10 different species of water mites which are Georgella helvetica, Eylais extendens, Hydrachna globose, Hydrachna prosifera, Hydrachna skorikowi, Hydrodroma despiciens, Hydryphantes dispar, Limnesia fulgida, Eylais se...10 different species of water mites which are Georgella helvetica, Eylais extendens, Hydrachna globose, Hydrachna prosifera, Hydrachna skorikowi, Hydrodroma despiciens, Hydryphantes dispar, Limnesia fulgida, Eylais setosa, Hydryphantes flexuosus were used in this study. The total masses of these species were measured as mg with the use of an elemental analyzer to calculate the percentage of the organic components of their structures. The achieved values were assessed separately for each species and element with the interpolation method. Out of these organic elements, the amount of C with an approximately value of 50% was the highest for all species while the amounts of S which was approximately 1% was determined as the lowest for almost all species. The observed values were discussed in terms of the systematic of water mites.展开更多
Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental mic...Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via LIBS. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation (RSD) approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of LIBS, a thermodynamic chart of four elements (Mg, Ca, Ba, and Na) was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by LIBS. The results demon- strated that LIBS is a promising technique for rapid elemental microanalysis of heterogeneous samples.展开更多
A nonlinear parabolic system is derived to describe incompressible nuclear waste-disposal contamination in porous media. A sequential implicit tirne-stepping is defined, in which the pressure and Darcy velocity of the...A nonlinear parabolic system is derived to describe incompressible nuclear waste-disposal contamination in porous media. A sequential implicit tirne-stepping is defined, in which the pressure and Darcy velocity of the mixture are approximated simultaneously by a mixed finite element method and the brine, radionuclid and heat are treated by a combination of a Galerkin finite element method and the method of characteristics. Optimal-order convergence in L2 is proved. Time-truncation errors of standard procedures are reduced by time stepping along the characteristics of the hyperbolic part of the brine, radionuclide and heal equalios, temporal and spatial error are lossened by direct compulation of the velocity in the mixed method, as opposed to differentiation of the pressure.展开更多
In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-d...In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-dimensional nonlinear time fractional thermal diffusion model.The time Caputo fractional derivative is approximated by using the L2-1formula,the first-order derivative and nonlinear term are discretized by some second-order approximation formulas,and the quadratic finite element is used to approximate the spatial direction.The error accuracy O(h3+t2)is obtained,which is verified by the numerical results.展开更多
Numerical experiments are given to verify the theoretical results for superconvergence of the elliptic problem by global and local L2-Projection methods.
Trace elements in four kinds of the Genus Hippophae L pulps were analysed byPIXE. Optimization of the system performance was done by carefully selecting the absorbers, Analytical sensitivities of the PIXE system were ...Trace elements in four kinds of the Genus Hippophae L pulps were analysed byPIXE. Optimization of the system performance was done by carefully selecting the absorbers, Analytical sensitivities of the PIXE system were obtained by means of "external standard method".展开更多
A modified penalty scheme is discussed for solving the Stokes problem with the Crouzeix-Raviart type nonconforming linear triangular finite element. By the L^2 projection method, the superconvergence results for the v...A modified penalty scheme is discussed for solving the Stokes problem with the Crouzeix-Raviart type nonconforming linear triangular finite element. By the L^2 projection method, the superconvergence results for the velocity and pressure are obtained with a penalty parameter larger than that of the classical penalty scheme. The numerical experiments are carried out to confirm the theoretical results.展开更多
Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type I...Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type II TEs have not been characterized at the molecular level in cowpea, this study was initiated to survey the presence of type II TEs in the cowpea genome. Type II TEs: Enhancer/Suppressor-mutator (En/Spm) and Miniature Inverted-repeat Transposable Elements (MITEs) were isolated and characterized. The sequence identity between the EnSpm TE clones was 46% at the nucleotide level (NL) and 30% at the amino acid level (AL) while that of MITEs was 71% at NL and 63% at AL. These cowpea En/Spm TEs were 80% homologous with En/Spm elements of other crops at NL and 46% at AL. The MITEs were 96% similar at NL and 18% homologous at AL. DNA gel blot analysis confirmed the presence of the En/Spm TEs in cowpea. RT-PCR (reverse transcriptase polymerase chain reaction) analysis showed that the VuEnSpm-3 and the MITE clone, VuPIF-1 were actively transcribed in wild type and mutant cowpea tissues. Overall, our data show that multiple, divergent lineages of En/Spm and MITEs are present in the cowpea genome, some of which are actively transcribed. Our findings also offer new molecular resource to further investigate the genetic determinants underlying previously described mutant cowpea phenotypes.展开更多
An active miniature inverted-repeat transposable element(MITE),MCL as-A,was previously identified from'Candidatus Liberibacter asiaticus'known to be associated with citrus Huanglongbing(HL B,yellow shoot disea...An active miniature inverted-repeat transposable element(MITE),MCL as-A,was previously identified from'Candidatus Liberibacter asiaticus'known to be associated with citrus Huanglongbing(HL B,yellow shoot disease).To explore the recent transposition status of MCLas-A,389'Ca.L.asiaticus'strains collected from nine regions in China were amplifed using a specific primer set and three representative'Ca.L.asiaticus'strains were analyzed by next-generation sequencing(NGS)approach.PCR and genomic analysis showed that the entire MCLas A was only present in 1.80%(7/389)and the jumping-out type of the MITE was predominant(8123%)in samples tested,suggesting high frequency transposition occurred in'Ca.L.asiaticus'strains recently collected from China.Biological roles of transposition of the active MITE remain to be determined.展开更多
[Objectives] To determine the content of 20 inorganic elements in 18 samples of roots, stems and leaves from of Arctium lappa L. produced in different areas. [Methods] The wet digestion and technique of inductively co...[Objectives] To determine the content of 20 inorganic elements in 18 samples of roots, stems and leaves from of Arctium lappa L. produced in different areas. [Methods] The wet digestion and technique of inductively coupled plasma emission spectrometry(ICP-OES) were used. [Results] 20 kinds of inorganic elements in the samples of A. lappa L. roots contained rich elements essential for human beings such as K, Ca, Na, P and trace elements Cu, Fe, Zn; heavy metals Pb, As, Cu, Cd in A. lappa L. samples did not exceed the limit, and Hg was not detected in all 12 samples; heavy metals in A. lappa L. roots harvested in 12 months did not exceed the limit. [Conclusions] Compared with the roots of A. lappa L., the inorganic elements in the stems and leaves of A. lappa L. were relatively less. The samples collected from Shuimo Town in Wenchuan County of Aba Prefecture with an altitude of 920 m showed little difference from samples collected from Qiongxi Town in Hongyuan County of Aba Prefecture with an altitude of 3 505 m in 20 kinds of inorganic elements.展开更多
An existence theorem of maximal elements for an L*-majorized correspondence defined on a non-paracompact H-space is established. As applications of the result, an equilibrium existence theorem for a non-paracompact g...An existence theorem of maximal elements for an L*-majorized correspondence defined on a non-paracompact H-space is established. As applications of the result, an equilibrium existence theorem for a non-paracompact generalized game in H-spaces with infinitely many players and with L*-majorized correspondences is given.展开更多
Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, te...Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments (DSAIFF), was employed to isolate the Mu flanking fragments (MFFs) of miol6. The target site duplications (TSDs) isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and miol6 was mapped in silico onto the physical position ranged from 229 965 021 to 229 965 409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of miol6 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of miol6 is alternated by Mu insertion.展开更多
