrogen removal and stain reduction. In the simulation of cold area or urban stormwater regulation, domestic research needs to reference from foreign research results. The research suggests that the key research directions of DRAINMOD model could be summarized as the following aspects:\mathrm{①}Simulating the migration of phosphorus, organic micro-pollutants and heavy metal elements and their impacts on soil and crops; \mathrm{②}Mechanism research on the freezing-thawing of snow and application in cold regions; \mathrm{③}Application in the construction of urban stormwater regulation facilities.  相似文献   

Bibliometric Analysis of Research Progress on Coastal Surface Water and Groundwater Interaction     

Tianzheng Cao  Dongmei Han  Xianfang Song  Wei Liu  Di Du 《地球科学进展》2020,35(2):154-166

The interactions among surface water, groundwater and seawater are closely related in the coastal area with complex hydrological conditions. A series of impacts from human activities and climate change are also more significant in this region. In order to understand the key knowledge and research status of surface water and groundwater interaction in coastal area, it is a useful method to analyze literatures in this research scope in the core database of Web of Science by using CiteSpace. The research achievements in this field were systematically sorted and potential research hotspots were explored, which may provide references for subsequent researches. The results show the following. \mathrm{①} The number of highly cited articles and highly burst articles in this research field has increased significantly since 2010. At present, this field is still in the development stage and has a broad research prospect. \mathrm{②} The United States, Australia, China and Germany have done plenty of researches on this issue and achieved a lot. At present, the number of research achievements supported by National Natural Science Foundation of China is in the lead over the world. \mathrm{③} Seawater intrusion, submarine groundwater discharge, the relationship between tide and hydrological conditions are the main research direction in this field. Hydrochemistry and isotopic analysis, and numerical simulation are the most important research methods in this field. \mathrm{④} The potential development directions and breakthroughs in this field include submarine groundwater discharge, the evolution of coastal mangrove wetlands, the migration and transformation of nutrients, the influences of different hydrological factors on coastal areas, and the impact of climate change on coastal areas. Overall, the future development of surface water and groundwater research in coastal areas is inseparable from the cross-integration of various disciplines, mutual verification of multiple methods and the introduction of new technical means.  相似文献   

A Bibliometric Investigation of Research on Social-Ecological System Resilience     

Xiaoqian Liu  Tao Pei  Hua Shu  Xizhang Gao 《地球科学进展》2019,34(7):765-777

The notion of Resilience of Social-Ecological Systems (ReSES) in balancing and sustaining development are increasingly breeding more multidisciplinary attentions from world scientists and government managers. However, with the tremendous growing in theoretical system, certain problems hinder the integration of theory and practice, such as the low degree of research recognition, lacking of unified paradigm, unevenly development of research topics, etc. Thus, it is an urgent need to sort out the construction, source and development in theory, and its gaps with practices. To identify the hotspot in current research, including the fundamental theories and methods, current focus and future trends, a bibliometric analysis integrating Citespace and TDA tools were made. Using searching queries on “system resilience”, 10 315 articles in Web of Science database were retrieved. Then, a series of contents were examined on these publications, including: \mathrm{①}topics division on co-occurrence network of keywords; \mathrm{②}journal and co-citation analysis of highly cited papers; \mathrm{③}trends by keyword burst analysis; \mathrm{④}changing of high-frequency categories and keywords. Several findings were achieved through scientometric analysis. Firstly, research on system resilience were summarized into five basic theoretical issues, namely, research objects, changes incentives, spatial and temporal scale, and adaptive measures. Secondly, by analyzing the knowledge atlas, it is found that the theory has developed for nearly 45 years since 1973. In the past 20 years, ecosystem resilience driven by climate changes has been one of the earliest and consistent research topics, and formed a well-developed theoretical framework. Over the past ten years, research on the system resilience on community and urban scale has rapidly become a hot topic. In the past five years, adaptation strategies such as social learning and knowledge dissemination have attracted increasing attentions. Overall, improving system simulation and scenario based adaptive management analysis can build the bridge of theoretical research and adaptive management practice.  相似文献   

Research Progress of Transportation Facilities Construction and Their Impact Assessment in the Qinghai Tibet Plateau     

