Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was sign...Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was significantly improved because of covalent bonds in the interfaces between the film and substrate,while only weak Van der Waals bonds existed at the interfaces within the particle-assembledβ-Fe_(2)O_(3)film prepared by electrophoretic deposition.The as-prepared planar films were thus able to withstand higher annealing temperature and stronger laser irradiation power in comparison with theβ-Fe_(2)O_(3)particle-assembly.Ti^(4+)doping was used to increase the concentration of carriers in the metastableβ-Fe_(2)O_(3)film.Compared with pureβ-Fe_(2)O_(3)photoanodes,the highest saturated photocurrent for water splitting over the Ti^(4+)-dopedβ-Fe_(2)O_(3)photoanode was increased by a factor of approximately three.Theβ-Fe_(2)O_(3)photoanode exhibited photochemical stability for water splitting for a duration exceeding 100 h,which indicates its important potential application in solar energy conversion.展开更多
We investigate neutron star properties by constructing a chiral SU(3) spontaneous breaking Lagrangian and using relativistic mean-field approximation. The results show that condensate appears at some baryon densities...We investigate neutron star properties by constructing a chiral SU(3) spontaneous breaking Lagrangian and using relativistic mean-field approximation. The results show that condensate appears at some baryon densities, and hyperons and exist in neutron star matter at high density. In this model, neutron star's maximum mass is with corresponding radius about 8 km.展开更多
The first-order-like phase transition (FOLT) in the dispersive optical bistability is investigated when the fluctuation in the incident light field is considered as colored noise. A unified colored-noise approximation...The first-order-like phase transition (FOLT) in the dispersive optical bistability is investigated when the fluctuation in the incident light field is considered as colored noise. A unified colored-noise approximation is applied to obtain the steady state distribution (SSD) when either the intensity or phase fluctuations of the incident field are included in the system. For intensity fluctuations only, the curve of SSD is changed from single extreme to two extremes, and then to three extremes. The colored nature of the noise can reduce the fluctuation in the system. However, for phase fluctuations only, the FOLT is mainly induced by the colored nature of the noise. The curve of SSD is changed from single extreme to three extremes directly. There is no FOLT existing for white noise.展开更多
lsochrysis zhangfiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under ni- trogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-ti...lsochrysis zhangfiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under ni- trogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction （qPCR） provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin （ACT）, α-tubulin （TUA）, β-tubulin （TUB）, ubiquitin （UBI）, 18S rRNA （18S） and one target gene, diacylglycerol acyltransferase （DGAT）, were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed 1. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experi- mental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expres- sion under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of/. zhangfiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.展开更多
The phase formation and thermoelectric(TE)properties in the central region of the Zn−Sb phase diagram were analyzed through synthesizing a series of Zn_(1+x)Sb(x=0,0.05,0.1,0.15,0.25,0.3)materials by reacting Zn and S...The phase formation and thermoelectric(TE)properties in the central region of the Zn−Sb phase diagram were analyzed through synthesizing a series of Zn_(1+x)Sb(x=0,0.05,0.1,0.15,0.25,0.3)materials by reacting Zn and Sb powders below the solidus line of the Zn−Sb binary phase diagram followed by furnace cooling.In this process,the nonstoichiometric powder blend crystallized in a combination of ZnSb andβ-Zn4Sb3 phases.Then,the materials were ground and hot pressed to form dense ZnSb/β-Zn4Sb3 composites.No traces of Sb and Zn elements or other phases were revealed by X-ray diffraction,high resolution transmission electron microscopy and electron energy loss spectroscopy analyses.The thermoelectric properties of all materials could be rationalized as a combination of the thermoelectric behavior of ZnSb andβ-Zn4Sb3 phases,which were dominated by the main phase in each sample.Zn1.3Sb composite exhibited the best thermoelectric performance.It was also found that Ge doping substantially increased the Seebeck coefficient of Zn1.3Sb and led to significantly higher power factor,up to 1.51 mW·m−1·K−2 at 540 K.Overall,an exceptional and stable TE figure of merit(ZT)of 1.17 at 650 K was obtained for Zn1.28Ge0.02Sb.展开更多
