To better reduce the carbon emissions of a park-integrated energy system(PIES),optimize the comprehensive operating cost,and smooth the load curve,a source-load flexible response model based on the comprehensive evalu...To better reduce the carbon emissions of a park-integrated energy system(PIES),optimize the comprehensive operating cost,and smooth the load curve,a source-load flexible response model based on the comprehensive evaluation index is proposed.Firstly,a source-load flexible response model is proposed under the stepped carbon trading mechanism;the organic Rankine cycle is introduced into the source-side to construct a flexible response model with traditional combined heat and power(CHP)unit and electric boiler to realize the flexible response of CHP to load;and the load-side categorizes loads into transferable,interruptible,and substitutable loads according to the load characteristics and establishes a comprehensive demand response model.Secondly,the analytic network process(ANP)considers the linkages between indicators and allows decision-makers to consider the interactions of elements in a complex dynamic system,resulting in more realistic indicator assignment values.Considering the economy,energy efficiency,and environment,the PIES optimization operation model based on the ANP comprehensive evaluation index is constructed to optimize the system operation comprehensively.Finally,the CPLEX solver inMATLABwas employed to solve the problem.The results of the example showthat the source-load flexible response model proposed in this paper reduces the operating cost of the system by 29.90%,improves the comprehensive utilization rate by 15.00%,and reduces the carbon emission by 26.98%,which effectively enhances the system’s economy and low carbon,and the comprehensive evaluation index based on the ANP reaches 0.95,which takes into account the economy,energy efficiency,and the environment,and is more superior than the single evaluation index.展开更多
Nonhuman primates(NHPs)present significant advantages over rodents for physiological and pharmacological investigations because of their higher genetic and physiological similarity to humans.
Building emission reduction is an important way to achieve China’s carbon peaking and carbon neutrality goals.Aiming at the problem of low carbon economic operation of a photovoltaic energy storage building system,a ...Building emission reduction is an important way to achieve China’s carbon peaking and carbon neutrality goals.Aiming at the problem of low carbon economic operation of a photovoltaic energy storage building system,a multi-time scale optimal scheduling strategy based on model predictive control(MPC)is proposed under the consideration of load optimization.First,load optimization is achieved by controlling the charging time of electric vehicles as well as adjusting the air conditioning operation temperature,and the photovoltaic energy storage building system model is constructed to propose a day-ahead scheduling strategy with the lowest daily operation cost.Second,considering inter-day to intra-day source-load prediction error,an intraday rolling optimal scheduling strategy based on MPC is proposed that dynamically corrects the day-ahead dispatch results to stabilize system power fluctuations and promote photovoltaic consumption.Finally,taking an office building on a summer work day as an example,the effectiveness of the proposed scheduling strategy is verified.The results of the example show that the strategy reduces the total operating cost of the photovoltaic energy storage building system by 17.11%,improves the carbon emission reduction by 7.99%,and the photovoltaic consumption rate reaches 98.57%,improving the system’s low-carbon and economic performance.展开更多
Iron-containing zeolite catalysts(Fe-zeolites)demonstrate exceptional performance in selective oxidation of methane to C1 oxygenates,while aerobic C-C coupling to C_(2) hydrocarbons has remained elusive.The heterogene...Iron-containing zeolite catalysts(Fe-zeolites)demonstrate exceptional performance in selective oxidation of methane to C1 oxygenates,while aerobic C-C coupling to C_(2) hydrocarbons has remained elusive.The heterogeneity of Fe species within zeolites,intertwined with kinetically competing over-oxidation processes,engenders ambiguities in determining catalytic pathways,thereby fundamentally impeding rational design of the catalyst.Here,we report that continuous aerobic C-C coupling of methane can be achieved under oxygen-lean conditions over tailored Fezeolites.Crucially,the oxygen-lean environment enables clear identification of distinct active-site roles:CO is directly generated on low-coordinated monomeric Fe sites,while C_(2) hydrocarbons formation predominantly occurs on coordinatively saturated monomeric Fe sites.Detailed spectroscopic studies and density functional theory(DFT)calculation reveals that steric effect of octahedral-coordinated monomeric Fe^(3+) Lewis acid sites(LAS)compels ^(*)CH_(3) species to preferentially bind to the Brønsted acid sites(BAS),facilitating C-C coupling and suppressing overoxidation.Furthermore,the Mars-van Krevelen(MvK)mechanism is verified as a feasible pathway for methane-to-ethane conversion.This work elucidates the critical role of Fe site coordination in dictating reaction pathways during oxygen-mediated methane conversion.展开更多
