Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction ...Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction kinetics and structural instability.This study overcomes these challenges by implementing a rapid,energy-efficient approach to develop a MOF-modulated MnP@Cu_(3)P heterostructure via a hydrothermal process followed by high-temperature phosphorization.The heterostructure demonstrates superior redox activity with enhanced stability and improved charge kinetics achieving a high specific capacity of 1131 C g^(-1)as supported by density functional theory findings of increased DOS near the Fermi level.The flexible supercapacitor achieves a peak energy density of 99.20 Wh kg^(-1)and power density of 15.40 kW kg^(-1).Simultaneously,it shows exceptional hydrogen evolution reaction performance with an overpotential of η_(10)=44 mV and η_(1000)=225 mV,attributed to electron transfer from Cu to Mn via P bridging,which shifts the active centers from Mn and Cu sites to the P site,confirmed by lowestΔG_(H)^(*)value of-0.16 eV.The overall water-splitting in full-cell electrocatalyzer delivers cell voltage of E_(20)=1.48 V and E_(1000)=1.88 V and setting a new standard in solar-to-hydrogen efficiency of 20.02%.The electrolyzer cell maintained prolonged stability at industrial-scale current densities of 1.0 A cm^(-2)under alkaline electrolysis achieving an estimated hydrogen production cost of INR 146.7 or US$1.67per kilogram aligning with the cost target of $2/kg by 2026 established by the Clean Hydrogen Electrolysis Program,U.S.department of energy.Furthermore,real-phase demonstration highlights the uninterrupted hydrogen production till 6-minutes via connecting this electrocatalyzer with photovoltaic-charged supercapacitors effectively addressing solar intermittency and gas fluctuations challenges in water-electrolysis.展开更多
In order to determine the design tide levels in the areas without measured tide level data, especially in the areas where it is difficult to measure tidal levels, a calculation method based on a numerical model of tid...In order to determine the design tide levels in the areas without measured tide level data, especially in the areas where it is difficult to measure tidal levels, a calculation method based on a numerical model of tidal current is proposed. The essentials of the method are described, and its application is illustrated with an example. The results of the application show that the design tide levels calculated by the method are close to those determined by long-time measured tide level data, and its calculation precision is high, so it is feasible to use the method to determine the design tide levels in the areas.展开更多
The State Council decided to raise the retail electricity price by 0.25 Yuan/kWh from July, 2008. This will, to some extent, relieve the conflicts between power supply and demand, and decrease the economic losses in
By using high-temperature deep-level transient spectroscopy （HT-DLTS） and other electrical measurement techniques, localized deep levels in n-type AlxGal xN epitaxial films with various A1 compositions （x = 0, 0.14...By using high-temperature deep-level transient spectroscopy （HT-DLTS） and other electrical measurement techniques, localized deep levels in n-type AlxGal xN epitaxial films with various A1 compositions （x = 0, 0.14, 0.24, 0.33, and 0.43） have been investigated. It is found that there are three distinct deep levels in AlxGal-xN films, whose level position with respect to the conduction band increases as AI composition increases. The dominant defect level with the activation energy deeper than 1.0 eV below the conduction band closely follows the Fermi level stabilization energy, indicating that its origin may be related to the defect complex, including the anti-site defects and divacancies in AlxGa1-xN films.展开更多
