信息时代街头官僚及其自由裁量权的变革与挑战

当前,新一代信息技术驱动着传统政府迈向数字政府、智慧政府,街头官僚亦不可避免地卷入这一变革浪潮中。本文对信息技术如何重塑街头官僚及其自由裁量权问题进行了讨论,提出要用发展的眼光看待信息时代街头官僚的变革趋势,做好充分准备应对信息技术,重塑街头官僚及其自由裁量权将带来的种种挑战。国家社会科学基金青年项目“转型期我国地方政府创新扩散机制研究”(16CZZ015)的资

武汉东湖颗粒有机碎屑碳、氮、磷的沉降速率

1983—1984年,测定了东湖水柱总沉降颗粒有机物中的碳、氮、磷、叶绿素a含量和浮游动物数量,以及该湖浮游动、植物优势种的干重/湿重、C/N及C/P比值。利用所得数值计算出其颗粒有机碎屑的沉降速率。东湖这两年的颗粒有机碎屑的沉降速率[g/m~2·a),Ⅰ站分别为10.67与10.97(碳),2.15与2.68(氮)及0.29与0.30(磷);Ⅱ站分别为10.35与7.26(碳),2.17与1.12(氮)及0.22与0.16(磷)。与水柱浮游植物净生产量相比,这两年有机碎屑碳的沉降量,Ⅰ站仅占1.96％

Horn Antenna Gain Measurement Based on Vector Network Analyzer

利用微波暗室、矢量网络分析仪、角锥喇叭天线以及电脑等设备建立了一套喇叭天线测量系统;采用两相同天线法,分别测量了4~6 GHz、6~8 GHz角锥喇叭天线的增益值,对测量数据进行误差分析和近距修正;并将增益的实测值与理论计算值进行对比.实验结果表明,近距修正后,所测量的4~6 GHz与6~8 GHz频段天线的增益实测值与理论值的最大偏差值分别为-0.20 dB和-0.19 dB,均在±0.25 dB范围内,符合标准增益天线增益的精度要求,也与天线出厂的指标相符,表明所建立的测量系统对于喇叭天线增益的测量有效可行.中航工业创新基金产学研项目(cxy2013XD28

基于信任的旅游目的地口碑推荐机制研究

旅游口碑推荐是旅游者在目的地完成一项旅游活动后对旅游产品以及目的地做出的综合性评价,并向他人进行推荐的过程,这里主要是指正面口碑的传播。口碑推荐有利于降低信息不对称条件下的旅游购买感知风险,是旅游者购买决策的重要依据。那么,究竟哪些因素影响旅游者进行口碑推荐?这些因素又是通过什么样的机制对口碑推荐产生作用?为此,文章以S-O-R理论为基础,实证分析了旅游者感知价值、功能一致性和旅游者目的地信任对口碑推荐意愿的影响效应,同时检验了意见领袖在其中是否起着调节作用。研究结果显示,感知价值对旅游者目的地信任和旅游口碑推荐意愿有着显著的正向影响;功能一致性对旅游者目的地信任的正向影响显著,而对旅游者口碑推荐意愿的正向影响不显著;旅游者目的地信任正向显著影响旅游者的口碑推荐意愿;在多群组结构方程模型分析中发现意见领袖的调节作用并不显著。该研究结果丰富和完善了口碑推荐意愿的理论,为目的地管理者实施有效的营销和管理提供了参考

Reflecting and scattering of acoustic wave from sea ices

北极海面冰层复杂多变,其对声波的反射和散射严重影响冰下水声信道的传输特性,建立海面冰层的声波反射和散射模型对冰下水声通信研究具有重要意义.假设海; 面冰层为多层固体弹性介质且冰-水界面粗糙,满足微扰边界条件,导出声波从海水介质入射到海面冰层时相干反射系数满足的线性方程组.对相干反射系数随声波; 频率、掠射角、冰层厚度的变化进行数值分析.进一步引入根据散射声场功率谱密度计算散射系数的方法,改变掠射角,对冰层厚度、散射掠角对散射系数的影响进; 行研究.In order to build an efficient underwater acoustic sensor network in the Arctic Ocean environment, transmission characteristics of under-ice acoustic channels need comprehensive understanding. The reflecting and scattering of acoustic waves from sea ices have great influences on under-ice acoustic channels. Both topology and structure of sea surface ices are very complex and variable. The physical dimension, acoustic property and interface roughness of sea ices depend not only on local environment, but also on climate and formation time. Therefore, it is of great significance to develop a model of reflecting and scattering of acoustic waves from sea ices for investigating the sound propagation in the under-ice environment. Assuming that sea ices are a multi-layered elastic solid medium and the ice-water interface is rough and satisfies the boundary condition of perturbation, we develop a system of linear equations to solve the coherent reflection coefficient of the incident sound wave from water to sea ice. The coherent reflection coefficient is a function of the frequency of sound wave and incident grazing angle, and is numerically evaluated. The influences of ice thickness and ice-water interface roughness on the coherent reflection coefficient are analyzed. Furthermore, the method of calculating scattering coefficient by using the power spectrum density of the scattering field is introduced. The scattering coefficient as a function of the scattering grazing angle is numerically evaluated. The influences of ice thickness and ice-water interface roughness on scattering coefficient are analyzed. The results show that both the coherent reflection coefficient and the scattering coefficient are dependent on the frequency of acoustic wave, ice thickness and grazing angle. The coherent reflection coefficient is close to 1.0 and the scattering coefficient is less than 0.01 when incident grazing angle is less than 15.. In addition, the frequency of acoustic wave and ice thickness have weak influences on them. However, the frequency of acoustic wave and ice thickness have significant influences on the coherent reflection coefficient and the scattering coefficient when the incident grazing angle is big, say, greater than 30.. In general, the thicker the ice is, the smaller the coherent reflection coefficient and the scattering coefficient are. The coherent reflection coefficient is less than 0.18 when the ice thickness is greater than 10.0 m and the frequency of acoustic waves is greater than 2 kHz. The ice-water interface roughness has great influences on both the coherent reflection coefficient and the scattering coefficient. The rougher of the ice-water interface is, the smaller the coherent reflection coefficient is, and the bigger the scattering coefficient is.National Natural Science Foundation of China [41276038

