摘要：The coolant pump impeller casting is the only rotating component in the nuclear island of an AP1000 nuclear power station, and is required to have a 60-year service time, which requires advanced materials and processing technologies to guarantee. In this paper, the casting process was studied, designed and modified by means of numerical simulation. The gating system was distributed symmetrically and the runner diameter was a little bigger for avoiding sand wash and turbulence;the feeding system focused on the solution of blades feeding, as some parts of which should reach Severity Level 1 radioactive testing standard. Therefore, upper and lower plates cooperating with chillers acted as feeding method besides additional 2-3 times thickness;in addition, lowering sand core strength, decreasing pouring temperature and increasing dimension allowance would be adopted to avoid crack defects. Finally, the pilot impeller was cast. The results show that the casting process design is reasonable, as the liquid rises very smoothly when pouring, and no volume defects are found by means of 100% radioactive testing. Based on this casting process, 16 coolant pump impellers have been successfully produced and delivered to customers.

摘要：为了研究挡块对桥梁横向地震响应的影响,选取了3座墩高配置不同的连续梁桥,建立了考虑桥台-背土相互作用、支座摩擦效应和挡块力学本构的非线性分析模型,采用时程法对比了在无挡块、弹性挡块、X型钢挡块和钢筋混凝土挡块工况下3座桥梁地震响应的变化。研究表明:限位能力越强的挡块对下部结构地震响应的影响越不利,钢筋混凝土挡块因易发生强度和刚度退化,影响相对最小;挡块会使不等墩高连续梁桥原本均匀分配的惯性力重新集中于矮墩,造成矮墩设计困难;当地震动较小时,采用钢筋混凝土挡块一方面具有较好的限位能力,另一方面对下部结构地震响应的影响也最小,但当地震动较大时,钢筋混凝土挡块几乎不起作用,钢挡块可发挥更好的限位作用。

摘要：工厂配电室低压无功补偿装置,由于设计的缺陷以及使用年代久远,性能不稳定多次发生供电中断事故,另外,目前的功率补偿容量已不能满足需求,需改造现在的无功补偿系统,以满足无功补偿需求的同时提高系统的稳定性。

摘要：Main observation and conclusion An HPLC-UV-guided separation was performed and four pairs of unprecedented macathiohydantoin dimers,lepithiohydimerins A—D(1—4)bearing a rare disulfide bond were isolated from the tubers of *** structures were unambiguously confirmed by NMR spectroscopic,X-ray crystallographic and electronic circular dichroism(ECD)*** the concentration of 20μmol/L,compounds 2-1,2-2,and 4-1 increased the viability of PC12 cells with the cell viability at(72.06±1.14)%,(72.64±1.49)%,and(70.93±1.22)%,***,the serial concentration experiment showed that they can protect PC12 cells in a dose-dependent manner.

摘要：套筒连接是预制混凝土结构最常用的连接方式,灌浆不饱满缺陷是影响灌浆套筒连接剪力墙抗震性能的主要因素,为明确灌浆缺陷对预制剪力墙抗震性能的影响,该研究同时开展了套筒连接和足尺剪力墙抗震性能试验。在连接层次,考虑4种灌浆缺陷率影响,设计制作5个连接试件进行了大变形反复拉压试验,通过与无缺陷试件对比明确了缺陷率对连接力学性能和破坏模式的影响,识别了发生钢筋滑移破坏的缺陷率阈值。在剪力墙构件层次,在连接试验的基础上,设计制作了1个无灌浆缺陷和1个设置了缺陷率阈值的足尺剪力墙试件,进行了拟静力抗震性能试验,对比分析试件的破坏模式、承载能力、变形能力和耗能能力。试验结果表明:对于12 mm直径的纵筋,就本研究所开展的实验而言,当灌浆缺陷率接近60%时,在钢筋达到约2倍屈服应变时发生钢筋滑移破坏,承载力急剧退化,延性远小于其他连接;不同于无缺陷剪力墙试件的弯曲破坏模式,60%灌浆缺陷的剪力墙试件在钢筋屈服后很快就发生了钢筋滑移,钢筋滑移后该试件呈现出明显的摇摆变形行为特征,试件承载力、变形能力和耗能能力显著低于无缺陷试件。

摘要：A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.

