Based on the force-heat equivalence energy density principle,a theoretical model for magnetic metallic materials is developed,which characterizes the temperature-dependent magnetic anisotropy energy by considering the...Based on the force-heat equivalence energy density principle,a theoretical model for magnetic metallic materials is developed,which characterizes the temperature-dependent magnetic anisotropy energy by considering the equivalent relationship between magnetic anisotropy energy and heat energy;then the relationship between the magnetic anisotropy constant and saturation magnetization is considered.Finally,we formulate a temperature-dependent model for saturation magnetization,revealing the inherent relationship between temperature and saturation magnetization.Our model predicts the saturation magnetization for nine different magnetic metallic materials at different temperatures,exhibiting satisfactory agreement with experimental data.Additionally,the experimental data used as reference points are at or near room temperature.Compared to other phenomenological theoretical models,this model is considerably more accessible than the data required at 0 K.The index included in our model is set to a constant value,which is equal to 10/3 for materials other than Fe,Co,and Ni.For transition metals(Fe,Co,and Ni in this paper),the index is 6 in the range of 0 K to 0.65T_(cr)(T_(cr) is the critical temperature),and 3 in the range of 0.65T_(cr) to T_(cr),unlike other models where the adjustable parameters vary according to each material.In addition,our model provides a new way to design and evaluate magnetic metallic materials with superior magnetic properties over a wide range of temperatures.展开更多
Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and...Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P < 0.0001) and the peat soil (r2 > 0.38, P < 0.002), and a negative relationship with water saturation increasing at the same temperature, especially 25 and 35 ℃, in the marsh soil (r2 > 0.70, P < 0.009) and the peat soil (r2 > 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils.展开更多
Frost heave in seasonally frozen regions is a one-dimensional process that could severely damage infrastructure subgrades.Stress state,temperature and water migration are important factors for frost heave.This work in...Frost heave in seasonally frozen regions is a one-dimensional process that could severely damage infrastructure subgrades.Stress state,temperature and water migration are important factors for frost heave.This work investigated the effects of soil temperature and volumetric water content on the transient frost heave ratio during the freezing of saturated silty clay in an open system and analyzed the relationships between the transient frost heave ratio and freezing rate and between temperature gradient and frost heave rate.The results show that the frost heave ratio,frost heave rate,and freezing rate are positively correlated with the temperature gradient since the temperature gradient drives the water migration during freezing,indicating the transient temperature gradient could be used to evaluate the frost heave of saturated silty clay.The transient freezing rate and transient frost heave ratio are logarithmically related to the transient frost heave ratio and transient temperature gradient,respectively.The effects of transient temperature gradient on frost heave are the principal mechanism responsible for different frost heave characteristics and uneven frost heave along a subgrade of the same soil type.展开更多
To clarify the optimal water management in large-scale fields under high temperatures at the ripening period,effective water managements during this period for improvement of yield,appearance quality and palatability ...To clarify the optimal water management in large-scale fields under high temperatures at the ripening period,effective water managements during this period for improvement of yield,appearance quality and palatability were investigated.Compared with intermittent irrigation and flooded irrigation,the soil temperature with saturated irrigation remained low throughout the day,and the decrease rate of the bleeding rate of hills was the lowest.These results suggested that the saturated irrigation maintained root activity.For the three irrigation types,the number of spikelets per m2 and 1000-grain weight were similar,however,saturated irrigation resulted in significantly higher rice yield due to improvement in the percentage of ripened grains.The saturated irrigation produced a high percentage of perfect rice grains and thicker brown rice grain,furthermore,the palatability of cooked rice was excellent because protein content and hardness/adhesion ratio were both low.Thus,under high-temperature ripening conditions,soil temperature was lowered and root activity was maintained when applying saturated irrigation after heading time.The results indicated that saturated irrigation is an effective countermeasure against high-temperature ripening damage.展开更多
We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position...We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position of the crossover peaks can move along the spectrum. Different velocity classes of atoms contribute to the crossover during the movement. We study the relationship between the intensity change of peaks and vapor temperature. Our experimental result around room temperature shows a deviation of less than 0.3 K. Compared with traditional thermometry using absorption spectroscopy, higher accuracy can theoretically be achieved with real-time thermometry.展开更多
