Subjects: Nuclear Science and Technology >> Radiation Physics and Technology submitted time 2024-05-01
Abstract： Abstract [Background]: The defects generated during the working process of metal materials have a significant impact on their performance. For example, the radiation-induced embrittlement and hardening of RPV steels are a factor of concern, which hinders the life extension of the RPV. Annealing treatment is applied to alleviate irradiation-induced precipitates and defects and recover RPV’s mechanical properties in the past few decades to extend the in-service lifetime of the RPV. Unfortunately, this conventional method generally requires a high treatment temperature and long operation time, inevitably wasting considerable energy due to the huge size of the RPV. Recently, as a more convenient and energy-saving method, the repair of metal defects by electropulsing treatment (EPT) has been developed.
[Purpose]: Design and construct a device for EPT processing of samples. The repairs of defects in electron irradiated and deformed iron and RPV steel after EPT has been investigated by using positron lifetime spectroscopy.
[Methods]: Electron irradiated pure iron and RPV steel samples were subjected to multi parameter EPT, and the changes in defects of the samples with EPT were characterized by positron lifetime spectroscopy. In addition, the mechanical properties of pure iron tensile samples were characterized by micro Vickers hardness, and the defect information was characterized by positron lifetime spectroscopy to investigate the relationship between macroscopic properties and microstructure.
[Results]: The defects introduced by electron irradiation in pure iron and RPV steel samples gradually recover after EPT and exhibit similar patterns to annealing treatment. After stretching, the number of defects in pure iron samples increases, leading to an increase in Vickers hardness. EPT can restore defect and reduce Vickers hardness.
[Conclusions]: The EPT equipment and method used in the experiment can indeed recover the defects of metal samples. The samples treated by EPT are characterized by positron lifetime spectroscopy, and defects generated by irradiation or deformation in pure iron and RPV steel can be partially repaired through EPT. The effect of defect repair is not only related to the initial state of the sample, but also to EPT’s parameters. As a new non-destructive testing method, positron annihilation is expected to provide a criterion for material damage or defect repair under the action of pulse current, which can conveniently, quickly, and sensitively detect the defect state of actual working components.
Subjects: Nuclear Science and Technology >> Nuclear Science and Technology submitted time 2024-04-22
Abstract： Abstract [Background]: The defects generated during the working process of metal materials have a significant impact on their performance. For example, the radiation-induced embrittlement and hardening of RPV steels are a factor of concern, which hinders the life extension of the RPV. Annealing treatment is applied to alleviate irradiation-induced precipitates and defects and recover RPV’s mechanical properties in the past few decades to extend the in-service lifetime of the RPV. Unfortunately, this conventional method generally requires a high treatment temperature and long operation time, inevitably wasting considerable energy due to the huge size of the RPV. Recently, as a more convenient and energy-saving method, the repair of metal defects by electropulsing treatment (EPT) has been developed.
[Purpose]: Design and construct a device for EPT processing of samples. The repairs of defects in electron irradiated and deformed iron and RPV steel after EPT has been investigated by using positron lifetime spectroscopy.
[Methods]: Electron irradiated pure iron and RPV steel samples were subjected to multi parameter EPT, and the changes in defects of the samples with EPT were characterized by positron lifetime spectroscopy. In addition, the mechanical properties of pure iron tensile samples were characterized by micro Vickers hardness, and the defect information was characterized by positron lifetime spectroscopy to investigate the relationship between macroscopic properties and microstructure.
[Results]: The defects introduced by electron irradiation in pure iron and RPV steel samples gradually recover after EPT and exhibit similar patterns to annealing treatment. After stretching, the number of defects in pure iron samples increases, leading to an increase in Vickers hardness. EPT can restore defect and reduce Vickers hardness.
[Conclusions]: The EPT equipment and method used in the experiment can indeed recover the defects of metal samples. The samples treated by EPT are characterized by positron lifetime spectroscopy, and defects generated by irradiation or deformation in pure iron and RPV steel can be partially repaired through EPT. The effect of defect repair is not only related to the initial state of the sample, but also to EPT’s parameters. As a new non-destructive testing method, positron annihilation is expected to provide a criterion for material damage or defect repair under the action of pulse current, which can conveniently, quickly, and sensitively detect the defect state of actual working components.
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：当今时代,新媒体环境的不断发展,为企业的广告营销工作带来了崭新的机遇和挑战。本文主要从新媒体环境下,企业的广告营销过程中所面临的机遇和挑战两个方面入手,概要论述了新媒体环境下企业广告营销工作加强创新改革的若干对策,以期为相关工作人员的学习和研究提供一定的借鉴作用。
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-11
Abstract： [Purpose/Significance] This paper researched the subject scientific data management services of special libraries, analyzed the demand side and supply side of scientific data management services, and explored the subject service system and service model of special libraries for scientific data management. [Method/Process] This paper researched the demand environment and demand subjects of scientific data management services, as well as the trend and service contents of subject scientific data management services in special libraries. Then, based on the scientific data lifecycle, this paper constructed a supply and demand matching "butterfly" system for scientific data management services, and finally proposed a "target-centric" subject scientific data management service model of special libraries. [Result/Conclusion] The paper constructed a subject scientific data management service system from the perspective of supply and demand matching, and introducted the " target-centric " theory to explore the scientific data management service model, aiming to strengthen the collaboration between the demand sides and supply sides of scientific data management, and enhance the service capacity and effectiveness of subject scientific data management services in special libraries.
