我国大麦价格波动特征及其影响因素分析

[目的]大麦价格剧烈波动会直接影响大麦种植户的生产积极性和大麦产业的平稳发展,研究大麦价格波动特征及其影响因素,有助于提升大麦产业链相关主体识别和应对市场风险的能力,促进大麦产业的健康发展。[方法]文章先采用HP滤波法和ARCH类模型分析了2011年4月至2017年2月我国大麦价格波动特征,然后采用脉冲响应函数分析了我国大麦价格波动影响因素。[结果]我国大麦价格波动存在明显的季节性和周期性,样本期内总体上呈现逐渐下降趋势;我国大麦价格具有显著的波动集聚性,我国大麦价格具有显著的不对称性;在该文选择的影响因素中,大麦进口量和国际大麦价格是影响我国大麦价格波动的主要因素。[结论]该文提出必须保障并提高国内大麦合理产能、完善大麦价格监测预警体系、加强国内大麦进口企业整合和推动大麦进口来源多元化的政策建议。     

一种改进的电力线通信系统脉冲噪声抑制方法

为了抑制脉冲噪声对电力线正交频分复用（OFDM）通信系统的影响，最常用的方法之一是在接收端OFDM解调器之前前置一个置零非线性单元，即传统置零法。然而，由于引入了非线性失真，其性能并不理想。针对传统置零法引起的非线性失真问题，提出了一种基于迭代消除非线性失真的改进置零法。首先，对接收到的时域OFDM信号进行脉冲噪声检测和置零处理；然后，在频域利用已检测的符号来重构时域置零处理引入的非线性失真，并通过迭代提高重构的准确性；最后，从频域接收信号中减去重构的非线性失真。仿真结果表明，所提改进算法与传统置零法相比，有非常大的性能提升，增强了电力线OFDM通信系统对脉冲噪声的抵抗能力。     

一款小型化S频段高谐波抑制功率放大器的设计

为了确保卫星系统电磁兼容性满足要求，设计了一款应用于卫星测控通信系统的小型化S频段高谐波抑制功率放大器。通过在功放输出端设置谐波抑制网络改善了电路的谐波抑制性能。采用集总与分布参数元件相结合匹配形式，实现了电路的小型化设计。电路尺寸38.5 mm×28.2 mm。通过对功放腔体结构进行细化建模仿真，确保了功放电路的稳定性。实测结果表明，当工作频率为2.52 GHz时，功放1 dB压缩点大于31 dBm，谐波抑制度大于61 dBc，功率附加效率高于35%，1 dB带宽大于320 MHz。与国内外同类产品相比，该功放在谐波抑制性能等方面具有明显优势。     

X频段高频谱纯度频率合成器设计

针对高灵敏度接收机对频率合成器的高技术指标要求，构建了一种融合了直接模拟、直接数字以及间接数字的频率合成技术方案，根据该方案，成功实现了频率合成器的工程研制。通过测试，频率合成器相位噪声达-112 dBc/Hz@5 kHz，杂散抑制优于-75 dBc，频率分辨率小于1 kHz，10 MHz跳频时间约为13 μs，满足了高灵敏度接收机对频率合成器的高技术指标要求，为高纯度频率合成器的实现提供了一条新途径。     

多波束移动卫星系统的自适应开环预编码方法

对于卫星移动通信系统，由于卫星与地面终端之间的相对运动以及星地间传输延迟，传统的基于理想信道信息的预编码方法是不适用的。针对这一问题，提出了一种基于开环信道估计的预编码方法。卫星端利用开环获取的部分信道信息实现多波束联合预编码，并导出了系统传输速率的闭合解析表达式。此外，为了克服强干扰环境下多波束预编码系统性能恶化问题，提出了一种自适应预编码传输方法。卫星发射机依据开环获得的慢时变用户位置信道信息和信道统计量信息，自适应地选择预编码方法或传统频率复用方法，实现最优的系统性能。理论分析和仿真结果表明，与传统的干扰抑制方法相比，所提方法能实现更优的系统性能，同时也克服了传统预编码方法的局限性。     