Birefringent materials play indispensable roles in modulating the polarization of light and are vital in the laser science and technology.Currently,the design of birefringent materials operating in the deep-ultraviole...Birefringent materials play indispensable roles in modulating the polarization of light and are vital in the laser science and technology.Currently,the design of birefringent materials operating in the deep-ultraviolet region(DUV,λ≤200 nm)is still a great challenge.In this work,we developed a new DUV birefringent crystal LiBO_(2) based on[BO2]∞infinite chains in the Li-B-O system,which simultaneously achieves the shortest UV cutoff edge(164 nm)and the largest birefringence(≥0.168 at 266 nm)among all the reported borate-based DUV birefringent materials.Single crystals of LiBO_(2) with dimensions up to Ø55×34 mm^(3) were grown by the Czochralski method,providing access to large-sized single crystal with low cost.Moreover,it has a high laser damage threshold and stable physicochemical properties.These outstanding characters unambiguously support that LiBO_(2) can be an excellent birefringent material for DUV application.展开更多
Non-human primates(NHPs)are increasingly used in preclinical trials to test the safety and efficacy of biotech-nology therapies.Nonetheless,given the ethical issues and costs associated with this model,it would be hig...Non-human primates(NHPs)are increasingly used in preclinical trials to test the safety and efficacy of biotech-nology therapies.Nonetheless,given the ethical issues and costs associated with this model,it would be highly advantageous to use NHP cellular models in clinical studies.However,developing and maintaining the naive state of primate pluripotent stem cells(PSCs)remains difficult as does in vivo detection of PSCs,thus limiting biotech-nology application in the cynomolgus monkey.Here,we report a chemically defined,xeno-free culture system for culturing and deriving monkey PSCs in vitro.The cells display global gene expression and genome-wide hypometh-ylation patterns distinct from monkey-primed cells.We also found expression of signaling pathways components that may increase the potential for chimera formation.Crucially for biomedical applications,we were also able to integrate bioluminescent reporter genes into monkey PsCs and track them in chimeric embryos in vivo and in vitro.The engineered cells retained embryonic and extra-embryonic developmental potential.Meanwhile,we generated a chimeric monkey carrying bioluminescent cells,which were able to track chimeric cells for more than 2 years in living animals.Our study could have broad utility in primate stem cell engineering and in utilizing chimeric monkey models forclinical studies.展开更多
文摘To better reduce the carbon emissions of a park-integrated energy system(PIES),optimize the comprehensive operating cost,and smooth the load curve,a source-load flexible response model based on the comprehensive evaluation index is proposed.Firstly,a source-load flexible response model is proposed under the stepped carbon trading mechanism;the organic Rankine cycle is introduced into the source-side to construct a flexible response model with traditional combined heat and power(CHP)unit and electric boiler to realize the flexible response of CHP to load;and the load-side categorizes loads into transferable,interruptible,and substitutable loads according to the load characteristics and establishes a comprehensive demand response model.Secondly,the analytic network process(ANP)considers the linkages between indicators and allows decision-makers to consider the interactions of elements in a complex dynamic system,resulting in more realistic indicator assignment values.Considering the economy,energy efficiency,and environment,the PIES optimization operation model based on the ANP comprehensive evaluation index is constructed to optimize the system operation comprehensively.Finally,the CPLEX solver inMATLABwas employed to solve the problem.The results of the example showthat the source-load flexible response model proposed in this paper reduces the operating cost of the system by 29.90%,improves the comprehensive utilization rate by 15.00%,and reduces the carbon emission by 26.98%,which effectively enhances the system’s economy and low carbon,and the comprehensive evaluation index based on the ANP reaches 0.95,which takes into account the economy,energy efficiency,and the environment,and is more superior than the single evaluation index.
基金financially supported by the National Natural Science Foundation of China(Grant No.U1602224)the National Key Research and Development Program of China(2018YFA0107902 and 2016YFA0101401)。
文摘Nonhuman primates(NHPs)present significant advantages over rodents for physiological and pharmacological investigations because of their higher genetic and physiological similarity to humans.
文摘Building emission reduction is an important way to achieve China’s carbon peaking and carbon neutrality goals.Aiming at the problem of low carbon economic operation of a photovoltaic energy storage building system,a multi-time scale optimal scheduling strategy based on model predictive control(MPC)is proposed under the consideration of load optimization.First,load optimization is achieved by controlling the charging time of electric vehicles as well as adjusting the air conditioning operation temperature,and the photovoltaic energy storage building system model is constructed to propose a day-ahead scheduling strategy with the lowest daily operation cost.Second,considering inter-day to intra-day source-load prediction error,an intraday rolling optimal scheduling strategy based on MPC is proposed that dynamically corrects the day-ahead dispatch results to stabilize system power fluctuations and promote photovoltaic consumption.Finally,taking an office building on a summer work day as an example,the effectiveness of the proposed scheduling strategy is verified.The results of the example show that the strategy reduces the total operating cost of the photovoltaic energy storage building system by 17.11%,improves the carbon emission reduction by 7.99%,and the photovoltaic consumption rate reaches 98.57%,improving the system’s low-carbon and economic performance.
