40 research outputs found
A perspective on meta-boundaries
The judicious design of electromagnetic boundary provides a crucial route to
control light-matter interactions, and it is thus fundamental to basic science
and practical applications. General design approaches rely on the manipulation
of bulk properties of superstrate or substrate and on the modification of
boundary geometries. Due to the recent advent of metasurfaces and
low-dimensional materials, the boundary can be flexibly featured with a surface
conductivity, which can be rather complex but provide an extra degree of
freedom to regulate the propagation of light. In this perspective, we denote
the boundary with a non-zero surface conductivity as the meta-boundary. The
meta-boundaries are categorized into four types, namely isotropic, anisotropic,
biisotropic and bianisotropic meta-boundaries, according to the electromagnetic
boundary conditions. Accordingly, the latest development for these four kinds
of meta-boundaries are reviewed. Finally, an outlook on the research tendency
of meta-boundaries is provided, particularly on the manipulation of
light-matter interactions by simultaneously exploiting meta-boundaries and
metamaterials
Low-velocity-favored transition radiation
When a charged particle penetrates through an optical interface, photon
emissions emerge - a phenomenon known as transition radiation. Being paramount
to fundamental physics, transition radiation has enabled many applications from
high-energy particle identification to novel light sources. A rule of thumb in
transition radiation is that the radiation intensity generally decreases with
the particle velocity v; as a result, low-energy particles are not favored in
practice. Here we find that there exist situations where transition radiation
from particles with extremely low velocities (e.g. v/c<0.001) exhibits
comparable intensity as that from high-energy particles (e.g. v/c=0.999), where
c is light speed in free space. The comparable radiation intensity implies an
extremely high photon extraction efficiency from low-energy particles, up to
eight orders of magnitude larger than that from high-energy particles. This
exotic phenomenon of low-velocity-favored transition radiation originates from
the excitation of Ferrell-Berreman modes in epsilon-near-zero materials. Our
findings may provide a promising route towards the design of integrated light
sources based on low-energy electrons and specialized detectors for
beyond-standard-model particles.Comment: 13 pages, 4 figure
Socio-economic inequalities in health service utilization among Chinese rural migrant workers with New Cooperative Medical Scheme: a multilevel regression approach
BackgroundWhile reducing inequity in health service utilization is an important goal of China's health system, it has been widely acknowledged that a huge number of rural migrant workers cannot be effectually protected against risks with the New Rural Cooperative Medical Insurance (NCMS).MethodData of the 2016 China Labor-force Dynamic Survey and the Chinese Urban Statistical Yearbook were used. The multilevel regression approach was implemented with a nationally representative sample of rural migrant workers with NCMS. Our study adopted the concentration index and its decomposition method to quantify the inequality of their health service utilization.ResultThe multilevel model analysis indicated that impact variables for health service utilization were not concentrated, especially the contextual and individual characteristics. The concentration indices of the probability of two weeks outpatient and the probability of inpatient were -0.168 (95%CI:-0.236,-0.092) and -0.072 (95%CI:-1.085,-0.060), respectively. The horizontal inequality indices for the probability of two-week outpatient and the probability of inpatient were -0.012 and 0.053, respectively.ConclusionThe health service utilization of rural migrant workers with NCMS is insufficient. Our study highlighted that substantial inequalities in their health service utilization did exist. In addition, their need of health service utilization increased the pro-poor inequality. Based on the findings, our study offered notable implications on compensation policies and benefit packages to improve the equality among rural migrant workers with NCMS
Case report: Acute pancreatitis in lung adenocarcinoma with small cell transformation after multiple line targeted therapy
In lung cancer, metastasis to the liver, bones, brain, and adrenal glands is more commonly observed, whereas pancreatic metastasis from lung cancer is relatively rare. We present a case of a patient with an 8-year history of lung adenocarcinoma (LUAD) who was admitted to our institution exhibiting symptoms consistent with acute pancreatitis. Subsequent histopathological examination through puncture confirmed the occurrence of pancreatic metastasis originating from small cell lung cancer (SCLC). During a multidisciplinary team discussion, we reached a consensus in diagnosing the patient with post-transformation small cell carcinoma alongside moderately severe pancreatitis, which was determined to be a consequence of pancreatic metastasis. The patient received a regimen of etoposide and cisplatin chemotherapy. This unique clinical case highlights the importance of further investigating the factors contributing to pancreatic metastasis in patients with lung cancer, as the underlying mechanisms remain unclear. Understanding these exceptional metastatic events is vital in devising effective therapeutic strategies and improving patient prognosis. Our findings emphasize the need for continued surveillance and comprehensive management of lung cancer patients, particularly those with resistant forms of the disease, to promptly identify and address the progression of metastatic events to uncommon sites such as the pancreas
Multiscale characterization of recurrence-based phase space networks constructed from time series
Multiprobe Radiation Simulation Method for Phased Array Radar Performance Evaluation
The phased array radar exhibits improved tracking accuracy and anti-jamming performance with multi-beam tracking, beam agility, and adaptive beam-forming capabilities. The performance evaluation of the phased array radar is essential for the product designing and development stage. However, the conventional injection simulation and triad radiation simulation methods are not suitable for phased array radars. Therefore, new methods for radiation simulation are required on an urgent basis for the performance evaluation of phased array radars in a reliable, reliable, and repeatable way. This paper focuses on designing a practical anechoic chamber system of multi-probe radiation suitable for phased array radars. The appropriate test distance, the physical size of the anechoic chamber, the multi-probe radiation signal model, and the number of probes required were discussed. Furthermore, an inversion method based on least squares was proposed to solve the complex weights of the probes, thereby simulating the desired apparent center position. The simulation results demonstrated the effectiveness of the proposed method