[Objectives]To improve the thermal insulation performance of solar greenhouses in winter,enhance solar energy utilization efficiency,reduce additional carbon emissions,and lower winter heating costs for greenhouses.[M...[Objectives]To improve the thermal insulation performance of solar greenhouses in winter,enhance solar energy utilization efficiency,reduce additional carbon emissions,and lower winter heating costs for greenhouses.[Methods]An active heat storage and release water bag was added inside the solar greenhouse.Comparative experiments were conducted between the experimental greenhouse K1 equipped with the heat storage water bag and the control greenhouse K2 under different winter night weather conditions.[Results]On sunny days,the maximum temperature difference between K1 and K2 was 2.3℃,and the average temperature during the water bag's heat release period increased by 2.2℃;on cloudy days,the maximum temperature difference was 2.2℃,and the average temperature increased by 2.0℃;on snowy days,the maximum temperature difference was 1.8℃,and the average temperature increased by 1.6℃.Additionally,the heat storage capacities of the water bag on sunny,cloudy,and snowy days were 491.4,453.6,and 365.4 MJ,respectively.The corresponding nighttime heat release amounts were 378,302.4,and 226.8 MJ,respectively.The corresponding heat storage-release efficiencies were 76%,66.2%,and 62%,respectively.The service life of the heat storage water bag can reach 10 years,with an annual operating cost of approximately 2500 yuan.[Conclusions]By comprehensively analyzing the initial costs,operating expenses,and cost savings rate compared to coal burning for current main energy-saving heat storage and warming equipment in solar greenhouses,this study provides reference suggestions for the promotion,application,and selection of winter heat storage and warming equipment for solar greenhouses in different regions.Users can choose to install the equipment based on the performance characteristics of the heat storage water bag and their actual needs.展开更多
Sintered metals serving as thermal interface materials(TIMs)with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications.Neverthe...Sintered metals serving as thermal interface materials(TIMs)with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications.Nevertheless,their thermal stabilities during high-temperature service provide significant challenges.Herein,a facile approach was developed for one-step synthesis of single-phase Ag-Cu supersaturated solid-solution nanoparticle(Ag-Cu SS-NP)pastes with adjustable Cu contents(up to 37.7 at.%),and they exhibited ultrahigh resistance to oxidation and excellent sinterability.A paste composed of Ag-Cu SS-NPs was sintered in air at 250℃ for 20 min,and this resulted in a dense supersaturated structure with an impressive thermal conductivity of 157.8 W/(m K)and a room-temperature shear strength of 133.4 MPa.Microstructural analyses demonstrated that Cu had precipitated from the Ag lattice to form Cu nanoprecipitates,which refined the grain sizes and induced high-density dislocations during sintering.For the pinning effect of dislocations and grain boundaries by the Cu nanoprecipitates and coherent twins,the high-temperature(400℃)shear strength of sintered Ag-Cu SS-NP joints was significantly improved by 67%(58.6 MPa),meanwhile the shear strength after long-term aging at 200 and 300℃for 960 h were increased by 123%(140.3 MPa)and 80%(82.4 MPa)compared to those of sintered Ag NP joints,respectively.The remarkable thermal stability is far superior to traditional TIMs,so the Ag-Cu SS-NP paste exhibits excellent potential as a TIM for high-temperature power device applications.展开更多
The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis ...The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis and peroxymonosulfate(PMS) activation.In order to fully utilize the luminous energy and realize the efficient activation of PMS,this work achieved successful construction of NiCo_(2)O_(4)/BiOCl/Bi_(24)O_(31)Br_(10) ternary Z-scheme heterojunction by simultaneously synthesizing BiOCl and NiCo_(2)O_(4) with NiCl_(2) and CoCl_(2) as the precursors.The intercalated BiOCl could serve as a carrier migration ladder to further achieve the spatial separation of electron-hole pairs,so that the oxidation and reduction processes separately occurred in different regions.Compared with the reported catalysts,the as-prepared composites exhibited the enhanced removal efficiency for tetracycline hydrochloride(TCH) in the visible light/PMS system,with a degradation efficiency of 85.30%in 2 min,and possessed good stability.Z-scheme heterojunction was shown to be beneficial for maximizing the superiority of photo-assisted Fenton-like reaction system.The experimental and characterization results confirmed that both non-radicals(^(1)O_(2)) and radicals(SO_(5)^(·-) and SO_(4)^(·-)) were involved in the reaction process and the SO_(5)^(·-)generated by the oxidation of PMS played a crucial role in the TCH degradation.The possible reaction mechanism was finally proposed.This study provided new insight into the Z-scheme heterostructure to promote the photo-assisted Fenton-like reaction.展开更多
