Plastic,renowned for its versatility,durability,and cost-effectiveness,is indispensable in modern society.Nevertheless,the annual production of nearly 400 million tons of plastic,coupled with a recycling rate of only ...Plastic,renowned for its versatility,durability,and cost-effectiveness,is indispensable in modern society.Nevertheless,the annual production of nearly 400 million tons of plastic,coupled with a recycling rate of only 9%,has led to a monumental environmental crisis.Plastic recycling has emerged as a vital response to this crisis,offering sustainable solutions to mitigate its environmental impact.Among these recycling efforts,plastic upcycling has garnered attention,which elevates discarded plastics into higher-value products.Here,electrocatalytic and photoelectrocatalytic treatments stand at the forefront of advanced plastic upcycling.Electrocatalytic or photoelectrocatalytic treatments involve chemical reactions that facilitate electron transfer through the electrode/electrolyte interface,driven by electrical or solar energy,respectively.These methods enable precise control of chemical reactions,harnessing potential,current density,or light to yield valuable chemical products.This review explores recent progress in plastic upcycling through electrocatalytic and photoelectrocatalytic pathways,offering promising solutions to the plastic waste crisis and advancing sustainability in the plastics industry.展开更多
Solar energy utilization has drawn attention due to ever-increasing environmental and energy issues.Photoelectrochemical(PEC)and photocatalytic(PC)water splitting for hydrogen production,which is the most popular and ...Solar energy utilization has drawn attention due to ever-increasing environmental and energy issues.Photoelectrochemical(PEC)and photocatalytic(PC)water splitting for hydrogen production,which is the most popular and well-established solar-to-chemical conversion process,has been studied thoroughly to date but is now facing limitations related to low conversion efficiency.To resolve this issue,research in PEC cells or photocatalysts has recently aimed to produce alternative value-added chemicals by modifying their redox reactions,which potentially enables high economic reward to compensate for the low efficiency.Here,various kinds of redox reactions that decouple classic water splitting reactions to produce value-added chemicals via PEC and PC processes are introduced.Successful coupling of CO_(2) reduction,O_(2) reduction and organic synthesis with either water oxidation or water reduction is comprehensively discussed from the perspective of basic fundamental and product selectivity in terms of the band structure of materials,cocatalyst design,and thermodynamics and kinetics of the reactions.Throughout the review,future challenges and opportunities are suggested with respect to the redesigned artificial synthesis,which might be an alternative development for the commercialization of PEC or PC value-added chemical production technologies in the near future.展开更多
The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1...The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1 and 1:2)on the organic product distribution(acetaldehyde,acetic acid and ethyl acetate)and pure hydrogen generation at different current densities operation levels.Physicochemical characterization of the catalysts was made by X-ray diffraction(XRD),temperature-programmed reduction(TPR)and N_(2) adsorption-desorption measurements.XRD patterns showed that Ru is introduced into the Pt structure,forming an alloy between both metals.Also,the degree of alloy was higher by increasing the Ru amounts.From TPR profiles Pt was found to be properly reduced while Ru was both in metallic state and forming RuO2.The electrochemical behaviour of each catalyst towards ethanol electroreforming process was investigated through electrochemical techniques in a half cell and a single proton exchange membrane(PEM)cell systems.An intermediate Pt:Ru ratio was found to result in high current density and electrochemical surface area(ECSA)values along with lower amounts of adsorbed species.Also,Ru addition seems to diminish the degree of degradation of the catalyst.Based on characterization and in agreement with essays carried out in a PEM cell at mild conditions(80℃ and 1 atm),PtRu/C 2:1 anode provided the best electrocatalytic results in terms of current density(740 mA cm^(-2)),hydrogen production and selectivity toward acetic acid(up to 15%apart from acetaldehyde and ethyl acetate)while requiring the lowest energy consumption.展开更多
The Gas-Oil Ratio(GOR)is a crucial production parameter in oil reservoirs.An increase in GOR results in higher gas production and lower oil production,potentially leading to well shut-ins due to economic infeasibility...The Gas-Oil Ratio(GOR)is a crucial production parameter in oil reservoirs.An increase in GOR results in higher gas production and lower oil production,potentially leading to well shut-ins due to economic infeasibility.This study focuses on a real fractured oil field that requires urgent production operations to reduce the producing GOR.In this study,the static model for the field was developed using commercial software,involving steps such as data collection,fault modeling,meshing,and statistical analysis to prepare for dynamic simulation.The dynamic model incorporates geometry,gridding,and rock properties from the static model,utilizing a dual-porosity approach for the naturally fractured reservoir and the Peng-Robinson equation for fluid phase behavior.Initial reservoir conditions,production history,and rock-fluid interactions were defined,with relative permeability curves