We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,ca...We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,calcination temperature of 900℃and calcination time of 120 min were identified as the optimal conditions to maximize the available Si content of the prepared Si fertilizer.The performance of the resulting product satisfies the Chinese agricultural standard for silica fertilizers,providing a new solution for the large-scale harmless and sustainable reuse of lithium pyroxene tailings.The X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)characterization elucidated the formation mechanism of silica fertilizers,and identified KAlSiO_(4)and K_(4)CaSi_(3)O_(9)as the primary silicates products.Observation of the surface morphology of the samples was conducted by scanning electron microscopy(SEM)and X-ray energy dispersive spectrometry(EDS),and compositional analysis of the micro-regions.The acceleration action of CaCO_(3)in the decomposition process of lithium pyroxene acid-leaching residues was demonstrated by the thermogravimetry-differential scanning calorimetry(TG-DSC)test.Determination of heavy metal elements in Si fertilizer was performed by ICP-OES.Potting experiments confirmed that the best growth of pakchoi was achieved when 5 g·kg^(-1)of Si fertilizer was applied.These evidence suggests that the Si fertilizer prepared in this study is a promising candidate for a silica-supplemented soil.展开更多
Hydrogen isotopic compositions of pyroxenes in peridotite xenoliths from the Nushan volcano, Anhui Province, SE China have been obtained using an ion probe (Cameca 1270). D/H ratios are constant within a single grain ...Hydrogen isotopic compositions of pyroxenes in peridotite xenoliths from the Nushan volcano, Anhui Province, SE China have been obtained using an ion probe (Cameca 1270). D/H ratios are constant within a single grain and among the different grains from the same sample. The lack of correlation between the D/H ratios and the hydrogen contents indicates that the hydrogen isotopic compositions are inherited from their mantle source. Combining with the δD values of coexisting amphiboles, it is inferred that the Nushan mantle experienced at least a two-stage metasomatic event. One was responsible for formation of amphiboles with extremely variable δD values, and the other was probably responsible for the high δD values (up to ?20‰) of some clinopyroxenes from peridotites, clinopyroxene and mica megacrysts. High δD values point to a subduction-related fluid being involved in one metasomatic event. The primary δD values (?90‰ to ?140‰) of the Nushan pyroxenes, together with data gleaned from the literature, suggest that the D/H ratios of the nominally anhydrous mineral reservoir might have differed from that of the other mantle hydrogen in being relatively depleted in D.展开更多
In order to derive the distribution of olivine and pyroxene in Crater Copernicus, we compute two band ratios （950/750 and 2 000/1 500 nm）, percent content of elements （Ai%, Ca%, Mg%, FeO%） and maturity （Is/FeO） ...In order to derive the distribution of olivine and pyroxene in Crater Copernicus, we compute two band ratios （950/750 and 2 000/1 500 nm）, percent content of elements （Ai%, Ca%, Mg%, FeO%） and maturity （Is/FeO） based on Clementine UVVIS and NIR image data. The central peaks of Copernicus, which are known to be olivine-rich or pyroxene-rich, are chosen as ＂ground truth＂ and ROIs used to derive the distribution of olivine and pyroxene with a decision tree and spectral angle mapper （SAM）. Additionally, we compared previous works and the extraction results coming from the decision tree and the SAM method. The extraction of olivine by both decision tree and SAM agrees well with the previous works＇ descriptions, and the result by SAM is more accurate than that by decision tree because spectral features are fully used in SAM. For pyroxene extraction, there is a difference between SAM and the decision tree; one of the reasons is that the decision tree does not fully take advantage of spectral features but is only based on statistics. SAM uses band indices that can be easily extended to other areas on the Moon.展开更多
