Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly ...Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly important for achieving high and stable wheat yields.In this study,Tongmai 6(insensitive)and Zhengmai 113(sensitive),which have different low-temperature sensitivities during germination were treated with low temperature during germination.The transcriptome,metabolome and physiological data revealed that low temperature decreased the germination rate,downregulated the expression of a large number of genes involved in regulating glycometabolism,and inhibited carbon,nitrogen(especially amino acids)and energy metabolism in the seeds.Arginine content increased at low temperature,and its increase in the low-temperature-tolerant variety was significantly greater than that in the sensitive variety.Arginine priming experiment showed that treatment with an appropriate concentration of arginine improved the seed germination rate.The conversion of starch to soluble sugar significantly increased under exogenous arginine conditions,the content of key metabolites in energy metabolism increased,and the utilization of ATP in the seeds increased.Taken together,arginine priming increased seed germination at low temperature by relieving inhibition of seed carbon and nitrogen metabolism and improving seed energy metabolism.展开更多
Li1.5Ga0.5Ti1.5(PO4)3(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects...Li1.5Ga0.5Ti1.5(PO4)3(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects of sintering temperature and holding time on relative density,phase composition,microstructure,bulk conductivity,and total conductivity.In the impedance test under frequency of 1-10~6 Hz,the bulk conductivity of the samples increased with increasing sintering temperature,and the total conductivity first increased and then decreased.SEM results showed that the average grain size in the ceramics was controlled by the sintering temperature,which increased from(0.54±0.01)μm to(1.21±0.01)μm when the temperature changed from 750 to 950°C.The relative density of the ceramics increased and then decreased with increasing temperature as the porosity increased.The holding time had little effect on the grain size growth or sample density,but an extended holding time resulted in crack generation that served to reduce the conductivity of the solid electrolyte.展开更多
Ocean temperature is an important physical variable in marine ecosystems,and ocean temperature prediction is an important research objective in ocean-related fields.Currently,one of the commonly used methods for ocean...Ocean temperature is an important physical variable in marine ecosystems,and ocean temperature prediction is an important research objective in ocean-related fields.Currently,one of the commonly used methods for ocean temperature prediction is based on data-driven,but research on this method is mostly limited to the sea surface,with few studies on the prediction of internal ocean temperature.Existing graph neural network-based methods usually use predefined graphs or learned static graphs,which cannot capture the dynamic associations among data.In this study,we propose a novel dynamic spatiotemporal graph neural network(DSTGN)to predict threedimensional ocean temperature(3D-OT),which combines static graph learning and dynamic graph learning to automatically mine two unknown dependencies between sequences based on the original 3D-OT data without prior knowledge.Temporal and spatial dependencies in the time series were then captured using temporal and graph convolutions.We also integrated dynamic graph learning,static graph learning,graph convolution,and temporal convolution into an end-to-end framework for 3D-OT prediction using time-series grid data.In this study,we conducted prediction experiments using high-resolution 3D-OT from the Copernicus global ocean physical reanalysis,with data covering the vertical variation of temperature from the sea surface to 1000 m below the sea surface.We compared five mainstream models that are commonly used for ocean temperature prediction,and the results showed that the method achieved the best prediction results at all prediction scales.展开更多
[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as...[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as the research objects,the changes in germination potential,germination index,plant height,biomass,and antioxidant enzyme activity of maize seeds were studied under optimal temperature conditions(25℃)and low temperature stress conditions(10℃).[Results]Under 10℃stress,the germination rate and germination index of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4.Under low temperature stress,Taitian 264 exhibited the least reduction in height and biomass,while Zhexuetian 1 had the most reduction.Additionally,the SOD and POD activities of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4 under both temperature conditions,while the MDA content of Taitian 264 was lower.Taitian 264 showed strong germination ability against low temperature stress.[Conclusions]This study provides a basis for timely sowing practices of sweet maize in agricultural production.展开更多
