免涂装低屈强比耐候桥梁钢的开发应用

通过优化成分设计以及轧制、热处理工艺,成功开发出8 ～ 80 mm厚度的免涂装低屈强比耐候桥梁钢.针对免涂装低屈强比耐候桥梁钢的工艺、金相组织和焊接性进行分析研究,结果表明:耐候桥梁钢Q345qENH～ Q690qENH的屈强比可以通过适量铁素体+不同形态贝氏体组织配比进行调控,使低温冲击韧性、低屈强比和耐候性同时得到保证,实现了优良的强度、冲击韧性和可焊性.     

Strong tribocatalytic dye degradation by tungsten bronze Ba4Nd2Fe2Nb8O30

The triboelectric effect has recently demonstrated its great potential in environmental remediation and even new energy applications for triggering a number of catalytic reactions by utilizing trivial mechanical energy. In this study, Ba₄Nd₂Fe₂Nb₈O₃₀ (BNFN) submicron powders were used to degrade organic dyes via the tribocatalytic effect. Under the frictional excitation of three PTFE stirring rods in a 5 mg/L RhB dye solution, BNFN demonstrates a high tribocatalytic degradation efficiency of 97% in 2 h. Hydroxyl radicals (?OH) and superoxide radicals (?O₂－) were also detected during the catalysis process, which proves that triboelectric energy stimulates BNFN to generate electron-hole pairs. The tribocatalysis of tungsten bronze BNFN submicron powders provides a novel and efficient method for the degradation of wastewater dye by utilizing trivial mechanical energy.     

Meticulously tailoring phase boundary in KNN-based ceramics to enhance piezoelectricity and temperature stability

Although KNN-based ceramics with high electrical properties are obtained through a variety of strategies, the temperature sensitivity is still one of the key technical bottlenecks hindering practical applications. Here, we use a new strategy, meticulously tailoring phase boundary, to refine the ferroelectric boundary of KNN-based ceramics, leading to high piezoelectricity companied with improving temperature stability. The highest d₃₃ value in this system reaches 501 pC/N with a T_C ∼ 240°C, whereas a large strain of ∼0.134% can be kept with 10% lower deterioration until 100°C. The origin of high piezoelectricity is mainly attributed to the well-preserved multiphase coexistence and the appearance of nanodomains, which greatly facilitate the polarization rotation. Instead of the changed intrinsic thermal insensitivity, the precision phase boundary engineering plays an important role in strengthening the temperature stability of electric-induced strain. This work provides a simple and effective method to obtain both high electrical properties and excellent thermal stability in KNN-based ceramics, which is expected to promote the practical applications in the future.     

高地压严重突出区域下向穿层钻孔预抽消突技术

利用工作面高抽巷施工掩护顺槽掘进工作面下向穿层条带预抽钻孔,通过对钻场底板深、浅孔注浆封堵围岩裂隙解决了孔内返水不畅难题;采取了"两堵一注"封孔方式确保封孔严密不漏气;孔内全程下吹水管,实现了单孔、分组、定时吹水工作目标,提高了下向消突钻孔抽采效果,形成了一套高效、快速的下向穿层钻孔消突管理模式,实现了高地压严重突出区域煤层高效消突以及技术经济一体化目标,安全经济效益显著。     

基于虚拟现实的复杂场景加载优化算法

目前大规模场景模型生成的需求量日益增加, 现提出了一种基于区域的自动 LOD (Levels Of Details)构建算法. 该算法基于动态网格简化算法, 在游戏设计制作的过程中, 游戏开发人员会经常需要对美工部门人员提供的模型进行优化. 为了可以使模型的面数得到简化, 并且不改变模型的外观. 当今流行的 LOD技术非常擅于处理这种情况, 判断模型与摄像机的距离如果超过一定范围之后, 自动调取不同层次的模型, 当模型距离摄像机很远的情况下使用面数低的模型替换高模, 这样可以提高帧率并且降低摄像机前的三角面以及顶点数从而减少渲染压力. 一般模型的简化分为静态和动态模型的简化.大部分情况下, 程序员会让美工部门提供几套不同面数的模型或者通过模型简化工具对高模进行减面并存成多个Mesh, 并在程序运行的时候, 根据模型与摄像机的距离远近动态的替换Mesh. 这是一种静态的方法.这里将尝试使用一种动态的网格简化和LOD技术相结合的方法. 这种新型算法的大大的简化了操作流程, 美术人员只需要提供一个模型, 程序员可以使用这种方法生成量级不同的低模, 根据摄像机与模型的远近自动的调取不同精度的模型.     

The Propagation Background in Social Networks: Simulating and Modeling

Machine Intelligence Research - Recent years have witnessed the booming of online social network and social media platforms, which leads to a state of information explosion. Though extensive...     

Isolation and identification of two major acylated anthocyanins from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) by UPLC‐QTOF‐MS/MS and NMR

In recent years, researches on the isolation and preparation of monomeric anthocyanins have intensified because of the requirements of quantitative and structure–bioactivity relationship analyses. However, simple and effective methods about the scale of monomeric anthocyanins from the natural purple sweet potato powder are rarely reported. In this study, high molecular weight acylated monomeric anthocyanins were isolated from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) via the combination of column chromatography and semi‐preparative HPLC technology and identified mainly by ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry/mass spectrometry (UPLC‐QTOF‐MS/MS) and ¹H and ¹³C nuclear magnetic resonance (NMR). Two major acylated anthocyanins were unambiguously determined as peonidin 3‐O‐(6‐O‐(E)‐caffeoyl‐(2‐O‐(6‐O‐p‐hydroxybenzoyl)‐β‐D‐glucopyranosyl)‐β‐D‐glucopyranoside)‐5‐O‐(β‐D‐glucopyranoside) and peonidin 3‐O‐(6‐O‐(E)‐caffeoyl‐(2‐O‐(6‐O‐(E)‐feruloyl)‐β‐D‐ glucopyranosyl)‐β‐D‐glucopyranoside)‐5‐O‐(β‐D‐glucopyranoside). The results of this study may help promote the purification of high molecular weight acylated anthocyanins from purple sweet potato as well as from other plant materials in nature.     

混炼方式对螺旋纳米碳纤维增强天然橡胶复合材料力学性能的影响

采用干法和湿法两种混炼工艺制备了螺旋纳米碳纤维(HCNFs)/炭黑(CB)/天然橡胶(NR)复合材料,通过扫描电镜、拉伸试验机和应变扫描仪分别对所制备复合材料的界面形貌、力学性能和Payne效应进行了测试分析,考察了混炼方式对复合材料宏观力学性能及Payne效应的影响。结果表明,与纯CB填料相比,在干湿两种混炼方式下,添加适量的HCNFs(1～6份)能提高HCNFs/CB/NR复合材料的300%定伸应力、扯断伸长率、拉伸强度和硬度。与干法混炼相比,湿法混炼能明显增强HCNFs/CB/NR复合材料的Payne效应,并提升在HCNFs高添加量(2～6份)条件下的拉伸强度和扯断伸长率,这主要源于湿法混炼能够有效改善HCNFs在橡胶基质中的分散性。