水下振动台关键技术的研究

本文从理论和实践两方面分析研究了水下振动台的若干关键技术问题,主要包括运动部件的设计、冷却系统的设计、密封系统的设计、压力平衡系统的设计等。解决了水下振动台设计所存在的难题。     

Lessons from seabird conservation in Alaskan longline fisheries

Although bycatch of seabirds and other long-lived species is a critical conservation issue in world fisheries, case studies documenting significant reductions in the mortality of these low-productivity species in a fishery are rare. We studied progress toward seabird conservation in the Alaskan longline fisheries, one of the largest and most diverse demersal fisheries. We generated annual seabird bycatch rates in 4 target fisheries and all fisheries combined from 23 years of fisheries observer data. We used 0-inflated negative binomial models to evaluate variables influencing seabird bycatch per unit effort (BPUE) in 2 target fisheries. Following adoption of streamer lines, at first voluntarily and then mandatorily, seabird BPUE was reduced by 77–90%, preventing mortality of thousands of birds per year. Despite this, BPUE increased significantly in 2 of 4 target fisheries since streamer lines were adopted. Although night setting yielded significant reductions (74–97%) in seabird BPUE and significant increases (7–11%) in fish catch per unit effort over daytime setting, nighttime setting increased the BPUE of Northern Fulmar (Fulmarus glacialis) by 40% and nontarget fish species by 5–17%. Thus, best practices to prevent seabird mortalities in longline fisheries varied by species assemblage and fishery. Our results inform global efforts toward fisheries bycatch reduction by illustrating that successful conservation requires fishery-specific solutions, strong industry support, constant vigilance in analysis and reporting observer data, and ongoing outreach to fleets, especially to vessels with anomalously high BPUE.     

噪声自动监测系统相关问题研究

总结了环境噪声人工监测方法的缺陷,然后从城市环境噪声数据的性质、噪声自动监测系统的物理构成、噪声监测子站的布设、噪声自动监测有效时间的确定这几个方面对噪声自动监测系统进行了相关问题的论述.     

China's endemic vertebrates sheltering under the protective umbrella of the giant panda

The giant panda attracts disproportionate conservation resources. How well does this emphasis protect other endemic species? Detailed data on geographical ranges are not available for plants or invertebrates, so we restrict our analyses to 3 vertebrate taxa: birds, mammals, and amphibians. There are gaps in their protection, and we recommend practical actions to fill them. We identified patterns of species richness, then identified which species are endemic to China, and then which, like the panda, live in forests. After refining each species' range by its known elevational range and remaining forest habitats as determined from remote sensing, we identified the top 5% richest areas as the centers of endemism. Southern mountains, especially the eastern Hengduan Mountains, were centers for all 3 taxa. Over 96% of the panda habitat overlapped the endemic centers. Thus, investing in almost any panda habitat will benefit many other endemics. Existing panda national nature reserves cover all but one of the endemic species that overlap with the panda's distribution. Of particular interest are 14 mammal, 20 bird, and 82 amphibian species that are inadequately protected. Most of these species the International Union for Conservation of Nature currently deems threatened. But 7 mammal, 3 bird, and 20 amphibian species are currently nonthreatened, yet their geographical ranges are <20,000 km² after accounting for elevational restriction and remaining habitats. These species concentrate mainly in Sichuan, Yunnan, Nan Mountains, and Hainan. There is a high concentration in the east Daxiang and Xiaoxiang Mountains of Sichuan, where pandas are absent and where there are no national nature reserves. The others concentrate in Yunnan, Nan Mountains, and Hainan. Here, 10 prefectures might establish new protected areas or upgrade local nature reserves to national status.     

