有孔内基础平台的竖直孔空心砖结构设计探讨

孔内基础平台设置在现有模数空心砖孔洞的上部,在孔洞内形成小平台,其能阻止砂浆掉落孔洞内,使空心砖的保温功能得以实现。孔内基础平台的设置将砖缝层平面摩擦改变为曲面摩擦,每一个孔洞的孔内基础砂浆与砖缝层面砂浆合为一体,砖缝层面摩擦力提升,墙体抗震能力提升。     

Heat propagation in thermally conductive polymers of PA6 and hexagonal boron nitride

Thermally conductive polymers offer new possibilities for the heat dissipation in electric and electronic components, for example, by a three‐dimensional shaping of the heat sinks. To face safety regulations, improved fire performance of those components is required. In contrast to unfilled polymers, those materials exhibit an entirely different thermal behavior. To investigate the flammability, a phosphorus flame retardant was incorporated into thermally conductive composites of polyamide 6 and hexagonal boron nitride. The flame retardant decreased the thermal conductivity only slightly. However, the burning behavior changed significantly, due to a different heat propagation, which was investigated using a thermographic camera. An optimum content of hexagonal boron nitride for a sufficient thermal conductivity and fire performance was found between 20 and 30 vol%. The improvement of the fire performance was due to a faster heat release out of the pyrolysis zone and an earlier decomposition of the flame retardant. For higher contents of hexagonal boron nitride, the heat was spread faster within the part, promoting an earlier ignition and increasing the decomposition rate of the flame retardant.     

The formation of fibrous structure of polyamide 6 induced by the three-step forming process and its prominent reinforcement in nitrile rubber

Nitrile rubber (NBR) blends with excellent performance have always been a hot research topic in petroleum field. Due to the excellent performance and compatibility of polyamide 6 (PA6), it provides an opportunity for the preparation of high-performance NBR/PA6 blends. In this article, NBR/PA6 blends were prepared by the three-step molding process. Experimentally, it was found that PA6 has a prominent reinforcement effect in NBR matrix. The variation of this mechanical property was investigated from different aspects of the crystal structure, crystallinities, phase morphology, and so on. It can be cleared that the formation of fibrous structure of PA6 phase is the main factor for reinforcement of the polymer blends. Meanwhile, the formation mechanism of the special phase structure induced by the three-step process is deeply expounded and its structural evolution schematic is established. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47472.     

Improved bio-hydrogen production by overexpression of glucose-6-phosphate dehydrogenase and FeFe hydrogenase in Clostridium acetobutylicum

Clostridium acetobutylicum is an attractive industrial microorganism for biochemical production, but there have been few attempts for bio-hydrogen production based on metabolic engineering. In this study, metabolically engineered C. acetobutylicum carrying glucose-6-phosphate dehydrogenase (zwf) and FeFe hydrogenase (hydA) were constructed as recombinant strains CA-zwf(pIMP-zwf) and CA-hydA(pMTL-hydA), respectively, to improve hydrogen productivity. The results showed that the engineered strains produced 1.15 and 1.39-fold higher hydrogen yield, respectively, than the wild type. Furthermore, when pH and glucose concentration were optimized for the CA-hydA strain, enhanced hydrogen productivity of 25.8% was achieved in 7 L jar scale fermentation. This result provides an insight into the future direction for metabolic engineering of C. acetobutylicum for improved hydrogen production.     

一种实现高压电容器带电倾斜旋转实验平台的研制

为方便高压电容器的性能评价实验，研制了一种高压电容器倾斜旋转实验平台，可实现电容器在高电压下带电旋转、带电倾斜等功能。试验场地的地面水平、通过测试线引入的电磁骚扰、高压连接线牵引应力等问题，在高压电容器的精密测量中，可能引入不可忽略的影响。本文对这些影响因素提出了解决措施，并基于试验平台，定量分析评价了试验场地不平对高压电容器电容量变化的影响，降低了高压标准电容器在高精度测量中的不确定度，为高压标准电容器的性能评价试验提供了重要的支撑。     

新型阶梯式浅吃水单立柱浮式风机平台水动力分析

常规的单立柱式(Spar)风力发电机平台,在水深较浅区域工作时,结构本身受吃水限制,工作效果较差。常规Spar重心较低,具有良好的稳定性,但是由于它往往具有超过100 m的吃水,因此使其不能应用于中近海域(水深小于100 m)。可设计研究一种适用于中国东海不超过100 m水深的中近海域新型浮式风机平台以解决此问题。针对NREL 5MW风机能应用于100 m水深的情况,对50 m吃水的新型Spar(SJTU-S4)及其系泊系统进行了概念设计研究。利用商业软件建立水动力模型,进行数值仿真,同时设计缩比模型试验,在上海交通大学海洋工程国家重点实验室(SKLOE)进行水动力性能测试。结果表明,本文研究的新阶梯式浅吃水单立柱浮式风机平台在100 m水深、多种海洋波浪环境下,通过试验和仿真验证,能够具有良好的运动响应,为风机提供较好的工作条件。     

考虑交叉销售的O2O供应链合作广告策略研究

基于网络零售平台与制造商的合作广告实践，运用Stackelberg博弈理论研究了平台交叉销售效应及合作广告引导作用对O2O供应链合作广告决策的影响，并通过数值算例对参与合作广告计划前后渠道成员的决策变量均衡结果和利润进行对比分析，研究发现平台交叉销售效应是影响网络零售平台合作广告计划制定和实施的关键因素，只有当其达到一定水平时，制造商才拥有参与网络零售平台合作广告计划的资格；在一定条件时，合作广告计划能够实现制造商和网络零售平台利润的提升；当平台交叉销售效应较大时，网络零售平台获得的利润大于制造商。     

招聘网站的岗位分析系统设计与实现

随着高校扩招，应届毕业生人数逐年增长，就业压力不容小觑。针对就业难的问题，进行招聘网站数据分析，挖 掘出岗位所需技能，再结合学生在校时所学课程，二者对比，就能很好地给学生推荐合适的工作，并且给学校专业人才培养方 案中的岗位职业定位     

基于艾默生DeltaV R6新功能块的设备控制模块开发

利用艾默生控制系统旧版本软件,开发开关量设备控制模块比较繁琐,需要借助大量的逻辑功能块与条件判断功能块进行辅助开发,程序结构复杂,逻辑不清晰,容易出错。新版本软件推出的新功能块解决了以上问题。以某火法铜冶炼工程为例,结合冶炼工艺特点,程序开发过程中通过解决不熟悉新功能块特点应用难问题,风机、泵、电动阀等设备控制模块开发难问题,开发出了满足控制要求的各种设备控制模块。利用新版本软件的新功能块,开发的设备控制模块在火法铜冶炼得到成功应用。     

基于物联网的智能化窨井管理系统的设计

通信管道承载着户外传输网络,是通信网络的生命管道。管道规模伴随着城市化进程快速成倍增长,但管道管理还处于传统的依赖人工专项梳理、专项盯防的模式。随着智慧城市建设的加速推进,采用“物理加锁+物联网管理平台”的创新管理方式,结合物联网技术和大数据技术,实现对流程、人员、设备的全方位管理。