3D reconstruction is the process of obtaining the three-dimensional shape or surface structure of an object, which is widely used in advanced manufacturing fields such as automotive, aerospace, ...industrial inspection, and reverse engineering. However, due to the structural characteristics of the component itself, the reflective properties of the coating material, and other factors, there may be specular reflection during image acquisition, making it difficult to achieve complete 3D reconstruction of the component. This paper proposes a method to address the problem of incomplete 3D reconstruction of strongly reflective objects by recognizing outlier points and filling point cloud holes. The proposed View-Transform-PointNet outlier point recognition network improves the alignment of the initial point cloud plane and implements secondary alignment of the point cloud based on the perpendicularity between the outlier plane in mixed reflection and the point cloud plane. The point cloud hole-filling method is based on the principle of outlier formation and approximates a local Gaussian distribution to linear variation. The distance between the end of each outlier plane and the real surface is calculated to repair the depth information of outlier points. The proposed method achieves a 39.4% increase in the number of point cloud filling, a 45.2% increase in the number of triangular mesh faces, a 46.9% increase in surface area, and a chamfer distance (CD) of 0.4471009, which is better than existing geometric repair methods in terms of standard deviation and smoothness. The method improves the alignment of initial point cloud planes and enhances the accuracy of outlier point recognition, which are the main innovative points of this study. The 3D reconstruction of the repaired point cloud model is achieved through Poisson equation and parameter adjustment. The proposed method reduces the error caused by large curvature in the boundary region and improves the smoothness and accuracy of the reconstructed model.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The copolyester poly(butylene glycol adipate-co-terephthalate/diphenylsilanediol adipate-co-terephthalate) (PBDAT) was synthesized by the melt polycondensation method using terephthalic acid, adipic ...acid, 1,4-butanediol, and diphenylsilylene glycol as the raw materials. The molecular chain structure, thermal properties, thermal stability, mechanical properties, and degradation behaviors of the copolyesters were investigated. The results showed that the prepared PBDAT copolyesters exhibited good thermal stability and mechanical properties. With the increase in diphenylsilanediol (DPSD) content, the thermal stability of PBDAT and the melting temperature both increased. The tensile strength and elastic modulus of PBDAT also exhibited an increasing tend. When the DPSD content was 12.5% (PBDAT-12.5), the tensile strength, the elastic modulus, and elongation at break were 30.56 MPa, 238 MPa, and 219%, respectively. With the increase in diphenylsilanediol content, the hydrophilicity of PBDAT decreased, but PBDAT still shows good degradability and the thermal degradation T5% temperature was 355 °C. The thermal degradation of PBDAT was also improved.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Guanxin V (GX), a traditional Chinese medicine formula, is safe and effective in the treatment of coronary artery disease. However, its protective effect on myocardial ischaemia reperfusion injury ...(MIRI) is unclear.
To investigate the cardioprotective effect of GX on MIRI and explore the potential mechanism.
Sprague-Dawley male rats were divided into Sham, MIRI and MIRI + GX groups. GX (6 g/kg) was administered to rats via intragastric administration for seven days before ischaemia reperfusion (IR) surgery. The infarct size, histopathology, serum enzyme activities, ultrastructure of the cardiac mitochondria were assessed. H9c2 cells were pre-treated with GX (0.5 mg/mL), and then exposed to hypoxia/reoxygenation (HR). The cell viability and LDH levels were measured. Network pharmacology was conducted to predict the potential mechanism. The related targets of GX were predicted using the TCMSP database, DrugBank database, etc. Finally, pharmacological experiments were used to validate the predicted results.
In vivo, GX significantly reduced the myocardial infarct size from 56.33% to 17.18%, decreased the levels of AST (239.32 vs. 369.18 U/L), CK-MB (1324.61 vs. 2066.47 U/L) and LDH (1245.26 vs. 1969.62 U/L), and reduced mitochondrial damage. In vitro, GX significantly increased H9c2 cell viability (IC
50
= 3.913 mg/mL) and inhibited the release of LDH (207.35 vs. 314.33). In addition, GX could maintain iron homeostasis and reduce oxidative stress level by regulating iron metabolism-associated proteins.