This paper studies the hydrous facies of mantle-derived megacrystclinopyroxenes and pyroxenes of xenoliths of pyroxenolite and spinel peridotite as well as garnetpyroxenolite in a kimberlitic lamprophyre pipe in Anyua...This paper studies the hydrous facies of mantle-derived megacrystclinopyroxenes and pyroxenes of xenoliths of pyroxenolite and spinel peridotite as well as garnetpyroxenolite in a kimberlitic lamprophyre pipe in Anyuan, Jiangxi, by Fourier Transform Infrared(FTIR). It explores the relationship between the water content of pyroxene on the one hand and itscomposition and source depths on the other hand. All the samples contain constitution water. Spectraof the clinopyroxene are dominated by two groups of bands: 3607-3630 cm^(-1) and 3522-3542 cm^(-1).Spectra of the orthopy-roxene are dominated by three groups of bands: 3410-3424 cm^(-1), 3510-3516cm^(-1) and 3560-3595 cm^(-1). The water content of the clinopyroxenes has a positive correlationwith their FeO and Al_2O_3 contents. The source depths of mantle-derived clinopyroxene megacrysts,pyroxenolite, spinel peritotite and garnet pyroxenelite increase gradually in order. The Al_2O_3 andwater contents of four pyroxenes have similar correlation with the source depths.展开更多
1 Introduction The howardite,eucrite and diogenite(HED)meteorites are ultramafic and mafic igneous rocks and impact-engendered breccias derived from a thoroughly differentiated asteroid 4 Vesta.Diogenites include duni...1 Introduction The howardite,eucrite and diogenite(HED)meteorites are ultramafic and mafic igneous rocks and impact-engendered breccias derived from a thoroughly differentiated asteroid 4 Vesta.Diogenites include dunites,展开更多
In order to explore synthetic method of pure sodium pyroxene,the pure chemical reagents of Na2CO3,Fe（OH）3 and H2SiO3were used as raw materials,and the possible solid phase reactions for Na2CO3-Fe（OH）3-H2SiO3system...In order to explore synthetic method of pure sodium pyroxene,the pure chemical reagents of Na2CO3,Fe（OH）3 and H2SiO3were used as raw materials,and the possible solid phase reactions for Na2CO3-Fe（OH）3-H2SiO3system in heating process had been studied by means of differential thermal analysis（DTA）and X-ray diffraction（XRD）. The influencing factors of sodium pyroxene（NaFeSi2O6）synthetic reaction,such as sintering temperature and holding time,had also been studied.The results show that sodium pyroxene can be largely synthesized at 737℃;it is helpful for synthesis of sodium pyroxene to increase sintering temperature appropriately,and the best temperature should be controlled at 900℃or so,because it will melt and decompose at temperatures higher than 900℃.In those influencing factors of sodium pyroxene synthesis the most important is temperature.The results will be helpful for providing pure NaFeSi2O6for further research on the formation of SFCA for NaFeSi2O6-KAlSi2O3-CaO-Fe2O3-CaF2 system in the sintering process of Bayan-obo iron ore.展开更多
Based on various statistical indices,the abilities of multi-generation reanalyses,namely the NCEP/NCAR Reanalysis 1(R1),the NCEP-DOE Reanalysis 2(R2)and the NCEP Climate Forecast System Reanalysis(CFSR),to reproduce t...Based on various statistical indices,the abilities of multi-generation reanalyses,namely the NCEP/NCAR Reanalysis 1(R1),the NCEP-DOE Reanalysis 2(R2)and the NCEP Climate Forecast System Reanalysis(CFSR),to reproduce the spatiotemporal characteristics of precipitation over Zhejiang Province are comprehensively compared.The mean absolute bias percentages for three reanalyses are 20%(R1),10%(R2)and 37%(CFSR).R2(R1)gives the best(worst)general depiction of the spatial characteristics of the observed precipitation climatology,whereas a significant wet bias is noticed in the CFSR.All reanalyses reasonably reproduce the interannual variability with the correlation coefficients of 0.72(R1),0.72(R2)and 0.84(CFSR).All reanalyses well represent the first two modes of the observed precipitation through Empirical Orthogonal Function analysis,with CFSR giving the best capture of the principal components.The root-mean-square error(RMSE)is the largest(smallest)in the CFSR(R2).The large RMSE of CFSR in summer(especially in June)contributes mostly to its systematic