Carotenoids are indispensable for both human health and plant survival.Citrus,is one of the fruit crops richest in carotenoid compounds,with approximately 115 kinds of carotenoids;tremendous diversity in carotenoids c...Carotenoids are indispensable for both human health and plant survival.Citrus,is one of the fruit crops richest in carotenoid compounds,with approximately 115 kinds of carotenoids;tremendous diversity in carotenoids composition and concentration exists among various species,showing different colors from nearly white to crimson.The carotenoid biosynthetic pathway and the key carotenogenic genes have been identified in citrus;however,the underlying regulatory mechanisms remain unclear.In this study,among the main species of genus Citrus(primitive,wild,and cultivated),we detected carotenoids in flavedo using High-Performance Liquid Chromatography,and analyzed variations in cis-acting elements in the promoters of key carotenoid pathway genes.Intriguingly,both carotenoid composition and content were generally increased during the evolution of citrus,and the corresponding variations in the promoters were identified,including the gain or loss of critical environmental stress-responsive elements and hormone-responsive elements,which are closely associated with carotenoid enhancement.In addition,pummelo has the most heat-responsive elements,but the Mangshan mandarin does not have this element in the promoters of PSY,which is highly related to their geographical origin and indicate that temperature is a critical environmental signal influencing carotenoid accumulation.Moreover,the abscisic acid-responsive motif was rich in almost all the seven species,but the ethylene-responsive motif was deficient,which demystified the unique phytohormone regulation mechanism of carotenoid accumulation in citrus.Overall,our study provides new insights into the molecular regulatory mechanism of carotenoid enhancement in the evolution of citrus,which can facilitate breeding and cultivation efforts to improve the nutritional quality and esthetic value in citrus and hopefully other fruit crops.展开更多
MicroRNAs (miRNAs) are derived from distinct loci in the genome and play crucial roles in RNA-mediated gene silencing mechanisms that regulate cellular processes during development and stress responses of plants. Th...MicroRNAs (miRNAs) are derived from distinct loci in the genome and play crucial roles in RNA-mediated gene silencing mechanisms that regulate cellular processes during development and stress responses of plants. The miRNAs are approximately 21 nucleotides long and code for the complementary strand to a larger genic mRNA. They are often found within the complementary primary transcript (pri-miRNAs). In the past few years, a growing number of soybean miRNAs have been discovered, however, little is known about the transcriptional regulation of these miRNAs. In this study, promoters and cis-acting elements of soybean miRNAs were analyzed using the genomic data for the first time. A total of 82 miRNAs were located among 122 loci in genome, some were present as double or multiple copies. Five clusters that included ten miRNAs were found in genome, and only one cluster share the same promoter. A total of 191 promoters from 122 loci of the soybean miRNA sequences were found and further analyzed. The results indicated that the conserved soybean miRNA genes had a greater proportion of promoters than that of non-conserved ones, and the distribution of the transcript start sites (TSSs) and TATA-boxes found had different motif styles between conserved and non-conserved miRNA genes. Furthermore, the cis-acting elements 5' of the TSSs were analyzed to obtain potential function and spatiotemporal expression pattern of miRNAs. The data obtained here may lead to the identification of specific sequences upstream of pre-miRNAs and the functional annotation of miRNAs in soybean.展开更多
A three-dimensional elasto-plastic finite element analysis of pre-twist process for a torsional axis made of 45GrNiMoVA steel, was carried out using a commercial finite element analysis code, MSC MARC 2001. The result...A three-dimensional elasto-plastic finite element analysis of pre-twist process for a torsional axis made of 45GrNiMoVA steel, was carried out using a commercial finite element analysis code, MSC MARC 2001. The results show that the critical pre-twist strain angle is 0.027 rad and the maximum elastic shear stress after pre-twist is 1694MPa for the torsional axis.展开更多
The distribution of selected critical elements in the sedimentary rocks of the Carboniferous coal-bearing series within the Polish Coal Basins is presented.Critical elements such as Be,Mg,Si,P,Sc,V,Co,Y,Nb,In,Sb,La,Ce...The distribution of selected critical elements in the sedimentary rocks of the Carboniferous coal-bearing series within the Polish Coal Basins is presented.Critical elements such as Be,Mg,Si,P,Sc,V,Co,Y,Nb,In,Sb,La,Ce,Hf,Ta,W,Bi were analysed using inductively-coupled plasma mass spectrometry(ICP/MS).Concentrations of elements such as Sb,Bi,In and,to a slightly lesser extent,Nb,as well as Sc,show average concentrations higher than those from the upper continental crust.The average concentrations of elements like Hf,Mg,P,Y,La,and Ce are slightly lower than in the upper continental crust.Other elements,such as Be,Co,Si,Ta,W and V have average concentrations that are similar,but slightly enriched or slightly depleted,relative to the upper continental crust.The research showed enrichment of some critical elements in the analysed samples,but not high enough that extraction would be economically viable.Statistical methods,which include correlation coefficients between elements and cluster analysis,reveal a strong positive correlation between elements like Be,Bi,Nb,Sc,Ta,W and V.Very high,almost total,positive correlation is also noted between La and Ce.展开更多
