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1. chinaXiv:202201.00098 [pdf]

新疆草地生态系统健康评价体系构建

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

草地是重要的陆地生态系统类型,草地生态系统健康评价是干旱区草地健康研究的重要组成部分。新疆位于中亚干旱区,典型的“山盆”地形结构孕育的天然草地具有鲜明的垂直地带性,又因水热组合差异形成了丰富多样的草地类型,这使得新疆草地生态系统健康评价成为一项系统的复杂工作,急需构建适用于新疆的草地生态系统健康评价体系。本研究以新疆草地生态系统为研究对象,构建新疆草地生态系统健康评价总体框架,从数据来源与评价方法阐述了新疆草地生态系统健康评价体系。基于草地样方、生物气象与多源遥感数据建立草地生态系统基础数据库,针对草地健康评价方法,明确评价目标,确定评价区域与参照系统,进而筛选评价指标,最后通过选择评价方法开展草地健康评价,采用四分法将评价结果划分为健康、亚健康、警戒与崩溃。采用该体系在新疆和田地区民丰县开展草地生态系统健康评价,结果显示围栏内的温性荒漠类草地处于健康状态,围栏外的温性荒漠类草地为亚健康状态。通过构建新疆草地生态系统健康评价体系,能够为基层草原部门开展草地生态健康评价提供参考,促进草地可持续发展。

submitted time 2022-01-26 From cooperative journals:《干旱区研究》 Hits18Downloads8 Comment 0

2. chinaXiv:202201.00064 [pdf]

Determination of neutron-skin thickness using configurational information entropy

Ma, Chun-Wang ; Liu, Yi-Pu; Wei, Hui-Ling; Pu, Jie; Cheng, Kai-Xuan; Wang, Yu-Ting
Subjects: Physics >> Nuclear Physics

Configurational information entropy (CIE) theory was employed to determine the neutron skin thickness of neutron-rich calcium isotopes. The nuclear density distributions and fragment cross-sections in 350 MeV/u 40-60Ca + 9Be projectile fragmentation reactions were calculated using a modified statistical abrasion-ablation model. CIE quantities were determined from the nuclear density, isotopic, mass, and charge distributions. The linear correlations between the CIE determined using the isotopic, mass, and charge distributions and the neutron skin thickness of the projectile nucleus show that CIE provides new methods to extract the neutron skin thickness of neutron-rich nuclei.

submitted time 2022-01-21 From cooperative journals:《Nuclear Science and Techniques》 Hits186Downloads63 Comment 0

3. chinaXiv:202201.00065 [pdf]

Anisotropy flows in Pb–Pb collisions at LHC energies from parton scatterings with heavy quark trigger

Wang, Hai; Chen, Jin-Hui
Subjects: Physics >> Nuclear Physics

By implementing an additional heavy quark–antiquark pair production trigger in a multiphase transport (AMPT) model, we study the effect on anisotropy flows of identified particles with a focus on charged particles and quarkonium (J/Ψ and Υ). A systematic increase in the collision rate for active partons in the AMPT model with such an implementation has been observed. It leads to a slight increase of identified particles anisotropy flows as a function of transverse momentum (pT ) and rapidity, and gives a better description of the experimental data of elliptic flow toward larger pT . Our approach provides an efficient way to study the heavy quark dynamics in the AMPT model at LHC energies.

submitted time 2022-01-21 From cooperative journals:《Nuclear Science and Techniques》 Hits183Downloads60 Comment 0

4. chinaXiv:202201.00057 [pdf]

Ladderpath theory: A new look at complexity and information

Liu, Yu; Di, Zengru; Gerlee, Philip
Subjects: Information Science and Systems Science >> Basic Disciplines of Information Science and Systems Science

The notion of information and complexity are important concepts in many scientific fields such as molecular biology, evolutionary theory and exobiology. Most measures of these quantities, such as Shannon entropy and related complexity measures, are only defined for objects drawn from a statistical ensemble and cannot be computed for single objects. We attempt to fill this gap by introducing the notion of a ladderpath which describes how an object can be decomposed into an hierarchical structure using repetitive elements. From the ladderpath two measures naturally emerge: the ladderpath-index and the order-index, which represent two axes of complexity. We show how the ladderpath theory can be applied to both strings and spatial patterns and argue that all systems that undergo evolution can be described as ladderpaths. Further, we discuss possible applications to human language and origins of life. The ladderpath theory provides a novel characterization of the information that is contained in a single object (or a system) and could aid in our understanding of evolving systems and the origin of life in particular.

submitted time 2022-01-19 Hits261Downloads95 Comment 0

5. chinaXiv:202201.00035 [pdf]

基于氘核碎裂的高能中子束的产生机制的研究

Wang, Rensheng; Ou, Li; Xiao, Zhigang
Subjects: Physics >> Nuclear Physics

在改进的量子分子动力学模型框架下,研究了高能氘核在重靶核作用下的碎裂过程,尤其近零度角产生的中子。模拟重现了 102 MeV d+C 反应中实验测量的中子双微分截面。根据模型与实验结果的一致性,论证了通过氘核在碳靶上碎裂而产生高能中子束的可行性。但因氘核内部核子的费米运动,使得包含实验室0°在内的中子能量具有相当大的能量展宽。基于模型计算,通过测量氘核碎裂过程中出射的伴随质子,出射中子能量可约束在5%(1σ)以内。进一步,本工作论证了基于伴随质子测量的单能高能中子束产生的可行性。

submitted time 2022-01-07 Hits2508Downloads159 Comment 0

6. chinaXiv:202201.00011 [pdf]

Determination of neutron-skin thickness using configurational information entropy

Ma, Chun-Wang ; Liu, Yi-Pu ; Wei, Hui-Ling ; Pu, Jie ; Cheng, Kai-Xuan ; Wang, Yu-Ting
Subjects: Physics >> Nuclear Physics

Configurational information entropy (CIE) theory was employed to determine the neutron skin thickness of neutron-rich calcium isotopes. The nuclear density distributions and fragment cross-sections in 350 MeV/u 40060Ca + 9Be projectile fragmentation reactions were calculated using a modified statistical abrasion-ablation model. CIE quantities were determined from the nuclear density, isotopic, mass, and charge distributions. The linear correlations between the CIE determined using the isotopic, mass, and charge distributions and the neutron skin thickness of the projectile nucleus show that CIE provides new methods to extract the neutron skin thickness of neutron-rich nuclei.

submitted time 2021-12-31 Hits2586Downloads159 Comment 0

7. chinaXiv:202112.00131 [pdf]

用CSHINE重建重离子反应中的裂变事件

刁昕玥; 关分海; 王轶杰; 秦雨浩; 秦智; 郭栋; 吴强华; 司大伟; 赵暄; 肖圣; 张耀鹏; 魏向伦; 邹海川; 杨贺润; 马朋; 胡荣江; 段利敏; Artur, Dobrowolski; Krzysztof, Pomorski; 肖志刚
Subjects: Physics >> Nuclear Physics

我们研究了在CSHINE上重建$ 25 MeV/u ^{86}Kr +^{208}Pb$ 反应中快裂变事件的方法。裂变碎片由三个大面积平行板雪崩计数器进行探测,它可以提供碎片的位置和到达的时间信息。起始时间信息由回旋加速器的高频信号给出。我们利用两个裂变碎片的速度,重建了裂变事件。裂变碎片的速度分布和方位差的展宽均随折叠角的增大而减小,这与快速裂变发生的图像一致。同时,裂变轴的各向异性角分布也一致地揭示了裂变事件的动力学特征。

submitted time 2021-12-25 Hits2676Downloads172 Comment 0

8. chinaXiv:202109.00023 [pdf]

