To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on sin...To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on single nucleotide polymorphism(SNP)markers.Ten pairs of primers with good polymorphism and high resolution were screened from 315 pairs of SNP primers by 3 broccoli accessions(inbred lines)with different phenotypes and maturity.The 10 pairs of SNP primers were selected,producing 78 alleles.The diversity analysis indicated that the polymorphism information content(PIC)of SNP primer ranged from 0.64 to 0.90.The observed number of alleles(Na)was 2.00,the effective number of alleles(Ne)was 1.11–2.00,the Nei’s gene diversity(H)was 0.10–0.50,and Shannon information index(I)was 0.20–0.70 using PopGene32 software.The clustering results showed that the 161 broccoli cultivars could be divided into 4 major subgroups(A,B,C and D),foreign cultivars were all assigned to subgroup A,and domestic cultivars were assigned to 3 subgroups of B,C,and D.This study indicated that some domestic cultivars and foreign cultivars were similar in genetic background,but most domestic cultivars were still different from the Japanese cultivars.When K=2,the population structure result presented that 161 broccoli cultivars could be divided into 1 simple group(2 groups)and 1 mixed group.When Q≥0.6,143(88.82%)broccoli cultivars belonged to the simple groups.In simple groups 68(42.24%)broccoli cultivars of group 1 were derived from Japan,the United States,Switzerland,the Netherlands,China-Taiwan,and China-Mainland;75(46.58%)broccoli cultivars belonged to group 2;when Q<0.6,18(11.18%)broccoli cultivars belonged to the mixed groups.This study is helpful to understand the diversity and resolution of broccoli cultivars from worldwide,which is beneficial to plant breeding and materials innovation.And meanwhile,this result is also used for construction of broccoli fingerprint serving for cultivar identification.展开更多
In this report,complete mitochondrial genome sequences of Laminaria cultivation variety 'Rongfu' were obtained.The results showed the length of circular molecule of mtDNA was 37 638 bp(64.7% A+T),encoding thre...In this report,complete mitochondrial genome sequences of Laminaria cultivation variety 'Rongfu' were obtained.The results showed the length of circular molecule of mtDNA was 37 638 bp(64.7% A+T),encoding three rRNAs(23S,16S and 5S),25 tRNAs,35 known mitochondrial proteins and 3 ORFs.Sequence alignment indicated its mtDNA genome was very similar to that of Laminaria japonica.Phylogenetic trees inferred from concatenated 30 mitochondrial genes showed that 'Rongfu',Laminaria japon-ica,Laminaria longipedalis,Laminaria diabolica,Laminaria religiosa and Laminaria ochotensis clustered together.In addition,compared with mitochondrial genome of L.japonica,'Rongfu' mtDNA lacked a non-coding region of 19 nucleotides,which was located between rRNA small subunit gene 3(rps3)and rRNA small subunit gene 9(rps9).Seven cultivation varieties of China were divided into two groups based on this non-coding region which was absent in 'Rongfu','Fujian' and 'Sanhai' while present in 'Ailunwan','Dongfang No.2','Dongfang No.3' and 'Zaohoucheng'.So this variation can be used in germplasm identification of cultivation variety.展开更多
Excellent results are obtained in structure analysis with jew phases of structure factors by the maximum-entropy method (MEM) for CaGaN PbCO3 and ReBe22 single crystals. The computation time and memory space are minim...Excellent results are obtained in structure analysis with jew phases of structure factors by the maximum-entropy method (MEM) for CaGaN PbCO3 and ReBe22 single crystals. The computation time and memory space are minimized by symmetry operations so that structure analysis by the MEM can be carried out with a personal computer.展开更多
With the remarkable growth of textual data sources in recent years,easy,fast,and accurate text processing has become a challenge with significant payoffs.Automatic text summarization is the process of compressing text...With the remarkable growth of textual data sources in recent years,easy,fast,and accurate text processing has become a challenge with significant payoffs.Automatic text summarization is the process of compressing text documents into shorter summaries for easier review of its core contents,which must be done without losing important features and information.This paper introduces a new hybrid method for extractive text summarization with feature selection based on text structure.The major advantage of the proposed summarization method over previous systems is the modeling of text structure and relationship between entities in the input text,which improves the sentence feature selection process and leads to the generation of unambiguous,concise,consistent,and coherent summaries.The paper also presents the results of the evaluation of the proposed method based on precision and recall criteria.It is shown that the method produces summaries consisting of chains of sentences with the aforementioned characteristics from the original text.展开更多
Erythromycin thiocyanate is widely used for the production of other macrolide antibiotics. In this work, a novel heterosolvate of this pharmaceutical compound has been obtained and characterized for the first time, wh...Erythromycin thiocyanate is widely used for the production of other macrolide antibiotics. In this work, a novel heterosolvate of this pharmaceutical compound has been obtained and characterized for the first time, which was transformed from the dihydrate form in the acetone solvent through evaporation crystallization. Thermal behavior together with compositional analysis revealed that both water and acetone molecules participated in the formation of the crystal lattice which is rarely reported before. The general chemical name of the heterosolvate may be defined as erythromycin thiocyanate sesquihydrate hemiacetonate. Furthermore, studies on solid-state spectral analysis provided strong evidence of intermolecular hydrogen bonds in heterosolvate crystals. According to the crystal structure determined by single crystal X-ray diffraction, the formation mechanism of the heterosolvate is proposed in which strong multihydrogen bondings between water and solute molecules form the layer structure. While acetone molecules form single-hydrogen bonds with solutes and reside in channels between layers. This well explains why acetone solvent is easy to escape from the crystal structure during desolvation.展开更多
The local structure of an alternative Pb(Zn1/3Nb2/3)O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb(Zn1/3Nb2/3)O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaT...The local structure of an alternative Pb(Zn1/3Nb2/3)O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb(Zn1/3Nb2/3)O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaTiO33 perovskite phase stabilizer. Then, x-ray absorption spectroscopy and density functional theory are employed to calculate the local structure configuration and formation energy of the prepared samples. Ba2+ is found to replace Pb2+ in AA-site with Zn2+ occupying BB-site in Pb(Zn1/3Nb2/3)O3, while in the neighboring structure, Ti4+4+ replaces Nb5+5+ in BB-site with Pb2+2+ occupying AA-site. With the substitution of BaTiO33 in Pb(Zn1/3Nb2/3)O3, the bond length between Zn2+ and Pb2+ is longer than that of the typical perovskite phase of Pb(Zn1/3Nb2/3)O3. This indicates the key role of BaTiO33 in decreasing the steric hindrance of Pb2+ lone pair, and the mutual interactions between Pb2+ lone pair and Zn2+ and the formation energy is seen to decrease. This finding of the formation energy and local structure configuration relationship can further extend a fundamental understanding of the role of BaTiO33 in stabilizing the perovskite phase in PbZn13Nb23O3-based materials, which in turn will lead to an improved preparation technique for desired electrical properties.展开更多
Standard mica was used to correct the X-ray powder diffraction instrument error and mathematic methods were employed to find the correction equation. By analyzing mullite sample and comparing the corrected and uncorre...Standard mica was used to correct the X-ray powder diffraction instrument error and mathematic methods were employed to find the correction equation. By analyzing mullite sample and comparing the corrected and uncorrected analysis results we found the former is obviously more reasonable. So the conclusion is that the X-ray powder diffraction instrument error greatly affects the crystalline structure analysis, and the above method is convenient and effective for the correction of instrument error.展开更多
The crystal structure of a solid electrolyte, beta-A12O3, was investigated by XRD analysis and demonstrated by Diamond software. Its chemical formula was verified by the Ag ion molten salt exchange method and X-ray fl...The crystal structure of a solid electrolyte, beta-A12O3, was investigated by XRD analysis and demonstrated by Diamond software. Its chemical formula was verified by the Ag ion molten salt exchange method and X-ray fluorescence analysis (XRF). The chemical formula of β- A12O3 is Na2O·8.52A12O3, and its crystal is of hexagonal, space group P63/mmc, with a = 5.5941 A and c = 22.5300 A. The chemical formula of β-Al20 is Na2O·6.03A12O3, and its crystal is of trigonal, space group R3m, with a = 5.6017 A and c = 33.6219 A. The maximum span in the sodion migration of β-phase (2.4283 A) is only about a third of that for the β-phase (6.9037 A), so the β-phase has higher ionic conductivity than the r-phase.展开更多
