快速校正天波雷达电离层相位污染的改进方法

时变的电离层会对天波超视距雷达(OTHR)回波信号相位进行调制,产生相位污染,导致回波谱展宽。最大似然估计(MLE)法具有比相位梯度法更佳的污染校正效果,但计算量非常大。通过引入投影近似子空间跟踪法,提出了一种改进的MLE方法。改进方法采用递归手段估计最大特征值对应的特征向量,避免了特征值分解过程,能够显著降低计算量,污染校正效果与MLE法相当。理论分析与仿真对比表明改进方法普适性强,计算量只有MLE法的万分之一,更适合工程实现。     

水权水市场建设试点示范性评价研究

在当前我国开展各级水权改革试点的背景下,以水权试点示范性作为研究对象,根据水权水市场建设工作的一般需要,遵循普适性、科学性、整体性、目的性、动态性的原则,建立了以确权工作、水市场建设、组织与监管、基础设施建设、改革与创新5项水权改革的工作内容为准则层的四级示范性评价体系,运用层次分析法对各指标权重进行赋值,采用德尔菲法原理对二级指标进行评分。运用该评价体系对山东省两个典型水权试点的示范性进行评价,并根据各自的试点任务对结果进行了修正,得到了两地水权改革工作的定量评价结果。该评价方法不局限于试点区的评估,也可用于今后水权工作的一般性绩效评估。     

“一碗水端不平”：领导者宽容差序、职场妒忌及其后果研究

员工犯错时，上级领导可能因差序格局而对不同下属给予不同程度的宽容，出现“一碗水端不平”的现象。领导者的宽容差序造成下属在情感或资源分配上的不平等，为员工之间的社会比较创造了可能。为了揭示领导者宽容差序对员工个体心理和行为的影响，基于社会比较理论，本研究构建了“宽容差序—职场妒忌—行为后果”的平行中介路径模型。通过问卷调研和统计分析，证实了领导者的宽容差序，一方面会增加员工的恶意妒忌，进而引发反生产行为；另一方面会使员工减少善意妒忌，进而减少工作投入。另外，通过间接和总体作用的抽样计算，发现领导者宽容差序总体上会导致员工降低工作投入及增加反生产行为。     

农户对耕地重金属污染治理的认知与满意度评价*——基于长株潭地区的调查

[目的]民以食为天,食以安为先。耕地是农业发展的物质基础,是国家粮食安全和农产品质量安全的源头保障。2013年湖南"镉大米风波"敲响了我国耕地重金属污染治理的警钟。农户是耕地的直接使用者,是耕地重金属污染治理与保护的真正主体,调动农户积极性是提高重金属污染耕地修复治理的效率与效果的关键。[方法]文章基于湖南省长株潭3市5县的181户农户调查数据,构建多元有序Logistic模型,实证分析农户对耕地重金属污染的认知及其对耕地重金属污染治理的满意度评价。[结果](1)受访农户对耕地重金属污染的认知水平较低,但对耕地重金属污染治理的满意度评价相对较高;(2)农户对耕地重金属污染的主观认知会影响其治理满意度评价,且农户对耕地重金属污染的认知越高,对治理的满意度评价越高;(3)农户的年龄和种植规模以及专业技术人员及时到位的指导也是显著影响农户满意度评价的重要因素。[结论]政府制定耕地重金属污染治理方案时应进一步鼓励农户进行土地流转扩大种植规模,加强对农户耕地重金属污染治理的技术培训和宣传,提高专业技术指导到位率。     

The influence of mindfulness on mental state with regard to safety among civil pilots

Civil pilots' mental state has an important impact on their safety operation behaviors. The goal of this paper is to explore the relationships between mindfulness and anxiety in Chinese airline pilots. 319 commercial civil pilots from China Southern Airlines Ltd. were investigated using three separate scales, which measured mindfulness, anxiety, and burnout. The results show that mindfulness has a negative effect on pilots' anxiety. Burnout partially mediates the relationships between mindfulness and anxiety. Thus, mindfulness primarily influences pilots’ anxiety indirectly, by affecting burnout. The findings with regard to mindfulness have important implications in terms of pilot selection and emotional intervention, which, if appropriately addressed, can contribute to improving aviation safety.     

