This paper introduces a small perturbation frequency domain thermal analysis model based on the nonlinear dynamics model.The model can be applied to study the high-precision temperature control of thermal systems unde...This paper introduces a small perturbation frequency domain thermal analysis model based on the nonlinear dynamics model.The model can be applied to study the high-precision temperature control of thermal systems under low-frequency complex perturbations.The frequency domain characteristics of the space gravitational wave detection satellite are analyzed,and a multi-channel perturbation structure is established.The effects of three kinds of heat flow perturbations,including external heat flow,power generation power,and waste heat of electronic equipment,on the temperature through five transfer paths are investigated.It has been discovered that the waste heat from electronic equipment inside the satellite has the most noticeable effect on the temperature power spectral density of temperature-sensitive optical loads,serving as the primary factor influencing thermal stability.For complex noise signals,the small perturbation analysis method can decompose the different frequency components or ranges,reducing the problem to linearized analysis and simplifying complex calculations.The results indicate that the temperature power spectral density decreases as signal frequency increases,with low-frequency signals exerting a greater influence on temperature stability.The small perturbation analysis method is a novel and effective method for temperature control of space thermal systems,with high accuracy and stability.展开更多
Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and signifi...Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and significant manual intervention.This study aims to optimize CT scanning parameters to enhance the accuracy of measuring crack widths and rebar volumes in reinforced concrete.Nine sets of specimens,each with varying rebar diameters and concrete cover thicknesses,were scanned before and after corrosion using an Optima CT scanner,followed by three-dimensional reconstructions using Avizo software.The effects of threshold values and“Erosion”coefficients on measurement accuracy were evaluated.The results demonstrated that an optimal lower threshold of 2950,combined with an‘Erosion’coefficient of 6,effectively limits the measurement error of rebar volumes to within 1%.The optimal threshold for measuring crack widths was influenced by the crack width,rebar diameter,and concrete cover thickness.Additionally,an optimized formula for determining crack measurement thresholds was proposed.This study significantly improves the accuracy of CT-based non-destructive testing(NDT)techniques,providing valuable insights for structural health monitoring(SHM).展开更多
Glioblastoma multiforme(GBM)is a highly aggressive and lethal brain tumor with limited treatment options.To improve therapeutic efficacy,we developed a novel multifunctional nanoplatform,GM@P(T/S),comprised of polymer...Glioblastoma multiforme(GBM)is a highly aggressive and lethal brain tumor with limited treatment options.To improve therapeutic efficacy,we developed a novel multifunctional nanoplatform,GM@P(T/S),comprised of polymeric nanoparticles coated with GBM cell membranes as well as co-loaded with temozolomide(TMZ)and superparamagnetic iron oxide(SPIO)nanoparticles.The successful preparation was confirmed in terms of particle size,morphology,stability,the in vitro drug release,and cellular uptake assays.We demonstrated that GM@P(T/S)exhibited the enhanced homotypic targeting,the prolonged blood circulation,and efficient bloodbrain barrier penetration in both in vitro and in vivo studies.The combination of TMZ and SPIO nanoparticles within GM@P(T/S)synergistically improved chemo-radiation therapy,leading to a reduced tumor growth,an increased survival,and minimal systemic toxicity in the orthotopic GBM mouse models.Our findings suggest that GM@P(T/S)holds a great promise as a targeted and efficient therapeutic strategy for GBM.展开更多
A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temper...A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temperatures and pressures,a high-temperature and high-pressure reactor,gas chromatograph,and other related experimental equipment were used to perform methane dissolution experiments,and a single surfactant sodium oleate(NaOA)and n-hexane demonstrated superior results.The single-factor experiments of temperature,pressure,and NaOA addition were performed and fitted via a response surface analysis.The optimal conditions for methane solubility were as follows:temperature of 34C,pressure of 4.5 MPa,NaOA addition of 85 g/L,and time of 1 h.The optimal effect of the surfactant-polyalkane system in dissolving methane was achieved with 32.31 mL/100 mL.Meanwhile,the change in the surface structure of coal before and after washing with the system was compared using scanning electron microscopy.The results indicated that the gas after washing with the surfactant-polyalkane system dissolved,and the surface pore structure of the coal changed.Moreover,the specific surface area and pore size of the coal surface increased after washing.Hence,the desorption of gas from the coal surface into the system becomes easy,thereby reducing the gas content in the coal sample.展开更多
