Group and group-interaction contribution method for estimating the melting temperatures of deep eutectic solvents

Deep eutectic solvents (DESs) are mixtures of two or more components that have lower melting temperatures compared to their constituting components. DESs possess many advantages, for example, low volatility, low flammability, and low toxicity, which make them promising alternatives to traditional organic solvents. The melting temperature, one of the important physical properties, is of essential importance for industrial applications. In this work, a group and group-interaction contribution method was proposed to estimate the melting temperatures of DESs using an extensive database (1528 DESs, 1541 data points). The average absolute relative deviation (%AARD) between the estimated and experimental values of the melting temperature was 5.67% for binary DESs. Subsequently, this method was also extended to estimate the melting temperature of ternary DESs, with the AARD of 6.13%. The results indicate the high accuracy and broad applicability of the method and pave the way for the rational design of task-specific DESs.     

苯酚与异丙醇烷基化合成异丙基苯酚的热力学和动力学

基于Benson基团贡献法研究苯酚与异丙醇烷基化反应过程,确定了主、副反应的反应热、平衡常数及平衡转化率,得到反映热力学性质的反应方程式并建立反应的网络结构,为该体系的工艺设计提供热力学依据。在苯酚与异丙醇物质的量比为0.5~2.0、温度(513.15~573.15)K、空速8 h-1和催化剂颗粒(40~60)目[相当于粒径(0.45~0.30)mm]条件下进行本征动力学实验。选用幂数型动力学模型,对参数进行估值。用Runge-Kutta法进行数值积分,Simplex法对参数进行优化,F统计法对模型进行检验,最终得到能较好描述反应的本征动力学模型。     

2011～2020年华北平原气溶胶光学厚度时空分布特征及潜在源分析

随着经济高速增长和城市化进程不断加快,华北平原区域性空气污染问题愈演愈烈。针对该区域开展长时序气溶胶光学厚度时空分布特征和潜在源分析研究,对华北平原大气污染治理具有重要意义。基于长时序MODIS/Terra C6.1 MOD04_L2气溶胶光学厚度产品,分析华北平原气溶胶光学厚度的时空分布特征,并利用后向轨迹聚类分析讨论华北平原7个重点城市气团输送的季节变化,并以污染较为严重的河北石家庄为例进行潜在源分析和浓度权重分析,探究影响其大气质量的污染物潜在源区。结果表明:2011～2020年华北平原气溶胶光学厚度月均值呈显著的周期性变化,以年为周期,每个周期内峰值一般出现在6月至8月; 气溶胶光学厚度月际年内呈单峰分布,峰值出现在6月(0.75),最小值出现在12月(0.37); 气溶胶光学厚度季均值从大到小依次为夏季(0.67)、春季(0.59)、冬季(0.49)、秋季(0.46); 10年间气溶胶光学厚度呈下降趋势,整体下降幅度达36.84%,其中2011年最高(0.72),2018年最低(0.45); 华北平原7个重点城市春、夏、秋、冬四季主要受短距离气团输送影响较大,长距离气团输送影响较小; 2014～2020年河北石家庄的空气质量优良天数占比相对较小,空气质量状况差,影响其空气质量的污染物多为本地生成,同时也受周边省市近距离输送的影响。     

环烷酸模型化合物酯化反应体系的热力学分析

以选取的环烷酸模型化合物为基础,利用热力学方法分析其酯化反应的可能性。由于环烷酸物质结构的特殊性,它们的热力学数据通常无法直接获取,采用了基团贡献法估算酯化反应体系中环烷酸及环烷酸酯在298.15K标准态下的生成焓和标准熵,同时确定了这两种物质等压热容随温度的变化关系,进而得到了不同温度条件下酯化反应的吉布斯自由能变及平衡常数。计算结果表明,酯化反应的平衡常数很大（107）,从而确定了该反应体系的可能性。     

巴西塞尔西培-阿拉戈斯盆地油气地质特征

对巴西塞尔西培-阿拉戈斯盆地的地层与沉积和石油地质等特征进行了综合研究。盆地的主要烃源岩为阿普第阶湖相高盐度灰质黑色页岩,主要油气储集层为上侏罗统粗粒河流相砂岩储层、下白垩统三角洲相与风成相砂岩、砾岩与砾质砂岩储层、上白垩统-古近系浊积砂岩储层,区域性盖层为Ibura段和Carmpolis段及上侏罗统页岩和蒸发岩,油气主要运移期和聚集期发生在渐新世及以后,同裂谷期地层的上段（地层-构造圈闭）以及裂后层系（Calumbi地层圈闭）为具备勘探潜力的有利目标段。     

