The characteristics of photosynthesis and water metabolism of Caragana microphylla Lam.,C. davazamcii Sancz. and C. korshinskii Kom. populations in different sites (117.6o-105.7o E, 44.6o-38.8o N)were studied. (1) Fro...The characteristics of photosynthesis and water metabolism of Caragana microphylla Lam.,C. davazamcii Sancz. and C. korshinskii Kom. populations in different sites (117.6o-105.7o E, 44.6o-38.8o N)were studied. (1) From the east to the west, the responses of the three species to photosyntheticallyavailable radiation (PAR) in net photosynthesis rate increased, the relative humidity of the air whichcorresponded to the occurrence of maximum photosynthesis rate decreased, and the corresponding airtemperature increased. Along the same gradient, the before-noon superiority of the photosynthesis be-came evident, and the photosynthesis rate and the light use efficiency (LUE ) increased, while the transp-iration rate decreased, thus the water use efficiency (WUE ) increased notably, and the leaf water contentdecreased gradually. From the east to the west, the plants took a water-saving strategy step by step withhigher photosynthesis rate and lower transpiration rate. These physiological changes in the plants wereadaptable to the conditions of light, temperature and humidity in the habitat of the plants, and might be thebiological foundation for the geographical transition among C. microphylla , C. davazamcii and C. korshinskii.(2) The adaptation of photosynthetic system of C. microphylla , C. davazamcii and C. korshinskii to PAR, airhumidity and temperature exhibited the interspecific continuity, which was consistent with theenvironmental gradient. In different species and different sites, the diurnal changes of net photosynthesisrate, the daily cumulative value of net photosynthesis, the diurnal changes of transpiration rate, the dailycumulative value of transpiration, the water use efficiency and the diurnal changes of leaf water contentvaried with longitudinal descent (from the east to the west). The characteristics of photosynthesis andwater metabolism indicated that the geographical transition among C. microphylla , C. davazamcii and C.korshinskii was in gradual change, and these three species formed a geographical cline.展开更多
As watershed algorithm suffers from over-segmentation problem, this paper presented an efficient method to resolve this problem. First, pre-process of the image using median filter is made to reduce the effect of nois...As watershed algorithm suffers from over-segmentation problem, this paper presented an efficient method to resolve this problem. First, pre-process of the image using median filter is made to reduce the effect of noise. Second, watershed algorithm is employed to provide initial regions. Third, regions are merged according to the information between the region and boundary. In the merger processing based on the region information, an adaptive threshold of the difference between the neighboring regions is used as the region merge criteria, which is based on the human visual character. In the merger processing on the boundary information, the gradient is used to judge the true boundary of the image to avoid merging the foreground with the background regions. Finally, post-process to the regions using mathematical morphology open and close filter is done to smooth object boundaries. The experimental results show that this method is very efficient.展开更多
To study the behavior of overlying strata and the likelihood of water inrush and quicksand with different mining sequences under an unconsolidated alluvium aquifer, a numerical model based on the fluid-solid coupling ...To study the behavior of overlying strata and the likelihood of water inrush and quicksand with different mining sequences under an unconsolidated alluvium aquifer, a numerical model based on the fluid-solid coupling theory was con- structed by FLAC3D. Simulation results revealed that the mining sequences had a significant influence on the seepage, dis- placement and failure characteristics of the overlying strata. In this kind of geological and hydrogeological conditions, the workface close to the outcrop of coal seam easily suffers from water inrush and quicksand during mining. In the simulation re- sults, the plastic zone, vertical displacement and pore water pressure in the overlying strata of the workface decrease more or less using the upward mining sequence than using the downward mining sequence. Therefore, the application of the upward mining sequence in the process of mining is preferential to prevent water inrush and quicksand.展开更多
