Crack Detection Method for Wind Turbine Tower Bolts Using Ultrasonic Spiral Phased Array.

High-strength bolts are crucial load-bearing components of wind turbine towers. They are highly susceptible to fatigue cracks over long-term service and require timely detection. However, due to the structural complexity and hidden nature of the cracks in wind turbine tower bolts, the small size of the cracks, and their variable propagation directions, detection signals carrying crack information are often drowned out by dense thread signals. Existing non-destructive testing methods are unable to quickly and accurately characterize small cracks at the thread roots. Therefore, we propose an ultrasonic phased array element arrangement method based on the Fermat spiral array. This method can greatly increase the fill rate of the phased array with small element spacing while reducing the effects of grating and sidelobes, thereby achieving high-energy excitation and accurate imaging with the ultrasonic phased array. This has significant theoretical and engineering application value for ensuring the safe and reliable service of key wind turbine components and for promoting the technological development of the wind power industry.

Near infrared luminescence properties and mechanism of high bismuth-doped SiO2-Al2O3-La2O3 glass.

This research investigated the wideband near-infrared spectroscopy characteristics of 60SiO2-25Al2O3-10La2O3 glass doped with high levels of bismuth up to 5 mol%. The near-infrared radiation range was explored under excitation wavelengths of 488 nm, 532 nm, 808 nm, and 980 nm, resulting in near-infrared radiation spanning from 1000 nm to 1800nm with Full Width at Half Maximum (FWHM) values of 313.0 nm, 336.3 nm, 296.2 nm, and 262.9 nm, respectively. Notably, the sample exhibited a lifetime of 1.473 ms when pumped at 808 nm, corresponding to a stimulated cross-section of σe=3.35 × 10-21 cm2. Through an in-depth investigation of the luminescence properties, the underlying physical mechanism behind the near-infrared luminescence was revealed. The emissions observed at approximately 1150 nm and 1300 nm were attributed to the aluminum-related bismuth active center (BAC-Al) and the silicon-related bismuth active center (BAC-Si), respectively. Furthermore, it is postulated that the emission at the 1150 nm band originates from the 3P1, 3P2 →3P0 transition of Bi+ and the 2D3/2 → 4S3/2 transition of Bi°, while the emission at the 1300 nm band may be linked to mixed valence states of Bi3+. This work will find potential applications in broadband near-infrared optical devices.

Advances in flavor peptides with sodium-reducing ability: A review.

Condiments (such as sodium chloride and glutamate sodium) cause consumers to ingest too much sodium and may lead to a variety of diseases, thus decreasing their quality of life. Recently, a salt reduction strategy using flavor peptides has been established. However, the development of this strategy has not been well adopted by the food industry. There is an acute need to screen for peptides with salty and umami taste, and to understand their taste characteristic and taste mechanism. This review provides a thorough analysis of the literature on flavor peptides with sodium-reducing ability, involving their preparation, taste characteristic, taste mechanism and applications in the food industry. Flavor peptides come from a wide range of sources and can be sourced abundantly from natural foods. Flavor peptides with salty and umami tastes are mainly composed of umami amino acids. Differences in amino acid sequences, spatial structures and food matrices will cause different tastes in flavor peptides, mostly attributed to the interaction between peptides and taste receptors. In addition to being used in condiments, flavor peptides have also anti-hypertensive, anti-inflammatory and anti-oxidant abilities, offering the potential to be used as functional ingredients, thus making their future in the food industry extremely promising.

The influence of media use degree on public depressive symptoms: mediating role of big five personality.

BACKGROUND: Mixed results have been found regarding the relationship between media use degree and depressive symptoms. The purpose of this study is to explore the relationship between media use degree, big five personality and depressive symptoms with a mediation model. METHOD: This was a cross-sectional study. With 9-item Patient Health Questionnaire (PHQ-9), 10-item Big Five Inventory (BFI-10) and self-designed media usage scale, 11,031 participants aged 12 and above in 120 cities in China were collected. Pearson correlation analysis and regression analysis were performed on the data. The Process plug-in was used to construct the mediation model and explore the relationship among media use degree, big five personality and depressive symptoms. The nonparametric percentile Bootstrap method was used to test the mediating effect of personality traits. RESULTS: The degree of media use was positively correlated with depressive symptoms (r = 0.20, P < 0.001), and big five personality played a mediating role between the degree of media use and depressive symptoms. Among five traits, extroversion (r=-0.12, P < 0.001), conscientiousness (r=-0.23, P < 0.001), openness (r=-0.03, P < 0.01) and agreeableness (r=-0.22, P < 0.001) were negatively correlated with depressive symptoms, and neuroticism (r = 0.25, P < 0.001) were positively correlated with depressive symptoms. In addition, extraversion (-0.004, -0.001), conscientiousness (-0.015, -0.008), agreeableness (-0.008, -0.001) and neuroticism (-0.015, -0.007) in big five personality played a mediating role between media use and depressive symptoms. CONCLUSION: The degree of media use positively predicted depressive symptoms, and excessive media use may bring risks to mental health. People with high neuroticism, low agreeableness, low conscientiousness and low extroversion are more likely to suffer from depressive symptoms.

