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Photoinhibition and Photoprotection in Ginkgo biloba leaves: Influence of Temperature, CO 2 and O 2 被引量:18
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作者 孟庆伟 Engelbert Weis +1 位作者 邹琦 赵世杰 《Acta Botanica Sinica》 CSCD 1999年第4期398-404,共7页
In midday ginkgo ( Ginkgo biloba L.) leaves have to bear photon flux density over 1400 μmol·m -2 ·s -1 in combination with high temperatures around 35 ℃ at natural habitat. They show typical mi... In midday ginkgo ( Ginkgo biloba L.) leaves have to bear photon flux density over 1400 μmol·m -2 ·s -1 in combination with high temperatures around 35 ℃ at natural habitat. They show typical midday depression of stomatal conductance and of CO 2 assimilation rate. The zeaxanthin changes with light intensity during the day. The influence of the combination of strong light and temperature on photoinhibition was also examined in the laboratory. A low CO 2 internal conductance (31 mmol·m -2 ·s -1 ) was found in ginkgo leaves, which had been exposed to excessive light at temperature between 15 ℃ and 35 ℃ with reduced CO 2 (80 μL·L -1 ) or oxygen (2%) for 2 h, causing a low CO 2 concentration at the carboxylation site and a high proportion of photorespiration. The ratio of electron transport to CO 2 fixation was rather high in ginkgo (16 e -/CO 2 at 25 ℃) as compared with other plants. It increased with temperature also in 2% O 2 which could not be explained solely as due to change of photorespiration. The reduction of oxygen in 340 or 80 μL·L -1 CO 2 had no effect on the extent of photoinhibition at all temperatures, which indicated that electron flow caused by photorespiration in excess light was negligible in protective effect in ginkgo leaves. However, a decreased CO 2 concentration increased photoinhibition, especially at high temperature. It is concluded that the dissipation of excessive excitation energy in the PSⅡ antennae through the xanthophyll cycle may be the major protective mechanism to preventing from the deteriorated effects of strong light in ginkgo leaves. 展开更多
关键词 Photoinhibition and photoprotection Ginkgo biloba PHOTORESPIRATION Xanthophyll cycle High temperature
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A spotlight on dosage and subject selection for effective neuroprotection: exploring the central role of mitochondria
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作者 John Mitrofanis Jonathan Stone +3 位作者 Michael R.Hamblin Pierre Magistretti Alim-Louis Benabid Glen Jeffery 《Neural Regeneration Research》 SCIE CAS 2025年第4期1081-1082,共2页
Neurons are notoriously vulnerable cell types.Even the slightest change in their internal and/or external environments will cause much distress and dysfunction,leading often to their death.A range of pathological cond... Neurons are notoriously vulnerable cell types.Even the slightest change in their internal and/or external environments will cause much distress and dysfunction,leading often to their death.A range of pathological conditions,including stroke,head trauma,and neurodegenerative disease,can generate stress in neurons,affecting their survival and proper function.In most neural pathologies,mitochondria become dysfunctional and this plays a pivotal role in the process of cell death.The challenge over the last few decades has been to develop effective interventions that improve neuronal homeostasis under pathological conditions.Such interventions,often referred to as disease-modifying or neuroprotective,have,however,proved frustratingly elusive,at both preclinical and,in particular,clinical levels.In this perspective,we highlight two factors that we feel are key to the development of effective neuroprotective treatments.These are:firstly,the choice of dose of intervention and method of application,and secondly,the selection of subjects,whether they be patients or the animal model. 展开更多
关键词 protective DOSAGE DISTRESS
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Assessing the corrosion protection property of coatings loaded with corrosion inhibitors using the real-time atmospheric corrosion monitoring technique
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作者 Xiaoxue Wang Lulu Jin +8 位作者 Jinke Wang Rongqiao Wang Xiuchun Liu Kai Gao Jingli Sun Yong Yuan Lingwei Ma Hongchang Qian Dawei Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期119-126,共8页
The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties ... The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating. 展开更多
关键词 atmospheric corrosion monitoring technology corrosion inhibitor COATING carbon steel corrosion protection
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Effects of the extrusion parameters on microstructure,texture and room temperature mechanical properties of extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy
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作者 Chenjin Zhang Guangyu Yang +4 位作者 Lei Xiao Zhiyong Kan Jing Guo Qiang Li Wanqi Jie 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期136-146,共11页
Microstructure,texture,and mechanical properties of the extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy were investigated at different extrusion temperatures(260 and 320℃),extrusion ratios(10:1,15:1,and 30:1),and extrusi... Microstructure,texture,and mechanical properties of the extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy were investigated at different extrusion temperatures(260 and 320℃),extrusion ratios(10:1,15:1,and 30:1),and extrusion speeds(3 and 6 mm/s).The experimental results exhibited that the grain sizes after extrusion were much finer than that of the homogenized alloy,and the second phase showed streamline distribution along the extrusion direction(ED).With extrusion temperature increased from 260 to 320℃,the microstructure,texture,and mechanical properties of alloys changed slightly.The dynamic recrystallization(DRX)degree and grain sizes enhanced as the extrusion ratio increased from 10:1 to 30:1,and the strength gradually decreased but elongation(EL)increased.With the extrusion speed increased from 3 to 6 mm/s,the grain sizes and DRX degree increased significantly,and the samples presented the typical<2111>-<1123>rare-earth(RE)textures.The alloy extruded at 260℃ with extrusion ratio of 10:1 and extrusion speed of 3 mm/s showed the tensile yield strength(TYS)of 213 MPa and EL of 30.6%.After quantitatively analyzing the contribution of strengthening mechanisms,it was found that the grain boundary strengthening and dislocation strengthening played major roles among strengthening contributions.These results provide some guidelines for enlarging the industrial application of extruded Mg-RE alloy. 展开更多
关键词 Mg-rare earth alloys extrusion temperature extrusion ratio extrusion speed strengthening mechanisms
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Ideal Bi‑Based Hybrid Anode Material for Ultrafast Charging of Sodium‑Ion Batteries at Extremely Low Temperatures
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作者 Jie Bai Jian Hui Jia +2 位作者 Yu Wang Chun Cheng Yang Qing Jiang 《Nano-Micro Letters》 SCIE EI CAS 2025年第3期152-167,共16页
Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability o... Sodium-ion batteries have emerged as competitive substitutes for low-temperature applications due to severe capacity loss and safety concerns of lithium-ion batteries at−20°C or lower.However,the key capability of ultrafast charging at ultralow temperature for SIBs is rarely reported.Herein,a hybrid of Bi nanoparticles embedded in carbon nanorods is demonstrated as an ideal material to address this issue,which is synthesized via a high temperature shock method.Such a hybrid shows an unprecedented rate performance(237.9 mAh g^(−1) at 2 A g^(−1))at−60℃,outperforming all reported SIB anode materials.Coupled with a Na_(3)V_(2)(PO_(4))_(3)cathode,the energy density of the full cell can reach to 181.9 Wh kg^(−1) at−40°C.Based on this work,a novel strategy of high-rate activation is proposed to enhance performances of Bi-based materials in cryogenic conditions by creating new active sites for interfacial reaction under large current. 展开更多
关键词 Bi nanoparticles High temperature shock High-rate activation Ultrafast charging Low-temperature sodium-ion batteries
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Novel Methodologies for Preventing Crack Propagation in Steel Gas Pipelines Considering the Temperature Effect
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作者 Nurlan Zhangabay Ulzhan Ibraimova +4 位作者 Marco Bonopera Ulanbator Suleimenov Konstantin Avramov Maryna Chernobryvko Aigerim Yessengali 《Structural Durability & Health Monitoring》 EI 2025年第1期1-23,共23页
Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crac... Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃ to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃ and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines. 展开更多
关键词 Crack propagation finite-element internal pressure PRESTRESSING steel gas pipeline temperature effect
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A PHYB-PIF4-auxin module promotes tomato graft formation in response to elevated ambient temperature
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作者 Xianmin Meng Feng Zhang +1 位作者 Wencai Yang Qingmao Shang 《Horticultural Plant Journal》 2025年第1期227-238,共12页
