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Antireflection or impedance matching is a topic that has been extensively researched by the optical and microwave communities over the past century and until today. However, due to the diverging wave impedances of TE (s) and TM (p) polarizations with increasing incident angle, it is impossible to achieve perfect matching simultaneously for both polarizations at an oblique incident angle with a single conventional matching layer. In this paper, we show that simultaneous perfecting matching of an arbitrary substrate at an arbitrary incident angle from air is possible with a single uniaxial metamaterial matching layer (UMML) that possesses specific permittivity and permeability tensors. We demonstrate this concept by synthesizing a physical UMML to match a high-index ({\epsilon}r= 10.2) substrate at 45{\deg}. The required permittivity and permittivity tensors of the UMML are achieved through the judicious control of the tangential and longitudinal electric and magnetic responses. Around -30 dB reflections are observed for both polarizations at the design angle. Building on the UMML concept, we design a novel radome in microwave regime with a near omni-directional matching performance. For incident angles from 0{\deg}-85{\deg}, reflections remain below -14 dB for both polarizations. To our best knowledge, this is the widest angular range that has been achieved while maintaining less than 5% power reflection for both polarizations. The proposed UMML concept offers a new paradigm for designing high-performance microwave, terahertz, and optical devices.

In traffic systems, cooperative driving has attracted the researchers attentions. A lot of works attempt to understand the effects of cooperative driving behavior and/or time delays on traffic flow dynamics for specific traffic flow model. This paper is a new attempt to investigate analyses of linear stability and weak nonlinear for the general car-following model with consideration of cooperation and time delays. We derive linear stability condition and study that how the combinations of cooperation and time delays affect the stability of traffic flow. Burgers equation and Korteweg de Vries (KdV) equation for car-following model considering cooperation and time delays are derived. Their solitary wave solutions and constraint conditions are concluded. We investigate the property of cooperative optimal velocity(OV) model which estimates the combinations of cooperation and time delays about the evolution of traffic waves using both analytic and numerical methods. The results indicate that delays and cooperation are model-dependent, and cooperative behavior could inhibit the stabilization of traffic flow. Moreover, delays of sensing to relative motion are easy to trigger the traffic waves; delays of sensing to host vehicle are beneficial to relieve the instability effect a certain extent.