101 research outputs found

    跨海集群工程节能减排关键技术研究

    Get PDF
    港珠澳大桥跨海集群工程囊括跨海桥梁、沉管隧道、离岸人工岛等多个领域。跨海集群工程由于建设期及运营期能耗巨大,国内外尚无节能减排的成套技术指导工程建设,成为制约跨海集群工程持续发展的瓶颈之一。本文依托港珠澳大桥跨海集群工程建设和运营过程,采用理论研究、数值分析及模拟测试等多种方法,开展了集群工程节能减排指标体系和长大沉管隧道通风、照明、人工岛运营节能减排关键技术研究,成果支撑了工程项目节能减排目标的实现

    基于遗传算法的分类规则序列生成

    Get PDF
    与当前常用的分类方法相比,遗传算法具有较强的伸缩性和全局搜索能力,易于并行计算等优点. 但通过遗传算 法得到的一组分类规则之间常常存在冲突. 本文先将分类规则表示成二进制编码,采用F2measure 作为适应度评估函 数,并设计了有效的杂交,变异等遗传算子,使遗传算法适合用在分类规则挖掘中. 在遗传算法中增加了冲突解决机制, 并结合顺序覆盖算法,使之可以得到分类规则的序列,解决了规则间的冲突,形成了一个完整的分类方法. 最后针对具体 实例作了测试,并将实验结果与分类算法J4. 8 得到的结果进行了对比,表明该方法略优于J4. 8

    The Effect of NaCl Stress on the Ion Absorbtion of Manilkara roxburghiana(Wight)Dubard

    Get PDF
    为了研究古巴牛乳树在nACl胁迫下的离子效应及抗性方式,本试验测定了古巴牛乳树根、枝条、叶在nACl胁迫下Cl-、nA+、k+、CA2+的含量及分布特点。结果表明:古巴牛乳树根、枝条、叶的Cl-、nA+、CA2+含量随处理浓度的提高而增加,k+、k+/nA+随处理浓度升高而降低;在8‰处理浓度时,根、枝条、叶中的Cl-含量分别为对照的7.86、11.82、16.53倍,nA+含量分别为对照的3.36、3.04、4.40倍,k+/nA+分别为0.17、0.25、0.16;相同处理浓度下,Cl-、k+、CA2+含量高低顺序均为:根<枝条<叶,nA+含量高低顺序为:枝条<根<叶;叶中的Cl-、nA+、k+、CA2+等4种离子含量均比根、枝条高。说明古巴牛乳树吸收Cl-、nA+、k+、CA2+后,较大部分的将4种离子输送至叶片中,推测其抗性方式为耐盐性。In order to study the ion response and mode of salinity resistance of M.roxburghiana,the contents and distribution of 4 kinds of ions(Cl-,Na+,K+,Ca2+)in roots,branches,leaves under NaCl stress were assayed.The results showed that Cl-,Na+,Ca2+ contents in M.roxburghiana roots,branches,leaves raised with the rising NaCl concentration,while K+content and the ratio of K+/Na+dropped.The Cl-content in roots,branches,leaves was respectively 7.86,11.82,16.53 times higher than that in the control under 8‰ NaCl and Na+content was respectively 3.36 times,3.04 times,4.40 times.The K+/Na+ratio in roots,branches,leaves was respectively 0.17,0.25,0.16.The Cl-,K+,Ca2+ contents followed the order: roots<branches<leaves,Na+content did: branches<roots<leaves.The 4 kinds of ions contents were larger in leaves than in branches or roots under the same NaCl concentration.The results showed most of the ions were transported to the leaves after entering the plants.It was deduced that the mode of salinity resistance was salt tolerance for M.roxburghiana and that the imbalance of Ca2+ related to the salt damage.厦门市科技计划项目(No.3502Z20092023