The commonly used oxide-supported metal catalysts are usually prepared in aqueous phase,which then often need to undergo calcination before usage.Therefore,the surface hydration and dehydration of oxide supports are c...The commonly used oxide-supported metal catalysts are usually prepared in aqueous phase,which then often need to undergo calcination before usage.Therefore,the surface hydration and dehydration of oxide supports are critical for the realistic modeling of supported metal catalysts.In this work,by ab initio molecular dynamics(AIMD)simulations,the initial anhydrous monoclinic ZrO_(2)(111)surfaces are evaluated within explicit solvents in aqueous phase at mild temperatures.During the simulations,all the two-fold-coordinated O sites will soon be protonated to form the acidic hydroxyls(HO_(L)),remaining the basic hydroxyls(HO^(∗))on Zr.The basic hydroxyls(HO^(∗))can easily diffuse on surfaces via the active proton exchange with the undissociated adsorption water(H_(2)O^(∗)).Within the temperatures ranging from 273 K to 373 K,in aqueous phase a certain representative equilibrium hydrated m-ZrO_(2)(¯111)surface is obtained with the coverage(θ)of 0.75 on surface Zr atoms.Later,free energies on the stepwise surface water desorption are calculated by density functional theory to mimic the surface dehydration under the mild calcination temperatures lower than 800 K.By obtaining the phase diagrams of surface dehydration,the representative partially hydrated m-ZrO_(2)(111)surfaces(0.25≤θ<0.75)at various calcination temperatures are illustrated.These hydrated m-ZrO_(2)(111)surfaces can be crucial and readily applied for more realistic modeling of ZrO_(2) catalysts and ZrO_(2)-supported metal catalysts.展开更多
The distribution of resources is the basis of safety management.Based on thesystematic analysis of a resource distribution system affecting the level of safety,the bestdistribution proportion between safety activities...The distribution of resources is the basis of safety management.Based on thesystematic analysis of a resource distribution system affecting the level of safety,the bestdistribution proportion between safety activities and production and best resources distributionproportion among the various links of security activities are presented.Moreover,itis stated that the distribution of resources law needs to be researched deeply in practicalwork to achieve optimization of safety management practice.展开更多
The parameters of gas exchange and chlorophyl fluorescence in leaves of six rare and endangered species Neolitsea sericea, Cinnamomum japonicum var. cheni , Sinojackia microcarpa, Discocleidion glabrum var. trichocarp...The parameters of gas exchange and chlorophyl fluorescence in leaves of six rare and endangered species Neolitsea sericea, Cinnamomum japonicum var. cheni , Sinojackia microcarpa, Discocleidion glabrum var. trichocarpum, Parrotia sub-aequalis, Cercidiphyl um japonicum were measured in fields. The results showed that there were significant differences in photosynthetic capacity, intrinsic water use effi-ciency (WUEi ), the efficiency of primary conversion of light energy of PSⅡ and its potential activity, the quantum yield of PSⅡ electron transport, and the potential ca-pacity of heat dissipation among the six species. However, there was no significant difference in WUE. The highest values of net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (gs) occurred in D. glabrum var. trichocarpum and the lowest in S. microcarpa. On the contrary, D. glabrum var. trichocarpum had the lowest WUE, intrinsic water use efficiency (WUEi ) and S. microcarpa had the highest. The results indicated that D. glabrum var. trichocarpum had higher photo-synthetic capacity and poorer WUE, while S. microcarpa had lower photosynthetic capacity and greater WUE. Furthermore, the mean values of maximal fluorescence (Fm), potential efficiency of primary conversion of light energy of PSⅡ (Fv/Fm),ΦPSⅡ, actual efficiency of primary conversion of light energy of PSⅡ (F′v/F′m) and non-photochemical quenching coefficient (NPQ) were the highest in S. micro-carpa, indicating that its PSⅡ had higher capacity of heat dissipation and could prevent photosynthetic apparatus from damage by excessive light energy. Correlation analysis showed that there were significant correlations among photosynthetic physi-ological parameters. However, the initial fluorescence (Fo) was not significantly cor-related with any other parameters. This study also revealed the extremely significant positive correlations between Pn and Tr, gs, apparent quantum yield (AQY), be-tween Tr and gs, between light saturation point (LSP) and AQY, between Fv/Fm and Fm, between ΦPSⅡ and photochemical quenching coefficient (qp), between Tr, gs and LSP, AQY. However, WUEi was significantly negatively correlated with Tr, gs, Pn, LSP and AQY.展开更多
This paper introduces the process of development and practical use implementation of an advanced river management system for supporting integrated water resources management practices in Asian river basins under the f...This paper introduces the process of development and practical use implementation of an advanced river management system for supporting integrated water resources management practices in Asian river basins under the framework of GEOSS Asia water cycle initiative (AWCI). The system is based on integration of data from earth observation satellites and in-situ networks with other types of data, including numerical weather prediction model outputs, climate model outputs, geographical infor- mation, and socio-economic data. The system builds on the water and energy budget distributed hydrological model (WEB-DHM) that was adapted for specific conditions of studied basins, in particular snow and glacier phenomena and equipped with other functions such as dam operation optimization scheme and a set of tools for climate change impact assess- ment to be able to generate relevant information for policy and decision makers. In situ data were archived for 18 selected ba- sins at the Data Integration and Analysis System (DIAS) of Japan and demonstration projects were carded out showing poten- tial of the new system. It included climate change impact assessment on hydrological regimes, which is presently a critical step for sound management decisions. Results of such three case studies in Pakistan, Philippines, and Vietnam are provided here.展开更多