wet bias.After 2001,the wet bias of CFSR substantially weakens,probably attributed to increasing observations assimilated in the CFSR.On a monthly basis,the percentage of neutral bias cases are similar for all reanalyses,while the ratio of positive(negative)bias cases for CFSR is distinctly larger(smaller)than that of R1 and R2.The proportions of negative bias cases for R1 and R2 begin to increase after 2001 while keeping stable for CFSR.On a daily basis,all reanalyses give good performances of reproducing light rain;however,the reflection of moderate rain and heavier rain by the CFSR is better than R1 and R2.Overall,despite being a third-generation reanalysis product,the CRSR does not exhibit comprehensive superiorities over R1 and R2 in all aspects on a regional scale.展开更多
The Moyar-Bhavani Shear Zone(MBSZ)of the South Indian Granulite Terrain(SIGT),a complex continental block formed by the accretion of various crustal units during the Archaean to Neoproterozoic,bear evidences of
In this paper,a new multi-generation system,incorporating solid oxide fuel cell(SOFC),gas turbine(GT),lithium bromide chiller,gas and heat storage components is proposed to address the issues of volatility in user loa...In this paper,a new multi-generation system,incorporating solid oxide fuel cell(SOFC),gas turbine(GT),lithium bromide chiller,gas and heat storage components is proposed to address the issues of volatility in user load and energy source input and mismatching between supply and demand.The dynamic model and control strategy of the system are established,and the system dynamic characteristics in response to solar DNI and external load disturbances are studied.The system can rapidly adjust the key output and input parameters to realize a new supply-demand balance in a shorter period of time by multiple PID control methods.The response processes of two combined cooling,heating and power(CCHP) systems with and without gas storage to cope with load changes are compared.The results show that the CCHP system with gas storage can effectively shorten the response time of load following.The solar collector and the SOFC-GT can reach a new equilibrium within a few tens of seconds under the controller.The response time of the methanol reactor is longer compared to those of solar collector and the SOFC-GT,taking several minutes to stabilize.When the cooling and heating load change,the system can adjust the output to the demand value within 500 and 260 seconds.展开更多
文摘We focus on a novel and economical route for the synthesis of Si fertilizer via the calcination method using lithium pyroxene acid-leaching residues as the starting materials.The molar ratio of Si/K/Ca of 1:1.4:0.8,calcination temperature of 900℃and calcination time of 120 min were identified as the optimal conditions to maximize the available Si content of the prepared Si fertilizer.The performance of the resulting product satisfies the Chinese agricultural standard for silica fertilizers,providing a new solution for the large-scale harmless and sustainable reuse of lithium pyroxene tailings.The X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)characterization elucidated the formation mechanism of silica fertilizers,and identified KAlSiO_(4)and K_(4)CaSi_(3)O_(9)as the primary silicates products.Observation of the surface morphology of the samples was conducted by scanning electron microscopy(SEM)and X-ray energy dispersive spectrometry(EDS),and compositional analysis of the micro-regions.The acceleration action of CaCO_(3)in the decomposition process of lithium pyroxene acid-leaching residues was demonstrated by the thermogravimetry-differential scanning calorimetry(TG-DSC)test.Determination of heavy metal elements in Si fertilizer was performed by ICP-OES.Potting experiments confirmed that the best growth of pakchoi was achieved when 5 g·kg^(-1)of Si fertilizer was applied.These evidence suggests that the Si fertilizer prepared in this study is a promising candidate for a silica-supplemented soil.
基金supported by the National Natural Science Foundation of China(Grants 49803002 and 40473007)Program for New Century Excellent Talents in University(NCET)the CAS-CNRS-CNR cooperative project.
