一类新型甘脲的合成

在碱的乙醇溶液中分别由苯偶酰和硫脲、4,4’-二甲氧基苯偶酰和硫脲为原料合成了两种新瓜环单体——硫代甘脲,并利用^1H NMR,^13C NMR,MS等方法对产物进行表征,表明产物为目标产物。还考察了2,3-丁二酮,3,4-己二酮,乙二醛等与硫脲的反应。     

《建筑施工技术》的教学改革

论述了建筑工程技术专业中《建筑施工技术》的教学改革思路的方法,摆脱原来传统的教学模式,结合高职教育的特点,提出课程设计新的理念,教学方法,教学模式。从而更好地与施工现场相结合,与生产实际相结合,以便培养建筑工程企业高素质技能型人才,从事建筑工程施工技术及管理工作。     

Investigation on Mechanical Properties of CMSLDS/Acrylate Copolymeric Blending Films for Warp Sizing

Carboxymethyl starch with lower degree of substitution was blended with acrylate copolymer for revealing the relation between mechanical properties and chemical structure of blending film.Effects of carboxymethylation of starch,acrylate constituent units of acrylate copolymers,and copolymer content of the film on the properties were investigated.The mechanical properties were evaluated in terms of tensile strength,breaking elongation,abrasion resistance,and flex-fatigue resistance.Film morphology was examined with X-ray diffraction (XRD),scanning electron microscopy (SEM),and atomic force microscope (AFM).It was found that the properties depended on the degree of substitution of carboxymethyl starch,chemical structure of acrylate units,and content of acrylate copolymer.Phase-separation of the two ingredients occurred within film matrix and the separation was decreased after starch carboxymethylation.Breaking elongation and flex-fatigue resistance of the film reached maximums when acrylate copolymer content was 50%.Excessively increasing the content of acrylate copolymer reduced the film properties.     

500kV输电线路风偏的探讨

随着我国500kV电网建设的快速发展,电网规模的不断扩大,各地区的输电线路日益增多,本文根据风偏闪落的原因,对500kV线路风偏跳闸进行技术分析并提出了相应的举措。     

贵州"两高"沿线特色农业气象灾害风险评估

特色农业种植受气象灾害影响明显,且受灾经济损失大,基于此,对贵州"两高"沿线主要特色农业产业种植提供气象灾害风险分析,针对春旱、夏旱、阴雨寡照、冰雹、倒春寒等气象灾害指数,统计分析研究区域内气象致灾因子,应用信息扩散法开展农业气象灾害风险评估,并采用多因子叠加分析法实现特色农业气象灾害综合风险区划.风险评估结果表明,蓝...     

紫外皮粉法测定倍花中单宁酸含量

用紫外皮粉法测定倍花中单宁酸的含量,并对实验结果进行方法学考察.经实验知在20 ℃下溶液的稳定性较好,铬皮粉在20 min后吸附达到完全,平均加标回收率为98.86%,RSD为0.85,精密度和重复性实验的RSD分别为0.07%和0.64%.用紫外皮粉法测试倍花中单宁酸含量得到的结果与用药典法测试得到的结果近似.     

响应面法优化田基黄总黄酮的吸附工艺

以田基黄为原料,选择乙醇质量分数、吸附温度和吸附时间为影响因子,总黄酮吸附率为响应值优化了大孔树脂对田基黄总黄酮的吸附工艺条件,应用Box-Behnken设计建立数学模型,并进行响应面分析.结果表明,用12%乙醇为溶剂,28 ℃温度下吸附36 min,总黄酮的吸附率为87.14%.