In this work,a parametric two-dimensional computational fluid dynamics(CFD)analysis of a solar chimney power plant(a prototype located in Manzanares,Spain)is presented to illustrate the effects of the solar radiation ...In this work,a parametric two-dimensional computational fluid dynamics(CFD)analysis of a solar chimney power plant(a prototype located in Manzanares,Spain)is presented to illustrate the effects of the solar radiation mode in the collector on the plant performances.The simulations rely on a mathematical model that includes solar radiation within the collector;energy storage;air flow and heat transfer,and a turbine.It is based on the Navier-Stokes equation for turbulent flow formulated according to the standard k-εmodel.Moreover,the Boussinesq approach is used to account for the fluid density variations.Different solar radiation modes in the collector are compared and discussed.The obtained results are also compared with available experimental results.It is shown that the radiation model is essential to avoid overestimation of the energy absorbed by the plant and that results based on a two-dimensional model can resemble closely those produced by three-dimensional models.展开更多
A study was conducted to determine the genetic diversity of 39 determinate and indeterminate tomato inbred lines collected from China, Japan, S. Korea, and USA. Using 35 SSR polymorphic markers, a total of 150 alleles...A study was conducted to determine the genetic diversity of 39 determinate and indeterminate tomato inbred lines collected from China, Japan, S. Korea, and USA. Using 35 SSR polymorphic markers, a total of 150 alleles were found with moderate levels of diversity, and a high number of unique alleles existing in these tomato lines. The mean number of alleles per locus was 4.3 and the average polymorphism information content (PIC) was 0.31. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) clustering at genetic similarity value of 0.85 grouped the inbred lines into four groups, where one USA cultivar formed a separate and more distant cluster. The most similar inbred lines are from USA, both with determinate type, whereas the most different lines are from USA (Us-16) and Japan (Ja-2) with determinate and indeterminate growth habit, respectively. Clustering was consistent with the known information regarding geographical location and growth habit. The genetic distance information reported in this study might be used by breeders when planning future crosses among these inbred lines.展开更多
Icosahedral quasicrystals are the most important and thermodynamically stable in all about 200 kinds of quasicrystals currently observed. Beyond the scope of classical elasticity, apart from a phonon displacement fiel...Icosahedral quasicrystals are the most important and thermodynamically stable in all about 200 kinds of quasicrystals currently observed. Beyond the scope of classical elasticity, apart from a phonon displacement field, there is a phason displacement field in the elasticity of the quasicrystal, which induces an important effect on the mechanical properties of the material and makes an analytical solution difficult to obtain. In this paper, a finite element algorithm for the static elasticity of icosahedral quasicrystals is developed by transforming the elastic boundary value problem of the icosahedral quasicrystals into an equivalent variational problem. Analytical and numerical solutions for an icosahedral A1-Pd-Mn quasicrystal cuboid subjected to a uniaxial tension with different phonon-phason coupling parameters are given to verify the validity of the numerical approach. A comparison between the analytical and numerical solutions of the specimen demonstrates the accuracy and efficiency of the present algorithm. Finally, in order to reveal the fracture behavior of the icosahedral A1-Pd-Mn quasicrystal, a cracked specimen with a finite size of matter is investigated, both with and without phonon-phason coupling. Meanwhile, the geometry factors are calculated, including the stress intensity factor and the crack opening displacement for the finite-size specimen. Computational results reveal the importance of pbonon-phason coupling effect on the icosahedral A1-Pd-Mn quasicrystal. Furthermore, the finite element procedure can be used to solve more complicated boundary value problems.展开更多
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to ...The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.展开更多
