悬挂式超细干粉在电缆火灾中的应用分析

悬浮超细干粉的应用技术在环境保护和安全性上都得到了众多的认同与赞赏。超细干粉与传统灭火剂相比,其颗粒大小小、灭火效率高,可以迅速减小火场的温度并减轻有毒有害气体的产生。超细干粉对于我们的人体健康及自然环境几乎没有任何伤害,从而满意了当代严格的环保标准。此外,这一悬挂的超级细干粉系统具有很高的自动化和智能化水平,能够对电缆火灾实施实时监视和自动触发,从而极大地提升了火灾的防控效能和安全性。

火灾中带裂缝钢筋混凝土梁承载力算法研究

火灾中带裂缝钢筋混凝土梁的承载能力研究可为工程实际应用提供参考。文章利用有限元分析软件ABAQUS对火灾中带裂缝钢筋混凝土梁内部的温度场进行分析,阐明了火灾中带裂缝钢筋混凝土梁内部温度场的分布规律,根据其分布规律确定了在不同耐火时刻有裂缝钢筋混凝土梁300和800℃的等温线,结合已有的高温下钢筋混凝土梁承载力计算公式,提出了火灾中带裂缝钢筋混凝土梁承载力计算公式。结果表明：在同样的受火条件下有裂缝时钢筋混凝土梁中钢筋位置的温度比是无裂缝时钢筋混凝土梁中钢筋位置的温度高55%~144%;有五条裂缝的钢筋混凝土梁中钢筋位置的温度比有一条裂缝的钢筋混凝土梁中钢筋位置的温度高2.7%~11.5%;带裂缝钢筋混凝土梁的承载力比无裂缝钢筋混凝土的承载力低47%~82%。

试论人在高层建筑火灾中的行为

火灾发生后,从起火冒烟到烈火冲天时间极短暂。在被火势围困的人员中,有的人慌不择路,跳楼丧生或造成残废,也有的人沉着冷静,化险为夷,这与被困人员在火灾中的行为有关。

火灾调查中物证损坏原因及防范措施探讨

发生火灾的原因比较复杂与多样,发生火灾事件后,火灾现场物证调查比较困难,因为火灾现场,大部分物件已经遭到大火燃烧而破损,增加了调查引发火灾原因的困难,影响火灾调查中物证取样的准确率.所以,需要保护好火灾现场一切烧伤痕迹,确保火灾现场被扑灭后,现场烧伤痕迹能够存在有效证据,避免在对火灾现场采集物证时对烧伤痕迹造成损坏.本文主要讲解火灾调查中物证损坏原因,如火灾现场物品勘查导致物证损坏,火灾现场提取物证时对物证造成损坏以及其他原因导致物证痕迹损坏.另外,本文还提出了防范火灾调查中物证损坏的措施,如加强火灾现场勘查保护,增强火调过程中防止物证损坏的对策,提高调查火灾结果质量等.

Coal fires in China

Coal fires have a very long history in China; the oldest coal fires have being burning for many million years. Up to now more than 56 coal fires spots were distin-guished. They mainly locate in West-North of China, North of China and East-North of China. About millions of tons of coal have been burned in fires every year. Xinjiang Autonomy is the most serious region in coal fires as it has 38 coal fires spots and about 6.85 million tons of coal was burned every year. Coal fires in China ignited by wildfires, spontaneous combustion and human being during mining activities. These fires have re-leased about 0.9 million tons of gasses (including CO, CO2, SO2, NO2 CH4, CO2, H2S etc.) into the atmosphere every year, most of which are brought to the east by wind and result-ing more heavier air pollution in northern China.

A Time-dependent Stochastic Grassland Fire Ignition Probability Model for Hulun Buir Grassland of China

Grassland fire is one of the most important disturbance factors in the natural ecosystems.This paper focuses on the spatial distribution of long-term grassland fire patterns in the Hulun Buir Grassland located in the northeast of Inner Mongolia Autonomous Region in China.The density or ratio of ignition can reflect the relationship between grassland fire and different ignition factors.Based on the relationship between the density or ratio of ignition in different range of each ignition factor and grassland fire events,an ignition probability model was developed by using binary logistic regression function and its overall accuracy averaged up to 81.7%.Meanwhile it was found that daily relative humidity,daily temperature,elevation,vegetation type,distance to county-level road,distance to town are more important determinants of spatial distribution of fire ignitions.Using Monte Carlo method,we developed a time-dependent stochastic ignition probability model based on the distribution of inter-annual daily relative humidity and daily temperature.Through this model,it is possible to estimate the spatial patterns of ignition probability for grassland fire,which will be helpful to the quantitative evaluation of grassland fire risk and its management in the future.

