为探究鸢乌贼(Sthenoteuthis oualaniensis)资源变化与海洋环境因子的关系,基于2019—2020年南海围网捕捞鸢乌贼的电子渔捞日志数据,首先分析了鸢乌贼资源的月间变动特征,之后利用结构方程模型解析海洋环境因子对其资源时空分布的影响...为探究鸢乌贼(Sthenoteuthis oualaniensis)资源变化与海洋环境因子的关系,基于2019—2020年南海围网捕捞鸢乌贼的电子渔捞日志数据,首先分析了鸢乌贼资源的月间变动特征,之后利用结构方程模型解析海洋环境因子对其资源时空分布的影响。结果表明:围网月间的平均单位捕捞努力量渔获量(Catch per unit effort,CPUE)变化趋势基本一致,年平均CPUE则为2020年大于2019年。南海鸢乌贼渔汛期为3—4月,高产区域集中在112°E—117°E、8°N—12°N,渔汛期CPUE呈现向东和向北偏移的趋势。海洋环境对鸢乌贼资源分布的综合影响系数为0.38,而海表盐度和光合有效辐射在海洋环境上的载荷量分别为0.87和0.82,两者是影响鸢乌贼资源分布的重要环境因子。所用结构方程模型为量化海洋环境因子与鸢乌贼资源分布之间的复杂关系提供了新的研究思路,可为鸢乌贼资源可持续利用和管理提供参考依据。展开更多
环境信用评价政策主要通过影响企业的生产经营和创新活动来影响产业结构升级。本文测算了2002~2021年283座城市的产业结构升级水平,并在此基础上通过构建多时点DID模型评估环境信用评价政策对城市产业结构升级的政策效果。研究发现:环...环境信用评价政策主要通过影响企业的生产经营和创新活动来影响产业结构升级。本文测算了2002~2021年283座城市的产业结构升级水平,并在此基础上通过构建多时点DID模型评估环境信用评价政策对城市产业结构升级的政策效果。研究发现:环境信用评价政策抑制了城市产业结构升级;这种抑制效果是以城市金融贷款数额作为中介路径产生的;且这种抑制作用存在着地区异质性,在非东部城市的作用是显著的,而在东部城市的作用却是不显著的。启示:政府应该健全环境信用评价政策机制、加大金融资本支持;企业应当节流开源,解决资金问题,加快创新,解决技术问题。The environmental credit evaluation policy mainly affects the upgrading of industrial structure by affecting the production, operation and innovation activities of enterprises. This paper calculates the upgrading level of industrial structure of 283 cities from 2002 to 2021, and on this basis, constructs a multi-time DID model to evaluate the effect of environmental credit evaluation policy on urban industrial structure upgrading. It is found that the environmental credit evaluation policy suppresses the upgrading of urban industrial structure, which takes the amount of urban financial loans as the intermediary path, and there is regional heterogeneity in this suppression. The role is significant in non-eastern cities, but not in eastern cities. Revelation: the government should improve the policy mechanism of environmental credit evaluation and increase the support of financial capital;enterprises should cut expenditure and open source, solve capital problems, speed up innovation and solve technical problems.展开更多
文摘为探究鸢乌贼(Sthenoteuthis oualaniensis)资源变化与海洋环境因子的关系,基于2019—2020年南海围网捕捞鸢乌贼的电子渔捞日志数据,首先分析了鸢乌贼资源的月间变动特征,之后利用结构方程模型解析海洋环境因子对其资源时空分布的影响。结果表明:围网月间的平均单位捕捞努力量渔获量(Catch per unit effort,CPUE)变化趋势基本一致,年平均CPUE则为2020年大于2019年。南海鸢乌贼渔汛期为3—4月,高产区域集中在112°E—117°E、8°N—12°N,渔汛期CPUE呈现向东和向北偏移的趋势。海洋环境对鸢乌贼资源分布的综合影响系数为0.38,而海表盐度和光合有效辐射在海洋环境上的载荷量分别为0.87和0.82,两者是影响鸢乌贼资源分布的重要环境因子。所用结构方程模型为量化海洋环境因子与鸢乌贼资源分布之间的复杂关系提供了新的研究思路,可为鸢乌贼资源可持续利用和管理提供参考依据。
文摘环境信用评价政策主要通过影响企业的生产经营和创新活动来影响产业结构升级。本文测算了2002~2021年283座城市的产业结构升级水平,并在此基础上通过构建多时点DID模型评估环境信用评价政策对城市产业结构升级的政策效果。研究发现:环境信用评价政策抑制了城市产业结构升级;这种抑制效果是以城市金融贷款数额作为中介路径产生的;且这种抑制作用存在着地区异质性,在非东部城市的作用是显著的,而在东部城市的作用却是不显著的。启示:政府应该健全环境信用评价政策机制、加大金融资本支持;企业应当节流开源,解决资金问题,加快创新,解决技术问题。The environmental credit evaluation policy mainly affects the upgrading of industrial structure by affecting the production, operation and innovation activities of enterprises. This paper calculates the upgrading level of industrial structure of 283 cities from 2002 to 2021, and on this basis, constructs a multi-time DID model to evaluate the effect of environmental credit evaluation policy on urban industrial structure upgrading. It is found that the environmental credit evaluation policy suppresses the upgrading of urban industrial structure, which takes the amount of urban financial loans as the intermediary path, and there is regional heterogeneity in this suppression. The role is significant in non-eastern cities, but not in eastern cities. Revelation: the government should improve the policy mechanism of environmental credit evaluation and increase the support of financial capital;enterprises should cut expenditure and open source, solve capital problems, speed up innovation and solve technical problems.
