河蟹幼蟹培育池浮游植物的群落结构

为科学评价河蟹幼蟹生态培育池塘的渔业生态环境质量状况,于2013年7—10月对上海市崇明县中华绒螯蟹Eriocheir sinensis幼蟹培育池的浮游植物群落结构和生物多样性动态进行了调查研究。结果表明:幼蟹培育池共出现浮游植物77种,隶属于7门37属,其中优势种16种;浮游植物的群落结构为蓝藻—绿藻型,蓝藻的优势度最高,而绿藻的种类最多;浮游植物生物密度变化范围为5.02×107~14.37×10~(7)cells/L,平均生物密度为8.88×107cells/L,生物量变化范围为14.70~52.85 mg/L,平均生物量为25.33 mg/L;幼蟹培育池的Shannon-Wiener多样性指数、Margalef丰富度指数和Pielou均匀度指数变化范围分别为2.73~3.07、0.99~1.48、0.74~0.90;浮游植物生物密度和生物量均在8月15日达到峰值,各月间仅9月与10月无显著性差异(P>0.05),各幼蟹培育池间均无显著性差异(P>0.05)。研究表明,河蟹幼蟹培育池浮游植物群落结构比较复杂,水体为α-中污型。     

白石水库浮游植物的群落结构研究

为给白石水库生态环境保护和渔业可持续发展提供科学依据和基础资料,于2013年8月—2014年7月对白石水库的浮游植物群落结构,包括浮游植物的种类组成、优势种、密度、生物量、生物多样性和时空格局进行了周年研究。结果表明:白石水库共发现浮游植物239种,其中绿藻138种,硅藻39种,裸藻26种,蓝藻19种,甲藻8种,金藻、隐藻、黄藻各3种;主要优势种为小席藻Phormidium tenue、啮蚀隐藻Cryptomonas erosa、尖针杆藻Synedra acus;调查期间浮游植物密度为13.44×106cells/L,生物量为11.33 mg/L,优势类群为硅藻、隐藻和蓝藻;浮游植物群落结构有明显的时空分布规律,其中浮游植物密度呈现出夏季>秋季>春季>冬季的变化规律,在空间分布上表现为凌河>牤牛>上游>下游>中游;根据浮游植物生物量的划分标准,白石水库属于富营养型水体;浮游植物均匀度指数为0.24~0.48,一周年的平均值为0.36,多样性指数为1.73~3.44,一周年的平均值为2.61。研究表明,白石水库目前处于中度污染状态,氮、磷对水库浮游植物的生长具有重要影响。     

联锁水工砌块在本溪太子河治理工程上的应用

本文介绍了护坡联锁水工砌块在辽宁本溪市太子河治理工程上的应用,从水工砌块的生产、铺设结构设计、施工工艺等方面分别进行了详细的介绍,总结了水工砌块保护美化生态环境、施工简单、不受季节影响等优点,具有很大发展潜力。     

美术教学的多样整合

美术教师在实施教学活动的同时,要考虑到小学生的实际接受情况,通过教学方法的多样整合,提高学生的学习兴趣。文章针对美术教学的意义、方法和多样性进行了探究,力求结合实际,建立完善的美术教学理论体系。     

呼吁丰富多样的保障住房种类

1 前言 在2009年3月11日的住房和城乡建设部新闻发布会上,有记者问:对既买不起经济适用房又不够廉租房条件的"夹心层",政府又如何解决?住建部副部长齐骥给出的回答是:要加快公共租赁房的建设.公共租赁房归政府或公共机构所有,用低于市场价或承租者能承受的价格向新就业职工出租.这一次简单对话,第一次给"夹心层"的住房难题带来官方的解决途径.在2013年3月召开的全国政协十二届一次会议中,全国人大代表、南开大学校长龚克提出:目前,保障房可以考虑进一步多样化,除了廉租房、公租房,还可以有更多其他的类型,想办法覆盖到更多的"夹心层"人群.     

