Structure of the condensed phase and char of fire-retarded PBT nanocomposites by TGA/ATR in N2

Recently phosphorous-based fire retardants and nanoparticles are promoted as alternatives to halogenated fire retardants to reduce toxicological damage to the environment. To assess the condensed phase during pyrolysis, this study presents thermal (by TGA in nitrogen) and condensed phase analyses of the residue (by FTIR–ATR) of PBT modified by a phosphinate FR and/or nanoparticles (sepiolite). The thermal analysis shows that the nanoparticles do not change the pyrolysis kinetics of PBT whereas the phosphinate FR does. The condensed phase analysis shows that both the phosphinate FR and the nanoparticles change the structure of the char compared to the structure of the char from pure PBT. In contrast to the pure polymer, which leaves a char consisting of oligomeric components of PBT, the fire-retarded polymer (by phosphinate and /or nanoparticles) leaves a char consisting of polycyclic aromatic hydrocarbons (PAH). The PAH structure of the char is expected to make the char stronger and capable to withstand erosion in full-scale fire tests. This observation is verified from the strength analysis of the char residue in intermediate-scale flammability experiments, such as those in the cone calorimeter, where char is formed behind the flames in the absence of oxygen.     

高层学生公寓给水排水设计探讨

结合福州地区大学城某高校高层学生公寓的用水特点，对给水系统最高日用水量、最大小时用水量、给水方式选择、节水措施采用；排水系统；消防系统设计中若干问题进行了探讨。     

The assessment of the damage probability of storage tanks in domino events triggered by fire

An approach aimed to the quantitative assessment of the risk caused by escalation scenarios triggered by fire was developed. Simplified models for the estimation of the vessel time to failure (ttf) with respect to the radiation intensity on the vessel shell were obtained using a multi-level approach to the analysis of vessel wall failure under different fire conditions. Each vessel “time to failure” calculated by this approach for the specific fire scenario of concern was compared to a reference time required for effective mitigation actions and related to the escalation probability. The failure probability of each vessel was correlated to the probability of scenarios involving multiple vessel failure as a consequence of the primary fire, thus allowing a comprehensive assessment of domino scenarios triggered by fire. The application of the methodology to the analysis of several case-studies allowed the estimation of the quantitative contribution of escalation events triggered by fire to the overall individual and societal risk indexes.     

红外光谱法测定聚(2,6-二溴-3-甲基苯醚)的分子量

用多相聚合方法合成了聚(2,6-二溴-3-甲基苯醚)。并利用元素分析、IR(红外)和NMR(核磁共振)对其结构进行了鉴定。用红外光谱法测得聚合物分子量倒数1/M_n与末端羟基的吸收强度E成正比关系: 1/M_n=1.15×10~(-4)+1.53×10~(-3)E。     

Prototyping a global algorithm for systematic fire-affected area mapping using MODIS time series data

The remote sensing of Earth surface changes is an active research field aimed at the development of methods and data products needed by scientists, resource managers, and policymakers. Fire is a major cause of surface change and occurs in most vegetation zones across the world. The identification and delineation of fire-affected areas, also known as burned areas or fire scars, may be considered a change detection problem. Remote sensing algorithms developed to map fire-affected areas are difficult to implement reliably over large areas because of variations in both the surface state and those imposed by the sensing system. The availability of robustly calibrated, atmospherically corrected, cloud-screened, geolocated data provided by the latest generation of moderate resolution remote sensing systems allows for major advances in satellite mapping of fire-affected area. This paper describes an algorithm developed to map fire-affected areas at a global scale using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance time series data. The algorithm is developed from the recently published Bi-Directional Reflectance Model-Based Expectation change detection approach and maps at 500 m the location and approximate day of burning. Improvements made to the algorithm for systematic global implementation are presented and the algorithm performance is demonstrated for southern African, Australian, South American, and Boreal fire regimes. The algorithm does not use training data but rather applies a wavelength independent threshold and spectral constraints defined by the noise characteristics of the reflectance data and knowledge of the spectral behavior of burned vegetation and spectrally confusing changes that are not associated with burning. Temporal constraints are applied capitalizing on the spectral persistence of fire-affected areas. Differences between mapped fire-affected areas and cumulative MODIS active fire detections are illustrated and discussed for each fire regime. The results reveal a coherent spatio-temporal mapping of fire-affected area and indicate that the algorithm shows potential for global application.     

天然气发动机技术发展研究

本文介绍了天然气的车辆技术发展和应用前景 ,分述了各种不同类型的天然气发动机的特点 ,并对提高天然气发动机的动力性能、排放性能的技术给予了详细的论述 .同时对液化天然气 ( L NG)发动机的开发和应用技术进行了探讨     

采用轿厢速度反馈控制的液压电梯系统

对液压电梯速度反馈单片机控制系统进行了理论设计和实验的研究。提出了液压电梯轿厢速度反馈的控制方案和单片机控制系统设计、实施方案，给出了液压电梯单片机速度控制系统数学模型和系统校正措施。由仿真结果与试验结果表明，速度反馈控制具有较优的动、静态性能。     

Participatory landscape analysis to guide restoration of ponderosa pine ecosystems in the American Southwest

Over the past 5 decades, stand-replacing crown fires have increased in size and frequency throughout the long-needled pine forests of the American Southwest. Suppression of frequent, low-intensity ground fires has resulted in dense stands of fire-prone trees over large areas. Efforts to restore forest structure to conditions that would permit a return to historical fire regimes, characterized by frequent ground fire, are hindered by the inability of managers and the public to compare the effects of alternative forest management practices on fire behavior and a host of other issues. Currently, forest management is mired in controversy, endangering ecosystem function, biodiversity, public safety, and municipal watersheds. Our research program, motivated by the need to examine cumulative effects of many independent management decisions over large planning areas, focuses on the development of spatial data and modeling tools that enable diverse stakeholders to work together to guide landscape-scale planning efforts. Data layers describing forest composition and structure facilitate modeling of fire threat and wildlife habitat over areas of several hundred thousand hectares. Modeling alternative forest management scenarios via a collaborative, public process fosters informed discourse and helps conflicting parties forge appropriate policy and identify management responses that meet restoration objectives.     

载人航天中的防火安全与微重力燃烧研究

简要阐述了载人航天器防火安全的重要性、面临的问题及解决途径。介绍了防火安全措施。对载人航天任务中所涉及的微重力燃烧研究的领域、特点及途径予以讨论。     

Evaluation of performance and load in simulated rescue tasks for a novel design SCBA: effect of weight,volume and weight distribution

A self-contained breathing apparatus (SCBA) with an innovative rucksack shape that provides a better distribution of its weight over the middle and lower parts of the back (device C: 6l, 13.7 kg) was compared with two conventional SCBA which differed from each other in volume and weight (A: 6l, 15 kg, B: 6.8l, 11.7 kg). Twelve fire-fighters (27-49 yr) performed three exercises while using the three SCBA in a systematically permuted sequence. The exercises consisted of simulated rescue work under natural climatic conditions in a dwelling on the second floor and several typical elements of severe fire-fighting actions. Duration, heart rate, breathing frequency, rectal temperature, and sweat loss were recorded. Perceived exertion was rated and the carrying features of the SCBA were subjectively evaluated. The exercise was executed faster with the rucksack device, heart rates were then lower and the carrying features were evaluated as better. Thus, the weight of the SCBA was shown to be less important than its distribution.