Extensive acidic soils,which suffer from accelerated soil acidification,are found in southern China.Soil acidity,aluminum toxicity,and nutrient deficiencies severely limited crop productivity in acidic soils.It has be...Extensive acidic soils,which suffer from accelerated soil acidification,are found in southern China.Soil acidity,aluminum toxicity,and nutrient deficiencies severely limited crop productivity in acidic soils.It has been widely reported that crop residue biochars can ameliorate acidic soils and increase crop productivity.Here,we summarized the positive effects and mechanisms involved in the correction of soil acidity,the alleviation of aluminum toxicity and the increase of soil pH buffering capacity by crop residue biochars.The carbonate,oxygen-containing functional groups and silicates in biochars are the major components responsible for their efficacy in amending acidic soils and resisting soil re-acidification.We conclude that application of crop residue biochars may be a better option than traditional liming to ameliorate acidic soils.Nonetheless,further researches into soil acidification are still required to address some issues that are controversial and poorly understood.展开更多
The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure chara...The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure characteristic on shift clutch engagement process was analyzed. The study results could be used to the characteristics match of the shift clutch with the hydraulic system of the high speed tracked vehicle power shift steering transmission and the performance prediction.展开更多
基金教育部人文社会科学重点研究基地重大项目"转型期企业集团成长模式及治理机制研究"(13JJD630005)教育部人文社会科学重点研究基地重大项目"混合所有制企业治理问题研究"(14JJD630006)+3 种基金教育部新世纪优秀人才支持计划项目"企业集团子公司治理机制:主导行为网络嵌入与机制设计"(NCET-11-0257)国家建设高水平大学公派研究生项目"Institutional complexitypyramid structure and top management turnover--Evidence from Chinese state-owned listed companies"(201406200040)
基金funded by the National Key Research and Development of China(2016YFD0200302)the National Key Basic Research Program of China(2014CB441003)
文摘Extensive acidic soils,which suffer from accelerated soil acidification,are found in southern China.Soil acidity,aluminum toxicity,and nutrient deficiencies severely limited crop productivity in acidic soils.It has been widely reported that crop residue biochars can ameliorate acidic soils and increase crop productivity.Here,we summarized the positive effects and mechanisms involved in the correction of soil acidity,the alleviation of aluminum toxicity and the increase of soil pH buffering capacity by crop residue biochars.The carbonate,oxygen-containing functional groups and silicates in biochars are the major components responsible for their efficacy in amending acidic soils and resisting soil re-acidification.We conclude that application of crop residue biochars may be a better option than traditional liming to ameliorate acidic soils.Nonetheless,further researches into soil acidification are still required to address some issues that are controversial and poorly understood.
文摘The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure characteristic on shift clutch engagement process was analyzed. The study results could be used to the characteristics match of the shift clutch with the hydraulic system of the high speed tracked vehicle power shift steering transmission and the performance prediction.
