Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(...Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.展开更多
Heteroatom-doped carbon-based transition-metal single-atom catalysts(SACs) are promising electrocatalysts for oxygen reduction reaction(ORR). Herein, with the aid of hierarchically porous silica as hard template, a fa...Heteroatom-doped carbon-based transition-metal single-atom catalysts(SACs) are promising electrocatalysts for oxygen reduction reaction(ORR). Herein, with the aid of hierarchically porous silica as hard template, a facile and general melting perfusion and mesopore-confined pyrolysis method was reported to prepare single-atomic Fe/N–S-doped carbon catalyst(FeNx/NC-S) with hierarchically porous structure and well-defined morphology. The FeNx/NC-S exhibited excellent ORR activity with a half-wave potential(E_(1/2)) of 0.92 V, and a lower overpotential of 320 mV at a current density of 10 mA cm^(-2)for OER under alkaline condition. The remarkable electrocatalysis performance can be attributed to the hierarchically porous carbon nanospheres with S doping and high content of Fe-Nx sites(up to 3.7 wt% of Fe), resulting from the nano-confinement effect of the hierarchically porous silica spheres(NKM-5) during the pyrolysis process. The rechargeable Zn-air battery with FeNx/NC-S as a cathode catalyst demonstrated a superior power density of 194.5 mW cm-2charge–discharge stability. This work highlights a new avenue to design advanced SACs for efficient sustainable energy storage and conversion.展开更多
Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatcllite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphi...Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatcllite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphisms repeatedly, and the polymorphic frequencies were 3.4-11.3% between the mutants and Yuexiangzhan. The polymorphic markers were randomly located on chromosomes. The more similar the plant types of the mutants like their original variety, the less polymorphic loci were detected. In addition, there was variation in the soluble protein contents among the leaves of mutants, and the contents were significantly lower than those of the original variety.展开更多
The presence of light element(s)in the Earth’s core is necessary in order to explain the observed density and velocity discrepancy for the core(Anderson and Ahrens,1994).O,Si,S,C and H were suggested as potential can...The presence of light element(s)in the Earth’s core is necessary in order to explain the observed density and velocity discrepancy for the core(Anderson and Ahrens,1994).O,Si,S,C and H were suggested as potential candidates based on cosmochemical considerations(Stevenson,1981).High-pressure experiment results,in conjunction with theoretical and cosmochemical evidences,argued that it is difficult for any one of them to account for the core展开更多
Electrochemical CO reduction reaction(CORR) provides a promising approach for producing valuable multicarbon products(C_(2+)), while the low solubility of CO in aqueous solution and high energy barrier of C–C couplin...Electrochemical CO reduction reaction(CORR) provides a promising approach for producing valuable multicarbon products(C_(2+)), while the low solubility of CO in aqueous solution and high energy barrier of C–C coupling as well as the competing hydrogen evolution reaction(HER) largely limit the efficiency for C_(2+)production in CORR. Here we report an overturn on the Faradaic efficiency of CORR from being HER-dominant to C_(2+)formation-dominant over a wide potential window, accompanied by a significant activity enhancement over a Moss-like Cu catalyst via pressuring CO. With the CO pressure rising from 1 to 40 atm, the C_(2+)Faradaic efficiency and partial current density remarkably increase from 22.8%and 18.9 mA cm^(-2)to 89.7% and 116.7 mA cm^(-2), respectively. Experimental and theoretical investigations reveal that high pressure-induced high CO coverage on metallic Cu surface weakens the Cu–C bond via reducing electron transfer from Cu to adsorbed CO and restrains hydrogen adsorption, which significantly facilitates the C–C coupling while suppressing HER on the predominant Cu(111) surface, thereby boosting the CO electroreduction to C_(2+)activity.展开更多
Lithium-sulfur(Li-S)battery is regarded as one of the most promising next-generation energy storage systems due to the ultra-high theoretical energy density of 2600 Wh kg^(-1).To address the insulation nature of sulfu...Lithium-sulfur(Li-S)battery is regarded as one of the most promising next-generation energy storage systems due to the ultra-high theoretical energy density of 2600 Wh kg^(-1).To address the insulation nature of sulfur,nanocarbon composition is essential to afford acceptable cycling capacity but inevitably sacrifices the actual energy density under working conditions.Therefore,rational structural design of the carbon/sulfur composite cathode is of great significance to realize satisfactory electrochemical performances with limited carbon content.Herein,the cathode carbon distribution is rationally regulated to construct high-sulfur-content and high-performance Li-S batteries.Concretely,a double-layer carbon(DLC)cathode is prepared by fabricating a surface carbon layer on the carbon/sulfur composite.The surface carbon layer not only provides more electrochemically active surfaces,but also blocks the polysulfide shuttle.Consequently,the DLC configuration with an increased sulfur content by nearly 10 wt%renders an initial areal capacity of 3.40 mAh cm^(-2) and capacity retention of 83.8%during 50 cycles,which is about two times than that of the low-sulfur-content cathode.The strategy of carbon distribution regulation affords an effective pathway to construct advanced high-sulfur-content cathodes for practical high-energy-density Li-S batteries.展开更多