The formation of lithium dendrites and the safety hazards arising from flammable liquid electrolytes have seriously hindered the development of high-energy-density lithium metal batteries.Herein,an emerging amide-base...The formation of lithium dendrites and the safety hazards arising from flammable liquid electrolytes have seriously hindered the development of high-energy-density lithium metal batteries.Herein,an emerging amide-based electrolyte is proposed,containing LiTFSI and butyrolactam in different molar ratios.1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropylether and fluoroethylene carbonate are introduced into the amide-based electrolyte as counter solvent and additives.The well-designed amide-based electrolyte possesses nonflammability,high ionic conductivity,high thermal stability and electrochemical stability(>4.7 V).Besides,an inorganic/organic-rich solid electrolyte interphase with an abundance of LiF,Li3N and Li-N-C is in situ formed,leading to spherical lithium deposition.The formation mechanism and solvation chemistry of amide-based electrolyte are further inves-tigated by molecular dynamics simulations and density functional theory.When applied in Li metal batteries with LiFePO4 and LiMn2O4 cathode,the amide-based electrolyte can enable stable cycling performance at room temperature and 60℃.This study provides a new insight into the development of amide-based electrolytes for lithium metal batteries.展开更多
Based on an analysis of the operational control behavior of operation experts on energy-intensive equipment,this paper proposes an intelligent control method for low-carbon operation by combining mechanism analysis wi...Based on an analysis of the operational control behavior of operation experts on energy-intensive equipment,this paper proposes an intelligent control method for low-carbon operation by combining mechanism analysis with deep learning,linking control and optimization with prediction,and integrating decision-making with control.This method,which consists of setpoint control,self-optimized tuning,and tracking control,ensures that the energy consumption per tonne is as low as possible,while remaining within the target range.An intelligent control system for low-carbon operation is developed by adopting the end-edge-cloud collaboration technology of the Industrial Internet.The system is successfully applied to a fused magnesium furnace and achieves remarkable results in reducing carbon emissions.展开更多
A series of large-area,flexible and transparent ultraviolet(UV)photodetectors(PDs)based on Ag nanowire(NW)@ZnO nanorods(NRs)are fabricated by an inexpensive,facile and effective approach.These Ag NW@ZnO NRs are succes...A series of large-area,flexible and transparent ultraviolet(UV)photodetectors(PDs)based on Ag nanowire(NW)@ZnO nanorods(NRs)are fabricated by an inexpensive,facile and effective approach.These Ag NW@ZnO NRs are successfully synthesized using a two-step method in an oil bath with a high surface-to-volume ratio and good crystallinity.The PDs are fabricated by drop-coating with different drop-coating times on the surface of polyethylene terephthalate(PET)coupled with Au electrodes.By optimizing the cross-linked network of Ag NW@ZnO NRs,PD2 with a size greater than 25 mm exhibits excellent photoresponse under UV light illumination of 365 nm(1.3 m W cm^(-2))with a bias of 5 V:a high sensitivity of over 10^(3),and a much shorter rise/decay time of 2.6 s/2.3 s.Simultaneously,the detector exhibits an average transmittance of more than 70%in the visible light region,as well as good flexibility and excellent mechanical stability under a bending angle of 120°over 1000 circles bending.These integral advantages have significant potential for practical applications and mass production.展开更多
Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ...Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.展开更多
The influence of thermal cycling on the microstructure and joint strength of Sn3.5Ag0.75Cu （SAC） and Sn63Pb37 （SnPb） solder joints was investigated. SAC and SnPb solder balls were soldered on 0.1 and 0.9 μm Au fi...The influence of thermal cycling on the microstructure and joint strength of Sn3.5Ag0.75Cu （SAC） and Sn63Pb37 （SnPb） solder joints was investigated. SAC and SnPb solder balls were soldered on 0.1 and 0.9 μm Au finished metallization, respectively. After 1000 thermal cycles between -40℃ and 125℃, a very thin intermetallic compound （IMC） layer containing Au, Sn, Ni, and Cu formed at the interface between SAC solder joints and underneath metallization with 0.1 μm Au finish, and （Au, Ni, Cu）Sn4 and a very thin AuSn-Ni-Cu IMC layer formed between SAC solder joints and underneath metallization with 0.9 μm Au finish. For SnPb solder joints with 0.1 μm Au finish, a thin （Ni, Cu, Au）3Sn4 IMC layer and a Pb-rich layer formed below and above the （Au, Ni）Sn4 IMC, respectively. Cu diffused through Ni layer and was involved into the IMC formation process. Similar interfacial microstructure was also found for SnPb solder joints with 0.9μm Au finish. The results of shear test show that the shear strength of SAC solder joints is consistently higher than that of SnPb eutectic solder joints during thermal cycling.展开更多
Alzheimer’s dementia(AD)and type 2 diabetes(T2D)are interrelated global public health problems,and the current epidemics of both AD and T2D are insulin resistance diseases.Thus,AD and T2D may share common risk factor...Alzheimer’s dementia(AD)and type 2 diabetes(T2D)are interrelated global public health problems,and the current epidemics of both AD and T2D are insulin resistance diseases.Thus,AD and T2D may share common risk factors such as an unhealthy diet,lifestyle,and obesity.Meat products is an important part of the diet of consumers worldwide.This systematic review and meta-analysis aims to assess and estimate the effect of meat products consumption on AD and T2D in humans.Web of Science,MEDLINE,PubMed,Cochrane Library,and Embase were searched from January 2012 to April 2024.29 articles reported 32 cohort studies with 1785769 subjects,with 3546 AD cases and 91092 T2D cases that met the inclusion criteria and were included in our analysis.Consumption of various meat products increased the risk of T2D(hazard ratios(HR)=1.19,95%confidence intervals(CI):1.13−1.26,P=0.000;I2=88.5%),consumption of smoked,grilled/roasted and fried meat products was more likely to induce T2D(HR=1.24,95%CI:1.18−1.30,P=0.000;I2=76.1%),but was borderline significant for the risk of AD(HR=1.11,95%CI:0.98−1.25,P=0.094;I2=58.8%),with consumption of mainly livestock and poultry products increasing the risk(HR=1.21,95%CI:1.03−1.42,P=0.017;I2=66.8%).The association between meat products consumption and AD risk was influenced by meat type and sample size,while the risk of T2D was influenced by meat type,follow-up and sex.A daily intake of 27,123 and 170 g of livestock products increased the risk of T2D by 10%,51%and 70%respectively,whereas the risk of T2D was reduced when the intake of various meat products was less than 23 g/day.展开更多
Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facet...Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system.MIL-68(In)was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity.However,its catalytic activity was constrained by severe carrier recombination and a lack of active sites.Herein,increased(001)facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In)through a one-pot solvothermal strategy.Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In)and other MIL-68(In/Co).The reaction kinetic constant and degradation efficiency of MIL-68(In/Co)were approximately twice and 17%higher than the pristine MIL-68(In)in 36 min reaction,respectively.Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In)facets,facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate(PMS).This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system,it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.展开更多
In this study,araucarene diterpenes,characterized by a pimarene skeleton with a variably oxidized side chain at C-13,were investigated.A total of 16 araucarene diterpenoids and their derivatives were isolated from the...In this study,araucarene diterpenes,characterized by a pimarene skeleton with a variably oxidized side chain at C-13,were investigated.A total of 16 araucarene diterpenoids and their derivatives were isolated from the woods of Agathis dammara,including 11 previously unreported compounds:dammaradione(1),dammarones D-G(2,5,14,15),dammaric acids B-F(8-12),and dammarol(16).The structures of these new compounds were elucidated using high-resolution electrospray ionization mass spectroscopy(HR-ESI-MS)and one-dimensional/two-dimensional(1D/2D)nuclear magnetic resonance(NMR),while their absolute configurations were determined through the electronic circular dichroism(ECD)exciton chirality method and Snatzke's method.The hypoglycemic activity of all isolated compounds was evaluated using a transgenic zebrafish model,and a structure-activity relationship(SAR)analysis was conducted.Araucarone(3)and dammaric acid C(9),serving as representative compounds,demonstrated significant hypoglycemic effects on zebrafish.The primary mechanism involves the promotion of pancreatic β cell regeneration and glucose uptake.Specifically,these compounds enhance the differentiation of pancreatic endocrine precursor cells(PEP cells)intoβcells in zebrafish.展开更多
The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,...The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.展开更多
Ag-Cu bimetallic nanoalloy,integrating the advantages of reducing migration and cost of nano-Ag and alleviating oxidation of nano-Cu,is a prospective bonding material for power electronic packaging.The Ag-coated Cu na...Ag-Cu bimetallic nanoalloy,integrating the advantages of reducing migration and cost of nano-Ag and alleviating oxidation of nano-Cu,is a prospective bonding material for power electronic packaging.The Ag-coated Cu nanoparticles(Cu@Ag NPs)paste can execute bonding with high quality at 250℃,and the achieved supersaturated Ag-Cu nanoalloy joint with ultrahigh shear strength(152 MPa)dramatically exceeds most nano-paste joints.The interstitial solid solutions with atomic-level metallurgical bonds at the interface dominantly promoted the shear strength.Besides,the numerous ultrafine nanograin,high proportion of low angle grain boundaries(7.44%)without deformation,and the Cu nanoprecipitates in the joint would improve subordinately.Furthermore,the high content(16.8%)of∑3 twin boundaries would contribute to the electrical and thermal conductivity.Thus,the multiple strengthening mechanisms with the solid solution,the second precipitated phase,and ultrafine nanograin can dramatically enhance shear strength and electro-thermal conductivity of joints for high-temperature device packaging.展开更多
Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process...Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are discussed.Results reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,respectively.After solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO phase.The Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on first-principles.Results show that the alloying ability of 18R is stronger than that of 14H.The reaction energies show that the 14H LPSO phase is more stable than the 18R LPSO.The elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental results.The precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the alloy.After solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,respectively.The elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr alloy.The improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed.展开更多
In this study, shear tests have been performed on the as-reflowed Sn3.5Ag solder bumps and joints to investigate the deformation behavior of Sn3.5Ag lead-free solder samples. Scanning electron microscopy （SEM） was e...In this study, shear tests have been performed on the as-reflowed Sn3.5Ag solder bumps and joints to investigate the deformation behavior of Sn3.5Ag lead-free solder samples. Scanning electron microscopy （SEM） was employed to characterize the microstructures of the samples and orientation imaging microscopy （OIM） with electron backscattered diffraction （EBSD） in SEM was used to obtain crystallographic orientation of grains to provide a detailed characterization of the deformation behavior in Sn3.5Ag solder samples after shear tests. The deformation behavior in solder samples under shear stress was discussed. The experimental results suggest that the dynamic recrystallization could occur under shear stress at room temperature and recrystallized grains should evolve from subgrains by rotation. Compared with that of non-recrystallized and as-reflowed microstructures, the microhardness of the recrystallized microstructure decreased after shear tests.展开更多