Grafting is an effective technique for increasing the resistance of vegetables to biotic and abiotic stresses.It has been widely applied to produce solanaceous and melon vegetables.Temperature is an important external... Grafting is an effective technique for increasing the resistance of vegetables to biotic and abiotic stresses.It has been widely applied to produce solanaceous and melon vegetables.Temperature is an important external factor affecting graft formation.However,the molecular mechanism by which external ambient temperature affects tomato graft formation remains unclear.In this study,we demonstrated that elevating ambient temperature during grafting to 35℃ for more than 24 h after grafting accelerated vascular reconnection.We generated self-or heterografted combinations between phyB1B2 and pif4 loss-of-function mutant and wild-type plants,and were mutants unresponsive to graft formation at elevated ambient temperature.In addition,elevated ambient temperature induced SlPIF4 expression during grafting.SlPIF4 directly binds the promoters of auxin biosynthesis genes SlYUCCAs and activates their expression.Further investigation revealed auxin accumulation in the graft junction under elevated ambient temperature.The results illuminate the mechanism by which the PHYB-PIF4-auxin module promotes tomato graft formation in response to elevated ambient temperature. 展开更多
关键词 Graft formation TOMATO temperature Vascular AUXIN
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Subsurface Temperature and Salinity Structures Inversion Using a Stacking-Based Fusion Model from Satellite Observations in the South China Sea
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作者 Can LUO Mengya HUANG +3 位作者 Shoude GUAN Wei ZHAO Fengbin TIAN Yuan YANG 《Advances in Atmospheric Sciences》 2025年第1期204-220,共17页
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
关键词 subsurface temperature and salinity structures clustering algorithms stacking strategy temperature and salinity fusion the South China Sea
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Advancements in implantable temperature sensors:Materials,mechanisms,and biological applications
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作者 Zhuofan Yang Hongcheng Song He Ding 《Journal of Semiconductors》 2025年第1期166-177,共12页
Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics,therapeutics,and life sciences research.This review classifies the materials used in these sensors... Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics,therapeutics,and life sciences research.This review classifies the materials used in these sensors into three categories:metal-based,inorganic semiconductor,and organic semiconductor materials.Metal-based materials are widely used in medical and industrial applications due to their linearity,stability,and reliability.Inorganic semiconductors provide rapid response times and high miniaturization potential,making them promising for biomedical and environmental monitoring.Organic semiconductors offer high sensitivity and ease of processing,enabling the development of flexible and stretchable sensors.This review analyzes recent studies for each material type,covering design principles,performance characteristics,and applications,highlighting key advantages and challenges regarding miniaturization,sensitivity,response time,and biocompatibility.Furthermore,critical performance parameters of implantable temperature sensors based on different material types are summarized,providing valuable references for future sensor design and optimization.The future development of implantable temperature sensors is discussed,focusing on improving biocompatibility,long-term stability,and multifunctional integration.These advancements are expected to expand the application potential of implantable sensors in telemedicine and dynamic physiological monitoring. 展开更多
关键词 IMPLANTABLE temperature sensors biological applications flexible electronics
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An integrated physiology and proteomics analysis reveals the response of wheat grain to low temperature stress during booting
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作者 Anmin Zhang Zihong Li +7 位作者 Qirui Zhou Jiawen Zhao Yan Zhao Mengting Zhao Shangyu Ma Yonghui Fan Zhenglai Huang Wenjing Zhang 《Journal of Integrative Agriculture》 2025年第1期114-131,共18页
