Noise traders,firm-specific uncertainty and technical trading effectiveness

This is the first study to document evidence of technical trading effectiveness at firm level in the Chinese A-share market by investigating the relationship between excess profits of technical trading rules and firm-specific characteristics. Our results reveal that firms with higher excess profits from technical trading have more noise traders and higher institutional ownership and that those firms tend to be growth firms with lower liquidity and higher firm-specific uncertainty. Further analysis shows that the profitability of technical trading rules is unsustainable and the excess profits of the highest technical trading profit quintile portfolio disappear in the following year.     

中国粳稻生产效率演变及区域差异

[目的]我国粳稻产量现阶段呈连续增长的态势,然而粳稻生产效率却存在无效率或波动剧烈的现象,研究我国的粳稻生产效率,有助于提升和稳定中国粳稻区域生产效率和水平从而间接保障我国粮食安全。[方法]使用超效率DEA方法测算中国13个粳稻生产省份的生产效率,分别从时间和区域上的差异进行分析。[结果]中国粳稻生产技术效率在时间趋势上逐渐趋于平稳,但是在2004—2007年间存在短暂的波动;在区域上主要是西南和东北粳稻生产区的技术效率水平较高,西北区在技术效率、纯技术效率与规模效率上都处于较低的水平;虽然河南、湖北、宁夏3个省份出现技术无效率,但规模报酬都处于递增的状态,仍有提升生产效率的潜力,应通过减少要素投入冗余来改变其无效率状态。[结论]粳稻生产技术无效率主要是由于种子费用、农药费用等生产要素的投入冗余造成的;若将来在保持纯技术效率和其他条件不变的情况下,通过提升规模效率水平会进一步提升我国粳稻的整体技术效率水平。基于上述分析有针对性地提出制定粳稻生产区域规划、发展适度规模经营、改善生产要素使用效率3方面的政策建议。     

微波消解-石墨炉原子吸收法测定金丝菊中镉的含量

本文采用硝酸-过氧化氢混合溶液,使用全自动微波消解仪消解金丝菊代用茶中的重金属镉,定容后用石墨炉原子吸收光谱法进行测定。结果表明,镉的工作曲线相关系数>0.995,相对标准偏差<4.4%,国家标准物质测定值在标示值范围内,回收率为92.5%~106.6%。该方法快速、准确,能够满足日常食品中镉的分析要求。     

基于均方差法的郑州市土地综合承载力评价

［目的］开展土地综合承载力评价是科学编制国土空间发展战略的基础。通过构建包含水土资源承载力、经济承载力和生态承载力3个维度土地综合承载力评价指标体系，定量刻画郑州市城市土地综合承载力的特征与轨迹。［方法］运用均方差法，选取2010—2016年郑州市城市土地综合承载力评价指标，分析其土地综合承载力特征。［结果］（1）总体上，郑州市城市土地综合承载力不断增强，水土资源承载力呈现先升—降—升的动态演变特征； 经济承载力持续增长，这源于郑州市土地经济效益的大幅提升； 生态承载力呈现波动性增强的演变特征。（2）郑州市城市土地综合承载力经历了较低—中等—较高发展历程，但土地综合承载力处于低层次的较高阶段，仍有较大提升空间。（3）为提高郑州市城市土地综合承载力，应加快“多规合一”规划的编制，科学划定城市增长边界和“三生”空间，转变城市发展理念，优化发展发展路径，提升城市土地综合承载力水平。［结论］郑州市城市土地综合承载力仍有较大提升空间，应加快建立土地综合承载力扩容的有效机制。     

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.     

ZigBee技术在火灾自动报警系统中的应用

随着我国经济的快速发展,国家越来越重视现有的专业性的有线火灾报警系统的管理和控制,为了进一步的提升火灾报警系统中的信息传输管理效率,及时有效地发现和分析火灾的实际情况,必须要提高建筑物的防火能力。因此,论文主要针对现阶段的ZigBee技术在火灾自动报警系统中的应用进行简要分析,并提出合理化建议。     

