Oxide-Scale Evolution on a New Ni–Fe-Based Superalloy at High Temperature

Oxidation of Metals - The isothermal oxidation behavior and oxide-scale evolution on a newly developed Ni–Fe-based superalloy were investigated. Three oxidation stages were generally...     

煤巷过断层破碎带施工工艺与支护技术实践

W1313回风顺槽在里程332 m处揭露正断层,对此采取了调整巷道顶板锚网索支护参数,采用圆木大板棚复合支护等措施,并加强了顶板、通风、掘锚机破岩、爆破作业和作业人员的安全管理,确保工作面过断层破碎带时的安全施工。     

以用户为中心的可见光通信协作传输中训练资源分配算法

以用户为中心的可见光通信协作传输是近年来出现的新架构,这导致虚拟小区之间出现重叠。为避免导频污染问题,每个虚拟小区中的光接入点(AP)或者虚拟小区中选择相同AP的用户发送的训练序列应该是正交的。针对可见光通信中以用户为中心的协作网络,研究训练资源的正交分配问题,提出了一种新的导频分配算法,联合导频分配和用户选择问题,以期最大限度地增加虚拟小区内可被接入的用户数。分析和仿真结果表明,该导频分配方案可以有效改善导频污染问题,提高训练资源利用率,并且相比已有的导频分配方案,性能有所改进。     

Synergistic flame retardant effects of activated carbon and molybdenum oxide in poly(vinyl chloride)

The synergistic effects of activated carbon (AC) and molybdenum oxide (MoO₃) in improving the flame retardancy of poly(vinyl chloride) (PVC) were investigated. The effects of AC, MoO₃ and their mixture with a mass ratio of 1:1 on the flame retardancy and smoke suppression properties of PVC were studied using the limiting oxygen index and cone calorimeter tests. It was found that the flame retardancy of the relatively cheaper AC was slightly weaker than that of MoO₃. In addition, the incorporation of AC and MoO₃ greatly reduced the total heat release and improved smoke suppressant property of PVC composites. When the total content of AC and MoO₃ was 10 phr, PVC/AC/MoO₃ had the lowest peak heat release rate and peak smoke production rate values of 173.80 kW m^?2 and 0.1472 m² s^?1, which represented reductions of 47.3 and 59.9%, respectively, compared with those of PVC. Furthermore, thermogravimetric analysis and gel content tests were used to analyze the flame retardant mechanism of AC and MoO₃, with results showing that AC could promote early crosslinking in PVC. Char residue left after heating at 500 °C was analyzed using scanning electron microscopy and Raman spectroscopy, and the results showed that MoO₃ produced the most compact char, with the smallest and most organized carbonaceous microstructures. © 2017 Society of Chemical Industry     

上水口环形吹氩对中间包内渣眼形成的影响

 中间包上水口环形吹氩可以在塞棒周围形成清洗钢液的环形气幕，同时部分氩气泡随钢液进入上水口内，可以减少非金属夹杂物在水口内壁的黏附，起到防止水口堵塞的作用。然而，不合理的吹氩量会导致中间包内液面渣层受过强的气液羽流冲击而形成渣眼，使得钢液裸露并发生二次氧化，严重影响铸坯质量。采用标准 k ε 湍流模型研究中间包内流体流动，采用DPM模型和VOF模型耦合方法，研究上水口环形吹氩条件下渣眼的形成及演化规律。结果表明，上水口环形吹氩在塞棒周围形成较强的上升流，塞棒上部邻近区域存在多个涡流区；在钢液涡流的影响下，中间包液渣下层远离塞棒区域，上层向塞棒区域迁移；随着吹氩量的增大，平均湍动能增大，塞棒附近钢液速度逐渐增大，钢渣界面钢液速度先增大后减小，渣眼边缘钢液速度先增大后减小然后再增大，速度与垂直方向夹角逐渐减小；增大吹氩量，中间包熔池液面形成以塞棒为中心的渣眼，渣眼面积逐渐增大。试验条件下不产生渣眼的临界吹氩量为4.2 L/min，对应的钢渣界面最大速度为0.247 m/s，与垂直方向夹角为70°。     

矿区、公园、城市、建筑——青龙山公园多功能馆设计

通过对宜兴丁蜀镇青龙山公园多功能馆项目设计和建造历程的回顾,在自然与人工、城市与建筑、可见与消隐、开放与持存的多重辩证关系中推进和展开关于地景、地方以及边界的讨论,试图进一步探讨在现有的空间规划和土地政策下,建筑基础设施化作为一种设计策略、将特殊场地再次纳入城市结构的可能性.     

Visual Detection of Adenosine Triphosphate by Taylor Rising: A Simple Point-of-Care Testing Method Based on Rolling Circle Amplification

Rapid and sensitive point-of-care testing (POCT) is an extremely critical mission in practical applications, especially for rigorous military medicine, home health care, and in the third world. Here, we report a visual POCT method for adenosine triphosphate (ATP) detection based on Taylor rising in the corner of quadratic geometries between two rod surfaces. We discuss the principle of Taylor rising, demonstrating that it is significantly influenced by contact angle, surface tension, and density of the sample, which are controlled by ATP-dependent rolling circle amplification (RCA). In the presence of ATP, RCA reaction effectively suppresses Taylor-rising behavior, due to the increased contact angle, density, and decreased surface tension. Without addition of ATP, untriggered RCA reaction is favorable for Taylor rising, resulting in a significant height. With this proposed method, visual sensitive detection of ATP without the aid of other instruments is realized with only a 5 μL droplet, which has good selectivity and a low detection limit (17 nM). Importantly, this visual method provides a promising POCT tool for user-friendly molecular diagnostics.     

Experimental and numerical study on compressive performance of perforated brick masonry after fire exposure

This paper discusses the compressive performance of perforated brick masonry after fire exposure. Compressive strength tests of the mortar, clay perforated brick, and perforated brick masonry specimens were performed in accordance with ISO834 fire tests of different durations. The temperature distribution of the masonry materials and specimens was simulated using the finite element software ABAQUS, with the thermal parameters of masonry materials recommended by European standard Eurocode 6 and related literature. The compressive strength reduction factors of mortar and clay perforated brick exposed to different fire durations were calculated via the layered method suggested by European standard Eurocode 1. In addition, the compressive strength reduction factors after cooldown were obtained from the experimental data of the masonry materials, and by considering further reductions in the compressive strength after cooling from high temperatures. Experimental data of the masonry specimens were compared with the numerical results obtained using the reduction factors proposed in this work. The comparison revealed an overall acceptable approximation. Thus, the method presented in this paper can be used to evaluate the residual capacity of masonry structures after fire.