Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which areat the root of well-known problems related to injection and production. In this study, a gas injection f...Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which areat the root of well-known problems related to injection and production. In this study, a gas injection floodingapproach is analyzed in the framework of numerical simulations. In particular, the sequence and timing of fracturechanneling and the related impact on production are considered for horizontal wells with different fracturemorphologies. Useful data and information are provided about the regulation of gas channeling and possible strategiesto delay gas channeling and optimize the gas injection volume and fracture parameters. It is shown that inorder to mitigate gas channeling and ensure high production, fracture length on the sides can be controlled andlonger fractures can be created in the middle by which full gas flooding is obtained at the fracture location in themiddle of the horizontal well. A Differential Evolution (DE) algorithm is provided by which the gas injectionvolume and the fracture parameters of gas injection flooding can be optimized. It is shown that an improvedoil recovery factor as high as 6% can be obtained.展开更多
The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free batteries.Herein,we report a pragmatic approach t...The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free batteries.Herein,we report a pragmatic approach to the in-situ construction of high-quality SEI by applying synergistic additives of Li NO_(3)and ethylene sulfite(ES)in the electrolyte.The obtained SEI exhibits a high average Young’s modulus(9.02GPa)and exchanging current density(4.59 mA cm^(-2)),which are 3.0 and 1.2 times as large as those using the sole additive of LiNO_(3),respectively.With this improved SEI,Li-dendrite growth and side reactions are effectively suppressed,leading to an ultra-high Coulombic efficiency(CE)of 99.7%for Li plating and stripping.When applying this improved electrolyte in full cells,it achieves a high capacity retention of 89.7%for over 150 cycles in a LiFePO_(4)||Li battery(~12 mg cm^(-2)cathode,50μm Li)and of 44.5%over 100 cycles in a LiFePO_(4)||Cu anode-free battery.展开更多
The cooperative model of a multi-subject Regional Integrated Energy System(RIES)is no longer limited to the trading of traditional energy,but the trading of new energy derivatives such as Green Certificates(GC),Servic...The cooperative model of a multi-subject Regional Integrated Energy System(RIES)is no longer limited to the trading of traditional energy,but the trading of new energy derivatives such as Green Certificates(GC),Service Power(SP),and CO_(2) will be more involved in the energy allocation of the cooperative model.This study was conducted for the multi-entity RIES cooperative model considering the trading of electronics,GC,SP,and CO_(2).First,a cooperative framework including wind-photovoltaic generation system(WG),combined heat and power system(CHP),and power-carbon-hydrogen load(PCH)is proposed,and the mechanism of energy derivatives trading is also analyzed.Then,the sub-models of each agent in the cooperative model are established separately so that WG has the capability of GC generation,CHP has the capability of GC and CO_(2) absorption,and PCH can realize the effective utilization of CO_(2).Then,the WG–CHP–PCH cooperative model is established and equated into two sub-problems of cooperative benefit maximization and transaction payment negotiation,which are solved in a distributed manner by the alternating directed multiplier method(ADMM).Finally,the effectiveness of the proposed cooperative model and distributed solution is verified by simulation.The simulation results show that the WG–CHP–PCH cooperative model can substantially improve the operational efficiency of each agent and realize the efficient redistribution of energy and its derivatives.In addition,the dynamic parameter adjustment algorithm(DP)is further applied in the solving process to improve its convergence speed.By updating the step size during each iteration,the computational cost,the number of iterations,and the apparent oscillations are reduced,and the convergence performance of the algorithm is improved.展开更多
Fluorinated salts and/or high salt concentrations are usually necessary to produce protective films on the electrodes for high-voltage aqueous batteries,yet these approaches increase the cost,toxicity and reaction res...Fluorinated salts and/or high salt concentrations are usually necessary to produce protective films on the electrodes for high-voltage aqueous batteries,yet these approaches increase the cost,toxicity and reaction resistances of battery.Herein,we report a dilute fluorine-free electrolyte design to overcome this dilemma.By using the LiClO_(4) salt and polyethylene glycol dimethyl ether(PED)solvent and optimizing the LiClO_(4)/PED/H_(2)O molar ratio,we formulate a 1 mol kg^(-1)3 V-class hybrid aqueous electrolyte that enables reversible charge/discharge of 2.5 V LiMn_(2)O_(4)|Li_(4)Ti_(5)O_(12) full cell at both low(0.5C,92.4%capacity retention in 300 cycles)and high(5C,80.4%capacity retention in 2000 cycles)rates.This excellent performance is reached even without the generation of protective film on either anode or cathode as identified by in/ex situ characterizations.The selection of appropriate ingredients that have both high stability and strong interactions with water is critical to widen the potential window of electrolyte while suppressing parasitic reactions on the electrodes.This work suggests that expensive and toxic fluorinate salts are no longer necessary for 3 V-class aqueous electrolytes,boosting the development of low-cost,environmentally-friendly,high-power and high-energy-density aqueous batteries.展开更多
