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Deceptive reviews on Web are a common phenomenon and how to detect them has a very important impact on products, services, and even business policies. In order to filter out deceptive reviews more accurately, a new model called Sentence Joint Topic Sentiment Model (SJTSM) is presented in this paper, which incorporates the sentence structure of reviews and the sentiment label information of words based on Latent Dirichlet Allocation (LDA) model to extract the review features. The proposed model employs Gibbs algorithm to estimate the maximum likelihood parameters and takes the vector of topic-sentiment distribution as the review features. Then a voting system of multiple-classifier, which takes the extracted review feature vector as its input is designed to realize the classification of deceptive review detection. The comparative experiments on different public datasets with other existing methods based on LDA model show that the new classifying system based on SJTSM model can achieve more satisfying classification results on deceptive review detection.

Rice in cold region is threatened by cold stress frequently, resulting in severe losses of rice production. In the present study, two rice varieties with contrast cold tolerance in the reproductive stage (Longjing25, cold tolerant; Longjing11 cold sensitive) were compared using RNA-seq technique. A total of 14,861 and 12,148 differentially expressed genes (DEGs) were obtained by comparison of LJ25 and LJ11 after 2 days and 4 days of cold stress challenge. Subsequent Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that five significant pathways were specifically enriched in LJ11. Starch and sucrose metabolism was the only one significant pathway (containing 47 DEGs) annotated in both of varieties during two cold treatment periods. By weighted gene co-expression network analysis (WGCNA), 14 co-expression gene modules were calculated, among which turquoise, cyan, and dark green were the most concerned modules, containing 4807, 2682, and 1174 DEGs, respectively. Finally, we analyzed the transcriptional factors (TFs), and TF families of MYB, zinc finger, AP2/ERF-AP2, bHLH, NAC, bZIP, and WRKY were the biggest seven subfamilies. Collectively, our findings provided valuable insights into the molecular and genetic mechanisms responsible for rice’s response to cold stress.

The effects of Nb addition on the microstructure and corrosion resistance of the as-rolled Ti-stabilized Fe-17Cr ferritic stainless steels were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction, pitting tests, and electrochemical measurements. TiN precipitate tends to form in the microstructure of Ti-stabilized Fe-17Cr ferritic stainless steel. After 0.1 wt. % Nb addition, (Ti, Nb) (C, N) composite precipitates with MgO and Al2O3 core form in the microstructure. After adding 0.1 wt. % Nb, the corrosion rate of the Ti-stabilized Fe-17Cr ferritic stainless steel in FeCl3 solution is decreased significantly. The corrosion current densities decrease in HNO3, NaOH, and NaCl solutions, and the pitting corrosion potentials can be improved in NaCl solution for the Fe-17Cr ferritic stainless steel with 0.1 wt. % Nb addition.

A WC-reinforced composite coating was fabricated on the surface of 45 steel samples by plasma, cladding process with WC powder added to the molten pool synchronously or in the tail of the molten pool. The microstructure, phase composition, and element distribution in the coating were analyzed. The results show that the undissolved WC particles and crystallized carbide (WC, W2C) were distributed uniformly in the sub-eutectic matrix in both cases. Fewer of the WC particles are dissolved in the matrix when they are injected into the tail of the molten pool. There are fewer needle-like tungsten carbide formations seen in the composite coating fabricated by back-feeding process than in that formed by synchronous feeding. The former results in a finer microstructure and a higher concentration gradient of elements near the interface between the WC particles and the coating matrix.

In this study, SiC particles were first coated with Cr to form a layer that can protect the SiC particles from dissolution in the molten pool. Then, the Cr-SiC powder was injected into the tail of molten pool during plasma-transferred arc welding process (PTAW), where the temperature was relatively low, to prepare Cr-SiC particles reinforced Fe-based alloy coating. The microstructure and phase composition of the powder and surface coatings were analyzed, and the element distribution and hardness at the interfacial region were also evaluated. The protective layer consists of Cr3Si, Cr7C3, and Cr23C6, which play an important role in the microstructure and mechanical properties. The protective layer is dissolved in the molten pool forming a flocculent region and a transition region between the SiC particles and the matrix. The tribological performance of the coating was also assessed using a ring-block sliding wear tester with GGr15 grinding ring under 490 and 980 N load. Cr-SiC particles-reinforced coating has a lower wear rate than the unreinforced coating.

In the present study, the effects of Mg, Cu, Sc and Zr combined additions on the microstructure and mechanical properties of hypoeutectic Al–Si cast alloy were systematically investigated. Characterization techniques such as optical microscopy (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), electron back-scatter diffraction (EBSD), atomic force microscopy (AFM), transmission electron microscope (TEM), Brinell hardness tester and universal testing machine were employed to analyze the microstructure and mechanical properties. The results showed that Sc served as modifier on the microstructure of Al–3Si–0.45Mg–0.45Cu–0.2Zr alloys, including modification of eutectic Si and grains. Extraordinarily, grain refinement was found to be related to the primary particles, which exhibited a close orientation to matrix. After T6 heat treatment, the grain structures were composed of nano-scaled secondary Al3(Sc, Zr) precipitates and spherical eutectic Si. Combined with T6 heat treatment, the highest hardness, yield strength, ultimate tensile strength and elongation were achieved in 0.56 wt.% Sc-modified alloy. Interestingly, the strength and ductility had a similar tendency. This paper demonstrated that combined additions of Mg, Cu, Sc and Zr could significantly improve the microstructure and performance of the hypoeutectic Al–Si cast alloy.

The impact-corrosion-abrasion resistance of the low carbon high alloy steel, which can be used for mill lining under impact-corrosion-abrasion condition, are tested in laboratory by means of a new kind of experimental facility. The industrial trial run in the same condition has also been completed. The results show that the new alloy containing 0.2 wt.% carbon, 9 wt.% chromium, and 2 wt.% nickel is consisted of lath martensite entirely, and is more than two times superior to Mn13 cast steel in impact-corrosion-abrasion resistance. Spelling is the leading wear mechanism in impact-corrosion-abrasion condition for this alloy, which is lighter than that of high manganese steels because of its better hardness-toughness match.

The impact corrosion-abrasion properties and mechanism of high manganese steel were investigated under different impact energies. The result shows that the wearability of the steel decreases with the increase of the impact energy. The dominant failure mechanism at a lower impact energy is the rupture of extrusion edge along root and a slight shallow-layer spalling. It transforms to shallow-layer fatigue flaking along with serious corrosion-abrasion when the impact energy is increased, and finally changes to bulk flaking of hardened layer caused by deep work-hardening and heavy corrosion-abrasion.