生态城市建设对策研究

以创建生态城市为突破口,提出了一系列切实可行的具体对策和措施.即,政府努力为生态城市建设创造良好的外部环境,企业及早将生态环境保护纳入决策层议事日程,市民积极参与生态城市的创建活动,等等.     

去眼柄对凡纳滨对虾(Litopenaeus vannamei)稚虾耗氧率昼夜节律的影响

采用流水装置测定去眼柄对凡纳滨对虾稚虾 (Litopenaeusvannamei)耗氧率昼夜节律的影响。实验水温为 2 5℃± 0 .5℃ ,实验虾规格为 (2 .2 6 6± 0 .0 13) g。实验结果表明 :1、去眼柄对凡纳滨对虾稚虾耗氧率的高峰和低峰发生的时间产生影响。正常组对虾耗氧率的高峰多发生在夜间 ,低峰多发生在日间 ;去眼柄后 ,对虾耗氧率的高峰和低峰则大都发生在日间 ;2、去眼柄对虾的日间和夜间的平均耗氧率差异不显著 (P >0 .0 5 ) ,而正常对虾夜间平均耗氧率显著高于日间 34.79% (P <0 .0 5 ) ;3、去眼柄对对虾的平均耗氧率未产生显著的影响(P >0 .0 5 )。     

Persistently declining oxygen levels in the interior waters of the eastern subarctic Pacific

Fifty years of measurements at Ocean Station Papa (OSP, 50°N, 145°W) show trends in the interior waters of the subarctic Pacific that are both impacted by short term (few years to bi-decadal) atmospheric or ocean circulation oscillations and by persistent climate trends. Between 1956 and 2006, waters below the ocean mixed layer to a depth of at least 1000 m have been warming and losing oxygen. On density surfaces found in the depth range 100-400 m (σ_θ = 26.3-27.0), the ocean is warming at 0.005-0.012 °C y⁻¹, whereas oxygen is declining at 0.39-0.70 μmol kg⁻¹ y⁻¹ or at an integrated rate of 123 mmol m⁻² y⁻¹ (decrease of 22% over 50 years). During this time, the hypoxic boundary (defined as 60 μmol O₂ kg⁻¹) has shoaled from ∼400 to 300 m. In the Alaska Gyre, the 26.2 isopycnal occasionally ventilates, whereas at OSP 26.0σ_θ has not been seen at the ocean surface since 1971 as the upper ocean continues to stratify. To interpret the 50 year record at OSP, the isopycnal transport of oxygenated waters within the interior of the subarctic Pacific is assessed by using a slightly modified “NO” parameter [Broecker, W., 1974. “NO” a conservative water-mass tracer. Earth and Planetary Science Letters 23, 100-107]. The highest nitrate-oxygen signature in interior waters of the North Pacific is found in the Bering Sea Gyre, Western Subarctic Gyre and East Kamchatka Current region as a consequence of winter mixing to the ∼26.6 isopycnal. By mixing with low NO waters found in the subtropics and Okhotsk Sea, this signature is diluted as waters flow eastward across the Pacific. Evidence of low NO waters flowing north from California is seen along the coasts of British Columbia and SE Alaska. Oxygen in the subsurface waters of the Alaskan Gyre was supplied ∼60% by subarctic and 40% by subtropical waters during WOCE surveys, whereas such estimates are shown to periodically vary by 20% at OSP. Other features discernable in the OSP data include periods of increased ventilation of deeper isopycnals on an ∼18 year cycle and strong, short term (few month) variability caused by passing mesoscale eddies. The potential impacts of declining oxygen on coastal ecosystems are discussed.     

不同光周期条件下罗氏沼虾幼体摄食量及发育的研究

于１９９１年３－５月，在光周期Ｌ：Ｄ为４：２０，８：１６，１２：１２和２４：０四种条件下以卤虫无节幼体作饵料，在三角烧瓶中对实验室孵化的罗氏沼虾通状休进行单只培养，测定各期状幼体的日摄食量和总摄食量，并观察幼体的发育情况，结果表明，随着光照时间的延长，特别是连续照明的条件与最短的光照时间条件相比，幼体的日摄食量增加４０％－１５０％，育成的Ｐ１体重增大４０％，且育成Ｐ１的时间缩短９ｄ，而幼体完成整个     

