维修时间不确定性下配电网灾后维修队安排的鲁棒恢复研究*

为最小化灾后配电网损失量,准确描述完整维修队工作时间（分为路途时间与具体维修时间）,依据台风路径对维修队所需路途时间进行分类,并利用期望概率描述具体维修时间的不确定性。建立2阶段分布式鲁棒优化模型,采用CCG算法分析国内某地区配电网算例发现:考虑维修时间不确定性可以有效减少配电网损失量。     

农村变电站生活污水处理现状与探讨

我国大部分变电站位于农村地区,因无接入城市污水管网条件,农村变电站生活污水需就地处理后达标排放。变电站生活污水存在水量少、时变化系数大等特点,现有处理工艺不能正常运行或无法达标排放。本文借鉴农村生活污水处理技术,提出了生物组合法处理对策,可为变电站生活污水处理提供参考。     

某型飞机4号油箱结构损伤分析及修复评估

目的 某型双座机使用中发现4号油箱存在不同程度结构损伤,分析其损伤原因和制定修理方案。方法 对4号油箱结构状态进行深入检查评估后,从结构损伤过程、载荷情况、设计制造和外场使用等方面综合分析损伤原因。对实际损伤结构进行强度计算和评估,制定结构损伤补强修理方案,并提出修理改进建议。结果 通过分析得出,损伤原因主要是4号油箱局部存在设计制造缺陷,且飞机在作大过载飞行时,4号油箱可能处于满油或大量余油的高负载状态。根据损伤原因制定的修理方案合理可行,通过了静强度校核和评估。结论 基于该损伤结构提出的修理方案通过实际修理验证,能够满足油箱结构强度设计要求,提出的改进建议能够改善飞机疲劳品质。     

An Assessment of Stakeholder Perceptions and Management of Noxious Alien Plants in Spain

Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts, there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species. Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management. In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of species are found in at least one protected area. According to respondents, the most frequently managed species are the most widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are poor and the few data indicate that the total actual expenditure amounted to 50,492,437 € in the last decade. The majority of respondents stated that management measures are insufficient to control alien plants due to limited economic resources, lack of public awareness and support, and an absence of coordination among different public administrations. Managers also expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants rather than with specific cost-efficient strategies to manage alien species.     

Monitoring Environmental Impact in the Upper Sonoran Lifestyle: A New Tool for Rapid Ecological Assessment

Characterized by expensive housing, high socioeconomic status, and topographic relief, Upper Sonoran Lifestyle communities are found primarily along the Wildland-Urban Interface (WUI) in the Phoenix, Arizona metro area. Communities like these sprawl into the wildlands in the United States Southwest, creating a distinct urban fringe. This article, through locational comparison, introduces and evaluates a new field assessment tool for monitoring anthropogenic impact on soil–vegetation interactions along the well-maintained multi-use recreational trails in Upper Sonoran Lifestyle region. Comparing data from randomly selected transects along other multi-use trails with data from a control site revealed three key indicators of anthropogenic disturbances on soil–vegetation interactions: soil disturbance, vegetation disturbance, and vegetation density. Soil and vegetation disturbance displayed an average distance decay exponent factor of −0.60, while vegetation density displayed a reverse decay average of 0.60. Other important indicators of disturbance included vegetation type, biological soil crusts, and soil bulk density. The predictive ability of this new field tool enhances its applicability, offering a powerful rapid ecological assessment method for monitoring long-term anthropogenic impact in the Upper Sonoran Lifestyle, and other sprawling cities along the WUI.     

Anaerobic ammonium oxidation by Nitrosomonas spp. and anammox bacteria in a sequencing batch reactor

A sequencing batch reactor (SBR) was inoculated with mixed nitrifying bacteria from an anoxic tank at the conventional activated sludge wastewater treatment plant in Nongkhaem, Bangkok, Thailand. This enriched nitrifying culture was maintained under anaerobic conditions using ammonium (NH(4)(+)) as an electron donor and nitrite (NO(2)(-)) as an electron acceptor. Autotrophic ammonium oxidizing bacteria survived under these conditions. The enrichment period for anammox culture was over 100 days. Both ammonium and nitrite conversion rates were proportional to the biomass of ammonium oxidizing bacteria; rates were 0.08 g N/gV SS/d and 0.05 g N/g VSS/d for ammonium and nitrite, respectively, in a culture maintained for 3 months at 42 mg N/L ammonium. The nitrogen transformation rate at a ratio of NH(4)(+)-N to NO(2)(-)-N of 1:1.38 was faster, and effluent nitrogen levels were lower, than at ratios of 1:0.671, 1:2.18, and 1:3.05. Fluorescent in situ hybridization (FISH) was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis). The ammonium oxidizing culture maintained at 42 mg N/L ammonium was enriched for Nitrosomonas spp. (30%) over Candidati B. anammoxidans and K. stuttgartiensis (2.1%) while the culture maintained at 210 mg N/L ammonium was dominated by Candidati B. anammoxidans and K. stuttgartiensis (85.6%). The specific nitrogen removal rate of anammox bacteria (0.6 g N/g anammox VSS/d) was significantly higher than that of ammonium oxidizing bacteria (0.4 g N/g Nitrosomonas VSS/d). Anammox bacteria removed up to 979 mg N/L/d of total nitrogen (ammonium:nitrite concentrations, 397:582 mg N/L). These results suggest significant promise of this approach for application to wastewater with high nitrogen but low carbon content, such as that found in Bangkok.     