文摘The characteristics of photosynthesis and water metabolism of Caragana microphylla Lam.,C. davazamcii Sancz. and C. korshinskii Kom. populations in different sites (117.6o-105.7o E, 44.6o-38.8o N)were studied. (1) From the east to the west, the responses of the three species to photosyntheticallyavailable radiation (PAR) in net photosynthesis rate increased, the relative humidity of the air whichcorresponded to the occurrence of maximum photosynthesis rate decreased, and the corresponding airtemperature increased. Along the same gradient, the before-noon superiority of the photosynthesis be-came evident, and the photosynthesis rate and the light use efficiency (LUE ) increased, while the transp-iration rate decreased, thus the water use efficiency (WUE ) increased notably, and the leaf water contentdecreased gradually. From the east to the west, the plants took a water-saving strategy step by step withhigher photosynthesis rate and lower transpiration rate. These physiological changes in the plants wereadaptable to the conditions of light, temperature and humidity in the habitat of the plants, and might be thebiological foundation for the geographical transition among C. microphylla , C. davazamcii and C. korshinskii.(2) The adaptation of photosynthetic system of C. microphylla , C. davazamcii and C. korshinskii to PAR, airhumidity and temperature exhibited the interspecific continuity, which was consistent with theenvironmental gradient. In different species and different sites, the diurnal changes of net photosynthesisrate, the daily cumulative value of net photosynthesis, the diurnal changes of transpiration rate, the dailycumulative value of transpiration, the water use efficiency and the diurnal changes of leaf water contentvaried with longitudinal descent (from the east to the west). The characteristics of photosynthesis andwater metabolism indicated that the geographical transition among C. microphylla , C. davazamcii and C.korshinskii was in gradual change, and these three species formed a geographical cline.
文摘As watershed algorithm suffers from over-segmentation problem, this paper presented an efficient method to resolve this problem. First, pre-process of the image using median filter is made to reduce the effect of noise. Second, watershed algorithm is employed to provide initial regions. Third, regions are merged according to the information between the region and boundary. In the merger processing based on the region information, an adaptive threshold of the difference between the neighboring regions is used as the region merge criteria, which is based on the human visual character. In the merger processing on the boundary information, the gradient is used to judge the true boundary of the image to avoid merging the foreground with the background regions. Finally, post-process to the regions using mathematical morphology open and close filter is done to smooth object boundaries. The experimental results show that this method is very efficient.
文摘To study the behavior of overlying strata and the likelihood of water inrush and quicksand with different mining sequences under an unconsolidated alluvium aquifer, a numerical model based on the fluid-solid coupling theory was con- structed by FLAC3D. Simulation results revealed that the mining sequences had a significant influence on the seepage, dis- placement and failure characteristics of the overlying strata. In this kind of geological and hydrogeological conditions, the workface close to the outcrop of coal seam easily suffers from water inrush and quicksand during mining. In the simulation re- sults, the plastic zone, vertical displacement and pore water pressure in the overlying strata of the workface decrease more or less using the upward mining sequence than using the downward mining sequence. Therefore, the application of the upward mining sequence in the process of mining is preferential to prevent water inrush and quicksand.
基金This work was supported by the National Natural Science Foundation of China(No.22022504,No.22003022)of ChinaNatural Science Foundation of Guangdong,China(No.2021A1515010213,No.2021A1515110406)+2 种基金Guangdong“Pearl River”Talent Plan(No.2019QN01L353)Higher Education Innovation Strong School Project of Guangdong Province of China(No.2020KTSCX122)Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002).Most calculations are performed on the CHEM Highperformance Computing Cluster(CHEM-HPC)located at the Department of Chemistry,Southern University of Science and Technology(SUSTech).The computational resources are also supported by the Center for Computational Science and Engineering at SUSTech.
