Measurement of the complex polar magneto-optical Kerr effect using weak measurement

Polar magneto-optical Kerr effect (PMOKE) is one of the most widely being applied magneto-optical Kerr effects (MOKE) due to the induced complex MOKE signal, consisting of the Kerr rotation angle and the ellipticity, is very sensitive to the magnetization component perpendicular to the magnetic surface. However, the Kerr rotation angle and the ellipticity invariably coexist and pose a challenge in their separation. This dual presence plays a pivotal role in defining the light intensity detected, ultimately restricting the advancements in the measurement precision. In this paper, we propose a weak measurement (WM) scheme to measure the complex MOKE in the pure polar configuration. Unlike the traditional MOKE or WM method using a quarter-wave-plate to measure the Kerr rotation angle and the ellipticity separately, we realize the simultaneous measurement of these two parameters in a single WM process using two new pointers, which possesses a larger linear response region compared with the previous amplified shift pointer. The measurement precision for the complex PMOKE angle reaches to $10^{-4}$ deg in our experiment. Besides, the complex magneto-optical constant Q is also calculated. This work is of great significance for the measurement of the complex PMOKE with high efficiency, ultra-precision, low cost, and is an important attempt to obtain complex physical quantities using WM

Ultrasensitive Biosensor with Hyperbolic Metamaterials Composed of Silver and Zinc Oxide

We propose a hyperbolic metamaterial-based surface plasmon resonance (HMM-SPR) sensor by composing a few pairs of alternating silver (Ag) and zinc oxide (ZnO) layers. Aiming to achieve the best design for the sensor, the dependence of the sensitivity on the incidence angle, the thickness of the alternating layer and the metal filling fraction are explored comprehensively. We find that the proposed HMM-SPR sensor achieves an average sensitivity of 34,800 nm per refractive index unit (RIU) and a figure of merit (FOM) of 470.7 RIU−1 in the refractive index ranging from 1.33 to 1.34. Both the sensitivity (S) and the FOM show great enhancement when compared to the conventional silver-based SPR sensor (Ag-SPR). The underlying physical reason for the higher performance is analyzed by numerical simulation using the finite element method. The higher sensitivity could be attributed to the enhanced electric field amplitude and the increased penetration depth, which respectively increase the interaction strength and the sensing volume. The proposed HMM-SPR sensor with greatly improved sensitivity and an improved figure of merit is expected to find application in biochemical sensing due to the higher resolution

Targeting stearoyl-coa desaturase enhances radiation induced ferroptosis and immunogenic cell death in esophageal squamous cell carcinoma

Overcoming resistance to radiation is a major challenge in cancer treatment. Stearoyl-coa desaturase (SCD1) is the enzyme responsible for oleic acid (OA) and palmitoleic acid (POA) formation. Here, we provided evidence that targeting SCD1 was capable of inducing ferroptosis and immunogenic cell death (ICD), thereby improving the radiation sensitivity of esophageal squamous cell carcinoma (ESCC). ESCC cell lines with high SCD1 expression were treated with MF-438 (SCD1 inhibitor) to determine cell viability. Colony formation assay was performed to evaluate the radiation sensitization of SCD1 inhibitor. Tumor cell ferroptosis and ICD was analyzed in MF-438, radiation therapy (RT) and the combination treatment group. The potential molecular mechanisms underlying MF-438 as a novel radiation sensitizer in ESCC were explored. We concluded by assessing SCD1 as a prognostic factor in ESCC. MF-438 exhibited antitumor activity in ESCC cells. Our outcomes revealed significant improvement of radiation sensitivity by MF-438. Moreover, the combination treatment enhanced tumor cell ferroptosis and ICD. Further analyses revealed SCD1 conferred radiation resistance via alleviating ferroptosis in tumor cells; targeting SCD1 inhibited the biosynthesis of OA and POA, and improved radiation induced ferroptosis in ESCC cells. Clinical analysis indicated high expression of SCD1 was associated with unfavorable survival in patients of ESCC. In summary, our results demonstrated that MF-438 acted as a ferroptosis inducer. Targeting SCD1 conferred the immunogenicity of ferroptotic cancer cells and increased the effectiveness of RT in ESCC. SCD1 could be considered as a useful prognostic indicator of survival in ESCC

