可持续能源转型:模型构建与分析

为研究可持续能源系统转型路径,以转型理论为概念框架,从宏观、中观和微观多层次对能源系统进行分析,建立了基于代理的系统动力学转型模型。模型选取当前能源消费结构中占较大比重的煤炭、石油、天然气、风能、水电、光伏和核能作为复杂代理,选取消费者作为简单代理,根据中国能源数据对其进行参数化,并模拟运行了能源系统从2016—2050年间各种类型能源消费比重变动的情形。研究结果显示:①外部景观信号的输入对于能源系统的可持续转型有着至关重要的作用。随着景观信号的输入,各类能源的相对比重发生复杂的相互作用,景观信号持续时间越长、强度越大,向可持续能源系统转型的速度越快、规模越大。②到2050年,可持续能源将占一次能源消费比重的60%左右,实现能源系统的可持续转型,其中,水电将在能源系统的可持续化转型中发挥重要的作用。③2030年以前,石油和天然气将是能源系统中煤炭消费比重下降的主要替代品,因为它们的应用技术已经发展成熟,而且它们更适应当前的基础设施,从短期来看相比可持续能源石油和天然气更有优势,在这种情形下,仍然需要继续支持可持续能源的发展,否则能源系统的可持续转型将不会发生。该研究主要探索通过当前能源系统的景观压力强度以及转型的进度,来量化未来需要输入的景观压力强度;通过模拟转型发生的具体情景,对转型的进展进行更清楚的界定,借此来评估二氧化碳的排放路径;模拟模型也可以评估各类能源在不同时间点上的各种可能性,以及探索各类可持续能源的发展潜力。     

Tightening the grip: environmental governance under Xi Jinping

In the space of a few years, China’s global image with regard to environmental matters has significantly improved. Particularly since Xi Jinping’s coming-to-power in 2012 China’s reputation in the global climate change regime has improved markedly and it has gained accolades for a new determination to reverse environmental degradation at home. China’s incipient green transformation is partly due to a new actor constellation in environmental governance, a striking feature of which is the prominence of ad hoc campaigns that offer quick results but that may undermine the creation of law-based enforcement mechanisms in the long term. Another development – China’s increasing use of emerging technologies and big data analytics – has given rise to new forms of government-business alliances. These new players and innovative approaches have injected momentum into China’s environmental governance system and suggest that, contrary to conventional wisdom, authoritarian regimes can be responsive to citizen demands under certain circumstances. Yet it remains to be seen whether long-term environmental goals can be met, due to a pervasive lack of accountability, the weakening of civil society and heavy constraints on public participation.     

New subjects in the politics of energy transition? Reactivating the northern German oil and gas infrastructure

The global circulation of the word ‘fracking’ seems to testify to a setback for energy transitions, a nexus that has not yet received much scholarly attention. In light of this, the controversy over fracking is understood as furthering infrastructural changes that are central to energy transitions. Infrastructure should not be understood as materiality per se but instead as sedimented but ultimately discursive elements that can be reactivated and rearticulated. Examining ‘infrastructure’ from the point of view of discourse theory places the focus on infrastructural change. Prior to 2011, the oil and gas infrastructure in northern Germany was largely invisible to the public. The subsequent reassembling of production with fracking facilitated the politicization not just of that term but also of the whole infrastructure. Instead of routinely reproducing the infrastructure, subjects that had formerly dominated the field were confronted with new and heterogeneous voices that challenged their agency.     

Traditional fire-use,landscape transition,and the legacies of social theory past

Fire-use and the scale and character of its effects on landscapes remain hotly debated in the paleo- and historical-fire literature. Since the second half of the nineteenth century, anthropology and geography have played important roles in providing theoretical propositions and testable hypotheses for advancing understandings of the ecological role of human–fire-use in landscape histories. This article reviews some of the most salient and persistent theoretical propositions and hypotheses concerning the role of humans in historical fire ecology. The review discusses this history in light of current research agendas, such as those offered by pyrogeography. The review suggests that a more theoretically cognizant historical fire ecology should strive to operationalize transdisciplinary theory capable of addressing the role of human variability in the evolutionary history of landscapes. To facilitate this process, researchers should focus attention on integrating more current human ecology theory into transdisciplinary research agendas.     

技术差距变动、研发资源驱动与技术进步效应

随着中国经济逐渐进入"新常态"时期,创新驱动经济增长已经成为中国经济增长和产业结构调整的新引擎。在创新驱动实现的过程中,研发驱动技术进步是关键环节。特别是,中国各地区之间技术差距较大,在不同技术差距下分析研发资源对技术进步的驱动效应尤为重要。本文以技术差距为转换变量,构建了中国高技术产业的面板平滑转换(PSTR)模型,对不同技术差距阶段研发、人力资本、溢出效应等对技术进步的差异化驱动效应进行了研究。研究结论发现,在技术差距的影响下,研发没有充分发挥对技术进步率的驱动效应,人力资本对技术进步率的影响呈现明显的非对称性,溢出效应对于技术进步的贡献不足。在不同技术差距间,存在着迅速和平缓两种转换机制。在快速转换机制中,研发溢出对技术进步的促进作用得以体现。而在慢速转换机制中,技术差距、人力资本对技术进步率的影响显著为正,两个转换机制中各变量的影响呈现"此消彼长"的关系。此外,技术差距适度时技术进步的"稳态"特征十分明显,而技术差距过小或过大时则是技术进步的不稳定区间。考虑到我国各地区高技术产业发展的多层次和多元化特征,各地区应根据技术水平的现状,选取适宜的高技术进行引进。关于高技术产业中的消化吸收能力不足问题,不能简单地依靠增大技术引进和消化吸收经费支出来解决。必须依靠加大技术后发地区的教育投入,提升落后地区的人力资本水平。最后,为充分实现不同地区高技术产业之间的协同创新与共同进步,还应着重组建协同创新机构,构建集成创新网络,进而形成区域内与地区间的功能互补与良好协作机制,实现高技术产业的可持续发展。     

