The United Nations International Conference on Space-based Technologies for Disaster Management, "Risk Assessment in the Context of Global Climate Change", was held in Beijing during November 7-9, 2012. The ...The United Nations International Conference on Space-based Technologies for Disaster Management, "Risk Assessment in the Context of Global Climate Change", was held in Beijing during November 7-9, 2012. The conference was co-organized by the United Nations Office for Outer Space Affairs (UNOOSA) and the Ministry of Civil affairs (MCA) of the People's Republic of China, in collaboration with the Ministry of Foreign Affairs of PRC, China National Space Administration (CNSA),展开更多
When building a model of a physical phenomenon or process, scientists face an inevitable compromise between the simplicity of the model (qualitative-quantitative set of variables) and its accuracy. For hundreds of yea...When building a model of a physical phenomenon or process, scientists face an inevitable compromise between the simplicity of the model (qualitative-quantitative set of variables) and its accuracy. For hundreds of years, the visual simplicity of a law testified to the genius and depth of the physical thinking of the scientist who proposed it. Currently, the desire for a deeper physical understanding of the surrounding world and newly discovered physical phenomena motivates researchers to increase the number of variables considered in a model. This direction leads to an increased probability of choosing an inaccurate or even erroneous model. This study describes a method for estimating the limit of measurement accuracy, taking into account the stage of model building in terms of storage, transmission, processing and use of information by the observer. This limit, due to the finite amount of information stored in the model, allows you to select the optimal number of variables for the best reproduction of the observed object and calculate the exact values of the threshold discrepancy between the model and the phenomenon under study in measurement theory. We consider two examples: measurement of the speed of sound and measurement of physical constants.展开更多
We perform a comparative st udy on the electroluminescence (EL) and photoluminescence (PL) of Si nanocrystaldoped SiO2 (nc-Si:SiO2) and SiO2, and clarify whether the contribution from Si nanocrystals in the EL ...We perform a comparative st udy on the electroluminescence (EL) and photoluminescence (PL) of Si nanocrystaldoped SiO2 (nc-Si:SiO2) and SiO2, and clarify whether the contribution from Si nanocrystals in the EL of nc-Si:SiO2 truly exists. The results unambiguously indicate the presence of EL of Si nanocrystals. The difference of peak positions between the EL and PL spectra are discussed. It is found that the normal method of passivation to enhance the PL of Si nanocrystals is not equally effective for the EL, hence new methods need to be explored to promote the EL of Si nanocrystals.展开更多
This work intends to manipulate the internal flow units in Zr_(55)Cu_(30)Ni_(5)Al_(10)bulk-metallic glasses(BMGs)through plasma-assisted hydrogenation to generate a positive microalloying effect on plasticity.Based on...This work intends to manipulate the internal flow units in Zr_(55)Cu_(30)Ni_(5)Al_(10)bulk-metallic glasses(BMGs)through plasma-assisted hydrogenation to generate a positive microalloying effect on plasticity.Based on the cooperative shear model theory,serration-flow statistics during nanoindentation loading and creep tests during the holding stage were used to analyze the influence of hydrogen on the behavior of flow units in BMGs.Experimental observations showed that the hydrogen in the Zr_(55)Cu_(30)Ni_(5)Al_(10)BMGs caused mechanical softening,plasticity improvement,and structural relaxation.Analysis also showed that the average volume,size,and activation energy of internal flow units in the BMGs all increased as a result of the increase in the hydrogen content.The hydrogenation in the BMGs was found to lead to a prolifera-tion of shear bands,which promoted plasticity.The aggregation of these internal flow units reduced the stress required for plastic deformation through shear bands,ultimately causing softening and structural relaxation.展开更多
The accounting result from science and technology innovation and the development of productivity, with management modes and financial reforms as its opportunity and the operation of international capital, as well as e...The accounting result from science and technology innovation and the development of productivity, with management modes and financial reforms as its opportunity and the operation of international capital, as well as economic integration helping improve it. An invention, a president, the occurrence of an organization, a historical lesson may directly or indirectly change accounting regulations, and even trigger an accounting revolution. We will put a variety of significant impacts on an accounting, so as to get a fundamental understanding of the close relationship between such events and accounting events, including innovation of accounting theory, and accounting practice; we adopted the "table-style" form of papers, with many self-evident and intuitive tables, we compile a series of major historical events reasonably. Only in accordance with evolution of objective environment, can we design proper accounting practice, and thus innovate and develop accounting.展开更多
See "The International System of Units (SI)," NIST Special Publication 330, B.N. Taylor, ed. (USGPO, Washington, DC, 1991); and "Guide for the Use of the International System of Units (SI)," NIST Special Pub...See "The International System of Units (SI)," NIST Special Publication 330, B.N. Taylor, ed. (USGPO, Washington, DC, 1991); and "Guide for the Use of the International System of Units (SI)," NIST Special Publication 811, 1995 edition, B.N. Taylor (USGPO, Washington, DC, 1995).展开更多