Human's real life is within a colorful world. Compared to the gray images, color images contain more information and have better visual effects. In today's digital image processing, image segmentation is an im...Human's real life is within a colorful world. Compared to the gray images, color images contain more information and have better visual effects. In today's digital image processing, image segmentation is an important section for computers to "understand" images and edge detection is always one of the most important methods in the field of image segmentation. Edges in color images are considered as local discontinuities both in color and spatial domains. Despite the intensive study based on integration of single-channel edge detection results, and on vector space analysis, edge detection in color images remains as a challenging issue.展开更多
With the increasing popularity of mobile devices and the wide adoption of mobile Apps,an increasing concern of privacy issues is raised.Privacy policy is identified as a proper medium to indicate the legal terms,such ...With the increasing popularity of mobile devices and the wide adoption of mobile Apps,an increasing concern of privacy issues is raised.Privacy policy is identified as a proper medium to indicate the legal terms,such as the general data protection regulation(GDPR),and to bind legal agreement between service providers and users.However,privacy policies are usually long and vague for end users to read and understand.It is thus important to be able to automatically analyze the document structures of privacy policies to assist user understanding.In this work we create a manually labelled corpus containing 231 privacy policies(of more than 566,000 words and 7,748 annotated paragraphs).We benchmark our data corpus with 3 document classification models and achieve more than 82%on F1-score.展开更多
Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were...Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.展开更多
At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is es...At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.展开更多
Structural analysis problems can be formulized as either root finding problems,or optimization problems.The general practice is to choose the first option directly or to convert the second option again to a root findi...Structural analysis problems can be formulized as either root finding problems,or optimization problems.The general practice is to choose the first option directly or to convert the second option again to a root finding problem by taking relevant derivatives and equating them to zero.The second alternative is used very randomly as it is and only for some simple demonstrative problems,most probably due to difficulty in solving optimization problems by classical methods.The method called TPO/MA(Total Potential Optimization using Metaheuristic Algorithms)described in this study successfully enables to handle structural problems with optimization formulation.Using metaheuristic algorithms provides additional advantages in dealing with all kinds of constraints.展开更多
[Objective] The study was to analyze the structure and function of HpaGXoo and the relationship between the two.[Method] Some related bioinformatics analysis software on internet such as NPSA,Swiss-Model,SAPS and Inte...[Objective] The study was to analyze the structure and function of HpaGXoo and the relationship between the two.[Method] Some related bioinformatics analysis software on internet such as NPSA,Swiss-Model,SAPS and InterPro Scan were adopted to analyze the structure and predict its function.[Result] HpaGXoo consists of 139 amino acids,and has many alpha-helical and coiled structure,no signal peptide on N-terminal and no transmembrane structure.It locates in bacterial cytoplasm.[Conclusion] The study will lay ...展开更多
To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "F...To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "Fuji", free spindle long shoot "Fuji", free spindle "Huaguan" were investigated in Xingtang County of Hebei Province by SPSS analysis. The results showed that the stem taperingness on free spindle short shoot "Fuji" was in negative correlation with central shaft, but the correlation was not significant. While the stem taperingness on free spindle long shoot "Fuji" was in positive correlation with central shaft, but the correlation was not significant either. The stern taperingness on free spindle "Huaguan" was in negative correlation with central shaft, and the correlation between the stem taperingness and the central shaft total length was significant at the level of 0.01. The results.provided scientific theoretical basis for guiding the dwarfing rootstocks close planting apple tree pruning technology.展开更多
