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The long-range crystallographic order and anisotropy in β-(AlxGa1−x)2O3 (x = 0.0, 0.06, 0.11, 0.17, 0.26) crystals, prepared by optical floating zone method with different Al composition, is systematically studied by spatial correlation model and using an angle-resolved polarized Raman spectroscopy. Alloying with aluminum is seen as causing Raman peaks to blue shift while their full widths at half maxima broadened. As x increased, the correlation length (CL) of the Raman modes decreased. By changing x, the CL is more strongly affected for low-frequency phonons than the modes in the high-frequency region. For each Raman mode, the CL is decreased by increasing temperature. The results of angle-resolved polarized Raman spectroscopy have revealed that the intensities of β-(AlxGa1−x)2O3 peaks are highly polarization dependent, with significant effects on the anisotropy with alloying. As the Al composition increased, the anisotropy of Raman tensor elements was enhanced for the two strongest phonon modes in the low-frequency range, while the anisotropy of the sharpest Raman phonon modes in the high-frequency region decreased. Our comprehensive study has provided meaningful results for comprehending the long-range orderliness and anisotropy in technologically important β-(AlxGa1−x)2O3 crystals.

We present a detailed study on the crystal structure of 0.10 mol% Ta-doped β-Ga2O3 crystals before and after annealing treatment in air by high-resolution X-ray diffraction and Raman spectroscopy, as well as the detection of point defects through the variation of photoluminescence excitation (PLE) and photoluminescence (PL) with temperature. Based on the experimental data, the band diagram of the 0.10 mol% Ta-doped β-Ga2O3 crystal is constructed. The crystal quality of the 0.10 mol% Ta-doped β-Ga2O3 crystal was improved after annealing treatment. The PL spectra exhibited two ultraviolet emission bands (UV ∼3.59 eV, UV′ ∼3.22 eV) and a blue emission band (BB ∼2.73 eV) , which are ascribed to the recombination of self-trapped excitons at the trigonal OI and OII sites and gallium vacancies in the (2−) charge state (tetrahedral site), respectively. The work function of the 0.10 mol% Ta-doped β-Ga2O3 crystal increased from 5.28 eV to 5.38 eV as a result of annealing treatment.

Allelochemicals exuded by Stellera chamaejasme into the soil environment could be an important factor which might contribute to its competitive behavior in nature. We aimed to explore the interacti...

Sentiment analysis is a process of analyzing, processing, concluding, and inferencing subjective texts with the sentiment. Companies use sentiment analysis for understanding public opinion, performing market research, analyzing brand reputation, recognizing customer experiences, and studying social media influence. According to the different needs for aspect granularity, it can be divided into document, sentence, and aspect-based ones. This article summarizes the recently proposed methods to solve an aspect-based sentiment analysis problem. At present, there are three mainstream methods: lexicon-based, traditional machine learning, and deep learning methods. In this survey article, we provide a comparative review of state-of-the-art deep learning methods. Several commonly used benchmark data sets, evaluation metrics, and the performance of the existing deep learning methods are introduced. Finally, existing problems and some future research directions are presented and discussed.

The objective of this study was to evaluate how a wide range (0–100%) of cellulose nanofiber (CNF) addition affects the mechanical properties of composite sheets made of bleached pulp fibers and CNFs. It was found that adding CNFs could reduce the porosity of the sheets, thus increasing the dry Young’s modulus within the CNF addition range of 0–100%, whereas the dry specific Young’s modulus of all the sheets was constant. The dry tensile strength of the sheets increased as the CNF addition increased to 70% because of the increased hydrogen bond density between the pulp fibers. However, there was no further improvement in the dry tensile strength when the CNF addition was more than 70%. Although the wet Young’s modulus decreased when the CNF addition was more than 20% owing to the increase in the thickness of the sheets, the wet tensile strength of the sheets increased almost linearly as more CNFs were added up to 70%, and the maximum wet strength retention reached nearly 10% at 40% CNF addition.

Two novel series of chalcone-based homoserine lactones were synthesized and their quorum sensing (QS) inhibitory activity was evaluated against Pseudomonas aeruginosa in vitro. Furthermore these compounds’ capacity for modulation of the LasR-dependent quorum sensing system of P. aeruginosa was identified. Among these compounds, (S)-2-((4-(3-(4-bromo-2-fluorophenyl) acryloyl) phenyl) amino)-N-(2-oxotetrahydrofuran-3-yl)acetamide exerted the inhibition of LasR-dependent QS system of P. aeruginosa in contrast to brominated furanone C30. Worthy of particular note, this research has delivered novel potent quorum sensing inhibitors (QSIs), which strongly inhibit the production of virulence factors in a wild type strain of this pathogenic bacterium.

