Addressing the contamination of antibiotics has attracted ever-increasing and imperative attention due to their widespread existence,easy-to-cause drug-resistant bacteria infection,coupled with their intrinsic toxicit...Addressing the contamination of antibiotics has attracted ever-increasing and imperative attention due to their widespread existence,easy-to-cause drug-resistant bacteria infection,coupled with their intrinsic toxicity and hazard to environments and human health.Herein,a novel CC/CoNi-LDH-10%Ce anode material was directly constructed through a simple and rapid electrodeposition strategy,serving as an efficacious electrocatalyst for removing ciprofloxacin(CIP)from aqueous solution.Such novel CC/CoNi-LDH-10%Ce anode delivered a higher charge transfer,relatively abundant oxygen vacancies,and a higher electrochemical active area.The as-fabricated CC/CoNi-LDH-10%Ce electrode achieved a substantially boosted CIP removal efficiency of 52.5%relative to that of pure CC at about 23.9%.Notably,doping an appropriate amount of Ce^(3+)can endow the pristine CC/CoNi-LDH with richer oxygen vacancies and excellent electrocatalytic performance.Additionally,the electrocatalytic oxidation of CIP was attributed to both direct oxidation on the electrode surface and indirect oxidation induced by the generated active species(superoxide radicals and hydroxyl radicals).This study provides a simple,universal and flexible tactic for other researchers in designing and manufacturing avenues of electrodes.展开更多
Objective High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory.Nogo-A is an important axonal growth inhibitory factor.However,its function in high-altitude hypoxia and its mechanism o...Objective High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory.Nogo-A is an important axonal growth inhibitory factor.However,its function in high-altitude hypoxia and its mechanism of action remain unclear.Methods In an in vivo study,a low-pressure oxygen chamber was used to simulate high-altitude hypoxia,and genetic or pharmacological intervention was used to block the Nogo-A/NgR1 signaling pathway.Contextual fear conditioning and Morris water maze behavioral tests were used to assess learning and memory in rats,and synaptic damage in the hippocampus and changes in oxidative stress levels were observed.In vitro,SH-SY5Y cells were used to assess oxidative stress and mitochondrial function with or without Nogo-A knockdown in Oxygen Glucose-Deprivation/Reperfusion(OGD/R)models.Results Exposure to acute high-altitude hypoxia for 3 or 7 days impaired learning and memory in rats,triggered oxidative stress in the hippocampal tissue,and reduced the dendritic spine density of hippocampal neurons.Blocking the Nogo-A/NgR1 pathway ameliorated oxidative stress,synaptic damage,and the learning and memory impairment induced by high-altitude exposure.Conclusion Our results demonstrate the detrimental role of Nogo-A protein in mediating learning and memory impairment under high-altitude hypoxia and suggest the potential of the Nogo-A/NgR1 signaling pathway as a crucial therapeutic target for alleviating learning and memory dysfunction induced by high-altitude exposure.展开更多
Sulfur-bearing species are widely utilized to investigate the physical structure of star-forming regions in interstellar media;however,the underlying sulfur chemistry in these environments remains poorly understood.Th...Sulfur-bearing species are widely utilized to investigate the physical structure of star-forming regions in interstellar media;however,the underlying sulfur chemistry in these environments remains poorly understood.Therefore,further studies of S-bearing species are fundamentally important,as they can enhance our understanding of the physical evolution of star-forming regions.This study presents observations of C_(2)S and C_(3)S in L1544,acquired using the Nanshan 26-m radio telescope,along with simulations of their chemical behavior using a one-dimensional physical model.The simulation results reveal significant radial variations in the column densities of C_(2)S and C_(3)S.Additionally,the column densities of both molecules are found to be sensitive to the cosmic ray ionization rate at several radial positions,while variations in the C/O ratio have comparatively minimal impact on L1544.展开更多