indicating a water-wet reservoir and low critical gas saturation affecting the GOR.To better understand the relationship between reservoir and production parameters,a detailed sensitivity analysis was performed using the Response Surface Methodology(RSM).Following the sensitivity analysis,a history matching process was conducted using the Designed Exploration and Controlled Evolution(DECE)optimizer to validate the model for future forecasts.Six operational scenarios were defined to decrease the production GOR and enhance final recovery from the field.The results indicate that the water injection scenario is effective in preventing the GOR increase by maintaining reservoir pressure,thereby sustaining production over a longer period.This scenario also improves oil recovery by approximately 6%compared to the base case.Finally,optimization was carried out using the DECE optimizer for each scenario to fine-tune the operational parameters.The goal was to maximize oil revenue for each scenario during the optimization process.This study stands out as one of the few that provides a comprehensive analysis of production behavior and development planning for a real fractured reservoir with high producing GOR.展开更多
As a Chinese proverb declares,"The beginningof wisdom is to call things by their right names."For an entrepreneur,the beginning of his success isto call his brand by a right name.A brand needs agood name as ...As a Chinese proverb declares,"The beginningof wisdom is to call things by their right names."For an entrepreneur,the beginning of his success isto call his brand by a right name.A brand needs agood name as much as the mankind does.A展开更多
Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogic...Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus, and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability.展开更多
Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the...Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the status of organic matter and nutrients in the soil but also affected the environmental quality. This article investigates the contents of organic carbon and the nutrients, and the change over the last 20 years in highly productive paddy soils and their environmental application. Field soils were sampled and the analytical results were compared with the corresponding values in the Second Soil Survey in Yujiang County of Jiangxi Province, China. The results showed that surface soils at a depth of 0-10 cm in highly productive paddy fields in Yujiang County of Jiangxi Province had contents of organic carbon (20.2 ±3.88) g kg^-1, total nitrogen (2.09±0.55) g kg^-1, and available phosphorus (42.7 ±32.7) mg kg^-1, respectively, which were all at very rich levels. Over the last 20 years, the organic carbon pool of the highly productive paddy soils reached a steady state. Total N and available P significantly increased, whereas available K changed a little. The amount and percentage of P immobilization in the surface soil (0-10 cm) of highly productive paddy fields were (142.7 ~ 41.1) mg kg-~ and (36.2~ 10.4)% of added P, and CEC (7.93 ~ 1.32) cmol kg-~. These two parameters were not higher than the mean values of paddy soils and upland red soils in the areas. Results also showed that fertilizer P in highly productive paddy soils had a high mobility and was prone to move toward a water body, which is the main source of nutrients causing eutrophication. Because of a weak K-fixing capacity, the available K content was not high in highly productive paddy soils. This suggests that attention should be paid to the K balance and the increase of soil K pool.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
Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are...Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.展开更多
Development strategy for heavy-oil reservoirs is one of the important research interests in China National Offshore Oil Corp. (CNOOC) that plans a highly effective development for heavy oil fields in multilayered fl...Development strategy for heavy-oil reservoirs is one of the important research interests in China National Offshore Oil Corp. (CNOOC) that plans a highly effective development for heavy oil fields in multilayered fluvial reservoirs because of their significant influence on marine oil and even on China's petroleum production. The characteristics analysis of multilayered fluvial reservoirs in the heavy oil fields in Bohai Bay indicates that large amounts ofoil were trapped in the channel, point bar and channel bar sands. The reserves distribution of 8 oilfields illustrates that the reserves trapped in the main sands, which is 20%-40% of all of the sand bodies, account for 70%-90% of total reserves of the heavy oil fields. The cumulative production from high productivity wells (50% of the total wells) was 75%-90% of the production of the overall oilfield, while only 3%-10% of the total production was from the low productivity wells (30% of the total wells). And the high productivity wells were drilled in the sands with high reserves abundance. Based on the above information the development strategy was proposed, which includes reserves production planning, selection of well configuration, productivity design, and development modification at different stages.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
