Temporal distribution characteristics of earthquakes in Taiwan, China

The characteristics of seismic temporal distribution represent an important basis for earthquake prediction and seismic hazard analysis. In this paper, based on the seismic catalogs in Taiwan, and using Poisson (exponential distribution), Gamma, Lognormal, Weibull, and Brownian passage time distributions as target models, we adopt the maximum likelihood method for estimating model parameters. The optimal model for describing the temporal distribution of earthquakes in Taiwan is determined according to the Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), K-S test, Chi-square test, and coefficient of determination R2 results. The results show that for moderate-strong earthquakes events (MW < 7.0), the Gamma distribution model can well describe the temporal distribution characteristics of earthquakes, while large earthquakes (MW ≥ 7.0) can be described entirely by exponential distribution. In addition, the temporal correlation between earthquakes is also examined through diffusion entropy analysis. The results show that seismic activity features temporal correlation, and earthquakes with relatively small magnitude (MW < 7) are affected by larger events (MW ≥ 7.0), thus suggesting long-term memory in time. In this study, the probability of the occurrence of a major earthquake in Taiwan is also calculated. The results show that the probability of an MW ≥ 7.0 earthquake in Taiwan in the next 10 years reaches 91.3%. The results may be used to inform the selection of seismic time distribution models and the calculation of seismic activity parameters in earthquake prediction and seismic hazard calculation, and hold scientific significance for understanding the mechanism of earthquake genesis

UWB indoor positioning optimization algorithm based on genetic annealing and clustering analysis

Indoor location information is an indispensable parameter for modern intelligent warehouse management and robot navigation. Indoor wireless positioning exhibits large errors due to factors such as indoor non-line-of-sight (NLOS) obstructions. In the present study, the error value under the time of arrival (TOA) algorithm was evaluated, and the trilateral positioning method was optimized to minimize the errors. An optimization algorithm for indoor ultra-wideband (UWB) positioning was designed, which was referred as annealing evolution and clustering fusion optimization algorithm. The algorithm exploited the good local search capability of the simulated annealing algorithm and the good global search capability of the genetic algorithm to optimize cluster analysis. The optimal result from sampled data was quickly determined to achieve effective and accurate positioning. These features reduced the non-direct aiming error in the indoor UWB environment. The final experimental results showed that the optimized algorithm significantly reduced noise interference as well as improved positioning accuracy in an NLOS indoor environment with less than 10 cm positioning error

Riemannian Surface on Carbon Anodes Enables Li-Ion Storage at −35 °C

Since sluggish Li$^{+}$ desolvation leads to severe capacity degradation of carbon anodes at subzero temperatures, it is urgently desired to modulate electron configurations of surface carbon atoms toward high capacity for Li-ion batteries. Herein, a carbon-based anode material (O-DF) was strategically synthesized to construct the Riemannian surface with a positive curvature, which exhibits a high reversible capacity of 624 mAh g$^{-1}$ with an 85.9% capacity retention at 0.1 A g$^{-1}$ as the temperature drops to −20 °C. Even if the temperature drops to −35 °C, the reversible capacity is still effectively retained at 160 mAh g$^{-1}$ after 200 cycles. Various characterizations and theoretical calculations reveal that the Riemannian surface effectively tunes the low-temperature sluggish Li$^{+}$ desolvation of the interfacial chemistry via locally accumulated charges of non-coplanar sp$^{x}$ (2 < x < 3) hybridized orbitals to reduce the rate-determining step of the energy barrier for the charge-transfer process. Ex-situ measurements further confirm that the sp$^{x}$-hybridized orbitals of the pentagonal defect sites should denote more negative charges to solvated Li$^{+}$ adsorbed on the Riemannian surface to form stronger Li–C coordinate bonds for Li$^{+}$ desolvation, which not only enhances Li-adsorption on the curved surface but also results in more Li$^{+}$ insertion in an extremely cold environment

Long-Term Efficacy of Ultrasound-Guided Percutaneous Transluminal Angioplasty for Arteriovenous Fistula Outflow Stenosis Caused by Venous Valve

Introduction: Venous valve-related stenosis (VVRS) is an uncommon type of failure of arteriovenous fistula among patients with end-stage renal disease (ESRD). There is a paucity of data on the long-term efficacy of ultrasound-guided percutaneous transluminal angioplasty (PTA) for VVRS. Methods: ESRD patients who underwent PTA because of VVRS between January 2017 and December 2021 at the First Affiliated Hospital of Chongqing Medical University were enrolled. Patients were classified into three cohorts (cohort1, VVRS located within 3 cm of the vein adjacent to the anastomosis; cohort2, VVRS located over 3 cm away from the anastomosis; cohort3, multiple stenoses). The patency rates were assessed by the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate Cox analyses were performed to identify the risk factors. Results: A total of 292 patients were enrolled, including 125 (42.8%), 111 (38.0%), and 56 (19.2%) patients in cohort1, cohort2, and cohort3, respectively. The median follow-up was 34.8 months. The 6-month, 1-year, 2-year, and 3-year primary patency rates were 86.0%, 69.4%, 47.5%, and 35.3%, respectively. The secondary patency rates were 94.5%, 89.4%, 75.5%, and 65.3%, respectively. Cohort1 showed a relatively better primary patency compared to cohort2 and cohort3. The secondary patency rates were comparable in the three cohorts. Duration of dialysis and VVRS type were potential factors associated with primary patency. Conclusions: This study showed acceptable long-term primary and secondary patency rates after PTA for VVRS in ESRD patients, especially for those with VVRS located within 3 cm of the vein adjacent to the anastomosis

