Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely comme...Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.展开更多
Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in biblio...Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in bibliometrics, Sustainability(a journal outside the discipline) and Scientometrics, the flagship journal in the field.Design/methodology/approach: The study identifies the need for developing tailored tools for improving the quality of thematic bibliometric analyses, and presents a framework that can guide the development of such tools. A total of 508 papers are analysed, 77% of Sustainability, and 23% published in Scientometrics, for the 2019-2021 period.Findings: An average of 2.6 shortcomings per paper was found for the whole sample, with an almost identical number of flaws in both journals. Sustainability has more flaws than Scientometrics in four of the seven parameters studied, while Scientometrics has more shortcomings in the remaining three variables.Research limitations: The first limitation of this work is that it is a study of two scientific journals, so the results cannot be directly extrapolated to the set of thematic bibliometric analyses published in journals from all fields.Practical implications: We propose the adoption of protocols, guidelines, and other similar tools, adapted to bibliometric practice, which could increase the thoroughness, transparency, and reproducibility of this type of research.Originality/value: These results show considerable room for improvement in terms of the adequate use and breakdown of methodological procedures in thematic bibliometric research, both in journals in the Information Science area and journals outside the discipline.展开更多
In this research,mechanical stress,static strain and deformation analyses of a cylindrical pressure vessel subjected to mechanical loads are presented.The kinematic relations are developed based on higherorder sinusoi...In this research,mechanical stress,static strain and deformation analyses of a cylindrical pressure vessel subjected to mechanical loads are presented.The kinematic relations are developed based on higherorder sinusoidal shear deformation theory.Thickness stretching formulation is accounted for more accurate analysis.The total transverse deflection is divided into bending,shear and thickness stretching parts in which the third term is responsible for change of deflection along the thickness direction.The axisymmetric formulations are derived through principle of virtual work.A parametric study is presented to investigate variation of stress and strain components along the thickness and longitudinal directions.To explore effect of thickness stretching model on the static results,a comparison between the present results with the available results of literature is presented.As an important output,effect of micro-scale parameter is studied on the static stress and strain distribution.展开更多
A new microelement method for the analyses of functionally graded structures was proposed. The key of this method is the maneuverable combination of two kinds of elements. Firstly, the macro elements are divided from ...A new microelement method for the analyses of functionally graded structures was proposed. The key of this method is the maneuverable combination of two kinds of elements. Firstly, the macro elements are divided from the functionally graded material structures by the normal finite elements. In order to reflect the functionally graded distributions of materials and the microconstitutions in each macro-element, the microelement method sets up the dense microelements in every macro-element, and translates nodes to the same as the normal finite elements by the degrees of freedom of all microelemental the compatibility conditions. This microelement method can fully reflect the micro constitutions and different components of materials, and its computational elements are the same as the normal finite elements, so it is an effective numerical method for the analyses of the functionally graded material structures. The three-dimensional analyses of functionally graded plates with medium components and different micro net structures are given by using the microelement method in this paper. The differences of the stress contour in the plane of functionally graded plates with different net microstructures are especially given in this paper.展开更多
Although tourism marketing has made great progress in recent years,researches on it are far from enough.Current re searches on tourism marketing at home and abroad lack pertinence and mostly provide theoretical basis ...Although tourism marketing has made great progress in recent years,researches on it are far from enough.Current re searches on tourism marketing at home and abroad lack pertinence and mostly provide theoretical basis for tourism development within a wide range.The researches on tourism marketing of Penglai are few and far between.Based on previous studies and the status quo of tourism marketing strategy,the below statements tries to find out existing problems of Penglai's tourism,put for ward countermeasures and propose feasible marketing patterns suitable for its tourism development.It subsequently concludes that it can make contribution to the sustainable development of Penglai's tourism and provide other county-level tourism cities with reference for marketing tourism marketing strategies.展开更多
Oral squamous cell carcinoma(OSCC) is the most prevalent and most commonly studied oral cancer. However, there is a void regarding the role that the oral microbiome may play in OSCC. Although the relationship between ...Oral squamous cell carcinoma(OSCC) is the most prevalent and most commonly studied oral cancer. However, there is a void regarding the role that the oral microbiome may play in OSCC. Although the relationship between microbial community composition and OSCC has been thoroughly investigated, microbial profiles of the human microbiome in cancer are understudied. Here we performed a small pilot study of community-wide metatranscriptome analysis to profile mRNA expression in the entire oral microbiome in OSCC to reveal molecular functions associated with this disease. Fusobacteria showed a statistically significantly higher number of transcripts at tumour sites and tumour-adjacent sites of cancer patients compared to the healthy controls analysed. Regardless of the community composition, specific metabolic signatures were consistently found in disease. Activities such as iron ion transport, tryptophanase activity, peptidase activities and superoxide dismutase were over-represented in tumour and tumour-adjacent samples when compared to the healthy controls. The expression of putative virulence factors in the oral communities associated with OSCC showed that activities related to capsule biosynthesis, flagellum synthesis and assembly, chemotaxis, iron transport, haemolysins and adhesins were upregulated at tumour sites. Moreover, activities associated with protection against reactive nitrogen intermediates, chemotaxis, flagellar and capsule biosynthesis were also upregulated in non-tumour sites of cancer patients. Although they are preliminary, our results further suggest that Fusobacteria may be the leading phylogenetic group responsible for the increase in expression of virulence factors in the oral microbiome of OSCC patients.展开更多
