Data on the distribution of dissolved inorganic carbon (DIC) were obtained from two cruises in the North Yellow Sea (NYS) and off the Qingdao Coast (QC) in October, 2007. Carbonate parameters were calculated. The conc...Data on the distribution of dissolved inorganic carbon (DIC) were obtained from two cruises in the North Yellow Sea (NYS) and off the Qingdao Coast (QC) in October, 2007. Carbonate parameters were calculated. The concentrations of DIC are from 1.896-2.229 mmolL-1 in the NYS and from 1.939-2.032 mmolL-1 off the QC. In the southwest of the NYS, DIC in the upper layers decreases from the north of the SP (Shandong Peninsula) shelf to the center of the NYS; whereas in the lower layers DIC increases from the north of the SP shelf to the center of the NYS and South Yellow Sea. In the northeast of the NYS, DIC in all layers in- creases from the YR (Yalu River) estuary to the centre of the NYS. The distribution of DIC in NYS can be used as an indicator of Yellow Sea Cold Water Mass (YSCWM). Air-sea CO2 fluxes were calculated using three models and the results suggest that both the NYS and the QC waters are potential sources of atmospheric CO2 in October.展开更多
Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and sca...Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and scaling ion concentrations during CO_(2) flooding in the Chang 8 block of Changqing Oilfield,the influence of precipitate on the physical properties of reservoirs was investigated,and the corresponding mathematical characterization model was established.The mathematical characterization equation was used to correct the numerical simulation model of E300 module in Eclipse software.The distribution pattern of inorganic salt precipitates during continuous CO_(2) flooding in Chang 8 block was simulated,and the influence of inorganic salt precipitates on oil recovery was predicted.The inorganic salt precipitate generated during CO_(2)-formation water reaction was mainly CaCO_(3),and the pressure difference and scaling ion concentration were proportional to the amount of precipitate generated,while the temperature was inversely proportional to the amount of precipitate.The rate of core porosity change before and after CO_(2) flooding was positively correlated with temperature and flooding pressure difference.The core porosity increase in the CO_(2)-formation water-core reaction experiment was always lower than that of CO_(2)-distilled water-core reaction experiment because of precipitation.The area around the production wells had the most precipitates generated with the injection of CO_(2).The oil field became poor in development because of the widely distributed precipitate and the recovery decreased to 33.45% from 37.64% after 20-year-CO_(2) flooding when considering of precipitation.展开更多
Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potentia...Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies.展开更多
喀斯特流域是岩石风化碳汇的关键区域,同时也是CO_(2)逸散研究的热点区域。为探究喀斯特地下河涌出后CO_(2)分压(pCO_(2))及其逸散通量的时空变化格局,选择喀斯特流域巴马盘阳河为对象,分析水体的pH、碱度、总溶解性固体(TDS)、溶解无机...喀斯特流域是岩石风化碳汇的关键区域,同时也是CO_(2)逸散研究的热点区域。为探究喀斯特地下河涌出后CO_(2)分压(pCO_(2))及其逸散通量的时空变化格局,选择喀斯特流域巴马盘阳河为对象,分析水体的pH、碱度、总溶解性固体(TDS)、溶解无机碳(DIC)、溶解有机碳(DOC)、pCO_(2)的时空变化特征,探讨pCO_(2)的调控因素并估算了CO_(2)逸散通量。结果表明,流域内地下水碱度、TDS、DIC和pCO_(2)显著高于地表水,表明喀斯特碳酸盐风化释放大量DIC进入地下水,地下水涌出后产生CO_(2)逸散降低了地表水DIC含量和pCO_(2)。在时间尺度上,旱季常规地表、地下水的碱度、TDS、DIC、pCO_(2)、CO_(2)逸散通量均显著高于雨季,主要归结于雨季雨水的稀释效应。然而次降雨事件下地表、地下水的pH、碱度、TDS、DIC、DOC、pCO_(2)无显著性差异,可能由于降雨量不足或降雨持续时间短。研究期间,巴马盘阳河流域地表水、地下水CO_(2)逸散通量范围分别为-0.10~9.20 kg C m^(-2)year^(-1),-0.12~17.28kg C m^(-2)year^(-1),平均CO_(2)逸散通量分别为1.06±1.46 kg C m^(-2)year^(-1)和2.40±3.14 kg C m^(-2)year^(-1),远高于全球主要大型流域的平均CO_(2)逸散通量(0.64 kg Cm^(-2)year^(-1))。阐明喀斯特流域的CO_(2)逸散通量及其时空变化特征对准确评估河流碳收支状况与评估岩石风化碳汇具有重要意义。展开更多
We present a study of magnetocaloric effect of the quasi-two-dimensional（2D） ferromagnet（CH_3NH_3）_2CuCl_4 in ab plane（easy-plane）. From the measurements of magnetic field dependence of magnetization at various ...We present a study of magnetocaloric effect of the quasi-two-dimensional（2D） ferromagnet（CH_3NH_3）_2CuCl_4 in ab plane（easy-plane）. From the measurements of magnetic field dependence of magnetization at various temperatures,we have discovered a large magnetic entropy change associated with the ferromagnetic–paramagnetic transition. The heat capacity measurements reveal an abnormal adiabatic change below the Curie temperature T_c^8.9 K, which is caused by the nature of quasi-2D layered crystal structure. These results suggest that perovskite organic–inorganic hybrids with a layered structure are suitable candidates as working substances in magnetic refrigeration technology.展开更多
文摘Data on the distribution of dissolved inorganic carbon (DIC) were obtained from two cruises in the North Yellow Sea (NYS) and off the Qingdao Coast (QC) in October, 2007. Carbonate parameters were calculated. The concentrations of DIC are from 1.896-2.229 mmolL-1 in the NYS and from 1.939-2.032 mmolL-1 off the QC. In the southwest of the NYS, DIC in the upper layers decreases from the north of the SP (Shandong Peninsula) shelf to the center of the NYS; whereas in the lower layers DIC increases from the north of the SP shelf to the center of the NYS and South Yellow Sea. In the northeast of the NYS, DIC in all layers in- creases from the YR (Yalu River) estuary to the centre of the NYS. The distribution of DIC in NYS can be used as an indicator of Yellow Sea Cold Water Mass (YSCWM). Air-sea CO2 fluxes were calculated using three models and the results suggest that both the NYS and the QC waters are potential sources of atmospheric CO2 in October.