Low temperature(LT)in spring has become one of the principal abiotic stresses that restrict the growth and development of wheat.Diverse analyses were performed to investigate the mechanism underlying the response of w... Low temperature(LT)in spring has become one of the principal abiotic stresses that restrict the growth and development of wheat.Diverse analyses were performed to investigate the mechanism underlying the response of wheat grain development to LT stress during booting.These included morphological observation,measurements of starch synthase activity,and determination of amylose and amylopectin content of wheat grain after exposure to treatment with LT during booting.Additionally,proteomic analysis was performed using tandem mass tags(TMT).Results showed that the plumpness of wheat grains decreased after LT stress.Moreover,the activities of sucrose synthase(SuS,EC 2.4.1.13)and ADP-glucose pyrophosphorylase(AGPase,EC 2.7.7.27)exhibited a significant reduction,leading to a significant reduction in the contents of amylose and amylopectin.A total of 509 differentially expressed proteins(DEPs)were identified by proteomics analysis.The Gene Ontology(GO)enrichment analysis showed that the protein difference multiple in the nutritional repository activity was the largest among the molecular functions,and the up-regulated seed storage protein(ssP)played an active role in the response of grains to LT stress and subsequent damage.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis showed that LT stress reduced the expression of DEPs such as sucrose phosphate synthase(SPS),glucose-1-phosphate adenylyltransferase(glgC),andβ-fructofuranosidase(FFase)in sucrose and starch metabolic pathways,thus affecting the synthesis of grain starch.In addition,many heat shock proteins(HsPs)were found in the protein processing in endoplasmic reticulum pathways,which can resist some damage caused by LT stress.These findings provide a new theoretical foundation for elucidating the underlying mechanism governing wheat yield developmentafterexposuretoLTstress inspring. 展开更多
关键词 low temperature at booting WHEAT GRAIN starch synthesis PROTEOMICS
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Experimental Study and a Modified Model for Temperature-Recovery Stress of Shape Memory Alloy Wire under Different Temperatures
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作者 Zhi-Xiang Wei Wen-Wei Wang +1 位作者 Yan-Jie Xue Wu-Tong ZhangQiu-Di Huang 《Structural Durability & Health Monitoring》 2025年第2期347-364,共18页
To investigate the performance of utilizing the shape memory effect of SMA(Shape Memory Alloy)wire to generate recovery stress,this paper performed single heating recovery stress tests and reciprocating heating-coolin... To investigate the performance of utilizing the shape memory effect of SMA(Shape Memory Alloy)wire to generate recovery stress,this paper performed single heating recovery stress tests and reciprocating heating-cooling recovery stress tests on SMA wire under varying initial strain conditions.The effects of various strains and different energized heating methods on the recovery stress of SMA wires were explored in the single heating tests.The SMA wire was strained from 2%to 8%initially,and two distinct heating approaches were employed:one using a large current interval for rapid heating and one using a small current interval for slower heating.The experimental outcomes reveal that during a single heating cycle,the temperature-recovery stress relationship of SMA wire exhibits three distinct stages:the martensite phase stage,the transition stage from martensite to austenite phase,and the austenite phase stage.Notably,the choice of heating method does not influence the maximum recovery stress value,and the correlation between initial strain and maximum recovery stress is predominantly linear.Moreover,conducting the reciprocating temperature rise and fall performance test is important to better simulate the scenario in practical engineering where multiple recovery stress in SMA wires for structural repair.In this test,two temperature cycling methods were studied:interval rise and fall,as well as direct rise and fall.In the case of utilizing the interval temperature rise and fall method,it was observed that the recovery stress associated with cooling was significantly higher than that corresponding to heating at the same temperature.Furthermore,the recovery stress was lower upon subsequent heating than that measured during the previous heating cycle.Based on the experimental results,a prediction model for the temperature-recovery stress relationship has been proposed to simplify numerical calculations.It is hoped that an approximate temperaturerecovery stress curve can be obtained from the parameters of the SMA wire.The calculated values derived from this model show good alignment with the measured values,indicating its reliability. 展开更多
关键词 SMA wire temperature recovery stress modified model phase transition
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Real-world cost-effectiveness of targeted temperature management in out-of-hospital cardiac arrest survivors: results from an academic medical center
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作者 Wachira Wongtanasarasin Daniel K.Nishijima +1 位作者 Wanrudee Isaranuwatchai Jeff rey S.Hoch 《World Journal of Emergency Medicine》 2025年第1期28-34,共7页