Bedrock weathering performs a significant influence on the evolution of Earth’s critical zone.Carbonate rock(dolostone),metamorphic rock(gneiss),and sedimentary rock(sandstone)geological formations in Yanshan Mountai...Bedrock weathering performs a significant influence on the evolution of Earth’s critical zone.Carbonate rock(dolostone),metamorphic rock(gneiss),and sedimentary rock(sandstone)geological formations in Yanshan Mountain,Hebei Province,are taken as objects to probe the controlling of geological formations on weathering characteristics,migration,and enrichment of elements as well as structure of Earth’s critical zone under the identical climate conditions through geological field survey,analysis on minerals component,element distribution in the weathering profile.The dolostone geological formation(DGF)is lithologically dominated by dolostone,characterized by the strongest and predominant chemical weathering.During bedrock weathering and pedogenesis,DGF is marked by significant depletion of CaO,Mg O,S,Mn,Mo and enrichment of N,K,Fe_(2)O_(3),and Zn with concentrations of P,Cu,and B keeping stable.Shortage of soil-forming materials and significant loss are driven by soil erosion,which results in thin regolith and soil.The soil thickness is less than 10 cm,and the regolith thickness is less than 30 cm.The vegetation community is predominantly rock arbor or brush,which is calcivorous and tolerant of barrenness.Plagiogneiss is a dominant rock type of gneiss geological formation(GGF),characterized by the weakest weathering and fast chemical and physical weathering rate.GGF is masked by significant depletion of P,K,CaO,MgO,Fe_(2)O_(3),Mn,Cu and enrichment of N,S,Mo,and B,with contents of Zn keeping stable.Both soil and regolith developed in GGF are relatively thick for one of the reasons that biotite expands during weathering.The soil thickness is more than 50 cm,and the regolith thickness ranges from 100 to 200 cm.The vegetation community is predominantly high-quality economic forests and various arbors because of the enrichment of nutrients in GGF.Sandstone is primarily a rock type of sandstone geological formation(SGF),characterized by moderate weathering degree and slow chemical weathering rate.SGF is marked by significant depletion of P,K,CaO,MgO,Fe_(2)O_(3),and enrichment of N,S,Mn,Cu,Zn,and Mo,with fluctuant changes of Zn and B.The thickness of soil developed in SGF varies between that of DGF and GGF.The soil thickness ranges from 30 to 50 cm,and the regolith thickness ranges from 50 to 100 cm.Chinese pines are widely spread on the shady slopes of SGF.Research provides theoretical support for screening dominant ecological resource areas,ecological industry development and ecological protection and restoration for Yanshan Mountain,Hebei Province.展开更多
In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement( CRCP) slab under vehicle loading, the elliptical load is translated into the square load based...In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement( CRCP) slab under vehicle loading, the elliptical load is translated into the square load based on the equivalence principle.The CRCP slab is analyzed to determine the cavity position beneath the slab under vehicle loading. The influences of cavity size on the CRCP slab's stress and vertical displacement are investigated. The study results showthat the formation of the cavity is unavoidable under traffic loading, and the cavity is located at the edge of the longitudinal crack and the slab corner.The cavity size exerts an obvious influence on the largest horizontal tensile stress and vertical displacement. The slab corner is the critical load position of the CRCP slab. The results can be used to assist the design of CRCP in avoiding cavities beneath slabs subject to vehicle loading.展开更多
A series of AZ80 billets were compressed with 60%height reduction on hot process simulator at 250,300,350,400℃ under strain rates of 0.01,0.1,1 and 10 s- 1.In order to predict the occurrence of surface fracture,the v...A series of AZ80 billets were compressed with 60%height reduction on hot process simulator at 250,300,350,400℃ under strain rates of 0.01,0.1,1 and 10 s- 1.In order to predict the occurrence of surface fracture,the values of the Cockcroft-Latham equation were calculated by the corresponding finite element numerical algorithm developed.A concept about damage incremental ratio in plastic deformation was defined as the ratio of damage increment at one step to the accumulated value.A method of finding the intersection of incremental ratio varying curve and simulation step axis was brought forward to make the fracture step certain. Then,the effects of temperature and strain rate on critical damage value were achieved.The results show that the critical damage value is not a constant but changes in a range of 0.021 8-0.378 0.It decreases significantly with the increase of strain rate at a certain temperature.While under a certain strain rate,the critical damage value has little change with the increase of temperature.展开更多