接种菌剂对城市污泥生物干化过程中干化效果和氮素转化的影响

以广州某污水处理厂压滤污泥为原料,木屑为调理剂,添加接种菌剂和碳源,采用间歇强制通风方式进行了周期8 d的生物干化实验,研究了不同接种菌剂量对生物干化过程中温度、含水率、pH、挥发分以及氮素形态转变的影响。实验共设4组,接种菌剂添加量分别为0、2‰、4‰和6‰,其他条件相同。实验结果表明,在接种菌剂添加量为4‰时,综合生物干化效果最好。堆体温度和pH在初期升高最快,含水率降低到51.73%,挥发分降低到42.04%。在氮素转化方面,污泥中的氮素在初期最容易向氨氮转化,而后期则较多的向硝氮转化。污泥的总氮含量从40.3 g/kg降低到27.6 g/kg,氮损失率为31.51%。     

钝顶螺旋藻固定模拟烟道气中的CO2

研究了钝顶螺旋藻对模拟烟道气中CO2的固定性能,及其对NOx和SOx水溶形态亚硝态氮、亚硫酸氢根的耐受性。结果显示:随CO2浓度的增加,藻细胞达到最大比生长速率的时间缩短,CO2浓度为15%时藻细胞比生长速率达到最大的时间最短,生物量最终达到最大值4.1 g/L;CO2浓度为15%时藻细胞的固碳率为12.34 mg/(L·h)。研究发现,钝顶螺旋藻能够耐受浓度小于10 mmol/L的亚硝态氮,可将其作为钝顶螺旋藻生长的唯一氮源,但藻生长的延迟期增长。钝顶螺旋藻能够耐受8 mmol/L的亚硫酸氢盐,可将其作为生长的唯一硫源,藻细胞6 d后开始快速增长。     

Potential effects of Thiram on medicago ‐ R. meliloti symbiotic association†

Abstract

The effects of Thiram and 2 commercial Thiram formulations on the growth and respiration of rhizobia were tested to compare the extent of bacteriostasis under controlled conditions. Although bacteriostasis was measurable at all concentrations tested, liquid cultures grew to maximum optical density in Thiram suspensions containing less than 10 μg/ml. Percentage germination, root elongation, and subsequent nodulation by R. meliloti of 2 cultivars of alfalfa, were determined in thiram suspensions to determine potential physiological effects of the fungicide on the host plant. Conditions were identified which produced enhancement or inhibition of germination, root elongation and development of nodular nitrogenase activity. At concentrations of the fungicide recommended for seed application, only minor, temporary bacteriostasis was observed as a possible negative effect while germination rates of fungi‐contaminated seed were markedly increased.     

森林转型、农地边际化与生态恢复

中国20世纪80年代迎来了国家土地利用形态的转型,即代表自然生态空间的森林面积降至低谷后反转向上,代表人类干扰较强的耕地面积从扩张到收缩.这是生态状况从整体恶化向整体改善转变的最直接原因.森林转型对应着国家经济社会发展的阶段性演进过程,存在着必然性.其直接原因,是农林交错带的农业在与森林竞争土地资源的过程中失去优势.伴随工业化和城市化的劳动力价格上升,生活水平提高带来的林木产品需求增加,是森林竞争力提高和农业竞争力下降的经济驱动力;而转型前农业扩张引起的生态退化,则是其政策驱动力.在中国森林转型初期,政策起到了关键的促进作用.随着城市化的加速发展,人口年龄结构向老年型转变,中国迎来了劳动力工资持续上涨的阶段.以坡耕地为代表的劳动力密集型农地利用方式,由于难以实现机械化,劳动生产率与平原区农业的差距将越来越大,被“边际化”的可能性越来越高.这给森林面积或自然生态空间的进一步扩张提供了机会.     

开发区的“第三次创业”:从工业园走向新城——以苏州工业园转型为例

开发区是全球化时代出现的新产业空间。开发区在我国经济发展和改革开放中,发挥了重要作用。理论界将我国开发区发展阶段总结为一次创业和二次创业两个阶段,但是目前我国开发区普遍出现了从工业园向新城区转型的趋向。从企业家型城市的理论视角,通过对苏州工业园发展与转型的实证研究,论证开发区建设进入第三次创业的新阶段———即从工业园向城市新区的转变。在新一轮转型中,苏州工业园实施了企业家的城市策略,采取了园区再定位、创造新城市空间等企业家城市行动,园区的新城功能和第三产业得到迅速发展。同时,研究也发现园区管委会的管治体系发生了根本变化,从促进经济增长管理向社会和城市综合管理转型。该研究将对我国新一轮开发区的转型具有重要启示。