[Newborn screening, clinical features and genetic analysis for Citrin deficiency in Henan province].

OBJECTIVE: To explore the prevalence, clinical features, genetic characteristics and prognosis of Citrin deficiency in Henan province of China. METHODS: A total of 986 565 neonates screened by tandem mass spectrometry at the Third Affiliated Hospital of Zhengzhou University from January 2013 to December 2021 were retrospectively analyzed. Analysis of SLC25A13 gene variants and parental verification were carried out for neonates suspected for Citrin deficiency by next-generation sequencing. The clinical, biochemical and genetic characteristics of Citrin deficiency patients were integrated to guide the diet treatment and follow up the growth and development. Paired-t test was used to compare the amino acid levels in the peripheral blood samples before and after the treatment. RESULTS: Nine cases of Citrin deficiency were diagnosed among the 986 565 neonates. Specific elevation of citrulline was observed in all of the 9 cases. Six variants were detected by genetic sequencing, among which c.852_855delTATG, c.615+5G>A, c.550C>T and IVS16ins3kb were known pathogenic variants, whilst c.1111_1112delAT and c.837T>A were unreported previously. The detection rate for c. 852_855delTATG was the highest (61.6%, 11/18), followed by IVS16ins3kb (16.7%, 3/18). The clinical symptoms of all patients were relieved after the treatment, and the blood amino acid profile and biochemical parameters were significantly improved by gradually falling within the normal range. By June 2022, all patients had shown a good prognosis. CONCLUSION: The prevalence of Citrin deficiency among neonates from Henan Province by tandem mass spectrometry is 1/109 618, and the carrier rate for the pathogenic variants of the SLC25A13 gene was 1/166. The c.852_855delTATG may be a hot spot variant among the patients. Discovery of the novel variants has enriched the mutational spectrum of the SLC25A13 gene. Above results have provided a basis for the early diagnosis, treatment, prognosis and genetic counseling for the affected families.

Improving Wear Resistance and Corrosive Resistance of Cemented Carbide for Mud Pulser Rotor by Deep Cryogenic Treatment.

Cemented carbide used in the rotor of a mud pulser is subjected to the scouring action of solid particles and corrosive mud media for a long time, which causes abrasive wear and electrochemical corrosion. To improve the wear and corrosive resistance of cemented carbide, samples with different cobalt content (WC-5Co, WC-8Co, and WC-10Co) receive deep cryogenic treatment (DCT) at -196 °C for 2.5 h. An optical metalloscope (OM) and X-ray diffractometer (XRD) are used to observe the phase changes of cemented carbides, and the XRD is also used to observe the change in residual stress on the cemented carbide's surface. A scanning electron microscope (SEM) is used to characterize the wear and electrochemical corrosion surface microstructure of cemented carbides (untreated and DCT). The results show that the DCT promotes the precipitation of the η phase, and the diffraction peak of ε-Co tends to intensify. Compared with the untreated, the wear rates of WC-5Co, WC-8Co, and WC-10Co can be reduced by 14.71%, 37.25%, and 41.01% by DCT, respectively. The wear form of the cemented carbides is mainly the extrusion deformation of Co and WC shedding. The precipitation of the η phase and the increase in WC residual compressive stress by DCT are the main reasons for the improvement of wear resistance. The electrochemical corrosion characteristic is the dissolution of the Co phase. DCT causes the corrosion potential of cemented carbide to shift forward and the corrosion current density to decrease. The enhancement of the corrosion resistance of cemented carbide caused by DCT is due to the Co phase transition, η phase precipitation, and the increase in the compressive stress of cemented carbide.

Formamidinium Lead Iodide-Based Inverted Perovskite Solar Cells with Efficiency over 25 % Enabled by An Amphiphilic Molecular Hole-Transporter.

