木材的生态学属性——木材是绿色环境人体健康的贡献者

系统归纳了木材的自然美与艺术特性、木材的碳素储存与环境效应,以及木材的智能性调节功能,并提出木材是"木材—人类—环境"关系中的天然元素,有益于优化环境,提高人类生活质量,能够为人类生活构成一个健康自然的绿色环境。     

Reaction Wood: Its Structure and Function: Lignification may generate the force active in restoring the trunks of leaning trees to the vertical

The mechanism by which the stems of trees recover after being bent or tilted out of the vertical is considered. The mechanical consequences of the tendency for the main stem apex to reerect itself and grow vertically or to be replaced by a vertically growing lateral branch, and of the asymmetrical radial growth of displaced stems, are pointed out. The asymmetry usually develops on the upper side of a bent or tilted hardwood stem and on the under side of a softwood stem. Since such asymmetry can usually be accounted for on the basis of accentuated development of wood rather than bark, the question of the possible functional significance of the wood arises. Experiments are cited to demonstrate that the wood (reaction wood) is effective as a means for assisting displaced stems to recover, contracting longitudinally on the upper side of a hardwood stem and expanding on the under side of a softwood stem. Consideration is then given to the structure, differentiation, and chemical composition of the reaction wood formed by hardwoods and softwoods with a view to locating the force active in aiding recovery and determining its origin. The consequences of associating the support of a still-growing stem displaced from the vertical with the idiosyncracies of secondary wall formation of reaction wood cells, and the reerection of such a stem with lignification of these walls, are explored. On this basis, the hypothesis is advanced that the recovery force is located in the region of differentiating reaction wood cells undergoing lignification, the active force arising from the swelling of cell walls as a result of deposition in them of lignin. Objections to the hypothesis are mentioned.     

基于农户视角农村生活垃圾治理费用支付意愿分析——以新疆昭苏县为例

通过对新疆昭苏县农户进行访谈和实际调研,运用Logistic回归方法分析了农户个体特征、农户家庭经济状况、农户环境认知程度、生活垃圾公共服务情况对农户生活垃圾治理费用支付意愿的影响。结果表明:农户健康状况、家庭年收入以及农户对生活垃圾治理公共设施的满意度和政府生活垃圾治理的信任程度对农户支付意愿有正向作用;农户年龄、农户家庭人口数量及农户了解生活垃圾分类程度对农户的支付意愿有负向作用。鉴于此,提出了相关对策建议,以期为制定昭苏县农村生活垃圾治理收费制度提供了科学依据。     

Earliest Radiocarbon Dates for Domesticated Animals: Europe is added to the Near East as another early center of domestication

Our dates show that cattle and pigs were first domesticated in Europe. Sheep, which were thought to have become extinct in Europe during the terminal Pleistocene, also appear first in Europe. However, there remains little doubt that sheep were first domesticated in the Near East or Turkey, since no wild sheep appear to have existed in Europe at the beginning of the Holocene. Dogs were domesticated in both the Near East and Europe at virtually the same time. In the Near East, Asiab, at around 8000 B.C., qualifies as the first center of goat domestication. It is also the earliest center of domestication for all animals we have dated here. Horses were first domesticated in the steppes of the Ukraine, perhaps even earlier than our dates indicate, since all of the samples found at Polling are virtually contemporaneous (Fig. 1). Undoubtedly, future research will alter the details of our overall impressions, especially after bones at earlier sites such as Nea Nikomedeia have been dated directly. But, on balance, there can be no doubt that southeastern Europe was as much an early center of domestication as the Near East was.