The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense ...The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense disturbance caused by typhoons.However,these responses have not been thoroughly investigated owing to the complicated marine environment.According to the satellite data,the SCS Basin was observed to have a strong sea surface temperature(SST)response to Typhoon Mangkhut,resulting in widespread SST cooling.A coupled model was used to investigate the atmospheric and oceanic responses to Typhoon Mangkhut.Best-track data,satellite SST,and ARGO measurements show that the coupled WRF-CROCO simulation displays better track,intensity,SST,temperature,and salinity profiles than those of the WRF-only simulation.Results show that the typhoon induced rightward intensifications in wind speed,ocean current,and SST.The following are some remarkable atmosphere and ocean responses:(1)the SST below the inner-core region is cooled by 1℃,resulting in a 37%-44%decrease in wet enthalpy,and the central pressure is increased by~9 hPa.Therefore,the changes in SST below the innercore region of the SCS Basin have a significant impact on air-sea fluxes under high-wind conditions;(2)the ocean boundary layer analysis shows that near-inertial oscillations on the right side of the typhoon track and a strong inertial current up to~2.28 m/s in the upper ocean were observed,which resonated with the local wind and flow field on the right side and induced strong SST cooling;(3)a decrease in SST decreased the moist static energy of the typhoon boundary layer,thereby weakening the typhoon’s intensity.The difference in equivalent potential temperature and sea surface pressure have a good correlation,indicating that the influence of moist static energy on typhoon intensity cannot be overlooked.展开更多
The global push for carbon neutrality highlights the need for rigorous assessments of whether national efforts align with stated targets.However,existing evaluations often prioritize commitments over tangible progress...The global push for carbon neutrality highlights the need for rigorous assessments of whether national efforts align with stated targets.However,existing evaluations often prioritize commitments over tangible progress,lacking comprehensive and transparent metrics.To bridge this gap,we develop a multidimensional indicator system that evaluates targets,policies,actions,and effectiveness across key areas,including policy implementation,technology deployment,financial investment,and international cooperation.While 151 countries have pledged carbon neutralityd19 of which are developing nations that made commitments in 2024dimplementation remains uneven.Only 72 countries have established complete policy frameworks,and advanced low-carbon technologies are concentrated in a handful of nations.Current trends indicate that global renewable energy capacity will reach just 2.7 times its 2022 level by 2030,falling short of the tripling target.Moreover,the global median action score in 2024 stands at only 25dfar below the target of 65dhighlighting the urgency for stronger efforts.Our findings reveal a significant gap between ambition and action,with renewable energy deployment lagging behind expectations.To accelerate progress,enhanced global cooperation,increased investment,and fewer barriers to technology diffusion are crucial.This study underscores the need for more implementationfocused tracking to ensure carbon neutrality commitments translate into measurable outcomes.展开更多
基金Supported by Hetian Prefecture Regional-Level Planning Project(20220219)。
文摘[Objectives]To improve the thermal insulation performance of solar greenhouses in winter,enhance solar energy utilization efficiency,reduce additional carbon emissions,and lower winter heating costs for greenhouses.[Methods]An active heat storage and release water bag was added inside the solar greenhouse.Comparative experiments were conducted between the experimental greenhouse K1 equipped with the heat storage water bag and the control greenhouse K2 under different winter night weather conditions.[Results]On sunny days,the maximum temperature difference between K1 and K2 was 2.3℃,and the average temperature during the water bag's heat release period increased by 2.2℃;on cloudy days,the maximum temperature difference was 2.2℃,and the average temperature increased by 2.0℃;on snowy days,the maximum temperature difference was 1.8℃,and the average temperature increased by 1.6℃.Additionally,the heat storage capacities of the water bag on sunny,cloudy,and snowy days were 491.4,453.6,and 365.4 MJ,respectively.The corresponding nighttime heat release amounts were 378,302.4,and 226.8 MJ,respectively.The corresponding heat storage-release efficiencies were 76%,66.2%,and 62%,respectively.The service life of the heat storage water bag can reach 10 years,with an annual operating cost of approximately 2500 yuan.[Conclusions]By comprehensively analyzing the initial costs,operating expenses,and cost savings rate compared to coal burning for current main energy-saving heat storage and warming equipment in solar greenhouses,this study provides reference suggestions for the promotion,application,and selection of winter heat storage and warming equipment for solar greenhouses in different regions.Users can choose to install the equipment based on the performance characteristics of the heat storage water bag and their actual needs.