A cross-sectional study: family communication, anxiety, and depression in adolescents: the mediating role of family violence and problematic internet use.

OBJECTIVE: The objective of this study is to explore the relationship between family communication, family violence, problematic internet use, anxiety, and depression and validate their potential mediating role. METHODS: The study population consisted of Chinese adolescents aged 12 to 18 years, and a cross-sectional survey was conducted in 2022. Structural equation models were constructed using AMOS 25.0 software to examine the factors that influence adolescent anxiety and depression and the mediating effects of problematic internet use and family violence. RESULTS: The results indicate that family communication was significantly and negatively related to family violence (ß = -.494, p < 0.001), problematic internet use (ß = -.056, p < .05), depression (ß = -.076, p < .01), and anxiety (ß = -.071, p < .05). And the finds also indicate that family violence mediated the relationships between family communication and depression (ß = -.143, CI: -.198 -.080), and between family communication and anxiety (ß = -.141; CI: -.198 -.074). Chain indirect effects between family communication and depression (ß = -.051; CI: -.081 -.030) or anxiety (ß = -.046; CI: -.080 -.043) via family violence and then through problematic internet use were also found in the present study. CONCLUSIONS: In conclusion, positive family communication is crucial in reducing anxiety and depression in adolescents. Moreover, problematic internet use and family violence mediate the effects of positive family communication on anxiety and depression. Therefore, improving family communication and promoting interventions aimed at reducing family violence and problematic internet use can help reduce anxiety and depression in adolescents, thus promoting their healthy development.

The effects and safety of omega-3 fatty for acute lung injury: a systematic review and meta-analysis.

BACKGROUND: Several randomized controlled trials (RCTs) have compared the treatment of acute lung injury (ALI) with omega-3 fatty, yet the results remained inconsistent. Therefore, we attempted this meta-analysis to analyze the role of omega-3 fatty in the treatment of ALI patients. METHODS: We searched PubMed databases from inception date to October 31, 2019, for RCTs that compared the treatment of ALI with or without omega-3 fatty. Two authors independently screened the studies and extracted data from the published articles. Summary mean differences (MD) with 95% confidence intervals (CI) were calculated for each outcome by fixed- or random-effects model. RESULTS: Six RCTs with a total of 277 patients were identified, of whom 142 patients with omega-3 fatty acid treatment and 135 patients without omega-3 fatty treatment. Omega-3 fatty treatments significantly improve the PaO2 (MD = 13.82, 95% CI 8.55-19.09), PaO2/FiO2 (MD = 33.47, 95% CI 24.22-42.72), total protein (MD = 2.02, 95% CI 0.43-3.62) in ALI patients, and omega-3 fatty acid treatments reduced the duration of mechanical ventilation (MD = - 1.72, 95% CI - 2.84 to - 0.60) and intensive care unit stay (MD = - 1.29, 95% CI - 2.14 to - 0.43) in ALI patients. CONCLUSIONS: Omega-3 fatty can effectively improve the respiratory function and promote the recovery of ALI patients. Future studies focused on the long-term efficacy and safety of omega-3 fatty use for ALI are needed.

Two-dimension and high-resolution demultiplexing of coaxial multiple orbital angular momentum beams.

A high-resolution demultiplexing method is proposed for the separation of coaxial multiple orbital angular momentum (OAM) beams which are created by a self-designed computer-generated hologram (CGH) encoded with logarithmic spiral phases. The logarithmic spiral phase, consisting of both azimuthal and radial phase, enables the two-dimensional demultiplexing of the OAM beams. The simulation and experiment results show that, with our method, the coaxial multiple OAM beams can be effectively separated in the specified plane. The overlap between the adjacent channel is greatly reduced by the high-resolution demultiplexing method, which is based on an optical geometrical transform and a coherent copy technique. The proposed method has great potential in increasing the number of spatial channels available for OAM multiplexing transmission system.

