Three-dimensional ocean subsurface temperature and salinity structures(OST/OSS)in the South China Sea(SCS)play crucial roles in oceanic climate research and disaster mitigation.Traditionally,real-time OST and OSS are ...Three-dimensional ocean subsurface temperature and salinity structures(OST/OSS)in the South China Sea(SCS)play crucial roles in oceanic climate research and disaster mitigation.Traditionally,real-time OST and OSS are mainly obtained through in-situ ocean observations and simulation by ocean circulation models,which are usually challenging and costly.Recently,dynamical,statistical,or machine learning models have been proposed to invert the OST/OSS from sea surface information;however,these models mainly focused on the inversion of monthly OST and OSS.To address this issue,we apply clustering algorithms and employ a stacking strategy to ensemble three models(XGBoost,Random Forest,and LightGBM)to invert the real-time OST/OSS based on satellite-derived data and the Argo dataset.Subsequently,a fusion of temperature and salinity is employed to reconstruct OST and OSS.In the validation dataset,the depth-averaged Correlation(Corr)of the estimated OST(OSS)is 0.919(0.83),and the average Root-Mean-Square Error(RMSE)is0.639°C(0.087 psu),with a depth-averaged coefficient of determination(R~2)of 0.84(0.68).Notably,at the thermocline where the base models exhibit their maximum error,the stacking-based fusion model exhibited significant performance enhancement,with a maximum enhancement in OST and OSS inversion exceeding 10%.We further found that the estimated OST and OSS exhibit good agreement with the HYbrid Coordinate Ocean Model(HYCOM)data and BOA_Argo dataset during the passage of a mesoscale eddy.This study shows that the proposed model can effectively invert the real-time OST and OSS,potentially enhancing the understanding of multi-scale oceanic processes in the SCS.展开更多
Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline.Therefore,it is crucial to quantify the critical condition when fine particle detachment occurs.Th...Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline.Therefore,it is crucial to quantify the critical condition when fine particle detachment occurs.The frequently observed deviations or even contradictions between experimental results and theoretical predictions of fines detachment arise from an insufficient understanding of adhesion force that can be highly influenced by salinity and temperature.To clarify the intrinsic influence of salinity and temperature on fines detachment,adhesion forces between carboxyl microspheres and hydrophilic silica substrates in an aqueous medium were measured at various salinities and tempera-tures using atomic force microscopy(AFM).The AFM-measured adhesion force decreases with increasing salinity or temperature.Trends of mean measured adhesion forces with temperature and salinity were compared with the DLVO and XDLVO theories.DLVO theory captured the trend with temperature via the impact of temperature on electric double layer interactions,whereas XDLVO theory captured the observed trend with salinity via the impact of salinity on the repulsive hydration force.Our results highlight the significance of hydration force in accurately predicting the fate of fines in porous media.展开更多
Over recent decades,increasing anthropogenic activities in the Strait of Georgia(SOG)have heightened the demand for enhanced environmental protection measures.This study presents a novel approach to improve the predic...Over recent decades,increasing anthropogenic activities in the Strait of Georgia(SOG)have heightened the demand for enhanced environmental protection measures.This study presents a novel approach to improve the prediction accuracy of water temperature and salinity dynamics in the strait through advanced machine learning techniques,offering valuable theoretical support for environmental planning,ecosystem management,and sustainable fisheries.We developed an innovative forecasting model by integrating empirical mode decomposition(EMD)with long short-term memory(LSTM)neural networks.The EMD-LSTM model demonstrated exceptional performance,achieving a strong Pearson correlation coefficient(>0.8)with observational data across three monitoring stations.Comparative analysis revealed the model’s superior predictive accuracy and adaptability over conventional backpropagation neural network(BPNN)and standalone LSTM approaches,with its advantages becoming increasingly evident in extended forecasting periods.The integration of time-domain multi-scale analysis with neural network architecture not only improved forecasting precision but also enhanced model interpretability by elucidating the spatial-temporal variations in water temperature and salinity patterns across different monitoring sites.This advanced forecasting framework shows significant potential for supporting high-precision marine environmental predictions in the SOG region,contributing to more effective marine resource management and conservation strategies.展开更多
Recently,allotriploids from Pacific oysters(Crassostrea gigas)and Fujian oysters(C.angulata)have been grown for aquaculture.However,the viability of these allotriploids remains uncertain.In this study,two autotriploid...Recently,allotriploids from Pacific oysters(Crassostrea gigas)and Fujian oysters(C.angulata)have been grown for aquaculture.However,the viability of these allotriploids remains uncertain.In this study,two autotriploids,TGG(diploid C.gigas♀×tetraploid C.gigas♂)and TAA(diploid C.angulata♀×tetraploid C.angulata♂),and two allotriploids,TGA(diploid C.gigas♀×tetraploid C.angulata♂)and TAG(diploid C.angulata♀×tetraploid C.gigas♂),were studied to assess the heterosis in growth and survival at different temperatures and salinities.The results showed that during the larval stage,TAG exhibited increased heterosis in growth and survival when temperature rose.During the adult stage,the growth of TGA significantly outperformed other triploids at higher temperatures(23 and 28℃)and salinities(25 and 30).In contrast,TAG demonstrated the highest survival probability across all conditions except at salinity 25,where it equaled TAA after day 19.The highest oxygen consumption rates(OCR)of TGA and TAG were observed at 23 and 28℃,while the ammonia excretion rate(AER)of TAG was significantly higher than that of TGA at 23℃.These physiological parameters reflect the advantage of TAG in terms of survival.Notably,the temperature coefficient of allotriploids was higher than that of autotriploids in the range of 18–23℃.At 28℃,TAG showed the highest superoxide dismutase(SOD)and catalase(CAT)activities and the lowest malondialdehyde(MDA)content,showing its advantage when encountering high-temperature.展开更多
