Safety assessment of the film boiling chemical vapor infiltration (FB-CVI) process through a system-theoretic accident model and process (STAMP)

Film boiling chemical vapor infiltration (FB-CVI) is considered as one of the fastest process methodologies for manufacturing carbon-carbon (C–C) composite products and possesses various advantages compared to conventional methodologies. However, there are safety concerns associated with this process for large-scale manufacturing, mainly owing to the intrinsic nature of the precursor and the process conditions. Considering the multifunctional interactions of the various systems during the process, a system-theoretic process analysis (STPA)/system theoretic accident model and process (STAMP) model is used to perform a safety analysis of the hazardous states of the FB-CVI process at the system level. As a case study, the FB-CVI process equipment employed for the manufacturing of C–C composites is considered. The safety constraints present in the system are assessed for adequacy through a hazard analysis by STPA/STAMP. The analysis through STPA/STAMP demonstrated the capability to create proactive strategies for the design and realization of process equipment that can be employed to manufacture C–C composite products through the FB-CVI process.     

Study on Assessing Economic Vulnerability of Small Island Regions

The main purpose of this study is to assess economic vulnerability of small island development regions as part of their sustainability constraints. By combining economic and environmental time series data, we assessed a composite index of economic vulnerability which is constructed from three exogenous variables, namely economic exposure, economic remoteness, and economic impact of environmental and natural disasters. We used the Amami Islands, Kagoshima Prefecture, Japan as the case studies for this paper.The results indicated that using a gross island products based valuation index, Kikaijima is the most vulnerable island in the Amami Islands with a composite economic vulnerability index (CEVI) value of 0.678, while by using a per capita based index, Okinoerabujima is considered the most vulnerable island with a CEVI value of 0.680. From the results we also revealed that smaller islands have relative higher vulnerability than the bigger one, which also confirms some previous country-level vulnerability studies.However, it is matter of fact that some islands that have relatively high vulnerability also have good economic performance as shown by their per capita income. In this regard, it can be argued that the success of these small islands could have been achieved in spite of and not because of their inherent vulnerability conditions as an indicator of sustainability constraint. Regarding these findings, we also examined a comparison between vulnerability results and the preliminary concept of an island's resilience in order to capture another perspective on sustainability assessment in a small island region.     

石臼漾人工湿地冬夏季全程氨氧化微生物的分布、群落结构及其影响因素研究

湿地作为水体与陆地之间的过渡地带,具有独特的生态环境特性,是氮循环反应的关键区域.研究湿地生态系统中的全程氨氧化过程（complete ammonia oxidation,comammox）,解析该区域中comammox细菌的分布与群落结构特征,补充了此前该新型氨氧化微生物在湿地生态系统中分布特征的研究空白,对于完善comammox细菌在各种不同生态系统中分布情况的研究具有重要意义.本研究在石臼漾人工湿地中于冬夏两季分别采集了大沟中心、大沟边缘、小沟中心和小沟边缘的表层沉积物样品,利用PCR、荧光定量PCR和amoA功能基因高通量测序等方法,解析人工湿地中comammox细菌的时空分布与群落结构特征.主要研究结果如下：①所有样品中均检测到了comammox细菌,其丰度为1.77×10⁵~4.07×10⁷ copies·g^-1.冬季,comammox细菌丰度在大沟中高于氨氧化细菌（ammonia oxidizing bacteria,AOB）和氨氧化古菌（ammonia oxidizing archaea,AOA）,在小沟中高于AOB,但低于AOA;夏季,comammox细菌丰度在所有样点中均高于AOB和AOA.②冬夏两季样品中,comammox细菌丰度与底物NH₄⁺-N浓度均呈负相关关系,且夏季样品中呈显著性负相关.③主坐标分析（Principle Coordinate Analysis,PCoA）与多样性分析结果表明,comammox细菌群落结构具有空间异质性,且冬季物种多样性高于夏季.     

Performance of different macrophytes in the decontamination of and electricity generation from swine wastewater via an integrated constructed wetland-microbial fuel cell process

Plants constitute a major element of constructed wetlands(CWs).In this study,a coupled system comprising an integrated vertical flow CW(IVCW) and a microbial fuel cell(MFC) for swine wastewater tre atment was developed to research the effects of macrophytes commonly employed in CWs,Canna indica,Acorus calamus,and Ipomoea aquatica,on decontamination and electricity production in the system.Because of the different root types and amounts of oxygen released by the roots,the rates of chemical oxygen demand(COD) and ammonium nitrogen(NH_4~+-N) removal from the swine wastewater differed as well.In the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,the COD removal rates were 80.20%,88.07%,84.70%,and 82.20%,respectively,and the NH_4~+-N removal rates were 49.96%,75.02%,70.25%,and 68.47%,respectively.The decontamination capability of the Canna indica system was better than those of the other systems.The average output voltages were 520±42,715±20,660±27,and 752±26 mV for the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,respectively,and the maximum power densities were 0.2230,0.4136,0.3614,and0.4964 W/m~3,respectively.Ipomoea aquatica had the largest effect on bioelectricity generation promotion.In addition,electrochemically active bacteria,Geobacter and Desulfuromonas,were detected in the anodic biofilm by high-throughput sequencing analysis,and Comamonas(Proteobacteria),which is widely found in MFCs,was also detected in the anodic biofilm.These results confirmed the important role of plants in IVCW-MFCs.     