Continuous application of organic fertilizers can cause accumulation of organic phosphorus(P)in soil,especially in the lowmolecular-weight organic phosphorus(LMWOP)forms.This organic P pool represents a potentially im...Continuous application of organic fertilizers can cause accumulation of organic phosphorus(P)in soil,especially in the lowmolecular-weight organic phosphorus(LMWOP)forms.This organic P pool represents a potentially important source of P for both plants and microorganisms.To understand the effect of long-term fertilization(30 years)(P-rich soil)vs.fallowing(P-poor soil)on the bioavailability and fate of LMWOP in subtropical paddy soils,we determined the sorption and mineralization of 14 C-labeled adenosine,adenosine monophosphate(AMP),adenosine diphosphate(ADP),and adenosine triphosphate(ATP)in each soil.The contents of carbon,nitrogen,and P in the P-rich soil were more than two times greater than those in the P-poor soil.The mineralization rates of the LMWOP compounds were faster in the P-rich soil compared to the P-poor soil,and followed the order AMP>ADP>ATP.Using sterilized soil,all forms of adenosine-P were strongly sorbed to the solid phase and reached saturation in a short time,with the adsorbance increasing with the number of phosphate groups.We concluded that the mineralization of LMWOP compounds was repressed slightly by sorption to the solid phase,but only in the short term.Thus,LMWOP compounds serve as readily available sources of C for microorganisms,making P available for themselves as well as for the plants.However,P accumulation and the progressive saturation of the P sorption sites in highly fertile soils may increase the potential risk of P runoff.展开更多
The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-s...The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-stable aggregate fractions and to study their influence on soil organic carbon (C<sub>org</sub>) content. Soil samples were taken from a forest-site, Gogerddan (G) and a semi-rural site, Hazelrigg (H) in Great Britain, from 0-2 and 2-5?cm and 0-4 and 8-12?cm soil depth, respectively. POPs analyzed were PAHs, PCBs, total DDT, PBDEs and HCB. The bulk soil analysis showed that the concentration of POPs was significantly higher (p?≤?0.05) in forest site G than in semi-rural site H, particularly at the surface soil levels compared to the subsurface soil depths in both sites. Total concentrations of PCBs and PAHs of both sites were positively correlated with C<sub>org</sub> contents. POPs concentrations and C<sub>org</sub>, N<sub>t</sub> contents of forest site G were significantly higher (p?≤?0.05) in water-stable macro aggregates (>0.25, >1, >2?mm) than the micro aggregates (>0.053?mm). The POP concentrations of all aggregate fractions after normalizing to their respective C<sub>org</sub> content were increased due higher contamination and strong sorption by C<sub>org</sub>. These results showed a strong effect of C<sub>org</sub> on the partitioning of organic pollutants to soil aggregate size fractions. The present study affirms the ecological significance of forest soils act as a potential sink of POPs. In summary, our results suggest that aggregate fractions may promote soil C storage and act as a potential POP sink in surface soil without increasing their concentration in the aggregate fraction of subsoil.展开更多
The simultaneous influence of thermal and mechanical treatment was applied to produce a geometrically complex shaft from 51CrV4 steel leading to the formation of mierostruetures which were significantly different from...The simultaneous influence of thermal and mechanical treatment was applied to produce a geometrically complex shaft from 51CrV4 steel leading to the formation of mierostruetures which were significantly different from each other. These mierostrue- rural differences were accompanied by a local change of mechanical properties in terms of hardness, electrical resistivity and especially internal friction. The Snoek-KSster peak was recognized and analyzed in the structure of this steel.展开更多
In a recent XUV photoabsorption spectrum of Cs Ⅲ ions by Cummings and O'Sullivan [2001 J. Phys. B 34 199], rather large linewidths were found for the 4d^95s^25p^6 - 4d^105s^25p^5 transition which are quite in disagr...In a recent XUV photoabsorption spectrum of Cs Ⅲ ions by Cummings and O'Sullivan [2001 J. Phys. B 34 199], rather large linewidths were found for the 4d^95s^25p^6 - 4d^105s^25p^5 transition which are quite in disagreement with corresponding quasi-relativistic multiconfiguration Hartree Fock (MCHF) calculation. In the present work, a detailed multiconfiguration Dirac-Fock study has been carried out to explore this discrepancy. Owing to the detailed consideration of electron correlation effects, some ‘forbidden' Auger decay channels, such as 4d^105s^25p^35d and 4d^105s^05p^6, would become ‘open'. As a result, remarkable improvement of the linewidths has been obtained in our calculation. Furthermore, the theoretical Auger spectrum of the 4d^ 95s^25p^6 core-excited states of Cs Ⅲ ions is Riven in the present work.展开更多