Untrained Metamaterial-Based Coded Aperture Imaging Optimization Model Based on Modified U-Net

Metamaterial-based coded aperture imaging (MCAI) is a forward-looking radar imaging technique based on wavefront modulation. The scattering coefficients of the target can resolve as an ill-posed inverse problem. Data-based deep-learning methods provide an efficient, but expensive, way for target reconstruction. To address the difficulty in collecting paired training data, an untrained deep radar-echo-prior-based MCAI (DMCAI) optimization model is proposed. DMCAI combines the MCAI model with a modified U-Net for predicting radar echo. A joint loss function based on deep-radar echo prior and total variation is utilized to optimize network weights through back-propagation. A target reconstruction strategy by alternatively using the imaginary and real part of the radar echo signal (STAIR) is proposed to solve the DMCAI. It makes the target reconstruction task turn into an estimation from an input image by the U-Net. Then, the optimized weights serve as a parametrization that bridges the input image and the target. The simulation and experimental results demonstrate the effectiveness of the proposed approach under different SNRs or compression measurements

Research on reliability index and failure probability of inherent defect insurance from the insurance perspective

With the continuous improvement of people ‘s living standards, people have put forward higher requirements for the safety and comfort of housing. Therefore, Inherent Defect Insurance, a financial method to guarantee the quality of construction projects, has also emerged. At present, China ‘s Inherent Defect Insurance has been gradually promoted, but its claim mechanism has not been analyzed and studied. From the perspective of construction engineering, this paper first makes a bibliometric analysis of the influencing factors of insurance claims that may be caused by construction engineering quality through VOSViewers, and the evaluation index system of inherent defects is constructed. Then, according to the influencing factors, the PSO-LSSVR model is adopted to fit the performance function of the inherent defects. Finally, based on the reliability design principle of engineering structure, the reliability index and failure probability of Inherent Defect Insurance are derived from the performance function of inherent defects. This paper also analyzes its application in insurance practice and determines the relationship between the number of insurance underwriting policies and the initial reserve of insurance at a certain risk level. This paper studies the probability of Inherent Defect Insurance by constructing the reliability model of inherent defect risks in construction quality, and analyzes the anti-risk ability of insurance companies from the perspective of claim, which provides scientific analysis methods and theoretical basis for the scientific decision-making of insurance companies

Fabrication of PCL Scaffolds by Supercritical CO2 Foaming Based on the Combined Effects of Rheological and Crystallization Properties

Polycaprolactone (PCL) scaffolds have recently been developed via efficient and green supercritical carbon dioxide (scCO2) melt-state foaming. However, previously reported gas-foamed scaffolds sometimes showed insufficient interconnectivity or pore size for tissue engineering. In this study, we have correlated the thermal and rheological properties of PCL scaffolds with their porous morphology by studying four foamed samples with varied molecular weight (MW), and particularly aimed to clarify the required properties for the fabrication of scaffolds with favorable interconnected macropores. DSC and rheological tests indicate that samples show a delayed crystallization and enhanced complex viscosity with the increasing of MW. After foaming, scaffolds (27 kDa in weight-average molecular weight) show a favorable morphology (pore size = 70–180 μm, porosity = 90% and interconnectivity = 96%), where the lowest melt strength favors the generation of interconnected macropore, and the most rapid crystallization provides proper foamability. The scaffolds (27 kDa) also possess the highest Young’s modulus. More importantly, owing to the sufficient room and favorable material transportation provided by highly interconnected macropores, cells onto the optimized scaffolds (27 kDa) perform vigorous proliferation and superior adhesion and ingrowth, indicating its potential for regeneration applications. Furthermore, our findings provide new insights into the morphological control of porous scaffolds fabricated by scCO2 foaming, and are highly relevant to a broader community that is focusing on polymer foaming