Video structure analysis is a basic requirement for most content-based video editing and processing systems. This paper presents a fast video structure analysis method based on image segmentation in each frame, with r...Video structure analysis is a basic requirement for most content-based video editing and processing systems. This paper presents a fast video structure analysis method based on image segmentation in each frame, with region matching between frames. The structure analysis decomposes the video into several moving objects, including information about their colors, positions, shapes, movements, and lifetimes. The method also supports user interactions to improve the results. The result shows that this method is fast and stable and can complete video analyzinq interactivelv.展开更多
In order to explore the nonlinear structure hidden in high-dimensional data, some dimen-sion reduction techniques have been developed, such as the Projection Pursuit technique (PP).However, PP will involve enormous co...In order to explore the nonlinear structure hidden in high-dimensional data, some dimen-sion reduction techniques have been developed, such as the Projection Pursuit technique (PP).However, PP will involve enormous computational load. To overcome this, an inverse regressionmethod is proposed. In this paper, we discuss and develop this method. To seek the interestingprojective direction, the minimization of the residual sum of squares is used as a criterion, andspline functions are applied to approximate the general nonlinear transform function. The algo-rithm is simple, and saves the computational load. Under certain proper conditions, consistencyof the estimators of the interesting direction is shown.展开更多
The band gap structures by arranging hybrid shunted piezoelectric materialswith resistance inductive (RL) circuit and negative impedance converter (NIC) closely and at in- tervals are presented. The theoretical mo...The band gap structures by arranging hybrid shunted piezoelectric materialswith resistance inductive (RL) circuit and negative impedance converter (NIC) closely and at in- tervals are presented. The theoretical model is built using transfer matrix method. Then the MATLAB computing language is utilized to simulate the band gap structures. Meanwhile, the effects of the resistance, inductance and capacitance on the local resonant gap are studied. By comparing different combinations of resistance, inductance and capacitance as well as different arrangement of circuits, a 13 kHz band gap is reached under the effect of arranging hybrid pe- riodic shunted piezoelectric patches at intervals and the stability of the system is also analyzed. It is proved that utilizing hybrid shunted piezoelectric patches would have a clear impact on the band gap structure of phononic crystal rods. Moreover, the band gap would be clearly enlarged by arranging hybrid piezoelectric patches at intervals.展开更多
Bimetallic clusters have aroused tremendous interest because the property changes like structure,size,and composition have occurred.Herein,a structural search of the global minimum for anionic LiMg_(n)^(-)(n=2-11) clu...Bimetallic clusters have aroused tremendous interest because the property changes like structure,size,and composition have occurred.Herein,a structural search of the global minimum for anionic LiMg_(n)^(-)(n=2-11) clusters is performed using an efficient crystal structure analysis by particle swarm optimization(CALYPSO) structural searching program with subsequent density functional theory(DFT) calculations.A great variety of low energetic isomers are converged,and the most stable ones are confirmed by comparing their total energy of each size.It is found that the LiMg_(n)^(-)clusters are structurally consistent with corresponding Mg clusters anions except for LiMg_(5)^(-)and LiMg_(7)^(-).In all the doped clusters,the Li atom prefers to occupy the convex position.Simulated photoelectron spectra(PES),Infrared(IR),and Raman spectra of LiMg_(n)^(-)could be used as an essential evidence for identifying cluster structures experimentally in the future.Stability study reveals that a tower-like structure of LiMg_(9)^(-)has prominent stability and can be identified as a magic number cluster.The reason might be that there are both closed-shell 1S^(2)1P^(6)1D^(10)2S^(2) electronic configurations and stronger Li-Mg bonds caused by sp hybridization in the LiMg_(9)^(-)cluster.展开更多
基金funded by the National Key Research and Development Plan(Grant No.2017YFD0101805)the National Science and Technology Foundation(Grant No.31501761)+2 种基金the National Modern Agricultural Industry Technology System Construction Special Fund Project(Grant No.CARS-23-A8)the Chinese Academy of Agricultural Sciences Science and Technology Innovation Project(Grant No.CAAS-ASTIP-IVF-CAAS)the State Key Laboratory of Vegetable Germplasm Innovation.