It is known that “Fish Oil” is the raw material that has lot of benefits for health, because fish oil consists of several necessary unsaturated fatty acids, particularly Omega-3 and Docosahexanoic acid (DHA). Omega-...It is known that “Fish Oil” is the raw material that has lot of benefits for health, because fish oil consists of several necessary unsaturated fatty acids, particularly Omega-3 and Docosahexanoic acid (DHA). Omega-3 can decrease triglyceride level, and then it can increase HDL cholesterol level. In addition, DHA can support brain cell synthesis and also nervous system for human.展开更多
High-energy density lithium-sulfur(Li-S) batteries have received intensive attention as promising energy storage system.Among diverse sulfur-based cathodes,sulfurized pyrolyzed poly(acrylonitrile)(S@pPAN)cathode deliv...High-energy density lithium-sulfur(Li-S) batteries have received intensive attention as promising energy storage system.Among diverse sulfur-based cathodes,sulfurized pyrolyzed poly(acrylonitrile)(S@pPAN)cathode delivered superior electrochemical performance.However,the sulfur content of S@pPAN is relatively low(<50 wt%),which significantly limits the energy density.Herein,a hydrogel SA-Cu binder was proposed with a crosslinking network constructed by Cu^(2+) ions.The introduction of Cu^(2+) ions enabled excellent electrochemical behaviors of S@pPAN cathode even with high sulfur content of 52.6 wt% via chemical interaction with sulfur and polysulfide.Moreover,a favorable cathode interphase was formed containing electrochemically active and conductive CuSx.S@pPAN/SA-Cu exhibited a high sulfur utilization of 85.3%,long cycling stability over 1000 cycles and remarkable capacity of 1200 mAh g_(s)^(-1) even at10 C.Furthermore,ascribed to the improved electrode structure,high-loading electrode(sulfur loading:4 mg cm^(-2)) displayed stable cycling with areal capacity of 5.26 mAh cm^(-2)(1315 mAh g_(s)^(-1)) after 40 cycles.This study provides new directions to prepare high-sulfur content and high-loading S@pPAN cathode for higher energy density.展开更多
On March 16–17, 2008, a sea fog occurred in Dianbai in the west of Guangdong Province and was accompanied by a high-pressure synoptic system. Using comprehensive observation datasets, this study analyzes the evolutio...On March 16–17, 2008, a sea fog occurred in Dianbai in the west of Guangdong Province and was accompanied by a high-pressure synoptic system. Using comprehensive observation datasets, this study analyzes the evolution of liquid water content during this sea fog and investigates the relationships between liquid water content and the average diameters and count densities of fog droplets, air temperature, wind speed and turbulence exchanges. The main results are presented as follows. (1) The sea fog showed a quasi-periodic oscillation characteristic, i.e., it developed, disappeared and then developed again. (2) During the sea fog, the number of fog droplets changed significantly while the changes in average diameter of the fog droplets were relatively small. The development and disappearance of the sea fog correlated significantly with the fog droplet numbers. (3) The air-cooling mechanism played a significant role in sea fog formation and development. However, the influences of this mechanism were not evident during fog persistence. (4) During sea fog formation, weak turbulence exchanges were helpful for fog formation. During sea fog development and persistence, liquid water content increased when turbulence exchanges weakened, and vice versa. The changes in turbulence exchanges were closely related to the quasi-periodic oscillations observed in sea fog presence.展开更多
