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Effects of Light and Temperature Factors on Biomass Accumulation of Winter Wheat
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作者 Pengli Ma Yihao Ma +2 位作者 Jinyong Pu Chunyu Zhao Weitai Wang 《Meteorological and Environmental Research》 CAS 2013年第8期41-46,共6页
[Objective] The study aimed to discuss the influence of light and temperature factors on biomass accumulation of winter wheat at each growth stage and changes in biomass of each organ. [Method] Based on the observatio... [Objective] The study aimed to discuss the influence of light and temperature factors on biomass accumulation of winter wheat at each growth stage and changes in biomass of each organ. [Method] Based on the observation data from Xifeng Agrometeorological Experiment Station of Gansu Province, including phenophase and yield factors of winter wheat in 1981 -2008, biomass at three-leaves, overwintering, jointing, heading, milky maturity, and maturity stages in 1995 -2008, and meteorological data in 1995 -2008, the variation patterns of the biomass accumulation and the influence of TEP (thermal effectiveness photosynthetically active radiation) on the biomass of winter wheat at every growth stage were ana- lyzed. [Result] The biomass accumulation of winter wheat in the whole growth period presented "S" curve, with the maximum value from heading to milky maturity stage. Since 1981, TEP from heading to milky maturity stage increased with a rate of 3. 314 MJ/(m2 · a), and the changing curves of TEP at other stages were like parable curves. TEP from turning green to jointing stage and from milky maturity to maturity stage had a higher value in the 1990s and a lower val.ue in the 1980s and early 21st century, while that from jointing to heading stage had a lower value in the 1990s but a higher value in the 1980s and early 21st century. There was a significant correlation between TEP at each growth stage and the actual yield. LAI (leaf area index) at each development stage also had a significant correlation with the utilization rate of TEP at corresponding stage. When LAI at jointing and heading stages increased by I, the utilization rate of TEP correspondingly increased by 0. 049 and 0.259 g/MJ respectively. [ Conclusion] The research could provide theoretical references for the scientific planting and management of winter wheat in future. Key words Light and temperature factors; Winter wheat; Biomass; Influence; China 展开更多
关键词 Light and temperature factors Winter wheat BIOMASS INFLUENCE China
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Factors Affecting Transformation Temperatures in Fe-Mn-Si-Cr-Ni Shape Memory Alloy 被引量:1
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作者 Yuhua WEN+, ding LI and Mingjing TU (Department of Materials Shaping and Controlling Engineering, Sichuan University, Chengdu 610065, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第5期537-539,共3页
The effects of prestrain and annealing temperature on phase transformation temperatures in Fel4Mn5Si8Cr4Ni shape memory alloy have been studied. The results showed that when the annealing temperature was 673 K, both t... The effects of prestrain and annealing temperature on phase transformation temperatures in Fel4Mn5Si8Cr4Ni shape memory alloy have been studied. The results showed that when the annealing temperature was 673 K, both the At and the Ms temperatures increased appreciably as the prestrain increased, the As temperature increased slightly with increasing prestrain; the resistivity difference at 303 K between the heating and cooling curve also increased with increasing prestrain, which agreed with the recovery strain. The shape memory effect in Fe-Mn-Si-Cr-Ni shape memory alloy is caused by the stress-induced γ→ε martensite transformation and its reverse transformation. When the prestrain was 10%, the Ms temperature decreased remarkably as the annealing temperature increased. 展开更多
关键词 factors Affecting Transformation temperatures in Fe-Mn-Si-Cr-Ni Shape Memory Alloy FE MN CR NI SI
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IMPROVEMENT OF REGIONAL PREDICTION OF SEA FOG ON GUANGDONG COASTLAND USING THE FACTOR OF TEMPERATURE DIFFERENCE IN THE NEAR-SURFACE LAYER 被引量:1
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作者 黄辉军 黄健 +2 位作者 刘春霞 毛伟康 毕雪岩 《Journal of Tropical Meteorology》 SCIE 2016年第1期66-73,共8页