Effectiveness and safety of a sports mouthguard depend on its thickness and material, and the thermoforming process affects these. The purpose of this study was to clarify the effects of differences in molding mechani...Effectiveness and safety of a sports mouthguard depend on its thickness and material, and the thermoforming process affects these. The purpose of this study was to clarify the effects of differences in molding mechanisms on the lower molding temperature limit and molding time in dental thermoforming. Ethylene vinyl acetate resin mouthguard sheet and two thermoforming machines;vacuum blower molding machine and vacuum ejector/pressure molding machine were used. The molding pressures for suction molding were −0.018 MPa for vacuum blower molding and −0.090 MPa for vacuum ejector molding, and for pressure molding was set to 0.090 MPa or 0.450 MPa. Based on the manufacturer’s standard molding temperature of 95˚C, the molding temperature was lowered in 2.5˚C increments to determine the lower molding temperature limit at which no molding defects occurred. In order to investigate the difference in molding time depending on the molding mechanism, the duration of molding pressure was adjusted in each molding machine, and the molding time required to obtain a sample without molding defects was measured. The molding time of each molding machine were compared using one-way analysis of variance. The lower molding temperature limit was 90.0˚C for the vacuum blower machine, 77.5˚C for the vacuum ejector machine, 77.5˚C for the pressure molding machine at 0.090 MPa, and 67.5˚C for the pressure molding machine at 0.45 MPa. The lower molding temperature limit was higher for lower absolute values of molding pressure. The molding time was shorter for pressure molding than for suction molding. Significant differences were observed between all conditions except between the pressure molding machine at 0.090 MPa and 0.45 MPa (P < 0.01). A comparison of the differences in lower molding temperature limit and molding time due to molding mechanisms in dental thermoforming revealed that the lower molding temperature limit depends on the molding pressure and that the molding time is longer for suction molding than for pressure molding.展开更多
Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests ...Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.展开更多
Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the...Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.展开更多
The mature seed of Paris polyphylla var.chinensis(PPC)is morphophysiologically dormant and develops differently under warm and cold temperatures.To elucidate the molecular mechanisms underlying temperature-dependent r...The mature seed of Paris polyphylla var.chinensis(PPC)is morphophysiologically dormant and develops differently under warm and cold temperatures.To elucidate the molecular mechanisms underlying temperature-dependent regulation of PPC seed dormancy and germination,we investigated the dynamic changes in PPC seed transcript levels under warm and cold temperature stratifications(WS and CS,respectively)by time-resolved RNA sequencing,focusing on genes related to hormone metabolism and signaling and cell wall remodeling(CWRM)and encoding transcription factors/regulators(TFs/TRs).A total of 48765 and 47836 differentially expressed genes(DEGs)were associated with WS and CS,respectively.Of these,17581 and 16652 DEGs,respectively,unique to WS and CS,and 5386 were common to both temperature stratifications across nine analyzed growth stages.The expression of hormone metabolism and signaling,TF/TR,and CWRM genes were closely associated with temperature.More genes related to gibberellin(GA),cytokinin,auxin,and brassinosteroid biosynthetic were upregulated in WS as compared to CS seeds,while genes related to dormancy release and germination were downregulated in WS seeds.However,only GA and abscisic acid levels were altered in PPC seeds breaking morphophysiological dormancy(MPD).Overall,37 TF and five TR families were upregulated whereas 24 TF and 16 TR families were downregulated in WS as compared to CS seeds.Most CWRM families were highly expressed under WS as compared to CS,suggesting that they promote endosperm weakening and embryo growth of WS seeds and facilitate MPD release and germination.A coexpression analysis revealed positive correlations between TFs/TRs and DEGs involved in hormone metabolism and signaling and CWRM.These results provided a basis for investigating the interaction between the endosperm and underdeveloped embryo in the regulation of PPC seed germination and seedling emergence.展开更多
The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side w...The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side walls and free surface of the channel have been taken from the literature. For each geometry, the volumetric flow rate, mean residence time and temperature drop as a function of the channel inclination angle were determined. The rectangular and trapezoidal geometries present the smallest temperature drops, while the triangular geometry presents the greatest temperature drop. The factors that most affect this drop are the value of the free surface area of the channel, and the average residence time of the molten metal in the channel.展开更多
A thermoelectric generation Stirling engine (TEG-Stirling engine) is discussed by employing a low temperature Stirling engine and the dissipative equation of motion derived from the method of thermomechanical dynamics...A thermoelectric generation Stirling engine (TEG-Stirling engine) is discussed by employing a low temperature Stirling engine and the dissipative equation of motion derived from the method of thermomechanical dynamics (TMD). The results and mechanism of axial flux electromagnetic induction (AF-EMI) are applied to a low temperature Stirling engine, resulting in a TEG-Stirling engine. The method of TMD produced thermodynamically consistent and time-dependent physical quantities for the first time, such as internal energy ℰ(t), thermodynamic work Wth(t), the total entropy (heat dissipation) Qd(t)and measure or temperature of a nonequilibrium state T˜(t). The TMD analysis produced a lightweight mechanical system of TEG-Stirling engine which derives electric power from waste heat of temperature (40˚CT100˚C) by a thermoelectric conversion method. An optimal low rotational speed about 30θ′(t)/(2π)60(rpm) is found, applicable to devices for sustainable, clean energy technologies. The stability of a thermal state and angular rotations of TEG-Stirling engine are specifically shown by employing properties of nonequilibrium temperature T˜(t), which is also applied to study optimal fuel-injection and combustion timings of heat engines.展开更多
