The change color effect of gold nanoparticle solutions was studied by means of resonance scattering and absorption spectrometry and scan electron microscopy. The red Au nanoparticles with a size of 10 nm exhibit a res...The change color effect of gold nanoparticle solutions was studied by means of resonance scattering and absorption spectrometry and scan electron microscopy. The red Au nanoparticles with a size of 10 nm exhibit a resonance absorption peak and a resonance scattering peak all at 525 nm. After some inorganic electrolyte was added to a red Au nanoparticles solution, the color of the solution became blue and the absorbance at (600_700) nm was significantly increased. The ratio of the concentration of monovalent cations, at which the resonance scattering of the system at 525 nm is maximal to that of divalent cations, is in the range of 100∶1_100∶1.8. It is in good agreement with the Schulze-Hardy rule of the coagulation value of electrolyte. After adding some cationic surfactants to the above solution, the color of the solution is in deep blue, with two resonance absorption peaks at 550 and 680 nm, and a greatly enhanced resonance scattering peak at 525 nm. The experiments demonstrate that the stronger the hydrophobicity of the cationic surfactant is, the stronger the change color effect of the Au nanoparticle solution promoted by cationic surfactant is. The change color effect of Au nanoparticle solution is resulted from the increased diameter of Au nanoparticles, and the changes of resonance absorption peak and resonance scattering.展开更多
With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts ...With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts operated over long time, measurement and calculation of NPP (net primary production) and biomass of biological community, and analysis of soil organic matter content show that the artificial alder and cypress mixed forest has outstanding eco-environmental effect: adjusting local climate, raising soil fertility, alleviating menace of drought, and raising NPP and biomass of biological community. It is very beneficial for improving ecological environment to afforest artificial alder and cypress mixed forest in populous Hilly Area of Central Sichuan Basin, China. Key Words: land use/land cover change (LUCC); eco-environmental effect; Hilly Area of Central Sichuan Basin; the artificial alder and cypress mixed forest展开更多
Regeneration of damaged innervations in the peripheral nervous system (PNS) has been well documented in both animals and human. After injury, the damaged neurite swells and undergoes retrograde degeneration. Once th...Regeneration of damaged innervations in the peripheral nervous system (PNS) has been well documented in both animals and human. After injury, the damaged neurite swells and undergoes retrograde degeneration. Once the debris is cleared, it begins to sprout and restore damaged connections. Damaged axons are able to regrow as long as the perikarya are intact and have made contact with the Schwann cells in the endoneurial channel[2]. Under appropriate conditions,展开更多
To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ...To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent.Electron microscopy,flow cytometry and RT-PCR were used to detect the changes in cell ultrastructure,apoptosis,cell cycle and the expression of cyclinB1 mRNA,respectively.Results After transfection of survivin ASODN,the expression of cyclinB1 mRNA in the cells significantly increased and increase in G2-M arrest and apoptosis appeared.Meanwhile,the cell ultrastructure had apoptotic changes such as chromatin condensation and apoptotic body formation.Conclusion Survivin ASODN can induce the expression of cyclinB1 that may result in G2-M arrest.Consequently,apoptosis is triggered.Survivin ASODN transfection might be an improtant new treatment for HCC.14 refs,2 figs,1 tab.展开更多
The research investigated the adaptation strategies to mitigate consequence of climate change on food crops farming in Oyo State.120 respondents were selected for this study using multi-stage sampling procedures.Prima...The research investigated the adaptation strategies to mitigate consequence of climate change on food crops farming in Oyo State.120 respondents were selected for this study using multi-stage sampling procedures.Primary data was collected through interview schedule and analyzed using both descriptive and inferential statistics.Available results indicated that 84.2% of the respondents were male,93.3% of them were married and maize(45.8%),cassava(37.5%)are the mainly crops cultivated.Results also revealed that 70.0% of the respondents have knowledge of climate change with majority(84.17%)of them regularly accessed information on climate change through radio and 88.3%of them claimed to adopt planting crops favorable for the present weather condition as an adaptation techniques to mitigate the consequences of climate change more frequently.Chi-square and Correlation results revealed a significant relationship existed between farmers educational levels(X2=4.861;p=0.003);household size(r=-0.089;p=0.002);knowledge(r=-0.157;p=0.002),and adaptation strategies to reduce the consequences of climate change on the food crops farming.It was recommended that food crop farmers should be provided with better education and sensitized in order for them to be acquainted with adaptation techniques and coping mechanisms that are currently been offered by research.展开更多