The inversion of ocean subsurface temperature and salinity(TS)is a hot topic and challenging problem in the oceanic sciences.In this study,a new method for the inversion of underwater TS in the South China Sea is prop...The inversion of ocean subsurface temperature and salinity(TS)is a hot topic and challenging problem in the oceanic sciences.In this study,a new method for the inversion of underwater TS in the South China Sea is proposed based on an improved generative adversarial network(GAN).The proposed model can derive the underwater TS from sea surface data(specifically,sea surface temperature and the sea surface height anomalies)with an eddy-resolving horizontal resolution of(1/12)°.For comparison,a robust statistics-based model,the Modular Ocean Data Assimilation System(MODAS),is also used to invert the subsurface TS in this study.Results show that the root-mean-square errors(RMSEs)of the TS inversions from the GAN-based model are significantly smaller than those from MODAS,especially in the thermocline of the South China Sea,where the RMSE of temperature can be reduced by up to 21.7%and the subsurface salinity RMSE is smaller than 0.32.In particular,the inversion results obtained using the proposed model are more accurate in either the seasonalscale or the synoptic-scale analysis.Firstly,the GAN-based model is more effective for the seasonal-scale extraction and diagnosis of the subsurface stratification,especially in the Luzon Strait and coastal shelf sea areas,in which stronger nonlinearities arise from the Kuroshio intrusion or complex coastal processes dominate the ocean subsurface dynamics.Secondly,the vertical heat pump and cold suction effects in the ocean's upper layers induced by the passage of a typhoon can be reflected more reasonably based on the synoptic-scale analysis with the proposed model.Furthermore,the underwater 3D structure of mesoscale eddies can be skillfully captured by AIGAN(Attention and Inception GAN),which can extract more refined eddy patterns with stronger recognition capability compared with the statistics-based MODAS.The present study can be extended to further explore the subsurface characteristics of the internal variability in the South China Sea.展开更多
High-temperature and high-salt reservoirs are often accompanied by serious gas channeling in gas flooding,which will greatly affect the effect of gas injection development,so in-situ foaming of temperature-resistant a...High-temperature and high-salt reservoirs are often accompanied by serious gas channeling in gas flooding,which will greatly affect the effect of gas injection development,so in-situ foaming of temperature-resistant and salt-resistant foaming agents is commonly used to control gas channeling.The feasibility of the compound system of dodecyl hydroxyl sulfobetaine(HSB12)andα-olefin sulfonate(AOS)as foaming agent for sandstone reservoir was studied at 130℃and 22×10^(4)mg/L.The results showed that the foaming agent(HSB12 and AOS were compounded in a 6:1 mass ratio,in this article,this foaming agent is simply referred to as SA61)had good solubility in 22×10^(4)mg/L simulated formation water.Besides,the foaming volume of SA61 and HSB12 was similar,but the foam decay half-life of SA61was 10-25 times higher than that of HSB12.The foaming performance of SA61 on the surface of quartz sand remained above 90%of that before adsorption.The strong interaction between HSB12 and AOS in the compound system SA61 was demonstrated by surface rheological measurements and NMR studies of surfactants.The results of co re flow test showed that SA61 had better mobility control ability than HSB12under the same surfactant concentration.In addition,SA61 showed a selective mobility reduction in2005.30 and 632.00 mD cores.The above research results can guide the selection and application of foaming agent in clastic reservoir.展开更多
Clay swelling and fines migration pose significant challenges to thermally enhanced oil recovery(EOR)operations,particularly in clay-rich formations.This study systematically investigates clay swelling behavior and pe...Clay swelling and fines migration pose significant challenges to thermally enhanced oil recovery(EOR)operations,particularly in clay-rich formations.This study systematically investigates clay swelling behavior and permeability impairment under high-temperature,low-salinity(HTLS) conditions and evaluates various inhibition methods to mitigate formation damage.To ensure realistic analysis,data and materials from a field with similar issues in Kazakhstan were used.Static/dynamic swelling tests demonstrated that a quaternary ammonium-based inhibitor consistently provided superior clay stabilization through effective ion exchange and surface charge modification mechanisms.In distilled water at 100℃,inhibitor-treated samples maintained 48.89 % of their original permeability,while untreated samples exhibited severe damage,retaining only 17.05 %.Additionally,this chemical inhibitor significantly lowered the critical salt concentration(CSC),effectively stabilizing clay at 4920 ppm salinity compared to 7380 ppm required without treatment.Scanning electron microscopy(SEM) imaging corroborated these results,revealing that inhibitor-treated clay maintains a compact and coherent structure,in stark contrast to the pronounced swelling,delamination,and structural deterioration observed in untreated clay samples.Nevertheless,this quaternary ammonium-based clay stabilizer presents a robust and promising solution for reducing clay swelling-induced damage,sustaining reservoir permeability,and improving thermal EOR performance in swelling-prone formations.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climb...Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climbing,the heat left her drenched in sweat,making her feel very cold.By midday,the temperature was approaching 20℃,and her heavy jacket had to be tied around her waist,becoming a burden during her hike.This outdoor adventure allowed her to appreciate the beautiful scenery,but also subjected her to repeated changes in temperature.展开更多
In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperat...In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.展开更多
Global warming induced by increased CO_(2) has caused marked changes in the ocean.Previous estimates of ocean salinity change in response to global warming have considerable ambiguity,largely attributable to the diver...Global warming induced by increased CO_(2) has caused marked changes in the ocean.Previous estimates of ocean salinity change in response to global warming have considerable ambiguity,largely attributable to the diverse sensitivities of surface fluxes.This study utilizes data from the Flux-Anomaly-Forced Model Intercomparison Project to investigate how ocean salinity responds to perturbations of surface fluxes.The findings indicate the emergence of a sea surface salinity(SSS)dipole pattern predominantly in the North Atlantic and Pacific fresh pools,driven by surface flux perturbations.This results in an intensification of the“salty gets saltier and fresh gets fresher”SSS pattern across the global ocean.The spatial pattern amplification(PA)of SSS under global warming is estimated to be approximately 11.5%,with surface water flux perturbations being the most significant contributor to salinity PA,accounting for 8.1% of the change after 70 years in experiments since pre-industrial control(piControl).Notably,the zonal-depth distribution of salinity in the upper ocean exhibits lighter seawater above the denser water,with bowed isopycnals in the upper 400 m.This stable stratification inhibits vertical mixing of salinity and temperature.In response to the flux perturbations,there is a strong positive feedback due to consequent freshening.It is hypothesized that under global warming,an SSS amplification of 7.2%/℃ and a mixed-layer depth amplification of 12.5%/℃ will occur in the global ocean.It suggests that the salinity effect can exert a more stable ocean to hinder the downward transfer of heat,which provides positive feedback to future global warming.展开更多