As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different...As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.展开更多
In this paper,we describe and analyze two datasets entitled“Homogenised monthly and daily temperature and precipitation time series in China during 1960–2021”and“Homogenised monthly and daily temperature and preci...In this paper,we describe and analyze two datasets entitled“Homogenised monthly and daily temperature and precipitation time series in China during 1960–2021”and“Homogenised monthly and daily temperature and precipitation time series in Greece during 1960–2010”.These datasets provide the homogenised monthly and daily mean(TG),minimum(TN),and maximum(TX)temperature and precipitation(RR)records since 1960 at 366 stations in China and 56stations in Greece.The datasets are available at the Science Data Bank repository and can be downloaded from https://doi.org/10.57760/sciencedb.01731 and https://doi.org/10.57760/sciencedb.01720.For China,the regional mean annual TG,TX,TN,and RR series during 1960–2021 showed significant warming or increasing trends of 0.27℃(10 yr)^(-1),0.22℃(10 yr)^(-1),0.35℃(10 yr)^(-1),and 6.81 mm(10 yr)-1,respectively.Most of the seasonal series revealed trends significant at the 0.05level,except for the spring,summer,and autumn RR series.For Greece,there were increasing trends of 0.09℃(10 yr)-1,0.08℃(10 yr)^(-1),and 0.11℃(10 yr)^(-1)for the annual TG,TX,and TN series,respectively,while a decreasing trend of–23.35 mm(10 yr)^(-1)was present for RR.The seasonal trends showed a significant warming rate for summer,but no significant changes were noted for spring(except for TN),autumn,and winter.For RR,only the winter time series displayed a statistically significant and robust trend[–15.82 mm(10 yr)^(-1)].The final homogenised temperature and precipitation time series for both China and Greece provide a better representation of the large-scale pattern of climate change over the past decades and provide a quality information source for climatological analyses.展开更多
The purpose is to study the influence of cooking and storage habits on the quality of macadamia nut oil,so as to provide reference for macadamia nut processingenterprises and consumers.Macadamia oil was treated at 100...The purpose is to study the influence of cooking and storage habits on the quality of macadamia nut oil,so as to provide reference for macadamia nut processingenterprises and consumers.Macadamia oil was treated at 100℃,200℃,300℃,microwave heating,45℃constant temperature storage,natural light for different times,and its acid value,peroxide value,squalene,sterol and fatty acid content were detected according to the national standard method.The results showed that the acid value and peroxide value increased with time.The acid value and peroxide value of macadamia oil cooked at 300℃and stored under natural light were higher than those heated by microwave and stored at 45℃,and increased rapidly with the increase of cooking and light time.The acid value was as high as 0.77 mg/g,with an increase of 63.8%,and the peroxide value was as high as 6.18 mg/g,with an increase of 43.7%.As for squalene,it decreased in varying degrees with heating time and storage time.Squalene in macadamia oil cooked at 300℃and stored under natural light were lower than those heated by microwave and stored at 45℃constant temperature,respectively,and decreased rapidly with the increase of cooking and light time,with the reduction ranges of 38.6%and28.4%respectively;Stigmasterol was not detected in macadamia oil.But in macadamia oil the content ofβ-sitosterol was 0.132 g/100 g,and the content did not change significantly in each treatmentgroup.In the experimental treatment group,the content of fatty acids in macadamia oil had different trends.After treatment at 300℃for 20 minutes,the content of oleic acid decreased by 75.66%,the content of palmitic acid decreased by 75.28%,and thecontent of palmitic acid decreased by 74.12%.In conclusion,low temperature heating,microwave heating and storage away from light can better preserve the quality of macadamia oil,this study will provide a theoretical basisfor the rational utilization of macadamia oil as cooking oil.展开更多
The response of seed germination to environmental factors can be estimated by nonlinear regression. The present study was performed to compare four nonlinear regression models(segmented, beta, beta modified, and dent-...The response of seed germination to environmental factors can be estimated by nonlinear regression. The present study was performed to compare four nonlinear regression models(segmented, beta, beta modified, and dent-like) to describe the germination rate–temperature relationships of milk thistle(Silybum marianum L.) at six constant temperatures, with the aim of identifying the cardinal temperatures and thermal times required to reach different germination percentiles. Models and statistical indices were calibrated using an iterative optimization method and their performance was compared by root mean square error(RMSE), coefficient of determination(R2) and Akaike information criterion correction(AICc). The beta model was found to be the best model for predicting the required time to reach 50% germination(D50),(R2= 0.99;RMSE = 0.004; AICc =-276.97). Based on the model outputs, the base, optimum, and maximum temperatures of seed germination were 5.19 ± 0.79, 24.01 ± 0.11, and 34.32 ± 0.36 °C,respectively. The thermal times required for 50% and 90% germination were 4.99 and7.38 degree-days, respectively.展开更多