The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different co...The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different concentrations of 2-hydroxypropyl-β- eyclodextrin on the stability of dihydroartemisinin at 50, 60, 70 and 80 ℃ was also studied. Inclusion complex of dihydroartemisinin with 2-hydroxypropyl-β-cyclodextrin was prepared and characterized by X-ray diffraction and differential scanning calorimetry. The 2-hydroxypropyl-β-cyclodextrin effectively inhibited the hydrolysis of dihydroartemisinin and greatly increased its solubility. Furthermore, we showed that the higher concentrations of 2-hydroxypropyl-β-cyclodextrin, the better stability and solubility of dihydroartemisinin. When the temperature was increased, the stability of dihydroartemisinin decreased. Our results indicated that 2-hydroxypropyl-β-cyclodextrin can be used as a stabilizer and solubilizer of dihydroartemisinin.展开更多
13-Amylase activity （BAA） and thermostability （BAT） are important traits for malt quality. In this study, 138 Tibetan annual wild barley accessions and 20 cultivated genotypes differing in BAh, were planted and an...13-Amylase activity （BAA） and thermostability （BAT） are important traits for malt quality. In this study, 138 Tibetan annual wild barley accessions and 20 cultivated genotypes differing in BAh, were planted and analyzed in 2009 and 2012. Significant differences were detected among genotypes in BAA and BAT. The cultivated genotypes had a mean BAA of 1137.6 U/g and a range of from 602.1 to 1407.5 U/g, while the wild accessions had a mean of 1517.9 U/g and a range of from 829.7 to 2310.0 U/g. The cultivated genotypes had a mean relative residual 13-amylase activity （RRBAA） of 61.6% and a range of from 22.2% to 82.3%, while the wild barleys had a mean of 57.8% and a range of from 21.9% to 96.1%. Moreover, there was a significant difference among genotypes in the response of RRBAA to the temperature and duration of heat treatment. The wild barleys had wider variation in BAA and BAT than cultivated genotvDes.展开更多
The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions o...The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.展开更多
文摘Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was significantly improved because of covalent bonds in the interfaces between the film and substrate,while only weak Van der Waals bonds existed at the interfaces within the particle-assembledβ-Fe_(2)O_(3)film prepared by electrophoretic deposition.The as-prepared planar films were thus able to withstand higher annealing temperature and stronger laser irradiation power in comparison with theβ-Fe_(2)O_(3)particle-assembly.Ti^(4+)doping was used to increase the concentration of carriers in the metastableβ-Fe_(2)O_(3)film.Compared with pureβ-Fe_(2)O_(3)photoanodes,the highest saturated photocurrent for water splitting over the Ti^(4+)-dopedβ-Fe_(2)O_(3)photoanode was increased by a factor of approximately three.Theβ-Fe_(2)O_(3)photoanode exhibited photochemical stability for water splitting for a duration exceeding 100 h,which indicates its important potential application in solar energy conversion.
基金The project supported in part by the Key Research Plan of Theoretical Physics and Cross Science under Grant No.90103018National Natural Science Foundation of China under Grant No.19975062
文摘We investigate neutron star properties by constructing a chiral SU(3) spontaneous breaking Lagrangian and using relativistic mean-field approximation. The results show that condensate appears at some baryon densities, and hyperons and exist in neutron star matter at high density. In this model, neutron star's maximum mass is with corresponding radius about 8 km.
文摘The first-order-like phase transition (FOLT) in the dispersive optical bistability is investigated when the fluctuation in the incident light field is considered as colored noise. A unified colored-noise approximation is applied to obtain the steady state distribution (SSD) when either the intensity or phase fluctuations of the incident field are included in the system. For intensity fluctuations only, the curve of SSD is changed from single extreme to two extremes, and then to three extremes. The colored nature of the noise can reduce the fluctuation in the system. However, for phase fluctuations only, the FOLT is mainly induced by the colored nature of the noise. The curve of SSD is changed from single extreme to three extremes directly. There is no FOLT existing for white noise.