AA8176型铝合金导线短路熔痕金相组织特征研究

AA8176型铝合金导线,常被应用在主配电盘与变压器之间。当导线一旦受到火灾破坏,产生短路故障时,出现的短路熔痕金相组织特征与铜、铝导线有所不同。因此,对AA8176型铝合金导线火灾中短路熔痕金相组织特征进行研究,采用辐射热盘加热、酒精燃烧、木材燃烧和汽油燃烧,来模拟真实火场热环境进行试验,利用金相法观察分析金相组织晶粒和内部孔洞特征。试验结果表明,AA8176型铝合金导线火灾中短路熔痕金相组织内部空洞多且密,熔痕端与本体的金相组织界限不明显,晶粒以柱状晶和胞状晶为主。在不同热环境下出现差别,辐射热盘和酒精加热条件下的熔痕内部孔洞形状规整,多呈圆形,晶粒多呈细长的柱状晶和胞状晶;木材和汽油燃烧则出现大量不规则形状的内部孔洞,晶粒更粗大;汽油燃烧条件下的熔痕金相组织存在特殊的长刺痕和刀口痕。为实际工作中区分火灾前短路熔痕,提供方法和借鉴。

Understory vascular plant community assembly in relation to time-since-fire and environmental variables in a Chinese boreal forest

Understanding the response of understory vegetation to fire disturbance is vital to biodiversity conservation and management of boreal forests. We surveyed understory vascular plant richness and composition, and measured related environmental variables along a toposequence within three successional stages, initial （3 years post-fire）, early （13 years post-fire） and late （〉1oo years post-fire） successional stages. Using permutation multivariate ANOVA and nonmetric multidimensional scaling, we analyzed how understory species richness and composition change as time-since-fire proceeds, and their correlative relationships with environmental variables. Species richness and composition showed significant differences among the three successional stages. Understory species richness and abundance were significantly associated with time-since-fire, topographic position, elevation and organic layer depth. Among these variables, time-since-fire had the strongest effect and topographic position was the second major factor on affecting understorycommunity assembly. In overwhelmed the effects addition, time-since-fire of soil pH in the initial successional stage and gravimetric soil moisture in early and late successional stages on understory species composition

Small-scale area survey and analysis of Xinjiang's coal field fire in China

In this paper, Xinjiang＇s coal field is selected as the investigation area. Through a series of field surveys in Xinjiang, we made the small-scale area analysis of coal field fire using the ground remote sensing technique, and presented the reasonable evaluation of thermal anomaly conditions of Xinjiang＇s coal field arising from coal self-ignition fires. The results show that the method of small-scale area analysis is available for examining the extinguished actuality of coal fires and detecting fire spots. Therefore, for the selected fire-extlngulshed coal field in Xinjiang, the fire extinguishing effect was effectively analyzed by the means, and the new hidden thermal dangers were sought and diagnosed. For the coal field where the fire has not been extinguished, the utilization of this means approximately identified the severity and range of the fire area, and provided the quantitative and ground references for extinguish engineering.

Review on safe blasting technology in high-temperature coal seams in China

In order to define the development direction of safe blasting technology in high-temperature coal seams in China, this paper presents a systematic, state-of-the-art review on safe blasting technology. Information such as high-temperature coal fire extinguishment and cooling, anti-high-temperature blasting supplies, heat insulation blasting setting, operation procedures for high-temperature blasting, and so on, are presented. Analysis shows that the development of effective technology for coal seam fire extinguishing and cooling, the manufacture of anti-high-temperature blasting supplies, especially priming materials, the development of heat insulation blasting setting, and the establishment of technical specifications suit large-scale blasting design and construction work at high-temperature coal seams, are the essential methods for safe blasting at high temperature coal seams.

A Potential Flood Hazard Caused by Tianchi Volcano Eruption in Changbai Mountain, Northeast China

Geohazards appear to be increasing in frequency globally. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented by the huge volume of water in Tianchi Lake, the unique geography of Changbai Mountain, and the limited flood control ability in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changbai volcano cooperatively, and Chinese government especially needs to prepare plans for fighting a flood in advance.