In this paper, novel mathematical expressions are derived for the Global Positioning System (GPS) receiver interference tolerance in the presence of different types of interference signals such as: continuous wave int...In this paper, novel mathematical expressions are derived for the Global Positioning System (GPS) receiver interference tolerance in the presence of different types of interference signals such as: continuous wave interference, narrowband interference, partial band interference, broadband interference, match spectrum interference and pulse interference. Also, in this paper the mean time to loss lock is determined in order to analyse the mentioned interferences effect on the GPS receiver. These derived analytical expressions are validated with the aid of extensive simulation experiments.展开更多
The ultimate goal of single-cell analyses is to obtain the biomolecular content for each cell in unicellular and multicellular organisms at different points of their life cycle under variable environmental conditions....The ultimate goal of single-cell analyses is to obtain the biomolecular content for each cell in unicellular and multicellular organisms at different points of their life cycle under variable environmental conditions.These require an assessment of:a)the total number of cells,b)the total number of cell types,and c)the complete and quantitative single molecular detection and identification for all classes of biopolymers,and organic and inorganic compounds,in each individual cell.For proteins,glycans,lipids,and metabolites,whose sequences cannot be amplified by copying as in the case of nucleic acids,the detection limit by mass spectrometry is about 105 molecules.Therefore,proteomic,glycomic,lipidomic,and metabolomic analyses do not yet permit the assembly of the complete single-cell omes.The construction of novel nanoelectrophoretic arrays and nano in microarrays on a single 1-cm-diameter chip has shown proof of concept for a high throughput platform for parallel processing of thousands of individual cells.Combined with dynamic secondary ion mass spectrometry,with 3D scanning capability and lateral resolution of 50 nm,the sensitivity of single molecular quantification and identification for all classes of biomolecules could be reached.Further development and routine application of such technological and instrumentation solution would allow assembly of complete omes with a quantitative assessment of structural and functional cellular diversity at the molecular level.展开更多
In order to push the grating-based phase contrast imaging system to be used in hospitM and laboratories, this paper designs and develops a novel structure of x-ray scintillator functioning also as an analyser grating,...In order to push the grating-based phase contrast imaging system to be used in hospitM and laboratories, this paper designs and develops a novel structure of x-ray scintillator functioning also as an analyser grating, which has been proposed for grating-based x-ray differential phase contrast imaging. According to this design, the scintillator should have a periodical structure in one dimension with the pitch equaling the period of self-image of the phase grating at the Talbot distance, where one half of the pitch is pixellated and is made of x-ray sensitive fluorescent material, such as CsI(T1), and the remaining part of the pitch is made of x-ray insensitive material, such as silicon. To realize the design, a deep pore array with a high aspect ratio and specially designed grating pattern are successfully manufactured on 5 inch silicon wafer by the photo-assisted electrochemical etching method. The related other problems, such as oxidation-caused geometrical distortion, the filling of CsI(T1) into deep pores and the removal of inside bubbles, have been overcome. Its pixel size, depth and grating pitch are 3 p.m^7.5 ~m, 150 p^m and 3 Ixm, respectively. The microstructure of the scintillator has been examined microscopically and macroscopically by scanning electron microscope and x-ray resolution chart testing, respectively. The preliminary measurements have shown that the proposed scintillator, also functioning as an analyser grating, has been successfully designed and developed.展开更多
Heat exchangers are widely used in industry, and analyses and optimizations of the performance of heat exchangers are important topics. In this paper, we define the concept of entropy resistance based on the entropy g...Heat exchangers are widely used in industry, and analyses and optimizations of the performance of heat exchangers are important topics. In this paper, we define the concept of entropy resistance based on the entropy generation analyses of a one-dimensional heat transfer process. With this concept, a two-stream parallel flow heat exchanger with viscous heating is analyzed and discussed. It is found that the minimization of entropy resistance always leads to the maximum heat transfer rate for the discussed two-stream parallel flow heat exchanger, while the minimizations of entropy generation rate, entropy generation numbers, and revised entropy generation number do not always.展开更多