[Objective] To investigate the optimal determination conditions of melamine in animal blood products by high performance liquid chromatography (HPLC). [ Method] The blood samples were extracted with ultrasonic in 1%...[Objective] To investigate the optimal determination conditions of melamine in animal blood products by high performance liquid chromatography (HPLC). [ Method] The blood samples were extracted with ultrasonic in 1% trichloroacetic acid (TDA) and acetonitrile. After purifying by solide phase extraction (SPE), the samples were analyzed by H PLC. r Result I The optimal conditions of HPLC were as follows: the chromatographic column was Zorbax SB-CS; the mobile phase was ion-pairs buffer-acetonitrile (95/5, V/V) ; the flow rate was 1.0 ml/min; the column temperature was 25 ℃ and the UV detection wavelength was 235 nm. The determined melamine concentration range was 0.001 -0.050 mg/ml; the linear correlation coefficient was 0.999 4; the concentration limit of melamine was 0.1 mg/kg; the average recovery rate of the melamine were 97.60% - 100.65%, and the relative standard deviation (RSD) was 1.23% -3.04%.[ Conclusion] The HPLC is simple, accurate and repeatable for determination of the melamine in animal blood products.展开更多
In order to further study the influence of high-yield-water on the productivity of CBM (coalbed methane) wells and the expulsion and production method carried out in CBM wells, by means of analyzing and researching ...In order to further study the influence of high-yield-water on the productivity of CBM (coalbed methane) wells and the expulsion and production method carried out in CBM wells, by means of analyzing and researching production characteris- tics and geologic condition of the CBM wells with high water yield in Yanchuannan block located at the eastern margin of Or- dos basin, the mechanism of high water yield decreasing the productivity of CBM well was discussed, and the expulsion and production method for this type of CBM well was proposed. The results show that high water yield would decrease the produc- tivity of CBM wells, and the mechanism is: first, in some circumstances, high water yield could reflect that there was dissipa- tion during the process of coalbed methane reservoir forming, which would lower the gas saturation of coal gas reservoir and reduce the productivity of CBM well; second, a large quantity of coalbed methane dissipated in the form of solution gas, caus- ing the practical reservoir pressure when gas appeared in casing to be lower than critical desorption pressure of the coal bed; finally, the CBM well with high water yield would have higher requirements of discharge and mining installation, system and continuity, and any link with problems would have a great impact on the well's productivity and would increase the difficulty of discharge and mining. In the case of wells with high water yield, the key is to select applicable discharge and mining installa- tion, which should be able to make the bottom hole flowing pressure decline smoothly and fast, and make the wells produce gas as quickly as possible but able to slow down the rate of discharge and mining properly when gas has appeared. In addition, in view of the CBM wells with high water yield, an installation lectotype method based on Darcy's law was proposed, which was found with good accuracy and practicability through field application.展开更多
Marine shale gas resources have great potential in the south of the Sichuan Basin in China.At present,the high-quality shale gas resources at depth of 2000–3500 m are under effective development,and strategic breakth...Marine shale gas resources have great potential in the south of the Sichuan Basin in China.At present,the high-quality shale gas resources at depth of 2000–3500 m are under effective development,and strategic breakthroughs have been made in deeper shale gas resources at depth of 3500–4500 m.To promote the effective production of shale gas in this area,this study examines key factors controlling high shale gas production and presents the next exploration direction in the southern Sichuan Basin based on summarizing the geological understandings from the Lower Silurian Longmaxi Formation shale gas exploration combined with the latest results of geological evaluation.The results show that:(1)The relative sea depth in marine shelf sedimentary environment controls the development and distribution of reservoirs.In the relatively deep water area in deep-water shelf,grade-I reservoirs with a larger continuous thickness develop.The relative depth of sea in marine shelf sedimentary environment can be determined by redox conditions.The research shows that the uranium to thorium mass ratio greater than 1.25 indicates relatively deep water in anoxic reduction environment,and the uranium to thorium mass ratio of 0.75–1.25 indicates semi-deep water in weak reduction and weak oxidation environment,and the uranium to thorium mass ratio less than 0.75 indicates relatively shallow water in strong oxidation environment.(2)The propped fractures in shale reservoirs subject to fracturing treatment are generally 10–12 m high,if grade-I reservoirs are more than 10 m in continuous thickness,then all the propped section would be high-quality reserves;in this case,the longer the continuous thickness of penetrated grade-I reservoirs,the higher the production will be.(3)The shale gas reservoirs at 3500–4500 m depth in southern Sichuan are characterized by high formation pressure,high pressure coefficient,well preserved pores,good pore structure and high proportion of free gas,making them the most favorable new field for shale gas exploration;and the pressure coefficient greater than 1.2 is a necessary condition for shale gas wells to obtain high production.(4)High production wells in the deep shale gas reservoirs are those in areas where Long11-Long13 sub-beds are more than 10 m thick,with 1500 m long horizontal section,grade-I reservoirs penetration rate of over 90%,and fractured by dense cutting+high intensity sand injection+large displacement+large liquid volume.(5)The relatively deep-water area in the deep-water shelf and the area at depth of 3500–4500 m well overlap in the southern Sichuan,and the overlapping area is the most favorable shale gas exploration and development zones in the southern Sichuan in the future.With advancement in theory and technology,annual shale gas production in the southern Sichuan is expected to reach 450×108 m3.展开更多