文摘Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and scaling ion concentrations during CO_(2) flooding in the Chang 8 block of Changqing Oilfield,the influence of precipitate on the physical properties of reservoirs was investigated,and the corresponding mathematical characterization model was established.The mathematical characterization equation was used to correct the numerical simulation model of E300 module in Eclipse software.The distribution pattern of inorganic salt precipitates during continuous CO_(2) flooding in Chang 8 block was simulated,and the influence of inorganic salt precipitates on oil recovery was predicted.The inorganic salt precipitate generated during CO_(2)-formation water reaction was mainly CaCO_(3),and the pressure difference and scaling ion concentration were proportional to the amount of precipitate generated,while the temperature was inversely proportional to the amount of precipitate.The rate of core porosity change before and after CO_(2) flooding was positively correlated with temperature and flooding pressure difference.The core porosity increase in the CO_(2)-formation water-core reaction experiment was always lower than that of CO_(2)-distilled water-core reaction experiment because of precipitation.The area around the production wells had the most precipitates generated with the injection of CO_(2).The oil field became poor in development because of the widely distributed precipitate and the recovery decreased to 33.45% from 37.64% after 20-year-CO_(2) flooding when considering of precipitation.
基金supported by the National Key Research and Development Program of China(2022YFD2300300)the National Natural Science Foundation of China(41907072)+1 种基金the Scientific Research Foundation of Zhejiang A&F University,China(2022LFR003)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(21)3007).
文摘Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies.
文摘喀斯特流域是岩石风化碳汇的关键区域,同时也是CO_(2)逸散研究的热点区域。为探究喀斯特地下河涌出后CO_(2)分压(pCO_(2))及其逸散通量的时空变化格局,选择喀斯特流域巴马盘阳河为对象,分析水体的pH、碱度、总溶解性固体(TDS)、溶解无机碳(DIC)、溶解有机碳(DOC)、pCO_(2)的时空变化特征,探讨pCO_(2)的调控因素并估算了CO_(2)逸散通量。结果表明,流域内地下水碱度、TDS、DIC和pCO_(2)显著高于地表水,表明喀斯特碳酸盐风化释放大量DIC进入地下水,地下水涌出后产生CO_(2)逸散降低了地表水DIC含量和pCO_(2)。在时间尺度上,旱季常规地表、地下水的碱度、TDS、DIC、pCO_(2)、CO_(2)逸散通量均显著高于雨季,主要归结于雨季雨水的稀释效应。然而次降雨事件下地表、地下水的pH、碱度、TDS、DIC、DOC、pCO_(2)无显著性差异,可能由于降雨量不足或降雨持续时间短。研究期间,巴马盘阳河流域地表水、地下水CO_(2)逸散通量范围分别为-0.10~9.20 kg C m^(-2)year^(-1),-0.12~17.28kg C m^(-2)year^(-1),平均CO_(2)逸散通量分别为1.06±1.46 kg C m^(-2)year^(-1)和2.40±3.14 kg C m^(-2)year^(-1),远高于全球主要大型流域的平均CO_(2)逸散通量(0.64 kg Cm^(-2)year^(-1))。阐明喀斯特流域的CO_(2)逸散通量及其时空变化特征对准确评估河流碳收支状况与评估岩石风化碳汇具有重要意义。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51371193 and 11534015)the Youth Innovation Promotion of the Chinese Academy of Sciences(Grant No.2013004)the Science Fund from the Chinese Academy of Sciences(Grant Nos.XDB07030200 and KJZD-EW-M05)
文摘We present a study of magnetocaloric effect of the quasi-two-dimensional（2D） ferromagnet（CH_3NH_3）_2CuCl_4 in ab plane（easy-plane）. From the measurements of magnetic field dependence of magnetization at various temperatures,we have discovered a large magnetic entropy change associated with the ferromagnetic–paramagnetic transition. The heat capacity measurements reveal an abnormal adiabatic change below the Curie temperature T_c^8.9 K, which is caused by the nature of quasi-2D layered crystal structure. These results suggest that perovskite organic–inorganic hybrids with a layered structure are suitable candidates as working substances in magnetic refrigeration technology.