In this paper,based on the generalized heat transfer law,an air conditioning system is analyzed with the entropy generation minimization and the entransy theory.Taking the coefficient of performance(denoted as COP) ...In this paper,based on the generalized heat transfer law,an air conditioning system is analyzed with the entropy generation minimization and the entransy theory.Taking the coefficient of performance(denoted as COP) and heat flow rate Qout which is released into the room as the optimization objectives,we discuss the applicabilities of the entropy generation minimization and entransy theory to the optimizations.Five numerical cases are presented.Combining the numerical results and theoretical analyses,we can conclude that the optimization applicabilities of the two theories are conditional.If Qout is the optimization objective,larger entransy increase rate always leads to larger Qout,while smaller entropy generation rate does not.If we take COP as the optimization objective,neither the entropy generation minimization nor the concept of entransy increase is always applicable.Furthermore,we find that the concept of entransy dissipation is not applicable for the discussed cases.展开更多
The water cooled ceramic breeder(WCCB) blanket employing pressurized water as a coolant is one of the breeding blanket candidates for the China Fusion Engineering Test Reactor(CFETR).Some updating of neutronics an...The water cooled ceramic breeder(WCCB) blanket employing pressurized water as a coolant is one of the breeding blanket candidates for the China Fusion Engineering Test Reactor(CFETR).Some updating of neutronics analyses was needed, because there were changes in the neutronics performance of the blanket as several significant modifications and improvements have been adopted for the WCCB blanket, including the optimization of radial build-up and customized structure for each blanket module. A 22.5 degree toroidal symmetrical torus sector 3 D neutronics model containing the updated design of the WCCB blanket modules was developed for the neutronics analyses. The tritium breeding capability, nuclear heating power, radiation damage,and decay heat were calculated by the MCNP and FISPACT code. The results show that the packing factor and^6 Li enrichment of the breeder should both be no less than 0.8 to ensure tritium self-sufficiency. The nuclear heating power of the blanket under 200 MW fusion power reaches201.23 MW. The displacement per atom per full power year(FPY) of the plasma-facing component and first wall reach 0.90 and 2.60, respectively. The peak H production rate reaches150.79 appm/FPY and the peak He production reaches 29.09 appm/FPY in blanket module #3.The total decay heat of the blanket modules is 2.64 MW at 1 s after shutdown and the average decay heat density can reach 11.09 kW m^(-3) at that time. The decay heat density of the blanket modules slowly decreases to lower than 10 W m^(-3) in more than ten years.展开更多
-On the basis of the data of geophysics and seismic activities, the analyses of the active faults, seismic activities and the sea floor unstable factors of the Zhujiang River Mouth Basin have been made so as to study ...-On the basis of the data of geophysics and seismic activities, the analyses of the active faults, seismic activities and the sea floor unstable factors of the Zhujiang River Mouth Basin have been made so as to study the characteristics of the compressional subactive continental margin of Cathaysian system, arc littoral strongly active fracture zone, the division of seismic subzone and seismic zone of the continental margin of northern South China Sea, the potential focal area, and to analyze the regional stability. We consider that the Zhujiang River Mouth Basin belongs to a stable or a moderately stable region.展开更多
An abundance of data from seismic and geodetic monitoring has provided new insight into dyke propagation and emplacement mechanisms.These studies show that faulting and fracturing is part of the magma
Zokors in the genus Eospalax,which are endemic to northern and western China,are subterranean rodents that inhabit various niches,including grasslands,high-altitude meadows,forests,and farmlands.Six species in Eospala...Zokors in the genus Eospalax,which are endemic to northern and western China,are subterranean rodents that inhabit various niches,including grasslands,high-altitude meadows,forests,and farmlands.Six species in Eospalax were described a century ago but their taxonomy and phylogeny remain controversial.In this study,we performed high-depth whole-genome sequencing of 47 zokor samples,comprising all six previously described species.Genomic analyses revealed a reliable and robust phylogeny of Eospalax and supported the validity of the six named species.According to the inferred phylogenetic relationships,Eospalax first divergent into two clades in the early Pliocene(ca.4.68 million years ago(Ma)),one inhabiting the highaltitude Qinghai-Xizang(Tibet)Plateau(QTP)and adjacent regions,and the another inhabiting the lowaltitude Loess Plateau and Qinling-Daba Mountains.The most recent divergences occurred between E.baileyi and E.smithii and between E.rufescens and E.rothschildi in the late Pliocene(ca.2.09 and 2.19 Ma,respectively).We also collected specimens of zokors in the southern Hengduan Mountains(Muli County,Sichuan Province),far from the known distributions of all other zokors.Morphological and molecular analyses strongly suggested that the specimens represent a new species,formally described here as Eospalax muliensis sp.nov.The new species belongs to the high-altitude clade and diverged from closely related species(ca.4.22 Ma)shortly after the first divergence in Eospalax.Interestingly,Eospalax muliensis sp.nov.possesses more supposedly plesiomorphic characters,suggesting a possible origin of the genus in the Hengduan Mountains.展开更多
In this paper the differences between Meiyu and Baiu front in 1983 have firstly been analysed, the trajectories of air on and to the north side of Meiyu and Baiu fronts during the Meiyu period have then been traced, a...In this paper the differences between Meiyu and Baiu front in 1983 have firstly been analysed, the trajectories of air on and to the north side of Meiyu and Baiu fronts during the Meiyu period have then been traced, and the forecasting and simulating of 4 sets of Meiyu onset of the year have finally been run utilizing the global model at UK Me-leorological Office. The results show: 1) Meiyu fronts are different from Baiu ones in temperature, humidity and stratification fields in lower atmosphere; and the possibly reasons for it are explained. 2) The Bay of Bengal is the main moisture source for Meiyu front, the South China Sea and the Pacific, for Baiu ones; and some existed arguments on it are also discussed. 3) The onset of Meiyu and its rainfall and rain belts are sensitive to the Tibetan Plateau, and the water vapour conditions over the Bay of Bengal and the South China Sea, but not sensitive to the SST over the equatorial area or to the East of Japan.展开更多