The influence of simultaneously applied mechanical and thermal treatment is used for producing a geometrically complex shaft from 51CrV4 steel resulting in widely differing formations of microstructures.Materials'...The influence of simultaneously applied mechanical and thermal treatment is used for producing a geometrically complex shaft from 51CrV4 steel resulting in widely differing formations of microstructures.Materials'properties such as internal friction(IF),hardness and electrical resistivity are affected by this change of microstructure formations.The Snoek–Koster peak is identified and analyzed in the actual steel structure.展开更多
Intracavity absorption spectroscopy is a strikingly sensitive technique that has been integrated with a two-wavelength setup to develop a sensor for human breath.Various factors are considered in such a scenario,out o...Intracavity absorption spectroscopy is a strikingly sensitive technique that has been integrated with a two-wavelength setup to develop a sensor for human breath.Various factors are considered in such a scenario,out of which Relative Intensity Noise(RIN)has been exploited as an important parameter to characterize and calibrate the said setup.During the performance of an electrical based assessment arrangement which has been developed in the laboratory as an alternative to the expensive Agilent setup,the optical amplifier plays a pivotal role in its development and operation,along with other components and their significance.Therefore,the investigation and technical analysis of the amplifier in the system has been explored in detail.The algorithm developed for the automatic measurements of the system has been effectively deployed in terms of the laser’s performance.With this in perspective,a frequency dependent calibration has been pursued in depth with this scheme which enhances the sensor’s efficiency in terms of its sensitivity.In this way,our investigation helps us in a better understanding and implementation perspective of the proposed system,as the outcomes of our analysis adds to the precision and accuracy of the entire system.展开更多
The photo-excitation and Auger decay processes of inner-shell double vacancy states 1s2s2p^6(1,3^S)3s3p of neutral neon atoms have been studied theoretically. Multi-configuration Dirac-Fock (MCDF) calculations hav...The photo-excitation and Auger decay processes of inner-shell double vacancy states 1s2s2p^6(1,3^S)3s3p of neutral neon atoms have been studied theoretically. Multi-configuration Dirac-Fock (MCDF) calculations have been carried out, with electron correlation effects taken into consideration. The relaxation of core and excited orbitals and configuration interaction are found to be crucial to creating the double vacancy states by single photo-absorption. The predominant decay paths for the double vacancy states turn out to be of the LLM Auger decay to 1s 2s^22p^53s(3p), KLL Auger decay to 1s^22s2p^43s3p, and KLM Auger decay to 1s^22p^63s(3p). They lead to further Auger decay, creating the neon ions of multiple charge states. For both double and single vacancy states the spectator type of Auger process is dominated in all the Auger decay processes. Theoretical Anger electron spectra are presented for further investigations, experimental and theoretical.展开更多
The present paper aims at making some observations on trade between the inhabitants of the Roman Empire and those dwelling outside its frontiers,but nevertheless living in the vicinity of Roman frontier zones.Using th...The present paper aims at making some observations on trade between the inhabitants of the Roman Empire and those dwelling outside its frontiers,but nevertheless living in the vicinity of Roman frontier zones.Using three examples-the Rhine frontier,the Middle Euphrates,and the Eastern Desert of Egypt-it highlights the importance of every-day economic interactions at the frontier zones of the Roman Empire.Furthermore,the paper offers some remarks on the different concepts of frontiers and borders in the Roman world.展开更多
In current research on the economy of the Hellenistic and Roman worlds it is taken for granted to use papyri as evidence for ancient economic structures,practices,and mentalities.Nevertheless,the utility of papyri is ...In current research on the economy of the Hellenistic and Roman worlds it is taken for granted to use papyri as evidence for ancient economic structures,practices,and mentalities.Nevertheless,the utility of papyri is all but selfevident,at least as far as research of the 20th century is concerned.Egypt including its source material was considered a special,particular case and thought to be entirely useless for writing economic history of Greece and Rome.This was especially true for primitivist orthodoxy.Moreover,it was particularly German scholarship that showed some neglect towards economic history and thus papyri.Against the background of the general discussion on the character of ancient economy the present paper aims to trace how and to what extent papyri were and are used as evidence.It starts with the outbreak of the Biicher-Meyer controversy and tries to pursue the discussion to the present day.展开更多
In recent decades, a considerable number of local breeds have been replaced by high-yielding breeds for reasons of profitability. Many local breeds are now threatened by extinction and the loss of their native genetic...In recent decades, a considerable number of local breeds have been replaced by high-yielding breeds for reasons of profitability. Many local breeds are now threatened by extinction and the loss of their native genetic diversity. The need to conserve breeds and their genetic diversity has a major importance due to the necessity for genetic change within and between populations. Novel approaches have to be explored and extended to maintain this genetic diversity. The aim of this study was the identification and implementation of breed-specific traits for a small, local sheep breed in northern Germany. The data comprised pedigree information, estimated breeding values (EBVs) of several conventional traits, and phenotypic information from a field experiment for two novel traits: 1) average daily gain under extensive circumstances (ADGE) and 2) ultrasonic measurements of muscle-fat ratio (UMFR). The experimental design included a dataset of 47 progeny from 14 pure-bred rams of German White-Headed Mutton (GWM). The methodical approach was divided into four parts: 1) the analysis of the breeding programme, 2) the identification of breed-specific traits, 3) the estimation and correlation of novel breeding values, and 4) the consequences of implementing these novel traits. Genetic parameters and correlations were conducted by applying linear mixed models. The estimates for the heritability (repeatability) were between 0.70 and 0.83 (0.42 and 0.46). The genetic correlation was positive (0.61) and in accordance with the phenotypic correlation (0.62). Average daily gain under intensive circumstances (ADGI) was moderately positive correlated with muscularity (0.60), as opposed to ADGE, which was moderately negative correlated with muscularity (-0.68). The EBV of ADGE was also moderately positive correlated with UMFR (0.64). Genetic response for ADGE enhanced to values of 481.09 g/day, 639.97 g/day, >700 g/day and >850 g/day for different selection intensity scenarios. Corresponding rates of inbreeding were 1.4%, 2.7%, 5.1%, and 7.9% after 10 years of selection. Genetic response for UMFR increased to 0.92, 1.34, 2.41, and >2.75, whereas remaining rates of inbreeding increased to 1.1%, 2.2%, 5.1%, and 7.9%. ADGI and ADGE were tendentially negatively correlated (-0.11), which strengthen the assumption of a biased ADGI. ADGE has a positive influence on meat-quality aspects (UMFR). Optimal use of reference sires with predefined selection intensity achieves genetic response for ADGE and UMFR with simultaneously acceptable rates of inbreeding.展开更多
This paper presents a case study on incidents of offshore pile running in layered soils.The study provides a detailed description of the seabed soil data,pile driving records,and field surveillance video observations....This paper presents a case study on incidents of offshore pile running in layered soils.The study provides a detailed description of the seabed soil data,pile driving records,and field surveillance video observations.Three-dimensional large deformation finite element(LDFE)analyses were conducted to retrospectively analyze the incidents,considering the remoulding of seabed soil and degradation of the pile-soil interface in the LDFE modeling.By comparing the field observations with the LDFE analysis,the mechanism of pile running was discussed,with a focus on investigating the pile penetration resistance in each layer.The study revealed that pile running in layered soils primarily resulted from a significant reduction in pile base resistance when transitioning from a strong layer to an adjacent weak layer.To further investigate the pile running mechanism in layered soils,a parametric study on the strength variation of adjacent soil layers and its influence on pile base resistance was conducted.Lastly,a simplified prediction model of pile base resistance,suitable for assessing the risk of pile running in layered soils,was proposed.展开更多
SiC BJT代表了最具吸引力的SiC开关结构之一,具有很低的电阻系数、较快的开关速度以及较小的温度依赖性。其良好的短路能力及不存在二次击穿可实现器件可靠工作。我们对与实际应用直接相关的器件性能进行了详细研究,并对以降耗为目的的...SiC BJT代表了最具吸引力的SiC开关结构之一,具有很低的电阻系数、较快的开关速度以及较小的温度依赖性。其良好的短路能力及不存在二次击穿可实现器件可靠工作。我们对与实际应用直接相关的器件性能进行了详细研究,并对以降耗为目的的驱动解决方案进行了测试。鉴于光伏系统降低成本的压力不断增加,我们额外进行了以实现节约为目的的实验,不仅基于SiC技术,同时包括新型磁芯材料方面。为此,我们在实验室中对一个额定功率为17kW的小型升压转换器进行了测试,并在本文中给出了结果。展开更多
文摘In this work,a parametric two-dimensional computational fluid dynamics(CFD)analysis of a solar chimney power plant(a prototype located in Manzanares,Spain)is presented to illustrate the effects of the solar radiation mode in the collector on the plant performances.The simulations rely on a mathematical model that includes solar radiation within the collector;energy storage;air flow and heat transfer,and a turbine.It is based on the Navier-Stokes equation for turbulent flow formulated according to the standard k-εmodel.Moreover,the Boussinesq approach is used to account for the fluid density variations.Different solar radiation modes in the collector are compared and discussed.The obtained results are also compared with available experimental results.It is shown that the radiation model is essential to avoid overestimation of the energy absorbed by the plant and that results based on a two-dimensional model can resemble closely those produced by three-dimensional models.
文摘A study was conducted to determine the genetic diversity of 39 determinate and indeterminate tomato inbred lines collected from China, Japan, S. Korea, and USA. Using 35 SSR polymorphic markers, a total of 150 alleles were found with moderate levels of diversity, and a high number of unique alleles existing in these tomato lines. The mean number of alleles per locus was 4.3 and the average polymorphism information content (PIC) was 0.31. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) clustering at genetic similarity value of 0.85 grouped the inbred lines into four groups, where one USA cultivar formed a separate and more distant cluster. The most similar inbred lines are from USA, both with determinate type, whereas the most different lines are from USA (Us-16) and Japan (Ja-2) with determinate and indeterminate growth habit, respectively. Clustering was consistent with the known information regarding geographical location and growth habit. The genetic distance information reported in this study might be used by breeders when planning future crosses among these inbred lines.
基金Project supported by the National Natural Science Foundation of China(Grant No.11172319)the Scientific Fund of Chinese Universities(Grant Nos.2011JS046 and 2013BH008)+1 种基金the Opening Fund of State Key Laboratory of Nonlinear Mechanics,Program for New Century Excellent Talents in University,China(Grant No.NCET-13-0552)the National Science Foundation for Post-doctoral Scientists of China(Grant No.2013M541086)
文摘Icosahedral quasicrystals are the most important and thermodynamically stable in all about 200 kinds of quasicrystals currently observed. Beyond the scope of classical elasticity, apart from a phonon displacement field, there is a phason displacement field in the elasticity of the quasicrystal, which induces an important effect on the mechanical properties of the material and makes an analytical solution difficult to obtain. In this paper, a finite element algorithm for the static elasticity of icosahedral quasicrystals is developed by transforming the elastic boundary value problem of the icosahedral quasicrystals into an equivalent variational problem. Analytical and numerical solutions for an icosahedral A1-Pd-Mn quasicrystal cuboid subjected to a uniaxial tension with different phonon-phason coupling parameters are given to verify the validity of the numerical approach. A comparison between the analytical and numerical solutions of the specimen demonstrates the accuracy and efficiency of the present algorithm. Finally, in order to reveal the fracture behavior of the icosahedral A1-Pd-Mn quasicrystal, a cracked specimen with a finite size of matter is investigated, both with and without phonon-phason coupling. Meanwhile, the geometry factors are calculated, including the stress intensity factor and the crack opening displacement for the finite-size specimen. Computational results reveal the importance of pbonon-phason coupling effect on the icosahedral A1-Pd-Mn quasicrystal. Furthermore, the finite element procedure can be used to solve more complicated boundary value problems.
