Under the background of complex international situation,how to build the special geo-economic space of China-Russia bor-der lies in strengthening their foreign trade resilience against external shocks.Based on empiric...Under the background of complex international situation,how to build the special geo-economic space of China-Russia bor-der lies in strengthening their foreign trade resilience against external shocks.Based on empirical evidence from ten prefecture-level China-Russia border regions in Northeast China,this paper analyzed the spatiotemporal evolution of foreign trade resilience under different shocks.Furthermore,through the Panel Regression model,the mechanism of the industrial structure on the foreign trade resilience in contraction period and expansion period was discussed.The results showed that:1)from 2004 to 2021,foreign trade in China-Russia border regions experienced five phases.The overall foreign trade resilience was higher than expected,showing a rising volatility trend,but there was significant spatial heterogeneity in the ability of cities to cope with shocks.2)Highly specialized clusters were mainly concentrated in Yichun,Heihe and Da Hinggan Ling Prefecture,while Mudanjiang and Yanbian performed better in related and unrelated diversification.3)In different stages of economic system evolution,the response mode,degree and result of border foreign trade resilience to regional industrial structure showed obvious stage characteristics.During the contraction period,related diversification was more conducive to improving the resistance through risk spillovers.During the expansion period,specialization played a more significant role in improving regional resilience through self-reinforcing effect.These results are beneficial for expanding the resilience theory,ensuring border economic security and optimizing border industrial investment layout.展开更多
本研究利用不同浓度NaCl溶液对10份谷子(Setaria italica L.)种质进行处理,通过分析其萌发期的相对发芽势、相对发芽率、相对芽长以及相对根长等4项指标,明确了适于谷子萌发期耐盐性鉴定的NaCl浓度为180 mmol/L。在该浓度下,利用主成分...本研究利用不同浓度NaCl溶液对10份谷子(Setaria italica L.)种质进行处理,通过分析其萌发期的相对发芽势、相对发芽率、相对芽长以及相对根长等4项指标,明确了适于谷子萌发期耐盐性鉴定的NaCl浓度为180 mmol/L。在该浓度下,利用主成分分析和聚类分析等方法,对180份种质资源进行了耐盐性综合评价和等级划分。结果显示,除相对发芽率和相对芽长之间相关性不显著以外,其余指标之间均呈极显著正相关;主成分分析结果表明,这4项指标可作为谷子耐盐性评价的重要指标;聚类分析结果将180份谷子种质分为极端耐盐、耐盐、盐敏感和极端盐敏感4类;进一步采用隶属函数进行综合评价,筛选到硷谷、衡谷12、齐头白、K-3606和晋谷20等5份极端耐盐种质材料。最后,在该浓度处理下,对黑枝谷×长农35号(极端盐敏感×耐盐)F7代重组近交系遗传群体进行了初步分析,发现40份株系耐盐性等级频率分布近似正态分布,表明该群体适宜耐盐QTL挖掘。研究结果说明,在180 mmol/L NaCl处理下,通过谷子萌发期相对发芽势、相对发芽率、相对芽长和相对根长等4个指标能较好地区分不同种质耐盐性的差异。展开更多
基金Under the auspices of National Natural Science Foundation of China(No.42071162,42101165)。
文摘Under the background of complex international situation,how to build the special geo-economic space of China-Russia bor-der lies in strengthening their foreign trade resilience against external shocks.Based on empirical evidence from ten prefecture-level China-Russia border regions in Northeast China,this paper analyzed the spatiotemporal evolution of foreign trade resilience under different shocks.Furthermore,through the Panel Regression model,the mechanism of the industrial structure on the foreign trade resilience in contraction period and expansion period was discussed.The results showed that:1)from 2004 to 2021,foreign trade in China-Russia border regions experienced five phases.The overall foreign trade resilience was higher than expected,showing a rising volatility trend,but there was significant spatial heterogeneity in the ability of cities to cope with shocks.2)Highly specialized clusters were mainly concentrated in Yichun,Heihe and Da Hinggan Ling Prefecture,while Mudanjiang and Yanbian performed better in related and unrelated diversification.3)In different stages of economic system evolution,the response mode,degree and result of border foreign trade resilience to regional industrial structure showed obvious stage characteristics.During the contraction period,related diversification was more conducive to improving the resistance through risk spillovers.During the expansion period,specialization played a more significant role in improving regional resilience through self-reinforcing effect.These results are beneficial for expanding the resilience theory,ensuring border economic security and optimizing border industrial investment layout.