The quality and safety of agricultural products are closely related to human health.They also play an important role in enhancing the competitiveness of China’s agricultural products market,shaping the brand value of...The quality and safety of agricultural products are closely related to human health.They also play an important role in enhancing the competitiveness of China’s agricultural products market,shaping the brand value of agricultural products,and promoting the high-quality development of agriculture.At present,there are still a series of problems in the quality and safety of agricultural products.Relevant departments of the state should strengthen guidance and supervision,improve the quality and safety awareness and management level of agricultural product producers,and encourage producers to participate in the product certification and process certification of agricultural products.In addition,it is necessary to take effective control measures in accordance with the certification requirements,to evaluate their effectiveness,so as to improve the quality and safety of agricultural products and promote the high-quality development of China’s agriculture.展开更多
As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect a...As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect and the theory of multiphase flow. With this model, the transient flow of gas well can be simulated by segmenting the curved part of tubing and calculating numerical solution with the method of characteristic curve. The results show that the higher the opening coefficient of the valve when closed, the larger the peak value of the wellhead pressure, the more gentle the pressure fluctuation, and the less obvious the pressure mutation area will be. On the premise of not exceeding the maximum shut-in pressure of the tubing, adopting large opening coefficient can reduce the impact of the pressure wave. The higher the cross-section liquid holdup, the greater the pressure wave speed, and the shorter the propagation period will be. The larger the liquid holdup, the larger the variation range of pressure, and the greater the pressure will be. In actual production, the production parameters can be adjusted to get the appropriate liquid holdup, control the magnitude and range of fluctuation pressure, and reduce the impact of water hammer effect. When the valve closing time increases, the maximum fluctuating pressure value of the wellhead decreases, the time of pressure peak delays, and the pressure mutation area gradually disappears. The shorter the valve closing time, the faster the pressure wave propagates. Case simulation proves that the transient flow model of gas well can optimize the reasonable valve opening coefficient and valve closing time, reduce the harm of water hammer impact on the wellhead device and tubing, and ensure the integrity of the wellbore.展开更多
From 1980’s decade,the introduction of carbon composite materials in structural applications has been consistently increased in the successive generations of civil aircraft from Single Aisle to Middle-long Range to a...From 1980’s decade,the introduction of carbon composite materials in structural applications has been consistently increased in the successive generations of civil aircraft from Single Aisle to Middle-long Range to achieve a culminant point with more than 50%in structure weight in recent commercial civil aircraft.This evolution,done through successive iterations,has been possible by combining in the same time the improvement of intrinsic composite material performances and its transformation into prepreg production technologies together with the development of new manufacturing process for material lay-up automation at composite shop-floor manufacturer of aircraft composite parts.New challenges are still coming to continuously develop materials and technologies in order to pursue the production more cost-effective composite parts.Associated to higher aircraft production rate for single aisle,new challenges may force material and aircraft designers and producers to furthermore drive new products and processes introduction and new ways of transformation within in next decade of composite aircraft designs.We propose to illustrate these trends using past and recent developments and our return of experience from Hexcel on Civil Aircraft programs.展开更多
From Jan. 1st, 2009, the value-added tax transformation will be performed in all industries around the country. Based on value-added tax types and retrospection of reform practices, this article analyzes the backgroun...From Jan. 1st, 2009, the value-added tax transformation will be performed in all industries around the country. Based on value-added tax types and retrospection of reform practices, this article analyzes the background of the national value-added tax transformation and points out the influence of full implementation of the value-added tax transformation on various enterprises.展开更多
1 Scope This standard specifies the classification, shape and dimension, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage, and quality certificate of high a...1 Scope This standard specifies the classification, shape and dimension, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage, and quality certificate of high alumina insulating bricks.展开更多