Kanas is a National Nature Reserve and National 5A Scenic Area,and it is also high on China’s National Natural Heritage List. In this paper,with an integrated analysis and comparative geo-graphical approach,the genes...Kanas is a National Nature Reserve and National 5A Scenic Area,and it is also high on China’s National Natural Heritage List. In this paper,with an integrated analysis and comparative geo-graphical approach,the genesis and current features of the Kanas landscape are analyzed systematically according to the criteria for outstanding universal values that must be met for designation by the United Nations as World Natural Heritage. It is concluded that Kanas has outstanding universal values in geosciences,biology and aesthetics. Through comparison with other World Natural Heritage sites of the same geological types,in the same biogeographic zone and in the same latitude,it is concluded that Kanas meets criteria vii,viii,ix and x for designation as World Natural Heritage. Thus,this work establishes a scientific foundation for nomination of Kanas for such a status.展开更多
Gene spectrum analysis has shown that gene expression and signaling pathways change dramatically after spinal cord injury,which may affect the microenvironment of the damaged site.Microarray analysis provides a new op...Gene spectrum analysis has shown that gene expression and signaling pathways change dramatically after spinal cord injury,which may affect the microenvironment of the damaged site.Microarray analysis provides a new opportunity for investigating diagnosis,treatment,and prognosis of spinal cord injury.However,differentially expressed genes are not consistent among studies,and many key genes and signaling pathways have not yet been accurately studied.GSE5296 was retrieved from the Gene Expression Omnibus DataSet.Differentially expressed genes were obtained using R/Bioconductor software(expression changed at least two-fold;P < 0.05).Database for Annotation,Visualization and Integrated Discovery was used for functional annotation of differentially expressed genes and Animal Transcription Factor Database for predicting potential transcription factors.The resulting transcription regulatory protein interaction network was mapped to screen representative genes and investigate their diagnostic and therapeutic value for disease.In total,this study identified 109 genes that were upregulated and 30 that were downregulated at 0.5,4,and 24 hours,and 3,7,and 28 days after spinal cord injury.The number of downregulated genes was smaller than the number of upregulated genes at each time point.Database for Annotation,Visualization and Integrated Discovery analysis found that many inflammation-related pathways were upregulated in injured spinal cord.Additionally,expression levels of these inflammation-related genes were maintained for at least 28 days.Moreover,399 regulation modes and 77 nodes were shown in the protein-protein interaction network of upregulated differentially expressed genes.Among the 10 upregulated differentially expressed genes with the highest degrees of distribution,six genes were transcription factors.Among these transcription factors,ATF3 showed the greatest change.ATF3 was upregulated within 30 minutes,and its expression levels remained high at28 days after spinal cord injury.These key genes screened by bioinformatics tools can be used as biological markers to diagnose diseases and provide a reference for identifying therapeutic targets.展开更多
Ultrasonic welding is an effective ways to achieve a non-reactive/immiscible heterogeneous metal connection, such as the connection of magnesium alloy and titanium alloy. But the thermal mechanism of magnesium alloy/t...Ultrasonic welding is an effective ways to achieve a non-reactive/immiscible heterogeneous metal connection, such as the connection of magnesium alloy and titanium alloy. But the thermal mechanism of magnesium alloy/titanium alloy ultrasonic welding has not been defined clearly. In this paper, the experimental and the finite element analysis were adopted to study the thermal mechanism during welding. Through the test, the temperature variation law during the welding process is obtained, and the accuracy of the finite element model is verified. The microscopic analysis indicates that at the welding time of 0.5 s, the magnesium alloy in the center of the solder joint is partially melted and generates the liquid phase. Through the finite element analysis, the friction coefficient of the magnesium–titanium ultrasonic welding interface can be considered as an average constant value of 0.28. The maximum temperature at the interface can exceed 600 ℃ to reach the melting point temperature of the magnesium alloy. The plastic deformation begins after 0.35 s and occurs at the magnesium side at the center of the interface.展开更多
Aluminum ablation by multiple femtosecond laser pulses is investigated via time-resolved shadowgraphs and scanning electron microscope (SEM) images of the ablation spot. The spatial distribution of the ejected mater...Aluminum ablation by multiple femtosecond laser pulses is investigated via time-resolved shadowgraphs and scanning electron microscope (SEM) images of the ablation spot. The spatial distribution of the ejected material and the radius of the shock wave generated during the ablation are found to vary with the increase in the number of pulses. In the initial two pulses, nearly concentric and semicircular stripes within the shock wave front are observed, unlike in subsequent pulses. Ablation by multiple femtosecond pulses exhibits different characteristics compared with the case induced by single femtosecond pulse because of the changes to the aluminum target surface induced by the preceding pulses.展开更多
基金This work was supported by the National Natural Science Foundation of China(52203066,51973157,61904123)the Tianjin Natural Science Foundation(18JCQNJC02900)+3 种基金the National innovation and entrepreneurship training program for college students(202310058007)the Tianjin Municipal college students’innovation and entrepreneurship training program(202310058088)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(Grant No.2018KJ196)the State Key Laboratory of Membrane and Membrane Separation,Tiangong University.