Adaptive moment estimation for polynomial nonlinear equalizer in PAM8-based optical interconnects.

Adaptive moment estimation (Adam) is a popular optimization method to estimate large-scale parameters in neural networks. This paper proposes the first use of Adam algorithm to fast and stably converge large-scale tap coefficients of polynomial nonlinear equalizer (PNLE) for 129-Gbit/s PAM8-based optical interconnects. PNLE is one of simplified Volterra nonlinear equalizer for making a trade-off between complexity and performance. Different from serial least-mean square (LMS) adaptive algorithm, Adam algorithm is a parallel processing algorithm, which can obtain globally optimal tap coefficients without being trapped in locally optimal tap coefficients. Timing error is one of the main obstacles to the PAM systems with high baud rate and high modulation order. Owing to parallel processing and global optimization, Adam algorithm has much better performance on resisting the timing error, which can achieve faster, more-stable and lower-MSE convergence compared to LMS adaptive algorithm. In conclusion, Adam algorithm shows great potential for converging the tap coefficients of PNLE in PAM8-based optical interconnects.

DD-OFDM transmission over few-mode fiber based on direct vector mode multiplexing.

The fiber vector eigenmode based mode division multiplexing (VMDM) transmission over few-mode fiber (FMF) with the 1st-order cylinder vector beams (CVBs) has been demonstrated. The performances of generated CVB using q-plate (QP) have been characterized before and after transmission over the FMF respectively based on the high-order Poincaré sphere model and polarization grating (PG). The measured minimum mode isolations between the two CVBs (TM01 and TE01 modes) of the used 4-mode FMF are about 16.8 dB after transmitting over 5 m and 12.5 dB over 100 m respectively. Then the dual-vector-mode-multiplexed transmissions over FMF of 96 Gb/s with length of 5m and 48 Gb/s of 100 m have been realized in combination with the modulation of direct-detection (DD) orthogonal-frequency-division-multiplexing (OFDM) without using multiple-input multiple-output (MIMO) digital signal processing (DSP). The experimental results indicate that the CVB-based technology could find the potential in large-capacity short-reach optical interconnects.

Measuring high-order optical orbital angular momentum with a hyperbolic gradually changing period pure-phase grating.

We present a method to measure the high-order orbital angular momentum (OAM) state of a light beam with a static hyperbolic gradually changing period pure-phase grating (HGCP-PPG). From the number and orientation of the fringes of the Hermite-Gaussian-like diffraction intensity pattern, the OAM state of the incident Laguerre-Gaussian beam can be measured. Experimental detection of the OAM state up to ±100-order has been achieved. This method is highly efficient and robust because the HGCP-PPG is adaptive to high-order OAM beam and tolerant of the misalignment of the incident OAM beam.

High-Temperature Sensor Based on Fabry-Perot Interferometer in Microfiber Tip.

A miniaturized tip Fabry-Perot interferometer (tip-FPI) is proposed for high-temperature sensing. It is simply fabricated for the first time by splicing a short length of microfiber (MF) to the cleaved end of a standard single mode fiber (SMF) with precise control of the relative cross section position. Such a MF acts as a Fabry-Perot (FP) cavity and serves as a tip sensor. A change in temperature modifies the length and refractive index of the FP cavity, and then a corresponding change in the reflected interference spectrum can be observed. High temperatures of up to 1000 °C are measured in the experiments, and a high sensitivity of 13.6 pm/°C is achieved. This compact sensor, with tip diameter and length both of tens of microns, is suitable for localized detection, especially in harsh environments.

Ultrasensitive Mach-Zehnder Interferometric Temperature Sensor Based on Liquid-Filled D-Shaped Fiber Cavity.

A liquid-filled D-shaped fiber (DF) cavity serving as an in-fiber Mach–Zehnder interferometer (MZI) has been proposed and experimentally demonstrated for temperature sensing with ultrahigh sensitivity. The miniature MZI is constructed by splicing a segment of DF between two single-mode fibers (SMFs) to form a microcavity (MC) for filling and replacement of various refractive index (RI) liquids. By adjusting the effective RI difference between the DF and MC (the two interference arms), experimental and calculated results indicate that the interference spectra show different degrees of temperature dependence. As the effective RI of the liquid-filled MC approaches that of the DF, temperature sensitivity up to −84.72 nm/°C with a linear correlation coefficient of 0.9953 has been experimentally achieved for a device with the MC length of 456 μm, filled with liquid RI of 1.482. Apart from ultrahigh sensitivity, the proposed MCMZI device possesses additional advantages of its miniature size and simple configuration; these features make it promising and competitive in various temperature sensing applications, such as consumer electronics, biological treatments, and medical diagnosis.