This paper aims to present the critical top tension for static equilibrium configurations of a steel catenary riser(SCR) by using the finite element method. The critical top tension is the minimum top tension that c...This paper aims to present the critical top tension for static equilibrium configurations of a steel catenary riser(SCR) by using the finite element method. The critical top tension is the minimum top tension that can maintain the equilibrium of the SCR. If the top tension is smaller than the critical value, the equilibrium of the SCR does not exist. If the top tension is larger than the critical value, there are two possible equilibrium configurations. These two configurations exhibit the nonlinear large displacement. The configuration with the smaller displacement is stable, while the one with larger displacement is unstable. The numerical results show that the increases in the riser's vertical distances, horizontal offsets, riser's weights, internal flow velocities, and current velocities increase the critical top tensions of the SCR. In addition, the parametric studies are also performed in order to investigate the limit states for the analysis and design of the SCR.展开更多
Recasting the BCS theory in the larger framework of the Bethe-Salpeter equation, a new equation is derived for the temperature-dependent critical current density jc(T) of an elemental superconductor (SC) directly in t...Recasting the BCS theory in the larger framework of the Bethe-Salpeter equation, a new equation is derived for the temperature-dependent critical current density jc(T) of an elemental superconductor (SC) directly in terms of the basic parameters of the theory, namely the dimensionless coupling constant [N(0)V], the Debye temperature θD and, additionally, the Fermi energy EF—unlike earlier such equations based on diverse, indirect criteria. Our approach provides an ab initio theoretical justification for one of the latter, text book equations invoked at T = 0 which involves Fermi momentum;additionally, it relates jc with the relevant parameters of the problem at T ≠ 0. Noting that the numerical value of EF of a high-Tc SC is a necessary input for the construction of its Fermi surface—which sheds light on its gap-structure, we also briefly discuss extension of our approach for such SCs.展开更多
Geochemical differentiation of soils has a series of consequences on plant and places pressure on the ecological environment.The quantitative evaluation of element migration in the Earth’s critical zone is a challeng...Geochemical differentiation of soils has a series of consequences on plant and places pressure on the ecological environment.The quantitative evaluation of element migration in the Earth’s critical zone is a challenging task.In this study,two demonstration study areas of Scutellaria baicalensis Georgi were selected,and multiple chemical weathering indexes,chemical loss fraction,mass migration coefficients and biological enrichment coefficient method were used to assess the ecological and geochemical suitability.The results show that for the element of Fe,Zn,Se,Cu,Co,Ni,Mo and Ge,the degree of weathering and soil maturation,were greater in the rhyolitic tuff area than in the Plagioclase gneiss area.In both research sites,the heavy metal level of samples in Scutellaria baicalensis Georgi did not exceed the standard limits.The plagioclase gneiss region’s surface soil environment was more alkaline,and the content of soil organic matter was lower,resulting in a higher bioenrichment intensity of Ge,Co,Cu,and Se elements in Scutellaria baicalensis Georgi than in the rhyolite-tuff area.The elements of Cd,Nb,Mo,Pb and As are considerably enriched in the soil of the plagioclase gneiss area but lost by leaching in the soil of the rhyolite tuff area,which is connected to the interplay of elemental abundance and human impact in the parent materials.This study provides a good example of how to assess growth suitability of Chinese medicinal materials in the Earth’s critical zone.展开更多
Presents the calculation of critical velocity, natural frequency and dynamic respondency of fluid conveying pipe are calculated under different boundary conditions using finite element method, and the use of calculati...Presents the calculation of critical velocity, natural frequency and dynamic respondency of fluid conveying pipe are calculated under different boundary conditions using finite element method, and the use of calculation results to design and research rocket pipes feeding fuel and watery turbine pipes conveying water etc.展开更多
基金This research was supported by National Key Research and Development Program of China(Grant No.2018YFD1000200)National Natural Science Foundation of China(Grant nos.31930095 and 31630065)We should thank Prof.Zuoxiong Liu for editing the English language of the manuscript.
