Three guests with two moiety probes for different Cucurbit[n = 6—8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)- adamataneamine and N-(2-methylenefurfuran)-ada...Three guests with two moiety probes for different Cucurbit[n = 6—8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)- adamataneamine and N-(2-methylenefurfuran)-adamataneamine. The probes are methyle-nepyridyl typically for Q[6] and adamataneamine typically for Q[7]. The host-guest complexes of Cucurbit[n = 6—8]urils with these guests have been investigated by using NMR techniques and ESMS method. Also, thermoanalysis has been used for exploring relationship of enthalpy and stability of the host-guest complexes.展开更多
The reactions of carboplatin ([Pt(NH3)2(CBDCA)], in which CBDCA is cyclobutane 1,1, dicarboxylate) with L selenomethionine (L Se MetH) and L methionine (L MetH) were investigated using electrospray mass spectroscopy (...The reactions of carboplatin ([Pt(NH3)2(CBDCA)], in which CBDCA is cyclobutane 1,1, dicarboxylate) with L selenomethionine (L Se MetH) and L methionine (L MetH) were investigated using electrospray mass spectroscopy (ESMS) and 2D HSQC NMR spectroscopy. The dominant products for both reactions are bis chelated complexes [Pt(L Se Met)2] and [Pt(L Met)2]. These results are different from those observed for the reactions of cisplatin ([PtCl2(NH3)]) with L Se MetH or L MetH, in which the main products are mono chelated complexes [PtCl(NH3)(L Se Met)] or [PtCl(NH3)(L Met)]. This work provides insights into the differences between cisplatin and carboplatin in their reactivity and mechanism of reaction.展开更多
This study assesses the ability of 10 Earth System Models(ESMs)that participated in the Coupled Model Intercomparison Project Phase 6(CMIP6)to reproduce the present-day inhalable particles with diameters less than 2.5...This study assesses the ability of 10 Earth System Models(ESMs)that participated in the Coupled Model Intercomparison Project Phase 6(CMIP6)to reproduce the present-day inhalable particles with diameters less than 2.5 micrometers(PM_(2.5))over Asia and discusses the uncertainty.PM_(2.5)accounts for more than 30%of the surface total aerosol(fine and coarse)concentration over Asia,except for central Asia.The simulated spatial distributions of PM_(2.5)and its components,averaged from 2005 to 2020,are consistent with the Modern-Era Retrospective Analysis for Research and Applications version 2(MERRA-2)reanalysis.They are characterized by the high PM_(2.5)concentrations in eastern China and northern India where anthropogenic components such as sulfate and organic aerosol dominate,and in northwestern China where the mineral dust in PM_(2.5)fine particles(PM_(2.5)DU)dominates.The present-day multimodel mean(MME)PM_(2.5)concentrations slightly underestimate ground-based observations in the same period of 2014–2019,although observations are affected by the limited coverage of observation sites and the urban areas.Those model biases partly come from other aerosols(such as nitrate and ammonium)not involved in our analyses,and also are contributed by large uncertainty in PM_(2.5)simulations on local scale among ESMs.The model uncertainties over East Asia are mainly attributed to sulfate and PM_(2.5)DU;over South Asia,they are attributed to sulfate,organic aerosol,and PM_(2.5)DU;over Southeast Asia,they are attributed to sea salt in PM_(2.5)fine particles(PM_(2.5)SS);and over central Asia,they are attributed to PM_(2.5)DU.They are mainly caused by the different representations of aerosols within individual ESMs including the representation of aerosol size distributions,dynamic transport,and physical and chemistry mechanisms.展开更多
The Bale mountains ecoregion in Ethiopia provides a number of benefits for the local communities mainly in terms of water supply,power generation,tourism activity,and irrigation development.Notwithstanding,the ecoregi...The Bale mountains ecoregion in Ethiopia provides a number of benefits for the local communities mainly in terms of water supply,power generation,tourism activity,and irrigation development.Notwithstanding,the ecoregion has been characterized primarily by recurring floods and droughts,as well as crop failure due to a variety of natural and human-activity-driven change factors.As a matter of fact,the purpose of this study would be to examine long-term changes and fluctuation in precipitation(PCP),maximum temperature(T_(max)),and minimum temperature(T_(min))in the Bale mountains ecoregion using ensembles of three climate models with three representative concentration pathways(RCPs)scenarios from the coupled model inter-comparison project phase five(CMIP5)dataset.Statistical downscaling model(SDSM)was applied to project PCP,T_(max),and T_(min)in the forthcoming period considering three RCPs:low emission(RCP2.6),intermediate(RCP4.5),and high emission(RCP8.5).SDSM's performance in capturing historical daily PCP,T_(max),and T_(min)has been validated using standard statistical metrics such as coefficient of determination(R^(2)),Nash Sutcliff efficiency(NSE),and root mean square error(RMSE).SDSM has the potential to generate a statistical transfer function between large-scale variables and local climate,allowing PCP,T_(max),and T_(min) to be downscaled to a point scale for the ecoregion.The magnitude of mean yearly changes in PCP,T_(max),and T_(min) were investigated throughout three thirty-year time slices,corresponding to the 2020s,2050s,and 2080s.The Mann-Kendall non-parametric test was used to analyse trends in PCP,T_(max),and T_(min) from 2011 to 2100.Inter-annual variability in PCP,T_(max),and T_(min) were investigated for the aforementioned period,taking standard deviation into account under each RCP scenarios.The results reveal that mean annual PCP,T_(max),and T_(min) are rising in all three time slices and in all three CMIP5 RCP scenarios as compared to the baseline scenario.Mean annual PCP is projected to incre展开更多
文摘Three guests with two moiety probes for different Cucurbit[n = 6—8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)- adamataneamine and N-(2-methylenefurfuran)-adamataneamine. The probes are methyle-nepyridyl typically for Q[6] and adamataneamine typically for Q[7]. The host-guest complexes of Cucurbit[n = 6—8]urils with these guests have been investigated by using NMR techniques and ESMS method. Also, thermoanalysis has been used for exploring relationship of enthalpy and stability of the host-guest complexes.