All-fiber second-order optical vortex generation based on strong modulated long-period grating in a four-mode fiber.

We propose an effective all-fiber method to generate a high-order optical vortex (OV) via twisting a strong modulated long-period fiber grating (LPFG) written in a four-mode fiber (4MF). With a special design and optimization of the procedures of CO2-laser irradiation, an LPFG with strong period deformation is achieved in the 4MF. Based on this LPFG, we can directly convert the linear polarization (LP) fiber fundamental mode (LP01) to the high-order LP core mode (LP21) with efficiency of 99.7% and then transform the LP21 mode into a high-order OV mode (±2 order). This is the first time, to the best of our knowledge, that ±2-order OV modes have been experimentally generated with just one fiber grating in an all-fiber-system.

Near-infrared absorbing compounds based on π-extended tetrathiafulvalene open-cage fullerenes.

Tetrathiafulvalene (TTF) is attached to open-cage fullerenes through a quinoxaline junction. The resulting linear π-conjugation system shows intense absorption in the near-infrared region. A unique o-diaminobenzene-induced furan ring formation process from a conjugated 1,4-dione moiety was observed on the rim of a 18-membered orifice.

Taste characteristics of salty peptides from Porphyra haitanensis and the synergistic saltiness enhancement with CaCl2.

The excessive consumption of sodium-containing seasonings has led to an increased burden on individuals' cardiovascular system and adversely affected their health. Recently, an innovative salt-reducing strategy utilizing salty peptides has emerged with promising prospects. In this study, Porphyra haitanensis salty peptides (PHSPs) was obtained through hydrolysis and ultrafiltration. The salty taste of 30 mg/mL PHSPs was comparable to that of about 40 mM NaCl. The higher proportion of umami and sweet amino acids in PHSPs was found, which contributed to the salty and umami taste. Factors affecting the flavor of PHSPs were also investigated. CaCl2 exhibited the excellent synergistic enhancement with PHSPs on the salty taste, while the bitter taste of CaCl2 was masked in the presence of PHSPs, which was attributed to the chelation between calcium and peptides. Above all, it is expected that PHSPs can be further developed and support the emerging salt-reducing strategy in food engineering.

The use of matrine to inhibit osteosarcoma cell proliferation via the regulation of the MAPK/ERK signaling pathway.

Background: Matrine is an alkaloid extracted from Sophorus beans of the legume family, and it has significant effects and a variety of pharmacological activities. Osteosarcoma(OS) is a common malignant bone tumor that is characterized by high incidence and rapid progression. There have been some preliminary studies on the therapeutic effect of matrine on OS, but the specific mechanism remains unclear. Objective: The aim of this study was to investigate the antitumor effect of matrine on HOS cells and the underlying molecular mechanism. Methods: The effects of matrine on the proliferation, apoptosis and cell cycle progression of HOS cells were determined by CCK-8 assay, TUNEL assay and flow cytometry in vitro. Wound healing and Transwell invasion assays were used to observe the effect of matrine on the migration and invasion of HOS cells. The mechanism underlying the antitumor effect of matrine on HOS cells was investigated by Western blotting. Results: Matrine significantly inhibited HOS cell proliferation, promoted HOS cell apoptosis, and arrested HOS cells in the G1 phase of the cell cycle. Both wound healing and Transwell invasion assays showed that matrine inhibited HOS cell migration and invasion. Western blotting results showed that matrine inhibited the activation of the MAPK/ERK signaling pathway. We found that matrine also downregulated Bcl-2 expression, which may be related to protein synthesis inhibition. Conclusion: Matrine can inhibit the proliferation of HOS cells, arrest HOS cells in the G1 phase, and promote HOS cell apoptosis through the MAPK/ERK signaling pathway.

Research on factors influencing Chinese parents' support for death education: a cross-sectional survey.