In this paper, we review the magnetic properties and magnetocaloric effects(MCE) of binary R–T(R = Pr, Gd, Tb,Dy, Ho, Er, Tm; T = Ga, Ni, Co, Cu) intermetallic compounds(including RGa series, RNi series, R_(12...In this paper, we review the magnetic properties and magnetocaloric effects(MCE) of binary R–T(R = Pr, Gd, Tb,Dy, Ho, Er, Tm; T = Ga, Ni, Co, Cu) intermetallic compounds(including RGa series, RNi series, R_(12)Co_7 series, R_3 Co series and RCu_2series), which have been investigated in detail in the past several years. The R–T compounds are studied by means of magnetic measurements, heat capacity measurements, magnetoresistance measurements and neutron powder diffraction measurements. The R–T compounds show complex magnetic transitions and interesting magnetic properties.The types of magnetic transitions are investigated and confirmed in detail by multiple approaches. Especially, most of the R–T compounds undergo more than one magnetic transition, which has significant impact on the magnetocaloric effect of R–T compounds. The MCE of R–T compounds are calculated by different ways and the special shapes of MCE peaks for different compounds are investigated and discussed in detail. To improve the MCE performance of R–T compounds,atoms with large spin(S) and atoms with large total angular momentum(J) are introduced to substitute the related rare earth atoms. With the atom substitution, the maximum of magnetic entropy change(?SM), refrigerant temperature width(Twidth)or refrigerant capacity(RC) is enlarged for some R–T compounds. In the low temperature range, binary R–T(R = Pr, Gd,Tb, Dy, Ho, Er, Tm; T = Ga, Ni, Co, Cu) intermetallic compounds(including RGa series, RNi series,R_(12)Co_7 series, R_3 Co series and RCu_2series) show excellent performance of MCE, indicating the potential application for gas liquefaction in the future.展开更多
Based on multi-type,multi-temporal remote sensing data,we have monitored recent changes in cultivated land use and vegetation,in sandy areas and salinized desertification in the Green Corridor zone of the main channel...Based on multi-type,multi-temporal remote sensing data,we have monitored recent changes in cultivated land use and vegetation,in sandy areas and salinized desertification in the Green Corridor zone of the main channel of the Tarim River Basin.The results of our investigation show that the ecological environment in the Green Corridor of the main channel of the Tarim River Basin has conspicuously improved from 2002 to 2004.These improvements show up largely in such aspects as an increase in the rate of vegetation cover,a reduction in desertification land areas and a weakening in the intensity of sandy and the salinized land.On the other hand,the cultivated area in the Tarim River Basin significantly increased from 2002 to 2004.The rate of growth in cultivated areas during this period was significantly higher than that from 1999 to 2002.The increase in the use of irrigation resulting from the substantial increase in cultivated areas has a long-term potential restraining effect on the restoration of ecological functions of the Tarim River.展开更多
The complex geographical environment in China makes its gravity signals miscellaneous.This work gives a comprehensive representation and explanation in secular trend of gravity change in different regions,the key feat...The complex geographical environment in China makes its gravity signals miscellaneous.This work gives a comprehensive representation and explanation in secular trend of gravity change in different regions,the key features of which include positive trend in inner Tibet Plateau and South China and negative trend in North China plain and high mountain Asia(HMA).We also present the patterns of amplitudes and phases of annual and semiannual change.The mechanism underlying the semiannual period is explicitly discussed.The displacement in three directions expressed in terms of geo-potential spherical coefficients and load Love numbers are given.A case study applied with these equations is presented.The results show that Global Positioning System(GPS) observations can be used to compare with Gravity Recovery and Climate Experiment(GRACE) derived displacement and the vertical direction has a signal-noise-ratio of about one order of magnitude larger than the horizontal directions.展开更多