文摘Carotenoids are indispensable for both human health and plant survival.Citrus,is one of the fruit crops richest in carotenoid compounds,with approximately 115 kinds of carotenoids;tremendous diversity in carotenoids composition and concentration exists among various species,showing different colors from nearly white to crimson.The carotenoid biosynthetic pathway and the key carotenogenic genes have been identified in citrus;however,the underlying regulatory mechanisms remain unclear.In this study,among the main species of genus Citrus(primitive,wild,and cultivated),we detected carotenoids in flavedo using High-Performance Liquid Chromatography,and analyzed variations in cis-acting elements in the promoters of key carotenoid pathway genes.Intriguingly,both carotenoid composition and content were generally increased during the evolution of citrus,and the corresponding variations in the promoters were identified,including the gain or loss of critical environmental stress-responsive elements and hormone-responsive elements,which are closely associated with carotenoid enhancement.In addition,pummelo has the most heat-responsive elements,but the Mangshan mandarin does not have this element in the promoters of PSY,which is highly related to their geographical origin and indicate that temperature is a critical environmental signal influencing carotenoid accumulation.Moreover,the abscisic acid-responsive motif was rich in almost all the seven species,but the ethylene-responsive motif was deficient,which demystified the unique phytohormone regulation mechanism of carotenoid accumulation in citrus.Overall,our study provides new insights into the molecular regulatory mechanism of carotenoid enhancement in the evolution of citrus,which can facilitate breeding and cultivation efforts to improve the nutritional quality and esthetic value in citrus and hopefully other fruit crops.
基金supported by the National High-Tech R&D Program of China (863 Program,2006AA100104-4)the Project of 948 from Ministryof Agriculture of China (2006-G5)+5 种基金the National Nature Science Foundation of China (30971810,60932008)the National Basic Research Program ofChina (973 Program, 2009CB118400)the Postdoctoral Fund in Heilongjiang Province, China (LBH-Z07228)the Foundation Projects of Northeast Agricultural University, Chinathe Technology Project of Education Ministry of Heilongjiang Province, China(11541025)the Technology Project of Harbin,China (2009RFQXN085)
文摘MicroRNAs (miRNAs) are derived from distinct loci in the genome and play crucial roles in RNA-mediated gene silencing mechanisms that regulate cellular processes during development and stress responses of plants. The miRNAs are approximately 21 nucleotides long and code for the complementary strand to a larger genic mRNA. They are often found within the complementary primary transcript (pri-miRNAs). In the past few years, a growing number of soybean miRNAs have been discovered, however, little is known about the transcriptional regulation of these miRNAs. In this study, promoters and cis-acting elements of soybean miRNAs were analyzed using the genomic data for the first time. A total of 82 miRNAs were located among 122 loci in genome, some were present as double or multiple copies. Five clusters that included ten miRNAs were found in genome, and only one cluster share the same promoter. A total of 191 promoters from 122 loci of the soybean miRNA sequences were found and further analyzed. The results indicated that the conserved soybean miRNA genes had a greater proportion of promoters than that of non-conserved ones, and the distribution of the transcript start sites (TSSs) and TATA-boxes found had different motif styles between conserved and non-conserved miRNA genes. Furthermore, the cis-acting elements 5' of the TSSs were analyzed to obtain potential function and spatiotemporal expression pattern of miRNAs. The data obtained here may lead to the identification of specific sequences upstream of pre-miRNAs and the functional annotation of miRNAs in soybean.
文摘A three-dimensional elasto-plastic finite element analysis of pre-twist process for a torsional axis made of 45GrNiMoVA steel, was carried out using a commercial finite element analysis code, MSC MARC 2001. The results show that the critical pre-twist strain angle is 0.027 rad and the maximum elastic shear stress after pre-twist is 1694MPa for the torsional axis.