When the electric field caused by voltage reaches a certain level,the charge on the compliant electrodes will not increase owing to the polarization saturation,which would limit the deformation of the dielectric elast...When the electric field caused by voltage reaches a certain level,the charge on the compliant electrodes will not increase owing to the polarization saturation,which would limit the deformation of the dielectric elastomer.Some experiments show that temperature also has a significant effect on the deformation of dielectric elastomer.In this work,a free energy model coupling temperature and polarization saturation is developed to characterize the thermoelectromechanical instability of dielectric elastomer.The results reveal that both the polarization saturation parameters and electric field have a significant influence on the actuation ability of the dielectric elastomer,and the increase of temperature enhances thermoelectromechanical stability.It is hoped that this work could guide the development of dielectric elastomer materials and application devices operating in variable temperatures.展开更多
Obstructive sleep apnea(OSA)is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive diseases.We utilized smart device-based photoplethysmography technology to collect sleep data from th...Obstructive sleep apnea(OSA)is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive diseases.We utilized smart device-based photoplethysmography technology to collect sleep data from the Chinese population from 2019 to 2022.Distributed lag nonlinear models combined with a generalized nonlinear model or a linear mixed effects model were used to investigate the shortterm associations between daily temperature and indicators of OSA severity.We included a total of 6,232,056 d of sleep monitoring data from 51,842 participants with moderate to severe risk of OSA from 313 Chinese cities.The relationships between ambient temperature and OSA exacerbation,apneahypopnea index(AHI),and minimum oxygen saturation(MinSpO_(2))were almost linear and present only on the same day.Higher temperatures were associated with a greater risk of OSA exacerbation,with an 8.4%(95%confidence interval(CI):7.6%–9.3%)increase per 10℃increase in temperature.A 10℃increase in daily temperature corresponded to an AHI increase of 0.70 events/h(95%CI:0.65–0.76)and a MinSpO_(2)decrease of 0.18%(95%CI:0.16%–0.19%).Exposure to elevated temperatures during the night can also lead to adverse effects.The effects of higher temperatures on OSA severity were stronger among men,participants with a body mass index24 kg/m2,those aged 45 years and older,individuals with a history of hypertension and diabetes,and during the cold season.This large-scale,nationwide,longitudinal study provides robust evidence suggesting that higher ambient temperatures may immediately worsen OSA.展开更多
The Lichi volcanics are a suite of mafic-intermediate-felsic rocks and are considered coeval with the Abor volcanics(~132 Ma) of the Siang window in the Eastern Himalaya. Here, we present the first report of trachytic...The Lichi volcanics are a suite of mafic-intermediate-felsic rocks and are considered coeval with the Abor volcanics(~132 Ma) of the Siang window in the Eastern Himalaya. Here, we present the first report of trachytic rocks from the Lichi volcanics, which are exposed in the Ranga valley, along the Kimin-Yazali road section in the Eastern Himalayan Region, Northeast India. The trachytes occur in close association with sandstones of the Gondwana Group of rocks and are characterised based on field, petrographical, and geochemical investigations.These fine-grained trachytes are composed of alkali feldspar, biotite, plagioclase, sodic-amphibole, apatite, illmenite, and titanite. The REE profiles of the evolved trachytic rocks(higher SiO_(2)content) display fractionated trends. The fractionation of accessory mineral phases, like apatite and titanite, was possibly responsible for the strongly fractionated REE patterns of the evolved samples.The trachytic rocks demonstrate high apatite saturation temperatures of 988 ± 14 ℃(1σ, n = 8). The Aluminium Saturation Index(< 1.1) and binary discrimination diagrams of these peralkaline trachytes define their affinity with A-type granitoids. Elemental ratios like Y/Nb, Nb/U,and Ce/Pb signify that the Lichi trachytes are differentiated products of mantle-derived ocean island basalts. Trace elemental discrimination diagrams Th/Yb versus Nb/Yb, Y versus Nb, and Y + Nb versus Rb reflect a within-plate tectonic regime for the trachytes. From the results presented in this work, we infer that the development of rifting events during the breakup of eastern Gondwana due to the onset of Kerguelen plume activity further led to underplating of basic magma in lower crustal levels. These parental basaltic magmas underwent fractionation processes forming differentiated trachyandesites and trachytes.Taking into consideration the similarities recorded between the Lichi volcanics and Abor volcanics, this study supports the idea that Kerguelen plume activities resulted in the emplacement of these volcanics in the Eastern Himalayas.展开更多
基金Project supported by the Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQ-MSX0391)。
文摘Based on the force-heat equivalence energy density principle,a theoretical model for magnetic metallic materials is developed,which characterizes the temperature-dependent magnetic anisotropy energy by considering the equivalent relationship between magnetic anisotropy energy and heat energy;then the relationship between the magnetic anisotropy constant and saturation magnetization is considered.Finally,we formulate a temperature-dependent model for saturation magnetization,revealing the inherent relationship between temperature and saturation magnetization.Our model predicts the saturation magnetization for nine different magnetic metallic materials at different temperatures,exhibiting satisfactory agreement with experimental data.Additionally,the experimental data used as reference points are at or near room temperature.Compared to other phenomenological theoretical models,this model is considerably more accessible than the data required at 0 K.The index included in our model is set to a constant value,which is equal to 10/3 for materials other than Fe,Co,and Ni.For transition metals(Fe,Co,and Ni in this paper),the index is 6 in the range of 0 K to 0.65T_(cr)(T_(cr) is the critical temperature),and 3 in the range of 0.65T_(cr) to T_(cr),unlike other models where the adjustable parameters vary according to each material.In addition,our model provides a new way to design and evaluate magnetic metallic materials with superior magnetic properties over a wide range of temperatures.
