Supernova calibration by gravitational wave

Hubble tension is one of the most important problems in cosmology. Although the local measurements on the Hubble constant with Type Ia supernovae (SNe Ia) are independent of cosmological models, they suffer the problem of zero-point calibration of the luminosity distance. The observations of gravitational waves (GWs) with space-based GW detectors can measure the luminosity distance of the GW source with high precision. By assuming that massive binary black hole mergers and SNe Ia occur in the same host galaxy, we study the possibility of re-calibrating the luminosity distances of SNe Ia by GWs. Then we use low-redshift re-calibrated SNe Ia to determine the local Hubble constant. We find that we need at least 7 SNe Ia with their luminosity distances re-calibrated by GWs to reach a 2\% precision of the local Hubble constant. The value of the local Hubble constant is free from the problems of zero-point calibration and model dependence, so the result can shed light on the Hubble tension.Comment: 22 pages, 5 figures, 2 tables; Comments are welcom

ALCAP: Alignment-Augmented Music Captioner

Music captioning has gained significant attention in the wake of the rising prominence of streaming media platforms. Traditional approaches often prioritize either the audio or lyrics aspect of the music, inadvertently ignoring the intricate interplay between the two. However, a comprehensive understanding of music necessitates the integration of both these elements. In this study, we delve into this overlooked realm by introducing a method to systematically learn multimodal alignment between audio and lyrics through contrastive learning. This not only recognizes and emphasizes the synergy between audio and lyrics but also paves the way for models to achieve deeper cross-modal coherence, thereby producing high-quality captions. We provide both theoretical and empirical results demonstrating the advantage of the proposed method, which achieves new state-of-the-art on two music captioning datasets

Heterogeneous Data Source Middleware

As the complexity of data sources increases, it becomes a significant challenge to develop and maintain applications which are required to interact with heterogeneous data sources. It becomes even more difficult when the intention of the application is to frequently modify the data source. Application developers must look into thousands lines of source code to locate the corresponding part and to modify them one by one. The diversity of data source properties and data schemas makes it complicated for the application to adapt to a new data source. In this thesis, a middleware solution is proposed to address this problem. Both permanent and real-time data should pass through the middleware during communication between the data source and the application, or among data sources. The middleware creates a data source service wrapper for each data source and uses an abstract class to shield different wrappers. A global-local mapping mechanism is used to eliminate the data schema incompatibility. In addition, xml technology is used to accomplish data transmission, which eases the interface design and ensures platform independency. At the same time, a Data Source Wizard has been developed to assist the maintainer of the middleware with items for middleware extensions. The Data Source Wizard makes it more convenient and standardized to add a new data source. The experience of integrating the middleware into this Android E-Health application has proved the flexibility and extensibility of the middleware. Because the middleware does not contain any specific business logic, it can be generally applied to other applications with different purposes

Preparation process of magnesium alloys by complex salt dehydration-electrochemical codeposition

High-purity anhydrous MgCl2-containing molten salt was directly synthesized from MgCl(2)6H(2)O via complex salts dehydration and protection. After that, Mg-Al and Mg-Zn alloys were prepared by electrochemical codeposition. The hydrolysis processes of magnesium chloride hexahydrate in various chloride mixtures were studied. Then, the preparation process was studied and the dehydration mechanism was put forward. NH(4)ClMgCl(2)nH(2)O formed under 300 degrees C inhibits the formation of hydrolysate during the dehydration process. KMgCl3 and K3NaMgCl6 formed above 400 degrees C can further protect the unstable anhydrous MgCl2. Therefore, high-purity anhydrous MgCl2-containing molten salt with w(MgO)/w(MgCl2) being 0.016wt.% was obtained. The current efficiency was above 81% and 97%, respectively, when preparing Mg-Al alloys and Mg-Zn alloys, and the alloying elements were distributed homogeneously in the alloy matrix

Supernova calibration by gravitational waves

Hubble tension is one of the most important problems in cosmology. Although the local measurements on the Hubble constant with Type Ia supernovae (SNe Ia) are independent of cosmological models, they suffer the problem of zero-point calibration of the luminosity distance. The observations of gravitational waves (GWs) with space-based GW detectors can measure the luminosity distance of the GW source with high precision. By assuming that massive binary black hole mergers and SNe Ia occur in the same host galaxy, we study the possibility of re-calibrating the luminosity distances of SNe Ia by GWs. Then we use low-redshift re-calibrated SNe Ia to determine the local Hubble constant. We find that we need at least 7 SNe Ia with their luminosity distances re-calibrated by GWs to reach a 2% precision of the local Hubble constant. The value of the local Hubble constant is free from the problems of zero-point calibration and model dependence, so the result can shed light on the Hubble tension