Formamidinium lead iodide (FAPbI3) represents an optimal absorber material in perovskite solar cells (PSCs), while the application of FAPbI3 in inverted-structured PSCs has yet to be successful, mainly owing to its inferior film-forming on hydrophobic or defective hole-transporting substrates. Herein, we report a substantial improvement of FAPbI3-based inverted PSCs, which is realized by a multifunctional amphiphilic molecular hole-transporter, (2-(4-(10H-phenothiazin-10-yl)phenyl)-1-cyanovinyl)phosphonic acid (PTZ-CPA). The phenothiazine (PTZ) based PTZ-CPA, carrying a cyanovinyl phosphonic acid (CPA) group, forms a superwetting hole-selective underlayer that enables facile deposition of high-quality FAPbI3 thin films. Compared to a previously established carbazole-based hole-selective material (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl)phosphonic acid (MeO-2PACz), the crystallinity of FAPbI3 is enhanced and the electronic defects are passivated by the PTZ-CPA more effectively, resulting in remarkable increases in photoluminescence quantum yield (four-fold) and Shockley-Read-Hall lifetime (eight-fold). Moreover, the PTZ-CPA shows a larger molecular dipole moment and improved energy level alignment with FAPbI3, benefiting the interfacial hole-collection. Consequently, FAPbI3-based inverted PSCs achieve an unprecedented efficiency of 25.35 % under simulated air mass 1.5 (AM1.5) sunlight. The PTZ-CPA based device shows commendable long-term stability, maintaining over 90 % of its initial efficiency after continuous operation at 40 °C for 2000 hours.

Molecular Symmetry of Small-Molecule Passivating Agents Improves Crystal Quality of Perovskite Solar Cells.

Direct interaction with the defect sites of perovskite, functional groups have become the focal point of attention as passivating agents. However, the molecular parent nucleus determines the overall physical properties of the molecule, including the push-pull electronic characteristics of the functional groups, which poses significant challenges in terms of selectivity. Here, we discovered that the binary acid structure based on thiophene as the parent nucleus, due to changes in molecular symmetry, caused significant changes in the molecular dipole moment, resulting in significant changes in the passivation effects on under-coordinated Pb2+ in perovskite solar cells. For the axially symmetric thiophen-2,5-dicarboxylic acid (TPDC), the high dipole moment formed a concentrated surface negative potential on the carboxyl group, showing significant superiority over the centrally symmetric thieno[3,2-b] thiophene-2,5-dicarboxylic acid (TTDC) in forming high-quality perovskite crystals, suppressing charge recombination, enhancing effective charge transport, and raising internal electric fields. The power conversion efficiencies of the fully printable mesoscopic perovskite solar cells based on TPDC and TTDC were 17.15 % and 14.79 %, respectively, exhibiting important research value in the field of small molecule passivation mechanism research.

Competitive Formation Mechanism for Bidentate Passivation of Halogen Vacancies in Perovskite Based on 6-Chloropurine.

For metal halide perovskite solar cells, bidentate passivation (BP) is highly effective, but currently, only passivation sites rather than molecular environments are being considered. Here, the authors report an effective approach for high-performance fully printable mesoscopic perovskite solar cells (FP-PSCs) through the BP strategy using the multidentate molecule 6-chloropurine (6-CP). By utilizing density functional theory (DFT) calculations, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) characterizations, the competition mechanism is identified of BP between the chlorine atom and neighboring nitrogen atom of the imidazole and pyrimidine rings. Through BP between the chlorine atom and adjacent nitrogen atom in imidazole, the power conversion efficiency (PCE) of the pristine samples is significantly enhanced from 16.25% to 17.63% with 6-CP. The formation of BP enhances interfacial hole selectivity and charge transfer, and suppresses nonradiative recombination, improving device stability under high humidity conditions. The competition mechanism of BP between two aromatic cycles provides a path for designing molecular passivants and selecting passivation pathways to approach theoretical limits.

Independent and joint trajectories of depression and anxiety symptoms among Chinese male sailors throughout a prolonged non-24-h rotating shift schedule at sea: a parallel-process growth mixture modeling approach.

