To predict the photocatalytic degradation rate of organic pollutants,and investigate the structure-activity relationship between pollutant molecular structures and degradation rate,a ma-chine learning model based on molecular fingerprints was developed.The model utilized a dataset comprising 523 records of 81 organic pollutants,with MACCS molecular fingerprints of pollu-tants and five experimental conditions(irradiance,temperature,catalyst dosage,initial pollutant concentration,and pH value)serving as input features.Ten machine learning algorithms were employed for modeling purposes.The results demonstrated that the LightGBM algorithm exhibi-ted the highest performance(R2=0.909 4).Additionally,the contribution of each input feature to the degradation rate was evaluated using the SHAP framework,to elucidate the specific factors influencing the degradation rate.The analysis revealed that the inherent structural characteristics of the pollutants played a pivotal role in determining the rate.Moreover,the pollutants contai-ning halogen atoms,nitrogen atoms,and unsaturated carbon within their molecular structures exhibited the fastest degradation rate,whereas those containing ether bonds or carbonyl groups exhibited the slowest degradation rate.
The main purpose of this article is to study the calculating problem of one kind fourth power mean of the generalized Kloosterman's sums and provide an accurate calculating formula for it utilizing analytical methods and character sums' properties. Simultaneously, the work also provides a fresh and valuable approach for researching the related power mean problem.
针对周代华夏族贵族阶层男性婚服类型的问题,结合相关历史文献和图绘资料,对周代华夏族上层社会的男性婚服进行了推导和梳理.结果表明:从文化背景和形成条件的角度,婚服是在周代逐步完善且在儒家思想影响之下逐渐构建而成的一种礼仪服饰文化,其形成和发展与当时的冠服制度和祭祀文化息息相关;从服饰类型的角度,周代华夏族贵族阶层的男性要依据其身份地位服用不同样式的婚服,士以上阶层亲迎时身穿冕服,头戴冕冠,足蹬赤舄,其身衣纹样和冕冠旒数随穿着者身份等级递增;而士人新婿则着爵弁服行礼,头戴爵弁,足配纁屦,其衣身并无章彩.
水性聚氨酯是一种环保的织物涂层剂,但存在防水性能差和吸湿返黏等问题,为此本研究制备了一种有机硅改性的多羟基聚氨酯乳液,配合可水分散的多异氰酸酯组成双组分水性聚氨酯织物涂层胶.结果表明:聚硅氧烷改性后聚氨酯乳液粒径增大,粒径分布变宽;当聚硅氧烷质量分数低于6%时乳液可以获得良好的储存稳定性;聚硅氧烷改性可以明显提高聚氨酯涂层表面疏水性,使其不易返黏,但使涂层后织物透湿性降低;交联剂的引入使涂层织物的耐静水压明显提高,且其不易吸湿返黏;但织物手感变得粗糙;当双组分水性聚氨酯的OH/NCO比值低于1∶3时仍能维持柔软手感.
为更好地促进服装热防护性能测评技术的发展,从标准化的测试装置和自开发类的测试装置2个角度出发,梳理防护服装热防护性能测试的相关设备.针对标准化测试装置,分析了其测评原理及局限;针对自开发类测试装置,主要从热灾害环境模拟、人体特性模拟、织物特性模拟3个角度进行总结,其中人体特性模拟方面归纳了自开发类测试装置对人体曲面形态、人体运动、人体出汗因素的模拟手段.分析表明,现有测试仪器主要采用单一形式的热源,而多灾害混合式热暴露环境的模拟还需进一步探索;适用于织物小样的台式测试设备应实现人体特性及织物特性的真实状态模拟;适用于服装整体的假人测试设备所模拟的测试条件应更加多样化.