The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of i...The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of its influence on fluid migration are of crucial importance.While previous studies have revealed that salinity changes can modulate fluid migration,the underlying mechanisms remain poorly understood.We employ molecular dynamics simulations to elucidate how salinity variations in ore-forming fluids modulate the adsorption onto calcite nanopore walls,thereby revealing the microscopic mechanisms governing ore fluid transport through calcite nano-fractures.The results show that the adsorption energy Eint of the solution on the calcite surface increased from -14,948.84±182.48 kcal/mol to -12,144.08±118.2 kcal/mol as salinity increased,which is conducive to the long-range transport of the fluid in the calcite nanopore.展开更多
Spikelet filling characteristics in early-season rice in southern China may be distinctive due to its exposure to high temperatures during the ripening period.However,limited information is currently available on thes...Spikelet filling characteristics in early-season rice in southern China may be distinctive due to its exposure to high temperatures during the ripening period.However,limited information is currently available on these characteristics.This study aimed to characterize spikelet filling in early-season rice and identify the key factors contributing to its improvement.Field experiments were conducted over two years(2021 and 2022)to mainly investigate the proportions of fully-filled,partially-filled,and empty spikelets,along with the biomass-fertilized spikelet ratio and harvest index,in 11 early-season rice varieties.The results revealed significant varietal variation in spikelet filling,with the proportion of fully-filled spikelets ranging from 60.6%to 81.1%in 2021 and from 66.3%to 79.2%in 2022.Among the 11 varieties,Liangyou 42,Lingliangyou 942,and Liangyou 287 exhibited relatively superior performance in spikelet filling.Linear regression revealed that,although a significant negative relationship existed between the proportion of fully-filled spikelets and both partially-filled and empty spikelets,the relationship with partially-filled spikelets was stronger.Additionally,the proportion of fully-filled spikelets showed a significant positive relationship with the harvest index but not with the biomass-fertilized spikelet ratio.These findings indicate that increasing the harvest index and reducing the occurrence of partially-filled grains are essential strategies for improving spikelet filling in early-season rice.展开更多
Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low ...Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low concentrations becomes critical for both environmental monitoring and human health. In this study, a novel Eu/Ce-codoped MOF-ZnO gas sensor was developed for the sensitive detection of n-butanol gas under ultraviolet activation at ambient temperature. A series of Eu/Ce-ZnO nanomaterials were synthesized via a simple co-precipitation route, by carefully designing the varied mass ratios of Eu and Ce incorporated into pristine ZnO derived from MOF precursors. The gas testing results revealed that introducing an appropriate amount of Eu and Ce would enlarge the specific surface area and enrich the oxygen vacancy content compared to pristine MOF-ZnO. Upon UV irradiation, the 0.03 wt% Eu 0.04 wt% Ce-ZnO sensor achieved a superior response of 611 for100 ppm n-butanol at room temperature, 15.28 times higher than that of pristine MOF-ZnO(40). Furthermore, the sensor presented rapid response/recovery times(15 s/28 s) and excellent selectivity. The above contributions pave the way for the promising development of highly sensitive, ultraviolet-enhanced gas sensors for ambient temperature detection of VOCs.展开更多
When the operating temperature of a solid oxide electrolysis cell(SOEC)is lower than the outlet temperature of a nuclear reactor,the reactor can be directly coupled with the SOEC as a high-temperature heat source.Howe...When the operating temperature of a solid oxide electrolysis cell(SOEC)is lower than the outlet temperature of a nuclear reactor,the reactor can be directly coupled with the SOEC as a high-temperature heat source.However,the key to the efficiency and return on investment of this hybrid energy system lies in the expected lifetime of the SOEC.This study assessed Ni-YSZ|YSZ|GDC|LSC fuel electrode support cells’long-term stability during electrolysis at 650℃with a current density of−0.5Acm^(−2)over 1818 h.The average voltage degradation rate of 2.63%kh^(−1)unfolded in two phases:an initial rapid decay(90 to 1120 h at 3.58%kh^(−1))and a stable decay(1120 to 1818 h at 2.14%kh^(−1)),emphasizing SOECs’probability coupling with nuclear reactors at 650℃.Post-1818-hour electrolysis revealed nickel particle formation associated with Ni(OH)_(x)diffusion and re-deposition,alongside a strontium-containing layer causing interface cracking.Despite minimal strontium segregation in the EDS,XPS data indicated surface segregation of Sr.This study provides crucial insights into prolonged SOEC operation,highlighting both its potential and challenges.展开更多
Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.Thi...Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.This viewpoint discusses a recent measurement of the QGP temperature at different stages at the Solenoidal Tracker at RHIC(STAR),which used e^(+)e^(-)pairs as penetrating probes.展开更多
Root-zone temperature(RZT)strongly affects plant growth,nutrient uptake and tolerance to environmental stress,making its regulation a key challenge in greenhouse cultivation in cold climates.This study aimed to assess...Root-zone temperature(RZT)strongly affects plant growth,nutrient uptake and tolerance to environmental stress,making its regulation a key challenge in greenhouse cultivation in cold climates.This study aimed to assess the potential of passive techniques,namely black polyethylene mulch and row covers,for modifying RZT dynamics in lettuce(Lactuca sativa L.)production and to evaluate the predictive performance of the eXtreme Gradient Boosting(XGBoost)algorithm.Experiments were conducted in Iğdır,Türkiye,over a 61-day period,with soil temperature continuously monitored at depths of 1-30 cm under mulched and non-mulched conditions,alongside measurements of greenhouse air temperature both with and without row covers.The application of row covers increased internal air temperature by 5.8℃,while mulching raised RZT by 0.6-1.3℃,with effects diminishing at deeper layers.XGBoost modeling achieved high predictive accuracy,with RMSE values of 0.150-0.189◦C and R^(2)values above 0.99,and feature-importance analysis indicated that neighboring soil depths were the strongest predictors of RZT.These findings show that integrating row covers and mulching can stabilize the root-zone microclimate without active heating.The XGBoost model provides a robust tool for forecasting soil temperature and supports sustainable greenhouse production in cold regions.展开更多