Yi Miao  Haimeng Liu  Jinping Song  Teqi Dai 《地球科学进展》2020,35(3):308-318

The Qinghai Tibet Plateau (QTP) is an important ecological security barrier region and strategic resource reserve base in China. It is of great significance to explore the construction and impact of its transportation facilities. Through combing the relevant research, we found that: \mathrm{①} With the construction of macro regional policies and major transportation facilities, the relevant research has been growing rapidly since 2000, and the contribution of Chinese Academy of Sciences, transportation universities and research institutions is outstanding; \mathrm{②} The key research of QTP's transportation facilities construction includes the constraints and countermeasures of permafrost melting, sandstorm, erosion and geological disasters, the development process of modern comprehensive transportation system and its spatial characteristics, and the evolution of multi-scale regional traffic connection and accessibility; \mathrm{③} The regional impact assessment of traffic facilities mainly focuses on ecological environment and social economy. The former results are mainly negative effects such as disturbing ecosystem, cutting landscape pattern, destroying vegetation cover and disturbing the normal living habits of wild animals, while the latter ones are mainly positive effects like promoting macro regional development, changing the spatial structure of regional development, and driving the development of tourism and other related industries. In general, the positive and negative effects of multi-dimensional and multi-scale show the characteristics of differentiation and multiple feedbacks. With the implementation of the Second Comprehensive Scientific Investigation on the QTP and the construction of Third Pole National Park Group, Sichuan-Tibet Railway and Qinghai-Tibet Expressway, we should further focus on the breakthroughs in key relevant technologies, the balance of transportation system with national strategies and regional functions, the combination of travel perception and comprehensive traffic accessibility, combing the comprehensive impact mechanism from the perspective of coupling and the construction of analysis framework that is in line with regional reality, etc.  相似文献   

新疆哈密金窝子矿田逆冲推覆构造及其控矿作用     

张旺生  曹新志  徐伯骏 《地质科技情报》2010,29(6)

金窝子矿田控矿构造复杂,成矿条件独特,金矿化类型多样。经研究,金窝子矿田的形成与中天山地块向北山裂谷带逆冲推覆作用有关。逆冲推覆造就了金窝子矿田北、中、南3个不同性质的断裂带及不同的金矿化物理、化学环境,并分别控制了金矿田与其相关的金矿化类型及其成矿作用和金矿成矿系列。  相似文献   

高氯酸盐自然衰减的柱实验研究     

梁凯旋  刘菲  张莉 《地学前缘》2022,29(3):207-216

高氯酸盐( {\mathrm{ClO}}_4^{-})是一种小分子量、有毒的无机络阴离子,普遍存在于环境中。由于其分子大小与碘离子相似,会干扰人体甲状腺的正常功能,因此其环境污染问题引起了广泛的关注。本文选取污染场地的天然河沙为试验材料,主要通过柱实验对地下水中 {\mathrm{ClO}}_4^{-}自然衰减过程进行研究,考察了铁氧化物、 {\mathrm{NO}}_3^{-}对 {\mathrm{ClO}}_4^{-}自然衰减过程产生的影响。结果表明,高氯酸盐自然衰减过程主要由微生物驱动,天然河沙可去除2 mg/L的 {\mathrm{ClO}}_4^{-},但其过程缓慢且还原量有限,长期去除率不超过10%,其限制因素为缺乏电子供体;铁氧化物可以促进 {\mathrm{ClO}}_4^{-}自然衰减,但当溶解性铁的浓度低于5.5 mg/L时,衰减过程开始受到影响;地下水中的 {\mathrm{NO}}_3^{-}会抑制 {\mathrm{ClO}}_4^{-}的降解,当 {\mathrm{NO}}_3^{-}低至10 mg/L或以下时, {\mathrm{ClO}}_4^{-}才开始明显降解。  相似文献   

Spatio-temporal Pattern of Remote Sensing Data Sources and Study Areas in Papers on Vegetation Cover Changes in China     