BACKGROUND: The predictive and protective effect of hardiness on mental health remains unclear among shift workers on non-24-h working schedules. The present study aimed to investigate the independent and joint trajectories of depression and anxiety symptoms and the role of hardiness during a prolonged period of non-24-h shift working schedule. METHODS: Four hundred nine Chinese male sailors (working on 18-h watchstanding schedule) were recruited and completed all 5-wave tests through online questionnaires (at Day 1, 14, 28, 42, 55, respectively) during a 55-day sailing. The questionnaires included sociodemographic variables, hardiness, depression and anxiety symptoms. Independent and joint trajectories of depression and anxiety symptoms were estimated by latent growth mixture models. The effect of hardiness on trajectories was examined by logistic regression models. RESULTS: 2 and 3 latent trajectories were identified for depression and anxiety symptoms, respectively. Based on initial levels and development trends, 3 distinct joint trajectories of depression and anxiety were identifed and named as: "Low-Inverted U" group (73.6%), "Moderate-Deterioration" group (6.9%), and "High-Stable" group (9.5%). Sailors with higher levels of hardiness were more likely to follow the "Low-Inverted U" trajectory of depression and anxiety symptoms (all p < 0.001). CONCLUSIONS: There existed individual differences in the trajectories of depression and anxiety. Hardiness may have a protective effect that can prevent and alleviate depression and anxiety symptoms. Therefore, hardiness-based intervention programs are encouraged among the shift workers on non-24-h working and rest schedules.

Fabrication of Dimples by Jet-ECM of Zr-Based Bulk Metallic Glasses with NaCl-Ethylene Glycol Electrolyte.

Zr-based bulk metallic glasses (BMGs) possess unique mechanical and biochemical properties, which have been widely noticed. Jet electrochemical machining (jet-ECM), characterized by a high-speed jet, is a non-contact subtractive method with a high resolution and a high material removal rate (MRR). Past work on the electropolishing of Zr-based BMGs has indicated the feasibility of the NaCl-Ethylene Glycol (EG) electrolyte. In this research, the jet-ECM of Zr-based BMGs in the NaCl-EG electrolyte was studied to explore the dissolving mechanisms and surface integrity according to the voltage, pulse-on time and effective voltage time. The diameter, depth and surface morphologies of dimples were evaluated. The results showed that using this alcohol-based electrolyte led to a desirable surface morphology. The diameter and depth of the dimples varied with the voltage and the effective voltage time in a significantly positive proportional manner. Additionally, cases based on multiple parameter sets exhibited different stray corrosion severity. Afterward, machining performance can be enhanced in the next stage by tuning machining parameters to obtain microscale dimples with better quality.

An Investigation in Sub-Millimeter Channel Fabrication by the Non-Aqueous Electrolyte Jet Machining of Zr-Based Bulk Metallic Glasses.

Zr-based bulk metallic glasses (BMGs) have many unique properties. Due to their excellent performance and manufacturing process, they have become a research focus in the material science community. Electrolyte Jet Machining (EJM) is a non-contact electrochemical processing method with high surface integrity and high material removal rate (MRR). In this research, the sub-millimeter channels fabricated by EJM on Zr-based BMGs have been studied to explore the dissolution mechanisms and surface integrity under different scanning rates and voltages. The results show that, with other machining parameters holding constant, an increase in voltage leads to a substantial enhancement in both the depth and width of the channels machined on Zr-based BMGs. Notably, the influence of voltage on the depth of the channels is particularly pronounced. Additionally, an escalation in scanning rate correlates with a decrease in channel depth, with minimal variation in channel width. This study indicates that alcohol-based EJM is an effective method to fabricate sub-millimeter channels and modulate structures on Zr-based BMGs.

Highly Stable, Mechanically Enhanced, and Easy-to-Collect Sodium Alginate/NZVI-rGO Gel Beads for Efficient Removal of Cr(VI).

