20 research outputs found

    农村留守经历大学生心理行为与人际关系分析

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    目的探讨农村留守经历大学生(URLB)心理行为特征以及与非URLB心理行为上的差异,为采取干预措施提供依据。方法采用流调中心用抑郁量表、状态特质焦虑问卷、简易应对方式问卷、自尊量表和大学生人际关系综合诊断量表对河北省2所高校的4080名大学生进行问卷调查。结果 URLB大学生负性情绪、积极应对方式、自尊和人际关系与非URLB大学生差异有统计学意义。相关分析表明,URLB大学生负性情绪、消极应对方式与人际关系呈显著正相关,积极应对方式、自尊与人际关系呈显著负相关。回归分析表明,URLB大学生负性情绪、应对方式和自尊对人际关系有显著的预测作用。结论 URLB与非URLB大学生在心理行为上差异有统计学意义,需要对URLB进行适当的心理干预

    Size Distribution of Particle and Polycyclic Aromatic Hydrocarbons in Particle Emissions from Simulated Emission Sources

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    采用再悬浮箱模拟得到不同粒径的烹调油烟、生物质和塑料燃烧烟尘、汽车尾气和发电机烟气等颗粒,并用gC/MS对不同粒径颗粒中18种多环芳烃(PAHS)进行了分析.结果表明,烹调油烟中颗粒物存在0.44~1.0μM和2.5~10μM两个峰值,稻草和木材燃烧排放烟尘只有0.44~1.0μM一个峰值,塑料燃烧排放烟尘的峰值不明显,汽车尾气尘因含有大量的水汽导致其粒径峰值出现在2.5~10μM,而发电机排放的烟尘约93%集中在≤2.5μM的粒径范围.烹调油烟和汽车尾气尘中低环数PAHS在2.5~10μM范围内的峰值明显;随环数增加,0.44~1.0μM范围内的峰值变得明显;不同排放源亚微米颗粒中单一PAH占全部颗粒态中该PAH的比例都呈现随分子量的增大而增大的趋势.烹调油烟和燃烧排放颗粒中PAHS的组成以菲占主导,但汽车尾气和发电机烟尘中含量最高的PAHS分别是萘和苯并[g,H,I]苝.来源特征比值的比较显示,烹调油烟与生物质燃烧颗粒中PAHS的源特征较为接近,但两者都不同于汽车尾气和发电机烟尘.Particles from cooking lampblack,biomass and plastics burning smoke,gasoline vehicular exhausts and gasoline generator exhausts were prepared in a resuspension test chamber and collected using a cascade MOUDI impactor.A total of 18 polycyclic aromatic hydrocarbons( PAHs) associated with particles were analyzed by GC-MS.The results showed that there were two peaks in the range of 0.44-1.0 μm and 2.5-10 μm for cooking lampblack,and only one peak in the range of 0.44-1.0 μm for straw and wood burning smoke.But there were no clear peak for plastics burning smoke.The peak for gasoline vehicular exhausts was found in the range of 2.5-10 μm due to the influence of water vapor associated with particles,while the particles from gasoline generator exhausts were mainly in the range of ≤2.5 μm( accounting for 93% of the total mass).The peak in 2.5-10 μm was clear for cooking lampblack and gasoline vehicular exhausts.The peak in the range of 0.44-1.0 μm became more and more apparent with the increase of PAHs molecular weight.The fraction of PAH on particles less than 1.0 μm to that on the total particles increased along with PAH's molecular weight.Phenanthrene was the dominant compound for cooking lampblack and combustion smoke,while gasoline vehicular exhausts and generator exhausts were characterized with significantly high levels of naphthalene and benzo[g,h,i]perylene, respectively.The distribution of source characteristic ratios indicated that PAHs from cooking lampblack and biomass burning were close and they were different from those of vehicular exhausts and generator exhausts.国家自然科学基金项目(40971257;41171365); 环境保护公益性行业科研专项(201009004

    五配位氧磷烷分子间配体交换反应-RNA水解和融合过程的化学模型(英文)

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    具有五元环和三配体结构的五配位氧磷烷(ab2)在碱催化条件下自发进行分子间的配体交换反应,产生不同配体组合的全部三种五配位氧磷烷(a3,b3和a2b).如果把其中a3与b3作为父代分子,其配体交换产生的五配位氧磷烷a2b和ab2可以视作子代分子,从而自发实现了分子结构的多样化.因此,五配位氧磷烷分子间配体交换反应可以作为研究生命过程中具有五配位磷中间体结构化学性质的模型,对理解基因转录和生命信息储存等过程中涉及的RNA分子剪接、水解和融合等重要生命过程的分子机制提供了重要依据.Project supported by the National Natural Science Foundation of China(Nos.21778042,41876072,21772163,41576081)the Xiamen Southern Oceanographic Center(No.17GYY002NF02)the Fundamental Research Funds for the Central Universities(No.20720170069)~

