Current Location:home > Browse

Authors

Institution

1. chinaXiv:202008.00076 [pdf]

Note on anomalies in field theories

刘昌勇
Subjects: Physics >> The Physics of Elementary Particles and Fields

In this note, we investigate the anomalies in field theories. The results of the anomalies through Feynman diagrams calculation are multi-valued function. These single-valued branches of multi-valued function are related to the bound states of neutral pseudoscalar mesons. Adding these bound state contributions, we obtain a new anomaly free condition that all the external particles are on-shell and find the non-perturbative mass spectrum of neutral pseudoscalar mesons. We also discuss the anomaly in 2 dimensional QFT.

submitted time 2020-11-02 Hits2839Downloads520 Comment 0

2. chinaXiv:202010.00080 [pdf]

微波热点出现与维持的物理机制探讨

Jianyi Ma; Yongxin Hu
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

微波加热反应和传统加热反应相比有反应速度快、产率高等特点。微波反应中不同于传统加热的现象被称为“微波效应”。被观测到的微波效应包括热现象、热点现象、选择性加热等。理解和有效控制微波效应中的微波热点效应对理解和应用微波加热至关重要。基于我们2016年提出的微波反应量子态识别主方程模型,本文研究发现微波热点这种非线性现象的出现,宏观上与体系的温度的不均匀分布及微波强度有关,微观上与微波吸收导致的非平衡行为直接关联。本文建议可以通过预先加热反应容器中的空间局域点从而在该点诱发微波热点,也可以通过激发特定分子中的局域基团来诱导分子内热点的形成。可控微波热点效应有望应用在其它领域,本文的结论表明从量子态层面理解宏观非平衡和非线性行为的物理机制是必要的。

submitted time 2020-10-26 Hits1098Downloads132 Comment 0

3. chinaXiv:202010.00065 [pdf]

非常规高温超导电子配对机制——过渡金属离子电子云的变化

周铁戈
Subjects: Physics >> Condensed Matter: Electronic Structure, Electrical, Magnetic, and Optical Properties

本文提出过渡金属离子电子云的变化是非常规高温超导中电子的配对媒介,这类似于晶格振动是常规超导中电子的配对媒介。采用TDDFT方法的计算结果表明,过渡金属离子电子云振动的频率接近晶格振动频率,能够被自由电子激发。三种铜氧化物高温超导的计算结果表明,超导转变温度与电子云振动的频率高度相关。同时阐述了电子云变化与晶格振动的不同,电子云振动的特殊性能够解释非传统超导中电子的实空间配对、赝能隙、d波对称和同位素效应等。

submitted time 2020-10-21 Hits1089Downloads128 Comment 0

4. chinaXiv:202010.00027 [pdf]

Evaluating agricultural water-use efficiency based on water footprint of crop values: a case study in Xinjiang of China

HAI Yang; LONG Aihua; ZHANG Pei; DENG Xiaoya; LI Junfeng; DENG Mingjiang
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Efficient agricultural water use is crucial for food safety and water conservation on a global scale. To quantitatively investigate the agricultural water-use efficiency in regions exhibiting the complex agricultural structure, this study developed an indicator named water footprint of crop values (WFV) that is based on the water footprint of crop production. Defined as the water volume used to produce a unit price of crop (m3/CNY), the new indicator makes it feasible to directly compare the water footprint of different crops from an economic perspective, so as to comprehensively evaluate the water-use efficiency under the complex planting structure. On the basis of WFV, the study further proposed an indicator of structural water-use coefficient (SWUC), which is represented by the ratio of water-use efficiency for a given planting structure to the water efficiency for a reference crop and can quantitatively describe the impact of planting structure on agricultural water efficiency. Then, a case study was implemented in Xinjiang Uygur Autonomous Region of China. The temporal and spatial variations of WFV were assessed for the planting industries in 14 prefectures and cities of Xinjiang between 1991 and 2015. In addition, contribution rate analysis of WFV for different prefectures and cities was conducted to evaluate the variations of WFV caused by different influencing factors: agricultural input, climatic factors, and planting structure. Results from these analyses indicated first that the average WFV of planting industries in Xinjiang significantly decreased from 0.293 m3/CNY in 1991 to 0.153 m3/CNY in 2015, corresponding to an average annual change rate of –3.532%. WFV in 13 prefectures and cities (with the exception of Karamay) has declined significantly during the period of 1991–2015, indicating that agricultural water-use efficient has effectively improved. Second, the average SWUC in Xinjiang decreased from 1.17 to 1.08 m3/CNY in the 1990s, and then declined to 1.00 m3/CNY in 2011–2015. The value of SWUC was highly consistent with the relative value of WFV in most prefectures and cities, showing that planting structure is one of the primary factors affecting regional agricultural water-use efficiency. Third, the contribution rate of WFV variations from human factors including agricultural input and planting structure was much more significant than that from climatic factors. However, the distribution of agricultural input and the adjustment of planting structure significantly differed among prefectures and cities, suggesting regional imbalances of agricultural development. This study indicated the feasibility and effectiveness of controlling agricultural water use through increasing technical input and rational selection of crops in the face of impending climate change. Specifically, we concluded that, the rational application of chemical fertilizers, the development of the fruit industry, and the strict restriction of the cotton industry should be implemented to improve the agricultural water-use efficiency in Xinjiang.

submitted time 2020-10-20 From cooperative journals:《Journal of Arid Land》 Hits1051Downloads138 Comment 0

5. chinaXiv:202010.00004 [pdf]

REBCO短样经热处理后的临界电流能力测试与性能退化情况分析

Lang Qin; QL Wang; Lei Wang; HB Sun; JH Liu
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