Based on the analysis of wind,ocean currents,sea surface temperature（SST） and remote sensing satellite altimeter data,the characteristics and possible causes of sea level anomalies in the Xisha sea area are investig...Based on the analysis of wind,ocean currents,sea surface temperature（SST） and remote sensing satellite altimeter data,the characteristics and possible causes of sea level anomalies in the Xisha sea area are investigated.The main results are shown as follows：（1） Since 1993,the sea level in the Xisha sea area was obviously higher than normal in 1998,2001,2008,2010 and 2013.Especially,the sea level in 1998 and 2010 was abnormally high,and the sea level in 2010 was 13.2 cm higher than the muti-year mean,which was the highest in the history.In 2010,the sea level in the Xisha sea area had risen 43 cm from June to August,with the strength twice the annual variation range.（2） The sea level in the Xisha sea area was not only affected by the tidal force of the celestial bodies,but also closely related to the quasi 2 a periodic oscillation of tropical western Pacific monsoon and ENSO events.（3）There was a significant negative correlation between sea level in the Xisha sea area and ENSO events.The high sea level anomaly all happened during the developing phase of La Ni-a.They also show significant negative correlations with Ni-o 4 and Ni-o 3.4 indices,and the lag correlation coefficients for 2 months and 3 months are–0.46 and –0.45,respectively.（4） During the early La Ni-a event form June to November in 2010,the anomalous wind field was cyclonic.A strong clockwise vortex was formed for the current in 25 m layer in the Xisha sea area,and the velocity of the current is close to the speed of the Kuroshio near the Luzon Strait.In normal years,there is a “cool eddy”.While in 2010,from July to August,the SST in the area was 2–3°C higher than that of the same period in the history.展开更多
【目的】陆架—边缘海作为海陆相互作用的关键区域,其沉积物蕴含着气候、海平面变化、生物地球化学循环和人类活动等重要信息。探讨末次冰消期以来沉积环境演化背景下南黄海中部泥质区有机碳埋藏的阶段性特征和影响因素具有重要意义。...【目的】陆架—边缘海作为海陆相互作用的关键区域,其沉积物蕴含着气候、海平面变化、生物地球化学循环和人类活动等重要信息。探讨末次冰消期以来沉积环境演化背景下南黄海中部泥质区有机碳埋藏的阶段性特征和影响因素具有重要意义。【方法】对取自该区东侧的H12岩心进行了AMS^(14)C测年、粒度、总有机碳(TOC)、总氮(TN)及稳定碳同位素(δ^(13)C)进行分析。【结果】相对低海平面时期(17~12.6 ka B.P.)发育硬质黏土层,TOC埋藏通量较高,以陆源有机质输入为主。海侵期(12.6~7.8 ka B.P.)受潮流侵蚀等动力作用影响,TOC来源为海陆混合源,陆源TOC埋藏通量在8 ka B.P.左右出现明显高值,对应沉积速率显著升高,可能反映季风驱动下沉积物供应和输送方式变化;高海平面时期(7.8 ka B.P.以来)以海源贡献为主;其中,5~2 ka B.P.,TOC含量在百年尺度上变化幅度较大,与黑潮强度减弱的阶段基本一致,TOC含量的高值整体对应于东亚冬季风的强盛期,可能反映冬季风驱动下黄海暖流的增强导致海洋初级生产力、水体环境的变化,进而对TOC埋藏的影响;~2 ka B.P.以来TOC变化幅度减小,海源有机质贡献整体增加,可能与ENSO(厄尔尼诺—南方涛动)活动的加强有关。【结论】海平面变化是末次冰消期以来南黄海中部有机碳埋藏演化的主控因素,而高海面以来TOC沉积记录阶段性变化可能跟东亚冬季风等影响下黄海暖流的变化及ENSO活动有关。展开更多
Use of numerical simulation of the tidal flow of the Changjiang River Estuary and the HuangpuRiver to forecast flood in the Taihu Lake lower reach drainage system for the case of future sea level riseof 0.4 m and 0.8 ...Use of numerical simulation of the tidal flow of the Changjiang River Estuary and the HuangpuRiver to forecast flood in the Taihu Lake lower reach drainage system for the case of future sea level riseof 0.4 m and 0.8 m,and floods preventing and reducing methods are discussed in this paper.展开更多
Interannual sea level variation is investigated with the oceanic and atmospheric datasets in the East China Sea (ECS). Two modes are distinct on the interannual timescale, illustrated as the basin mode and the dipole ...Interannual sea level variation is investigated with the oceanic and atmospheric datasets in the East China Sea (ECS). Two modes are distinct on the interannual timescale, illustrated as the basin mode and the dipole mode. They account for 20% and 18% to the total interannual sea level variance respectively. The basin mode corresponds to the variability of the Kuroshio transport which is modulated by the PDO while the dipole mode is likely related to the local oceanic and atmospheric adjustment. Large-scale atmospheric circulation effect is dominant in influencing the interannual sea level in the ECS. ECS sea level responds barotropically to the basin-wide wind field, which illustrates negative correlation to the zonal-mean wind stress curl in the Pacific Ocean. Sea level variation exhibits the negative correlation at 8 years lag with the basin mean wind stress curl anomalies on the interannual timescale. The lagging years are consistent with the timescale that the baroclinic Rossby waves propagate westward in the North Pacific Ocean. Wind stress curl anomalies could also change the strength of the Kuroshio transport, and thus affect the local sea level through sea surface height adjustment. Local oceanic and atmospheric effect illustrates as another influence process. Steric effect contributes more than 20% to the interannual sea level gradually in a belt from the Fujian and Zhejiang coasts to the Korea/Tsushima strait. Especially in the northeast part, its contribution could be up to 60%. While for the local atmospheric process, zonal wind acts as a more important role on sea level than meridional component.展开更多
