Using the daily temperature data of 95 meteorological stations from Sichuan-Chongqing Region and its surrounding areas, this paper adopted these methods （e.g., linear regression, trend coefficient, geographical stati...Using the daily temperature data of 95 meteorological stations from Sichuan-Chongqing Region and its surrounding areas, this paper adopted these methods （e.g., linear regression, trend coefficient, geographical statistics, gray relational analysis and spatial analysis functions of GIS） to analyze the relations of temperature variability with topography, latitude and longitude. Moreover, the rank of gray correlation between temperature variability and elevation, longitude, latitude, topographic position and surface roughness also was meas- ured. These results indicated： （1） The elevation affected temperature variability most obviously, followed by latitude, and longitude. The slope of the linear regression between temperature change rate and elevation, latitude and longitude was 0.4142, 0.0293 and -0.3270, respectively （2） The rank of gray correlation between temperature change rate and geographic factors was elevation 〉 latitude 〉 surface roughness 〉 topographic position 〉 longitude. The gray correla- tion degree between temperature change rate and elevation was 0.865, followed by latitude with 0.796, and longitude with 0.671. （3） The rate of temperature change enhanced with the increase of elevation. Especially, the warming trend was significant in the plateau and mountain areas of western Sichuan, and mountain and valley areas of southwestern Sichuan （with the warming rate of 0.74℃/10a during the 1990s）. However, there was a weak warming trend in Sichuan Basin and its surrounding low mountain and hilly areas. （4） The effects of latitude on temperature change rate presented the specific regulation, which the warming rate of low-latitude areas was more significant than that of high-latitude areas. However, they were consistent with the regulation that the increasing of low temperature controlled most of the warming trend, due to the effects of terrain and sically, temperature variability along longitude elevation on annual mean temperature. （5） Ba- direction resulted from the regular change of elevation along longitude. It was suggested that, in Sichuan-Chongqing Region, special features of temperature variability largely depended on the terrain complexity （e.g., undulations, mutations and roughness）. The elevation level controlled only high or low annual mean temperature and the range of temperature change rate in the macro sense.展开更多
Relationships between nonoptimal temperatures and cardiovascular disease(CVD)mortality have been well documented.However,evidence of the association between temperature variability(TV)and CVD morbidity is limited.This...Relationships between nonoptimal temperatures and cardiovascular disease(CVD)mortality have been well documented.However,evidence of the association between temperature variability(TV)and CVD morbidity is limited.This study aimed to quantify the risk and burden of CVD-related hospitalization associated with the magnitude and direction of TV.Data on meteorology and population-based hospitalizations for myocardial infarction(MI)and stroke were collected in Guangzhou,China,from 2013 to 2017.Hourly temperature variability(HTV)was measured as the standard deviation of hourly temperature records over specific exposure days.The direction(upward or downward)of HTV was defined as the average daily mean temperature change relative to that of the previous day during the exposure period.Quasi-Poisson regression was applied to assess the impact of HTV after adjusting for the daily mean temperature,and the hospitalization fractions attributable to HTV were calculated.A 1℃-increase in HTV was significantly associated with a 2.24%and 1.72%increase in hospitalizations for MI and hemorrhagic stroke(HS)at lag 0–1 d,respectively,and a 1.55%increase in hospitalizations for ischemic stroke(IS)at lag 0–3 d.During the study period,5.99%,4.64%,and 4.53%of MI,HS,and IS hospitalizations,respectively,were attributable to HTV.The upward TV exerts acute effects on CVD hospital admissions,whereas the impact of downward TV generally lags.These findings highlight the importance of the magnitude and direction of temperature fluctuations,in addition to the mean level,in assessing the adverse health impacts of temperature variations.展开更多
Accurate skin temperature is one of the critical factors in successfully assimilating satellite radiance data over land.However,model-simulated skin temperature may not be accurate enough.To address this issue,an exte...Accurate skin temperature is one of the critical factors in successfully assimilating satellite radiance data over land.However,model-simulated skin temperature may not be accurate enough.To address this issue,an extended skin temperature control variable(TSCV) approach is proposed in a variational assimilation framework,which also considers the background error correlation between skin temperature and atmospheric variables.A series of single observation tests and a 10-day cycling assimilation experiment were conducted to evaluate the impact of the TSCV approach on the assimilation of AMSU-A and ATMS(Advanced Technology Microwave Sounder) microwave temperature-sounding channels over land.The results of the single observation tests show that by applying the TSCV approach,not only the direct analysis of skin temperature is realized,but also the interaction between skin temperature and atmospheric variables can be achieved during the assimilation process.The results of the cycling experiment demonstrate that the TSCV approach improves the skin temperature analysis,which in turn reduces the RMSE of the surface variables and low-level air temperature forecasts.The TSCV approach also reduces the difference between the observed and simulated brightness temperatures of both microwave and infrared window channels over land,suggesting that the approach can facilitate the radiance simulation of these channels,thus contributing to the assimilation of window channels.展开更多
Climate variability is an important inherent characteristic of climate and it varies on all timescales. Through examination of temperature variability on multiple temporal scales at 63 stations over the eastern and ce...Climate variability is an important inherent characteristic of climate and it varies on all timescales. Through examination of temperature variability on multiple temporal scales at 63 stations over the eastern and central Tibetan Plateau （TP） during 1960-2008, we find decreasing trends in daily and intraannual temperature, especially in cold seasons （autumn and winter）. These changes are more sensitive than those in the eastern China coastal region at the same latitude and indicate an asymmetric change of temperature, with hourly, daily, and monthly trends in cold periods stronger than those in warm periods during the recent years. The variation of interannual temperature is complex, showing an increasing trend in autumn and winter and decreasing trend in spring and summer, which is similar to those in the northern polar region. The changes of multiscale variability of temperature are mainly related to changes of atmospheric water vapor, cloudiness, anthropogenic aerosols, monsoon-driven climate, and some local factors. To find the influences of local conditions on temperature variability, we analyze the effects of altitude, topography, and urbanization. The results show that elevation is strongly and positively related to diurnal temperature range （DTR） and slightly positively related to interannual temperature variability （IVT）, but intraannual temperature variability shows no clear elevation dependency. Topography and urbanization also play important roles in multiscale temperature variability. Finally, strong relationships are observed between temperature variability on each scale and different extreme indices.展开更多