To understand how temperature varies in urban Shanghai under the background of global climate change and how it is affected by urbanization, the Shanghai temperature responses to global warming were analyzed, and then...To understand how temperature varies in urban Shanghai under the background of global climate change and how it is affected by urbanization, the Shanghai temperature responses to global warming were analyzed, and then the temperature trends of urban and suburb stations under different climatic backgrounds were obtained. The urbanization effects on temperature were studied by comparing urban stations to suburb stations, the relationship between urbanization variables and temperature components were obtained, and observation data of surface and high level were combined to assess the contribution of urbanization effect. In the last part of the paper, the cause of urbanization effects on temperature was discussed. The results indicated: The long term change trend of Shanghai annual mean temperature is 1.31/100a from 1873 to 2004, the periods of 1921 – 1948 and 1979 – 2004 are warmer, and the 1979 – 2004 period is the warmest; compared to suburb stations, the representative urban station has slower decreases in the cool period and faster increases in the warm one; the urban and suburb temperatures have distinct differences resulting from urbanization and the differences are increasing by the year, with the difference of mean temperature and minimum temperature being the greatest in fall and that of maximum temperature being the largest in summer between the urban and suburban areas. The urbanization process accelerates the warming speed, with the minimum temperature being the most obvious; the urbanization effect contributes a 0.4°C increase in 1980s and 1.1°C in 1990s to the annual mean temperature.展开更多
The magnetic properties and magnetocaloric effect(MCE) in EuTi1-xCoxO3(x = 0, 0.025, 0.05, 0.075, 0.1) compounds have been investigated. When the Ti^4+ ions were substituted by Co2+ions, the delicate balance was...The magnetic properties and magnetocaloric effect(MCE) in EuTi1-xCoxO3(x = 0, 0.025, 0.05, 0.075, 0.1) compounds have been investigated. When the Ti^4+ ions were substituted by Co2+ions, the delicate balance was changed between antiferromagnetic(AFM) and ferromagnetic(FM) phases in the EuTiO3 compound. In EuTi1-xCoxO3 system, a giant reversible MCE and large refrigerant capacity(RC) were observed without hysteresis. The values of -△SM^max were evaluated to be around 10 J·kg^-1·K^-1 for EuTi0.95Co0.05O3 under a magnetic field change of 10 kOe. The giant reversible MCE and large RC suggests that EuTi1-xCoxO3 series could be considered as good candidate materials for low-temperature and low-field magnetic refrigerant.展开更多
The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced...The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced about 44 Ma in the polar re- gions as the seas cooled following the loss of the circum-equatorial ocean. Before then, a mega warm period lasted for more than 200 Ma. The frequency of the major cold events within the present mega cold period is increasing, with each continent being un- der the influence of a different set of climatic controls. There are many causes of these shifts in climate, ranging from fluctuating meridional ocean currents, rearrangement of tectonic plates, and changes in ocean gateways. These are enhanced by a combination of Milankovitch cycles and many other medium to small oscillations and cyclic controls that cause the daily, monthly, and season- al fluctuations in weather. Examples are given of how these can cause a change from cold to warm events, or vice versa, at pre- sent-day or mega scales, aided by eustatic changes in sea levels and changes in the distribution of air masses, sea ice, and snow.展开更多
An investigation on the magnetostructural transformation and magnetocaloric properties of Ni48-xCo2Mn38+xSn12(x = 0, 1.0, 1.5, 2.0, and 2.5) ferromagnetic shape memory alloys is carried out. With the partial replac...An investigation on the magnetostructural transformation and magnetocaloric properties of Ni48-xCo2Mn38+xSn12(x = 0, 1.0, 1.5, 2.0, and 2.5) ferromagnetic shape memory alloys is carried out. With the partial replacement of Ni by Mn in the Ni_(48)Co2Mn38Sn12 alloy, the electron concentration decreases. As a result, the martensitic transformation temperature is decreased into the temperature window between the Curie-temperatures of austenite and martensite. Thus, the samples with x = 1.5 and 2.0 exhibit the magnetostructural transformation between the weak-magnetization martensite and ferromagnetic austenite at room temperature. The structural transformation can be induced not only by the temperature,but also by the magnetic field. Accompanied by the magnetic-field-induced magnetostructural transformation, a considerable magnetocaloric effect is observed. With the increase of x, the maximum entropy change decreases, but the effective magnetic cooling capacity increases.展开更多
