为了研究不同开口形式的封闭式声屏障在高速列车所产生风压作用下的受力特征,以某高铁声屏障为研究对象,利用有限元软件Midas建立顶部不同开口间距的双侧封闭式声屏障及顶部不同覆盖长度的单侧封闭式声屏障整体模型;将速度为350 km/h的列车驶过时产生的脉动风压激励时程作用于声屏障结构整体模型,计算得到声屏障结构的静力响应和动力时程曲线;最后计算动力放大系数.研究结果表明:双侧封闭式声屏障顶部增加开口间距和单侧封闭式声屏障顶部覆盖长度减小都有利于风压的释放,改善结构受力情况,随着开口间距增加或覆盖长度减小,有利作用愈加明显;对于双侧封闭式声屏障,开口2 m时立柱最大动应力是开口8 m时立柱最大应力的1.15倍,放大系数也增加0.12;对于单侧封闭式声屏障中,覆盖8 m时立柱的最大动应力是覆盖2 m时立柱的最大动应力的1.28倍,放大系数也增加0.37.

在线消费是当今互联网时代日益普遍的消费形式.与传统线下消费相比,在线消费环境更简单,消费者心理却更复杂,适合借助神经科学工具打开消费者大脑中的"黑箱",解释消费者行为.然而,消费者神经科学作为一种新兴的研究视角目前并未普及,且相关研究主要聚焦于传统线下消费,对在线消费者行为关注较少.鉴于此,本文首先阐述了消费者神经科学的概念内涵与发展历程,分析了神经科学方法区别于传统消费者行为学研究方法的主要优势,并介绍了EEG/ERPs、fMRI、眼球追踪技术三种在在线消费者行为研究中应用较为普遍的神经科学工具.随后,本文介绍了用于刻画在线消费者行为模式的AISAS模型,该模型将在线消费者行为划分为五个阶段,本文以此为框架梳理了上述三种神经科学工具在在线消费者行为各个阶段研究中的具体应用.本研究总结了不同工具在在线消费者行为研究中的适用范围,并结合在线消费的特点提出了未来的研究方向,有助于推进在线消费者行为研究.

Objective:To compare the efficiency of autoregressive integrated moving average (ARIMA) model and exponential smoothing model in predicting the reported cases of hepatitis A in China, so as to provide an appropriate model for the surveillance and early warning of hepatitis A.Methods:Monthly reported cases of hepatitis A in China between 2010 to 2020 were collected from the Data-center of China Public Health Science. ARIMA model and exponential smoothing model were used for data fitting to get the optimal models, respectively. The selected models were used to predict the monthly reported cases from Jan to Oct 2021 and the prediction accuracies were compared.Results:The optimal ARIMA model was ARIMA (1, 1, 0) (1, 0, 0) 12 while Holt-Winters multiplicative model was the optimal model for exponential smoothing method. For the two models, the mean absolute percentage errors were 15.64% and 13.08%, and the mean absolute errors were 144 and 124, respectively. Conclusions:Holt-Winters multiplicative model showed better prediction accuracy, and can be used in fittings and predictions in time series with minor fluctuation.

为研究核基质结合区对逆转录病毒载体表达外源基因的调控作用,将CAT基因插入到载体pLXSN中构建出中间载体,构建出在5′端和3′端含人β?珠蛋白核基质结合区的载体.逆转录载体转染PA317细胞后G418筛选,提取PA317阳性细胞病毒上清液转染Bel?7404,经G418筛选出阳性细胞.测定3组CAT报告基因表达量.结果显示,与中间载体相比,3′端含核基质结合区的载体可以显著提高CAT报告基因的表达量(P<0.05),而5′端含MAR序列的载体不能显著提高基因表达水平(P>0.05).以上结果表明MAR介导逆转录表达载体能提高外源报告基因CAT的表达水平,且MAR对转基因表达调控作用与其在载体上插入位置有关.

