渡槽结构考虑流固耦合的横向地震响应研究

渡槽结构是一种薄壁杆件结构,有其自身特点,依据符拉索夫(Volasov)及豪斯纳尔(Housner)理论建立考虑槽内水体流固耦合的渡槽薄壁结构空间地震响应分析模型,该模型综合考虑了渡槽横向、竖向、纵向、自由扭转、约束扭转变形以及槽内水体对槽身的流-固相互作用等。由能量原理推导给出了渡槽薄壁梁段单元刚度矩阵及质量矩阵,建立了渡槽结构无水空载及槽内有水时横向地震响应计算方程。利用该模型对某单墩渡槽进行了多工况地震时程响应计算,经与解析解比较,证明模型的正确性,同时说明在地震荷载作用下,渡槽在无水空载及设计水位时的横向位移有所变化。模型计算简单易行,是考虑槽内水体流固耦合作用的渡槽薄壁结构实用的地震响应分析模型。     

在制氧机开车状态下处理导叶阀电机故障

由于进口导叶阀电机突然损坏 ,冷水机组出口水温升高 ,使制氧工况恶化 ,在制氧机不能停机的状况下 ,处理了这一起故障 ,使制氧机得以连续运行。     

在竞争和挑战中皮化经营公司的发展策略

通过分析目前我国皮化供应市场的特点，皮化经营公司的经营状况及其所面临的处境，对皮化经营公司的发展提出了应对措施。     

Comparison of a‐Si and Poly‐Si for AMOLED displays

Abstract— The characteristics of OLED backplanes including the intrinsic properties of a‐Si TFTs and LTPS TFTs will be reviewed. While LTPS TFTs reveal satisfactory stability in AMOLED‐display applications, a‐Si AMOLEDs show better uniformity and are capable of driving OLEDs. However, the stability of a‐Si TFTs under long‐term operation is still unacceptable and remains to be the key issue constraining the commercialization of a‐Si TFT AMOLEDs.     

浙北地区村域体系重组演进的实践反思

本文通过探讨迁村并点、中心村建设等方面的内容，总结反思了近几年来浙北地区村域体系重组演进过程中的一些实践成果，并结合具体案例提出了相关的应对原则与方式。     

United friction resistance in open channel flows

It is now over half a century since Keulegan conducted his open channel flow experiments.Over the past decades,many empirical formulae were proposed based on his results,however,there is still not a combined expression to describe the effects of friction over all hydraulic regions in open channel flows.Therefore,in this letter,based on the analysis of the implicit model and the logarithmic matching method,the results of Keulegan(for authentic experiment data are no longer available,here we adopt the analytical solutions given by Dou)are rescaled into one monotone curve by combining the Reynolds number and the relative roughness of the river bed.A united expression that could cover the entire turbulence regions and be validated with Dou’s analytical solutions is suggested to estimate the friction factor throughout the turbulent region in open channel flows,with higher accuracy than that of the previous formulas.     

Dynamic credit reservation for online charging of regular Internet of things traffic

According to the specifications of the Third Generation Partnership Project (3GPP), any online charging system must determine a granted unit (GU) and make reservations for each session before the serving network delivers the service. Allocating insufficient GUs to user equipment may incur excessive quantities of reservation messages; conversely, providing excessive GUs could result in an unbalanced distribution of resources. Therefore, a prudent investigation of a reservation scheme for multiple Internet of things (IoT) devices is urgently needed. In this paper, we focus on IoT devices with regular traffic, which usually generate numerous routine traffic events and few event‐driven traffic events. We combine a fixed‐order quantity model (sometimes called a Q model) and propose a novel solution to this issue. To the best of our knowledge, this is the first research to propose a solution based on such a concept. Compared with typical schemes, the simulation results show that our proposed scheme can maintain the success rate with a smaller‐than‐usual number of messages.     

Improved microstructure and properties of the gelatin film produced through prior cross‐linking induced by horseradish peroxidase,glucose oxidase and glucose

The effects of prior enzymatic cross‐linking of bovine gelatin via horseradish peroxidase, glucose oxidase and glucose on microstructure and properties of the target film (cross‐linked gelatin film) were assessed. The cross‐linked gelatin film exhibited similar film thickness and moisture content, lower water solubility and higher opacity than the gelatin film directly prepared with bovine gelatin. The cross‐linked gelatin film also demonstrated improved thermal stability and mechanical properties, characterised by higher melting point and glass transition temperature, enhanced tensile strength and elongation at break and greater storage modulus. Prior gelatin cross‐linking resulted in 30.2% and 68.6% reductions in water vapour and CO₂ permeability of the cross‐linked gelatin film, respectively, but did not affect oil permeability. Furthermore, the cross‐linked gelatin film possessed smaller cross‐sectional voids (diameter 100?360 nm vs. 200?595 nm) than the bovine gelatin film. This study shows that cross‐linking can efficiently improve film microstructure and properties of the gelatin‐like products.