One of the key issues facing the global society today is to find renewable and sustainable energy sources. Hydrogen has gained much attention in recent years since it is one of fuels for fuel cells. It emits no carbon...One of the key issues facing the global society today is to find renewable and sustainable energy sources. Hydrogen has gained much attention in recent years since it is one of fuels for fuel cells. It emits no carbon dioxide when it is used and so on. In this study, a great rate production of high pressure hydrogen rich gas from glycerol/water/metal mixtures was developed since glycerol has become one of the enormous industrial by-products, especially from biodiesel processing plants. It was found that cobalt was the optimum metal additive among tested metals of aluminum, cobalt, magnesium and nickel in terms of a hydrogen producing rate, a hydrogen partial pressure and a conversion ratio from 50 mol% glycerol/water mixtures under an operating temperature of 723 K. Concretely, hydrogen rich gas with concentration about 64%<sub>H<sub>2</sub></sub> and high partial pressure about 4 MPa<sub>N,H<sub>2</sub></sub> could be produced at the great producing rate of 42.9 L<sub>N,H<sub>2</sub></sub> dm<sup>-2</sup>min<sup>-1</sup> and high conversion ratio about 60%<sub>H<sub>2</sub></sub>. All the produced hydrogen rich gases from glycerol/water/metal mixtures were by no means inferior to pure hydrogen as a fuel for the polymer elec-trolyte fuel cell.展开更多
High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2...High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2Se3+ In2Se3) ratio was varied from 0 to 0.13, and the properties of the thin films were investigated. XRD studies demonstrated that the prepared thin films had a chalcopyrite Cu(In,Ga)Se2 structure. The S/(Se+S) mole ratio in the thin films was within the range from 0 to 0.04. The band gaps of Cu(In,Ga)Se2 thin films increased from 1.30 eV to 1.59 eV with increasing the ?In2S3 /(Ga2Se3+ In2Se3) ratio.展开更多
The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare th...The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.展开更多
According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and exis...According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and existing problems concerning high-quality inbred rice va- riety in Guangxi: the rice quality has been greatly improved,but the amylose content is still low; a series of scented rice varieties with high quality and high yield have been bred,such as Zhongguangxiang No. 1,Sanxiang 628,Guixiang No. 1,Liufengxiangzhan,Jiafuxiang No. 1, Zhaoxiang No. 1; the production of high-quality inbred rice during the period 2009-2011 was significantly enhanced,annually more than 66 00 kg / ha,but the disease resistance of rice variety bred was generally poor,and disease-resistant breeding stuck in the mud. Henceforth it is necessary to be oriented by the rice market,and take the rice type with long grain,high adhesive strength,medium-low amylose content and low chalkiness degree as the breeding objectives; introduce the existing high-quality variety resources with medium amylose content at home and abroad,then directly use them or innovate upon them as hybrid strain; take the thick-and-long-grain rice type as breeding objectives,and further improve the yield per unit area of high-quality inbred rice by improving the thousand-grain weight; increase capital investment,improve breeding techniques,strengthen disease-resistant and degeneration-resistant breeding,and improve the application of modern biotechnology in the breeding of high-quality inbred rice.展开更多
Ying-Qiong Basin in the west of South China Sea contains plenty of abnormal high-pressure gas reservoirs, whose stress sensitivity is crucial for well productivity. To explore the influence of stress sensitivity on pr...Ying-Qiong Basin in the west of South China Sea contains plenty of abnormal high-pressure gas reservoirs, whose stress sensitivity is crucial for well productivity. To explore the influence of stress sensitivity on production, the variable outlet back pressure stress sensitivity experiments were applied to test core sample permeability under different burden pressure and obtain the relational expression of power function of core stress sensitivity. Afterwards, new productivity equation is deduced in consideration of reservoir stress sensitivity, and the affection of stress sensitivity on production is analyzed. The result demonstrates close link between stress sensitivity and productivity, since single well production decreases dramatically when reservoir stress sensitivity has been taken into account. This research is constructive for well-testing data interpretation in stress sensitive gas reservoirs.展开更多
To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful...To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful experiences and failure lessons of project construction technology application scientifically, Sinopec has established an integrated technical standard system for the exploration and development of ultra deep and high sour gas fields. The system consists of 51 enterprise standards and covers 7 professions including geophysical prospecting, drilling, drilling log, well logging, gas formation test and production, sour gas gathering and transferring system, and HSE (health,safety,environment). It guides and guarantees the safe, high-quality and high-efficiency project construction effectively by means of enhancing the engineering design criterion, recommending the data processing and interpretation methods, identifying the requirements of operation and field inspection and standardizing the application of technical equipments.展开更多
Lithium-sulfur(Li-S)batteries are the promising next-generation secondary energy storage systems,because of their advantages of high energy density and environmental friendliness.Among numerous cathode materials,organ...Lithium-sulfur(Li-S)batteries are the promising next-generation secondary energy storage systems,because of their advantages of high energy density and environmental friendliness.Among numerous cathode materials,organosulfur polymer materials have received extensive attentions because of their controllable structure and uniform sulfur distribution.However,the sulfur content of most organosulfur polymer cathodes is limited(S content<60%)due to the addition of large amounts of conductive agents and binders,which adversely affects the energy density of Li-S batteries.Herein,a hyperbranched sulfur-rich polymer based on modified polyethyleneimine(Ath-PEI)named carbon nanotubeentangled poly(allyl-terminated hyperbranched ethyleneimine-random-sulfur)(CNT/Ath-PEI@S)was prepared by sulfur polymerization and used as a Li-S battery cathode.The high intrinsic viscosity of Ath-PEI provided considerable adhesion and avoided the addition of PVDF binder,thereby increasing the sulfur content of cathodes to 75%.Moreover,considering the uniform distribution of elemental sulfur by the polymer,the utilization of sulfur was successfully improved,thus improving the rate capability and discharge capacity of the battery.The binder-free,sulfur-rich polymer cathode exhibited ultra-high initial discharge capacity(1520.7 mAh g^(−1) at 0.1 C),and high rate capability(804 mAh g^(−1) at 2.0 C).And cell-level calculations show that the electrode exhibits an initial capacity of 942.3 mAh g^(−1) electrode,which is much higher than those of conventional sulfur-polymer electrodes reported in the literature.展开更多
The paper is devoted to the two-phase flow simulation.The gas-condensate mixture flow in a horizontal pipe under high pressure is considered.The influence of the equation of state(EOS)choice for mixture properties mod...The paper is devoted to the two-phase flow simulation.The gas-condensate mixture flow in a horizontal pipe under high pressure is considered.The influence of the equation of state(EOS)choice for mixture properties modelling on the flow regime calculation results is studied for gas with high content of methane homologues.An analytical overview of the methods to predict the flow pattern is provided.Based on this analysis,two techniques are selected.For these techniques,values of density and viscosity for each phase are required.Density calculation for the gas phase is performed with Van der Waals based EOS.The propriate EOS is selected based on studies of calculation errors for test mixtures.Calculation of liquid phase density is done by means of Patela-Teja and Guo-Du equations,two different models are considered for viscosity estimation.The flow patterns of gas-condensate mixture in a range of temperatures and pressures are calculated and verified via probability map.The results of study allow to recommend the Brusilovsky EOS for calculation of densities for similar gas mixtures and make more rigorous flow regime evaluation.The probability map shows that for the chosen composition and parameters of media the flow pattern is mostly transitional between segregated and annular independent from EOS.展开更多
Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding ...Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2- on alumina product quality is eliminated. However, the removal efficiency of 2?32OS in sodium aluminate solution is very low by this method. Both S2- and 2?32OS in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.展开更多
A oilfield was an oil reservoir with strong bottom water in offshore, the water cut was as high as 96%. In the high water cut stage, the most effective way of increasing oil production was to extract liquid and increa...A oilfield was an oil reservoir with strong bottom water in offshore, the water cut was as high as 96%. In the high water cut stage, the most effective way of increasing oil production was to extract liquid and increase oil. The processing capacity of oilfield fluid was limited by the conditions. By using Petrel-RE-2017 software, combining reservoir engineering and percolation mechanics methods, this paper analyzes the effect of large-scale liquid pumping, expand coverage and shut-in coning in oil reservoirs with bottom water, and formulates the adjustment strategy of single well production structure of the whole oilfield. It was confirmed that large-scale liquid production can expand coverage and shutting down well can reduce water cut. It can provide reference and guidance for oil field with strong bottom water when it encounters bottleneck of liquid treatment capacity.展开更多
基金the National Natural Science Foundation of China(52103093)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2021QNRC001)+2 种基金the Jiangxi Provincial Natural Science Foundation(20212BAB214048)Science and Technology Support Project of Shangrao(2020L009,2021J006)Science and Technological Project of Education Department of Jiangxi(GJJ211704)for funding their contributions to this paper。
文摘Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.
基金supported by National Natural Science Foundation of China (21773128)。
文摘Heteroatom-doped carbon-based transition-metal single-atom catalysts(SACs) are promising electrocatalysts for oxygen reduction reaction(ORR). Herein, with the aid of hierarchically porous silica as hard template, a facile and general melting perfusion and mesopore-confined pyrolysis method was reported to prepare single-atomic Fe/N–S-doped carbon catalyst(FeNx/NC-S) with hierarchically porous structure and well-defined morphology. The FeNx/NC-S exhibited excellent ORR activity with a half-wave potential(E_(1/2)) of 0.92 V, and a lower overpotential of 320 mV at a current density of 10 mA cm^(-2)for OER under alkaline condition. The remarkable electrocatalysis performance can be attributed to the hierarchically porous carbon nanospheres with S doping and high content of Fe-Nx sites(up to 3.7 wt% of Fe), resulting from the nano-confinement effect of the hierarchically porous silica spheres(NKM-5) during the pyrolysis process. The rechargeable Zn-air battery with FeNx/NC-S as a cathode catalyst demonstrated a superior power density of 194.5 mW cm-2charge–discharge stability. This work highlights a new avenue to design advanced SACs for efficient sustainable energy storage and conversion.
文摘Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatcllite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphisms repeatedly, and the polymorphic frequencies were 3.4-11.3% between the mutants and Yuexiangzhan. The polymorphic markers were randomly located on chromosomes. The more similar the plant types of the mutants like their original variety, the less polymorphic loci were detected. In addition, there was variation in the soluble protein contents among the leaves of mutants, and the contents were significantly lower than those of the original variety.
文摘The presence of light element(s)in the Earth’s core is necessary in order to explain the observed density and velocity discrepancy for the core(Anderson and Ahrens,1994).O,Si,S,C and H were suggested as potential candidates based on cosmochemical considerations(Stevenson,1981).High-pressure experiment results,in conjunction with theoretical and cosmochemical evidences,argued that it is difficult for any one of them to account for the core
基金financial support from the National Key R&D Program of China (Nos. 2022YFA1504500, 2022YFA1503100)the National Natural Science Foundation of China (Nos. 21988101, 21890753, 22225204, 92145301, 22002160 and 22272174)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB36030200)the CAS Project for Young Scientists in Basic Research (No. YSBR-028)the Fundamental Research Funds for the Central Universities (No. 20720220008)the Dalian National Lab for Clean Energy (DNL Cooperation Fund 202001)the Innovation Research Fund Project of DICP (No. DICP I202016)。
文摘Electrochemical CO reduction reaction(CORR) provides a promising approach for producing valuable multicarbon products(C_(2+)), while the low solubility of CO in aqueous solution and high energy barrier of C–C coupling as well as the competing hydrogen evolution reaction(HER) largely limit the efficiency for C_(2+)production in CORR. Here we report an overturn on the Faradaic efficiency of CORR from being HER-dominant to C_(2+)formation-dominant over a wide potential window, accompanied by a significant activity enhancement over a Moss-like Cu catalyst via pressuring CO. With the CO pressure rising from 1 to 40 atm, the C_(2+)Faradaic efficiency and partial current density remarkably increase from 22.8%and 18.9 mA cm^(-2)to 89.7% and 116.7 mA cm^(-2), respectively. Experimental and theoretical investigations reveal that high pressure-induced high CO coverage on metallic Cu surface weakens the Cu–C bond via reducing electron transfer from Cu to adsorbed CO and restrains hydrogen adsorption, which significantly facilitates the C–C coupling while suppressing HER on the predominant Cu(111) surface, thereby boosting the CO electroreduction to C_(2+)activity.