基金supported by the National Natural Science Foundation of China(Nos.52075125 and 52105331)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515010591)the Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20210324124203009,JSGG20201102154600003,GXWD20231130103814001,and GXWD20220721182229001).
文摘Sintered metals serving as thermal interface materials(TIMs)with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications.Nevertheless,their thermal stabilities during high-temperature service provide significant challenges.Herein,a facile approach was developed for one-step synthesis of single-phase Ag-Cu supersaturated solid-solution nanoparticle(Ag-Cu SS-NP)pastes with adjustable Cu contents(up to 37.7 at.%),and they exhibited ultrahigh resistance to oxidation and excellent sinterability.A paste composed of Ag-Cu SS-NPs was sintered in air at 250℃ for 20 min,and this resulted in a dense supersaturated structure with an impressive thermal conductivity of 157.8 W/(m K)and a room-temperature shear strength of 133.4 MPa.Microstructural analyses demonstrated that Cu had precipitated from the Ag lattice to form Cu nanoprecipitates,which refined the grain sizes and induced high-density dislocations during sintering.For the pinning effect of dislocations and grain boundaries by the Cu nanoprecipitates and coherent twins,the high-temperature(400℃)shear strength of sintered Ag-Cu SS-NP joints was significantly improved by 67%(58.6 MPa),meanwhile the shear strength after long-term aging at 200 and 300℃for 960 h were increased by 123%(140.3 MPa)and 80%(82.4 MPa)compared to those of sintered Ag NP joints,respectively.The remarkable thermal stability is far superior to traditional TIMs,so the Ag-Cu SS-NP paste exhibits excellent potential as a TIM for high-temperature power device applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52170079 and U20A20322)the Programme of Introducing Talents of Discipline to Universities,China(No.B16020)。
文摘The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis and peroxymonosulfate(PMS) activation.In order to fully utilize the luminous energy and realize the efficient activation of PMS,this work achieved successful construction of NiCo_(2)O_(4)/BiOCl/Bi_(24)O_(31)Br_(10) ternary Z-scheme heterojunction by simultaneously synthesizing BiOCl and NiCo_(2)O_(4) with NiCl_(2) and CoCl_(2) as the precursors.The intercalated BiOCl could serve as a carrier migration ladder to further achieve the spatial separation of electron-hole pairs,so that the oxidation and reduction processes separately occurred in different regions.Compared with the reported catalysts,the as-prepared composites exhibited the enhanced removal efficiency for tetracycline hydrochloride(TCH) in the visible light/PMS system,with a degradation efficiency of 85.30%in 2 min,and possessed good stability.Z-scheme heterojunction was shown to be beneficial for maximizing the superiority of photo-assisted Fenton-like reaction system.The experimental and characterization results confirmed that both non-radicals(^(1)O_(2)) and radicals(SO_(5)^(·-) and SO_(4)^(·-)) were involved in the reaction process and the SO_(5)^(·-)generated by the oxidation of PMS played a crucial role in the TCH degradation.The possible reaction mechanism was finally proposed.This study provided new insight into the Z-scheme heterostructure to promote the photo-assisted Fenton-like reaction.
基金supported by the National Natural Science Foundation of China(21905069,52002094)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507183907224,KQTD20170809110344233)+2 种基金the Economic,Trade and Information Commission of Shenzhen Municipality through the Graphene Manufacture Innovation Center(201901161514)the Guangdong Province Covid-19 Pandemic Control Research Fund(2020KZDZX1220)the School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(DD29100027).
