摘要：Molecular nitrogen is relatively inert and the activation of its triple bond is full of challenges and of ***,searching for an efficiently heterogeneous catalyst with high stability and dispersion is one of the important targets of chemical ***,we report a Ba‐K/Ru‐MC catalyst with Ru particle size of 1.5–2.5 nm semi‐embedded in a mesoporous C matrix and with dual promoters of Ba and K that exhibits a higher activity than the supported Ba‐Ru‐K/MC catalyst,although both have similar metal particle sizes for ammonia ***,the Ba‐K/Ru‐MC catalyst is more active than commercial fused Fe catalysts and supported Ru *** techniques such as high‐resolution transmission electron microscopy,N2 physisorption,CO chemisorption,and temperature‐programmed reduction suggest that the Ru nanoparticles have strong interactions with the C matrix in Ba‐K/Ru‐MC,which may facilitate electron transport better than supported nanoparticles.

摘要：The development of efficient and stable non-mercury catalysts for the chlor-alkali industry is desirable but remains a great ***,we design a series of ruthenium catalysts for acetylene hydrochlorination by regulating the electronic structure of ruthenium ions through coordination with various ligands(thiourea,phenanthroline,and L-lactic).The turnover frequencies(TOFs)and apparent activation energies for the acetylene hydrochlorination have a linear relationship with the binding energy of Ru3+in the ruthenium *** synergetic effect of the ruthenium ion and ligands plays an important role in acetylene *** Ru-Thi/AC catalyst with thiou­rea as the ligand shows the highest TOF and stability in acetylene *** present study provides a rational method to regulate the electronic structure of supported metal catalysts with high catalytic performance exhibited by the carbon-supported heterogeneous catalysts.

摘要：信贷欺诈审核是金融欺诈检测领域的研究热点与难点,尤其是大规模金融信贷交易场景下的欺诈检测问题。然而,信贷欺诈审核过程中的欺诈者类节点数量分布极不平衡和欺诈者节点伪装自身问题一直是其所面临的重要挑战。基于此,面向大规模互联网金融信贷动态图提出融合重构子图选择和强化邻域过滤的图神经网络(RSRF-GNN)模型,以提高信贷欺诈审核的有效性。该方法从数据角度定义欺诈者数量分布不平衡和欺诈伪装问题。依据节点类别和出入度信息设计重构平衡子图选择模块以解决欺诈者数量分布不平衡问题。针对欺诈伪装问题,设计动态过滤邻域节点嵌入的邻域过滤模块。设计了边聚合模块聚合中心节点的邻域边嵌入,进一步提高中心节点邻域嵌入信息表达效果。为验证RSRF-GNN模型的有效性,在真实数据集DGraph-Fin上进行实验,结果表明RSRF-GNN模型在有效性方面比现有模型有较大提升。RSRF-GNN模型在AUC上提高了5~8个百分点,AP分数表现提高了18~29个百分点,模型性能优势显著。

摘要：提出一种基于在线产品评论的竞争情报挖掘方法,将网络评论文本中的关键信息应用于乘用车设计开发中。结合LDA和TF-IDF算法,从主题特征和情感态度特征获取不同车型评论主题情感倾向性估值,并对应2009—2019年的乘用车销量,构建用户偏好分析的面板数据模型。结果显示:该方法能够有效地提取网络评论情报信息;通过与年份的交互作用分析产品需求趋势,过去11年间消费者只对油耗的关注度降低了8.64%,对动力、空间、外观、内饰和舒适性的关注度分别上升了3.16%,6.80%,89.69%,13.38%和18.47%。其中,与生活品质更加密切的外观、内饰和舒适性等指标的增量远高于传统关注的动力和空间指标。这表明燃油经济性越来越不受关注,已不再成为消费者购买乘用车的决定性因素。

摘要：为提升学生综合能力,培养创新型人才,在基础化学实验教学中引入了项目制研究性学习法。将知识面宽、应用性广、前沿性强的科研课题“胶体金纳米颗粒的制备及应用”打造为创新探索性实验项目。以科研项目为牵引,以问题为导向,以综合能力培养为目标,引导学生进行主动学习、团队协作、自主设计探究,不断提升自身能力素养。在实验教学过程中不断迭代改进教学方法,创设更加开放、自主的实验环境,完善多维性评价体系,总结项目制研究性学习法的应用要点及注意事项,最终为基础化学实验课程提供了一种培养本科生创新思维和科研能力的教学模式。

摘要：在固定床反应器中对Ba～Ru—K／AC催化剂在相应的工业条件下[温度（350—450）℃，压力10MPa，V（H2）：V（N2）=1．0、1．5、2．0、2．5和3．0，空速（60000—180000）h^-1]，进行了系列动力学测试。采用改进的Temkin动力学方程对实验数据进行拟合，考虑到H：和NH，的吸附对催化剂作用的阻碍效应，优化得到动力学模型参数n、α、w1和W2分别为1、0．15、0．5和1．4。结果表明，在Temkin方程中加入H，和NH，的吸附项能够获得可靠的动力学模型，用Arrhenius和Van’t Hoff方程对动力学和热力学参数k、Km和‰。，进行线性拟合，得到氨合成反应的活化能为90．2kJ·mol^-1，远低于铁基催化剂，说明Ru上N2的解离吸附活化能垒远低于传统磁铁矿基催化剂和维氏体基催化剂。H2的吸附热为76．2kJ·mol^-1，证明Ba—Ru—K／AC催化剂上H2的吸附较强烈，对N2的吸附有强烈的抑制作用。改进的Temkin动力学方程能应用于使用Ru／C催化剂的氨合成反应器的设计和操作。

摘要：本文研究二维装载约束下带时间窗的飞翼车车辆路径优化问题(2L-CFWVRPTW),建立同时考虑车载重心和飞翼车两侧装载约束的数学模型.针对飞翼车两侧开门的特殊装箱模型,设计devide分厢策略,开发分厢最少开放空间和精英遗传算法相结合的混合启发式算法(EGA-DeLOS),算法中引入重心约束改进装厢适应度函数.经典算例测试结果表明:EGA-DeLOS算法能够解决飞翼车二维装载约束下的车辆路径问题,重心约束能够提高装箱解的适用性,并且能够有效求解2L-CFWVRPTW问题,为使用飞翼车的物流企业提供科学的决策支持.

摘要：Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at ***, we synthesized Bi_(2)O_(3)-polyoxometalate heterostructure SNWs(PMB SNWs), and fabricated super-aligned PMB SNWs films(S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide(LPS)shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur(Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.

摘要：以喷水推进舰船为研究对象,基于计算流体动力学(CFD)方法获得其水动力导数,在设计航速下对其进行矢量运动控制仿真研究。采用STAR-CCM+开发CFD求解器,采用流体域体积(VOF)方法求解自由面,选用Realizable k-ε模型作为湍流模型。通过纯横荡试验和纯艏摇试验的平面运动机构试验对船体受到的横向力和摇艏力矩进行分析,得到水动力导数,并构建适用于喷水推进舰船的操纵运动模型。结合建立的操纵运动模型设计喷水推进船的艏向控制器并进行矢量控制仿真,验证所提方法的可行性。

摘要：针对红外图像对比度低、细节不清晰等问题,提出一种基于改进加权引导滤波的红外图像增强算法。首先将原图与梯度图叠加构建引导图像;其次利用canny算子修正边缘权重因子实现保边滤波;然后依据模糊理论设计模糊集增强算法增强图像细节信息;最后应用BM3D去除图像噪声,得到最终增强图像。经对比实验验证,该算法可以有效地提升图像对比度、增强细节信息、去除无关噪声,与参考算法相比,平均梯度提升了2.48%~7.47%,信息熵提升了5.19%~9.76%,结构相似性提升了0.85%~2.58%,视觉效果获得明显改善,可以满足实际应用需求。