According to the Doehlert's matrix method, the adsorbent derived from sewage sludge was prepared through chemical activation under controlling the pyrolysis temperature and hold time. The characteristic parameters...According to the Doehlert's matrix method, the adsorbent derived from sewage sludge was prepared through chemical activation under controlling the pyrolysis temperature and hold time. The characteristic parameters including the total yield, adsorption of methylene blue, adsorption of iodine, BET surface area, micro-pore volume are 35%—49%, 16.5—38 mg/g, 285—362 mg/g, 185—359 m2/g, and 0.112—0.224 m3/g, respectively. According to the experimental data, the multi-linear regression method was adopted to fit the relations between the characteristic parameters and influential factors. At final, through optimization method, the optimal adsorbent is obtained when using 62 min as hold time and 1105K as pyrolysis temperature. Under the conditions, the adsorbent was produced and compared the characteristic parameters with model forecast value, the coherence is satisfied.展开更多
In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron micr...In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.展开更多
Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningf...Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems.Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures(5℃/1℃, 15℃/5℃, 20℃/5℃, 25℃/10℃ and 30℃/15℃) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016.Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light.We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination.It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures.There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination.Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow.Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer.Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.展开更多
Objective:To study the number of leptospirosis cases in relations to the seasonal pattern,and its association with climate factors.Methods:Time series analysis was used to study the time variations in the number of le...Objective:To study the number of leptospirosis cases in relations to the seasonal pattern,and its association with climate factors.Methods:Time series analysis was used to study the time variations in the number of leptospirosis cases.The Autoregressive Integrated Moving Average (ARIMA) model was used in data curve fitting and predicting the next leptospirosis cases. Results:We found that the amount of rainfall was correlated to leptospirosis cases in both regions of interest,namely the northern and northeastern region of Thailand,while the temperature played a role in the northeastern region only.The use of multivariate ARIMA(ARIMAX) model showed that factoring in rainfall(with an 8 months lag) yields the best model for the northern region while the model,which factors in rainfall(with a 10 months kg) and temperature(with an 8 months lag) was the best for the northeaslern region.Conclusions:The models are able to show the trend in leptospirosis cases and closely fit the recorded data in both regions.The models can also be used to predict the next seasonal peak quite accurately.展开更多
We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holdin...We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holding time on crystalline, microstructure and content of aluminum titanate materials to determine the preferred calcining temperature and holding time. XRD and SEM methods were utilized to characterize the crystalline and microstructure of each specimen, Rietveld Quantification software was used for the determination of different crystalline contents of specimens, and Philips plus software was applied to determine the cell parameters of aluminium titanate in different specimens. According to the experimental results, preferred calcining temperature is determined as 1400℃ and preferred holding time is 2 h, at which the grains of aluminum titanate grow completely and the purity of aluminum titanate is 97.2wt%.展开更多
Objective To examine the effect of hydraulic residence time (HRT) on the performance and stability, to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor (CABR), a...Objective To examine the effect of hydraulic residence time (HRT) on the performance and stability, to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor (CABR), and hence to gain a deeper insight into microbial responses to hydraulic shocks on the base of the relationships among macroscopic performance, catabolic intermediate, and microcosmic alternation. Methods COD, VFAs, and microbial activity were detected with constant feed strength (300 mg/L) at different HRTs (9-18 h) and temperatures (10℃-28℃) in a CABR. Results The removal efficiencies declined with the decreases of HRTs and temperatures. However, the COD removal load was still higher at short HRT than at long HRT. Devastating reactor performance happened at temperature of 10℃ and at HRT of 9 h. HRTs had effect on the VFAs in the reactor slightly both at high and low temperatures, but the reasons differed from each other. Microbial activity was sensitive to indicate changes of environmental and operational parameters in the reactor. Conclusion The CABR offers to certain extent an application to treat dilute wastewater under a hydraulic-shock at temperatures from 10℃to 28℃.展开更多
基金supported by the Key Research and Development Program of Shaanxi(2021NY-083)the National Natural Science Foundation of China(31871567).
