城市生命线系统的非工程防灾减灾

城市生命线系统的防灾减灾分为工程措施和非工程措施，研究和实践通常都偏重于前者。从工程措施作用的有限性、新型生命线系统灾害的特点及灾害损失类型的变化论证了加强非工程措施的必要性，进而说明了如何从管理体制、技术立法、灾害保险及灾害教育等方面构建城市生命线系统的非工程防灾减灾体系。     

Morphology, growth and carbohydrate storage of the plant Typha angustifolia at different water depths

Morphological characteristics, growth and carbohydrate storage dynamics of Typha angustifolia in relation to water depth were investigated. The study was based on observations carried out in two stands, namely Akigase and Teganuma, for two growth seasons. The latter stand was about two times deeper than the former. Teganuma stands exhibited significantly higher number of thick shoots compared to those of Akigase. Conversely, the difference in shoot heights between the two stands was insignificant. The same was true for rhizome lengths. Rhizome diameters were significantly bigger for Teganuma compared to Akigase. Furthermore, both the above and belowground biomass were significantly higher for Teganuma compared to those of Akigase. Teganuma stands allocated 55% of the total biomass to the aboveground parts, while Akigase stands allocated 60%. Similarly, Teganuma exhibited significantly higher stocks of total non-structural carbohydrates (TNC) compared to Akigase. The higher number of thick shoots and the relatively bigger rhizome diameters in Teganuma are seemingly important tolerance strategies in maintaining effective aeration into the rhizosphere, by reducing internal resistance. In addition, the higher TNC stocks and biomass help not only to enhance survival under anoxia for longer durations, they also provide firm substrate anchorage in the deeper Teganuma stands.     

GOALS IN WASTEWATER TREATMENT1

Within a few years all domestic wastewater effluents in the United States will be subjected to a minimum of a properly operated primary and secondary treatment process. This implies a very high degree of removal of the more readily biologically degradable material as measured by the BOD test. This practice will to a large degree negate the value of the BOD test as a pollution parameter. Organic carbon appears to be a more suitable means for determining the strength of a wastewater or for controlling the operation of physical and chemical treatment processes. Studies were conducted to determine the effect of time of passage on the ratio of organic carbon to BOD, COD and carbohydrate. The ratio was found to vary with both time and the state of the sample. The carbon content was reduced to a lesser degree than the other parameters. Organic carbon content appears to correlate better with COD than with BOD. The efficiency of a chemical precipitation process can be determined on the basis of organic carbon removal.     

重大危险源区域事故应急非结构化模糊决策应用研究

针对目前我国应对重大危险源突发事故的管理和决策主要依赖于相关领导或专家掌握的知识及经验的现状,将非结构化模糊决策方法(Non-structural Fuzzy Decision Method,NSFDM)和事故后果模拟方法相结合,以区域范围内受重大危险源潜在事故影响的企业为决策对象,以减小事故影响范围,降低事故严重程度为目标,建立起重大危险源区域事故应急决策的多准则决策方法,以期帮助安监职能部门优化配置应急救援资源,提高应急响应绩效,减少国家和人民的经济和财产损失。以广州市某公司丙烷储罐区为实例,在对其进行沸腾液体扩展蒸气爆炸(Boiling Liquid Expanding Va-por Explosion,BLEVE)事故模拟的基础上,运用非结构化模糊决策方法,对该丙烷储罐区BLEVE事故的处理,提供了应急决策支持。     

Potential environmental factors influencing mucilage formation in the northern Adriatic Sea

In the northern Adriatic Sea, Mediterranean Sea, the mucilage phenomenon is usually related to the aggregation of extracellular organic matter of phytoplanktonic origin under special seasonal and trophic conditions. Environmental factors, such as temperature, salinity, nitrogen, phosphorus and N/P ratio as well as polysaccharide and monosaccharide levels in the presence and absence of mucilage were investigated in the northern Adriatic Sea. Variations in temperature and salinity during spring in years characterised by mucilage events have been recognised having an important role in preparing a favourable physical environment where mucilage formation could take place. Since the DIN/TP ratio increased markedly during the spring months (March–April) in 2002, 2003 and 2004, preceding the early summer mucilage outbreaks, it appeared that the DIN/TP ratio may be a more robust predictor than the DIN/DIP ratio, which, although more commonly used, exhibited a discontinuous trend. The contents of total carbohydrates, including monosaccharides and polysaccharides, in seawater also varied according to the presence or absence of mucilage, with an increase of polysaccharide levels during the late spring or early summer in the period of the mucilage appearance. The role of carbohydrates in the macro-aggregate formation was also investigated.     