文摘To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on single nucleotide polymorphism(SNP)markers.Ten pairs of primers with good polymorphism and high resolution were screened from 315 pairs of SNP primers by 3 broccoli accessions(inbred lines)with different phenotypes and maturity.The 10 pairs of SNP primers were selected,producing 78 alleles.The diversity analysis indicated that the polymorphism information content(PIC)of SNP primer ranged from 0.64 to 0.90.The observed number of alleles(Na)was 2.00,the effective number of alleles(Ne)was 1.11–2.00,the Nei’s gene diversity(H)was 0.10–0.50,and Shannon information index(I)was 0.20–0.70 using PopGene32 software.The clustering results showed that the 161 broccoli cultivars could be divided into 4 major subgroups(A,B,C and D),foreign cultivars were all assigned to subgroup A,and domestic cultivars were assigned to 3 subgroups of B,C,and D.This study indicated that some domestic cultivars and foreign cultivars were similar in genetic background,but most domestic cultivars were still different from the Japanese cultivars.When K=2,the population structure result presented that 161 broccoli cultivars could be divided into 1 simple group(2 groups)and 1 mixed group.When Q≥0.6,143(88.82%)broccoli cultivars belonged to the simple groups.In simple groups 68(42.24%)broccoli cultivars of group 1 were derived from Japan,the United States,Switzerland,the Netherlands,China-Taiwan,and China-Mainland;75(46.58%)broccoli cultivars belonged to group 2;when Q<0.6,18(11.18%)broccoli cultivars belonged to the mixed groups.This study is helpful to understand the diversity and resolution of broccoli cultivars from worldwide,which is beneficial to plant breeding and materials innovation.And meanwhile,this result is also used for construction of broccoli fingerprint serving for cultivar identification.
基金supported by funds of the National Department Public Benefit Research Foundation of China (Nos. 200805075, 200903030)the National Natural Science Foundation of China (No. 40606035)the National Agricultural Transformation (2010GB23600666)
文摘In this report,complete mitochondrial genome sequences of Laminaria cultivation variety 'Rongfu' were obtained.The results showed the length of circular molecule of mtDNA was 37 638 bp(64.7% A+T),encoding three rRNAs(23S,16S and 5S),25 tRNAs,35 known mitochondrial proteins and 3 ORFs.Sequence alignment indicated its mtDNA genome was very similar to that of Laminaria japonica.Phylogenetic trees inferred from concatenated 30 mitochondrial genes showed that 'Rongfu',Laminaria japon-ica,Laminaria longipedalis,Laminaria diabolica,Laminaria religiosa and Laminaria ochotensis clustered together.In addition,compared with mitochondrial genome of L.japonica,'Rongfu' mtDNA lacked a non-coding region of 19 nucleotides,which was located between rRNA small subunit gene 3(rps3)and rRNA small subunit gene 9(rps9).Seven cultivation varieties of China were divided into two groups based on this non-coding region which was absent in 'Rongfu','Fujian' and 'Sanhai' while present in 'Ailunwan','Dongfang No.2','Dongfang No.3' and 'Zaohoucheng'.So this variation can be used in germplasm identification of cultivation variety.