The relationship between the factor of temperature difference of the near-surface layer(T_(1000 hPa)-T_(2m))and sea fog is analyzed using the NCEP reanalysis with a horizontal resolution of l°xl°(2000 to 201... The relationship between the factor of temperature difference of the near-surface layer(T_(1000 hPa)-T_(2m))and sea fog is analyzed using the NCEP reanalysis with a horizontal resolution of l°xl°(2000 to 2011) and the station observations(2010 to 2011).The element is treated as the prediction variable factor in the GRAPES model and used to improve the regional prediction of sea fog on Guangdong coastland.(1) The relationship between this factor and the occurrence of sea fog is explicit:When the sea fog happens,the value of this factor is always large in some specific periods,and the negative value of this factor decreases significantly or turns positive,suggesting the enhancement of warm and moist advection of air flow near the surface,which favors the development of sea fog.(2) The transportation of warm and moist advection over Guangdong coastland is featured by some stages and the jumping among these states.It also gets stronger over time.Meanwhile,the northward propagation of warm and moist advection is quite consistent with the northward advancing of sea fog from south to north along the coastland of China.(3) The GRAPES model can well simulate and realize the factor of near-surface temperature difference.Besides,the accuracy of regional prediction of marine fog,the relevant threat score and Heidke skill score are all improved when the factor is involved. 展开更多
关键词 weather prediction regional prediction of marine fog Guangdong coastland GRAPES model factor of near-surface temperature difference
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Physical, Psychological, and Social Health Impact of Temperature Rise Due to Urban Heat Island Phenomenon and Its Associated Factors 被引量:3
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作者 Li Ping WONG Haridah Alias +2 位作者 Nasrin Aghamohammadi Sima Aghazadeh Nik Meriam Nik Sulaiman 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第7期545-550,共6页
The Urban Heat Island Effect(UHI)has now become a commonly observed phenomenon worldwide.Indeed,it has become a significant environmental effect of urbanisation.In Malaysia,research results showed that UHI effects a... The Urban Heat Island Effect(UHI)has now become a commonly observed phenomenon worldwide.Indeed,it has become a significant environmental effect of urbanisation.In Malaysia,research results showed that UHI effects are very evident in several cities such as Kuala Lumpur and Putrajaya.UHI effect has long been observed to cause temperature of cities. 展开更多
关键词 AS UHI PSYCHOLOGICAL and Social Health Impact of temperature Rise Due to Urban Heat Island Phenomenon and Its Associated factors PHYSICAL
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Analysis on Change Characteristics of Diurnal Temperature Range in Benxi County from 1958 to 2010
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作者 Wang Fuchun Song Jifeng 《Meteorological and Environmental Research》 CAS 2014年第9期1-4,共4页
Based on annual mean maximum and minimum temperatures,diurnal temperature range,precipitation,sunshine,total cloud cover and water barometric pressure data in Benxi County from 1958 to 2010,using statistical analysis,... Based on annual mean maximum and minimum temperatures,diurnal temperature range,precipitation,sunshine,total cloud cover and water barometric pressure data in Benxi County from 1958 to 2010,using statistical analysis,the results show that the annual and seasonal diurnal temperature ranges present significant decreasing tendencies,and the reducing tendency is the most remarkable in winter. Autumn reducing tendency is stronger than that in spring,and it is the weakest in summer. Annual and seasonal average temperatures,average maximum and minimum temperatures all present the remarkable rising trends. Rising trend of the minimum temperature is more significant than that of the maximum temperature. The monthly mean diurnal temperature range also presents reducing tendency,and the most reducing scope appear in January and February. Annual and season diurnal temperature range changes are related to sunshine,mean minimum temperature,mean maximum temperature,precipitation,total cloud cover and water barometric pressure,but various essential factors are different in each season. Annual mean temperature,annual mean minimum temperature,annual mean maximum temperature and annual diurnal temperature range all have sudden changes,but the age is inconsistent. 展开更多
关键词 Diurnal temperature range Change characteristics Influence factor China
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RELATIONSHIPS BETWEEN PRECEDING PACIFIC SEA SURFACE TEMPERATURES AND SUBTROPICAL HIGH INDEXES OF MAIN RAINING SEASONS
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作者 姚愚 严华生 《Journal of Tropical Meteorology》 SCIE 2009年第1期97-101,共5页
