基于SBO-PP模型的水资源可持续发展能力评价模型及应用

为利用投影寻踪(PP)技术科学,客观评价区域水资源可持续发展能力,基于生态环境、水资源和经济社会因素选取20个指标构建区域水资源可持续发展能力评价指标体系。利用新型仿生群体智能算法——凉亭鸟优化(SBO)算法优化PP技术最佳投影方向,提出SBO-PP水资源可持续发展能力评价模型,并构建灰狼优化(GWO)算法-PP模型、人工蜂群(ABC)算法-PP模型、差分进化(DE)算法-PP模型、地理生物学优化(BBO)算法-PP模型、粒子群优化(PSO)算法-PP模型作对比,以云南省2006—2015年及2020年水资源可持续发展能力评价为例进行实例研究。结果表明:SBO算法优化PP技术获得的适应度值优于GWO、ABC、DE、BBO和PSO算法,具有较好的求解精度、稳健性能和极值寻优能力。SBO-PP模型对云南省2006—2007年水资源可持续发展能力评价为"较差",2008—2015年评价为"中等",2020年评价为"较强"。     

济南市水资源承载力及可持续利用对策

水是人类生存和发展的物质基础,但随着社会经济的发展,水的供需矛盾日益尖锐,水资源承载力成为水资源安全战略研究的一个基础;通过对济南水资源承载力分析和预测,为可持续发展提供对策.     

黑龙江省生态足迹分析

根据生态足迹的概念和计算方法,对黑龙江省2005年生态足迹进行了计算和分析。结果表明,黑龙江省2005年人均生态足迹为2.525 hm2,而实际生态承载力为1.395 hm2,人均生态足迹赤字为1.297 hm2,表明黑龙江的发展处在一种不可持续的状态。     

Influence of livelihoods on climate change adaptation for smallholder farmers in the Mekong Delta Vietnam

Farmers in the Vietnamese Mekong Delta face a wide range of climate-related and hydrological factors which threaten rice production. Smallholder farmers must adapt to climate change to sustain rice production as their central and most important livelihood activity. A sample was stratified across agro-ecological areas in the Delta affected by flooding, alluvial soils, acid sulphate soils, and saline water intrusion and by derived farmer typologies. A rural livelihoods approach was used in focus group discussions and in-depth interviews to identify and enumerate enabling and constraining adaptation factors. Smallholders experienced diverse natural hazards such as floods, abnormal rains, high temperatures, water scarcity, and salinity intrusion specific to the agro-ecological areas. Adaptation was constrained by labour shortages, water quality, topography, access to combine harvesters, transportation infrastructure, dryers and household savings. Adaptation was enabled by farming techniques and experience, cooperative groups, water quantity, access to information, and ability to purchase agro-chemicals through credit. Small farmers (< 1?ha) were more constrained than large farmers (> 1?ha) who had an expanded livelihood asset base. A range of policy implications are discussed, but adaptation is not just about technological fixes but requires overall improvements in a range of human, social and financial components.     

Learning Sustainability? Absorptive capacities as drivers of sustainability in MNCs’ purchasing

MNCs are expected to operate in a sustainable fashion. Implementation of sustainability requires the ability to acknowledge external (sustainability-related) knowledge, and to apply it in intra-company activities such as purchasing. We focus on absorptive capacities as potential drivers of sustainability, and investigate the effect that a purchasing function’s capacity to absorb and process knowledge has on social and environmental sustainability practices, and subsequently on economic performance in purchasing. We compare MNCs and non-MNCs using a structural equation model of a large set of survey data from four European countries and find that only realized absorptive capacities impact sustainability practices in purchasing and this impact is smaller in MNCs than in other companies. We suggest that companies respond to the demand for sustainability by strengthening their implementation capabilities: the potential to acquire and transform knowledge within a purchasing function is less relevant, and what matters is its application.     

