弱势群体获取公共信息面临的障碍及对策

本文介绍了弱势群体和公共信息服务的内涵,分析了弱势群体公共信息获取面临的障碍,在此基础上,提出了完善弱势群体获取公共信息服务的对策。     

Fusarium solani Upregulated Sesquiterpene Synthase Expression,Sesquiterpene Production and Allelopathic Activity in Piper betle L.

Activators of sesquiterpene synthase (STS) gene expression and sesquiterpene production in Piper betle L. were examined using quantitative real time PCR and gas chromatography mass spectrometry methods, and the allelopathic activity of untreated and Fusarium solani-treated betel extracts was tested on seed germination and on the shoot and root growth of Thai rice variety PSL2 (Oryza sativa cv. Phitsanulok 2) and three dominant paddy weeds (Eclipta prostrata, Echinochloa crus-galli and Chloris barbata). The results demonstrated that F. solani dramatically upregulated STS expression and productions of β-cubebene, β-caryophyllene and germacrene D sesquiterpene when compared with the untreated control, and that betel extracts had a greater inhibitory effect on weeds than on rice. The effects were more clearly detected on seed germination and root growth than on shoot growth, and they were found to be dose-dependent. It is also noted that F. solani-treated extract had stronger effects than the untreated extract. The species most sensitive to the allelopathic effects was C. barbata, germination of which was completely inhibited even at a dose of 0.1 mg/mL untreated extract. With regards to rice, although betel extract at 1.0 mg/mL showed no inhibition on germination, it affected the elongation of rice roots, in addition to those of the tested weeds. The obtained data suggested that F. solani has potential as an activator of sesquiterpene allelochemical production via STS expression, the latter leading to the treated betel extract having a stronger phytotoxic effect. These results were beneficial in the promotion of natural herbicide production using biotechnology.     

CNKI漫游账号管理研究

CNKI漫游账号不受机构IP范围的限制,合法用户在任何地方登录,均可免费使用关联到机构馆的资源、功能和服务。本文探讨了CNKI漫游账号的创建方法、分配和管理问题。     

接入管理技术在城市道路平面交叉口中的应用

城市道路平面交叉口是城市路网中重要的节点,也是事故频发和造成交通延误的瓶颈点。概述了接入管理技术的概念和设计原则,介绍了在城市道路平面交叉口中典型的接入管理技术。对改善城市道路平面交叉口交通安全及促使城市可持续发展具有重要的参考价值。     

烷基-二醇基硅胶填料的合成及对莠去净类除草剂的在线分离

三步合成了烷基-二醇基硅胶(ADS)色谱材料，首先用γ-缩水甘油醚氧丙基三甲氧基硅烷把功能基团键合到硅胶基体上，再把该环氧化硅胶与硬脂酸反应以制备酯型十八烷基反相填料，最后在20MPa压力下装成色谱预柱(35×4.6mm I.D)。用该预柱通过六通阀后接ODS分析柱(250×4.6mm I.D)，构成中心切割二维HPLC。该系统能对具有一定疏水性的化合物进行在线富集，实现环境及生物复杂样品直接进样分离分析。使用该系统对尿中的莠去净和西玛津残留进行了分离分析，以含有0.1%乙酸的酸性水缓冲液对加标尿液中莠去净类化合物保留在预柱上，干扰分析的大分子被排阻而无保留通过，其它干扰分子保留小而通过，再切换六通阀，以乙腈和0.1%乙酸水溶液进行梯度洗脱，进而在下一级ODS分析柱上进行分离（紫外检测225nm），两种除草剂的分离分析取得了良好的定性定量结果     

Practical Method of High-Speed Access for Medical Digital Image Sequences

The high-speed access for medical digital image sequences was restricted to special device and complicated system in the past. The authors present a new method of high-speed access for medical digital image sequences which can be performed on general computer by means of the combination of Serial ATA(SATA) and Redundant Array of Independent Disk(RAID).Then they introduce the scheme of system configuration and software program. Lastly the testing result is given and the speediness,cheapness and conveniency of this method are elucidated.     

Research on Cooperative Design Network Security Based on IP-VPN

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.     

Influence of MUD on the System Capability of CDMA

In CDMA communication system, the relativities between users result in Multiple Access Interference (MAI). With the increase of users, MAI becomes the main jam of broadband CDMA communication system. Multi-User Detection (MUD) is the most important technology of anti-jamming in the broadband CDMA communication system, which can eliminates MAI effectively by using the information of all user signals to detection single. This paper analyze the expression of system capability without MUD and with MUD, and puts forward the way to increase system capability by using MUD. Then the influence of MUD on CDMA system capability is discussed by MATLAB emulation. Basing analysis and emulation, the conclusion is got: the higher the MUD efficiency, the better the improvement of CDMA system capability; under the same MUD efficiency, the lower data rate, the smaller inter-cell interference, the lower the ratio of bit energy to power spectrum, the better the improvement of CDMA system capability.     

Intensification or extensification? Factors affecting technology use in peri-urban lowlands along an agro-ecological gradient in West Africa

The paper analyses whether the increased use of lowlands in proximity to urban centres in West Africa is associated with technological intensification or extensification. Technologies are typified in terms of their orientation – land or labour saving – and market dependence for their procurement and reviews the factors driving and modifying their use in lowlands. The factors associated with technology use are analyzed empirically using geo-referenced lowland data around four urban centers along an ecological gradient in Côte d’Ivoire and Mali. The technologies analyzed include both external inputs (fertilizer, pesticide, herbicide, improved varieties) and crop management practices (plot level bunding, rice transplanting and rice direct seeding). Results from binomial logit models highlight the prominent positive and non-linear role of proximity to urban markets for the technological intensification of lowlands – an issue associated with factor scarcities and the transaction costs for procurement and marketing. Technology use in lowlands is also associated with the agro-ecological gradient, lowland development and non-native lowland users. A common thread linking these variables is that they modify resource scarcity and therefore intensification incentives. Lowlands are not always as valuable as they may seem and there may be limited incentives to intensify. Instances of significant lowland cultivation and intensification in the study sites tend to be associated with specific opportunities – driven by market opportunities and modified by seasonal, institutional or development-induced relative land scarcity. Market access is therefore a necessary but not sufficient factor for the technological intensification of lowland use. There is a need for better targeting of development efforts in terms of enabling lowland intensification or extensification as appropriate.     

数字技能如何影响农民电商参与行为？——基于信息获取的中介效应分析

为探究数字技能对农民电商参与行为的影响及作用机制,基于2020年中国乡村振兴综合调查（CRRS）数据,立足“手段-自由-成就”的可行信息能力理论,构建“数字技能-信息获取-电商参与”的理论分析框架,采用二元Probit、Tobit和中介效应等分析方法,从信息获取的中介视角实证检验数字技能对农民电商参与决策及程度的影响,并进行稳健性检验和异质性分析。结果表明：1）数字技能对农民电商参与决策和程度均具有显著正向影响;2）信息获取在数字技能对农民电商参与决策和程度的影响中存在部分中介效应,中介效应占总效应的比重分别为11.76%和11.73%;3）数字技能对收入水平较高、受教育水平较高的农民,电商参与决策和参与程度的正向影响更为显著。政府应从有效提升农民数字技能水平,稳步实现信息获取自由,加强关注农民内部分化3方面提升农民电商参与率和程度。