Spectrum Broadening due to Nonselective Linear Absorption

Zhang, Xingchu ; She, Weilong
Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics

The position and linewidth of emission spectrum reflect the physical information inside an object observed. So keeping them from distortion is very important in the measurement of spectrum. However, the emission spectra are not always kept their forms. We let the near-infrared emission of a sodium lamp pass through a nonselective linear absorbing filter and then observe the emission spectrum. It is found that the spectral lines will be broadened when the power of the emission just after the filter becomes low enough, and the lower the transmittance of the filter is, the more obvious the effect is. This is another broadening effect different from the known ones and is likely to be another independent evidence for discrete wavelet structure of classical plane light waves.

submitted time 2021-12-20 Hits6928Downloads470 Comment 0

9. chinaXiv:202112.00121 [pdf]

Micromagnetic simulation for probabilistic magnetization switching process of a spin-orbit true random number generator

Yi Cao; Nan Zhang
Subjects: Physics >> Condensed Matter: Electronic Structure, Electrical, Magnetic, and Optical Properties

True random number generator (TRNG) is an important component for modern information security technologies. Among the candidates, TRNG with spin-orbit torque (SOT)-induced probabilistic magnetization switching is competitive for its advantages in anti-radiation, unlimited endurance, robust stability, and broad temperature range. However, realization of a SOT-TRNG requires intensive understanding of the magnetic dynamic process under a spin-orbit current. Here, we performed micromagnetic simulation of the SOT-induced probabilistic magnetization switching by using Mumax 3. Without thermal noise, identical magnetic moment precessions were found between repeated simulation cycles, resulting in deterministic magnetization switching. When thermal noises were taken into account, stochastic precession trails and thereby probabilistic magnetization switching were finally obtained. Our results suggest the Mumax 3 to be a practical tool for simulating the probabilistic magnetization switching behavior of a SOT-TRNG, as well as highlighting the crucial role of thermal noise during the during the simulation.

submitted time 2021-12-18 Hits2268Downloads181 Comment 0

10. chinaXiv:202112.00082 [pdf]

博斯腾湖小湖区湿地生态需水量阈值研究

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

湿地生态需水量阈值是其生态系统发生质变的临界条件,一旦某阈值被超越,系统的某些 物质平衡关系、功能、健康就会受到影响,而月尺度的湿地生态需水量阈值研究有助于水资源优化 配置。针对博斯腾湖小湖区芦苇沼泽镶嵌交错明水塘道的景观结构,结合遥感数据同步获取大范 围数据的优势,利用长时间序列的水面面积频率分析,确定月尺度最小、中等和理想状态的小湖区 湿地明水区面积;采用蒸发皿观测值计算法,核算小湖区湿地的月尺度最小、中等和理想生态耗水量。结果表明:小湖区湿地全年月平均最小、中等和理想的生态水面面积为 14.47 km2、21.56 km2、 26.75 km2;小湖区湿地生长季 3—9 月最小生态需水量为 0.22×108 m3、0.35×108 m3、0.44×108 m3、0.51×108 m3、0.39×108 m3、0.41×108 m3、0.28×108 m3,其中 6 月最大,3 月最小,小湖区湿地年最小生态 需水量约为 3.02×108 m3;如若同时满足小湖区湿地生态目标芦苇生长所需动态水位,3—9 月最小 生态需水量为 0.40×108 m3、0.52×108 m3、0.79×108 m3、0.86×108 m3、2.31×108 m3、0.41×108 m3、0.28×108 m3,其中 7 月最大,9 月最小,小湖区湿地年最小生态需水量约为 5.99×108 m3。本研究计算结果可用于小湖区湿地年、月尺度来水分配及出水调控,有利于提高区域水资源利用效率,确保小湖生态可持续发展。

submitted time 2021-12-14 From cooperative journals:《干旱区地理》 Hits2539Downloads134 Comment 0

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