Solving optimization problems plays a vital role in ensuring the secure and economic operation of distribution systems.To enhance computational efficiency,this paper proposes a general simplification and acceleration ...Solving optimization problems plays a vital role in ensuring the secure and economic operation of distribution systems.To enhance computational efficiency,this paper proposes a general simplification and acceleration method for distribution system optimization problems.Firstly,the capacity boundary and voltage boundary model of distribution systems are established.The relative position between the two boundaries reflects the strength of capacity and voltage constraints,leading to the definition of two critical feeder lengths(CFLs)to quantify these strengths.Secondly,simplification criteria and an acceleration method are proposed.Given a distribution system,if the distance from the end load/DG node to the slack bus is less than the corresponding CFL,we can conclude that the capacity constraints are stricter than the voltage constraints.Then,the distribution system can be simplified by adopting DC power flow model or disregarding the voltage constraints.After that,the reference value tables of CFL are presented.Finally,the effectiveness of the proposed method is verified by exemplifying the method in network reconfiguration and reactive power optimization problems.By implementing the proposed acceleration method,a significant reduction in computation time is achieved while ensuring accuracy.This method applies to most urban distribution systems in optimization problems involving power flow equations or voltage constraints.展开更多
Flowering time is a critical agronomic trait in rice,directly influencing grain yield and adaptability to specific planting regions and seasons.Florigens,including FLOWERING LOCUST(FT)proteins Hd3a(OsFTL2)and RFT1(OsF...Flowering time is a critical agronomic trait in rice,directly influencing grain yield and adaptability to specific planting regions and seasons.Florigens,including FLOWERING LOCUST(FT)proteins Hd3a(OsFTL2)and RFT1(OsFTL3),play central roles in transmitting flowering signals through rice's photoperiod regulatory network.While Hd3a and RFT1have been extensively studied,the functions and interactions of other FT-like proteins remain unclear,limiting advancements in breeding strategies for early-maturing rice varieties.Here,we demonstrate that the florigen-like protein OsFTL1 forms a florigen activation complex(FAC)and promotes flowering under both short-day and long-day conditions.OsFTL1 localizes to the nucleus and cytoplasm,with predominant expression in the shoot base,facilitating its mobilization to the shoot apical meristem(SAM)to initiate flowering.Overexpression of OsFTL1(OsFTL1-OE)in leaves or shoot bases significantly accelerates flowering and alters plant architecture.In the nucleus,OsFTL1interacts with GF14c and OsFD1 to form an FAC,activating OsMADS14 and OsMADS15 expression to drive flowering.Markedly,OsFTL1-OE plants deficient in Hd3a and RFT1 exhibited earlier flowering compared with wild-type plants,indicating that OsFTL1 can independently promote flowering.Furthermore,haplotype analysis identified OsFTL1-Hap3,a beneficial variant associated with early flowering and comparable grain yields.These findings revealed that OsFTL1 can substitute for Hd3a and RFT1 in FAC formation,promoting flowering across photoperiods,and highlighting its potential application in breeding early-maturing,high-yield rice varieties suitable for diverse environments.展开更多
The Medium Energy X-ray telescope(ME) is one of the three main telescopes on board the Insight hard X-ray modulation telescope(Insight-HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN detectors sensitive i...The Medium Energy X-ray telescope(ME) is one of the three main telescopes on board the Insight hard X-ray modulation telescope(Insight-HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN detectors sensitive in 5-30 ke V with a total geometrical area of 952 cm^2. The application specific integrated circuit(ASIC) chip, VA32TA6, is used to achieve low power consumption and low readout noise. The collimators define three kinds of field of views(FOVs) for the telescope, 1°×4°, 4°×4°,and blocked ones. Combination of such FOVs can be used to estimate the in-orbit X-ray and particle background components.The energy resolution of ME is ~3 ke V at 17.8 ke V(FWHM) and the time resolution is 255 μs. In this paper, we introduce the design and performance of ME.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFC2204400)。
文摘This paper introduces a small perturbation frequency domain thermal analysis model based on the nonlinear dynamics model.The model can be applied to study the high-precision temperature control of thermal systems under low-frequency complex perturbations.The frequency domain characteristics of the space gravitational wave detection satellite are analyzed,and a multi-channel perturbation structure is established.The effects of three kinds of heat flow perturbations,including external heat flow,power generation power,and waste heat of electronic equipment,on the temperature through five transfer paths are investigated.It has been discovered that the waste heat from electronic equipment inside the satellite has the most noticeable effect on the temperature power spectral density of temperature-sensitive optical loads,serving as the primary factor influencing thermal stability.For complex noise signals,the small perturbation analysis method can decompose the different frequency components or ranges,reducing the problem to linearized analysis and simplifying complex calculations.The results indicate that the temperature power spectral density decreases as signal frequency increases,with low-frequency signals exerting a greater influence on temperature stability.The small perturbation analysis method is a novel and effective method for temperature control of space thermal systems,with high accuracy and stability.