BACKGROUND Chronic liver injury(CLI) is now a worldwide disease. However, there is no effective treatment. Pyroptosis plays an essential role in CLI. Dihydromyricetin(DHM) resists oxidation and protects the liver. We ...BACKGROUND Chronic liver injury(CLI) is now a worldwide disease. However, there is no effective treatment. Pyroptosis plays an essential role in CLI. Dihydromyricetin(DHM) resists oxidation and protects the liver. We hypothesize that the beneficial effect of DHM on CLI is related to its effect on the expression of pyroptosisrelated molecules. Therefore, we studied the influence of DHM on CLI and pyroptosis.AIM To study the role of pyroptosis in the pathogenesis of CLI and the therapeutic mechanism of DHM.METHODS Thirty-two mice were randomly divided into four groups: The control group was injected with olive oil, the carbon tetrachloride(CCl4) group was injected with CCl4, the vehicle group was injected with hydroxypropyl-β-cyclodextrin while injecting CCl4 and the DHM group was injected with DHM while injecting CCl4. After four weeks of treatment, liver tissues from the mice were stained with hematoxylin and eosin, and oil red O. Blood was collected from the angular vein for serological analysis. The severity of CLI was estimated. Some liver tissue was sampled for immunohistochemistry, Western blotting and quantitative reverse transcription PCR to observe the changes in pyroptosis-related molecules.RESULTS Serum total cholesterol, low density lipoprotein, aspartate aminotransferase(AST) and alanine aminotransferase(ALT) in the CCl4 group were higher than those in the control group, and serum total cholesterol, low density lipoprotein, AST and ALT in the DHM group were lower than those in the vehicle group. Hematoxylin and eosin and oil red O staining showed that there were more lipid droplets in the CCl4 group than in the control group, and there were fewer lipid droplets in the DHM group than in the vehicle group. Western blotting showed that the expression of the pyroptosis-related molecules caspase-1, NOD-, LRR-and pyrin domain-containing 3(NLRP3) and gasdermin D(GSDMD)-N in the CCl4 group was higher than that in the control group, while expression of these proteins in the DHM group was lower than that in the vehicle group. Quantitative reverse transcription PCR results showed that the expression of the pyroptosis-related genes caspase-1, NLRP3, GSDMD and interleukin-1β(IL-1β) in the CCl4 group was higher than that in the control group, while there was no significant change in NLRP3 and caspase-1 expression in the DHM group compared with that in the vehicle group, and the expression of GSDMD and IL-1β was decreased.CONCLUSION DHM improves CCl4-induced CLI and regulates the pyroptosis pathway in hepatocytes. DHM may be a potential therapeutic agent for CLI.展开更多
Ga-free InAs/InAsSb type-Ⅱ superlattices(T2SL) have extensive application prospective in infrared photodetectors. Achieving higher operation temperature is critical to its commercial applications. Here, a fractional ...Ga-free InAs/InAsSb type-Ⅱ superlattices(T2SL) have extensive application prospective in infrared photodetectors. Achieving higher operation temperature is critical to its commercial applications. Here, a fractional monolayer alloy method was used to grow InAsSb alloy with better controlled alloy composition. The as-grown T2SL gave eleven satellite peaks and a first satellite peak with a narrow full-width-half-maximum (FWHM) of 20.5arcsec (1 arcsec=0.01592°). Strain mapping results indicated limited Sb diffusion through the As-Sb exchange process at the interface. Moreover, unlike interface states caused by the As-Sb exchange effect, this relatively clear interface was distinctive with localized states with higher activation energies of the non-radiative recombination process ((18±1) meV and (84±12) meV at different temperature ranges), which means that this interface state introduced by fractional monolayer alloy growth method can effectively suppress Auger recombination process in T2SL. Through this interface engineering of InAs/InAsSb Type-Ⅱ superlattice, it achieved detective photoluminescence (PL) signal with the center wavelength of 9μm at 250K.展开更多
In the field of glucose sensors,the development of inexpensive and high-efficiency electrochemical glucose sensors is the current research hotspot.In this paper,CuO-Co_(3)O_(4)composite with a prickly-sphere-like morp...In the field of glucose sensors,the development of inexpensive and high-efficiency electrochemical glucose sensors is the current research hotspot.In this paper,CuO-Co_(3)O_(4)composite with a prickly-sphere-like morphology is prepared by the facile hydrothermal method for the non-enzymatic electrochemical glucose detection.X-ray diffraction,scanning electron microscopy,transmission electron microscopy,energy-dispersive X-ray spec-troscopy,and X-ray photoelectron spectroscopy are