BACKGROUND: Targeted temperature management(TTM) is a common therapeutic intervention, yet its cost-effectiveness remains uncertain. This study aimed to evaluate the real-world cost-effectiveness of TTM compared with ... BACKGROUND: Targeted temperature management(TTM) is a common therapeutic intervention, yet its cost-effectiveness remains uncertain. This study aimed to evaluate the real-world cost-effectiveness of TTM compared with that of conventional care in adult out-of-hospital cardiac arrest(OHCA) survivors using clinical patient-level data.METHODS: We conducted a retrospective cohort study at an academic medical center in the USA to assess the cost-effectiveness of TTM in adult non-traumatic OHCA survivors between 1 January, 2019 and 30 June, 2023. The primary outcome was survival to hospital discharge. Incremental cost-effectiveness ratios(ICERs) were calculated and compared with various decision makers' willingness to pay. Cost-effectiveness acceptability curves were utilized to evaluate the economic attractiveness of TTM. Uncertainty about the incremental cost and effect was explored with a 95% confidence ellipse.RESULTS: Among 925 non-traumatic OHCA survivors, only 30(3%) received TTM. After adjusting for potential confounders, the TTM group did not demonstrate a significantly lower cost(delta cost-$5,141, 95% confidence interval [95% CI]: $-35,347 to $25,065, P=0.79) and higher survival to hospital discharge(delta effect 6%, 95% CI:-11% to 23%, P=0.41). Additionally, a 95% confidence ellipse indicated uncertainty reflected by evidence that the true value of the ICER could be in any of the quadrants of the cost-effectiveness plane.CONCLUSION: Although TTM did not demonstrate a clear survival benefit in this study, its potential cost-effectiveness warrants further investigation with larger sample sizes. These findings highlight the need for additional research to optimize TTM use in OHCA care and inform resource allocation decisions. 展开更多
关键词 Out-of-hospital cardiac arrest Targeted temperature management COST-EFFECTIVENESS SURVIVAL Real-world data
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Evaluation of ERA5 reanalysis temperature data over the Qilian Mountains of China
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作者 ZHAO Peng HE Zhibin 《Journal of Mountain Science》 2025年第1期198-209,共12页
Air temperature is an important indicator to analyze climate change in mountainous areas.ERA5 reanalysis air temperature data are important products that were widely used to analyze temperature change in mountainous a... Air temperature is an important indicator to analyze climate change in mountainous areas.ERA5 reanalysis air temperature data are important products that were widely used to analyze temperature change in mountainous areas.However,the reliability of ERA5 reanalysis air temperature over the Qilian Mountains(QLM)is unclear.In this study,we evaluated the reliability of ERA5 monthly averaged reanalysis 2 m air temperature data using the observations at 17 meteorological stations in the QLM from 1979 to 2017.The results showed that:ERA5 reanalysis monthly averaged air temperature data have a good applicability in the QLM in general(R2=0.99).ERA5 reanalysis temperature data overestimated the observed temperature in the QLM in general.Root mean square error(RMSE)increases with the increasing of elevation range,showing that the reliability of ERA5 reanalysis temperature data is worse in higher elevation than that in lower altitude.ERA5 reanalysis temperature can capture observational warming rates well.All the smallest warming rates of observational temperature and ERA5 reanalysis temperature are found in winter,with the warming rates of 0.393°C/10a and 0.360°C/10a,respectively.This study will provide a reference for the application of ERA5 reanalysis monthly averaged air temperature data at different elevation ranges in the Qilian Mountains. 展开更多
关键词 ERA5 Reanalysis data Air temperature Qilian Mountains Climate change
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Modeling of Spring Phenology of Boreal Forest by Coupling Machine Learning and Diurnal Temperature Indicators
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作者 DENG Guorong ZHANG Hongyan +3 位作者 HONG Ying GUO Xiaoyi YI Zhihua EHSAN BINIYAZ 《Chinese Geographical Science》 2025年第1期38-54,共17页
