贫困山区生态渔业扶贫模式的实践与思考从湖北恩施到贵州六盘水

科学技术的发展和应用始终以国家需要和人民诉求为导向,科技扶贫是脱贫攻坚工作的重要方式之一。根据部分贫困地区人均可用耕地少、水域面积广的地理资源特点,中国科学院水生生物研究所在湖北省恩施市龙凤镇和贵州省六盘水市水城县的扶贫实践中总结出一套“中科院技术+当地政府+当地龙头企业+贫困户/贫困集体”的生态渔业扶贫模式。即联合当地政府和龙头企业,在合理构建鱼类群落结构的基础上,科学利用山区水资源,可在保障水质的同时给周边渔农民带来经济收入。生态渔业扶贫模式的示范与推广不仅保护了生态环境,还有效促进了贫困山区水产养殖业的科学发展,使得当地群众增强了生态文明意识,掌握了一定的科学养殖技术,加速了贫困户增收脱贫,体现了扶贫模式的“造血”功能,保障了贫困户脱贫不返贫

斜爆轰发动机燃烧机理试验研究

为了研究斜爆轰发动机的稳定燃烧机理,开展了飞行马赫数9的斜爆轰发动机的数值模拟研究和试验研究。设计了全尺度斜爆轰发动机模型,发动机的总长度为2.8m。采用两级进气道压缩,每级压缩角度均为15°。利用三个小支板在进气道前缘主流核心区中进行氢气的喷射和混合。采用带化学反应的雷诺平均N-S方程、SST k-ω模型以及9组分19步反应的基元反应模型,对氢气混合过程和发动机燃烧过程进行了数值模拟研究。结果表明,氢气在进气道内混合得比较均匀,在燃烧室内获得了稳定的斜爆轰流场和正爆轰流场。在激波风洞中开展了马赫数9状态下的斜爆轰发动机稳定燃烧机理试验研究,在50ms的风洞有效试验时间内获得了持续稳定的斜爆轰流场,试验结果与数值模拟结果吻合较好,表明在试验中形成了斜爆轰波。研究结果证明了斜爆轰发动机的技术可行性

贫困山区生态渔业扶贫模式的实践与思考从湖北恩施到贵州六盘水

科学技术的发展和应用始终以国家需要和人民诉求为导向,科技扶贫是脱贫攻坚工作的重要方式之一。根据部分贫困地区人均可用耕地少、水域面积广的地理资源特点,中国科学院水生生物研究所在湖北省恩施市龙凤镇和贵州省六盘水市水城县的扶贫实践中总结出一套&ldquo;中科院技术+当地政府+当地龙头企业+贫困户/贫困集体&rdquo;的生态渔业扶贫模式。即联合当地政府和龙头企业,在合理构建鱼类群落结构的基础上,科学利用山区水资源,可在保障水质的同时给周边渔农民带来经济收入。生态渔业扶贫模式的示范与推广不仅保护了生态环境,还有效促进了贫困山区水产养殖业的科学发展,使得当地群众增强了生态文明意识,掌握了一定的科学养殖技术,加速了贫困户增收脱贫,体现了扶贫模式的&ldquo;造血&rdquo;功能,保障了贫困户脱贫不返贫。</p

Experimental demonstration of forced initiation of kerosene oblique detonation by an on-wedge trip in an ODE model

The first free-jet experiment of a kerosene-fueled oblique detonation engine, conducted in a large-scale hypersonic shock tunnel, is reported in this paper. A novel initiation-control technique using a small on-wedge trip is proposed to overcome the initiation issue of oblique detonation waves (ODWs) encountered when liquid hydrocarbon fuel is used. The results show that the kerosene-fueled ODW fails to initiate within the length-limited combustor without the trip but is successfully initiated when the trip is used, which demonstrates the effectiveness of the proposed initiation-control method. The feasibility of kerosene-fueled oblique detonation propulsion technology is also demonstrated. Novelty and significance statement The feasibility of liquid-hydrocarbon-fueled oblique detonation propulsion technology was demonstrated by performing free-jet shock tunnel experiments of a kerosenefueled oblique detonation engine. To address the initiation issue of oblique detonation waves encountered when liquid hydrocarbon fuel such as kerosene is used, a novel but simple initiation-control technique was proposed and experimentally validated. Stabilized oblique detonation waves were implemented in the combustor, and the detailed flow structures of different oblique detonation combustion modes were clarified. The proposed technique and the results provide significant reference to the future development of oblique detonation engines. (c) 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved