The reasonable quantification of the concrete freezing environment on the Qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering ma...The reasonable quantification of the concrete freezing environment on the Qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering managers should take into account. In this paper, we propose a more realistic method to calculate the number of concrete freeze–thaw cycles(NFTCs) on the QTP. The calculated results show that the NFTCs increase as the altitude of the meteorological station increases with the average NFTCs being 208.7. Four machine learning methods, i.e., the random forest(RF) model, generalized boosting method(GBM), generalized linear model(GLM), and generalized additive model(GAM), are used to fit the NFTCs. The root mean square error(RMSE) values of the RF, GBM, GLM, and GAM are 32.3, 4.3, 247.9, and 161.3, respectively. The R^(2) values of the RF, GBM, GLM, and GAM are 0.93, 0.99, 0.48, and 0.66, respectively. The GBM method performs the best compared to the other three methods, which was shown by the results of RMSE and R^(2) values. The quantitative results from the GBM method indicate that the lowest, medium, and highest NFTC values are distributed in the northern, central, and southern parts of the QTP, respectively. The annual NFTCs in the QTP region are mainly concentrated at 160 and above, and the average NFTCs is 200 across the QTP. Our results can provide scientific guidance and a theoretical basis for the freezing resistance design of concrete in various projects on the QTP.展开更多
目的:探讨育龄期女性癌症患者生育忧虑的相关因素。方法:计算机检索PubMed、the Cochrane Library、Web of Science、Embase、Medline、中国知网、万方数据库、维普数据库、中国医学生物文献服务系统数据库中有关育龄期癌症患者生育忧...目的:探讨育龄期女性癌症患者生育忧虑的相关因素。方法:计算机检索PubMed、the Cochrane Library、Web of Science、Embase、Medline、中国知网、万方数据库、维普数据库、中国医学生物文献服务系统数据库中有关育龄期癌症患者生育忧虑相关因素的研究,对符合纳入标准的文献进行文献质量评价、内容提取和分析。结果:最终纳入25篇研究,共6516例患者。汇总分析得到48个相关因素,分为社会人口学(15个)、癌症及相关治疗(9个)、生殖生育(13个)、心理因素(11个)4个方向。结论:育龄期癌症患者得生育忧虑受到社会人口学、癌症及相关治疗、生殖生育、心理因素等各方面的影响,应引起关注。展开更多
基金supported by Shandong Provincial Natural Science Foundation (grant number: ZR2023MD036)Key Research and Development Project in Shandong Province (grant number: 2019GGX101064)project for excellent youth foundation of the innovation teacher team, Shandong (grant number: 2022KJ310)。
文摘The reasonable quantification of the concrete freezing environment on the Qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering managers should take into account. In this paper, we propose a more realistic method to calculate the number of concrete freeze–thaw cycles(NFTCs) on the QTP. The calculated results show that the NFTCs increase as the altitude of the meteorological station increases with the average NFTCs being 208.7. Four machine learning methods, i.e., the random forest(RF) model, generalized boosting method(GBM), generalized linear model(GLM), and generalized additive model(GAM), are used to fit the NFTCs. The root mean square error(RMSE) values of the RF, GBM, GLM, and GAM are 32.3, 4.3, 247.9, and 161.3, respectively. The R^(2) values of the RF, GBM, GLM, and GAM are 0.93, 0.99, 0.48, and 0.66, respectively. The GBM method performs the best compared to the other three methods, which was shown by the results of RMSE and R^(2) values. The quantitative results from the GBM method indicate that the lowest, medium, and highest NFTC values are distributed in the northern, central, and southern parts of the QTP, respectively. The annual NFTCs in the QTP region are mainly concentrated at 160 and above, and the average NFTCs is 200 across the QTP. Our results can provide scientific guidance and a theoretical basis for the freezing resistance design of concrete in various projects on the QTP.
文摘目的:探讨育龄期女性癌症患者生育忧虑的相关因素。方法:计算机检索PubMed、the Cochrane Library、Web of Science、Embase、Medline、中国知网、万方数据库、维普数据库、中国医学生物文献服务系统数据库中有关育龄期癌症患者生育忧虑相关因素的研究,对符合纳入标准的文献进行文献质量评价、内容提取和分析。结果:最终纳入25篇研究,共6516例患者。汇总分析得到48个相关因素,分为社会人口学(15个)、癌症及相关治疗(9个)、生殖生育(13个)、心理因素(11个)4个方向。结论:育龄期癌症患者得生育忧虑受到社会人口学、癌症及相关治疗、生殖生育、心理因素等各方面的影响,应引起关注。
文摘目的:检索、遴选分析痴呆病人激越及攻击行为的相关证据,呈现其非药物管理的研究现状、文献质量,最终形成最佳证据。方法:基于Joanna Briggs Institute(JBI)构建的PIPOST模式确定研究问题,结合证据资源的“6S”金字塔模型依次检索2012年1月—2022年1月发布在加拿大安大略注册护士协会(RNAO)、英国国家卫生与临床优化研究所(NICE)、中国医脉通、PubMed、EMbase、Web of Science、the Cochran Library、BMJ Best Practice、CINAHL、中国知网、中国生物医学文献数据库、万方数据库、维普数据库的相关文献。结果:共纳入文献18篇,其中指南5篇,系统评价4篇,专家共识2篇,随机对照试验7篇,从纳入的文献中综合出25条最佳证据,共4个维度,分别是痴呆病人激越及攻击行为的评估识别、非药物干预措施、控制诱因、培训与教育。结论:对于痴呆病人激越和攻击行为,目前提倡以非药物干预为主,医务人员应使用合适的工具评估病人症状,并推荐采用具有针对性的非药物干预措施。另外,还应对医护人员、家属进行预防管理激越及攻击行为相关知识培训。
