基于HFACS的民机总装过程人为失误风险分析

为解决民用飞机制造过程中人为失误风险评估不确定性问题,提出一种基于人因分析与分类系统(HFACS)模型的风险分析方法。首先,采用故障模式与影响分析(FMEA)法评估民用飞机总装过程中人为失误的风险,结合国际民航组织(ICAO)的人为因素分类方法提出改进的HFACS模型,并将其作为人为失误发生度和难检度的评估依据;其次,采用粗糙集方法处理评估信息的不确定性问题;然后,应用偏好顺序结构评估法(PROMETHEE II)处理人为失误风险评估和排序问题,并评估其改进优先级;最后,分析某民用飞机制造企业总装过程中的人为失误风险,验证所提方法的有效性。结果表明:所提方法能为民用飞机制造企业人为失误风险评估提供合理的评估依据和有效的评估方法。     

可靠性评价方法在炼化企业电网中的应用

介绍了国内外电力系统可靠性发展现状,分析了炼化企业生产特点,着重介绍了炼化企业电力系统可靠性评价内容,比较了公用电网与炼化企业的不同性质,说明了二者可靠性评价方法的不同,最后用计算实例说明了可靠性计算方法在炼化企业电力系统中的应用,根据计算结果提出了加强炼化电网可靠性的措施。     

南方典型城市污水处理厂碳排放特征及降碳策略研究

在当前全球气候变化的大背景下,城镇生活污水处理厂作为城镇供排水系统的组成部分,是重要的温室气体排放源之一。基于排放因子法,对中国东南沿海某省会城市4座不同工艺的生活污水处理厂进行了碳排放核算,分析了不同工艺之间的碳排放特征和强度的差异。研究对象包括采用卡鲁塞尔氧化沟（OD）、厌氧-缺氧-好氧（A²/O）、厌氧-缺氧-好氧与膜生物反应器结合（A²/O+MBR）以及循环式活性污泥法（CASS）工艺的污水处理厂。结果表明,4座污水处理厂的碳排放总量和结构存在显著差异。A²/O+MBR工艺因其高能耗和药剂使用导致碳排放强度最高,平均为0.403 kg CO₂-eq/m³;CASS工艺由于其周期性运行模式,N₂O排放占比显著,但其电力和药剂消耗有明显优势。OD和A²/O工艺运行稳定,碳排放强度波动较小。研究发现,处理水量和进水TN浓度是影响碳排放强度的关键因素,其中,A²/O+MBR工艺表现出显著的规模效应。基于上述分析,提出了南方地区污水处理厂的碳削减对策,包括低碳规划、工艺选择、运行优化和因子本地化等方面。通过这些策略,可以有效减少污水处理过程中的碳排放,推动污水处理向低碳高效方向发展。     

3S技术在林纸一体化项目生态环境影响评价中的应用

文章以梧州市某林浆纸一体化原料林建设项目为例,借助3S技术分析原料林基地建设对生态环境的影响,探讨3S技术在生态环境影响评价中的应用。     

Differences in plant species diversity between conifer (<Emphasis Type="Italic">Pinus tabulaeformis</Emphasis>) plantations and natural forests in middle of the Loess plateau

We compared differences in plant species diversity between conifer (Pinus tabulaeformis) plantations and natural secondary forests in the middle of the Loess plateau. The goal of the study was to examine the differences in the effect of stand development on species diversity and in species responses to changes between forest types and between forest layers. To clarify the effects of differences in forest management, we emphasized the functional types of plant species occurring in each forest type. The result as follow: (1) The H′ and S of tree layer were significantly lower in natural conifer forest than old conifer and secondary forest, but were not different compared with mid aged conifer forest. The H′ and S of shrub layer were significantly lower in mid aged conifer forest compared with other forest types. The H′ of herb layer showed no significant differences in the four forest types. The evenness index (J′) of tree layer of mid aged conifer forest was lower than other forest communities and its J′ of shrub layer was highest although its richness of shrub layer was lower than in the other forest types. (2) The analysis of β diversity index also indicated large differences between conifer plantations and natural forests. Although the tree layer species were similar in old plantation and natural conifer forests, they differed greatly between the natural conifer and secondary forests. The natural conifer and secondary forest species composition in shrub layer differed significantly from those in plantation and secondary plots. Tree species were significantly less common in plantations than in abandoned coppice forests. Species composition in the herb layer of different forest types was similar. (3) The management of P. tabulaeformis plantations alters plant species composition considerably; the number of sub tall-tree species is increased in old aged conifer forest, especially species dispersed by animals. Plantation management appears to affect ecological processes through seed dispersal. From the perspective of management, the change in the structure and composition of the canopy in plantations could affect the behavior of dispersers and regeneration.     