Improving processor frequency to strengthen massive data processing capability will lead to incremen-tal server marginal costs and bring about a series of problems such as power consumption,managementcomplexity,etc.Ba...Improving processor frequency to strengthen massive data processing capability will lead to incremen-tal server marginal costs and bring about a series of problems such as power consumption,managementcomplexity,etc.Based on the field programmable gate array(FPGA),TCP offload engine(TOE),zero-copy and other key technologies,this paper describes the design and realization of a reconfigurable accel-erator board.In this board,TCP/IP protocol will be moved to high-speed reconfigurable acceleratorboard.The packets will be labeled according to the protocol and submitted to the upper data processingsoftware after IP-quintuple filtering in hardware.Reconfigurable accelerator board obtains higher perfor-mance speed-up compared with ordinary NIC card.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2023-00302697,2022H1D3A3A01077254)。
文摘Plastic,renowned for its versatility,durability,and cost-effectiveness,is indispensable in modern society.Nevertheless,the annual production of nearly 400 million tons of plastic,coupled with a recycling rate of only 9%,has led to a monumental environmental crisis.Plastic recycling has emerged as a vital response to this crisis,offering sustainable solutions to mitigate its environmental impact.Among these recycling efforts,plastic upcycling has garnered attention,which elevates discarded plastics into higher-value products.Here,electrocatalytic and photoelectrocatalytic treatments stand at the forefront of advanced plastic upcycling.Electrocatalytic or photoelectrocatalytic treatments involve chemical reactions that facilitate electron transfer through the electrode/electrolyte interface,driven by electrical or solar energy,respectively.These methods enable precise control of chemical reactions,harnessing potential,current density,or light to yield valuable chemical products.This review explores recent progress in plastic upcycling through electrocatalytic and photoelectrocatalytic pathways,offering promising solutions to the plastic waste crisis and advancing sustainability in the plastics industry.
基金Sungsoon Kim,Kwang Hee Kim and Cheoulwoo Oh contributed equally as cofirst authors.Kan Zhang acknowledges the support from NSFC(51802157,21902104)the Natural Science Foundation of Jiangsu Province of China(BZ2020063)Jong Hyeok Park acknowledges the support from the National Research Foundation(NRF)of Korea(2019R1A4A1029237,2021M3E6A1015823,2017M3A7B4041987).
文摘Solar energy utilization has drawn attention due to ever-increasing environmental and energy issues.Photoelectrochemical(PEC)and photocatalytic(PC)water splitting for hydrogen production,which is the most popular and well-established solar-to-chemical conversion process,has been studied thoroughly to date but is now facing limitations related to low conversion efficiency.To resolve this issue,research in PEC cells or photocatalysts has recently aimed to produce alternative value-added chemicals by modifying their redox reactions,which potentially enables high economic reward to compensate for the low efficiency.Here,various kinds of redox reactions that decouple classic water splitting reactions to produce value-added chemicals via PEC and PC processes are introduced.Successful coupling of CO_(2) reduction,O_(2) reduction and organic synthesis with either water oxidation or water reduction is comprehensively discussed from the perspective of basic fundamental and product selectivity in terms of the band structure of materials,cocatalyst design,and thermodynamics and kinetics of the reactions.Throughout the review,future challenges and opportunities are suggested with respect to the redesigned artificial synthesis,which might be an alternative development for the commercialization of PEC or PC value-added chemical production technologies in the near future.
基金the Spanish Ministry of Economy and Competitiveness(projects CTQ2016-75491-R)for the financial support。
文摘The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1 and 1:2)on the organic product distribution(acetaldehyde,acetic acid and ethyl acetate)and pure hydrogen generation at different current densities operation levels.Physicochemical characterization of the catalysts was made by X-ray diffraction(XRD),temperature-programmed reduction(TPR)and N_(2) adsorption-desorption measurements.XRD patterns showed that Ru is introduced into the Pt structure,forming an alloy between both metals.Also,the degree of alloy was higher by increasing the Ru amounts.From TPR profiles Pt was found to be properly reduced while Ru was both in metallic state and forming RuO2.The electrochemical behaviour of each catalyst towards ethanol electroreforming process was investigated through electrochemical techniques in a half cell and a single proton exchange membrane(PEM)cell systems.An intermediate Pt:Ru ratio was found to result in high current density and electrochemical surface area(ECSA)values along with lower amounts of adsorbed species.Also,Ru addition seems to diminish the degree of degradation of the catalyst.Based on characterization and in agreement with essays carried out in a PEM cell at mild conditions(80℃ and 1 atm),PtRu/C 2:1 anode provided the best electrocatalytic results in terms of current density(740 mA cm^(-2)),hydrogen production and selectivity toward acetic acid(up to 15%apart from acetaldehyde and ethyl acetate)while requiring the lowest energy consumption.
