In order to reduce the uncertainty of offline land surface model （LSM） simulations of land evapotranspiration （ET）, we used ensemble simulations based on three meteorological forcing datasets [Princeton, ITPCAS （...In order to reduce the uncertainty of offline land surface model （LSM） simulations of land evapotranspiration （ET）, we used ensemble simulations based on three meteorological forcing datasets [Princeton, ITPCAS （Institute of Tibetan Plateau Research, Chinese Academy of Sciences）, Qian] and four LSMs （BATS, VIC, CLM3.0 and CLM3.5）, to explore the trends and spatiotemporal characteristics of ET, as well as the spatiotemporal pattern of ET in response to climate factors over China's Mainland during 1982-2007. The results showed that various simulations of each member and their arithmetic mean （EnsAVlean） could capture the spatial distribution and seasonal pattern of ET sufficiently well, where they exhibited more significant spatial and seasonal variation in the ET compared with observation-based ET estimates （Obs_MTE）. For the mean annual ET, we found that the BATS forced by Princeton forcing overestimated the annual mean ET compared with Obs_MTE for most of the basins in China, whereas the VIC forced by Princeton forcing showed underestimations. By contrast, the Ens_Mean was closer to Obs_MTE, although the results were underestimated over Southeast China. Furthermore, both the Obs_MTE and Ens_Mean exhibited a significant increasing trend during 1982-98; whereas after 1998, when the last big EI Nifio event occurred, the Ens_Mean tended to decrease significantly between 1999 and 2007, although the change was not significant for Obs_MTE. Changes in air temperature and shortwave radiation played key roles in the long-term variation in ET over the humid area of China, but precipitation mainly controlled the long-term variation in ET in arid and semi-arid areas of China.展开更多
Developed here is an integrated framework for identifying production–living–ecological space(PLES)quantitatively at grid scale from the perspective of multifunction land use,and 25 compound space types are classifie...Developed here is an integrated framework for identifying production–living–ecological space(PLES)quantitatively at grid scale from the perspective of multifunction land use,and 25 compound space types are classified to highlight the multiple functions of PLES.As a typical mountainous city in northern Hebei province,Zhangjiakou is used as a case study,and the results show that more than 80%of the land space in Zhangjiakou has remarkable triple functionality.The living-dominated space and the production-dominated space are distributed mainly in the valleys of the Yanghe,Sanggan,and Huliu rivers and have obvious spatial consistency,while the ecological-dominated space is concentrated mostly at the eastern Yanshan Mountains and southern Taihang Mountains and complements the other two types of space.The former two are spatially fragmented,while the latter has been expanding to the periphery over time.From 1990 to 2015,the ecological-dominated space has increased the most by 1555.02 km^(2),while the living-dominated space has increased the least by 816.79 km^(2).The types of PLES are more diverse in the medium and low mountains and the areas with gentle slope,and the influencing factors include natural ecological environment,socioeconomic development,human consumption demand,and institutional policies.Therefore,these findings can mitigate conflicts among PLES in mountainous and similar areas,and promote the balanced development of land space.展开更多
This paper analyzes the sources of heat losses in magnetic fluid bearings,proposes various cou-pling relationships of physical fields,divides the coupled heat transfer surfaces while ensuring the continuity of heat fl...This paper analyzes the sources of heat losses in magnetic fluid bearings,proposes various cou-pling relationships of physical fields,divides the coupled heat transfer surfaces while ensuring the continuity of heat flux density,and analyzes the overall heat dissipation pathways of the bearings.By changing parameters such as input current,rotor speed,and inlet oil flow rate,the study applies a multi-physics field coupling method to investigate the influence of different parameters on the temper-ature field and heat dissipation patterns of the bearings,which is then validated through experi-ments.This research provides a theoretical basis for the optimal design of magnetic fluid bearing sys-tems.展开更多
