Cubically convergent methods for selecting the regularization parameters in linear inverse problems

AbstractWe present three cubically convergent methods for choosing the regularization parameters in linear inverse problems. The detailed algorithms are given and the convergence rates are estimated. Our basic tools are Tikhonov regularization and Morozov's discrepancy principle. We prove that, in comparison with the standard Newton method, the computational costs for our cubically convergent methods are nearly the same, but the number of iteration steps is even less. Numerical experiments for an elliptic boundary value problem illustrate the efficiency of the proposed algorithms

Fiber Optic Sensor Fused Additive Manufacturing

This dissertation research establishes the foundation for converging disciplines to fiber optic sensors and additive manufacturing for smart part fabrication for energy system applications. Through innovation in numerical designs, thorough studies of layer-by-layer additive manufacturing procedures, and innovation in high-temperature fiber optic sensor development, this dissertation presents fiber optic sensor embedding in metals for smart component manufacturing. In this dissertation, standard telecom-grade single-mode optical fibers were metalized by nickel sulfamate electroplating method. Through electroplating process optimization, residual strain of fiber coating induced on optical fiber were controlled to ensure metal integrity of fiber sensors. Using Laser Engineered Net Shaping (LENS) process, metalized fiber sensors were embedded into objects with flat surfaces and curved surfaces to fabricate smart components. Using Rayleigh optical frequency domain reflectometry technology, the embedded fiber optic sensors were used to perform accurate and distributed temperature and strain sensing with 5 mm spatial resolution. Finite element analyses were performed to study additive manufacturing process. Plastic and elastic residual strain distributed incurred by the process were calculated and compared with measurement results obtained by embedded sensors. Both temperature and strain measured by fiber sensors are in excellent agreement with numerical simulations. Using embedded fiber sensor measurement results are cue, various laser processes were applied to further temper properties of metal components. This dissertation explores potentials on using adaptive optical technology to perform rapid and high precision laser shock peening to mitigate residual strain induced by additive manufacturing. Using embedded fiber sensors, laser shock peening induced strain modifications were measured with high spatial resolution to improve properties and accuracy of 3D manufactured metal components against corrosion. Research discussed in this dissertation has advanced both fiber optic sensing technology and additive manufacturing. By incorporating advanced optical sensing technology directly into the component’s design and additive manufacturing processes, this research results in new manufacturing techniques to produce a wide array of smart parts for advanced energy systems. The seamless incorporation of multi-functional fiber optic devices into components and parts common to advanced energy system will enable and facilitate condition-based monitoring of key components and systems of fossil, renewable and nuclear power systems to improve safety and efficiency of fossil-fuel energy power generation

Quark model with Hidden Local Symmetry and its application to TccT_{cc}

We propose a chiral quark model including the $\omega$ and $\rho$ meson contributions in addition to the $\pi$ and $\sigma$ meson contributions. We show that the masses of the ground state baryons such as the nucleon, $\Lambda_c$ and $\Lambda_b$ are dramatically improved in the model with the vector mesons compared with the one without them. The study of the tetraquark $T_{cc}$ is also performed in a coupled channel calculation and the resultant mass is much closer to the experiment than the result without vector meson contribution. This approach could be applied in future study of multi-quark systems.Comment: 6 pages, 4 figure

Biochemical properties of oxidases of Yali pear

The biochemical properties of polyphenol oxidase (PPO), peroxidase (POD) and ascorbate peroxidase (APX) from Yali pear were investigated. The optimum pH and temperature of three enzymes was 5.6, 4.0, 7.0 and 20, 40, 50°C, respectively. Enzyme kinetics results showed that the Michaelis constant (Km) and maximum velocity (Vmax) of PPO for catechol were 0.22 M and 1111 U/ml/min. The Km and Vmax values of POD for guaiacol were 0.14 M and 1429 U/ml/min. The Km of APX for ascorbic acid and H2O2 were 0.41 and 0.083 mM, respectively, and the Vmax of APX was 455 and 208 U/ml/min for ascorbic acid and H2O2, respectively. The inhibitory effects of the four inhibitors (ascorbic acid, citric acid, L-cysteine and phytic acid) on each enzyme were different, suggesting that the composite inhibitor is more appropriate for processing of Yali pear.Keywords: Yali pear, polyphenol oxidase, peroxidase, ascorbate peroxidase, biochemical propert

Viruses mobilize plant immunity to deter nonvector insect herbivores.

A parasite-infected host may promote performance of associated insect vectors; but possible parasite effects on nonvector insects have been largely unexplored. Here, we show that Begomovirus, the largest genus of plant viruses and transmitted exclusively by whitefly, reprogram plant immunity to promote the fitness of the vector and suppress performance of nonvector insects (i.e., cotton bollworm and aphid). Infected plants accumulated begomoviral βC1 proteins in the phloem where they were bound to the plant transcription factor WRKY20. This viral hijacking of WRKY20 spatiotemporally redeployed plant chemical immunity within the leaf and had the asymmetrical benefiting effects on the begomoviruses and its whitefly vectors while negatively affecting two nonvector competitors. This type of interaction between a parasite and two types of herbivores, i.e., vectors and nonvectors, occurs widely in various natural and agricultural ecosystems; thus, our results have broad implications for the ecological significance of parasite-vector-host tripartite interactions

Photonic Hook-Assisted Contrast-Enhanced Super-Resolution Imaging Using Janus Microspheres

Microsphere-assisted imaging is a promising label- free super-resolution imaging technique. Its performance is sig- nificantly affected by the photonic nanojet (PNJ) of microspheres. Recently, a new type of curved PNJ, i.e. the photonic hook (PH), was discovered, which shows promising potential for various applications. This Letter presented a contrast-enhanced super- resolution imaging technique utilizing the PHs generated by Janus microspheres. We demonstrated that the Janus micro- spheres can be fabricated using a one-step deposition process, they exhibit superior imaging performance to pristine micro- spheres, and their field-of-view and imaging contrast can be easily adjusted by changing the coating thickness. In addition, we demonstrated that the imaging contrast of Janus microspheres can be further enhanced by using polarized illumination

Focusing light with a metal film coated patchy particle

Microsphere-assisted super-resolution imaging is a promising technique that can significantly enhance the resolution of conventional optical microscopes. The focus of a classical microsphere is called photonic nanojet, which is a symmetric high-intensity electromagnetic field. Recently, patchy microspheres have been reported to have superior imaging performance than pristine microspheres, and coating microspheres with metal films leads to the formation of photonic hooks, which can enhance the imaging contrast of microspheres. Understanding the influence of metal patches on the near-field focusing of patchy particles is important for the rational design of a nanostructured microlens. In this work, we theoretically and experimentally showed that the light waves can be focused and engineered using patchy particles. When coating dielectric particles with Ag films, light beams with a hook-like structure or S-shaped structure can be generated. Simulation results show that the waveguide ability of metal films and the geometric asymmetry of patchy particles cause the formation of S-shaped light beams. Compared with classical photonic hooks, S-shaped photonic hooks have a longer effective length and a smaller beam waist at far-field region. Experiments were also carried out to demonstrate the generation of classical and S-shaped photonic hooks from patchy microspheres