文摘The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.
基金funded by the Natural Science Foundation of Hunan Province,China(2020JJ4563)the National Natural Science Foundation of China(4181101348)+2 种基金the Innovation Groups of Natural Science Foundation of Hunan Province(2019JJ10003)the Chinese Academy of Sciences President’s International Fellowship Initiative to Anna Gunina(2019VCC0003)the Talented Young Scientist Program(TYSP)to Mostafa Zhran supported by the China Science and Technology Exchange Center(Egypt-19-004)。
文摘Continuous application of organic fertilizers can cause accumulation of organic phosphorus(P)in soil,especially in the lowmolecular-weight organic phosphorus(LMWOP)forms.This organic P pool represents a potentially important source of P for both plants and microorganisms.To understand the effect of long-term fertilization(30 years)(P-rich soil)vs.fallowing(P-poor soil)on the bioavailability and fate of LMWOP in subtropical paddy soils,we determined the sorption and mineralization of 14 C-labeled adenosine,adenosine monophosphate(AMP),adenosine diphosphate(ADP),and adenosine triphosphate(ATP)in each soil.The contents of carbon,nitrogen,and P in the P-rich soil were more than two times greater than those in the P-poor soil.The mineralization rates of the LMWOP compounds were faster in the P-rich soil compared to the P-poor soil,and followed the order AMP>ADP>ATP.Using sterilized soil,all forms of adenosine-P were strongly sorbed to the solid phase and reached saturation in a short time,with the adsorbance increasing with the number of phosphate groups.We concluded that the mineralization of LMWOP compounds was repressed slightly by sorption to the solid phase,but only in the short term.Thus,LMWOP compounds serve as readily available sources of C for microorganisms,making P available for themselves as well as for the plants.However,P accumulation and the progressive saturation of the P sorption sites in highly fertile soils may increase the potential risk of P runoff.
基金financed by the Higher Education Commission(HEC) of Pakistan and German Academic Exchange Service(DAAD)
文摘The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-stable aggregate fractions and to study their influence on soil organic carbon (C<sub>org</sub>) content. Soil samples were taken from a forest-site, Gogerddan (G) and a semi-rural site, Hazelrigg (H) in Great Britain, from 0-2 and 2-5?cm and 0-4 and 8-12?cm soil depth, respectively. POPs analyzed were PAHs, PCBs, total DDT, PBDEs and HCB. The bulk soil analysis showed that the concentration of POPs was significantly higher (p?≤?0.05) in forest site G than in semi-rural site H, particularly at the surface soil levels compared to the subsurface soil depths in both sites. Total concentrations of PCBs and PAHs of both sites were positively correlated with C<sub>org</sub> contents. POPs concentrations and C<sub>org</sub>, N<sub>t</sub> contents of forest site G were significantly higher (p?≤?0.05) in water-stable macro aggregates (>0.25, >1, >2?mm) than the micro aggregates (>0.053?mm). The POP concentrations of all aggregate fractions after normalizing to their respective C<sub>org</sub> content were increased due higher contamination and strong sorption by C<sub>org</sub>. These results showed a strong effect of C<sub>org</sub> on the partitioning of organic pollutants to soil aggregate size fractions. The present study affirms the ecological significance of forest soils act as a potential sink of POPs. In summary, our results suggest that aggregate fractions may promote soil C storage and act as a potential POP sink in surface soil without increasing their concentration in the aggregate fraction of subsoil.
