Metal-organic frameworks(MOFs),which are constructed by metal ions or clusters with organic ligands,have shown great potential in gas storage and separation,luminescence,catalysis,drug delivery,sensing,so on.More than...Metal-organic frameworks(MOFs),which are constructed by metal ions or clusters with organic ligands,have shown great potential in gas storage and separation,luminescence,catalysis,drug delivery,sensing,so on.More than 20,000 MOFs have been reported by adjusting the composition and reaction conditions,most of them were synthesized by hydrothermal or solvothermal methods.The conventional solvothermal methods are favorable for the slow crystallization of MOFs to obtain single crystals or highly crystalline powders,which are suitable for the structure analysis.However,their harsh synthesis conditions,long reaction time,difficulty in continuous synthesis limit their scale-up in industrial production and application.Meanwhile,shaping or processing is also required to bring MOF crystals and powders into the market.Therefore,this review demonstrates the crystallization mechanisms of MOFs to understand how the synthetic parameters affect the final products.Additionally,a variety of promising synthetic routes which can be used for large scale synthesis were reviewed in details.Lastly,the prospects of MOF shaping and processing are provided to promote their industrial application.展开更多
Generally fuzzy control system (FCS) is worked in washing machine. For the fuzzy set theory, membership functions are the building blocks. In a fuzzy set, fuzziness is determined by its membership functions. The shape...Generally fuzzy control system (FCS) is worked in washing machine. For the fuzzy set theory, membership functions are the building blocks. In a fuzzy set, fuzziness is determined by its membership functions. The shapes of membership functions are important, because it has an effect on fuzzy inference system. The shapes of membership functions can be triangular, trapezoidal and gaussian. The most widely used triangular membership function is used in this paper, because it can capture the short time period. In washing machine, open loop control system is found. This paper applies a fuzzy synthetic evaluation method (FSEM) for washing cloth in washing machine as FSEM can handle the multiple criteria with the help of evaluation matrix generated from membership function and weight matrix generated by Analytical Hierarchy Process (AHP). The purpose of this research is to minimize the wash time. By applying FSEM, we get a wash time which is less than that wash time got from applying the Mamdani approach in FCS. An example is given for illustration. For more reduction of wash time, statistical averaging method is also used. To reduce the wash time, statistical averaging method can be used in Mamdani approach also.展开更多
Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial pane...Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.展开更多
In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and ch...In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and chemical stabilities.This review summarizes the latest strategies of synthesizing ZIF-67-based materials by exploring the prominent examples.Then,the recent progress in the applications of ZIF-67-based materials in heterogeneous catalysis,including catalysis of the redox reactions,addition reactions,esterification reactions,Knoevenagel condensations,and hydrogenation-dehydrogenation reactions,has been elaborately discussed.Finally,we end this work by shedding some light on the large-scale industrial production of ZIF-67-based materials and their applications in the future.展开更多
Lithium-sulfur(Li-S)batteries,although a promising candidate of next-generation energy storage devices,are hindered by some bottlenecks in their roadmap toward commercialization.The key challenges include solving the ...Lithium-sulfur(Li-S)batteries,although a promising candidate of next-generation energy storage devices,are hindered by some bottlenecks in their roadmap toward commercialization.The key challenges include solving the issues such as low utilization of active materials,poor cyclic stability,poor rate performance,and unsatisfactory Coulombic efficiency due to the inherent poor electrical and ionic conductivity of sulfur and its discharged products(e.g.,Li2S2 and Li_(2)S),dissolution and migration of polysulfide ions in the electrolyte,unstable solid electrolyte interphase and dendritic growth on an odes,and volume change in both cathodes and anodes.Owing to the high specific surface area,pore volume,low density,good chemical stability,and particularly multimodal pore sizes,hierarchical porous carbon(HPC)mate rials have received considerable attention for circumventing the above pro blems in Li-S batteries.Herein,recent progress made in the synthetic methods and deployment of HPC materials for various components including sulfur cathodes,separators and interlayers,and lithium anodes in Li-S batteries is presented and summarized.More importantly,the correlation between the structures(pore volume,specific surface area,degree of pores,and heteroatom-doping)of HPC and the electrochemical performances of Li-S batteries is elaborated.Finally,a discussion on the challenges and future perspectives associated with HPCs for Li-S batteries is provided.展开更多
Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity,selectivity,wide concentration range,low detection limits,and excellent recyclabil...Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity,selectivity,wide concentration range,low detection limits,and excellent recyclability.Spinel NiCo2O4 mixed oxides have drawn considerable attention recently due to their outstanding advantages including large specific surface area,high permeability,short electron,and ion diffusion pathways.Because of the rapid development of non-enzyme biosensors,the current state of methods for synthesis of pure and composite/hybrid NiCo2P4 materials and their subsequent electrochemical biosensing applications are systematically and comprehensively reviewed herein.Comparative analysis reveals better electrochemical sensing of bioanalytes by one-dimensional and two-dimensional NiCo2O4 nano-/microstructures than other morphologies.Better biosensing efficiency of NiCo2O4 as compared to corresponding individual metal oxides,viz.NiO and Co3O4,is attributed to the close intrinsic-state redox couples of Ni3+/Ni2+(0.58 V/0.49 V) and Co3+/Co2+(0.53 V/0.51 V).Biosensing performance of NiCo2O4 is also significantly improved by making the composites of NiCo2O4 with conducting carbonaceous materials like graphene,reduced graphene oxide,carbon nanotubes(single and multi-walled),carbon nanofibers;conducting polymers like polypyrrole(PPy),polyaniline(PANI);metal oxides NiO,Co3O4,SnO2,MnO2;and metals like Au,Pd,etc.Various factors affecting the morphologies and biosensing parameters of the nano-/microstructured NiCo2O4 are also highlighted.Finally,some drawbacks and future perspectives related to this promising field are outlined.展开更多
Insufficient assessment of emission reduction effects still exists in the carbon emission rights trading system,a major environmental regulation measure in China.Based on the data from the carbon trading pilot coverin...Insufficient assessment of emission reduction effects still exists in the carbon emission rights trading system,a major environmental regulation measure in China.Based on the data from the carbon trading pilot covering the years from 2007 to 2017,this study combined the synthetic control method with dynamic spatial Durbin model to comprehensively evaluate the spatial emission reduction effects of carbon trading policies.The results showed that:①The carbon trading policies promoted carbon emission reductions in the pilot regions,among which Tianjin and Hubei responded significantly,and also helped to suppress carbon emissions in the neighboring areas.②Long-term emission reduction effect from carbon emissions trading became gradually significant,while the indirect emission reduction effect was relatively weaker.③In term of reducing carbon emissions,the economic development channel played a key role,but it had a threat to the promotion of carbon emissions in the surrounding areas.Energy consumption was the main obstacle to the growth of carbon emissions.④In the long run,technological progress tended to become the key to the effective implementation of potential emission reduction effects of carbon trading policies.Based on the above findings,we suggest that the construction of a national carbon trading market should be promoted,the balanced development and orderly advancement of regional carbon trading markets should be paid attention to,the coordinated development of green economy as well as knowledge and technology exchange and cooperation among regions should be strengthened to form a low carbon development model among regions.展开更多
In the paper, members in farmer cooperatives are selected as investigation subjects. By using fuzzy synthetic evaluation methods, functions of farmer cooperatives, which include six functions as follows: providing tec...In the paper, members in farmer cooperatives are selected as investigation subjects. By using fuzzy synthetic evaluation methods, functions of farmer cooperatives, which include six functions as follows: providing technology and information, marketing, processing and transportation, standardized services, and credit services and rights protection, are analyzed. The quantitative analysis is conducted on the developmental status of the functions of farmer cooperatives. The evaluation results are taken as evidence to anticipate the problems in the development of farmer cooperatives and then countermeasures are put forward, including intensifying the construction of actual functions of farmer cooperatives; contracting diversified credit and loan services; improving comprehensive strength of farmer cooperatives and taking the path of combining professional and comprehensive developmental paths. This study improves our knowledge on the development of farmer cooperatives and provides new insights to solve the problems that arise following the development.展开更多
With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry o...With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.展开更多