文摘Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly important for achieving high and stable wheat yields.In this study,Tongmai 6(insensitive)and Zhengmai 113(sensitive),which have different low-temperature sensitivities during germination were treated with low temperature during germination.The transcriptome,metabolome and physiological data revealed that low temperature decreased the germination rate,downregulated the expression of a large number of genes involved in regulating glycometabolism,and inhibited carbon,nitrogen(especially amino acids)and energy metabolism in the seeds.Arginine content increased at low temperature,and its increase in the low-temperature-tolerant variety was significantly greater than that in the sensitive variety.Arginine priming experiment showed that treatment with an appropriate concentration of arginine improved the seed germination rate.The conversion of starch to soluble sugar significantly increased under exogenous arginine conditions,the content of key metabolites in energy metabolism increased,and the utilization of ATP in the seeds increased.Taken together,arginine priming increased seed germination at low temperature by relieving inhibition of seed carbon and nitrogen metabolism and improving seed energy metabolism.
基金funded by the National Natural Science Foundation of China(Nos.51672310,51272288,51972344)。
文摘Li1.5Ga0.5Ti1.5(PO4)3(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects of sintering temperature and holding time on relative density,phase composition,microstructure,bulk conductivity,and total conductivity.In the impedance test under frequency of 1-10~6 Hz,the bulk conductivity of the samples increased with increasing sintering temperature,and the total conductivity first increased and then decreased.SEM results showed that the average grain size in the ceramics was controlled by the sintering temperature,which increased from(0.54±0.01)μm to(1.21±0.01)μm when the temperature changed from 750 to 950°C.The relative density of the ceramics increased and then decreased with increasing temperature as the porosity increased.The holding time had little effect on the grain size growth or sample density,but an extended holding time resulted in crack generation that served to reduce the conductivity of the solid electrolyte.
基金The National Key R&D Program of China under contract No.2021YFC3101603.
文摘Ocean temperature is an important physical variable in marine ecosystems,and ocean temperature prediction is an important research objective in ocean-related fields.Currently,one of the commonly used methods for ocean temperature prediction is based on data-driven,but research on this method is mostly limited to the sea surface,with few studies on the prediction of internal ocean temperature.Existing graph neural network-based methods usually use predefined graphs or learned static graphs,which cannot capture the dynamic associations among data.In this study,we propose a novel dynamic spatiotemporal graph neural network(DSTGN)to predict threedimensional ocean temperature(3D-OT),which combines static graph learning and dynamic graph learning to automatically mine two unknown dependencies between sequences based on the original 3D-OT data without prior knowledge.Temporal and spatial dependencies in the time series were then captured using temporal and graph convolutions.We also integrated dynamic graph learning,static graph learning,graph convolution,and temporal convolution into an end-to-end framework for 3D-OT prediction using time-series grid data.In this study,we conducted prediction experiments using high-resolution 3D-OT from the Copernicus global ocean physical reanalysis,with data covering the vertical variation of temperature from the sea surface to 1000 m below the sea surface.We compared five mainstream models that are commonly used for ocean temperature prediction,and the results showed that the method achieved the best prediction results at all prediction scales.
基金Supported by Zhejiang Basic Public Welfare Research Program Project(LGN21C020006)Key Research and Development Project of Zhejiang Province(2021C02057)+1 种基金Zhejiang Major Science and Technology Project of Agricultural New Variety(Upland Food)Breeding(2021C02064)Key Research and Development Project of Zhejiang Province(2022C04024).
文摘[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as the research objects,the changes in germination potential,germination index,plant height,biomass,and antioxidant enzyme activity of maize seeds were studied under optimal temperature conditions(25℃)and low temperature stress conditions(10℃).[Results]Under 10℃stress,the germination rate and germination index of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4.Under low temperature stress,Taitian 264 exhibited the least reduction in height and biomass,while Zhexuetian 1 had the most reduction.Additionally,the SOD and POD activities of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4 under both temperature conditions,while the MDA content of Taitian 264 was lower.Taitian 264 showed strong germination ability against low temperature stress.[Conclusions]This study provides a basis for timely sowing practices of sweet maize in agricultural production.
文摘Effectiveness and safety of a sports mouthguard depend on its thickness and material, and the thermoforming process affects these. The purpose of this study was to clarify the effects of differences in molding mechanisms on the lower molding temperature limit and molding time in dental thermoforming. Ethylene vinyl acetate resin mouthguard sheet and two thermoforming machines;vacuum blower molding machine and vacuum ejector/pressure molding machine were used. The molding pressures for suction molding were −0.018 MPa for vacuum blower molding and −0.090 MPa for vacuum ejector molding, and for pressure molding was set to 0.090 MPa or 0.450 MPa. Based on the manufacturer’s standard molding temperature of 95˚C, the molding temperature was lowered in 2.5˚C increments to determine the lower molding temperature limit at which no molding defects occurred. In order to investigate the difference in molding time depending on the molding mechanism, the duration of molding pressure was adjusted in each molding machine, and the molding time required to obtain a sample without molding defects was measured. The molding time of each molding machine were compared using one-way analysis of variance. The lower molding temperature limit was 90.0˚C for the vacuum blower machine, 77.5˚C for the vacuum ejector machine, 77.5˚C for the pressure molding machine at 0.090 MPa, and 67.5˚C for the pressure molding machine at 0.45 MPa. The lower molding temperature limit was higher for lower absolute values of molding pressure. The molding time was shorter for pressure molding than for suction molding. Significant differences were observed between all conditions except between the pressure molding machine at 0.090 MPa and 0.45 MPa (P < 0.01). A comparison of the differences in lower molding temperature limit and molding time due to molding mechanisms in dental thermoforming revealed that the lower molding temperature limit depends on the molding pressure and that the molding time is longer for suction molding than for pressure molding.
