Search for charm-quark production via dimuons in neutrino telescopes

Dimuon events induced by charm-quark productions from neutrino deep inelastic scattering (DIS) processes have been studied in traditional DIS experiments for decades. The recent progress in neutrino telescopes makes it possible to search for such dimuon events at energies far beyond the laboratory scale. In this study, we construct a simulation framework to calculate yields and distributions of dimuon signals in an IceCube-like km³ scale neutrino telescope. Owing to the experimental limitation in the resolution of double-track lateral distance, only dimuons produced outside the detector volume are considered. Detailed information about simulation results for a 10-year exposure is presented. As an earlier paper[Physical Review D 105, 093005 (2022)] and ours report on a similar situation, we use that paper as a baseline to conduct comparisons. We then estimate the impacts of different calculation methods of muon energy losses. Finally, we study the experimental potential of dimuon searches under the hypothesis of single-muon background only. Our results based on a simplified double-track reconstruction indicate a moderate sensitivity, especially with the ORCA configuration. Further developments on both the reconstruction algorithm and possible detector designs are thus required and are under investigation.     

地圈动力学的THMCB多元关联过程及其分析

地圈中广泛发育的动力学过程属于多元关联过程,它们是在岩土圈与水圈、大气圈、生物圈相互作用中进行的。它们的活动可以概括为热力学、流体力学、固体力学、化学和生物学等基本物质运动的作用及系统的演化。由于它们之间有着互动影响和制约,以及由此引发的能量的转换和参数的变异,因而密切相关。本文建议确立THMCB多元关联过程的概念,开展多元关联过程的研究和分析,以期对地圈动力学过程进行系统有效的综合评价和预测。     

Herbart and “Psychological Research on the Strength of a Given Impression”

Herbart in 1812 published an analysis of sensory process formation, using differential equations, and attempted to relate within the same model considerations of upper and lower limits of sensory intensity, and the time course of process evolution within those limits. The analysis he proposed anticipates later psychophysics by at least half a century. It is perhaps the earliest example of a formal nonlinear dynamical treatment in theoretical psychology.     

干摩擦条件下聚甲醛塑料动力齿轮传动啮合效率的分析研究与计算

从高分子材料的粘弹性力学模型出发，推导出塑料与钢齿轮副粘滞发热损耗功率的计算公式，并以此为基础，结合塑料材料的弹性模量和滑动摩擦系数的测试数据，考虑温度、弹性模量、摩擦系数及载荷之间复杂的偶合关系，研究并提出了一种在干摩擦条件下塑料与钢齿轮副啮合效率的数值计算方法，运用这种方法，可以方便地获得任意啮合位置的瞬时啮合效率及一个啮合循环中的平均啮合效率，通过对聚甲醛与４５＾＃钢齿轮副的计算发现，在干摩     

填充聚四氟乙烯对尼龙6摩擦磨损性能影响的研究

用Timken试验机考察了热压成形的PTFE填充尼龙6在干摩擦状态下的摩擦磨损性能及PTFE填充量、滑动速度和负荷对摩擦磨损的影响,并用X-光电子能谱仪(XPS)和电子探针(EPMA)研究了金属偶件摩擦表面转移膜的组成与形貌。结果表明,在给定的试验条件下,填充PTFE能够有效地改善尼龙6的摩擦磨损性能,PTFE的填充量在8～20％(vol)之间时的效果较好,8％PTFE填充尼龙6的PV值可比纯尼龙6的高1倍;填充PTFE的效用主要取决于转移膜的特性和PTFE在转移膜中的富集量。     

Defect assessment procedure based on ductile tearing process

Strain hardening, crack growth resistance and nonuniform load distribution have significant effects on the ductile tearing process. A defect assessment procedure incorporating with the above features is proposed in the present paper, with the final appearance of “design curves” to facilitate engineering applications.     

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简述了多刚体系统接触及碰撞动力学的研究方法，详细回顾了考虑库仑摩擦的多刚 体系统的能量不协调、Painlev\'{e}疑难及碰撞恢复系数等该领域中难点问题的研 究进展，探讨了解决该难点问题的研究思路，指出了未来该领域的研究方向.     

Laboratory optimization of the soil digging process

A new idea for the optimization of digging using earth-working machinery is presented and experimentally verified. This idea is based on the conclusions derived from previous papers presented by the same authors, that the soil cutting trajectories incorporating the generated shear band as a part of them are the optimal ones. Dividing the whole excavation task into several repeatable cycles for which the soil free boundary before and after the experiment are similar the optimization of a single cycle plays a significant role in the energetic efficiency of the whole task. A single cycle of the working process is defined using several basing parameters. The influence of each parameter on the specific unit energy of the process was experimentally verified. Finally, a set of values for the discussed parameters is recommended for the particular soil and tool shape.     

力学系统的扩散运动及量子化

研究位形由扩散过程定义的力学系统．利用变分的路径计算给出系统广义坐标表示的动力学方程，该方程连同连续方程描述系统量子波动随时间演化的概率进程．文末的表示定理指出，在满足适当正规条件的扩散过程和Ｓｃｈｒｄｉｎｇｅｒ方程的解（波函数）之间存在一一对应关系     

摩擦过程中真实接触面积的灰色分析

灰色系统理论是近几年以随机过程为研究对象而形成和发展起来的，在农业和自动控制等方面的研究与应用发展较快．为了使这种理论应用于摩擦学研究领域，从光全反射测量和计算机数值计算两方面，考察了粗糙表面接触时真实接触面积的随机特性，指出摩擦过程中的真实接触面积是一种含有随机成分的变化量，研究目标应当侧重于真实接触面积的变化趋势和范围，而不是它的精确解．在此基础上，首次利用灰色系统理论，分别对静态和动态接触条件下真实接触面积的变化规律进行了灰色分析，建立了精度比较高的预测真实接触面积的灰色模型ＣＭ（１，１）．这种模型对动、静接触面积的计算值与实测值具有良好的一致性，可以用于动态跟踪描述摩擦过程中真实接触面积的变化规律