Meta-analysis of CO_(2) conversion,energy efficiency,and other performance data of plasma-catalysis reactors with the open access PIONEER database

This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been developed and is available online to the public.The simple and fast visualisation of the state of the art puts new results into context,identifies literal gaps in data,and consequently points towards promising research routes.More advanced data extraction illustrates the impact that the database can have in the understanding of plasma-catalyst coupling.Lessons learned from the review of a large amount of literature during the setup of the database lead to best practice advice to increase comparability between future CO_(2)plasma-catalytic studies.Finally,the community is strongly encouraged to contribute to the database not only to increase the visibility of their data but also the relevance of the comparisons allowed by this tool.

DP-DQPSK Optical Access System Integrated with Fiber and Free-Space Downlink for High Spectral Efficiency Application

In this letter, we present the generation, the balanced detection, and the transmission performance evaluation of dual polarization differential quadrature phase shift keying (DP-DQPSK) signals in optical access system integrated with fiber and free-space downlink. Polarization-multip- lexed (POLMUX) technique is introduced in the system for high spectral efficiency access utilization. 10 Gb/s DP-DQPSK downlink signals are successfully transmitted over 50 km SMF-28 and a 800 m wireless optical channel under the bad weather condition, such as fog and haze. The results show that the potentiality of DP-DQPSK optical access system is integrated with fiber and free- space downlink for providing flexible user access with high bandwidth efficiency.

Exploiting Spectral-Energy Efficiency Tradeoff with Fairness in Non-Orthogonal Multiple Access Systems

The spectral efficiency(SE)and energy efficiency(EE)tradeoff while ensuring rate fairness among users in non-orthogonal multiple access(NOMA)systems is investigated.In order to characterize the SE-EE tradeoff with rate fairness,a multi-objective optimization(MOO)problem is first formulated,where the rate fairness is represented with theα-fair utility function.Then,the MOO problem is converted into a single-objective optimization(SOO)problem by the weighted sum method.To solve the converted non-convex SOO problem,we apply sequential convex programming,which helps to propose a general power allocation algorithm to realize the SE-EE tradeoff with rate fairness.We prove the convergence of the proposed algorithm and the convergent solution satisfies the KKT conditions.Simulation results demonstrate the proposed power allocation algorithm can achieve various levels of rate fairness,and higher fairness results in degraded performance of SE-EE tradeoff.A pivotal conclusion is reached that NOMA systems significantly outperform orthogonal multiple access systems in terms of SE-EE tradeoff with the same level of rate fairness.

Energy efficiency aware dynamic rate and power adaptation in carrier sensing based WLANs under Rayleigh fading and shadowing

We consider the problem of energy efficiency aware dynamic adaptation of data transmission rate and transmission power of the users in carrier sensing based Wireless Local Area Networks(WLANs)in the presence of path loss,Rayleigh fading and log-normal shadowing.For a data packet transmission,we formulate an optimization problem,solve the problem,and propose a rate and transmission power adaptation scheme with a restriction methodology of data packet transmission for achieving the optimal energy efficiency.In the restriction methodology of data packet transmission,a user does not transmit a data packet if the instantaneous channel gain of the user is lower than a threshold.To evaluate the performance of the proposed scheme,we develop analytical models for computing the throughput and energy efficiency of WLANs under the proposed scheme considering a saturation traffic condition.We then validate the analytical models via simulation.We find that the proposed scheme provides better throughput and energy efficiency with acceptable throughput fairness if the restriction methodology of data packet transmission is included.By means of the analytical models and simulations,we demonstrate that the proposed scheme provides significantly higher throughput,energy efficiency and fairness index than a traditional non-adaptive scheme and an existing most relevant adaptive scheme.Throughput and energy efficiency gains obtained by the proposed scheme with respect to the existing adapting scheme are about 75%and 103%,respectively,for a fairness index of 0.8.We also study the effect of various system parameters on throughput and energy efficiency and provide various engineering insights.