The roles of diurnal temperature in providing heat accumulation and chilling requirements for vegetation spring phenology differ.Although previous studies have established a stronger correlation between leaf onset and... The roles of diurnal temperature in providing heat accumulation and chilling requirements for vegetation spring phenology differ.Although previous studies have established a stronger correlation between leaf onset and diurnal temperature than between leaf onset and average temperature,current research on modeling spring phenology based on diurnal temperature indicators remains limited.In this study,we confirmed the start of the growing season(SOS)sensitivity to diurnal temperature and average temperature in boreal forest.The estimation of SOS was carried out by employing K-Nearest Neighbor Regression(KNR-TDN)model,Random Forest Regres-sion(RFR-TDN)model,eXtreme Gradient Boosting(XGB-TDN)model and Light Gradient Boosting Machine model(LightGBM-TDN)driven by diurnal temperature indicators during 1982-2015,and the SOS was projected from 2015 to 2100 based on the Coupled Model Intercomparison Project Phase 6(CMIP6)climate scenario datasets.The sensitivity of boreal forest SOS to daytime temperature is greater than that to average temperature and nighttime temperature.The LightGBM-TDN model perform best across all vegetation types,exhibiting the lowest RMSE and bias compared to the KNR-TDN model,RFR-TDN model and XGB-TDN model.By incorporating diurn-al temperature indicators instead of relying only on average temperature indicators to simulate spring phenology,an improvement in the accuracy of the model is achieved.Furthermore,the preseason accumulated daytime temperature,daytime temperature and snow cover end date emerged as significant drivers of the SOS simulation in the study area.The simulation results based on LightGBM-TDN model exhibit a trend of advancing SOS followed by stabilization under future climate scenarios.This study underscores the potential of diurn-al temperature indicators as a viable alternative to average temperature indicators in driving spring phenology models,offering a prom-ising new method for simulating spring phenology. 展开更多
关键词 spring phenology diurnal temperature machine learning future climate scenarios boreal forest
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Numerical Simulation of Flow and Temperature Distribution in a Bottom-Blown Copper Bath
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作者 Teng Xia Xiaohui Zhang +4 位作者 Ding Ma Zhi Yang Xinting Tong Yutang Zhao Hua Wang 《Fluid Dynamics & Materials Processing》 2025年第1期121-140,共20页
Smelting with oxygen bottom blowing is one of the main methods used in the frame of copper pyrometallurgy.With this approach,feed materials and oxygen-enriched air are introduced in reversed order to enhance multiphas... Smelting with oxygen bottom blowing is one of the main methods used in the frame of copper pyrometallurgy.With this approach,feed materials and oxygen-enriched air are introduced in reversed order to enhance multiphaseflow within the furnace.Understanding the flow structure and temperature distribution in this setup is crucial foroptimizing production.In this study,gas-liquid interactions,and temperature profiles under varying air-injectionconditions are examined by means of numerical simulation for a 3.2 m×20 m furnace.The results indicate that thehigh-velocity regions are essentially distributed near the lance within the reaction region and the flue gas outlet,while low-velocity regions are located close to the furnace walls on both side of the reaction region.Dead regionsappear in the sedimentation region,with gas velocities surpassing those of the molten phase.As the injection rateincreases from 0.50 to 0.80 Nm3/s,the stabilization time of the average liquid surface velocity decreases from 2.6 sto 1.9 s,exhibiting a similar trend to the gas holdup.During stabilization,the average liquid surface velocity risesfrom 0.505 to 0.702 m/s.The average turbulent kinetic energy(TKE)of the fluid in the molten bath increases from0.095 to 0.162 m^(2)/s^(2).The proportion of the area distribution with TKE greater than 0.10 m^(2)/s^(2) and the gas holdupat steady state both rise with an increase in the injection quantity.The maximum splashing height of the melt growsfrom approximately 0.756 to 1.154 m,with the affected area expanding from 14.239 to 20.498 m^(2).Under differentworking conditions with varying injection quantities,the average temperature changes in melt zone and flue gaszone of the furnace are small.The temperature in the melt and in the flue-gas zone spans the interval 1200℃–1257℃,and 1073℃–1121℃,respectively.The temperature distribution of the melt and flue gas reveals a patterncharacterized by elevated temperatures in the reaction zone,gradually transitioning to lower temperatures in thesedimentation region. 展开更多
关键词 Copper smelting bottom-blown melting furnace flow characteristics temperature distribution numerical simulation
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Application of high temperature heat pipe in hypersonic vehicles thermal protection 被引量:9
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作者 白穜 张红 许辉 《Journal of Central South University》 SCIE EI CAS 2011年第4期1278-1284,共7页