Purpose:This study sought to explore the effect of intraoperative mean blood glucose levels and variability on postoperative acute kidney injury(AKI)in children undergoing congenital cardiac surgery.Methods:We conduct...Purpose:This study sought to explore the effect of intraoperative mean blood glucose levels and variability on postoperative acute kidney injury(AKI)in children undergoing congenital cardiac surgery.Methods:We conducted a prospective nested case-control study in children(age<18 years)undergoing congenital heart surgery with cardiopulmonary bypass(CPB)at the Fuwai Hospital between April 01,2022 and July 30,2022.Cases were individuals who developed AKI within the first postoperative 7 days(AKI group)and controls were those without AKI(Non-AKI group)according to KDIGO criteria.AKI and Non-AKI groups unmatched and 1:1 matched by age,sex,and baseline serum creatinine were separately analyzed.Multivariate logistic and conditional logistic regressions were used to assess the associations between blood glucose variables and AKI.Results:688 consecutively approached patients were included in the final analysis.On multivariate analysis,intra-CPB(adjusted odds ratio[OR]0.802;95%confidence interval[CI],0.706 to 0.912;p=0.001)and post-CPB(adjusted OR 0.830;95%CI,0.744 to 0.925;p=0.001)blood glucose levels were associated with postoperative AKI.There were no significant differences in pre-CPB blood glucose(adjusted OR 0.926;95%CI,0.759 to 1.129;p=0.446)or intraoperative glycemic fluctuations(adjusted OR 0.905;95%CI,0.723 to 1.132;p=0.382)between AKI and Non-AKI groups.Results based on matched cases and controls were consistent with those from the unmatched analyses.Conclusion:Higher intraoperative blood glucose levels during and after CPB were protective factors against postoperative AKI in pediatric patients after congenital heart surgery.展开更多
A homologous gene of basic-helix-loop-helix AtTT8 in Arabidopsis thaliana was identified in juice sac cells of pulp tissues from blood orange(Citrus sinensis cv‘Tarocco’),which was designated as CsTT8 in this study....A homologous gene of basic-helix-loop-helix AtTT8 in Arabidopsis thaliana was identified in juice sac cells of pulp tissues from blood orange(Citrus sinensis cv‘Tarocco’),which was designated as CsTT8 in this study.Additionally,the mRNA levels of TT8 with the full-length open reading frame were significantly higher in‘Tarocco’than in mutant fruit lacking pigment in pulp or peel tissues.However,an alternative splicing transcript,Δ15-TT8,with the fourth exon skipped,was also identified from transcripts different in length from that in‘Tarocco’.The mRNA levels ofΔ15-TT8 were higher in mutant fruit lacking pigment in pulp or peel tissues than in the wild type.Therefore,the TT8/Δ15-TT8 mRNA level ratio was found to be crucial for sufficient pigment in either pulp or peel tissues.TT8 from blood orange fruit demonstrated the capacity for nucleus localization and binding to other proteins.In contrast,Δ15-TT8,lacking the fourth exon,lost its ability to interact with RUBY1 and to localize at the nucleus.Using a dual luciferase reporter assay and transient overexpression in tobacco,we proved that two regulatory complexes formed by a functional TT8 with different MYB(v-myb avian myeloblastosis viral oncogene homolog)-type partners significantly promoted expression of an anthocyanin biosynthetic gene and a proton pumping gene,leading to anthocyanin and citrate production.Our findings suggest that TT8,rather than dysfunctionalΔ15-TT8,is possibly involved in modulating anthocyanin biosynthesis and its transport into vacuoles by proton gradients.However,increased mRNA levels of the dysfunctional alternative splicing transcript may act as a negative feedback to downregulate TT8 expression and limit anthocyanin accumulation in blood oranges.展开更多
Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is d...Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is difficult.Here,we show that overexpression of the single gene SlMYB75(SlMYB75-OE)is effective at improving multiple fruit quality traits.In these engineered fruits,the anthocyanin content reached 1.86mg g−1 fresh weight at the red-ripe stage,and these SlMYB75-OE tomatoes displayed a series of physiological changes,including delayed ripening and increased ethylene production.In addition to anthocyanin,the total contents of phenolics,flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6,4,and 1.2 times,respectively,compared to those of wild-type(WT)fruits.Interestingly,a number of aroma volatiles,such as aldehyde,phenylpropanoid-derived and terpene volatiles,were significantly increased in SlMYB75-OE fruits,with some terpene volatiles showing more than 10 times higher levels than those in WT fruits.Consistent with the metabolic assessment,transcriptomic profiling indicated that the genes involved in the ethylene signaling,phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits.Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC,AADC2 and TPS genes.The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality.展开更多
Mesoscale eddies play vital roles in ocean processes.Although previous studies focused on eddy surface features and individual three-dimensional(3D)eddy cases in the northwestern Pacific Ocean,the analysis of unique e...Mesoscale eddies play vital roles in ocean processes.Although previous studies focused on eddy surface features and individual three-dimensional(3D)eddy cases in the northwestern Pacific Ocean,the analysis of unique eddy3D regional characteristics is still lacking.A 3D eddy detection scheme is applied to 9 years(2000-2008)of eddyresolving Regional Ocean Modeling System(ROMS)output to obtain a 3D eddy dataset from the surface to a depth of 1000 m in the northwestern Pacific Ocean(15°-35°N,120°-145°E).The 3D characteristics of mesoscale eddies are analyzed in two regions,namely,Box1(Subtropical Countercurrent,15°-25°N,120°-145°E)and Box2(Southern Kuroshio Extension,25°-35°N,120°-145°E).In Box1,the current is characterized by strong vertical shear and weak horizontal shear.In Box2,the current is characterized by the strong Kuroshio,topographic effect,and the westward propagation of Rossby waves.The results indicate the importance of baroclinic instability in Box1,whereas in Box2,both the barotropic and baroclinic instability are important.Moreover,the mesoscale eddies’properties in Box1 and Box2 are distinct.The eddies in Box1 have larger number and radius but a shorter lifetime.By contrast,Box2 has fewer eddies,which have smaller radius but longer lifetime.Vertically,more eddies are detected at the subsurface than at the surface in both regions;the depth of 650 m is the turning point in Box1.Above this depth,the number of cyclonic eddies(CEs)is larger than that of anticyclonic eddies(AEs).In Box2,the number of CEs is dominant vertically.Eddy kinetic energy(EKE)and mean normalized relative vorticity in Box2are significantly higher than those in Box1.With increasing depth,the attenuation trend of EKE and relative vorticity of Box1 become greater than those of Box2.Furthermore,the upper ocean(about 300 m in depth)contains 68.6%of the eddies(instantaneous eddy).Only 16.6%of the eddies extend to 1000 m.In addition,about87%of the eddies are bowl-shaped eddies in the two regions.Only about 3%are cone-shaped eddies.With increasing depth of the eddies,the proportion of bowl-shaped eddies gradually decreases.Conversely,the coneand lens-shaped eddies are equal in number at 700-1000 m,accounting for about 30%each.Studying the 3D characteristics of eddies in two different regions of the northwestern Pacific Ocean is an important stepping stone for discussing the different eddy generation mechanisms.展开更多