REBCO超导磁体制作过程中,需要使用桥接连接相邻的双饼,桥接部位REBCO带材经过高温焊接过程,性能可能发生退化。本论文对REBCO材料性能退化进行了实际测试,并简单介绍了其原因。实验通过高温热处理来模拟REBCO带材桥接时的高温过程,获得了经过不同温度与时长热处理后的REBCO短样,并在液氮条件下进行了临界电流能力测试,与未经热处理的REBCO带材进行对比,分析了几种带材性能退化的程度及在实际磁体组装中的影响。本论文的结论能够对REBCO带材的处理、接头的工艺和磁体的制作起到一定积极作用。

submitted time 2020-10-12 Hits2525Downloads265 Comment 0

6. chinaXiv:201910.00072 [pdf]

不确定性原理与客观确定性判则

段德龙
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

[目的] 分析解决不确定性原理及量子理论在物理诠释方面的分歧。 [方法] 对海森堡不确定性原理数学关系式的原始推导、物理涵义以及爱因斯坦光子箱思想实验进行了重新检视分析,并考察了不同作用图景下该关系式的极限。 [结果] 在电磁作用图景下,通过对量子力学量的统计分布及其全概率空间的分析,首次获得了非统计诠释下的不确定性关系式在数学上被破坏的结果;利用傅里叶变换,导出了虚拟作用图景下相应共轭力学量的标准差约束关系式;通过考察电磁作用图景、引力作用图景以及虚拟作用图景所构成的集合,率先得到了微观量子客体力学状态的确定性判则;经过对爱因斯坦光子箱思想实验的重新检视分析,证伪了玻尔在索尔维会议上的论证结论。 [局限]未分析量子纠缠。 [结论] ①非统计诠释存在逻辑矛盾,不确定性关系、现行量子力学理论仅在统计诠释下,才能对微观量子客体在电磁作用图景中的力学状态作出恰当的描述;② 确定性判则显示,微观粒子的力学状态具有客观确定性,其波函数是对电磁作用图景下的微观粒子力学状态统计呈现相的表述;量子力学非统计诠释所指称的个体几率性实质是微观粒子与作用图景之间互作用统计呈现相的概率反映。

submitted time 2020-09-28 Hits17459Downloads1219 Comment 0

7. chinaXiv:202009.00053 [pdf]

A study of a scalar field probes micro space-time

Jian-Bo Deng; Miao-Yi Deng; Qi-Qi Fan
Subjects: Physics >> The Physics of Elementary Particles and Fields

In this work, we try to find a way to describe the physical law of micro-world under the frame of a space-time theory. By introducing a scalar field D(x), we rewrite the action of conventional field theory and the Lagrangian describing the motion of the particle, where a modified space-time relation is obtained. To prove the correctness of this attempt, we derive the Klein-Gordon equation by the Hamilton-Jacobi method in four dimensional form.

submitted time 2020-09-17 Hits2747Downloads331 Comment 0

8. chinaXiv:202009.00012 [pdf]

Shadows of rotating Hayward-de Sitter black holes with astrometric observables

Peng-Zhang He; Qi-Qi Fan; Hao-Ran Zhang; Jian-Bo Deng
Subjects: Physics >> Geophysics, Astronomy, and Astrophysics

Motivated by recent work on rotating black hole shadow [Phys. Rev. D101, 084029 (2020)], we investigate the shadow behaviors of rotating Hayward-de Sitter black hole for static observers at a finite distance in terms of astronomical observables. This paper uses the newly introduced distortion parameter in [arXiv:2006.00685] to describe the shadow's shape quantitatively. We show that the spin parameter would distort shadows and the magnetic monopole charge would increase the degree of deformation. At the same time, the distortion could be relieved because of the cosmological constant and the distortion would increase with the distance from the black hole. Besides, the spin parameter, magnetic monopole charge and cosmological constant increase will cause the shadow to shrink.

submitted time 2020-09-09 Hits5677Downloads407 Comment 0

9. chinaXiv:202009.00011 [pdf]

The cosmological constant from space-time discreteness

Qi-Qi Fan; Cong Li; Hao-Ran Zhang; Peng-Zhang He,; Jian-Bo Deng
Subjects: Physics >> The Physics of Elementary Particles and Fields

We regard the background of space-time as a physical system composed of discrete volume elements at the Planck scale and get the internal energy of space-time by Debye model. A temperature-dependent minimum energy limit of the particles is proposed from the thermal motion part of the internal energy. As decreases of the temperature caused by the expansion of the universe, more and more particles would be "released" because of the change of the energy limit, we regard these new particles as a source of dark energy. The minimum energy limit also leads to a corrected number of particles in universe and a modified conservation equation. According to the modified conservation equation, an effective cosmological constant consistent with its observed value is obtained.

submitted time 2020-09-06 Hits3831Downloads340 Comment 0

10. chinaXiv:202008.00089 [pdf]

On the description of particle system motion

吴峰
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Based on the concepts of infinitesimal and super real time-space composed of monads, the equations describing the particle flow are proposed. After the initial conditions are given, the state of the particle system at any time can be obtained by solving these equations. The physical properties of the granular matter, such as the moving velocity, the rotation angle, the angular velocity of rotation, the temperature, the pressure, the density, the mass, etc. at any time and space position are obtained. It is also to obtain that the translational motion is not dependent on rotation motion ofthe particles and can be separately analyzed. For a stationary particle system, theconditions that must be met by the force and force moment on the particles in thesystem are given. On this basis, the properties of the granular matter at rest can befurther explored for.

submitted time 2020-08-25 Hits3963Downloads388 Comment 0

12345678910  Last  Go  [193 Pages/ 1925 Totals]