used to analyze the structure,composition,and morphology of the material.In addition,the electrochemical catalytic perfor-mance of CuO-Co_(3)O_(4)to glucose is obtained by cyclic voltammetry and chronoamperometry.The excellent elec-trochemical sensing performance may be attributed to the large number of catalytic sites in the prickly-sphere-like composite and the synergistic effect of Cu and Co.Under an applied voltage of 0.55 V,CuO-Co_(3)O_(4)composite shows sensitivity to glucose(1503.45μA·(mmol·L^(-1))^(-1)-cm^(-2)),a low detection limit(21.95μmol·L^(-1)),excellent selectivity,a high level of reproducibility,and good sta-bility.This indicates that the CuO-Co_(3)O_(4)composite has a broad prospect of non-enzymatic glucose sensing application.展开更多
Greenhouse gas（GHG） emissions from oil and gas systems are an important component of the GHG emission inventory. To assess the carbon emissions from oilfield-produced water under atmospheric conditions correctly, in...Greenhouse gas（GHG） emissions from oil and gas systems are an important component of the GHG emission inventory. To assess the carbon emissions from oilfield-produced water under atmospheric conditions correctly, in situ detection and simulation experiments were developed to study the natural release of GHG into the atmosphere in the Shengli Oilfield,the second largest oilfield in China. The results showed that methane（CH4） and carbon dioxide（CO2） were the primary gases released naturally from the oilfield-produced water.The atmospheric temperature and release time played important roles in determining the CH4 and CO2emissions under atmospheric conditions. Higher temperatures enhanced the carbon emissions. The emissions of both CH4 and CO2from oilfield-produced water were highest at 27°C and lowest at 3°C. The bulk of CH4 and CO2was released from the oilfield-produced water during the first release period, 0–2 hr, for each temperature, with a maximum average emission rate of 0.415 g CH4/（m3·hr） and 3.934 g CO2/（m3·hr）, respectively. Then the carbon emissions at other time periods gradually decreased with the extension of time. The higher solubility of CO2 in water than CH4 results in a higher emission rate of CH4 than CO2over the same release duration. The simulation proved that oilfield-produced water is one of the potential emission sources that should be given great attention in oil and gas systems.展开更多
Detector has become an indispensable part of human beings.The increasing demand for photodetectors with high performance has promoted the research of novel materials.At the same time,with the development of rising mat...Detector has become an indispensable part of human beings.The increasing demand for photodetectors with high performance has promoted the research of novel materials.At the same time,with the development of rising material system,two-dimensional(2D)materials attract a lot of attention,while the suitable option for fabricating photodetector is still limited.The prospering of bismuth chalcogenides injected new vitality for material field,thereinto,the unique topological insulator characteristics make the research on bismuth selenide(Bi_(2)X_(3))and bismuth telluride(Bi_(2)X_(3)) intriguing.2D Bi_(2)X_(3) also exhibits unique features among various 2D materials,of which,the adjustable narrow energy band gap and polarization-sensitive photocurrent contribute to the promising application of high performance and broadband photodetector.In this review,from a bottom-up perspective,we summarize fundamental properties,synthesis method,photodetector performance of 2D Bi_(2)X_(3) based on the previous study,which provide an overall perspective of 2D Bi_(2)X_(3).Wherein,the section of the photodetector is specifically discu ssed with regard to pure Bi_(2)X_(3) photodetector and heterojunction photodetector.A brief summary and outlook were also explored in the end.展开更多
This paper contributes to the literatures about Chinese commercial banks technical efficiency. In order to eliminate the deviation of efficiency scores caused by an undesirable output that is represented by banks’ no...This paper contributes to the literatures about Chinese commercial banks technical efficiency. In order to eliminate the deviation of efficiency scores caused by an undesirable output that is represented by banks’ non-performing loans, the estimation is based on an enhanced parametric hyperbolic distance function which considers not only desirable outputs but also undesirable outputs. Furthermore, we extend the model to divide the factors that affecting technical efficiency into direct factors and indirect factors and exclude the influence of the latter when analyzing the determiners of banks technical efficiency. The validity of this model is examined by a panel of bank data from 2004-2010.展开更多