This paper creates an extended import-competitive economy-energy-environmental input/output model and employs a structural decomposition analysis (SDA) approach based on double-layer nested structural formulae to br...This paper creates an extended import-competitive economy-energy-environmental input/output model and employs a structural decomposition analysis (SDA) approach based on double-layer nested structural formulae to break down China's carbon dioxide emissions growth between 1992 and 2007from three perspectives: the overall economy, by-industry and by industrial sectors. Analysis results indicate that the energy intensity effect remains the biggest factor behind carbon emissions reduction. This paper also .found that between 2002 and 2007, China's carbon emissions growth obviously accelerated compared to the previous period, which indicates a "high carbon" tendency in the new round of industrialization. Therefore, in addition to developing a circular economy and clean production, accelerating the phasing out of backward capacities, and developing new energies, China should further encompass the positive role of energy intensity.展开更多
The 4M crop model was used to investigate the prospective effects of climate change on the agro-ecological characteristics of Hungary.The model was coupled with a detailed meteorological database and spatial soil info...The 4M crop model was used to investigate the prospective effects of climate change on the agro-ecological characteristics of Hungary.The model was coupled with a detailed meteorological database and spatial soil information systems covering the whole territory of Hungary.Plant-specific model parameters were determined by inverse modeling.Future meteorological data were produced from the present meteorological data by combining a climate change scenario and a stochastic weather generator.Using the available and the generated data,the present and the prospective agro-ecological characteristics of Hungary were determined.According to the simulation results,average yields will decrease considerably(-30%)due to climate change.The rate of nitrate leaching will prospectively decrease as well.The fluctuations of both the yields and the annual nitrate leaching rates will most likely increase approaching the end of the twenty-first century.On the basis of the simulation results,the role of autumn crops is likely to become more significant in Hungary.The achieved results can be generalized for more extended regions based on the concept of spatial(geographical)analogy.展开更多
The microstructure, magnetic entropy changes, hysteresis and magnetic properties of La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.5–x)Si_x(x=0.4, 0.5, 0.6, 0.7) compounds were studied by X-ray diffraction(XRD) and a sup...The microstructure, magnetic entropy changes, hysteresis and magnetic properties of La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.5–x)Si_x(x=0.4, 0.5, 0.6, 0.7) compounds were studied by X-ray diffraction(XRD) and a superconducting quantum interference device magnetometer(SQUID). The results showed that all the compounds presented cubic Na Zn13-type structure. Their Curie temperatures changed complicatedly with decreasing Al content due to changes of antiferromagnetic and ferromagnetic interaction. Under a field change from 0 to 2 T, the maximum magnetic entropy change for La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.1)Si_(0.4), La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.0)Si_(0.5), La_(0.8)Ce_(0.2)Fe_(11.5)Al_(0.9)Si_(0.6) and La_(0.8)Ce_(0.2)Fe_(11.5)Al_(0.8)Si_(0.7) were found to be –9.6, –4.8, –5.8 and –11.7 J/(kg·K), respectively. Moreover, their hysteresis losses were 1.13 J/(kg·K) or less. The large magnetic entropy changed and small hysteresis losses made them potential candidates for practical magnetic refrigeration application.展开更多
Objective To explore the the effect of the changes of ghrelin and its receptor(GHSR1a)on accelerating diabetic encephalopathy by blood glucose fluctuation in GK rats.Methods Eight male wistar rats were set as normal c...Objective To explore the the effect of the changes of ghrelin and its receptor(GHSR1a)on accelerating diabetic encephalopathy by blood glucose fluctuation in GK rats.Methods Eight male wistar rats were set as normal control group(NC).16 male GK rats were randomly divided into sustained hyperglycemia group(MS)and blood glucose fluctuation group(MF).MF group展开更多
