基于要素视角的“一带一路”国家绿色发展效率的驱动力研究

绿色发展的内涵在于构建与资源消耗和污染排放脱钩的绿色经济增长模式,最终实现经济、社会与自然系统的共生与多元化发展。研究"一带一路"沿线国家的绿色发展效率及驱动机制对推动"绿色之路"建设具有重要的理论和实践意义。但目前学界在驱动机制方面未见对技术变化偏向性的探究,因而缺少从要素视角促进绿色技术进步、推动绿色发展的理论基础。以"一带一路"沿线37个国家为样本,以绿色全要素生产率为绿色发展的表征指标,采用数据包络分析方法测度1995至2019年间各国绿色发展趋势和技术变化特征,在此基础上探讨技术变化的要素偏向性对不同类型国家绿色发展的驱动特征。主要研究结论为：（1）多数国家的绿色发展水平呈上升趋势,绿色全要素生产率年均增长率为0.70%;（2）技术进步是沿线国家绿色发展的核心驱动因素,其中中性技术进步是主要动力,而偏向性技术变化却倾向于降低绿色发展效率;（3）基于绿色发展特征将沿线国家分为强、较强、较弱和弱四种类型。各类国家的绿色技术进步均以中性技术进步为驱动力量,而偏向性技术进步普遍呈能源密集型和生态环境恶化型特征。类型I中绿色发展快于GDP发展的国家,其偏向性技术在投入要素中偏向能源,而在产出要素中偏向期望产出,呈现能源密集型和生态环境友好型特征,说明其低碳政策已对技术进步产生了促进作用,而能源规制的激励作用仍有待于加强。基于研究结果,提出优化经济发展的宏观衡量指标,以节能低碳规制促进偏向性绿色技术进步是促进"一带一路"沿线国家绿色发展的关键路径。     

Effect of maturation conditions on light and temperature requirements during seed germination of Citrullus colocynthis from the Arabian Desert

• Seed germination of Citrullus colocynthis, as in many other species of Cucurbitaceae, is inhibited by light, particularly at low temperatures. Germination response to light and temperature has been attributed to day length and temperature during seed maturation. This study assessed the effects of these factors on the germination response of C. colocynthis to temperature and light quality.
• Ripe fruits were collected from natural habitats during December and February and germinated at three temperatures (15/25, 20/30 and 25/35 °C) in five light treatments (dark, white light and Red:Far Red (R:FR) ratios of 0.30, 0.87 and 1.19). Additionally, unripe fruits were also collected from natural habitats and completed their maturation in growth chambers under different day lengths (6, 16 and 24 h of darkness) at 10/20 °C, and in darkness at both 10/20 °C and 25/35 °C. Mature seeds of the different treatments were germinated in the same five light treatments at 15/25 °C.
• Germination was significantly higher in the dark than that in any light treatment. Seeds matured at higher temperatures (i.e. seeds from the December collection and those matured at 25/35 °C) had significantly higher germination than those matured at lower temperatures (i.e. seeds from the February collection and those matured at 10/20 °C). Dark germination was significantly higher for the December collection than for the February collection. Seeds of the two collections germinated in the dark only at 15/25 °C. However, seeds matured in a growth chamber at 10/20 °C in darkness germinated at 15/25 °C in all light treatments, except for the R:FR ratio 0.30. Seeds of the different treatments failed to germinate in FR‐rich light.
• This study demonstrates that both temperature and day length during seed maturation play significant roles in the germination response of C. colocynthis. Additionally, the dark requirement for germination is likely beneficial for species with the larger seeds, such as C. colocynthis, which produce bigger seedlings that are able to emerge from deep soils and are competitively superior under dense vegetation and resource‐limited conditions.

     

提升生态系统质量和稳定性的生态学原理及技术途径之探讨

提升生态系统质量和稳定性是国家生态环境建设的迫切任务,但生态系统质量及其稳定性的生态学原理是亟待阐述的生态学难题。本文在梳理生态系统质量和稳定性的影响因素及其相互作用关系基础上,从生物集聚与结构嵌套的自组织、生态要素关联及生态过程耦合、生态系统整体性及功能涌现、生态服务外溢及功效权衡、资源供给能力和环境适宜性的协同互作、自然变化和人类活动交互影响等视角,论述了生态系统质量及其稳定性演变的生态学原理,并围绕生态系统宏观格局调整、自然保护地体系建设、区域复合生态系统综合管理、退化生态系统恢复、受损生态系统重建、典型生态系统过程管理等层级,提出了提升生态系统质量及其稳定性的技术途径与管理策略。     

