A systematic review of occupational exposure to respirable coal mine dust(RCMD)in the U.S.mining industry

Cumulative inhalation of respirable coal mine dust(RCMD)can lead to severe lung diseases,including coal worker's pneu-moconiosis(CWP),silicosis,mixed dust pneumoconiosis,dust-related diffuse fibrosis(DDF),and progressive massive fibrosis(PMF).Statistics from the number of reported cases showed a significant decrease in the progression of respiratory diseases in the 1990s.However,an unexpected increase in the number of CWP cases was reported in the late 1990s.To date,there has been no comprehensive systematic review to assess all contributing factors to the resurgence of CWP cases.This study aims to investigate the effects of various mining parameters on the prevalence of CWP in coal mines.A systematic review using the preferred reporting items for systematic reviews and meta-analysis(PRISMA)method was conducted to investigate the health effects of RCMD exposure and identify the factors that may contribute to the recent resurgence of CWP cases.The systematic review yielded a total of 401 papers,which were added to the database.The total number of 148 and 208 papers were excluded from the database in the process of screening and eligibility,respectively.Then,18 papers were considered for data selection and full-text assessment.The review revealed that factors including geographic location,mine size,mining operation type,coal-seam thickness,coal rank,changes in mining practices,technology advancement,and engi-neering dust control practices are contributing to the recent resurgence of CWP among coal workers.However,the evidence for root causes is limited owing to the methodological constraints of the studies;therefore,further detailed studies are needed.

Review and Comment of the Book “Syntax,a Minimalist Program”

In the present article I will first give a brief summary of the content of the book.Then I discuss some limitations of the book as well as my personal viewpoint about what the book fails to clarify and explain.

Whole-brain radiation therapy alone vs. combined therapy with stereotactic radiosurgery for the treatment of limited brain metastases: A systematic review

Objective The aim of the study was to compare the efficacy and safety of whole brain radiotherapy(WBRT) used alone and combined with stereotactic radiosurgery(SRS) in the treatment of limited(1–4)brain metastases. Methods We searched for randomized controlled and matched-pair analysis trials comparing WBRT plus SRS versus WBRT alone for brain metastases. The primary outcomes were the overall survival(OS), intracranial control(IC), and localcontrol(LC). The secondary outcome was radiation toxicity. The log hazard ratios(lnHRs) and their variances were extracted from published Kaplan-Meier curves and pooled using the generic inverse variance method in the RevMan 5.3 software. The non-pooled outcome measures were evaluated using descriptive analysis. Results Three randomized controlled trials and two matched-pair analysis studies were included. There was no difference in the OS for limited brain metastases between the two groups [lnHR 0.91(95% CI 0.76–1.09, P = 0.32) vs. 0.72(95% CI 0.44–1.19, P = 0.20)]. The LC and IC were significantly higher in the combined treatment group [lnHR 0.69(95% CI 0.55–0.86, P = 0.001) vs. 0.41(95% CI 0.29–0.58, P < 0.0001)]. For patients with a single lesion, one trial showed a higher survival in the combined treatment group(median OS: 6.5 months vs. 4.9 months, P = 0.04). The combined treatment was not associated with significantly higher incidence of radiation toxicity. Conclusion Combined treatment with WBRT plus SRS should be recommended for patients with limited brain metastases based on the better LC and IC without increased toxicity. It should also be considered a routine treatment option for patients with solitary brain metastases based on the prolonged OS.

Theoretical and experimental assessment of a novel method to establish the complete measurement range of the calorimeter and its limit of detection and quantification

For determining the accuracy of a calorimeter over the instrument’s entire measuring range,a novel method has been established.For this new approach,(a)benzoic acid(C_(6)H_(5)CO_(2)H) as a certified reference material(CRM),(b)SiO_(2) and(c)a mixture of CRM benzoic acid and SiO_(2) have been used.To illustrate the essential difference between 1)the novel analytical method for control of the entire measurement range and 2)the calorimeter calibration,both applications of benzoic acid(BA)have been demonstrated.An experimental result showed that BA was successfully used to check the whole calorimeter measurement range.The results also showed that the same new method was successfully applied to determine the limit of detection and quantification.A new instrument testing process and a new measurement technique have thus been established.In this way,the cost of using CRM to control the accuracy of measuring the entire measuring range of the calorimeter,as shown in this paper,is minimized.The requirements of the ISO/IEC 17025:2017 standard are satisfied.ISO/IEC 17025:2017,together with ISO 9001:2015(quality management systems),ISO 14001:2015(relate to environmental protection)and ISO45001:2018(occupational safety),constitute an integrated quality system by which a testing laboratory may also accredit.