文摘The formation of lithium dendrites and the safety hazards arising from flammable liquid electrolytes have seriously hindered the development of high-energy-density lithium metal batteries.Herein,an emerging amide-based electrolyte is proposed,containing LiTFSI and butyrolactam in different molar ratios.1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropylether and fluoroethylene carbonate are introduced into the amide-based electrolyte as counter solvent and additives.The well-designed amide-based electrolyte possesses nonflammability,high ionic conductivity,high thermal stability and electrochemical stability(>4.7 V).Besides,an inorganic/organic-rich solid electrolyte interphase with an abundance of LiF,Li3N and Li-N-C is in situ formed,leading to spherical lithium deposition.The formation mechanism and solvation chemistry of amide-based electrolyte are further inves-tigated by molecular dynamics simulations and density functional theory.When applied in Li metal batteries with LiFePO4 and LiMn2O4 cathode,the amide-based electrolyte can enable stable cycling performance at room temperature and 60℃.This study provides a new insight into the development of amide-based electrolytes for lithium metal batteries.
基金supported by the Science and Technology Major Project 2020 of Liaoning Province,China(2020JH1/10100008)National Natural Science Foundation of China(61991404 and 61991400)111 Project 2.0(B08015)。
文摘Based on an analysis of the operational control behavior of operation experts on energy-intensive equipment,this paper proposes an intelligent control method for low-carbon operation by combining mechanism analysis with deep learning,linking control and optimization with prediction,and integrating decision-making with control.This method,which consists of setpoint control,self-optimized tuning,and tracking control,ensures that the energy consumption per tonne is as low as possible,while remaining within the target range.An intelligent control system for low-carbon operation is developed by adopting the end-edge-cloud collaboration technology of the Industrial Internet.The system is successfully applied to a fused magnesium furnace and achieves remarkable results in reducing carbon emissions.
基金supported by the National Natural Science Foundation of China(No.51775140)partially supported by the Shenzhen Science and Technology Plan(No.JCYJ20180507183511908)+2 种基金the National Science and Technology Major Project(No.2017-VⅠ-0009-0080)the Key-Area Research and Development Program of Guangdong Province(No.2019B010935001)the Industry and Information Technology Bureau of Shenzhen Municipality(No.201806071354163490)。
文摘A series of large-area,flexible and transparent ultraviolet(UV)photodetectors(PDs)based on Ag nanowire(NW)@ZnO nanorods(NRs)are fabricated by an inexpensive,facile and effective approach.These Ag NW@ZnO NRs are successfully synthesized using a two-step method in an oil bath with a high surface-to-volume ratio and good crystallinity.The PDs are fabricated by drop-coating with different drop-coating times on the surface of polyethylene terephthalate(PET)coupled with Au electrodes.By optimizing the cross-linked network of Ag NW@ZnO NRs,PD2 with a size greater than 25 mm exhibits excellent photoresponse under UV light illumination of 365 nm(1.3 m W cm^(-2))with a bias of 5 V:a high sensitivity of over 10^(3),and a much shorter rise/decay time of 2.6 s/2.3 s.Simultaneously,the detector exhibits an average transmittance of more than 70%in the visible light region,as well as good flexibility and excellent mechanical stability under a bending angle of 120°over 1000 circles bending.These integral advantages have significant potential for practical applications and mass production.
基金the financial support provided by the National Natural Science Foundation of China(Grant No.11872013).
文摘Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.
文摘The influence of thermal cycling on the microstructure and joint strength of Sn3.5Ag0.75Cu （SAC） and Sn63Pb37 （SnPb） solder joints was investigated. SAC and SnPb solder balls were soldered on 0.1 and 0.9 μm Au finished metallization, respectively. After 1000 thermal cycles between -40℃ and 125℃, a very thin intermetallic compound （IMC） layer containing Au, Sn, Ni, and Cu formed at the interface between SAC solder joints and underneath metallization with 0.1 μm Au finish, and （Au, Ni, Cu）Sn4 and a very thin AuSn-Ni-Cu IMC layer formed between SAC solder joints and underneath metallization with 0.9 μm Au finish. For SnPb solder joints with 0.1 μm Au finish, a thin （Ni, Cu, Au）3Sn4 IMC layer and a Pb-rich layer formed below and above the （Au, Ni）Sn4 IMC, respectively. Cu diffused through Ni layer and was involved into the IMC formation process. Similar interfacial microstructure was also found for SnPb solder joints with 0.9μm Au finish. The results of shear test show that the shear strength of SAC solder joints is consistently higher than that of SnPb eutectic solder joints during thermal cycling.
基金supported by the Agricultural Science and Technology Innovation Program,Institute of Food Science and Technology,Chinese Academy of Agricultural Sciences under Grant CAAS-ASTIP-2023-IFSTGuangdong Provincial Key R&D Programme(2023B0202080003).