In this study, the trends of upper-air temperatures are analysed by utilising radiosonde observations for the barometric levels at 700, 500, 300, 200, 150, 100 and 50 hPa from five meteorological stations within the A...In this study, the trends of upper-air temperatures are analysed by utilising radiosonde observations for the barometric levels at 700, 500, 300, 200, 150, 100 and 50 hPa from five meteorological stations within the Arabian Peninsula from January 1986 to August 2015. The mean monthly variations of the temperatures at these levels are characterised and established. The magnitudes of the annual trends of the mean temperatures for each site for the selected barometric levels are studied and statistically tested using Mann-Kendall rank statistics at different significance levels. The temperature trends at different pressure levels show that the upper troposphere and lower stratosphere are warming, while the middle troposphere is cooling which is consistent with the findings of other studies. The variations in upper air temperature observed in this study can be attributed to a range of factors, including increasing greenhouse gas concentrations, changes in atmospheric circulation patterns, variations in solar activity, aerosols and volcanic eruptions, and land use and land cover change.展开更多
The traditional anomaly （TA） reference frame and its corresponding anomaly for a given data span changes with the extension of data length. In this study, the modulated annual cycle （MAC）, instead of the widely us...The traditional anomaly （TA） reference frame and its corresponding anomaly for a given data span changes with the extension of data length. In this study, the modulated annual cycle （MAC）, instead of the widely used climatological mean annual cycle, is used as an alternative reference frame for computing climate anomalies to study the multi-timescale variability of surface air temperature （SAT） in China based on homogenized daily data from 1952 to 2004. The Ensemble Empirical Mode Decomposition （EEMD） method is used to separate daily SAT into a high frequency component, a MAC component, an interannual component, and a decadal-to-trend component. The results show that the EEMD method can reflect historical events reasonably well, indicating its adaptive and temporally local characteristics. It is shown that MAC is a temporally local reference frame and will not be altered over a particular time span by an exten-sion of data length, thereby making it easier for physical interpretation. In the MAC reference frame, the low frequency component is found more suitable for studying the interannual to longer timescale variability （ILV） than a 13-month window running mean, which does not exclude the annual cycle. It is also better than other traditional versions （annual or summer or winter mean） of ILV, which contains a portion of the annual cycle. The analysis reveals that the variability of the annual cycle could be as large as the magnitude of interannual variability. The possible physical causes of different timescale variability of SAT in China are further discussed.展开更多
A new static microwave sounding unit （MSU） channel 4 weighting function is obtained from using Coupled Model Inter-comparison Project, Phase 5 （CMIP5） historical multimodel simulations as inputs into the fast Radi...A new static microwave sounding unit （MSU） channel 4 weighting function is obtained from using Coupled Model Inter-comparison Project, Phase 5 （CMIP5） historical multimodel simulations as inputs into the fast Radiative Transfer Model for TOVS （RTTOV v10）. For the same CMIP5 model simulations, it is demonstrated that the computed MSU channel 4 brightness temperature （T4） trends in the lower stratosphere over both the globe and the tropics using the proposed weighting function are equivalent to those calculated by RTTOV, but show more cooling than those computed using the traditional UAH （University of Alabama at Huntsville） or RSS （Remote Sensing Systems in Santa Rosa, California） static weighting functions. The new static weighting function not only reduces the computational cost, but also reveals reasons why trends using a radiative transfer model are different from those using a traditional static weighting function. This study also shows that CMIP5 model simulated T4 trends using the traditional UAH or RSS static weighting functions show less cooling than satellite observations over the globe and the tropics. Although not completely removed, this difference can be reduced using the proposed weighting function to some extent, especially over the tropics. This work aims to explore the reasons for the trend differences and to see to what extent they are related to the inaccurate weighting functions. This would also help distinguish other sources for trend errors and thus better understand the climate change in the lower stratosphere.展开更多
This work examines the spatial and temporal patterns of seasonal sea surface temperatures (SSTs) across the Gulf of Mexico (GoM) for the period 1901-2010. The Extended Reconstructed Sea Surface Temperature, version 4 ...This work examines the spatial and temporal patterns of seasonal sea surface temperatures (SSTs) across the Gulf of Mexico (GoM) for the period 1901-2010. The Extended Reconstructed Sea Surface Temperature, version 4 (ERSST.v4), dataset was selected for this study over other reconstructions because of its 2° × 2° grid cell spatial resolution, its recent update to adjust for known biases in SST observations, and its ability to be compared to other in situ studies of GoM SSTs. The monthly ERSST.v4 data were averaged seasonally for each year and grid cell in the GoM. Seasonal SST trends were then calculated for each grid cell with varying start dates (e.g., 1901-2010, 1911- 2010) to account for nonlinear SST changes over the study period. Results indicate that the GoM SSTs closely resemble those of global annual temperature trends: SSTs warmed from 1901 to ~1940, followed by a period with little trend or a slight cooling until the mid-1970s, and then a warming afterwards through 2010. The spatial patterns and magnitudes of SST changes, however, varied by season and location within the GoM. The spatial patterns involved gradients with latitudinal and/or longitudinal components: a southwest-northeast (warmer-cooler) gradient in winter, an east-west (warmer-cooler) gradient in spring and fall, and a northwest-southeast (warmer-cooler) gradient in summer. The magnitude of SST changes tended to be largest in summer, followed by spring, fall, and winter. The long-term (1901-2010) SST trends were significant throughout the GoM in summer and fall, but only significant towards the southwestern GoM in winter and spring. These results have implications in discussion of climate change and its impacts on tropical activity in the GoM Basin.展开更多
Variable temperature and pressure adsorption tests were conducted on four coal samples with different coal ranks, under simulated temperatures and pressures corresponding to coal reservoirs at different depths. The re...Variable temperature and pressure adsorption tests were conducted on four coal samples with different coal ranks, under simulated temperatures and pressures corresponding to coal reservoirs at different depths. The regularity of the variation in the amounts of adsorption by coals under variable temperature and pressure and 30 ℃ isothermal conditions are compared and the adsorption characteristics of coal under the composite effect of temperature and pressure were obtained. The adsorption test and data processing method of coal under variable temperature and pressure are presented and the effect of the mechanism of temperature and pressure on the adsorption capacity of coal has been studied. The research results are of significant importance in the investigation of coalbed methane storage mechanism and for the prediction of the amounts of coalbed methane at various depths.展开更多
Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate chang...Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate change is a natural phenomenon,many research scientists are widely in agreement that the increase in temperature in the 20 th century is anthropologically related.The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally.In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness.This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia.The comparison of decadal variation of precipitation and temperature anomalies before the 1970 s found general increases which were mostly varying.But beyond the 1970 s,global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period.There are frequent changes and a shift westward of the Indian summer monsoon.Although precipitation is observed to be 70%below normal levels,in some areas the topography affects the intensity of rainfall.These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future.The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human,financial,infrastructure and food security of the region.展开更多
By utilizing multiple datasets from various sources available for the last 100 years, the existence for the interdecadal change of the winter sea surface temperature（SST） variability in the Kuroshio Extension（KE） ...By utilizing multiple datasets from various sources available for the last 100 years, the existence for the interdecadal change of the winter sea surface temperature（SST） variability in the Kuroshio Extension（KE） region is investigated. And its linkage with the Aleutian Low（AL） activity changes is also discussed. The results find that the KE SST variability exhibits the significant ~6 a and ~10 a oscillations with obvious interdecadal change. The ~6 a oscillation is mainly detected during 1930–1950, which is largely impacted by the anomalous surface heat flux forcing and Ekman heat transport associated with the AL intensity variation. The ~10 a oscillation is most evident after the 1980s, which is predominantly triggered by the AL north-south shift through the bridge of oceanic Rossby waves.展开更多
Polyether-polyurethane zwitterionomers based on 4, 4'-diphenylmethane diisocyanate(MDI), methyl diethanolamine (MDEA), and polytetramethylene oxide glycol (PTMO) werestudied with variable-temperature wide-line ~1H...Polyether-polyurethane zwitterionomers based on 4, 4'-diphenylmethane diisocyanate(MDI), methyl diethanolamine (MDEA), and polytetramethylene oxide glycol (PTMO) werestudied with variable-temperature wide-line ~1H NMR. It is found that upon ionization, degree ofphase separation in the polymer system decreased at first due to the loss of hard segmentregularity, while further ionization increased the degree of phase separation through increasinghard phase cohesion and difference of polarity between hard and soft segments.展开更多
Conductive n type a Si∶H∶Y alloy films with the conductivity as high as 60 S/cm have been deposited on Si substrate by radio frequency sputtering. In the temperature range 20～300 K, for samples with large Y conte...Conductive n type a Si∶H∶Y alloy films with the conductivity as high as 60 S/cm have been deposited on Si substrate by radio frequency sputtering. In the temperature range 20～300 K, for samples with large Y contents, the thermally activated conduction is also observed and the plots of lg σ vs. 1/ T can be fitted by two linear functions with different slopes. The corresponding temperatures of the kinks between the two straight lines depend on the Y contents in the samples. For small Y content films, the conductivities can be fitted to the funciton σ∝ exp (-1/ T 1/4 ). The present results are interpreted using different conduction mechanisms in different temperature ranges for samples with different Y contents.展开更多
We present a system-level model with an on-chip temperature compensation technique for a CMOS-MEMS monolithic calorimetric flow sensing SoC.The model encompasses mechanical,thermal,and electrical domains to facilitate...We present a system-level model with an on-chip temperature compensation technique for a CMOS-MEMS monolithic calorimetric flow sensing SoC.The model encompasses mechanical,thermal,and electrical domains to facilitate the co-design of a MEMS sensor and CMOS interface circuits on the EDA platform.The compensation strategy is implemented on-chip with a variable temperature difference heating circuit.Results show that the linear programming for the low-temperature drift in the SoC output is characterized by a compensation resistor Rc with a resistance value of 748.21Ωand a temperature coefficient of resistance of 3.037×10−3℃^(−1) at 25℃.Experimental validation demonstrates that within an ambient temperature range of 0–50℃ and a flow range of 0-10 m/s,the temperature drift of the sensor is reduced to±1.6%,as compared to±8.9%observed in a counterpart with the constant temperature difference circuit.Therefore,this on-chip temperature-compensated CMOS-MEMS flow sensing SoC is promising for low-cost sensing applications such as respiratory monitoring and smart energy-efficient buildings.展开更多
Under recent Arctic warming,boreal winters have witnessed severe cold surges over both Eurasia and North America,bringing about serious social and economic impacts.Here,we investigated the changes in daily surface air...Under recent Arctic warming,boreal winters have witnessed severe cold surges over both Eurasia and North America,bringing about serious social and economic impacts.Here,we investigated the changes in daily surface air temperature(SAT)variability during the rapid Arctic warming period of 1988/89–2015/16,and found the daily SAT variance,mainly contributed by the sub-seasonal component,shows an increasing and decreasing trend over eastern Eurasia and North America,respectively.Increasing cold extremes(defined as days with daily SAT anomalies below 1.5 standard deviations)dominated the increase of the daily SAT variability over eastern Eurasia,while decreasing cold extremes dominated the decrease of the daily SAT variability over North America.The circulation regime of cold extremes over eastern Eurasia(North America)is characterized by an enhanced high-pressure ridge over the Urals(Alaska)and surface Siberian(Canadian)high.The data analyses and model simulations show the recent strengthening of the high-pressure ridge over the Urals was associated with warming of the Barents–Kara seas in the Arctic region,while the high-pressure ridge over Alaska was influenced by the offset effect of Arctic warming over the East Siberian–Chukchi seas and the Pacific decadal oscillation(PDO)–like sea surface temperature(SST)anomalies over the North Pacific.The transition of the PDO-like SST anomalies from a positive to negative phase cancelled the impact of Arctic warming,reduced the occurrence of extreme cold days,and possibly resulted in the decreasing trend of daily SAT variability in North America.The multi-ensemble simulations of climate models confirmed the regional Arctic warming as the driver of the increasing SAT variance over eastern Eurasia and North America and the overwhelming effect of SST forcing on the decreasing SAT variance over North America.Therefore,the regional response of winter cold extremes at midlatitudes to the Arctic warming could be different due to the distinct impact of decadal SST anomalies.展开更多
