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  • 1
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    Online Resource
    Thermal Stability, Optical and Electrical Properties of Substoichiometric Molybdenum Oxide
    MDPI AG ; 2023
    In:  Materials Vol. 16, No. 7 ( 2023-04-02), p. 2841-
    Details
    In: Materials, MDPI AG, Vol. 16, No. 7 ( 2023-04-02), p. 2841-
    Abstract: Substoichiometric molybdenum oxide ceramics have aroused widespread interest owing to their promising optical and electrical performance. In this work, the thermal stability and decomposition mechanism of Mo9O26 and Mo4O11 at 700–1000 °C and 700–1100 °C were investigated, respectively. Based on this information, MoOx (2 〈 x 〈 3) bulk ceramics were prepared by spark plasma sintering (SPS). The results show that Mo9O26 is stable up to 790 °C in an argon atmosphere. As the temperature rises, it decomposes into Mo4O11. Mo4O11 can exist stably at 830 °C, beyond which it will convert to MoO2. The MoOx ceramic bulks with four different components (MoO2.9, MoO2.8, MoO2.7 and MoO2.6) were successfully sintered by SPS, and their relative density was greater than 96.4% as measured by the Archimedes principle. The reflectivity of MoOx ceramic bulk is low and only 6.3% when the composition is MoO2.8. The resistivity increases from 10−3 to 10−1 Ωcm with the increase in the O/Mo atomic ratio x. In general, the thermal stability information provides a theoretical basis for the processing of MoOx materials, such as the sintering of the MoOx target. The optical and electrical properties show that MoOx is a low-reflective conductive oxide material with great photoelectric application value.
    Type of Medium: Online Resource
    ISSN: 1996-1944
    URL: Article
    DOI: 10.3390/ma16072841
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2487261-1
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  • 2
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    Mechanical and Thermal Properties of Thermally Conductive Enhanced Paraffin/Gypsum Composites
    MDPI AG ; 2023
    In:  Processes Vol. 11, No. 4 ( 2023-03-25), p. 999-
    Details
    In: Processes, MDPI AG, Vol. 11, No. 4 ( 2023-03-25), p. 999-
    Abstract: The low thermal conductivity of gypsum-based composites containing phase change materials (PCMs) has limited their application in construction materials. In this study, the mechanical and thermal properties and microstructures of paraffin (PA)/gypsum composites containing iron powder, copper powder, and expanded graphite were characterized by a universal testing machine, thermogravimetry, differential scanning calorimetry, and scanning electron microscopy. The PA/gypsum composites had optimal mechanical properties when the PA content was 20 wt.%. The compressive and flexural strengths were 9.46 MPa and 3.57 MPa, respectively. When the copper powder content increased, the densities and porosities of the PA/gypsum composites containing the copper powder did not largely change. The average density and porosity of the composites were 1.17 g/cm3 and 46%, respectively. The compressive and flexural strengths of the PA/gypsum composite containing 8 wt.% copper powder were optimal. A phase change temperature of 48.8 °C was obtained when 8 wt.% copper powder was added to the PA/gypsum composite. The thermal conductivities of the PA/gypsum composites were lower than those of PA/gypsum composites with 8 wt.% iron powder, 8 wt.% copper powder, or 8 wt.% expanded graphite. Parts of coarse calcium sulfate dihydrate crystals were present at the interfaces between the gypsum and PA, which indicated that the growth of calcium sulfate dihydrate crystals was affected by the copper powder.
