14 research outputs found

    新疆水资源开发和优化配置研究

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    随着新疆工业和城市建设高速发展,人口和灌溉面积快速增长,水资源供需矛盾日益严重,水资源开发利用导致的生态环境问题日益突出。因此,深入思考和研究新疆水资源开发利用方略,制定科学合理水资源开发利用的优化配置战略,对于确保新疆经济社会可持续发展、生态环境良性循环有着十分现实的实践意义

    塔里木河下游植被生态风险遥感定量评估

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    以我国最大的内陆河——塔里木河下游区段为研究区域,将遥感、地理信息系统等技术手段与模糊数学方法相结合,根据ERA框架和层次分析思想,建立塔河下游植被的生态风险评估指标,运用模糊综合评判的方法进行塔河下游植被生态风险的遥感定量评估.评估结果:①塔河下游的植被生态风险程度较重,普遍都是中度、重度风险;②从英苏到台特玛湖河段植被风险最大;③明显呈现出下游上段植被风险小于下游下段,绿洲内部植被风险小于绿洲外围;④偏离河道越远,植被风险越大.植被生态风险评估数据的获取是采用遥感与地面相结合的方法,这在今后的生态风险评估研究中将有很大的应用潜力.利用RS和GIS技术手段并结合景观生态、模型预测的生态风险评估正处于研究开发阶段,如何把这些方法运用到干旱区特殊环境的生态风险评估之中,将是干旱区环境研究的一个新方向

    快速流化床径向空隙率分布的进一步研究

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    本工作进一步研究了颗粒物性以及快速床直径对径向空隙率分布的影响.在三种不同大小的快速床中的实验结果表明,对于直径约为50μm的 A 类物料快速床,径向空隙率分布仅依赖于截面平均空隙率,而操作条件,颗粒密度和床层直径无直接影响。不同条件下的几乎全部径向空隙率分布实验结果均可用下面简单的经验关联式足够满意地给予描述:ε=(?)(0.191+φ~(2.5)+3φ~(11)

    ~(12)C~(6+)离子辐照对4种农作物种子出苗率及幼苗生长的研究

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    以能量为80MeV/u的12C6+离子为诱变源辐照油菜、胡麻、大葱和兵豆的干种子后,研究了不同剂量处理对4种农作物M1和M2代种子出苗率及幼苗生长的影响。实验结果表明:重离子所导致的M1代生物学效应因不同的物种而表现出一定的差异,适当剂量C离子辐照促进了油菜和胡麻M1代出苗率和幼苗的生长;而不同剂量的C离子辐照抑制了大葱的出苗率和幼苗的生长;兵豆3个剂量下的出苗率和对照相差很小,但90Gy辐照有利于其生长。到了M2代,4种作物辐照组的发芽率都低于各自的对照组;30Gy剂量下的油菜、胡麻和兵豆长势最好;大葱依然是对照的长势最好

    ~(12)C~(6+)重离子辐照胡麻种子初步研究

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    本文研究了6×108cm-2、1.8×109cm-2和3.6×109cm-2的12C6+重离子束辐照对胡麻种子M1代生物学性状和DNA分子多态性等方面的影响。6×108cm-2辐照处理可引起胡麻发芽率提高,促进植株株高,增强花粉活力。同时辐照处理使胡麻种子千粒重和含油量有不同程度提高,辐射剂量越高,两者数值越大,3.6×109cm-2辐射剂量的胡麻种子千粒重和含油量与对照组的相比分别高出了16.5%和19.9%,此外在此剂量处发现了花粉发生了形态变化。辐照处理对胡麻DNA分子也产生了影响,筛选出的14个随机引物可以扩增出清晰、稳定、重复性好的DNA片段,有52个是多态性DNA片段,比率为52.5%

    Core-Shell Structured Ru@PtRu Nanoflower Electrocatalysts toward Alkaline Hydrogen Evolution Reaction

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    本文通过分步还原Ru、Pt前驱体,制备了以Ru为核、PtRu合金为壳的[email protected]纳米花电催化剂,其平均直径为16.5±4.0 nm. 利用高分辨电子显微镜、电感耦合等离子体原子发射光谱和X射线光电子能谱等表征了这种电催化剂的结构和组成. 在1 mol·L -1 KOH水溶液中,核壳结构[email protected]/C纳米花氢析出反应的过电位为22 mV(@10 mA·cm -2),耐久性测试后过电位增加至30 mV(@10 mA·cm -2),明显优于商业Pt/C电催化剂(初始值:60 mV@10 mA·cm -2,耐久性测试后:85 mV@10mA·cm -2). 显著提高的电化学活性可能源于核壳结构[email protected]纳米花的电子效应和几何效应,耐久性的改善可能源于核壳结构[email protected]纳米花结构的稳定性.Water electrolysis for hydrogen production is beneficial for solving the problem of energy crisis and environmental issues. It is necessary to study highly active and cost-effective catalysts toward hydrogen evolution reaction (HER) to reduce the consumption of noble metals. Herein, we report the synthesis of core-shell structured [email protected] nanoflowers electrocatalyst by stepwise reduction of Ru and Pt precursors in the mixture of oleylamine and benzyl alcohol at 160 oC. The average diameter of the resultant [email protected] was 16.5±4.0 nm with a bulk atomic ratio between Pt and Ru of 0.24:1 and a surface ratio of 3.3:1 between Pt and Ru. Therefore, we speculate the formation of core-shell structure with Ru as the core and PtRu alloy as the shell. The performance of the electrocatalyst toward alkaline HER was tested in 1.0 mol·L -1 KOH aqueous solution. The [email protected] exhibited pronounced alkaline HER activity with a small overpotential of 22 mV at 10 mA·cm -2, a low Tafel slope of 43 mV·dec -1, and a high mass activity of 5.68 A·mg -1Pt+Ru at an overpotential of 100 mV, all largely surpassing commercial Pt/C (60 mV, 101 mV·dec -1, 1.53 A·mg -1Pt). The attained [email protected] also held outstanding long-term cycling stability. After 10,000 potential cycles from 0.1 to -0.1 V (vs. RHE), the overpotential increased to 30 mV at 10 mA·cm -2, while increased to 85 mV for Pt/C. The significantly improved electrochemical activity may be derived from the electronic and geometric effects of the electrocatalyst. The improvement of durability may be due to the stability of the flower-like dendritic morphology.国家重点研发计划课题No(2019YFB1504501);大连理工大学重点专项No(DUT19ZD208);大连理工大学重点专项No(DUT20ZD208);中央引导地方专项No(2020JH6/10500021);辽宁省重点研发计划项目No(2020JH2/10100025);大连市重点学科重大项目资助No(2020JJ25CY003)通讯作者:宋玉江E-mail:[email protected]:SONGYu-jiangE-mail:[email protected]大连理工大学化工学院精细化工国家重点实验室,辽宁 大连 116024State Key Laboratory of Fine Chemicals, School of Chemical Engineering,Dalian University of Technology, Dalian 116024, Liaoning, Chin
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