Search

We propose three mode converters based on coupling of the fundamental mode and the first group higher-order modes in fiber tapers, angled fiber facets, and transversely dislocated fibers, respectively. The insertion loss and coupling efficiency of the fiber tapers are 0.541 dB and 10.6% respectively, which are much better than those of the angled fiber facets (2.4 dB and 2.9%) or the transversely dislocated fibers (1.2 dB and 5.6%). Cylindrical vector beams are delivered from an erbium-doped fiber laser after separately incorporating the mode converters into the cavity. The output spectra of three lasers are located at 1548.7 nm with the same 3-dB bandwidth of 0.03 nm, and spatial distributions are switchable between radially and azimuthally polarized states by adjusting the incident polarization state of the fundamental mode. The linear-cavity all-fiber lasers are capable of generating flexible and cost-effective cylindrical vector beams, which are quite attractive for fiber-based sensing and communications. [ABSTRACT FROM AUTHOR]

As climate warming intensifies, reducing greenhouse gas emissions has become a national consensus for many countries. Green finance plays an important role in promoting energy efficiency and lowering such emissions, but there is scant literature that analyzes the impacts and mechanisms of green finance on energy efficiency. Based on China's provincial panel data from 2010 to 2018, this research measures the green finance index using the panel entropy weighting method and systematically evaluates the relationship between green finance and energy efficiency using the fixed-effects model. The results show the following. (1) Green finance significantly contributes to energy efficiency and remains the same after a series of robustness tests such as endogeneity treatment, replacement of explanatory and interpreted variables, and replacement of regression models. (2) Green technology innovation and energy structure optimization are the transmission mechanism of green finance for energy efficiency, which means that green finance improves energy efficiency by promoting green technology innovation and energy structure optimization. (3) There is regional heterogeneity, temporal heterogeneity, and industry heterogeneity in the impact of green finance on energy efficiency. The positive effects of green finance on energy efficiency are more pronounced in resource-dependent regions, regions with irrational industrial structure, north regions, industrial sectors, and after 2013. The conclusions of this paper offer some policy recommendations, including promoting the development of green finance, building a cooperation platform for green finance and technological innovation, enhancing the depth and breadth of renewable energy utilization, and building differentiated green finance strategies according to local conditions. [ABSTRACT FROM AUTHOR]

The retinoblastoma gene ( RB1 ) has been implicated as a tumor suppressor in multiple myeloma (MM), yet its role remains unclear because in the majority of cases with 13q14 deletions, un-mutated RB1 remains expressed from the retained allele. To explore the role of Rb1 in MM, we examined the functional consequences of single- and double-copy Rb1 loss in germinal center B cells, the cells of origin of MM. We generated mice without Rb1 function in germinal center B cells by crossing Rb1 Flox/Flox with C-γ-1-Cre (Cγ1) mice expressing the Cre recombinase in class-switched B cells in a p107 −/− background to prevent p107 from compensating for Rb1 loss ( Cγ1-Rb1 F/F -p107 −/− ). All mice developed normally, but B cells with two copies of Rb1 deleted ( Cγ1-Rb1 F/F -p107 −/− ) exhibited increased proliferation and cell death compared with Cγ1-Rb1 +/+ -p107 −/− controls ex vivo. In vivo, Cγ1-Rb1 F/F -p107 −/− mice had a lower percentage of splenic B220+ cells and reduced numbers of bone marrow antigen-specific secreting cells compared with control mice. Our data indicate that Rb1 loss induces both cell proliferation and death in germinal center B cells. Because no B-cell malignancies developed after 1 year of observation, our data also suggest that Rb1 loss is not sufficient to transform post-germinal center B cells and that additional, specific mutations are likely required to cooperate with Rb1 loss to induce malignant transformation. [ABSTRACT FROM AUTHOR]

• The FE model of the propeller-shaft system is established, whose accuracy is validated through the experiments. • The underwater sound radiation characteristics of the vessel under different directions excitation are studied, including axial excitation, transverse and vertical ones. We found that the natural modes of the propulsion system, especially the bending mode of the propeller, play a key role in the vibro-acoustic responses. • The excitation from the propeller blade is found to be amplified by the propulsion system, and we found that, at low-frequency range, this amplification effect is more remarkable when the direction of the excitation is an axial one than the transverse and vertical ones. • The radiated sound power of the hull structure is compared with that of the propeller at low-frequency range, in which the flow-induced noise is taken into account. We found that although the sound power portion radiated directly from the propeller structure is not so remarkable as that of the hull itself, the magnitude of the flow-induced noise is significant, especially in transverse- and vertical excitation cases. The radiated noise induced by the unsteady propeller forces is an important part of the vessel's total acoustic radiation. Therefore, understanding the role of propeller-shafting system in force transmission characteristics is necessary investigate the underwater vibro-acoustic responses of a vessel. This study compared the contribution of hull and propeller-shafting system to the radiated sound power under the propeller forces in different directions. First, a finite element/boundary element (FE/BE) model of a hull with relatively detailed substructures was developed to study the system's vibro-acoustic characteristics, in which the pulsating pressure at the propeller blade was transmitted to the hull through the propulsion system. The accuracy of the model was validated by experimental results. Second, finite element/boundary element method (FEM/BEM) was used to study the vibro-acoustic characteristics of the submerged system and the amplification effects of the propeller-shafting system. Finally, the radiated sound power of the propeller and the hull were compared, considering the flow-induced noise generated by the water surrounding the propeller. Results show that while it is reasonable to ignore the sound power generated by the elastic propeller structure, the flow-induced noise still needs to be considered, especially when the forces are applied to the propeller in the transverse and vertical directions. [ABSTRACT FROM AUTHOR]