The results of four versions of IAP/LASG Global Ocean-Atmosphere-Land System Model (GOALS) are analyzed separately over the oceans and over continents, and compared with observed data. Some fundamental atmospheric var...The results of four versions of IAP/LASG Global Ocean-Atmosphere-Land System Model (GOALS) are analyzed separately over the oceans and over continents, and compared with observed data. Some fundamental atmospheric variables including surface air temperature (SAT), sea level pressure (SLP) and precipitation are examined to evaluate the ability of the GOALS model to simulate the contemporary climate and climate variability. In general, all four versions of the GOALS model are capable of reproducing the main features of the mean state and seasonal variation of the observed climate with reasonable accuracy. The evaluation also reveals some weakness of the model. According to this study, we can clearly see that the essential discrepancy of global averaged SLP lies over the continents in boreal summer. The simulated higher SAT over land versus the observed is mainly due to the effect of the land surface process. It is worth noting the underestimation by simulated precipitation rates mostly appears over the oceans, yet over-land precipitation is higher in high and middle latitudes than the observed for the boreal winter. Through intercomparisons among different versions of the model, it can be clearly seen that the incorporation of the diurnal cycle of solar radiation apparently improves the simulation of SAT, especially in the low and middle latitudes over land. Also, the introduction of the diurnal cycle shows a great improvement in precipitation in tropical continents and wintertime precipitation in high and middle latitudes. Furthermore, based on the daily flux anomaly exchange scheme (DFA), the latest version of GOALS model simulated over-ocean temperature variability is improved in the low and middle latitudes. Having compared the standard deviation of the annual mean surface air temperature (SAT) simulated by the GOALS model to observation, it is found that all four versions of the GOALS model underestimate surface air temperature variability over both oceans and land relative to observations. Several factors that may contribute to these differences between simulated and observed temperature variability are identified.展开更多
The effect of curing regime on degree ofAl3＋ substituting for Si^4＋ （Al/Si ratio） in C-S-H gels of hardened Portland cement pastes was investigated by 29Si magic angel spinning （MAS） nuclear magnetic resonance ...The effect of curing regime on degree ofAl3＋ substituting for Si^4＋ （Al/Si ratio） in C-S-H gels of hardened Portland cement pastes was investigated by 29Si magic angel spinning （MAS） nuclear magnetic resonance （NMR） with deconvolution technique. The curing regimes included the constant temperature （20, 40, 60 and 80 ℃） and variable temperature （simulated internal temperature of mass concrete with 60 ℃ peak）. The results indicate that constant temperature of 20 ℃ is beneficial to substitution ofAl3＋ for Si4＋, and AI/Si ratio changes to be steady after 180 d. The increase of Al/Si ratio at 40 ℃is less than that at 20℃ for 28 d. The other three regimes of high temperature increase Al/Si ratio only before 3 d, on the contrary to that from 3 to 28 d. However, the 20 ℃ curing stage from 28 to 180 d at variable temperature regime, is beneficial to the increase of AI/Si ratio which is still lower than that at constant temperature regime of 20 ℃ for the same age. A nonlinear relation exists between the Al/Si ratio and temperature variation or mean chain length （MCL） of C-S-H gels, furthermore, the amount ofAl3＋ which can occupy the bridging tetrahedra sites in C-S-H structure is insufficient in hardened Portland cement pastes.展开更多
In order to promote the application of clean energy technology in clothing and promote the integration of industrial development and artificial intelligence wearable technology,this study elaborates the energy applica...In order to promote the application of clean energy technology in clothing and promote the integration of industrial development and artificial intelligence wearable technology,this study elaborates the energy application characteristics of intelligent wearable products at home and abroad and its application in different fields,aiming at the current research status of wearable technology in the field of textile and clothing.The wearable distributed generation technology is classified,and a creative clothing design for detecting climate temperature is designed.Based on the monitoring of body temperature,the changes in clothing pattern color can reflect people’s health and emotional status.At the same time,it can also be applied to the screening of abnormal body temperature during the COVID-19.展开更多
Using a homogenized daily maximum temperature(T_(max))dataset across China,this study characterized the spatiotemporal variation of the onset date of extreme hot days in a year(i.e.,FirstEHD)during 1960-2018.Inhomogen...Using a homogenized daily maximum temperature(T_(max))dataset across China,this study characterized the spatiotemporal variation of the onset date of extreme hot days in a year(i.e.,FirstEHD)during 1960-2018.Inhomogeneous trends of FirstEHD over China during 1960-2018 can be found,with the advanced trend of FirstEHD over most parts in China,while a number of stations in North-Central China(NC)show the delayed trend of FirstEHD.Moreover,there exist interdecadal changes of FirstEHD trend,with a remarkable difference in the trend magnitude before and after the 1990s over South China(SC),and the sign of trend can even reverse from negative to positive after the 1990s in Xinjiang(XJ)and Yangtze River Basin(YR),and from positive to negative in NC.The overall trends of FirstEHD over NC,YR,and XJ during 1960-2018 are dominated by the trends before the 1990s,while they are dominated by the sharp advance after the 1990s over SC.It is further found that the trend of FirstEHD can generally be explained by the long-term trend in T_(max) over most parts of China,but the contribution from T_(max) variabilities is also non-negligible and can even account for more than 75% of the overall trend over NC.The possible factors responsible for the decadal changes in FirstEHD trends are also discussed.展开更多
Understanding the thermal stability of the proteins in human serum is essential since human serum is the important source of pharmaceutical proteins. Near-infrared（NIR） spectroscopy was applied to the investigation ...Understanding the thermal stability of the proteins in human serum is essential since human serum is the important source of pharmaceutical proteins. Near-infrared（NIR） spectroscopy was applied to the investigation of thermal changes in secondary structure and hydration of human serum proteins.However, as a multicomponent system, the overlap of the broad NIR bands makes the structural analysis very difficult directly using the spectra of serum samples. Therefore, continuous wavelet transform（CWT） was used to improve the resolution of NIR spectra, and Monte Carlo-uninformative variable elimination（MC-UVE） method was applied to the selection of the variables associated with the proteins for the structural analysis. The variables（5956, 5867, 5815, 5747, 4525, 4401, 4359 and 4328 cm^-1） related to protein secondary structures and those（7074, 6951, 6827 and 6700 cm 1） connected with water species were selected. Then, the thermal stability was analyzed through the intensity variations of the selected variables with temperature from 30℃ to 80 ℃. It was found that the variation of the spectral variables related to both a-helix and b-sheet changes apparently around 60 ℃, indicating the beginning of the thermal denaturation and the transition from a-helix to b-sheet. Moreover, an obvious change was found around 60℃for the content of the water specie S3, i.e., the water cluster containing three hydrogen bonds. The result demonstrates that MC-UVE can identify the protein-related NIR spectral variables, and the water species may be a marker for investigation of the structural change of proteins in biochemical systems.展开更多