The conventional saponification method could result in lower recoveries and artificial changes of longchain fatty acids. The main reason is the error judgment of the intermediate layer suspended between the aqueous an...The conventional saponification method could result in lower recoveries and artificial changes of longchain fatty acids. The main reason is the error judgment of the intermediate layer suspended between the aqueous and organic layer during the liquid–liquid extraction process.This study shows that the intermediate layer consists of lots of medium- to long-chain carboxylic salts for their special physical and chemical properties. An improved saponification extraction method is also developed and the results show that the carboxylic salts distributed in the intermediate layer could be obtained completely, which greatly enhances the authenticity and accuracy of fatty acid analysis. Additionally, the possible reasons of formation of the intermediate layer are also discussed.展开更多
High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarif...High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.展开更多
基金the funds granted by the Ningxia Natural Science Foundation(2023AAC05003,2024AAC03048,2024AAC03051)the National Natural Science Foundation of China(22108130,22368039)+1 种基金the Ningxia Key Research&Development Program(2023BDE03001)the Ningxia Overseas Returnee Innovation and Entrepreneurship Project for the financial support。
文摘Addressing the contamination of antibiotics has attracted ever-increasing and imperative attention due to their widespread existence,easy-to-cause drug-resistant bacteria infection,coupled with their intrinsic toxicity and hazard to environments and human health.Herein,a novel CC/CoNi-LDH-10%Ce anode material was directly constructed through a simple and rapid electrodeposition strategy,serving as an efficacious electrocatalyst for removing ciprofloxacin(CIP)from aqueous solution.Such novel CC/CoNi-LDH-10%Ce anode delivered a higher charge transfer,relatively abundant oxygen vacancies,and a higher electrochemical active area.The as-fabricated CC/CoNi-LDH-10%Ce electrode achieved a substantially boosted CIP removal efficiency of 52.5%relative to that of pure CC at about 23.9%.Notably,doping an appropriate amount of Ce^(3+)can endow the pristine CC/CoNi-LDH with richer oxygen vacancies and excellent electrocatalytic performance.Additionally,the electrocatalytic oxidation of CIP was attributed to both direct oxidation on the electrode surface and indirect oxidation induced by the generated active species(superoxide radicals and hydroxyl radicals).This study provides a simple,universal and flexible tactic for other researchers in designing and manufacturing avenues of electrodes.
基金supported by Beijing Natural Science Foundation(No.7232090)the National Natural Science Foundation of China(82101306)the Scientific and Technological Innovation 2030(2021ZD0201100).
文摘Objective High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory.Nogo-A is an important axonal growth inhibitory factor.However,its function in high-altitude hypoxia and its mechanism of action remain unclear.Methods In an in vivo study,a low-pressure oxygen chamber was used to simulate high-altitude hypoxia,and genetic or pharmacological intervention was used to block the Nogo-A/NgR1 signaling pathway.Contextual fear conditioning and Morris water maze behavioral tests were used to assess learning and memory in rats,and synaptic damage in the hippocampus and changes in oxidative stress levels were observed.In vitro,SH-SY5Y cells were used to assess oxidative stress and mitochondrial function with or without Nogo-A knockdown in Oxygen Glucose-Deprivation/Reperfusion(OGD/R)models.Results Exposure to acute high-altitude hypoxia for 3 or 7 days impaired learning and memory in rats,triggered oxidative stress in the hippocampal tissue,and reduced the dendritic spine density of hippocampal neurons.Blocking the Nogo-A/NgR1 pathway ameliorated oxidative stress,synaptic damage,and the learning and memory impairment induced by high-altitude exposure.Conclusion Our results demonstrate the detrimental role of Nogo-A protein in mediating learning and memory impairment under high-altitude hypoxia and suggest the potential of the Nogo-A/NgR1 signaling pathway as a crucial therapeutic target for alleviating learning and memory dysfunction induced by high-altitude exposure.