The Conflicted State and Agrarian Transformation in Pink Tide Venezuela

Can radical political‐economic transformation be achieved by electoral regimes that have not thoroughly reconstructed the state? Contemporary Venezuela offers an optimal venue for examining this question. The Chavista movement did not replace the previous state: instead, its leaders attempted to reform existing state entities and establish new ones in pursuit of its transformation agenda. It has also used its oil wealth to support cooperatively‐oriented economic activity, without necessarily fundamentally altering the property structure. Thus, the social change‐oriented political economy exists alongside the traditional one. Focusing on agrarian transformation, we examine ethnographically how these factors have impacted the state's capacity to attain its goal of national food sovereignty. We find that the state's ability to accomplish this objective has been compromised by lack of agency‐level capacity, inter‐agency conflict and the persistence of the previously‐extant agrarian property structure. These dynamics have influenced the state to shift from its initial objective of food sovereignty to a policy of nationalist food security.     

Crowding standards at Petra Archaeological Park: a comparative study of McKercher's five types of heritage tourists

To achieve sustainability in heritage tourism, tourists should be placed at the heart of the management and planning processes. Indicators and standards-based frameworks were developed in the field of outdoor recreation management to manage and measure crowding and other problematic issues in parks and related areas. Using normative theory and visual research methods, this article aims to examine crowding standards of tourists at Petra Archaeological Park, and compare these standards between the types of heritage tourists suggested by a model developed by Bob McKercher. Results showed that tourists’ acceptability levels go down with an increasing number of tourists, and tourists who are highly motivated to visit heritage sites (i.e. purposeful and sightseeing heritage tourists) had the most restrictive acceptable number of tourists at the park. The normative standards formulated in this article provided a guidance to manage crowding at Petra.     

海洋产业金融缺口测量及成因分析

论文对海洋产业中存在的金融供不应求现象进行研究,通过戈登·史密斯的金融结构变迁理论和涉海上市公司财务数据定量化测算我国海洋经济中的金融缺口量及其变化态势,发现2007年至2013年变化呈现多阶段性。该缺口所呈现波动中逐年扩大的特点,既有随着宏观经济状况、政策同步变化的原因,更有着深层次的经济根源原因。论文结合市场在解决海洋产业特点及海洋金融供需双方特点,提出海洋金融补贴方式改进和海洋金融生态优化的政策建议,以期解决海洋产业中出现的金融缺口。     

预制节段拼装预应力混凝土箱梁胶接缝抗剪性能研究

由于节段间接缝的影响,导致预制节段预应力混凝土箱梁接缝处抗剪机理与连续整跨梁存在较大差异,在计算抗剪承载力时无法直接应用整跨梁抗剪计算公式。首先对节段拼装箱梁接缝处的抗剪机理进行分析,得到影响计算抗剪承载力的关键参数;其次在已有计算公式的基础上,考虑混凝土立方体抗压强度和接缝处键齿数等参数的影响,提出适用于这种抗剪承载力的计算公式;最后将提出的计算公式与试验数据对比,表明该计算公式中的参数物理意义明确,计算精度较高,为预制节段拼装预应力混凝土箱梁结构的设计及应用提供了一定理论基础。     

Knowledge diversity and coordination: The effect of intrafirm inventor task networks on absorption speed

Research Summary: We combine the absorptive capacity and social network theory approaches to predict how intrafirm “whole” network characteristics affect the firm's speed of absorption of external knowledge to produce inventions. We start from the widely accepted view that distant, externally‐developed knowledge is difficult to absorb into the focal firm's own knowledge production. We suggest that high levels of intrafirm inventor task network diversity and task network density are essential for a diversity of knowledge inputs and coordinated actions regarding knowledge transfer, which in turn, reduces problems related to the absorption of knowledge—especially in the case of knowledge that is distant from the focal firm. The results of an event history study of 113 pharmaceutical firms that engaged in technology in‐licensing from 1986 to 2003 provide general support for our hypotheses. Managerial Summary: Firms keen to keep up with an uncertain and ever‐changing industry environment, can benefit from the speedy introduction of inventions. We examine how firms absorb licensed‐in technologies to nurture the rapid development of own related inventions. We show that a firm's absorption speed depends on the characteristics of the internal collaboration networks among the firm's inventor employees. More specifically, technologically diverse and well‐connected inventor networks improve the firm's ability to absorb external technologies quickly. This applies especially to externally acquired technologies that are unfamiliar to the firm. Depending on the distance of the acquired technology from the focal firm combined with speed‐inducing inventor network characteristics, our estimates suggest that firms can reduce the time needed for absorption by several months.