The glass transition temperature(T_(g))of styrene-butadiene rubber(SBR)is a key parameter determining its low-temperature flexibility and processing performance.Accurate prediction of T_(g)is crucial formaterial desig...The glass transition temperature(T_(g))of styrene-butadiene rubber(SBR)is a key parameter determining its low-temperature flexibility and processing performance.Accurate prediction of T_(g)is crucial formaterial design and application optimisation.Addressing the limitations of traditional experimental measurements and theoretical models in terms of efficiency,cost,and accuracy,this study proposes a machine learning prediction framework that integrates multi-model ensemble and Bayesian optimization by constructing a multi-component feature dataset and algorithm optimization strategy.Based on the constructed high-quality dataset containing 96 SBR samples,ninemachine learning models were employed to predict the T_(g)of SBR and compare their prediction performance.Ultimately,aGPR-XGBoost mixed model was constructed through model ensemble,achieving high-precision prediction with R^(2)values greater than 0.9 on both the training and test sets.Further feature attribution and local effect analysis were conducted using feature analysis methods such as SHAP and ALE,revealing the nonlinear influence patterns of various components on T_(g),providing a theoretical basis for SBR formulation design and T_(g)regulation.The machine learning prediction framework established in this study combines high-precision prediction with interpretability,significantly enhancing the prediction performance of the T_(g)of SBR.It offers an efficient tool for SBR molecular design and holds great potential for promotion and application.展开更多
This study presents a numerical investigation of the transient relaxation dynamics of a near-critical CO_(2)droplet immersed in a warmer supercritical environment composed of the same fluid.Three thermodynamic regimes...This study presents a numerical investigation of the transient relaxation dynamics of a near-critical CO_(2)droplet immersed in a warmer supercritical environment composed of the same fluid.Three thermodynamic regimes were analysed:quasi-critical(T_(r)=1.01,P_(r)=1.01),transitional(T_(r)=2.01,P_(r)=1.01),and deep supercritical(T_(r)=5.01,P_(r)=3.01).Theevolution of density,temperature,and velocity fieldswas examined to characterize the internal structure and stability of the interfacial transition layer.The evolution of density,temperature,and velocity fields highlights the competition between thermal diffusion,compressibility,andmass confinement in shaping the stability of the interfacial transition layer.Near the critical point,strong gradients and flux discontinuities emerge,consistent with known instabilities,whereas higher reduced conditions promote homogenization and stabilized transport.In the deep supercritical regime,smooth and nearly uniform fields indicate robust thermal stability.The model is validated against prior studies on droplet evaporation under supercritical and trans-critical conditions.Beyond theoretical insights,the results underline practical implications for advanced propulsion,heat transfer,and evaporation systems as well as for safe CO_(2)supercritical storage and extraction processes in energy,aerospace,pharmaceutical,and materials industries.展开更多
For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism resp...For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism responsible is unclear.In this study,‘Hongzaosu’pear(Pyrus pyrifolia×Pyrus communis)fruit were treated with a low nighttime temperature(LNT,16℃)or a warm nighttime temperature(WNT,26℃),with sampling conducted within two diurnal cycles.The results showed that LNT promoted anthocyanin accumulation in the fruit skin.The structural anthocyanin biosynthetic genes PpCHS,PpF3H,and PpUFGT exhibited a rhythmic increase in expression at night under LNT.To examine the underlying mechanism,RNA sequencing was conducted using pear calli exposed to LNT and WNT for different durations(24,48,72,or 96 h).Transcriptome analysis revealed 285 differentially expressed genes(DEGs)common to all pairwise comparisons of LNT-and WNT-treated calli of‘Clapp's Favorite’(P.communis)at the sampling time points.KEGG pathway and gene ontology enrichment analyses indicated that the common DEGs were enriched in secondary metabolic processes and phenylpropanoid metabolic processes,which are associated with anthocyanin biosynthesis.The transcription factor PpCDF5,which was responsive to LNT,was selected for further study.Dual-luciferase assays showed that PpCDF5 activated the transcription of anthocyanin biosynthetic genes PpMYB10,PpCHS,PpF3H,PpDFR,PpANS,and PpUFGT.The yeast one-hybrid and EMSA assays demonstrated that PpCDF5 directly binds to the PpF3H promoter,which contains an AAAG motif.Overexpression of PpCDF5 in pear calli and transient overexpression in pear fruit both increased anthocyanin accumulation.The results indicate that PpCDF5 is involved in LNT-induced anthocyanin biosynthesis in pear fruit and provide insights into the molecular regulation of commercial fruit coloration.展开更多
基金jointly supported by the National Key Research and Development Program of China(2022YFC3104304)the National Natural Science Foundation of China(Grant No.41876011)+1 种基金the 2022 Research Program of Sanya Yazhou Bay Science and Technology City(SKJC-2022-01-001)the Hainan Province Science and Technology Special Fund(ZDYF2021SHFZ265)。
文摘Three-dimensional ocean subsurface temperature and salinity structures(OST/OSS)in the South China Sea(SCS)play crucial roles in oceanic climate research and disaster mitigation.Traditionally,real-time OST and OSS are mainly obtained through in-situ ocean observations and simulation by ocean circulation models,which are usually challenging and costly.Recently,dynamical,statistical,or machine learning models have been proposed to invert the OST/OSS from sea surface information;however,these models mainly focused on the inversion of monthly OST and OSS.To address this issue,we apply clustering algorithms and employ a stacking strategy to ensemble three models(XGBoost,Random Forest,and LightGBM)to invert the real-time OST/OSS based on satellite-derived data and the Argo dataset.Subsequently,a fusion of temperature and salinity is employed to reconstruct OST and OSS.In the validation dataset,the depth-averaged Correlation(Corr)of the estimated OST(OSS)is 0.919(0.83),and the average Root-Mean-Square Error(RMSE)is0.639°C(0.087 psu),with a depth-averaged coefficient of determination(R~2)of 0.84(0.68).Notably,at the thermocline where the base models exhibit their maximum error,the stacking-based fusion model exhibited significant performance enhancement,with a maximum enhancement in OST and OSS inversion exceeding 10%.We further found that the estimated OST and OSS exhibit good agreement with the HYbrid Coordinate Ocean Model(HYCOM)data and BOA_Argo dataset during the passage of a mesoscale eddy.This study shows that the proposed model can effectively invert the real-time OST and OSS,potentially enhancing the understanding of multi-scale oceanic processes in the SCS.