In order to develop further the application of high temperature heat pipe in hypersonic vehicles thermal protection, the principles and characteristics of high temperature heat pipe used in hypersonic vehicles thermal... In order to develop further the application of high temperature heat pipe in hypersonic vehicles thermal protection, the principles and characteristics of high temperature heat pipe used in hypersonic vehicles thermal protection were introduced. The methods of numerical simulation, theory analysis and experiment research were utilized to analyze the frozen start-up and steady state characteristic of the heat pipe as well as the machining improvement for fabricating irregularly shaped heat pipe which is suitable for leading edge of hypersonic vehicles. The results indicate that the frozen start-up time of heat pipe is long (10 min) and there exists large temperature difference along the heat pipe (47 ℃/cm), but the heat pipe can reduce the temperature in stagnation area of hypersonic vehicles from 1 926 to 982 ℃ and work normally during 1 000-1 200℃. How to improve the maximum heat transfer capability and reduce the time needed for start-up from frozen state of the heat pipe by optimizing thermostructure such as designing of a novel wick with high performance is the key point in hypersonic vehicles thermal protection of heat pipe. 展开更多
关键词 thermal protection high temperature heat pipe heat transfer limit start-up time
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Assessment of ecological geological vulnerability in Mu Us Sandy Land based on GIS and suggestions of ecological protection and restoration
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作者 Jian-yu Liu Hong-feng Nie +6 位作者 Liang Xu Chun-lei Xiao Wei Li Guo-li Yuan Yan-peng Huang Xin-yang Ji Tian-qi Li 《China Geology》 2025年第1期117-140,共24页
Eco-geological vulnerability assessment is a significant research topic within the field of eco-geology,but it remains poorly studied.The Mu Us Sandy Land,located in the central part of the farming-pastoral ecotone in... Eco-geological vulnerability assessment is a significant research topic within the field of eco-geology,but it remains poorly studied.The Mu Us Sandy Land,located in the central part of the farming-pastoral ecotone in northern China,plays a critical role in maintaining the ecological security pattern in this region.However,this sandy land also faces severe sandy desertification and ecological degradation.This study conducted a regional eco-geological vulnerability assessment of the Mu Us Sandy Land using a comprehensive index evaluation method based on eco-geological theories and survey results.To construct an appropriate index system for the eco-geological vulnerability assessment of the Mu Us Sandy Land,the study considered the sandy land’s unique characteristics and identified 15 factors of five categories,namely geology,meteorology,soil,topography,and vegetation.The paper calculated the comprehensive weights of all the indices using the analytic hierarchy process(AHP)and the entropy weight method(EWM).Furthermore,it established the eco-geological vulnerability index(EGVI)and obtained the assessment results.The results showed that the eco-geological vulnerability of the Mu Us Sandy Land gradually intensifies from east to west,manifested as vulnerable eco-geological conditions overall.Specifically,extremely vulnerable zones are found in the northwestern and southeastern parts of the study area,highly vulnerable zones in the western and southern parts,moderately vulnerable zones in the central part,and slightly and potentially vulnerable zones in the eastern and southern parts.Areas with high spatial autocorrelations include the northern Uxin Banner-Otog Banner-Angsu Town area,the surrounding areas of Hongdunjie Town in the southeastern part of the study area,the Hongshiqiao Township-Xiaohaotu Township area,Otog Front Banner,and Bainijing Town,which should be prioritized in the ecological conservation and restoration.Additionally,the paper proposed suggestions for the ecological conservation and restoration of county-level administrative areas in the study area.Overall,the findings provide a valuable reference for the ecological conservation and restoration of the Mu Us Sandy Land and other desert areas in arid and semi-arid regions. 展开更多
关键词 Eco-geological vulnerability Analytic hierarchy process Entropy weight method Evaluation and zonation Mu Us Sandy Land Geology-meteorology-soil-topography-vegetation Precipitation and groundwater Environmental protection and restoration Environmental restoration engineering Inner Mongolia Plateau
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Bio-Inspired Microwave Modulator for High-Temperature Electromagnetic Protection,Infrared Stealth and Operating Temperature Monitoring 被引量:3
