1,117 research outputs found
Revisit of directed flow in relativistic heavy-ion collisions from a multiphase transport model
We have revisited several interesting questions on how the rapidity-odd
directed flow is developed in relativistic Au+Au collisions at
= 200 and 39 GeV based on a multiphase transport model. As the
partonic phase evolves with time, the slope of the parton directed flow at
midrapidity region changes from negative to positive as a result of the later
dynamics at 200 GeV, while it remains negative at 39 GeV due to the shorter
life time of the partonic phase. The directed flow splitting for various quark
species due to their different initial eccentricities is observed at 39 GeV,
while the splitting is very small at 200 GeV. From a dynamical coalescence
algorithm with Wigner functions, we found that the directed flow of hadrons is
a result of competition between the coalescence in momentum and coordinate
space as well as further modifications by the hadronic rescatterings.Comment: 8 pages, 8 figures, version after major revisio
Associated production of the top-pions and single top at hadron colliders
In the context of topcolor assisted technicolor(TC2) models, we study the
production of the top-pions with single top quark via the
processes and ,
and discuss the possibility of detecting these new particles at Tevatron and
LHC. We find that it is very difficult to observe the signals of these
particles via these processes at Tevatron, while the neutral and charged
top-pions and can be detecting via considering
the same sign top pair event and the (or )
event at LHC, respectively.Comment: latex files,14 pages, 7 figures. Accepted for publication in Phys.
Rev.
5-(2,4-Dichlorophenoxy)-1,3-dimethyl-1H-pyrazole-4-carbaldehyde
In the title molecule, C12H10Cl2N2O2, the benzene and pyrazole rings form a dihedral angle of 72.8 (3)°. In the crystal, weak intermolecular C—H⋯O hydrogen bonds link the molecules into chains along [01]
Generic Design Methodology for Smart Manufacturing Systems From a Practical Perspective. Part II—Systematic Designs of Smart Manufacturing Systems
In a traditional system paradigm, an enterprise reference model provides the guide for practitioners to select manufacturing elements, configure elements into a manufacturing system, and model system options for evaluation and comparison of system solutions against given performance metrics. However, a smart manufacturing system aims to reconfigure different systems in achieving high-level smartness in its system lifecycle; moreover, each smart system is customized in terms of the constraints of manufacturing resources and the prioritized performance metrics to achieve system smartness. Few works were found on the development of systematic methodologies for the design of smart manufacturing systems. The novel contributions of the presented work are at two aspects: (1) unified definitions of digital functional elements and manufacturing systems have been proposed; they are generalized to have all digitized characteristics and they are customizable to any manufacturing system with specified manufacturing resources and goals of smartness and (2) a systematic design methodology has been proposed; it can serve as the guide for designs of smart manufacturing systems in specified applications. The presented work consists of two separated parts. In the first part of paper, a simplified definition of smart manufacturing (SM) is proposed to unify the diversified expectations and a newly developed concept digital triad (DT-II) is adopted to define a generic reference model to represent essential features of smart manufacturing systems. In the second part of the paper, the axiomatic design theory (ADT) is adopted and expanded as the generic design methodology for design, analysis, and assessment of smart manufacturing systems. Three case studies are reviewed to illustrate the applications of the proposed methodology, and the future research directions towards smart manufacturing are discussed as a summary in the second part
Generic Design Methodology for Smart Manufacturing Systems from a Practical Perspective, Part I—Digital Triad Concept and Its Application as a System Reference Model
Rapidly developed information technologies (IT) have continuously empowered manufacturing systems and accelerated the evolution of manufacturing system paradigms, and smart manufacturing (SM) has become one of the most promising paradigms. The study of SM has attracted a great deal of attention for researchers in academia and practitioners in industry. However, an obvious fact is that people with different backgrounds have different expectations for SM, and this has led to high diversity, ambiguity, and inconsistency in terms of definitions, reference models, performance matrices, and system design methodologies. It has been found that the state of the art SM research is limited in two aspects: (1) the highly diversified understandings of SM may lead to overlapped, missed, and non-systematic research