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The non-isothermal crystallization behaviors of CaO-BaO-Al 2 O 3 -based mold fluxes in which SiO 2 had been replaced by Na 2 O were investigated, using an infrared furnace combined with digital microscopy as well as X-ray diffraction. The initial crystallization temperatures, crystalline phases generated at different cooling rates, crystallization rates, Ozawa indices N O (as determined using Mo's equation) and effective crystallization activation energies (as determined using the Friedman equation) were evaluated. The initial crystallization temperature increased along with the Na 2 O content in the flux. In addition, the precipitation of CaF 2 crystals was inhibited while the growth of CaAl 2 O 4 crystals was enhanced at Na 2 O concentrations over 4 wt%. Increasing the cooling rate inhibited the precipitation of MgAl 6 O 10 , and of CaSiO 3 , MgAl 2 SiO 6 and NaAlSi 3 O 8 , respectively, in fluxes containing 0, 4 and 8 wt% Na 2 O (NS1, NS2 and NS3 samples). The peak instantaneous and average crystallization rates in these specimens were increased as the Na 2 O level was raised, as a direct result of changes in their N O values. The NS1 flux consistently had the lowest N O value, while the NS2 had the largest value in the primary stage of crystallization but the central value in the secondary stage, and the N O values of the NS3 flux exhibited the opposite trend. The effective crystallization activation energies decreased with increasing Na 2 O levels, and this was evidently an important factor affecting the initial crystallization temperature. [ABSTRACT FROM AUTHOR]

Abstract A comprehensive comparison study of the UV–visible photoresponse properties of non-aligned carbothermal ZnO nanowires (ZNWs) composited with reduced graphene oxide (RGO) and single-walled carbon nanotubes (SWCNTs) is presented. The RGO/ZNWs composites (GZWs) and SWCNTs/ZNWs composites (CZWs) have been successfully synthetized through UV-assisted photochemical reduction of GO in ZNWs suspension and ultrasonic stirring technology, respectively. The optimal contents of RGO and SWCNTs incorporated into ZNWs were determined for achieving maximum photoresponse, respectively. Experimentally, the optimal GZWs and CZWs exhibit significant enhancement in photoelectric properties than pure ZNWs. It is demonstrated that the GZWs-based photodetector has higher photoresponsivity (∼16 AW-1) than CZWs-based photodetector under low UV irradiation (<10 μWcm−2) and at 1.0 V bias, while the CZWs-based photodetector has higher on/off current ratio (8.41 × 104) and faster response time (1.99 s of rise-time and 0.39 s of decay-time) than GZWs-based one. The detail physics mechanism on the effects of RGO and SWCNTs on photoelectric characteristics of ZNWs is presented with the interface charge transfer due to the chemisorption and photo-desorption of oxygen. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

This paper explores and studies recommendation technologies based on content filtering and user collaborative filtering and proposes a hybrid recommendation algorithm based on content and user collaborative filtering. This method not only makes use of the advantages of content filtering but also can carry out similarity matching filtering for all items, especially when the items are not evaluated by any user, which can be filtered out and recommended to users, thus avoiding the problem of early level. At the same time, this method also takes advantage of the advantages of collaborative filtering. When the number of users and evaluation levels are large, the user rating data matrix of collaborative filtering prediction will become relatively dense, which can reduce the sparsity of the matrix and make collaborative filtering more accurate. In this way, the system performance will be greatly improved through the integration of the two. On the basis of the improved collaborative filtering algorithm, a hybrid algorithm based on content and improved collaborative filtering was proposed. By combining user rating with item features, a user feature rating matrix was established to replace the traditional user-item rating matrix. K-means clustering was performed on the user set and recommendations were made. The improved algorithm can solve the problem of data sparsity of traditional collaborative filtering algorithm. At the same time, for new projects, it can also predict users who may be interested in new projects according to the matching of project characteristics and user characteristics scoring matrix and generate push list, which effectively solve the problem of new projects in "cold start." The experimental results show that the improved algorithm in this paper plays a significant role in solving the speed bottleneck problems of data sparsity, cold start, and online recommendation and can ensure a better recommendation quality. [ABSTRACT FROM AUTHOR]

