Silver catalysts supported over activated carbons for the selective oxidation of CO in excess hydrogen: effects of different treatments on the supports

Commercial activated carbon (AC) was used as a support either in its original form or after various modifications, giving diverse textural and surface chemical characteristics. The changes of these properties were monitored by N₂ adsorption–desorption isotherms, temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Ag catalysts were prepared over the AC supports by a conventional wet impregnation method. The catalytic performances of supported Ag/AC catalysts in the selective oxidation of CO in excess H₂ were tested. The results indicate the textural and surface chemical characteristics are responsible for the different catalytic performances.     

无线可充能传感器网络的锚点算法与移动设备调度研究

由于传感器的电池容量和存储容量有限,导致无法持续对传感器进行能量补充并收集传感器生成的感测数据。针对该问题,研究了周期性能量补充和数据收集问题,提出了一种用于充能和数据收集的方法,包括基于网格的算法(GBA)、基于支配集的算法(DSBA)和基于圆相交的算法(CIBA)。通过这三种方法或两两相结合的方法找到锚点集合,通过移动设备调度算法调度最小数量的移动设备来访问生成的锚点。仿真结果验证了所提方法的有效性。与联合能量数据采集(JEDA)算法、最小覆盖圆(SEC)算法相比,所提CIBA需要的移动设备数量最少,总移动距离也最短,具有良好的综合性能。     

Advancing Africa’s Great Lakes research and academic potential: Answering the call for harmonized,long-term,collaborative networks and partnerships

The African Great Lakes (AGL) have rich fisheries and are renowned “biodiversity hotspots”. Consequently the AGL and the ecosystem services they provide, underpin the welfare and livelihoods of over 50 million people across 10 countries. Despite the recognized importance of the AGL, these vital ecosystems and their livelihood support systems are threatened by numerous anthropogenic stressors at local, regional, and global scales. Past and continued efforts to address critical challenges on these lakes are often short-term, parochial, disparate, and uncoordinated resulting in a lack of comprehensive and comparable scientific data and inadequate resources to influence evidence-based policy. Over the past two decades, several international workshops, conferences and scientific publications have identified the need for collaboration, knowledge sharing, and harmonization of research and management as key elements to enhance conservation efforts in the AGL. In this commentary, we introduce the African Center for Aquatic Research and Education (ACARE), which aims to strengthen research and provide the scientific evidence needed to make informed decisions related to sustainable fisheries and aquatic resource management in the AGL. To do this, ACARE will administer a highly collaborative network of experts with three long-term goals: (1) strengthen global and regional research partnerships; (2) establish transboundary and inter-jurisdictional lake advisory groups; and (3) build capacity of freshwater scientists through experiential education and public engagement.     

面向多区域防洪的长江上游水库群协同调度模型

长江上游水库群是长江流域防洪工程体系的重要组成部分,承担着水库所在河流、川渝河段以及长江中下游的防洪任务。长江流域面积广大,水系众多,洪水地区组成与遭遇十分复杂,防洪需求众多,防洪对象分散,且要兼顾发电、航运、供水、生态、库区安全等多种因素,水库群防洪调度面临大规模、多区域、多层次等协同调度技术难题。以长江上游25座控制性水库为研究对象,基于防洪格局和防洪任务将水库群防洪调度划分为核心、骨干和群组水库,阐明了水库群多区域协调防洪的调度节点和角色定位,提出了兼顾"时-空-量-序-效"多维属性的模型功能结构,构建了长江上游水库群多区域协同防洪调度模型,并在长江流域防洪调度形成示范应用,以挖掘长江上游水库群防洪调度潜力,进而提升长江流域防洪调度管理水平。     

Characteristics of coal sludge slurry prepared by a wet-grinding process

Coal sludge slurry(CSS) is an alternative fuel and a potential competitive method for sludge reduction.Based on the researches of coal water slurry, we studied CSSs by using a wet-grinding process with different types of regional municipal sludge(sludge) in an orthogonal experiment. The sludge type,sludge mixing proportion, dosage of dispersant, and grinding time were tested in this study. The results show that water content and its occurrence characteristics in the sludge have primary hindering influences on slurry ability. The range of fixed-viscosity concentrations with raw wet sludge is from 50.78%to 44.40%(by weight), while the range is from 53.35% to 51.51%(by weight) with dry sludge. All of the CSSs exhibit shear-thinning behaviors with different variation trends, especially the CSSs with more than 15%(by weight) raw wet sludge in it. Adding the same proportion of raw wet sludge increases the thixotropic properties of CSSs and the highest area of thixotropy loop is 3065 Pa/s, while the highest value of dry sludge is 1798 Pa/s. Hydrophilic group plays an important role in adsorbing water and building three-dimension networks with other particles, which is the main reason for CSS properties.Therefore, the mechanism can be used to find the way for making high quality CSS.     

模糊综合评价在集气站安全评价中的应用

运用模糊综合评价理论对影响集气站的安全因素进行了系统的分析和归类。综合考虑影响集气站的各种因素,结合生产实际,将模糊综合评价运用于集气站安全评价,评价结果与实际相符,并对提升集气站的安全管理水平给出了合理的建议。     

创新要素集聚与区域创新绩效研究——基于浙江中小企业的实证分析

本文在对浙江中小企业发展模式探讨的基础上,以人才要素、资金要素、技术要素和研发要素四个维度构建了浙江中小企业创新要素集聚的评价指标体系,并且对中小企业创新要素集聚与创新绩效之间的关系进行了理论论述和实证分析。研究结果发现,人才要素、技术要素是推动浙江中小企业创新绩效提升的关键因素,而中小企业集群所衍生出的内部“技术锁定”是影响中小企业资金要素、研发要素对创新绩效产生作用的原因所在。     

油田站外单管集油辅助工艺对比

为了解决部分油井无法单管输送的问题,采用PIPESIM模拟软件对不同含水率、不同集输半径和不同产液量油井的集输管线进行计算分析,同时结合各油田单管集输设计经验,得出中质原油站外系统单管集油工艺改造的技术界限,而对于达不到技术界限的油井,可以通过辅助措施实现单管集油,通过对比电磁加热器、空气源热泵、管道内置电伴热、井口气电加热器、油井保温隔热油管、地热、太阳能光热技术及井口加药等单管辅助措施的原理及工艺特点,最终确定在不同工况条件下的辅助单管集输措施,为油田站外单管集输工艺选择和优化提供了理论依据。     

组态压铸机

本文中采用MCGS通用版组态软件来完成通用工作站的数据采集和加工、实时和历史数据处理、报警和安全机制、流程控制、压射曲线和报表输出等日常性监控事务来实现对压铸机的控制 .在该体系中,通过在人机界面创建图形对象并调整画面的布局,组态配置不同的参数以完成不同的功能,所有的控制信息与数据信息都在其服务器的人机界面上统一管理、分配,因此,系统的维护更加简单、有效,信息的提供方式更为一致,可以更方便地得到最全面、及时的现场信息.实际运行表明,所提出的方法实现简单、占用资源少、系统稳定可靠,具有很好的应用价值.     

Students Weigh In: Usability Test of Online Library Tutorials

Librarians can improve their online tutorials by borrowing usability testing techniques from the computer science field to improve the human-computer interface. This study involved a multimethod usability test of librarian-created tutorials to determine what students learned, how they felt on several affective questions, and what they suggested for improving the tutorials. Results of pre- and post-tests showed that student knowledge increased, and surveys and focus group findings lean to several suggestions for improving engagement and placing tutorials where they will be most effective. This case study demonstrates the value of user input to improve the effectiveness of online instruction for information literacy.