摘要：为解决放射性废树脂长距离管道输送过程中废树脂沉积造成管道局部热点的工程难题,通过流动理论计算和管道综合受力分析,并结合实际的工程设计,建设了一套约1300 m的废树脂长距离输送管道系统。该管道采用内壁整体光滑设计思想,管道热补偿利用管道自补偿、大弯曲半径方形补偿器和空间Z形补偿结构等,阀门、管件均订制与管道内径匹配,安装完毕后,进行了液压、模拟输送和工程验证试验。验证结果表明,该废树脂输送管道解决了长距离管道输送过程中废树脂沉积造成管道局部热点的工程问题,系统固有安全性高、操作简便,显著缩短操作时间、减少二次放射性废物产生、降低人员劳动强度和受照剂量,工程应用效果良好。

摘要：Creation of freeways in a membrane accelerates water transport for efficient desalination;however,the synthesis of target membrane materials is very *** the present study,the molecular-design strategy is developed for the synthesis of porous aromatic framework(PAF)membranes with rigid and open networks to regulate water ***-based monomers in triangle shape are designed for the construction of PAF-98 and its sister frameworks,and these PAF membranes are formed through trifluoromethanesulfonic acid *** rigidity and geometry of the monomers endow PAFs with unique structures of connected pores with edging size(4.5–6.7Å)between water(2.8Å)and hydrated sodium molecules(7.2Å),enabling effective differentiation of water and *** fabricated membranes with high flexibility and continuity are ideal for water desalination,and reverse osmosis experiments demonstrate that the three PAF membranes are selective for permeation of water molecules over hydrated sodium *** water flux of 547.1 L m^(-2) h^(-1) and high rejection degree of 90%are obtained on a representative membrane of PAF-98-E;and the desalination performance is superior to currently available membrane ***,PAF-98-E membrane is capable of rejecting various cations with high efficiency in real seawater,holding great promise in practical water desalination application.

摘要：Glass-forming ability is a long-standing concern in the field of metallic glasses(MGs),which greatly limits their maximum casting size and extensive *** this work,we report an ultrasonic-assisted rapid cold welding of bulk MGs without using any *** with various compositions are welded together under a 20,000-Hz highfrequency ultrasonic vibration without losing their amorphous *** ultrasonic technology offers the advantages of rapid bonding(<1 s)at low temperature(near room temperature)and low stress(<1 MPa).According to the phenomenon observed in the experiment,the activated fresh atoms diffuse through the broken channel port under continuous rupture of the oxide layer,and the ultrasonic vibration accelerates the atomic-diffusion ***,stable bonding of the MG interface is *** universal ultrasonic-assisted welding process can realize the composition design of dissimilar MGs as well as tuning of new materials with new performance.

摘要：由于设计选材、施工技术等问题,房建工程混凝土结构防渗漏效果存在一定差异,论文主要从材料、温度、水化热、结构设计、外加剂等方面分析了房建施工中混凝土结构渗漏的原因,总结了混凝土结构防渗漏工艺要点,并探索了混凝土结构裂缝处理方案。

摘要：Nanomaterials have been applied as antibacterial agents by virtue of their unique functioning mechanism different from that of conventional *** oxide nanoparticles(CeO2 NPs)are important antibacterial agents due to their relatively low toxicity to normal cells and their distinct antibacterial mechanism based on the reversible conversion between two valence states of Ce(III)/Ce(IV).Some studies have been conducted to explore their antibacterial activities;however,systematic research reviews on the related mechanisms and influencing factors are still quite *** this review,we discuss the plausible mechanisms of the antibacterial activity of CeO2 NPs,analyze different influencing factors,and summarize various research reports on antibacterial effects on *** and *** also propose the potential applications and prospects,and hope to provide an in-depth understanding on the antibacterial mechanism and a better guidance to the design and applications of this promising antibacterial material in the future.

摘要：针对柱塞泵故障诊断中存在的振动数据不平稳和诊断精度低问题,提出一种考虑传感器位置信息的Bagging集成卷积神经网络(Sensors location considered-bagging-convolution neural network,SLC-B-CNN)故障诊断模型。首先将短时傅里叶变换后的二维振动时频信息与经独热编码后的传感器位置信息匹配以构建数据集,然后设计混合双输入CNN模型作为基分类器,最后将数据集输入以简单平均法聚合的SLC-B-CNN模型中,在实验柱塞泵数据集上验证了所提出的SLC-B-CNN模型,在测试集上的准确率高达92%,各类故障平均召回率为89%,表现优于CNN模型和随机森林(Random forest,RF)模型。

