保定市主要作物需水量和缺水量特征分析

[目的]对作物需水量及缺水量的研究是了解和合理配置农业灌溉用水的基础,对提高农业用水效率有重大意义。[方法]选取河北省保定市为研究区域,利用Penman-Monteith公式和分段单值平均作物系数法对冬小麦、夏玉米和棉花的作物需水量和缺水量等指标进行计算,通过Mann-Kendall检验法对保定市近60年来的作物需水量和缺水量等的变化趋势进行分析。[结果]3种主要作物的需水量、有效降雨量和缺水量的最大值均出现在作物发育中期;其中除冬小麦的有效降雨量以0.208mm/10年的速率呈不显著性增长趋势外,其他作物的各指标变化则均呈减少趋势;从突变现象来看,夏玉米和棉花的各指标发生明显变化的时期相近,需水量出现明显拐点的时刻在2008年以后,有效降水量在1968年以前和2014年两个时期,缺水量分别在2011年和2012年。[结论]该研究结果为保定市乃至河北省的农作物灌溉效率的提高及水资源规划与管理的完善提供了理论依据,具有一定的现实意义。     

An investigation of the influence of cinema environment on advertising effectiveness

Many advertisers are looking to cinema advertising as a nontraditional medium to reach consumers. Although several scholars have examined the effectiveness of this advertising vehicle, there is a dearth of empirically grounded research on how to improve such effectiveness. This study, based on the reactance and the equity theories, is probably the first academic project investigating how to manipulate an advertising environment in a real movie theatre to maximize advertising effectiveness. Results indicated that audiences in a distractive environment held a more positive attitude toward cinema advertising in general, but those in a restrictive environment were more likely to remember the advertised brands. In addition, the provision of ticket price information improved audiences’ acceptance of cinema advertising, but did not enhance recall. Moreover, the influence of ambient scent emitted into the atmosphere in a cinema room on ad recall dissipated when movie viewers became accustomed to such stimuli. Based on these findings, theoretical discussions and recommendations for practising managers were made.     

不同技术密度部门工业智能化的就业效应——来自中国制造业的证据

本文通过引入智能化资本重构任务模型,刻画不同技术密度部门中工业智能化升级对就业人数变动的影响机理,利用省级面板数据检验智能化升级对高、低技术密度部门就业的净影响效应,同时结合企业面板数据验证了智能化就业效应的传导渠道.研究表明:在中国当前发展阶段的高、低技术密度部门工业智能化升级都能够显著促进就业增加,且高技术密度部门的就业增加效应要明显高于低技术密度部门;在低技术密度部门工业智能化升级能够激发其利用技术扩散,而在高技术密度部门则倾向于通过生产规模扩张渠道,促进部门内部不同规模的就业增加;智能化升级的正向就业效应在非国有控股企业和东部地区企业中最为突出.     

气候变化与旅游研究综述

全球气候变化是当今自然地理学研究的重要课题之一,同时因直接或间接地对旅游业发展产生影响而受到广泛关注。通过对全球气候变化与旅游相关的现有研究梳理发现:相关研究成果丰富,理论框架基本成熟,研究时空尺度广泛,定性与定量方法兼顾,重视以低碳旅游为热点的策略研究。在后续研究中需要进一步考虑旅游市场需求影响;在气候变化视角上重视积极影响研究;气候指数和模型的适用性和客观性仍有待深入讨论;小气候与环境的微观变化对景区或某些景观的影响讨论不足;需要重视综合指标和多维体系的构建。     

How to inhibit a partner's strong and weak forms of opportunism: Impacts of network embeddedness and bilateral TSIs

This study investigates the moderating effects of a firm's network embeddedness and a partner's transactional specific investments (TSIs) on relationships between the firm's TSIs and its partner's strong- and weak-form opportunism, and compares the efficiency among these moderator variables. The regression results suggest that (1) a firm's TSIs are positively related to partner's opportunism when network embeddedness and the partner's TSIs are relatively low; but (2) a firm's TSIs are negatively related to partner's opportunism when network embeddedness and the partner's TSIs are relatively high. Furthermore (3) network embeddedness is more effective in inhibiting partner's weak-form opportunism than in inhibiting strong-form opportunism resulting from the firm's TSIs. Finally (4) with regard to the relationship between TSIs and weak-form opportunism, the negative moderating effect of network embeddedness is greater than the negative moderating effect of partner's TSIs. This study explains reasons why conflicting views exist about the relationship between TSIs and partner's opportunism, reveals the differences in the moderating effects of network embeddedness and partner's TSIs, and makes new contributions to both transaction cost theory and embeddedness literature. It also provides, for firms involved in TSIs in a buyer–supplier relationship, insightful managerial suggestions about ways to reduce their partner's varying forms of opportunism.     

