乌鳢仔鱼生化成分变化与其行为的关系

研究了１～１６ｄ龄乌鳢仔鱼水分、Ｎａ＋、Ｋ＋、脂肪和蛋白质含量的变化及其主要摄食行为．结果表明，初孵仔鱼含水量为５０．１５％～５２．４０％，并随发育进展持续上升到８６．３５％～８６．８６％，而仔鱼干重则在第６ｄ最低．Ｎａ＋、Ｋ＋在仔鱼前期波动较大，第８ｄ后稳步上升，脂肪食量在孵出后的前４ｄ基本上保持不变，第５ｄ下降１５．８５％，第６ｄ下降３４．３８％，此后一直下降．蛋白质含量前８ｄ变化很小，第８ｄ后开始大幅上升．结合行为学观察认为，油球在仔鱼前期主要作为“浮力器官”（ｂｕｏｙａｎｃｙｏｒｇａｎ），在后期则可补偿摄入能量的不足．     

旅游中心地空间外向度及等级体系研究--以全国27个优秀旅游城市为例

采用旅游流强度模型，比较了全国27个主要旅游城市的旅游外向功能量及旅游流强度，并在此基础上运用主成分分析和聚类分析方法，将它们划分为5个等级体系，并对各级旅游中心地进行了评价。研究表明，我国旅游中心地区域发展不平衡，发展态势与我国经济发展态势基本吻合，从发展水平看，沿海高于内陆，东部高于西部，南方高于北方；旅游流强度能较好地刻画旅游中心城市的等级，旅游流强度大的城市，旅游中心地级别愈高，旅游业愈发达，反之亦然。     

ON PRECIPITATION SENSOR NETWORK DENSITIES FOR EVALUATING WINTERTIME OROGRAPHIC CLOUD SEEDING EXPERIMENTS1

Principal component analysis is used to investigate density requirements of wintertime orographic cloud seeding experiment precipitation sensor networks. Three passes in the vicinity of Climax, Colorado are studied. The eighteen or more evenly spaced precipitation sensors of each pass are almost completely described by three principal components. These three principal components appear to represent (i) mean precipitation, (ii) slope orientation to storm systems, and (iii) elevation. Evaluation of these principal components is implemented with two distribution-free tests, a proportionality test and the runs test. The results of this study suggest that the loss of experimental information caused by low density precipitation sensor networks may be of little consequence.     

Phytoremediation of urban wastewater by model wetlands with ornamental hydrophytes

Phytoremediation offers a cost-effective,non-intrusive,and safe alternative to conventional cleanup techniques.In this study,we used ornamental hydrophytes plants as constructed wetlands to treat urban or rural domestic wastewater.Most ornamental hydrophytes adapted to the wastewater well,and were fairly efficient in scavenging BOD_5(biological oxygen demand 5 d),COD(chemical oxygen demand),TN(total nitrogen),TP(total phosphorus)and heavy metals(Cr,Pb,Cd)in the wastewater.However,the efficiency varied a lot for various species to different contaminants,Iris pseudacorus L.and Acorus gramineus Soland were good choices for treatment of composite-polluted urban wastewater.Some variation in the change of membrane peroxidation and endogenous protective system in responses to wastewater was found among six hydrophytes,which have a correlation with the efficiency of wastewater treatment.It may demonstrate that the developed antioxidative systems of I.pseudacorus and A.gramineus contributed much to their superiority. On the other hand,interaction of different components in the wastewater might have certain effects on phytoremediation.     

车用动力电池单体自动化拆解线有害气体控制实验研究

以动力电池单体自动化拆解线的混合废气为研究对象,通过实验考查了碱液吸收、活性炭吸附及碱液吸收+活性炭组合工艺对拆解线混合废气的处理效果,结果显示,混合废气先经碱液吸收,再经活性炭吸附之后,出口浓度比国家排放标准限值低;当质量分数为10%的碱溶液吸收时间为2~3 s、煤质柱状活性炭接触时间为1~2 s时,恶臭物质去除率达95.0%,氟化物去除率达91.8%;整个废气处理系统具有很好的实际应用前景,经测算,装机功率小于1 k W/1 000 m3,运行成本小于1元/1 000 m3。     