Jiamei Wu  Qiuzhi Peng  Yizhong Huang  Liang Huang 《地球科学进展》1986,35(9):978-989

The study on vegetation cover changes based on remote sensing data sources is an important component and frequent topic of earth surface process research. In order to review and summarize the remote sensing data sources and the spatio-temporal pattern of the study areas for vegetation cover changes in China from the perspective of bibliometrics and GIS spatial presentation， the information of remote sensing data sources and study areas were extracted from 1 021 papers on vegetation. Then the composition of remote sensing data sources and their temporal changes in heat which is termed as study frequency， the spatio-temporal scale characteristics of remote sensing data sources and study areas， and the distributions and change characteristics of hot study regions were analyzed. The results show that \mathrm{①} the number of papers is increasing gradually， and the frequency of each remote sensing data source is basically consistent with its available timing； \mathrm{②} the average period length of the remote sensing data used is gradually elongated， and the spatial resolution of remote sensing data is positively correlated with the size of study areas stably； \mathrm{③} the hot study regions are concentrated in the Loess Plateau area， and the core of the northern arid and semi-arid areas. These results can provide a basic reference for understanding the spatio-temporal pattern and the change trend on the utilization of remote sensing data sources and hot regions for vegetation change studies.  相似文献   

Research and Understanding of the Evolution of the Yellow River Valley in Lanzhou     

Xin He  Xiaofei Hu  Baotian Pan 《地球科学进展》2020,35(4):404-413

As the turning point of the Yellow River flowing from the Tibetan Plateau to the Loess Plateau, the valley evolution of Lanzhou Basin is of great significance to the study of the evolution of the Yellow River system in different geomorphic units. The evolution of the Yellow River Valley in Lanzhou has been studied for nearly 100 years. In the process of research, important research results and understandings have been obtained as follows: \mathrm{①} The denudation surface develops above the Yellow River Valley in Lanzhou Basin, and the broad and continuous 9-level terrace develops in the valley. The age of the denudation surface and 9-level Yellow River terrace was systematically determined by using a variety of dating techniques. \mathrm{②} The development pattern of the strath terraces of the Yellow River in Lanzhou was put forward. Under the background of long-term ground uplift, climate change controls the age of terrace formation, and the rate of uplift affects the number of terrace. \mathrm{③} The age of the highest terrace of the Yellow River in the basins from Lanzhou to the upper reaches of the Yellow River is gradually younger. It is revealed that the formation of the present pattern in the upper reach of the Yellow River is the result of the headward erosion from Lanzhou Basin and the drainage intergration of the internal flow basin. At the same time, the chronology of terrace sequence still needs to be deepened, the characteristics of regional tectonic uplift and deformation are lack of direct evidence, the development pattern of terrace needs to be verified by model simulation, the geomorphic response of drainage change is not clear, and the river process recorded by the deposition of terrace flood plain is lack of attention. All those issues will be the focus of future research.  相似文献   

Potential Evapotranspiration Characteristic and Its Abrupt Change Across the Qinghai-Tibetan Plateau and Its Surrounding Areas in the Last 50 Years   总被引：1，自引：0，他引：1  

Tianci Yao  Hongwei Lu  Qing Yu  Wei Feng 《地球科学进展》2020,35(5):534-546

Daily routine observation data from 274 meteorological stations in the Qinghai-Tibetan Plateau and its surrounding areas from 1970 to 2017 were utilized to examine the spatial patterns and abrupt changes of potential evapotranspiration with the formula of FAO Penman-Monteith, in consideration of China’s eco-geographical divisions. The results showed that \mathrm{①} annual and seasonal average potential evapotranspiration, except for summer and winter, displayed a distinct spatial pattern in the Qinghai-Tibetan Plateau and its surrounding areas, with higher values in the north and south but lower values in the middle; the time when monthly potential evapotranspiration reached its maximum or minimum showed clearly zonal differences, namely earlier in the south and later in the north. \mathrm{②} The prevailing mean and trend abrupt changes of potential evapotranspiration were observed in the study area, while there were large differences in the abrupt change time in different regions and seasons. Specifically, the mean abrupt change was dominated by positive mutation, with generally the earliest abrupt change time occurring in spring and the latest appearing in winter; the trend abrupt change pattern was mainly described as the process shifting from a downward trend to an upward trend, the trend change points in year, spring, autumn and winter were postponed gradually from the northeast to the southwest with a delay of about 20, 10, 20 and 5 years, respectively. Comparatively, the abrupt change time of potential evapotranspiration trend in the whole plateau was later than that in the whole buffer zone, with a respective lag of 5, 1, 12, 5 and 4 years. \mathrm{③} Corresponding to the periodic change of potential evapotranspiration, significant evaporation paradox only scattered through the study area during the period before the trend change point (2007), but it was absent afterwards and would not appear in the future. The above findings will provide a scientific basis for further understanding the climate change and eco-hydrological process of the Qinghai-Tibetan Plateau and its surrounding areas in global warming.  相似文献   