臭氧污染、氮沉降和干旱胁迫交互作用对杨树叶和细根非结构性碳水化合物的影响

快速城市化和工业化进程,导致植物生长季常暴露于高浓度地表臭氧（O₃）、干旱和氮（N）沉降的环境中.为探究植物非结构性碳水化合物（NSC）及其组分（可溶性糖和淀粉）对多重环境因子胁迫的响应格局,本实验设置2个O₃处理（对照,以过滤空气计;增加O₃,未过滤空气+40 nmol·mol^-1 O₃）、2个水分处理（充分灌溉;干旱,60%灌溉）和2个N添加处理［不加氮;加氮,50 kg·（hm²·a）^-1尿素］,研究三因子交互作用对杨树叶片和细根NSC及其组分的影响.结果表明,O₃胁迫显著增加杨树叶片可溶性糖和细根淀粉含量,降低叶片淀粉和总NSC含量.干旱胁迫显著降低叶片淀粉和总NSC含量,增加细根可溶性糖和总NSC含量.氮添加对叶和细根NSC及其组分无显著影响.叶片和细根NSC及其组分与光合速率、生物量存在显著正相关关系.随着胁迫因子数量的增加,叶片NSC呈现下降趋势,而细根NSC呈现上升趋势.本研究发现环境胁迫可促使植物叶片中的淀粉转化为可溶性糖,并将叶片中的NSC转移到根部储藏,这可能是植物抵御胁迫环境的一种应对策略.     

Chemical Composition of the Leaves of Plants with Different Ecological Strategies from the Boreal Zone

The content of main chemical components (total nitrogen and carbon, soluble and polymeric sugars, organic acids, and mineral substances) were studied in the leaves of 73 boreal plant species with different types of Grime–Ramenskii strategies. The type of ecological strategy was demonstrated to be related to the chemical composition of the leaf, with the substances studied falling into two groups. The concentrations of the substances belonging to the first group (nitrogen, organic acids, and mineral substances) were minimum in stress-tolerant and maximum in ruderal species. With respect to the type of strategy, these concentrations increased in the following series: S C R. Conversely, the concentrations of the substances of the second group (carbon and soluble sugars) decreased in this series. The nitrogen concentration and the carbon-to-nitrogen concentration ratio in leaves may be used for identifying the types of strategies.     

非结构因素对石灰石水浴脱硫的影响

使用烟气净化测试系统 ,通过模拟烟气冷态正交实验 ,研究非结构因素对石灰石水浴脱硫的影响。经实验结果方差分析可知 ,在影响脱硫效率的诸因素中 ,烟气喷管在水中的插入深度为最显著因子 ,烟气中的二氧化硫浓度为次显著因子 ,钙硫比及喷管风速则为较显著因子。     

Effects of warming on leaf non-structural carbohydrates and carbon and nitrogen isotopes of Cunninghamia lanceolata saplings during different seasons北大核心CSCD

To reveal the response of non-structural carbohydrates (NSC) and carbon and nitrogen isotopes in plant leaves to global warming, we conducted soil warming experiments in the Fujian Sanming Forest Ecosystem and Global Change National Observation and Research Station of China. We designed two treatments: control (CT) and warming (W; cable heating, +4 ℃). Heating cables were installed 20 cm from each other at a depth of 10 cm and were heated in March 2016. In this study, Cunninghamia lanceolata saplings were used to analyze seasonal changes in leaf non-structural carbohydrates, and carbon and nitrogen isotopes. The results showed that (1) warming significantly reduced the soluble sugar, starch, and NSC content of leaves in spring but without any significant difference during other seasons. (2) Leaf δ13C increased significantly in spring and winter after warming, whereas leaf δ15N did not change significantly. (3) No significant correlation was observed between leaf δ13C, δ15N, or NSC content during the warming treatment, but a negative correlation was observed between leaf δ15N, δ13C, and sugar to starch ratio. A positive correlation between leaf δ15N and starch content was identified. In summary, when temperature increases, plants adjust the NSC content during different seasons for osmotic regulation, change the characteristics of the nutrient cycle, and alter the plant water and nutrient use strategies to maintain plant growth. In the future, we should further study the seasonal variation characteristics of NSC content and isotopes and the relationship between NSC content and the carbon and nitrogen cycles in plants under the context of long-term warming. © 2022 Science Press. All rights reserved.     

HYDRAULIC AND ECONOMIC BENEFITS OF DOWNSPOUT DWERSION1

ABSTRACT: A downspout diversion program in an urban area is evaluated to assess the impacts on sanitary sewer flow volumes and cost effectiveness. Sanitary sewer flows and wastewater treatment cost data are compared for the five years before and 1.25 years after the downspout diversion was completed. In order to establish a cause and effect relationship between flow volumes and downspout diversion, measurements of precipitation, consumption patterns, and system loss (maintenance, fire flows, main ruptures) for the before and after time periods were obtained. The results indicate the downspout diversion contributed to a reduction of over 25 percent in the mean flow volumes within the sanitary sewer collection network during all rainfall events, with flow reductions ranging from 25 percent to 62 percent for rainfall depths between 6 mm (0.25 inches) and 25.4 mm (1.0 inches). Costs incurred for wastewater treatment were also reduced significantly, as overtime for overflow maintenance was eliminated. Downspout diversion is a viable nonstructural alternative for sthrmwater flow reduction in highly urbanized communities which may lack available space for large scale detention facilities.