    Type of Medium: Online Resource
    ISSN: 2227-9717
    URL: Article
    DOI: 10.3390/pr11040999
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2720994-5
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  • 3
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    Genesis of the Large-Scale Kamado Magnesite Deposit on the Tibetan Plateau
    MDPI AG ; 2023
    In:  Minerals Vol. 14, No. 1 ( 2023-12-29), p. 45-
    Details
    In: Minerals, MDPI AG, Vol. 14, No. 1 ( 2023-12-29), p. 45-
    Abstract: Lacustrine strata-bound magnesite deposits associated with Alpine-type ultramafic rocks are hydrothermal in origin. The magnesite ores of the Kamado deposit are unconformably underlain by mid-Jurassic marine carbonate and ultramafic rocks of the Bangong-Nujiang ophiolite suite and are in fault contact with hanging wall rocks composed of siliceous sinter. Three types of cryptocrystalline magnesite ores can be identified in Kamado: (1) strata-bound massive magnesites, representing the main ore type in the upper part; (2) banded ores in the lower part; and (3) some vein and stockwork ore in the ultramafic wall rocks. Integrated scanning electron microscopy, C–O isotope analysis, and geochemical analyses were carried out on the Kamado deposit. The results indicate that: (1) the orebody is composed of magnesite, with accessory minerals of aragonite, opal, and chromite; (2) the siliceous sinter and relatively high B (32.0–68.1 ppm) and Li (14.7–23.4 ppm) contents of the magnesite ores reflect long-term spring activity in Kamado; (3) the light carbon (δ13CV-PDB: −4.7 ± 0.3‰ to −4.1 ± 0.6‰) and oxygen isotopic compositions (δ18OV-SMOW: +12.3 ± 0.3 to +16.3 ± 0.1‰) of the stockwork ores in the foot wall rocks indicated that the carbon in fractures in the ultramafic rocks is from a mixture of marine carbonate and oxidized organic-rich sedimentary rocks, reflecting a typical “Kraubath-type” magnesite deposit; and (4) the relatively heavy carbon isotopic (δ13CV-PDB: +8.7 ± 0.4‰ to +8.8 ± 0.3‰) composition of the banded magnesite ores in the lower segment may have formed from heavy CO2 generated by anaerobic fermentation in the lakebed. Additionally, the carbon isotopic (δ13CV-PDB: +7.3 ± 0.3‰ to +7.7 ± 0.7‰) composition of the massive magnesite ores in the upper segment indicates a decline in the participation of anaerobic fermentation. As this economically valuable deposit is of the strata-bound massive ore type, Kamado can be classified as a lacustrine hydrothermal-sedimentary magnesite deposit, formed by continuous spring activities under salt lakes on the Tibetan Plateau, with the Mg mainly being contributed by nearby ultramafic rocks and the carbon mainly being sourced from atmosphere-lake water exchange, with minor amounts from marine carbonate strata.
    Type of Medium: Online Resource
    ISSN: 2075-163X
    URL: Article
    DOI: 10.3390/min14010045
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2655947-X
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  • 4
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    Berberine Improves Cognitive Impairment by Simultaneously Impacting Cerebral Blood Flow and β-Amyloid Accumulation in an APP/tau/PS1 Mouse Model of Alzheimer’s Disease
    MDPI AG ; 2021
    In:  Cells Vol. 10, No. 5 ( 2021-05-11), p. 1161-
    Details
    In: Cells, MDPI AG, Vol. 10, No. 5 ( 2021-05-11), p. 1161-
    Abstract: Alzheimer’s disease (AD) is accompanied by β-amyloid (Aβ), neurofibrillary tangles, and neuron cell death, and is one of the most commonly occurring diseases among the elderly. The pathology of AD is complex, involving Aβ overproduction and accumulation, tau hyperphosphorylation, and neuronal loss. In addition, chronic cerebral hypoperfusion (CCH) is ubiquitous in the AD patients and plans a pivotal role in triggering and exacerbating the pathophysiological progress of AD. The goal of this study was to investigate the neuroprotective properties of berberine (BBR) and the underlying mechanism. During the study, BBR was administrated to treat the triple-transgenic mouse model of Alzheimer’s disease (3×Tg AD). To thoroughly evaluate the effects of the BBR administration, multiple manners were utilized, for instance, 3D arterial spin labeling technique, Morris water maze assay, immunofluorescence staining, TUNEL assay, laser speckle contrast imaging, western blotting, etc. The results showed that BBR ameliorated cognitive deficits in 3×Tg AD mice, reduced the Aβ accumulation, inhibited the apoptosis of neurons, promoted the formation of microvessels in the mouse brain by enhancing brain CD31, VEGF, N-cadherin, Ang-1. The new vessels promoted by BBR were observed to have a complete structure and perfect function, which in turn promoted the recovery of cerebral blood flow (CBF). In general, berberine is effective to 3×Tg AD mice, has a neuroprotective effect, and is a candidate drug for the multi-target prevention and treatment of AD.