An exotic insect Aethiocarenus burmanicus gen. et sp. nov. (Aethiocarenodea ord. nov., Aethiocarenidae fam. nov.) from mid-Cretaceous Myanmar amber     

《Cretaceous Research》2017

An exotic wingless female insect in mid-Cretaceous Myanmar amber is described as Aethiocarenus burmanicus sp. et gen. nov. in the order Aethiocarenodea ord. nov. and family Aethiocarenidae fam. nov. The distinguishing feature of Aethiocarenus burmanicus sp. et gen. nov. is its unique head, the dorsum of which is shaped like an isosceles right triangle with the hypotenuse at the top and vertex positioned at the base of the neck. While insects with triangular-shaped heads are common today, the hypotenuse of the triangle is always located at the base of the head and attached to the neck, with the vertex at the apex of the head. Other features of the fossil are the long narrow, flat body, long slender legs, especially the hind pair that are twice the length of the abdomen, lack of wings, protruding eyes, paired ocelli, secretory glands located on the dorsum of the neck and swollen abdomen bearing paired segmented cerci.  相似文献   

Dynamic Relationship Between Entrainment Rate and Summer Monsoon in the Transition Area of Monsoon in the East of Northwest China     

Yanying Li  Ying Cai  Chunyan Zhang  Ting Zeng  Jiping Yang 《地球科学进展》2019,34(12):1316-1327

Entrainment rate refers to the ratio of surrounding air quality to air quality involved in rising unit distance, including turbulent entrainment and dynamic entrainment, which are applied to the boundary layer parametrization of convective clouds, the improvement of numerical model, the observation of cloud droplet spectral dispersion and the study of tropical cyclones.Based on the daily data at 07:00 and 19:00 every 10 m of five stations such as Minqin, Yuchong, Pingliang, Yinchuan and Yan'an from May to September during 2006-2016, combined with the daily observation data on the ground, the Entrainment Rates(ER) of different heights were calculated, and the relationships between ER and height in different regions, precipitation as well as monsoon during the monsoon period were further obtained. The main results were as follows:\mathrm{①} The ER was proportional to air temperature and saturated water vapor pressure, but inversely proportional to relative humidity. The relative humidity threshold of cloud was 65%. The higher the relative humidity threshold was, the lower the cloud height of different orders of precipitation was, and the cloud height was higher with the increase of rainfall. \mathrm{②}ER had obvious diurnal changes and regional differences: It was obviously smaller at 07:00 than at 19:00 from ground to 3 km, which weakened with the increase of height in the near surface , but strengthened with the increase of height above 500 m; From small to large, the monsoon affected area, the monsoon swing area and the non-monsoon area were in turn, and there was no regional difference above 3 km. \mathrm{③} ER was closely related to the intensity and property of precipitation in monsoon period. The ER weakened with the enhancement of rain intensity from near ground to below 600 m, but strengthened with the enhancement of rain intensity from 500 m to 2~3 km.From near ground to below 700 m, the ER of stable precipitation was strong, but that of convective precipitation was strong above 700 m. The convective precipitation had big saturated water vapor pressure and strong ER , while the stable precipitation had big saturated water vapor density, rich water vapor but weak ER. \mathrm{④}The relationship between ER and monsoon as well as its duration: From no monsoon to monsoon ER was weakened, the strongest maximum height was also decreasing. There was no significant difference in the duration of ER between the non-monsoon area and the monsoon affected area, but the longer the monsoon swing area lasted in the near ground layer, the smaller the ER was, while the opposite was at 1~2 km in the high altitude. \mathrm{⑤}The relationship between ER and the APO monsoon intensity index showed that: At 07:00, the ER strengthened with height from near ground to below 800 m, but weakened with height above 800 m,and the monsoon intensity was not related to the ER. At 19:00, the ER strengthened with the height near ground but weakened with the height above 300 m, and the stronger the monsoon was, the smaller the ER was. The ER weakened with the decrease of boundary layer height.  相似文献   