Objective: This study aims to explore the factors influencing Chinese parents' attitudes toward death education. Given the current lack of such education in China, this research is particularly significant. Death education is vital for shaping the values of young people and alleviating mental health issues, such as depression and suicidal tendencies. By identifying these influencing factors, this study seeks to provide guidance for policymakers and educators in promoting the development and widespread adoption of death education. Methods: To do so, a national cross-sectional quota sample of 12,435 Chinese parents was used. Borrowing from social-ecological theory, the researchers carried out multiple stepwise regression analyses to examine the individual, family, and social-level factors that shape the supportive attitudes of Chinese parents toward death education. Results: The findings revealed that at the individual level, parent (ß = 0.04, p < 0.001), education level (ß = 0.07, p < 0.001), and religious belief (ß = -0.02, p < 0.05) were significant predictors of Chinese parents' support for death education. Meanwhile, at the family and social level, average monthly household income (ß = 0.07, p < 0.001), family health (ß = 0.03, p < 0.05), family communication (ß = 0.02, p < 0.05), social support (ß = 0.15, p < 0.001), neighborhood relations (ß = 0.11, p < 0.001), and social network size (ß = 0.05, p < 0.001) were significant predictors of Chinese parents' supportive attitudes toward death education. Conclusion: Based on these findings, it is suggested that the relevant development, planning, publicity, and public welfare groups and government departments should promote death education, provide more social support, and encourage neighborhood harmony. As higher education and average monthly household income were found to significantly impact the support, the government should improve access to higher education and actively work to increase residents' income to facilitate the development of death education.

The Influence of Identity Bubble Reinforcement on the Happiness Index among Chinese Medical Staff: The Mediating Role of General Self-Efficacy.

Objective: This study aimed to explore the mediating role of general self-efficacy in the influence of social media identity bubble reinforcement on the happiness index among Chinese medical staff. Methods: This study utilized data (n = 877) from the 2022 Psychological and Behavioral Investigation of Chinese Residents (PBICR) related to medical staff. Correlation analysis was performed using SPSS 26.0 software, and the relationships between general self-efficacy, social media identity bubble reinforcement, and the happiness index of Chinese medical staff were examined using AMOS 23.0 software. Results: The happiness index of Chinese medical staff was scored at 2.93 ± 1.21 for each item. Social media identity bubble reinforcement among Chinese medical staff was positively correlated with general self-efficacy (r = 0.380, P < .001), as well as with the happiness index (r = 0.330, P < .001). General self-efficacy was positively correlated with the happiness index (r = 0.575, P < .001) and was found to mediate the relationship between social media identity bubble reinforcement and the happiness index of Chinese medical staff. In terms of the mediating effect of social media identity bubble reinforcement, the direct effect's 95% confidence interval (CI) was 0.031-0.142, accounting for 34.68% of the total effect, which is statistically significant (P = .015), while the 95% CI of the indirect effect was 0.125-0.212, representing 65.32% of the total effect, also statistically significant (P = .005). Conclusion: Social media identity bubble reinforcement and general self-efficacy were found to be important factors influencing the happiness index of medical staff. Hospital managers and policymakers can thus enhance the social media identity bubble reinforcement and general self-efficacy of Chinese medical staff through effective measures to improve their happiness indices.

The Impact of Problematic Internet Use on Adolescent Loneliness-Chain Mediation Effects of Social Support and Family Communication.

Purpose: To explore the relationship between adolescents' problematic Internet use and loneliness and the mediating roles of social support and family communication. Methods: A questionnaire survey of 2483 adolescents aged 12-17 years in 148 cities in China was conducted using the Problematic Internet Use Scale, the Collaborative Social Support Scale, the Family Communication Scale, and the Loneliness Scale. The data were statistically analyzed by SPSS 26.0 and validated by AMOS 28.0. Structural equation modelling (SEM) was conducted to test the effects of problematic Internet use on adolescents' loneliness and the mediating effects of perceptions of social support and family communication. Results: There was a significant positive effect of adolescents' problematic Internet use on loneliness (B-0.471, P<0.001), and the mediating effects of perceptual social support (0.003, 0.012) and family communication (0.008, 0.019) were found to play a chain effect between adolescents' problematic Internet use and loneliness, respectively. Use and feelings of loneliness played a chain mediating role (0.002, 0.006). Conclusion: This study identified the effects of adolescent problematic Internet use on loneliness and its mechanism of action, emphasized the importance of social support and family communication, and provided practical insights for improving family parenting styles and preventing and intervening in adolescent loneliness problems.