Simultaneous anammox and denitrification(SAD) is an efficient approach to treat wastewater having a low C/N ratio;however, few studies have investigated a combination of SAD and partial nitritation(PN). In this study,...Simultaneous anammox and denitrification(SAD) is an efficient approach to treat wastewater having a low C/N ratio;however, few studies have investigated a combination of SAD and partial nitritation(PN). In this study, a lab-scale up-flow blanket filter(UBF) and zeolite sequence batch reactor(ZSBR) were continuously operated to implement SAD and PN advantages, respectively. The UBF achieved a high total nitrogen(TN) removal efficiency of over 70% during the start-up stage(days 1–50), and reached a TN removal efficiency of 96%in the following 90 days(days 51–140) at COD/NH_(4)^(+)-N ratio of 2.5. The absolute abundance of anammox bateria increased to the highest value of 1.58 × 107copies/μL DNA;Comamonadaceae was predominant in the UBF at the optimal ratio. Meanwhile, ZSBR was initiated on day 115 as fast nitritation process to satisfy the influent requirement for the UBF. The combined process was started on day 140 and then lasted for 30 days, during the combined process, between the two reactors, the UBF was the main contributor for TN(66.5% ± 4.5%)and COD(71.8% ± 4.9%) removal. These results demonstrated that strong SAD occurred in the UBF when following a ZSBR with in-situ NOB elimination. This research presents insights into a novel biological nitrogen removal process for low C/N ratio wastewater treatment.展开更多
The localization of a stationary transmitter using moving receivers is considered.The original Direct Position Determination(DPD) methods, with combined Time Difference of Arrival(TDOA) and Frequency Difference of Arr...The localization of a stationary transmitter using moving receivers is considered.The original Direct Position Determination(DPD) methods, with combined Time Difference of Arrival(TDOA) and Frequency Difference of Arrival(FDOA), do not perform well under low Signal-toNoise Ratio(SNR), and worse still, the computation cost is difficult to accept when the computational capabilities are limited.To get better positioning performance, we present a new DPD algorithm that proves to be more computationally efficient and more precise for weak signals than the conventional approach.The algorithm partitions the signal received with the same receiver into multiple non-overlapping short-time signal segments, and then uses the TDOA, the FDOA and the coherency among the short-time signals to locate the target.The fast maximum likelihood estimation, one iterative method based on particle filter, is designed to solve the problem of high computation load.A secondary but important result is a derivation of closed-form expressions of the Cramer-Rao Lower Bound(CRLB).The simulation results show that the algorithm proposed in this paper outperforms the traditional DPD algorithms with more accurate results and higher computational efficiency, and especially at low SNR, it is more close to the CRLB.展开更多
Plant architecture is an important factor for crop production. Some members of micro RNA156(mi R156) and their target genes SQUAMOSA Promoter-Binding Protein-Like(SPL) were identi fi ed to play essential roles in the ...Plant architecture is an important factor for crop production. Some members of micro RNA156(mi R156) and their target genes SQUAMOSA Promoter-Binding Protein-Like(SPL) were identi fi ed to play essential roles in the establishment of plant architecture. However, the roles and regulation of mi R156 is not well understood yet. Here, we identi fi ed a T-DNA insertion mutant Osmtd1(Oryza sativa multi-tillering and dwarf mutant). Osmtd1 produced more tillers and displayed short stature phenotype. We determined that the dramatic morphological changes were caused by a single T-DNA insertion in Osmtd1. Further analysis revealed that the T-DNA insertion was located in the gene Os08g34258 encoding a putative inhibitor I family protein. Os08g34258 was knocked out and Osmi R156 f was signi fi cantly upregulated in Osmtd1. Overexpression of Os08g34258 in Osmtd1 complemented the defects of the mutant architecture, while overexpression of Osmi R156 f in wild-type rice phenocopied Osmtd1. We showed that the expression of Os SPL3, Os SPL12,and Os SPL14 were signi fi cantly downregulated in Osmtd1 or Osmi R156 f overexpressed lines, indicating that Os SPL3,Os SPL12, and Os SPL14 were possibly direct target genes of Osmi R156 f. Our results suggested that Osmi R156 f controlledplant architecture by mediating plant stature and tiller outgrowth and may be regulated by an unknown protease inhibitor I family protein.展开更多
With the rapid growth of power systems measurements in terms of size and complexity,discovering statistical patterns for a large variety of real-world applications such as renewable energy prediction,demand response,e...With the rapid growth of power systems measurements in terms of size and complexity,discovering statistical patterns for a large variety of real-world applications such as renewable energy prediction,demand response,energy disaggregation,and state estimation is considered a crucial challenge.In recent years,deep learning has emerged as a novel class of machine learning algorithms that represents power systems data via a large hypothesis space that leads to the state-of-the-art performance compared to most recent data-driven algorithms.This study explores the theoretical advantages of deep representation learning in power systems research.We review deep learning methodologies presented and applied in a wide range of supervised,unsupervised,and semi-supervised applications as well as reinforcement learning tasks.We discuss various settings of problems solved by discriminative deep models including stacked autoencoders and convolutional neural networks as well as generative deep architectures such as deep belief networks and variational autoencoders.The theoretical and experimental analysis of deep neural networks in this study motivates longterm research on optimizing this cutting-edge class of models to achieve significant improvements in the future power systems research.展开更多