文摘Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and significant manual intervention.This study aims to optimize CT scanning parameters to enhance the accuracy of measuring crack widths and rebar volumes in reinforced concrete.Nine sets of specimens,each with varying rebar diameters and concrete cover thicknesses,were scanned before and after corrosion using an Optima CT scanner,followed by three-dimensional reconstructions using Avizo software.The effects of threshold values and“Erosion”coefficients on measurement accuracy were evaluated.The results demonstrated that an optimal lower threshold of 2950,combined with an‘Erosion’coefficient of 6,effectively limits the measurement error of rebar volumes to within 1%.The optimal threshold for measuring crack widths was influenced by the crack width,rebar diameter,and concrete cover thickness.Additionally,an optimized formula for determining crack measurement thresholds was proposed.This study significantly improves the accuracy of CT-based non-destructive testing(NDT)techniques,providing valuable insights for structural health monitoring(SHM).
基金supported by the National Natural Science Foundation of China(Grant Nos.82073308 and 82104089)。
文摘Glioblastoma multiforme(GBM)is a highly aggressive and lethal brain tumor with limited treatment options.To improve therapeutic efficacy,we developed a novel multifunctional nanoplatform,GM@P(T/S),comprised of polymeric nanoparticles coated with GBM cell membranes as well as co-loaded with temozolomide(TMZ)and superparamagnetic iron oxide(SPIO)nanoparticles.The successful preparation was confirmed in terms of particle size,morphology,stability,the in vitro drug release,and cellular uptake assays.We demonstrated that GM@P(T/S)exhibited the enhanced homotypic targeting,the prolonged blood circulation,and efficient bloodbrain barrier penetration in both in vitro and in vivo studies.The combination of TMZ and SPIO nanoparticles within GM@P(T/S)synergistically improved chemo-radiation therapy,leading to a reduced tumor growth,an increased survival,and minimal systemic toxicity in the orthotopic GBM mouse models.Our findings suggest that GM@P(T/S)holds a great promise as a targeted and efficient therapeutic strategy for GBM.
基金the financial support of project No.FRFIC-20-01 and No.FRF-IC-19-013the Fundamental Research Funds for the Central Universities,China project No.51974015,No.51904292,and No.51474017+5 种基金the National Natural Science Foundation of China,China project No.2018YFC0810600the National Key Research and Development Program of China,China project No.2017CXNL02the Fundamental Research Funds for the Central Universities(China University of Mining and Technology),China project No.BK20180655the Natural Science Foundation of Jiangsu Province,China project No.WS2018B03the State Key Laboratory Cultivation Base for Gas Geology and Gas Control(Henan Polytechnic University),China and project No.E21724the Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines of China(Hunan University of Science and Technology),China.
文摘A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temperatures and pressures,a high-temperature and high-pressure reactor,gas chromatograph,and other related experimental equipment were used to perform methane dissolution experiments,and a single surfactant sodium oleate(NaOA)and n-hexane demonstrated superior results.The single-factor experiments of temperature,pressure,and NaOA addition were performed and fitted via a response surface analysis.The optimal conditions for methane solubility were as follows:temperature of 34C,pressure of 4.5 MPa,NaOA addition of 85 g/L,and time of 1 h.The optimal effect of the surfactant-polyalkane system in dissolving methane was achieved with 32.31 mL/100 mL.Meanwhile,the change in the surface structure of coal before and after washing with the system was compared using scanning electron microscopy.The results indicated that the gas after washing with the surfactant-polyalkane system dissolved,and the surface pore structure of the coal changed.Moreover,the specific surface area and pore size of the coal surface increased after washing.Hence,the desorption of gas from the coal surface into the system becomes easy,thereby reducing the gas content in the coal sample.