文摘Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.
文摘Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in bibliometrics, Sustainability(a journal outside the discipline) and Scientometrics, the flagship journal in the field.Design/methodology/approach: The study identifies the need for developing tailored tools for improving the quality of thematic bibliometric analyses, and presents a framework that can guide the development of such tools. A total of 508 papers are analysed, 77% of Sustainability, and 23% published in Scientometrics, for the 2019-2021 period.Findings: An average of 2.6 shortcomings per paper was found for the whole sample, with an almost identical number of flaws in both journals. Sustainability has more flaws than Scientometrics in four of the seven parameters studied, while Scientometrics has more shortcomings in the remaining three variables.Research limitations: The first limitation of this work is that it is a study of two scientific journals, so the results cannot be directly extrapolated to the set of thematic bibliometric analyses published in journals from all fields.Practical implications: We propose the adoption of protocols, guidelines, and other similar tools, adapted to bibliometric practice, which could increase the thoroughness, transparency, and reproducibility of this type of research.Originality/value: These results show considerable room for improvement in terms of the adequate use and breakdown of methodological procedures in thematic bibliometric research, both in journals in the Information Science area and journals outside the discipline.
文摘In this research,mechanical stress,static strain and deformation analyses of a cylindrical pressure vessel subjected to mechanical loads are presented.The kinematic relations are developed based on higherorder sinusoidal shear deformation theory.Thickness stretching formulation is accounted for more accurate analysis.The total transverse deflection is divided into bending,shear and thickness stretching parts in which the third term is responsible for change of deflection along the thickness direction.The axisymmetric formulations are derived through principle of virtual work.A parametric study is presented to investigate variation of stress and strain components along the thickness and longitudinal directions.To explore effect of thickness stretching model on the static results,a comparison between the present results with the available results of literature is presented.As an important output,effect of micro-scale parameter is studied on the static stress and strain distribution.
基金supported by the National Natural Science Foundation of China (No.10432030)the National Youth Science Foundation of China (No.10802091)the Scientific and Technical Foundation of China University of Mining and Technology (No.2007B013)
文摘A new microelement method for the analyses of functionally graded structures was proposed. The key of this method is the maneuverable combination of two kinds of elements. Firstly, the macro elements are divided from the functionally graded material structures by the normal finite elements. In order to reflect the functionally graded distributions of materials and the microconstitutions in each macro-element, the microelement method sets up the dense microelements in every macro-element, and translates nodes to the same as the normal finite elements by the degrees of freedom of all microelemental the compatibility conditions. This microelement method can fully reflect the micro constitutions and different components of materials, and its computational elements are the same as the normal finite elements, so it is an effective numerical method for the analyses of the functionally graded material structures. The three-dimensional analyses of functionally graded plates with medium components and different micro net structures are given by using the microelement method in this paper. The differences of the stress contour in the plane of functionally graded plates with different net microstructures are especially given in this paper.
文摘Although tourism marketing has made great progress in recent years,researches on it are far from enough.Current re searches on tourism marketing at home and abroad lack pertinence and mostly provide theoretical basis for tourism development within a wide range.The researches on tourism marketing of Penglai are few and far between.Based on previous studies and the status quo of tourism marketing strategy,the below statements tries to find out existing problems of Penglai's tourism,put for ward countermeasures and propose feasible marketing patterns suitable for its tourism development.It subsequently concludes that it can make contribution to the sustainable development of Penglai's tourism and provide other county-level tourism cities with reference for marketing tourism marketing strategies.
基金supported by the Evans Center for Interdisciplinary Biomedical Research ARC on ‘Oral microbiome in AhR activation and oral cancer development and progression’ at Boston University (http://www.bumc.bu.edu/evanscenteribr/)the Forsyth Institute pilot grant programme
文摘Oral squamous cell carcinoma(OSCC) is the most prevalent and most commonly studied oral cancer. However, there is a void regarding the role that the oral microbiome may play in OSCC. Although the relationship between microbial community composition and OSCC has been thoroughly investigated, microbial profiles of the human microbiome in cancer are understudied. Here we performed a small pilot study of community-wide metatranscriptome analysis to profile mRNA expression in the entire oral microbiome in OSCC to reveal molecular functions associated with this disease. Fusobacteria showed a statistically significantly higher number of transcripts at tumour sites and tumour-adjacent sites of cancer patients compared to the healthy controls analysed. Regardless of the community composition, specific metabolic signatures were consistently found in disease. Activities such as iron ion transport, tryptophanase activity, peptidase activities and superoxide dismutase were over-represented in tumour and tumour-adjacent samples when compared to the healthy controls. The expression of putative virulence factors in the oral communities associated with OSCC showed that activities related to capsule biosynthesis, flagellum synthesis and assembly, chemotaxis, iron transport, haemolysins and adhesins were upregulated at tumour sites. Moreover, activities associated with protection against reactive nitrogen intermediates, chemotaxis, flagellar and capsule biosynthesis were also upregulated in non-tumour sites of cancer patients. Although they are preliminary, our results further suggest that Fusobacteria may be the leading phylogenetic group responsible for the increase in expression of virulence factors in the oral microbiome of OSCC patients.