Access数据库技术及其应用研究

文章主要研究Access数据库技术及其应用,首先介绍Access数据库技术的理论基础,包括数据库结构、数据库安全性、数据库存储空间,然后探讨Access数据库技术的应用方法,包括数据存储和管理、报表生成和打印、数据库设计和开发等,最后对基于Access数据库的实例应用进行分析,展示Access数据库在提高工作效率、优化数据管理和增强决策能力等方面的作用。

基于BOPPPS模型和思维导图的Access数据库课程教学设计

阐述BOPPPS模式和思维导图开展Access数据库课程教学设计,分析BOPPPS模型和思维导图的特点,探讨Access数据库课程教学设计中的应用,包括课堂引入、课程目标、参与式学习、考试评估。

基于Access的移动信息数据库设计与优化

随着移动设备的普及和移动应用的快速发展,基于Access的移动信息数据库设计成为信息技术领域的一个重要课题。文中探讨了如何设计和优化一个高效、安全且用户友好的移动信息数据库。首先,分析了移动信息数据库的概述、业务需求,然后提出了一个基于Access的数据库设计方案,包括数据模型、数据库E-R图设计和数据库表结构设计等。接着,讨论了数据库性能优化的方法,如索引设计、结构优化和数据压缩。最后,评估了所设计数据库的实际应用前景,并提出了未来工作的方向。

Access数据库课程混合式教学模式实践研究

Access数据库课程是中职院校针对计算机专业学生开展的核心必修课,但传统教学模式下学生个性化需求与教学环境不匹配,导致了学生成绩的不及格率高。为此,本文将SPOC与翻转课堂模式的混合教学策略融入Access数据库课程的教学,重构教学大纲和教学资源及模块,重视过程化考核。通过对学生的考试数据与平台活跃度展开相关分析和回归分析,发现混合模式教学构建了差异化、多维度及涵盖广泛的教学环境,进一步促进了优质教学资源的共享,增强了学生的学习效果,提高了教师的教学质量,为教学智能化奠定了基础。

将Access数据库中图文信息导出到Word文档的方法

该文介绍了将Access数据库中的图文混编内容导出到Word文档的方法,并给出了用Visual Basic 6.0实现的程序实例。

Toward the Energy Efficiency of Resource Allocation Algorithms for OFDMA Downlink MIMO Systems

The problem of the simultaneous multi-user resource allocation algorithm in orthogonal frequency division multiple access(OFDMA)based systems has recently attracted significant interest.However,most studies focus on maximizing the system throughput and spectral efficiency.As the green radio is essential in 5G and future networks,the energy efficiency becomes the major concern.In this paper,we develop four resource allocation schemes in the downlink OFDMA network and the main focus is on analyzing the energy efficiency of these schemes.Specifically,we employ the advanced multi-antenna technology in a multiple input-multiple output(MIMO)system.The first scheme is based on transmit spatial diversity(TSD),in which the vector channel with the highest gain between the base station(BTS)and specific antenna at the remote terminal(RT)is chosen for transmission.The second scheme further employs spatial multiplexing on the MIMO system to enhance the throughput.The space-division multiple-access(SDMA)scheme assigns single subcarrier simultaneously to RTs with pairwise“nearly orthogonal”spatial signatures.In the fourth scheme,we propose to design the transmit beamformers based on the zero-forcing(ZF)criterion such that the multi-user interference(MUI)is completely removed.We analyze the tradeoff between the throughput and power consumption and compare the performance of these schemes in terms of the energy efficiency.

浅析Access数据库在高校招生管理系统中的应用

随着计算机技术的突飞猛进,Access数据库的进步,全国高校应该充分地将Access数据库应用于招生管理系统当中。本文就将针对Access数据库在高校招生管理系统中的应用进行简要的分析和研究。

基于Access的灌溉信息管理系统

针对目前灌溉试验资料的管理、整编、归档、查询仍靠试验人员手工完成的落后局面,为有效地管理和查询灌溉试验数据,在windows 2000或windows XP操作系统下,使用Access开发了灌溉信息管理查询系统。该系统具有对灌溉试验数据进行输入、查询、修改、删除等功能,系统不仅功能全面,且可靠性高,稳定性好,界面可视性强,易于操作。

基于Visual Basic 2008的Access数据库类的设计

数据库系统是应用程序中的基本元素,而Access数据库最为轻便,可以满足大部分小型应用软件的需求。本文设计了一个Access数据库类ADO_NET_ACCESS,提供了Access数据库操作的常用方法和属性,并给出了测试结果。