THE SPECIFIC CHARACTER OF LIMIT ERRORS IN CLOSE RANGE PHOTOGRAMMETRY

Close_range photogrammetry is to determine the shape and size of the object,instead of it’s absolute position.Therefore,at first,any translation and rotation of the photogrammetric model of the object caused by whole geodesic,photographic and photogrammetric procedures in close_range photogrammetry could not be considered.However,it is necessary to analyze all the reasons which cause the deformations of the shape and size and to present their corresponding theories and equations.This situation,of course,is very different from the conventional topophotogrammetry.In this paper some specific characters of limit errors in close_range photogrammerty are presented in detail,including limit errors for calibration of interior elements for close_range cameras,the limit errors of relative and absolute orientations in close_range photogrammetric procedures,and the limit errors of control works in close_range photogrammetry.A theoretical equation of calibration accuracy for close_range camerais given.Relating to the three examples in this paper,their theoretical accuracy requirement of interior elements of camera change in the scope of ±(0.005～0.350) mm.This discussion permits us to reduce accuracy requirement in calibration for an object with small relief,but the camera platform is located in violent vibration environment.Another theoretical equation of relative RMS of base lines ( m S/S ) and the equation RMS of start direction are also presented.It is proved that the m S/S could be equal to the relative RMS of m Δ X / Δ X .It is also proved that the permitting RMS of start direction is much bigger than the traditionally used one.Some useful equations of limit errors in close_range photogrammetry are presented as well.Suggestions mentioned above are perhaps beneficial for increasing efficiency,for reducing production cost.

On the Special Application of the Principle of Proportionality under Emergency State

As the two fundamental aspects of modern society,the emergency state and the routine state are not exceptions to the rule of law.They just abide by special legal rules and must adhere to the spirit of the rule of law,such as human rights protection and power restrictions and apply the principle of proportionality.In a state of emergency,public interests are faced with major and urgent threats.In this state,the positioning of the purpose,the examination of the consequences,or the measurement of the legal benefits of the purpose and the consequences all have a certain degree of particularity and complexity.In order to increase the rationality of the principle of proportionality in the state of emergency,and to perform its value function scientifically and effectively,it is necessary to adopt loose application standards based on the characteristics of the state of emergency,grasp the key application links,and limit the scope of application to the review of the rationality of the exercise of emergency powers.Judgment of the legitimacy of the purpose of the exercise of emergency powers and the derogation of civil rights such as human dignity are not within the scope of the principle of proportionality.

Coordination of multiple mobile robots with limited communication range in pursuit of single mobile target in cluttered environment

This paper addresses the problem of coordinating multiple mobile robots in searching for and capturing a mobile target,with the aim of reducing the capture time.Compared with the previous algorithms,we assume that the target can be detected by any robot and captured successfully by two or more robots.In this paper,we assume that each robot has a limited communication range.We maintain the robots within a mobile network to guarantee the successful capture.In addition,the motion of the target is modeled and incorporated into directing the motion of the robots to reduce the capture time.A coordination algorithm considering both aspects is proposed.This algorithm can greatly reduce the expected time of capturing the mobile target.Finally,we validate the algorithm by the simulations and experiments.

