Usually, there are several methods, e.g. experiment, interpolation experiment-based, analytic function, and Monte-Carlo simulation, to calculate the response functions in LaBr3（Ce） detectors. In logging applications...Usually, there are several methods, e.g. experiment, interpolation experiment-based, analytic function, and Monte-Carlo simulation, to calculate the response functions in LaBr3（Ce） detectors. In logging applications, the experiment-based methods cannot be adopted because of their limitations. Analytic function has the advantage of fast calculating speed, but it is very difficult to take into account many effects that occur in practical applications. On the contrary, Monte-Carlo simulation can deal with physical and geometric configurations very tactfully. It has a distinct advantage for calculating the functions with complex configurations in borehole. A new application of LaBr3（Ce） detector is in natural gamma-rays borehole spectrometer for uranium well logging. Calculation of response functions must consider a series of physical and geometric factors under complex logging conditions, including earth formations and its relevant parameters, different energies, material and thickness of the casings, the fluid between the two tubes, and relative position of the LaBr3（Ce） crystal to steel ingot at the front of logging tube. The present work establishes Monte-Carlo simulation models for the above-mentioned situations, and then performs calculations for main gamma-rays from natural radio-elements series. The response functions can offer experimental directions for the design of borehole detection system, and provide technique basis and basic data for spectral analysis of natural gamma-rays, and for sonrceless calibration in uranium quantitative interpretation.展开更多
A ball valve is a common mechanical product for connecting and closing a media outlet in equipment. To adapt to pipes of different sizes, a ball valve is often designed into a serial product of standard specifications...A ball valve is a common mechanical product for connecting and closing a media outlet in equipment. To adapt to pipes of different sizes, a ball valve is often designed into a serial product of standard specifications. In accordance with usual routine designing, it is demanded to draw a set of blueprints for every specification and to mark its sizes. We propose using the configuration functions in the three dimensional designing software SolidWords to realize the ball valve product＇s serialization for effective designing. It only requires designing a set of blueprint integrated with a serial parts designing chart. In this way, it can accomplish the designing process of a numeral blueprint. Successful applications proves that this method is practical for serial parts＇ design.展开更多
An analytic configuration interaction method based on variationally optimized internally orthogonalized modified Laguerre orbitals is presented. We have developed the corresponding computer code. For application, we s...An analytic configuration interaction method based on variationally optimized internally orthogonalized modified Laguerre orbitals is presented. We have developed the corresponding computer code. For application, we study the 1s2s ^1S isoelectronic sequence from helium to neon, and compare with other methods. By taking into account the Eekart upper-bound theorem, we obtained more accurate and more intuitively understandable results than Hartree-Fock and multi-configuration Hartree-Fock reported results.展开更多
The adsorption configurations of molecules adsorbed on substrates can significantly affect their physical and chemical properties. A standing configuration can be difficult to determine by traditional techniques, such...The adsorption configurations of molecules adsorbed on substrates can significantly affect their physical and chemical properties. A standing configuration can be difficult to determine by traditional techniques, such as scanning tunneling microscopy(STM) due to the superposition of electronic states. In this paper, we report the real-space observation of the standing adsorption configuration of phenylacetylene on Cu(111) by non-contact atomic force microscopy(nc-AFM).Deposition of phenylacetylene at 25 K shows featureless bright spots in STM images. Using nc-AFM, the line features representing the C–H and C–C bonds in benzene rings are evident, which implies a standing adsorption configuration. Further density functional theory(DFT) calculations reveal multiple optimized adsorption configurations with phenylacetylene breaking its acetylenic bond and forming C–Cu bond(s) with the underlying copper atoms, and hence stand on the substrate.By comparing the nc-AFM simulations with the experimental observation, we identify the standing adsorption configuration of phenylacetylene on Cu(111). Our work demonstrates an application of combining nc-AFM measurements and DFT calculations to the study of standing molecules on substrates, which enriches our knowledge of the adsorption behaviors of small molecules on solid surfaces at low temperatures.展开更多
We have systematically investigated the geometrical structures, relative stabilities and electronic properties of small bimetallic AunBe （n = 1, 2, . .. 8） clusters using a density functional method at BP86 level. T...We have systematically investigated the geometrical structures, relative stabilities and electronic properties of small bimetallic AunBe （n = 1, 2, . .. 8） clusters using a density functional method at BP86 level. The optimized geometries reveal that the impurity beryllium atom dramatically affects the structures of the Aun clusters. The averaged binding energies, fragmentation energies, second-order difference of energies, the highest occupied-lowest unoccupied molecular orbital energy gaps and chemical hardness are investigated, All of them exhibit a pronounced odd-even alternation, manifesting that the clusters with even number of gold atoms possess relatively higher stabilities. Especially, the linear Au2Be cluster is magic cluster with the most stable chemical stability. According to the natural population analysis, it is found that charge-transferring direction between Au atom and Be atom changes at the size of n = 4.展开更多
The paper describes research aimed at developing a configuration system to support theconceptual design of mechanical fasteners. A prototype configuration system has been developedwhich allows designers to interactive...The paper describes research aimed at developing a configuration system to support theconceptual design of mechanical fasteners. A prototype configuration system has been developedwhich allows designers to interactively configure fastener designs using geometric and functionalicons , freely without regard to physical constraints, with the aim of forming candidate designs.Candidate designs are then passed to the qualitative modeller which uses qualrtative reasoningtechniques to evaluate the configuration. Supporting the above design procedure is a knowledgebase which contains object descriptions of fasteners and fastener features (given in terms ofgeometry, function, performance, material,installation). Design rules (expressing spatial andcasual relationships of fastener features),which are required during the evaluation of candidatefastener configurations, are also contained in the knowledge base.展开更多
基金supported by Key Laboratory of Radioactive Geology and Exploration Technology Fundamental Science for National Defense(No. 2011RGET04)East China Institute of Technology, and National Natural Science Foundation of China (No. 41074078)
文摘Usually, there are several methods, e.g. experiment, interpolation experiment-based, analytic function, and Monte-Carlo simulation, to calculate the response functions in LaBr3（Ce） detectors. In logging applications, the experiment-based methods cannot be adopted because of their limitations. Analytic function has the advantage of fast calculating speed, but it is very difficult to take into account many effects that occur in practical applications. On the contrary, Monte-Carlo simulation can deal with physical and geometric configurations very tactfully. It has a distinct advantage for calculating the functions with complex configurations in borehole. A new application of LaBr3（Ce） detector is in natural gamma-rays borehole spectrometer for uranium well logging. Calculation of response functions must consider a series of physical and geometric factors under complex logging conditions, including earth formations and its relevant parameters, different energies, material and thickness of the casings, the fluid between the two tubes, and relative position of the LaBr3（Ce） crystal to steel ingot at the front of logging tube. The present work establishes Monte-Carlo simulation models for the above-mentioned situations, and then performs calculations for main gamma-rays from natural radio-elements series. The response functions can offer experimental directions for the design of borehole detection system, and provide technique basis and basic data for spectral analysis of natural gamma-rays, and for sonrceless calibration in uranium quantitative interpretation.