基金the National Natural Science Foundation of China(No.31901300)Natural Science Foundation of Guizhou Province+2 种基金China(No.(2019)1165)Science and Technology Foundation of Guizhou ProvinceChina(No.[2018]137,No.[2018]133)。
文摘Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.
基金supported by the Project of State Grid Hebei Electric Power Co.,Ltd.(SGHEYX00SCJS2100077).
文摘Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.
基金supported by the CAMS Innovation Fund for Medical Sciences (CIFMS) (2017-I2M-3-013)the National Key Research and Development Program of China (Grant No. 2017YFC1700706)the National Natural Science Foundation of China (Grant No. 31471575).
文摘The mature seed of Paris polyphylla var.chinensis(PPC)is morphophysiologically dormant and develops differently under warm and cold temperatures.To elucidate the molecular mechanisms underlying temperature-dependent regulation of PPC seed dormancy and germination,we investigated the dynamic changes in PPC seed transcript levels under warm and cold temperature stratifications(WS and CS,respectively)by time-resolved RNA sequencing,focusing on genes related to hormone metabolism and signaling and cell wall remodeling(CWRM)and encoding transcription factors/regulators(TFs/TRs).A total of 48765 and 47836 differentially expressed genes(DEGs)were associated with WS and CS,respectively.Of these,17581 and 16652 DEGs,respectively,unique to WS and CS,and 5386 were common to both temperature stratifications across nine analyzed growth stages.The expression of hormone metabolism and signaling,TF/TR,and CWRM genes were closely associated with temperature.More genes related to gibberellin(GA),cytokinin,auxin,and brassinosteroid biosynthetic were upregulated in WS as compared to CS seeds,while genes related to dormancy release and germination were downregulated in WS seeds.However,only GA and abscisic acid levels were altered in PPC seeds breaking morphophysiological dormancy(MPD).Overall,37 TF and five TR families were upregulated whereas 24 TF and 16 TR families were downregulated in WS as compared to CS seeds.Most CWRM families were highly expressed under WS as compared to CS,suggesting that they promote endosperm weakening and embryo growth of WS seeds and facilitate MPD release and germination.A coexpression analysis revealed positive correlations between TFs/TRs and DEGs involved in hormone metabolism and signaling and CWRM.These results provided a basis for investigating the interaction between the endosperm and underdeveloped embryo in the regulation of PPC seed germination and seedling emergence.
文摘The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side walls and free surface of the channel have been taken from the literature. For each geometry, the volumetric flow rate, mean residence time and temperature drop as a function of the channel inclination angle were determined. The rectangular and trapezoidal geometries present the smallest temperature drops, while the triangular geometry presents the greatest temperature drop. The factors that most affect this drop are the value of the free surface area of the channel, and the average residence time of the molten metal in the channel.
文摘A thermoelectric generation Stirling engine (TEG-Stirling engine) is discussed by employing a low temperature Stirling engine and the dissipative equation of motion derived from the method of thermomechanical dynamics (TMD). The results and mechanism of axial flux electromagnetic induction (AF-EMI) are applied to a low temperature Stirling engine, resulting in a TEG-Stirling engine. The method of TMD produced thermodynamically consistent and time-dependent physical quantities for the first time, such as internal energy ℰ(t), thermodynamic work Wth(t), the total entropy (heat dissipation) Qd(t)and measure or temperature of a nonequilibrium state T˜(t). The TMD analysis produced a lightweight mechanical system of TEG-Stirling engine which derives electric power from waste heat of temperature (40˚CT100˚C) by a thermoelectric conversion method. An optimal low rotational speed about 30θ′(t)/(2π)60(rpm) is found, applicable to devices for sustainable, clean energy technologies. The stability of a thermal state and angular rotations of TEG-Stirling engine are specifically shown by employing properties of nonequilibrium temperature T˜(t), which is also applied to study optimal fuel-injection and combustion timings of heat engines.
基金supported by the Gorgan University of Agricultural Sciences and Natural ResourcesSabz Fanavaran Loozan Shomal Company+1 种基金University of GuilanGuilan Science and Technology Park, Iran
文摘As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.