基金supported by the National Natural Science Foundation of China(No.52177105).
文摘Solving optimization problems plays a vital role in ensuring the secure and economic operation of distribution systems.To enhance computational efficiency,this paper proposes a general simplification and acceleration method for distribution system optimization problems.Firstly,the capacity boundary and voltage boundary model of distribution systems are established.The relative position between the two boundaries reflects the strength of capacity and voltage constraints,leading to the definition of two critical feeder lengths(CFLs)to quantify these strengths.Secondly,simplification criteria and an acceleration method are proposed.Given a distribution system,if the distance from the end load/DG node to the slack bus is less than the corresponding CFL,we can conclude that the capacity constraints are stricter than the voltage constraints.Then,the distribution system can be simplified by adopting DC power flow model or disregarding the voltage constraints.After that,the reference value tables of CFL are presented.Finally,the effectiveness of the proposed method is verified by exemplifying the method in network reconfiguration and reactive power optimization problems.By implementing the proposed acceleration method,a significant reduction in computation time is achieved while ensuring accuracy.This method applies to most urban distribution systems in optimization problems involving power flow equations or voltage constraints.
基金supported by grants from the Key Program of National Natural Science Foundation of China(32330079)the STI 2030-Major Projects(2023ZD0407203)+2 种基金the Innovation Program of Chinese Academy of Agricultural Sciences,the Nanfan Special Project of CAAS(YBXM02)the China Postdoctoral Science Foundation(2023M743846)the Youth Program of National Natural Science Foundation of China(32401746)。
文摘Flowering time is a critical agronomic trait in rice,directly influencing grain yield and adaptability to specific planting regions and seasons.Florigens,including FLOWERING LOCUST(FT)proteins Hd3a(OsFTL2)and RFT1(OsFTL3),play central roles in transmitting flowering signals through rice's photoperiod regulatory network.While Hd3a and RFT1have been extensively studied,the functions and interactions of other FT-like proteins remain unclear,limiting advancements in breeding strategies for early-maturing rice varieties.Here,we demonstrate that the florigen-like protein OsFTL1 forms a florigen activation complex(FAC)and promotes flowering under both short-day and long-day conditions.OsFTL1 localizes to the nucleus and cytoplasm,with predominant expression in the shoot base,facilitating its mobilization to the shoot apical meristem(SAM)to initiate flowering.Overexpression of OsFTL1(OsFTL1-OE)in leaves or shoot bases significantly accelerates flowering and alters plant architecture.In the nucleus,OsFTL1interacts with GF14c and OsFD1 to form an FAC,activating OsMADS14 and OsMADS15 expression to drive flowering.Markedly,OsFTL1-OE plants deficient in Hd3a and RFT1 exhibited earlier flowering compared with wild-type plants,indicating that OsFTL1 can independently promote flowering.Furthermore,haplotype analysis identified OsFTL1-Hap3,a beneficial variant associated with early flowering and comparable grain yields.These findings revealed that OsFTL1 can substitute for Hd3a and RFT1 in FAC formation,promoting flowering across photoperiods,and highlighting its potential application in breeding early-maturing,high-yield rice varieties suitable for diverse environments.
基金the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(Grant No.XDA040102).
文摘The Medium Energy X-ray telescope(ME) is one of the three main telescopes on board the Insight hard X-ray modulation telescope(Insight-HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN detectors sensitive in 5-30 ke V with a total geometrical area of 952 cm^2. The application specific integrated circuit(ASIC) chip, VA32TA6, is used to achieve low power consumption and low readout noise. The collimators define three kinds of field of views(FOVs) for the telescope, 1°×4°, 4°×4°,and blocked ones. Combination of such FOVs can be used to estimate the in-orbit X-ray and particle background components.The energy resolution of ME is ~3 ke V at 17.8 ke V(FWHM) and the time resolution is 255 μs. In this paper, we introduce the design and performance of ME.