基金supported by Scientific and Technological Key Project of Shanxi Province(20191102003)National Key Research and Development Program(2016YFA0202500)+1 种基金the National Natural Science Foundation of China(21776019)Beijing Natural Science Foundation(L182021)。
文摘Lithium-sulfur(Li-S)battery is regarded as one of the most promising next-generation energy storage systems due to the ultra-high theoretical energy density of 2600 Wh kg^(-1).To address the insulation nature of sulfur,nanocarbon composition is essential to afford acceptable cycling capacity but inevitably sacrifices the actual energy density under working conditions.Therefore,rational structural design of the carbon/sulfur composite cathode is of great significance to realize satisfactory electrochemical performances with limited carbon content.Herein,the cathode carbon distribution is rationally regulated to construct high-sulfur-content and high-performance Li-S batteries.Concretely,a double-layer carbon(DLC)cathode is prepared by fabricating a surface carbon layer on the carbon/sulfur composite.The surface carbon layer not only provides more electrochemically active surfaces,but also blocks the polysulfide shuttle.Consequently,the DLC configuration with an increased sulfur content by nearly 10 wt%renders an initial areal capacity of 3.40 mAh cm^(-2) and capacity retention of 83.8%during 50 cycles,which is about two times than that of the low-sulfur-content cathode.The strategy of carbon distribution regulation affords an effective pathway to construct advanced high-sulfur-content cathodes for practical high-energy-density Li-S batteries.
基金Project supported by the National Natural Science Foundation of China(Grant No.51172089)the Education Department of Henan Province,China(Grant No.12A430010)the Fundamental Research Funds for the Universities of Henan Province,China(Grant No.NSFRF140110)
文摘It is known that “Fish Oil” is the raw material that has lot of benefits for health, because fish oil consists of several necessary unsaturated fatty acids, particularly Omega-3 and Docosahexanoic acid (DHA). Omega-3 can decrease triglyceride level, and then it can increase HDL cholesterol level. In addition, DHA can support brain cell synthesis and also nervous system for human.
基金financially supported by the National Natural Science Foundation of China (U1705255 and 21975158)the Program of Shanghai Academic Research Leader (20XD1401900)the Key-Area Research and Development Program of Guangdong Province (2019B090908001)。
文摘High-energy density lithium-sulfur(Li-S) batteries have received intensive attention as promising energy storage system.Among diverse sulfur-based cathodes,sulfurized pyrolyzed poly(acrylonitrile)(S@pPAN)cathode delivered superior electrochemical performance.However,the sulfur content of S@pPAN is relatively low(<50 wt%),which significantly limits the energy density.Herein,a hydrogel SA-Cu binder was proposed with a crosslinking network constructed by Cu^(2+) ions.The introduction of Cu^(2+) ions enabled excellent electrochemical behaviors of S@pPAN cathode even with high sulfur content of 52.6 wt% via chemical interaction with sulfur and polysulfide.Moreover,a favorable cathode interphase was formed containing electrochemically active and conductive CuSx.S@pPAN/SA-Cu exhibited a high sulfur utilization of 85.3%,long cycling stability over 1000 cycles and remarkable capacity of 1200 mAh g_(s)^(-1) even at10 C.Furthermore,ascribed to the improved electrode structure,high-loading electrode(sulfur loading:4 mg cm^(-2)) displayed stable cycling with areal capacity of 5.26 mAh cm^(-2)(1315 mAh g_(s)^(-1)) after 40 cycles.This study provides new directions to prepare high-sulfur content and high-loading S@pPAN cathode for higher energy density.
基金Natural Science Foundation of China (40675013)Foundation project of Nanjing University of Information Science & TechnologyProject on natural science for universities and colleges in Jiangsu province
文摘On March 16–17, 2008, a sea fog occurred in Dianbai in the west of Guangdong Province and was accompanied by a high-pressure synoptic system. Using comprehensive observation datasets, this study analyzes the evolution of liquid water content during this sea fog and investigates the relationships between liquid water content and the average diameters and count densities of fog droplets, air temperature, wind speed and turbulence exchanges. The main results are presented as follows. (1) The sea fog showed a quasi-periodic oscillation characteristic, i.e., it developed, disappeared and then developed again. (2) During the sea fog, the number of fog droplets changed significantly while the changes in average diameter of the fog droplets were relatively small. The development and disappearance of the sea fog correlated significantly with the fog droplet numbers. (3) The air-cooling mechanism played a significant role in sea fog formation and development. However, the influences of this mechanism were not evident during fog persistence. (4) During sea fog formation, weak turbulence exchanges were helpful for fog formation. During sea fog development and persistence, liquid water content increased when turbulence exchanges weakened, and vice versa. The changes in turbulence exchanges were closely related to the quasi-periodic oscillations observed in sea fog presence.