基金Natural Science Foundation of Chongqing, No.2010JJ0069 Science and Technology Great Special Project on Controlling and Fathering Water Pollution during the National 12th Five-year Plan, No.2012ZX07104-003
文摘Using the daily temperature data of 95 meteorological stations from Sichuan-Chongqing Region and its surrounding areas, this paper adopted these methods （e.g., linear regression, trend coefficient, geographical statistics, gray relational analysis and spatial analysis functions of GIS） to analyze the relations of temperature variability with topography, latitude and longitude. Moreover, the rank of gray correlation between temperature variability and elevation, longitude, latitude, topographic position and surface roughness also was meas- ured. These results indicated： （1） The elevation affected temperature variability most obviously, followed by latitude, and longitude. The slope of the linear regression between temperature change rate and elevation, latitude and longitude was 0.4142, 0.0293 and -0.3270, respectively （2） The rank of gray correlation between temperature change rate and geographic factors was elevation 〉 latitude 〉 surface roughness 〉 topographic position 〉 longitude. The gray correla- tion degree between temperature change rate and elevation was 0.865, followed by latitude with 0.796, and longitude with 0.671. （3） The rate of temperature change enhanced with the increase of elevation. Especially, the warming trend was significant in the plateau and mountain areas of western Sichuan, and mountain and valley areas of southwestern Sichuan （with the warming rate of 0.74℃/10a during the 1990s）. However, there was a weak warming trend in Sichuan Basin and its surrounding low mountain and hilly areas. （4） The effects of latitude on temperature change rate presented the specific regulation, which the warming rate of low-latitude areas was more significant than that of high-latitude areas. However, they were consistent with the regulation that the increasing of low temperature controlled most of the warming trend, due to the effects of terrain and sically, temperature variability along longitude elevation on annual mean temperature. （5） Ba- direction resulted from the regular change of elevation along longitude. It was suggested that, in Sichuan-Chongqing Region, special features of temperature variability largely depended on the terrain complexity （e.g., undulations, mutations and roughness）. The elevation level controlled only high or low annual mean temperature and the range of temperature change rate in the macro sense.
基金supported by the National Natural Science Foundation of China(Nos.82373679 and 81973140).
文摘Relationships between nonoptimal temperatures and cardiovascular disease(CVD)mortality have been well documented.However,evidence of the association between temperature variability(TV)and CVD morbidity is limited.This study aimed to quantify the risk and burden of CVD-related hospitalization associated with the magnitude and direction of TV.Data on meteorology and population-based hospitalizations for myocardial infarction(MI)and stroke were collected in Guangzhou,China,from 2013 to 2017.Hourly temperature variability(HTV)was measured as the standard deviation of hourly temperature records over specific exposure days.The direction(upward or downward)of HTV was defined as the average daily mean temperature change relative to that of the previous day during the exposure period.Quasi-Poisson regression was applied to assess the impact of HTV after adjusting for the daily mean temperature,and the hospitalization fractions attributable to HTV were calculated.A 1℃-increase in HTV was significantly associated with a 2.24%and 1.72%increase in hospitalizations for MI and hemorrhagic stroke(HS)at lag 0–1 d,respectively,and a 1.55%increase in hospitalizations for ischemic stroke(IS)at lag 0–3 d.During the study period,5.99%,4.64%,and 4.53%of MI,HS,and IS hospitalizations,respectively,were attributable to HTV.The upward TV exerts acute effects on CVD hospital admissions,whereas the impact of downward TV generally lags.These findings highlight the importance of the magnitude and direction of temperature fluctuations,in addition to the mean level,in assessing the adverse health impacts of temperature variations.
基金sponsored by the National Natural Science Foundation of China(Grant No.42075148)the High-Performance Computing Center of Nanjing University of Information Science & Technology for supporting this work。
文摘Accurate skin temperature is one of the critical factors in successfully assimilating satellite radiance data over land.However,model-simulated skin temperature may not be accurate enough.To address this issue,an extended skin temperature control variable(TSCV) approach is proposed in a variational assimilation framework,which also considers the background error correlation between skin temperature and atmospheric variables.A series of single observation tests and a 10-day cycling assimilation experiment were conducted to evaluate the impact of the TSCV approach on the assimilation of AMSU-A and ATMS(Advanced Technology Microwave Sounder) microwave temperature-sounding channels over land.The results of the single observation tests show that by applying the TSCV approach,not only the direct analysis of skin temperature is realized,but also the interaction between skin temperature and atmospheric variables can be achieved during the assimilation process.The results of the cycling experiment demonstrate that the TSCV approach improves the skin temperature analysis,which in turn reduces the RMSE of the surface variables and low-level air temperature forecasts.The TSCV approach also reduces the difference between the observed and simulated brightness temperatures of both microwave and infrared window channels over land,suggesting that the approach can facilitate the radiance simulation of these channels,thus contributing to the assimilation of window channels.
基金Supported by the National Natural Science Foundation of China (41171345)Chinese Academy of Sciences (KZCX2-YW-QN303)Fundamental Research Funds for Central Universities of China
文摘Climate variability is an important inherent characteristic of climate and it varies on all timescales. Through examination of temperature variability on multiple temporal scales at 63 stations over the eastern and central Tibetan Plateau （TP） during 1960-2008, we find decreasing trends in daily and intraannual temperature, especially in cold seasons （autumn and winter）. These changes are more sensitive than those in the eastern China coastal region at the same latitude and indicate an asymmetric change of temperature, with hourly, daily, and monthly trends in cold periods stronger than those in warm periods during the recent years. The variation of interannual temperature is complex, showing an increasing trend in autumn and winter and decreasing trend in spring and summer, which is similar to those in the northern polar region. The changes of multiscale variability of temperature are mainly related to changes of atmospheric water vapor, cloudiness, anthropogenic aerosols, monsoon-driven climate, and some local factors. To find the influences of local conditions on temperature variability, we analyze the effects of altitude, topography, and urbanization. The results show that elevation is strongly and positively related to diurnal temperature range （DTR） and slightly positively related to interannual temperature variability （IVT）, but intraannual temperature variability shows no clear elevation dependency. Topography and urbanization also play important roles in multiscale temperature variability. Finally, strong relationships are observed between temperature variability on each scale and different extreme indices.