Subjects: Mathematics >> Applied Mathematics submitted time 2022-10-12
Abstract：随机函数可逆性问题是密码学中一类重要的问题，例如Hash函数原像恢复，分组密码密钥恢复，离散对称问题求解等等。在这个工作中，我们将随机函数可逆性问题从一维推广到高维，并提出了一个新的广义生日碰撞原理。基于该原理，我们给出了多随机函数可逆性问题的一个求解算法。该算法可以解决1980年Hellman在分组密码TMTO攻击中只能使用一对明密文数据而不能使用多个数据的公开问题，以及Biryukov和Shamir在2000年提出的带BSW采样的TMDTO攻击中只能使用极其少量的明密文数据而不是全部数据的公开问题。
Peer Review Status:
Awaiting Review
Subjects: Physics >> Geophysics, Astronomy, and Astrophysics submitted time 2021-06-26
Abstract： In this paper we introduced a parameter n to characterize the variation of the speed of light between different inertial systems. In order to satisfy the well-known fundamental principle and not violate some reliable experiments’ results, we should impose some necessary constraints on n. Firstly and importantly, the introduction of n should be in agree with the following three principles: (1)we can define the time in the whole space with a prescribed clock synchronization, (2)the time-space is uniform and the space is isotropic and (3)all the inertial systems are equivalent, which are the inheritance of the special relativity (SR). With some constraints on n, we construct a general coordinate transformation to meet the symmetry of inertial systems. In recent years, many theories have shown the interest in the breakdown of the Lorentz invariance at ultrahigh energy scale, such as the quantum gravity, which imply that the energy of particle has a limited value (called the “Planck energy”) rather than be infinite derived from the Lorentz model. So we construct an expression for n to characterize the violation of Lorentz model. And further, by comparing with the well-known rainbow model, we found that the "maximum energy" derived in our paper is somewhat related to the "maximum energy" assumed in the rainbow model." "
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2021-02-14
Abstract： " "
Peer Review Status:Awaiting Review
Subjects: Physics >> Geophysics, Astronomy, and Astrophysics submitted time 2021-01-24
Abstract： In this paper we re-investigated the relationship between the symmetry of inertial systems and the Lorentz transformation. We found that when we just follow the following three principles: (1)we can define the time in the whole space with a prescribed clock synchronization, (2)the time-space is uniform and the space is isotropic and (3)all the inertial systems are equivalent, then we can totally construct a general coordinate transformation to meet the symmetry of inertial systems, and with a special assumption on the speed of light, we can construct a non-Lorentz transformation between inertial systems to make the particle’s energy have a limited value, which is similar to the rainbow model. Similar to the usual Lorentz violating models, the non-Lorentz transformation in this paper lead to a new modified disperse relation. We applied the obtained disperse relation to analyze the photon’s arrival time lag effect in astronomy and found that the "maximum energy" derived in our model is somewhat related to the "maximum energy" assumed in the rainbow model.
Peer Review Status:Awaiting Review
Subjects: Psychology >> Cognitive Psychology submitted time 2020-07-04
Abstract： "
Subjects: Physics >> Geophysics, Astronomy, and Astrophysics submitted time 2019-11-09
Abstract： In Lorentz violation models, the rainbow model is usually discussed, as the rainbow model can make the energy of a particle have a limit rather than be infinite derived from the Lorentz transformation, which is considered to be necessary in the theory of Quantum Gravity. However, this paper shows that it isn’t necessary to restrict the speed of light to be a constant when we just agree with the next three principles: (1)we can define the time in the whole space with a prescribed clock synchronization, (2)the time-space is uniform and the space is isotropic and (3)all the inertial systems are equivalent. And base on the above three principles and as a result of variable speed of light, we can construct a general coordinate transformation to satisfy the symmetry of inertial systems and construct a non-Lorentz transformation between inertial systems to make the energy of a particle have a limit, which is the same as the rainbow model. In addition, in recent papers, as a test at the ultrahigh energy scale, the rainbow model is used to study the Gamma ray burst, such as the GRB 160509A event, which was strongly suggested that there exists a linear relation between the variable speed of light and the photon’s energy. So we also analyzed the same event and we found that our model also support the same conclusion as the rainbow model and there was some correlation between our model and the rainbow model. In final we briefly discussed how to verify the two models in the future particle’s experiments at the ultrahigh energy scale.
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2018-09-12
Abstract： In this paper, the inverse dissipation dispersity is introduced in the Newtonian Dynamics equation, and the equation of motion of the object in the isolated gravitational system is studied. It is found that at large scale it can derive the cosmic expansion dynamics equation similar to the model and derive the asymptotic flat rotational velocity property of spiral galaxies,which it is unlike the usual dark matter model that the asymptotic flat rotational velocity property is the result of time accumulation rather than the direct effect of mechanics, and the Tully-Fisher relationship is discussed and it is found the natural constants in the MOND model that and the form of the function have a clear corresponding physical meaning in the model of this paper.
Peer Review Status:Awaiting Review
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