Standards are the scientific basis and an important factor for the assessment of the quality of goods.In International Sale of Goods Law,they are consistent with and complementary to the“general provision”on“ordina...Standards are the scientific basis and an important factor for the assessment of the quality of goods.In International Sale of Goods Law,they are consistent with and complementary to the“general provision”on“ordinary purposes”used to assess the quality of goods.Based on analyses of theories and legal practices and by reviewing the relationship between standards and“ordinary purposes,”in this article,I attempt to find out what standards affect the ascertaining of“ordinary purposes”and present a summary of the preconditions for the sellers’obligatory observance of such standards to provide guidance for the accurate application of other“general provisions”through the use of standards.展开更多
文摘The United Nations International Conference on Space-based Technologies for Disaster Management, "Risk Assessment in the Context of Global Climate Change", was held in Beijing during November 7-9, 2012. The conference was co-organized by the United Nations Office for Outer Space Affairs (UNOOSA) and the Ministry of Civil affairs (MCA) of the People's Republic of China, in collaboration with the Ministry of Foreign Affairs of PRC, China National Space Administration (CNSA),
文摘When building a model of a physical phenomenon or process, scientists face an inevitable compromise between the simplicity of the model (qualitative-quantitative set of variables) and its accuracy. For hundreds of years, the visual simplicity of a law testified to the genius and depth of the physical thinking of the scientist who proposed it. Currently, the desire for a deeper physical understanding of the surrounding world and newly discovered physical phenomena motivates researchers to increase the number of variables considered in a model. This direction leads to an increased probability of choosing an inaccurate or even erroneous model. This study describes a method for estimating the limit of measurement accuracy, taking into account the stage of model building in terms of storage, transmission, processing and use of information by the observer. This limit, due to the finite amount of information stored in the model, allows you to select the optimal number of variables for the best reproduction of the observed object and calculate the exact values of the threshold discrepancy between the model and the phenomenon under study in measurement theory. We consider two examples: measurement of the speed of sound and measurement of physical constants.
基金Supported by the National Natural Science Foundation of China under Grant No 60638010, and the Ministry of Education of China under Grant No 20060246028.
文摘We perform a comparative st udy on the electroluminescence (EL) and photoluminescence (PL) of Si nanocrystaldoped SiO2 (nc-Si:SiO2) and SiO2, and clarify whether the contribution from Si nanocrystals in the EL of nc-Si:SiO2 truly exists. The results unambiguously indicate the presence of EL of Si nanocrystals. The difference of peak positions between the EL and PL spectra are discussed. It is found that the normal method of passivation to enhance the PL of Si nanocrystals is not equally effective for the EL, hence new methods need to be explored to promote the EL of Si nanocrystals.
基金supported the National Natural Science Foundation of China(51401129)Natural Science Foundation of Liaoning Province(2019-ZD-0216,20180510056)+2 种基金Foundation of Liaoning Province Education Administration(LQGD2019001)support from the National Science Foundation(DMR1611180 and 1809640)with the program directorssupported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,Materials Sciences and Engineering Division under Contract No.DEAC02–05-CH11231。
文摘This work intends to manipulate the internal flow units in Zr_(55)Cu_(30)Ni_(5)Al_(10)bulk-metallic glasses(BMGs)through plasma-assisted hydrogenation to generate a positive microalloying effect on plasticity.Based on the cooperative shear model theory,serration-flow statistics during nanoindentation loading and creep tests during the holding stage were used to analyze the influence of hydrogen on the behavior of flow units in BMGs.Experimental observations showed that the hydrogen in the Zr_(55)Cu_(30)Ni_(5)Al_(10)BMGs caused mechanical softening,plasticity improvement,and structural relaxation.Analysis also showed that the average volume,size,and activation energy of internal flow units in the BMGs all increased as a result of the increase in the hydrogen content.The hydrogenation in the BMGs was found to lead to a prolifera-tion of shear bands,which promoted plasticity.The aggregation of these internal flow units reduced the stress required for plastic deformation through shear bands,ultimately causing softening and structural relaxation.
文摘The accounting result from science and technology innovation and the development of productivity, with management modes and financial reforms as its opportunity and the operation of international capital, as well as economic integration helping improve it. An invention, a president, the occurrence of an organization, a historical lesson may directly or indirectly change accounting regulations, and even trigger an accounting revolution. We will put a variety of significant impacts on an accounting, so as to get a fundamental understanding of the close relationship between such events and accounting events, including innovation of accounting theory, and accounting practice; we adopted the "table-style" form of papers, with many self-evident and intuitive tables, we compile a series of major historical events reasonably. Only in accordance with evolution of objective environment, can we design proper accounting practice, and thus innovate and develop accounting.
文摘See "The International System of Units (SI)," NIST Special Publication 330, B.N. Taylor, ed. (USGPO, Washington, DC, 1991); and "Guide for the Use of the International System of Units (SI)," NIST Special Publication 811, 1995 edition, B.N. Taylor (USGPO, Washington, DC, 1995).
文摘Standards are the scientific basis and an important factor for the assessment of the quality of goods.In International Sale of Goods Law,they are consistent with and complementary to the“general provision”on“ordinary purposes”used to assess the quality of goods.Based on analyses of theories and legal practices and by reviewing the relationship between standards and“ordinary purposes,”in this article,I attempt to find out what standards affect the ascertaining of“ordinary purposes”and present a summary of the preconditions for the sellers’obligatory observance of such standards to provide guidance for the accurate application of other“general provisions”through the use of standards.