Tetralin-1-carboxamides are frequently incorporated in myriad medicinally important molecules.However,their existing synthetic routes not only suffer from some drawbacks such as tedious procedures,harsh reaction condi...Tetralin-1-carboxamides are frequently incorporated in myriad medicinally important molecules.However,their existing synthetic routes not only suffer from some drawbacks such as tedious procedures,harsh reaction conditions,narrow substrate scope,low yields,and environmental problems,but are also based upon the elaboration of uneasily available non-linear tetralin derivatives.Herein,we describe a metal-and additive-free visible light-induced[4+2]annulation of two simple linear starting materials,namely acrylamides and 2-benzyl-2-bromocarbonyls,through a cascade C(sp^(3))-Br/C(sp^(2))-H bond cleavage,double C-C bond formation,and aromatization sequence.The developed protocol provides a convenient,efficient,and green approach to a variety of tetralin-1-carboxamide derivatives with good functional group compatibility.Importantly,the resulting products could also undergo the Licl-mediated mono-decarboxylative cyclization process to further furnish the architecturally novel bridged polycyclic imides with excellentcis-diastereoselectivities.展开更多
NiH-catalyzed multicomponent reductive hydrofunctionalization of alkenes is an attractive but poorly explored approach to rapidly increasing molecular complexity.In this process,the selective generation of the desired...NiH-catalyzed multicomponent reductive hydrofunctionalization of alkenes is an attractive but poorly explored approach to rapidly increasing molecular complexity.In this process,the selective generation of the desired product can be challenging.Herein,we report that a highly chemo-,regio-and enantioselective reductive hydrocarbonylation of alkenes has been achieved using a chloroformate ester as a source of CO.A wide range of structurally diverseα-hydroxy ketones,privileged structural elements in bioactive molecules and useful building blocks,were obtained from such reactions with high enantiomeric purity.展开更多
This report discloses a distinctive palladium-catalyzed sequential tandem cyclization reaction of two molecular haloalkynes and one molecular N-alkylanilines,leading to the efficient assembly of various 3-halo-1,2,5-t...This report discloses a distinctive palladium-catalyzed sequential tandem cyclization reaction of two molecular haloalkynes and one molecular N-alkylanilines,leading to the efficient assembly of various 3-halo-1,2,5-triarylpyrrole derivatives.Two carbon-carbon tri-ple bonds and one carbon-halogen bond in two molecular haloalkynes are transformed conveniently in one single step,which may involve the aminoalkynylation of haloalkyne and cyclization of the newly formed enyne intermediate.The high chemo-and regiose-lectivities,good functional group tolerance and late-stage modification of the halopyrrole products further illustrate the synthetic value of this strategy.展开更多
Metal-organic framework(MOF)materials have attracted intense scientific interest in the solar cell research community owing to their unique physiochemical properties and various preparation methods.The photovoltaic pe...Metal-organic framework(MOF)materials have attracted intense scientific interest in the solar cell research community owing to their unique physiochemical properties and various preparation methods.The photovoltaic performance and stability of resultant optoelectronic devices can also be improved by adopting MOF materials.This review pays close attention to the summary and generalization of recent representative achievements in solar cells by utilizing MOFs,including dye-sensitized solar cells,perovskite solar cells,organic solar cells,and so on.展开更多
Polysubstituted pyrroles are very important scaffolds in many bioactive natural products and synthetic pharmaceuticals.Here,a new gold-catalyzed cycloaddition of alkynes with azadienes to access tetrasubstituted pyrro...Polysubstituted pyrroles are very important scaffolds in many bioactive natural products and synthetic pharmaceuticals.Here,a new gold-catalyzed cycloaddition of alkynes with azadienes to access tetrasubstituted pyrroles is demonstrated.The neighboring hydroxylmethyl group serves a very important directing group through an addition/cycloaddition/elimination cascade.Diverse polysubstituted pyrroles were synthesized in good yields under mild conditions in one step,and tricyclic pyrrole containing heterocycles were easily obtained through derivatization.展开更多
The chemistry of alkoxy radicals was extensively explored during the period of 1960s to 1990s,but it has remained dormant for the past few decades.Recently,alkoxy radicals attract the attentions again,because new meth...The chemistry of alkoxy radicals was extensively explored during the period of 1960s to 1990s,but it has remained dormant for the past few decades.Recently,alkoxy radicals attract the attentions again,because new methods for generating alkoxy radical species have emerged.These newly developed methods are mainly based on the photolysis by visible light under mild conditions,thus allowing for new transformations of the carbon-centered radical species that are generated from theβ-scission or hydrogen abstraction of the alkoxy radicals.展开更多