In this article,we study a 2D nonlinear time-fractional Rayleigh-Stokes problem,which has an anomalous subdiffusion term,on triangular meshes by quadratic finite volume element schemes.Time-fractional derivative,defin...In this article,we study a 2D nonlinear time-fractional Rayleigh-Stokes problem,which has an anomalous subdiffusion term,on triangular meshes by quadratic finite volume element schemes.Time-fractional derivative,defined by Caputo fractional derivative,is discretized through L2−1σformula,and a two step scheme is used to approximate the time first-order derivative at time tn−α/2,where the nonlinear term is approximated by using a matching linearized difference scheme.A family of quadratic finite volume element schemes with two parameters are proposed for the spatial discretization,where the range of values for two parameters areβ1∈(0,1/2),β2∈(0,2/3).For testing the precision of numerical algorithms,we calculate some numerical examples which have known exact solution or unknown exact solution by several kinds of quadratic finite volume element schemes,and contrast with the results of an existing quadratic finite element scheme by drawing diversified comparison plots and showing the detailed data of L2 error results and convergence orders.Numerical results indicate that,L2 error estimate of one scheme with parameters β_(1)=(3−√3)/6,β2=(6+√3−√21+6√3)/9 is O(h^(3)+△t^(2)),and L^(2) error estimates of other schemes are O(h^(2)+△t^(2)),where h and △t denote the spatial and temporal discretization parameters,respectively.展开更多
The levels and compartmentalization of Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Tb, Hf, Ta, Au, Th, and U in Phragmites australis (Cav.) Trin. ex...The levels and compartmentalization of Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Tb, Hf, Ta, Au, Th, and U in Phragmites australis (Cav.) Trin. ex Steud., Carex conescens L. and Cladophora sericea (Hudson) Kutzing from the Caucasian coast of the Black Sea-Anapa recreational region was investigated by Neutron Activation Analysis. The study touches upon subject of the sediment-to-plant and root-to-leaf elemental transfer as well as of the influence of anthropogenic pollution on wetland ecosystems in zone of resort. The content of the majority of considered elements was found higher in the belowground organs of P. australis than in the aboveground tissues while a reverse regularity was evidenced for C. conescens. The levels of elements decrease from bottom sediments to aquatic plants with the notable exception of the halogens Cl, Br and I that presented 5 to 100 fold higher content in plants than in sediments. The increased levels of As, Mo, and Sb in some soil and sediment samples most probably indicate the anthropogenic pollution. It recommends them for a continuous monitoring of the same area.展开更多
文摘10 different species of water mites which are Georgella helvetica, Eylais extendens, Hydrachna globose, Hydrachna prosifera, Hydrachna skorikowi, Hydrodroma despiciens, Hydryphantes dispar, Limnesia fulgida, Eylais setosa, Hydryphantes flexuosus were used in this study. The total masses of these species were measured as mg with the use of an elemental analyzer to calculate the percentage of the organic components of their structures. The achieved values were assessed separately for each species and element with the interpolation method. Out of these organic elements, the amount of C with an approximately value of 50% was the highest for all species while the amounts of S which was approximately 1% was determined as the lowest for almost all species. The observed values were discussed in terms of the systematic of water mites.
基金supported by National Natural Science Foundation of China(No.81303218)Beijing Municipal Government for the University Affiliated with the Party Central CommitteeDoctoral Fund of Ministry of Education of China(No.20130013120006)
文摘Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via LIBS. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation (RSD) approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of LIBS, a thermodynamic chart of four elements (Mg, Ca, Ba, and Na) was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by LIBS. The results demon- strated that LIBS is a promising technique for rapid elemental microanalysis of heterogeneous samples.
基金The research was supported by the Natural Science Foundation of China
文摘A nonlinear parabolic system is derived to describe incompressible nuclear waste-disposal contamination in porous media. A sequential implicit tirne-stepping is defined, in which the pressure and Darcy velocity of the mixture are approximated simultaneously by a mixed finite element method and the brine, radionuclid and heat are treated by a combination of a Galerkin finite element method and the method of characteristics. Optimal-order convergence in L2 is proved. Time-truncation errors of standard procedures are reduced by time stepping along the characteristics of the hyperbolic part of the brine, radionuclide and heal equalios, temporal and spatial error are lossened by direct compulation of the velocity in the mixed method, as opposed to differentiation of the pressure.