基金supported by the National Key Basic Research Program of China (973 Program) (No.2005CB422005)the National Natural Science Foundation of China (No.30700108)the Forestry Commonweal Program of China(No.200804005).
文摘Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P < 0.0001) and the peat soil (r2 > 0.38, P < 0.002), and a negative relationship with water saturation increasing at the same temperature, especially 25 and 35 ℃, in the marsh soil (r2 > 0.70, P < 0.009) and the peat soil (r2 > 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils.
基金supported by the National Natural Science Foundation of China(No.51808128)the Natural Science Foundation of Fujian Province(No.2022J01091)。
文摘Frost heave in seasonally frozen regions is a one-dimensional process that could severely damage infrastructure subgrades.Stress state,temperature and water migration are important factors for frost heave.This work investigated the effects of soil temperature and volumetric water content on the transient frost heave ratio during the freezing of saturated silty clay in an open system and analyzed the relationships between the transient frost heave ratio and freezing rate and between temperature gradient and frost heave rate.The results show that the frost heave ratio,frost heave rate,and freezing rate are positively correlated with the temperature gradient since the temperature gradient drives the water migration during freezing,indicating the transient temperature gradient could be used to evaluate the frost heave of saturated silty clay.The transient freezing rate and transient frost heave ratio are logarithmically related to the transient frost heave ratio and transient temperature gradient,respectively.The effects of transient temperature gradient on frost heave are the principal mechanism responsible for different frost heave characteristics and uneven frost heave along a subgrade of the same soil type.
基金supported by the grants from the Project of the National Agriculture and Food Research Organization Bio-oriented Technology Research Advancement Institution in Japan(the Special Scheme to Create Dynamism in Agriculture,Forestry and Fisheries through Deploying Highly Advanced Technology)(Grant No.shoNavi1000)。
文摘To clarify the optimal water management in large-scale fields under high temperatures at the ripening period,effective water managements during this period for improvement of yield,appearance quality and palatability were investigated.Compared with intermittent irrigation and flooded irrigation,the soil temperature with saturated irrigation remained low throughout the day,and the decrease rate of the bleeding rate of hills was the lowest.These results suggested that the saturated irrigation maintained root activity.For the three irrigation types,the number of spikelets per m2 and 1000-grain weight were similar,however,saturated irrigation resulted in significantly higher rice yield due to improvement in the percentage of ripened grains.The saturated irrigation produced a high percentage of perfect rice grains and thicker brown rice grain,furthermore,the palatability of cooked rice was excellent because protein content and hardness/adhesion ratio were both low.Thus,under high-temperature ripening conditions,soil temperature was lowered and root activity was maintained when applying saturated irrigation after heading time.The results indicated that saturated irrigation is an effective countermeasure against high-temperature ripening damage.
基金supported by the National Natural Science Foundation of China (Grant No. 61703025)。
文摘We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position of the crossover peaks can move along the spectrum. Different velocity classes of atoms contribute to the crossover during the movement. We study the relationship between the intensity change of peaks and vapor temperature. Our experimental result around room temperature shows a deviation of less than 0.3 K. Compared with traditional thermometry using absorption spectroscopy, higher accuracy can theoretically be achieved with real-time thermometry.
基金This work was supported by the National Natural Science Foundation of China(Grant 11772109).
