用判别指数选周期预报强汛年

以信阳强汛年（６～８月区域平均雨量≥７００ｍｍ）为对象,用判别指数法提取有效周期,并将多个有效周期相迭加,建立预报判别模型。用１９７４～１９９３年历史资料回代,强汛年预报成功率达到７１．４％。经过１９９４～１９９８年试用,成功地报准了强汛年（１９９６年）。     

海藻中溴酚化合物研究进展

<正>海洋作为全球至为重要的资源库,为人们提供了丰富的生物资源。海藻是海洋代谢的原动力,由于其特殊的生存环境,使得其机体内生成许多结构新颖、活性独特的次生代谢产物,为获得全新结构的新药提供了宝贵的化合物来源。与陆生植物     

2000-06-02江淮切变大暴雨过程分析

通过对 2 0 0 0 - 0 6 - 0 2暖切变大暴雨过程的高空、地面天气形势和主要影响系统及物理量要素场的分析 ,揭示了该次区域性大暴雨的成因     

内蒙古中西部区域发展与水资源合理配置的多目标分析

结合内蒙古西部地区在社会经济发展进程中出现的生态环境恶化及水资源未充分合理利用的现实问题,建立了该区域基于水资源开发利用的宏观经济及生态系统的多目标模型.在多目标优化预测中,利用天然草场的载畜量为传递因子,拟定包含生态质量信息的"绿色净面积"为目标变量之一,宏观的刻画了牧区草原生态与经济的相互作用过程.模型研究了节水力度、区外工程投资力度、草原载畜量、供水工程规划等4个可决策边界条件的不同方案对区域可持续发展的驱动和影响.在牧区发展策略方面,模型计算出不同边界条件下的最佳减畜速率.通过天然草原生态系统服务价值和模型目标变量接口的计算,进一步支持了模型优化所得的减畜方案.     

大型海藻吸附水体中重金属离子的机理及影响因素

随着现代工业的发展,人类的生存环境日益恶化,水体污染已经成为影响人类健康的重要因素。工业生产过程中往往会产生大量含铬、铜、汞、镍、铅、硒、锌等重金属离子的废水或固体废弃物,如果这些有害离子得不到及时有效的处理,就会对生态环境和人类健康产生不良影响,而且还会给国民经济造成重大损失。     

急流对海河南系一次特大暴雨影响的数值试验

利用ＭＭ４中尺度模式,模拟了１９９６年８月发生在太行山南段的一次特大暴雨过程。采用对比试验的方法,先后研究了减弱低空急流和减弱高空急流后,降水及物理量的变化。数值试验结果表明,低空急流和高空急流对本次暴雨过程的形成与维持均有促进作用;相比之下,低空急流对暴雨的影响更为显著。     

Biosorption and desorption of Cd^2＋ from wastewater by dehydrated shreds of Cladophorafascicularis

The adsorption and desorption of algae Cladophora fascicularis and their relation with initial Cd^2＋ concentration, initial pH, and co-existing ions were studied. Adsorption equilibrium and biosorption kinetics were established from batch experiments. The adsorption equilibrium was adequately described by the Langmuir isotherm, and biosorption kinetics was in pseudo-second order model. The experiment on co-existing ions showed that the biosorption capacity of biomass decreased with an increasing concentration of competing ions. Desorption experiments indicated that EDTA was efficient desorbent for recovery from Cd^2＋. With high capacities of metal biosorption and desorption, the biomass of Cladophora fascicularis is promising as a cost-effective biosorbent for the removal of Cd^2＋ from wastewater.     

The chemical constituents from red alga <Emphasis Type="Italic">Gymnogongrus flabelliformis</Emphasis> Harv.

Eight compounds were isolated from red alga Gymnogongrus flabelliformis Harv. In normal phase silica gel, Sephadex LH-20 gel column chromatography, reverse phase HPLC, and recrystallization. Based on MS and ID NMR spectroscopic data, their structures were determined as： stigmast-4-en-3-one （Ⅰ）, cholest-4-en-3-one （Ⅱ）, cholesterol （m）, uracil （Ⅳ）, uridine （V）, adenosine （Ⅵ）, succinic acid （Ⅶ）, and 5-hydroxy-4-methyl-5-pentyl-2,5-dihydro-furan-2-on （Ⅷ）. All of them were obtained from this species for the first time. Cytotoxicity of these compounds was screened using standard MTT method, but all the compounds were inactive （IC50 〉 10 μg/ml）.