文摘Excellent results are obtained in structure analysis with jew phases of structure factors by the maximum-entropy method (MEM) for CaGaN PbCO3 and ReBe22 single crystals. The computation time and memory space are minimized by symmetry operations so that structure analysis by the MEM can be carried out with a personal computer.
文摘With the remarkable growth of textual data sources in recent years,easy,fast,and accurate text processing has become a challenge with significant payoffs.Automatic text summarization is the process of compressing text documents into shorter summaries for easier review of its core contents,which must be done without losing important features and information.This paper introduces a new hybrid method for extractive text summarization with feature selection based on text structure.The major advantage of the proposed summarization method over previous systems is the modeling of text structure and relationship between entities in the input text,which improves the sentence feature selection process and leads to the generation of unambiguous,concise,consistent,and coherent summaries.The paper also presents the results of the evaluation of the proposed method based on precision and recall criteria.It is shown that the method produces summaries consisting of chains of sentences with the aforementioned characteristics from the original text.
文摘Erythromycin thiocyanate is widely used for the production of other macrolide antibiotics. In this work, a novel heterosolvate of this pharmaceutical compound has been obtained and characterized for the first time, which was transformed from the dihydrate form in the acetone solvent through evaporation crystallization. Thermal behavior together with compositional analysis revealed that both water and acetone molecules participated in the formation of the crystal lattice which is rarely reported before. The general chemical name of the heterosolvate may be defined as erythromycin thiocyanate sesquihydrate hemiacetonate. Furthermore, studies on solid-state spectral analysis provided strong evidence of intermolecular hydrogen bonds in heterosolvate crystals. According to the crystal structure determined by single crystal X-ray diffraction, the formation mechanism of the heterosolvate is proposed in which strong multihydrogen bondings between water and solute molecules form the layer structure. While acetone molecules form single-hydrogen bonds with solutes and reside in channels between layers. This well explains why acetone solvent is easy to escape from the crystal structure during desolvation.
基金Supported by the Thailand Research Fund under Grant No TRG5880097
文摘The local structure of an alternative Pb(Zn1/3Nb2/3)O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb(Zn1/3Nb2/3)O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaTiO33 perovskite phase stabilizer. Then, x-ray absorption spectroscopy and density functional theory are employed to calculate the local structure configuration and formation energy of the prepared samples. Ba2+ is found to replace Pb2+ in AA-site with Zn2+ occupying BB-site in Pb(Zn1/3Nb2/3)O3, while in the neighboring structure, Ti4+4+ replaces Nb5+5+ in BB-site with Pb2+2+ occupying AA-site. With the substitution of BaTiO33 in Pb(Zn1/3Nb2/3)O3, the bond length between Zn2+ and Pb2+ is longer than that of the typical perovskite phase of Pb(Zn1/3Nb2/3)O3. This indicates the key role of BaTiO33 in decreasing the steric hindrance of Pb2+ lone pair, and the mutual interactions between Pb2+ lone pair and Zn2+ and the formation energy is seen to decrease. This finding of the formation energy and local structure configuration relationship can further extend a fundamental understanding of the role of BaTiO33 in stabilizing the perovskite phase in PbZn13Nb23O3-based materials, which in turn will lead to an improved preparation technique for desired electrical properties.
基金This work was financially supported by the Natural Science Foundation of Fujian Province (No. K03007)
文摘Standard mica was used to correct the X-ray powder diffraction instrument error and mathematic methods were employed to find the correction equation. By analyzing mullite sample and comparing the corrected and uncorrected analysis results we found the former is obviously more reasonable. So the conclusion is that the X-ray powder diffraction instrument error greatly affects the crystalline structure analysis, and the above method is convenient and effective for the correction of instrument error.