Nanoscale zero-valent iron (NZVI) is a material that is extensively applied for water pollution treatment, but its poor dispersibility, easy oxidation, and inconvenient collection limit its application. To overcome these drawbacks and limit secondary contamination of nanomaterials, we confine NZVI supported by reduced graphene oxide (rGO) in the scaffold of sodium alginate (SA) gel beads (SA/NZVI-rGO). Scanning electron microscopy showed that the NZVI was uniformly dispersed in the gel beads. Fourier transform infrared spectroscopy demonstrated that the hydrogen bonding and conjugation between SA and rGO allowed the NZVI-rGO to be successfully embedded in SA. Furthermore, the mechanical strength, swelling resistance, and Cr(VI) removal capacity of SA/NZVI-rGO were enhanced by optimizing the ratio of NZVI and rGO. Interestingly, cation exchange may drive Cr(VI) removal above 82% over a wide pH range. In the complex environment of actual Cr(VI) wastewater, Cr(VI) removal efficiency still reached 70.25%. Pseudo-first-order kinetics and Langmuir adsorption isotherm are preferred to explain the removal process. The mechanism of Cr(VI) removal by SA/NZVI-rGO is dominated by reduction and adsorption. The sustainable removal of Cr(VI) by packed columns could be well fitted by the Thomas, Adams-Bohart, and Yoon-Nelson models, and importantly, the gel beads maintained integrity during the prolonged removal. These results will contribute significant insights into the practical application of SA/NZVI-rGO beads for the Cr(VI) removal in aqueous environments.

Psychometric properties of the Brief Version of Pittsburgh Sleep Quality Index (B-PSQI) among Chinese male sailors on 18-hr rotating shift schedule.

Sleep problems among shift workers have emerged as a public health concern in recent years. However, few validation studies of self-reported sleep quality questionnaires were performed among shift workers. The present study aimed to examine the psychometric properties of the Brief Version of Pittsburgh Sleep Quality Index (B-PSQI) in a shift workers sample. In total, 443 Chinese male sailors were recruited, of whom 46.95% (n = 208) were watchstanding sailors on 18-hr working schedule at sea. All participants completed the B-PSQI, the Insomnia Severity Index (ISI), the Self-Rating Depression Scale, and Self-Rating Anxiety Scale before and after a 30-day saling. Forty watchstanding sailors were selected to wear wrist actigraphy throughout the sailing. The results showed that the B-PSQI had acceptable internal consistency reliability in different sailor groups. Confirmatory factor analysis showed optimal fit of the single-factor model of the B-PSQI in different sailor groups. Furthermore, scalar invariance between watchstanding and day-working sailors was supported, as well as longitudinal scalar invariance across time. In addition, receiver operating characteristic analysis showed that the B-PSQI yields high discrimination power to detect poor sleep quality using ISI ≥ 8 criterion. However, a lack of intermethod agreement across the B-PSQI and actigraphy was found in this study. Moreover, the total scores of B-PSQI were positively related to depression and anxiety symptoms in the present sample. The B-PSQI is a reliable and valid sleep quality measure and a useful screening tool for sleep disorders among Chinese male sailors. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Investigation on low-loss hollow-core anti-resonant terahertz fiber.

In this work, a hollow-core anti-resonant terahertz (THz) fiber with elliptical cladding and nested tubes is proposed and fabricated. It is an effective way to reduce the loss of THz waves by transmitting them in an air core and breaking the material absorption. After parameter optimization of the initial structure, multiple transmission windows exist in the 0.2-0.8 THz band, where confinement loss is as low as 3.47×10-3cm-1 at 0.8 THz. At 0.2-0.7 THz, confinement losses lie between 10-3 and 10-2cm-1. The 3D printed samples are characterized by a THz time-domain spectroscopy system. Experimental results showed that the designed fiber structure transmits loss coefficients up to 10-2cm-1 in the 0.2-0.8 THz band (the minimum value is located at 0.46 THz, corresponding to a loss coefficient of 0.0284cm-1). The experiments show that the designed THz fiber achieves a good transmission effect.

