A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation metho...A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation method.The physico-chemical properties of the samples were extensively characterized by N_(2) physisorption,X-ray diffraction,Raman spectroscopy,scanning electron micro scopy and energy-dispersive Xray spectroscopy element mapping,X-ray photoelectron spectroscopy,H_(2)-temperature programmed reduction,ammonia temperature programmed desorption,and in-situ diffuse reflectance infrared Fourier transform spectroscopy.The catalytic activity and resistance to water vapor and SO_(2) of the asprepared catalysts for the SCR of NO_(x) with NH_(3) were evaluated at 50-250℃ and GHSV of 80000 mL/(gcat·h).The results reveal that MnCeO_(x)/TiO_(2)-Al_(2)O_(3) exhibits higher activity and better SO_(2) tolerance than MnCeO_(x)/TiO_(2).Combining with the characterization results,the enhanced activity and SO_(2) tolerance of MnCeO_(x)/TiO_(2)-Al_(2)O_(3) can be mainly attributed to higher relative concentrations of Mn4+and chemisorbed oxygen species,stronger reducibility,and larger adsorption capacity for NH_(3) and NO,which originate from the larger specific surface area and pore volume,higher dispersion of Mn and Ce species compared with MnCeO_(x)/TiO_(2).Moreover,in situ DRIFTS was used to investigate the reaction mechanism,and the results indicate that the NH_(3)-SCR reaction over MnCeO_(x)/TiO_(2) and MnCeO_(x)/TiO_(2)-Al_(2)O_(3) takes place by both the E-R and L-H mechanisms.展开更多
Salt and low temperature were both very important factors for soybean production. It was necessary to improve the salt stress and low-temperature tolerance of soybean. The main purpose of this paper was to map the qua...Salt and low temperature were both very important factors for soybean production. It was necessary to improve the salt stress and low-temperature tolerance of soybean. The main purpose of this paper was to map the quantitative trait loci(QTL) related with salt tolerance and low- temperature tolerance at germination stage with backcross introgression lines(BILs),and analyze the genetic overlap between them. There were 22 QTL located with BC2 F4 introgression populations after salt stress,and 15 QTL were mapped after low-temperature stress. Seven overlapping QTLs between salt tolerance and low-temperature tolerance were detected on 6 linkage groups at germination stage. In total,there were 31.81 % of salt tolerance and low-temperature tolerance loci existed genetic overlap.展开更多
Monitoring various internal parameters plays a core role in ensuring the safety of lithium-ion batteries in power supply applications.It also influences the sustainability effect and online state of charge prediction....Monitoring various internal parameters plays a core role in ensuring the safety of lithium-ion batteries in power supply applications.It also influences the sustainability effect and online state of charge prediction.An improved multiple feature-electrochemical thermal coupling modeling method is proposed considering low-temperature performance degradation for the complete characteristic expression of multi-dimensional information.This is to obtain the parameter influence mechanism with a multi-variable coupling relationship.An optimized decoupled deviation strategy is constructed for accurate state of charge prediction with real-time correction of time-varying current and temperature effects.The innovative decoupling method is combined with the functional relationships of state of charge and open-circuit voltage to capture energy management ef-fectively.Then,an adaptive equivalent-prediction model is constructed using the state-space equation and iterative feedback correction,making the proposed model adaptive to fractional calculation.The maximum state of charge estimation errors of the proposed method are 4.57%and 0.223%under the Beijing bus dynamic stress test and dynamic stress test conditions,respectively.The improved multiple feature-electrochemical thermal coupling modeling realizes the effective correction of the current and temperature variations with noise influencing coefficient,and provides an efficient state of charge prediction method adaptive to complex conditions.展开更多
