129 research outputs found

    Perturbations of eventually differentiable and eventually norm-continuous semigroups on Banach spaces

    Get PDF
    AbstractIn this paper we discuss perturbations of eventually differentiable and eventually norm-continuous semigroups on a Banach space. Two kinds of new perturbation theorems are obtained

    Failure mechanism and practical load-carrying capacity calculation method of welded hollow spherical joints connected with circular steel tubes

    Full text link
    p. 2679-2691According to the ultimate load-carrying capacity obtained from finite element analysis, data point is designed based on orthogonal method, utilizing F-inspection from mathematical statistics to perform multi-parameter and single-factor significance analysis of compressive load capacity. The result indicates that yield strength of spherical material fy are the critical factor that influence the load carrying capacity of hollow spherical joint, as well as wall thickness t, outer diameter of sphere D and outer diameter of steel tube d. Comparatively destructive experiments on 8 typical full-scale joints made from two different graded material, Q235B and Q345B, were conducted to understand directly the structural behavior and the collapse mechanism of the joint, and also to validate the finite element analysis and parameter study. Finally, the simplified theoretical solution is also derived for the loading-carrying capacity of the joint based on the punching shear failure model, and the basic form for the design equation is obtained. By applying the results from the simplified theoretical solution, finite element analysis and experimental study, and utilizing the theory of mathematic statistics and regression analysis, the practical calculation method is established for the load-carrying capacity of the joints subjected to axial compressive forces. By the check of large amount of experiment data, the calculation result obtained from this formula is consistent with experiment result, and the practical formula has safety reserve meeting the regulation in national codes. The achievements from this study can be applied for direct design , and also provide a reference for the revision of relevant design codes.Xue, W.; Yang, L.; Zhang, Q.; Wang, P. (2009). Failure mechanism and practical load-carrying capacity calculation method of welded hollow spherical joints connected with circular steel tubes. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/660

    Hallucinating very low-resolution and obscured face images

    Get PDF
    Most of the face hallucination methods are designed for complete inputs. They will not work well if the inputs are very tiny or contaminated by large occlusion. Inspired by this fact, we propose an obscured face hallucination network(OFHNet). The OFHNet consists of four parts: an inpainting network, an upsampling network, a discriminative network, and a fixed facial landmark detection network. The inpainting network restores the low-resolution(LR) obscured face images. The following upsampling network is to upsample the output of inpainting network. In order to ensure the generated high-resolution(HR) face images more photo-realistic, we utilize the discriminative network and the facial landmark detection network to better the result of upsampling network. In addition, we present a semantic structure loss, which makes the generated HR face images more pleasing. Extensive experiments show that our framework can restore the appealing HR face images from 1/4 missing area LR face images with a challenging scaling factor of 8x.Comment: 20 pages, Submitted to Pattern Recognition Letter

    High channel count and high precision channel spacing multi-wavelength laser array for future PICs

    Get PDF
    Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%

    Increased lymphangiogenesis in joints of mice with inflammatory arthritis

    Get PDF
    Angiogenesis is involved in the pathogenesis of inflammatory arthritis, but little is known about the role of lymphangiogenesis in this setting. Here, we examined whether tumor necrosis factor (TNF) stimulates osteoclast precursors (OCPs) to produce the lymphatic growth factor, vascular endothelial growth factor-C (VEGF-C), and induce lymphangiogenesis. We used TNF-transgenic (Tg) mice and mice with serum-induced arthritis. OCPs were purified by fluorescence-activated cell sorting of CD11b+/Gr-1-/lo blood or bone marrow cells and subjected to microarray analysis or were generated from spleen or joint cells and treated with TNF. Expression of VEGFs was analyzed and examined by real-time reverse transcription-polymerase chain reaction and Western blotting. Immunostaining and magnetic resonance imaging were used to quantify lymphatic vessels and volumes of synovium and draining lymph nodes. TNF stimulated VEGF-C expression by OCPs and increased nuclear factor-kappa B (NF-κB) binding to an NF-κB sequence in the VEGF-C promoter. OCPs from joints of TNF-Tg mice express high levels of VEGF-C. Lymphatic vessel numbers and size were markedly increased in joint sections of TNF-Tg mice and mice with serum-induced arthritis. The severity of synovitis correlated with draining lymph node size. In summary, TNF induces OCPs to produce VEGF-C through NF-κB, leading to significantly increased lymphangiogenesis in joints of arthritic mice. The lymphatic system may play an important role in the pathogenesis of inflammatory arthritis

    High-Power AlGaInAs/InP DFB Lasers with Low Divergence Angle

    Get PDF
    High-power semiconductor DFB lasers with low divergence angle fundamental transverse mode operating at wavelengths near 1.31 μm have many applications such as analog and digital fiber communication, WDM pump sources, spectroscopy, remote sensing, free-space communication, laser-based radar, and wavelength conversion in nonlinear materials [1]. These devices can potentially reduce system costs by simplifying optical alignment and package processes [2]. Devices with narrow far-field patterns (FFPs) are highly desirable for simple, high-yield optical alignment, as a low divergence angle improves the coupling efficiency and imposes less stringent tolerances in the alignment between the device and the single-mode fiber (SMF). Until now most of the high-power low divergence angle 1.31 μm DFB laser is based on InGaAsP/InP material system which has lower characteristic temperature value T 0 [3]. Here we first demonstrate the high-power fundamental transverse mode 1.31 μm AlGaInAs/InP DFB laser with low divergence angle, enabling uncooled continuous-wave (CW) operation at high ambient temperatures

    Regrowth-free AlGaInAs MQW polarization controller integrated with sidewall grating DFB laser

    Full text link
    We report an AlGaInAs multiple quantum well integrated source of polarization controlled light consisting of a polarization mode converter PMC, differential phase shifter(DPS), and a side wall grating distributed-feedback DFB laser. We demonstrate an asymmetrical stepped-height ridge waveguide PMC to realize TE to TM polarization conversion and a symmetrical straight waveguide DPS to enable polarization rotation from approximately counterclockwise circular polarization to linear polarization. Based on the identical epitaxial layer scheme, all of the PMC, DPS, and DFB laser can be integrated monolithically using only a single step of metalorganic vapor phase epitaxy and two steps of III V material dry etching. For the DFB-PMC device, a high TE to TM polarization conversion efficiency 98% over a wide range of DFB injection currents is reported at 1555 nm wavelength. For the DFB-PMC-DPS device, a 60 degree rotation of the Stokes vector was obtained on the Poincar\'e sphere with a range of bias voltage from 0 V to -4.0 V at IDFB is 170 mA.Comment: arXiv admin note: text overlap with arXiv:2210.1051
    corecore