文摘Alzheimer’s dementia(AD)and type 2 diabetes(T2D)are interrelated global public health problems,and the current epidemics of both AD and T2D are insulin resistance diseases.Thus,AD and T2D may share common risk factors such as an unhealthy diet,lifestyle,and obesity.Meat products is an important part of the diet of consumers worldwide.This systematic review and meta-analysis aims to assess and estimate the effect of meat products consumption on AD and T2D in humans.Web of Science,MEDLINE,PubMed,Cochrane Library,and Embase were searched from January 2012 to April 2024.29 articles reported 32 cohort studies with 1785769 subjects,with 3546 AD cases and 91092 T2D cases that met the inclusion criteria and were included in our analysis.Consumption of various meat products increased the risk of T2D(hazard ratios(HR)=1.19,95%confidence intervals(CI):1.13−1.26,P=0.000;I2=88.5%),consumption of smoked,grilled/roasted and fried meat products was more likely to induce T2D(HR=1.24,95%CI:1.18−1.30,P=0.000;I2=76.1%),but was borderline significant for the risk of AD(HR=1.11,95%CI:0.98−1.25,P=0.094;I2=58.8%),with consumption of mainly livestock and poultry products increasing the risk(HR=1.21,95%CI:1.03−1.42,P=0.017;I2=66.8%).The association between meat products consumption and AD risk was influenced by meat type and sample size,while the risk of T2D was influenced by meat type,follow-up and sex.A daily intake of 27,123 and 170 g of livestock products increased the risk of T2D by 10%,51%and 70%respectively,whereas the risk of T2D was reduced when the intake of various meat products was less than 23 g/day.
基金supported by the National Natural Science Foundation of China(Nos.52100087,52170079,U20A20322)Science and Technology Development Program of Jilin Province,China(Nos.20220508100RC,20230402035GH).
文摘Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system.MIL-68(In)was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity.However,its catalytic activity was constrained by severe carrier recombination and a lack of active sites.Herein,increased(001)facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In)through a one-pot solvothermal strategy.Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In)and other MIL-68(In/Co).The reaction kinetic constant and degradation efficiency of MIL-68(In/Co)were approximately twice and 17%higher than the pristine MIL-68(In)in 36 min reaction,respectively.Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In)facets,facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate(PMS).This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system,it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.
基金supported by the Traditional Chinese Medicine Foundation of Xiamen City,China(No.XWZY-2023-0303)the Natural Science Foundation of Xiamen City,China(No.3502Z20227162)。
文摘In this study,araucarene diterpenes,characterized by a pimarene skeleton with a variably oxidized side chain at C-13,were investigated.A total of 16 araucarene diterpenoids and their derivatives were isolated from the woods of Agathis dammara,including 11 previously unreported compounds:dammaradione(1),dammarones D-G(2,5,14,15),dammaric acids B-F(8-12),and dammarol(16).The structures of these new compounds were elucidated using high-resolution electrospray ionization mass spectroscopy(HR-ESI-MS)and one-dimensional/two-dimensional(1D/2D)nuclear magnetic resonance(NMR),while their absolute configurations were determined through the electronic circular dichroism(ECD)exciton chirality method and Snatzke's method.The hypoglycemic activity of all isolated compounds was evaluated using a transgenic zebrafish model,and a structure-activity relationship(SAR)analysis was conducted.Araucarone(3)and dammaric acid C(9),serving as representative compounds,demonstrated significant hypoglycemic effects on zebrafish.The primary mechanism involves the promotion of pancreatic β cell regeneration and glucose uptake.Specifically,these compounds enhance the differentiation of pancreatic endocrine precursor cells(PEP cells)intoβcells in zebrafish.
基金National Natural Science Foundation of China (Grant No.11872013) to provide fund for conducting experiments。
文摘The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.
基金This work was financially supported by the National Natu-ral Science Foundation of China(No.NSFC 51775140)A part of the work was also supported by the National Science and Technology Major Project(No.2017-VI-0009-0080)+2 种基金the Guangdong Province key research and development program(No.2019B010935001)the Shenzhen Science and Technology Plan(No.JCYJ20180507183511908)Bureau of Industry and Information Technology of Shenzhen through the Innovation Chain and Industry Chain(No.201806071354163490).
文摘Ag-Cu bimetallic nanoalloy,integrating the advantages of reducing migration and cost of nano-Ag and alleviating oxidation of nano-Cu,is a prospective bonding material for power electronic packaging.The Ag-coated Cu nanoparticles(Cu@Ag NPs)paste can execute bonding with high quality at 250℃,and the achieved supersaturated Ag-Cu nanoalloy joint with ultrahigh shear strength(152 MPa)dramatically exceeds most nano-paste joints.The interstitial solid solutions with atomic-level metallurgical bonds at the interface dominantly promoted the shear strength.Besides,the numerous ultrafine nanograin,high proportion of low angle grain boundaries(7.44%)without deformation,and the Cu nanoprecipitates in the joint would improve subordinately.Furthermore,the high content(16.8%)of∑3 twin boundaries would contribute to the electrical and thermal conductivity.Thus,the multiple strengthening mechanisms with the solid solution,the second precipitated phase,and ultrafine nanograin can dramatically enhance shear strength and electro-thermal conductivity of joints for high-temperature device packaging.