文摘The distribution of selected critical elements in the sedimentary rocks of the Carboniferous coal-bearing series within the Polish Coal Basins is presented.Critical elements such as Be,Mg,Si,P,Sc,V,Co,Y,Nb,In,Sb,La,Ce,Hf,Ta,W,Bi were analysed using inductively-coupled plasma mass spectrometry(ICP/MS).Concentrations of elements such as Sb,Bi,In and,to a slightly lesser extent,Nb,as well as Sc,show average concentrations higher than those from the upper continental crust.The average concentrations of elements like Hf,Mg,P,Y,La,and Ce are slightly lower than in the upper continental crust.Other elements,such as Be,Co,Si,Ta,W and V have average concentrations that are similar,but slightly enriched or slightly depleted,relative to the upper continental crust.The research showed enrichment of some critical elements in the analysed samples,but not high enough that extraction would be economically viable.Statistical methods,which include correlation coefficients between elements and cluster analysis,reveal a strong positive correlation between elements like Be,Bi,Nb,Sc,Ta,W and V.Very high,almost total,positive correlation is also noted between La and Ce.
基金Research Program of Tianjin North China Geological Exploration BureauHK2021-B15,Daqing Fu+4 种基金Geological Survey Program of China Geological SurveyMinistry of Natural ResourcesDD20190822,Xiaofeng WeiS&T Program of Hebei(CN),19224205DHao Wei。
文摘Bedrock weathering performs a significant influence on the evolution of Earth’s critical zone.Carbonate rock(dolostone),metamorphic rock(gneiss),and sedimentary rock(sandstone)geological formations in Yanshan Mountain,Hebei Province,are taken as objects to probe the controlling of geological formations on weathering characteristics,migration,and enrichment of elements as well as structure of Earth’s critical zone under the identical climate conditions through geological field survey,analysis on minerals component,element distribution in the weathering profile.The dolostone geological formation(DGF)is lithologically dominated by dolostone,characterized by the strongest and predominant chemical weathering.During bedrock weathering and pedogenesis,DGF is marked by significant depletion of CaO,Mg O,S,Mn,Mo and enrichment of N,K,Fe_(2)O_(3),and Zn with concentrations of P,Cu,and B keeping stable.Shortage of soil-forming materials and significant loss are driven by soil erosion,which results in thin regolith and soil.The soil thickness is less than 10 cm,and the regolith thickness is less than 30 cm.The vegetation community is predominantly rock arbor or brush,which is calcivorous and tolerant of barrenness.Plagiogneiss is a dominant rock type of gneiss geological formation(GGF),characterized by the weakest weathering and fast chemical and physical weathering rate.GGF is masked by significant depletion of P,K,CaO,MgO,Fe_(2)O_(3),Mn,Cu and enrichment of N,S,Mo,and B,with contents of Zn keeping stable.Both soil and regolith developed in GGF are relatively thick for one of the reasons that biotite expands during weathering.The soil thickness is more than 50 cm,and the regolith thickness ranges from 100 to 200 cm.The vegetation community is predominantly high-quality economic forests and various arbors because of the enrichment of nutrients in GGF.Sandstone is primarily a rock type of sandstone geological formation(SGF),characterized by moderate weathering degree and slow chemical weathering rate.SGF is marked by significant depletion of P,K,CaO,MgO,Fe_(2)O_(3),and enrichment of N,S,Mn,Cu,Zn,and Mo,with fluctuant changes of Zn and B.The thickness of soil developed in SGF varies between that of DGF and GGF.The soil thickness ranges from 30 to 50 cm,and the regolith thickness ranges from 50 to 100 cm.Chinese pines are widely spread on the shady slopes of SGF.Research provides theoretical support for screening dominant ecological resource areas,ecological industry development and ecological protection and restoration for Yanshan Mountain,Hebei Province.
基金The Science Foundation of Ministry of Transport of the People's Republic of China(No.200731822301-7)
文摘In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement( CRCP) slab under vehicle loading, the elliptical load is translated into the square load based on the equivalence principle.The CRCP slab is analyzed to determine the cavity position beneath the slab under vehicle loading. The influences of cavity size on the CRCP slab's stress and vertical displacement are investigated. The study results showthat the formation of the cavity is unavoidable under traffic loading, and the cavity is located at the edge of the longitudinal crack and the slab corner.The cavity size exerts an obvious influence on the largest horizontal tensile stress and vertical displacement. The slab corner is the critical load position of the CRCP slab. The results can be used to assist the design of CRCP in avoiding cavities beneath slabs subject to vehicle loading.
