民航维修单位质量控制员胜任力模型研究

民航维修单位质量控制员的胜任力是维修单位质量控制员实施维修质量控制工作的关键因素,也是判定维修质量控制员工作绩效优异与否的重要指标.采取理论与实践相结合的研究方法,采取行为事件访谈法对维修质量控制员进行访谈,收集其胜任力信息,依据实证调研的结果及相关文献研究成果,建立了包含4个一级胜任力指标和17个二级胜任力指标的维修单位质量控制员胜任力模型.其中得到9项维修单位质量控制员核心胜任力模型,运用超级决策软件(SD)对建立的模型准确性进行验证.     

Antimony speciation and contamination of waters in the Xikuangshan antimony mining and smelting area,China

Water samples from Xikuangshan (China), the world largest antimony (Sb) mine with a Sb mining and smelting history of more than 200 years, were analyzed. These water samples ranged from stream water in the vicinity of the mining and smelting area that received seepage from ore residues to the underground mine-pit drainage. The concentrations of total Sb, Sb (III) and Sb (V) of the samples were determined by HPLC-ICP-MS. In addition, water pH and concentrations of major cations and anions were analyzed. All 18 samples demonstrated total Sb concentrations with ppm levels from 0.33 ppm to 11.4 ppm, which is two to three orders of magnitude higher compared to the typical concentration of dissolved Sb in unpolluted rivers (less than 1 ppb). This is probably the first time that such high Sb contents have been documented with complete environmental information. Distribution of total Sb and Sb species was investigated, taking into account the respective local environment (in the mining area or close to the smelter, etc.). Sb (V) was the predominant valence in all 18 samples. Only trace levels of Sb (III) were detected in 4 of the 18 samples. Geochemical speciation modeling showed the dominant species was Sb(OH)₆⁻. It is also probably the first time that such high Sb contents have been documented in the natural environment with Sb speciation distribution information. Several potential oxidation pathways are also discussed that might have facilitated the oxidation of Sb (III) in the natural environment. Signs of intoxication were observed among local mine workers with extensive exposure to different forms of Sb for a long period of time.     

低温等离子体协同分子筛净化甲苯的性能研究

本文开展了介质阻挡放电等离子体协同分子筛材料在常温常压下氧化甲苯的研究.结果表明,该系统对甲苯的去除效率与应用电压、分子筛种类有关.甲苯转化率随峰值电压的提高而提高,最高去除率可以达到48.1％.分子筛单位吸附量与该系统对甲苯转化率有关,吸附量越大的分子筛,甲苯转化率越高.     

鸭子河湿地的生态健康评价与恢复研究

从湿地现状、服务功能和外环境影响3方面构建了城镇区域内湿地生态健康评价指标体系,采用层次分析法（AHP）和模糊综合评价法,对广汉鸭子河湿地这一城镇区域内河滩型湿地生态系统健康状况进行评价。结果表明,在广汉市城市化进程中,该湿地的生态系统受到了一定程度的影响,就总体而言,湿地生态系统结构完整,基本功能依然具备,但栖息地功能有一定的退化,在整体上属于亚健康状态。根据评价结果及退化成因分析,提出了相应的恢复措施,对广汉市城市化进程中鸭子河湿地的保护提供了重要的决策依据,对同类型的湿地保护具有指导意义和借鉴价值。     

有机污染物应急监测的样品前处理技术

样品前处理是有机污染物应急监测中的重要环节。介绍了热分离进样杆、分散液液微萃取、搅拌棒吸附萃取、固相微萃取等适合于有机污染物应急监测的样品前处理技术,并概述了它们在环境分析领域的应用进展。如何将这些前处理技术与自身拥有的应急监测设备有效结合是环境监测技术人员亟待解决的问题。     

Comparison of Morphodynamic Models for the Lower Yellow River1

Xia, Junqiang, Zhengbing Wang, Yanping Wang, and Xin Yu, 2012. Comparison of Morphodynamic Models for the Lower Yellow River. Journal of the American Water Resources Association (JAWRA) 1‐18. DOI: 10.1111/jawr.12002 Abstract: Significant channel adjustments often occur during flood seasons in the Lower Yellow River (LYR), and it is a challenging work to accurately simulate the morphodynamic processes in the LYR using numerical models. A comparison of two morphodynamic models (Delft3D and 2DLLCDM) for the LYR is presented herein to identify critical improvements for these models. The concepts of these models are first compared with each other. The models were then used to simulate the processes of flood routing, sediment transport, and morphological changes occurring in a braided reach of the LYR. The differences were investigated between the simulated results from these models and corresponding field measurements, and the results indicate that: (1) the hydrodynamic processes calculated by both models agree closely with the measurements if an appropriate Manning’s roughness coefficient is used; (2) the concentrations of suspended load at the downstream boundary calculated by the models agree reasonably with the observed data; and (3) the predicted cross‐sectional profiles obtained from these models do not correspond well with the measurements. Based on these findings, the weak aspects of the models are clarified, and three critical improvements are recommended, including: (1) the development of roughness predictor; (2) the refinement of graded sediment transport capacity formulation; and (3) the consideration of bank erosion module. These improvements need to be implemented in the future.     

Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment: A review

• Diversity and detection methods of pathogenic microorganisms in sludge. • Control performance of sludge treatment processes on pathogenic microorganisms. • Risk of pathogen exposure in sludge treatment and land application. The rapid global spread of coronavirus disease 2019 (COVID-19) has promoted concern over human pathogens and their significant threats to public health security. The monitoring and control of human pathogens in public sanitation and health facilities are of great importance. Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants (WWTPs). It is an important sink of different pollutants and pathogens, and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health. However, there is a lack of comprehensive analysis of the diversity, exposure risks, assessment methods and inactivation techniques of pathogenic microorganisms in sludge. Based on this consideration, this review summarizes the control performance of pathogenic microorganisms such as enterovirus, Salmonella spp., and Escherichia coli by different sludge treatment technologies, including composting, anaerobic digestion, aerobic digestion, and microwave irradiation, and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed. Additionally, this study reviews the diversity, detection methods, and exposure risks of pathogenic microorganisms in sludge. This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.     

Distribution of antibiotic resistance genes and their association with bacteria and viruses in decentralized sewage treatment facilities

• Distribution of ARGs in decentralized sewage facilities were investigated. • Bacitracin-ARGs were most predominant ARGs in rural wastewater. • ARGs were identified in bacterial and viral community. • ARGs of rpoB, drfE, gyrA and parC were both correlated with bacteria and phages. • More attention should be paid to the risk of spreading ARG by phages. The distribution of antibiotic resistance genes (ARGs) has been intensively studied in large-scale wastewater treatment plants and livestock sources. However, small-scale decentralized sewage treatment facilities must also be explored due to their possible direct exposure to residents. In this study, six wastewater treatment facilities in developed rural areas in eastern China were investigated to understand their risks of spreading ARGs. Using metagenomics and network analysis tools, ARGs and bacterial and viral communities were identified in the influent (INF) and effluent (EFF) samples. The dominant ARGs belonged to the bacitracin class, which are different from most of municipal wastewater treatment plants (WWTPs). The dominant hosts of ARGs are Acidovorax in bacterial communities and Prymnesiovirus in viral communities. Furthermore, a positive relationship was found between ARGs and phages. The ARGs significantly correlated with phages were all hosted by specific genera of bacteria, indicating that phages had contributed to the ARG’s proliferation in sewage treatment facilities. Paying significant concern on the possible enhanced risks caused by bacteria, viruses and their related ARGs in decentralized sewage treatment facilities is necessary.     

Water resource conservation promotes synergy between economy and environment in China’s northern drylands

•Considering evenness provides a more accurate assessment of sustainable development. •Water resource conservation drives industrial transformation. •Synergy between economic development and environmental protection is achieved. •Regional collaboration over water could promote sustainable development in drylands. Water resource availability is the major limiting factor for sustainable development in drylands. Climate change intensifies the conflicting water demands between people and the environment and highlights the importance of effective water resource management for achieving a balance between economic development and environmental protection. In 2008, Inner Mongolia, typical dryland in northern China, proposed strict regulations on water exploitation and utilization aimed at achieving sustainable development. Our study is the first to investigate the effectiveness and performance of these long-standing water conservation regulations. Our analyses found that the regulations drove industrial transformation, evidenced by the decreasing proportion of environmentally harmful industries such as coal and steel, and the increasing proportion of tertiary industries (especially tourism). Following industrial transformation, economic development decoupled from industrial water consumption and subsequently led to reduced negative environmental impacts. Based on these results, adaptive strategies were developed for 12 cities by revealing and integrating their development pathways and relative status in achieving sustainable development. Integration and cooperation between cities were proposed, e.g., a water trade agreement between eastern Inner Mongolia (an economically underdeveloped region with relatively abundant water resources) and central Inner Mongolia (an economically developed region with high water stress). Such an agreement may enable the holistic achievement of sustainable development across regions. By integrating the findings of our research, our study presents a reproducible framework for water-management-based sustainable development strategies in drylands.