基金supports from the National Natural Science Foundation of China(Grant No.52474059,Grant No.52174046)are greatly acknowledged.
文摘Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline.Therefore,it is crucial to quantify the critical condition when fine particle detachment occurs.The frequently observed deviations or even contradictions between experimental results and theoretical predictions of fines detachment arise from an insufficient understanding of adhesion force that can be highly influenced by salinity and temperature.To clarify the intrinsic influence of salinity and temperature on fines detachment,adhesion forces between carboxyl microspheres and hydrophilic silica substrates in an aqueous medium were measured at various salinities and tempera-tures using atomic force microscopy(AFM).The AFM-measured adhesion force decreases with increasing salinity or temperature.Trends of mean measured adhesion forces with temperature and salinity were compared with the DLVO and XDLVO theories.DLVO theory captured the trend with temperature via the impact of temperature on electric double layer interactions,whereas XDLVO theory captured the observed trend with salinity via the impact of salinity on the repulsive hydration force.Our results highlight the significance of hydration force in accurately predicting the fate of fines in porous media.
基金The National Natural Science Foundation of China under contract Nos 52239005,52322109 and U22A2012the R&D Program of Guangdong Provincial Department of Science and Technology under contract No.2024B1212040004.
文摘Over recent decades,increasing anthropogenic activities in the Strait of Georgia(SOG)have heightened the demand for enhanced environmental protection measures.This study presents a novel approach to improve the prediction accuracy of water temperature and salinity dynamics in the strait through advanced machine learning techniques,offering valuable theoretical support for environmental planning,ecosystem management,and sustainable fisheries.We developed an innovative forecasting model by integrating empirical mode decomposition(EMD)with long short-term memory(LSTM)neural networks.The EMD-LSTM model demonstrated exceptional performance,achieving a strong Pearson correlation coefficient(>0.8)with observational data across three monitoring stations.Comparative analysis revealed the model’s superior predictive accuracy and adaptability over conventional backpropagation neural network(BPNN)and standalone LSTM approaches,with its advantages becoming increasingly evident in extended forecasting periods.The integration of time-domain multi-scale analysis with neural network architecture not only improved forecasting precision but also enhanced model interpretability by elucidating the spatial-temporal variations in water temperature and salinity patterns across different monitoring sites.This advanced forecasting framework shows significant potential for supporting high-precision marine environmental predictions in the SOG region,contributing to more effective marine resource management and conservation strategies.
基金grants from the National Key R&D Program of China(No.2022YFD2400305)the Excellent Seed Project of Shandong Province(No.2022LZGCQY010)+1 种基金the Science and Technology Program of Fujian Province(No.2024N3003)the Research on Breeding Technology of Candidate Species for Guangdong Modern Marine Ranching(No.2024-MRB00-001)。
文摘Recently,allotriploids from Pacific oysters(Crassostrea gigas)and Fujian oysters(C.angulata)have been grown for aquaculture.However,the viability of these allotriploids remains uncertain.In this study,two autotriploids,TGG(diploid C.gigas♀×tetraploid C.gigas♂)and TAA(diploid C.angulata♀×tetraploid C.angulata♂),and two allotriploids,TGA(diploid C.gigas♀×tetraploid C.angulata♂)and TAG(diploid C.angulata♀×tetraploid C.gigas♂),were studied to assess the heterosis in growth and survival at different temperatures and salinities.The results showed that during the larval stage,TAG exhibited increased heterosis in growth and survival when temperature rose.During the adult stage,the growth of TGA significantly outperformed other triploids at higher temperatures(23 and 28℃)and salinities(25 and 30).In contrast,TAG demonstrated the highest survival probability across all conditions except at salinity 25,where it equaled TAA after day 19.The highest oxygen consumption rates(OCR)of TGA and TAG were observed at 23 and 28℃,while the ammonia excretion rate(AER)of TAG was significantly higher than that of TGA at 23℃.These physiological parameters reflect the advantage of TAG in terms of survival.Notably,the temperature coefficient of allotriploids was higher than that of autotriploids in the range of 18–23℃.At 28℃,TAG showed the highest superoxide dismutase(SOD)and catalase(CAT)activities and the lowest malondialdehyde(MDA)content,showing its advantage when encountering high-temperature.
