碱金属硝酸盐在1,2-丙二醇—水混合溶剂中15℃和45℃的溶解行为研究

采用自制的相平衡研究装置,用密度-折光率联合的方法,测定了碱金属硝酸盐在1,2-丙二醇/水(0～1)混合溶剂中15℃和45℃时的平衡溶解度.利用DMA4500密度计和RXA170折光率仪测定了饱和溶液15℃和45℃下的密度和折光率.实验结果表明,随着混合溶剂中1,2-丙二醇含量增加,碱金属硝酸盐的溶解度降低.饱和溶液的密度随着混合溶剂中1,2-丙二醇含量的增加而减小,但折光率却呈现出增加的趋势.用四参数经验关联方程对所有饱和体系的溶解度、折光率及密度数据进行了拟合.盐析率结果表明,1,2-丙二醇对碱金属硝酸盐都有盐析作用,温度升高,盐析率稍微增大.     

隧道施工地层危险性评估模型研究

随着交通基础设施建设的大规模展开,对隧道工程需求量越来越大,隧道施工中的安全和风险控制问题变得更加突出。不利地层条件一直是影响隧道施工安全和风险的关键因素。利用相互作用矩阵确定各个主要地层参数的相对权重,采用概率方法和Monte Carlo模拟技术处理地层参数取值的不确定性,提出地层危险性指数计算公式和地层危险性等级划分方法,建立隧道施工地层危险性评估模型,并对不同地层危险性等级隧道施工风险管理的原则性对策提出建议。     

关于f(k)fn的值分布

利用Nevanlinna值分布理论,讨论了f(k)fn的值分布,推广了Hayman、仪洪勋和叶寿桢等人的相关结果.     

不同行业工业用地集约利用水平比较研究——以江苏省典型区域为例

研究目的：通过对不同行业工业用地集约利用水平的测算,揭示其集约利用水平及其差异性;研究方法：以江苏省典型城市为研究区域,在工业企业调研的基础上,通过建立不同行业工业用地集约利用评价指标体系,评价研究区域工业行业用地集约利用水平;研究结果：江苏省典型区域不同行业工业用地集约利用水平存在显著差异,其中交通运输设备制造业、纺织服装、鞋、帽制造业、通信设备、计算机及其他电子设备制造业的用地集约水平最高,而医药制造业、专用设备制造业用地集约水平较低;研究结论：根据集约用地评价结果,对江苏省工业行业采取针对性的措施提高其集约利用水平,以缓解江苏省经济社会发展过程中人多地少的矛盾,为经济的进一步快速发展提供条件。     

Characterstics of seasonal variations of leaf n-alkanes and n-alkenes in modern higher plants in Qingjiang, Hubei Province, China

On the basis of GC and GC-MS analyses, the seasonal variation of leaf lipids is observed in five plant species in Qingjiang in Hubei Province. The CPI values （carbon preference index） of n-alkanes decrease gradually from May to November, though the carbon number distributions and the predominant carbon number in an individual species keep unchanged. The declined CPI values might be caused by the leaf fading, which is further supported by a comparison of the defoliated leaves with the fresh leaves. This observation infers the CPI values of n-alkanes in Quaternary sediments can be used as a tool to index the humification, and thus the climatic and the environmental conditions. The plants analyzed here show a remarkable difference in n-alkanes abundance, suggesting their differential contribution to the n-alkanes identified in sediments. The abundance and the compound species of the n-alkenes detected in the plant leaves change greatly with the seasons due to the influence of temperature, with the least compounds being identified in August.     

Structures of magnetic null points in reconnection diffusion region: Cluster observations

Magnetic reconnection is a very important and fundamental plasma process in transferring energy from magnetic field into plasma. Previous theory, numerical simulations and observations mostly concentrate on 2-dimensional （2D） model; however, magnetic reconnection is a 3-dimensional （3D） nonlinear process in nature. The properties of reconnection in 3D and its associated singular structure have not been resolved completely. Here we investigate the structures and charactedstics of null points inside the reconnection diffusion region by introducing the discretized Poincar6 index through Gauss integral and using magnetic field data with high resolution from the four satellites of Cluster mission. We estimate the velocity and trajectory of null points by calculating its position in different times, and compare and discuss the observations with different reconnection models with null points based on characteristics of electric current around null points.     

Relationship between Chinese speech intelligibility and speech transmission index in rooms using dichotic listening

Speech intelligibility （SI） is an important index for the design and assessment of speech purpose hall. The relationship between Chinese speech intelligibility scores in rooms and speech transmission index （STI） under diotic listening condition was studied using monaural room impulse responses obtained from the room acoustical simulation software Odeon in previous paper. The present study employs the simulated binaural room impulse responses and auralization technique to obtain the subjective Chinese speech intelligibility scores using rhyme test. The relationship between Chinese speech intelligi-bility scores and STI is built and validated in rooms using dichotic （binaural） listening. The result shows that there is a high correlation between Chinese speech intelligibility scores and STI using dichotic listening. The relationship between Chinese speech intelligibility scores and STI under diotic and dichotic listening conditions is also analyzed. Compared with diotic listening, dichotic （binaural） listening （an actual listening situation） can improve 2.7dB signal-to-noise ratio for Mandarin Chinese speech intelligibility. STI method can predict and evaluate the speech intelligibility for Mandarin Chinese in rooms for dichotic （binaural） listening.     

临界法测三棱镜的折射率

临界法测三棱镜的折射率不仅方法直观而且精度也较高。本文介绍了用临界法测三棱镜的折射率的基本操作方法,给出了临界法测折射率的计算公式。     

可拓综合指数及其在水环境质量评价中的应用

针对现有环境质量评价指数的不足,提出了一种基于可拓理论的新指数——可拓综合指数(EQI): EQI=sum from j=1 to m j·(?)_j(p)/sum from j=1 to m(?)_j(p)。其中,K_j(p)为待评对象p关于等级j的关联度。构建了基于MS Excel和MATLAB并通过Excellink联系的可拓综合评价系统,主要包括评价标准数据库模块和可拓质量评价模块,有简单关联函数法、层次分析法、特尔菲法3种赋权方法可资选择。应用于流溪河水质评价,所得结果与文献报道和水质实际情况吻合。     

基于指标体系的流域水安全诊断评价模型

 为在随机、模糊、经验等不确定性环境下定量评价流域水安全系统的总体状况,识别使流域水安全系统或其子系统处于不安全的主要指标,在流域水安全的理论分析、专家咨询和调研基础上建立了流域水安全诊断评价指标体系和评价等级标准,提出用基于加速遗传算法的模糊层次分析法筛选指标、确定水安全评价系统中各指标和子系统的权重,用集对分析方法构造流域水安全评价指标样本值隶属于可变模糊集“水安全诊断评价标准等级”的相对隶属度函数,建立了流域水安全诊断评价模型（SPA-DAM）。SPA-DAM在巢湖流域水安全诊断评价中的结果说明：流域近7a来水安全等级值均处于临界安全附近,虽存在缓慢改善的趋势,但由于水资源安全和水灾害防治安全程度不高、波动性大,水环境安全和社会经济安全程度不高、改善缓慢,因此总体上该流域的水安全形势不容乐观;合理调控水资源利用率、人均水资源量、单位面积化肥施用量、环保投资占GDP比例、单位面积蓄水工程总库容、水利工程投资占GDP比例、区域开发指数、人口密度和科技教育投入占GDP比例等关键指标,是提高该流域水安全保障程度的重要措施。SPA-DAM的评价结果可靠合理,方法简便实用,在已知等级评价标准的多层次系统诊断评价问题中具有一定的应用价值。