基金supported by NSFC projects(21203095)China Postdoctoral Science Foundation Projects(2012M511261)Jiangsu Colleges and Universities Advantage Discipline Construction projects
文摘The crystal structure of a solid electrolyte, beta-A12O3, was investigated by XRD analysis and demonstrated by Diamond software. Its chemical formula was verified by the Ag ion molten salt exchange method and X-ray fluorescence analysis (XRF). The chemical formula of β- A12O3 is Na2O·8.52A12O3, and its crystal is of hexagonal, space group P63/mmc, with a = 5.5941 A and c = 22.5300 A. The chemical formula of β-Al20 is Na2O·6.03A12O3, and its crystal is of trigonal, space group R3m, with a = 5.6017 A and c = 33.6219 A. The maximum span in the sodion migration of β-phase (2.4283 A) is only about a third of that for the β-phase (6.9037 A), so the β-phase has higher ionic conductivity than the r-phase.
基金National Natural Science Foundation of China (No.60374071)
文摘Human's real life is within a colorful world. Compared to the gray images, color images contain more information and have better visual effects. In today's digital image processing, image segmentation is an important section for computers to "understand" images and edge detection is always one of the most important methods in the field of image segmentation. Edges in color images are considered as local discontinuities both in color and spatial domains. Despite the intensive study based on integration of single-channel edge detection results, and on vector space analysis, edge detection in color images remains as a challenging issue.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.61802275 and U1836214)the Innovation fund of Tianjin University(2020XRG-0022).
文摘With the increasing popularity of mobile devices and the wide adoption of mobile Apps,an increasing concern of privacy issues is raised.Privacy policy is identified as a proper medium to indicate the legal terms,such as the general data protection regulation(GDPR),and to bind legal agreement between service providers and users.However,privacy policies are usually long and vague for end users to read and understand.It is thus important to be able to automatically analyze the document structures of privacy policies to assist user understanding.In this work we create a manually labelled corpus containing 231 privacy policies(of more than 566,000 words and 7,748 annotated paragraphs).We benchmark our data corpus with 3 document classification models and achieve more than 82%on F1-score.
基金supported by grants from the National Key R&D Program of China(2019YFC1606701)。
文摘Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.
基金National Natural Science Fund of China under Nos.52168072 and 51808467High-level Talents Support Plan of Yunnan Province of China(2020)。
文摘At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.
文摘Structural analysis problems can be formulized as either root finding problems,or optimization problems.The general practice is to choose the first option directly or to convert the second option again to a root finding problem by taking relevant derivatives and equating them to zero.The second alternative is used very randomly as it is and only for some simple demonstrative problems,most probably due to difficulty in solving optimization problems by classical methods.The method called TPO/MA(Total Potential Optimization using Metaheuristic Algorithms)described in this study successfully enables to handle structural problems with optimization formulation.Using metaheuristic algorithms provides additional advantages in dealing with all kinds of constraints.
基金Supported by Langfang Teachers College Research Grant(LSZB200803)~~
文摘[Objective] The study was to analyze the structure and function of HpaGXoo and the relationship between the two.[Method] Some related bioinformatics analysis software on internet such as NPSA,Swiss-Model,SAPS and InterPro Scan were adopted to analyze the structure and predict its function.[Result] HpaGXoo consists of 139 amino acids,and has many alpha-helical and coiled structure,no signal peptide on N-terminal and no transmembrane structure.It locates in bacterial cytoplasm.[Conclusion] The study will lay ...
基金Supported by the China Agriculture Research System(CARS-28)the Project of the Science and Technology Department of Hebei Province(11220104D-1)~~
文摘To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "Fuji", free spindle long shoot "Fuji", free spindle "Huaguan" were investigated in Xingtang County of Hebei Province by SPSS analysis. The results showed that the stem taperingness on free spindle short shoot "Fuji" was in negative correlation with central shaft, but the correlation was not significant. While the stem taperingness on free spindle long shoot "Fuji" was in positive correlation with central shaft, but the correlation was not significant either. The stern taperingness on free spindle "Huaguan" was in negative correlation with central shaft, and the correlation between the stem taperingness and the central shaft total length was significant at the level of 0.01. The results.provided scientific theoretical basis for guiding the dwarfing rootstocks close planting apple tree pruning technology.