基金the support from the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2024D01E37)the National Science Foundation of China(Grant No.12473025)+5 种基金funded by the National Natural Science Foundation of China(Grant Nos.12373026,12203091,12173075,and 11973076)the Xinjiang Tianchi Talent Program(2024)the support from the Xinjiang Tianchi Talent Program(2023)the Shanghai Natural Science Foundation(Grant No.22ZR1421400)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2022D01A156)partially funded by the Regional Collaborative Innovation Project of Xin jiang Uyghur Autonomous Region(Grant No.2022E01050)。
文摘Sulfur-bearing species are widely utilized to investigate the physical structure of star-forming regions in interstellar media;however,the underlying sulfur chemistry in these environments remains poorly understood.Therefore,further studies of S-bearing species are fundamentally important,as they can enhance our understanding of the physical evolution of star-forming regions.This study presents observations of C_(2)S and C_(3)S in L1544,acquired using the Nanshan 26-m radio telescope,along with simulations of their chemical behavior using a one-dimensional physical model.The simulation results reveal significant radial variations in the column densities of C_(2)S and C_(3)S.Additionally,the column densities of both molecules are found to be sensitive to the cosmic ray ionization rate at several radial positions,while variations in the C/O ratio have comparatively minimal impact on L1544.
基金Supported by National Natural Science Foundation of China,No. 81873769Beijing Municipal Natural Science Foundation,No. 7162098。
文摘BACKGROUND Chronic liver injury(CLI) is now a worldwide disease. However, there is no effective treatment. Pyroptosis plays an essential role in CLI. Dihydromyricetin(DHM) resists oxidation and protects the liver. We hypothesize that the beneficial effect of DHM on CLI is related to its effect on the expression of pyroptosisrelated molecules. Therefore, we studied the influence of DHM on CLI and pyroptosis.AIM To study the role of pyroptosis in the pathogenesis of CLI and the therapeutic mechanism of DHM.METHODS Thirty-two mice were randomly divided into four groups: The control group was injected with olive oil, the carbon tetrachloride(CCl4) group was injected with CCl4, the vehicle group was injected with hydroxypropyl-β-cyclodextrin while injecting CCl4 and the DHM group was injected with DHM while injecting CCl4. After four weeks of treatment, liver tissues from the mice were stained with hematoxylin and eosin, and oil red O. Blood was collected from the angular vein for serological analysis. The severity of CLI was estimated. Some liver tissue was sampled for immunohistochemistry, Western blotting and quantitative reverse transcription PCR to observe the changes in pyroptosis-related molecules.RESULTS Serum total cholesterol, low density lipoprotein, aspartate aminotransferase(AST) and alanine aminotransferase(ALT) in the CCl4 group were higher than those in the control group, and serum total cholesterol, low density lipoprotein, AST and ALT in the DHM group were lower than those in the vehicle group. Hematoxylin and eosin and oil red O staining showed that there were more lipid droplets in the CCl4 group than in the control group, and there were fewer lipid droplets in the DHM group than in the vehicle group. Western blotting showed that the expression of the pyroptosis-related molecules caspase-1, NOD-, LRR-and pyrin domain-containing 3(NLRP3) and gasdermin D(GSDMD)-N in the CCl4 group was higher than that in the control group, while expression of these proteins in the DHM group was lower than that in the vehicle group. Quantitative reverse transcription PCR results showed that the expression of the pyroptosis-related genes caspase-1, NLRP3, GSDMD and interleukin-1β(IL-1β) in the CCl4 group was higher than that in the control group, while there was no significant change in NLRP3 and caspase-1 expression in the DHM group compared with that in the vehicle group, and the expression of GSDMD and IL-1β was decreased.CONCLUSION DHM improves CCl4-induced CLI and regulates the pyroptosis pathway in hepatocytes. DHM may be a potential therapeutic agent for CLI.