Can limiting bedtime smartphone use improve next-day working memory among undergraduates with problematic smartphone use?

This study implemented a longitudinal self-control intervention experiment to examine whether limiting bedtime smartphone use can improve next-day working memory among individuals with problematic smartphone use (PSU). 156 Chinese undergraduates with PSU completed the 6-day experiment (3 nights for intervention condition and 2 nights for control condition). All participants were asked to complete N-back tests in the afternoon everyday during the experiment. The results indicated that limiting smartphone use in bed improved next-day working memory. Therefore, limiting smartphone use in bed is a potential remedy for daily cognitive impairments induced by PSU.

Can restricting while-in-bed smartphone use improve sleep quality via decreasing pre-sleep cognitive arousal among Chinese undergraduates with problematic smartphone use? Longitudinal mediation analysis using parallel process latent growth curve modeling.

BACKGROUND AND AIM: Problematic smartphone use (PSU) has become a global public health problem. Excessive while-in-bed smartphone use may result in poor sleep quality. The present study aimed to examine whether restricting while-in-bed smartphone use can improve sleep quality and the mediating role of pre-sleep cognitive arousal in this process. METHODS: A total 152 Chinese undergraduates with symptoms of PSU (Smartphone Addiction Scale-Short Version [SAS-SV] > 31) were recruited and randomly assigned to the intervention group (N = 76) and the control group (N = 76) for a 4-week follow-up experiment. Sleep quality (assessed by the Pittsburgh Sleep Quality Index) and pre-sleep cognitive arousal (assessed by the Pre-sleep Arousal Scale-Cognitive Arousal) were measured at baselime, Week1, Week2, Week3, and Week4. The longitudinal mediation model was analyzed using parallel process latent growth curve modeling. The significance of indirect effect was tested by 95% biascorrected accelerated confidence intervals on the basis of 5000 bootstrap samples. RESULTS: The initial level of sleep quality was positively associated with the initial level of pre-sleep cognitive arousal. The intervention decreased pre-sleep cognitive arousal and increased sleep quality. The slope of pre-sleep cognitive arousal was positively associated with the slope of sleep quality. The mediating effect of pre-sleep cognitive arousal was significant. DISCUSSION: Restricting while-in-bed smartphone use can improve sleep quality via decreasing pre-sleep cognitive arousal among Chinese undergraduates with symptoms of PSU. These results suggests that restricting while-in-bed smartphone use is a potential remedy for sleep disturbance induced by PSU.

Psychometric properties of the 10-item Connor-Davidson Resilience Scale in Chinese military personnel.

Background: The 10-item Connor-Davidson Resilience Scale (CD-RISC-10) is a widely used assessment of resilience. However, psychometric properties of the Chinese version of CD-RISC-10 have not been well investigated in a Chinese military personnel sample. Methods: A total of 3,129 Chinese military personnel completed the CD-RISC-10, Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS). Among them, 528 recruits completed the CD-RISC-10, SAS, and SDS again after 3-month basic military training (BMT). Meanwhile, the commanding officers were asked to rate recruits' training performance on the training performance rating scale for recruits (TPRS). Confirmatory factor analysis (CFA) was implemented to examine the single-factor model of the CD-RISC-10, and multigroup CFA was conducted to test measurement invariance across military rank (officers vs. enlisted), gender (male vs. female), and time (before and after 3-month BMT). Internal consistency was evaluated using Cronbach's α and McDonald's ω, and test-retest reliability was tested using the intra-class correlation coefficient (ICC). The criterion-related validity of CD-RISC was evaluated using Pearson's correlation analysis between the CD-RISC-10 total score and SAS scores, SDS scores, and training performance ratings. Results: The single-factor model of the CD-RISC-10 showed adequate fit (CFI = 0.955-0.970, TLI = 0.943-0.962, RMSEA = 0.059-0.072) in all examined subsamples (male, female, officer, and enlisted), and strict invariance was also supported across military rank, gender, and time (ΔCFI ≤ 0.001, ΔTLI ≤ 0.005, ΔRMSEA ≤ 0.006). The CD-RISC-10 showed good internal consistency in all subsamples (Cronbach's α of > 0.93 and McDonald's ω of > 0.93) and good test-retest reliability (ICC = 0.88). Moreover, concurrent and predictive validity with the SAS and SDS scores were good (r = -0.68 to -0.49, p < 0.001). The resilience level of recruits at the beginning of BMT was significantly associated with training performance rated by supervisors after training (r = 0.29, p < 0.001). Conclusion: The psychometric evidence reported in this study suggests that the CD-RISC-10 is a reliable and valid assessment of resilience and a potential predictor for mental health and military performance in Chinese military personnel.