基金funded by the Hellenic and Chinese Governments,in the frame of the Greek-Chinese R&T Cooperation Programme project“Comparative study of extreme climate indices in China and Europe/Greece,based on homogenised daily observations—CLIMEX”(Contract T7ΔKI-00046)the National Key Technologies Research and Development Program“Comparative study of changing climate extremes between China and Europe/Greece based on homogenised daily observations”(Grant No.2017YFE0133600)。
文摘In this paper,we describe and analyze two datasets entitled“Homogenised monthly and daily temperature and precipitation time series in China during 1960–2021”and“Homogenised monthly and daily temperature and precipitation time series in Greece during 1960–2010”.These datasets provide the homogenised monthly and daily mean(TG),minimum(TN),and maximum(TX)temperature and precipitation(RR)records since 1960 at 366 stations in China and 56stations in Greece.The datasets are available at the Science Data Bank repository and can be downloaded from https://doi.org/10.57760/sciencedb.01731 and https://doi.org/10.57760/sciencedb.01720.For China,the regional mean annual TG,TX,TN,and RR series during 1960–2021 showed significant warming or increasing trends of 0.27℃(10 yr)^(-1),0.22℃(10 yr)^(-1),0.35℃(10 yr)^(-1),and 6.81 mm(10 yr)-1,respectively.Most of the seasonal series revealed trends significant at the 0.05level,except for the spring,summer,and autumn RR series.For Greece,there were increasing trends of 0.09℃(10 yr)-1,0.08℃(10 yr)^(-1),and 0.11℃(10 yr)^(-1)for the annual TG,TX,and TN series,respectively,while a decreasing trend of–23.35 mm(10 yr)^(-1)was present for RR.The seasonal trends showed a significant warming rate for summer,but no significant changes were noted for spring(except for TN),autumn,and winter.For RR,only the winter time series displayed a statistically significant and robust trend[–15.82 mm(10 yr)^(-1)].The final homogenised temperature and precipitation time series for both China and Greece provide a better representation of the large-scale pattern of climate change over the past decades and provide a quality information source for climatological analyses.
基金Science and Technology Project of Guangdong Forestry Society,Grant/Award Number:2020-GDFS-KJ-05Guangzhou Science and Technology Project,Grant/Award Number:202201011039Guangdong Science and Technology plan project,Grant/Award Number:2023B0208010001.
文摘The purpose is to study the influence of cooking and storage habits on the quality of macadamia nut oil,so as to provide reference for macadamia nut processingenterprises and consumers.Macadamia oil was treated at 100℃,200℃,300℃,microwave heating,45℃constant temperature storage,natural light for different times,and its acid value,peroxide value,squalene,sterol and fatty acid content were detected according to the national standard method.The results showed that the acid value and peroxide value increased with time.The acid value and peroxide value of macadamia oil cooked at 300℃and stored under natural light were higher than those heated by microwave and stored at 45℃,and increased rapidly with the increase of cooking and light time.The acid value was as high as 0.77 mg/g,with an increase of 63.8%,and the peroxide value was as high as 6.18 mg/g,with an increase of 43.7%.As for squalene,it decreased in varying degrees with heating time and storage time.Squalene in macadamia oil cooked at 300℃and stored under natural light were lower than those heated by microwave and stored at 45℃constant temperature,respectively,and decreased rapidly with the increase of cooking and light time,with the reduction ranges of 38.6%and28.4%respectively;Stigmasterol was not detected in macadamia oil.But in macadamia oil the content ofβ-sitosterol was 0.132 g/100 g,and the content did not change significantly in each treatmentgroup.In the experimental treatment group,the content of fatty acids in macadamia oil had different trends.After treatment at 300℃for 20 minutes,the content of oleic acid decreased by 75.66%,the content of palmitic acid decreased by 75.28%,and thecontent of palmitic acid decreased by 74.12%.In conclusion,low temperature heating,microwave heating and storage away from light can better preserve the quality of macadamia oil,this study will provide a theoretical basisfor the rational utilization of macadamia oil as cooking oil.
文摘The response of seed germination to environmental factors can be estimated by nonlinear regression. The present study was performed to compare four nonlinear regression models(segmented, beta, beta modified, and dent-like) to describe the germination rate–temperature relationships of milk thistle(Silybum marianum L.) at six constant temperatures, with the aim of identifying the cardinal temperatures and thermal times required to reach different germination percentiles. Models and statistical indices were calibrated using an iterative optimization method and their performance was compared by root mean square error(RMSE), coefficient of determination(R2) and Akaike information criterion correction(AICc). The beta model was found to be the best model for predicting the required time to reach 50% germination(D50),(R2= 0.99;RMSE = 0.004; AICc =-276.97). Based on the model outputs, the base, optimum, and maximum temperatures of seed germination were 5.19 ± 0.79, 24.01 ± 0.11, and 34.32 ± 0.36 °C,respectively. The thermal times required for 50% and 90% germination were 4.99 and7.38 degree-days, respectively.