基金supported by the National Research and Development Program of China(Grant No.2021YFC2803003)the National Natural Science Foundation of China(Grant No.42375143)。
文摘The inversion of ocean subsurface temperature and salinity(TS)is a hot topic and challenging problem in the oceanic sciences.In this study,a new method for the inversion of underwater TS in the South China Sea is proposed based on an improved generative adversarial network(GAN).The proposed model can derive the underwater TS from sea surface data(specifically,sea surface temperature and the sea surface height anomalies)with an eddy-resolving horizontal resolution of(1/12)°.For comparison,a robust statistics-based model,the Modular Ocean Data Assimilation System(MODAS),is also used to invert the subsurface TS in this study.Results show that the root-mean-square errors(RMSEs)of the TS inversions from the GAN-based model are significantly smaller than those from MODAS,especially in the thermocline of the South China Sea,where the RMSE of temperature can be reduced by up to 21.7%and the subsurface salinity RMSE is smaller than 0.32.In particular,the inversion results obtained using the proposed model are more accurate in either the seasonalscale or the synoptic-scale analysis.Firstly,the GAN-based model is more effective for the seasonal-scale extraction and diagnosis of the subsurface stratification,especially in the Luzon Strait and coastal shelf sea areas,in which stronger nonlinearities arise from the Kuroshio intrusion or complex coastal processes dominate the ocean subsurface dynamics.Secondly,the vertical heat pump and cold suction effects in the ocean's upper layers induced by the passage of a typhoon can be reflected more reasonably based on the synoptic-scale analysis with the proposed model.Furthermore,the underwater 3D structure of mesoscale eddies can be skillfully captured by AIGAN(Attention and Inception GAN),which can extract more refined eddy patterns with stronger recognition capability compared with the statistics-based MODAS.The present study can be extended to further explore the subsurface characteristics of the internal variability in the South China Sea.
基金financial support from the Major Scientific and Technological Projects of CNPC(Award No.ZD2019-183-007)。
文摘High-temperature and high-salt reservoirs are often accompanied by serious gas channeling in gas flooding,which will greatly affect the effect of gas injection development,so in-situ foaming of temperature-resistant and salt-resistant foaming agents is commonly used to control gas channeling.The feasibility of the compound system of dodecyl hydroxyl sulfobetaine(HSB12)andα-olefin sulfonate(AOS)as foaming agent for sandstone reservoir was studied at 130℃and 22×10^(4)mg/L.The results showed that the foaming agent(HSB12 and AOS were compounded in a 6:1 mass ratio,in this article,this foaming agent is simply referred to as SA61)had good solubility in 22×10^(4)mg/L simulated formation water.Besides,the foaming volume of SA61 and HSB12 was similar,but the foam decay half-life of SA61was 10-25 times higher than that of HSB12.The foaming performance of SA61 on the surface of quartz sand remained above 90%of that before adsorption.The strong interaction between HSB12 and AOS in the compound system SA61 was demonstrated by surface rheological measurements and NMR studies of surfactants.The results of co re flow test showed that SA61 had better mobility control ability than HSB12under the same surfactant concentration.In addition,SA61 showed a selective mobility reduction in2005.30 and 632.00 mD cores.The above research results can guide the selection and application of foaming agent in clastic reservoir.
文摘Clay swelling and fines migration pose significant challenges to thermally enhanced oil recovery(EOR)operations,particularly in clay-rich formations.This study systematically investigates clay swelling behavior and permeability impairment under high-temperature,low-salinity(HTLS) conditions and evaluates various inhibition methods to mitigate formation damage.To ensure realistic analysis,data and materials from a field with similar issues in Kazakhstan were used.Static/dynamic swelling tests demonstrated that a quaternary ammonium-based inhibitor consistently provided superior clay stabilization through effective ion exchange and surface charge modification mechanisms.In distilled water at 100℃,inhibitor-treated samples maintained 48.89 % of their original permeability,while untreated samples exhibited severe damage,retaining only 17.05 %.Additionally,this chemical inhibitor significantly lowered the critical salt concentration(CSC),effectively stabilizing clay at 4920 ppm salinity compared to 7380 ppm required without treatment.Scanning electron microscopy(SEM) imaging corroborated these results,revealing that inhibitor-treated clay maintains a compact and coherent structure,in stark contrast to the pronounced swelling,delamination,and structural deterioration observed in untreated clay samples.Nevertheless,this quaternary ammonium-based clay stabilizer presents a robust and promising solution for reducing clay swelling-induced damage,sustaining reservoir permeability,and improving thermal EOR performance in swelling-prone formations.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
文摘Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climbing,the heat left her drenched in sweat,making her feel very cold.By midday,the temperature was approaching 20℃,and her heavy jacket had to be tied around her waist,becoming a burden during her hike.This outdoor adventure allowed her to appreciate the beautiful scenery,but also subjected her to repeated changes in temperature.
基金supported by the National Natural Science Foundation of China (Grant Nos.12074213 and 11574108)the Major Basic Program of Natural Science Foundation of Shandong Province (Grant No.ZR2021ZD01)the Natural Science Foundation of Shandong Province (Grant No.ZR2023MA082)。
文摘In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.