扑救高层建筑火灾的潜在危险及预防措施

高层建筑火灾扑救难度大,易造成救援人员的伤亡,至今仍是世界性的消防难题。本文通过对高层建筑火灾中危及消防员安全的因素进行了分析,并具体提出了避险的措施。

消防的"被动"与"主动"

和以残酷著称的战争一样,火灾的残酷性和摧残性一点也不亚于战争。据山东省青岛市消防部门不完全统计:2000年1月至2003年1月,青岛市火灾总体形势平稳,每年平均火灾2264起,3年中火灾造成的财产损火却累计达上千万元,死亡人数更是每年高达23人。 造成火灾的最主要原因竟是居民或单位用火不慎引发的。比如。

居民火患猛于虎

好人一生平安,这是世间所有善良人的共同心愿。然而,在我们的生活中,却往往会有意想不到的灾难降临,其中火灾,就常常充当起了诱发灾难的重要角色。

Climatic and fire determinants of early life-history stages in the Mediterranean shrub Cistus albidus

Aims Cistus albidus reproductive traits have been studied on typical Mediterranean shrublands along a water availability gradient in Northeastern Iberian Peninsula.Germination of this species is known to be highly favoured by fire.Moreover,Mediterranean species are particularly dependent on water availability.Therefore,we establish the hypothesis that in addition to fire disturbance,seedling recruitment in this Mediterranean seeder will be improved in drought-induced episodes resulting in generalized canopy die-off.Methods Individuals of several populations of C.albidus were collected and the size,weight and number of fruits and seeds were measured.Germination tests were also carried out on five pre-germination treatments:seeds’exposure to heat shock,imbibition,two cycles of imbibition/desiccation and the combination of heat shock and imbibition and imbibition/desiccation cycles.Moreover,the number of seedlings after a drought event was surveyed in the field and correlated with canopy die-off.Important findings Our study shows the variability of the C.albidus reproductive traits,such as germination rate or fruit production,along the water availability gradient.This variability resulted in a decrease in fruit production but an increase in successful germination under drier conditions.Cistus albidus seeds increased germination with heat,demonstrating their ability to successfully establish after fire.However,recruitment was not exclusively fire dependent since seedling establishment was higher under C.albidus canopies that had collapsed after the extreme drought.Finally,adult density increased C.albidus die-off and mortality,as well as seedling establishment.These results suggest that this species exhibits a trade-off between different reproductive outcomes(i.e.seed production vs.viability),which in turn is determined by climate.This study also provides evidence of how intra-specific competition,climate,particularly drought events and fire disturbance,can determine the success of key early stages of the life history of a common,representative Mediterranean fire-prone seeder shrub.

Estimation of Direct Carbon Emissions from Chinese Forest Fires

Many studies indicated that the products of biosphere burning have short and long-term effectson the atmosphere. Vegetation burning can produce some gases which have significant influence onenvironment, including some greenhouse gases as CO2 and CH4, etc. Smoke aerosols produced fromburning also influence global climate and atmospheric chemistry. The paper calculates the consumedbiomass due to forest fires according to the statistics of forest fires from 1991 to 2000 and research resultsof biomass of Chinese forests. During the study period, forest fires burned average 5 Tg ~7 Tg biomasseach year and directly emitted 20.24 Tg^28.56 Tg carbon. In 1991~2000, average emission of carbondioxide and CH4 account for 2.7%~3.9% and 3.3%~4.7% of the total emission of China (calculating withthe data of 2000), respectively.

The PCDD/PCDF Dioxin Releases in the Climate of Environment of Jordan in the Period (2000-2008)

Many environment problems of the full using of several categories of processing include mining,heat generators,direct combustion of forest fires,cement production,power plant,transport,medical waste.Dioxin/furan releases from these categories are one of these environment problems.Possible lines of reducing the PCDD/PCDF (Polychlorinated dibenzo-para-dioxins/Polychlorinated dibenzofurans) releases from these categories are elucidated.The contribution of this paper is present the identification and estimation of the latest figure of dioxin/furan releases in the climate of environment of Jordan in the period 2000-2008 from the following categories (cement,aluminum,ceramic,medical waste,power plant,land fill,ferrous and non-ferrous metals,uncontrolled combustion process (biomass burning,waste burning,accidental fires in house,transport).These finding shows the sign of growth of estimated PCDD/PCDF releases from categories which did not calculated and followed after 2003.The result shows the highest PCDD/PCDF release from landfill fires (62.75 g TEQ/year),medical waste (8.8264 g TEQ/year),and transport (3.0145 g TEQ/year).Jordan seeks by next years,a reduction in total releases of dioxins and furans from sources resulting from human activity.This challenge will apply to the aggregate of releases to the air nationwide and of releases to the water within the Jordan area.Jordan should conduct air monitoring for dioxin in order to track fluctuations in atmospheric deposition levels.