基金financially supported by the National Natural Science Foundation of China (Nos. 62074018 and 61704011)the China Postdoctoral Science Foundation Funded Project (Nos. 2019M652176 and 2019M661680)+4 种基金the Developing Project of Science and Technology of Jilin Province (Nos. 20200301052RQ, 20200201266JC, 20190701029GH, 20180519017JH and 20180520177JH)the Project of Education Department of Jilin Province (No. JJKH20210831KJ)the Natural Science Foundation of Guangdong Province (No. 2020A1515010868)Shenzhen Fundamental Research Fund (No. JCYJ20180307151538972)supported by R&D project of Collighter Co., Ltd。
文摘Ga-free InAs/InAsSb type-Ⅱ superlattices(T2SL) have extensive application prospective in infrared photodetectors. Achieving higher operation temperature is critical to its commercial applications. Here, a fractional monolayer alloy method was used to grow InAsSb alloy with better controlled alloy composition. The as-grown T2SL gave eleven satellite peaks and a first satellite peak with a narrow full-width-half-maximum (FWHM) of 20.5arcsec (1 arcsec=0.01592°). Strain mapping results indicated limited Sb diffusion through the As-Sb exchange process at the interface. Moreover, unlike interface states caused by the As-Sb exchange effect, this relatively clear interface was distinctive with localized states with higher activation energies of the non-radiative recombination process ((18±1) meV and (84±12) meV at different temperature ranges), which means that this interface state introduced by fractional monolayer alloy growth method can effectively suppress Auger recombination process in T2SL. Through this interface engineering of InAs/InAsSb Type-Ⅱ superlattice, it achieved detective photoluminescence (PL) signal with the center wavelength of 9μm at 250K.
基金financially supported by the National Natural Science Foundation of China (Nos.62074018 and 62174015)the Developing Project of Science and Technology of Jilin Province (No.20200301052RQ)+1 种基金the Project of Education Department of Jilin Province (No.JJKH20210831KJ)the Science and Technology Foundation of State Grid Corporation of China (No. SGTJDK00DYJS2000148)
文摘In the field of glucose sensors,the development of inexpensive and high-efficiency electrochemical glucose sensors is the current research hotspot.In this paper,CuO-Co_(3)O_(4)composite with a prickly-sphere-like morphology is prepared by the facile hydrothermal method for the non-enzymatic electrochemical glucose detection.X-ray diffraction,scanning electron microscopy,transmission electron microscopy,energy-dispersive X-ray spec-troscopy,and X-ray photoelectron spectroscopy are used to analyze the structure,composition,and morphology of the material.In addition,the electrochemical catalytic perfor-mance of CuO-Co_(3)O_(4)to glucose is obtained by cyclic voltammetry and chronoamperometry.The excellent elec-trochemical sensing performance may be attributed to the large number of catalytic sites in the prickly-sphere-like composite and the synergistic effect of Cu and Co.Under an applied voltage of 0.55 V,CuO-Co_(3)O_(4)composite shows sensitivity to glucose(1503.45μA·(mmol·L^(-1))^(-1)-cm^(-2)),a low detection limit(21.95μmol·L^(-1)),excellent selectivity,a high level of reproducibility,and good sta-bility.This indicates that the CuO-Co_(3)O_(4)composite has a broad prospect of non-enzymatic glucose sensing application.