With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects... With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects of SSTs on five subtropical high indexes differ in seasons and regions. The variation of SSTs mostly affects the area and intensity indexes of the subtropical high, followed by the western ridge index, and the effect on the ridge line index is more remarkable than on the north boundary index. The results of factor analysis reveals that the first common factor of SST of each season reflected mainly the inverse relation of SSTs variation between the central and eastern part of equatorial Pacific and the western Pacific, which correlates better with the subtropical high indexes in the main raining seasons than other common factors of SST. The analysis of interdecadal variation indicated that the variation of SSTs was conducive to the emergence of the La Ni?a event before the end of 1970s, such that in the summer the subtropical high is likely to be weaker and smaller and located eastward and northward. After the 1980s, the opposite characteristics prevailed. 展开更多
关键词 climatology relationship correlation analysis factor analysis sea surface temperature subtropical high index
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X-Ray and Neutron Diffraction Studies on Thermal Parameters of Thalous Bromide
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作者 J.Bashir R.T.A.Khan +1 位作者 T.Ikeda KenichiOhshima 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第2期189-190,共2页
Thermal parameters of TIBr were determined using both X-ray and neutron diffraction techniques. The data was analysed by Rietveld profile refinement procedure. From the neutron diffraction data, due to weak odd-order ... Thermal parameters of TIBr were determined using both X-ray and neutron diffraction techniques. The data was analysed by Rietveld profile refinement procedure. From the neutron diffraction data, due to weak odd-order reflections, it was not possible to determine the individual thermal parameters. TheX-ray diffraction measurements yielded BT1=0.296(5) nm2 and BBr=0.162(5) nm2. The overall isotropic value, B was 0.252(7) nm2 which is in good agreement with B=0.230(8) nm2 obtained from present neutron diffraction measurements. The present values are also in good agreement with theoretical estimates obtained from the shell models. 展开更多
关键词 Thallium bromide temperature factors Debye temperature Rietveld refinement Neutron diffraction X-ray diffraction
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The balance of flexibility and rigidity in the active site residues of hen egg white lysozyme
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作者 齐建勋 江凡 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第5期460-470,共11页
The crystallographic temperature factors (B factor) of individual atoms contain important information about the thermal motion of the atoms in a macromolecule. Previously the theory of flexibility of active site has... The crystallographic temperature factors (B factor) of individual atoms contain important information about the thermal motion of the atoms in a macromolecule. Previously the theory of flexibility of active site has been established based on the observation that the enzyme activity is sensitive to low concentration denaturing agents. It has been found that the loss of enzyme activity occurs well before the disruption of the three-dimensional structural scaffold of the enzyme. To test the theory of conformational flexibility of enzyme active site, crystal structures were perturbed by soaking in low concentration guanidine hydrochloride solutions. It was found that many lysozyme crystals tested could still diffract until the concentration of guanidine hydrochloride reached 3 M. It was also found that the B factors averaged over individually collected data sets were more accurate. Thus it suggested that accurate measurement of crystal temperature factors could be achieved for medium-high or even medium resolution crystals by averaging over multiple data sets. Furthermore, we found that the correctly predicted active sites included not only the more flexible residues, but also some more rigid residues. Both the flexible and the rigid residues in the active site played an important role in forming the active site residue network, covering the majority of the substrate binding residues. Therefore, this experimental prediction method may be useful for characterizing the binding site and the function of a protein, such as drug targeting. 展开更多
关键词 crystallographic temperature factor DENATURATION conformational flexibility active siteprediction