According to the service environment of subway structure,experiment is carried out to simulate influence of different loading levels to reinforcement corrosion of R.C element affected by stray current and chlorine sal...According to the service environment of subway structure,experiment is carried out to simulate influence of different loading levels to reinforcement corrosion of R.C element affected by stray current and chlorine salt solution. The current density of the corrosion is measured with the linear polarization resistance method,together with the qualitative analysis and quantitative calculation. Experiment shows that rebar corrosion current density increase accordingly with the increase of loading level. The quantitative relations and the time of rust corrosion of reinforcement are obtained.展开更多
Circle points discharge tube current controller is a new type device to limit the output of high voltage discharge current. Circle points uniform corona discharge to form air ionization current in the discharge tube. ...Circle points discharge tube current controller is a new type device to limit the output of high voltage discharge current. Circle points uniform corona discharge to form air ionization current in the discharge tube. On the outside, even if the discharge electrode is spark discharging or the two discharge electrodes are short circuited, the air ionization current in the tube remains within a stable range, and there is no spark discharge. In this case, when the discharge current only increases slightly, the requirement to limited current is obtained. By installing the controller at a discharge pole with a small power but high voltage supply, we can realize the shift between the continuous spark line discharge and corona discharge. This provides a new simple device for spark discharge research and is a supplement to the Townsend discharge experiment.展开更多
With the acceleration of urbanization,urban development poses a growing demand for land.China's national conditions of a large population with relatively little arable land require us to intensively use land,and m...With the acceleration of urbanization,urban development poses a growing demand for land.China's national conditions of a large population with relatively little arable land require us to intensively use land,and more and more departments have been aware of the importance of intensive urban land use.The study on the current land use in the urban area of Ma'anshan City,is not only conducive to adjustment of land use layout and structure as well as urban ecological construction,but also of guiding significance to the economical and intensive land use in Ma'anshan City.This paper first describes the natural,social and economic situation of Ma'anshan's urban area,then analyzes the land use structure,layout and problems,and finally puts forth the recommendations for improving current land use situation in the urban area of Ma'anshan City.展开更多
Multilevel inverters are well used in grid connected domestic photovoltaic applications because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress...Multilevel inverters are well used in grid connected domestic photovoltaic applications because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress across the power devices. However, this kind of inverter has to be modified to both limit common-mode currents and improve the robustness of the system. This paper presents a new mixed 5-level inverter that meets these challenges. The operating principle of the converter is proposed. Several experimental measurements are described to validate this new concept. The output voltage and current and the THD of the output voltage are particularly discussed.展开更多