We report the investigation on the low-temperature oxidation of cyclohexane in a jet-stirred reactor over 500-742 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry （SVUV-PIMS） was used for identify...We report the investigation on the low-temperature oxidation of cyclohexane in a jet-stirred reactor over 500-742 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry （SVUV-PIMS） was used for identifying and quantifying the oxidation species. Major products, cyclic olefins, and oxygenated products including reactive hydroperoxides and high oxygen compounds were detected. Compared with n-alkanes, a narrow low-temperature window （-80 K） was observed in the low-temperature oxidation of cyclohexane. Besides, a kinetic model for cyclohexane oxidation was developed based on the CNRS model [Combust. Flame 160, 2319 （2013）], which can better capture the experimental results than previous models. Based on the modeling analysis, the 1,5-H shift dominates the crucial isomerization steps of the first and second O2 addition products in the low-temperature chain branching process of cyclohexane. The negative temperature coefficient behavior of cyclohexane oxidation results from the reduced chain branching due to the competition from chain inhibition and propagation reactions, i.e. the reaction between cyclohexyl radical and O2 and the de- composition of cyclohexylperoxy radical, both producing cyclohexene and HO2 radical, as well as the decomposition of cyclohexylhydroperoxy radical producing hex-5-en-l-al and OH radical.展开更多
Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)...Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.展开更多
The observations from 14-yr long-term investigation on the soil-water losses in the sloping red-earth (slope 8°- 15°) showed that soil-water losses were closely correlated with land slope and vegetative cove...The observations from 14-yr long-term investigation on the soil-water losses in the sloping red-earth (slope 8°- 15°) showed that soil-water losses were closely correlated with land slope and vegetative coverage. Runoff rate in sloping red-earth could be reduced doubly by exploitation, while the soil erosion was enhanced doubly during the first two years after exploitation. Subsequently, it tended to be stable. Soil erosion was highly positively correlated with land slope, i. e. soil erosion increased by 120 t km-2 yr-1 with a slope increase of 1°. On the contrary, soil erosion was highly negatively correlated with vegetative coverage, i. e. soil erosion was limited at 200 t km-2 yr-1 below as the vegetative coverage exceeded 60%. Furthermore, soil erosion was highly related with planting patterns, i. e. soil erosion in contour cropping pattern would be one sixth of that in straight cropping. Based on the view of soil nutrient balance and test data, it was first suggested that the soil loss tolerance in Q2 red clay derived red-earth should be lower than 300 t km-2 yr-1.展开更多
Marginal scleractinian corals growing at their latitudinal limits should be quite sensitive to variations in winter sea surface temperatures(SSTs). An extreme cold event occurring in early 2008 offered a unique opport...Marginal scleractinian corals growing at their latitudinal limits should be quite sensitive to variations in winter sea surface temperatures(SSTs). An extreme cold event occurring in early 2008 offered a unique opportunity to examine the effect of cold-water anomalies on Porites lutea corals and their physiological tolerance and acclimation in the subtropical northern South China Sea(NSCS). Besides in-situ observation, a subsequent aquarium-based experiment was designed for reproducing the chilling process and a 50-year-long Sr/Ca ratio profile from two P. lutea skeletal slabs was analyzed for reconstructed the historical annual minimum SSTs which ceased Porites calcification. The 2008 low-temperature anomaly caused the minimum daily mean SSTs dropped below 13°C in the Daya Bay. The stress symptoms displayed by local P. lutea colonies included polyp retraction, reduced coloration and pale, but none showed tissue sloughing. The ability of P. lutea to survive implied its tolerance of extreme low temperatures. Here we suggest a model on the tolerance of high-latitude Porites under low-temperature stresses, which is when SSTs drop below 18°C, Porites corals contract their tentacles(losing heterotrophic capability), then cease calcification(reducing energy consumption), and meanwhile maintain relatively high levels of zooxanthellae density(sustaining host’s life via photosynthetic capacity of symbiotic zooxanthellae). This study revealed remarkable acclimatization of P. lutea corals to low temperature extremes. This acclimatization is beneficial for Porites corals in the NSCS to expand their living ranges towards the higher-latitude areas and have the potential to be the incipient reef former.展开更多
An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coeffic...An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coefficient is derived,which takes into account of several factors affecting the manufacturing cost,including the forming means of the blank,size,machining surface features,operator’s skills and machinability of materials. The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance,and,hence,an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient,the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation,which indicates the increase of the tolerance’s effects on the total manufacturing cost and,therefore,a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient,accurate and practicable.展开更多