The Kidney Specific Protein myo-Inositol Oxygenase, a Potential Biomarker for Diabetic Nephropathy

Background/Aims: Renal tubular injury plays an important role in the progression of diabetic nephropathy (DN). However, there is a lack of specific biomarkers for tubular damage in incipient DN. We have evaluated the role of myo-inositol oxygenase (MIOX) in the tubular injury of DN, but whether it could serve as a new biomarker for the early diagnosis of DN is unclear. Methods: Ninety patients with type 2 diabetes mellitus (T2DM) were divided into normoalbuminuria, microalbuminuria and macroalbuminuria groups. Fifteen patients from the last group were pathologically diagnosed as type 2 DN (T2DN), and fifteen patients with minimal change disease served as a control group. The expression of MIOX and silent information regulator 1 (Sirt1) in renal biopsies was determined by immunohistochemistry (IHC), and serum/urine MIOX, Sirt1, KIM-1 and NGAL were measured using enzyme-linked immunosorbent assays (ELISAs). Spearman’s correlation and multiple regression analyses were carried out for statistical analyses. Results: Compared with the controls, MIOX expression was significantly increased in the renal tissues of T2DN patients, and was positively correlated with tubulointerstitial lesions and renal ROS production but inversely correlated with Sirt1 expression. In addition, the serum and urine MIOX were significantly increased and gradually elevated with the increasing of UACR. Interestingly, elevated MIOX levels in serum and urine were found in diabetic patients without early signs of glomerular damage (normoalbuminuric group). Further multivariate regression analysis showed that sMIOX and uMIOX correlated significantly with HbA1c, serum creatinine and logUACR, respectively. Conclusion: These data indicate that increased MIOX expression in the kidney contributes to tubular damage in DN. The concentration of MIOX in the serum and urine may serve as a new biomarker for the early diagnosis of DN

A Diol-Based-Matrix Solid-Phase Dispersion Method for the Simultaneous Extraction and Determination of 13 Compounds From Angelicae Pubescentis Radix by Ultra High-Performance Liquid Chromatography

A simple and eco-friendly Diol-based-matrix solid-phase dispersion method (MSPD) was optimized and established to simultaneously extract 13 bioactive compounds (7 coumarins and 6 phenolic acids) in Angelicae Pubescentis Radix (APR) by ultrahigh performance liquid chromatography coupled with photodiode array detector (UHPLC-PDA). Diol was chosen as the dispersing sorbent and methanol solution was used as the elution solvent. The preparation procedures for the MSPD including the types of sorbents, mass ratio of matrix to sorbent, grinding time, type, concentration and volume of elution solvent were investigated. Under the optimal conditions, good recoveries of the 13 target compounds were obtained in the range of 94.8–107% (RSD &lt; 3.22%). The limits of detection (LODs) and limits of quantitation (LOQs) were in the ranges of 0.08–0.12 μg mL-1 and 0.16–0.24 μg mL-1, respectively. Compared with the traditional method, it was a green and environmentally friendly technique. The results proved that the established method was successfully applied to the extraction and determination of 13 target bioactive compounds for quality control in APR

A multi -Kalman filtering approach for video tracking of human -delineated objects in cluttered environments

In this paper, we propose a new approach that uses a motion-estimation based framework for video tracking of objects in cluttered environments. Our approach is semi-automatic, in the sense that a human is called upon to delineate the boundary of the object to be tracked in the first frame of the image sequence. The approach presented requires no camera calibration; therefore it is not necessary that the camera be stationary. The heart of the approach lies in extracting features and estimating motion through multiple applications of Kalman filtering. The estimated motion is used to place constraints on where to seek feature correspondences; successful correspondences are subsequently used for Kalman-based recursive updating of the motion parameters. Associated with each feature is the frame number in which the feature makes its first appearance in an image sequence. All features that make first-time appearance in the same frame are grouped together for Kalman-based updating of motion parameters. Finally, in order to make the tracked object look visually familiar to the human observer, the system also makes its best attempt at extracting the boundary contour of the object—a difficult problem in its own right since self-occlusion created by any rotational motion of the tracked object would cause large sections of the boundary contour in the previous frame to disappear in the current frame. Boundary contour is estimated by projecting the previous-frame contour into the current frame for the purpose of creating neighborhoods in which to search for the true boundary in the current frame. Our approach has been tested on a wide variety of video sequences, some of which are shown in this paper

Typical interference analysis of FHD-2B observation data at Datong seismic station

The geomagnetic observation data of FHD-2B at Datong seismic station in Shanxi is mainly affected by the interference of the instrument’s own observation system and the surrounding environment. Since the performance of the instrument is nearly stable after delivery, we can improve the quality of observation data by improving the environment. In this paper, the quality of observation data from 2017 to 2021 was evaluated from three aspects: continuity rate, integrity rate and background noise, and it is found that the background noise level of the instrument has been significantly reduced since the instrument was updated in June 2019. By analyzing the data curves of different interferences such as construction interference, vehicle interference, high-voltage direct current transmission interference and power failure, it is found that the construction interference is generally manifested in the same period of time when each component is interfered, and the interference amplitude is different; the interference of high-voltage direct current transmission is usually serious in Z component, which can be processed through the interference period given by the National Geomagnetic Network Center and combined with the data of surrounding geomagnetic stations; vehicle interference interferes with each component of data, corresponding to vehicle activity period; the power failure interference shows that the observed data curves of D, H and Z components become thicker, burrs increase, and even wrong data appear, which can be solved by modifying the parameters of the instrument home page. The characteristics of different interference curves are summarized, which is convenient for workers to use FHD-2B geomagnetic data correctly for seismic research