水足迹视角下三江平原地区农业水土资源配置效率研究

[目的]三江平原地区是我国重要的商品粮基地,其农业水土资源相对丰富但水土资源配置效率不佳,亟待改善。[方法]运用投入导向型数据包络分析(DEA)方法,对水足迹视角下的三江平原地区农业水土资源配置效率进行评价。[结果]2015年,三江平原地区农业水土资源配置综合有效的地区仅占5%,总体来看,农业水土资源配置的技术效率略好于规模效率;水土资源投入冗余状况分析表明,友谊县、虎林市、宝清县、汤原县、富锦市、同江市等8个县、市辖区的农业水土资源投入合理,其他地区都存在不同程度的冗余现象;分作物来看,水稻生产的水土资源配置技术效率高于其他三大旱作。[结论]完善农业基础设施配套工程,提高水土资源配置的技术效率,是提高其规模效率,进而实现综合有效的关键。     

“引洮工程”引发的受水区污染治理研究

[目的]为了解决甘肃中部安定区、陇西县、渭源县、临洮县、榆中县和会宁县的人畜饮水、工业用水、生态用水及农业灌溉用水问题,引洮工程通过九甸峡水利枢纽抬高水位将黄河上游洮河支流水资源引入受水区。在受水区,在调水增加本区供水总量的同时,相应增加了增量水资源使用后带来的废污水,客观上对污染治理工作水平提出了更高要求,轻视排污问题将加剧受水区乃至下游的水系污染程度,影响受水区经济社会的可持续发展。[方法]文章采用文献研究法从理论上探讨了环境容量、排污权及其关系。采用定额计量法计算了调水带来的COD和氨氮增量。[结果]调水使得受水区COD和氨氮每年分别增加6 914. 30t和1 440. 48t。就COD而言,受水区平均排放量占该区环境容量的51. 12%,似有较多的容量结余,但区内排放极不平衡,榆中和会宁已经超排。就氨氮而言,受水区平均排放量将占该区环境容量的151. 55%,总体超排很严重。区内除临洮以外,其余5县区均超排,其中,榆中和会宁超排1倍以上。[结论]排污量是假定增量污水符合二级排放标准的前提下计算的,如果处理率低、排放达标率低,则超排现象会更为严重。对此,要从宏观上进行综合治理,诸如完善政府、社会与市场共同治污机制、排污权配置的过渡性制度安排、污水处理企业改革及引导受水区进行产业结构调整等。     

Research on the impact of mega-projects on carrying capacity of cities taking the first-line project of the West-East gas pipeline as an example

With the acceleration of China’s urbanization, the functions and benefits of mega-projects are required higher. With the deepening of “the Silk Road Economic Belt and the 21st-Century Maritime Silk Road”, the quantitative evaluation of multinational investment projects will help strengthen cross-border communication among government, society and enterprises, which provide a basis for mutual trust. This study empirically analyzes and evaluates the impact of mega-projects on carrying capacity of cities, by using the DID method based on the panel data of 15 cities in China from 2000 to 2013. The results show that the construction and operation of the first-line project of the West-East gas pipeline has a significant positive impact on the improvement of carrying capacity of cities along the line. However, the degree of impact on three dimensions is slightly different. The impact on the social carrying capacity is the greatest, then the ecological and economic carrying capacity. Therefore, the decisions of domestic mega-projects should be unified with urban planning to promote the sustainable development of China’s economy and social. The investment of mega-projects abroad should also be coordinated with the carrying capacity of host cities, in order to enhance the competitiveness and creativity of Chinese multinational mega-projects investment.     

Elasticity of substitution and technical efficiency: evidence from the US electricity generation

ABSTRACT

The implications of national or regional energy policies for technical efficiency and environmental outcomes in electricity generation depend on fossil fuel input substitution. This study uses state level data to examine fossil fuel (coal and natural gas) substitution in electricity generation under increased availability of natural gas in the United States. We observe that changes in elasticities of substitution from pre-2009 to post-2009 differ across states suggesting that the effects of increased availability of inexpensive natural gas on electricity generation have been spatially heterogeneous. We rely on the observed heterogeneity to assess the effects of fossil fuel input substitution on technical efficiency and CO₂ emissions. The results reveal that state level elasticity of substitution between natural gas and coal has a positive effect on technical efficiency and a negative effect on CO₂ emissions. Therefore, future policy design and analyses should reflect the implications for regional elasticities of fossil fuel substitution and associated environmental outcomes.