Double-sided Pattern Design on Patterned Sapphire Substrate of GaN-based LEDs

Abstract-In this paper, we established a optical model and made an analysis of GaN-based LED flip chip by double-sided PSS (patterned sapphire substrate). The result analysis shows that the small distance and large radius of micro-cylinder and micro-hemisphere for cylindrical and hemispherical PSS would be more effective to enhance LED efficacy. The hemispherical pattern is more efficient than the cylindrical for enhancement for the light extraction efficiency (LEE) of PSS-LED flip chip. The light extraction efficiency of micro-hemispherical PSS-LED chip is twice than that on the non-patterned (or normal planar) sapphire substrate (non-PSS)

Highly Sensitive Multi-Channel Biosensor for Low-Interference Simultaneous Detection

In this paper, we propose a multi-channel photonic crystal fiber sensor, which adopts dual-polarization and multiple materials to effectively reduce the mutual interference between channels and enhance the surface plasmon resonance, thus achieving simultaneous detection of a multi-channel with low interference. Four channels are polished around the cylindrical fiber, and then different metal films (gold or silver) and plasmonic materials (titanium dioxide, thallium pentoxide, or graphene) are added to the sensing area of each channel. All channels detect refractive indices in the range of 1.34 to 1.42. The sensing performance of the fiber optic sensor was numerically investigated using the full vector finite element method. After the optimization of structural parameters, the maximum wavelength sensitivity of channel-1, channel-2, channel-3, and channel-4 are 49,800 nm/RIU, 49,000 nm/RIU, 35,900 nm/RIU, and 36,800 nm/RIU, respectively. We have theoretically analyzed the sensor’s capabilities for partial bio-detection and simulated its detection capability with a wavelength sensitivity of 11,500 nm/RIU for normal red blood cells and 12,200 nm/RIU for MCF-7 cancerous cells. Our proposed sensor has a novel design, can detect multiple channels simultaneously, has strong anti-interference capability and high sensitivity, and has good sensing characteristics

Integrated Multifunctional Graphene Discs 2D Plasmonic Optical Tweezers for Manipulating Nanoparticles

Optical tweezers are key tools to trap and manipulate nanoparticles in a non-invasive way, and have been widely used in the biological and medical fields. We present an integrated multifunctional 2D plasmonic optical tweezer consisting of an array of graphene discs and the substrate circuit. The substrate circuit allows us to apply a bias voltage to configure the Fermi energy of graphene discs independently. Our work is based on numerical simulation of the finite element method. Numerical results show that the optical force is generated due to the localized surface plasmonic resonance (LSPR) mode of the graphene discs with Fermi Energy Ef = 0.6 eV under incident intensity I = 1 mW/μm2, which has a very low incident intensity compared to other plasmonic tweezers systems. The optical forces on the nanoparticles can be controlled by modulating the position of LSPR excitation. Controlling the position of LSPR excitation by bias voltage gates to configure the Fermi energy of graphene disks, the nanoparticles can be dynamically transported to arbitrary positions in the 2D plane. Our work is integrated and has multiple functions, which can be applied to trap, transport, sort, and fuse nanoparticles independently. It has potential applications in many fields, such as lab-on-a-chip, nano assembly, enhanced Raman sensing, etc

Photonic spin Hall effect of monolayer black phosphorus in the Terahertz region

As a two-dimensional (2D) material, black phosphorus (BP) has attracted significant attention owing to exotic physical properties such as low-energy band gap, high carrier mobility, and strong in-plane anisotropy. The striking in-plane anisotropy is a promising candidate for novel light-matter interaction. Here, we investigate the photonic spin Hall effect (PSHE) on a monolayer of BP. Due to the in-plane anisotropic property of BP, the PSHE is accompanied with Goos-Hänchen and Imbert-Fedorov effects, resulting in an asymmetric spin splitting. The asymmetric spin splitting can be flexibly tuned by the angle between the incident plane and the armchair crystalline direction of BP and by the carrier density via a bias voltage. The centroid displacements of two opposite spin components of the reflected beam along directions parallel and perpendicular to the incident plane can be considered as four independent channels for information processing. The potential application in barcode-encryption is proposed and discussed. These findings provide a deeper insight into the spin-orbit interaction in 2D material and thereby facilitate the development of optoelectronic devices in the Terahertz region