    五配位氧磷烷分子间配体交换反应-RNA水解和融合过程的化学模型(英文)

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    具有五元环和三配体结构的五配位氧磷烷(ab2)在碱催化条件下自发进行分子间的配体交换反应,产生不同配体组合的全部三种五配位氧磷烷(a3,b3和a2b)。如果把其中a3与b3作为父代分子,其配体交换产生的五配位氧磷烷a2b和ab2可以视作子代分子,从而自发实现了分子结构的多样化。因此,五配位氧磷烷分子间配体交换反应可以作为研究生命过程中具有五配位磷中间体结构化学性质的模型,对理解基因转录和生命信息储存等过程中涉及的RNA分子剪接、水解和融合等重要生命过程的分子机制提供了重要依据

    多元文化背景下的边缘书写:东南亚女性文学与中国少数民族女性文学的比较研究

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    本书主要包括绪论,第一章越南女性文学与壮族女性文学,第二章马来西亚女性与回族女性文学,第三章泰国女性文学与壮、满族女性文学,第四章 菲律宾女性文学与彝族女性文学,第五章 印度尼西亚女性文学与回族女性文学,第六章 缅甸女性文学与满族、藏族女性文学,第七章 新加坡女性文学与满族女性文学等内容

    The mechanical response of liquids depositing on a reed

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    A composite reed flexural vibration method is used to investigate the dynamic mechanical responses of deposited liquids. The composite vibration system consists of a substrate reed with a hole and of liquids deposited inside the hole. The mechanical response of the composite system was monitored in the process of evaporation of deposited liquids such as deionized water, n-propanol and ethanol. The mechanical energy dissipation increases firstly and shows a sudden decrease nearly at the end of the evaporation process. The main contribution to the mechanical energy dissipation is identified to be the damping of liquid surface wave when liquids are inside the hole. This work provides a convenient way to investigate the damping of liquid surface wave by the composite reed vibration method

    Subject identification and social network analysis of intelligent community operation(智慧社区运营的主体识别与社会网络分析)

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    伴随着对社区治理的关注,如何通过提升社区的智能化保障居民生活的安全性、舒适度以及提升公众的参与水平已经成为当前的热点问题。传统的智慧社区运营管理理论仅考虑少数利益主体,并未关注多方利益主体,且大多研究未涉及多方利益主体的网络关系。基于此,从社区智慧运营“需求-供给-调控”等维度识别智慧社区运营的主体要素,深入调查智慧社区运营的利益主体,构建关系矩阵并绘制社会网络结构图,基于UCINET 6.0软件分析网络的密度、中心性以及影响力,识别关键因素并提出多维度的政策建议,为多方参与下的智慧社区协同发展提供理论支撑

    GCr15轴承钢氮离子注入的研究

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    本文研究了GCr15钢在100keVN~+离子注入后耐磨性和硬度的变化,用AES、CEMS、XRD等方法对注入层进行了成分和物相分析。实验表明,注入层中的ξ-Fe_2N及ε-Fe~(2+x)(C_7,N)非磁性相能显著提高试样的耐磨性能。在实验条件下,有效改善GCr15钢耐磨性能的N~+注入剂量应≥5×10~(17)N~+/cm~2

    美人蕉cannaindica内生细菌促生能力及其强化水体的净化作用

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    从美人蕉(Canna indica)植物体内分离内生细菌.通过测定内生细菌产吲哚乙酸(IAA)、铁载体、固氮、溶磷能力筛选出3株内生细菌C01、C16、C20.本试验的目的为评价接种内生细菌能否促进美人蕉种子萌发和幼苗生长,并通过小型浮床水质净化试验,评价接种内生细菌后的美人蕉对水体中营养物质的去除效果.结果表明:C01、C16、C20促进了美人蕉种子的萌发、生长,C16试验组萌发率为83.3%,显著高于对照组31.1%;C16显著提高了植株的株高和根长,分别比对照组高出23.33%、40.44%.水质净化实验阶段,C16试验组总磷、总氮的去除率分别达到88.4%、96.9%,分别比对照组高出26.4%、15.6%.最终,C01、C16试验组生物量、根长都显著高于对照组.C16试验组植株体内可溶性糖含量、可溶性蛋白显著高于对照组317.3%、97.8%.经鉴定,C01为荧光假单胞菌(Pseudomonas fluorescens),C16为肠杆菌(Enterobacter sp.),C20为欧文氏菌(Erwinia sp.)
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