A method of estimating the safe storage life （τ）, self-accelerating decomposition temperature （TsADT） and critical temperature of thermal explosion （Tb） of double-base propellant using isothermal and non-isothe...A method of estimating the safe storage life （τ）, self-accelerating decomposition temperature （TsADT） and critical temperature of thermal explosion （Tb） of double-base propellant using isothermal and non-isothermal decomposition behaviours is presented. For double-base propellant composed of 56±1wt% of nitrocellulose （NC）, 27±0.5wt% of nitroglycerine （NG）, 8.15±0.15wt% of dinitrotoluene （DNT）, 2.5±0.1wt% of methyl centralite, 5.0±0.15wt% of catalyst and 1.0±0.1wt% of other, the values of r of 49.4 years at 40℃, of TSAOT of 151.35℃ and of Tb of 163.01℃ were obtained.展开更多
The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the...The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the LIBs at low temperatures, the synergistic effects originating from the cathode, anode, electrolyte, and separators to the batteries are still not clear. Here, the 21700-type cylindrical batteries were evaluated at a wide range of temperatures to investigate the failure mechanism of batteries. Voltage relaxation, and the post-mortem analysis combined with the electrochemical tests, unravel that the capacity degradation of batteries at low temperature is related to the lithium plating at graphite anodes,the formation of unsatisfied solid deposited/decomposed electrolyte mixture phase on the anode, the precipitation of solvent in the electrolytes and the block of separator pores, and the uneven dissolved transition metal-ions from the cathode. We hope this finding may open up a new avenue to alleviate the capacity degradation of advanced LIBs at low temperatures and shed light on the development of outstanding low-temperature LIBs via simultaneous optimization of all the components including electrodes, electrolytes and separators.展开更多
The K−shell emission spectra of laser-produced aluminum plasma are measured by a space-resolved spectrometer consisting of a flat crystal spectrometer with a 20μm wide space−resolved slit.By using the approximation o...The K−shell emission spectra of laser-produced aluminum plasma are measured by a space-resolved spectrometer consisting of a flat crystal spectrometer with a 20μm wide space−resolved slit.By using the approximation of the steady collisional-radiative equilibrium model,the interstage line intensity ratios of Ly-αresonance line to He−αresonance line are given as a function of electron temperature.The spectra profiles are decomposed to resonance line and the overlapped high-order satellites manifold.Thus reliable electron temperature is deduced from the interstage line intensity ratios of the decomposed resonance lines.The results of spaced-resolved temperature are compared with the hydrodynamic simulations.The diagnostics of electron temperature for laser-produced plasma is developed.展开更多
Acetic acid bacteria capable of growing at 30°C - 37°C were collected from various decomposed fruits available in Bangladeshi local markets in order to assess their suitability for vinegar production. ...Acetic acid bacteria capable of growing at 30°C - 37°C were collected from various decomposed fruits available in Bangladeshi local markets in order to assess their suitability for vinegar production. Initially, 42 microorganisms were isolated from decomposed fruits like grapes, mangoes, pineapples, oranges, safeda etc. during summer when temperature reaches up to 37°C. Then their growths were checked in YPG medium containing various ethanol concentrations at different time point at 37°C. From the preliminary screening, 15 Gram negative bacterial isolates have produced halos or yellow zone around the colonies on YPG agar plate at 37°C which indicated acetic acid production capability by those bacteria. Furthermore, acetic acid production rates were determined by titration method and about 3 - 6.9 gm/100ml acetic acid were estimated by using 4% ethanol at 37°C by shaking culture for 3 days. Several biochemical analysis revealed that our collection contained huge amount of acetic acid producing bacteria and some of them could be potential candidates for vinegar production.展开更多
A hysteresis-less inverted perovskite solar cell(PSC)with power conversion efficiency(PCE)of 13.57%was successfully achieved based on the thermal-decomposed NiO_(x) hole contact layer,possessing better electron blocki...A hysteresis-less inverted perovskite solar cell(PSC)with power conversion efficiency(PCE)of 13.57%was successfully achieved based on the thermal-decomposed NiO_(x) hole contact layer,possessing better electron blocking and hole extraction properties for its suitable work function and high-conduction band edge position.Herein,the transparent and high-crystalline NiO_(x) film is prepared by thermal-decomposing of the solution-derived Ni(OH)_(2) film in our study,which is then employed as hole transport layer(HTL)of the organic–inorganic hybrid PSCs.Reasonably,the post-annealing treatment,especially for the annealing temperature,could greatly affect the Ni(OH)_(2) decomposition process and the quality of decomposed NiO_(x) nanoparticles.The vital NiO_(x) HTLs with discrepant morphology,crystallinity and transmission certainly lead to a wide range of device performance.As a result,an annealing process of 400℃/2 h significantly promotes the photovoltaic properties of the NiO_(x) layer and the further device performance.展开更多
基金We are grateful to the National Natural Science Foundation of China （No. 20573098）
文摘A method of estimating the safe storage life （τ）, self-accelerating decomposition temperature （TsADT） and critical temperature of thermal explosion （Tb） of double-base propellant using isothermal and non-isothermal decomposition behaviours is presented. For double-base propellant composed of 56±1wt% of nitrocellulose （NC）, 27±0.5wt% of nitroglycerine （NG）, 8.15±0.15wt% of dinitrotoluene （DNT）, 2.5±0.1wt% of methyl centralite, 5.0±0.15wt% of catalyst and 1.0±0.1wt% of other, the values of r of 49.4 years at 40℃, of TSAOT of 151.35℃ and of Tb of 163.01℃ were obtained.