Storage is widely considered in economic dispatch(ED)problems.To prevent simultaneous charging and discharging of a storage device,a storage-concerned ED problem should involve complementarity constraints for every st...Storage is widely considered in economic dispatch(ED)problems.To prevent simultaneous charging and discharging of a storage device,a storage-concerned ED problem should involve complementarity constraints for every storage device to make the problem strongly non-convex.In this case,the conventional Karush-Kuhn-Tucker optimality conditions are unsuitable,and the methods that are normally effective are also invalid.In our recent paper,we proposed a new exact relaxation method that directly removes the complementarity constraints from a storageconcerned ED model to make it convex and easy to solve.This paper extends the previous study by presenting and analyzing two new groups of sufficient conditions that guarantee exact relaxation.Different application conditions of these groups of sufficient conditions are discussed.Numerical tests are performed to show the benefit of using the exact relaxation method and the different suitable application conditions of these groups of sufficient conditions.This paper contributes to a wide application of exact relaxation in storage-concerned ED problems.展开更多
Contingency analysis(CA)requires fast execution time for real-time power system operations.Because CA problems can naturally be divided into separate subtasks,parallel computing helps to speed up the computation time....Contingency analysis(CA)requires fast execution time for real-time power system operations.Because CA problems can naturally be divided into separate subtasks,parallel computing helps to speed up the computation time.This paper proposes a master/slave parallel computing architecture and studies the computation of CA in a large-scale power system through high performance computing,adopting a message passing interface for implementation.In particular,although the execution time of CA varies,there is a tradeoff between having an imbalanced workload and"paying"a synchronization penalty for parallel computing:either factor blocks the progress of scalability.The proposed layered dynamic scheduling method is effective to tackle the challenge of high synchronization cost and workload imbalance and have the potential to further scale for the N-2 contingency analysis.展开更多
Boosting the resilience of power systems is a core requirement of smart grids. In fact, resilience enhancement is crucial to all critical infrastructure systems.In this study, we review the current research on system ...Boosting the resilience of power systems is a core requirement of smart grids. In fact, resilience enhancement is crucial to all critical infrastructure systems.In this study, we review the current research on system resilience enhancement within and beyond smart grids. In addition, we elaborate on resilience definition and resilience quantification and discuss several challenges and opportunities for system resilience enhancement. This study aims to deepen our understanding of the concept of resilience and develop a wide perspective on enhancing the system resilience for critical infrastructures.展开更多
A continuous-wave Nd:YVO4/BaWO4 Raman laser generating simultaneous multi-wavelength first-Stokes and second-Stokes emissions is demonstrated for the first time, to the best of our knowledge. Investigations concerning...A continuous-wave Nd:YVO4/BaWO4 Raman laser generating simultaneous multi-wavelength first-Stokes and second-Stokes emissions is demonstrated for the first time, to the best of our knowledge. Investigations concerning different pump spot sizes and crystal lengths were conducted to improve the thermal effect and pump absorption. Three first-Stokes lasers at 1103.6, 1175.9, and 1180.7 nm and two second-Stokes lasers at 1145.7 and 1228.9 nm are obtained simultaneously using the Raman shifts of 925 cm-1 and 332 cm-1 in BaWO4 and 890 cm-1 in YVO4. At the incident pump power of 23.1 W, 1.24 W maximum Raman output power is achieved,corresponding to an optical conversion efficiency of 5.4%. We also present a theoretical analysis of the competition between different Stokes lines.展开更多
A solution to the power flow problem is imperative for many power system applications and several iterative approaches are employed to achieve this objective.However,the chance of finding a solution is dependent on th...A solution to the power flow problem is imperative for many power system applications and several iterative approaches are employed to achieve this objective.However,the chance of finding a solution is dependent on the choice of the initial point because of the nonconvex feasibility region of this problem.In this paper,a non-iterative approach that leverages a convexified relaxed power flow problem is employed to verify the existence of a feasible solution.To ensure the scalability of the proposed convex relaxation,the problem is formulated as a sparse semi-definite programming problem.The variables associated with each maximal clique within the network form several positive semidefinite matrices.Perturbation and network reconfiguration schemes are employed to improve the tightness of the proposed convex relaxation in order to validate the existence of a feasible solution for the original non-convex problem.Multiple case studies including an ill-conditioned power flow problem are examined to show the effectiveness of the proposed approach to find a feasible solution.展开更多
基金supported by the Forward Looking Basic Major Scientific and Technological Projects of CNPC (Grant No.2021DJ2202).
