三角褐指藻紫外线诱变及高产EPA藻株选育     

刘红全  潘艺华  林小园  李洁琼  袁莎  卢恩秋 《海洋科学》2017,41(9):87-93

利用紫外诱变法对三角褐指藻(Phaeodactylum tricornutum)进行诱变育种。实验得到三角褐指藻的最佳紫外辐射剂量为18 W的紫外灯距离藻液35 cm照射15 min。通过单细胞分离技术获得1株突变株UP1,与出发藻株相比,突变株UP1的EPA产量提高10.2%。研究了诱变株的最适生长及产EPA的条件,结果表明UP1在NaNO_3 75 mg/L,p H 7.5,昼夜温度17~15℃,接种量为10%时培养7天,具有最大的生长速率和EPA产量。探讨了诱变株的遗传稳定性,结果表明诱变株可稳定遗传。  相似文献   

微绿球藻的研究进展   总被引：1，自引：0，他引：1  

余颖  陈必链 《海洋通报》2005,24(6):75-81

微绿球藻富含EPA,被认为是一种很有潜力的EPA来源,引起人们广泛的研究兴趣.本文介绍了国内外近年来微绿球藻生长条件及脂肪酸积累调控、生理学特性、规模培养、藻种诱变及作为饵料的应用等方面的研究进展.微绿球藻喜强光,适温范围较广,对pH适应性较强.营养盐、植物生长调节剂、消毒剂、敌草隆和UV等均对藻的生长和EPA合成有影响.微绿球藻的一系列色素如叶绿素a、玉米黄质、角黄素和虾青素等都有较高的含量,可作为商业上的色素来源.采用室内及室外平板式光生物反应器、垂直式平板生物反应器等规模培养微绿球藻获得成功.  相似文献   

ILLUDAS and PSRM‐QUAL predictive ability in small urban areas and comparison with other models     

Vassilios A. Tsihrintzis  Clara B. Sidan 《水文研究》2008,22(17):3321-3336

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Modelling and assessment of hydrological changes in a developing urban catchment          下载免费PDF全文

Mingfu Guan  Nora Sillanpää  Harri Koivusalo 《水文研究》2015,29(13):2880-2894

Urbanization strongly changes natural catchment by increasing impervious coverage and by creating a need for efficient drainage systems. Such land cover changes lead to more rapid hydrological response to storms and change distribution of peak and low flows. This study aims to explore and assess how gradual hydrological changes occur during urban development from rural area to a medium‐density residential catchment. The Stormwater Management Model (SWMM) is utilized to simulate a series of scenarios in a same developing urban catchment. Sub‐hourly hydro‐meteorological data in warm season is used to calibrate and validate the model in the fully developed catchment in 2006. The validated model is then applied to other cases in development stage and runoff management scenarios. Based on the simulations and observations, three key problems are solved: (1) how catchment hydrology changes with land cover change, (2) how urban development changes pre‐development flows, and (3) how stormwater management techniques affect catchment hydrology. The results show that the low‐frequency flow rates had remarkably increased from 2004 to 2006 along with the increase of impervious areas. Urbanization in the residential catchment expands the runoff contributing area, accelerates hydrological response, raises peak flows in an order of magnitude of over 10, and more than doubles the total runoff volume. The effects of several LID controls on runoff hydrograph were simulated, and the techniques were able to reduce flows towards the pre‐development levels. However, the partly restored flow regime was still clearly changed in comparison to the pre‐development flow conditions. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Assessment of the SWMM model uncertainties within the generalized likelihood uncertainty estimation (GLUE) framework for a high‐resolution urban sewershed          下载免费PDF全文

Ning Sun  Bongghi Hong  Myrna Hall 《水文研究》2014,28(6):3018-3034

This research incorporates the generalized likelihood uncertainty estimation (GLUE) methodology in a high‐resolution Environmental Protection Agency Storm Water Management Model (SWMM), which we developed for a highly urbanized sewershed in Syracuse, NY, to assess SWMM modelling uncertainties and estimate parameters. We addressed two issues that have long been suggested having a great impact on the GLUE uncertainty estimation: the observations used to construct the likelihood measure and the sampling approach to obtain the posterior samples of the input parameters and prediction bounds of the model output. First, on the basis of the Bayes' theorem, we compared the prediction bounds generated from the same Gaussian distribution likelihood measure conditioned on flow observations of varying magnitude. Second, we employed two sampling techniques, the sampling importance resampling (SIR) and the threshold sampling methods, to generate posterior parameter distributions and prediction bounds, based on which the sampling efficiency was compared. In addition, for a better understanding of the hydrological responses of different pervious land covers in urban areas, we developed new parameter sets in SWMM representing the hydrological properties of trees and lawns, which were estimated through the GLUE procedure. The results showed that SIR was a more effective alternative to the conventional threshold sampling method. The combined total flow and peak flow data were an efficient alternative to the intensive 5‐min flow data for reducing SWMM parameter and output uncertainties. Several runoff control parameters were found to have a great effect on peak flows, including the newly introduced parameters for trees. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