文摘One of the key issues facing the global society today is to find renewable and sustainable energy sources. Hydrogen has gained much attention in recent years since it is one of fuels for fuel cells. It emits no carbon dioxide when it is used and so on. In this study, a great rate production of high pressure hydrogen rich gas from glycerol/water/metal mixtures was developed since glycerol has become one of the enormous industrial by-products, especially from biodiesel processing plants. It was found that cobalt was the optimum metal additive among tested metals of aluminum, cobalt, magnesium and nickel in terms of a hydrogen producing rate, a hydrogen partial pressure and a conversion ratio from 50 mol% glycerol/water mixtures under an operating temperature of 723 K. Concretely, hydrogen rich gas with concentration about 64%<sub>H<sub>2</sub></sub> and high partial pressure about 4 MPa<sub>N,H<sub>2</sub></sub> could be produced at the great producing rate of 42.9 L<sub>N,H<sub>2</sub></sub> dm<sup>-2</sup>min<sup>-1</sup> and high conversion ratio about 60%<sub>H<sub>2</sub></sub>. All the produced hydrogen rich gases from glycerol/water/metal mixtures were by no means inferior to pure hydrogen as a fuel for the polymer elec-trolyte fuel cell.
文摘High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2Se3+ In2Se3) ratio was varied from 0 to 0.13, and the properties of the thin films were investigated. XRD studies demonstrated that the prepared thin films had a chalcopyrite Cu(In,Ga)Se2 structure. The S/(Se+S) mole ratio in the thin films was within the range from 0 to 0.04. The band gaps of Cu(In,Ga)Se2 thin films increased from 1.30 eV to 1.59 eV with increasing the ?In2S3 /(Ga2Se3+ In2Se3) ratio.
基金This work was supported by the National Natural Science Foundation of China
文摘The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.
基金Supported by Guangxi Innovation Team Project,National Modern Agricultural Technology System(nycytxgxcxtd-01)Guangxi Scientific Research and Technological Development Project(10100004-1A)Guangxi Natural Science Foundation(2011GXNSFB018043)
文摘According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and existing problems concerning high-quality inbred rice va- riety in Guangxi: the rice quality has been greatly improved,but the amylose content is still low; a series of scented rice varieties with high quality and high yield have been bred,such as Zhongguangxiang No. 1,Sanxiang 628,Guixiang No. 1,Liufengxiangzhan,Jiafuxiang No. 1, Zhaoxiang No. 1; the production of high-quality inbred rice during the period 2009-2011 was significantly enhanced,annually more than 66 00 kg / ha,but the disease resistance of rice variety bred was generally poor,and disease-resistant breeding stuck in the mud. Henceforth it is necessary to be oriented by the rice market,and take the rice type with long grain,high adhesive strength,medium-low amylose content and low chalkiness degree as the breeding objectives; introduce the existing high-quality variety resources with medium amylose content at home and abroad,then directly use them or innovate upon them as hybrid strain; take the thick-and-long-grain rice type as breeding objectives,and further improve the yield per unit area of high-quality inbred rice by improving the thousand-grain weight; increase capital investment,improve breeding techniques,strengthen disease-resistant and degeneration-resistant breeding,and improve the application of modern biotechnology in the breeding of high-quality inbred rice.
文摘Ying-Qiong Basin in the west of South China Sea contains plenty of abnormal high-pressure gas reservoirs, whose stress sensitivity is crucial for well productivity. To explore the influence of stress sensitivity on production, the variable outlet back pressure stress sensitivity experiments were applied to test core sample permeability under different burden pressure and obtain the relational expression of power function of core stress sensitivity. Afterwards, new productivity equation is deduced in consideration of reservoir stress sensitivity, and the affection of stress sensitivity on production is analyzed. The result demonstrates close link between stress sensitivity and productivity, since single well production decreases dramatically when reservoir stress sensitivity has been taken into account. This research is constructive for well-testing data interpretation in stress sensitive gas reservoirs.
文摘To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful experiences and failure lessons of project construction technology application scientifically, Sinopec has established an integrated technical standard system for the exploration and development of ultra deep and high sour gas fields. The system consists of 51 enterprise standards and covers 7 professions including geophysical prospecting, drilling, drilling log, well logging, gas formation test and production, sour gas gathering and transferring system, and HSE (health,safety,environment). It guides and guarantees the safe, high-quality and high-efficiency project construction effectively by means of enhancing the engineering design criterion, recommending the data processing and interpretation methods, identifying the requirements of operation and field inspection and standardizing the application of technical equipments.