基金supported by the Strategic Priority Research Program-Climate Change:Carbon Budget and Relevant Issues of the Chinese Academy of Sciences(No.XDA05030300)
文摘Greenhouse gas（GHG） emissions from oil and gas systems are an important component of the GHG emission inventory. To assess the carbon emissions from oilfield-produced water under atmospheric conditions correctly, in situ detection and simulation experiments were developed to study the natural release of GHG into the atmosphere in the Shengli Oilfield,the second largest oilfield in China. The results showed that methane（CH4） and carbon dioxide（CO2） were the primary gases released naturally from the oilfield-produced water.The atmospheric temperature and release time played important roles in determining the CH4 and CO2emissions under atmospheric conditions. Higher temperatures enhanced the carbon emissions. The emissions of both CH4 and CO2from oilfield-produced water were highest at 27°C and lowest at 3°C. The bulk of CH4 and CO2was released from the oilfield-produced water during the first release period, 0–2 hr, for each temperature, with a maximum average emission rate of 0.415 g CH4/（m3·hr） and 3.934 g CO2/（m3·hr）, respectively. Then the carbon emissions at other time periods gradually decreased with the extension of time. The higher solubility of CO2 in water than CH4 results in a higher emission rate of CH4 than CO2over the same release duration. The simulation proved that oilfield-produced water is one of the potential emission sources that should be given great attention in oil and gas systems.
基金financially supported by the National Key Research and Development Program of China(No.2019YFA0705201)Heilongjiang Touyan Team。
文摘Detector has become an indispensable part of human beings.The increasing demand for photodetectors with high performance has promoted the research of novel materials.At the same time,with the development of rising material system,two-dimensional(2D)materials attract a lot of attention,while the suitable option for fabricating photodetector is still limited.The prospering of bismuth chalcogenides injected new vitality for material field,thereinto,the unique topological insulator characteristics make the research on bismuth selenide(Bi_(2)X_(3))and bismuth telluride(Bi_(2)X_(3)) intriguing.2D Bi_(2)X_(3) also exhibits unique features among various 2D materials,of which,the adjustable narrow energy band gap and polarization-sensitive photocurrent contribute to the promising application of high performance and broadband photodetector.In this review,from a bottom-up perspective,we summarize fundamental properties,synthesis method,photodetector performance of 2D Bi_(2)X_(3) based on the previous study,which provide an overall perspective of 2D Bi_(2)X_(3).Wherein,the section of the photodetector is specifically discu ssed with regard to pure Bi_(2)X_(3) photodetector and heterojunction photodetector.A brief summary and outlook were also explored in the end.
文摘This paper contributes to the literatures about Chinese commercial banks technical efficiency. In order to eliminate the deviation of efficiency scores caused by an undesirable output that is represented by banks’ non-performing loans, the estimation is based on an enhanced parametric hyperbolic distance function which considers not only desirable outputs but also undesirable outputs. Furthermore, we extend the model to divide the factors that affecting technical efficiency into direct factors and indirect factors and exclude the influence of the latter when analyzing the determiners of banks technical efficiency. The validity of this model is examined by a panel of bank data from 2004-2010.
基金supports by the National Natural Science Foundation of China (No.41003021)the Key Laboratory Project of Gansu Province (Grant No.1309RTSA041)
文摘The conventional saponification method could result in lower recoveries and artificial changes of longchain fatty acids. The main reason is the error judgment of the intermediate layer suspended between the aqueous and organic layer during the liquid–liquid extraction process.This study shows that the intermediate layer consists of lots of medium- to long-chain carboxylic salts for their special physical and chemical properties. An improved saponification extraction method is also developed and the results show that the carboxylic salts distributed in the intermediate layer could be obtained completely, which greatly enhances the authenticity and accuracy of fatty acid analysis. Additionally, the possible reasons of formation of the intermediate layer are also discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.62074018,62174015 and 62275032)the Developing Project of Science and Technology of Jilin Province(No.20210509061RQ)+3 种基金the Natural Science Foundation of Jilin Province(No.20210101473JC)National Key R&D Program of China(No.2021YFB3201901)The Natural Science Foundation of Chongqing China(No.cstc2021jcyjmsxmX1060)supported by R&D project of Collighter Co.,Ltd。
文摘High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.