文摘In this study, the trends of upper-air temperatures are analysed by utilising radiosonde observations for the barometric levels at 700, 500, 300, 200, 150, 100 and 50 hPa from five meteorological stations within the Arabian Peninsula from January 1986 to August 2015. The mean monthly variations of the temperatures at these levels are characterised and established. The magnitudes of the annual trends of the mean temperatures for each site for the selected barometric levels are studied and statistically tested using Mann-Kendall rank statistics at different significance levels. The temperature trends at different pressure levels show that the upper troposphere and lower stratosphere are warming, while the middle troposphere is cooling which is consistent with the findings of other studies. The variations in upper air temperature observed in this study can be attributed to a range of factors, including increasing greenhouse gas concentrations, changes in atmospheric circulation patterns, variations in solar activity, aerosols and volcanic eruptions, and land use and land cover change.
基金supported by Grant 2006CB400504 from the National Basic Research Program of ChinaGrant LCS-2006-03 fromthe Laboratory for Climate Studies, China MeteorologicalAdministration+1 种基金sponsored by the National Science Foundation of USA (ATM-0653136, ATM-0917743)sponsored by National Key Technologies R&D Pro-gram under Grant No. 2007BAC29B03
文摘The traditional anomaly （TA） reference frame and its corresponding anomaly for a given data span changes with the extension of data length. In this study, the modulated annual cycle （MAC）, instead of the widely used climatological mean annual cycle, is used as an alternative reference frame for computing climate anomalies to study the multi-timescale variability of surface air temperature （SAT） in China based on homogenized daily data from 1952 to 2004. The Ensemble Empirical Mode Decomposition （EEMD） method is used to separate daily SAT into a high frequency component, a MAC component, an interannual component, and a decadal-to-trend component. The results show that the EEMD method can reflect historical events reasonably well, indicating its adaptive and temporally local characteristics. It is shown that MAC is a temporally local reference frame and will not be altered over a particular time span by an exten-sion of data length, thereby making it easier for physical interpretation. In the MAC reference frame, the low frequency component is found more suitable for studying the interannual to longer timescale variability （ILV） than a 13-month window running mean, which does not exclude the annual cycle. It is also better than other traditional versions （annual or summer or winter mean） of ILV, which contains a portion of the annual cycle. The analysis reveals that the variability of the annual cycle could be as large as the magnitude of interannual variability. The possible physical causes of different timescale variability of SAT in China are further discussed.
基金supported by the National Program on Key Basic Research Projects of China(Grant Nos.2010CB951604 and 2010CB28402)
文摘A new static microwave sounding unit （MSU） channel 4 weighting function is obtained from using Coupled Model Inter-comparison Project, Phase 5 （CMIP5） historical multimodel simulations as inputs into the fast Radiative Transfer Model for TOVS （RTTOV v10）. For the same CMIP5 model simulations, it is demonstrated that the computed MSU channel 4 brightness temperature （T4） trends in the lower stratosphere over both the globe and the tropics using the proposed weighting function are equivalent to those calculated by RTTOV, but show more cooling than those computed using the traditional UAH （University of Alabama at Huntsville） or RSS （Remote Sensing Systems in Santa Rosa, California） static weighting functions. The new static weighting function not only reduces the computational cost, but also reveals reasons why trends using a radiative transfer model are different from those using a traditional static weighting function. This study also shows that CMIP5 model simulated T4 trends using the traditional UAH or RSS static weighting functions show less cooling than satellite observations over the globe and the tropics. Although not completely removed, this difference can be reduced using the proposed weighting function to some extent, especially over the tropics. This work aims to explore the reasons for the trend differences and to see to what extent they are related to the inaccurate weighting functions. This would also help distinguish other sources for trend errors and thus better understand the climate change in the lower stratosphere.
文摘This work examines the spatial and temporal patterns of seasonal sea surface temperatures (SSTs) across the Gulf of Mexico (GoM) for the period 1901-2010. The Extended Reconstructed Sea Surface Temperature, version 4 (ERSST.v4), dataset was selected for this study over other reconstructions because of its 2° × 2° grid cell spatial resolution, its recent update to adjust for known biases in SST observations, and its ability to be compared to other in situ studies of GoM SSTs. The monthly ERSST.v4 data were averaged seasonally for each year and grid cell in the GoM. Seasonal SST trends were then calculated for each grid cell with varying start dates (e.g., 1901-2010, 1911- 2010) to account for nonlinear SST changes over the study period. Results indicate that the GoM SSTs closely resemble those of global annual temperature trends: SSTs warmed from 1901 to ~1940, followed by a period with little trend or a slight cooling until the mid-1970s, and then a warming afterwards through 2010. The spatial patterns and magnitudes of SST changes, however, varied by season and location within the GoM. The spatial patterns involved gradients with latitudinal and/or longitudinal components: a southwest-northeast (warmer-cooler) gradient in winter, an east-west (warmer-cooler) gradient in spring and fall, and a northwest-southeast (warmer-cooler) gradient in summer. The magnitude of SST changes tended to be largest in summer, followed by spring, fall, and winter. The long-term (1901-2010) SST trends were significant throughout the GoM in summer and fall, but only significant towards the southwestern GoM in winter and spring. These results have implications in discussion of climate change and its impacts on tropical activity in the GoM Basin.
基金Project 2002CB211703 supported by the National Basic Research Program of China
文摘Variable temperature and pressure adsorption tests were conducted on four coal samples with different coal ranks, under simulated temperatures and pressures corresponding to coal reservoirs at different depths. The regularity of the variation in the amounts of adsorption by coals under variable temperature and pressure and 30 ℃ isothermal conditions are compared and the adsorption characteristics of coal under the composite effect of temperature and pressure were obtained. The adsorption test and data processing method of coal under variable temperature and pressure are presented and the effect of the mechanism of temperature and pressure on the adsorption capacity of coal has been studied. The research results are of significant importance in the investigation of coalbed methane storage mechanism and for the prediction of the amounts of coalbed methane at various depths.
