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Model hubs with many pre-trained models (PTMs) have become a cornerstone of deep learning. Although built at a high cost, they remain under-exploited|practitioners usually pick one PTM from the provided model hub by popularity and then fine-tune the PTM to solve the target task. This naïve but common practice poses two obstacles to full exploitation of pre-trained model hubs: first, the PTM selection by popularity has no optimality guarantee, and second, only one PTM is used while the remaining PTMs are ignored. An alternative might be to consider all possible combinations of PTMs and extensively fine-tune each combination, but this would not only be prohibitive computationally but may also lead to statistical over-fitting. In this paper, we propose a new paradigm for exploiting model hubs that is intermediate between these extremes. The paradigm is characterized by two aspects: (1) We use an evidence maximization procedure to estimate the maximum value of label evidence given features extracted by pre-trained models. This procedure can rank all the PTMs in a model hub for various types of PTMs and tasks before fine-tuning. (2) The best ranked PTM can either be fine-tuned and deployed if we have no preference for the model's architecture or the target PTM can be tuned by the top K ranked PTMs via a Bayesian procedure that we propose. This procedure, which we refer to as B-Tuning, not only improves upon specialized methods designed for tuning homogeneous PTMs, but also applies to the challenging problem of tuning heterogeneous PTMs where it yields a new level of benchmark performance. [ABSTRACT FROM AUTHOR]

We report on the fabrication of planar waveguide and ridge waveguides in a KTN crystal by using swift heavy C5+ ions irradiation and femtosecond laser ablation. The reconstructed refractive index profile of the irradiated KTN waveguide illustrates an optical well and barrier distribution. The confocal Raman spectra suggest that the enhanced tetragonality and the lattice damage occurs in the waveguide region and the optical barrier area, respectively. The optical spatial solitons at 632.8 nm are observed from the planar waveguide and the ridge waveguides with a width of 60 μm and 20 μm, respectively, at room temperature. [ABSTRACT FROM AUTHOR]

Three-dimensional multi-mode interference devices are demonstrated using a single-mode fiber (SMF) center-spliced to a section of polygon-shaped core multimode fiber (MMF). This simple structure can effectively generate well-localized self-focusing spots that match to the layout of a chosen multi-core fiber (MCF) as a launcher device. An optimized hexagon-core MMF can provide efficient coupling from a SMF to a 7-core MCF with an insertion loss of 0.6 dB and a power imbalance of 0.5 dB, while a square-core MMF can form a self-imaging pattern with symmetrically distributed 2 × 2, 3 × 3 or 4 × 4 spots. These spots can be directly received by a two-dimensional detector array. The device can work as a vector curvature sensor by comparing the relative power among the spots with a resolution of ∼0.1° over a 1.8 mm-long MMF. [ABSTRACT FROM AUTHOR]

We have prepared BaTiO3 thin films by metal–organic decomposition, focusing on the effects of a final annealing in oxygen. In particular, we investigated the relation between the resistive switching and ferroelectric properties and the behaviors of the resultant resistive hysteresis and switching in the films. The films annealed in oxygen showed the hysteresis of bipolar-type switching with a current on/off ratio from 100 to 1000 for both bias polarities. It was particularly noted that abrupt peaks of the leakage current density occurred in the hysteretic resistivity curve. We consider that the abrupt increase in current density is related to the polarization reversal due to ferroelectricity in the BaTiO3 film. However, the main resistive switching mode was not affected by this behavior, thus suggesting that polarization reversal is insufficient to control the hysteresis in the total resistivity. [ABSTRACT FROM AUTHOR]

Electrostatic electret generator has attracted a lot of attention in recent years, but their low power density cannot be ignored. Based on the existing research, this paper increases its power density from two aspects, including in-plane and in-space aspects. In the plane aspect, through simulation analysis, we can draw a conclusion that the output power can be increased effectively by using the bipolar charging method. From the perspective of space, the power density can be increased several times by connecting the output ends of the multi-layer generation structure. By integrating the method into the electrostatic electret generator, the power output can be effectively increased, which is suitable to the application of higher energy requirements in the specific field and a certain application prospect. [ABSTRACT FROM AUTHOR]

