基于消费者低碳偏好的供应链碳减排策略     

熊榕  梁承姬  韩婷婷 《上海海事大学学报》2019,40(4):52-60

针对一个占主导地位的零售商和两个制造商(名牌产品和普通产品制造商)组成的二级供应链,考虑制造商之间的定价顺序和低碳偏好消费者对普通产品的接受度,分别构建普通产品制造商采用或不采用减排技术情景下的收益模型,得出各情景下最优零售价格和收益。研究发现:零售商选择销售哪种产品与顾客对普通产品的接受度有关;普通产品制造商的减排策略主要取决于减排成本。在相同减排策略下,若顾客对普通产品接受度较大,制造商同时定价时产品的最优零售价小于等于不同时定价时产品的最优零售价,而同时定价时制造商的最优收益大于等于不同时定价时的最优收益,因此两个制造商应同时定价以获得更大的收益。  相似文献   

A meta-analytic review of interventions to improve children’s attitudes toward their peers with intellectual disabilities     

《Contemporary educational psychology》2021

Children’s biases toward their peers with intellectual disabilities tend to have negative developmental and social consequences for those with intellectual disabilities. As a result, researchers developed intervention programs to reduce biases toward children with intellectual disabilities. This meta-analysis is a quantitative summary of 59 studies and 144 hypothesis tests involving intervention programs to change children’s attitudes toward their peers with intellectual disabilities. Results revealed an overall significant effect (d = 0.44): following intervention programs, children’s attitudes toward their peers with intellectual disabilities increased. Moderators indicate that the most effective interventions were those that occurred over multiple sessions, involved active engagement in multiple strategies and social interactions, emphasized equal status contact that was unstructured or indirect, and had little adult guidance. Interventions had no effect on changing children’s perceptions of competence and participants in junior high had more negative attitudes following the interventions. Findings provide guidance for researchers, educators, and counselors who seek methodologies to reduce biases toward children with intellectual disabilities.  相似文献   

基于AIS数据的船舶排放估测模型与实船验证     

王直欢  王维勋  施欣 《上海海事大学学报》2019,40(4):12-16

为提升船舶能耗和排放估测的准确性和灵活性,提出面向船舶自动识别系统(automatic identification system, AIS)大数据的完全自下而上的船舶能耗和排放估测新方法。该方法视船舶为一种基于船舶航迹的线排放源,在构建船舶网格化轨迹模型的基础上,考虑每个网格航段的持续时间和发动机负载,实现船舶能耗和排放的精细化建模,统一船舶排放总量和空间分布计算。实船应用表明,该方法可提供更加准确的船舶能耗估计,并可灵活计算各种航行状态、船队规模和时空尺度的能耗和排放清单。  相似文献   

掺混生物柴油对6135Aca型柴油机NO_x排放的影响机理     

刘杰  魏立江  魏海军 《上海海事大学学报》2019,40(3):111-115

为探究船舶柴油机排放的NO_x中各成分的主要生成机理,基于6135Aca型柴油机,利用AVL Fire建立仿真模型,探究掺混生物柴油在不同负荷下对NO_x成分之间转换的影响机理。结果显示:柴油机排放的NO_2主要通过HO_2氧化NO生成,且高温和氧质量分数会影响NO_2的生成,其中高温会抑制NO_2的生成,氧质量分数增加会促进NO_2的生成;掺混生物柴油和增加负荷会使喷雾贯穿距增大,高温区域增加,从而抑制NO_2生成;掺混生物柴油使得燃烧室内氧含量增加,进而HO_2量增加促进NO_2生成;掺混比例较小时,NO_2主要受高温区域影响,当掺混到达一定比例时贯穿距不再增大,这时NO_2主要受氧含量影响。本文得到的NO_2生成机理,对降低NO_x中NO_2的排放比例有一定指导意义。  相似文献   

低负荷加压训练改善自发性高血压大鼠的血压效果及机制研究     

谭朝文  赵彦  俞莹莹  马晓缓  郑玉婵 《体育科学》2020,(3):46-53,63

目的:探究低负荷加压训练对自发性高血压大鼠的降压效果及其作用机制。方法:选取4周龄雄性自发性高血压大鼠,随机分为对照组(高血压安静组)、低负荷训练组、低负荷加压训练组和高负荷训练组。低负荷训练组进行35%~55%1RM递进式低负荷爬梯训练,低负荷加压训练组进行30%~40%血流受限结合35%~55%1RM递进式低负荷爬梯训练,高负荷训练组进行55%~75%1RM递进式高负荷爬梯训练,训练后测定血压、血液中内皮素-1、血管内皮生长因子、一氧化氮合成酶的表达和心肌组织中内皮型一氧化氮合成酶的表达。结果:1)与对照组、高负荷训练组相比,低负荷加压训练组收缩压、舒张压显著下降(P<0.05);与低负荷训练组相比,低负荷加压训练组舒张压显著下降(P<0.05)。2)与对照组相比,低负荷加压训练组血液中内皮素-1表达显著下调(P<0.05),血管内皮生长因子和一氧化氮合成酶表达显著上调(P<0.05);3)与对照组相比,低负荷加压训练组心肌中内皮型一氧化氮合成酶表达显著上调(P<0.05);4)在低负荷加压训练组中,收缩压与内皮素-1呈正相关,相关性分析具有统计学意义(P<0.05);收缩压与一氧化氮合成酶、血管内皮生长因子、内皮型一氧化氮合成酶均呈负相关,相关性分析具有统计学意义(P<0.05)。结论:1)低负荷加压训练降压效果优于高负荷训练;2)低负荷加压训练能够通过下调血液中内皮素-1的表达,上调血液中血管内皮生长因子和一氧化氮合成酶的表达,同时上调心肌中内皮型一氧化氮合成酶表达,改善内皮细胞功能,达到降压的效果。  相似文献   

