With the purpose of searching for a convenient process to synthesize nanoparticles with special structure,a simple solid-state reaction in the presence of nonionic surfactant OP-10 at room temperature was adopted to p...With the purpose of searching for a convenient process to synthesize nanoparticles with special structure,a simple solid-state reaction in the presence of nonionic surfactant OP-10 at room temperature was adopted to prepare copper nitrate hydroxide(Cu_(2)(OH)_(3)NO_(3))nanorings with an average internal diameter of 250 nm and average wall thickness of 100 nm.The formation of Cu_(2)(OH)_(3)NO_(3) nanorings has a close relation with OP-10.Transmission electron microscopy(TEM),field emission scanning electron microscopy(FESEM),thermogravimetric analysis(TGA)and X-ray diffractometry(XRD)were used to characterize the obtained nanorings.The UV-Vis spectrum shows that the optical property of Cu_(2)(OH)_(3)NO_(3) nanorings is similar to that of CuO or CuS.The synthesis method used here proves both simplicity and high efficiency.展开更多
An unprecedented copper nitrate-mediated bond cleavage of alkynes was developed for the modular synthesis of isoxazoles,where either C—S bond or C≡C triple bond was cleaved selectively.Substituents attached to the C...An unprecedented copper nitrate-mediated bond cleavage of alkynes was developed for the modular synthesis of isoxazoles,where either C—S bond or C≡C triple bond was cleaved selectively.Substituents attached to the C≡C triple bonds could differentiate the chemical bonds cleavage and reaction pathways disparately.Various transformations of products illustrate promising applications of the given protocols.展开更多
The oxidation of lignite and bituminous coal samples modified by 5 wt%(in terms of dry salt)addition of copper salts Cu(NO_(3))_(2),CuSO_(4),and Cu(CH_(3)COO)_(2) was studied.The samples’reactivity was studied by the...The oxidation of lignite and bituminous coal samples modified by 5 wt%(in terms of dry salt)addition of copper salts Cu(NO_(3))_(2),CuSO_(4),and Cu(CH_(3)COO)_(2) was studied.The samples’reactivity was studied by thermogravimetry within a temperature range of 45–600℃ at a heating rate of 2.5℃/min in an oxidizing environment.The introduction of activating additives has resulted in a significant decrease in the temperature of intense oxidation onset(ΔT_(i)=20/94℃),in a reduction in the sample residence time in the volatile matter release region(Δt_(e)=2/22 min)and the total duration of the coal combustible mass oxidation(Δt_(f)=8/14 min).The Friedman method was used to calculate the activation energy values for the oxidation process of the modified samples.The maximum change in activation energy values was observed for the bituminous coal sample.The possible mechanism behind the action of the copper-salt additives,which activate the oxidation of lignite and bituminous coal,is discussed.According to the data of mass spectrometric analysis,the concentration of NOx in the reaction products decreases as the temperature of the activated oxidation process is shifted towards the low-temperature region.展开更多
Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol(PEG200)and Cu(NO3)2 as precursors are presented.It was found that PEG200 and sucrose were novel ch...Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol(PEG200)and Cu(NO3)2 as precursors are presented.It was found that PEG200 and sucrose were novel chelates and Cu(NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route.The precursor solution was prepared by mixing yttrium trifluoroacetate,barium trifluoroacetate,and copper nitrate in solvent of methanol with chelates including PEG200 and sucrose.YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate,following vacuum drying,rapid calcining,firing and oxygen annealing.The prepared films were characterized by optical microscope(OM),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results showed that films were crack-free and homogeneous,stronger tendency of(00l)texture,uniform with less pore,pure c-axis orientation.The films showed good superconducting properties,with Tc of 90 K and critical current density(Jc)of 1 MA/cm2(77 K,0 T).This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.展开更多
The effect of the amount of precipitant ammonia on the Cu0/Cu＋ratio of Cu/Si O2 prepared by the deposition–precipitation method is investigated. Species at different preparation stages, resulted from the amount of a...The effect of the amount of precipitant ammonia on the Cu0/Cu＋ratio of Cu/Si O2 prepared by the deposition–precipitation method is investigated. Species at different preparation stages, resulted from the amount of ammonia used, are identified by the XRD and FTIR techniques. Chrysocolla together with either copper nitrate hydroxide or copper hydroxide coexist in the uncalcined catalysts. Upon calcination, the latter two species are converted to Cu O particles while chrysocolla remains. Following reduction, Cu O is transformed to metallic Cu and chrysocolla is converted to Cu2 O. The value of Cu0/Cu＋ratio can be evaluated using the peak areas in their TPR profiles. Hydrogenation of dimethyl oxalate（DMO） to ethylene glycol（EG） shows that the selectivity of EG depends on the Cu0/Cu＋ratio. Catalyst prepared with the addition of ammonia solution at n（NH3）/n（Cu2＋） = 0.9 for precipitation–deposition gains a more suitable Cu0/Cu＋ratio upon reduction and thus has a higher selectivity for EG.展开更多
基金Project(IMPQ29080005)supported by the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology,ChinaProject(IMJQ10070013)supported by the Research Foundation in Harbin Institute of Technology(Weihai),China。
文摘With the purpose of searching for a convenient process to synthesize nanoparticles with special structure,a simple solid-state reaction in the presence of nonionic surfactant OP-10 at room temperature was adopted to prepare copper nitrate hydroxide(Cu_(2)(OH)_(3)NO_(3))nanorings with an average internal diameter of 250 nm and average wall thickness of 100 nm.The formation of Cu_(2)(OH)_(3)NO_(3) nanorings has a close relation with OP-10.Transmission electron microscopy(TEM),field emission scanning electron microscopy(FESEM),thermogravimetric analysis(TGA)and X-ray diffractometry(XRD)were used to characterize the obtained nanorings.The UV-Vis spectrum shows that the optical property of Cu_(2)(OH)_(3)NO_(3) nanorings is similar to that of CuO or CuS.The synthesis method used here proves both simplicity and high efficiency.