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作者 Xuan Yang Yuping Duan +4 位作者 Shuqing Li Huifang Pang Lingxi Huang Yuanyuan Fu Tongmin Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第2期124-135,共12页
High-temperature electromagnetic(EM) protection materials integrated of multiple EM protection mechanisms and functions are regarded as desirable candidates for solving EM interference over a wide temperature range.In... High-temperature electromagnetic(EM) protection materials integrated of multiple EM protection mechanisms and functions are regarded as desirable candidates for solving EM interference over a wide temperature range.In this work,a novel microwave modulator is fabricated by introducing carbonyl iron particles(CIP)/resin into channels of carbonized wood(C-wood).Innovatively,the spaced arrangement of two microwave absorbents not only achieves a synergistic enhancement of magnetic and dielectric losses,but also breaks the translational invariance of EM characteristics in the horizontal direction to obtain multiple phase discontinuities in the frequency range of 8.2-18.0 GHz achieving modulation of reflected wave radiation direction.Accordingly,CIP/C-wood microwave modulator demonstrates the maximum effective bandwidth of 5.2 GHz and the maximum EM protection efficiency over 97% with a thickness of only 1.5 mm in the temperature range 298-673 K.Besides,CIP/C-wood microwave modulator shows stable and low thermal conductivities,as well as monotonic electrical conductivity-temperature characteristics,therefore it can also achieve thermal infrared stealth and working temperature monitoring in wide temperature ranges.This work provides an inspiration for the design of high-temperature EM protection materials with multiple EM protection mechanisms and functions. 展开更多
关键词 Microwave modulator Electromagnetic protection High temperatures temperature monitoring Carbonized wood
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Tree-Temperature Monitoring for Frost Protection of Orchards in Semi-Arid Regions Using Sprinkler Irrigation 被引量:15
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作者 Ali Asghar Ghaemi Mohammad Rafie Rafiee Ali Reza Sepaskhah 《Agricultural Sciences in China》 CSCD 2009年第1期98-107,共10页
Automated over-tree sprinkler irrigation systems were developed and tested in two orchards located in two separate locations in southern Iran (a 0.17 ha peach orchard and a 0.24 ha orange orchard) to protect peach b... Automated over-tree sprinkler irrigation systems were developed and tested in two orchards located in two separate locations in southern Iran (a 0.17 ha peach orchard and a 0.24 ha orange orchard) to protect peach blossoms and orange trees leaves and fruits from low temperature damage. The experiment used a system that monitored the trees and air temperatures using two thermistors. The water application rate by the irrigation system was determined by an energy balance as implemented by the software FROSTPRO, In the peach orchard, the system was tested during three frost events during the spring of 2003 and three other events during the spring of 2004. The system successfully kept peach flowers above the critical temperature, i.e., -4.0℃ in spring 2004 (control block -4.12℃, and sprinkled block +0.5℃) during all events. Similar results were obtained in the orange orchard during three frost events in the winter of 2004, during which the tree temperatures were at least 2.5℃ above the critical temperature. Results from field tests show that the system can effectively protect the peach blossoms from damage. Determination done after the frost events showed a 12% blossom kill in the sprinkled blocks while in the unsprinkled control block a 41.5% blossom kill. Calculations indicated that when using variable application rates, the amount of water used can be reduced by 54.3%. Spatial distribution of minimum temperatures during the three frosts was also studied in Jahrom, Iran. Results showed a significant temperature control in the experimental block, especially in the central part of the orchard, but the block margins (about 3.6% of the total area) were at the risk of low temperature due to the wind drift effects. 展开更多
关键词 AUTOMATED sprinkler irrigation FROSTPORO frost protection peach orchard orange orchard
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High Temperature Corrosion and Protection of Titanium Alloys and TiAl Intermetallics 被引量:1
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作者 唐兆麟 王福会 吴维 《Rare Metals》 SCIE EI CAS CSCD 1996年第3期203-207,共5页
High temperature corrsoion and protection of trtanium alloys and TiAl intermetallics are reviewed, andsome suggestions on the development of protective coatings are put forward.
关键词 TiAl intermetallics Titanium alloys High temperature corro-sion protective coating
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