    Type of Medium: Online Resource
    ISSN: 2073-4409
    URL: Article
    DOI: 10.3390/cells10051161
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2661518-6
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  • 5
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    Tandem Mass Tag-Based Quantitative Proteomics Analysis of Gonads Reveals New Insight into Sexual Reversal Mechanism in Chinese Soft-Shelled Turtles
    MDPI AG ; 2022
    In:  Biology Vol. 11, No. 7 ( 2022-07-20), p. 1081-
    Details
    In: Biology, MDPI AG, Vol. 11, No. 7 ( 2022-07-20), p. 1081-
    Abstract: Chinese soft-shelled turtles display obvious sex dimorphism. The exogenous application of hormones (estradiol and methyltestosterone) can change the direction of gonadal differentiation of P. sinensis to produce sex reversed individuals. However, the molecular mechanism remains unclear. In this study, TMT-based quantitative proteomics analysis of four types of P. sinensis (female, male, pseudo-female, and pseudo-male) gonads were compared. Quantitative analysis of 6107 labeled proteins in the four types of P. sinensis gonads was performed. We identified 440 downregulated and 423 upregulated proteins between pseudo-females and males, as well as 394 downregulated and 959 upregulated proteins between pseudo-males and females. In the two comparisons, the differentially expressed proteins, including K7FKG1, K7GIQ2, COL4A6, K7F2U2, and K7FF80, were enriched in some important pathways, such as focal adhesion, endocytosis, apoptosis, extracellular matrix-receptor interaction, and the regulation of actin cytoskeleton, which were upregulated in pseudo-female vs. male and downregulated in pseudo-male vs. female. In pathways such as ribosome and spliceosome, the levels of RPL28, SRSF3, SNRNP40, and HNRNPK were increased from male to pseudo-female, while they decreased from female to pseudo-male. All differentially expressed proteins after sexual reversal were divided into six clusters, according to their altered levels in the four types of P. sinensis, and associated with cellular processes, such as embryonic development and catabolic process, that were closely related to sexual reversal. These data will provide clues for the sexual reversal mechanism in P. sinensis.
    Type of Medium: Online Resource
    ISSN: 2079-7737
    URL: Article
    DOI: 10.3390/biology11071081
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2661517-4
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  • 6
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    HLNet Model and Application in Crop Leaf Diseases Identification
    MDPI AG ; 2022
    In:  Sustainability Vol. 14, No. 14 ( 2022-07-21), p. 8915-
    Details
    In: Sustainability, MDPI AG, Vol. 14, No. 14 ( 2022-07-21), p. 8915-
    Abstract: Crop disease has been a severe issue for agriculture, causing economic loss for growers. Thus, disease identification urgently needs to be addressed, especially for precision agriculture. As of today, deep learning has been widely used for crop disease identification combined with optical imaging sensors. In this study, a lightweight convolutional neural network model is designed and validated on two publicly available imaging datasets and one self-built dataset with 28 types of leaf and leaf disease images of 6 crops as the research object. This model is an improvement of the existing convolutional neural network, reducing the floating-point operations by 65%. In addition, dilated depth-wise convolutions were used to increase the network receptive field and improve the model recognition accuracy without affecting the network computational speed. Meanwhile, two attention mechanisms are optimized to reduce attention module computation, improving the capability of the model to select the correct regions of interest. After training, this model achieved an average accuracy of 99.86%, and the image calculation speed was 0.173 s. Comparing with 11 backbone models and 5 latest crop leaf disease identification studies, the proposed model achieved the highest accuracy. Therefore, this model with an advantage of balancing between the calculation speed and recognition accuracy. Furthermore, the proposed model provides a theoretical basis and technical support for the practical application and mobile terminal applications of crop disease recognition in precision agriculture.
    Type of Medium: Online Resource
    ISSN: 2071-1050
    URL: Article
    DOI: 10.3390/su14148915
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2518383-7
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  • 7
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    Review of Visual Simultaneous Localization and Mapping Based on Deep Learning
    MDPI AG ; 2023
    In:  Remote Sensing Vol. 15, No. 11 ( 2023-05-25), p. 2740-
    Details
    In: Remote Sensing, MDPI AG, Vol. 15, No. 11 ( 2023-05-25), p. 2740-
    Abstract: Due to the limitations of LiDAR, such as its high cost, short service life and massive volume, visual sensors with their lightweight and low cost are attracting more and more attention and becoming a research hotspot. As the hardware computation power and deep learning develop by leaps and bounds, new methods and ideas for dealing with visual simultaneous localization and mapping (VSLAM) problems have emerged. This paper systematically reviews the VSLAM methods based on deep learning. We briefly review the development process of VSLAM and introduce its fundamental principles and framework. Then, we focus on the integration of deep learning and VSLAM from three aspects: visual odometry (VO), loop closure detection, and mapping. We summarize and analyze the contribution and weakness of each algorithm in detail. In addition, we also provide a summary of widely used datasets and evaluation metrics. Finally, we discuss the open problems and future directions of combining VSLAM with deep learning.