文摘When the electric field caused by voltage reaches a certain level,the charge on the compliant electrodes will not increase owing to the polarization saturation,which would limit the deformation of the dielectric elastomer.Some experiments show that temperature also has a significant effect on the deformation of dielectric elastomer.In this work,a free energy model coupling temperature and polarization saturation is developed to characterize the thermoelectromechanical instability of dielectric elastomer.The results reveal that both the polarization saturation parameters and electric field have a significant influence on the actuation ability of the dielectric elastomer,and the increase of temperature enhances thermoelectromechanical stability.It is hoped that this work could guide the development of dielectric elastomer materials and application devices operating in variable temperatures.
基金supported by the Shanghai Municipal Science and Technology Major Project(2023SHZDZX02)Shanghai B&R Joint Laboratory Project(22230750300)+2 种基金Shanghai International Science and Technology Partnership Project(21230780200)the Shanghai Committee of Science and Technology(21TQ015)the Shanghai 3-year Public Health Action Plan(GWVI-11.2-YQ32).
文摘Obstructive sleep apnea(OSA)is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive diseases.We utilized smart device-based photoplethysmography technology to collect sleep data from the Chinese population from 2019 to 2022.Distributed lag nonlinear models combined with a generalized nonlinear model or a linear mixed effects model were used to investigate the shortterm associations between daily temperature and indicators of OSA severity.We included a total of 6,232,056 d of sleep monitoring data from 51,842 participants with moderate to severe risk of OSA from 313 Chinese cities.The relationships between ambient temperature and OSA exacerbation,apneahypopnea index(AHI),and minimum oxygen saturation(MinSpO_(2))were almost linear and present only on the same day.Higher temperatures were associated with a greater risk of OSA exacerbation,with an 8.4%(95%confidence interval(CI):7.6%–9.3%)increase per 10℃increase in temperature.A 10℃increase in daily temperature corresponded to an AHI increase of 0.70 events/h(95%CI:0.65–0.76)and a MinSpO_(2)decrease of 0.18%(95%CI:0.16%–0.19%).Exposure to elevated temperatures during the night can also lead to adverse effects.The effects of higher temperatures on OSA severity were stronger among men,participants with a body mass index24 kg/m2,those aged 45 years and older,individuals with a history of hypertension and diabetes,and during the cold season.This large-scale,nationwide,longitudinal study provides robust evidence suggesting that higher ambient temperatures may immediately worsen OSA.
基金the DST-SERB grant vide Project No. CRG/2020/002635the CSIR-JRF fellowship No. 09/1236(11154)/2021-EMR-Ithe DST-INSPIRE fellowship No. IF210186。
文摘The Lichi volcanics are a suite of mafic-intermediate-felsic rocks and are considered coeval with the Abor volcanics(~132 Ma) of the Siang window in the Eastern Himalaya. Here, we present the first report of trachytic rocks from the Lichi volcanics, which are exposed in the Ranga valley, along the Kimin-Yazali road section in the Eastern Himalayan Region, Northeast India. The trachytes occur in close association with sandstones of the Gondwana Group of rocks and are characterised based on field, petrographical, and geochemical investigations.These fine-grained trachytes are composed of alkali feldspar, biotite, plagioclase, sodic-amphibole, apatite, illmenite, and titanite. The REE profiles of the evolved trachytic rocks(higher SiO_(2)content) display fractionated trends. The fractionation of accessory mineral phases, like apatite and titanite, was possibly responsible for the strongly fractionated REE patterns of the evolved samples.The trachytic rocks demonstrate high apatite saturation temperatures of 988 ± 14 ℃(1σ, n = 8). The Aluminium Saturation Index(< 1.1) and binary discrimination diagrams of these peralkaline trachytes define their affinity with A-type granitoids. Elemental ratios like Y/Nb, Nb/U,and Ce/Pb signify that the Lichi trachytes are differentiated products of mantle-derived ocean island basalts. Trace elemental discrimination diagrams Th/Yb versus Nb/Yb, Y versus Nb, and Y + Nb versus Rb reflect a within-plate tectonic regime for the trachytes. From the results presented in this work, we infer that the development of rifting events during the breakup of eastern Gondwana due to the onset of Kerguelen plume activity further led to underplating of basic magma in lower crustal levels. These parental basaltic magmas underwent fractionation processes forming differentiated trachyandesites and trachytes.Taking into consideration the similarities recorded between the Lichi volcanics and Abor volcanics, this study supports the idea that Kerguelen plume activities resulted in the emplacement of these volcanics in the Eastern Himalayas.