The aim of this research was to evaluate the salinity tolerance in prairie grass populations at the seedling stage quantifying the variability and the influence of physiological traits related to it. Salinity toleranc...The aim of this research was to evaluate the salinity tolerance in prairie grass populations at the seedling stage quantifying the variability and the influence of physiological traits related to it. Salinity tolerance, in </span><i><span style="font-family:Verdana;">Bromus</span></i> <i><span style="font-family:Verdana;">catharticus</span></i><span style="font-family:Verdana;"> Vahl (prairie grass) populations collected in different environments of the Pampean Phytogeography region (Argentine) was evaluated at the seedling stage, using controlled condition of temperature and light. It was adopted a completely randomized design using 3 plots with three plants each one per population and two levels of treatment: 0 mM and 100 mM NaCl. Morphological, biomass and membrane stability root and shoot traits were studied. A factorial ANOVA with interaction was estimated. Then one way ANOVA for all seedling traits in both treatments allowed estimating variance components, coefficient of genotypic determination (CGD) and variation index (VI). Comparisons between populations were made using Tukey test (at 5% of probability). Phenotypic correlations among traits were calculated and then a path coefficient analysis separated direct and indirect effects at 100 and 0 mM NaCl. No significant interactions “Population × Treatment” were found for any character. The saline stress caused a pairing in the population means for the most traits. Coefficients of variation were mainly higher when the seedlings grew without stress (0 mM) because it allowed a greater potential genotypic expression. The absence of significant interactions denotes a good homeostatic capacity of the prairie grass facing that abiotic stress. Leaf length, shoot length and root dry matter were the variables with the largest direct and indirect effects. Our results showed an increase for them at salt and demonstrated intraspecific variation, possibly in relation with the origin sites. Plants under stress showed a marked resilience, in order to quickly restore the same biomass allocation patterns that occur in non-stress environment.展开更多
Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during pla...Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during planting.In this study,transcriptomic profiles of low-temperature-and normal-temperature-germinated seeds of Xinluzao 25,a variety with low-temperature tolerance and high germination rates,were analyzed and compared.The following results were obtained.(1)A total of 81.06 Gb of clean data were obtained after transcriptome sequencing and assembly,and 76,931 non-redundant Unigene sequences were obtained after data consolidation and concatenation;of these,69,883 Unigene sequences were annotated.In addition,55,463 Unigene transcript sequences(72.2%)were annotated for Gene Ontology(GO)classification,and 26,629 genes were involved in 50 metabolic pathways identified by Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.(2)Three main pathways related to low-temperature tolerance of seed germination were identified:starch and sucrose metabolism,phenylpropanoid biosynthesis,and cysteine and methionine metabolism.Their main molecular functions involve the regulation of abscisic acid and activities of enzymes such as amylase,peroxidase,and oxidoreductase.During germination at low temperature,more genes were down-regulated than up-regulated genes at the protrusion stage(2 mm),and more genes were up-regulated than down-regulated at the germination stage(30 mm)after protrusion.(3)The enzyme activities at the two stages showed that amylase,peroxidase,catalase,and glutathione reductase had higher activities when the seeds germinated at 15℃.In this study,high expression of amylase,peroxidase,catalase,and glutathione reductase genes may be the main cause of increased tolerance to low temperature.展开更多
Ablotlc stress, such as salt, drought and extreme temperature, can result in enhanced production of reactive oxygen species （ROS）. Plants have developed both enzymatic ROS-scavenging and non-enzymatic ROS-scavenging...Ablotlc stress, such as salt, drought and extreme temperature, can result in enhanced production of reactive oxygen species （ROS）. Plants have developed both enzymatic ROS-scavenging and non-enzymatic ROS-scavenging systems. The major ROS-scavenging enzymes of plants include superoxide dismutase （SOD）, ascorbate peroxldaae （APX）, catalaae （CAT）, glutathione peroxldaae （GPX） and peroxiredoxina （Prxa）. In the present work, we identified a gene encoding chloroplast-located peroxiredoxin Q, SsPrxQ, from Suaeda salsa L. located at chloroplast. Overexpression of SsPrxQ In Arabidopsis leads to an increase In salt and low-temperature tolerance.展开更多