The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x (x=0.01 and 0.03) alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scannin...The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x (x=0.01 and 0.03) alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimeter (DSC) and magnetization measurements. The results of energy dispersive X-ray analysis (EDX) and X-ray diffraction analyses showed that the composition and crystal structure of the alloys were desired. DSC measurements were performed to determine the transformation temperatures for each alloy. Both alloys exhibited the first order phase transition around room temperature. The alloys showed an anti-ferromagnetic transition around 60 K. The isothermal magnetic entropy changes of the alloys were determined from the isothermal magnetization measurements by using the Maxwell relation. The maximum values of isothermal magnetic entropy change of the Gd5Ge2.05-xSi1.95-xMn2x alloy with x=0.01 was found to be -12.1 and -19.8 J/(kg·K) using Maxwell equation around 268 K in applied fields of 2 and 5 T, respectively.展开更多
Objective To explore the effects of cognitive intervention on the quality of life in patients with functional dyspepsia(FD).Methods From May 2013 to February2015,a total of 412 patients with FD were enrolled,cognition...Objective To explore the effects of cognitive intervention on the quality of life in patients with functional dyspepsia(FD).Methods From May 2013 to February2015,a total of 412 patients with FD were enrolled,cognition of the disease and the quality of life were assessed by disease cognitive simple questionnaire(B-IPQ)and Nepean dyspepsia index(NDI).The patients also re-展开更多
基金Supported by National Natural Science Foundation of China(No. 2 0 36 5 0 0 1) and Natural Funds of Guangxi Province
文摘The change color effect of gold nanoparticle solutions was studied by means of resonance scattering and absorption spectrometry and scan electron microscopy. The red Au nanoparticles with a size of 10 nm exhibit a resonance absorption peak and a resonance scattering peak all at 525 nm. After some inorganic electrolyte was added to a red Au nanoparticles solution, the color of the solution became blue and the absorbance at (600_700) nm was significantly increased. The ratio of the concentration of monovalent cations, at which the resonance scattering of the system at 525 nm is maximal to that of divalent cations, is in the range of 100∶1_100∶1.8. It is in good agreement with the Schulze-Hardy rule of the coagulation value of electrolyte. After adding some cationic surfactants to the above solution, the color of the solution is in deep blue, with two resonance absorption peaks at 550 and 680 nm, and a greatly enhanced resonance scattering peak at 525 nm. The experiments demonstrate that the stronger the hydrophobicity of the cationic surfactant is, the stronger the change color effect of the Au nanoparticle solution promoted by cationic surfactant is. The change color effect of Au nanoparticle solution is resulted from the increased diameter of Au nanoparticles, and the changes of resonance absorption peak and resonance scattering.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(KZCX1-SW-01-01B)Cultivatlon Foundation of Institute of Mountain Hazards and Environment,CAS
文摘With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts operated over long time, measurement and calculation of NPP (net primary production) and biomass of biological community, and analysis of soil organic matter content show that the artificial alder and cypress mixed forest has outstanding eco-environmental effect: adjusting local climate, raising soil fertility, alleviating menace of drought, and raising NPP and biomass of biological community. It is very beneficial for improving ecological environment to afforest artificial alder and cypress mixed forest in populous Hilly Area of Central Sichuan Basin, China. Key Words: land use/land cover change (LUCC); eco-environmental effect; Hilly Area of Central Sichuan Basin; the artificial alder and cypress mixed forest
文摘Regeneration of damaged innervations in the peripheral nervous system (PNS) has been well documented in both animals and human. After injury, the damaged neurite swells and undergoes retrograde degeneration. Once the debris is cleared, it begins to sprout and restore damaged connections. Damaged axons are able to regrow as long as the perikarya are intact and have made contact with the Schwann cells in the endoneurial channel[2]. Under appropriate conditions,
文摘To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent.Electron microscopy,flow cytometry and RT-PCR were used to detect the changes in cell ultrastructure,apoptosis,cell cycle and the expression of cyclinB1 mRNA,respectively.Results After transfection of survivin ASODN,the expression of cyclinB1 mRNA in the cells significantly increased and increase in G2-M arrest and apoptosis appeared.Meanwhile,the cell ultrastructure had apoptotic changes such as chromatin condensation and apoptotic body formation.Conclusion Survivin ASODN can induce the expression of cyclinB1 that may result in G2-M arrest.Consequently,apoptosis is triggered.Survivin ASODN transfection might be an improtant new treatment for HCC.14 refs,2 figs,1 tab.