文摘Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which areat the root of well-known problems related to injection and production. In this study, a gas injection floodingapproach is analyzed in the framework of numerical simulations. In particular, the sequence and timing of fracturechanneling and the related impact on production are considered for horizontal wells with different fracturemorphologies. Useful data and information are provided about the regulation of gas channeling and possible strategiesto delay gas channeling and optimize the gas injection volume and fracture parameters. It is shown that inorder to mitigate gas channeling and ensure high production, fracture length on the sides can be controlled andlonger fractures can be created in the middle by which full gas flooding is obtained at the fracture location in themiddle of the horizontal well. A Differential Evolution (DE) algorithm is provided by which the gas injectionvolume and the fracture parameters of gas injection flooding can be optimized. It is shown that an improvedoil recovery factor as high as 6% can be obtained.
基金supported by the National Natural Science Foundation of China(21975207,52202303)the Westlake Education Foundation,and the Zhejiang Provincial Natural Science Foundation of China(LQ21B030006)。
文摘The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free batteries.Herein,we report a pragmatic approach to the in-situ construction of high-quality SEI by applying synergistic additives of Li NO_(3)and ethylene sulfite(ES)in the electrolyte.The obtained SEI exhibits a high average Young’s modulus(9.02GPa)and exchanging current density(4.59 mA cm^(-2)),which are 3.0 and 1.2 times as large as those using the sole additive of LiNO_(3),respectively.With this improved SEI,Li-dendrite growth and side reactions are effectively suppressed,leading to an ultra-high Coulombic efficiency(CE)of 99.7%for Li plating and stripping.When applying this improved electrolyte in full cells,it achieves a high capacity retention of 89.7%for over 150 cycles in a LiFePO_(4)||Li battery(~12 mg cm^(-2)cathode,50μm Li)and of 44.5%over 100 cycles in a LiFePO_(4)||Cu anode-free battery.
基金supported in part by the Science and Technology Project of State Grid Corporation of China under Grant(No.52272220002T)in part by the project supported by Sichuan Provincial key research and development program of China(No.2022YFG0123)in part by Central Government Funds for Guiding Local Scientific and Technological Development of China(No.2021ZYD0042).
文摘The cooperative model of a multi-subject Regional Integrated Energy System(RIES)is no longer limited to the trading of traditional energy,but the trading of new energy derivatives such as Green Certificates(GC),Service Power(SP),and CO_(2) will be more involved in the energy allocation of the cooperative model.This study was conducted for the multi-entity RIES cooperative model considering the trading of electronics,GC,SP,and CO_(2).First,a cooperative framework including wind-photovoltaic generation system(WG),combined heat and power system(CHP),and power-carbon-hydrogen load(PCH)is proposed,and the mechanism of energy derivatives trading is also analyzed.Then,the sub-models of each agent in the cooperative model are established separately so that WG has the capability of GC generation,CHP has the capability of GC and CO_(2) absorption,and PCH can realize the effective utilization of CO_(2).Then,the WG–CHP–PCH cooperative model is established and equated into two sub-problems of cooperative benefit maximization and transaction payment negotiation,which are solved in a distributed manner by the alternating directed multiplier method(ADMM).Finally,the effectiveness of the proposed cooperative model and distributed solution is verified by simulation.The simulation results show that the WG–CHP–PCH cooperative model can substantially improve the operational efficiency of each agent and realize the efficient redistribution of energy and its derivatives.In addition,the dynamic parameter adjustment algorithm(DP)is further applied in the solving process to improve its convergence speed.By updating the step size during each iteration,the computational cost,the number of iterations,and the apparent oscillations are reduced,and the convergence performance of the algorithm is improved.
基金supported by the Westlake Education Foundation and National Natural Science Foundation of China(21975207)。
文摘Fluorinated salts and/or high salt concentrations are usually necessary to produce protective films on the electrodes for high-voltage aqueous batteries,yet these approaches increase the cost,toxicity and reaction resistances of battery.Herein,we report a dilute fluorine-free electrolyte design to overcome this dilemma.By using the LiClO_(4) salt and polyethylene glycol dimethyl ether(PED)solvent and optimizing the LiClO_(4)/PED/H_(2)O molar ratio,we formulate a 1 mol kg^(-1)3 V-class hybrid aqueous electrolyte that enables reversible charge/discharge of 2.5 V LiMn_(2)O_(4)|Li_(4)Ti_(5)O_(12) full cell at both low(0.5C,92.4%capacity retention in 300 cycles)and high(5C,80.4%capacity retention in 2000 cycles)rates.This excellent performance is reached even without the generation of protective film on either anode or cathode as identified by in/ex situ characterizations.The selection of appropriate ingredients that have both high stability and strong interactions with water is critical to widen the potential window of electrolyte while suppressing parasitic reactions on the electrodes.This work suggests that expensive and toxic fluorinate salts are no longer necessary for 3 V-class aqueous electrolytes,boosting the development of low-cost,environmentally-friendly,high-power and high-energy-density aqueous batteries.
基金the CAMS Innovation Fund for Medical Sciences(CIFMS)(2021-I2M-C&T-B-036).