湖水源热泵系统冷排水对浮游植物影响试验研究

针对湖泊热环境容量小,生态系统脆弱的特征,以三峡库区重庆段湖泊水体为研究对象。采用物理模拟的方法,对湖水源热泵系统冷排水对湖泊藻类及叶绿素含量的影响进行了系统的研究。结果表明:冷排水对藻类总量增长有明显抑制作用,试验水体藻类正负增长的临界温度在4.5~6.2℃之间;冷排水对湖泊优势藻类种群及比例变化有较为明显的影响,并且会使藻类种群数减少;冷排水显著降低湖泊叶绿素a的含量,对浮游植物总量增长有较大影响,且原水氮磷含量越高其影响程度也越大。     

城市绿化物种多样性的优点——梅州市"创园"中物种多样性的应用

城市绿化物种的多样性不仅能绿化城市,更能美化城市.在倡导低碳生活的今天,城市绿化不能再是绿色篱笆一条街,休闲公园只见草的景象了.我们需要草木皆兵,百花齐放,争奇斗艳和错落有致的多样化,生态化和乡土化的城市园林,让城市园林形成和谐的生态系统,充分展现绿化遮荫、减噪、滤尘,达到绿化、彩化的效果.     

用多样的预习作业提高学生数学学习的有效性

预习是课堂教学的前提,有助于学生提高课堂学习的效率,有利于调动学生学习的积极性和主动性。在预习中,学生发现学习内容的难点,可以带着问题在课堂上进行交流和讨论,解决了学习中的疑难。预习时,教师可根据不同的课程内容设计多样化的预习作业,从而提高学生的数学学习效率。     

乌鲁木齐市居住区木本植物物种多样性调查研究

居住区绿地是城市园林绿地系统的组成部分,研究居住区植物多样性可为城市生物多样性保护提供基础数据。采用典型抽样法,对乌鲁木齐市具代表性的居住区的木本植物物种多样性进行了分析研究。结果表明:4个居住区共有26科47属88种木本植物。从居住区绿地的乔、灌层分析比较得出,居住区乔木层物种组成结构复杂;灌木层物种多样性指数、均匀度指数相对较低,物种多样性仍有较大的提升空间;从居住区的4种绿地类型来看,公共绿地的物种多样性水平较高,道路绿地的物种多样性水平最低;在居住区树种的选择上,野生观赏植物资源的应用未得到重视。     

郑州市公园绿地木本植物物种多样性研究

采用典型抽样法,对郑州市公园绿地木本植物的树种组成、植物来源、物种多样性指数等进行了调查统计和比较分析.研究表明:郑州市公园绿地内木本植物种类比较丰富,共有54科103属173种,其中,郑州本地种29种,占总数的16.8%,国内引进种110种,占总数的63.5%,国外引进种34种,占总数的19.7%.郑州市不同类型公园绿地乔木物种丰富度稍大于灌木.Simpson多样性指数和Shannon-Wiener多样性指数表现出相同趋势,乔木层Simpson多样性指数均在0.5以上,乔木的多样性指数大干灌木.Pielou均匀度在不同类型的公园绿地之间差别不大,集中在0.70～0.86之间,乔木均匀度仍大于灌木.     

一次辽河文化的洗礼辽宁盘锦市辽河美术馆设计

文章以辽河美术馆的创作为引导,探讨了建筑创作过程中对传统地域文化精神的继承,对时代背景、对当地建筑创作提出了自己的观点。     

河流硅藻指数在太子河水生态健康评价中的应用研究

为了用硅藻指数评价太子河的水生态健康状况,于2012年5月对太子河河岸不同土地利用方式(森林用地、森林耕作用地、耕地和城镇建设用地)下的38个采样点位进行了调查研究,并应用6项硅藻指数(硅藻生物指数IBD、硅藻属指数IDG、特定污染敏感指数IPS、欧盟硅藻指数CEE、硅藻营养化指数TDI和戴斯指数DESCY)对太子河的水生态环境进行健康评估。结果表明:MRPP结果显示,太子河流域4种土地利用类型具有显著的空间异质性(P<0.05);太子河流域香农多样性指数、均匀度指数和物种丰富度的平均值分别为2.96、0.72和18,物种密度为7.83×106cells/cm2;根据相关分析显示,硅藻指数之间、硅藻指数与水环境因子之间具有显著的相关性(P<0.05);根据K-S检验,6项硅藻指数均符合正态分布;根据线性回归方程分析,D-IBI与IBD、IPS、IDG、CEE、TDI、DESCY均呈显著的线性回归关系(P<0.05),表明6项硅藻指数在太子河流域具有较好的适用性;用硅藻指数评价太子河流域的结果显示,太子河上游地区水生态健康状况较好,中游地区水生态健康状况一般,下游地区水生态健康状况较差。     