基金Projects(CSTC,cstc2009aa3012-1)supported by Science and Technology Committee of Chongqing,ChinaProject(20100470813)supported by China Postdoctoral Science FoundationProject(2010011511)supported by Sharing Fund of Chongqing University’s Large-scale Equipment
文摘A series of AZ80 billets were compressed with 60%height reduction on hot process simulator at 250,300,350,400℃ under strain rates of 0.01,0.1,1 and 10 s- 1.In order to predict the occurrence of surface fracture,the values of the Cockcroft-Latham equation were calculated by the corresponding finite element numerical algorithm developed.A concept about damage incremental ratio in plastic deformation was defined as the ratio of damage increment at one step to the accumulated value.A method of finding the intersection of incremental ratio varying curve and simulation step axis was brought forward to make the fracture step certain. Then,the effects of temperature and strain rate on critical damage value were achieved.The results show that the critical damage value is not a constant but changes in a range of 0.021 8-0.378 0.It decreases significantly with the increase of strain rate at a certain temperature.While under a certain strain rate,the critical damage value has little change with the increase of temperature.
基金supported by the Thailand Research Fund(TRF)through the Royal Golden Jubilee Ph.D.Program(Grant No.PHD/0112/2553)the National Research University(NRU)initiative
文摘This paper aims to present the critical top tension for static equilibrium configurations of a steel catenary riser(SCR) by using the finite element method. The critical top tension is the minimum top tension that can maintain the equilibrium of the SCR. If the top tension is smaller than the critical value, the equilibrium of the SCR does not exist. If the top tension is larger than the critical value, there are two possible equilibrium configurations. These two configurations exhibit the nonlinear large displacement. The configuration with the smaller displacement is stable, while the one with larger displacement is unstable. The numerical results show that the increases in the riser's vertical distances, horizontal offsets, riser's weights, internal flow velocities, and current velocities increase the critical top tensions of the SCR. In addition, the parametric studies are also performed in order to investigate the limit states for the analysis and design of the SCR.
文摘Recasting the BCS theory in the larger framework of the Bethe-Salpeter equation, a new equation is derived for the temperature-dependent critical current density jc(T) of an elemental superconductor (SC) directly in terms of the basic parameters of the theory, namely the dimensionless coupling constant [N(0)V], the Debye temperature θD and, additionally, the Fermi energy EF—unlike earlier such equations based on diverse, indirect criteria. Our approach provides an ab initio theoretical justification for one of the latter, text book equations invoked at T = 0 which involves Fermi momentum;additionally, it relates jc with the relevant parameters of the problem at T ≠ 0. Noting that the numerical value of EF of a high-Tc SC is a necessary input for the construction of its Fermi surface—which sheds light on its gap-structure, we also briefly discuss extension of our approach for such SCs.
基金funded by the China Geological Survey,grant number DD20190822。
文摘Geochemical differentiation of soils has a series of consequences on plant and places pressure on the ecological environment.The quantitative evaluation of element migration in the Earth’s critical zone is a challenging task.In this study,two demonstration study areas of Scutellaria baicalensis Georgi were selected,and multiple chemical weathering indexes,chemical loss fraction,mass migration coefficients and biological enrichment coefficient method were used to assess the ecological and geochemical suitability.The results show that for the element of Fe,Zn,Se,Cu,Co,Ni,Mo and Ge,the degree of weathering and soil maturation,were greater in the rhyolitic tuff area than in the Plagioclase gneiss area.In both research sites,the heavy metal level of samples in Scutellaria baicalensis Georgi did not exceed the standard limits.The plagioclase gneiss region’s surface soil environment was more alkaline,and the content of soil organic matter was lower,resulting in a higher bioenrichment intensity of Ge,Co,Cu,and Se elements in Scutellaria baicalensis Georgi than in the rhyolite-tuff area.The elements of Cd,Nb,Mo,Pb and As are considerably enriched in the soil of the plagioclase gneiss area but lost by leaching in the soil of the rhyolite tuff area,which is connected to the interplay of elemental abundance and human impact in the parent materials.This study provides a good example of how to assess growth suitability of Chinese medicinal materials in the Earth’s critical zone.
文摘Presents the calculation of critical velocity, natural frequency and dynamic respondency of fluid conveying pipe are calculated under different boundary conditions using finite element method, and the use of calculation results to design and research rocket pipes feeding fuel and watery turbine pipes conveying water etc.