文摘Purpose:This study sought to explore the effect of intraoperative mean blood glucose levels and variability on postoperative acute kidney injury(AKI)in children undergoing congenital cardiac surgery.Methods:We conducted a prospective nested case-control study in children(age<18 years)undergoing congenital heart surgery with cardiopulmonary bypass(CPB)at the Fuwai Hospital between April 01,2022 and July 30,2022.Cases were individuals who developed AKI within the first postoperative 7 days(AKI group)and controls were those without AKI(Non-AKI group)according to KDIGO criteria.AKI and Non-AKI groups unmatched and 1:1 matched by age,sex,and baseline serum creatinine were separately analyzed.Multivariate logistic and conditional logistic regressions were used to assess the associations between blood glucose variables and AKI.Results:688 consecutively approached patients were included in the final analysis.On multivariate analysis,intra-CPB(adjusted odds ratio[OR]0.802;95%confidence interval[CI],0.706 to 0.912;p=0.001)and post-CPB(adjusted OR 0.830;95%CI,0.744 to 0.925;p=0.001)blood glucose levels were associated with postoperative AKI.There were no significant differences in pre-CPB blood glucose(adjusted OR 0.926;95%CI,0.759 to 1.129;p=0.446)or intraoperative glycemic fluctuations(adjusted OR 0.905;95%CI,0.723 to 1.132;p=0.382)between AKI and Non-AKI groups.Results based on matched cases and controls were consistent with those from the unmatched analyses.Conclusion:Higher intraoperative blood glucose levels during and after CPB were protective factors against postoperative AKI in pediatric patients after congenital heart surgery.
基金This work was supported by Sichuan Province International Science and Technology Innovation and Cooperation Program(22GJHZ0183)the Chengdu Municipality Technology Innovation and Development Program(2022-YF05-00450-SN).
文摘A homologous gene of basic-helix-loop-helix AtTT8 in Arabidopsis thaliana was identified in juice sac cells of pulp tissues from blood orange(Citrus sinensis cv‘Tarocco’),which was designated as CsTT8 in this study.Additionally,the mRNA levels of TT8 with the full-length open reading frame were significantly higher in‘Tarocco’than in mutant fruit lacking pigment in pulp or peel tissues.However,an alternative splicing transcript,Δ15-TT8,with the fourth exon skipped,was also identified from transcripts different in length from that in‘Tarocco’.The mRNA levels ofΔ15-TT8 were higher in mutant fruit lacking pigment in pulp or peel tissues than in the wild type.Therefore,the TT8/Δ15-TT8 mRNA level ratio was found to be crucial for sufficient pigment in either pulp or peel tissues.TT8 from blood orange fruit demonstrated the capacity for nucleus localization and binding to other proteins.In contrast,Δ15-TT8,lacking the fourth exon,lost its ability to interact with RUBY1 and to localize at the nucleus.Using a dual luciferase reporter assay and transient overexpression in tobacco,we proved that two regulatory complexes formed by a functional TT8 with different MYB(v-myb avian myeloblastosis viral oncogene homolog)-type partners significantly promoted expression of an anthocyanin biosynthetic gene and a proton pumping gene,leading to anthocyanin and citrate production.Our findings suggest that TT8,rather than dysfunctionalΔ15-TT8,is possibly involved in modulating anthocyanin biosynthesis and its transport into vacuoles by proton gradients.However,increased mRNA levels of the dysfunctional alternative splicing transcript may act as a negative feedback to downregulate TT8 expression and limit anthocyanin accumulation in blood oranges.
基金supported by the National Key Research and Development Program(2016YFD0400101)the National Natural Science Foundation of China(31572175,31772370)+1 种基金the Fundamental Research Funds for the Central Universities(2018CDXYSM0021)the Committee of Science and Technology of Chongqing(cstckjcxljrc15).
文摘Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is difficult.Here,we show that overexpression of the single gene SlMYB75(SlMYB75-OE)is effective at improving multiple fruit quality traits.In these engineered fruits,the anthocyanin content reached 1.86mg g−1 fresh weight at the red-ripe stage,and these SlMYB75-OE tomatoes displayed a series of physiological changes,including delayed ripening and increased ethylene production.In addition to anthocyanin,the total contents of phenolics,flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6,4,and 1.2 times,respectively,compared to those of wild-type(WT)fruits.Interestingly,a number of aroma volatiles,such as aldehyde,phenylpropanoid-derived and terpene volatiles,were significantly increased in SlMYB75-OE fruits,with some terpene volatiles showing more than 10 times higher levels than those in WT fruits.Consistent with the metabolic assessment,transcriptomic profiling indicated that the genes involved in the ethylene signaling,phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits.Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC,AADC2 and TPS genes.The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality.
基金The National Natural Science Foundation of China under contract Nos NSFC 41806030 and 42076021the China Ocean Mineral Resources Research and Development Association Program under contract No.DY135-E2-3-01+4 种基金the Basic Scientific Research Business Expenses of Zhejiang Provincial Universities under contract No.2020J00007the project of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract No.LTO1807the project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2020SP007the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.311020004the Strategic Priority Research Program of Chinese Academy of Sciences under contract No.XDB42000000。
文摘Mesoscale eddies play vital roles in ocean processes.Although previous studies focused on eddy surface features and individual three-dimensional(3D)eddy cases in the northwestern Pacific Ocean,the analysis of unique eddy3D regional characteristics is still lacking.A 3D eddy detection scheme is applied to 9 years(2000-2008)of eddyresolving Regional Ocean Modeling System(ROMS)output to obtain a 3D eddy dataset from the surface to a depth of 1000 m in the northwestern Pacific Ocean(15°-35°N,120°-145°E).The 3D characteristics of mesoscale eddies are analyzed in two regions,namely,Box1(Subtropical Countercurrent,15°-25°N,120°-145°E)and Box2(Southern Kuroshio Extension,25°-35°N,120°-145°E).In Box1,the current is characterized by strong vertical shear and weak horizontal shear.In Box2,the current is characterized by the strong Kuroshio,topographic effect,and the westward propagation of Rossby waves.The results indicate the importance of baroclinic instability in Box1,whereas in Box2,both the barotropic and baroclinic instability are important.Moreover,the mesoscale eddies’properties in Box1 and Box2 are distinct.The eddies in Box1 have larger number and radius but a shorter lifetime.By contrast,Box2 has fewer eddies,which have smaller radius but longer lifetime.Vertically,more eddies are detected at the subsurface than at the surface in both regions;the depth of 650 m is the turning point in Box1.Above this depth,the number of cyclonic eddies(CEs)is larger than that of anticyclonic eddies(AEs).In Box2,the number of CEs is dominant vertically.Eddy kinetic energy(EKE)and mean normalized relative vorticity in Box2are significantly higher than those in Box1.With increasing depth,the attenuation trend of EKE and relative vorticity of Box1 become greater than those of Box2.Furthermore,the upper ocean(about 300 m in depth)contains 68.6%of the eddies(instantaneous eddy).Only 16.6%of the eddies extend to 1000 m.In addition,about87%of the eddies are bowl-shaped eddies in the two regions.Only about 3%are cone-shaped eddies.With increasing depth of the eddies,the proportion of bowl-shaped eddies gradually decreases.Conversely,the coneand lens-shaped eddies are equal in number at 700-1000 m,accounting for about 30%each.Studying the 3D characteristics of eddies in two different regions of the northwestern Pacific Ocean is an important stepping stone for discussing the different eddy generation mechanisms.