An efficient and practical synthesis of heterocyclic nucleosides is developed by a catalyst-free highly regioselective and diastereose-lective[3+2]annulation of a-purine-substituted acrylates with nitrones.The reactio...An efficient and practical synthesis of heterocyclic nucleosides is developed by a catalyst-free highly regioselective and diastereose-lective[3+2]annulation of a-purine-substituted acrylates with nitrones.The reaction operates with excellent functional group toler-ance,very mild reaction conditions,and with the green,sustainable,and eco-friendly 2-methyltetrahydrofuran(2-MeTHF)as sol-vent.Compared with other reactions of electron-deficient olefin dipolarophiles with nitrones,different regioselective cycloaddition products were observed in this work.This 1,3-dipolar cycloaddition reaction gives a series of isoxazolidinyl nucleosides in good to excellent yields with promising applications in biochemistry and medicinal chemistry.展开更多
A general and straightforward strategy for the synthesis of thioester-substituted oxindoles via a palladium-catalyzed thiocarbonyla-tive cyclization process has been developed.With sulfonyl chlorides as promising sulf...A general and straightforward strategy for the synthesis of thioester-substituted oxindoles via a palladium-catalyzed thiocarbonyla-tive cyclization process has been developed.With sulfonyl chlorides as promising sulfur source,a wide range of thioester-substituted oxindoles were obtained in moderate to high yields.Both aryl and alkyl sulfonyl chlorides were well tolerated,and Mo(CO)6 played a dual role as both a CO source and a reductant in this approach.展开更多
While the accelerated polymerization of N-carboxyanhydrides (NCAs) has been utilized to synthesize versatile polypeptide materials in an efficient manner with minimized side reactions, the preparation of polypeptide-b...While the accelerated polymerization of N-carboxyanhydrides (NCAs) has been utilized to synthesize versatile polypeptide materials in an efficient manner with minimized side reactions, the preparation of polypeptide-based inorganic/organic hybrid materials with the acceleration strategy remained largely unexplored. Herein, we report the accelerated ring-opening polymerization (ROP) of NCAs mediated by amine-modified inorganic nano-initiators, such as mesoporous silica nanoparticles (MSN-NH2), which is driven by the cooperative effect of the neighboring α-helical polypeptide chains in a dichloromethane (DCM)/water biphasic system. Well-defined nano-hybrids were prepared within 15 min from non-purified NCA monomers, through in situ purification and subsequent ultrafast polymerization process. NCAs can be rapidly initiated by amino groups of MSN uniformly dispersed at the interface of DCM and water, and subsequently formed the well-defined polypeptides within 15 min. The prepared inorganic/organic nano-hybrid with MSN as the core and polypeptide as the shell adopted spherical morphology and uniform size distribution due to the excellent controllability of ROP. Besides, this system is also suitable for a variety of NCAs and inorganic nano-initiators. This research allows efficient and rapid preparation of inorganic/organic nano-hybrids, and further promotes the extensive application of this material in the biomedical fields.展开更多
Fused polycyclic N-heterocycles are very important scaffolds in biomedicinal chemistry and materials science.Intramolecular alkyne hydroamination is a powerful method for the construction of N-heterocycles.In the last...Fused polycyclic N-heterocycles are very important scaffolds in biomedicinal chemistry and materials science.Intramolecular alkyne hydroamination is a powerful method for the construction of N-heterocycles.In the last two decades,copper-catalyzed domino reactions based on intramolecular alkyne hydroamination has emerged as a robust strategy for assembling various fused polycyclic N-heterocycles.Great progress has been achieved in this area.This short review covers the advances made in copper-catalyzed domino synthesis of fused polycyclic N-heterocycles based on the strategy from 2008 to 2023,and will hopefully serve as an inspiration towards the exploration of new copper-catalyzed versions of the transformation.The domino transformations are introduced and discussed from five aspects according to the different key processes involved in these reactions.展开更多
Isoindigo(IID)is widely used as organic dye and conjugated unit in opto-electronic materials.Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties.Herein,we dev...Isoindigo(IID)is widely used as organic dye and conjugated unit in opto-electronic materials.Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties.Herein,we developed a direct C-H/N-H activation method of IIDs via double alkyne annulations and synthesizedπ-extended IIDs with two pairs of 5/7 membered rings.The structure of theπ-extended IIDs was characterized and confirmed by^(1)H NMR,^(13)C NMR,HRMS and X ray crystal analysis.Their physical properties were characterized by UV-vis absorption,cyclic voltammetry and thermogravimetric analysis.The absorption coefficient of the annulated products enhanced significantly compared with the non-annulated analogue.展开更多
基金the National Natural Science Foundation of China(Nos.21971017,21901019,and 22205018)the National Key Research and Development Program of China(No.2020YFB1506300),and Beijing Institute of Technology Research Fund Program.