基金Supported by the National Key Basic Research and Development (973) Program of China (No. 2006CB303106)the Specialized Research Fund for the Doctoral Program of Higher Education of MOE, P.R.C. (No. 20060003057)and the Basic Research Foun-dation of Tsinghua National Laboratory for Information Science and Technology (TNList)
文摘Video structure analysis is a basic requirement for most content-based video editing and processing systems. This paper presents a fast video structure analysis method based on image segmentation in each frame, with region matching between frames. The structure analysis decomposes the video into several moving objects, including information about their colors, positions, shapes, movements, and lifetimes. The method also supports user interactions to improve the results. The result shows that this method is fast and stable and can complete video analyzinq interactivelv.
基金This project is supported by the National Natural Science Foundation of China
文摘In order to explore the nonlinear structure hidden in high-dimensional data, some dimen-sion reduction techniques have been developed, such as the Projection Pursuit technique (PP).However, PP will involve enormous computational load. To overcome this, an inverse regressionmethod is proposed. In this paper, we discuss and develop this method. To seek the interestingprojective direction, the minimization of the residual sum of squares is used as a criterion, andspline functions are applied to approximate the general nonlinear transform function. The algo-rithm is simple, and saves the computational load. Under certain proper conditions, consistencyof the estimators of the interesting direction is shown.
基金supported by the National Natural Science Foundation of China(11202056)the Fundamental Research Funds for the Central Universities(HEUCFQ20150305)
文摘The band gap structures by arranging hybrid shunted piezoelectric materialswith resistance inductive (RL) circuit and negative impedance converter (NIC) closely and at in- tervals are presented. The theoretical model is built using transfer matrix method. Then the MATLAB computing language is utilized to simulate the band gap structures. Meanwhile, the effects of the resistance, inductance and capacitance on the local resonant gap are studied. By comparing different combinations of resistance, inductance and capacitance as well as different arrangement of circuits, a 13 kHz band gap is reached under the effect of arranging hybrid pe- riodic shunted piezoelectric patches at intervals and the stability of the system is also analyzed. It is proved that utilizing hybrid shunted piezoelectric patches would have a clear impact on the band gap structure of phononic crystal rods. Moreover, the band gap would be clearly enlarged by arranging hybrid piezoelectric patches at intervals.
基金Project supported by the National Natural Science Foundation of China(Grant No.11404008)the Innovation Training Program for College Students of Shanxi Province of China(Grant No.S201910721061)the Innovation Training Program for College Students of Baoji University of Arts and Sciences(Grant No.20191XJ087)。
文摘Bimetallic clusters have aroused tremendous interest because the property changes like structure,size,and composition have occurred.Herein,a structural search of the global minimum for anionic LiMg_(n)^(-)(n=2-11) clusters is performed using an efficient crystal structure analysis by particle swarm optimization(CALYPSO) structural searching program with subsequent density functional theory(DFT) calculations.A great variety of low energetic isomers are converged,and the most stable ones are confirmed by comparing their total energy of each size.It is found that the LiMg_(n)^(-)clusters are structurally consistent with corresponding Mg clusters anions except for LiMg_(5)^(-)and LiMg_(7)^(-).In all the doped clusters,the Li atom prefers to occupy the convex position.Simulated photoelectron spectra(PES),Infrared(IR),and Raman spectra of LiMg_(n)^(-)could be used as an essential evidence for identifying cluster structures experimentally in the future.Stability study reveals that a tower-like structure of LiMg_(9)^(-)has prominent stability and can be identified as a magic number cluster.The reason might be that there are both closed-shell 1S^(2)1P^(6)1D^(10)2S^(2) electronic configurations and stronger Li-Mg bonds caused by sp hybridization in the LiMg_(9)^(-)cluster.