文摘The simultaneous influence of thermal and mechanical treatment was applied to produce a geometrically complex shaft from 51CrV4 steel leading to the formation of mierostruetures which were significantly different from each other. These mierostrue- rural differences were accompanied by a local change of mechanical properties in terms of hardness, electrical resistivity and especially internal friction. The Snoek-KSster peak was recognized and analyzed in the structure of this steel.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10434100 and 10774122)the Core-University Program between Japanese Society of Promotion of Science and Chinese Academy of Sciencesthe Foundation of Center of theoretical Nuclear Physics of National Laboratory of Heavy Ion Accelerator of Lanzhou,and the Foundation of Northwest Normal University (Grant No NWNU-KJCXGC-03-21)
文摘In a recent XUV photoabsorption spectrum of Cs Ⅲ ions by Cummings and O'Sullivan [2001 J. Phys. B 34 199], rather large linewidths were found for the 4d^95s^25p^6 - 4d^105s^25p^5 transition which are quite in disagreement with corresponding quasi-relativistic multiconfiguration Hartree Fock (MCHF) calculation. In the present work, a detailed multiconfiguration Dirac-Fock study has been carried out to explore this discrepancy. Owing to the detailed consideration of electron correlation effects, some ‘forbidden' Auger decay channels, such as 4d^105s^25p^35d and 4d^105s^05p^6, would become ‘open'. As a result, remarkable improvement of the linewidths has been obtained in our calculation. Furthermore, the theoretical Auger spectrum of the 4d^ 95s^25p^6 core-excited states of Cs Ⅲ ions is Riven in the present work.
文摘The influence of simultaneously applied mechanical and thermal treatment is used for producing a geometrically complex shaft from 51CrV4 steel resulting in widely differing formations of microstructures.Materials'properties such as internal friction(IF),hardness and electrical resistivity are affected by this change of microstructure formations.The Snoek–Koster peak is identified and analyzed in the actual steel structure.
基金This work was supported in part by the German Academic Exchange Service(Deutsche Akademische Austausch Dienst(DAAD)),and in part by the University of Kassel.
文摘Intracavity absorption spectroscopy is a strikingly sensitive technique that has been integrated with a two-wavelength setup to develop a sensor for human breath.Various factors are considered in such a scenario,out of which Relative Intensity Noise(RIN)has been exploited as an important parameter to characterize and calibrate the said setup.During the performance of an electrical based assessment arrangement which has been developed in the laboratory as an alternative to the expensive Agilent setup,the optical amplifier plays a pivotal role in its development and operation,along with other components and their significance.Therefore,the investigation and technical analysis of the amplifier in the system has been explored in detail.The algorithm developed for the automatic measurements of the system has been effectively deployed in terms of the laser’s performance.With this in perspective,a frequency dependent calibration has been pursued in depth with this scheme which enhances the sensor’s efficiency in terms of its sensitivity.In this way,our investigation helps us in a better understanding and implementation perspective of the proposed system,as the outcomes of our analysis adds to the precision and accuracy of the entire system.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10434100,10774122)the Core-University Program between Japanese Society of Promotion of Science and Chinese Academy of Sciences+1 种基金the Foundation of Center of Theoretical Nuclear Physics of National Laboratory of Heavy Ion Accelerator of Lanzhouthe Foundation of Northwest Normal University (Grant No NWNU-KJCXGC-03-21)
文摘The photo-excitation and Auger decay processes of inner-shell double vacancy states 1s2s2p^6(1,3^S)3s3p of neutral neon atoms have been studied theoretically. Multi-configuration Dirac-Fock (MCDF) calculations have been carried out, with electron correlation effects taken into consideration. The relaxation of core and excited orbitals and configuration interaction are found to be crucial to creating the double vacancy states by single photo-absorption. The predominant decay paths for the double vacancy states turn out to be of the LLM Auger decay to 1s 2s^22p^53s(3p), KLL Auger decay to 1s^22s2p^43s3p, and KLM Auger decay to 1s^22p^63s(3p). They lead to further Auger decay, creating the neon ions of multiple charge states. For both double and single vacancy states the spectator type of Auger process is dominated in all the Auger decay processes. Theoretical Anger electron spectra are presented for further investigations, experimental and theoretical.
文摘The present paper aims at making some observations on trade between the inhabitants of the Roman Empire and those dwelling outside its frontiers,but nevertheless living in the vicinity of Roman frontier zones.Using three examples-the Rhine frontier,the Middle Euphrates,and the Eastern Desert of Egypt-it highlights the importance of every-day economic interactions at the frontier zones of the Roman Empire.Furthermore,the paper offers some remarks on the different concepts of frontiers and borders in the Roman world.