文摘A ball valve is a common mechanical product for connecting and closing a media outlet in equipment. To adapt to pipes of different sizes, a ball valve is often designed into a serial product of standard specifications. In accordance with usual routine designing, it is demanded to draw a set of blueprints for every specification and to mark its sizes. We propose using the configuration functions in the three dimensional designing software SolidWords to realize the ball valve product＇s serialization for effective designing. It only requires designing a set of blueprint integrated with a serial parts designing chart. In this way, it can accomplish the designing process of a numeral blueprint. Successful applications proves that this method is practical for serial parts＇ design.
基金Project supported by the National Natural Science Foundation of China （Grant No 10347126）. Acknowledgements Xiong Zhuang acknowledges the Greek State Scholarship Foundation （I.K.Y.） and the National Hellenic Research Foundation Scholarship that partially supported this work.
文摘An analytic configuration interaction method based on variationally optimized internally orthogonalized modified Laguerre orbitals is presented. We have developed the corresponding computer code. For application, we study the 1s2s ^1S isoelectronic sequence from helium to neon, and compare with other methods. By taking into account the Eekart upper-bound theorem, we obtained more accurate and more intuitively understandable results than Hartree-Fock and multi-configuration Hartree-Fock reported results.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0202300 and 2018YFA0305800)the National Natural Science Foundation of China(Grant Nos.61888102,61474141,and 21661132006)+2 种基金the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11604373)the Outstanding Youth Science Foundation,China(Grant No.61622116)the Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(Grant Nos.XDB28000000 and XDB30000000)
文摘The adsorption configurations of molecules adsorbed on substrates can significantly affect their physical and chemical properties. A standing configuration can be difficult to determine by traditional techniques, such as scanning tunneling microscopy(STM) due to the superposition of electronic states. In this paper, we report the real-space observation of the standing adsorption configuration of phenylacetylene on Cu(111) by non-contact atomic force microscopy(nc-AFM).Deposition of phenylacetylene at 25 K shows featureless bright spots in STM images. Using nc-AFM, the line features representing the C–H and C–C bonds in benzene rings are evident, which implies a standing adsorption configuration. Further density functional theory(DFT) calculations reveal multiple optimized adsorption configurations with phenylacetylene breaking its acetylenic bond and forming C–Cu bond(s) with the underlying copper atoms, and hence stand on the substrate.By comparing the nc-AFM simulations with the experimental observation, we identify the standing adsorption configuration of phenylacetylene on Cu(111). Our work demonstrates an application of combining nc-AFM measurements and DFT calculations to the study of standing molecules on substrates, which enriches our knowledge of the adsorption behaviors of small molecules on solid surfaces at low temperatures.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974138)
文摘We have systematically investigated the geometrical structures, relative stabilities and electronic properties of small bimetallic AunBe （n = 1, 2, . .. 8） clusters using a density functional method at BP86 level. The optimized geometries reveal that the impurity beryllium atom dramatically affects the structures of the Aun clusters. The averaged binding energies, fragmentation energies, second-order difference of energies, the highest occupied-lowest unoccupied molecular orbital energy gaps and chemical hardness are investigated, All of them exhibit a pronounced odd-even alternation, manifesting that the clusters with even number of gold atoms possess relatively higher stabilities. Especially, the linear Au2Be cluster is magic cluster with the most stable chemical stability. According to the natural population analysis, it is found that charge-transferring direction between Au atom and Be atom changes at the size of n = 4.
文摘The paper describes research aimed at developing a configuration system to support theconceptual design of mechanical fasteners. A prototype configuration system has been developedwhich allows designers to interactively configure fastener designs using geometric and functionalicons , freely without regard to physical constraints, with the aim of forming candidate designs.Candidate designs are then passed to the qualitative modeller which uses qualrtative reasoningtechniques to evaluate the configuration. Supporting the above design procedure is a knowledgebase which contains object descriptions of fasteners and fastener features (given in terms ofgeometry, function, performance, material,installation). Design rules (expressing spatial andcasual relationships of fastener features),which are required during the evaluation of candidatefastener configurations, are also contained in the knowledge base.
