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Purpose: To study the health effects of coal mine environment on workers, to discover early effective biomarkers. Methods: A cross-sectional survey was conducted with 502 in-service workers, and the population was divided into the coal miner and the auxiliary worker. Clinical examinations were carried out by qualified doctors. Peripheral blood was collected to measure blood biochemistry, hemogram and karyotype apoptosis. Results: All workers were healthy and showed no difference in age, height, weight and BMI between groups. The education level and working years of coal miners were significantly lower than that of auxiliary workers (P < 0.05). Compared with auxiliary workers, the concentration and percentage of LYMPH, BASO, EO, RBC and the concentration of HGB of coal miners decreased (P < 0.05). The percentage of NEUT of coal miners increased (P < 0.05). The coal miner presented higher BUN, lower CRE, and higher BUN/CRE (P < 0.05). The proportion of karyotype apoptosis of coal miners was higher (P < 0.05). Conclusions: The coal mine environment impacts immune system, induces adverse effects on renal function and enhances the risk of anemia of coal miners. And karyotype apoptosis, LYMPH, BUN/CRE and HGB can be used as early effective biomarkers for coal miners.

Exposure to heavy metals has been related to decreased lung function in workers. However, due to limitations in statistical methods for mixtures, previous studies mainly focused on single or several toxic metals, with few studies involving metal exposome and lung function.The study aimed to evaluate the effects of co-exposure to the metal mixtures on multiple parameters of pulmonary function tests and to identify the elements that play an essential role in elastic-net regression (ENET), multivariate linear regression, bayesian kernel machine regression (BKMR), and quantile g-computation (QG-C) models.We have recruited 186 welders from Anhui (China) in 2019. And their end-of-shift urine and lung function measure data were collected with informed consent. The urinary concentrations of 23 metals were measured by inductively coupled urinary mass spectrometry. The lung function measures including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) were also detected as outcome indicators. Four statistical methods, ENET, multivariate linear regression, BKMR, and QG-C models were used to evaluate the associations of element mixtures on lung function comprehensively.Lead and cadmium were negatively associated with FVC and FEV1, nickel and chromium were inversely associated with PEF, and strontium showed significant positive effects in linear regression models, which were consistent with the results in BKMR and QG-C models. Both BKMR and QG-C models showed a significantly negative overall effect of metal mixtures on lung function parameters (FVC, FEV1, and PEF). Meanwhile, BKMR showed the non-linear relationships of cadmium with FVC.Multi-pollutant mixtures of metals were negatively associated with lung function. Lead, cadmium, nickel, and strontium might be crucial elements. Our findings highlight a need to prioritize workers' environmental health, and guide future research into the toxic mechanisms of metal-mediated lung function injury.

Recombinant forms contribute substantially to the genetic diversity of HIV-1. Recent studies have also revealed that three major viral strains (CRF07_BC, CRF01_AE, and subtype B) have been cocirculating among men who have sex with men (MSM) in Anhui, suggesting a high probability of generating new recombinants. In this study, we reported a novel CRF01_AE and CRF07_BC HIV-1 recombinant form in MSM in Fuyang city of China. Two near full-length genome (NFLG) named FY184 and FY208 were successfully obtained. The genomic composition analysis of the NFLG reveals that it was divided into four segments by three breakpoints, with two regions of CRF07_BC inserted into a CRF01_AE backbone's gag and pol regions. The CRF01_AE regions were originated from a subcluster lineage of CRF01_AE, which is mainly circulating among MSM in China. The emergence of a novel recombinant of CRF01_AE/CRF07_BC is indicative of the increasing genetic diversity of the HIV epidemic in MSM in Anhui.