磁赤铁矿/多羧基有机酸体系中五氯酚的异相光化学降解

自然界广泛存在的铁氧化物与多羧基有机酸在光照条件下能够由内源自身生成活性物过氧化氢,构成异相类Fenton体系降解污染物.在实验室构建了由磁赤铁矿和多羧基有机酸组成的光化学体系,研究了五氯酚在此体系中的降解和脱氯.结果表明,五氯酚在此异相光化学体系中的降解效率受波长范围、有机酸种类和氧气的显著影响.在UV-A波长范围,五氯酚具有较高的光降解效率.草酸能够显著促进五氯酚在磁赤铁矿中的异相光降解,但柠檬酸不具有此作用.氧气是体系中生成各种含氧活性物的必要条件.五氯酚在此体系中的降解遵循一级反应动力学.最佳实验条件下,五氯酚1 h的降解率可达80%以上,脱氯率可达35%以上.对体系主要活性物过氧化氧的定量研究较好的解释了体系在各种条件下的活性差异.     

Photo-Induced OH reactions of naphthalene and its oxidation products on SiO2

The photo-induced degradation of naphthalene, 1,4-naphthoquinone, 1-naphthol and 1-NO₂ naphthalene, adsorbed on silica gel, and with the addition of nitrogenous air pollutants e.g. NO₂ (as KNO₂) was investigated. Results indicate that compounds adsorbed onto a solid carrier are degraded when irradiated with UV light (λ > 290 nm) in the presence of nitrites. The key species initiating the naphthalene degradation is the OH-radical which is generated through the photolysis of NO₂. Reaction products identified were 2-formyl-cinnamaldehyde, 1,4-naphthoquinone, nitronaphthol, o-phthaldialdehyde, phthalide and nitronaphthalene. A mass balance between 40–50% was achieved. Under the same irradiation conditions, 1-NO₂ naphthalene is mainly degraded by direct photolysis while degradation of 1-naphthol and 1,4-naphthoquinone proceeds via the reaction with OH-radicals. Identified products were hydroxy-nitro-nitroso- and quinones compounds.     

非均相Fenton反应技术研究进展

Fenton氧化法是较为常用的一种高级氧化技术。非均相Fenton反应适用的pH值范围较宽，能避免均相Fenton反应产生铁泥沉淀的缺点，成为近年来Fenton反应的重要研究方向。本文对非均相Fenton氧化技术的研究现状及发展动态进行较为详尽的评述。     

多相芬顿-活性炭工艺强化饮用水消毒效果

为了考察多相芬顿-活性炭工艺对饮用水中微生物消毒效果的影响,采用中试对活性炭工艺与多相芬顿-活性炭工艺进行了对比研究。该中试对水中溶解性有机物(DOC)、总细菌16S rRNA、三磷酸腺苷(ATP)及胞外多聚物(EPS)含量与性质进行了分析。结果表明,多相芬顿-活性炭工艺能够将出水DOC浓度控制在(0.90±0.11) mg·L-1,并使得EPS减少83.2%,降低EPS中蛋白质/多糖(PN/PS)比值,其凝聚性明显下降,在相同氯浓度投加情况下水中微生物16S rRNA基因拷贝数去除量提高了3.5个对数量级,ATP浓度降低为0.016 nmol·L-1。因此,多相芬顿-活性炭工艺明显提高了对有机物的去除能力,显著降低EPS中蛋白质的含量,使得微生物凝聚性变差,微生物更加容易被消毒剂灭活,该工艺强化了饮用水消毒效果。     

催化湿式氧化中多相非贵金属催化剂的研究进展

催化湿式氧化（CWAO）法是一种利用溶解氧去除废水中高毒性、难降解污染物的新型水处理技术。在催化湿式氧化中应用的催化剂有贵金属催化剂和非贵金属催化剂两种。在零附加值的废水处理过程中,使用非贵金属催化剂替代贵金属催化剂,在经济上更具有优势。对近年来用于催化湿式氧化废水处理过程中的多相非贵金属催化剂进行了综述。     

Renewable Resources and Economic Sustainability: A Dynamic Analysis with Heterogeneous Time Preferences

In recent years there has been increasing interest in the study of economic sustainability and its relationship with natural resources. This paper attempts to shed some light on the issue by taking into account the individual variations in time preferences for consumption and resource amenity. We characterize the long-run steady state, analyze its asymptotic stability, and explore the transational dynamics from any initial state. The welfare implications of the optimal path are also discussed.