铜基电催化剂在CO_(2)还原反应(CO_(2)RR)中产高附加值产物的潜力巨大,是实现碳负排放的一种很有前景的途径。同时,安培级电流是实现多碳(C_(2+))产业化的关键。然而,由于复杂的电子传递过程和不可避免的副反应,工业电流密度下的C_(2+)...铜基电催化剂在CO_(2)还原反应(CO_(2)RR)中产高附加值产物的潜力巨大,是实现碳负排放的一种很有前景的途径。同时,安培级电流是实现多碳(C_(2+))产业化的关键。然而,由于复杂的电子传递过程和不可避免的副反应,工业电流密度下的C_(2+)选择性仍然不令人满意。在此,我们开发了一种碳修饰策略来优化局部环境并调节中间产物在Cu活性位点的吸附。结果表明,Cu-Cx催化剂(x为催化剂中C的原子百分数)能有效催化CO_(2)RR生成C_(2+)产物。特别是在流动池中,Cu-C6%在−0.72 V vs.RHE(相对可逆氢电极)条件下,电流密度可达1.25 A∙cm^(−2),C_(2)H_(4)和C_(2+)产物的法拉第效率(FE)分别可达54.4%和80.2%。原位光谱分析和密度泛函理论(DFT)计算表明,C的存在调节了*CO在Cu表面的吸附,降低了C―C耦合的能垒,从而促进了C_(2+)产物的生成。展开更多
基金supported financially by the Ministry of Textiles(Grant No-2/3/2021-NTTM(Pt.)),Govt.of India。
文摘Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction kinetics and structural instability.This study overcomes these challenges by implementing a rapid,energy-efficient approach to develop a MOF-modulated MnP@Cu_(3)P heterostructure via a hydrothermal process followed by high-temperature phosphorization.The heterostructure demonstrates superior redox activity with enhanced stability and improved charge kinetics achieving a high specific capacity of 1131 C g^(-1)as supported by density functional theory findings of increased DOS near the Fermi level.The flexible supercapacitor achieves a peak energy density of 99.20 Wh kg^(-1)and power density of 15.40 kW kg^(-1).Simultaneously,it shows exceptional hydrogen evolution reaction performance with an overpotential of η_(10)=44 mV and η_(1000)=225 mV,attributed to electron transfer from Cu to Mn via P bridging,which shifts the active centers from Mn and Cu sites to the P site,confirmed by lowestΔG_(H)^(*)value of-0.16 eV.The overall water-splitting in full-cell electrocatalyzer delivers cell voltage of E_(20)=1.48 V and E_(1000)=1.88 V and setting a new standard in solar-to-hydrogen efficiency of 20.02%.The electrolyzer cell maintained prolonged stability at industrial-scale current densities of 1.0 A cm^(-2)under alkaline electrolysis achieving an estimated hydrogen production cost of INR 146.7 or US$1.67per kilogram aligning with the cost target of $2/kg by 2026 established by the Clean Hydrogen Electrolysis Program,U.S.department of energy.Furthermore,real-phase demonstration highlights the uninterrupted hydrogen production till 6-minutes via connecting this electrocatalyzer with photovoltaic-charged supercapacitors effectively addressing solar intermittency and gas fluctuations challenges in water-electrolysis.
基金The National Key Fundamental Research and Development Program ("973" Program) of China under contract No. 2010CB429001
文摘In order to determine the design tide levels in the areas without measured tide level data, especially in the areas where it is difficult to measure tidal levels, a calculation method based on a numerical model of tidal current is proposed. The essentials of the method are described, and its application is illustrated with an example. The results of the application show that the design tide levels calculated by the method are close to those determined by long-time measured tide level data, and its calculation precision is high, so it is feasible to use the method to determine the design tide levels in the areas.
文摘The State Council decided to raise the retail electricity price by 0.25 Yuan/kWh from July, 2008. This will, to some extent, relieve the conflicts between power supply and demand, and decrease the economic losses in
基金supported by the National Basic Research Program of China(Grant No.2012CB619300)the National Natural Science Foundation of China(Grant Nos.11174008 and 61361166007)
文摘By using high-temperature deep-level transient spectroscopy （HT-DLTS） and other electrical measurement techniques, localized deep levels in n-type AlxGal xN epitaxial films with various A1 compositions （x = 0, 0.14, 0.24, 0.33, and 0.43） have been investigated. It is found that there are three distinct deep levels in AlxGal-xN films, whose level position with respect to the conduction band increases as AI composition increases. The dominant defect level with the activation energy deeper than 1.0 eV below the conduction band closely follows the Fermi level stabilization energy, indicating that its origin may be related to the defect complex, including the anti-site defects and divacancies in AlxGa1-xN films.