文摘The research investigated the adaptation strategies to mitigate consequence of climate change on food crops farming in Oyo State.120 respondents were selected for this study using multi-stage sampling procedures.Primary data was collected through interview schedule and analyzed using both descriptive and inferential statistics.Available results indicated that 84.2% of the respondents were male,93.3% of them were married and maize(45.8%),cassava(37.5%)are the mainly crops cultivated.Results also revealed that 70.0% of the respondents have knowledge of climate change with majority(84.17%)of them regularly accessed information on climate change through radio and 88.3%of them claimed to adopt planting crops favorable for the present weather condition as an adaptation techniques to mitigate the consequences of climate change more frequently.Chi-square and Correlation results revealed a significant relationship existed between farmers educational levels(X2=4.861;p=0.003);household size(r=-0.089;p=0.002);knowledge(r=-0.157;p=0.002),and adaptation strategies to reduce the consequences of climate change on the food crops farming.It was recommended that food crop farmers should be provided with better education and sensitized in order for them to be acquainted with adaptation techniques and coping mechanisms that are currently been offered by research.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274357,51501005,51590880,and 11674008)the Fundamental Research Funds for the Central Universities,China(Grant No.FRF-TP-15-010A1)+1 种基金the China Postdoctoral Science Foundation(Grant No.2016M591071)the Key Research Program of the Chinese Academy of Sciences(Grant No.KJZD-EW-M05)
文摘In this paper, we review the magnetic properties and magnetocaloric effects(MCE) of binary R–T(R = Pr, Gd, Tb,Dy, Ho, Er, Tm; T = Ga, Ni, Co, Cu) intermetallic compounds(including RGa series, RNi series, R_(12)Co_7 series, R_3 Co series and RCu_2series), which have been investigated in detail in the past several years. The R–T compounds are studied by means of magnetic measurements, heat capacity measurements, magnetoresistance measurements and neutron powder diffraction measurements. The R–T compounds show complex magnetic transitions and interesting magnetic properties.The types of magnetic transitions are investigated and confirmed in detail by multiple approaches. Especially, most of the R–T compounds undergo more than one magnetic transition, which has significant impact on the magnetocaloric effect of R–T compounds. The MCE of R–T compounds are calculated by different ways and the special shapes of MCE peaks for different compounds are investigated and discussed in detail. To improve the MCE performance of R–T compounds,atoms with large spin(S) and atoms with large total angular momentum(J) are introduced to substitute the related rare earth atoms. With the atom substitution, the maximum of magnetic entropy change(?SM), refrigerant temperature width(Twidth)or refrigerant capacity(RC) is enlarged for some R–T compounds. In the low temperature range, binary R–T(R = Pr, Gd,Tb, Dy, Ho, Er, Tm; T = Ga, Ni, Co, Cu) intermetallic compounds(including RGa series, RNi series,R_(12)Co_7 series, R_3 Co series and RCu_2series) show excellent performance of MCE, indicating the potential application for gas liquefaction in the future.
基金Financial support for this work was provided by the National Natural Science Foundation of China (No. 41040011)the Fun-damental Research Funds for the Central Universities (No.CHD2010JC103)
文摘Based on multi-type,multi-temporal remote sensing data,we have monitored recent changes in cultivated land use and vegetation,in sandy areas and salinized desertification in the Green Corridor zone of the main channel of the Tarim River Basin.The results of our investigation show that the ecological environment in the Green Corridor of the main channel of the Tarim River Basin has conspicuously improved from 2002 to 2004.These improvements show up largely in such aspects as an increase in the rate of vegetation cover,a reduction in desertification land areas and a weakening in the intensity of sandy and the salinized land.On the other hand,the cultivated area in the Tarim River Basin significantly increased from 2002 to 2004.The rate of growth in cultivated areas during this period was significantly higher than that from 1999 to 2002.The increase in the use of irrigation resulting from the substantial increase in cultivated areas has a long-term potential restraining effect on the restoration of ecological functions of the Tarim River.
基金supported financially by the National Natural Science Foundation of China(41174063,41331066 and41474059)the CAS/CAFEA International Partnership Program for Creative Research Teams(KZZD-EW-TZ-19)the SKLGED Foundation(2014-1-1-E)
文摘The complex geographical environment in China makes its gravity signals miscellaneous.This work gives a comprehensive representation and explanation in secular trend of gravity change in different regions,the key features of which include positive trend in inner Tibet Plateau and South China and negative trend in North China plain and high mountain Asia(HMA).We also present the patterns of amplitudes and phases of annual and semiannual change.The mechanism underlying the semiannual period is explicitly discussed.The displacement in three directions expressed in terms of geo-potential spherical coefficients and load Love numbers are given.A case study applied with these equations is presented.The results show that Global Positioning System(GPS) observations can be used to compare with Gravity Recovery and Climate Experiment(GRACE) derived displacement and the vertical direction has a signal-noise-ratio of about one order of magnitude larger than the horizontal directions.
