Maintaining an adequate security level of cultivated land is essential for the healthy and sustainable survival of China’s large and growing population.We constructed a cultivated land security evaluation index syste...Maintaining an adequate security level of cultivated land is essential for the healthy and sustainable survival of China’s large and growing population.We constructed a cultivated land security evaluation index system,combined with an improved TOPSIS method by taking into account the balance and stability of quantitative,qualitative,and ecological security.We applied this improved method to an evaluation of the state of cultivated land security and analyzed its spatiotemporal variation in Yingtan City(Jiangxi Province,China)from 1995 to 2015.The drivers of the changes in cultivated land security were investigated via a spatial regression model,which can eliminate the effect of spatial autocorrelation.The results showed that cultivated land security decreased rapidly from 1995 to 2005,although it tended to rise slowly in the subsequent period from 2005 to 2015.Areas deemed to be in a highly dangerous state were mainly distributed in the Yuehu District,while those that were secure appeared primarily in the southern mountainous area,with the area in a generally dangerous state extending to the west in the same direction as urban development.Among the examined drivers,social-economic factors and policy factors significantly influenced the cultivated land security.Our work suggests that government managers should take appropriate measures to improve cultivated land security according to its spatiotemporal variations and the underpinning drivers in this region.展开更多
For the past few years,Yingtan has been making efforts in deepening supply-side reform.With quality improvement and benefit increase as its core,with technology progress and collaborative innovation as its driving for...For the past few years,Yingtan has been making efforts in deepening supply-side reform.With quality improvement and benefit increase as its core,with technology progress and collaborative innovation as its driving force,Yingtan has been actively improving an“eight in one”copper industry covering copper raw material,copper smelting,copper processing,copper trading,copper R&D,展开更多
采用电化学阻抗和慢应变速率方法,结合扫描电子显微镜,研究了不同阴极极化电位下X80钢在鹰潭土壤模拟溶液中的应力腐蚀行为。结果表明:鹰潭土壤模拟溶液中,X80钢/溶液界面处电荷转移电阻随阴极极化程度增加先升后降。在自腐蚀电位条件...采用电化学阻抗和慢应变速率方法,结合扫描电子显微镜,研究了不同阴极极化电位下X80钢在鹰潭土壤模拟溶液中的应力腐蚀行为。结果表明:鹰潭土壤模拟溶液中,X80钢/溶液界面处电荷转移电阻随阴极极化程度增加先升后降。在自腐蚀电位条件下开裂机理为阳极溶解,当外加电位为-1000 m V(vs SCE),应力腐蚀敏感性最低,此电位为最佳保护电位;继续增大阴极极化程度,应力腐蚀敏感性增加,此时开裂机制为氢和应力协同作用下的氢致开裂。展开更多
In order to study the stress corrosion cracking （SCC） of X70 pipeline steel and its weld joint in acid soil environment of southeast of China, two simulating methods were used here. The one was to obtain the bad mic...In order to study the stress corrosion cracking （SCC） of X70 pipeline steel and its weld joint in acid soil environment of southeast of China, two simulating methods were used here. The one was to obtain the bad microstructures in heat affected zone by annealing at 1300℃ for 10 min and air cooling to room temperature, the other was to get a series of simulating solutions of the acid soil environment. SCC susceptibilities of X70 pipeline steels＇before and after being normalized in the simulated solutions were studied by slow strain rate test （SSRT） and microstructural observation of fracture areas. Potentiodynamic polarization curves were used to study the electrochemical behaviour of different microstructures. SCC does occur to both the as-received material and normalized microstructure after heat treatment as the polarization potential decreased. Hydrogen embrittlement （HE） is indicated occurring to all tested materials at -850 mV （vs SCE） and -1200 mV（vs SCE）. The SCC mechanisms are different within varying potential range. Anodic dissolution is the key cause as polarization potential higher than null current potential, and HE will play a more important role as polarization potential lower than the null current potential.展开更多
基金The Research Project of Humanities and Social Sciences in Colleges and Universities of Jiangxi Province(JC19221)The National Natural Science Foundation of China(41361049)The Ganpo“555”Talent Research Funds of Jiangxi Province China(201295)。
文摘Maintaining an adequate security level of cultivated land is essential for the healthy and sustainable survival of China’s large and growing population.We constructed a cultivated land security evaluation index system,combined with an improved TOPSIS method by taking into account the balance and stability of quantitative,qualitative,and ecological security.We applied this improved method to an evaluation of the state of cultivated land security and analyzed its spatiotemporal variation in Yingtan City(Jiangxi Province,China)from 1995 to 2015.The drivers of the changes in cultivated land security were investigated via a spatial regression model,which can eliminate the effect of spatial autocorrelation.The results showed that cultivated land security decreased rapidly from 1995 to 2005,although it tended to rise slowly in the subsequent period from 2005 to 2015.Areas deemed to be in a highly dangerous state were mainly distributed in the Yuehu District,while those that were secure appeared primarily in the southern mountainous area,with the area in a generally dangerous state extending to the west in the same direction as urban development.Among the examined drivers,social-economic factors and policy factors significantly influenced the cultivated land security.Our work suggests that government managers should take appropriate measures to improve cultivated land security according to its spatiotemporal variations and the underpinning drivers in this region.
文摘For the past few years,Yingtan has been making efforts in deepening supply-side reform.With quality improvement and benefit increase as its core,with technology progress and collaborative innovation as its driving force,Yingtan has been actively improving an“eight in one”copper industry covering copper raw material,copper smelting,copper processing,copper trading,copper R&D,
文摘采用电化学阻抗和慢应变速率方法,结合扫描电子显微镜,研究了不同阴极极化电位下X80钢在鹰潭土壤模拟溶液中的应力腐蚀行为。结果表明:鹰潭土壤模拟溶液中,X80钢/溶液界面处电荷转移电阻随阴极极化程度增加先升后降。在自腐蚀电位条件下开裂机理为阳极溶解,当外加电位为-1000 m V(vs SCE),应力腐蚀敏感性最低,此电位为最佳保护电位;继续增大阴极极化程度,应力腐蚀敏感性增加,此时开裂机制为氢和应力协同作用下的氢致开裂。
基金supported by the Chinese National Sci-ence and Technology Infrastructure Platforms Construc-tion Project (No. 2005DKA 10400)the Major Foun-dation in the Tenth Five-Year Development Plan of China(No. 50499333-08).
文摘In order to study the stress corrosion cracking （SCC） of X70 pipeline steel and its weld joint in acid soil environment of southeast of China, two simulating methods were used here. The one was to obtain the bad microstructures in heat affected zone by annealing at 1300℃ for 10 min and air cooling to room temperature, the other was to get a series of simulating solutions of the acid soil environment. SCC susceptibilities of X70 pipeline steels＇before and after being normalized in the simulated solutions were studied by slow strain rate test （SSRT） and microstructural observation of fracture areas. Potentiodynamic polarization curves were used to study the electrochemical behaviour of different microstructures. SCC does occur to both the as-received material and normalized microstructure after heat treatment as the polarization potential decreased. Hydrogen embrittlement （HE） is indicated occurring to all tested materials at -850 mV （vs SCE） and -1200 mV（vs SCE）. The SCC mechanisms are different within varying potential range. Anodic dissolution is the key cause as polarization potential higher than null current potential, and HE will play a more important role as polarization potential lower than the null current potential.