基金supported by the National Key Research and Development Program of China[grant No.2018YFB2001800]National Natural Science Foundation of China[grant No.51871184]Dalian High-level Talents Innovation Support Program[grant No.2021RD06]。
文摘Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are discussed.Results reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,respectively.After solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO phase.The Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on first-principles.Results show that the alloying ability of 18R is stronger than that of 14H.The reaction energies show that the 14H LPSO phase is more stable than the 18R LPSO.The elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental results.The precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the alloy.After solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,respectively.The elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr alloy.The improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed.
基金supported by the National Natural Science Foundation of China under Grant No.50905042the Shenzhen Special Funds for Overseas High-level Talents(No. KQC201109020053A)+1 种基金Shenzhen Technological Innovation Project (No.CXZZ20120829103358067)the Shenzhen Special Funds for Strategic Emerging Industries(No.JCYJ20120613140542764)
文摘In this study, shear tests have been performed on the as-reflowed Sn3.5Ag solder bumps and joints to investigate the deformation behavior of Sn3.5Ag lead-free solder samples. Scanning electron microscopy （SEM） was employed to characterize the microstructures of the samples and orientation imaging microscopy （OIM） with electron backscattered diffraction （EBSD） in SEM was used to obtain crystallographic orientation of grains to provide a detailed characterization of the deformation behavior in Sn3.5Ag solder samples after shear tests. The deformation behavior in solder samples under shear stress was discussed. The experimental results suggest that the dynamic recrystallization could occur under shear stress at room temperature and recrystallized grains should evolve from subgrains by rotation. Compared with that of non-recrystallized and as-reflowed microstructures, the microhardness of the recrystallized microstructure decreased after shear tests.
基金Supported by the National Natural Science Foundation of China (No. 41620104003)the Postgraduate Research and Practice Innovation Program of Jiangsu Province (Nos. SJKY19_0951, KYCX21_0959)
文摘The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense disturbance caused by typhoons.However,these responses have not been thoroughly investigated owing to the complicated marine environment.According to the satellite data,the SCS Basin was observed to have a strong sea surface temperature(SST)response to Typhoon Mangkhut,resulting in widespread SST cooling.A coupled model was used to investigate the atmospheric and oceanic responses to Typhoon Mangkhut.Best-track data,satellite SST,and ARGO measurements show that the coupled WRF-CROCO simulation displays better track,intensity,SST,temperature,and salinity profiles than those of the WRF-only simulation.Results show that the typhoon induced rightward intensifications in wind speed,ocean current,and SST.The following are some remarkable atmosphere and ocean responses:(1)the SST below the inner-core region is cooled by 1℃,resulting in a 37%-44%decrease in wet enthalpy,and the central pressure is increased by~9 hPa.Therefore,the changes in SST below the innercore region of the SCS Basin have a significant impact on air-sea fluxes under high-wind conditions;(2)the ocean boundary layer analysis shows that near-inertial oscillations on the right side of the typhoon track and a strong inertial current up to~2.28 m/s in the upper ocean were observed,which resonated with the local wind and flow field on the right side and induced strong SST cooling;(3)a decrease in SST decreased the moist static energy of the typhoon boundary layer,thereby weakening the typhoon’s intensity.The difference in equivalent potential temperature and sea surface pressure have a good correlation,indicating that the influence of moist static energy on typhoon intensity cannot be overlooked.
基金supported by the National Natural Science Foundation of China(No.72140002,72348001 and 72204137).
文摘The global push for carbon neutrality highlights the need for rigorous assessments of whether national efforts align with stated targets.However,existing evaluations often prioritize commitments over tangible progress,lacking comprehensive and transparent metrics.To bridge this gap,we develop a multidimensional indicator system that evaluates targets,policies,actions,and effectiveness across key areas,including policy implementation,technology deployment,financial investment,and international cooperation.While 151 countries have pledged carbon neutralityd19 of which are developing nations that made commitments in 2024dimplementation remains uneven.Only 72 countries have established complete policy frameworks,and advanced low-carbon technologies are concentrated in a handful of nations.Current trends indicate that global renewable energy capacity will reach just 2.7 times its 2022 level by 2030,falling short of the tripling target.Moreover,the global median action score in 2024 stands at only 25dfar below the target of 65dhighlighting the urgency for stronger efforts.Our findings reveal a significant gap between ambition and action,with renewable energy deployment lagging behind expectations.To accelerate progress,enhanced global cooperation,increased investment,and fewer barriers to technology diffusion are crucial.This study underscores the need for more implementationfocused tracking to ensure carbon neutrality commitments translate into measurable outcomes.