基金supported by the Open Research Fund of Engineering and Technical Center of Hunan Provincial Environmental Protection for River-Lake Dredging Pollution Control (No. EPD202002)Scientific Research Project of Education Department of Hunan Province (No. 20C0057)the Science and Technology Department of Hunan Province (Nos. 2021JJ10007, 2021NK2015)。
文摘Simultaneous anammox and denitrification(SAD) is an efficient approach to treat wastewater having a low C/N ratio;however, few studies have investigated a combination of SAD and partial nitritation(PN). In this study, a lab-scale up-flow blanket filter(UBF) and zeolite sequence batch reactor(ZSBR) were continuously operated to implement SAD and PN advantages, respectively. The UBF achieved a high total nitrogen(TN) removal efficiency of over 70% during the start-up stage(days 1–50), and reached a TN removal efficiency of 96%in the following 90 days(days 51–140) at COD/NH_(4)^(+)-N ratio of 2.5. The absolute abundance of anammox bateria increased to the highest value of 1.58 × 107copies/μL DNA;Comamonadaceae was predominant in the UBF at the optimal ratio. Meanwhile, ZSBR was initiated on day 115 as fast nitritation process to satisfy the influent requirement for the UBF. The combined process was started on day 140 and then lasted for 30 days, during the combined process, between the two reactors, the UBF was the main contributor for TN(66.5% ± 4.5%)and COD(71.8% ± 4.9%) removal. These results demonstrated that strong SAD occurred in the UBF when following a ZSBR with in-situ NOB elimination. This research presents insights into a novel biological nitrogen removal process for low C/N ratio wastewater treatment.
基金supported by the National Natural Science Foundation of China(No.61401513)
文摘The localization of a stationary transmitter using moving receivers is considered.The original Direct Position Determination(DPD) methods, with combined Time Difference of Arrival(TDOA) and Frequency Difference of Arrival(FDOA), do not perform well under low Signal-toNoise Ratio(SNR), and worse still, the computation cost is difficult to accept when the computational capabilities are limited.To get better positioning performance, we present a new DPD algorithm that proves to be more computationally efficient and more precise for weak signals than the conventional approach.The algorithm partitions the signal received with the same receiver into multiple non-overlapping short-time signal segments, and then uses the TDOA, the FDOA and the coherency among the short-time signals to locate the target.The fast maximum likelihood estimation, one iterative method based on particle filter, is designed to solve the problem of high computation load.A secondary but important result is a derivation of closed-form expressions of the Cramer-Rao Lower Bound(CRLB).The simulation results show that the algorithm proposed in this paper outperforms the traditional DPD algorithms with more accurate results and higher computational efficiency, and especially at low SNR, it is more close to the CRLB.
基金supported by the National Natural Science Foundation of China (no. 91317312 and 91117006)Open Foundation Project for Hunan Provincial Higher Institutional Innovation Platform (no. 09K052)Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization (no. 12KFXM05)
文摘Plant architecture is an important factor for crop production. Some members of micro RNA156(mi R156) and their target genes SQUAMOSA Promoter-Binding Protein-Like(SPL) were identi fi ed to play essential roles in the establishment of plant architecture. However, the roles and regulation of mi R156 is not well understood yet. Here, we identi fi ed a T-DNA insertion mutant Osmtd1(Oryza sativa multi-tillering and dwarf mutant). Osmtd1 produced more tillers and displayed short stature phenotype. We determined that the dramatic morphological changes were caused by a single T-DNA insertion in Osmtd1. Further analysis revealed that the T-DNA insertion was located in the gene Os08g34258 encoding a putative inhibitor I family protein. Os08g34258 was knocked out and Osmi R156 f was signi fi cantly upregulated in Osmtd1. Overexpression of Os08g34258 in Osmtd1 complemented the defects of the mutant architecture, while overexpression of Osmi R156 f in wild-type rice phenocopied Osmtd1. We showed that the expression of Os SPL3, Os SPL12,and Os SPL14 were signi fi cantly downregulated in Osmtd1 or Osmi R156 f overexpressed lines, indicating that Os SPL3,Os SPL12, and Os SPL14 were possibly direct target genes of Osmi R156 f. Our results suggested that Osmi R156 f controlledplant architecture by mediating plant stature and tiller outgrowth and may be regulated by an unknown protease inhibitor I family protein.