The temperature coefficient of permittivity(TCε)of BaTiO_(3)–Bi(Me)O_(3) solid solutions were investigated.It was determined that as the tolerance factor was decreased with the addition of Bi(Me)O_(3),the TCε shift...The temperature coefficient of permittivity(TCε)of BaTiO_(3)–Bi(Me)O_(3) solid solutions were investigated.It was determined that as the tolerance factor was decreased with the addition of Bi(Me)O_(3),the TCε shifted from large negative values to TCε values approaching zero.It is proposed that the different bonding nature of the dopant cation affects the magnitude and temperature stability of the permittivity.This study suggests that the relationship between tolerance factor and TCε can be used as a guide to design new dielectric compounds exhibiting temperature-stable high permittivity characteristics,which is similar to past research on perovskite and pyrochlore-based microwave dielectrics.展开更多
基金Project supported by the Alliance Project of Shanghai City in China(LM201641)。
文摘A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation method.The physico-chemical properties of the samples were extensively characterized by N_(2) physisorption,X-ray diffraction,Raman spectroscopy,scanning electron micro scopy and energy-dispersive Xray spectroscopy element mapping,X-ray photoelectron spectroscopy,H_(2)-temperature programmed reduction,ammonia temperature programmed desorption,and in-situ diffuse reflectance infrared Fourier transform spectroscopy.The catalytic activity and resistance to water vapor and SO_(2) of the asprepared catalysts for the SCR of NO_(x) with NH_(3) were evaluated at 50-250℃ and GHSV of 80000 mL/(gcat·h).The results reveal that MnCeO_(x)/TiO_(2)-Al_(2)O_(3) exhibits higher activity and better SO_(2) tolerance than MnCeO_(x)/TiO_(2).Combining with the characterization results,the enhanced activity and SO_(2) tolerance of MnCeO_(x)/TiO_(2)-Al_(2)O_(3) can be mainly attributed to higher relative concentrations of Mn4+and chemisorbed oxygen species,stronger reducibility,and larger adsorption capacity for NH_(3) and NO,which originate from the larger specific surface area and pore volume,higher dispersion of Mn and Ce species compared with MnCeO_(x)/TiO_(2).Moreover,in situ DRIFTS was used to investigate the reaction mechanism,and the results indicate that the NH_(3)-SCR reaction over MnCeO_(x)/TiO_(2) and MnCeO_(x)/TiO_(2)-Al_(2)O_(3) takes place by both the E-R and L-H mechanisms.
文摘Salt and low temperature were both very important factors for soybean production. It was necessary to improve the salt stress and low-temperature tolerance of soybean. The main purpose of this paper was to map the quantitative trait loci(QTL) related with salt tolerance and low- temperature tolerance at germination stage with backcross introgression lines(BILs),and analyze the genetic overlap between them. There were 22 QTL located with BC2 F4 introgression populations after salt stress,and 15 QTL were mapped after low-temperature stress. Seven overlapping QTLs between salt tolerance and low-temperature tolerance were detected on 6 linkage groups at germination stage. In total,there were 31.81 % of salt tolerance and low-temperature tolerance loci existed genetic overlap.
基金supported by the National Natural Science Foundation of China(No.62173281)the Natural Science Foundation of Sichuan Province(No.23ZDYF0734 and No.2023NSFSC1436)the Fund of Robot Technology Used for Special Environment Key Laboratory of Sichuan Province(No.18kftk03).
文摘Monitoring various internal parameters plays a core role in ensuring the safety of lithium-ion batteries in power supply applications.It also influences the sustainability effect and online state of charge prediction.An improved multiple feature-electrochemical thermal coupling modeling method is proposed considering low-temperature performance degradation for the complete characteristic expression of multi-dimensional information.This is to obtain the parameter influence mechanism with a multi-variable coupling relationship.An optimized decoupled deviation strategy is constructed for accurate state of charge prediction with real-time correction of time-varying current and temperature effects.The innovative decoupling method is combined with the functional relationships of state of charge and open-circuit voltage to capture energy management ef-fectively.Then,an adaptive equivalent-prediction model is constructed using the state-space equation and iterative feedback correction,making the proposed model adaptive to fractional calculation.The maximum state of charge estimation errors of the proposed method are 4.57%and 0.223%under the Beijing bus dynamic stress test and dynamic stress test conditions,respectively.The improved multiple feature-electrochemical thermal coupling modeling realizes the effective correction of the current and temperature variations with noise influencing coefficient,and provides an efficient state of charge prediction method adaptive to complex conditions.
