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1. chinaXiv:202101.00052 [pdf]

Geochemical baseline determination and contamination of heavy metals in the urban topsoil of Fuxin City, China

ZHANG Hua; YU Miao; XU Hongjia; WEN Huan; FAN Haiyan; WANG Tianyi; LIU Jiangang
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Urban topsoil is the most frequent interface between human society and natural environment. The accumulation of heavy metals in the urban topsoil has a direct effect on residents' life and health. The geochemical baseline of heavy metals is an objective description of the general level of heavy metals in the urban topsoil. Meanwhile, the determination of geochemical baseline is necessary for regional environmental management, especially in coal cities prone to heavy metal pollution. Heavy metal pollution has become an environmental problem in Fuxin City, China for a long time. To establish the geochemical baseline of heavy metals in the topsoil of Fuxin City and to evaluate the ecological risk of the topsoil, we collected 75 topsoil samples (0–20 cm) and analyzed the concentrations of Cu, Ni, Zn, Pb, Cr, Cd, Hg and As through X-ray fluorescence spectrometry, atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. We determined the geochemical baseline of heavy metals in the topsoil of Fuxin City by using iteration removal, box-whisker plot, cumulative frequency curve and reference metal normalization; evaluated the contamination risk and ecological risk of the topsoil by using the baseline factor index, Nemerow index and Hakanson potential ecological risk index; and identified the source category of heavy metals in the topsoil by using a pedigree clustering heatmap. Results showed that the geochemical baseline values were 42.86, 89.34, 92.23, 60.55, 145.21, 0.09, 0.08 and 4.17 mg/kg for Cu, Ni, Zn, Pb, Cr, Cd, Hg and As, respectively. The results of Nemerow index and Hakanson potential ecological risk index indicated that the urban topsoil in the study area was slightly contaminated and suffering low potential ecological risk. The main contaminated areas dominated in the middle part and northeast part of the study area, especially in the western Haizhou Strip Mine. The result of baseline factor index indicated that Hg and Cd were the major pollution elements. Using a pedigree clustering heatmap, we divided the sources of these heavy metals into three types: type I for Ni and Cr, largely represented the enrichment of heavy metals from natural sources; type II for Cu, Pb, Zn, Cd and As, mainly represented the enrichment of heavy metals from anthropogenic sources; and type III for Hg, represented the form of both natural and anthropogenic inputs.

submitted time 2021-01-15 From cooperative journals:《Journal of Arid Land》 Hits45Downloads19 Comment 0

2. chinaXiv:202101.00003 [pdf]

On dark matter

Xian-Qiao Yu
Subjects: Physics >> The Physics of Elementary Particles and Fields

In this article, first we review the current evidences for the existence of dark matter, and then we examine possible candidates for dark matter. Possible experiments are suggested which might test the nature of dark matter.

submitted time 2021-01-05 Hits440Downloads84 Comment 0

3. chinaXiv:202012.00021 [pdf]

Experimental Observation of Thermal Energies of Helium-4 Superflows

Yu, Yongle; Luo, Hailin
Subjects: Physics >> Condensed Matter: Electronic Structure, Electrical, Magnetic, and Optical Properties

We observed a counter-intuitive remarkable heating phenomenon generated by helium-4 superflows. This phenomenon establishes that superflows carry thermal energies and entropies, which is in contrast to the hypothesis of the two-fluid model. Quantum many-body theory of superfluids provides a natural understanding of the phenomenon.

submitted time 2020-12-12 Hits899Downloads138 Comment 0

4. 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 Hits5462Downloads685 Comment 0

5. 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 Hits3140Downloads288 Comment 0

6. 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 Hits3340Downloads306 Comment 0

7. 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》 Hits2886Downloads273 Comment 0

8. 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 Hits4761Downloads417 Comment 0

9. 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 Hits22611Downloads1435 Comment 0

10. 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 Hits4792Downloads451 Comment 0

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