Contact experiments between low‐reactivity CaO–BaO–Al2O3‐based mold fluxes, F1 and F2, and 1.4–2.2 mass% of Al‐containing steels are conducted to investigate the effect of interfacial reaction on mold flux properties and the ultimate limit of reaction duration capacity of the developed mold flux. F1 contains 30.76% CaO, 17.03% Al2O3, 13.40% BaO, and 10.70% SiO2, whereas F2 consists of 27.90% CaO, 23.60% Al2O3, 12.90% BaO, and 9.57% SiO2 of the mass. The pre‐ and post‐experimental wettability of slag samples on steel substrates and the lubrication behavior of slags are discussed. The main results reveal that SiO2, Na2O, and B2O3 in the mold flux react with [Al] in the molten steel at steel–slag interface. The variations in slag properties indicate that both reaction durations between F1 reacting with twinning‐induced plasticity (TWIP) and F2 reacting with 20Mn23AlV steel can last for 40 min, whereas F2 has wider potential applicability for the continuous casting of Al‐containing steels. Interfacial reaction deteriorates the wettability of slag F2 on 20Mn23AlV steel substrate and reduces slag consumption, as equilibrium contact angle increases from approximately 3° to 37°, but slag consumption prediction is 0.22 kg m−2, which is likely to meet the requirement for lubrication. [ABSTRACT FROM AUTHOR]

We report the development of non-noble transition metal sulfide catalysts Mn-CuS-x for high-efficiency and selective H 2 O 2 production. In this study, we synthesized Mn-CuS-x with coral-shaped hierarchical porous structure through one-pot hydrothermal reaction. The Mn-CuS-x possesses large specific surface area with plenty of crystalline defects via heteroatom doping of Mn. The Mn-CuS-x kinetically favored 2e− pathway over 4e− pathway, resulting in high selectivity (>92%) to H 2 O 2 production and high H 2 O 2 concentration (∼24.5 mM at 0.6 V vs. RHE) within 3 h for the optimized Mn-CuS-2 catalysts (synthesized with a molar ratio of 1:3:8 (MnCl 2 ·4 H 2 O: CuCl 2 ·2 H 2 O: C 2 H 5 NS)). The Mn-CuS-2 showed excellent stability, indicating that the Mn-CuS electrocatalysts can simultaneously achieve both high stability and enhanced H 2 O 2 production. Our first-principles calculations further confirmed that the heteroatom Mn doping to CuS thermodynamically makes the 2e–-ORR pathway more favorable. This study provides a green, low-cost, and efficient route to produce H 2 O 2 , which is very promising for generating chemicals and liquid fuels. [Display omitted] • Coral-shaped Mn-CuS is synthesized via one-pot hydrothermal reaction. • The Mn-CuS possesses hierarchical porous structure and large specific surface area. • A large number of crystalline defects are introduced into the Mn-CuS via Mn doping. • The 2e− pathway is kinetically favored over 4e− pathway to H 2 O 2 for Mn-CuS. • The Mn-CuS shows high selectivity (>92%) and H 2 O 2 concentration ∼24.5 mM at 0.6 V. [ABSTRACT FROM AUTHOR]

The complete crystallization process of mold slag in the crucible (inner diameter: 6.2 mm) was successfully recorded in situ using a digital optical microscope and image processing software in an infrared furnace (IR‐MOP). The crystallization behavior of non‐volatile mold slag tested with the new method is consistent with the findings of differential scanning calorimetry (DSC) analysis. Although the volatilization ratios of volatile mold slag during both DSC and SHTT experiments are greater than 8%, it is less than 1.2% during IR‐MOP experiments equipped with an isolated observation system, which explains why the difference in the initial crystallization temperature measured by the three methods was very large. Therefore, IR‐MOP equipped with an isolated observation system can record and accurately measure the crystallization behavior of volatile mold slag. [ABSTRACT FROM AUTHOR]

Imitating the painting style of one caricature source is an interesting and important application. It requires to capture the caricature style from one reference image, and generate target caricature image with similar style representation based on one source photo. Recently, image-to-image translation is a proven and potential framework for photo-to-caricature task. However, it still suffers from three drawbacks: (1) annotating aligned photo-to-caricature pairs is expensive and time-consuming; (2) the photo-to-caricature requires to capture and exaggerate the high-level semantic representations; and (3) the multiple painting styles increase the translation difficulty. To tackle these issues, we propose an innovative representation-guided photo-to-caricature translation framework based on unpaired images. The representation-guided scheme is designed to transfer the selected caricature style. To improve image synthesis quality, we introduce one feature-pyramid adversarial network (FPAN) to provide multiple feature-level constrains. The comprehensive experiments on various caricature datasets show excellent imitation capabilities of the proposed method. [Display omitted] • We present an unpaired representation-guided framework for photo-to-caricature translation. • We include a feature-pyramid adversarial training architecture to improve the translation quality. • We create an additional information flow to improve the generator efficiency. The additional interaction offers clues to the generator and helps the generator distinguish the specific content and domain style latent codes more efficiently. [ABSTRACT FROM AUTHOR]