Effects of the Chinese arable land fallow system and land-use change on agricultural production and on the economy

This study focuses on economic effects of arable land fallow system and land-use change in China using a dynamic single-country, multi-regional computable general equilibrium model. Land supply is adjusted endogenously in our model. Land use in each of 31 provinces is tracked by a land-use change module, which is calibrated with satellite data. Our results reveal that the expansion of real output can be attributed to the increase in capital stock as a result of the growth of investment due to the imposition of the arable land fallow system in China. And the growth of investment is caused by the release of labor from agriculture The reduced supply of arable land in agricultural land contraction regions is partially offset by the increasing arable land in agricultural land expansion regions. Rural households benefit more than urban households from the arable land fallow policy due to relatively higher income and lower rural CPI.     

苹果中镉的快速测定及方法评估

为评估不同快检试剂盒检测苹果中镉的适应性,以阿克苏苹果为检测样品,实验采用国家标准《食品安全国家标准食品中镉的测定》(GB 5009.15—2014)作为参比方法,分别选择两家快检试剂盒,根据《食品快速检测方法评价技术规范》对其快检适应性进行了评估.结果表明,利用参比方法和快检试剂盒均未从苹果样品中发现镉污染.通过对苹果样品添加镉的标准物质评估其适应性,结果表明,试剂盒1灵敏度为100％,特异性为100％,假阴性率为0,假阳性率为0,相对准确度为100％,显著性差异为0;试剂盒2灵敏度为0,特异性为100％,假阴性率为100％,假阳性率为0,相对准确度为14.3％,显著性差异为58.02％.     

Perceptions of protective actions for a water contamination emergency

Local authorities who believe their water systems are contaminated need to warn those at risk to take protective actions. In the past, such efforts have often achieved only partial success in preventing people from deciding to continue consumption of contaminated drinking water. To examine the possible antecedents of decisions to comply with water consumption advisories, this study examined 110 Boston residents’ actual protective actions and 203 Texas students’ expected protective actions; their perceptions of three protective actions on seven attributes; and their risk perceptions, water contamination experience, facilitating conditions, and demographic characteristics. The profiles of the protective actions for the hazard-related and resource-related attributes suggest reasons why people preferred to use bottled water rather than boil or personally chlorinate water. In particular, perceived effectiveness in protecting health was the most important correlate of protective action, which means that a protective action can have a high level of implementation even though it has poor ratings on other attributes such as cost. In addition, this study indicates public health officials may also need to address people’s misconceptions about the hazard-related and resource-related attributes of any relevant protective actions. Finally, consistent with an extensive body of previous research, students were similar to residents in many important respects even though were some statistically significant differences.     

基于预编码与导频分配的大规模MIMO导频污染抑制

导频污染问题是限制大规模多输入多输出(MIMO)系统性能的主要影响因素。针对这个问题，提出了一种基于改进预编码和最优导频分配策略的大规模MIMO系统导频污染抑制算法。首先，在系统下通过基于改进遗传优化算法的最大化信干噪比(SINR)预编码算法，获得最优预编码矩阵；然后，通过基于用户信道条件优劣的最优导频分配策略对每个小区用户进行导频分配，从而实现大规模MIMO系统导频污染抑制。通过Matlab仿真结果可知，相对于传统的SINR预编码算法，所提算法的复杂度降低了65%左右，而导频污染抑制性能提升了30%左右。该算法能够有效抑制导频污染，提升大规模MIMO系统的性能。     

自贸试验区负面清单模式下事中事后监管

我国自贸试验区负面清单的外资管理模式在本质上给外资和内资企业创造了公平竞争的市场法制环境,这种管理模式顺应了国际投资规则发展的新趋势,与我国正在进行的行政体制改革相契合。在负面清单模式下,我国政府监管体系在理念、体制和效果上面临重重挑战。自贸试验区的设立以开放投资为起点,以开放促进改革,政府管理由事前审批逐步转为事中事后监管,最终落实政府职能的根本性转变。负面清单模式的完善不仅应着力于修订负面清单文本,更为重要的是建立和完善事中事后监管制度。自贸试验区的事中事后监管在理念转变、立法完善、监管主体等方面还存在一些问题。应该从转变监管理念、完善立法、构建信息平台、监管主体多元化和完善社会征信体系等方面对事中事后监管制度进行完善。