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Variation of Soil CO_2 Flux and Carbon Density in Three Apline Meadows
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作者 Wei Wei Cao Wenxia Zhang Xiaojiao 《Animal Husbandry and Feed Science》 CAS 2015年第1期50-53,共4页
Three alpine meadows were chosen from the eastern margin of the Qilian Mountain:Polygonum viviparum meadow(P),Stipa capillata grassland(S)and Rhododendron simsii shrub meadow(R);LI-8100 A soil CO2 flux auto-mon... Three alpine meadows were chosen from the eastern margin of the Qilian Mountain:Polygonum viviparum meadow(P),Stipa capillata grassland(S)and Rhododendron simsii shrub meadow(R);LI-8100 A soil CO2 flux auto-monitoring system and lab analysis were applied to analyze the soil organic carbon density,dynamics of carbon flux,and their relationship with environmental factors.The results showed that different vegetations varied greatly in soil organic carbon density:R 〉 S 〉 P,and the soil carbon density reduced with the increasing depth;soil CO2flux:S 〉 P 〉 R,and sample plot P and S showed unimodal changes.The peak values appeared at 14:00-15:00 p.m.;soil CO2 flux was negatively correlated with near-ground air humidity and carbon content,positively correlated with soil temperature and near-ground air temperature,and showed no obvious correlation with soil moisture. 展开更多
关键词 Alpine meadow Soil respiration Soil organic carbon Climatic factor Soil temperature
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Analyses toward factors influencing sealing clearance of a metal rubber seal and derivation of a calculation formula 被引量:2
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作者 Yan Hui Zhao Yalei +1 位作者 Liu Jianguo Jiang Hongyuan 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2016年第1期292-296,共5页
Sealing clearance is a key factor for a metal rubber seal's sealability. The expansion coef- ficient and expansion deformation in the radial direction of metal rubber have been obtained through a thermal expansion ex... Sealing clearance is a key factor for a metal rubber seal's sealability. The expansion coef- ficient and expansion deformation in the radial direction of metal rubber have been obtained through a thermal expansion experiment of metal rubber. The influence of the elastic modulus to the sealing clearance has been analyzed theoretically. By combining the temperature and elasticity factors of metal rubber with the elastic mechanics theory, the calculation formula of the sealing clearance has been derived, and the values of the sealing clearance and the leakage rate in certain working conditions have been calculated. Experimental results are consistent with calculation results in a high degree. The calculation formula of the sealing clearance can explain the influences of the temperature and elastic modulus factors of metal rubber on the sealing clearance. It can pro- vide guidance for the study of sealing mechanism of metal rubber seals. 展开更多
关键词 Elastic mechanics theoryElastic modulus factor Metal rubber SEALS temperature factor
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Magnetic properties and magnetic exchange interactions in Gd_(1–x)RE_x(RE=Pr,Nd) alloys 被引量:1
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作者 肖素芬 陈云贵 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第5期489-494,共6页
The effect of Pr,Nd addition on the magnetic properties and magnetic exchange interaction of gadolinium alloys was systematically studied.Curie temperature TC and magnetic moment of Gd(1–x)REx(RE=Pr,Nd)systems wi... The effect of Pr,Nd addition on the magnetic properties and magnetic exchange interaction of gadolinium alloys was systematically studied.Curie temperature TC and magnetic moment of Gd(1–x)REx(RE=Pr,Nd)systems with x〈0.05 were investigated.When x〈0.05,Pr and Nd formed respectively with Gd continuous solid solution which has the crystalline structure HCP.Study on the magnetic behavior indicated that at near room temperature,the simple ferromagnetism prevailed in these two systems of alloy.The Curie temperature and magnetic moment of Gd(1–x)REx alloy decreased with RE(RE= Pr,Nd)content x increasing.The de Gennes factor of Gd(1–x)REx alloy which was associated with the exchange interaction between magnetic spin components also decreased with RE content increasing.The above results showed that the magnetic exchange interaction between magnetic atoms in gadolinium could be effectively changed by the Pr,Nd addition. 展开更多
关键词 Gd(1–x)REx(RE=Pr Nd)alloys Curie temperature magnetic moment de Gennes factor G rare earths
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