基金the National Natural Science Fund(11661058,11761053)Natural Science Fund of Inner Mongolia Autonomous Region(2016MS0102,2017MS0107)+1 种基金Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT-17-A07)National Undergraduate Innovative Training Project of Inner Mongolia University(201710126026).
文摘In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-dimensional nonlinear time fractional thermal diffusion model.The time Caputo fractional derivative is approximated by using the L2-1formula,the first-order derivative and nonlinear term are discretized by some second-order approximation formulas,and the quadratic finite element is used to approximate the spatial direction.The error accuracy O(h3+t2)is obtained,which is verified by the numerical results.
文摘Numerical experiments are given to verify the theoretical results for superconvergence of the elliptic problem by global and local L2-Projection methods.
基金The Project Supported by National Natural Science Foundation of China
文摘Trace elements in four kinds of the Genus Hippophae L pulps were analysed byPIXE. Optimization of the system performance was done by carefully selecting the absorbers, Analytical sensitivities of the PIXE system were obtained by means of "external standard method".
基金supported by the National Natural Science Foundation of China (Nos. 10971203 and 11271340)the Research Fund for the Doctoral Program of Higher Education of China (No. 20094101110006)
文摘A modified penalty scheme is discussed for solving the Stokes problem with the Crouzeix-Raviart type nonconforming linear triangular finite element. By the L^2 projection method, the superconvergence results for the velocity and pressure are obtained with a penalty parameter larger than that of the classical penalty scheme. The numerical experiments are carried out to confirm the theoretical results.
文摘Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type II TEs have not been characterized at the molecular level in cowpea, this study was initiated to survey the presence of type II TEs in the cowpea genome. Type II TEs: Enhancer/Suppressor-mutator (En/Spm) and Miniature Inverted-repeat Transposable Elements (MITEs) were isolated and characterized. The sequence identity between the EnSpm TE clones was 46% at the nucleotide level (NL) and 30% at the amino acid level (AL) while that of MITEs was 71% at NL and 63% at AL. These cowpea En/Spm TEs were 80% homologous with En/Spm elements of other crops at NL and 46% at AL. The MITEs were 96% similar at NL and 18% homologous at AL. DNA gel blot analysis confirmed the presence of the En/Spm TEs in cowpea. RT-PCR (reverse transcriptase polymerase chain reaction) analysis showed that the VuEnSpm-3 and the MITE clone, VuPIF-1 were actively transcribed in wild type and mutant cowpea tissues. Overall, our data show that multiple, divergent lineages of En/Spm and MITEs are present in the cowpea genome, some of which are actively transcribed. Our findings also offer new molecular resource to further investigate the genetic determinants underlying previously described mutant cowpea phenotypes.
基金Funded by the National Natural Science Foundation of China(31671992,31871925)the National Key R&D Program of China(2018YFD0201500)the Key R&D Program of Guangxi,China(Gui Ke AA18118046).
文摘An active miniature inverted-repeat transposable element(MITE),MCL as-A,was previously identified from'Candidatus Liberibacter asiaticus'known to be associated with citrus Huanglongbing(HL B,yellow shoot disease).To explore the recent transposition status of MCLas-A,389'Ca.L.asiaticus'strains collected from nine regions in China were amplifed using a specific primer set and three representative'Ca.L.asiaticus'strains were analyzed by next-generation sequencing(NGS)approach.PCR and genomic analysis showed that the entire MCLas A was only present in 1.80%(7/389)and the jumping-out type of the MITE was predominant(8123%)in samples tested,suggesting high frequency transposition occurred in'Ca.L.asiaticus'strains recently collected from China.Biological roles of transposition of the active MITE remain to be determined.