基金supported by the Laoshan Laboratory[grant number LSKJ202202403]the National Natural Science Foundation of China[grant number 42030410]+1 种基金additionally supported by the Startup Foundation for Introducing Talent of NUISTJiangsu Innovation Research Group[grant number JSSCTD202346]。
文摘Global warming induced by increased CO_(2) has caused marked changes in the ocean.Previous estimates of ocean salinity change in response to global warming have considerable ambiguity,largely attributable to the diverse sensitivities of surface fluxes.This study utilizes data from the Flux-Anomaly-Forced Model Intercomparison Project to investigate how ocean salinity responds to perturbations of surface fluxes.The findings indicate the emergence of a sea surface salinity(SSS)dipole pattern predominantly in the North Atlantic and Pacific fresh pools,driven by surface flux perturbations.This results in an intensification of the“salty gets saltier and fresh gets fresher”SSS pattern across the global ocean.The spatial pattern amplification(PA)of SSS under global warming is estimated to be approximately 11.5%,with surface water flux perturbations being the most significant contributor to salinity PA,accounting for 8.1% of the change after 70 years in experiments since pre-industrial control(piControl).Notably,the zonal-depth distribution of salinity in the upper ocean exhibits lighter seawater above the denser water,with bowed isopycnals in the upper 400 m.This stable stratification inhibits vertical mixing of salinity and temperature.In response to the flux perturbations,there is a strong positive feedback due to consequent freshening.It is hypothesized that under global warming,an SSS amplification of 7.2%/℃ and a mixed-layer depth amplification of 12.5%/℃ will occur in the global ocean.It suggests that the salinity effect can exert a more stable ocean to hinder the downward transfer of heat,which provides positive feedback to future global warming.
基金financed jointly by the National Major Science and Technology Special Project on Deep Earth Exploration(2024ZD1001701-5)the National Natural Science Foundation of China(42472127,42172086)+2 种基金the Yunnan Major Project of Basic Research(202401BN070001-002)Yunnan Mineral Resources Prediction and Evaluation Engineering Research Center(2011)Innovation Team Program of Kunming University of Science and Technology,Yunnan Province。
文摘The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of its influence on fluid migration are of crucial importance.While previous studies have revealed that salinity changes can modulate fluid migration,the underlying mechanisms remain poorly understood.We employ molecular dynamics simulations to elucidate how salinity variations in ore-forming fluids modulate the adsorption onto calcite nanopore walls,thereby revealing the microscopic mechanisms governing ore fluid transport through calcite nano-fractures.The results show that the adsorption energy Eint of the solution on the calcite surface increased from -14,948.84±182.48 kcal/mol to -12,144.08±118.2 kcal/mol as salinity increased,which is conducive to the long-range transport of the fluid in the calcite nanopore.
基金funded by the Earmarked Fund for China Agriculture Research System,grant number CARS-01-33.
文摘Spikelet filling characteristics in early-season rice in southern China may be distinctive due to its exposure to high temperatures during the ripening period.However,limited information is currently available on these characteristics.This study aimed to characterize spikelet filling in early-season rice and identify the key factors contributing to its improvement.Field experiments were conducted over two years(2021 and 2022)to mainly investigate the proportions of fully-filled,partially-filled,and empty spikelets,along with the biomass-fertilized spikelet ratio and harvest index,in 11 early-season rice varieties.The results revealed significant varietal variation in spikelet filling,with the proportion of fully-filled spikelets ranging from 60.6%to 81.1%in 2021 and from 66.3%to 79.2%in 2022.Among the 11 varieties,Liangyou 42,Lingliangyou 942,and Liangyou 287 exhibited relatively superior performance in spikelet filling.Linear regression revealed that,although a significant negative relationship existed between the proportion of fully-filled spikelets and both partially-filled and empty spikelets,the relationship with partially-filled spikelets was stronger.Additionally,the proportion of fully-filled spikelets showed a significant positive relationship with the harvest index but not with the biomass-fertilized spikelet ratio.These findings indicate that increasing the harvest index and reducing the occurrence of partially-filled grains are essential strategies for improving spikelet filling in early-season rice.
基金supported by the National Natural Science Foundation of China (Grant No. 12304467)the China Postdoctoral Science Foundation (Grant No. 2023M732175)。
文摘Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low concentrations becomes critical for both environmental monitoring and human health. In this study, a novel Eu/Ce-codoped MOF-ZnO gas sensor was developed for the sensitive detection of n-butanol gas under ultraviolet activation at ambient temperature. A series of Eu/Ce-ZnO nanomaterials were synthesized via a simple co-precipitation route, by carefully designing the varied mass ratios of Eu and Ce incorporated into pristine ZnO derived from MOF precursors. The gas testing results revealed that introducing an appropriate amount of Eu and Ce would enlarge the specific surface area and enrich the oxygen vacancy content compared to pristine MOF-ZnO. Upon UV irradiation, the 0.03 wt% Eu 0.04 wt% Ce-ZnO sensor achieved a superior response of 611 for100 ppm n-butanol at room temperature, 15.28 times higher than that of pristine MOF-ZnO(40). Furthermore, the sensor presented rapid response/recovery times(15 s/28 s) and excellent selectivity. The above contributions pave the way for the promising development of highly sensitive, ultraviolet-enhanced gas sensors for ambient temperature detection of VOCs.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0400000),the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2021253)+1 种基金the Major Science and Technology Projects of China National Offshore Oil Corporation Limited during the 14th Five Year Plan(No.KJGG-2022-12-CCUS-030500)the Photon Science Center for Carbon Neutrality of Chinese Academy of Science.
文摘When the operating temperature of a solid oxide electrolysis cell(SOEC)is lower than the outlet temperature of a nuclear reactor,the reactor can be directly coupled with the SOEC as a high-temperature heat source.However,the key to the efficiency and return on investment of this hybrid energy system lies in the expected lifetime of the SOEC.This study assessed Ni-YSZ|YSZ|GDC|LSC fuel electrode support cells’long-term stability during electrolysis at 650℃with a current density of−0.5Acm^(−2)over 1818 h.The average voltage degradation rate of 2.63%kh^(−1)unfolded in two phases:an initial rapid decay(90 to 1120 h at 3.58%kh^(−1))and a stable decay(1120 to 1818 h at 2.14%kh^(−1)),emphasizing SOECs’probability coupling with nuclear reactors at 650℃.Post-1818-hour electrolysis revealed nickel particle formation associated with Ni(OH)_(x)diffusion and re-deposition,alongside a strontium-containing layer causing interface cracking.Despite minimal strontium segregation in the EDS,XPS data indicated surface segregation of Sr.This study provides crucial insights into prolonged SOEC operation,highlighting both its potential and challenges.