文摘Metal-organic frameworks(MOFs),which are constructed by metal ions or clusters with organic ligands,have shown great potential in gas storage and separation,luminescence,catalysis,drug delivery,sensing,so on.More than 20,000 MOFs have been reported by adjusting the composition and reaction conditions,most of them were synthesized by hydrothermal or solvothermal methods.The conventional solvothermal methods are favorable for the slow crystallization of MOFs to obtain single crystals or highly crystalline powders,which are suitable for the structure analysis.However,their harsh synthesis conditions,long reaction time,difficulty in continuous synthesis limit their scale-up in industrial production and application.Meanwhile,shaping or processing is also required to bring MOF crystals and powders into the market.Therefore,this review demonstrates the crystallization mechanisms of MOFs to understand how the synthetic parameters affect the final products.Additionally,a variety of promising synthetic routes which can be used for large scale synthesis were reviewed in details.Lastly,the prospects of MOF shaping and processing are provided to promote their industrial application.
文摘Generally fuzzy control system (FCS) is worked in washing machine. For the fuzzy set theory, membership functions are the building blocks. In a fuzzy set, fuzziness is determined by its membership functions. The shapes of membership functions are important, because it has an effect on fuzzy inference system. The shapes of membership functions can be triangular, trapezoidal and gaussian. The most widely used triangular membership function is used in this paper, because it can capture the short time period. In washing machine, open loop control system is found. This paper applies a fuzzy synthetic evaluation method (FSEM) for washing cloth in washing machine as FSEM can handle the multiple criteria with the help of evaluation matrix generated from membership function and weight matrix generated by Analytical Hierarchy Process (AHP). The purpose of this research is to minimize the wash time. By applying FSEM, we get a wash time which is less than that wash time got from applying the Mamdani approach in FCS. An example is given for illustration. For more reduction of wash time, statistical averaging method is also used. To reduce the wash time, statistical averaging method can be used in Mamdani approach also.
文摘Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.
基金financial support from the National Natural Science Foundation of China(22008032)the Guangdong Basic and Applied Basic Research Foundation(2019A1515110706)+1 种基金the Shandong Provincial Natural Science Foundation(ZR2020ZD08)the Guangdong Provincial Key Lab of Green Chemical Product Technology(GC202111)
文摘In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and chemical stabilities.This review summarizes the latest strategies of synthesizing ZIF-67-based materials by exploring the prominent examples.Then,the recent progress in the applications of ZIF-67-based materials in heterogeneous catalysis,including catalysis of the redox reactions,addition reactions,esterification reactions,Knoevenagel condensations,and hydrogenation-dehydrogenation reactions,has been elaborately discussed.Finally,we end this work by shedding some light on the large-scale industrial production of ZIF-67-based materials and their applications in the future.
基金Yinyu Xiang is very grateful to the China Scholarship Council(CSC:No.201806950083)for his PhD scholarship。
文摘Lithium-sulfur(Li-S)batteries,although a promising candidate of next-generation energy storage devices,are hindered by some bottlenecks in their roadmap toward commercialization.The key challenges include solving the issues such as low utilization of active materials,poor cyclic stability,poor rate performance,and unsatisfactory Coulombic efficiency due to the inherent poor electrical and ionic conductivity of sulfur and its discharged products(e.g.,Li2S2 and Li_(2)S),dissolution and migration of polysulfide ions in the electrolyte,unstable solid electrolyte interphase and dendritic growth on an odes,and volume change in both cathodes and anodes.Owing to the high specific surface area,pore volume,low density,good chemical stability,and particularly multimodal pore sizes,hierarchical porous carbon(HPC)mate rials have received considerable attention for circumventing the above pro blems in Li-S batteries.Herein,recent progress made in the synthetic methods and deployment of HPC materials for various components including sulfur cathodes,separators and interlayers,and lithium anodes in Li-S batteries is presented and summarized.More importantly,the correlation between the structures(pore volume,specific surface area,degree of pores,and heteroatom-doping)of HPC and the electrochemical performances of Li-S batteries is elaborated.Finally,a discussion on the challenges and future perspectives associated with HPCs for Li-S batteries is provided.
