Assessing the effects of disease and bleaching on Florida Keys corals by fitting population models to data

Coral diseases have increased in frequency over the past few decades and have important influences on the structure and composition of coral reef communities. However, there is limited information on the etiologies of many coral diseases, and pathways through which coral diseases are acquired and transmitted are still in question. Furthermore, it is difficult to assess the impacts of disease on coral populations because outbreaks often co-occur with temperature-induced bleaching and anthropogenic stressors. We developed spatially explicit population models of coral disease and bleaching dynamics to quantify the impact of six common diseases on Florida Keys corals, including aspergillosis, dark spots, white band, white plague, white patch, and Caribbean yellow band. Models were fit to an 8-year data set of coral abundance, disease prevalence, and bleaching prevalence. Model selection was used to assess alternative pathways for disease transmission, and the influence of environmental stressors, including sea temperature and human population density, on disease prevalence and coral mortality. Classic disease transmission from contagious to susceptible colonies provided the best-fit model only for aspergillosis. For other diseases, external disease forcing, such as through a vector or directly from pathogens in the environment, provided the best fit to observed data. Estimates of disease reproductive ratio values (R₀) were less than one for each disease, indicating coral colonies were below densities required for diseases to become established through contagious spread alone. Incidences of white band and white patch disease were associated with greater susceptibility or slower recovery of bleached colonies, and no disease outbreaks were associated with periods of elevated sea temperatures alone. Projections of best-fit models indicated that, atleast during the period of this study, disease and bleaching did not have substantial impacts on populations and impaired rates of population growth appeared to be attributable to other stressors. By applying epidemiological models to field data, our study gives qualitative insights into the dynamics of coral diseases, relative stressor impacts, and directions for future research.     

基于风险耦合理论的航空装备本质安全管理研究

为提高航空装备的本质安全管理水平,奠定新一代航空装备安全服役的良好基础,基于目前本质安全管理理论片面强调组成元素自身本质安全度的提高,忽略系统组元间耦合交互作用的现实,提出了一种基于风险耦合理论的航空装备本质安全管理模型。对航空事故本质致因和耦合风险理论进行了分析,指出耦合风险的原因主要在于各系统组元在容错性、兼容性和标准化等方面存有缺陷。构建了基于耦合理论的飞机本质安全管理图示模型,强调系统宏观安全度的提高在于组元的本质安全化和对组元内部及组元之间耦合风险的有效管控,建立了系统安全度和耦合风险度计算模型,为航空装备服役安全性的提高提供了新理念。     

石化企业设备密封点泄漏检测技术研究

介绍了国内外泄漏检测技术研究现状及发展趋势.利用专业的泄漏检测仪器设备,依据泄漏检测工作流程,对某石化企业进行了全面的泄漏检测.泄漏检测数据统计分析结果表明,企业密封点的外漏比较严重,内漏较轻;加氢装置、油品车间、气分装置、延迟焦化、重整加氢车间和聚丙烯装置密封点泄漏比较严重;采样口、排凝口、调节阀、阀门、阀杆、火嘴、长明灯和法兰泄漏较为严重;红外热像技术在设备密封点气体泄漏检测方面功能强大,应用前景广阔.同时对检测到的泄漏点和问题给企业提出了建议和措施.     

特种劳动防护用品生产企业基本情况统计分析

国家于2006年开始对21种特种劳动防护用品实行安全标志管理,到目前为止,已有786家特种劳动防护用品生产企业获得了安全标志许可证书。本文通过对786家获得安全标志许可证书的特种劳动防护用品生产企业的数量、分布、注册资金、人数以及产品种类等相关数据进行统计,分析了当前我国的劳动防护用品生产企业整体现状,即还处于水平较低、实力较弱的状态,并提出了加强劳动防护用品生产企业力量的措施和建议,包括降低劳动防护用品生产企业税负,发放低息贷款,加强科研经费的投入等。     

基于战略投送策略的电磁频谱保障技术研究

实践表明,在投送的过程中谁能有效地对交通线进行控制与使用,谁的胜数就大,反之就会陷入被动的局面。袭击、封锁和破坏我方交通运输是客观存在的。而适时展开整体防卫,统一使用军地防空力量实行一体化区域防空,加强电磁频谱装备建设和技术安全保障,加强主要投送装备的自卫火力和电子对抗系统,就能使投送力量具有一定的防护能力,从而提高投送装备安全保障的水平。     

Coal sector reform and its implications for the power sector in China

Coal is the major primary energy which fuels the economic growth in China. The Soviet-style institution of the coal sector was adopted after the People’s Republic was founded in 1949. But since the end of 1970s there have been major changes: the market mechanism was introduced to the coal sector and the Major State Coal mines were transferred from central to local governments. This paper explains these market-oriented and decentralized reforms and explores their implications for the power sector, now the largest single consumer of coal. The argument of this paper is that the market-oriented and decentralized reforms in the coal sector were influenced by the changes in state energy investment priority as well as the relationship between the central and local governments in the context of broader reforms within China’s economy. However, these market-oriented and decentralized reforms have not equally influenced the power sector. Even though initial coal sector reform spurred power generation, the subsequent fragmented reforms raise concern about electricity shortages.     

绝缘电阻表的禁忌分析与对策

根据绝缘电阻表的设计原理、技术条件和计量工程及电气安全的技术要求,结合实际工作中的经验教训,针对绝缘电阻表在应用中的错误行为,阐述了绝缘电阻表在选用、接线、摇测、读数和保养等主要使用环节方面的十六种禁忌行为,而且对每种禁忌行为均提出了正确的测试操作方法及预防措施。     

美军核生化个体防护装备发展现状与趋势

美军认为,在核生化污染区域采取行动中,个体防护装备性能的高低和救治程序是否得当,直接关系到作战行动的成败。经过多年的不断发展,目前,美军士兵已配备了从防护面具到防护靴的全套防护装备,能够为士兵在核生化沾染区域作战提供全身有效防护,可有效防止士兵受到核生化战剂的侵害,从而保证了部队的战斗力。目前已呈现出了标准化、系列化程度高,防护性能好,生理负担低,舒适性高等发展特点。深入研究美军个体防护装备的发展现状与趋势,对于今后我军个体防护装备的发展具有十分重要的启示和借鉴意义。     

个体防护装备在火场勘验作业中的选用与管理

近年来,火灾调查人员的职业安全与健康问题已引起相关部门的重视。个体防护装备的合理正确选用在避免火场勘验作业伤害中起着至关重要的作用。因此,一线火调人员对个体防护装备需求的呼声越来越高。本文分析了火场勘验作业中常见的危险源,并根据各种危害类别及形式探讨火调人员个体防护装备的选用与管理,以期能够有效防止或减少火场勘验作业伤害事故的发生,保障火场勘验人员的生命健康,提高我国消防部队一线火调人员的整体战斗力。     

一种航空装备系统中本质安全人的构建方法

据统计,各种事故因素中人为失误占80%,为提高航空装备系统的服役安全性,需要在其使用管理中构建本质安全人.在对本质安全人进行定义并分析构建必要性后,提出了航空装备系统本质安全人的构建方法,建立了人员安全行为控制模型,最后指出本质安全人可靠性增长与本质安全人的构建有着共同的努力方向.对于航空装备系统服役安全性的提高有一定...