Elemental ratios Zr/Hf and Nb/Ta are expected to be constant and of chondritic value （-36.30 and -17.57, respectively） in mantle and mantle-derived rocks. Studies in recent years have shown, however, that these two ...Elemental ratios Zr/Hf and Nb/Ta are expected to be constant and of chondritic value （-36.30 and -17.57, respectively） in mantle and mantle-derived rocks. Studies in recent years have shown, however, that these two ratios do vary in some of these rocks. For example, MORB-like seamount lavas from flanks of the East Pacific Rise （EPR） show a correlated Zr/Hf （-25-50） and Nb/Ta （-9-18） variation. These two ratios are also correlated with ratios of more incompatible over less incompatible elements （e.g., La/Sm, Rb/Cs, Th/U, Nb/U, Sm/Yb） and with radiogenic isotope ratios （e.g., 87 Sr/86Sr, 143Nd/144Nd）. Furthermore, abyssal peridotites, which are melting residues for MORB, also show a huge correlated variation between Zr/Hf （-2.5-335） and Nb/Ta （-1-170）. All these observations plus a correlated variation between Zr/Hf （-22-48） and Nb/Ta （-10-23） in lunar rocks are consistent with the Zr-Hf and Nb-Ta fractionation being of magmatic origin. This contrasts with the common view that geochemical processes cannot readily fractionate them. As charges and ionic radii are the principal factors in the general theory of elemental fractionation, this theory cannot explain the fractionation of these two element pairs with the same charges （i.e., 5＋ for Nb and Ta, and 4＋ for Zr and Hf） and essentially the same ionic size （i.e., RNb/RTa=1.000, Rzr/RHf=1.006 to -1.026 for coordination numbers of 6, 7, 8 and 12）. We explore the possibilities of other factors and processes （e.g., mass-dependent fractionation during magmatism） that may cause the observed Nb-Ta and Zr-Hf fractionation. We emphasize that understanding the correlated Nb-Ta and Zr-Hf fractionation ＂known＂ to take place during magmatism is fundamental for improved understanding of elemental fractionations through other earth processes in various tectonic environments, including the origin and evolution of continental crust, which has a characteristic subchondritic Nb/Ta value of -11-12.展开更多
Compact calli derived from immature spikelet of a foxtail millet variety—Jigu 11cann’t be directly used for protoplast isolation because of its firm physical structure,and must beloosened with subculturing in M<s...Compact calli derived from immature spikelet of a foxtail millet variety—Jigu 11cann’t be directly used for protoplast isolation because of its firm physical structure,and must beloosened with subculturing in M<sub>1</sub>,M<sub>2</sub> and M<sub>3</sub> media successively and altering these media compo-sitions.The loosened calli can be selected from the regulation and used for protoplast isolationsuccessfully.Rate of protoplast division in KM<sub>8</sub>P medium was 12.3—33.5%.Calli derivedthrough protoplast division are loose and cann’t be used directly for plan regeneration because ofits soft physical structure.When they were subcultured in N<sub>6</sub>—1,N<sub>6</sub>—2,N<sub>6</sub>—3 and N<sub>6</sub>—4 media,in which the media compositions were changed,the compact calli were obtained and 129 plantletswere regenerated from them.101 plants,which grew to maturity after transplanting the plantletsinto field,exhibited sterility in some degree.Most of the subsequent lines derived from the regen-erated plants were sterile and only two lines could get normal reproduction.展开更多
For the study of main traits of purple-flashed sweetpotato in different soil and ecological environments, 18 cultivars of purple-flashed sweetpotato with different enthocyenin contents were planted at Yancheng and Xuz...For the study of main traits of purple-flashed sweetpotato in different soil and ecological environments, 18 cultivars of purple-flashed sweetpotato with different enthocyenin contents were planted at Yancheng and Xuzhou separately. The main quality traits were determined. The results showed the quality traits of purple-fleshed sweetpotato were significantly influenced by soil and ecological environments. Geno- type （G）, environment （E） and genotype x environment （GxE） interaction had signif- icantiy effects on the contents of anthocyanin, dry matter, starch, protein, reducing sugar and soluble sugar in storage roots. Anthocyanin content was most easily af- fected by the environment. The E effect on anthocyanin content was greater than G and GxE effects. However, the GxE interaction effects on other 5 quality traits were greater than G and E effects. The 6 quality traits were significantly different at 1% level under different environments respectively. The contents of dry matter, starch and anthocyenin were higher in Yancheng than in Xuzhou, while the contents of protein, reducing sugar and soluble sugar were higher in Xuzhou. The variation co- efficients of all quality traits at Yancheng and Xuzhou were in the same order： an- sugar〉protein〉starch, the variation coefficient of anthocyanin content was higher in Xuzhou, and the variation coefficients of other 5 traits were higher in Yancheng. Correlation analysis showed that the reducing sugar and solu- ble sugar contents were negatively correlated with starch content, and had no sig- nifiant correlation with anthocyanin and protein contents. Dry matter content and starch content were positively correlated, and anthocyanin content and other quality traits had no significant correlation.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.4140508391437220 and 41305066)+1 种基金the Natural Science Foundation of Hunan Province(Grant No.2015JJ3098)the Fund Project for The Education Department of Hunan Province(Grant No.14C0897)