文摘In this paper, novel mathematical expressions are derived for the Global Positioning System (GPS) receiver interference tolerance in the presence of different types of interference signals such as: continuous wave interference, narrowband interference, partial band interference, broadband interference, match spectrum interference and pulse interference. Also, in this paper the mean time to loss lock is determined in order to analyse the mentioned interferences effect on the GPS receiver. These derived analytical expressions are validated with the aid of extensive simulation experiments.
文摘The ultimate goal of single-cell analyses is to obtain the biomolecular content for each cell in unicellular and multicellular organisms at different points of their life cycle under variable environmental conditions.These require an assessment of:a)the total number of cells,b)the total number of cell types,and c)the complete and quantitative single molecular detection and identification for all classes of biopolymers,and organic and inorganic compounds,in each individual cell.For proteins,glycans,lipids,and metabolites,whose sequences cannot be amplified by copying as in the case of nucleic acids,the detection limit by mass spectrometry is about 105 molecules.Therefore,proteomic,glycomic,lipidomic,and metabolomic analyses do not yet permit the assembly of the complete single-cell omes.The construction of novel nanoelectrophoretic arrays and nano in microarrays on a single 1-cm-diameter chip has shown proof of concept for a high throughput platform for parallel processing of thousands of individual cells.Combined with dynamic secondary ion mass spectrometry,with 3D scanning capability and lateral resolution of 50 nm,the sensitivity of single molecular quantification and identification for all classes of biomolecules could be reached.Further development and routine application of such technological and instrumentation solution would allow assembly of complete omes with a quantitative assessment of structural and functional cellular diversity at the molecular level.
基金supported by the Major Program of the National Natural Science Foundation of China (Grant No. 60532090)
文摘In order to push the grating-based phase contrast imaging system to be used in hospitM and laboratories, this paper designs and develops a novel structure of x-ray scintillator functioning also as an analyser grating, which has been proposed for grating-based x-ray differential phase contrast imaging. According to this design, the scintillator should have a periodical structure in one dimension with the pitch equaling the period of self-image of the phase grating at the Talbot distance, where one half of the pitch is pixellated and is made of x-ray sensitive fluorescent material, such as CsI(T1), and the remaining part of the pitch is made of x-ray insensitive material, such as silicon. To realize the design, a deep pore array with a high aspect ratio and specially designed grating pattern are successfully manufactured on 5 inch silicon wafer by the photo-assisted electrochemical etching method. The related other problems, such as oxidation-caused geometrical distortion, the filling of CsI(T1) into deep pores and the removal of inside bubbles, have been overcome. Its pixel size, depth and grating pitch are 3 p.m^7.5 ~m, 150 p^m and 3 Ixm, respectively. The microstructure of the scintillator has been examined microscopically and macroscopically by scanning electron microscope and x-ray resolution chart testing, respectively. The preliminary measurements have shown that the proposed scintillator, also functioning as an analyser grating, has been successfully designed and developed.
基金supported by the National Natural Science Foundation of China(Grant No.51106082)the Tsinghua University Initiative Scientific Research Program
文摘Heat exchangers are widely used in industry, and analyses and optimizations of the performance of heat exchangers are important topics. In this paper, we define the concept of entropy resistance based on the entropy generation analyses of a one-dimensional heat transfer process. With this concept, a two-stream parallel flow heat exchanger with viscous heating is analyzed and discussed. It is found that the minimization of entropy resistance always leads to the maximum heat transfer rate for the discussed two-stream parallel flow heat exchanger, while the minimizations of entropy generation rate, entropy generation numbers, and revised entropy generation number do not always.
基金Project supported by the Youth Programs of Chongqing Three Gorges University,China(Grant No.13QN18)
文摘In this paper,based on the generalized heat transfer law,an air conditioning system is analyzed with the entropy generation minimization and the entransy theory.Taking the coefficient of performance(denoted as COP) and heat flow rate Qout which is released into the room as the optimization objectives,we discuss the applicabilities of the entropy generation minimization and entransy theory to the optimizations.Five numerical cases are presented.Combining the numerical results and theoretical analyses,we can conclude that the optimization applicabilities of the two theories are conditional.If Qout is the optimization objective,larger entransy increase rate always leads to larger Qout,while smaller entropy generation rate does not.If we take COP as the optimization objective,neither the entropy generation minimization nor the concept of entransy increase is always applicable.Furthermore,we find that the concept of entransy dissipation is not applicable for the discussed cases.