以某大厦空气源热泵热水系统为实际工程背景,针对原有空气源热泵热水系统存在的混水损失、开停损失、热泵能效不高等问题进行改进,本文设计了一种双温水箱结合梯级加热、部分开停的空气源热泵热水系统.本文利用数值仿真方法搭建了热水系统仿真模型,并对改进前后的热水系统进行节能分析,结果表明:双温水箱方案可以有效减少混水损失,降低热泵冷凝温度,提高机组能效,系统供热能力可提升2％～5％,节能量可达10％～12％;在此基础上引入梯级加热可进一步提升能效,在用水比例高时提升明显,达15％～17％.

研究目的:郑北大桥索梁锚固结构采用锚拉板结构形式,该区域构造复杂,焊缝交错,部分位置存在明显的应力集中现象,恒载作用下易发生塑性破坏,反复荷载作用下易产生疲劳破坏.通过建立精细化有限元模型,分析锚拉板式索梁锚固结构的易损部位,对局部细节进行设计参数优化,从而改善其恒载和活载下的受力性能.提取疲劳易损部位热点应力,通过热点应力S-N曲线和线性累积损伤理论计算其疲劳寿命,验证参数优化效果. 研究结论:(1)在原设计的基础上适当优化锚拉板厚度能有效改善锚拉板式索梁锚固结构恒载下受力性能,防止材料塑性破坏;(2)经热点应力法计算疲劳寿命验证,在原设计的基础上适当优化圆形过渡区半径、锚拉板厚度、锚筒厚度能提升锚拉板的疲劳寿命;(3)本文研究结论可运用于今后的斜拉桥锚拉板式索梁锚固结构的设计中,以供相关设计人员参考.

文章提出驱动行业工业互联网可持续发展的四大逻辑:价值逻辑、科学逻辑、技术逻辑和商业逻辑.价值逻辑从用户价值创造视角探讨平台的终极愿景;科学逻辑在原理级上探讨平台如何实现向行业用户的价值传递;技术逻辑在科学逻辑指导下,从工程实现视角探讨什么样的技术架构体系才能够持续、稳定、可靠地支撑终极愿景;商业逻辑则从平台可持续发展视角探讨建设模式、服务模式、推广模式、治理模式和商业模式如何协调一致,进而实现源源不断的商业价值流.

随着信息网络技术的发展,虚拟仿真实验在实验教学中扮演着越来越重要的角色.本文首先分析传统细胞生物学实验的教学现状,进而阐述了细胞生物学虚拟仿真实验教学模式的构建理念、拟构建基础性实验和综合性实验2单元共9模块的实验教学内容、虚拟仿真实验教学模式的几点思考.虚拟仿真实验资源能够拓展实验教学的广度和深度,延伸实验教学的时间和空间,激发学生的学习兴趣,提高学生实践创新能力.

通过查阅相关文献并结合相关的监测结果,探究层流洁净手术室感染的现状、影响因素以及存在的问题,提出合理的建议来完善层流洁净手术室管理制度和工作流程,使层流洁净手术室各环节变得更为科学化、合理化,确保有效的降低层流洁净手术室感染发生率.

分析汽车用减震塔铸件的结构特征,设计了其压铸工艺,然后利用数值模拟方法分析了铝液的流动及充型过程.结果表明,铝液在减震塔型腔中充型较为平稳,前端含氧化夹杂、卷气量大的铝液全部进入溢流槽中,避免了铸件内部因卷气而产生缺陷.另外,通过局部激冷等方法,解决了局部厚大部位易产生缩孔缺陷的问题,最终获得品质良好的铝合金减震塔压铸件.

连续刚构桥刚度较大,抗风性能较好,但在施工阶段的最大双悬臂状态下刚度较小,自然风会诱发结构抖振效应,因此需对该状态进行抗风性能研究.文章以主跨为200 m的连续刚构桥为研究对象,对引桥最大双悬臂施工状态进行风致内力计算,发现不同风速重现期下,不平衡风载变化对墩底扭矩影响最显著;该状态结构的风致振动不会引发桥上人员的舒适性问题;在施工状态设计基准风速条件下,主梁悬臂端竖向抖振位移较大,需采取适当控制措施.