温度及体重对娩鱼幼鱼耗氧率和排氨率的影响

利用实验生态学方法研究了不同温度及体重对鲵鱼Miichthys miiuy幼鱼的呼吸、排泄的影响。结果表明，不同温度和体重对鲵鱼幼鱼耗氧率、排氨率有显著影响（P〈0．05），耗氧率随温度的升高而增大并呈指数相关，相关方程为：Ro=0．168e^0.035 5T （R^2=0．96071）；鲵鱼幼鱼耗氧率和排氨率随体重的增加而下降并呈幂函数相关，相关方程分别为：Ro=0．613 9W^-0.403 1（R^2=0．994 3），RN=25．055W^-0.287 7（R^2=0．9978）。O／N比也随着温度升高和体重增加而升高，不同温度下鲵鱼幼鱼平均O／N比值为21．963，呼吸Q10平均是1．415，排泄Q10平均是1．419；不同规格鲵鱼幼鱼平均O／N比值为21．855。10—30℃鲵鱼幼鱼主要以蛋白质为能源，脂肪和碳水化合物其次。随着温度的升高，鲵鱼幼鱼的蛋白质代谢比率降低，而脂肪和碳水化合物的代谢比率增大。     

Beyond affordable shelters: Subsidized housing and surrounding environments for pedestrian safety

Beyond the provision of affordable housing itself, planners and policymakers have raised concerns as to whether subsidized housing developments provide “suitable living environments” for the nation's poor. Despite numerous concerns regarding unfavorable living environments and the neighborhood context of subsidized housing, we have limited understanding as to whether built environments around subsidized housing ensure pedestrian safety. This study addressed this gap by examining how built environments around Low Income Housing Tax Credit (LIHTC) sites affect pedestrian-vehicle crashes in Austin, Texas. We employed the two-level negative binomial regression to clarify the impacts of street segment-level and neighborhood-level built environments on pedestrian crashes around LIHTC complexes. We found that higher speed roads, traffic-generating land uses, higher transit stop densities, and higher four-or-more-leg intersection densities may hinder pedestrian safety. Conversely, local roads as well as single-family residential parcels and connected sidewalks along street segments may enhance pedestrian safety around LIHTC complexes. Our results may inform planners and policymakers on how to enhance pedestrian safety for subsidized housing by modifying surrounding environments and how to provide better site selection considerations for subsidized housing to ensure pedestrian safety.     

Not only tourism: unravelling suburbanization,second-home expansion and “rural” sprawl in Catalonia,Spain

This study illustrates multifaceted urbanization patterns and processes in a coastal region of Catalonia (northeastern Spain) as a paradigmatic example of the socio-economic transformations typically observed in the northern Mediterranean basin since World War II. By focusing on the expanding tourism industry, second-home expansion, infrastructural development and sprawl around traditional rural centres, the paper assesses the effects of long-term economic, demographic, social and cultural transformations on rural landscapes in Alt Empordà, the so-called “Catalan Tuscany”. The stratification of distinct urbanization waves and the underlying socio-economic processes observed in Alt Empordà reflect population dynamics and settlement morphologies typical of rural districts moving rapidly towards a suburban spatial organization. Recent urban dynamics in Mediterranean rural systems deserve further investigation in order to shed light on latent suburbanization processes involving marginal European regions.     

住宿业节能减碳研究进展及启示

在全球致力于积极应对气候变化的时代背景下,旅游业已成为许多国家和地区实施经济低碳转型的优势产业、先导产业和窗口产业,而住宿业则在此中发挥着重要的作用。本文从必要性、障碍因素和对策措施3个方面梳理了住宿业节能减碳的相关研究成果,并对住宿业能耗和碳排放核算的方法进行了归纳总结,在此基础上探讨了已有研究存在的不足之处,并指出进一步研究的方向。综述发现：国外相关研究已有一定基础,但住宿业能耗与碳排放的核算方法体系还有待深入探讨;国内对于住宿业节能减碳的必要性、能耗与碳排放核算等也有一些尝试研究,但总体仍相对滞后,缺乏研究的系统性和深度。后续研究应在借鉴国际相关研究经验的基础上,紧扣中国住宿业实情,通过加强对非星级住宿企业的分析以全面把握研究对象,确立能耗和碳排放核算框架、完善核算方法体系,通过分阶段、分类型、分区域核算与分析进一步拓展住宿业节能减碳的研究内容。