基金supported by the National Special Project for Magnetic Confined Nuclear Fusion Energy(Grant Nos 2013GB108004,2014GB119000,and 2015BG108002)
文摘The water cooled ceramic breeder(WCCB) blanket employing pressurized water as a coolant is one of the breeding blanket candidates for the China Fusion Engineering Test Reactor(CFETR).Some updating of neutronics analyses was needed, because there were changes in the neutronics performance of the blanket as several significant modifications and improvements have been adopted for the WCCB blanket, including the optimization of radial build-up and customized structure for each blanket module. A 22.5 degree toroidal symmetrical torus sector 3 D neutronics model containing the updated design of the WCCB blanket modules was developed for the neutronics analyses. The tritium breeding capability, nuclear heating power, radiation damage,and decay heat were calculated by the MCNP and FISPACT code. The results show that the packing factor and^6 Li enrichment of the breeder should both be no less than 0.8 to ensure tritium self-sufficiency. The nuclear heating power of the blanket under 200 MW fusion power reaches201.23 MW. The displacement per atom per full power year(FPY) of the plasma-facing component and first wall reach 0.90 and 2.60, respectively. The peak H production rate reaches150.79 appm/FPY and the peak He production reaches 29.09 appm/FPY in blanket module #3.The total decay heat of the blanket modules is 2.64 MW at 1 s after shutdown and the average decay heat density can reach 11.09 kW m^(-3) at that time. The decay heat density of the blanket modules slowly decreases to lower than 10 W m^(-3) in more than ten years.
基金This study granted by the Scientific Foundation of the China Academy of Science, is one of the stage results of the subject (R850835). A symposium of the International Petroleum Geological Conference of Northern South China Sea Continental Shelf, 1987
文摘-On the basis of the data of geophysics and seismic activities, the analyses of the active faults, seismic activities and the sea floor unstable factors of the Zhujiang River Mouth Basin have been made so as to study the characteristics of the compressional subactive continental margin of Cathaysian system, arc littoral strongly active fracture zone, the division of seismic subzone and seismic zone of the continental margin of northern South China Sea, the potential focal area, and to analyze the regional stability. We consider that the Zhujiang River Mouth Basin belongs to a stable or a moderately stable region.
文摘An abundance of data from seismic and geodetic monitoring has provided new insight into dyke propagation and emplacement mechanisms.These studies show that faulting and fracturing is part of the magma
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK05010218,2019QZKK05010110)National Natural Science Foundation of China(32100339,31871277)+2 种基金supported by the Yunling Scholar ProjectTen-Thousand Talents Plan of Yunnan Provincesupported by the Youth Innovation Promotion Association,Chinese Academy of Sciences。
文摘Zokors in the genus Eospalax,which are endemic to northern and western China,are subterranean rodents that inhabit various niches,including grasslands,high-altitude meadows,forests,and farmlands.Six species in Eospalax were described a century ago but their taxonomy and phylogeny remain controversial.In this study,we performed high-depth whole-genome sequencing of 47 zokor samples,comprising all six previously described species.Genomic analyses revealed a reliable and robust phylogeny of Eospalax and supported the validity of the six named species.According to the inferred phylogenetic relationships,Eospalax first divergent into two clades in the early Pliocene(ca.4.68 million years ago(Ma)),one inhabiting the highaltitude Qinghai-Xizang(Tibet)Plateau(QTP)and adjacent regions,and the another inhabiting the lowaltitude Loess Plateau and Qinling-Daba Mountains.The most recent divergences occurred between E.baileyi and E.smithii and between E.rufescens and E.rothschildi in the late Pliocene(ca.2.09 and 2.19 Ma,respectively).We also collected specimens of zokors in the southern Hengduan Mountains(Muli County,Sichuan Province),far from the known distributions of all other zokors.Morphological and molecular analyses strongly suggested that the specimens represent a new species,formally described here as Eospalax muliensis sp.nov.The new species belongs to the high-altitude clade and diverged from closely related species(ca.4.22 Ma)shortly after the first divergence in Eospalax.Interestingly,Eospalax muliensis sp.nov.possesses more supposedly plesiomorphic characters,suggesting a possible origin of the genus in the Hengduan Mountains.
文摘In this paper the differences between Meiyu and Baiu front in 1983 have firstly been analysed, the trajectories of air on and to the north side of Meiyu and Baiu fronts during the Meiyu period have then been traced, and the forecasting and simulating of 4 sets of Meiyu onset of the year have finally been run utilizing the global model at UK Me-leorological Office. The results show: 1) Meiyu fronts are different from Baiu ones in temperature, humidity and stratification fields in lower atmosphere; and the possibly reasons for it are explained. 2) The Bay of Bengal is the main moisture source for Meiyu front, the South China Sea and the Pacific, for Baiu ones; and some existed arguments on it are also discussed. 3) The onset of Meiyu and its rainfall and rain belts are sensitive to the Tibetan Plateau, and the water vapour conditions over the Bay of Bengal and the South China Sea, but not sensitive to the SST over the equatorial area or to the East of Japan.
