镁合金表面冷喷涂快凝Zn-Al合金粉末的研究

对镁合金表面冷喷涂快凝Zn-Al合金粉末工艺进行了研究，观察了涂层微观组织，并分析了涂层与基体之间的结合，测定了涂层的硬度和涂层与基体的结合强度。结果表明，采用冷喷涂技术制备的快凝Zn—Al合金粉末涂层组织致密，基体与涂层的结合处只产生塑性变形并且无熔化现象，涂层硬度比基体硬度显著提高。     

计及线路传输能力的新能源电力系统灵活性评估及优化调度方法

新能源大规模接入电网对电力系统灵活调节能力带来巨大挑战,针对目前电力系统灵活性评估及优化调度集中于供需匹配而缺乏对线路传输能力的考虑,提出了计及线路传输能力的新能源电力系统灵活性评估及优化调度方法。首先,分析线路传输能力对灵活性需求实现的影响,并计及新能源及负荷的波动性和不确定性,量化节点灵活性需求及其在线路上的分配。然后,从资源灵活性裕量和线路灵活性传输裕量两个角度提出系统灵活性不足量评估指标,多方面评估系统灵活性。将该评估指标作为机会约束条件,构建考虑资源-线路双重裕量的优化调度模型。采用线性化手段和基于拉丁超立方抽样的机会约束确定性转化方法将优化调度模型化简为混合整数线性规划模型以降低求解难度。最后,采用改进IEEE39节点系统和某实际电网进行仿真验证,结果表明所提方法能够减轻线路阻塞,减少切负荷量,提高新能源消纳。     

Ultrabroadband MoS2 Photodetector with Spectral Response from 445 to 2717 nm

Photodetectors with excellent detecting properties over a broad spectral range have advantages for the application in many optoelectronic devices. Introducing imperfections to the atomic lattices in semiconductors is a significant way for tuning the bandgap and achieving broadband response, but the imperfection may renovate their intrinsic properties far from the desire. Here, by controlling the deviation from the perfection of the atomic lattice, ultrabroadband multilayer MoS₂ photodetectors are originally designed and realized with the detection range over 2000 nm from 445 nm (blue) to 2717 nm (mid‐infrared). Associated with the narrow but nonzero bandgap and large photoresponsivity, the optimized deviation from the perfection of MoS₂ samples is theoretically found and experimentally achieved aiming at the ultrabroadband photoresponse. By the photodetection characterization, the responsivity and detectivity of the present photodetectors are investigated in the wavelength range from 445 to 2717 nm with the maximum values of 50.7 mA W^?1 and 1.55 × 10⁹ Jones, respectively, which represent the most broadband MoS₂ photodetectors. Based on the easy manipulation, low cost, large scale, and broadband photoresponse, this present detector has significant potential for the applications in optoelectronics and electronics in the future.     

新型节能材料——导热胶泥在沥青输送管道上的应用

通过对沥青管道伴热方式优缺点的分析;热利用效果比较;各种加热、伴热方式投资情况的对比;实际应用效果的分析,说明新型伴热材料——导热胶泥和新型伴热方式——外管线+导热胶泥伴热在沥青管道输送中的应用效果。该伴热方式施工简单、投资小、热利用率高,可以达到夹套管伴热的效果,在工程设计中广泛应用。     

金陵连续重整装置长周期运转的问题及对策

中国石油化工股份有限公司金陵分公司连续重整装置采用UOP超低压专利技术,设计规模1.0 M t/a。装置运行过程中发现因循环水质量差和流量小导致增压机冷却效果差;因重整产氢纯度低导致其中C2以上烃类在氢还原气氛下发生氢解反应;电阻丝局部积炭,热量传递效果变差;氧化镁绝缘层过热变薄失去绝缘效果,致使还原电加热器接地故障跳停;因抽提塔界面波动过大、溶剂脏、消泡剂泵故障、汽提塔负荷增大引起汽提塔冲塔等问题。提出了优化循环水流程、改造抽空器、引用PSA高纯度氢作为还原氢、降低抽提溶剂比、改变异构化轻烃流程等一系列措施,基本解决了制约装置长周期运行的问题。同时也指出了制约装置大负荷生产存在的＂瓶颈＂。     

Detection of surface roughness of mechanical drawings with deep learning

Journal of Mechanical Science and Technology - Engineering drawing inspection is important to CAD modeling of mechanical parts. Traditional inspection methods mainly rely on manual analysis by...     

Direct Coagulation Casting of Alumina Suspension from Calcium Citrate Assisted by pH Shift

Direct coagulation casting of alumina suspension via controlled release of high valence counter ions (DCC–HVCI) using calcium citrate as coagulating agent was reported. Hydrolysis of glycerol diacetate shifts the pH of suspension to weakly acidic region which helps to decompose calcium citrate and release calcium ions. The effect of concentration of glycerol diacetate and calcium citrate on the pH and viscosity of alumina suspension was investigated at 25°C and 60°C, respectively. The pH of suspensions with glycerol diacetate and calcium citrate decreases to 8.6 and 7.5 treated at 25°C and 60°C, respectively. It is indicated that high viscosity is achieved by adding 2 vol% glycerol diacetate and 0.5 wt% calcium citrate which is enough to coagulate the suspension. Green body with compressive strength of 1.0 MPa is obtained by treating the alumina suspension with 2 vol% glycerol diacetate and 0.5 wt% calcium citrate at 60°C for 1 h. The alumina ceramics sintered at 1550°C have homogeneous microstructure with relative density above 99.0%.     

基于同步挤压提取变换的滚动轴承故障诊断研究

滚动轴承是大型机械设备的重要部件,起着非常重要的作用.当轴承发生故障时,如不及时修复或更换,将严重影响设备的寿命.时频分析方法是一种非常有效的故障特征提取工具,已得到广泛的应用;同时,时频分布的能量聚集性影响故障特征提取效果,因此,一种能量更加集中的时频分析方法对机械信号处理与故障诊断起着至关重要的作用.提出了一种全新...     

铝锆有机金属偶联剂对超细碳酸钙表面性能的影响

利用铝锆有机金属偶联剂对超细碳酸钙进行表面改性。讨论了改性前后超细碳酸钙的润湿性、沉降体积等表面性质的变化。结果表明:改性后的超细碳酸钙与水的接触角增大;红外光谱和能谱分析表明,在无机碳酸钙粉体表面接枝上了铝锆有机基团;通过扫描电镜可以看出,改性后的超细碳酸钙在有机介质中的分散性得到改善。     

Purely Electrical Controllable Complete Spin Logic in a Single Magnetic Heterojunction

Fully electrical manipulation of magnetism, preferably through spin current, is highly desired to achieve energy-efficient, nonvolatile, and programmable spin logic devices. It is demonstrated in this study that in a single Pt/IrMn/Co/Ru/CoPt heterojunction, all 16 Boolean logic functions can be realized in a purely electrical way, relying on electrical manipulation of magnetic-field-free spin-orbit torque (SOT) switching. By applying current pulses along with two orthogonal directions, the exchange bias between IrMn and Co, and the SOT switching polarity (clockwise or counterclockwise) of perpendicularly magnetized CoPt, can be reversibly controlled, enabling complete spin logic within a single nonvolatile memory. This study makes a significant step towards practical electrical programmable spin logic devices.