文摘In order to reduce the uncertainty of offline land surface model （LSM） simulations of land evapotranspiration （ET）, we used ensemble simulations based on three meteorological forcing datasets [Princeton, ITPCAS （Institute of Tibetan Plateau Research, Chinese Academy of Sciences）, Qian] and four LSMs （BATS, VIC, CLM3.0 and CLM3.5）, to explore the trends and spatiotemporal characteristics of ET, as well as the spatiotemporal pattern of ET in response to climate factors over China's Mainland during 1982-2007. The results showed that various simulations of each member and their arithmetic mean （EnsAVlean） could capture the spatial distribution and seasonal pattern of ET sufficiently well, where they exhibited more significant spatial and seasonal variation in the ET compared with observation-based ET estimates （Obs_MTE）. For the mean annual ET, we found that the BATS forced by Princeton forcing overestimated the annual mean ET compared with Obs_MTE for most of the basins in China, whereas the VIC forced by Princeton forcing showed underestimations. By contrast, the Ens_Mean was closer to Obs_MTE, although the results were underestimated over Southeast China. Furthermore, both the Obs_MTE and Ens_Mean exhibited a significant increasing trend during 1982-98; whereas after 1998, when the last big EI Nifio event occurred, the Ens_Mean tended to decrease significantly between 1999 and 2007, although the change was not significant for Obs_MTE. Changes in air temperature and shortwave radiation played key roles in the long-term variation in ET over the humid area of China, but precipitation mainly controlled the long-term variation in ET in arid and semi-arid areas of China.
基金National Natural Science Foundation of China,No.41971238,No.42101282,No.42001234。
文摘Developed here is an integrated framework for identifying production–living–ecological space(PLES)quantitatively at grid scale from the perspective of multifunction land use,and 25 compound space types are classified to highlight the multiple functions of PLES.As a typical mountainous city in northern Hebei province,Zhangjiakou is used as a case study,and the results show that more than 80%of the land space in Zhangjiakou has remarkable triple functionality.The living-dominated space and the production-dominated space are distributed mainly in the valleys of the Yanghe,Sanggan,and Huliu rivers and have obvious spatial consistency,while the ecological-dominated space is concentrated mostly at the eastern Yanshan Mountains and southern Taihang Mountains and complements the other two types of space.The former two are spatially fragmented,while the latter has been expanding to the periphery over time.From 1990 to 2015,the ecological-dominated space has increased the most by 1555.02 km^(2),while the living-dominated space has increased the least by 816.79 km^(2).The types of PLES are more diverse in the medium and low mountains and the areas with gentle slope,and the influencing factors include natural ecological environment,socioeconomic development,human consumption demand,and institutional policies.Therefore,these findings can mitigate conflicts among PLES in mountainous and similar areas,and promote the balanced development of land space.
基金the National Natural Science Foundation of China(No.52075468)the Natural Science Foundation of Hebei Province(No.E2020203052)+1 种基金the Key Scientific Research Projects of North China University of Technology(No.ZD-YG-202306-23)the Tangshan Science and Technology Project(No.23130201E).
文摘This paper analyzes the sources of heat losses in magnetic fluid bearings,proposes various cou-pling relationships of physical fields,divides the coupled heat transfer surfaces while ensuring the continuity of heat flux density,and analyzes the overall heat dissipation pathways of the bearings.By changing parameters such as input current,rotor speed,and inlet oil flow rate,the study applies a multi-physics field coupling method to investigate the influence of different parameters on the temper-ature field and heat dissipation patterns of the bearings,which is then validated through experi-ments.This research provides a theoretical basis for the optimal design of magnetic fluid bearing sys-tems.