文摘To understand how temperature varies in urban Shanghai under the background of global climate change and how it is affected by urbanization, the Shanghai temperature responses to global warming were analyzed, and then the temperature trends of urban and suburb stations under different climatic backgrounds were obtained. The urbanization effects on temperature were studied by comparing urban stations to suburb stations, the relationship between urbanization variables and temperature components were obtained, and observation data of surface and high level were combined to assess the contribution of urbanization effect. In the last part of the paper, the cause of urbanization effects on temperature was discussed. The results indicated: The long term change trend of Shanghai annual mean temperature is 1.31/100a from 1873 to 2004, the periods of 1921 – 1948 and 1979 – 2004 are warmer, and the 1979 – 2004 period is the warmest; compared to suburb stations, the representative urban station has slower decreases in the cool period and faster increases in the warm one; the urban and suburb temperatures have distinct differences resulting from urbanization and the differences are increasing by the year, with the difference of mean temperature and minimum temperature being the greatest in fall and that of maximum temperature being the largest in summer between the urban and suburban areas. The urbanization process accelerates the warming speed, with the minimum temperature being the most obvious; the urbanization effect contributes a 0.4°C increase in 1980s and 1.1°C in 1990s to the annual mean temperature.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504266,51271192,51322605,and 51371075)the Natural Science Foundation of Tianjin,China(Grant No.17JCQNJC02300)
文摘The magnetic properties and magnetocaloric effect(MCE) in EuTi1-xCoxO3(x = 0, 0.025, 0.05, 0.075, 0.1) compounds have been investigated. When the Ti^4+ ions were substituted by Co2+ions, the delicate balance was changed between antiferromagnetic(AFM) and ferromagnetic(FM) phases in the EuTiO3 compound. In EuTi1-xCoxO3 system, a giant reversible MCE and large refrigerant capacity(RC) were observed without hysteresis. The values of -△SM^max were evaluated to be around 10 J·kg^-1·K^-1 for EuTi0.95Co0.05O3 under a magnetic field change of 10 kOe. The giant reversible MCE and large RC suggests that EuTi1-xCoxO3 series could be considered as good candidate materials for low-temperature and low-field magnetic refrigerant.
文摘The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced about 44 Ma in the polar re- gions as the seas cooled following the loss of the circum-equatorial ocean. Before then, a mega warm period lasted for more than 200 Ma. The frequency of the major cold events within the present mega cold period is increasing, with each continent being un- der the influence of a different set of climatic controls. There are many causes of these shifts in climate, ranging from fluctuating meridional ocean currents, rearrangement of tectonic plates, and changes in ocean gateways. These are enhanced by a combination of Milankovitch cycles and many other medium to small oscillations and cyclic controls that cause the daily, monthly, and season- al fluctuations in weather. Examples are given of how these can cause a change from cold to warm events, or vice versa, at pre- sent-day or mega scales, aided by eustatic changes in sea levels and changes in the distribution of air masses, sea ice, and snow.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51601092,51571121,and 11604148)the Fundamental Research Funds for the Central Universities,China(Grant Nos.30916011344 and 30916011345)+5 种基金Jiangsu Natural Science Foundation for Distinguished Young Scholars,China(Grant No.BK20140035)China Postdoctoral Science Foundation(Grant No.2016M591851)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20160833 and BK20160829)Qing Lan Project of Jiangsu Province,ChinaPriority Academic Program Development of Jiangsu Higher Education Institutions,ChinaNMG–NJUST Joint Scholarship Program for Ishfaq Ahmad Shah(Student ID:914116020118)
文摘An investigation on the magnetostructural transformation and magnetocaloric properties of Ni48-xCo2Mn38+xSn12(x = 0, 1.0, 1.5, 2.0, and 2.5) ferromagnetic shape memory alloys is carried out. With the partial replacement of Ni by Mn in the Ni_(48)Co2Mn38Sn12 alloy, the electron concentration decreases. As a result, the martensitic transformation temperature is decreased into the temperature window between the Curie-temperatures of austenite and martensite. Thus, the samples with x = 1.5 and 2.0 exhibit the magnetostructural transformation between the weak-magnetization martensite and ferromagnetic austenite at room temperature. The structural transformation can be induced not only by the temperature,but also by the magnetic field. Accompanied by the magnetic-field-induced magnetostructural transformation, a considerable magnetocaloric effect is observed. With the increase of x, the maximum entropy change decreases, but the effective magnetic cooling capacity increases.