文摘The Gas-Oil Ratio(GOR)is a crucial production parameter in oil reservoirs.An increase in GOR results in higher gas production and lower oil production,potentially leading to well shut-ins due to economic infeasibility.This study focuses on a real fractured oil field that requires urgent production operations to reduce the producing GOR.In this study,the static model for the field was developed using commercial software,involving steps such as data collection,fault modeling,meshing,and statistical analysis to prepare for dynamic simulation.The dynamic model incorporates geometry,gridding,and rock properties from the static model,utilizing a dual-porosity approach for the naturally fractured reservoir and the Peng-Robinson equation for fluid phase behavior.Initial reservoir conditions,production history,and rock-fluid interactions were defined,with relative permeability curves indicating a water-wet reservoir and low critical gas saturation affecting the GOR.To better understand the relationship between reservoir and production parameters,a detailed sensitivity analysis was performed using the Response Surface Methodology(RSM).Following the sensitivity analysis,a history matching process was conducted using the Designed Exploration and Controlled Evolution(DECE)optimizer to validate the model for future forecasts.Six operational scenarios were defined to decrease the production GOR and enhance final recovery from the field.The results indicate that the water injection scenario is effective in preventing the GOR increase by maintaining reservoir pressure,thereby sustaining production over a longer period.This scenario also improves oil recovery by approximately 6%compared to the base case.Finally,optimization was carried out using the DECE optimizer for each scenario to fine-tune the operational parameters.The goal was to maximize oil revenue for each scenario during the optimization process.This study stands out as one of the few that provides a comprehensive analysis of production behavior and development planning for a real fractured reservoir with high producing GOR.
文摘As a Chinese proverb declares,"The beginningof wisdom is to call things by their right names."For an entrepreneur,the beginning of his success isto call his brand by a right name.A brand needs agood name as much as the mankind does.A
基金supported by the National Natural Science Foundation of China (31401308, 31371555 and 31671445)
文摘Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus, and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability.
基金supported by the National Natural Science Foundation of China(40471066)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX1-SW-01-05).
文摘Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the status of organic matter and nutrients in the soil but also affected the environmental quality. This article investigates the contents of organic carbon and the nutrients, and the change over the last 20 years in highly productive paddy soils and their environmental application. Field soils were sampled and the analytical results were compared with the corresponding values in the Second Soil Survey in Yujiang County of Jiangxi Province, China. The results showed that surface soils at a depth of 0-10 cm in highly productive paddy fields in Yujiang County of Jiangxi Province had contents of organic carbon (20.2 ±3.88) g kg^-1, total nitrogen (2.09±0.55) g kg^-1, and available phosphorus (42.7 ±32.7) mg kg^-1, respectively, which were all at very rich levels. Over the last 20 years, the organic carbon pool of the highly productive paddy soils reached a steady state. Total N and available P significantly increased, whereas available K changed a little. The amount and percentage of P immobilization in the surface soil (0-10 cm) of highly productive paddy fields were (142.7 ~ 41.1) mg kg-~ and (36.2~ 10.4)% of added P, and CEC (7.93 ~ 1.32) cmol kg-~. These two parameters were not higher than the mean values of paddy soils and upland red soils in the areas. Results also showed that fertilizer P in highly productive paddy soils had a high mobility and was prone to move toward a water body, which is the main source of nutrients causing eutrophication. Because of a weak K-fixing capacity, the available K content was not high in highly productive paddy soils. This suggests that attention should be paid to the K balance and the increase of soil K pool.
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supported by the National Natural Science Foundation of China(31972576)the Beijing Natural Science Foundation(6202004)+2 种基金the Special Program on Science and Technology Innovation Capacity Building of BAAFS(KJCX20180414 and KJCX201914)the USDA National Institute of Food and Agriculture(2018-68003-27462 and 2018-33610-28252)the Oklahoma Center for the Advancement of Science and Technology(AR19-27)。
文摘Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.
文摘Development strategy for heavy-oil reservoirs is one of the important research interests in China National Offshore Oil Corp. (CNOOC) that plans a highly effective development for heavy oil fields in multilayered fluvial reservoirs because of their significant influence on marine oil and even on China's petroleum production. The characteristics analysis of multilayered fluvial reservoirs in the heavy oil fields in Bohai Bay indicates that large amounts ofoil were trapped in the channel, point bar and channel bar sands. The reserves distribution of 8 oilfields illustrates that the reserves trapped in the main sands, which is 20%-40% of all of the sand bodies, account for 70%-90% of total reserves of the heavy oil fields. The cumulative production from high productivity wells (50% of the total wells) was 75%-90% of the production of the overall oilfield, while only 3%-10% of the total production was from the low productivity wells (30% of the total wells). And the high productivity wells were drilled in the sands with high reserves abundance. Based on the above information the development strategy was proposed, which includes reserves production planning, selection of well configuration, productivity design, and development modification at different stages.