    The Physiological Response of Synsepalum dulcifcum Denill Leaves to NaCl Stress

    Get PDF
    为明确神秘果(Synsepalum dulcifcum Denill)的耐盐能力,研究其在NaCl胁迫下的适应机制并丰富果树的耐盐机理,通过盆栽试验法,以0、2‰、4‰、6‰、8‰NaCl溶液分别对幼苗进行胁迫处理,测定叶片叶绿素、渗透调节物质、抗氧化物酶、丙二醛含量及土壤实际盐度。结果表明:在NaCl胁迫下,神秘果叶片的叶绿素合成受到明显抑制;超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性随浓度增加而显著升高,过氧化氢酶(CAT)活性则是先升后降,在4‰时达到最高;可溶性蛋白含量与处理浓度呈负相关;脯氨酸、可溶性糖含量和对照相比有显著增加,推测脯氨酸和可溶性糖在胁迫过程中起着重要的渗透调节作用。To clear the tolerance and adaptive mechanism of S. dulcifcum and to rich the theory about the salt tolerance mechanism of fruit trees. The potted plants were watered with 0, 2‰, 4‰, 6‰, 8‰ NaCl and the physiological characteristics including the changes about chlorophyll, soluble protein, soluble proline, soluble sugar,SOD, POD, CAT, MDA of NaCl stress in S. dulcifcum leaves were measured. The result showed that the chlorophyll synthesis was significantly restricted under NaCl stress. The activity of SOD or POD increased clearly with the NaCl concentration, and the CAT activity increased to a peak under 4‰ NaCl and then dropped. The content of soluble protein dropped under NaCl stress while that of proline, soluble sugar increased significantly. It was deduced that proline or soluble sugar working as osmotic potentials in cells played a key role in salt tolerance of S. dulcifcum.厦门市科技计划项目(No.3502Z20092023

    Experimental Study on the Combined Evaporation Effect and Thermocapillary Convection in a Thin Liquid Layer

    Get PDF
    The coupling mechanisms and flow characteristics of thermocapillary convection in a thin liquid layer with evaporating interface were studied. The planar liquid layer, with the upper surface open to air, was imposed externally horizontal temperature differences. The measured average evaporating rates and interfacial temperature profiles indicated the relative importance of evaporation effect and thermocapillary convection under different temperature gradients. A temperature jump was found at the interface, which was thought to be related to the influence of evaporation effect. All above mentioned results were repeated in a rarely evaporating liquid to compare the influence of evaporation effect

    Sessile Drop in Microgravity: Creation, Contact Angle and Interface

    Get PDF
    We present in this paper the results obtained from a parabolic flight campaign regarding the contact angle and the drop interface behavior of sessile drops created under terrestrial gravity (1g) or in microgravity (mu g). This is a preliminary study before further investigations on sessile drops evaporation under microgravity. In this study, drops are created by the mean of a syringe pump by injection through the substrate. The created drops are recorded using a video camera to extract the drops contact angles. Three fluids have been used in this study : de-ionized water, HFE-7100 and FC-72 and two heating surfaces: aluminum and PTFE. The results obtained evidence the feasibility of sessile drop creation in microgravity even for low surface tension liquids (below 15 mN m (-aEuro parts per thousand 1)) such as FC-72 and HFE-7100. We also evidence the contact angle behavior depending of the drop diameter and the gravity level. A second objective of this study is to analyze the drop interface shape in microgravity. The goal of the these experiments is to obtain reference data on the sessile drop behavior in microgravity for future experiments to be performed in an French-Chinese scientific instrument (IMPACHT)

