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Fluid activity during exhumation of deep-subducted continental plate

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Chinese Science Bulletin 2004年第10期49卷 985-998页

作者： ZHeNGYongfei SchoolofearthandSpaceSciences UniversityofScienceandTechnol-ogyofChinaHefei230026China(e-mail:yfzheng@***)

It is well known that a great deal of fluid wasreleased during subduction of oceanic crust, resulting in arcmagmatism, quartz veining and metamorphic mineralizationof syn-subduction. In contrast, the process of continentalsubduction is characterized by the relative lack of fluid andthus no arc magmatism has been found so far. During exhu-mation of deep-subducted continental crust, nevertheless,significant amounts of aqueous fluid became available fromthe decomposition of hydrous minerals, the decrepitation ofprimary fluid inclusions, and the exsolution of structuralhydroxyls. This kind of metamorphic fluid has recently at-tracted widespread interests and thus been one of the mostimportant targets in deciphering the geological processesconcerning metamorphism, magmatism and mineralizationin collisional orogens. A large number of studies involvingstable isotopes, fluid inclusions and petrological phase rela-tionships have been accomplished in past a few years withrespect to the mobility and amount of metamorphic fluid inUHP metamorphic rocks from the Dabie-Sulu orogenic *** results demonstrate that the fluid activity during theexhumation of deep-subducted continental crust has the fol-lowing effects: (1) amphibolite-facies retrogression due topervasive fluid flow; (2) formation of HP quartz veins withineclogites due to channelized fluid flow; and (3) partial melt-ing of overlying crustal rocks due to focused fluid flow, pro-ducing syn-exhumation magmatism within the orogenic *** particular, the aqueous fluid released by decompressionexsolution of hydroxyl from UHP minerals is characterizedby low salinity and is capable of resulting in pervasive andchannellized flow. Therefore, the intensive study of fluid ac- tivity during exhumation of UHP metamorphic rocks can notonly provide insight into geodynamic processes that occurred in continental collisional belts, but also shed light on under- standing of crust-mantle recycling and relevant magmatism in subduction

关键词：大陆板快深俯冲含水矿物超高压变质减压剥落流活性结构羟基稳定同位素流包含物岩石

Factors Influencing Runoff P Losses from Farmlands of the Dianchi Lake Watershed in Yunnan, China

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Pedosphere 2004年第2期14卷 259-262页

作者： ZHANGNai-Ming YUYang,HONGBo CHeNJian-Jun ZHANGYu-Juan CollegeofResourcesandenvironmentalScience YunnanAgriculturalUniversityYunnan650201（China）.E-mail：zhangnaiming@sinacorn

effects of factors such as slope, surface soil textuie, fertilization andcrop cover with different rainfall intensities on phosphorus (P) losses in farmland runoff of theDianchi Lake Watershed in Yunnan Province of China were studied through a rainfall simulation testusing a red soil, one of the most widely distributed soils of the study area. Results showed thatthe runoff concentrations of total phosphorus (TP) and P losses differed with the slope, beinghighest when the slope was 18 deg. At twodifferent rainfall intensities, the runoff TP and P losseshad a similar decreasing trend as the surface soil texture became coarser, therefore applying thegrit would decrease P in runofi from soils of farmland on slopes with heavier textures. With wheatas a crop cover the runoff TP concentrations and P losses were significantly lower than those of thebare soil. This showed that plant cover would greatly decrease P in runoff from the farmland of thestudy area. The TP concentration in runoff from the soil two days after fertilization doubled whencompared with that from the non-fertilized soil, indicating that fertilization could mean a dramaticrise in P runoff if irrigation or heavy rainfall occurred immediately after application and that nofertilization before a rain and no irrigation immediately after fertilization would reduce runoff Ploss from the farmland of the study area.

关键词： non-point source (NPS) pollution phosphorus runoff

Sedentary behavior and physical activity predicting depressive symptoms in adolescents beyond attributes of health-related physical fitness

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Journal of Sport and Health Science 2018年第4期7卷 489-496页

作者： gene l.farren tao zhang xiangli gu katherine t.thomas Department of Kinesiology Health Promotionand RecreationUniversity of North TexasDentonTX 76203USA Corresponding author.e-mail address：Gene.Farren@unt.edu