文摘Hydrogen isotopic compositions of pyroxenes in peridotite xenoliths from the Nushan volcano, Anhui Province, SE China have been obtained using an ion probe (Cameca 1270). D/H ratios are constant within a single grain and among the different grains from the same sample. The lack of correlation between the D/H ratios and the hydrogen contents indicates that the hydrogen isotopic compositions are inherited from their mantle source. Combining with the δD values of coexisting amphiboles, it is inferred that the Nushan mantle experienced at least a two-stage metasomatic event. One was responsible for formation of amphiboles with extremely variable δD values, and the other was probably responsible for the high δD values (up to ?20‰) of some clinopyroxenes from peridotites, clinopyroxene and mica megacrysts. High δD values point to a subduction-related fluid being involved in one metasomatic event. The primary δD values (?90‰ to ?140‰) of the Nushan pyroxenes, together with data gleaned from the literature, suggest that the D/H ratios of the nominally anhydrous mineral reservoir might have differed from that of the other mantle hydrogen in being relatively depleted in D.
基金supported by the Research Foundation of Science and Technology, China University of Geosciences (Wuhan)the Fundamental Research Funds for the Central Universities (No. 2010119047)
文摘In order to derive the distribution of olivine and pyroxene in Crater Copernicus, we compute two band ratios （950/750 and 2 000/1 500 nm）, percent content of elements （Ai%, Ca%, Mg%, FeO%） and maturity （Is/FeO） based on Clementine UVVIS and NIR image data. The central peaks of Copernicus, which are known to be olivine-rich or pyroxene-rich, are chosen as ＂ground truth＂ and ROIs used to derive the distribution of olivine and pyroxene with a decision tree and spectral angle mapper （SAM）. Additionally, we compared previous works and the extraction results coming from the decision tree and the SAM method. The extraction of olivine by both decision tree and SAM agrees well with the previous works＇ descriptions, and the result by SAM is more accurate than that by decision tree because spectral features are fully used in SAM. For pyroxene extraction, there is a difference between SAM and the decision tree; one of the reasons is that the decision tree does not fully take advantage of spectral features but is only based on statistics. SAM uses band indices that can be easily extended to other areas on the Moon.
基金the National Natural Science Foundation of China(Grant No.49672105).
文摘This paper studies the hydrous facies of mantle-derived megacrystclinopyroxenes and pyroxenes of xenoliths of pyroxenolite and spinel peridotite as well as garnetpyroxenolite in a kimberlitic lamprophyre pipe in Anyuan, Jiangxi, by Fourier Transform Infrared(FTIR). It explores the relationship between the water content of pyroxene on the one hand and itscomposition and source depths on the other hand. All the samples contain constitution water. Spectraof the clinopyroxene are dominated by two groups of bands: 3607-3630 cm^(-1) and 3522-3542 cm^(-1).Spectra of the orthopy-roxene are dominated by three groups of bands: 3410-3424 cm^(-1), 3510-3516cm^(-1) and 3560-3595 cm^(-1). The water content of the clinopyroxenes has a positive correlationwith their FeO and Al_2O_3 contents. The source depths of mantle-derived clinopyroxene megacrysts,pyroxenolite, spinel peritotite and garnet pyroxenelite increase gradually in order. The Al_2O_3 andwater contents of four pyroxenes have similar correlation with the source depths.
基金funded by the National Natural Science Foundation of China (Grant No. 41173077)Chinese science and technology basic conditions platform project of Ministryof Science and Technology (2005DKA21406-9)Science and technology plan projects in guangxi(AD16450001)
文摘1 Introduction The howardite,eucrite and diogenite(HED)meteorites are ultramafic and mafic igneous rocks and impact-engendered breccias derived from a thoroughly differentiated asteroid 4 Vesta.Diogenites include dunites,
基金Item Sponsored by National Natural Science Foundation of China (50944049)
文摘In order to explore synthetic method of pure sodium pyroxene,the pure chemical reagents of Na2CO3,Fe（OH）3 and H2SiO3were used as raw materials,and the possible solid phase reactions for Na2CO3-Fe（OH）3-H2SiO3system in heating process had been studied by means of differential thermal analysis（DTA）and X-ray diffraction（XRD）. The influencing factors of sodium pyroxene（NaFeSi2O6）synthetic reaction,such as sintering temperature and holding time,had also been studied.The results show that sodium pyroxene can be largely synthesized at 737℃;it is helpful for synthesis of sodium pyroxene to increase sintering temperature appropriately,and the best temperature should be controlled at 900℃or so,because it will melt and decompose at temperatures higher than 900℃.In those influencing factors of sodium pyroxene synthesis the most important is temperature.The results will be helpful for providing pure NaFeSi2O6for further research on the formation of SFCA for NaFeSi2O6-KAlSi2O3-CaO-Fe2O3-CaF2 system in the sintering process of Bayan-obo iron ore.