Background The proportion of older HIV-1 infected people in China has increased rapidly in recent years. Elucidation of the transmission characteristics of this high-risk population subgroup is helpful for the development of tailored interventions. Methods A phylogenetic analysis was performed that uses available HIV-1 pol sequences amplified with nested RT-PCR from plasma samples of all newly diagnosed participants spanning from October 2017 to September 2018 in Fuyang, Anhui Province. Transmission clusters were identified as two or more sequences that shared a corresponding node with an aLRT-SH value ≥90 in the maximum-likelihood phylogenetic tree and had an overall mean genetic distance of ≤1.5%. A local transmission cluster was defined as a cluster that had more than 80% of its sequences from Fuyang. The role of older people in local HIV-1 transmission was determined using an integration of molecular and demographic data. Results Of 362 available sequences, 14 subtypes, and 28 local transmission clusters were identified. It was found that the proportion of older people in the local transmission cluster (69/77, 89.61%) was much higher than that of younger people (46/114, 40.35%) (χ2 test, P 0.05). Conclusion By combining phylogenetic analyses with demographic data, more detailed information was provided about the local transmission structure in Fuyang. These findings suggested that older people play an important role in local transmission, and more tailored interventions for this population subgroup are urgently needed.

In this paper, a high step-up boost converter with multiplier voltage cells (abbreviated as MVC Boost Converter) is proposed. The proposed converters has the advantages of high boost level, good freedom of voltage regulation, low voltage stress of the switch, etc., and is suitable for high voltage gain places. This paper analyses the working principle and working process of the converter during steady-state operation. Finally, the experimental results verify the rationality of the working process of the circuit and the implementability of the converter.

To investigate the effects of secondary dust exposure after whole-lung lavage (WLL) on the clinical symptoms, arterial blood gas parameters, and pulmonary function in subjects with pneumoconiosis and patients with stage I coal workers' pneumoconiosis (CWP).The subjects with pneumoconiosis and patients with stage I CWP who underwent WLL in our hospital during the study period were selected. All patients were divided into postoperative dust exposure group (n = 86) and lavage control group (n = 86) according to whether they were exposed to dust after conventional operation. In addition, their workmates with similar age, history of dust exposure, and type of dust exposure were selected as non-lavage control group (n = 86). Follow-up was performed before and at one month and one year after WLL to evaluate clinical symptoms, arterial blood gas parameters, and pulmonary function.One month after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non-lavage control group (P0.01). One year after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non?lavage control group (P0.01), and the lavage control group had a significantly lower clinical score than the postoperative dust exposure group (P0.01). One month after operation, the arterial partial pressure of oxygen (PaO2) of the postoperative dust-exposure group and lavage control group were significantly higher than their preoperative values and the arterial PaO2 of the non-lavage control group (P0.01). One year after operation, the lavage control group had significantly higher arterial PaO2 than the postoperative dust exposure group and the arterial PaO2 of the non-lavage control group was significantly lower than its preoperative value and the arterial PaO2 of the postoperative dust exposure group and lavage control group (P0.05 or P0.01); the postoperative dust exposure group showed a significant decrease in arterial PaO2 (P0.01), while the lavage control group showed a significant increase in arterial PaO2 (P0.01). The partial pressure of carbon dioxide showed no significant differences between the three groups before and at one month and one year after operation (P0.05).Dust exposure should be avoided after WLL to ensure the treatment outcome.

This paper presents a new resonant soft-switching quasi-Z-source inverter. On the basis of the quasi-Z-source inverter, the proposed inverter inherits the features of high voltage boost ability, circuit simplicity and high reliability. A resonant network with coupled inductor is employed to achieve the soft-switching scheme. All active devices (switches and diodes) in the inverter are tuned on and off under zero voltage or zero-current switching condition. The principle of the proposed converter and analysis of operation are proposed. Simulation and experimental results are given to illustrate the soft-switching characteristics. The theoretical analysis and simulation agrees well with experimental results.