旅游城市形象和情感联结对旅游意愿的影响

在\"认知—情感—态度—行为\"理论的基础上,以厦门市为数据收集地,通过结构方程模型就旅游城市形象、情感联结、目的地态度对潜在旅游者旅游意愿的影响进行了分析。结果显示:潜在旅游者与旅游城市的情感联结显著正向影响其旅游意愿;旅游城市形象对旅游者的旅游意愿具有显著正向影响;通过情感联结对旅游者旅游意愿的间接影响优于其对旅游者旅游意愿的直接影响;情感联结对旅游者旅游意愿的直接效应是旅游城市形象对旅游者旅游意愿效应的近两倍。据此认为,情感联结在旅游者目的地选择中具有十分重要的作用

Foreign Exchange Market Intervention,Exchange Rate and Monetary Policy —— On the Effectiveness of Sterilized Intervention

通过VAr模型、grAngEr因果关系检验、脉冲累积响应和非线性回归方法分析了我国外汇市场干预、汇率和货币政策之间的动态相互关系,以及我国外汇市场冲销干预的有效性。研究结果表明:央行通过外汇市场干预试图稳定汇率,在一定程度上导致了国内货币供给增加,货币供给增加又会导致汇率升值;央行的外汇干预操作并未考虑到干预可能带来的国内货币市场失衡的影响,同时这种干预并不能有效地影响汇率;为了缓解通胀压力,央行通过提高利率回收部分货币投放。此外,在考察期内的三个阶段,央行冲销政策的有效性也是不同的。This paper analyzes the dynamic mutual relations among China's foreign exchange market intervention,RMB exchange rate and monetary policy,as well as the effectiveness of sterilization via the VAR model,Granger causality test,accumulated impulse response and the non-linear regression methods.The empirical results suggest that: the central bank tries to stabilize the exchange rate by the foreign exchange market intervention.To a certain extent,foreign exchange intervention will increase the domestic money supply,and the increased money supply will lead to the appreciation response of exchange-rate.The central bank does not take into account the possible impact of imbalances in the domestic money market,while the central bank's foreign exchange intervention should not be able to effectively influence the exchange rate.In order to ease inflationary pressures,the central bank would recover part of money supply by raising interest rates.In addition,during the three stages of the empirical study,the effectiveness of the central bank's sterilization policy was different.国家社科基金项目“中国外汇储备风险测度及管理研究”(07BJY157

厦门大学图书馆学科服务改革实践

厦门大学图书馆在现有\"由下至上\"及\"兼职分散式\"学科馆员模式下,进行了多年的实践,取得了一定的经验。在经历了一系列的学科服务的探索后,其开始面对学科服务的困境,重新思考学科服务的未来。为了促进学科服务全面发展且加快学科服务的效率,厦门大学图书馆从组织架构上进行了改革——增加学科服务带头人领导的\"由上至下\"的管理模式与协调员扁平化组织模式,以实现具有图书馆统一理念的学科服务

基于邻域粗糙集的多标记属性约简算法

在多标记学习中,属性约简是解决多标记数据维数灾难的一个关键技术.针对邻域粗糙集属性约简在计算正域代价较大和多标记数据中标记具有不同的强弱性问题,提出了基于邻域粗糙集的多标记属性约简算法.该算法首先利用样本在整个属性空间下到其异类样本的平均距离与到其同类样本的平均距离的差值对标记进行加权;其次,利用取整函数对样本空间进行划分,提出了一种新的多标记邻域粗糙集快速计算正域的方法;最后,根据前向贪心搜索算法进行属性约简,以获得一组新的属性排序.实验给出了5个多标记数据集在4个评价准则上的对比结果,实验结果分析表明了所提算法的有效性.国家青年科学基金项目(N61603173);;福建省自然科学基金项目(2018J01422);;浙江省海洋大数据挖掘与应用重点实验室开放课题(OBDMA201603

传播的艺术:中美比喻说服的逻辑间距

比喻是传播中广泛使用的一种艺术.比喻中本体和喻体之间的关系体现了中美文化不同的思维方式.相对而言,中国比喻典型为直觉推理,美国比喻典型为形式逻辑.对中关大学生施测的结果,对两种比喻类型,整体思维高的中国大学生更易理解直觉推理比喻;分析思维高的美国大学生更易理解形式逻辑比喻.对中国大学生的思维方式启动实验表明,思维方式可以通过相关材料启动,并可以影响到广告中比喻的说服效果.启动整体思维的材料尚需进一步的研究.国家自然科学基金项目“东西方不同文化思维方式对广告说服的影响”(项目(71372076)的研究成果