GX can attenuate MIRI via regulating iron homeostasis, indicating that GX may act as a potential candidate for the treatment of MIRI.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The effects of size and europium concentration on photoluminescence properties of La2O2S: Eu3+ nanocrystals (∼20 nm) and the corresponding bulk were studied. The results indicate that in ...nanocrystals, the absorption edge largely shifted to blue in comparison to the bulk, which was mainly attributed to the variation of phonon-excitation relaxation. Two excitation bands were observed, located at ∼250 and ∼330 nm, respectively, corresponding to the charge transfer (CT) transitions of Eu−O and Eu−S. Relative to the CT transition of Eu−O, that of Eu−S increased greatly with europium concentration. The dependence of photoluminescence intensity on concentration showed that in the nanocrystals and the bulk, Eu3+ ions had two different quenching mechanisms, respectively, the exchange interaction and electric dipole−dipole interaction.
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IJS, KILJ, NUK, PNG, UL, UM
Under a simple redox system of selenite and ascorbic acid, we used Gracilaria lemaneiformis polysaccharides (GLPs) as a stabilizer and dispersing agent to generate well-dispersed and stable selenium ...nanoparticles (SeNPs). The size, stability, morphology and physicochemical properties of GLPs-SeNPs were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Ultraviolet-visible spectroscopy (UV–vis), Fourier transform infrared (FT-IR) spectra, energy dispersive X-ray (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric (TG). The results showed that orange-red, amorphous, zero-valent and spherical GLPs-SeNPs with mean diameter of approximately 92.5 nm were successfully prepared, which exhibited good storage stability at 4 °C and remaining highly stable at different ion strengths and pH. The 2,2-diphenyl-1-pycrylhydrazyl (DPPH), 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and superoxide anion radical (O2•−) radical scavenging ability of GLPs-SeNPs were higher than those of bare SeNPs, GLPs and sodium selenite (Na2SeO3), and could reach 103.41%, 94.23%, 86% at a concentration of 1.5 mg/mL, respectively. Besides, GLPs-SeNPs also showed higher inhibitory effects on α-amylase and α-glucosidase. In vitro cytotoxicity assay and hemolysis activity examinations indicated that GLPs-SeNPs have excellent biocompatibility. Therefore, the GLPs-SeNPs might be used as a potential antioxidant agent and antidiabetic agent for food and medical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Red emitting nanophosphors of CaTiO3:Pr3+ with various particle sizes were prepared by sol−gel methods and structurally characterized by X-ray diffraction and field emission scanning electron ...microscopy. The fluorescent and phosphorescent properties of CaTiO3:Pr3+ nanoparticles as a function of particle sizes were investigated by using photoluminescence and photoluminescence excitation spectra as well as time decay patterns of fluorescence and phosphorescence. On the analysis of the longer lifetimes at 300 K as compared to that at 77 K and the appearance of maximal photoluminescence, the dependence of photoluminescence on phosphorescence is demonstrated. A very highly efficient phosphorescence recombination channel in the nanophosphor is proposed and discussed. This work provides a promising method to develop novel phosphors by manipulating the number of traps on the surface of nanophosphors through adjusting the particle size.