基金supported by the Hundred Talent Program of the Chinese Academy of Sciences (No.A1097)National High Technology Research and Development Program ‘863’ (2012AA052101)+2 种基金Liaoning Provincial Natural Science Foundation (2012010263)Knowledge Innovation Programs of Dalian Institute of Chemical Physics,CAS (K2010A13)China Postdoctoral Science Foundation Funded Project (2014M551139)
文摘lsochrysis zhangfiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under ni- trogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction （qPCR） provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin （ACT）, α-tubulin （TUA）, β-tubulin （TUB）, ubiquitin （UBI）, 18S rRNA （18S） and one target gene, diacylglycerol acyltransferase （DGAT）, were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed 1. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experi- mental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expres- sion under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of/. zhangfiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.
文摘The phase formation and thermoelectric(TE)properties in the central region of the Zn−Sb phase diagram were analyzed through synthesizing a series of Zn_(1+x)Sb(x=0,0.05,0.1,0.15,0.25,0.3)materials by reacting Zn and Sb powders below the solidus line of the Zn−Sb binary phase diagram followed by furnace cooling.In this process,the nonstoichiometric powder blend crystallized in a combination of ZnSb andβ-Zn4Sb3 phases.Then,the materials were ground and hot pressed to form dense ZnSb/β-Zn4Sb3 composites.No traces of Sb and Zn elements or other phases were revealed by X-ray diffraction,high resolution transmission electron microscopy and electron energy loss spectroscopy analyses.The thermoelectric properties of all materials could be rationalized as a combination of the thermoelectric behavior of ZnSb andβ-Zn4Sb3 phases,which were dominated by the main phase in each sample.Zn1.3Sb composite exhibited the best thermoelectric performance.It was also found that Ge doping substantially increased the Seebeck coefficient of Zn1.3Sb and led to significantly higher power factor,up to 1.51 mW·m−1·K−2 at 540 K.Overall,an exceptional and stable TE figure of merit(ZT)of 1.17 at 650 K was obtained for Zn1.28Ge0.02Sb.
文摘The effect of various concentrations of 2-hydroxypropyl-β-cyclodextrin （HP-β-CD） on the solubility of dihydroartemisinin （DHA） in aqueous solution at different pHs was investigated. The influence of different concentrations of 2-hydroxypropyl-β- eyclodextrin on the stability of dihydroartemisinin at 50, 60, 70 and 80 ℃ was also studied. Inclusion complex of dihydroartemisinin with 2-hydroxypropyl-β-cyclodextrin was prepared and characterized by X-ray diffraction and differential scanning calorimetry. The 2-hydroxypropyl-β-cyclodextrin effectively inhibited the hydrolysis of dihydroartemisinin and greatly increased its solubility. Furthermore, we showed that the higher concentrations of 2-hydroxypropyl-β-cyclodextrin, the better stability and solubility of dihydroartemisinin. When the temperature was increased, the stability of dihydroartemisinin decreased. Our results indicated that 2-hydroxypropyl-β-cyclodextrin can be used as a stabilizer and solubilizer of dihydroartemisinin.
基金Project supported by the National Natural Science Foundation of China （Nos. 31330055 and 31201205）, the Zhejiang Provincial Natural Science Foundation of China （No. Z3110054）, the 948 Project of Ministry of Agriculture of China （No. 2012-Z25）, and the China Agriculture Research System （No. CARS-05）
文摘13-Amylase activity （BAA） and thermostability （BAT） are important traits for malt quality. In this study, 138 Tibetan annual wild barley accessions and 20 cultivated genotypes differing in BAh, were planted and analyzed in 2009 and 2012. Significant differences were detected among genotypes in BAA and BAT. The cultivated genotypes had a mean BAA of 1137.6 U/g and a range of from 602.1 to 1407.5 U/g, while the wild accessions had a mean of 1517.9 U/g and a range of from 829.7 to 2310.0 U/g. The cultivated genotypes had a mean relative residual 13-amylase activity （RRBAA） of 61.6% and a range of from 22.2% to 82.3%, while the wild barleys had a mean of 57.8% and a range of from 21.9% to 96.1%. Moreover, there was a significant difference among genotypes in the response of RRBAA to the temperature and duration of heat treatment. The wild barleys had wider variation in BAA and BAT than cultivated genotvDes.
基金Project supported by the Natural Science Foundation of Heilongjiang Province of China(No.C2017029)the Academic Research Program of Northeast Agricultural University(No.16XG21)the National“Twelfth Five-Year”Plan for Science and Technology Support Program of China(No.2013BAD18B06)
文摘The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.