基金supported by the National Natural Science Foundation of China (U1664255, 21875022, 51802020, U1564206)the National Key R&D Program of China (2016YFB0100301)+2 种基金the Science and Technology Innovation Foundation of Beijing Institute of Technology Chongqing Innovation Center (2020CX5100006)the Young Elite Scientists Sponsorship Program by CAST (2018QNRC001)support from Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the LIBs at low temperatures, the synergistic effects originating from the cathode, anode, electrolyte, and separators to the batteries are still not clear. Here, the 21700-type cylindrical batteries were evaluated at a wide range of temperatures to investigate the failure mechanism of batteries. Voltage relaxation, and the post-mortem analysis combined with the electrochemical tests, unravel that the capacity degradation of batteries at low temperature is related to the lithium plating at graphite anodes,the formation of unsatisfied solid deposited/decomposed electrolyte mixture phase on the anode, the precipitation of solvent in the electrolytes and the block of separator pores, and the uneven dissolved transition metal-ions from the cathode. We hope this finding may open up a new avenue to alleviate the capacity degradation of advanced LIBs at low temperatures and shed light on the development of outstanding low-temperature LIBs via simultaneous optimization of all the components including electrodes, electrolytes and separators.
基金by the National High-Tech Program of Chinathe National Natural Science Foundation of China under Grant Nos 10734140,10874156 and 10875109.
文摘The K−shell emission spectra of laser-produced aluminum plasma are measured by a space-resolved spectrometer consisting of a flat crystal spectrometer with a 20μm wide space−resolved slit.By using the approximation of the steady collisional-radiative equilibrium model,the interstage line intensity ratios of Ly-αresonance line to He−αresonance line are given as a function of electron temperature.The spectra profiles are decomposed to resonance line and the overlapped high-order satellites manifold.Thus reliable electron temperature is deduced from the interstage line intensity ratios of the decomposed resonance lines.The results of spaced-resolved temperature are compared with the hydrodynamic simulations.The diagnostics of electron temperature for laser-produced plasma is developed.
文摘Acetic acid bacteria capable of growing at 30°C - 37°C were collected from various decomposed fruits available in Bangladeshi local markets in order to assess their suitability for vinegar production. Initially, 42 microorganisms were isolated from decomposed fruits like grapes, mangoes, pineapples, oranges, safeda etc. during summer when temperature reaches up to 37°C. Then their growths were checked in YPG medium containing various ethanol concentrations at different time point at 37°C. From the preliminary screening, 15 Gram negative bacterial isolates have produced halos or yellow zone around the colonies on YPG agar plate at 37°C which indicated acetic acid production capability by those bacteria. Furthermore, acetic acid production rates were determined by titration method and about 3 - 6.9 gm/100ml acetic acid were estimated by using 4% ethanol at 37°C by shaking culture for 3 days. Several biochemical analysis revealed that our collection contained huge amount of acetic acid producing bacteria and some of them could be potential candidates for vinegar production.
基金funded by the National Natural Science Foundation of China(51502239)China Postdoctoral Science Foundation(2017T100751)+1 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2016JQ6058)Postdoctoral Science Foundation in Shaanxi Province of China and the 111 Project of China(B14040)。
文摘A hysteresis-less inverted perovskite solar cell(PSC)with power conversion efficiency(PCE)of 13.57%was successfully achieved based on the thermal-decomposed NiO_(x) hole contact layer,possessing better electron blocking and hole extraction properties for its suitable work function and high-conduction band edge position.Herein,the transparent and high-crystalline NiO_(x) film is prepared by thermal-decomposing of the solution-derived Ni(OH)_(2) film in our study,which is then employed as hole transport layer(HTL)of the organic–inorganic hybrid PSCs.Reasonably,the post-annealing treatment,especially for the annealing temperature,could greatly affect the Ni(OH)_(2) decomposition process and the quality of decomposed NiO_(x) nanoparticles.The vital NiO_(x) HTLs with discrepant morphology,crystallinity and transmission certainly lead to a wide range of device performance.As a result,an annealing process of 400℃/2 h significantly promotes the photovoltaic properties of the NiO_(x) layer and the further device performance.