生物法脱除污水处理厂硫化氢的研究

试验并研究了生物滴滤塔处理污水处理厂硫化氢气体的技术,分析了负荷、压降、温度等因素对生物法脱除硫化氢恶臭气体工艺的影响。     

Filament-Based Atmospheric Dispersion Model to Achieve Short Time-Scale Structure of Odor Plumes

This article presents the theoretical motivation, implementation approach, and example validation results for a computationally efficient plume simulation model, designed to replicate both the short-term time signature and long-term exposure statistics of a chemical plume evolving in a turbulent flow. Within the resulting plume, the odor concentration is intermittent with rapidly changing spatial gradient. The model includes a wind field defined over the region of interest that is continuous, but which varies with location and time in both magnitude and direction. The plume shape takes a time varying sinuous form that is determined by the integrated effect of the wind field. Simulated and field data are compared. The motivation for the development of such a simulation model was the desire to evaluate various strategies for tracing odor plumes to their source, under identical conditions. The performance of such strategies depends in part on the instantaneous response of target receptors; therefore, the sequence of events is of considerable consequence and individual exemplar plume realizations are required. Due to the high number of required simulations, computational efficiency was critically important.     

嘉善冬季PM2.5化学组分特征及来源分析

为研究嘉兴地区嘉善冬季污染时段和清洁时段PM_2.5化学组分特征,结合气象数据对2019年1月嘉兴市嘉善县善西超级站在线自动监测PM_2.5及化学组分数据、气态污染物(NO₂和SO₂)进行了分析.结果表明,2019年1月嘉善善西超级站污染时段PM_2.5浓度(97.18μg·m^-3)为清洁时段(36.77μg·m^-3)的2.6倍.污染时段水溶性离子浓度(41.58μg·m^-3)较清洁时段(19.82μg·m^-3)高21.76μg·m^-3,但占比有所降低,含碳组分比例增加.OC;EC比值为3.93,可能受到燃煤及机动车排放的共同影响.低风速及高湿有利于NO₂和SO₂等气态污染物进行二次转化,污染时段硫转化率和氮转化率均比清洁时段高,分别增高7.93%和54.11%,说明NOx向硝酸盐二次转化较为明显,导致颗粒物浓度升高.聚类分析结果显示67.34%气流来自北方,且相应的气流轨迹上污染物浓度比周边高,说明污染物存在一定的长距离输送.结合风玫瑰图可以看出,污染主要为本地及其周边的输送,污染物的长距离输送在短时会使污染浓度突增.因此,在重点关注本地及周边污染的同时,偏北气流下的污染物区域输送不可忽视.     

Post-mating odor in females of the solitary bee, Andrena nigroaenea (Apoidea, Andrenidae), inhibits male mating behavior

We investigated odor changes and their behavioral significance in the solitary, ground-nesting bee Andrena nigroaenea. We used gas chromatography with electroantennographic detection and performed behavioral tests with males in the field using natural odor samples and synthetic compounds. We found that only cuticle extracts of young females elicited copulation attempts in the males. We demonstrated that among the 17 compounds which triggered electroantennographic responses, all-trans-farnesyl hexanoate and all-trans-farnesol were significantly more abundant in unattractive cuticle extracts of A. nigroaenea females. Dufour’s gland extracts of these females also contained greater amounts of both compounds. In bioassays using synthetic farnesyl hexanoate and farnesol we found that these compounds inhibit copulation behavior in the males. Farnesyl hexanoate is probably synthesized in Dufour’s gland and used by females for lining brood cells. We interpret the semiochemical function of farnesyl hexanoate and its precursor farnesol to have evolved secondarily. As an outcome of sexual selection, it facilitates the discrimination by males of receptive females from nesting and thus already mated individuals. The dual function of these compounds represents an elegant parsimony in the chemical communication system of this insect. Received: 19 January 2000 / Revised: 29 May 2000 / Accepted: 24 June 2000     

天津市大气环境监测数据的主成分分析

本文采用主成分分析法分析了天津市大气环境监测数据,得到两个主成分;环境质量主成分和风沙主成分;根据主成分点图,将一年分成３个阶段;采暖期,非采暖期和风沙期。