文摘Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity,selectivity,wide concentration range,low detection limits,and excellent recyclability.Spinel NiCo2O4 mixed oxides have drawn considerable attention recently due to their outstanding advantages including large specific surface area,high permeability,short electron,and ion diffusion pathways.Because of the rapid development of non-enzyme biosensors,the current state of methods for synthesis of pure and composite/hybrid NiCo2P4 materials and their subsequent electrochemical biosensing applications are systematically and comprehensively reviewed herein.Comparative analysis reveals better electrochemical sensing of bioanalytes by one-dimensional and two-dimensional NiCo2O4 nano-/microstructures than other morphologies.Better biosensing efficiency of NiCo2O4 as compared to corresponding individual metal oxides,viz.NiO and Co3O4,is attributed to the close intrinsic-state redox couples of Ni3+/Ni2+(0.58 V/0.49 V) and Co3+/Co2+(0.53 V/0.51 V).Biosensing performance of NiCo2O4 is also significantly improved by making the composites of NiCo2O4 with conducting carbonaceous materials like graphene,reduced graphene oxide,carbon nanotubes(single and multi-walled),carbon nanofibers;conducting polymers like polypyrrole(PPy),polyaniline(PANI);metal oxides NiO,Co3O4,SnO2,MnO2;and metals like Au,Pd,etc.Various factors affecting the morphologies and biosensing parameters of the nano-/microstructured NiCo2O4 are also highlighted.Finally,some drawbacks and future perspectives related to this promising field are outlined.
文摘Insufficient assessment of emission reduction effects still exists in the carbon emission rights trading system,a major environmental regulation measure in China.Based on the data from the carbon trading pilot covering the years from 2007 to 2017,this study combined the synthetic control method with dynamic spatial Durbin model to comprehensively evaluate the spatial emission reduction effects of carbon trading policies.The results showed that:①The carbon trading policies promoted carbon emission reductions in the pilot regions,among which Tianjin and Hubei responded significantly,and also helped to suppress carbon emissions in the neighboring areas.②Long-term emission reduction effect from carbon emissions trading became gradually significant,while the indirect emission reduction effect was relatively weaker.③In term of reducing carbon emissions,the economic development channel played a key role,but it had a threat to the promotion of carbon emissions in the surrounding areas.Energy consumption was the main obstacle to the growth of carbon emissions.④In the long run,technological progress tended to become the key to the effective implementation of potential emission reduction effects of carbon trading policies.Based on the above findings,we suggest that the construction of a national carbon trading market should be promoted,the balanced development and orderly advancement of regional carbon trading markets should be paid attention to,the coordinated development of green economy as well as knowledge and technology exchange and cooperation among regions should be strengthened to form a low carbon development model among regions.
基金Supported by Humanities and Social Sciences Fund of Ministry of Education (2010-2012,09YJA790165)
文摘In the paper, members in farmer cooperatives are selected as investigation subjects. By using fuzzy synthetic evaluation methods, functions of farmer cooperatives, which include six functions as follows: providing technology and information, marketing, processing and transportation, standardized services, and credit services and rights protection, are analyzed. The quantitative analysis is conducted on the developmental status of the functions of farmer cooperatives. The evaluation results are taken as evidence to anticipate the problems in the development of farmer cooperatives and then countermeasures are put forward, including intensifying the construction of actual functions of farmer cooperatives; contracting diversified credit and loan services; improving comprehensive strength of farmer cooperatives and taking the path of combining professional and comprehensive developmental paths. This study improves our knowledge on the development of farmer cooperatives and provides new insights to solve the problems that arise following the development.
基金supported by the Major Program of National Social Science Foundation,China(19ZDA083)National Natural Science Foundation,China(71603193 and 71974151)Teaching&Research Project of Wuhan University,China(1201-413200127)。
文摘With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.
基金supported by the National Natural Science Foundation of China(Nos.22101237,22171233)the Science and Technology Program of Sichuan Province(Nos.2022YFS0608,2022NSFSC1219)+1 种基金the Open Project Program of Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province(Nos.HYX21003,HYX22008)the research fund of Southwest Medical University(2021ZKMS042).
文摘Tetralin-1-carboxamides are frequently incorporated in myriad medicinally important molecules.However,their existing synthetic routes not only suffer from some drawbacks such as tedious procedures,harsh reaction conditions,narrow substrate scope,low yields,and environmental problems,but are also based upon the elaboration of uneasily available non-linear tetralin derivatives.Herein,we describe a metal-and additive-free visible light-induced[4+2]annulation of two simple linear starting materials,namely acrylamides and 2-benzyl-2-bromocarbonyls,through a cascade C(sp^(3))-Br/C(sp^(2))-H bond cleavage,double C-C bond formation,and aromatization sequence.The developed protocol provides a convenient,efficient,and green approach to a variety of tetralin-1-carboxamide derivatives with good functional group compatibility.Importantly,the resulting products could also undergo the Licl-mediated mono-decarboxylative cyclization process to further furnish the architecturally novel bridged polycyclic imides with excellentcis-diastereoselectivities.
基金Support was provided by NSFC (92156004,22271143,22271146)NSF of Jiangsu Province (BK20190281,BK20201245)+1 种基金programs for high-level entrepreneurial and innovative talents introduction of Jiangsu Province (group program),Fundamental Research Funds for the Central Universities (020514380282)Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University.Gao Deng thanks the National College Students'Innovation and Entrepreneurship Training Program (0205145031).
文摘NiH-catalyzed multicomponent reductive hydrofunctionalization of alkenes is an attractive but poorly explored approach to rapidly increasing molecular complexity.In this process,the selective generation of the desired product can be challenging.Herein,we report that a highly chemo-,regio-and enantioselective reductive hydrocarbonylation of alkenes has been achieved using a chloroformate ester as a source of CO.A wide range of structurally diverseα-hydroxy ketones,privileged structural elements in bioactive molecules and useful building blocks,were obtained from such reactions with high enantiomeric purity.
基金The authors thank the National Natural Science Foundation of China(22071063 and 21871095)the Guangdong Basic and Applied Basic Research Foundation(2021B1515020058)the Key-Area Research and Development Program of Guangdong Province(2020B010188001)forfinancialsupport.
文摘This report discloses a distinctive palladium-catalyzed sequential tandem cyclization reaction of two molecular haloalkynes and one molecular N-alkylanilines,leading to the efficient assembly of various 3-halo-1,2,5-triarylpyrrole derivatives.Two carbon-carbon tri-ple bonds and one carbon-halogen bond in two molecular haloalkynes are transformed conveniently in one single step,which may involve the aminoalkynylation of haloalkyne and cyclization of the newly formed enyne intermediate.The high chemo-and regiose-lectivities,good functional group tolerance and late-stage modification of the halopyrrole products further illustrate the synthetic value of this strategy.
基金The authors would like to acknowledge funding support from the National Natural Science Foundation of China(U21A20172,21975028)the Beijing Natural Science Foundation(JQ19008)the China Postdoctoral Science Foundation(2020M670144).
文摘Metal-organic framework(MOF)materials have attracted intense scientific interest in the solar cell research community owing to their unique physiochemical properties and various preparation methods.The photovoltaic performance and stability of resultant optoelectronic devices can also be improved by adopting MOF materials.This review pays close attention to the summary and generalization of recent representative achievements in solar cells by utilizing MOFs,including dye-sensitized solar cells,perovskite solar cells,organic solar cells,and so on.
基金the financial support from the Natural Science Foundation of China and Shandong Province(Nos.21971149,92156007,ZR2019ZD45,ZR2020KB005)the Fundamental Research Funds of Shandong University。
文摘Polysubstituted pyrroles are very important scaffolds in many bioactive natural products and synthetic pharmaceuticals.Here,a new gold-catalyzed cycloaddition of alkynes with azadienes to access tetrasubstituted pyrroles is demonstrated.The neighboring hydroxylmethyl group serves a very important directing group through an addition/cycloaddition/elimination cascade.Diverse polysubstituted pyrroles were synthesized in good yields under mild conditions in one step,and tricyclic pyrrole containing heterocycles were easily obtained through derivatization.
基金The project is supported by NSFC(91956104),BNLMS,and Laboratory for Synthetic Chemistry and Chemical Biology of Health@InnoHK of ITC,HKSAR.
文摘The chemistry of alkoxy radicals was extensively explored during the period of 1960s to 1990s,but it has remained dormant for the past few decades.Recently,alkoxy radicals attract the attentions again,because new methods for generating alkoxy radical species have emerged.These newly developed methods are mainly based on the photolysis by visible light under mild conditions,thus allowing for new transformations of the carbon-centered radical species that are generated from theβ-scission or hydrogen abstraction of the alkoxy radicals.
基金We gratefully acknowledge HKBU RC-Tier 2 Start-up Grant for financial support.