Direct Z-scheme GaN/WSe2 heterostructure for enhanced photocatalytic water splitting under visible spectrum.

van der Waals heterostructures are widely used in the field of photocatalysis due to the fact that their properties can be regulated via an external electric field, strain engineering, interface rotation, alloying, doping, etc. to promote the capacity of discrete photogenerated carriers. Herein, we fabricated an innovative heterostructure by piling monolayer GaN on isolated WSe2. Subsequently, a first principles calculation based on density functional theory was performed to verify the two-dimensional GaN/WSe2 heterostructure and explore its interface stability, electronic property, carrier mobility and photocatalytic performance. The results demonstrated that the GaN/WSe2 heterostructure has a direct Z-type band arrangement and possesses a bandgap of 1.66 eV. The built-in electric field is caused by the transfer of positive charge between the WSe2 layers to the GaN layer, directly leading to the segregation of photogenerated electron-hole pairs. The GaN/WSe2 heterostructure has high carrier mobility, which is conducive to the transmission of photogenerated carriers. Furthermore, the Gibbs free energy changes to a negative value and declines continuously during the water splitting reaction into oxygen without supplementary overpotential in a neural environment, satisfying the thermodynamic demands of water splitting. These findings verify the enhanced photocatalytic water splitting under visible light and can be used as the theoretical basis for the practical application of GaN/WSe2 heterostructures.

Development and validation of the while-in-bed-smartphone-use-induced sleep procrastination scale (WSPS) in Chinese undergraduates with/without problematic smartphone use.

PURPOSE: Problematic smartphone use (PSU) has become a global public health problem. Excessive while-in-bed smartphone use may result in sleep procrastination and other negative outcomes. The present study aimed to develop and validate a new scale called WSPS to assess while-in-bed-smartphone-use-induced sleep procrastination among undergraduates. METHODS: In total, 910 Chinese undergraduates completed the collection of WSPS, smartphone addiction scale-short version (SAS-SV), bedtime procrastination scale, Pittsburgh sleep quality index, and Zung self-rating depression scale. The whole sample were randomly splited in the exploratory factor analysis (EFA) sample (n = 455) and confirmatory factor analysis (CFA) sample (n = 455). 40 undergraduates with PSU (SAS-SV > 31) and 40 without PSU were asked to keep sleep diary for 2 weeks and complete the WSPS again. RESULTS: EFA and CFA supported a six-item unidimensional structure of the WSPS. The WSPS demonstrated acceptable internal consistency among undergraduates. The WSPS showed good concurrent validity with other relevant variables including PSU, BP, sleep quality, and depression. Scalar invariance of the WSPS between undergraduates with/without PSU was supported, as well as scalar invariance across gender. The WSPS showed good convergent validity with self-report everyday while-in-bed smartphone use duration and good discriminant validity with sleep duration and sleep onset latency recorded by sleep diary. The WSPS also presented good test-retest reliability among undergraduates with/without PSU. CONCLUSION: The WSPS is a reliable and valid measure of while-in-bed-smartphone-use-induced sleep procrastination in undergraduates with/without PSU.