基金supported by the Science and Technology Project of State Grid Corporation of China(No.5455HJ180018).
文摘With the rapid growth of power systems measurements in terms of size and complexity,discovering statistical patterns for a large variety of real-world applications such as renewable energy prediction,demand response,energy disaggregation,and state estimation is considered a crucial challenge.In recent years,deep learning has emerged as a novel class of machine learning algorithms that represents power systems data via a large hypothesis space that leads to the state-of-the-art performance compared to most recent data-driven algorithms.This study explores the theoretical advantages of deep representation learning in power systems research.We review deep learning methodologies presented and applied in a wide range of supervised,unsupervised,and semi-supervised applications as well as reinforcement learning tasks.We discuss various settings of problems solved by discriminative deep models including stacked autoencoders and convolutional neural networks as well as generative deep architectures such as deep belief networks and variational autoencoders.The theoretical and experimental analysis of deep neural networks in this study motivates longterm research on optimizing this cutting-edge class of models to achieve significant improvements in the future power systems research.
基金This work was supported in part by Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.51621065)the National Natural Science Foundation of China(No.51537006)the China Postdoctoral Science Foundation(No.2016M600091 and 2017T100078).
文摘Storage is widely considered in economic dispatch(ED)problems.To prevent simultaneous charging and discharging of a storage device,a storage-concerned ED problem should involve complementarity constraints for every storage device to make the problem strongly non-convex.In this case,the conventional Karush-Kuhn-Tucker optimality conditions are unsuitable,and the methods that are normally effective are also invalid.In our recent paper,we proposed a new exact relaxation method that directly removes the complementarity constraints from a storageconcerned ED model to make it convex and easy to solve.This paper extends the previous study by presenting and analyzing two new groups of sufficient conditions that guarantee exact relaxation.Different application conditions of these groups of sufficient conditions are discussed.Numerical tests are performed to show the benefit of using the exact relaxation method and the different suitable application conditions of these groups of sufficient conditions.This paper contributes to a wide application of exact relaxation in storage-concerned ED problems.
基金The submitted manuscript has been created by UChicago Argonne,LLC,Operator of Argonne National Laboratory(“Argonne”).Argonne,a U.S.Department of Energy Office of Science laboratory,is operated under Contract No.DE-AC02-06CH11357.
文摘Contingency analysis(CA)requires fast execution time for real-time power system operations.Because CA problems can naturally be divided into separate subtasks,parallel computing helps to speed up the computation time.This paper proposes a master/slave parallel computing architecture and studies the computation of CA in a large-scale power system through high performance computing,adopting a message passing interface for implementation.In particular,although the execution time of CA varies,there is a tradeoff between having an imbalanced workload and"paying"a synchronization penalty for parallel computing:either factor blocks the progress of scalability.The proposed layered dynamic scheduling method is effective to tackle the challenge of high synchronization cost and workload imbalance and have the potential to further scale for the N-2 contingency analysis.
基金supported by the Key Program of National Natural Science Foundation of China (Grant No. 51537010)the National Basic Research Program (973 Program) (Grant No. 2013CB228206)supported by the U.S. Department of Energy’s Office of Electricity Delivery and Energy Reliability
文摘Boosting the resilience of power systems is a core requirement of smart grids. In fact, resilience enhancement is crucial to all critical infrastructure systems.In this study, we review the current research on system resilience enhancement within and beyond smart grids. In addition, we elaborate on resilience definition and resilience quantification and discuss several challenges and opportunities for system resilience enhancement. This study aims to deepen our understanding of the concept of resilience and develop a wide perspective on enhancing the system resilience for critical infrastructures.
基金supported by the National Natural Science Foundation of China (No. 11774301)the Young Scientists Fund of the National Natural Science Foundation of China (Nos. 11804292 and 61805210)。
文摘A continuous-wave Nd:YVO4/BaWO4 Raman laser generating simultaneous multi-wavelength first-Stokes and second-Stokes emissions is demonstrated for the first time, to the best of our knowledge. Investigations concerning different pump spot sizes and crystal lengths were conducted to improve the thermal effect and pump absorption. Three first-Stokes lasers at 1103.6, 1175.9, and 1180.7 nm and two second-Stokes lasers at 1145.7 and 1228.9 nm are obtained simultaneously using the Raman shifts of 925 cm-1 and 332 cm-1 in BaWO4 and 890 cm-1 in YVO4. At the incident pump power of 23.1 W, 1.24 W maximum Raman output power is achieved,corresponding to an optical conversion efficiency of 5.4%. We also present a theoretical analysis of the competition between different Stokes lines.
基金supported by Technology Project of State Grid Corporation of China(No.SGRIJSKJ(2016)800).
文摘A solution to the power flow problem is imperative for many power system applications and several iterative approaches are employed to achieve this objective.However,the chance of finding a solution is dependent on the choice of the initial point because of the nonconvex feasibility region of this problem.In this paper,a non-iterative approach that leverages a convexified relaxed power flow problem is employed to verify the existence of a feasible solution.To ensure the scalability of the proposed convex relaxation,the problem is formulated as a sparse semi-definite programming problem.The variables associated with each maximal clique within the network form several positive semidefinite matrices.Perturbation and network reconfiguration schemes are employed to improve the tightness of the proposed convex relaxation in order to validate the existence of a feasible solution for the original non-convex problem.Multiple case studies including an ill-conditioned power flow problem are examined to show the effectiveness of the proposed approach to find a feasible solution.