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 the Shanghai Key Development Project of Agriculture Science and Technology (2009 No.6-3)
文摘[Objective] To investigate the optimal determination conditions of melamine in animal blood products by high performance liquid chromatography (HPLC). [ Method] The blood samples were extracted with ultrasonic in 1% trichloroacetic acid (TDA) and acetonitrile. After purifying by solide phase extraction (SPE), the samples were analyzed by H PLC. r Result I The optimal conditions of HPLC were as follows: the chromatographic column was Zorbax SB-CS; the mobile phase was ion-pairs buffer-acetonitrile (95/5, V/V) ; the flow rate was 1.0 ml/min; the column temperature was 25 ℃ and the UV detection wavelength was 235 nm. The determined melamine concentration range was 0.001 -0.050 mg/ml; the linear correlation coefficient was 0.999 4; the concentration limit of melamine was 0.1 mg/kg; the average recovery rate of the melamine were 97.60% - 100.65%, and the relative standard deviation (RSD) was 1.23% -3.04%.[ Conclusion] The HPLC is simple, accurate and repeatable for determination of the melamine in animal blood products.
文摘In order to further study the influence of high-yield-water on the productivity of CBM (coalbed methane) wells and the expulsion and production method carried out in CBM wells, by means of analyzing and researching production characteris- tics and geologic condition of the CBM wells with high water yield in Yanchuannan block located at the eastern margin of Or- dos basin, the mechanism of high water yield decreasing the productivity of CBM well was discussed, and the expulsion and production method for this type of CBM well was proposed. The results show that high water yield would decrease the produc- tivity of CBM wells, and the mechanism is: first, in some circumstances, high water yield could reflect that there was dissipa- tion during the process of coalbed methane reservoir forming, which would lower the gas saturation of coal gas reservoir and reduce the productivity of CBM well; second, a large quantity of coalbed methane dissipated in the form of solution gas, caus- ing the practical reservoir pressure when gas appeared in casing to be lower than critical desorption pressure of the coal bed; finally, the CBM well with high water yield would have higher requirements of discharge and mining installation, system and continuity, and any link with problems would have a great impact on the well's productivity and would increase the difficulty of discharge and mining. In the case of wells with high water yield, the key is to select applicable discharge and mining installa- tion, which should be able to make the bottom hole flowing pressure decline smoothly and fast, and make the wells produce gas as quickly as possible but able to slow down the rate of discharge and mining properly when gas has appeared. In addition, in view of the CBM wells with high water yield, an installation lectotype method based on Darcy's law was proposed, which was found with good accuracy and practicability through field application.
基金Supported by the China National Science and Technology Major Project(2016ZX05062)the PetroChina Science and Technology Major Project(2016E-0611)
文摘Marine shale gas resources have great potential in the south of the Sichuan Basin in China.At present,the high-quality shale gas resources at depth of 2000–3500 m are under effective development,and strategic breakthroughs have been made in deeper shale gas resources at depth of 3500–4500 m.To promote the effective production of shale gas in this area,this study examines key factors controlling high shale gas production and presents the next exploration direction in the southern Sichuan Basin based on summarizing the geological understandings from the Lower Silurian Longmaxi Formation shale gas exploration combined with the latest results of geological evaluation.The results show that:(1)The relative sea depth in marine shelf sedimentary environment controls the development and distribution of reservoirs.In the relatively deep water area in deep-water shelf,grade-I reservoirs with a larger continuous thickness develop.The relative depth of sea in marine shelf sedimentary environment can be determined by redox conditions.The research shows that the uranium to thorium mass ratio greater than 1.25 indicates relatively deep water in anoxic reduction environment,and the uranium to thorium mass ratio of 0.75–1.25 indicates semi-deep water in weak reduction and weak oxidation environment,and the uranium to thorium mass ratio less than 0.75 indicates relatively shallow water in strong oxidation environment.(2)The propped fractures in shale reservoirs subject to fracturing treatment are generally 10–12 m high,if grade-I reservoirs are more than 10 m in continuous thickness,then all the propped section would be high-quality reserves;in this case,the longer the continuous thickness of penetrated grade-I reservoirs,the higher the production will be.(3)The shale gas reservoirs at 3500–4500 m depth in southern Sichuan are characterized by high formation pressure,high pressure coefficient,well preserved pores,good pore structure and high proportion of free gas,making them the most favorable new field for shale gas exploration;and the pressure coefficient greater than 1.2 is a necessary condition for shale gas wells to obtain high production.(4)High production wells in the deep shale gas reservoirs are those in areas where Long11-Long13 sub-beds are more than 10 m thick,with 1500 m long horizontal section,grade-I reservoirs penetration rate of over 90%,and fractured by dense cutting+high intensity sand injection+large displacement+large liquid volume.(5)The relatively deep-water area in the deep-water shelf and the area at depth of 3500–4500 m well overlap in the southern Sichuan,and the overlapping area is the most favorable shale gas exploration and development zones in the southern Sichuan in the future.With advancement in theory and technology,annual shale gas production in the southern Sichuan is expected to reach 450×108 m3.