基金supported by the National Natural Science Foundation of China(No.91641205,No.51622605,No.91541201)the Shanghai Science and Technology Committee(No.17XD1402000)
文摘We report the investigation on the low-temperature oxidation of cyclohexane in a jet-stirred reactor over 500-742 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry （SVUV-PIMS） was used for identifying and quantifying the oxidation species. Major products, cyclic olefins, and oxygenated products including reactive hydroperoxides and high oxygen compounds were detected. Compared with n-alkanes, a narrow low-temperature window （-80 K） was observed in the low-temperature oxidation of cyclohexane. Besides, a kinetic model for cyclohexane oxidation was developed based on the CNRS model [Combust. Flame 160, 2319 （2013）], which can better capture the experimental results than previous models. Based on the modeling analysis, the 1,5-H shift dominates the crucial isomerization steps of the first and second O2 addition products in the low-temperature chain branching process of cyclohexane. The negative temperature coefficient behavior of cyclohexane oxidation results from the reduced chain branching due to the competition from chain inhibition and propagation reactions, i.e. the reaction between cyclohexyl radical and O2 and the de- composition of cyclohexylperoxy radical, both producing cyclohexene and HO2 radical, as well as the decomposition of cyclohexylhydroperoxy radical producing hex-5-en-l-al and OH radical.
基金supported by the National Natural Science Foundation of China(22279025,21773048)the Natural Science Foundation of Heilongjiang Province(LH2021A013)+1 种基金the Sichuan Science and Technology Program(2021YFSY0022)the Fundamental Research Funds for the Central Universities(2023FRFK06005,HIT.NSRIF202204)。
文摘Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.
文摘The observations from 14-yr long-term investigation on the soil-water losses in the sloping red-earth (slope 8°- 15°) showed that soil-water losses were closely correlated with land slope and vegetative coverage. Runoff rate in sloping red-earth could be reduced doubly by exploitation, while the soil erosion was enhanced doubly during the first two years after exploitation. Subsequently, it tended to be stable. Soil erosion was highly positively correlated with land slope, i. e. soil erosion increased by 120 t km-2 yr-1 with a slope increase of 1°. On the contrary, soil erosion was highly negatively correlated with vegetative coverage, i. e. soil erosion was limited at 200 t km-2 yr-1 below as the vegetative coverage exceeded 60%. Furthermore, soil erosion was highly related with planting patterns, i. e. soil erosion in contour cropping pattern would be one sixth of that in straight cropping. Based on the view of soil nutrient balance and test data, it was first suggested that the soil loss tolerance in Q2 red clay derived red-earth should be lower than 300 t km-2 yr-1.
基金The National Basic Research Program(973 Program)of China under contract Nos 2013CB956103 and 2013CB956104the National Natural Science Foundation of China under contract Nos 41306109,41476038 and 41676049the Youth Innovation Promotion Association CAS under contract No.2015284
文摘Marginal scleractinian corals growing at their latitudinal limits should be quite sensitive to variations in winter sea surface temperatures(SSTs). An extreme cold event occurring in early 2008 offered a unique opportunity to examine the effect of cold-water anomalies on Porites lutea corals and their physiological tolerance and acclimation in the subtropical northern South China Sea(NSCS). Besides in-situ observation, a subsequent aquarium-based experiment was designed for reproducing the chilling process and a 50-year-long Sr/Ca ratio profile from two P. lutea skeletal slabs was analyzed for reconstructed the historical annual minimum SSTs which ceased Porites calcification. The 2008 low-temperature anomaly caused the minimum daily mean SSTs dropped below 13°C in the Daya Bay. The stress symptoms displayed by local P. lutea colonies included polyp retraction, reduced coloration and pale, but none showed tissue sloughing. The ability of P. lutea to survive implied its tolerance of extreme low temperatures. Here we suggest a model on the tolerance of high-latitude Porites under low-temperature stresses, which is when SSTs drop below 18°C, Porites corals contract their tentacles(losing heterotrophic capability), then cease calcification(reducing energy consumption), and meanwhile maintain relatively high levels of zooxanthellae density(sustaining host’s life via photosynthetic capacity of symbiotic zooxanthellae). This study revealed remarkable acclimatization of P. lutea corals to low temperature extremes. This acclimatization is beneficial for Porites corals in the NSCS to expand their living ranges towards the higher-latitude areas and have the potential to be the incipient reef former.
文摘An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coefficient is derived,which takes into account of several factors affecting the manufacturing cost,including the forming means of the blank,size,machining surface features,operator’s skills and machinability of materials. The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance,and,hence,an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient,the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation,which indicates the increase of the tolerance’s effects on the total manufacturing cost and,therefore,a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient,accurate and practicable.