Effective extraction of lithium from high Mg2+/Li+ ratio brine lakes is of great challenge. In this work, organic–inorganic hybrid silica nanofiltration (NF) membranes were prepared by dip-coating a 1,2-bis(triethoxysilyl)ethane (BTESE)-derived separation layer on tubular TiO2 support, for efficient separation of LiCl and MgCl2 salt solutions. We found that the membrane calcinated at 400 °C (M1–400) could exhibit a narrow pore size distribution (0.63–1.66 nm) owing to the dehydroxylation and the thermal degradation of the organic bridge groups. All as-prepared membranes exhibited higher rejections to LiCl than to MgCl2, which was attributed to the negative charge of the membrane surfaces. The rejection for LiCl and MgCl2 followed the order: LiCl > MgCl2, revealing that Donnan exclusion effect dominated the salt rejection mechanism. In addition, the triple-coated membrane calcined at 400 °C (M3–400) exhibited a permeability of about 9.5 L ∙ m−2 ∙ h−1 ∙ bar−1 for LiCl or MgCl2 solutions, with rejections of 74.7% and 20.3% to LiCl and MgCl2, respectively, under the transmembrane pressure at 6 bar. Compared with the previous reported performance of NF membranes for Mg2+/Li+ separation, the overall performance of M3–400 is highly competitive. Therefore, this work may provide new insight into designing robust silica-based ceramic NF membranes with negative charge for efficient lithium extraction from salt lakes.

Wire rod and bar rolling is an essential process in a steel production system (SPS). This work considers a lexicographic bi-objective scheduling problem originated from it. As a medium process in SPS, both the impacts of its upstream process, i.e., release time constraints, and the requirements of its downstream process, i.e., due time constraints, on SPS performance, must be considered. The concerned problem aims to minimize the number of tardy tasks as a main objective and total setup time as a secondary one. It is solved via a two-stage method. The first-stage problem is handled with an off-the-shelf optimization software, and the second one with iterated greedy algorithms (IGAs). We compare the performance of IGAs under different strategies and select the best one to solve it. By comparing the experimental results an exact single-objective method’s, this paper shows that the proposed method can solve the problem fast with excellent results in terms of the number of tardy tasks and setup time, i.e., the secondary objective, on average. Its usage can result in significant performance improvement in steel production over the existing practice.

With the increasing incidence of antibiotic resistance, there is an urgent need to develop new antibiotics with excellent activity against drug-resistant bacteria. Three novel series of tylosin semisynthetic derivatives were designed, synthesized and evaluated for their antibacterial activities against various Gram-positive and Gram-negative bacteria. Among these derivatives, compound C-2 demonstrated potent antibacterial activity against both gram-positive and gram negative bacteria, and non mutagenic. More importantly, compound C-2 displayed high antimicrobial potency against Gram-positive bacteria in a murine model, and was found to be more efficient than tildipirosin. Thus, compound C-2 had great potential as a promising lead compound for the treatment of bacterial infection.

A healthy mental status of students plays an important role in getting quality of education. Hence, research on the prediction of college students’ mental health status is of great importance and considered as a hot area of research. In this specific research study, back propagation (BP) algorithm is adopted to learn verities of characteristics of different students from the historical data of the students including: psychological characteristics, basic personal characteristics, and socio-economic characteristics. In the initial stage of the modeling, data preprocessing steps are used to prepare the data to be used by the BP algorithm for building model. The rationales behind the use of BP algorithm are its capability of handling heterogeneity of data and exploring correlations among different characteristics. The proposed model enhances the capability of BP algorithm for risk prediction of psychological problem of the students and achieves higher precision of psychological problem prediction. The results obtained show that the error between the predicted and measured values is 0.88%.

Efficient and refined three-dimensional (3D) reconstruction of industrial parts has become an urgent need in the field of advanced manufacturing, and it’s a great challenge when facing in-motion and online inspection requirements of high dynamic range (HDR) surfaces that have large reflectivity variations. This paper proposes a method using RGB line-scan cameras to realize in-motion multiple-shot 3D shape measurements with RGB channel fusion to increase the measurement dynamic range. First, multi-channel one-dimensional background-normalized Fourier transform profilometry (MC-1DBNFTP) is proposed as an effective in-motion HDR method. Second, for HDR surfaces with strongly overexposed areas, we propose a solution that obtains 6 results of different dynamic ranges for fusion with only 5 projected patterns, which further extends the measurement dynamic range while ensuring the small projection period. Third, we develop a fusion method based on reliability evaluation, which is more reliable than the existing methods in fringe projection systems. In addition, colored textures can be mapped to the reconstructed surfaces. Experimental results prove that the proposed method realizes accurate and reliable in-motion 3D reconstruction of HDR surfaces.

A fixed optical fiber solar system for long distance daylighting used in buildings is proposed. Its structure and working principle have been introduced. The proposed system takes the advantages of both light pipe and traditional optical fiber system and overcomes their shortcomings. The receiving surface of the new system is like a spherical sunflower. It has a simple structure, good integrity, flexible light transmission and light redistribution characteristics. Especially, it does not require a tracking device. Both the theoretical analysis and field test have proved that the system has the same reception feature as the traditional optical fiber system with a tracking device. Its graph of the illuminance roughly follows the fluctuation of the curve of the solar irradiance. A small test system with a solar receiving area of 1.69 × 10−2 m2 and receiving angle of 32° was made to verify the feasibility of the fixed optical fiber system. Experimental result had proved that the proposed system is feasible. On average, the output illuminance inside a small test room is up to about 180 lx in a distance of 0.4 m from the bundled end of the fibers with the solar irradiance being about 600 W/m2, approximately 300 lx under approximately 800 W/m2. The simple structure, expectable low cost, almost maintenance-free and a predictable long life of the new system will facilitate the mass production and the viable commercialization of daylighting systems.