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IJS, KILJ, NUK, PNG, UL, UM
Near-surface ozone pollution is becoming an increasingly serious air quality issue in China, especially in “2 + 26” cities (Beijing-Tianjin-Hebei and nearby cities). HN2 + 26 cities (“2 + 26” cities ...of Henan Province) are located in the south of “2 + 26” cities, with frequent and severe ozone pollution events in recent years. This study investigated the diurnal evolution characteristics of ozone formation sensitivity (OFS) of HN2 + 26 cities from May to September in 2021 by the innovative combination of Global Ozone Monitoring Experiment (GOME-2B) and Ozone Monitoring Instrument (OMI) satellite data, and assessed the impact of ozone pollution control measures (OPCMs) implemented from June 26 to July 1, 2021. The localized FNR (ratio of formaldehyde to nitrogen dioxide of satellite measurement) threshold (1.4–2.55) was established, and it was found that OFS in May–September 2021 was mainly in VOCs-limited regime in the morning (∼10:00), while transitional/NOx-limited regime in the afternoon (∼14:00). Three periods (before, during and after the OPCMs) were divided to evaluate the impact of OPCMs on OFS. It was indicated that OPCMs had no impact on the morning OFS, but had a significant impact on the afternoon OFS. Specifically, the OFS in two industrial cities Xinxiang (XX) and Zhengzhou (ZZ) shifted from transitional regime to NOx-limited regime after the OPCMs. We further investigated OFS differences between urban and suburban areas and found that OFS shift of XX only existed in urban areas, while that of ZZ existed in both urban and suburban areas. We compared their measures and found that it is effective to take hierarchical control measures on different levels of ozone pollution days to alleviate ozone pollution. This study provides an improved understanding of diurnal evolution characteristics of OFS and the impacts of OPCMs on it, which will provide a theoretical basis for formulating more scientific ozone pollution control policies.
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•Localized FNR threshold (1.4–2.55) of Henan Province “2 + 26” cities was determined.•Diurnal variation characteristics of OFS were analyzed by combining two satellites.•Ozone pollution control measures had a significant impact on afternoon OFS.•OFS in urban and suburban areas under ozone pollution control measures was compared.•Graded control measures for different levels of O3 pollution days are more effective.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Near surface ozone is a typical secondary pollutant, and is mostly generated by a series of complex photochemical reactions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the air ...under sunlight. At present, a large number of studies have applied FNR (a ratio of formaldehyde (HCHO) to nitrogen dioxide (NO2) retrieved by satellite) indicator to study the ozone formation sensitivity (OFS). OFS analysis is critical for taking targeted ozone pollution prevention and control measures. Regional OFS can be more accurately diagnosed by utilizing localized FNR threshold. In this study, localized FNR thresholds were established for four severe ozone polluted urban agglomerations in China (Beijing-Tianjin-Hebei (BTH) region, Yangtze River Delta (YRD) region, Pearl River Delta (PRD) region, and Chengdu-Chongqing (CY) region), based on the statistical analysis between FNR (obtained from OMI observation, with daily transit time of approximately 13:45 local standard time) and ΔO3/ΔNO2 (the ratio of ozone change to nitrogen dioxide change between two consecutive months, obtained from ground measurements) from 2014 to 2016. And these thresholds were verified by the statistical analysis between FNR and ΔO3/O3 (ozone change rate between two consecutive months), and between FNR and O3 concentration during the OFS significant shift months. Furthermore, the results were also compared and verified with the method proposed by previous studies. The results indicate that there are significant regional dependences in the FNR threshold, and the lower–upper limits for the four urban agglomerations are as follows: 0.65–1.21 for BTH, 0.64–1.48 for the YRD, 1.25–2.39 for the PRD, and 1.44–3.69 for CY (FNR < lower limit indicates VOCs-limited regime; lower limit < FNR < upper limit indicates transitional regime; FNR > upper limit indicates NOx-limited regime). This method eliminates the problems associated with the undifferentiated use of FNR thresholds in different regions and significantly reduces the deviations for OFS.
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•Monthly variation differences of OFS were found in four urban agglomerations.•FNR threshold was determined by its statistical relationship with ΔO3/ΔNO2.•Localized FNR thresholds of four urban agglomerations were established.•Localized FNR thresholds significantly reduced the deviations with other studies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