基金Zhejiang Province Basic Public Welfare Program(LGF19D050001)Key R&D Program of Zhejiang Province(2021C02036)+2 种基金China Meteorological Administration Special Fund for Forecasters(CMAYBY2019-048)National Key R&D Program of China(2018YFC1505601)Key Program of Zhejiang Meteorological Bureau(2020ZD14)。
文摘Based on various statistical indices,the abilities of multi-generation reanalyses,namely the NCEP/NCAR Reanalysis 1(R1),the NCEP-DOE Reanalysis 2(R2)and the NCEP Climate Forecast System Reanalysis(CFSR),to reproduce the spatiotemporal characteristics of precipitation over Zhejiang Province are comprehensively compared.The mean absolute bias percentages for three reanalyses are 20%(R1),10%(R2)and 37%(CFSR).R2(R1)gives the best(worst)general depiction of the spatial characteristics of the observed precipitation climatology,whereas a significant wet bias is noticed in the CFSR.All reanalyses reasonably reproduce the interannual variability with the correlation coefficients of 0.72(R1),0.72(R2)and 0.84(CFSR).All reanalyses well represent the first two modes of the observed precipitation through Empirical Orthogonal Function analysis,with CFSR giving the best capture of the principal components.The root-mean-square error(RMSE)is the largest(smallest)in the CFSR(R2).The large RMSE of CFSR in summer(especially in June)contributes mostly to its systematic wet bias.After 2001,the wet bias of CFSR substantially weakens,probably attributed to increasing observations assimilated in the CFSR.On a monthly basis,the percentage of neutral bias cases are similar for all reanalyses,while the ratio of positive(negative)bias cases for CFSR is distinctly larger(smaller)than that of R1 and R2.The proportions of negative bias cases for R1 and R2 begin to increase after 2001 while keeping stable for CFSR.On a daily basis,all reanalyses give good performances of reproducing light rain;however,the reflection of moderate rain and heavier rain by the CFSR is better than R1 and R2.Overall,despite being a third-generation reanalysis product,the CRSR does not exhibit comprehensive superiorities over R1 and R2 in all aspects on a regional scale.
文摘The Moyar-Bhavani Shear Zone(MBSZ)of the South Indian Granulite Terrain(SIGT),a complex continental block formed by the accretion of various crustal units during the Archaean to Neoproterozoic,bear evidences of
基金supported by the Major Program of the National Natural Science Foundation of China (No.52090064)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (No.51821004)。
文摘In this paper,a new multi-generation system,incorporating solid oxide fuel cell(SOFC),gas turbine(GT),lithium bromide chiller,gas and heat storage components is proposed to address the issues of volatility in user load and energy source input and mismatching between supply and demand.The dynamic model and control strategy of the system are established,and the system dynamic characteristics in response to solar DNI and external load disturbances are studied.The system can rapidly adjust the key output and input parameters to realize a new supply-demand balance in a shorter period of time by multiple PID control methods.The response processes of two combined cooling,heating and power(CCHP) systems with and without gas storage to cope with load changes are compared.The results show that the CCHP system with gas storage can effectively shorten the response time of load following.The solar collector and the SOFC-GT can reach a new equilibrium within a few tens of seconds under the controller.The response time of the methanol reactor is longer compared to those of solar collector and the SOFC-GT,taking several minutes to stabilize.When the cooling and heating load change,the system can adjust the output to the demand value within 500 and 260 seconds.