文摘The aim of this research was to evaluate the salinity tolerance in prairie grass populations at the seedling stage quantifying the variability and the influence of physiological traits related to it. Salinity tolerance, in </span><i><span style="font-family:Verdana;">Bromus</span></i> <i><span style="font-family:Verdana;">catharticus</span></i><span style="font-family:Verdana;"> Vahl (prairie grass) populations collected in different environments of the Pampean Phytogeography region (Argentine) was evaluated at the seedling stage, using controlled condition of temperature and light. It was adopted a completely randomized design using 3 plots with three plants each one per population and two levels of treatment: 0 mM and 100 mM NaCl. Morphological, biomass and membrane stability root and shoot traits were studied. A factorial ANOVA with interaction was estimated. Then one way ANOVA for all seedling traits in both treatments allowed estimating variance components, coefficient of genotypic determination (CGD) and variation index (VI). Comparisons between populations were made using Tukey test (at 5% of probability). Phenotypic correlations among traits were calculated and then a path coefficient analysis separated direct and indirect effects at 100 and 0 mM NaCl. No significant interactions “Population × Treatment” were found for any character. The saline stress caused a pairing in the population means for the most traits. Coefficients of variation were mainly higher when the seedlings grew without stress (0 mM) because it allowed a greater potential genotypic expression. The absence of significant interactions denotes a good homeostatic capacity of the prairie grass facing that abiotic stress. Leaf length, shoot length and root dry matter were the variables with the largest direct and indirect effects. Our results showed an increase for them at salt and demonstrated intraspecific variation, possibly in relation with the origin sites. Plants under stress showed a marked resilience, in order to quickly restore the same biomass allocation patterns that occur in non-stress environment.
基金funded by the Science and Technology Project of Henan Provincial Department of Science and Technology(Item No.222102110282).
文摘Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during planting.In this study,transcriptomic profiles of low-temperature-and normal-temperature-germinated seeds of Xinluzao 25,a variety with low-temperature tolerance and high germination rates,were analyzed and compared.The following results were obtained.(1)A total of 81.06 Gb of clean data were obtained after transcriptome sequencing and assembly,and 76,931 non-redundant Unigene sequences were obtained after data consolidation and concatenation;of these,69,883 Unigene sequences were annotated.In addition,55,463 Unigene transcript sequences(72.2%)were annotated for Gene Ontology(GO)classification,and 26,629 genes were involved in 50 metabolic pathways identified by Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.(2)Three main pathways related to low-temperature tolerance of seed germination were identified:starch and sucrose metabolism,phenylpropanoid biosynthesis,and cysteine and methionine metabolism.Their main molecular functions involve the regulation of abscisic acid and activities of enzymes such as amylase,peroxidase,and oxidoreductase.During germination at low temperature,more genes were down-regulated than up-regulated genes at the protrusion stage(2 mm),and more genes were up-regulated than down-regulated at the germination stage(30 mm)after protrusion.(3)The enzyme activities at the two stages showed that amylase,peroxidase,catalase,and glutathione reductase had higher activities when the seeds germinated at 15℃.In this study,high expression of amylase,peroxidase,catalase,and glutathione reductase genes may be the main cause of increased tolerance to low temperature.
文摘Ablotlc stress, such as salt, drought and extreme temperature, can result in enhanced production of reactive oxygen species （ROS）. Plants have developed both enzymatic ROS-scavenging and non-enzymatic ROS-scavenging systems. The major ROS-scavenging enzymes of plants include superoxide dismutase （SOD）, ascorbate peroxldaae （APX）, catalaae （CAT）, glutathione peroxldaae （GPX） and peroxiredoxina （Prxa）. In the present work, we identified a gene encoding chloroplast-located peroxiredoxin Q, SsPrxQ, from Suaeda salsa L. located at chloroplast. Overexpression of SsPrxQ In Arabidopsis leads to an increase In salt and low-temperature tolerance.
文摘The temperature coefficient of permittivity(TCε)of BaTiO_(3)–Bi(Me)O_(3) solid solutions were investigated.It was determined that as the tolerance factor was decreased with the addition of Bi(Me)O_(3),the TCε shifted from large negative values to TCε values approaching zero.It is proposed that the different bonding nature of the dopant cation affects the magnitude and temperature stability of the permittivity.This study suggests that the relationship between tolerance factor and TCε can be used as a guide to design new dielectric compounds exhibiting temperature-stable high permittivity characteristics,which is similar to past research on perovskite and pyrochlore-based microwave dielectrics.