    Type of Medium: Online Resource
    ISSN: 2072-4292
    URL: Article
    DOI: 10.3390/rs15112740
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2513863-7
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  • 8
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    Target Localization and Power Allocation Using Wireless Energy Harvesting Sensors
    MDPI AG ; 2021
    In:  Electronics Vol. 10, No. 21 ( 2021-10-24), p. 2592-
    Details
    In: Electronics, MDPI AG, Vol. 10, No. 21 ( 2021-10-24), p. 2592-
    Abstract: As radio-frequency (RF) based wireless energy harvesting technology can provide remote and continuous power to low-power devices, e.g., wireless sensors, it may be a substitute for batteries and extend the lifetime of the wireless sensor networks. In this paper, we propose a wireless energy harvesting localization system (WEHLoc), which contains batteryless wireless sensors as anchors and an energy access point (E-AP) to transfer power to the anchors. We consider a passive target localization scenario, in which the anchors monitor the target and send the sensed ranging data back to the E-AP. Additionally, we formulate the optimal estimation accuracy problem which is a 0–1 mixed-integer programming problem and relates to the energy beam, target transmitted power, and deployed anchor density. Then, we develop the power allocation scheme of the E-AP to solve the objective. In order to reduce the complexity, we propose a heuristic method that converts the maximum estimation accuracy problem into the energy efficiency problem and use linear programming to solve them. The simulations demonstrate that WEHLoc can be massively deployed in a wide area, and the estimation error and the power consumption are relatively low.
    Type of Medium: Online Resource
    ISSN: 2079-9292
    URL: Article
    DOI: 10.3390/electronics10212592
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2662127-7
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  • 9
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    CRLB Analysis for Passive Sensor Network Localization Using Intelligent Reconfigurable Surface and Phase Modulation
    MDPI AG ; 2022
    In:  Electronics Vol. 12, No. 1 ( 2022-12-31), p. 202-
    Details
    In: Electronics, MDPI AG, Vol. 12, No. 1 ( 2022-12-31), p. 202-
    Abstract: Passive wireless sensor network (PWSN) requires high positioning for network management. The harvested energy of the passive sensor is modulated as the ranging data and the position is derived accordingly. Thus, the wireless power transfer (WPT) is a dominant factor for such localization. With the help of intelligent reconfigurable surface (IRS), the WPT efficiency can be significantly improved. In this paper, we propose the Fisher information matrix (FIM) and the Cramér–Rao lower bound (CRLB) analyzing model of the PWSN localization. We prove the impacts of phase modulation of IRS on the localization performance. Based on our analysis, we develop an approximation algorithm and a genetic algorithm to control the IRS phases. Then, the localization accuracy of PWSN can be further improved. The simulation results demonstrate that the phase modulation based on GA can achieve high accurate localization for PWSN using IRS.
    Type of Medium: Online Resource
    ISSN: 2079-9292
    URL: Article
    DOI: 10.3390/electronics12010202
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662127-7
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  • 10
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    Low FT3/FT4 Ratio Is Linked to Poor Prognosis of Acute Myocardial Infarction in Euthyroid Patients with Type 2 Diabetes Mellitus
    MDPI AG ; 2022
    In:  Journal of Clinical Medicine Vol. 11, No. 21 ( 2022-11-03), p. 6530-
    Details
    In: Journal of Clinical Medicine, MDPI AG, Vol. 11, No. 21 ( 2022-11-03), p. 6530-
    Abstract: This is an observational, retrospective, single-center study aimed to determine whether the free triiodothyronine (FT3) to free thyroxine (FT4) ratio was related to acute myocardial infarction (AMI) prognosis in individuals with type 2 diabetes mellitus (T2DM). A total of 294 euthyroid T2DM patients with new-onset AMI were enrolled. FT3/FT4 ratio tertiles were used to categorize patients into Group 1 (FT3/FT4 ≥ 4.3), Group 2 (3.5 ≤ FT3/FT4 〈 4.3), and Group 3 (FT3/FT4 〈 3.5). Major adverse cardiac events (MACE), including nonfatal myocardial infarction, target vessel revascularization (TVR), and cardiac mortality, served as the primary endpoint. Group 3 demonstrated a considerably higher incidence of MACE than the other two groups over the average follow-up duration of 21 ± 6.5 months (all p 〈 0.001). Multivariable Cox regression analysis showed that a low FT3/FT4 ratio was an independent risk factor for MACE after AMI (Group 1 as a reference; Group 2: hazard ratio [HR] 1.275, 95% confidence interval [CI] : 0.563–2.889, p = 0.561; Group 3: HR 2.456, 95% CI: 1.105–5.459, p = 0.027). Moreover, the area under the receiver-operating characteristic curve (AUC) indicates a good predictive value of FT3/FT4 ratio for MACE (AUC = 0.70). Therefore, in T2DM patients with AMI, a low FT3/FT4 ratio was strongly linked to poor prognosis.
    Type of Medium: Online Resource
    ISSN: 2077-0383
    URL: Article
    DOI: 10.3390/jcm11216530
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662592-1
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