文摘Based on the analysis of wind,ocean currents,sea surface temperature（SST） and remote sensing satellite altimeter data,the characteristics and possible causes of sea level anomalies in the Xisha sea area are investigated.The main results are shown as follows：（1） Since 1993,the sea level in the Xisha sea area was obviously higher than normal in 1998,2001,2008,2010 and 2013.Especially,the sea level in 1998 and 2010 was abnormally high,and the sea level in 2010 was 13.2 cm higher than the muti-year mean,which was the highest in the history.In 2010,the sea level in the Xisha sea area had risen 43 cm from June to August,with the strength twice the annual variation range.（2） The sea level in the Xisha sea area was not only affected by the tidal force of the celestial bodies,but also closely related to the quasi 2 a periodic oscillation of tropical western Pacific monsoon and ENSO events.（3）There was a significant negative correlation between sea level in the Xisha sea area and ENSO events.The high sea level anomaly all happened during the developing phase of La Ni-a.They also show significant negative correlations with Ni-o 4 and Ni-o 3.4 indices,and the lag correlation coefficients for 2 months and 3 months are–0.46 and –0.45,respectively.（4） During the early La Ni-a event form June to November in 2010,the anomalous wind field was cyclonic.A strong clockwise vortex was formed for the current in 25 m layer in the Xisha sea area,and the velocity of the current is close to the speed of the Kuroshio near the Luzon Strait.In normal years,there is a “cool eddy”.While in 2010,from July to August,the SST in the area was 2–3°C higher than that of the same period in the history.
文摘【目的】陆架—边缘海作为海陆相互作用的关键区域,其沉积物蕴含着气候、海平面变化、生物地球化学循环和人类活动等重要信息。探讨末次冰消期以来沉积环境演化背景下南黄海中部泥质区有机碳埋藏的阶段性特征和影响因素具有重要意义。【方法】对取自该区东侧的H12岩心进行了AMS^(14)C测年、粒度、总有机碳(TOC)、总氮(TN)及稳定碳同位素(δ^(13)C)进行分析。【结果】相对低海平面时期(17~12.6 ka B.P.)发育硬质黏土层,TOC埋藏通量较高,以陆源有机质输入为主。海侵期(12.6~7.8 ka B.P.)受潮流侵蚀等动力作用影响,TOC来源为海陆混合源,陆源TOC埋藏通量在8 ka B.P.左右出现明显高值,对应沉积速率显著升高,可能反映季风驱动下沉积物供应和输送方式变化;高海平面时期(7.8 ka B.P.以来)以海源贡献为主;其中,5~2 ka B.P.,TOC含量在百年尺度上变化幅度较大,与黑潮强度减弱的阶段基本一致,TOC含量的高值整体对应于东亚冬季风的强盛期,可能反映冬季风驱动下黄海暖流的增强导致海洋初级生产力、水体环境的变化,进而对TOC埋藏的影响;~2 ka B.P.以来TOC变化幅度减小,海源有机质贡献整体增加,可能与ENSO(厄尔尼诺—南方涛动)活动的加强有关。【结论】海平面变化是末次冰消期以来南黄海中部有机碳埋藏演化的主控因素,而高海面以来TOC沉积记录阶段性变化可能跟东亚冬季风等影响下黄海暖流的变化及ENSO活动有关。
基金the National Natural Science Foundation of China and the Chinese Academy of Sciences.
文摘Use of numerical simulation of the tidal flow of the Changjiang River Estuary and the HuangpuRiver to forecast flood in the Taihu Lake lower reach drainage system for the case of future sea level riseof 0.4 m and 0.8 m,and floods preventing and reducing methods are discussed in this paper.