基金supported by the Chinese 111 Project (No. B07011)the National Natural Science Foundation of China (No. 91014003)
文摘Elemental ratios Zr/Hf and Nb/Ta are expected to be constant and of chondritic value （-36.30 and -17.57, respectively） in mantle and mantle-derived rocks. Studies in recent years have shown, however, that these two ratios do vary in some of these rocks. For example, MORB-like seamount lavas from flanks of the East Pacific Rise （EPR） show a correlated Zr/Hf （-25-50） and Nb/Ta （-9-18） variation. These two ratios are also correlated with ratios of more incompatible over less incompatible elements （e.g., La/Sm, Rb/Cs, Th/U, Nb/U, Sm/Yb） and with radiogenic isotope ratios （e.g., 87 Sr/86Sr, 143Nd/144Nd）. Furthermore, abyssal peridotites, which are melting residues for MORB, also show a huge correlated variation between Zr/Hf （-2.5-335） and Nb/Ta （-1-170）. All these observations plus a correlated variation between Zr/Hf （-22-48） and Nb/Ta （-10-23） in lunar rocks are consistent with the Zr-Hf and Nb-Ta fractionation being of magmatic origin. This contrasts with the common view that geochemical processes cannot readily fractionate them. As charges and ionic radii are the principal factors in the general theory of elemental fractionation, this theory cannot explain the fractionation of these two element pairs with the same charges （i.e., 5＋ for Nb and Ta, and 4＋ for Zr and Hf） and essentially the same ionic size （i.e., RNb/RTa=1.000, Rzr/RHf=1.006 to -1.026 for coordination numbers of 6, 7, 8 and 12）. We explore the possibilities of other factors and processes （e.g., mass-dependent fractionation during magmatism） that may cause the observed Nb-Ta and Zr-Hf fractionation. We emphasize that understanding the correlated Nb-Ta and Zr-Hf fractionation ＂known＂ to take place during magmatism is fundamental for improved understanding of elemental fractionations through other earth processes in various tectonic environments, including the origin and evolution of continental crust, which has a characteristic subchondritic Nb/Ta value of -11-12.
文摘Compact calli derived from immature spikelet of a foxtail millet variety—Jigu 11cann’t be directly used for protoplast isolation because of its firm physical structure,and must beloosened with subculturing in M<sub>1</sub>,M<sub>2</sub> and M<sub>3</sub> media successively and altering these media compo-sitions.The loosened calli can be selected from the regulation and used for protoplast isolationsuccessfully.Rate of protoplast division in KM<sub>8</sub>P medium was 12.3—33.5%.Calli derivedthrough protoplast division are loose and cann’t be used directly for plan regeneration because ofits soft physical structure.When they were subcultured in N<sub>6</sub>—1,N<sub>6</sub>—2,N<sub>6</sub>—3 and N<sub>6</sub>—4 media,in which the media compositions were changed,the compact calli were obtained and 129 plantletswere regenerated from them.101 plants,which grew to maturity after transplanting the plantletsinto field,exhibited sterility in some degree.Most of the subsequent lines derived from the regen-erated plants were sterile and only two lines could get normal reproduction.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-11,sweetpotato)Jiangsu Science and Technology Support Program(BE2014315)+1 种基金Jiangsu Agricultural Science and Technology Independent Innovation Fund(CX(13)2032)Jiangsu Key Research and Development Program(modern agriculture)(BE2015313)~~
文摘For the study of main traits of purple-flashed sweetpotato in different soil and ecological environments, 18 cultivars of purple-flashed sweetpotato with different enthocyenin contents were planted at Yancheng and Xuzhou separately. The main quality traits were determined. The results showed the quality traits of purple-fleshed sweetpotato were significantly influenced by soil and ecological environments. Geno- type （G）, environment （E） and genotype x environment （GxE） interaction had signif- icantiy effects on the contents of anthocyanin, dry matter, starch, protein, reducing sugar and soluble sugar in storage roots. Anthocyanin content was most easily af- fected by the environment. The E effect on anthocyanin content was greater than G and GxE effects. However, the GxE interaction effects on other 5 quality traits were greater than G and E effects. The 6 quality traits were significantly different at 1% level under different environments respectively. The contents of dry matter, starch and anthocyenin were higher in Yancheng than in Xuzhou, while the contents of protein, reducing sugar and soluble sugar were higher in Xuzhou. The variation co- efficients of all quality traits at Yancheng and Xuzhou were in the same order： an- sugar〉protein〉starch, the variation coefficient of anthocyanin content was higher in Xuzhou, and the variation coefficients of other 5 traits were higher in Yancheng. Correlation analysis showed that the reducing sugar and solu- ble sugar contents were negatively correlated with starch content, and had no sig- nifiant correlation with anthocyanin and protein contents. Dry matter content and starch content were positively correlated, and anthocyanin content and other quality traits had no significant correlation.