Forest Fire Environment and Characteristics in Northeastern China

Forest fires occurrence is influenced by many factors, such as inter-annual weather variations and regional fuel distributions. Fires occurrence in different forest region has distinct spatial and temporal characteristics. The paper studied the natural forest fire environment in Northeastern China, as well as forest fires occurrence, burned area and fire seasons in Northeastern Forest Region. The result shows that more than 50% of annual burned area occurred in Northeast China Forest Region. Main fire seasons in the region are spring and autumn. Fires occurrence in spring is larger than that in autumn. There are few fires in summer. The authors' suggestions for fire management department are to emphasize the fuel management, improve the roads conditions, and enhance the fires control ability.

Fire occurrence in relation to bamboo dominance in the Qinling Mountains of China: Evidence from phytolith and charcoal records in Holocene sediments

he internal genetic clock of semelparous mast-flowering bamboo species creates gregarious regions of flowering and death, thus leading to fuel-load accumulation that potentially promotes fire（Fire-Cycle Hypothesis）. Higher abundance of bamboo could be expected to provide greater fuel loads after flowering. Here, we investigated the possible link between bamboo dominance and fire occurrence. As the main food source for the giant panda in the Qinling Mountains of China, Bashania fargesii（Farges Canebrake） and Fargesia qinlingensis（Arrow Bamboo） dominate lower（1000–1900 m） and higher elevations（1800–2700 m）, respectively. Four soil profiles（elevation ranging from 1240 to 2170 m） in areas of known recent bamboo flowering events（~1980） and adjacent non-flowering sites were assessed for phytoliths and charcoal. Characteristic phytoliths were chosen to describe bamboo dynamics, and charcoal particles were extracted from the soil to reconstruct fire history. Carbon 14 dating of soil charcoal samples was conducted using an accelerator mass spectrometry technique. In addition, we chose two depths（28–52 and 90–100 cm） in one Bashania profile（B. fargesii forest） and one Fargesia profile（F. qinlingensis forest） for phytolith dating. Our findings indicate that bamboo has been a dominant component of these ecosystems almost for the entire profile; some 6400 yrs for Bashania and ca. 10000 yrs for the Fargesia. It is also clear from the charcoal and phytolith data that bamboo abundance and recent mast flowering were significantly related to fire occurrence for lower elevation Bashania while the higher elevation Fargesia was not. One of the four profiles had chronological charcoal records throughout and the oldest charcoal aged was ~1410 yr BP, suggesting an anthropogenic origin. The mixing of phytolith and charcoal made it unrealistic to describe temporal dynamics of bamboo and fire events, and thus our interpretation is cognizant of the dating discrepancies and conservative（less-speculative）. Due to the long history of bamboo and much shorter history of fire within the profile, our data lend little evidence to the Fire-Cycle Hypothesis.

Seasonal fires shape the germinable soil seed bank community in eastern Mediterranean woodlands

We explored if and how seasonal fires interact with microhabitat type(i.e.under Pistacia shrub,under Cistus shrub or a canopy gap)to influence the composition of the germinable soil seed bank(GSSB)community in a typical eastern Mediterranean woodland.We conducted a field experiment,involving prescribed spring and autumn burns,and thereafter quantified the seed germination patterns using soil samples collected from both burned and adjacent unburned control plots.Soil temperature was significantly higher during autumn burns,while being more variable during spring burns.Fire caused overall reductions in GSSB density,richness and diversity.The reductions in GSSB richness and diversity were significantly stronger under Pistacia and Cistus shrubs located within plots subjected to autumn burns,and these patterns were mainly evident among annuals.GSSB density of dwarf shrubs was higher in samples collected from burned plots,and this pattern was more pronounced in samples collected under Pistacia and Cistus shrubs.Together with the appearance of unique species,seasonal fires led to significant changes in the composition of the GSSB community.Our results illustrate that seasonal fires interact with spatial heterogeneity to influence the composition of the GSSB community mostly via differential effects on the germination densities of annuals and dwarf shrubs.These findings imply that the increase in the frequency of seasonal fires,which has occurred in the eastern Mediterranean basin during the last few decades,may translate into a shift in eco-evolutionary selection pressures,operating on plants inhabiting this unique ecosystem.