    引江济淮工程对派河水环境的影响

    Get PDF
    引江济淮工程是淮河流域水资源战略配置及巢湖和淮河水环境综合治理的重要措施,并列入国家加快推进的172项重大水利工程。引江济淮工程派河段是按照丰、枯水期严格设计的,派河水质不仅直接影响巢湖口的水质,还将间接影响淮河水质。结合派河现状水文、水质条件,采用明槽恒定均匀流公式预测了引江济淮工程对派河规划年水文情势的影响,预测结果表明:工程实施后,派河水位将升高1. 01~2. 32 mm,流速将增大0. 24~0. 33 m/s,流量将增大76~103 m3/s;采用一维稳态稀释、降解综合模型对工程实施后派河国控断面水质的变化进行预测,以枯、丰水期的污染物背景浓度值为基础,考虑了枯、丰水期输水方向的变化,水质预测结果表明工程实施后水质将有较大改善。国家科技重大专项水体污染控制与管理“清水廊道技术标准化与产业推广模式构建”(2017ZX07603-004-04

    福建武夷山黄山松群落的钾、钠累积与循环

    Get PDF
    本文主要讨论武夷山黄山松群落的钾、钠累积和循环。测定结果表明:(1)群落现存量中钾、钠的库量分别为35.876g/m~2和2.637g/m~2,其中地上部分为19.944g/m~2(占总库量的55.59%)和1.817g/m~2(占68.90%);地下部分别为15.932g/m~2(占44.41%)和0.820g/m~2(占31.10%);(2)在钾、钠的生物循环中,年吸收量分别为2.230g/m~2·a和0.136g/m~2·a;年存留量分别为2.230g/m~2·a和0.036g/m~2·a;(3)钾的周转期55年,钠的周转期75年,钾的周转比钠快;(4)钾的富集率为1.160,说明该群落中林木仍在对钾吸收累积;而钠的富集率为0.929,说明了在该群落中林木对钠不再累积

    珠穆朗玛峰北坡6000m以上主要生境细菌群落特征

    Get PDF
    流式细胞技术及构建的细菌16S rRNA基因文库揭示了珠穆朗玛峰北坡6600~8000m表层雪中细菌的数量,以及6000m冰塔林、6350m冰川融水和6600m表层雪中细菌的群落特征.珠峰北坡表层雪中细菌数量高于南极地区,但与其他高山雪中相似.表层雪中细菌的数量有随海拔升高而增多的趋势,但与离子的浓度相关性不太.珠峰北坡冰冻环境中的细菌16S rRNA序列与土壤、湖泊和河流、动植物体及其他冷冻环境中细菌的相似.冰塔林、冰川融水和表层雪中细菌具不同的群落特征,Cytophaga-Flavobacterium-Bacteroides(CFB)类群细菌在冰川融水中占绝对优势,冰塔林中属于β-Proteobacteria和CFB类的细菌为优势种,而表层雪中细菌则以β-Proteobacteria和Actinobacteria类的细菌为主,不同生境中细菌群落的不同可能是由于细菌的沉积后变化引起.国家重点基础研究发展计划项目(批准号:2005CB422004);; 国家自然科学基金项目(批准号:40121101,40401054);; 中国科学院创新项目(批准号:KZCX3-SW-339);; “百人计划”项目及国际社会公益项目(批准号:2005DIA3J106

    珠穆朗玛峰地区东绒布冰川冰雪微生物群落及其季节变化

    Get PDF
    通过流式细胞计数和构建环境样品16S rRNA基因的克隆文库,分析了珠穆朗玛峰地区东绒布冰川冰雪微生物数量和菌群结构特征及其与季节变化的关系.珠峰地区冰雪微生物的16S rRNA基因序列分属于α,β,γ-变形菌纲,放线菌门,厚壁菌门,CFB,蓝细菌,真核质体,待定门TM7共9大类,以γ-变形菌纲为主要类群,其中Acinetobacter和Leclercia属是整个菌群中的优势属.微生物的数量和菌群结构具有明显的季节特征,夏季微生物的数量高于冬季;菌群结构具有一些共有属种的同时,在夏、冬季雪中具有各自特有的属种,共有属种推测是青藏高原局地源的微生物,序列同源性分析结果表明,夏季较多细菌属种与海洋环境相关,冬季细菌则具有更强的耐冷性.微生物明显的季节变化可能是受珠峰地区夏季和冬季不同水汽来源的影响
    corecore