基金the National Natural Science Foundation of China(Nos.22171178,21871174 to B.X.)Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-09-E00008 to B.X.)for financial support+2 种基金The Sailing Program of Science and Technology Commission of Shanghai Municipality(22YF1413200 to M.G.)Young Talents Sailing Project(Shanghai University to M.G.)Shanghai Overseas Leading Talents Project(M.G.)are also appreciated.
文摘An unprecedented copper nitrate-mediated bond cleavage of alkynes was developed for the modular synthesis of isoxazoles,where either C—S bond or C≡C triple bond was cleaved selectively.Substituents attached to the C≡C triple bonds could differentiate the chemical bonds cleavage and reaction pathways disparately.Various transformations of products illustrate promising applications of the given protocols.
基金This work was supported by the Ministry of Science and Higher Education of the Russian Federation(projects No.FSWW-2020-0022 and AAAA-A17-117041710086-6).
文摘The oxidation of lignite and bituminous coal samples modified by 5 wt%(in terms of dry salt)addition of copper salts Cu(NO_(3))_(2),CuSO_(4),and Cu(CH_(3)COO)_(2) was studied.The samples’reactivity was studied by thermogravimetry within a temperature range of 45–600℃ at a heating rate of 2.5℃/min in an oxidizing environment.The introduction of activating additives has resulted in a significant decrease in the temperature of intense oxidation onset(ΔT_(i)=20/94℃),in a reduction in the sample residence time in the volatile matter release region(Δt_(e)=2/22 min)and the total duration of the coal combustible mass oxidation(Δt_(f)=8/14 min).The Friedman method was used to calculate the activation energy values for the oxidation process of the modified samples.The maximum change in activation energy values was observed for the bituminous coal sample.The possible mechanism behind the action of the copper-salt additives,which activate the oxidation of lignite and bituminous coal,is discussed.According to the data of mass spectrometric analysis,the concentration of NOx in the reaction products decreases as the temperature of the activated oxidation process is shifted towards the low-temperature region.
基金National High Technology Research and Development Program of China("863"Program)(2009AA03Z203)
文摘Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol(PEG200)and Cu(NO3)2 as precursors are presented.It was found that PEG200 and sucrose were novel chelates and Cu(NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route.The precursor solution was prepared by mixing yttrium trifluoroacetate,barium trifluoroacetate,and copper nitrate in solvent of methanol with chelates including PEG200 and sucrose.YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate,following vacuum drying,rapid calcining,firing and oxygen annealing.The prepared films were characterized by optical microscope(OM),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results showed that films were crack-free and homogeneous,stronger tendency of(00l)texture,uniform with less pore,pure c-axis orientation.The films showed good superconducting properties,with Tc of 90 K and critical current density(Jc)of 1 MA/cm2(77 K,0 T).This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.
基金Funding for the present study from the National Basic Research Program of China(973 Program,No.2011CB710800)the Opening Foundation(2014)of Zhejiang Zanyu Technology Co.,Ltd
文摘The effect of the amount of precipitant ammonia on the Cu0/Cu＋ratio of Cu/Si O2 prepared by the deposition–precipitation method is investigated. Species at different preparation stages, resulted from the amount of ammonia used, are identified by the XRD and FTIR techniques. Chrysocolla together with either copper nitrate hydroxide or copper hydroxide coexist in the uncalcined catalysts. Upon calcination, the latter two species are converted to Cu O particles while chrysocolla remains. Following reduction, Cu O is transformed to metallic Cu and chrysocolla is converted to Cu2 O. The value of Cu0/Cu＋ratio can be evaluated using the peak areas in their TPR profiles. Hydrogenation of dimethyl oxalate（DMO） to ethylene glycol（EG） shows that the selectivity of EG depends on the Cu0/Cu＋ratio. Catalyst prepared with the addition of ammonia solution at n（NH3）/n（Cu2＋） = 0.9 for precipitation–deposition gains a more suitable Cu0/Cu＋ratio upon reduction and thus has a higher selectivity for EG.