火山渣吸附地下水中大肠杆菌噬菌体特性研究     

张玉玲  尹斯琦  司超群  王茜  初文磊 《地学前缘》2021,28(5):167-174

为了分析火山渣吸附去除地下水中大肠杆菌噬菌体作用特性,通过室内实验,考察火山渣吸附地下水中vB_EcoM-ep3大肠杆菌噬菌体效果,同时用等量沸石与石英砂做对照,进一步分析地下水中水化学因素(Fe²⁺、Fe³⁺、Mn²⁺、 {\mathrm{SO}}_4^{2-}、 {\mathrm{NH}}_4^{+}、 {\mathrm{NO}}_3^{-}、 {\mathrm{NO}}_2^{-}、Ca²⁺、Mg²⁺、 {\mathrm{CO}}_3^{2-}、 {\mathrm{HCO}}_3^{-}和pH值)对其吸附效果影响;通过微观检测技术,分析大肠杆菌噬菌体生物学特性和火山渣吸附前后微观结构变化。研究结果表明:火山渣吸附效率优于沸石和石英砂,最大饱和吸附量达到2.245×10⁵ pfu/g;水化学因素对火山渣吸附效果影响存在差异性,其中Fe²⁺、Fe³⁺起到促进作用, {\mathrm{SO}}_4^{2-}、三氮和碱度起到抑制作用,低浓度Mn²⁺( C_{\mathrm{M}{\mathrm{n}}^{2+}}<10 mg/L)和Ca²⁺( C_{\mathrm{C}{\mathrm{a}}^{2+}}<100 mg/L)起到轻微促进作用,超过该浓度则表现为抑制作用;pH值对火山渣吸附效果影响较大,pH值越大,吸附效果越差。vB_EcoM-ep3大肠杆菌噬菌体头部为等边六角形,全身直径约为(53±2) nm,尾部长约为(107±3) nm,由尾管和尾丝组成,可伸缩。具有蜂窝状结构的火山渣吸附大肠杆菌噬菌体后表面孔隙大部分被填充。  相似文献   

压力对淤泥中C-N-S-Fe-H2O体系的影响     

彭子琪  马腾  刘妍君  陈娟  邱文凯  刘锐 《地学前缘》2021,28(5):79-89

C、N、S、Fe是地下水中控制氧化-还原反应的主要元素,淤泥是黏土的演化初期,淤泥演化为黏土过程中会影响含水层水量水质,可能会造成地下水污染;其中的水岩相互作用可以概化为C-N-S-Fe-H₂O体系的相互作用。淤泥演化过程的实质是淤泥在压力的作用下孔隙度不断变小,逐渐固结成岩;淤泥内部不断发生生物地球化学反应,C-N-S-Fe-H₂O体系驱动各种物质的形态结构不断发生改变,其中加压速率和加压模式会影响淤泥里的C、N、S、Fe重要组分固液相的转化。本研究运用自主研发设计的增压装置,探究在3种加压速率(0.04 MPa/12 h、0.04 MPa/24 h、0.04 MPa/36 h)和加压模式(0.040.02 MPa/12 h、0.04 MPa/12 h、0.040.06 MPa/12 h)的情况下,固体介质中C、N、S、Fe向孔隙水释放的规律。结果表明:(1)匀速加压速率越慢,加压初期溶解性有机碳(DOC)、 {\mathrm{SO}}_4^{2-}释放速率越快, {\mathrm{NO}}_3^{-}和Fe²⁺浓度变化增大;DOC、 {\mathrm{SO}}_4^{2-}、 {\mathrm{NO}}_3^{-}、Fe²⁺释放总量越多。(2)不同的加压模式,加速加压(0.040.06 MPa/12 h)下 {\mathrm{NO}}_3^{-}、Fe²⁺的浓度波动较大;DOC、 {\mathrm{NO}}_3^{-}、 {\mathrm{SO}}_4^{2-}和Fe²⁺的总释放量为加速加压(0.040.06 MPa/12 h)大于匀速加压(0.04 MPa/12 h)。(3)加压过程中,DOC和 {\mathrm{SO}}_4^{2-}呈显著正相关,改变加压速率会改变DOC, {\mathrm{NO}}_3^{-}、 {\mathrm{SO}}_4^{2-}和Fe²⁺的相关性。本研究表明改变加压速率和加压模式会对DOC、 {\mathrm{NO}}_3^{-}、 {\mathrm{SO}}_4^{2-}和Fe²⁺的释放速率、释放总量和C、N、S、Fe的转化造成影响,其本质为氧化-还原反应和水岩相互作用的强弱发生了变化;本研究为地质演化过程中压力导致的主要元素变化提供了新的认识,认识到了隔水层会影响含水层的水质和水量,为原生劣质地下水的成因和地下水污染防治提供了新思路。  相似文献   