Good laboratory practice (GLP) plays an important role in pre-clinical studies,which are a key stage in new drug research and development (R&D).The development of GLP in China started in the late 1990s.Following 20 years of developments,GLP system has already been established in this country.This review firstly evaluated all the institutions in this field,and described the annual number and total number of institutions,the distribution of GLP institutions,the types of GLP institutions,and the service provided by these GLP institutions.Since the initiation of the National Key Technology R&D Program during the 11th Five-Year Plan,it had a significant effect on the development of GLP.Therefore,the institutions which have undertaken projects from this program will be introduced later.We also described the infrastructure of hardware and software in GLP institutions along with their faults,such as variation in development and the lack of innovation.

近年来我国在创新驱动发展战略指导下,根据科技体制改革总体部署,相继出台了一系列有关科技计划项目管理的文件,如《关于深化中央财政科技计划(专项、基金等)管理改革方案》(国发[2014] 64号)、《中央财政科技计划(专项、基金等)监督工作暂行规定》(国科发政[2015]471号)、《科技监督评估体系建设工作方案》(国科发政[2016]79号)等.特别是,2016年3月科技部发布《中央财政科技计划(专项、基金等)项目管理专业机构管理暂行规定》,进一步明确了专业机构在科技计划项目管理中的地位和职责,我国科技计划项目管理也随之进入一个新的阶段.依托专业机构管理科技计划项目是我国科技体制改革的重要环节,对提高科技计划项目组织实施高效运转有着重要意义.

通过统计我国典型油罐火灾案例,计算出实际火场的泡沫灭火剂实战系数,提出了油罐火灾泡沫灭火剂实际用量的3个影响因素:泡沫飞散罐外因素、着火油罐内部影响因素、气候影响因素.采用层次分析法建立了泡沫灭火剂用量评价数学模型,再将数学模型计算得到的结果与统计得到的实战系数进行对比,分析误差,有助于消防部队在火灾现场更加科学、合理地调用泡沫灭火剂.

In every historical stage of social development, due to the impact of specific political, economic, cultural and other factors at the time, the landscape environment wil have different forms of artistic expression and its characteristics, reflecting the traditional culture of the people to some extent, understanding and grasp. This article from the landscape and urban context inheritance perspective on how to build a modern landscape design thinking in traditional culture connotation.

Because of the traditional concept of culture rediscovered and support among the people,Chinese traditional culture with unique form of national symbols are reinterpreted, which becomes the bright points of modern design. This paper brielfy expounds the symbols of traditional Chinese culture combined with the actual case analysis,summarizes the present situation of the modern landscape design from the aspects of painting,color,and the traditional symbols with comparative study on the experiment and application of Chinese traditional cultural elements in modern landscape.This paper has practical signiifcance and reference value for the design of modern landscape,inheritance and development of traditional Chinese cultural spirit.

Color is an important element of an urban image,but the studies on urban architecture color in China are still in the primary stage. According to the status quo research and color analysis,comprehension and initial awareness of Tianjin urban architecture color planning and control are formed. Taking architectural color planning in Tianjin central district as an example,the article explores control methods as well as the development status of urban architecture color planning.

Objective To discuss the value of combined detection of lipids various components to predicting type 2 diabetes with coronary heart disease(CHD).Methods 64 cases patients with type 2 diabetes combined CHD were set as observation group,and 32 cases patients with simple type 2 diabetes were set as control group.Cholesterol(TC),triacylglycerol(TG),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),apolipoprotein A1(ApoA1),apolipoprotein B(ApoB),lipoprotein(a) of 2 groups were detected,and Gensini score were used.Results The level of TC、TG、LDL-C、ApoB、Lp(a)and score of Gensini in observation group were higher than those of control group,and the level of HDL-C、ApoA1 and ApoA1/ApoB were lower than those of control group,the difference were statistically significant(P0.05 or P0.01).The correlation analysis showed that ApoA1、HDL-C in observation group were negative correlation with Gensini score,but positive correlation with TC 、TG、LDL-C、Lp(a)、ApoB.ApoB and LDL-C accounted for the largest percentage in all of the anomaly blood lipid indicators of observation group.Conclusion Lipid metabolism of patients with type 2 diabetes combined CHD has an obvious disorder,lipids various components are closely related with type 2 diabetes combined CHD,especially for ApoB and LDL-C.