文摘In current research on the economy of the Hellenistic and Roman worlds it is taken for granted to use papyri as evidence for ancient economic structures,practices,and mentalities.Nevertheless,the utility of papyri is all but selfevident,at least as far as research of the 20th century is concerned.Egypt including its source material was considered a special,particular case and thought to be entirely useless for writing economic history of Greece and Rome.This was especially true for primitivist orthodoxy.Moreover,it was particularly German scholarship that showed some neglect towards economic history and thus papyri.Against the background of the general discussion on the character of ancient economy the present paper aims to trace how and to what extent papyri were and are used as evidence.It starts with the outbreak of the Biicher-Meyer controversy and tries to pursue the discussion to the present day.
基金Financial support from the ministry of Energy,Agriculture,Environment,Nature,and Digitalization within the framework of the European Innovation Partnership(EIP Agri).
文摘In recent decades, a considerable number of local breeds have been replaced by high-yielding breeds for reasons of profitability. Many local breeds are now threatened by extinction and the loss of their native genetic diversity. The need to conserve breeds and their genetic diversity has a major importance due to the necessity for genetic change within and between populations. Novel approaches have to be explored and extended to maintain this genetic diversity. The aim of this study was the identification and implementation of breed-specific traits for a small, local sheep breed in northern Germany. The data comprised pedigree information, estimated breeding values (EBVs) of several conventional traits, and phenotypic information from a field experiment for two novel traits: 1) average daily gain under extensive circumstances (ADGE) and 2) ultrasonic measurements of muscle-fat ratio (UMFR). The experimental design included a dataset of 47 progeny from 14 pure-bred rams of German White-Headed Mutton (GWM). The methodical approach was divided into four parts: 1) the analysis of the breeding programme, 2) the identification of breed-specific traits, 3) the estimation and correlation of novel breeding values, and 4) the consequences of implementing these novel traits. Genetic parameters and correlations were conducted by applying linear mixed models. The estimates for the heritability (repeatability) were between 0.70 and 0.83 (0.42 and 0.46). The genetic correlation was positive (0.61) and in accordance with the phenotypic correlation (0.62). Average daily gain under intensive circumstances (ADGI) was moderately positive correlated with muscularity (0.60), as opposed to ADGE, which was moderately negative correlated with muscularity (-0.68). The EBV of ADGE was also moderately positive correlated with UMFR (0.64). Genetic response for ADGE enhanced to values of 481.09 g/day, 639.97 g/day, >700 g/day and >850 g/day for different selection intensity scenarios. Corresponding rates of inbreeding were 1.4%, 2.7%, 5.1%, and 7.9% after 10 years of selection. Genetic response for UMFR increased to 0.92, 1.34, 2.41, and >2.75, whereas remaining rates of inbreeding increased to 1.1%, 2.2%, 5.1%, and 7.9%. ADGI and ADGE were tendentially negatively correlated (-0.11), which strengthen the assumption of a biased ADGI. ADGE has a positive influence on meat-quality aspects (UMFR). Optimal use of reference sires with predefined selection intensity achieves genetic response for ADGE and UMFR with simultaneously acceptable rates of inbreeding.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51879183,51890913)Sino-German Mobility Programme(Grant No.M-0045)。
文摘This paper presents a case study on incidents of offshore pile running in layered soils.The study provides a detailed description of the seabed soil data,pile driving records,and field surveillance video observations.Three-dimensional large deformation finite element(LDFE)analyses were conducted to retrospectively analyze the incidents,considering the remoulding of seabed soil and degradation of the pile-soil interface in the LDFE modeling.By comparing the field observations with the LDFE analysis,the mechanism of pile running was discussed,with a focus on investigating the pile penetration resistance in each layer.The study revealed that pile running in layered soils primarily resulted from a significant reduction in pile base resistance when transitioning from a strong layer to an adjacent weak layer.To further investigate the pile running mechanism in layered soils,a parametric study on the strength variation of adjacent soil layers and its influence on pile base resistance was conducted.Lastly,a simplified prediction model of pile base resistance,suitable for assessing the risk of pile running in layered soils,was proposed.