文摘According to the Doehlert's matrix method, the adsorbent derived from sewage sludge was prepared through chemical activation under controlling the pyrolysis temperature and hold time. The characteristic parameters including the total yield, adsorption of methylene blue, adsorption of iodine, BET surface area, micro-pore volume are 35%—49%, 16.5—38 mg/g, 285—362 mg/g, 185—359 m2/g, and 0.112—0.224 m3/g, respectively. According to the experimental data, the multi-linear regression method was adopted to fit the relations between the characteristic parameters and influential factors. At final, through optimization method, the optimal adsorbent is obtained when using 62 min as hold time and 1105K as pyrolysis temperature. Under the conditions, the adsorbent was produced and compared the characteristic parameters with model forecast value, the coherence is satisfied.
文摘In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.
基金funded by the Science and Technology Plan Project of Xinjiang Uygur Autonomous Region (2016B03040)the National Natural Science Foundation of China (31570529, 31660162, 31971428, 31770638)the Youth Innovation Promotion Association of Chinese Academy of Sciences (2018477)
文摘Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems.Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures(5℃/1℃, 15℃/5℃, 20℃/5℃, 25℃/10℃ and 30℃/15℃) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016.Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light.We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination.It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures.There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination.Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow.Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer.Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.
基金supported by Centre of Encellecne Mathentatics CHEThailand finanieally Sudaral Chadsuthi is supported by the Commission on Higher Education Thailand for its grant support under the Strategie Scholarships for Frintier Research Network for joint Ph.D.Programssupported by the National Science and Technology Development Agency (NSTDA) and Faculty of Science,Mahidol University
文摘Objective:To study the number of leptospirosis cases in relations to the seasonal pattern,and its association with climate factors.Methods:Time series analysis was used to study the time variations in the number of leptospirosis cases.The Autoregressive Integrated Moving Average (ARIMA) model was used in data curve fitting and predicting the next leptospirosis cases. Results:We found that the amount of rainfall was correlated to leptospirosis cases in both regions of interest,namely the northern and northeastern region of Thailand,while the temperature played a role in the northeastern region only.The use of multivariate ARIMA(ARIMAX) model showed that factoring in rainfall(with an 8 months lag) yields the best model for the northern region while the model,which factors in rainfall(with a 10 months kg) and temperature(with an 8 months lag) was the best for the northeaslern region.Conclusions:The models are able to show the trend in leptospirosis cases and closely fit the recorded data in both regions.The models can also be used to predict the next seasonal peak quite accurately.
基金supported by the Natural Science Foundation of Fujian Province (No. T08J0129)the Science and Technology Developing Foundation of Fuzhou University (No. 2008-XQ-001)2007-year New Century Talents Supporting Program of Fujian Province (No.XSJRC2007-17)
文摘We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holding time on crystalline, microstructure and content of aluminum titanate materials to determine the preferred calcining temperature and holding time. XRD and SEM methods were utilized to characterize the crystalline and microstructure of each specimen, Rietveld Quantification software was used for the determination of different crystalline contents of specimens, and Philips plus software was applied to determine the cell parameters of aluminium titanate in different specimens. According to the experimental results, preferred calcining temperature is determined as 1400℃ and preferred holding time is 2 h, at which the grains of aluminum titanate grow completely and the purity of aluminum titanate is 97.2wt%.
基金project supported by the Science and Technology Department of Zhejiang Province (2005C13003).
文摘Objective To examine the effect of hydraulic residence time (HRT) on the performance and stability, to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor (CABR), and hence to gain a deeper insight into microbial responses to hydraulic shocks on the base of the relationships among macroscopic performance, catabolic intermediate, and microcosmic alternation. Methods COD, VFAs, and microbial activity were detected with constant feed strength (300 mg/L) at different HRTs (9-18 h) and temperatures (10℃-28℃) in a CABR. Results The removal efficiencies declined with the decreases of HRTs and temperatures. However, the COD removal load was still higher at short HRT than at long HRT. Devastating reactor performance happened at temperature of 10℃ and at HRT of 9 h. HRTs had effect on the VFAs in the reactor slightly both at high and low temperatures, but the reasons differed from each other. Microbial activity was sensitive to indicate changes of environmental and operational parameters in the reactor. Conclusion The CABR offers to certain extent an application to treat dilute wastewater under a hydraulic-shock at temperatures from 10℃to 28℃.