航空装备腐蚀维护维修新材料研究进展

针对海洋环境下服役航空装备极易发生腐蚀的问题,介绍了清洗剂、去腐蚀产物膏、缓蚀剂等腐蚀维护维修新材料的研究进展,包括功能、分类、技术指标等。清洗剂用于航空装备的日常清洗、维护以及维修,去除油污等污染物,防止腐蚀;去腐蚀产物膏用于外场航空装备腐蚀产物的原位去除;缓蚀剂用于在不能对现役航空装备的防护体系进行大幅改动的情况下,针对海洋环境下航空装备的防腐蚀需求,对航空装备进行附加防护或临时防护。综合运用腐蚀维护维修新材料进行航空装备的腐蚀防护,可以预防和减少腐蚀的发生,及时对腐蚀部位进行修复,保障航空装备的使用性能和战斗力。     

Toxic effects of orimulsion on rainbow trout <Emphasis Type="Italic">oncorhynchus mykiss</Emphasis>

GOAL, SCOPE AND BACKGROUND: Orimulsion (stable emulsion of natural bitumen and water) is a new imported industrial fuel in Lithuania. No data on its toxicity to fish is freely available. The aim of this study was to investigate sensitivity of rainbow trout (Oncorhynchus mykiss) to acute and chronic toxicity of orimulsion and to estimate the Maximum Acceptable Toxicant Concentration (MATC) of orimulsion to fish. METHODS: Laboratory tests were conducted on rainbow trout in all stages of development (embryos, larvae, adults). Acute toxicity (96-hour duration) and long-term (28 or 60-day duration) tests evaluating the wide range spectrum of biological indices were performed under semi-static conditions. RESULTS AND DISCUSSION: Median lethal concentration (96-hour LC50) values and their 95% confidence intervals derived from the tests were: 0.1 (0.09-0.12) to embryos, 0.06 (0.05-0.07) to larvae and 2.22 (2.02-2.43) to adult fish, and 28-day LC50 to adult fish was found to be 0.26 (0.21-0.32) g/l of total orimulsion respectively. The acute toxicity of orimulsion to rainbow trout can be characterised by a narrow zone of toxic effect and a sharp boundary between lethal and sublethal concentrations. The lowest 'safe' or 'no-effect' concentration values of total orimulsion obtained in long-term tests were equal to 0.09 g/l to adult fish, 0.019 g/l to embryos, and 0.0017 g/l to larvae. Proposed value of 'application factor' for orimulsion was found to be equal to 0.03. Since orimulsion has the property to disperse in all water volume, its toxic effect on fish can be characterised by the combined effects of dispersion and water-soluble-fraction. CONCLUSIONS: Maximum Acceptable Toxicant Concentration (MATC) of 0.0017 g/l of total orimulsion to fish was derived from long-term tests based on the most sensitive parameter of rainbow trout larvae (relative mass increase at the end of the test). According to substance toxicity classification accepted for Lithuanian inland waters, orimulsion can be referred to substances of 'moderate' toxicity to fish. RECOMMENDATIONS AND OUTLOOK: For prediction and evaluation of toxic impact of orimulsion accident spills on fish, some recommendations should be given. Since orimulsion has the property to disperse in all water volume during short time periods, the amounts of both spilled orimulsion and polluted water should be ascertained. Once both parameters are known, the real concentration of orimulsion in the water body must be determined. Then this concentration must be compared with 'safe' concentration to fish. By use of 'application factor' 0.03, approximate MATC for other fish species can be estimated when only acute toxicity data (96-hour LC50 value) is available.     

超细粉煤灰-氟石膏在道路修补工程中的综合利用研究

针对我国现有水泥混凝土路面的破坏问题,研究开发了以工业废料——超细粉煤灰和氟石膏为主要组分的水泥基道路修补材料,利用氟石膏与超细粉煤灰在水泥水化过程中的相互激发作用,通过试验优选出超细粉煤灰-氟石膏高性能道路修补材料,并应用于道路修补混凝土的配制,同时测试了其力学性能及部分长期性能,试验表明其性能优良,在此基础上对其水化硬化机理作了初步的探讨.     

重金属-多氯联苯复合污染土壤同步洗脱

电子垃圾拆解区土壤具有重金属与有机物复合污染的特性,尤其以Cu、Pb、Cd和多氯联苯(PCBs)的复合污染较为突出。为了同步脱除土壤中重金属与PCBs,选用增溶物质:Tween 80、TX-100、SDBS、β-环糊精与螯合剂柠檬酸依次组合进行复合污染土壤淋洗实验,应用批量平衡震荡法研究它们对重金属(Cu、Pb、Cd)与PCBs(Aroclor 1254)的洗脱效果。通过比较洗脱效果、环境友好性等方面,得出非离子表面活性剂Tween 80与天然螯合剂柠檬酸2种淋洗剂复合最佳;进一步研究两者的淋洗先后顺序、浓度配比、洗脱时间及淋洗剂pH对污染土壤洗脱效果的影响,结果表明,在Tween 80和柠檬酸均为10 g/L、pH=6、淋洗时间12 h时淋洗效果达到最佳,对Cu、Pb、Cd及PCBs的洗脱率分别达到98.77%、55.92%、66.82%和58.01%。因此,利用Tween80和柠檬酸组合可同时有效去除土壤重金属和PCBs,是复合污染土壤淋洗修复的有效淋洗剂。