This paper presents a generic reactance source power converter (abbreviated as X-source converter), which is a generic topology for buck-boost single-stage converter, employs a unique reactance circuit (consists of at least one pair of LC filter) to couple the converter main circuit to the power stage, thus providing unique features that cannot be obtained in the V-source converter and C-source converter where a capacitor and inductor are used, respectively. To describe the constitute forms, derivation strategies and operating principle, this paper focuses on an X-source inverter (XSI) as an example. Two derivation methods for X-source inverter have been proposed, named as SR-XSI method and DR-XSI method, with which the various XSI has derived from two-stage converter (DC-DC converter cascaded VSI). The ZSI and qZSI has proved to be the typical XSI, which is equivalent to SEPIC XSI and Cuk XSI, respectively. A new Buck-boost XSI, based on the DR-XSI method, has been presented. The principle of the proposed converter, analysis of operation, and design guideline are included. Experimental results of the 1kW Buck-boost XSI prototype are given for hardware verification. The theoretical analysis and simulation agrees well with experimental results.

This paper presents a IPM based SRD system, which achieves some advantages: such as safety reliability and simple design. It focus on the analysis of varies operation modes of single IPM based SRD system, studying the intention of design process in detail: including freewheeling procession, transferring, and operating states of clockwise and anticlockwise rotation condition, it offers reference for designer to select devices of the main circuit and decrease the project exploiting time. The theoretical analysis is verified by experimental results.

A hybrid energy storage with super capacitor and batteries for energy storage unit in wind-pv hybrid streetlight system has been presented. Hybrid energy storage system with super capacitor is given priority to, supplemented by the batter provide adequate, stable and reliable energy guarantee for wind-pv hybrid streetlight system. With this technique a lighter and smaller energy storage system can be achieved which enhances the performance of wind-pv hybrid streetlight system. Super capacitor has drawn more and more attention on energy storage systems because of its advantages of high power density, high charging speed, long service life and small size, light weight and extremely high cycling capability. In this way the batteries can ensure only the average power and the super capacitors can ensure the power variations. When power is greatly change, super capacitors have energy storage buffer action. Storing capacity of super capacitor and variable current control function of parallel controller can reduce times of tiny battery charging and discharging, reduce the discharge depth, prolong the service life of the battery, which basiciy solved the problem of wind-pv hybrid streetlight system. The lifetime of the batteries, weight and volume of the HESS in wind-pv hybrid streetlight can thus been improved. The simulation results verified the validity of proposed control strategy.

This paper presents a critical evaluation of the effect of voltage sags on Quasi-Z-source inverter based adjustable speed drives (qZSI-ASD), analyzes the behaviour of qZSI-ASD under the balanced and unbalanced sags. The voltage-tolerance curves are obtained to assess the sensitivity of the qZSI-ASD under the balanced voltage sags, which quite similar to the ZSI-ASD system. In particular the Quasi-Z-source network capacitor voltage variation under unbalanced voltage sag and its dependence on source impedance, Z-source network passive device values, and shoot-through duty cycle is derived. The larger Z-source network values, the smaller dc-link voltage variation under the voltage sag. The proposed representation can be established for any other three-phase equipment and used for sensitivity assessment. By controlling the shoot-through duty cycle, the qZSI-ASD system provides ride-through to voltage sags, both balanced and unbalanced sags. The simulation results are presented to verify the proposed concept and theoretical analysis.

This paper proposes a novel PWM current source rectifier — Z-source inverter adjustable-speed system (abbreviated as PWM CSR-qZSI ASD). The operating principle, control strategy and circuit analysis have been given. The benefits of the presented ASD system have been analyzed in detail. The proposed PWM CSR-qZSI ASD system have many advantages, it providing a bidirectional power flow, maintaining the unity power factor, reducing the input line current harmonics, providing ride-through during the voltage sags and voltage swells without any additional circuits, and makes the inverter modulation index high during low-speed operation. Analysis and simulation results will be demonstrate these features.

Stigma is a significant barrier to effective control of HIV/AIDS, despite laws to control it. The purpose of this study was to examine factors associated with HIV stigma in a rural Chinese community. A survey was conducted in north-west Anhui province among 963 residents to assess HIV-related knowledge, attitudes, and behaviors. Participants scored a mean of 16.6/26 (63.8%) for knowledge. Sixty-eight percent of respondents held at least one fear of casual transmission, 42% would blame people living with HIV/AIDS (PLHA) for their disease, and 73% thought having HIV is shameful. More than half reported that they had observed at least one stigmatizing behavior toward PLHA in their villages. Multivariable analysis indicated that people with higher education, higher HIV knowledge, higher household wealth and who learned about HIV from professional sources were less likely to hold a stigmatizing attitude, while people who had observed discriminating behaviors toward PLHA in their community and lived in villages with fewer PLHA were more likely to hold a stigmatizing attitude. Despite education campaigns, knowledge remains low and stigmatizing attitudes and behaviors toward PLHA remain a problem.