利用Access2010数据库建立疼痛科患者信息管理系统

目的:制作疼痛科患者信息管理系统,实现患者及科室资料的信息化管理。方法:根据我院疼痛科实际情况,利用Microsoft Office Access 2010创建数据库,通过操作数据库完成疼痛科患者信息的登记、查询、浏览,疗效、不良反应、工作量的统计,医疗质量的监控、随访,彩色图文报表、图表的生成与打印以及各类数据的维护与导出,并且能够根据实际工作需要不断更新。结果:通过1年时间的使用,登记患者病例资料约2千多例,治疗信息1万余条,该系统运行稳定、数据安全、使用方便。结论:该系统界面友好、易学、易用,可快速录入资料,不仅方便患者资料的查询、统计及科室的量化考核、质控,而且便于指导临床诊治、方便科研和教学工作,为进一步回顾性及前瞻性研究提供信息支持。

利用Access软件实现药品编码升位

目的快速、有效地实现药品编码升位。方法采用Office系统Access软件程序建立药品编码数据库,包含分类属性码、品种序号码、产地码、剂型码、剂量码、包装码等字段。各字段先分别录入,再进行合并,即可实现编码的升位。结果利用Access数据库,可顺利将我院原有的药品编码由7位3级升位至14位6级。结论Access软件简单易用,其分字段编码录入便于药品信息的输入、维护与扩展,可独立进行编码升位而不影响现有医院信息系统药品信息的使用。

Access编制数据库在白内障病例管理中的应用

目的 应用微机对白内障病例进行管理 ,实现病例管理自动化。方法 根据患者姓名、晶状体等各项临床信息 ,在 Windows98及以上版本的操作平台上 ,应用 Access2 0 0 0建立患者信息病例库。结果 建立 Access病例库管理白内障病例 ,病例存储量大 ,查询方便快捷 ,数据处理方便。结论 Access2 0 0

睡眠呼吸暂停低通气综合症Access数据库的建立及应用

目的建立关系型数据库保存和管理睡眠呼吸暂停低通气综合症(SAHS)患者临床资料,并进行其应用价值的探讨。方法复习睡眠医学中心597例SAHS患者的病案资料,根据阻塞性睡眠呼吸暂停低通气综合征诊治指南制定408个字段,利用Access2010软件建立含表、查询、窗体、报表的数据库。结果在6个月的时间内建立了SAHS Access数据库,并成功应用于临床及科研工作。结论利用Access2010建立SAHS临床资料数据库简单易行,该数据库具有较强的数据处理能力,提高了医护人员的工作效率,规范了SAHS作为慢性疾病的系统管理,同时有利于临床随访及科研。

ACCESS数据库应用开发特色及方法

为了进一步加强Ｖｉｓｕａｌ－Ｂａｓｉｃ的应用系统开发范围，作者在分析ＡＣＣＥＳＳ数据库结构的基础上，探讨了用ＡＣＣＥＳＳ进行应用系统开发的特色，并阐述了ＡＣＣＥＳＳ的常用开发方法。实践证明，完全能达到用户共享，有较小的冗余度和较高的数据与程序独立性的要求。

基于Visual FoxPro环境ACCESS数据库操作的实现

在Visual FoxPro中使用ACCESS数据库,能够克服其自身存在的数据库、数据表与索引文件分离、数据表安全性不高等不利因素,较好地发挥二者在数据库管理与编程方面的优势。鉴于这方面的资料较少,系统地阐述Visual FoxPro环境下ACCESS数据库的操作方法,实现在Visual FoxPro中ACCESS数据库的建立、压缩与修复;数据表的建立、结构与记录的维护;Visual FoxPro数据库与ACCESS数据库的相互转换、Visual FoxPro中通用字段与ACCESS中OLE字段的数据转换等方法是很多用户的客观需求。用Visual FoxPro编程方式全面操纵ACCESS数据库具有重要的理论与应用价值。

基于Delphi与Access的人力资源信息管理系统设计

伴随科技的飞速发展,许多企业面临着信息化建设,作为企业核心的人力资源,合理的信息化建设对企业的发展至关重要。针对这一问题,提出并设计了基于Delphi与Access的人力资源信息管理系统。以Delphi 7.0和Access 2000作为开发工具,设计的人力资源信息管理系统是一种开发迅速,成本低廉和运行高效的管理系统,与大型企业相比,更适合中小型企业人力资源的信息化建设。