efforts in advancing the theory and methodologies in the field of SM; (2) few works have been found that focus on the development of generic design methodologies for smart manufacturing systems from the practice perspective. The novelty of this paper consists of two main aspects which are reported in two parts respectively. In the first part, a simplified definition of SM is proposed to unify the existing diversified expectations, and a newly developed concept named digital triad (DT-II) is adopted to define a reference model for SM. The common features of smart manufacturing systems in various applications are identified as functional requirements (FRs) in systems design. To model a system that is capable of reconfiguring itself to adapt to changes, the concept of IoDTT is proposed as a reference model for smart manufacturing systems. In the second part, these two concepts are used to formulate a system design problem, and a generic methodology, based on axiomatic design theory (ADT), is proposed for the design of smart manufacturing systems
5-Chloro-1,3-dimethyl-1H-pyrazole-4-carbaldehyde
In the title compound, C6H7ClN2O, the molecules are situated on mirror planes, so H atoms of two methyl groups were treated as rotationally disordered over two orientations each. The crystal packing exhibits weak intermolecular C—H⋯O interactions and short Cl⋯N contacts of 3.046 (2) Å
Optical Flow Sensor/INS/Magnetometer Integrated Navigation System for MAV in GPS-Denied Environment
The drift of inertial navigation system (INS) will lead to large navigation error when a low-cost INS is used in microaerial vehicles (MAV). To overcome the above problem, an INS/optical flow/magnetometer integrated navigation scheme is proposed for GPS-denied environment in this paper. The scheme, which is based on extended Kalman filter, combines INS and optical flow information to estimate the velocity and position of MAV. The gyro, accelerator, and magnetometer information are fused together to estimate the MAV attitude when the MAV is at static state or uniformly moving state; and the gyro only is used to estimate the MAV attitude when the MAV is accelerating or decelerating. The MAV flight data is used to verify the proposed integrated navigation scheme, and the verification results show that the proposed scheme can effectively reduce the errors of navigation parameters and improve navigation precision
Extending the first-order post-Newtonian scheme in multiple systems to the second-order contributions to light propagation
In this paper, we extend the first-order post-Newtonian scheme in multiple
systems presented by Damour-Soffel-Xu to the second-order contribution to light
propagation without changing the virtueof the scheme on the linear partial
differential equations of the potential and vector potential. The spatial
components of the metric are extended to second order level both in a global
coordinates () and a local coordinates (). The
equations of (or ) are obtained from the field equations.The
relationship between and are presented in this paper also. In
special case of the solar system (isotropic condition is applied ()), we obtain the solution of . Finally, a further extension
of the second-order contributions in the parametrized post-Newtonian formalism
is discussed.Comment: Latex2e; 6 pages PS fil
Protection effect of sanguinarine on whole-body exposure of X radiation in BALB/c mice
To investigate the effects of sanguinarine (SAN) on acute radiation induced injury in mice, 45 mice were randomly divided into control, 10 Gy and SAN+10 Gy groups. Mice in the 10 Gy and SAN+10 Gy groups were exposed to single X-ray radiation with an accumulated dose of 10 Gy. Mice in the SAN+10 Gy group were administered intraperitoneally with 2.5 mg/kg body weight of SAN before radiation. Five days after radiation exposure, 5 mice from each group were sacrificed and samples of the small intestine, lung, spleen and liver were fixed for histopathological examinations. Compared with the 10 Gy group, radiation sickness was obviously delayed or attenuated in the SAN+10 Gy group. Survival analysis showed a significant difference between 2 radiation groups (PPara investigar os efeitos da sanguinarina (SAN) em lesões induzidas em ratos por radiação aguda, 45 ratos foram aleatoriamente divididos em grupo controle, grupo 10 Gy e grupo SAN+10 Gy. Os ratos dos grupos 10 Gy e SAN+10 Gy foram expostos à radiação de raio-X simples com uma dose acumulada de 10 Gy. Aos ratos do grupo SAN+10 Gy administraram-se, intraperitonealmente, 2.5 mg/kg de peso de SAN antes da radiação. Aos 5 dias de exposição à radiação, sacrificaram-se 5 ratos de cada grupo e retiraram-se amostras do intestino delgado, pulmões, baço e fígado para exames histopatológicos. Comparando com o grupo 10 Gy, a doença por radiação foi claramente atrasada e atenuada no grupo SAN+10 Gy. A análise de sobrevivência mostrou diferença significativa entre os dois grupos de radiação (
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