文摘Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.This viewpoint discusses a recent measurement of the QGP temperature at different stages at the Solenoidal Tracker at RHIC(STAR),which used e^(+)e^(-)pairs as penetrating probes.
文摘Root-zone temperature(RZT)strongly affects plant growth,nutrient uptake and tolerance to environmental stress,making its regulation a key challenge in greenhouse cultivation in cold climates.This study aimed to assess the potential of passive techniques,namely black polyethylene mulch and row covers,for modifying RZT dynamics in lettuce(Lactuca sativa L.)production and to evaluate the predictive performance of the eXtreme Gradient Boosting(XGBoost)algorithm.Experiments were conducted in Iğdır,Türkiye,over a 61-day period,with soil temperature continuously monitored at depths of 1-30 cm under mulched and non-mulched conditions,alongside measurements of greenhouse air temperature both with and without row covers.The application of row covers increased internal air temperature by 5.8℃,while mulching raised RZT by 0.6-1.3℃,with effects diminishing at deeper layers.XGBoost modeling achieved high predictive accuracy,with RMSE values of 0.150-0.189◦C and R^(2)values above 0.99,and feature-importance analysis indicated that neighboring soil depths were the strongest predictors of RZT.These findings show that integrating row covers and mulching can stabilize the root-zone microclimate without active heating.The XGBoost model provides a robust tool for forecasting soil temperature and supports sustainable greenhouse production in cold regions.
基金supported by the National Natural Science Foundation of China(grant numbers 52250357 and 52203003).
文摘The glass transition temperature(T_(g))of styrene-butadiene rubber(SBR)is a key parameter determining its low-temperature flexibility and processing performance.Accurate prediction of T_(g)is crucial formaterial design and application optimisation.Addressing the limitations of traditional experimental measurements and theoretical models in terms of efficiency,cost,and accuracy,this study proposes a machine learning prediction framework that integrates multi-model ensemble and Bayesian optimization by constructing a multi-component feature dataset and algorithm optimization strategy.Based on the constructed high-quality dataset containing 96 SBR samples,ninemachine learning models were employed to predict the T_(g)of SBR and compare their prediction performance.Ultimately,aGPR-XGBoost mixed model was constructed through model ensemble,achieving high-precision prediction with R^(2)values greater than 0.9 on both the training and test sets.Further feature attribution and local effect analysis were conducted using feature analysis methods such as SHAP and ALE,revealing the nonlinear influence patterns of various components on T_(g),providing a theoretical basis for SBR formulation design and T_(g)regulation.The machine learning prediction framework established in this study combines high-precision prediction with interpretability,significantly enhancing the prediction performance of the T_(g)of SBR.It offers an efficient tool for SBR molecular design and holds great potential for promotion and application.
文摘This study presents a numerical investigation of the transient relaxation dynamics of a near-critical CO_(2)droplet immersed in a warmer supercritical environment composed of the same fluid.Three thermodynamic regimes were analysed:quasi-critical(T_(r)=1.01,P_(r)=1.01),transitional(T_(r)=2.01,P_(r)=1.01),and deep supercritical(T_(r)=5.01,P_(r)=3.01).Theevolution of density,temperature,and velocity fieldswas examined to characterize the internal structure and stability of the interfacial transition layer.The evolution of density,temperature,and velocity fields highlights the competition between thermal diffusion,compressibility,andmass confinement in shaping the stability of the interfacial transition layer.Near the critical point,strong gradients and flux discontinuities emerge,consistent with known instabilities,whereas higher reduced conditions promote homogenization and stabilized transport.In the deep supercritical regime,smooth and nearly uniform fields indicate robust thermal stability.The model is validated against prior studies on droplet evaporation under supercritical and trans-critical conditions.Beyond theoretical insights,the results underline practical implications for advanced propulsion,heat transfer,and evaporation systems as well as for safe CO_(2)supercritical storage and extraction processes in energy,aerospace,pharmaceutical,and materials industries.
基金supported by the National Natural Science Foundation of China(Grant Nos.32072545,32272639 and 32260745)Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LTGN23C150009 and LY22C150003)Zhejiang University Experimental Technology Research Project(Grant No.SYBJS202217).
文摘For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism responsible is unclear.In this study,‘Hongzaosu’pear(Pyrus pyrifolia×Pyrus communis)fruit were treated with a low nighttime temperature(LNT,16℃)or a warm nighttime temperature(WNT,26℃),with sampling conducted within two diurnal cycles.The results showed that LNT promoted anthocyanin accumulation in the fruit skin.The structural anthocyanin biosynthetic genes PpCHS,PpF3H,and PpUFGT exhibited a rhythmic increase in expression at night under LNT.To examine the underlying mechanism,RNA sequencing was conducted using pear calli exposed to LNT and WNT for different durations(24,48,72,or 96 h).Transcriptome analysis revealed 285 differentially expressed genes(DEGs)common to all pairwise comparisons of LNT-and WNT-treated calli of‘Clapp's Favorite’(P.communis)at the sampling time points.KEGG pathway and gene ontology enrichment analyses indicated that the common DEGs were enriched in secondary metabolic processes and phenylpropanoid metabolic processes,which are associated with anthocyanin biosynthesis.The transcription factor PpCDF5,which was responsive to LNT,was selected for further study.Dual-luciferase assays showed that PpCDF5 activated the transcription of anthocyanin biosynthetic genes PpMYB10,PpCHS,PpF3H,PpDFR,PpANS,and PpUFGT.The yeast one-hybrid and EMSA assays demonstrated that PpCDF5 directly binds to the PpF3H promoter,which contains an AAAG motif.Overexpression of PpCDF5 in pear calli and transient overexpression in pear fruit both increased anthocyanin accumulation.The results indicate that PpCDF5 is involved in LNT-induced anthocyanin biosynthesis in pear fruit and provide insights into the molecular regulation of commercial fruit coloration.
