湖南省农业生态与农业经济耦合性测度

[目的]考察湖南省近9年来农业生态与农业经济系统耦合发展现状,探究二者发展过程中的规律,以期找出二者协调发展模式,并为湖南省农业生态环境保护、农业经济发展提供决策依据。[方法]运用耦合协调度模型,基于熵权法为各指标进行客观确定权重,结合2007~2015年湖南省农业生态与农业经济发展的相关数据,确定农业生态与农业经济的耦合匹配分析模型,采用熵值赋权法确定各项指标的权重,构建农业生态—农业经济耦合协调评价指标体系。[结果]研究结果表明,2007~2015年湖南省农业生态与农业经济的耦合协调发展基本稳定,耦合度值均在0.9以上,二者呈协调发展趋势。其中,2014年和2015年二者的耦合度较高,分别为0.975 3和0.984 3,说明湖南省在这两年的农业生态与农业经济的协调性好,农业经济与农业生态能够相互有效促进彼此的发展。同时,仍需时刻关注生态环境的承载力,降低对自然资源的无序攫取,实现经济的可持续发展。     

Trade-offs between Asset Location and Proximity to Home: Evidence from REIT Property Sell-offs

The Journal of Real Estate Finance and Economics - We examine property sell-offs by real estate investment trusts (REITs) and find that investors respond favorably to sales of properties located...     

农作物面积抽样单元空间变异性及其对抽样外推效率的影响

［目的］联合遥感和传统抽样方法的空间抽样技术是进行大区域农作物面积监测的有效手段。但传统抽样要求抽样单元间相互独立，并未考虑到区域农作物空间变异性的存在对农作物面积空间抽样效率是否有影响及其影响程度如何，从而限制了农作物面积监测的效率和精度。［方法］文章以吉林省德惠市为研究区，利用变异函数分别对10种抽样单元尺度内玉米和水稻种植面积的空间变异性进行定量评价。选择3种空间抽样方案（简单随机抽样、系统抽样、分层抽样），分别计算不同空间变异程度下的样本容量（n）、抽样相对误差（Re）和总体总值估计量的变异系数（CV（Y︿））作为空间抽样效率的评价指标，定量分析空间变异性对农作物面积空间抽样效率的影响，提出适宜空间变异农作物的空间抽样优化方案。［结果］(1)玉米和水稻面积的空间变异性（反映为基台值C0+C）均随着抽样单元尺度的增加逐渐而减小，其中500m×500m和2 500m×2 500m抽样单元尺度下农作物面积的空间自相关程度相对最小。(2)相同抽样比下，农作物面积在3种抽样方法下的相对误差和变异系数均随着空间变异性的减小（抽样单元尺度增加）逐渐增大，其中玉米和水稻在分层抽样条件下的相对误差和变异系数具有相对最小值，分别限制在10%和20%以内，其次为系统抽样（Re<40%，CV（Y︿）<88%）和简单随机抽样（Re<50%，CV（Y︿）<75%）。 在抽样方法被选定的情况下，两种农作物的分层抽样相对误差变化率随着抽样比的增加迅速降低，当抽样比增至5%时，其相对误差和变异系数的变化率基本趋于稳定，继续增加抽样比来提高抽样精度的效果甚微。 在3 500m×3 500m抽样单元尺度内，按5%抽样比确定的样本容量对玉米和水稻面积进行分层抽样时，可达到95%的抽样精度（Re<5%）。 综合农作物在不同抽样单元尺度下的空间变异特征和空间抽样效率，基于2 500m×2 500m的抽样单元尺度和5%抽样比进行分层抽样的空间变异性农作物空间抽样方案是一种高精度、低成本、代表性强的空间抽样方案。［结论］该研究为区域农作物面积抽样调查方法的改善和抽样效率的提高提供技术支持和参考依据。     

Cost-effectiveness of second-line atezolizumab in Canada for advanced non-small cell lung cancer (NSCLC)

Aim: To assess the cost-effectiveness in Canada of atezolizumab compared with docetaxel or nivolumab for the treatment of advanced NSCLC after first-line platinum-doublet chemotherapy.

Materials and methods: A three-state partitioned-survival model was developed. Clinical inputs were obtained from the phase III OAK trial comparing atezolizumab with docetaxel in patients with advanced NSCLC who progressed after first-line platinum-doublet chemotherapy. Overall survival (OS) and progression-free survival (PFS) were extrapolated beyond the trial period using parametric models. A cure model assuming a 1% cure fraction was fitted to the OS data for atezolizumab. Outcomes for nivolumab were informed by a network meta-analysis (NMA) vs atezolizumab. Resource use and costs were informed by clinical expert opinion and published Canadian sources. Utility values were obtained from the OAK trial. The perspective of the analysis was that of the Canadian publicly-funded healthcare system. The base case time horizon was 10?years, and the discount rate was 1.5% annually for both costs and effects. Scenario analyses were performed to test the robustness of the results and all analyses were performed probabilistically.

Results: Atezolizumab demonstrated a quality-adjusted life-year (QALY) gain of 0.60 compared with docetaxel at an incremental cost of $85,073, resulting in an incremental cost-effectiveness ratio (ICER) of $142,074/QALY. Atezolizumab dominated nivolumab (regardless of dosing regimen), based on modest differences in both QALYs and costs. Docetaxel was most likely to be cost effective at willingness-to-pay (WTP) thresholds below $125,000/QALY gained, while atezolizumab was most likely to be cost effective beyond this WTP threshold. In most scenario analyses, the results remained robust to changes in parameters. A reduced time horizon and alternative approaches to the NMA had the greatest impact on cost-effectiveness results.