文摘An efficient and practical synthesis of heterocyclic nucleosides is developed by a catalyst-free highly regioselective and diastereose-lective[3+2]annulation of a-purine-substituted acrylates with nitrones.The reaction operates with excellent functional group toler-ance,very mild reaction conditions,and with the green,sustainable,and eco-friendly 2-methyltetrahydrofuran(2-MeTHF)as sol-vent.Compared with other reactions of electron-deficient olefin dipolarophiles with nitrones,different regioselective cycloaddition products were observed in this work.This 1,3-dipolar cycloaddition reaction gives a series of isoxazolidinyl nucleosides in good to excellent yields with promising applications in biochemistry and medicinal chemistry.
基金We thank the financial supports from the Natural Science Foundationof Zhejiang Province(LY21B020010).
文摘A general and straightforward strategy for the synthesis of thioester-substituted oxindoles via a palladium-catalyzed thiocarbonyla-tive cyclization process has been developed.With sulfonyl chlorides as promising sulfur source,a wide range of thioester-substituted oxindoles were obtained in moderate to high yields.Both aryl and alkyl sulfonyl chlorides were well tolerated,and Mo(CO)6 played a dual role as both a CO source and a reductant in this approach.
基金supported by the National Natural Science Foundation of China(22101194 and 52273144)Science and Technology Department of Jiangsu Province(BK20210733).
文摘While the accelerated polymerization of N-carboxyanhydrides (NCAs) has been utilized to synthesize versatile polypeptide materials in an efficient manner with minimized side reactions, the preparation of polypeptide-based inorganic/organic hybrid materials with the acceleration strategy remained largely unexplored. Herein, we report the accelerated ring-opening polymerization (ROP) of NCAs mediated by amine-modified inorganic nano-initiators, such as mesoporous silica nanoparticles (MSN-NH2), which is driven by the cooperative effect of the neighboring α-helical polypeptide chains in a dichloromethane (DCM)/water biphasic system. Well-defined nano-hybrids were prepared within 15 min from non-purified NCA monomers, through in situ purification and subsequent ultrafast polymerization process. NCAs can be rapidly initiated by amino groups of MSN uniformly dispersed at the interface of DCM and water, and subsequently formed the well-defined polypeptides within 15 min. The prepared inorganic/organic nano-hybrid with MSN as the core and polypeptide as the shell adopted spherical morphology and uniform size distribution due to the excellent controllability of ROP. Besides, this system is also suitable for a variety of NCAs and inorganic nano-initiators. This research allows efficient and rapid preparation of inorganic/organic nano-hybrids, and further promotes the extensive application of this material in the biomedical fields.
基金financial supports from the Natural Science Foundation of Zhejiang Province(LY21B020005)the National Natural Science Foundation of China(21202152).
文摘Fused polycyclic N-heterocycles are very important scaffolds in biomedicinal chemistry and materials science.Intramolecular alkyne hydroamination is a powerful method for the construction of N-heterocycles.In the last two decades,copper-catalyzed domino reactions based on intramolecular alkyne hydroamination has emerged as a robust strategy for assembling various fused polycyclic N-heterocycles.Great progress has been achieved in this area.This short review covers the advances made in copper-catalyzed domino synthesis of fused polycyclic N-heterocycles based on the strategy from 2008 to 2023,and will hopefully serve as an inspiration towards the exploration of new copper-catalyzed versions of the transformation.The domino transformations are introduced and discussed from five aspects according to the different key processes involved in these reactions.
基金This work is supported by the NSFC(Nos.22071254,21790363,22021002,22090021,22171245)X.-S.Zhang is grateful for the funding from Youth Innovation Promotion Association CAs(No.2021032)+1 种基金This work is also supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.121111KYSB20200022)the CAS-Croucher Funding Scheme for Joint Laboratories.
文摘Isoindigo(IID)is widely used as organic dye and conjugated unit in opto-electronic materials.Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties.Herein,we developed a direct C-H/N-H activation method of IIDs via double alkyne annulations and synthesizedπ-extended IIDs with two pairs of 5/7 membered rings.The structure of theπ-extended IIDs was characterized and confirmed by^(1)H NMR,^(13)C NMR,HRMS and X ray crystal analysis.Their physical properties were characterized by UV-vis absorption,cyclic voltammetry and thermogravimetric analysis.The absorption coefficient of the annulated products enhanced significantly compared with the non-annulated analogue.