Background： Sedentary behavior （SB）, physical activity （PA）, and attributes of physical fitness have been shown to be related to depressive symptoms in adolescents. The purpose of the present study was to investigate whether SB and fitness-producing activity predicted depression in active adolescents over and above gender and fitness attributes. Methods： Participants were 249 adolescents （age： 12.85 ± 0.89 years, mean ± SD） from 3 public middle schools who wore Actical accelerometers to assess their SB and PA. Participants also completed the FITNeSSGRAM health-related fitness assessment and a brief depression questionnaire. A 3-step hierarchical regression analysis was conducted with gender and fitness attributes （i.e., body mass index （BMI）, maximal volume oxygen uptake （VO2max）, curlups, and pushups）, moderate- and vigorous-intensity activity, and SB entered in respective steps. Results： Regression analysis indicated activity variables （i.e., moderate- and vigorous-intensity activity） significantly predicted depression （△R^2= 0.12, p 〈 0.01） beyond gender and fitness attributes. Overall, gender, fitness attributes, activity variables, SB explained 31% of the variance in depression. Structure coefficients revealed VO2max （rs= -0.77）, moderate-intensity activity （rs= -0.67）, vigorous-intensity activity （rs = -0.81）, and SB （rs = 0.57） were substantially correlated with the criterion variable; thus, they were the strongest predictors of depression. Conclusion： The findings of the current study indicated SB and PA were both significant predictors of depression; however, sufficient fitness-producing activity and adequate cardiorespiratory fitness may nullify the negative influence of SB on depressive symptoms in active adolescents.2018 Published by elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//***/licenses/by-nc-nd/4.0/）.

关键词： Accelerometers Adolescent health Cardiorespiratory fitness FITNeSSGRAM Mental health Moderate-to-vigorous-intensity activity

Quantificational analysis on progress of river water quality in China

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Journal of environmental Sciences 2009年第6期21卷 770-773页

作者： YUN Yi,ZOU Zhihong,FeNG Wei,RU Mai School of economics and Management,Beihang University,Beijing 100191,China. [a]School of economics and Management Beihang University Beijing 100191 China. E-mail: winniecloud81@***

In order to understand the dynamic change of water quality in a specific period of time,a type of possibility transition matrix based on the theory of Markov process was *** transition possibility with a weight to calculate the degree of absolute advancement was given based on the result of water quality *** concept of relative advancement was *** was used to evaluate the extent of water quality changed in a period of *** method was used to calculate the degrees of relative advancement for 4 rivers in China,and the results were analyzed.

关键词： water quality evaluation possibility transition matrix Markov process degree of advancement

eFFeCT OF GROUNDWATeR TABLe CONTROL ON WATeR SAVING IRRIGATIONSTRATeGIeS IN THe QINGTONGXIA IRRIGATION DISTRICT

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Journal of Hydrodynamics 2004年第2期16卷 166-175页

作者： WANGXiu-gui HOLLANDeRSP.H.J. StateKeyLaboratoryofWaterResourcesandHydropowerengineeringScience WuhanUniversityWu-han430072Chinae-mail.xgwang@wuhee*** InternationalInstituteforInfrastructural HydraulicandEnvironmentalEngineeringTheNetherlands

This paper focuses on the analysis of the effects of groundwater tablecontrol under different irrigation water amounts on the water and salinity balance and on cropyield. Two experimental areas, the Pingluo and Huinong experimental sites, were selected to collectthe required data. The agro-hydrological model Soil-Water-Atmosphere-Plant (SWAP) was used toanalyse the water flows and salt transport processes for different groundwater levels and irrigationscenarios. Six scenarios, which resulted from different groundwater table regimes combined withdifferent irrigation amounts, were simulated. The results show that high ground-water tables due tothe excessive irrigation are the main cause of the large amount of drainage water and low cropyield; reducing irrigation water without a lower groundwater table will not lead to a largereduction of the drainage water, and will reduce the crop yield even more; to lower the groundwatertable is a good measure to control the drainage water and increase crop yield.

关键词： water saving irrigation field drainage saline water irrigation watermanagement

Double catholyte electrochemical approach for preparing ferrate-aluminum: a compound oxidant-coagulant for water purification

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Journal of environmental Sciences 2002年第1期14卷 49-53页

作者： QuJH LeiPJ StateKeyLaboratoryofenvironmentalAquaticChemistry ResearchCenterforEco－EnvironmentalSciencesChineseAcademyofSciencesBeijing100085China.E－mail：jhqu@*** StateKeyLaboratoryofenvironmental

Ferrate is an excellent water treatment agent for its multi functions in oxidation, disinfection, coagulation and adsorption, but its coagulation ability depends on its dosage and is after its oxidation. This paper focuses on preparing a new kind of ferrate combined with alum to enhance its coagulation function for water purification. An effective electrolysis reactor was designed and employed in the test. Some key parameters in the process of electrolysis concerning the preparation efficiency, such as the current density, temperature and alkalinity were also investigated. The proper conditions for ferrate alum preparation were determined. Under the condition of 5V given voltage, 6h electrolyzing interval, below 2% alum concentration (in weight), a combined liquid ferrate alum products was successfully prepared, which contained 0.0294 mol/L FeO 2- 4 and 0.0302 mol/L total soluble ferron with 2% Al 2O 3. There was no insoluble ferron produced by controlling an optimum electrochemical condition.