Estimation of Thermodynamic Properties of Polysaccharides

Polysaccharides are the most important components of herbal biomass with a high application potential. Their thermochemical characteristics, however, have been little studied. In the present paper, an effective thermodynamic analysis was carried out with the aim of setting a method for reasonably estimating the thermochemical properties of polysaccharides such as cellulose. The properties of formation and heat capacities were estimated by general thermodynamic methods like group contribution methods as well as methods followed from synthetic polymer studies. The results were compared with those obtained by empirical correlations derived from the data for short chain carbohydrates, the only literature data available for validation. The properties were determined depending on the degree of polymerization and temperature.     

基于1H NMR测定和基团贡献法预测石油馏分的热化学性质

测定了两种原油 2 0个石油馏分的¹H NMR谱和氢、碳元素含量等结构参数 ,以及馏分的燃烧焓、蒸发焓等热化学性质 .假设每个石油馏分仅由CH₃ 、CH₂ 、CH、ACH和C这 5种简单基团构成 ,基于¹H NMR测定和元素分析结果解出石油馏分平均分子结构中的基团数目 ,再用纯有机物的基团贡献法预测石油馏分的燃烧焓、蒸发焓 ,预测值与实验数据吻合良好     

利用贡献率分析法研究河道型水库两岸滑坡发育规律

通过实地调查发现金沙江向家坝段大多数滑坡发育于坝址-新市镇侏罗系地层,且为顺层滑坡,顺层滑坡在水库蓄水后容易复活且顺层岸坡在水库蓄水后容易发生新的滑坡.通过实地调查并借助勘察资料建立该段滑坡数据库,研究坝址-新市镇段不同岩层倾角、不同岸坡结构类型、不同河流弯曲类型对滑坡发育的影响,并且定量统计这3种因数的各种类型分别对滑坡的贡献率.结果表明:层面倾角为10°～ 19°的岸坡,对滑坡贡献率最高,层面倾角为30°～34°的岸坡对滑坡贡献率最低;缓倾外顺向层状岸坡对滑坡贡献率最高,中倾外顺向层状岸坡对滑坡贡献率最低;河流的凹岸对滑坡贡献率最高,凸岸贡献率最低.所得研究结果与实际情况较为吻合,为水库岸坡危险评价提供量化标准,同时为库区以后的规划建设提供选址依据.     

支持向量机模型改进及在短期边际电价预测中的应用

传统的最小二乘支持向量机模型对训练样本的各个输入点同等看待,各输入向量的贡献度是相同,未对离群点加以考虑.在最小二乘支持向量机模型中引入隶属度的相关理论并建立模糊隶属度函数,对离群点和正常点赋予不同的贡献度,建立了模糊最小二乘支持向量机模型.最后,以美国PJM电力市场的边际电价预测为例,验证了本文模型的预测精度比传统的最小二乘向量机模型高50％左右,且复杂程度基本不变.     

Delays caused by motorized vehicles unable to clear intersections in China： Graphical analysis

In many Chinese cities,motorized vehicles （M-vehicles） move slowly at intersections due to the interference of a large number of non-motorized vehicles （NM-vehicles）.The slow movement makes a part of M-vehicles fail to leave intersections timely after the traffic signal tums red,and thereby conflicts between vehicles from two directions occur.The phenomenon was analyzed graphically by using the cumulative vehicle curve.Delays in three cases were modeled and compared：NM-vehicle priorities and M-vehicle priorities with all-red intervals unable to release all vehicles,and longer all-red intervals ensuring release all vehicles.Marginal delays caused by two illegal behaviors that occasionally happened in mixed traffic intersections were also investigated.It is concluded that increasing the speed of M-vehicles leaving intersections and postponing the entering of NM-vehicles are the keys in mathematics,although they are uneasy in disordered mixed traffic intersections due to a dilemma between efficiency and orders in reality.The results could provide implications for the traffic management in the cities maintaining a large number of M-and NM-vehicles.