网络媒体关注、审计质量与风险抑制——基于深圳主板A股上市公司的经验数据

以我国深圳证券交易所主板2011—2016年A股上市公司为样本，通过计算可操纵性应计利润衡量审计质量，使用上市公司违规数据衡量经营和交易违规风险与虚假披露风险，考察网络媒体关注的风险抑制作用。研究发现：网络媒体关注度与审计质量具有风险抑制效应，且网络媒体关注对风险的抑制作用更显著；进一步地，网络媒体关注可通过提高审计质量来抑制企业违规风险，审计质量在网络媒体关注与风险抑制之间发挥部分中介作用。     

A train of thought in product experientiality: Working memory,distraction, and inconsistencies in cue order effects

The sequence of informational cues and the level of distraction have an impact on the judgment of a product’s quality and preference. Two quasi-experimental studies (N_total = 340) investigate the influence of the force behind the processing of these cues – working memory (WM). Previous research found that, in the presence of a distractor, high WM individuals are more able to recall the initial cue, and thus derive their product judgment from the initial strong cue. Study 1 contradicts these findings and raises important methodological questions regarding the conceptualization of strong and weak cues. Specifically, commonly accepted strong cues (e.g., product reputation) might not influence consumers as expected. Additionally, in a sequence of product evaluation with high vs. low degree of experientiality, study 2 reveals that consumers tend to show a primacy effect that is stronger for higher levels of WM capacity. Moreover, in a sequence of assessing low vs. high degree of experientiality products, consumers reveal stronger recency effects, thus showing that WM reinforces this recency effect. Our findings have important implications for marketers by suggesting that consumers with high WMC are more able to process complex stimuli and retrieve previously presented information on a product quality. These consumers also have a higher tendency to retrieve more information from product scenarios with a high degree of experientiality.     

Leader Emergence in Nascent Venture Teams: The Critical Roles of Individual Emotion Regulation and Team Emotions

This study advances a theory of how different aspects of emotion regulation influence individual leader emergence in the intensely emotional context of nascent venture teams. Despite the growing amount of research on the role of leadership in the entrepreneurial process, the emergence of leaders in nascent venture teams has rarely been explored. Drawing on theories and research on leadership emergence and emotion regulation, we argue that the two aspects of emotion regulation (i.e., reappraisal and suppression) exert opposite effects on the degree to which nascent venture team members come to perceive an individual as a leader. We also theorize that team emotions arising from affective events moderate the relationship between reappraisal and leader emergence in such teams. Data from 103 nascent venture teams without prior leaders show a negative relationship between individuals’ trait disposition to suppress emotions and their emergence as leaders, and a positive relationship between their trait disposition to reappraise emotions and their emergence as leaders. Moreover, we find that negative team emotions magnify the positive association between reappraisal and leader emergence, while positive team emotions mitigate it. We discuss the implications of our findings for the literature on entrepreneurial leadership, entrepreneurial emotions, and leadership in general.     

Cognition,Social Impulse,and the Principle of Adaptation: Insights into the Peirce-Veblen Connection

This article seeks to offer insights into the connections between Charles S. Peirce and Thorstein B. Veblen regarding their understanding of the logic of scientific thought and cognition. In this sense, this work explores how both Veblen and Peirce dismissed the Cartesian notion of unmediated cognition and how they sought to depict cognition as a process. Furthermore, this article presents Peirce’s concept of “social impulse” and Veblen’s “principle of adaptation” as complementary perspectives on science and cognition that have strong evolutionary content.     

两种自适应杂波抑制技术的比较：AMTI及ADPCA技术性能的分析和比较

本文在讨论机载雷达地面杂波回波的基础上，分析了ＡＭＴＩ和ＡＤＰＣＡ系统的性能。对这两个系统从原理上，并利用计算机模拟结果及实验结果进行了比较。本文将有助于工程实现。