文摘Interannual sea level variation is investigated with the oceanic and atmospheric datasets in the East China Sea (ECS). Two modes are distinct on the interannual timescale, illustrated as the basin mode and the dipole mode. They account for 20% and 18% to the total interannual sea level variance respectively. The basin mode corresponds to the variability of the Kuroshio transport which is modulated by the PDO while the dipole mode is likely related to the local oceanic and atmospheric adjustment. Large-scale atmospheric circulation effect is dominant in influencing the interannual sea level in the ECS. ECS sea level responds barotropically to the basin-wide wind field, which illustrates negative correlation to the zonal-mean wind stress curl in the Pacific Ocean. Sea level variation exhibits the negative correlation at 8 years lag with the basin mean wind stress curl anomalies on the interannual timescale. The lagging years are consistent with the timescale that the baroclinic Rossby waves propagate westward in the North Pacific Ocean. Wind stress curl anomalies could also change the strength of the Kuroshio transport, and thus affect the local sea level through sea surface height adjustment. Local oceanic and atmospheric effect illustrates as another influence process. Steric effect contributes more than 20% to the interannual sea level gradually in a belt from the Fujian and Zhejiang coasts to the Korea/Tsushima strait. Especially in the northeast part, its contribution could be up to 60%. While for the local atmospheric process, zonal wind acts as a more important role on sea level than meridional component.
基金National Natural Science Foundation of China (Granted No.50808005)National"11-5"Science and Technology Supporting Program(Granted No.2006BAJ27B04)Major Program of Beijing Municipal Natural Science Foundation(Granted No.8100001)
文摘According to the service environment of subway structure,experiment is carried out to simulate influence of different loading levels to reinforcement corrosion of R.C element affected by stray current and chlorine salt solution. The current density of the corrosion is measured with the linear polarization resistance method,together with the qualitative analysis and quantitative calculation. Experiment shows that rebar corrosion current density increase accordingly with the increase of loading level. The quantitative relations and the time of rust corrosion of reinforcement are obtained.
文摘Circle points discharge tube current controller is a new type device to limit the output of high voltage discharge current. Circle points uniform corona discharge to form air ionization current in the discharge tube. On the outside, even if the discharge electrode is spark discharging or the two discharge electrodes are short circuited, the air ionization current in the tube remains within a stable range, and there is no spark discharge. In this case, when the discharge current only increases slightly, the requirement to limited current is obtained. By installing the controller at a discharge pole with a small power but high voltage supply, we can realize the shift between the continuous spark line discharge and corona discharge. This provides a new simple device for spark discharge research and is a supplement to the Townsend discharge experiment.
基金Supported by Fund Project of Ma'anshan Municipal Bureau of Land and Resources
文摘With the acceleration of urbanization,urban development poses a growing demand for land.China's national conditions of a large population with relatively little arable land require us to intensively use land,and more and more departments have been aware of the importance of intensive urban land use.The study on the current land use in the urban area of Ma'anshan City,is not only conducive to adjustment of land use layout and structure as well as urban ecological construction,but also of guiding significance to the economical and intensive land use in Ma'anshan City.This paper first describes the natural,social and economic situation of Ma'anshan's urban area,then analyzes the land use structure,layout and problems,and finally puts forth the recommendations for improving current land use situation in the urban area of Ma'anshan City.
文摘Multilevel inverters are well used in grid connected domestic photovoltaic applications because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress across the power devices. However, this kind of inverter has to be modified to both limit common-mode currents and improve the robustness of the system. This paper presents a new mixed 5-level inverter that meets these challenges. The operating principle of the converter is proposed. Several experimental measurements are described to validate this new concept. The output voltage and current and the THD of the output voltage are particularly discussed.
文摘铜基电催化剂在CO_(2)还原反应(CO_(2)RR)中产高附加值产物的潜力巨大,是实现碳负排放的一种很有前景的途径。同时,安培级电流是实现多碳(C_(2+))产业化的关键。然而,由于复杂的电子传递过程和不可避免的副反应,工业电流密度下的C_(2+)选择性仍然不令人满意。在此,我们开发了一种碳修饰策略来优化局部环境并调节中间产物在Cu活性位点的吸附。结果表明,Cu-Cx催化剂(x为催化剂中C的原子百分数)能有效催化CO_(2)RR生成C_(2+)产物。特别是在流动池中,Cu-C6%在−0.72 V vs.RHE(相对可逆氢电极)条件下,电流密度可达1.25 A∙cm^(−2),C_(2)H_(4)和C_(2+)产物的法拉第效率(FE)分别可达54.4%和80.2%。原位光谱分析和密度泛函理论(DFT)计算表明,C的存在调节了*CO在Cu表面的吸附,降低了C―C耦合的能垒,从而促进了C_(2+)产物的生成。