文摘The commonly used oxide-supported metal catalysts are usually prepared in aqueous phase,which then often need to undergo calcination before usage.Therefore,the surface hydration and dehydration of oxide supports are critical for the realistic modeling of supported metal catalysts.In this work,by ab initio molecular dynamics(AIMD)simulations,the initial anhydrous monoclinic ZrO_(2)(111)surfaces are evaluated within explicit solvents in aqueous phase at mild temperatures.During the simulations,all the two-fold-coordinated O sites will soon be protonated to form the acidic hydroxyls(HO_(L)),remaining the basic hydroxyls(HO^(∗))on Zr.The basic hydroxyls(HO^(∗))can easily diffuse on surfaces via the active proton exchange with the undissociated adsorption water(H_(2)O^(∗)).Within the temperatures ranging from 273 K to 373 K,in aqueous phase a certain representative equilibrium hydrated m-ZrO_(2)(¯111)surface is obtained with the coverage(θ)of 0.75 on surface Zr atoms.Later,free energies on the stepwise surface water desorption are calculated by density functional theory to mimic the surface dehydration under the mild calcination temperatures lower than 800 K.By obtaining the phase diagrams of surface dehydration,the representative partially hydrated m-ZrO_(2)(111)surfaces(0.25≤θ<0.75)at various calcination temperatures are illustrated.These hydrated m-ZrO_(2)(111)surfaces can be crucial and readily applied for more realistic modeling of ZrO_(2) catalysts and ZrO_(2)-supported metal catalysts.
文摘The distribution of resources is the basis of safety management.Based on thesystematic analysis of a resource distribution system affecting the level of safety,the bestdistribution proportion between safety activities and production and best resources distributionproportion among the various links of security activities are presented.Moreover,itis stated that the distribution of resources law needs to be researched deeply in practicalwork to achieve optimization of safety management practice.
基金Supported by Natural Science Foundation of Zhejiang Province(LY13C160007)Special Fund for Graduate Innovative Projects in Jiangxi Province(YC2014-B035)Lin’an Scientific and Technological Program of Zhejiang Province(201411)
文摘The parameters of gas exchange and chlorophyl fluorescence in leaves of six rare and endangered species Neolitsea sericea, Cinnamomum japonicum var. cheni , Sinojackia microcarpa, Discocleidion glabrum var. trichocarpum, Parrotia sub-aequalis, Cercidiphyl um japonicum were measured in fields. The results showed that there were significant differences in photosynthetic capacity, intrinsic water use effi-ciency (WUEi ), the efficiency of primary conversion of light energy of PSⅡ and its potential activity, the quantum yield of PSⅡ electron transport, and the potential ca-pacity of heat dissipation among the six species. However, there was no significant difference in WUE. The highest values of net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (gs) occurred in D. glabrum var. trichocarpum and the lowest in S. microcarpa. On the contrary, D. glabrum var. trichocarpum had the lowest WUE, intrinsic water use efficiency (WUEi ) and S. microcarpa had the highest. The results indicated that D. glabrum var. trichocarpum had higher photo-synthetic capacity and poorer WUE, while S. microcarpa had lower photosynthetic capacity and greater WUE. Furthermore, the mean values of maximal fluorescence (Fm), potential efficiency of primary conversion of light energy of PSⅡ (Fv/Fm),ΦPSⅡ, actual efficiency of primary conversion of light energy of PSⅡ (F′v/F′m) and non-photochemical quenching coefficient (NPQ) were the highest in S. micro-carpa, indicating that its PSⅡ had higher capacity of heat dissipation and could prevent photosynthetic apparatus from damage by excessive light energy. Correlation analysis showed that there were significant correlations among photosynthetic physi-ological parameters. However, the initial fluorescence (Fo) was not significantly cor-related with any other parameters. This study also revealed the extremely significant positive correlations between Pn and Tr, gs, apparent quantum yield (AQY), be-tween Tr and gs, between light saturation point (LSP) and AQY, between Fv/Fm and Fm, between ΦPSⅡ and photochemical quenching coefficient (qp), between Tr, gs and LSP, AQY. However, WUEi was significantly negatively correlated with Tr, gs, Pn, LSP and AQY.
基金the Asia Pacific Network for Global Change Research(APN)for financial support of the AWCI activities through several projects funded under the APN programmes
文摘This paper introduces the process of development and practical use implementation of an advanced river management system for supporting integrated water resources management practices in Asian river basins under the framework of GEOSS Asia water cycle initiative (AWCI). The system is based on integration of data from earth observation satellites and in-situ networks with other types of data, including numerical weather prediction model outputs, climate model outputs, geographical infor- mation, and socio-economic data. The system builds on the water and energy budget distributed hydrological model (WEB-DHM) that was adapted for specific conditions of studied basins, in particular snow and glacier phenomena and equipped with other functions such as dam operation optimization scheme and a set of tools for climate change impact assess- ment to be able to generate relevant information for policy and decision makers. In situ data were archived for 18 selected ba- sins at the Data Integration and Analysis System (DIAS) of Japan and demonstration projects were carded out showing poten- tial of the new system. It included climate change impact assessment on hydrological regimes, which is presently a critical step for sound management decisions. Results of such three case studies in Pakistan, Philippines, and Vietnam are provided here.