Grating waveguides by machine learning for augmented reality.

We propose a machine-learning-based method for grating waveguides and augmented reality, significantly reducing the computation time compared with existing finite-element-based numerical simulation methods. Among the slanted, coated, interlayer, twin-pillar, U-shaped, and hybrid structure gratings, we exploit structural parameters such as grating slanted angle, grating depth, duty cycle, coating ratio, and interlayer thickness to construct the gratings. The multi-layer perceptron algorithm based on the Keras framework was used with a dataset comprised of 3000-14,000 samples. The training accuracy reached a coefficient of determination of more than 99.9% and an average absolute percentage error of 0.5%-2%. At the same time, the hybrid structure grating we built achieved a diffraction efficiency of 94.21% and a uniformity of 93.99%. This hybrid structure grating also achieved the best results in tolerance analysis. The high-efficiency artificial intelligence waveguide method proposed in this paper realizes the optimal design of a high-efficiency grating waveguide structure. It can provide theoretical guidance and technical reference for optical design based on artificial intelligence.

Self-Assembled Tetratic Crystals by Orthogonal Colloidal Force.

Bonding simple building blocks to create crystalline materials with design has been sophisticated in the molecular world, but this is still very challenging for anisotropic nanoparticles or colloids, because the particle arrangements, including position and orientation, cannot be manipulated as expected. Here biconcave polystyrene (PS) discs to present a shape self-recognition route are used, which can control both the position and orientation of particles during self-assembly by directional colloidal forces. An unusual but very challenging two-dimensional (2D) open superstructure-tetratic crystal (TC)-is achieved. The optical properties of the 2D TCs are studied by the finite difference time domain method, showing that the PS/Ag binary TC can be used to modulate the polarization state of the incident light, for example, converting the linearly polarized light into left-handed or right-handed circularly polarized light. This work paves an important way for self-assembling many unprecedented crystalline materials.

Long short-term memory network of machine learning for compensating temperature error of a fiber optic gyroscope independent of the temperature sensor.

We present an artificial intelligence compensation method for temperature error of a fiber optic gyroscope (FOG). The difference from the existing methods is that the compensation model finally determined by this method only uses the FOG's data to complete the regression prediction of the temperature error and eliminate the dependency on the temperature sensor. In the experimental stage, the proposed method performs temperature experiments with three varying trends of temperature heating, holding, and cooling and obtains sufficient output data sets of the FOG. Taking the output time series of the FOG as the input sample and based on the long short-term memory network of machine learning, the training, validation, and test of the model are completed. From the two perspectives of network learning ability and the improvement degree of the FOG's performance, four indicators, including root mean square error, error cumulative distribution function, FOG bias stability, and Allan variance analysis are selected to evaluate the performance of the compensation model comprehensively. Compared with the existing methods using temperature information for prediction and compensation, the results show that the error compensation method without temperature information proposed can effectively improve the accuracy of the FOG and reduce the complexity of the compensation system. The work can also provide technical references for error compensation of other sensors.

Hybrid design approach of optical phased array with wide beam steering range and low side-lobe level.

In this paper, an optical phased array (OPA) with wide beam steering angle and low side-lobe level is designed based on the hybrid approach of particle swarm optimization (PSO) and convex optimization (CVX). The optimization process is divided into two steps. First, the antenna spacing distribution of the OPA is designed to obtain a wide beam steering range by using a PSO algorithm. Second, based on the antenna spacing distribution obtained in the previous step, the CVX algorithm is used to obtain the excitation amplitude and phase distribution of the OPA under different beam steering angles. By using this approach, we design an OPA with 1024 antennas. The beam steering range of the OPA is ±60° and the side-lobe level is reduced to -24.65 dB.