文摘This paper creates an extended import-competitive economy-energy-environmental input/output model and employs a structural decomposition analysis (SDA) approach based on double-layer nested structural formulae to break down China's carbon dioxide emissions growth between 1992 and 2007from three perspectives: the overall economy, by-industry and by industrial sectors. Analysis results indicate that the energy intensity effect remains the biggest factor behind carbon emissions reduction. This paper also .found that between 2002 and 2007, China's carbon emissions growth obviously accelerated compared to the previous period, which indicates a "high carbon" tendency in the new round of industrialization. Therefore, in addition to developing a circular economy and clean production, accelerating the phasing out of backward capacities, and developing new energies, China should further encompass the positive role of energy intensity.
基金The authors gratefully acknowledge the financial support of the ONTTECH Project(TECH-08-A3/2-2008-0379).
文摘The 4M crop model was used to investigate the prospective effects of climate change on the agro-ecological characteristics of Hungary.The model was coupled with a detailed meteorological database and spatial soil information systems covering the whole territory of Hungary.Plant-specific model parameters were determined by inverse modeling.Future meteorological data were produced from the present meteorological data by combining a climate change scenario and a stochastic weather generator.Using the available and the generated data,the present and the prospective agro-ecological characteristics of Hungary were determined.According to the simulation results,average yields will decrease considerably(-30%)due to climate change.The rate of nitrate leaching will prospectively decrease as well.The fluctuations of both the yields and the annual nitrate leaching rates will most likely increase approaching the end of the twenty-first century.On the basis of the simulation results,the role of autumn crops is likely to become more significant in Hungary.The achieved results can be generalized for more extended regions based on the concept of spatial(geographical)analogy.
基金Project supported by the Science and Technology Development Fund of Higher Education of Tianjin,China(20130301)the Tianjin Research Program of Application Foundation and Advanced Technology,China(14JCQNJC4000)the National Natural Science Foundation of China(11604242)
文摘The microstructure, magnetic entropy changes, hysteresis and magnetic properties of La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.5–x)Si_x(x=0.4, 0.5, 0.6, 0.7) compounds were studied by X-ray diffraction(XRD) and a superconducting quantum interference device magnetometer(SQUID). The results showed that all the compounds presented cubic Na Zn13-type structure. Their Curie temperatures changed complicatedly with decreasing Al content due to changes of antiferromagnetic and ferromagnetic interaction. Under a field change from 0 to 2 T, the maximum magnetic entropy change for La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.1)Si_(0.4), La_(0.8)Ce_(0.2)Fe_(11.5)Al_(1.0)Si_(0.5), La_(0.8)Ce_(0.2)Fe_(11.5)Al_(0.9)Si_(0.6) and La_(0.8)Ce_(0.2)Fe_(11.5)Al_(0.8)Si_(0.7) were found to be –9.6, –4.8, –5.8 and –11.7 J/(kg·K), respectively. Moreover, their hysteresis losses were 1.13 J/(kg·K) or less. The large magnetic entropy changed and small hysteresis losses made them potential candidates for practical magnetic refrigeration application.
文摘Objective To explore the the effect of the changes of ghrelin and its receptor(GHSR1a)on accelerating diabetic encephalopathy by blood glucose fluctuation in GK rats.Methods Eight male wistar rats were set as normal control group(NC).16 male GK rats were randomly divided into sustained hyperglycemia group(MS)and blood glucose fluctuation group(MF).MF group
文摘The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x (x=0.01 and 0.03) alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimeter (DSC) and magnetization measurements. The results of energy dispersive X-ray analysis (EDX) and X-ray diffraction analyses showed that the composition and crystal structure of the alloys were desired. DSC measurements were performed to determine the transformation temperatures for each alloy. Both alloys exhibited the first order phase transition around room temperature. The alloys showed an anti-ferromagnetic transition around 60 K. The isothermal magnetic entropy changes of the alloys were determined from the isothermal magnetization measurements by using the Maxwell relation. The maximum values of isothermal magnetic entropy change of the Gd5Ge2.05-xSi1.95-xMn2x alloy with x=0.01 was found to be -12.1 and -19.8 J/(kg·K) using Maxwell equation around 268 K in applied fields of 2 and 5 T, respectively.
文摘Objective To explore the effects of cognitive intervention on the quality of life in patients with functional dyspepsia(FD).Methods From May 2013 to February2015,a total of 412 patients with FD were enrolled,cognition of the disease and the quality of life were assessed by disease cognitive simple questionnaire(B-IPQ)and Nepean dyspepsia index(NDI).The patients also re-