文摘Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate change is a natural phenomenon,many research scientists are widely in agreement that the increase in temperature in the 20 th century is anthropologically related.The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally.In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness.This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia.The comparison of decadal variation of precipitation and temperature anomalies before the 1970 s found general increases which were mostly varying.But beyond the 1970 s,global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period.There are frequent changes and a shift westward of the Indian summer monsoon.Although precipitation is observed to be 70%below normal levels,in some areas the topography affects the intensity of rainfall.These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future.The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human,financial,infrastructure and food security of the region.
基金The National Basic Research Program(973 program)of China under contract No.2013CB956203the National Natural Science Foundation of China under contract No.41375063
文摘By utilizing multiple datasets from various sources available for the last 100 years, the existence for the interdecadal change of the winter sea surface temperature（SST） variability in the Kuroshio Extension（KE） region is investigated. And its linkage with the Aleutian Low（AL） activity changes is also discussed. The results find that the KE SST variability exhibits the significant ~6 a and ~10 a oscillations with obvious interdecadal change. The ~6 a oscillation is mainly detected during 1930–1950, which is largely impacted by the anomalous surface heat flux forcing and Ekman heat transport associated with the AL intensity variation. The ~10 a oscillation is most evident after the 1980s, which is predominantly triggered by the AL north-south shift through the bridge of oceanic Rossby waves.
基金This work is supported by the National Natural Science Foundation of China and the Foundation of Nation’s Education Committee for Young Scientists.
文摘Polyether-polyurethane zwitterionomers based on 4, 4'-diphenylmethane diisocyanate(MDI), methyl diethanolamine (MDEA), and polytetramethylene oxide glycol (PTMO) werestudied with variable-temperature wide-line ~1H NMR. It is found that upon ionization, degree ofphase separation in the polymer system decreased at first due to the loss of hard segmentregularity, while further ionization increased the degree of phase separation through increasinghard phase cohesion and difference of polarity between hard and soft segments.
文摘Conductive n type a Si∶H∶Y alloy films with the conductivity as high as 60 S/cm have been deposited on Si substrate by radio frequency sputtering. In the temperature range 20～300 K, for samples with large Y contents, the thermally activated conduction is also observed and the plots of lg σ vs. 1/ T can be fitted by two linear functions with different slopes. The corresponding temperatures of the kinks between the two straight lines depend on the Y contents in the samples. For small Y content films, the conductivities can be fitted to the funciton σ∝ exp (-1/ T 1/4 ). The present results are interpreted using different conduction mechanisms in different temperature ranges for samples with different Y contents.
基金supported by the National Natural Science Foundation of China(62474115,52105582)Natural Science Foundation of Guangdong Province(2024A1515030026,2022A1515010894)+1 种基金Fundamental Research Foundation of Shenzhen(JCYJ20210324095210030,JCYJ20220818095810023,ZDSYS20220527171402005)the State Key Laboratory of Radio Frequency Heterogeneous Integration(Independent Scientific Research Program No.2024013)for Linze Hong,Ke Xiao,Xiangyu Song,and Wei Xu.
文摘We present a system-level model with an on-chip temperature compensation technique for a CMOS-MEMS monolithic calorimetric flow sensing SoC.The model encompasses mechanical,thermal,and electrical domains to facilitate the co-design of a MEMS sensor and CMOS interface circuits on the EDA platform.The compensation strategy is implemented on-chip with a variable temperature difference heating circuit.Results show that the linear programming for the low-temperature drift in the SoC output is characterized by a compensation resistor Rc with a resistance value of 748.21Ωand a temperature coefficient of resistance of 3.037×10−3℃^(−1) at 25℃.Experimental validation demonstrates that within an ambient temperature range of 0–50℃ and a flow range of 0-10 m/s,the temperature drift of the sensor is reduced to±1.6%,as compared to±8.9%observed in a counterpart with the constant temperature difference circuit.Therefore,this on-chip temperature-compensated CMOS-MEMS flow sensing SoC is promising for low-cost sensing applications such as respiratory monitoring and smart energy-efficient buildings.
基金This study was jointly supported by the National Key R&D Program(Grant No.2018YFC1505904)the National Natural Science Foundation of China(Grant Nos.41830969 and 41705052)the Basic Scientific Research and Operation Foundation of CAMS(Grant No.2018Z006).
文摘Under recent Arctic warming,boreal winters have witnessed severe cold surges over both Eurasia and North America,bringing about serious social and economic impacts.Here,we investigated the changes in daily surface air temperature(SAT)variability during the rapid Arctic warming period of 1988/89–2015/16,and found the daily SAT variance,mainly contributed by the sub-seasonal component,shows an increasing and decreasing trend over eastern Eurasia and North America,respectively.Increasing cold extremes(defined as days with daily SAT anomalies below 1.5 standard deviations)dominated the increase of the daily SAT variability over eastern Eurasia,while decreasing cold extremes dominated the decrease of the daily SAT variability over North America.The circulation regime of cold extremes over eastern Eurasia(North America)is characterized by an enhanced high-pressure ridge over the Urals(Alaska)and surface Siberian(Canadian)high.The data analyses and model simulations show the recent strengthening of the high-pressure ridge over the Urals was associated with warming of the Barents–Kara seas in the Arctic region,while the high-pressure ridge over Alaska was influenced by the offset effect of Arctic warming over the East Siberian–Chukchi seas and the Pacific decadal oscillation(PDO)–like sea surface temperature(SST)anomalies over the North Pacific.The transition of the PDO-like SST anomalies from a positive to negative phase cancelled the impact of Arctic warming,reduced the occurrence of extreme cold days,and possibly resulted in the decreasing trend of daily SAT variability in North America.The multi-ensemble simulations of climate models confirmed the regional Arctic warming as the driver of the increasing SAT variance over eastern Eurasia and North America and the overwhelming effect of SST forcing on the decreasing SAT variance over North America.Therefore,the regional response of winter cold extremes at midlatitudes to the Arctic warming could be different due to the distinct impact of decadal SST anomalies.