基金Supported by The National Key Research and Development Program of China(2018YFC1708005)Science and Technology Planning Project of Sichuan Province(2016NZYZF0007)+1 种基金Fourth National Survey of Traditional Chinese Medicine Resources Program(2017)Innovating Research Program of Postgraduates of Southwest University for Nationalities in 2019(CX2019SZ175)
文摘[Objectives] To determine the content of 20 inorganic elements in 18 samples of roots, stems and leaves from of Arctium lappa L. produced in different areas. [Methods] The wet digestion and technique of inductively coupled plasma emission spectrometry(ICP-OES) were used. [Results] 20 kinds of inorganic elements in the samples of A. lappa L. roots contained rich elements essential for human beings such as K, Ca, Na, P and trace elements Cu, Fe, Zn; heavy metals Pb, As, Cu, Cd in A. lappa L. samples did not exceed the limit, and Hg was not detected in all 12 samples; heavy metals in A. lappa L. roots harvested in 12 months did not exceed the limit. [Conclusions] Compared with the roots of A. lappa L., the inorganic elements in the stems and leaves of A. lappa L. were relatively less. The samples collected from Shuimo Town in Wenchuan County of Aba Prefecture with an altitude of 920 m showed little difference from samples collected from Qiongxi Town in Hongyuan County of Aba Prefecture with an altitude of 3 505 m in 20 kinds of inorganic elements.
基金Supported by the NNSF of China(10571081)the Natural Science Foundation of Beijing Education Department(KM200710772007).
文摘An existence theorem of maximal elements for an L*-majorized correspondence defined on a non-paracompact H-space is established. As applications of the result, an equilibrium existence theorem for a non-paracompact generalized game in H-spaces with infinitely many players and with L*-majorized correspondences is given.
基金supported by the High-Tech R&D Program of China(2006AA10A106)the open funds of the National Key Laboratory of Crop Genetic Improvement and China National Fundamental Fund of Personnel Training (J0730649)
文摘Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments (DSAIFF), was employed to isolate the Mu flanking fragments (MFFs) of miol6. The target site duplications (TSDs) isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and miol6 was mapped in silico onto the physical position ranged from 229 965 021 to 229 965 409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of miol6 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of miol6 is alternated by Mu insertion.
基金This work was partially supported by the National Natural Science Foundation of China(No.11871009).
文摘In this article,we study a 2D nonlinear time-fractional Rayleigh-Stokes problem,which has an anomalous subdiffusion term,on triangular meshes by quadratic finite volume element schemes.Time-fractional derivative,defined by Caputo fractional derivative,is discretized through L2−1σformula,and a two step scheme is used to approximate the time first-order derivative at time tn−α/2,where the nonlinear term is approximated by using a matching linearized difference scheme.A family of quadratic finite volume element schemes with two parameters are proposed for the spatial discretization,where the range of values for two parameters areβ1∈(0,1/2),β2∈(0,2/3).For testing the precision of numerical algorithms,we calculate some numerical examples which have known exact solution or unknown exact solution by several kinds of quadratic finite volume element schemes,and contrast with the results of an existing quadratic finite element scheme by drawing diversified comparison plots and showing the detailed data of L2 error results and convergence orders.Numerical results indicate that,L2 error estimate of one scheme with parameters β_(1)=(3−√3)/6,β2=(6+√3−√21+6√3)/9 is O(h^(3)+△t^(2)),and L^(2) error estimates of other schemes are O(h^(2)+△t^(2)),where h and △t denote the spatial and temporal discretization parameters,respectively.
文摘The levels and compartmentalization of Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Tb, Hf, Ta, Au, Th, and U in Phragmites australis (Cav.) Trin. ex Steud., Carex conescens L. and Cladophora sericea (Hudson) Kutzing from the Caucasian coast of the Black Sea-Anapa recreational region was investigated by Neutron Activation Analysis. The study touches upon subject of the sediment-to-plant and root-to-leaf elemental transfer as well as of the influence of anthropogenic pollution on wetland ecosystems in zone of resort. The content of the majority of considered elements was found higher in the belowground organs of P. australis than in the aboveground tissues while a reverse regularity was evidenced for C. conescens. The levels of elements decrease from bottom sediments to aquatic plants with the notable exception of the halogens Cl, Br and I that presented 5 to 100 fold higher content in plants than in sediments. The increased levels of As, Mo, and Sb in some soil and sediment samples most probably indicate the anthropogenic pollution. It recommends them for a continuous monitoring of the same area.