Synthesis of SAPO-34 from metakaolin: Crystallization mechanism of SAPO-34 and transformation processes of metakaolin

SAPO-34 molecular sieve was hydrothermally synthesized using metakaolin as the single Si and partial AI source. Crystallization mechanism of SAPO-34 and transformation processes of metakaolin were investigated by studying effect of metakaolin content on the products, and Si, Al and P coordination environments of the products by XRD, SEM, EDX, N-2 adsorption-desorption and NMR. The results showed that SAPO-34 with high purity could be prepared within a wide range of metakaolin content. Synthesis of SAPO-34 with all Si in isolated state demonstrated that SAPO-34 crystallization proceeded by a solution-mediated transport mechanism. Increase of the Si/P ratio in the medium caused increase of Si content in the newly formed SAPO-34 lattice. Transformation processes of metakaolin were followed by (1) dissolution of the Al-O and Si-O layers, (2) appearance of the primary building units (PBUs) in a low Si content, (3) initial crystallization of SAPO-34 in isolated Si state, (4) occurrence of the PBUs in a high Si content, (5) incorporation of Si domains into SAPO-34 crystals and (6) formation of the Si-rich amorphous materials. The results drawn are useful to understand crystallization mechanisms of SAPO molecular sieves from metakaolin and from other Si and/or Al chemicals. (C) 2012 Elsevier Inc. All rights reserved

Dispersion of kaolin powders in silica sols

The dispersion properties of kaolin powders in silica sols were investigated by electrokinetic, viscosity and theological measurements. Silica sol improved the dispersion of kaolin powders by increasing the negative charges on kaolinite particles. Electrophoretic mobility and viscosity of the kaolin particles in silica sol changed significantly in comparison with dispersions in deionized water. The kaolinite particles in silica sol showed a maximum of the electrophoretic mobility and a minimum in viscosity around pH 11.5. The viscosity of the dispersion reached a minimum when the silica sal concentration was 5 mass%. The flow behavior was non-Newtonian showing shear-thinning. When the solid content exceeded 45 mass%, the dispersion showed pronounced thixotropic behavior. (C) 2010 Elsevier B.V. All rights reserved

Synthesis, characterization and crystallization mechanism of SAPOs from natural kaolinite

Calcined natural kaolinite (i.e. metakaolin) was used as a combinational Si and Al source to synthesize SAPO-5, -11, -20, -34, -44, and -47. The reactivity of metakaolin with related chemicals was studied, and the solid structural evolution process of SAPO-34 was exemplified to show the crystallization mechanism of SAPOs from kaolinite. The results indicated that the products had excellent crystallinity. The Si and/or Al of metakaolin had good coordination capability with related ligands. The crystallization process of SAPO-34 from kaolinite is summarized as three stages. In the first stage of calcination (at 1073 K), kaolinite is destructured and activated. In the second stage of aging and initial heating, the surface of metakaolin is gelated and the coordinated units are stripped down to transform into the primary building units (PBUs) with increasing temperature. At a desirable temperature, the PBUs stack to form the nuclei. In the final step, crystallization is triggered when the mixture is heated up to 423 K. NMR results illustrated that Si directly participated in the crystallization of SAPO-34 mainly as Si monomer state. Formation of SAPO-34 from kaolinite, as well as other SAPOs, is believed to proceed following an activation-gelation-crystallization mechanism. (C) 2010 Elsevier Inc. All rights reserved

Synthesis of SAPO-34 using metakaolin in the presence of beta-cyclodextrin

SAPO-34 molecular sieves were synthesized by the addition of beta-cyclodextrin (beta-CD) as crystal growth inhibitor using metakaolin as silicon and aluminum sources. Properties of the obtained samples were characterized by XRD, SEM, N-2 adsorption-desorption, FTIR, XRF, EDX, NH3-TPD and Si-29 MAS NMR. When beta-CD was added, crystal size of the SAPO-34 crystals decreased. Variation of Si content from the crystal center to surface decreased while total Si content hardly changed. Si-29 MAS NMR results showed that beta-CD contributed to better Si dispersion and decreased the size of Si(4Si) patches. Moreover, the MTO (methanol-to-olefin) process was conducted to investigate the influence of beta-CD on catalytic performance. The synthesized sample with molar ratio of beta-CD/Al2O3 equaling 0.055 remained active for 610 min while the sample synthesized without beta-CD for only 280 min, which indicates that the lifetime of catalyst synthesized with beta-CD is greatly prolonged. (C) 2015 Science Press and Dalian Institute of Chemical Physics. All rights reserved.</p