Optimal trajectory and heat load analysis of different shape lifting reentry vehicles for medium range application

The objective of the paper is to compute the optimal burn-out conditions and control requirements that would result in maximum down-range/cross-range performance of a waverider type hypersonic boost-glide(HBG) vehicle within the medium and intermediate ranges,and compare its performance with the performances of wing-body and lifting-body vehicles vis-a-vis the g-load and the integrated heat load experienced by vehicles for the medium-sized launch vehicle under study.Trajectory optimization studies were carried out by considering the heat rate and dynamic pressure constraints.The trajectory optimization problem is modeled as a nonlinear,multiphase,constraint optimal control problem and is solved using a hp-adaptive pseudospectral method.Detail modeling aspects of mass,aerodynamics and aerothermodynamics for the launch and glide vehicles have been discussed.It was found that the optimal burn-out angles for waverider and wing-body configurations are approximately 5° and 14.8°,respectively,for maximum down-range performance under the constraint heat rate environment.The down-range and cross-range performance of HBG waverider configuration is nearly 1.3 and 2 times that of wing-body configuration respectively.The integrated heat load experienced by the HBG waverider was found to be approximately an order of magnitude higher than that of a lifting-body configuration and 5 times that of a wing-body configuration.The footprints and corresponding heat loads and control requirements for the three types of glide vehicles are discussed for the medium range launch vehicle under consideration.

Wide-range characteristics of beam perveance and saddle point potential of LIPS-200 ion thruster

Both the long-life and multi-mode versions of LIPS-200 ion thruster are under investigation in LIP(Lanzhou Institute of Physics).To confirm the feasible ranges of the beam current and accel(abbreviation for accelaration)grid potential to apply to the thruster,the wide-range beam perveance(the state of beam focus)and saddle point potential(the lowest potential along beamlet centerline)characteristics of LIPS-200 are studied with a test-verified PIC-MCC(Particle in Cell-Monte Carlo Collisions)model.These characteristics are investigated with both the initial and the eroded states of the accel grid aperture diameter.The results show that the feasible ranges of these parameters with respect to perveance/crossover(overfocused)limit extend as the operating time accumulates,while the feasible range of accel grid potential narrows due to a reduced EBSF(electron backstreaming failure)margin.The feasible ranges determined by the initial condition are:(i)the beam current up to 0.981 A,and(ii)the accel grid potential up to−85 V.A 23%enlargement of the aperture diameter would bring up to 48 V of EBSF margin loss.

Performance analysis of optical burst switching node with limited wavelength conversion capabilities

The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.

Aperture Efficiency Study of Square Reflect Array Antennas

This paper presents a detailed study of square reflect array (RA) antenna aperture efficiency (ηa). Effects of quantization-phase and limited phase-range errors on radiation pattern, half-power beam width (HPBW) and ηa for different feed locations are investigated. Results show an in-crease in side-lobe levels (SLLs) and a slightly reduction in ηa with quantization-phase augmentation or element phase-range reduction, however, the effects on HPBW are negligible. Nevertheless, the degradation in ηa is negligible when the quantization-phase is lower than 30° or phase-range is more than 300°. Parametric studies have been carried out to provide design guidelines to maximize ηa. It is perceived that the offset-angle plays an important role to determine ηa, especially for feed with narrow beam width.

IEC/TC1082024年春季工作组会议综述

介绍IEC/TC108 HBSDT工作组2024年春季虚拟会议情况,包括对IEC 62368-1:2023的新技术提案讨论、特别小组讨论、解释组文件讨论及相关决议讨论等。

YSZ基极限电流型NO_(x)传感器研究进展

随着汽车尾气排放标准更加严格,NO_(x)传感器作为主要排放处理技术-选择性催化还原系统(SCR)的核心部件成为当下的研究热点。YSZ作为固体电解质的极限电流型传感器在监测精度和控制成本上有着显著作用。综述了近年极限电流型氧传感器和NO_(x)传感器的研究进展。介绍了传感器的历史发展、结构和工作机理。重点阐述了扩散层、电极层的材料选择和结构组成对传感器性能的影响。基于目前集成MEMS气体薄膜传感器的发展以及传感单元结构多腔耦合组合模型的不断完善,提出未来亟待解决的问题,预测可能的发展方向。

中域理论在慢性病护理中应用的研究进展

总结了中域理论在慢性病护理中的应用现状以及理论发展过程中的衍生理论在慢性病中的应用,为增加慢性病护理实践的理论依据提供参考,并为促进中域理论在我国护理领域的应用发展提供基础。