The search for cell-permeable drugs has conventionally focused on low-molecular weight (MW), nonpolar, rigid chemical structures. However, emerging therapeutic strategies break traditional drug design rules by employing flexibly linked chemical entities composed of more than one ligand. Using complementary genome-scale chemical-genetic approaches we identified an endogenous chemical uptake pathway involving interferon-induced transmembrane proteins (IFITMs) that modulates the cell permeability of a prototypical biopic inhibitor of MTOR (RapaLink-1, MW: 1784 g/mol). We devised additional linked inhibitors targeting BCR-ABL1 (DasatiLink-1, MW: 1518 g/mol) and EIF4A1 (BisRoc-1, MW: 1466 g/mol), uptake of which was facilitated by IFITMs. We also found that IFITMs moderately assisted some proteolysis-targeting chimeras and examined the physicochemical requirements for involvement of this uptake pathway. [ABSTRACT FROM AUTHOR]

The load-displacement curves of six types of roof-to-wall connection joints were obtained through uplift experiments, while the mechanical properties of each type of joint were compared and analyzed, and the applicability of each joint was verified by the Foschi load-displacement curve model simulation. The specimens were made of three kinds of wood (Pinus sylvestris (PS), Spruce-Pine-Fir (SPF), and Douglas fir (DF)) and two different metal connectors (A-type and B-type), and then the monotonic pullout tests were conducted on each specimen. The failure modes of each group of specimens were analyzed, and the characteristic values analysis method was used to analyze and compare the characteristic values of the load-displacement curves of each specimen, including six characteristic values: maximum load, yield load, deformation capacity, energy dissipation capacity, ductility ratio, and initial stiffness. The results showed that the load capacity of TA group (specimens with A-type metal connectors) was much greater than that of TB group (specimens with Btype metal connectors). The specimens made of DF had the best mechanical performance, but the specimens of DF group were prone to brittle failure. Finally, the fitting parameters of the Foschi model applicable to such joints were obtained. [ABSTRACT FROM AUTHOR]

In this paper, the macroscopic and microscopic deformation caused by sodium penetration in the carbon cathode has been studied during aluminum electrolysis. The distributions of sodium concentration in the carbon cathode has been measured by SEMEDS. The microstructure change caused by the gradient of the sodium concentration in the carbon cathode has been studied using transmission electron microscopy (TEM). The results indicate that sodium penetration decreases with the increase of the penetration depth. The stresses caused by the gradient of the sodium concentration result in a remarkable change for the microstructure of the carbon cathode. The formation of dislocations resulting in dislocation arrays and the development of kink band networks bring about material damage growth and possibly subsequent weakening of the cathode. These results can provide useful information that is helpful in developing an improved comprehending of the microscopic deformation mechanism of the carbon cathode during aluminum electrolysis. [ABSTRACT FROM AUTHOR]

Thermal conversion of phytoremediation plant waste into biochar was performed as a safe approach for organic waste management. In this work, a promising phytoremediation plant-Silphium perfoliatum L. was pyrolyzed for biochar production at 350, 550 and 750 °C. The long-term leaching risk of potentially toxic metals (PTMs) in the derived biochars and the oxidation resistance of the biochars were investigated. The results showed that PTMs in the biochar could transform into more stable and less toxic forms with the elevated pyrolysis temperature. PTMs leaching behavior in the 350 °C biochar was considerably sensitive to the leaching while that in the 750 °C biochar was not affected. The biochar produced at a higher temperature possessed a greater oxidation resistance with little amount of C loss, and the stronger oxidation resistance would prevent the release of metals bound to the organic matter. The findings of this study demonstrated that high-temperature pyrolysis was able to reduce the potential risk of PTMs and ensure carbon stability. [ABSTRACT FROM AUTHOR]