Hydrachemical Characteristics at the Seismic Stations in Songyuan District,Jilin Province     

Liu Yi&#x  nan  Sun Fengxia  Cui Yueju  Pan Xiaodong  Ma Mingzhi  Zhang Xin  Du Jianguo 《地球科学进展》2017,32(8):810-817

The hydrochemical types and origins of underground water in Songyuan and vicinity, Liaoning Province were discussed based on the hydrochemical composition, δD and δ¹⁸O. The water samples from eight wells were collected 4 times during 2014 to 2015. The main ion concentrations of water were analyzed with an Ion Chromatography. Isotopic compositions of hydrogen and oxygen were analyzed with the Liquid Water Isotope Analyzer. The mineralization (TDS) of the water ranged from 125.4 mg/L to 19 350.9 mg/L. Values of δD and δ¹⁸O ranged from -71.7‰ to -98.1‰ and from -9.0‰ to -12.5‰, respectively. The isotopic data indicated that the water originated from meteorological precipitation. The chemical compositions of Taolaizhao phreatic water were influenced by the human activity while the other water samples collected from artesian well were less affected by the human activity. Water in Changling, Dongdashi, Taohaotai, Qianan and Ningjiang were characterized by HCO₃-Na with low TDS values. Such chemical types of water with fluctuations of Na⁺, SO42- and δ¹⁸O drift were resulted from dissolving silicate minerals and adding surfactant during oil exploitation. Fresh water in Fuyu well was Cl-Na type, which was influenced by acid injection during oil exploitation. Water in Qianguo well was characterized by Cl-Na type with TDS up to 19 350.9 mg/L, the obvious fluctuations of hydrogen and oxygen isotopes and increasing ion concentrations in the Qianguo well may be caused by the earthquakes that occurred in the sampling duration. The results will provide the background of hydrochemistry, and will be of benefit to monitoring earthquake and certificating seismic-chemical anomalies in the future.  相似文献   

Biological Processes Responsible for Travertine Deposition: A Review and Future Prospect     

Zhijun Wang  Jianjun Yin  Junbing Pu  Daoxian Yuan 《地球科学进展》2019,34(6):606-617

The investigation of biological processes responsible for travertine deposition allows us to better understand the travertine petrographic and geochemical signatures as proxies of climatic and environmental change. This paper reviewed the organisms associated with travertines, the biotic micro-fabrics formed within travertines, the biological processes associated with travertine precipitation and their controls on travertine geochemical properties. Prospects of the future research on biological processes responsible for travertine precipitation were provided. Bacteria, algae and mosses are the most important organisms that involve in the precipitation of travertines. The growth of these organisms leads to the formation of a range of various porosity, crystal fabrics and lamination within travertines. Three main biological processes responsible for travertine deposition can be classified, including \mathrm{①} a process of aquatic plant growth generating a turbulent condition and consequent CO₂ evasion, \mathrm{②} a metabolic (mainly photosynthetic) process mediating carbonate precipitation and \mathrm{③} a ‘surface-control’ process influencing nucleation and crystal growth. These processes play an important role in the migration and transformation of elements in travertine-depositing system and thus determine the properties of water chemistry and geochemistry of carbonate deposits. Travertine deposits have great potential to be valuable records for the geobiological study. Further investigation is required to simultaneously track biotic and abiotic interactions in modern travertine-depositing environments and quantify the contribution of these two processes and apply the results to accurately interpret travertine records.  相似文献