基金CNPC Innovation Found,Grant/Award Number:2021DQ02-1001Liao Ning Revitalization Talents Program,Grant/Award Number:XLYC1907144+2 种基金Xinghai Talent Cultivation Plan,Grant/Award Number:X20200303National Outstanding Youth Science Fund,Grant/Award Number:52222314Fundamental Research Funds for the Central Universities,Grant/Award Numbers:DUT22JC02,DUT22LAB605。
文摘Lithium-sulfur(Li-S)batteries are the promising next-generation secondary energy storage systems,because of their advantages of high energy density and environmental friendliness.Among numerous cathode materials,organosulfur polymer materials have received extensive attentions because of their controllable structure and uniform sulfur distribution.However,the sulfur content of most organosulfur polymer cathodes is limited(S content<60%)due to the addition of large amounts of conductive agents and binders,which adversely affects the energy density of Li-S batteries.Herein,a hyperbranched sulfur-rich polymer based on modified polyethyleneimine(Ath-PEI)named carbon nanotubeentangled poly(allyl-terminated hyperbranched ethyleneimine-random-sulfur)(CNT/Ath-PEI@S)was prepared by sulfur polymerization and used as a Li-S battery cathode.The high intrinsic viscosity of Ath-PEI provided considerable adhesion and avoided the addition of PVDF binder,thereby increasing the sulfur content of cathodes to 75%.Moreover,considering the uniform distribution of elemental sulfur by the polymer,the utilization of sulfur was successfully improved,thus improving the rate capability and discharge capacity of the battery.The binder-free,sulfur-rich polymer cathode exhibited ultra-high initial discharge capacity(1520.7 mAh g^(−1) at 0.1 C),and high rate capability(804 mAh g^(−1) at 2.0 C).And cell-level calculations show that the electrode exhibits an initial capacity of 942.3 mAh g^(−1) electrode,which is much higher than those of conventional sulfur-polymer electrodes reported in the literature.
基金supported under the strategic academic leadership program“Priority 2030”of the Russian Federation(Agreement 075-15-2021-1333 dated 30.09.2021).
文摘The paper is devoted to the two-phase flow simulation.The gas-condensate mixture flow in a horizontal pipe under high pressure is considered.The influence of the equation of state(EOS)choice for mixture properties modelling on the flow regime calculation results is studied for gas with high content of methane homologues.An analytical overview of the methods to predict the flow pattern is provided.Based on this analysis,two techniques are selected.For these techniques,values of density and viscosity for each phase are required.Density calculation for the gas phase is performed with Van der Waals based EOS.The propriate EOS is selected based on studies of calculation errors for test mixtures.Calculation of liquid phase density is done by means of Patela-Teja and Guo-Du equations,two different models are considered for viscosity estimation.The flow patterns of gas-condensate mixture in a range of temperatures and pressures are calculated and verified via probability map.The results of study allow to recommend the Brusilovsky EOS for calculation of densities for similar gas mixtures and make more rigorous flow regime evaluation.The probability map shows that for the chosen composition and parameters of media the flow pattern is mostly transitional between segregated and annular independent from EOS.
基金Project(51404121)supported by the National Natural Science Foundation of ChinaProject(KKSY201452041)supported by Yunnan Provincal Personnel Training Funds for Kunming University of Science and Technology,China
文摘Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2- on alumina product quality is eliminated. However, the removal efficiency of 2?32OS in sodium aluminate solution is very low by this method. Both S2- and 2?32OS in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.
文摘A oilfield was an oil reservoir with strong bottom water in offshore, the water cut was as high as 96%. In the high water cut stage, the most effective way of increasing oil production was to extract liquid and increase oil. The processing capacity of oilfield fluid was limited by the conditions. By using Petrel-RE-2017 software, combining reservoir engineering and percolation mechanics methods, this paper analyzes the effect of large-scale liquid pumping, expand coverage and shut-in coning in oil reservoirs with bottom water, and formulates the adjustment strategy of single well production structure of the whole oilfield. It was confirmed that large-scale liquid production can expand coverage and shutting down well can reduce water cut. It can provide reference and guidance for oil field with strong bottom water when it encounters bottleneck of liquid treatment capacity.