文摘The quality and safety of agricultural products are closely related to human health.They also play an important role in enhancing the competitiveness of China’s agricultural products market,shaping the brand value of agricultural products,and promoting the high-quality development of agriculture.At present,there are still a series of problems in the quality and safety of agricultural products.Relevant departments of the state should strengthen guidance and supervision,improve the quality and safety awareness and management level of agricultural product producers,and encourage producers to participate in the product certification and process certification of agricultural products.In addition,it is necessary to take effective control measures in accordance with the certification requirements,to evaluate their effectiveness,so as to improve the quality and safety of agricultural products and promote the high-quality development of China’s agriculture.
基金Supported by National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05026-002,2016ZX05028-001,2016ZX05024-005)
文摘As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect and the theory of multiphase flow. With this model, the transient flow of gas well can be simulated by segmenting the curved part of tubing and calculating numerical solution with the method of characteristic curve. The results show that the higher the opening coefficient of the valve when closed, the larger the peak value of the wellhead pressure, the more gentle the pressure fluctuation, and the less obvious the pressure mutation area will be. On the premise of not exceeding the maximum shut-in pressure of the tubing, adopting large opening coefficient can reduce the impact of the pressure wave. The higher the cross-section liquid holdup, the greater the pressure wave speed, and the shorter the propagation period will be. The larger the liquid holdup, the larger the variation range of pressure, and the greater the pressure will be. In actual production, the production parameters can be adjusted to get the appropriate liquid holdup, control the magnitude and range of fluctuation pressure, and reduce the impact of water hammer effect. When the valve closing time increases, the maximum fluctuating pressure value of the wellhead decreases, the time of pressure peak delays, and the pressure mutation area gradually disappears. The shorter the valve closing time, the faster the pressure wave propagates. Case simulation proves that the transient flow model of gas well can optimize the reasonable valve opening coefficient and valve closing time, reduce the harm of water hammer impact on the wellhead device and tubing, and ensure the integrity of the wellbore.
文摘From 1980’s decade,the introduction of carbon composite materials in structural applications has been consistently increased in the successive generations of civil aircraft from Single Aisle to Middle-long Range to achieve a culminant point with more than 50%in structure weight in recent commercial civil aircraft.This evolution,done through successive iterations,has been possible by combining in the same time the improvement of intrinsic composite material performances and its transformation into prepreg production technologies together with the development of new manufacturing process for material lay-up automation at composite shop-floor manufacturer of aircraft composite parts.New challenges are still coming to continuously develop materials and technologies in order to pursue the production more cost-effective composite parts.Associated to higher aircraft production rate for single aisle,new challenges may force material and aircraft designers and producers to furthermore drive new products and processes introduction and new ways of transformation within in next decade of composite aircraft designs.We propose to illustrate these trends using past and recent developments and our return of experience from Hexcel on Civil Aircraft programs.
文摘From Jan. 1st, 2009, the value-added tax transformation will be performed in all industries around the country. Based on value-added tax types and retrospection of reform practices, this article analyzes the background of the national value-added tax transformation and points out the influence of full implementation of the value-added tax transformation on various enterprises.
文摘1 Scope This standard specifies the classification, shape and dimension, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage, and quality certificate of high alumina insulating bricks.
基金the National High Technology Research and Development Programme of China(No2007AA01Z115)
文摘Improving processor frequency to strengthen massive data processing capability will lead to incremen-tal server marginal costs and bring about a series of problems such as power consumption,managementcomplexity,etc.Based on the field programmable gate array(FPGA),TCP offload engine(TOE),zero-copy and other key technologies,this paper describes the design and realization of a reconfigurable accel-erator board.In this board,TCP/IP protocol will be moved to high-speed reconfigurable acceleratorboard.The packets will be labeled according to the protocol and submitted to the upper data processingsoftware after IP-quintuple filtering in hardware.Reconfigurable accelerator board obtains higher perfor-mance speed-up compared with ordinary NIC card.