基金supported by the National Key R&D Program of China(No.2022YFA1504700)the National Natural Science Foundation of China(Nos.22378414 and 21908236)the Youth Innovation Promotion Association CAS(No.2022287).
文摘Iron-containing zeolite catalysts(Fe-zeolites)demonstrate exceptional performance in selective oxidation of methane to C1 oxygenates,while aerobic C-C coupling to C_(2) hydrocarbons has remained elusive.The heterogeneity of Fe species within zeolites,intertwined with kinetically competing over-oxidation processes,engenders ambiguities in determining catalytic pathways,thereby fundamentally impeding rational design of the catalyst.Here,we report that continuous aerobic C-C coupling of methane can be achieved under oxygen-lean conditions over tailored Fezeolites.Crucially,the oxygen-lean environment enables clear identification of distinct active-site roles:CO is directly generated on low-coordinated monomeric Fe sites,while C_(2) hydrocarbons formation predominantly occurs on coordinatively saturated monomeric Fe sites.Detailed spectroscopic studies and density functional theory(DFT)calculation reveals that steric effect of octahedral-coordinated monomeric Fe^(3+) Lewis acid sites(LAS)compels ^(*)CH_(3) species to preferentially bind to the Brønsted acid sites(BAS),facilitating C-C coupling and suppressing overoxidation.Furthermore,the Mars-van Krevelen(MvK)mechanism is verified as a feasible pathway for methane-to-ethane conversion.This work elucidates the critical role of Fe site coordination in dictating reaction pathways during oxygen-mediated methane conversion.
基金financially supported by the National Natural Science:Foundation of China(61875229 and 61922084)the West Light Foundation of CAS(2020-JCTD-0021.the Youth Innovation Promotion Association of CAS(2020429)the Scence and Technology Service Network Iitiative of CAS(KFJ-STS-QYZD-1301.and the Instrument Developing Project of CAS(GJISTD20200007).
文摘Birefringent materials play indispensable roles in modulating the polarization of light and are vital in the laser science and technology.Currently,the design of birefringent materials operating in the deep-ultraviolet region(DUV,λ≤200 nm)is still a great challenge.In this work,we developed a new DUV birefringent crystal LiBO_(2) based on[BO2]∞infinite chains in the Li-B-O system,which simultaneously achieves the shortest UV cutoff edge(164 nm)and the largest birefringence(≥0.168 at 266 nm)among all the reported borate-based DUV birefringent materials.Single crystals of LiBO_(2) with dimensions up to Ø55×34 mm^(3) were grown by the Czochralski method,providing access to large-sized single crystal with low cost.Moreover,it has a high laser damage threshold and stable physicochemical properties.These outstanding characters unambiguously support that LiBO_(2) can be an excellent birefringent material for DUV application.
基金supported by grants from the National Key R&D Program of China(2021YFA0805700 and 2021YFA1102000)the National Natural Science Foundation of China(U2102204)the Natural Science Foundation of Yunnan Province(202001BC070001 and 202102AA100053).
文摘Non-human primates(NHPs)are increasingly used in preclinical trials to test the safety and efficacy of biotech-nology therapies.Nonetheless,given the ethical issues and costs associated with this model,it would be highly advantageous to use NHP cellular models in clinical studies.However,developing and maintaining the naive state of primate pluripotent stem cells(PSCs)remains difficult as does in vivo detection of PSCs,thus limiting biotech-nology application in the cynomolgus monkey.Here,we report a chemically defined,xeno-free culture system for culturing and deriving monkey PSCs in vitro.The cells display global gene expression and genome-wide hypometh-ylation patterns distinct from monkey-primed cells.We also found expression of signaling pathways components that may increase the potential for chimera formation.Crucially for biomedical applications,we were also able to integrate bioluminescent reporter genes into monkey PsCs and track them in chimeric embryos in vivo and in vitro.The engineered cells retained embryonic and extra-embryonic developmental potential.Meanwhile,we generated a chimeric monkey carrying bioluminescent cells,which were able to track chimeric cells for more than 2 years in living animals.Our study could have broad utility in primate stem cell engineering and in utilizing chimeric monkey models forclinical studies.