关键词： combined ferrate alum electrochemical preparation oxidation coagulation

effectiveness of vegetation on phosphorus removal from reclaimed water by a subsurface flow wetland in a coastal area

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Journal of environmental Sciences 2011年第10期23卷 1594-1599页

作者： Baoqing Shan Liang Ao Chunming Hu Jiayu Song Research Center for eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China. E-mail： bqshan@***

This work was conducted to evaluate the effectiveness and influence factors of vegetation on phosphorus （P） removal from reclaimed water in constructed wetlands. Comparisons were conducted between one pilot scale subsurface flow wetland （P-SSFW） and two demonstration subsurface flow wetlands, which were series-wound and named as first subsurface flow wetland （F-SSFW）, and second subsurface flow wetland （S-SSFW）, respectively. The three wetlands had the same vegetation and substrate, but different pH values, total dissolved solids （TDS） and P loads. Results showed that the P content in the vegetation shoots of the F-SSFW was 2.16 rag/g, while 2.31 mg/g in the S-SSFW and 2.69 mg/g in the P-SSFW. These differences were likely caused by the higher pH and TDS in the reclaimed water. The P content also differed among the tissues of the plant, which were 5.94-6.44 mg/g, 2.20-2.77 mg/g, 1.31-1.46 mg/g and 1.53-1.88 mg/g in the flowers, leaves, stems, and roots, respectively. The greatest discrepancy was observed in the leaves, indicating that the environment of the wetlands had the greatest influence on the leaves. When the total phosphorus （TP） load was lower, the proportion of P removed by vegetation assimilation was 16.17% in the P-SSFW, 12.90% in the F-SSFW and 13.29% in the S-SSFW. However, the relative removal efficiency by vegetation among the three wetlands did not vary greatly from that observed in other studies. Moreover, the influence of pH, TDS and TP load was not as great as the influence of the vegetation species, type of substrate, influent style or climate.

关键词： wetland reclaimed water phosphorus coastal area Phragmites communis Trim

Singular perturbation analysis of dynamic fields in a thermoelastic solid with a small surface-breaking crack

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Acta Mechanica Sinica 2006年第5期22卷 449-454页

作者： e. Zhelezina liv.ac.uk A. B. Movchan I. S. Jones ljmu.ac.uk Department of Mathematical Sciences University of Liverpool Liverpool L69 3BX UK e-mail: ezzh School of engineering John Moores University Liverpool L3 3AF UK e-mail: i.s.jones

An asymptotic analysis is presented for a dynamic problem of a semi-infinite isotropic thermoelastic solid with a small surface breaking crack. The exterior surface of the solid is subjected to a series of short thermal pulses. The crack surface is traction free and an ideal thermal contact is assumed across the crack. The stress intensity factor is asymptotically evaluated as a function of the crack depth and time. The effect of a boundary layer associated with the diffusive term is identified. The theoretical model is supplied with numerical simulations.

关键词： Thermoelasticity Surface breakingcrack Weight function method Stress intensity factor Thermal shock

The affect of industrial activities on zinc in alluvial egyptian soil determined using neutron activation analysis

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Journal of environmental Sciences 2002年第3期14卷 330-332页

作者： Abde.MF Abde.N SoilandWaterPollutionUnit NuclearResearchCenterCairoEgypt NuclearPhysicsLaboratory PhysicsDepartmentFacultyofGirlsAinShamsUniversityCairoEgypt.E－mail：mamsab@***

Thirty two surface (0—20 cm) soil samples were collected from different locations in egypt representing non polluted, moderately and highly polluted soils. The aim of this study was to evaluate total Zn content in alluvial soils of Nile Delta in egypt by using the delayed neutron activation analysis technique (DNAA), in the irradiation facilities of the first egyptian research reactor (eT RR 1). The gamma ray spectra were recorded with a hyper pure germanium detection system. The well resolved gamma ray peak at 1116.0 keV was efficiently used for 65 Zn content determination. Zn content in non polluted soil samples ranged between 74.1 and 103.8 ppm with an average of 98.5±5.1 ppm. Zn content in moderately polluted soils ranged between 136.0 and 232.5 ppm with an average of 180.1±32.6 ppm. The highest Zn levels ranging from 240.0 and 733.0 ppm with an average of 410.3±54.4 ppm, were observed in soil samples collected from, either highly polluted agricultural soils exposed to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

关键词： elemental analysis pollution neutron activation analysis