There has been growing interest in the possibility of testing more precisely the assumption of statistical isotropy of primordial density perturbations. If it is to be tested with galaxy surveys at distance scales < or = 10 Mpc, then nonlinear evolution of anisotropic power must be understood. To this end, we calculate the angular dependence of the power spectrum to third order in perturbation theory for a primordial power spectrum with a quadrupole dependence on the wave vector direction. Our results suggest that primordial power anisotropies will be suppressed by < or = 7% in the quasilinear regime. We also show that the skewness in the statistically anisotropic theory differs by no more than 1% from that in the isotropic theory.
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http://dx.doi.org/10.1103/PhysRevLett.100.071301 | DOI Listing |
Sci Rep
January 2025
Fugu Energy Investment Group Shagoucha Mining Co., Ltd.,, Fugu, 719000, China.
The formation and development of plastic zone in the surrounding rock is the essence of large deformation damage to the surrounding rock in deep, highly stressed roadway. The -850 m roadway of the Qujiang mine is laid flat longitudinally under the 805 working face and coal pillar, and under the influence of the mining movement of the upper working face and the pre-stressing pressure of the coal pillar, the periphery of the roadway is no longer a pure non-uniform stress field, but a non-uniform stress field with both vertical and horizontal dynamic pressure. Based on the Hoek-Brown strength criterion, the unified strength theory is modified and the nonlinear unified strength theory of rock is established by comprehensively considering the intermediate principal stress, rock properties and rock structure.
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January 2025
Department of Geography, Faculty of Science, Environment and Economy, University of Exeter, Exeter, UK.
Understanding the effects of multiple stressors has become a major focus in ecology and evolution. While many studies have investigated the combined effects of stressors, revealing massive variability, a mechanistic understanding that reconciles the diversity of multiple stressor outcomes is lacking. Here, we show how performance curves can fill this gap by revealing mechanisms that shape multiple stressor outcomes.
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January 2025
ENET Centre, VSB-Technical University of Ostrava, Ostrava, 708 00, Czech Republic.
Identifying the parameters of a solar photovoltaic (PV) model optimally, is necessary for simulation, performance assessment, and design verification. However, precise PV cell modelling is critical for design due to many critical factors, such as inherent nonlinearity, existing complexity, and a wide range of model parameters. Although different researchers have recently proposed several effective techniques for solar PV system parameter identification, it is still an interesting challenge for researchers to enhance the accuracy of the PV system modelling.
View Article and Find Full Text PDFJ Med Virol
January 2025
Department of Rheumatology and Immunology, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, Jiangsu, China.
Varicella, a highly contagious disease caused by the varicella-zoster virus (VZV), remains prevalent in China despite the introduction of the varicella vaccine in 1997. The current vaccination protocol in China involves a voluntary, self-funded single-dose regimen. This study aims to investigate the longevity of immune response in Chinese children following two-dose varicella vaccination administered at different intervals, with the objective of optimizing vaccination strategies.
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January 2025
The Fourth Engineering Co., LTD, China Railway Fourth Bureau, Hefei, 230012, People's Republic of China.
Research investigating the complex mechanical properties and energy evolution mechanisms of frozen calcareous clay under the influence of multiple factors is crucial for optimizing the artificial ground freezing method in shaft sinking, thereby enhancing construction quality and safety. In this study, a four-factor, four-level orthogonal test was devised, taking into account temperature, confining pressure, dry density, and water content. The complex nonlinear curvilinear relationship between deviatoric stress, volume strain, and axial strain of frozen calcareous clay under different interaction levels was analyzed.
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