已建城市排水管网的排涝能力评估方法     

唐清华  何沛英  朱志华  张明珠  刘浩 《热带地理》2016,36(4):626-632

以SWMM 模型为平台构建已建城市区域排涝模型,以广州市芳村高尔夫地块为研究区域,基于研究区域实测降雨、径流等资料对模型进行参数率定和验证,模拟在不同暴雨重现期下已建城市区域雨水管网的排涝能力。研究结果表明：该区域遭遇2 a 一遇暴雨时,J14、J15 和J31 等3 个排水节点出现积水;当遭遇5 a 一遇时,J15 片区和J31 节点出现较为严重的积水,其中J15 和J31 节点积水量分别达到1 674、546 m³;积水时间分别为0.5、0.4 h。针对研究区域排水管网排涝能力偏低的现状,建议结合LID（Low Impact Development）措施,削减暴雨洪峰流量,提高区域排涝能力。文章构建的已建城市排水管网排涝能力评估方法,可识别区域主要积水黑点及管道满流管段,提供了一种动态、定性和定量评估排水管网能力的方法。  相似文献   

Improving flood forecasting using an input correction method in urban models in poorly gauged areas     

Maria Clara Fava  Maurizio Mazzoleni  Narumi Abe  Eduardo Mario Mendiondo  Dimitri P. Solomatine 《水文科学杂志》2020,65(7):1096-1111

ABSTRACT

Poorly monitored catchments could pose a challenge in the provision of accurate flood predictions by hydrological models, especially in urbanized areas subject to heavy rainfall events. Data assimilation techniques have been widely used in hydraulic and hydrological models for model updating (typically updating model states) to provide a more reliable prediction. However, in the case of nonlinear systems, such procedures are quite complex and time-consuming, making them unsuitable for real-time forecasting. In this study, we present a data assimilation procedure, which corrects the uncertain inputs (rainfall), rather than states, of an urban catchment model by assimilating water-level data. Five rainfall correction methods are proposed and their effectiveness is explored under different scenarios for assimilating data from one or multiple sensors. The methodology is adopted in the city of São Carlos, Brazil. The results show a significant improvement in the simulation accuracy.  相似文献   

Convergence or divergence?: Status and prospects for US climate strategy     

Atle Christer Christiansen 《Climate Policy》2003,3(4):343-358

The objective of this paper is to assess recent developments and prospects for future changes in United States (US) climate strategy. In doing so, the paper explores some of the key factors that have shaped strategies and policies to date, distinguishing between factors related to institutional and governance structures, linkages between science and policy, energy technology and the role of interest groups. Against this background, the paper attempts to explore future development paths for US climate policy. More specifically, the paper assesses opportunities for policy changes compared to the preferences of the current administration, and the prospects for future linkages between US and international climate change strategies. In brief, the paper argues that substantial changes are unlikely to take place in the near to medium term, leaving open, however, the possibility of wide-ranging changes in domestic politics or major incidents that could facilitate a shift in the perceived need for near-term action.  相似文献   

微拟球藻I 型脂酰辅酶A: 二脂酰甘油酰基转移酶编码基因NoDGAT1A的功能分析     

辛一  路延笃  徐健 《海洋科学》2015,39(10):15-20

从微拟球藻高产油藻株IMET1 的cDNA 中, 克隆出一个I 型脂酰辅酶A: 二脂酰甘油酰基转移酶的编码基因NoDGAT1A, 该基因共编码437 个氨基酸, 与拟南芥I 型DGAT 的氨基酸序列相似度为38%, 且含有至少9 段高疏水区。随后, NoDGAT1A被转化入营养缺陷型酿酒酵母三脂酰甘油合成突变株H1246 中进行诱导表达。结果表明, 在外加二十碳五烯酸(EPA)时, 表达NoDGAT1A 的H1246 能够产生三脂酰甘油(TAG), 针对其TAG 的分析表明, 与酵母DGAT 相比, 表达NoDGAT1A 的H1246 产生的TAG 中含有更多的EPA, 说明NoDGAT1A 具有更强的合成含EPA 的TAG 之能力。此外, 16: 0(63.82%)和18: 0(27.98%)是其TAG 中主要的脂肪酸链成分, 说明NoDGAT1A 合成的TAG 侧链仍以长链饱和脂肪酸为主。NoDGAT1A对微拟球藻中TAG 的合成具有重要作用, 也为以微拟球藻为模式的产油微藻TAG 和EPA 代谢网络提供参考。  相似文献   

温度、光照、pH值对后棘藻生长及脂肪酸含量的影响   总被引：3，自引：0，他引：3  

徐年军  张学成 《中国海洋大学学报(自然科学版)》2001,31(4):541-547

报道了环境因子对富含 EPA (2 0∶ 5ω3)的海洋微藻后棘藻 (Ellipsoidion sp.) 70 - 0 1的生长速度、总脂及脂肪酸含量的影响。结果表明 ,后棘藻具有较快的生长速度和较高的脂肪酸含量 ,总脂含量为 31～ 36 % ,主要脂肪酸为 14∶ 0、16∶ 0、16∶ 1、18∶ 1ω9、18∶ 1ω7、18∶ 2 ω6、2 0∶ 4 ω6、2 0∶ 5ω3。生长的温度范围为 15～ 30℃ ,2 5℃时生长速度最快。温度对总脂含量影响很小 ,但对EPA和 PUFA含量影响较大。在 2 5℃时有最大的 EPA和 PUFA含量。适宜光强为 10 8.75μmolm-2 s-1～ 2 4 4 .15μmolm-2 s-1,在 145.54μmolm-2 s-1时 EPA产率较大。在起始 p H6 .5～ 9范围内 ,p H8.5时有最大的生长速率和总脂含量 ,而 EPA和 PUFA在起始 p H7.5时最大 ,分别占脂肪酸的 18.77%和 2 3.38%。实验条件下后棘藻 EPA产率最大的条件为温度 2 5℃ ,光强 145.54μmolm-2 s-1,p H为 7.5～ 8.5。  相似文献