基金This study was supported by the National Natural Science Foundation of China under Grant No. 49875012.
文摘The results of four versions of IAP/LASG Global Ocean-Atmosphere-Land System Model (GOALS) are analyzed separately over the oceans and over continents, and compared with observed data. Some fundamental atmospheric variables including surface air temperature (SAT), sea level pressure (SLP) and precipitation are examined to evaluate the ability of the GOALS model to simulate the contemporary climate and climate variability. In general, all four versions of the GOALS model are capable of reproducing the main features of the mean state and seasonal variation of the observed climate with reasonable accuracy. The evaluation also reveals some weakness of the model. According to this study, we can clearly see that the essential discrepancy of global averaged SLP lies over the continents in boreal summer. The simulated higher SAT over land versus the observed is mainly due to the effect of the land surface process. It is worth noting the underestimation by simulated precipitation rates mostly appears over the oceans, yet over-land precipitation is higher in high and middle latitudes than the observed for the boreal winter. Through intercomparisons among different versions of the model, it can be clearly seen that the incorporation of the diurnal cycle of solar radiation apparently improves the simulation of SAT, especially in the low and middle latitudes over land. Also, the introduction of the diurnal cycle shows a great improvement in precipitation in tropical continents and wintertime precipitation in high and middle latitudes. Furthermore, based on the daily flux anomaly exchange scheme (DFA), the latest version of GOALS model simulated over-ocean temperature variability is improved in the low and middle latitudes. Having compared the standard deviation of the annual mean surface air temperature (SAT) simulated by the GOALS model to observation, it is found that all four versions of the GOALS model underestimate surface air temperature variability over both oceans and land relative to observations. Several factors that may contribute to these differences between simulated and observed temperature variability are identified.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2009CB623201)National Natural Science Foundation of China(No.51302070)
文摘The effect of curing regime on degree ofAl3＋ substituting for Si^4＋ （Al/Si ratio） in C-S-H gels of hardened Portland cement pastes was investigated by 29Si magic angel spinning （MAS） nuclear magnetic resonance （NMR） with deconvolution technique. The curing regimes included the constant temperature （20, 40, 60 and 80 ℃） and variable temperature （simulated internal temperature of mass concrete with 60 ℃ peak）. The results indicate that constant temperature of 20 ℃ is beneficial to substitution ofAl3＋ for Si4＋, and AI/Si ratio changes to be steady after 180 d. The increase of Al/Si ratio at 40 ℃is less than that at 20℃ for 28 d. The other three regimes of high temperature increase Al/Si ratio only before 3 d, on the contrary to that from 3 to 28 d. However, the 20 ℃ curing stage from 28 to 180 d at variable temperature regime, is beneficial to the increase of AI/Si ratio which is still lower than that at constant temperature regime of 20 ℃ for the same age. A nonlinear relation exists between the Al/Si ratio and temperature variation or mean chain length （MCL） of C-S-H gels, furthermore, the amount ofAl3＋ which can occupy the bridging tetrahedra sites in C-S-H structure is insufficient in hardened Portland cement pastes.
文摘In order to promote the application of clean energy technology in clothing and promote the integration of industrial development and artificial intelligence wearable technology,this study elaborates the energy application characteristics of intelligent wearable products at home and abroad and its application in different fields,aiming at the current research status of wearable technology in the field of textile and clothing.The wearable distributed generation technology is classified,and a creative clothing design for detecting climate temperature is designed.Based on the monitoring of body temperature,the changes in clothing pattern color can reflect people’s health and emotional status.At the same time,it can also be applied to the screening of abnormal body temperature during the COVID-19.
基金funded by the National Key Research and De-velopment Program of China[Grant number 2017YFA0604304]the National Natural Science Foundation of China[Grant number 41661144032].
文摘Using a homogenized daily maximum temperature(T_(max))dataset across China,this study characterized the spatiotemporal variation of the onset date of extreme hot days in a year(i.e.,FirstEHD)during 1960-2018.Inhomogeneous trends of FirstEHD over China during 1960-2018 can be found,with the advanced trend of FirstEHD over most parts in China,while a number of stations in North-Central China(NC)show the delayed trend of FirstEHD.Moreover,there exist interdecadal changes of FirstEHD trend,with a remarkable difference in the trend magnitude before and after the 1990s over South China(SC),and the sign of trend can even reverse from negative to positive after the 1990s in Xinjiang(XJ)and Yangtze River Basin(YR),and from positive to negative in NC.The overall trends of FirstEHD over NC,YR,and XJ during 1960-2018 are dominated by the trends before the 1990s,while they are dominated by the sharp advance after the 1990s over SC.It is further found that the trend of FirstEHD can generally be explained by the long-term trend in T_(max) over most parts of China,but the contribution from T_(max) variabilities is also non-negligible and can even account for more than 75% of the overall trend over NC.The possible factors responsible for the decadal changes in FirstEHD trends are also discussed.
基金supported by National Natural Science Foundation of China(No.21475068)
文摘Understanding the thermal stability of the proteins in human serum is essential since human serum is the important source of pharmaceutical proteins. Near-infrared（NIR） spectroscopy was applied to the investigation of thermal changes in secondary structure and hydration of human serum proteins.However, as a multicomponent system, the overlap of the broad NIR bands makes the structural analysis very difficult directly using the spectra of serum samples. Therefore, continuous wavelet transform（CWT） was used to improve the resolution of NIR spectra, and Monte Carlo-uninformative variable elimination（MC-UVE） method was applied to the selection of the variables associated with the proteins for the structural analysis. The variables（5956, 5867, 5815, 5747, 4525, 4401, 4359 and 4328 cm^-1） related to protein secondary structures and those（7074, 6951, 6827 and 6700 cm 1） connected with water species were selected. Then, the thermal stability was analyzed through the intensity variations of the selected variables with temperature from 30℃ to 80 ℃. It was found that the variation of the spectral variables related to both a-helix and b-sheet changes apparently around 60 ℃, indicating the beginning of the thermal denaturation and the transition from a-helix to b-sheet. Moreover, an obvious change was found around 60℃for the content of the water specie S3, i.e., the water cluster containing three hydrogen bonds. The result demonstrates that MC-UVE can identify the protein-related NIR spectral variables, and the water species may be a marker for investigation of the structural change of proteins in biochemical systems.