辽河特大桥混凝土设计及耐久性研究

对辽河特大桥工程六系列混凝土进行了配合比设计,对各系列混凝土的力学和耐久性进行了系统试验。试验结果表明:提高混凝土耐海水的侵蚀能力,必须提高其抗氯离子渗透性能。采用双掺和三掺矿物掺和料,水胶比低于0.38,胶凝材料总量不少于470kg/m3,可有效降低氯离子扩散系数,提高混凝土抗海水侵蚀能力。采用F ick模型,合理推测出结构达100年使用年限,结构各部位保护层厚度。     

Phytoplankton development and ecological status during a cyanobacterial bloom in a tributary bay of the Three Gorges Reservoir, China

Reservoirs can provide suitable conditions for cyanobacterial bloom development, which may impact on water quality and biological communities. Weekly surveys in a cyanobacterial bloom process were carried out in the mainstream and Xiangxi Bay of the Three Gorges Reservoir (China), from June 6 to July 18 in 2008. By application of the phytoplankton functional group approach, the spatiotemporal pattern, impact factors, and the ecological status based on Q index (assemblage index) were analyzed. The depth of euphotic layer was apparently the key factor driving the phytoplankton functional group variations. Longitudinal patterns of phytoplankton distribution were detected during this bloom: in the beginning phase, groups D (mainly Stephanodiscus hantzschii) and B (Cyclotella stelligera) dominated in the mainstream of the Three Gorges Reservoir and the mouth area of Xiangxi Bay, group Y (Cryptomonas species) dominated in the upper area, while groups J (mainly Pediastrum duplex), F (mainly Sphaerocystis schroeteri) and G (Pandorina morum and Eudorina elegans) were important in other areas; in the mid phase, group M became absolutely dominant in the whole region; and in the ending phase, besides groups M and Y, groups X2 (Chroomonas acuta, Pyramimonas nanella, etc.) and Lo (Ceratium hirundinella) became more important in the lower and upper area respectively. Generally the ecological status was bad, temporally varied with the bloom process. No spatial difference of ecological status was found in the mainstream, while longitudinal patterns in Xiangxi Bay were detected for different phases: firstly a few sites had relatively better status than the others, then nearly all the sites were in the bad condition, and at last the status in the downstream was better than that in the upstream. The longitudinal patterns of ecological status were related to phytoplankton distribution, disturbed by jacking from the downstream and flood from the upstream of Xiangxi Bay.     

Occurrence and risk assessment of acidic pharmaceuticals in the Yellow River, Hai River and Liao River of north China

Pharmaceuticals in the aquatic environment have received great attentions from the general and scientific community due to their potential impacts on ecological and human health. We investigated the occurrence of twelve acidic pharmaceuticals and herbicides (salicylic acid, clofibric acid, ibuprofen, gemfibrozil, fenoprofen, naproxen, ketoprofen, mefenamic acid, tolfenamic acid, diclofenac, meclofenamic acid and indomethacin) in surface waters of the Yellow River, Hai River and Liao River in north China during the wet and dry seasons and assessed the potential risks to aquatic organisms posed by these acidic compounds. Seven acidic compounds were detected in the rivers, including five non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, diclofenac, mefenamic acid and naproxen), and two blood lipid regulators (clofibric acid and gemfibrozil). The concentrations for acidic pharmaceuticals in the Yellow River and Liao River were in most cases higher in the dry season than in the wet season, but the concentrations of acidic compounds in the Hai River were generally higher in July than in November. High concentrations of these detected compounds in the Yellow River, Hai River and Liao River were found more frequently at those sites located in metropolitan areas, lower reaches or river confluences. Only diclofenac and ibuprofen were found to have medium to high risks in the three rivers based on the calculated risk quotients.     