Considering the significant magnetic saturation and the double salient poles of Switched Reluctance Motor (SRM), this paper presents a new method combining the Rapid Nonlinear Simulation Method with the Equivalent Magnet Circuit Analysis Model, which can make the accuracy and rapidity of the calculation of the performance of SRM achieved. This paper also presents a model of SRM, implements the rapid nonlinear simulation method to the model and lay the necessary foundation for SRM optimization.

This paper presents a direct peak dc-link boost voltage PID-like fuzzy controller in Z-source inverter. With this technique a constant peak dc-link voltage can be achieved with an excellent transient performance which enhances the rejection of disturbance, including the input voltage and load current variation, and solves the problem of the local dynamic output feedback stabilization of the serious non-minimum phase system, simplifies the controller design. The small-signal model of the Z-source network and non-minimum phase phenomenon of the control-to-output voltage transfer functions have been discussed in detail. The two zeros (a LHP zero and a RHP zero) of the control-to- peak dc-link voltage transfer function results in the impossible to design a good controller for dc-link voltage with linear strategy. A phase plane is presented to describe the control effort transient response, analyze system stability, and modify the rule matrices of fuzzy controller. The proposed technique was verified on a 20-kW prototype. The experimental results meet the simulation and analysis results very well.

Based on space-vector PWM (SVPWM) techniques, this paper proposes a new unified voltage vector of the Z-source inverter, which is composed of the traditional voltage vector and the unique boost factor of the Z-source inverter. On the basis of this unified voltage vector, a close- loop unified control technique is proposed from the viewpoint of global inverter operation, which can improve the stability of the inverter system, keep the minimum voltage stress across the switches with variable input voltage, and implement the linear control of the output voltage. In addition, only the output voltage needs to be sensed in the unified control technique, unlike the traditional control methods that use both the output and capacitor voltages. This control method is also simple and easy implementation for digital control. Furthermore, various conventional voltage-source inverters (VSI) SVPWM control strategies (include internal current control) can be applied to the unified control technique. The feasibility of the proposed control method has been verified by the simulation and experimental results.

A feedforward compensator applied in Z-source inverter ASD system has been presented. With this technique a constant peak dc-link voltage can be achieved with an excellent transient performance which enhances the rejection of input voltage ripple, and have good ride- through for voltage-sags. The effect of six pulse input voltage ripple which result from front-end diode rectifier has been described in detail, and the compensator is designed. The Z-source inverter ASD system with feedforward compensator has rapid transient response and good ride-through for voltage sag. It is very suitable for practical application due to its simplified controller design. The proposed technique was verified on a 10-kW prototype. The experimental and simulation results verified the theory very well.

This paper presents a new adjustable-speed drives (ASD) system which based on the high-performance Z-source inverter (named high-performance Z-source inverter ASD system). It can overcome limitations of original Z-source inverter ASD system. The proposed Z-source inverter ASD system can operate at wide range load (even no-load) with small inductor which is very suitable for ASD system, eliminate the possibility of the DC-link voltage aberrances, simplify the Z-source network inductor and controller design, increase the inverter modulation index M, thus, decrease the ripple current by changing the magnitude and distribution of the harmonics and then decrease the iron loss of the motor. The operation modes, voltage relationship of the proposed Z-source inverter ASD system, and a partly PAM/PWM control strategy, which consists with the V/f law, have been described in detail. Finally, simulation and experimental results verified the validity of the proposed high-performance Z-source inverter ASD system.