Conclusion: Atezolizumab represents a cost-effective therapeutic option in Canada for the treatment of patients with advanced NSCLC who progress after first-line platinum doublet chemotherapy.     

供应链视角下餐饮O2O模式的配送路径优化

O2O最后一公里配送往往需要综合考虑时间和成本的关系,研究平台对订单的分配和路径优化对提升O2O供应链的整体效率和产业链升级具有十分重要的意义。从餐饮商家和O2O平台两个主要参与者出发对物流配送系统进行研究,提出了适合于O2O餐饮供应链的配送网络,并考虑道路阻塞、最大里程数等约束,搭建了上层模型最短时间、下层模型最低成本的双层规划模型,进而通过NSGA-Ⅱ算法求得可行解,最后验证了算法的可行性,为进一步研究O2O配送提供了新的解决思路。     

The initiation of audit committee interlocks and the contagion of accounting policy choices: evidence from special items

Review of Accounting Studies - We document that the initiation of audit committee interlocks is associated with contagion in reported special items. We argue that this is, in part, attributable to...     

土豆红豆鱼香肠的研制

鱼香肠是以鱼肉为主要原料灌制的香肠。它营养丰富、味道鲜美、风味独特,深受广大消费者喜爱,尤其是老人和儿童。鱼香肠的优点是有外包衣(畜肠衣或塑肠衣)使鱼肉与外界隔绝,流通方便,卫生条件较好,加工后可长期保存。本文通过正交实验,探讨土豆和红豆添加量对鱼肉香肠感官质量的影响,逐步确定土豆和红豆的最优添加量,最终确定了新型鱼香肠最优配比为:以鱼肉质量计,土豆添加量:37%,红豆添加量:38%,畜肉添加量:15%,板油添加量:7.5%,淀粉添加量:5.6%,精盐添加量:2.25%,咖喱粉添加量:0.43%,胡椒粉添加量:0.06%,味精添加量:0.2%。     

采用COTS器件的低轨星载收发信机设计与实现

在性能、成本和可靠性的多重约束下，采用商用货架（Commercial Off-The-Shelf,COTS）器件设计了一种高性能、低成本星载收发信机。该收发信机的硬件设计不但可同时满足星地和星间应用需要，而且还具有支持多波束、多信道接入的特点。软件设计主要解决了大多普勒频偏条件下的低信噪比解调和变长以太网数据帧的高效处理等问题。地面测试结果表明，在250 kb/s ~ 14 Mb/s信息速率范围内，误比特率低于1.0×10-6时所需的解调信噪比(Eb/N0)不超过2.8 dB，发射信号误差矢量幅度不超过1.9%，高速应用时处理时延可低至3.0 ms。为降低COTS收发信机的可靠性风险，分别在元器件、电路和系统层面进行了有针对性的可靠性保证措施。该设计经过了在轨测试的验证，对其他低轨商业通信载荷的研制有一定的参考价值。     

Rotating group representatives and group members’ requests in repeated public goods game

ABSTRACT

This study investigated the effect of group representatives on contribution behaviour in response to group members’ requests in repeated public goods games. Data came from 135 students in 15 groups enrolled in the experiment, grouped in the following treatments: no group representatives (NR, NRG) and group representatives (R1, R2). We also tested initial requests wherein the group members’ initial requests (i.e. NRG, R2) mediated the positive relationship between individual-level contribution preferences and group contributions. We used a fixed-effects GLS regression and IV regression to analyse the effect of group representatives and group members’ requests. The results indicated the following: (a) rotating group representative/group members’ requests was related to group contributions at the session (within-members) and group (between-group) levels; (b) the reactions to members’ requests positively predicted group contributions; (c) subjects in the no group representatives treatment formed their requests by relying more on previous group contributions than subjects in the group representatives treatment, who relied more on the previous group members’ requests; and (d) the initial requests explained long-term contribution levels, which resulted in variations in group contributions observed between the NRG and R2 treatments. Our findings highlight the role of rotating group representatives in stimulating cooperation among members, while group members’ requests impel individuals to make contribution decisions at the group level.     

江苏省生态农业与生态旅游业耦合研究

[目的]目前我国正处于关键的经济转型期,生态农业和生态旅游业作为生态文明建设的重要产业之一,其耦合发展对于存进产业结构优化升级具有重要作用。[方法]通过构建生态农业与生态旅游业指标体系,采用灰色关联法计算江苏省生态农业与生态旅游业的关联度,进一步通过耦合协调度模型分析两者的协调程度。[结果]生态农业系统与生态旅游系统中的旅游经济、旅游资源和旅游价值的关联度分别为0.719,0.673和0.621,大小顺序分别为旅游经济旅游资源旅游价值,而生态旅游系统与生态农业系统中生态系统、经济系统和社会系统的关联度分别为0.687,0.700和0.626,大小顺序分别为经济系统生态系统社会系统,耦合作用均分别为较强、较强和中等。2012~2016年江苏省生态农业和生态旅游业耦合度处于磨合阶段,但一直在增加,同时耦合水平经历了初级协调发展水平到中级协调发展水平的过程。[结论]江苏省生态农业和生态旅游业的耦合发展仍有进步的空间,今后应加强耦合发展机制,推动两大耦合产业走向更深更广的发展领域,促进生态文明建设,同时保证生态产业的可持续健康发展。