Restoration of the lower reaches of the Tarim River in China

The middle and lower reaches of the Tarim River are areas of rich biodiversity and natural resources in the inland arid region of China. However, the Tarim River and its associated wetlands have been severely damaged and fragmented during the past several decades. To restore the deteriorated ecosystem and preserve the endangered riverine vegetation along the Tarim River, a project for releasing water from upper dams to the lower reaches of the Tarim River was initiated by China’s government in 2000. Between 2000 and 2005, we monitored the responses of groundwater levels and vegetation to this mitigation along nine transects spaced at mean intervals of 45 km along the river from Daxihaizi Reservoir, the source of water conveyance, to the Lake Taitema, the mouth of the Tarim River. We found that average groundwater levels rose significantly from 8 to 4 m below ground surface. Species diversity did not change during the 5-year period, but the total vegetation coverage and canopy size of some species significantly increased. The endangered tree species, Populus euphratica, started to regenerate. Our results indicated that species diversity might recover very slowly, even if the trial water release program became a permanent river management practice. Management decisions about allocating limited water supplies among competing uses in arid regions will ultimately determine whether degraded river ecosystems, such as the Tarim River, can be restored.     

印染废水处理厂二级出水的硫自养反硝化脱氮工艺

采用硫/白云石自养反硝化脱氮工艺处理印染废水处理厂二级出水,考察不同污泥接种方式、水力停留时间（HRT）、温度及进水负荷对系统脱氮效果的影响。结果表明：反应器在3 d内即可完成快速启动,工程应用中可不接种污泥;反应器最佳HRT为20 min,TN去除率为40.2%,但反冲洗频率加快;温度、进水负荷对系统脱氮效果影响较大,当温度在25~30 ℃之间,TN平均去除率为43.8%;当进水负荷为（1.37±0.15）kg·（m3·d）-1,TN平均去除率为37.1%,反应器具有较强的抗冲击负荷能力。     

基于Nataf变换的相关随机数算法及其应用

针对极值风浪荷载之间的相关性,提出了一种基于Nataf变换的相关非高斯分布随机数算法,用来生成极值风浪荷载随机向量;运用该方法讨论了基于独立风浪的荷载效应和基于相关风浪的荷载效应的极值之间的关系,并且对不同的风浪联合荷载效应的拟合方法进行了评定;应用最小二乘法及极值Ⅰ型分布拟合实际风、浪荷载效应,然后对此分布模型运用Nataf变换随机数算法和一般随机数算法生成随机向量,最后通过与实际风浪联合荷载效应比较,验证了所提方法的有效性。     

黑碳气溶胶研究概况

黑碳气溶胶是大气气溶胶的重要组成部分,由于其在全球气候变化和区域空气质量中的双重作用,黑碳已经成为目前全球气候变化研究中备受关注的焦点之一。在查阅近年国内外相关文献资料基础上,分析了黑碳气溶胶的来源和源强分布,结果表明工业源和居民生活消费源是大气中黑碳气溶胶最主要的贡献者,全球黑碳排放空间分布不均匀,与区域经济发展和人口密度相一致;总结了黑碳气溶胶的基本特性及其影响,重点探讨了黑碳对气候的影响机理,结果表明黑碳气溶胶既可以通过直接气候效应改变地-气系统的辐射平衡,又可以通过云反射效应、地表下垫面改变效应以及作为云凝结核间接影响区域或全球气候;随后对黑碳气溶胶的典型测量方法的优缺点进行了对比分析;最后介绍了黑碳研究领域中存在的主要问题,并对黑碳气溶胶研究的发展方向进行了展望。