光学阱中Λ增强型灰色黏团冷却辅助原子装载

Λ增强型灰色黏团冷却技术(Λgray molasses cooling,Λ-GMC)已被广泛用于制备低于亚多普勒温度极限的冷原子样品实验中.本文设计搭建了宽范围、快速调谐的激光系统,其调谐范围最高可达600 MHz.基于该激光系统,于光学微腔中心通过铯原子D2线Λ-GMC冷却辅助腰斑大小为15μm的交叉偶极阱中原子的装载,相比于传统的偏振梯度冷却辅助装载,原子数增加了约4倍,原子温度由25μK降低至8μK.该实验对超冷原子样品实验制备和单原子阵列俘获等研究具有重要借鉴意义.

论行政复议机关调查取证的限度

新《行政复议法》第45条规定复议机关有权调查取证,但是未明确可以调查收集哪些证据。依据《行诉法解释》第22条第1款和第135条第3款,复议机关可以为原行政行为补充调查取证,并据此作出维持复议决定。复议机关补充调查取证的实质是,把原来不符合法律规定的行政行为修复为符合法律规定,面临一系列难以化解的合法性质疑。“行政一体化”理论和行政争议实质性化解理论主张复议机关全面调查取证,但前者颠覆了行政复议的性质,错误地把行政复议作为后续行政程序,后者仅以“未再启动新的法律程序”目的为基点,忽视行政复议的监督与救济功能。在监督行政与救济权利的视野下,即使为实质性化解行政争议,复议机关调查取证的范围也应当限于程序性事项、核实当事人证据三性、证明原行政行为违法或申请人实体诉求成立以及涉及公共利益的事项。

基于雷达测距的飞行器交会对接误差补偿控制技术

为解决由视线倾角、视线偏角过大造成的飞行器对接存在误差的问题,实现飞行器交会轨迹的精准对接,提出基于雷达测距的飞行器交会对接误差补偿控制技术;建立空间参考坐标系,根据轨道根数计算结果,推导动力学状态方程,实现对飞行器交会对接过程中的动力学作用分析;按照雷达测距原理,计算飞行器的理论飞行时长及雷达装置作用距离,再联合相关参数指标,确定精度极限的取值范围,实现基于雷达测距的对接误差控制;在三坐标测量机结构模型中,定义飞行位姿拟合条件,再根据位姿误差求解结果,实现对误差参数的补偿修正处理,完成基于雷达测距的飞行器交会对接误差补偿控制方法的设计;对比实验结果表明,应用所提方法可以同时将视线倾角、视线偏角的取值控制在0~45.0°的范围之内,能够较好地解决飞行器错误对接的问题,符合精准对接飞行器交会轨迹的实际应用需求。

空间转向视域下全民健身公共服务供给的困囿、审视与突破路径

随着数字化时代的发展,新兴技术不断被应用于体育领域,给物质空间带来了前所未有的“空间”冲击,生产空间也相应地“转向”。本文采用文献资料法、逻辑分析法等研究方法,从空间转向视角入手,将供给服务与特定的“空间实践”结合,洞悉全民健身公共服务供给空间的主体、内容、客体等在空间实践的运作方式并进行分析,发现我国全民健身公共服务供给面临着困囿:供给主体空间区隔化、供给内容结构失衡、需求主体空间挤压等。通过审视多维度、复杂结构的空间为供给服务带来更多的研究视角,进而提出全民健身公共服务供给的突破路径,即释放智能化平台潜能,构建多元协同一体的供给空间;拓展场景式服务区域,营造互联互通多维的健身空间;完善个人化精准定制,获得健全均衡发展的需求空间。

行动不便老年人居家护理服务偏好研究进展

行动不便老年人居家护理需求迫切,但其对居家护理服务利用率不高。利用行动不便老年人的服务偏好优化居家护理服务是提高服务利用率的有效途径。本文从行动不便老年人居家护理服务偏好的研究方法、服务特征偏好及偏好相关因素等方面进行综述,旨在为提高行动不便老年人居家护理服务利用率提供参考。