基金funded by the Project of Science and Tech-nology Plan of Xinjiang Uygur Autonomous Region (200933128)the National Natural Science Foundation of China (40671057)the Chinese Academy of Sciences Visiting Professorship for Senior International Scientists (2009S1-35)
文摘Kanas is a National Nature Reserve and National 5A Scenic Area,and it is also high on China’s National Natural Heritage List. In this paper,with an integrated analysis and comparative geo-graphical approach,the genesis and current features of the Kanas landscape are analyzed systematically according to the criteria for outstanding universal values that must be met for designation by the United Nations as World Natural Heritage. It is concluded that Kanas has outstanding universal values in geosciences,biology and aesthetics. Through comparison with other World Natural Heritage sites of the same geological types,in the same biogeographic zone and in the same latitude,it is concluded that Kanas meets criteria vii,viii,ix and x for designation as World Natural Heritage. Thus,this work establishes a scientific foundation for nomination of Kanas for such a status.
基金supported by the Natural Science Foundation of Shaanxi Province of China,No.2018JQ8029(to LG)
文摘Gene spectrum analysis has shown that gene expression and signaling pathways change dramatically after spinal cord injury,which may affect the microenvironment of the damaged site.Microarray analysis provides a new opportunity for investigating diagnosis,treatment,and prognosis of spinal cord injury.However,differentially expressed genes are not consistent among studies,and many key genes and signaling pathways have not yet been accurately studied.GSE5296 was retrieved from the Gene Expression Omnibus DataSet.Differentially expressed genes were obtained using R/Bioconductor software(expression changed at least two-fold;P < 0.05).Database for Annotation,Visualization and Integrated Discovery was used for functional annotation of differentially expressed genes and Animal Transcription Factor Database for predicting potential transcription factors.The resulting transcription regulatory protein interaction network was mapped to screen representative genes and investigate their diagnostic and therapeutic value for disease.In total,this study identified 109 genes that were upregulated and 30 that were downregulated at 0.5,4,and 24 hours,and 3,7,and 28 days after spinal cord injury.The number of downregulated genes was smaller than the number of upregulated genes at each time point.Database for Annotation,Visualization and Integrated Discovery analysis found that many inflammation-related pathways were upregulated in injured spinal cord.Additionally,expression levels of these inflammation-related genes were maintained for at least 28 days.Moreover,399 regulation modes and 77 nodes were shown in the protein-protein interaction network of upregulated differentially expressed genes.Among the 10 upregulated differentially expressed genes with the highest degrees of distribution,six genes were transcription factors.Among these transcription factors,ATF3 showed the greatest change.ATF3 was upregulated within 30 minutes,and its expression levels remained high at28 days after spinal cord injury.These key genes screened by bioinformatics tools can be used as biological markers to diagnose diseases and provide a reference for identifying therapeutic targets.
基金Supported by National Natural Science Foundation of China(Grant Nos.U1764251,51775160)Fundamental Research Funds for the Central Universities of China(Grant No.DUT19LAB24)
文摘Ultrasonic welding is an effective ways to achieve a non-reactive/immiscible heterogeneous metal connection, such as the connection of magnesium alloy and titanium alloy. But the thermal mechanism of magnesium alloy/titanium alloy ultrasonic welding has not been defined clearly. In this paper, the experimental and the finite element analysis were adopted to study the thermal mechanism during welding. Through the test, the temperature variation law during the welding process is obtained, and the accuracy of the finite element model is verified. The microscopic analysis indicates that at the welding time of 0.5 s, the magnesium alloy in the center of the solder joint is partially melted and generates the liquid phase. Through the finite element analysis, the friction coefficient of the magnesium–titanium ultrasonic welding interface can be considered as an average constant value of 0.28. The maximum temperature at the interface can exceed 600 ℃ to reach the melting point temperature of the magnesium alloy. The plastic deformation begins after 0.35 s and occurs at the magnesium side at the center of the interface.
基金Project supported by the Science and Technology Development Fund Planning Project for the Universities of Tianjin,China(Grant No.20140902)the Natural Science Foundation of Tianjin City,China(Grant No.16JCQNJC01900)+1 种基金the National Natural Science Foundation of China(Grant Nos.51376136and 61474082)the Science and Technology Achievement Award Project for the Universities of Tianjin,China
文摘Aluminum ablation by multiple femtosecond laser pulses is investigated via time-resolved shadowgraphs and scanning electron microscope (SEM) images of the ablation spot. The spatial distribution of the ejected material and the radius of the shock wave generated during the ablation are found to vary with the increase in the number of pulses. In the initial two pulses, nearly concentric and semicircular stripes within the shock wave front are observed, unlike in subsequent pulses. Ablation by multiple femtosecond pulses exhibits different characteristics compared with the case induced by single femtosecond pulse because of the changes to the aluminum target surface induced by the preceding pulses.