Comparison of Haptic and Biometric Properties,Bacterial Load,and Student Perception of Fixative Solutions: Formaldehyde Versus Chilean Conservative Fixative Solution with and without Formaldehyde in Pig Kidneys     

Marianne Skopnik-Chicago  Katherine Poblete-Cordero  Natali Zamora  Roberto Bastías  Pablo A. Lizana 《Anatomical sciences education》2021,14(6):836-846

One of the most widely used solutions to fix and preserve organic tissues is formaldehyde, despite reservations regarding its toxicity and the fact that formaldehyde-embalmed bodies lose their original characteristics. Anatomy laboratories have been replacing formaldehyde with solutions that retain the characteristics of fresh tissue. For this purpose, alternative solutions with a very low concentration of formaldehyde or without any formaldehyde have been analyzed. The objective of this study was to compare biometry, coloration, haptic properties, and bacterial load on animal specimens (pig kidneys) embalmed with formaldehyde, and with Chilean Conservative Fixative Solution with and without formaldehyde (formaldehyde chCFS and formaldehyde-free chCFS). Also, the perception of health and biological science students toward specimens treated with different solutions was assessed. The results indicated that there were no significant differences in specimens’ retraction, or bacterial load. Students showed a preference for organs embalmed in formaldehyde chCFS and formaldehyde-free chCFS; indicating that with these treatments they could better visualize structures and that the prosections had greater flexibility and the colors were more similar to those of fresh tissue. Additionally, students recommended the material embalmed in formaldehyde chCFS and formaldehyde-free chCFS for anatomy learning. In contrast, students indicated that formaldehyde-fixation negatively affected their practical experience. In conclusion, embalming with formaldehyde chCFS or formaldehyde-free chCFS provides an advantageous practical experience over the use of formaldehyde and may be an alternative to replace the use of formaldehyde in anatomy laboratories.  相似文献   

Subspace design of low-rank estimators for higher-order statistics     

Ivan Bradaric  Athina P. Petropulu  Konstantinos I. Diamantaras 《Journal of The Franklin Institute》2002,339(2):161-187

Higher-order statistics (HOS) are well known for their robustness to additive Gaussian noise and ability to preserve phase. HOS estimates, on the other hand, have been criticized for high complexity and the need for long data in order to maintain small variance. Since rank reduction offers a general principle for reduction of estimator variance and complexity, we consider the problem of designing low-rank estimators for HOS. We propose three methods for choosing the transformation matrix that reduces the mean-square error (MSE) associated with the low-rank HOS estimates. We also demonstrate the advantages of using low-rank third-order moment estimates for blind system estimation. Results indicate that the full rank MSE corresponding to some data length N can be attained by a low-rank estimator corresponding to a length significantly smaller than N.  相似文献   

排污权初始分配的有偿性研究   总被引：16，自引：0，他引：16  

李爱年  胡春冬 《中国软科学》2003,(5):17-21

排污权初始分配在计划经济时代是以无偿为特征、以多数人为少数排污者支付环境容量资源为代价的。在转型时期，我国建立了排污收费制度，初步确立了隐性的排污权有偿分配制度，但相关法律规定是分散的、不一致的，随着开放的扩大和市场经济体制的建立，有必要进一步改变“环境无价”的观念，建立显性的有偿分配排污权的机制。  相似文献   

能源技术进步对石油需求及节油减排潜力的影响——基于多因素视角的研究   总被引：1，自引：0，他引：1  

伍亚 《科技管理研究》2016,(5):199-203

从技术进步、结构调整、城镇化等角度出发,探讨我国石油需求的影响机制。研究表明,(1)技术进步对抑制石油增长的作用较小,其节油空间有待提升;(2)经济结构和城镇化是拉动石油需求的主因;(3)GDP、城镇化率与石油需求之间具有单向因果关系,以节油为目的的能源政策不会损害经济增长和城镇化推进。结合情景分析,评估2015—2025年节油减排潜力,提出未来节油减排的政策建议。  相似文献   

以二氧化碳规模化利用技术为核心的碳减排方案          下载免费PDF全文

陈倩倩  顾宇  唐志永  孙予罕 《中国科学院院刊》2019,34(4):478-487

碳资源是人类社会发展进入工业时代的基石。人类大量使用含碳资源产生的二氧化碳(CO_2)不应给人类社会带来威胁,更不应是碳资源利用的终结者,而是人类实现可持续发展必须善加利用的资源。文章在国内CO_2利用技术研发取得了可喜进展的基础上,提出了几种未来可能适合于中国的以CO_2规模化利用技术为核心的碳减排方案,包括化石能源耦合CO_2的转化利用技术、零碳能源耦合CO_2的转化利用技术以及温和条件下CO_2直接转化利用技术等。基于我国能源消费结构、短中期化石能源的主导地位以及可再生能源日新月异的发展,化石能源的易获取性和低成本使得其耦合CO_2的转化利用技术方案近年来飞速发展,并可能将在近期带来巨大碳减排潜力和经济效益;零碳能源发电技术的突飞猛进有利于核能/可再生能源发电耦合CO_2生产燃料化学品技术的发展,成为中期最具竞争力的CO_2大规模利用技术;远期来说太阳能驱动的CO_2温和转化可以实现真正意义上的生态碳循环,是远期最有前景的CO_2还原技术。  相似文献