农户生态耕种行为及其影响因素研究——以江西省为例

[目的]为清晰识别影响农户生态耕种行为的主要因素,以期为加强耕地生态保护、保障农作物质量安全、提升农户耕种收益、实现农业现代化目标提供参考。[方法]基于江西省11市47县(区)1488份农户微观调查数据,在分析农户生态耕种特征基础上,运用二元Logistic和Probit模型对农户生态耕种行为影响因素开展实证研究。[结果]农户生态耕种10种具体行为的采纳情况差异明显,其中施用有机肥采纳程度最高,生态农业模式采纳程度最低。农户采纳生态耕种整体水平不高,但仍具备进一步推广的潜力。家庭劳动力比重、生态耕种成本认知、新型农业经营主体、法律法规认知、生态耕种收益认知、生计分化和生态环境认知等解释变量是影响农户生态耕种行为的主要内部因素,政府补贴、农田基础设施、生产交流程度、耕地质量变化和生态耕种信息获取难度等则是主要的外部影响因素。[结论]政府及基层管理部门应在推动农户非农就业生计、大力培育新型农业经营主体、加强生态耕种宣传与推广、完善政策扶持与管控机制等方面制定针对性的政策措施。     

春季石家庄市水体浮游植物群落结构调查与分析

为探索春季石家庄市水体浮游植物群落组成与结构特点,及其主要环境影响因素,对水体中浮游植物的种类组成、细胞密度、环境因子等指标进行了调查,分析了其物种优势度、多样性指数,并对各水体的浮游植物组成与环境因子进行了聚类分析和相关性分析。结果发现:在春季的石家庄市水体中,共检出浮游植物7门47属76种,以绿藻门种类最多,约占总数的39.47%,其次为硅藻和蓝藻,裸藻、金藻、黄藻和甲藻种类很少且仅在个别采样点位出现。水体中硅藻细胞密度最高,平均为1.0×10~7 cells/L,占丰度组成的61.84%,其次为绿藻和蓝藻。值得注意的是,岗南水库是所有水体中仅有的金藻丰富型水体,它的金藻细胞密度高达4.5×10~6 cells/L。物种优势度分析和多样性指数分析显示,石家庄市水体中以中度富营养型指示藻类为优势类群,基本处于中度污染水平;水体聚类分析表明,石家庄市水体的浮游植物组成受整体水环境因素影响不明显;而单环境因子数据及其与浮游植物的相关性分析表明,石家庄市水质酸化严重(pH值低于6.0),除科大牧星湖和岗南水库外,多数水体处于劣V类水平,主要超标物为pH值、总磷、总氮和COD,而这可能是导致蓝藻、绿藻等耐污性种类大量繁殖的主要因素。因此,对石家庄市水体中浮游植物群落组成与结构变化的生物学监测,是进行石家庄市地表水水质监测及生态保护的重要途径。     

中国“一带一路”战略定位的三个问题

"一带一路"战略在大方向基本清晰的情况下,在战略定位上仍然存在着三个有待进一步厘清的问题,包括:"一带一路"是全球战略还是区域战略?"一带一路"应以多重双边伙伴关系为基础还是应以跨区域整合为基础?"一带一路"战略应以西北方向为优先还是应以东南方向为优先?对这三个问题的诠释对于"一带一路"战略的推进有着极为重要的意义。这一战略虽然表现出了一定的全球战略的特征,但在本质上还是区域性的;其的推进必须以多重双边伙伴关系为基础。就目前的具体政治形势与经济形势来看,"一带一路"战略开拓西北面临更大的不确定性。     

CEO Stock‐Based Incentive Compensation and Firm Performance: A Quantile Regression Approach

This study employs the quantile regression model to examine the non‐monotonic impact of CEO stock‐based compensation on firm performance, using the data for U.S. non‐financial firms from 1993 to 2005. The results indicate that while the impact of CEO stock‐based pay on firm performance is positive for firms in the higher earnings quantile levels, the impact is negative for firms in the lower levels. In addition, the “V‐shaped” relationship between CEO stock‐based pay and firm performance satisfactorily explains the longstanding disagreement among earlier studies with regard to whether CEO stock‐based pay can enhance firm performance. Furthermore, the quantile‐varying pattern of the impact of stock‐based compensation on firm performance is robust after controlling for the industrial and yearly effects. It is also robust to the use of the pay‐for‐performance sensitivity as an alternative explanatory variable or the market‐based measure of performance as the dependent variable, or the consideration of the suspected endogenous problem between firm performance and stock‐based compensation.     

城市群高质量发展的理论逻辑与路径选择

现代化后发赶超要求以城市群作为主体空间形态,实现效率增进、功能跃升、均衡发展和开放合作.城市群正日益成为托起中国现代化的巨擘,目前我国19个城市群之间规模结构差异较大,以东部城市群发展质量最高.城市群发展失衡的原因在于,城市群城镇体系不合理、公共服务一体化存在障碍、区域一体化发展体制机制有待健全、城际间综合交通网络体系亟待完善.适应现代化发展要求,我国需要在城市群加快推动形成快速便捷的综合交通体系与一体化发展体制机制,以都市圈为载体优化城市群空间格局与推动城市群协同发展,加快构建包容共享的公共服务体系,提升城市群的开放发展水平,引领中国现代化发展.