The first SHRIMP zircon U–Pb ages from coal beds close to the end-Permian mass extinction are reported C1 seam in Yantang Mine Laibin Town, Xuanwei County, eastern Yunnan Province. Zircons were extracted kaolinite claystone layers, defined as tonsteins (volcanic ash deposits), sub-seam B1 and B3 of C1. 252.0 ± 2.3 Ma 250.3 2.1 for B3, respectively. Within analytical uncertainties, these include time period onset at 251.941 0.037 Ma, which was obtained marine Meishan section Zhejiang...

Introduction COVID-19, being a new type of infectious disease, holds significant implications for scientific prevention and control to understand its spatiotemporal transmission process. This study examines the diverse spatial patterns COVID-19 within Wuhan by analyzing early case data alongside urban infrastructure information. Methods Through co-location analysis, we assess both local global risks linked epidemic. In addition, use Geodetector, identifying facilities displaying unique risk...

Abstract Background Parenting styles play a critical role in children’s development, especially for those families with depressed parent. To date, no study has explored whether youth perceptions of parenting style are heterogeneous parent or associated internalizing symptoms. Methods Participants were children aged 8–16 years who had major depressive disorder; they enrolled through their parents, outpatients at two hospitals Ningxia. measured using the Parental Bonding Instrument. Youth...

In this paper, a fuzzy PID control method is proposed to solve the effect of dynamic uncertainty and external load permanent-magnet linear synchronous motor (PMLSM). First, mathematical model PMLSM established, algorithm are all described briefly. Second, improve performance drive system, controller constructed by designed. It applied speed-control loop system cope with load. Finally, servo simulated composed PMLSM, other elements established verify effectiveness high system.

Objective: This study combines quantitative research of personality traits with demographic data to analyze the influencing factors mental health freshmen in colleges and universities, provides a reference to/from future college freshmen's education management. Methods: A census method was used survey admitted Yangtze University, including general characteristics, 16-person cartel questionnaire (16-PF), 90-item self-assessment scale (SCL-90). Results: The status universities good, 16.2%...

This paper investigates the cooperative linear output regulation problem of a class heterogeneous networked systems with common reference input but different disturbances for individual nodes. A novel distributed control law is presented based on dynamic measurement feedback. It shown that overall closed-loop system asymptotically stable and errors approach zero as time goes to infinity under sufficient necessary condition. Finally, numerical example provided demonstrate effectiveness proposed law.

Airport gates are one of the congestion points air transportation system. When an arriving ∞ight lands on a runway, it is possible that cannot pull into its gate. We deflne this phenomenon as gate-waiting delay. This paper analyzes degree to which gate waiting problem and functional causes waiting. Analysis performance data for OEP 35 airports summer 2007 identifled that: (i) Signiflcant delays, in more than 30% aircraft delayed, occurred at 10 airports, (ii) major delays rare events (e.g.,...

Shale oil is mainly extracted by fracturing. However, it difficult to determine the optimum construction parameters obtain maximum productivity. In this paper, a fuzzy comprehensive production evaluation model for fractured shale horizontal wells based on random forest algorithm and coordinated principal component analysis proposed. The fracturing of target are optimized combining with an orthogonal experimental design. was used calculate importance data sample factors. main controlling...

Carbon nanorods with abundant N/O heteroatoms and hierarchical pores achieve a high-rate Na-ion storage (336/196 mA h g −1 at 0.1/20 A ).

The shape control and active vibration for the laminated shell bonded with piezoelectric sensors actuators is researched in this paper. A set of equations, sensing equations actuating are derived through using finite element method modal theory shell, then model converted into form state space transfer function. From view energy dissipation, optimized placement sensor actuator units analyzed genetic algorithm. interdisciplinary structure dynamic control, based on engineering background,...

This paper develops a fuzzy logic controller (FLC) for the temperature. Temperature is very popular parameter in industry, which leads an important role industry process control. There nonlinearity, time lag, inertia, uncertainty and so on .The advantage of this method that proposed FLC has characteristics robustness. In order to control systems contain nonlinearities or uncertainties, strategies must deal with effects these. With development intelligent control, Fuzzy-PID based Fuzzy more...

A new structure of rotary magnetorheological damper(MRD) was designed. The working area the rotor has a T-shaped cross section that makes and stator have multiple areas, which increases reduces moment inertia rotor. Based on characteristics fluid (MRF) core material, design magnetic field damper carried out to obtain electrical structural parameters main part damper. finite element method is used analyze electromagnetic MRD, relevant physical quantity in obtained. Finally, simulation results...

In this paper, a novel approach is proposed for Synthetic Aperture Radar (SAR) target classification based on multi-aspect multi-feature collaborative representation. Firstly, principal component analysis (PCA), wavelet and 2-dimensional slice Zernike moments (2DSZM) features are extracted from SAR images. Next, the strong correlation among adjacent aspect images, we extend basic representation (CRC) model to neighbourhood CRC model. For each feature of current test sample, samples regarded...

This article is based on artificial intelligence technology to recognize and identify risks in college sport. The application of motion recognition first need collect the source data, store collected data server database, learner’s real-time return it database achieve purpose monitoring. It found that identification risk sources sports courses, there are a total 4 first-level factors, namely teacher student environmental school management 15 second-level which teaching preparation, process,...

Characteristics of water and salt transport in layered soils with the loess soil layer overlapping different particle size sandy layer, was investigated two dimensions chamber. The results show that, finger flow occurs when wetting front enters into low soil, accumulative infiltration is greater for coarser than that finer one. behavior movement are disagree since content profile has a significant difference treatments almost same. further analysis explains this phenomenon mainly caused by...

In order to enhance the sealing performance of rubber core in ram blowout preventer, this paper designed a new structure which embedded half-PTFE ring central based on characteristics failure mode contact surface. Through carrying out experiment under different temperature and pressure determine constitutive relation core, has established 3D model drill pipe, accomplished finite element analysis 20MPa compared with general core. The results show that surface between whole is stress...

Magnetorheological (MR) fluid as a new smart material has done well in the vibration and impact control engineering fields because of its good electromechanical coupling characteristics, preferable dynamic performance higher sensitivity. And success MRF been apparent many applied fields, such semi-active suspension, civil engineering, etc. So far, little research about MR damper into weapon system. Its primary purpose this study is to identify controability artillery recoil mechanism...

This research was developed and aimed at an embedded controller to achieve active variable damping control magnetorheological fluid damper under impact load. Its character of load is firstly analyzed its working principle MR applied into anti-shock engineering design also introduced. Then, test has been done by using the rig in order investigate response time dampers Based on measuring results, some factors effecting delay are analyzed. And simulation results prove that current can be...

This article is based on basic data such as field surveys and literature surveys, contrasting analyzing the distribution of Callicarpa nudiflora by different zoning methods, sources, spatial scales. The results showed that there were certain differences in obtained using qualitative description, similar ecological environment, niche model, to divide C. nudiflora, but all them could reflect degrees. Among them, description division method has advantages macro guidance a large scale. range...

摘要: 标签碰撞增加了射频识别(RFID)系统的时间开销和无源标签的能量消耗，降低了识别速率。该文提出了一种适用于标签识别码连续的防碰撞算法UIG算法，该算法首先根据公司编码和产品编码将所有标签分组，再由产品序列号的碰撞信息生成每组的两个初始标签识别码。最后，通过对初始标签识别码分别连续减1和加1识别出所有标签。性能分析和仿真结果显示，该算法在时间复杂度和通信复杂度上都有很大改善，吞吐率得到了大大的提高。 关键词: 射频识别技术 / 防碰撞算法 时间复杂度 通信复杂度