新疆棉农对农业面源污染防治的态度和支付意愿研究

农业面源污染问题已经成为我国面临的最严重的环境污染问题之一,农户对农业面源污染防治的态度和支付意愿研究,对于政府制定相关政策措施意义重大。分别采用李克特五点量表、条件价值评估法、多元有序Logistic模型回归等方法对(1)棉农对农业面源污染防治的态度,(2)棉农对农业面源污染防治的支付意愿(WTP),(3)影响棉农支付意愿的社会经济因素进行研究。结果表明:新疆棉农对农业面源污染防治的态度非常积极,但是当与自身利益相冲突时,则趋向于以牺牲环境为代价;新疆每户棉农对农业面源污染防治的支付意愿是113.96元/年,49.64%的被调查者选择的支付区间是[12,60)元/年,累计百分比占70.65%;农户的教育水平和是否参加过农业专业合作组织是新疆农户农业面源污染防治支付意愿的主要影响因素。基于此,得出结论并提出相应的对策建议。     

河南省农业面源污染成因分析

近年来,农业面源污染给我国农村生态环境造成了一定的破坏,挖掘农业面源污染的成因及问题对今后农业面源污染的治理具有重要意义。文章以河南省为探讨对象,首先阐述了农业面源污染含义及主要特点。利用文献分析和统计方法对河南省农业化学品投入使用及污染情况进行分析,2007~2014年河南省化肥及农药产量和使用量均呈上涨趋势,污染面积及范围进一步扩大,面源污染的主要来源是化肥、农药、秸秆及生活垃圾。而人口快速增长、经济利益驱使、政策方面不健全是造成农业面源污染主要原因。该文认为,解决农业面源污染应从推广减量技术,积极发展有机(生态)农业;提高思想认识,树立科学农业发展理念;大力推广精准农业,减轻面源污染程度;建立健全环境法规,完善政策及管理体系等4个方面入手,以期为其他地区农业面源污染治理提供借鉴和参考。     

基于SWOT分析理论的施工企业安全管理要点

针对近几年施工企业安全形势严峻,安全管理急需转型的形势完成本文。本文通过对企业安全管理的内部能力与外部因素运用SWOT分析,阐述了施工企业安全管理战略从过去突击式的安全大检查到以预防为主的危险源辨识管控的转变。     

一种改进的CPFSK信号频率估计方法

针对突发信号解调中多普勒频偏大的问题，提出了一种改进的连续相位移频键控信号(CPFSK)频率估计方法。首先接收信号平方运算使信号的调制指数加倍，再通过一次离散傅里叶变换(DFT)，用搜索信号平方谱谱峰的方法实现突发信号频率估计。仿真实验表明，在低信噪比条件下，该算法的频率估计精度比经典的相位差频率估计算法提高了20%；该算法与广泛用于高动态突发信号的频率插值估计算法相比，同道干扰信道下信干比改善可达4 dB，DFT长度缩短约1/3。     

The effectiveness of fear appeals in ‘green’ advertising: An analysis of creative,consumer, and source variables*

This study focused on the effectiveness of fear appeal messages used to arouse a threat in green advertising. An experiment recruited 175 participants to test the influence of the advertising appeal (fear vs. non-fear appeal), source (for-profit vs. non-profit organizations), and involvement with the environment on attitude toward the ad (A_ad), attitude toward the product (A_p) and purchase intention (PI). Results revealed that a fear appeal in a green ad negatively affected A_ad and A_p and that participants who were highly involved with the environment were more likely to have positive attitudes toward the green ad and advertised green product as well as a stronger intent to purchase it. The source type in the green ad did not affect ad effectiveness and involvement with the environment did not moderate the effects of either appeal or source.     

Ka频段双模航空客舱宽带卫星通信系统总体设计

针对民航市场对客舱宽带卫星通信的迫切需求，提出了一种基于Ka频段高通量卫星的双模解决方案。研究了系统设计的诸多方面，包括卫星资源选择、网络结构、技术体制和适航性。详细介绍了机载设备的组成和双模工作原理，分析了几个与设计实现密切相关的技术指标。方案设计和技术指标分析结果对实际工程应用有一定的参考价值。     

政府补助企业的主要动机研究——基于我国A股上市公司面板数据的实证检验

上市公司获得的政府补助数额巨大且逐年增长，引起了广泛的质疑，而现有研究对政府补助企业的动机尚无一致的结论。基于理性经济人理论，考虑制度更改和环境变化的影响，以2007—2015年我国上市公司为研究样本，实证检验政府补助企业的主要动机，结果表明：政府补助企业的主要动机在于扩大就业和帮助上市公司“保牌”，最终目的是促进经济的增长；而增加税收和帮助上市公司达到配股要求不是政府补助企业主要考虑的因素，也没有明显证据证明国有企业比民营企业更容易获得政府补助。应完善资本市场退市制度，加强对政府补助的审批和监管，提高政府补助的资源配置效率，并积极引导政府补助发挥更好的社会效益。     

Regulation of relationships between heterogeneous farmers and an aquifer accounting for lag effects

Many environmental problems are due to damage caused by pollutants that accumulate with a time lag following their emission. In this study, we focus on nitrates used in agriculture, which can pollute groundwater many years after their initial application. A dynamic optimal control problem with heterogeneous farmers is proposed. The usual structural parameters such as the discount rate, the natural clearing rate and the lagged time interval between the occurrence of soil‐level pollution and the impact on groundwater are taken into account. We also examine pollution as caused by a continuous set of farms characterised by their individual performance index and by their individual marginal contribution to the pollution. The issue is further investigated by taking account of change in the information context, successively related to perfect information and to asymmetric information. As a result, when the delay between the spreading of N‐fertilizer and the impact on the aquifer increases, that is, the longer the lag, the steady‐state pollution stock and the steady‐state shadow price of the stock both increase. Moreover, we show that the optimal regulation may require a decreasing amount of fertilizer over time, even in the case of initial underpollution.     

Current issues and research trends on open-source software communities

Open source software (OSS) projects represent a new paradigm of software creation and development based on hundreds or even thousands of developers and users organised in the form of a virtual community. The success of an OSS project is closely linked to the successful organisation and development of the virtual community of support group. This paper reviews different fields and research topics related to the OSS communities such as collective intelligence, the structure of OSS communities, their success, communities as virtual organisations, motivation, shared knowledge, innovation and learning. The main challenges, results obtained, and the knowledge areas are detailed for each topic.     

Foresighting FLOSS (free/libre/open source software) from a developing country perspective: The case of Turkey

Since free/libre open source software (FLOSS) promotes collaboration and contributions from different parties in software production and innovation processes, it can create a unique opportunity for developing countries, by generating an innovative capability in software technology. To benefit from this opportunity, it is important to understand the strategic factors and future trends that affect the development of an efficient FLOSS economy in developing countries.This paper aims to examine the strategic factors and future trends that are likely to affect the development and deployment of FLOSS in Turkey. Based on the internal and external factors identified through the practice of technological foresight, a SWOT analysis will be carried out to identify the strengths, weaknesses, opportunities and threats for Turkey in creating a competitive software industry that can benefit from the advantages of FLOSS. Accordingly, with regard to the required technical infrastructure, an innovative/competitive business climate, skilled human resources and support for institutional structures, policy suggestions are outlined here that could be usefully implemented by government, industry and universities.