4,379 research outputs found
Global polarization of QGP in non-central heavy ion collisions at high energies
Due to the presence of a large orbital angular momentum of the parton system
produced at the early stage of non-central heavy-ion collisions, quarks and
anti-quarks are shown to be polarized in the direction opposite to the reaction
plane which is determined by the impact-parameter and the beam momentum. The
global quark polarization via elastic scattering was first calculated in an
effective static potential model, then using QCD at finite temperature with the
hard-thermal-loop re-summed gluon propagator. The measurable consequences are
discussed. Global hyperon polarization from the hadronization of polarized
quarks are predicted independent of the hadronization scenarios. It has also
been shown that the global polarization of quarks and anti-quarks leads also to
spin alignment of vector mesons. Dedicated measurements at RHIC are underway
and some of the preliminary results are obtained. In this presentation, the
basic idea and main results of global quark polarization are presented. The
direct consequences such as global hyperon polarization and spin alignment are
summarized.Comment: plenary talk at the 19th International Conference on
Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006), Shanghai, China,
November 14-20, 200
Elliptic flow of meson and strange quark collectivity at RHIC
Based on A Multi-Phase Transport (AMPT) model, we have studied the elliptic
flow of mesons from reconstructed decay channel at
the top Relativistic Heavy Ion Collider energy at Brookhaven National
Laboratory. The dependences of on transverse momentum and
collision centrality are presented and the rescattering effect of mesons
in the hadronic phase is also investigated. The results show that experimental
measurement of for mesons can retain the early collision
information before decays and that the value obeys the
constituent quark number scaling which has been observed for other mesons and
baryons. Our study indicates that the mostly reflects partonic
level collectivity developed during the early stage of the nucleus-nucleus
collision and the strange and light up/down quarks have developed similar
angular anistropy properties at the hadronization.Comment: 5 pages and 5 figures; accepted by Physical Review
A knowledge-based ideation approach for bio-inspired design
Bio-inspired design (BID) involves generating innovative ideas for engineering design by drawing inspiration from natural biological phenomena and systems, using a form of design-by-analogy. Despite its many successes, BID approaches encounter research challenges including unstructured data and existing models that hinder comprehension and processing, limited focus on finding biological knowledge compared to defined problems, and insufficient guidance of the ideation process with algorithms. This paper proposes a knowledge-based approach to address the challenges. The approach involves transforming unstructured data into structured knowledge, including information about natural sources, their benefits, and applications. The structured knowledge is then used to construct a semantic network, enabling designers to retrieve information for BID in two ways. Furthermore, a three-step ideation method is developed to encourage divergent thinking and explore additional potential solutions by drawing inspiration and utilizing knowledge. The knowledge-based BID approach is implemented as a tool and design cases are conducted to illustrate the process of applying this tool for BID
Quality Evaluation Of Heshouwu, A Wudang Taoist Medicine In China
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System Framework for Digital Monitoring of the Construction of Asphalt Concrete Pavement Based on IoT, BeiDou Navigation System, and 5G Technology
In the construction of asphalt pavement, poor quality is often the main reason for damage to the pavement, which necessitates the use of monitoring systems during the construction stage. Therefore, this study focuses on building an asphalt concrete pavement construction monitoring system to monitor the construction phase. Through a literature review and semi-structured interviews with industry experts, this paper provides an in-depth understanding of the goals and obstacles of asphalt pavement monitoring and discusses directions for improvement. Subsequently, based on the analysis of the interview results, a system framework for asphalt concrete pavement construction monitoring was constructed, and the system was successfully developed and applied to a highway construction project. The results show that the monitoring system significantly improves the construction quality of asphalt concrete pavement, improves the intelligent level of pavement construction management, and promotes the digital development of highway construction
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