制备方法对CuO／ZrO2催化剂性能的影响

考察了以共沉淀法及浸渍法（其中ＺｒＯ２载体是由超临界干燥法得到的超细粒子）制得的ＣｕＯ／ＺｒＯ２催化剂对ＣＯ／２Ｈ２合成甲醇的性能。结果表明浸渍法所得催化剂的活性显著优于共沉淀法所得催化剂的活性。在此两种方法制得的催化剂上,甲醇的选择性均很高（大于９８％）,反应温度对催化剂活性的影响均较为显著。考察了ＺｒＯ２载体比表面积对ＣｕＯ／ＺｒＯ２催化剂活性的影响,发现载体的比表面积在３１６～２２０ｍ２·ｇ－１之间时,对应ＣｕＯ／ＺｒＯ２催化剂对ＣＯ／２Ｈ２合成甲醇的活性最佳。     

CuO／ZrO2中铜与二氧化锆载体的相互作用表征

通过Ｘ－射线衍射、Ｘ－射线光电子能谱,电子顺磁共振和Ｘ－射线吸收近边结构等测试,发现ＣｕＯ／ＺｒＯ２中铜与二氧化锆载体间存在着相互作用,此相互作用导致铜离子的微观结构与纯氧化铜中铜离子的微观结构不同。     

清代各省采买滇铜的运输问题

滇铜是清代矿业兴盛的主要表现之一,因之成为史学界研究的热点问题。但是,关于清代滇铜外运的研究大多集中于京运方面,对各省采买滇铜的运输问题关注不够。从两者所铸铜钱的流通范围以及促进区域之间的经济交流方面而言,各省采运滇铜的作用和影响并不亚于京运。     

Ka波段全相参雷达收发射频前端系统组件研制

提出了一种Ka波段全相参雷达收发前端电路的设计方法,该设计方法综合考虑了收发变频本振(频综)和收发射频前端电路的特点和设计要求,对上/下变频的频率分配进行优化规划,充分利用了直接数字频率合成(DDS)、锁相环(PLL)和FPGA等的优点,从而既降低本振的实现难度,又可在频谱纯度(相噪和杂散水平)与变频时间等关键技术指标上得到了较高的综合表现。基于此,研制实现了一款性能优良的Ka波段全相参雷达收发前端系统组件,该组件已成功地应用在某Ka波段全相参雷达系统中。实测结果表明:当S/C波段的PLL本振源最小步进15MHz、带宽480MHz时,发射端杂散电平小于-65dBc,接收端杂散小于-70dBc,相噪水平优于-94dBc/Hz@1kHz,系统最大变频(频差480MHz)时间小于15μs。     

Sustainable Operations Management

Operations management researchers and practitioners face new challenges in integrating issues of sustainability with their traditional areas of interest. During the past 20 years, there has been growing pressure on businesses to pay more attention to the environmental and resource consequences of the products and services they offer and the processes they deploy. One symptom of this pressure is the movement towards triple bottom line reporting (3BL) concerning the relationship of profit, people, and the planet. The resulting challenges include integrating environmental, health, and safety concerns with green‐product design, lean and green operations, and closed‐loop supply chains. We review these and other “sustainability” themes covered in the first 50 issues of Production and Operations Management and conclude with some thoughts on future research challenges in sustainable operations management.     

《锁相环路原理》CAI课件的设计与特点

主要介绍《锁相环路原理》ＣＡＩ课件的总体设计思想和程序设计方法,并通过示例反映了该课件的功能与特点     

火焰原子吸收法测定锡粉中Fe,Cu,Pb,Sb和Ca的含量

用ＨＣｌＨＮＯ３ 溶解试样,在相同量的试液中,分别加入浓度依次递增的５ 种元素的标准溶液,用空气乙炔火焰原子吸收法测定Ｆｅ,Ｃｕ ,Ｐｂ ,Ｓｂ 和Ｃａ 的含量,建立了优化的测定条件,并对可能存在的元素进行了干扰实验．方法的回收率为９８ ．５ ％ ～１０２ ．０ ％ ,相对标准偏差为１ ．３ ％ ～２ ．８ ％ ．     

闭环模糊控制系统稳定性判据的分析

在分析闭环模糊控制系统模型及稳定性充分条件和必要条件的基础上 ,提出了闭环模糊控制系统稳定性判据 ,并加以证明 ,仿真结果表明判据是有效的 .     

间羧基苦胺酸偶氮变色酸与铜的显色反应研究

在磷酸介质中,Cu2+离子与间羧基苦胺酸偶氮变色酸反应生成络合比为12的稳定蓝色络合物,该络合物在663 nm处有最大吸收,其摩尔吸光系数为2.88×104L·mol-1·cm-1,Cu2+离子含量在0～25μg/25ml范围内遵守比尔定律,方法用于铝合金中铜含量的测定,铜的标准回收率在95%～102%之间,结果满意.     

Joint Life‐Cycle Dynamics of New and Remanufactured Products

Many products considered for remanufacturing are durables that exhibit a well‐pronounced product life cycle—they diffuse gradually through the market. The remanufactured product, which is a cheaper substitute for the new product, is often put on the market during the life cycle of the new product and affects its sales dynamics. In this paper, we study the integrated dynamic management of a portfolio of new and remanufactured products that progressively penetrate a potential market over the product life cycle. To this end, we extend the Bass diffusion model in a way that maintains the two essential features of remanufacturing settings: (a) substitution between new and remanufactured products, and (b) a constraint on the diffusion of remanufactured products due to the limited supply of used products that can be remanufactured. We identify characteristics of the diffusion paths of new and remanufactured products. Finally, we analyze the impact of levers such as remanufacturability level, capacity profile and reverse channel speed on profitability.