酵母基因组共表达基因簇与其上游顺式作用元件的关系

ＤＮＡ微阵列技术的快速发展开辟了从表达图谱研究基因组功能的新途径。酵母全基因组的测定和基因组表达图谱数据的发表使其成为研究真核基因转录调控机制的首选目标。运用生物信息学的工具研究了酵母基因组中基因上游顺式调控元件与基因组表达图谱的关系。结果表明,表达紧密关系的同一簇基因都具有若干特异的顺式作用元件,其表达受到相应反式调控因子的控制。找到的位点中,一部分与已知顺式作用元件相对应;另一部分可能是新的顺     

杏品种的低温需求量研究

对杏的３９个品种的低温需求量进行了测定,结果表明：休眠在２６℃±２℃条件下,２－３周后以５０％萌芽为解除自然休眠标准,在陕西杨陵地区以犹它模型计算的累计低温单位数在不同年份均比≤７．２℃和０－７．２℃低温累计小时数重演性高且最稳定,预测自然休眠结束期准确性高,适合原产中国的杏品种作为低温需求量计算标准。各个杏品种的低温需求量在４４０－７７０ｈ之间。辽宁、新疆、青海、甘肃等地区的品种比陕西关中、河南、山东、山西等地区的品种的低温需求量长,陕西南部地区的品种低温需求量最短     

Rethinking stone age economics: Some speculations concerning the pre-Columbian Yanoama economy

The introduction of steel tools and new crops radically transformed the Yanoama Indians' pre-Columbian economy. A consideration of the impact of these innovations allows for the reconstruction of that economy which suggests a higher dependence upon foraging, a lower population density, more mobile settlement pattern, and heavier workload, than today. This reconstruction challenges both current speculations about pre-Columbian Amazonian economic systems which apply Sahlins' concept of aboriginal affluence and those concerning the relationship between Amazonian environment and cultural development. This reconstruction, confirmed in part by fragmentary historical sources, explores some of the dramatic changes which must have taken place since contact. The Yanoama's agricultural subsistence base is a recent innovation, made possible since contact by new tools and new crops.This article has benefitted considerably from conversations with Emilio Fuentes to whom I offer my gratitude. I would also like to thank the anonymous reviewer who made detailed comments on a first draft.     

利用畜禽粪便生产生物有机复合肥的发酵工艺研究

该文研究了以畜禽粪便为原料,接种固氮、解磷、解钾、除臭等多功能微生物,好气性发酵生产生物有机肥料的方法,研制了发酵槽的自动翻拌机等专用设施,确定了相关技术参数。     

Niche position, but not niche breadth, differs in two coexisting amphibians having contrasting trends in Europe

Aim We explored general habitat‐related explanations (niche breadth and niche position) to the contrasting status of two amphibian species that have largely overlapping ranges and habitats – the rare and declining crested newt (Triturus cristatus), and the more common smooth newt (Triturus vulgaris). These closely related and ecologically similar species provide an excellent opportunity to study those methodologically challenging hypotheses, and this is the first such study on amphibians. Location Denmark. Methods We derived multivariate habitat models from 27 characteristics of 210 ponds and their surroundings, and their occupation by newts. In addition to the model performance, niche breadths were compared using the mean beta diversity of amphibian communities in the presence of each newt species. Results For each newt species, the habitat models comprised three variables and correctly classified 74% of observations. Diverse invertebrate fauna (prey base) and shorter distances to other ponds inhabited by conspecifics were positive for both species, while the surrounding habitat (notably dry grasslands with forests) was important for the crested newt and the sediment type of the pond for the smooth newt only. Beta diversity of the amphibian communities of occupied ponds did not differ between the two newt species. Hence, in an area of frequent coexistence, habitat requirements of the species differed in key variables, not in the extent of specialization. Main conclusions Our study supported the niche position rather than the niche‐breadth hypothesis of rarity. We suggest that the rarity and/or continuing decline of the crested newt is related to the degradation of (semi)natural terrestrial habitats around suitable water bodies in Europe. Consequently, special restoration of such habitats has a high potential for the recovery of this rare species, while general pond management appeared more beneficial for the common smooth newt.