Contributions of genotoxic precursors from tributary rivers and sewage effluents to the Yodo River in Japan

The cause of water pollution in the Yodo River was examined regarding the mutagenic potentials formed by chlorination of river waters and sewage effluents along the river. Mutagenicity of the extracts from chlorinated waters was measured by Ames test using S. typhimurium TA100 strain without metabolic activation. Mutagenic formation potentials of sewage effluents were 4-5 times higher than those of the three tributary river waters, the Kizu, Uji and Katsura Rivers. The contribution rates of the pollution loads from the three river waters and total of four sewage effluents to the Yodo River were revealed to be 10.2%, 42.2%, 22.1% and 25.5%, respectively. The rate of the sewage effluents occupied one-fourth and exceeded the rates of the Kizu and Katsura Rivers. The contribution rate of the two sewage effluents to the Katsura River was 46.3%. It could be confirmed that the relationship between COD and MFP in river waters and sewage effluents was very high with a correlation coefficient. These results indicated that the waters inflowing to the Yodo River were contaminated with numerous organic compounds, and the sewage effluents especially contribute to the formation of genotoxicity by the interaction between chlorine and organic components as genotoxic precursors in the purification plants.     

太子河防洪综合整治工程浸没问题分析与评价

通过勘察和分析,确定了拦河坝库区两岸浸没影响范围和浸没影响程度,为工程的设计和施工提出合理化建议和措施,指导浸没影响区内建筑物的搬迁安置及铁路的加固改造,有效调整农田浸没区的种植结构,减少浸没危害损失.     

Phytoplankton growth control and risk of cyanobacterial blooms in the lower Senegal River delta region

Eutrophication, and the resulting proliferation of phytoplankton can affect water quality. Although environmental and ecological processes that lead to phytoplankton proliferations in temperate areas have received considerable attention, scientific background regarding this topic in tropical areas, especially West Africa, are scarce. In this study, bioassays in batch cultures were carried out in order to identify factors that may be stimulating or limiting the biomass of phytoplankton at various sites in the lower Senegal River delta region. Complete factorial designs were used to test several factors both alone and combined (nitrogen, phosphorus, sulfate, EDTA and trace elements, stirring). The effects of these factors on the growth of the whole phytoplankton communities were followed by the daily measurement of in vivo fluorescence. At all but two of the sites, enrichment with certain nutrients significantly stimulated phytoplankton biomass growth, with nitrogen and/or phosphorus appearing to be the primary limiting factor(s). Nitrogen was the primary limiting factor in coastal ocean waters and in the Senegal River estuary. In the freshwater ecosystems studied, nitrogen and phosphorus acted as alternating or concomitant limiting factors. We assessed the changes in the phytoplankton composition induced by nutrient enrichments in Lake Guiers, a drinking water reservoir for the population of Dakar. Our findings lead us to define the conditions of a possible proliferation of the potentially toxic cyanobacterium Cylindrospermopsis raciborskii mainly in response to phosphorus inputs.     

辽河特细砂分形特征及特细砂混凝土性能研究

针对辽河中下游特细砂产量大、亟待开发利用的现状,展开辽河特细砂及特细砂混凝土相关研究;首先通过加密筛分试验确定该地区特细砂分布情况,并结合分形理论探讨其颗粒级配的分形特征,进而进行特细砂混凝土的试验研究,确定不同特细砂混凝土间和易性与强度的差异,并同普通中砂混凝土相应性能进行比较分析;最终,确定该地区特细砂粒度分布情况、测定了砂样的分维值并探讨了其对特细砂的表征意义,同时,获得特细砂混凝土强度随水灰比提高而下降、砂率在27％左右的特细砂混凝土强度会出现峰值、流动性低于同条件中砂混凝土等的性能规律,以期为当地工程应用提供有价值的参考,开启特细砂资源利用的崭新篇章.