文摘The reactions of carboplatin ([Pt(NH3)2(CBDCA)], in which CBDCA is cyclobutane 1,1, dicarboxylate) with L selenomethionine (L Se MetH) and L methionine (L MetH) were investigated using electrospray mass spectroscopy (ESMS) and 2D HSQC NMR spectroscopy. The dominant products for both reactions are bis chelated complexes [Pt(L Se Met)2] and [Pt(L Met)2]. These results are different from those observed for the reactions of cisplatin ([PtCl2(NH3)]) with L Se MetH or L MetH, in which the main products are mono chelated complexes [PtCl(NH3)(L Se Met)] or [PtCl(NH3)(L Met)]. This work provides insights into the differences between cisplatin and carboplatin in their reactivity and mechanism of reaction.
基金Supported by the National Key Research and Development Program of China(2016YFA0602100)UK–China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.
文摘This study assesses the ability of 10 Earth System Models(ESMs)that participated in the Coupled Model Intercomparison Project Phase 6(CMIP6)to reproduce the present-day inhalable particles with diameters less than 2.5 micrometers(PM_(2.5))over Asia and discusses the uncertainty.PM_(2.5)accounts for more than 30%of the surface total aerosol(fine and coarse)concentration over Asia,except for central Asia.The simulated spatial distributions of PM_(2.5)and its components,averaged from 2005 to 2020,are consistent with the Modern-Era Retrospective Analysis for Research and Applications version 2(MERRA-2)reanalysis.They are characterized by the high PM_(2.5)concentrations in eastern China and northern India where anthropogenic components such as sulfate and organic aerosol dominate,and in northwestern China where the mineral dust in PM_(2.5)fine particles(PM_(2.5)DU)dominates.The present-day multimodel mean(MME)PM_(2.5)concentrations slightly underestimate ground-based observations in the same period of 2014–2019,although observations are affected by the limited coverage of observation sites and the urban areas.Those model biases partly come from other aerosols(such as nitrate and ammonium)not involved in our analyses,and also are contributed by large uncertainty in PM_(2.5)simulations on local scale among ESMs.The model uncertainties over East Asia are mainly attributed to sulfate and PM_(2.5)DU;over South Asia,they are attributed to sulfate,organic aerosol,and PM_(2.5)DU;over Southeast Asia,they are attributed to sea salt in PM_(2.5)fine particles(PM_(2.5)SS);and over central Asia,they are attributed to PM_(2.5)DU.They are mainly caused by the different representations of aerosols within individual ESMs including the representation of aerosol size distributions,dynamic transport,and physical and chemistry mechanisms.
文摘The Bale mountains ecoregion in Ethiopia provides a number of benefits for the local communities mainly in terms of water supply,power generation,tourism activity,and irrigation development.Notwithstanding,the ecoregion has been characterized primarily by recurring floods and droughts,as well as crop failure due to a variety of natural and human-activity-driven change factors.As a matter of fact,the purpose of this study would be to examine long-term changes and fluctuation in precipitation(PCP),maximum temperature(T_(max)),and minimum temperature(T_(min))in the Bale mountains ecoregion using ensembles of three climate models with three representative concentration pathways(RCPs)scenarios from the coupled model inter-comparison project phase five(CMIP5)dataset.Statistical downscaling model(SDSM)was applied to project PCP,T_(max),and T_(min)in the forthcoming period considering three RCPs:low emission(RCP2.6),intermediate(RCP4.5),and high emission(RCP8.5).SDSM's performance in capturing historical daily PCP,T_(max),and T_(min)has been validated using standard statistical metrics such as coefficient of determination(R^(2)),Nash Sutcliff efficiency(NSE),and root mean square error(RMSE).SDSM has the potential to generate a statistical transfer function between large-scale variables and local climate,allowing PCP,T_(max),and T_(min) to be downscaled to a point scale for the ecoregion.The magnitude of mean yearly changes in PCP,T_(max),and T_(min) were investigated throughout three thirty-year time slices,corresponding to the 2020s,2050s,and 2080s.The Mann-Kendall non-parametric test was used to analyse trends in PCP,T_(max),and T_(min) from 2011 to 2100.Inter-annual variability in PCP,T_(max),and T_(min) were investigated for the aforementioned period,taking standard deviation into account under each RCP scenarios.The results reveal that mean annual PCP,T_(max),and T_(min) are rising in all three time slices and in all three CMIP5 RCP scenarios as compared to the baseline scenario.Mean annual PCP is projected to incre