摘要：发射平台导流槽在火箭发射过程中承受着燃气高温和局部冲击力的作用,容易出现局部裂纹扩展导致的断裂失效,影响火箭的安全发射。文中采用扩展有限元法(XFEM),对含初始裂纹的导流槽结构进行数值模拟分析。在ABAQUS软件平台上建立导流槽的有限元模型,施加高温与冲击荷载,选定受冲击的下表面上易发生裂纹扩展的3个热点位置;对于易发生裂纹扩展的热点位置的板架采用体单元模拟,其余部位采用壳单元模拟,通过多点约束耦合不同单元的节点自由度,从而建立含裂纹导流槽的扩展有限元模型;采用最大主应力准则作为裂纹起裂准则,得出各热点位置处在单次冲击荷载作用下,会发生裂纹扩展的初始裂纹长度,裂纹起裂的时间、扩展速率及扩展路径。

摘要：针对现有物联网在线测量系统存在的参数测量周期长,异常反馈不及时的问题,设计了基于BP神经网络算法的多参数在线测量物联网系统。该系统通过感知层、网络传输层及应用层完成参数的采集、分析处理及显示,其核心在于系统应用层加入BP神经网络算法对实时采集参数进行优化处理,来缩短参数测量时间。通过算法仿真实验可知,本文所提出的基于BP神经网络算法优化的在线测量系统,对于加快数据采集时间,提高制造过程系统反馈调节速度,有着很好的效果。

摘要：As a novel zero-dimensional(0D)material,metal carbides and/or carbonitrides(MXenes)quantum dots(MQDs)show unique photoluminescence properties and excellent ***,due to the limited synthesis methods and research to date,many new features have yet to be ***,to explore their new properties and expand biological applications,chlorine and nitrogen co-doped Ti_(3)C_(2)MXene quantum dots(Cl,N-Ti_(3)C_(2)MQDs)were designed and synthesized,and their hydroxyl radical scavenging properties were investigated for the first time,revealing outstanding ***,N-Ti_(3)C_(2)MQDs was directly stripped from bulk Ti_(3)Al C_(2)by electrochemical etching,while N and Cl are successfully introduced to carbon skeleton and Ti boundaries in the etching process by electrochemical reactions between selected electrolytes and Ti_(3)C_(2)skeleton,*** obtained Cl,N-Ti_(3)C_(2)MQDs exhibit large surface-to-volume ratio due to small particle size(ca.3.45 nm)and excellent higher scavenging activity(93.3%)and lower usage(12.5μg/m L)towards hydroxyl radicals than the previous reported graphene-based *** underlying mechanism of scavenging activity was also studied based on the reduction experiment with potassium permanganate(KMnO_(4)).The reducing ability of the intrinsic Ti_(3)C_(2)structure and electron donation of double dopants are the main contributors to the outstanding scavenging activity.

摘要：【目标】针对不能直接用作路基填料的武汉市两湖隧道东湖段固化淤泥,提出基于绿色环保的氯氧镁水泥,结合高钙粉煤灰和粒化高炉矿渣这2种工业固废料,复合而成镁质水泥基多组分胶凝材料(M—F—G),对固化淤泥进一步加以改性的方法。评价氯氧镁水泥基的多组分胶凝材料改善固化淤泥路用性能的效果,并探明其微观机理,为固化淤泥的路基填料化利用技术提供参考。【方法】通过界限含水率、加州承载比、压缩性、水稳定性、扫描电镜和核磁共振等宏、微观试验,研究了多组分胶凝材料配比、养护龄期等因素对固化淤泥改性效果的影响及其微观机制。【结果】M—F—G多组分胶凝材料使固化淤泥的液限、塑性指数和压缩系数降低,而加州承载比和水稳定性显著提高;粉煤灰+矿渣的“双掺”比仅粉煤灰或仅矿渣的“单掺”与氯氧镁水泥发生的水化反应更为充分,改性效果更佳。微观试验揭示,由M—F—G多组分胶凝材料改性生成的水化产物能有效地降低固化淤泥的孔隙率,水化硅酸镁(M—S—H)型凝胶物质包覆土颗粒并形成蜂窝结构,从而使固化淤泥的路用性质得到了显著的改善。【应用】综合试验结果与路基规范要求,提出了镁质水泥基多组分胶凝材料的最优配比和改性固化淤泥的最佳养护龄期。