过硫酸钠缓释材料的释放性能及其对2, 4-二硝基甲苯的降解效果

针对原位化学氧化技术修复土壤和地下水时氧化剂因释放过快而导致的利用率低等问题,通过熔化成型法制备过硫酸钠缓释材料,分析石蜡、硅砂和过硫酸钠不同配比对材料成型度和释放性能的影响,研究缓释过程中溶液pH的变化,探讨其在水溶液中的缓释行为及其对2,4-二硝基甲苯（2,4-DNT）的降解效果.结果表明:当固定过硫酸钠质量为6 g、硅砂质量为18 g、蜡砂比（石蜡、硅砂质量之比）为1:4~1:8时,过硫酸钠缓释材料成型度适中,且过硫酸钠的累积缓释量随着时间的延长而逐渐增大,第31天时过硫酸钠累积释放百分比为74.67%~88.40%,可实现过硫酸钠的持续可控释放.当硅砂质量为18 g、蜡砂比为1:1~1:6时,过硫酸钠累积释放百分比随着过硫酸钠质量的增加而增大,且溶液中的pH呈先降低后上升的变化规律.缓释材料缓释前后实物图和显微镜分析结果显示,过硫酸钠缓释材料的释放是一个由外到内、速率由快变慢最终趋于平稳的过程.过硫酸钠质量为12 g、硅砂质量为18 g、蜡砂比为1:4的缓释材料对2,4-DNT具有较好的降解效果,第16次置换浓度为0.2 mg/L的2,4-DNT水溶液时,2,4-DNT的降解率为56.38%.研究显示,改变制备材料的配比可有效实现缓释材料中过硫酸钠的缓慢释放及对污染物的有效降解,可为原位化学氧化修复土壤和地下水提供理论支撑.      

新型防腐涂层对直升机典型结构材料防护性能研究

目的研究新型防腐涂层对直升机典型结构用铝合金及复合材料在热带海洋性气候环境下的防护性能,并与原防护涂层进行对比。方法通过测试涂层腐蚀后的形貌、光泽度、色差、电化学阻抗等,对比新/原涂层对直升机典型结构用铝合金和复合材料的防护性能。结果经过2年腐蚀后,新涂层表面无明显变化,而原涂层表面有轻微腐蚀,光泽度和色差下降较大。电化学阻抗测试表明,暴露前后涂层结构无明显变化,涂层阻抗值呈现持续下降的趋势,但是原涂层阻抗下降更快。结论新涂层对直升机典型铝合金和复合材料有更好的防护性,更加适于海洋性环境的使用。     

包装箱用碳纤维增强复合材料贮存寿命研究

目的研究碳纤维增强复合材料贮存条件下的性能变化趋势和寿命评估。方法对碳纤维增强复合材料开展四个不同温度条件下的热氧老化试验,按试验周期定期取样开展冲击性能测试,对试验数据采用寿命预估方法进行处理,对材料性能进行预估。结果通过数据计算分别得到我国热带海洋、干热沙漠等典型气候条件下的碳纤维增强复合材料贮存寿命分别为17.21~35.89年。结论碳纤维增强复合材料具有较好的贮存性能,在较为严酷的热带海洋气候和给定的失效判据条件下,寿命预计为17.21年。试验和数据处理方法可以较好地预计材料的性能变化趋势和开展寿命评估。     

腾冲县北海湿地自然保护区生态旅游开发初探

充分利用自然保护区的旅游资源优势发展旅游业，但不合理的开发会使生态环境遭到破坏、生物多样性逐渐丧失、湿地水质面临污染等等。在分析腾冲北海湿地自然保护区发展生态旅游的基础上对旅游开发中存在的问题提出对策和建议。     

20世纪80年代以来挠力河流域湿地景观变化过程研究

挠力河流域面积为241.67×104hm₂。其自然条件决定了该流域具有极丰富的湿地生物多样性。从1980年以来,由于经济的快速发展,该流域湿地景观和土地利用发生了显著的变化。自然湿地资源从1982年的53.32×104hm₂变成2000年的17.17×104hm₂,减少了67.8%;而水田面积却增加了38.5倍,同时,旱田面积也大幅度增加。该文利用遥感和GIS技术,对近20年来该流域湿地景观变化过程进行时空定量分析;并结合流域土地利用/土地覆盖类型的动态变化,探讨流域在经济快速发展中土地利用与湿地之间的演化规律及其对湿地的影响机制。     

河南省黄河湿地生态旅游资源的开发与保护研究

河南黄河湿地旅游资源丰富,有各具特色的湿地景观、复杂多样的生物景观、丰富的地文景观、悠久的历史人文景观和工程园林景观等多种景观类型;但目前存在着开发利用程度较低,市场营销不够、景点开发质量不高,旅游设备简陋、基础设施落后,景点少、点热面冷,人才缺乏、经营管理水平低等众多问题;最后从旅游功能分区、旅游开发、旅游管理、旅游线路设计、旅游环境监测、区域旅游联合、加大宣传力度等方面提出了河南黄河湿地生态旅游资源开发的对策.