This paper presents a high-performance Z-source inverter is proposed in this paper, which can overcome limitations of traditional Z-source inverter. The proposed Z-source inverter can operate at wide range load (even no-load) with small inductor, eliminate the possibility of the dc-link voltage drops, and simplify the inductor and controller design. The operation modes, voltage relationship of the proposed Z-source inverter, and control strategy for switch SW7 has been described in detail. Finally, experimental results verified the validity of the proposed high-performance Z-source inverter.

This paper presents a PID controller for dc-link boost voltage in Z-source inverter. With this technique a constant capacitor voltage can be achieved with an excellent transient performance which enhances the rejection of disturbance, including the input voltage ripple and load current variation, and have good ride-through for voltage-sags. The shoot-through duty cycle modulation strategy for control the dc-link boost voltage have been described in detail, which simplify the controller design and improve the transient response. The simulation and experimental results verified the validity of proposed control strategy.

A PID controller for direct peak dc-link boost voltage in Z-source inverter has been introduced. With this technique a high-performance inverter output voltage can be achieved with an excellent transient performance which enhances the rejection of disturbance, including the input voltage ripple and load current variation, and have good ride-through for voltage-sags. The peak dc-link voltage direct sensing & scaling method, and modified modulation strategy have been described, which simplify the controller design, improve the transient response and decrease the voltage stress across the switches. The proposed technique was verified on a 10-kW prototype. The experimental results meet the simulation and analysis results very well.

This paper makes the research on an impedance-source rectifier (abbreviated as Z-source rectifier), describes the operating principle, operating modes, and its concept and superiority. Analysis and simulation results show that the three-phase Z-source rectifier can buck-boost voltage by using the shoot-through state, which is harmful for the conventional VSR. It needs small dc-link inductor L and capacitor C, and makes the input unity power factor become possible without any additional circuits, minimize component count, and increase efficiency

This paper presents a novel buck/boost Z-Source rectifier, in which an impedance network is employed to couple the rectifier main circuit to the load, thus it provides unique features that cannot be obtained in a traditional full-bridge rectifier. The Z-Source rectifier can access buck or boost function without using two-stage power conversion, so it overcomes the limitations of the traditional cascaded buck rectifier. The simulation and experiment had been presented to verify the proposed theories.

This paper presents the analysis of dynamic response of the ZVS Z-source rectifier and design of the closed-loop controllers for both the z-source rectifier and the z-network circuit. Due to the unique Z-network, the transient response is found to be challenging in controlling the ZVS Z-source rectifier. By combining the traditional PWM rectifier model and equivalent model of the z-network. The ZVS Z-Source rectifier model is proposed. Through detailed analysis, the controllers are designed to obtain the steady DC-link voltage and a sinusoidal AC voltage under linear loads.

This paper proposes a novel ZVS Z-source rectifier, describes the operating principle, control strategy, and superiority. The three-phase ZVS Z-source rectifier implements the zero voltage turn-on (ZVS) for power transistors and zero-current turn-off (ZCOFF) for diodes without any additional circuits. It can buck and boost input voltage, and increase the reliability of the circuit. Thus it provides a low-cost, reliable, and highly efficient single-stage structure for buck or boost power conversion.

The suspension system of the Maglev vehicle has nonlinear and hysteresis characters. The equilibrium point of maglev system is unstable. It is very difficult to control the suspension system with fine dynamic and static characteristics. A composite model combining PID algorithm with fuzzy control is proposed and a composite fuzzy-PID controller is designed. The proposed algorithm is verified through the simulation and experiment.

Very few papers have been published on sensorless control of surface permanent magnet synchronous motor (SPMSM). The difficulty with nonsalient rotor is the equal inductances along both d and q axes. In this paper, a new approach to sensorless speed control and initial rotor position estimation for a SPMSM drive is presented. At a rotating condition, speed and rotor position estimation of SPMSM drive is obtained through an observer with compensation by only measuring phase voltages and currents. The initial rotor position is performed by using the nonlinear magnetization characteristics of the stator core caused by the rotor magnets. Experimental results show that in both steady and transient state, the system can achieve expected performances.