摘要：为保证所设计的双列角接触球轴承符合实际生产要求,采用数值计算和有限元分析相结合的方法进行载荷分布与接触应力分析。采用试验研究的方式进行轴承寿命与可靠性分析,在双列角接触球轴承失效特征分析中,运用威布尔分布函数来获取失效特征。通过参数估计对数据进行处理,计算出样本轴承的形状参数、尺度参数、基本额定寿命及中值额定寿命。根据计算结果对双列角接触球轴承的可靠性做出预测。

摘要：目的 本研究拟制备一种具有微孔结构的聚氨酯(polyurethane, PU)薄膜的医用补片表层材料,并对PU微孔薄膜的材料学特性和生物学性能进行评价,以期提升盆底修复补片材料的临床适用性。方法 采用PU预聚体发泡技术制备表面具有微孔结构的PU薄膜,通过调节最佳PU预聚体异氰酸根指数(R值)和发泡环境相对湿度(relative humidity, RH),制备PU微孔薄膜。采用扫描电子显微镜观察PU微孔薄膜表面形貌,利用红外光谱、拉曼光谱和水接触角分析PU微孔薄膜的化学结构亲水性;体外评价PU微孔薄膜浸提液对L929小鼠成纤维细胞增殖的影响,并观察PU微孔薄膜对L929小鼠成纤维细胞黏附和形态的影响和对RAW264.7小鼠单核巨噬细胞的影响;使用Sprague Dawley(SD)大鼠评价PU微孔薄膜的体内免疫反应和组织再生。结果 PU预聚体R值=1.5,发泡环境RH=70%时PU薄膜形成明显的微孔,且均匀致密;与PU薄膜相比较,PU微孔薄膜的化学结构无明显改变,其水接触角[(55.7±1.5)°]低于PU薄膜[(69.5±1.7)°]和聚丙烯(polypropylene, PP)的水接触角[(104.3±2.2)°](P<0.05),显示出较强的亲水性;PU微孔薄膜浸提液具有良好体外生物相容性,可促进L929小鼠成纤维细胞增殖,同时PU微孔薄膜表面形态有利于L929小鼠成纤维细胞的黏附,细胞呈铺展生长,其表面形貌可以抑制RAW264.7小鼠单核巨噬细胞肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)、白细胞介素(interleukin, IL)-1β分泌,促进IL-10、IL-4分泌,与24 h相比较,培养72 h时PU薄膜组和PU微孔薄膜组TNF-α、IL-1β表达水平降低,且低于PP薄膜组(P<0.05);其中,PU微孔薄膜组TNF-α和IL-10表达水平降低最明显;而IL-10、IL-4表达水平增加,且高于PP薄膜组(P<0.01),其中,PU微孔薄膜组IL-4表达水平增加最显著。PU微孔薄膜植入体内后植入微环境炎症较轻,未见明显的纤维囊形成,植入后60 d, PU微孔薄膜部分降解,膜中央出现大量的胶原纤维生长和肌肉形成。结论 PU微孔薄膜具有良好的亲水性和生物相容性,其表面形貌可调节增加细胞的黏附、调控RAW264.7小鼠单核巨噬细胞的功能以及促进组织修复,为女性盆底修复重建补片材料的设计提供了新思路。

摘要：针对现阶段房建工程中墙体砌筑施工与加固工程的相关问题,分析了墙体砌筑施工的基本步骤和技术要点,提出了嵌入钢筋加固墙体的方法和要点。以某希望小学工程为对象,对墙体的砌筑施工和加固工程进行质量检测控制。结果显示,墙体的物理特性均符合建筑要求,墙体温度均衡,约为16~24℃,相对湿度为4%~13%,全部合格。加固后的墙体相比于未加固墙体刚性程度极大提高,累计耗能提高约2倍。

摘要：随着地下工程的不断增多,地下结构浮起破坏也日益突出,针对地下结构抗浮技术的研究也越来越多。文章从浮起破坏模式、浮力计算以及抗浮控制技术三个方面,对近年来关于地下结构抗浮技术的研究成果进行了梳理。地下结构浮起破坏模式主要包括局部浮起破坏、局部整体浮起破坏和整体浮起破坏,且多发生在施工期。由大量试验可知,砂土层中地下结构所受浮力测试值与按阿基米德定律计算值吻合较好,黏土层中则存在差异。抗浮措施以前多注重被动抗浮,现在则更关注主动抗浮。同时在大量分析基础上,认为地下结构抗浮技术还存在施工期抗浮控制不够重视、地下水浮力测试不精准、抗浮设防水位确定不一致以及抗浮控制措施的耐久性和有效性不好保障等问题。在此基础上,针对如何控制施工期抗浮、创新浮力测试装置以及抗浮控制措施设计重点提出了建议,可为地下结构抗浮技术研究提供借鉴。