This study was to explore the diversity of rhizosphere and endophytic microbial communities and the correlation with soil environmental factors of

Black soybean (Glycine max (L.) Merr.) is rich in phenolic compounds, and processing technology has a significant effect on the content and activity of phenolic compounds. However, the mechanism of nine steaming and nine sun-drying processing technique is not fully understood. This paper presents the changes of phenolics content, phenolic acids composition and their influence on antioxidant activity before and after in vitro simulated gastrointestinal digestion of black soybeans (BS) under the process of nine steaming nine sun-drying. Results showed that the total phenolic content (TPC) and total flavonoids content (TFC) in BS were reduced by the heat treatment method, and exhibited a decreasing trend with more steaming and sun-drying cycle. During in vitro digestion, the contents and bioaccessibility of 12 phenolic acids (PA-12) in BS were highest in the stomach, followed by mouth and the intestine. The bioaccessibility of PA-12 in steamed and sun-dried BS was higher than that of raw black soybeans (S0D0) after digestion. It reached maximum after digestion at the third steaming and sun-drying cycle (i.e. S3D3), wherein the phenolic acids with the highest bioaccessibility were syringic acid, gallic acid, ferulic acid and chlorogenic acid. Syringic acid, in particular, increased significantly during digestion compared with that before digestion, which also increased during processing. The antioxidant activity of in vitro digested BS products with appropriate steaming and sun-drying degree increased compared with S0D0. Principal component analysis (PCA) showed that the in vitro digestion-induced properties of steamed and sun-dried BS could be well distinguished. The results confirm that the phenolic compounds and bioaccessibility of nine steamed nine sun-dried BS must be taken into account when assessing the improvement of human health.

In this study, we synthesized four series of novel L-homoserine lactone analogs and evaluated their in vitro quorum sensing (QS) inhibitory activity against two biomonitor strains, Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Studies of the structure-activity relationships of the set of L-homoserine lactone analogs indicated that phenylurea-containing N-dithiocarbamated homoserine lactones are more potent than (Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone (C30), a positive control for biofilm formation. In particular, compared with C30, QS inhibitor 11f significantly reduced the production of virulence factors (pyocyanin, elastase and rhamnolipid), swarming motility, the formation of biofilm and the mRNA level of QS-related genes regulated by the QS system of PAO1. These results reveal 11f as a potential lead compound for developing novel antibacterial quorum sensing inhibitors.

Imbalanced data is one type of datasets that are frequently found in real-world applications, e.g., fraud detection and cancer diagnosis. For this type of datasets, improving the accuracy to identify their minority class is a critically important issue. Feature selection is one method to address this issue. An effective feature selection method can choose a subset of features that favor in the accurate determination of the minority class. A decision tree is a classifier that can be built up by using different splitting criteria. Its advantage is the ease of detecting which feature is used as a splitting node. Thus, it is possible to use a decision tree splitting criterion as a feature selection method. In this paper, an embedded feature selection method using our proposed weighted Gini index &#x0028 WGI &#x0029 is proposed. Its comparison results with Chi2, F-statistic and Gini index feature selection methods show that F-statistic and Chi2 reach the best performance when only a few features are selected. As the number of selected features increases, our proposed method has the highest probability of achieving the best performance. The area under a receiver operating characteristic curve &#x0028 ROC AUC &#x0029 and F-measure are used as evaluation criteria. Experimental results with two datasets show that ROC AUC performance can be high, even if only a few features are selected and used, and only changes slightly as more and more features are selected. However, the performance of Fmeasure achieves excellent performance only if 20 &#x0025 or more of features are chosen. The results are helpful for practitioners to select a proper feature selection method when facing a practical problem.

Exploration and discovery of the relationship between social media activities and rare-event evolution have been investigated by many researchers in recent years. Their investigations have revealed the existence of such relationship. Furthermore, some researchers regard finding either a temporal or spatial pattern of social media activities as a way to evaluate the evolution of rare event. However, most of them fail to deduce an accurate time point when a rare event highly impacts social media activities. This paper concentrates on the intensity of information volume and proposes an innovative data processing method based on clustering algorithms. The proposed method can characterize the evolution of a rare event in the real world by analyzing social media activities in the virtual world. This exploration contributes to study changes of social media activities in the time domain. A case study is based on Hurricane Sandy that occurred in 2012. Social media data collected from Twitter during its arrival time span are adopted to evaluate the feasibility and effectiveness of our proposed method. First, this paper confirms that a strong correlation between a rare event and social media activities does exist. Next, it uncovers that a time difference does exist between the real and virtual worlds. In general, this paper gives a novel idea that deduces a temporal pattern of social media activities during the occurrence of rare events.