The quality and flavor of scallops changes during the fresh dry rehydration process.In order to control the changes after rehydration,a scallop pretreatment method was adopted.The pretreatment method involved impregna...The quality and flavor of scallops changes during the fresh dry rehydration process.In order to control the changes after rehydration,a scallop pretreatment method was adopted.The pretreatment method involved impregnating fresh scallops with 0.2 g/100 m L konjac glucomannan(KGM),carrageenan(CA),and sodium alginate(SA)before the drying and rehydration process.After rehydration,the KGM treated samples had better water retention and the highest betaine content.The CA treated samples had a deepened yellow color and the highest content of flavoring amino acids(FAA)and inosine monophosphate(IMP).What’s more,a total of 77 volatile compounds were detected,with a maximum of 15 esters.The highest proportion in the four groups was eugenol,followed by n-hexadecanoic acid,methyl hexadecanoate etc.The SA group had no significant contribution in terms of quality and taste.The samples pretreated with KGM had the best quality,and those pretreated by CA had the best flavor.展开更多
Rockburst is a dynamic phenomenon accompanied by acoustic emission(AE)activities.It is difficult to predict rockburst accurately.Based on the fast Fourier transform(FFT)method and the information entropy theory,the ev...Rockburst is a dynamic phenomenon accompanied by acoustic emission(AE)activities.It is difficult to predict rockburst accurately.Based on the fast Fourier transform(FFT)method and the information entropy theory,the evolution model of dominant frequency entropy was established.The AE energy,frequency and stress were synthetically considered to predict rockburst.Under the triaxial and the single-face unloading tests,the relationship between AE energy and the development of internal cracks was analyzed.Using the FFT method,the distribution characteristics of AE dominant frequency values were obtained.Based on the information entropy theory,the dominant frequencies evolved patterns were ascertained.It was observed that the evolution models of the dominant frequency entropy were nearly the same and shared a characteristic“undulation-decrease-rise-sharp decrease”pattern.Results show that AE energy will be released suddenly before rockburst.The density of intermediate frequency increased prior to rockburst.The dominant frequency entropy reached a relative maximum value before rockburst,and then decreased sharply.These features could be used as a precursory information for predicting rockburst.The proposed relative maximum value could be as a key point to predict rockburst.This is a meaningful attempt on predicting rockburst.展开更多
CRTS-II slab ballastless track on bridge is a unique system in China high speed railway.The application of longitudinal continuous track system has obviously changed dynamic characteristics of bridge structure.The bri...CRTS-II slab ballastless track on bridge is a unique system in China high speed railway.The application of longitudinal continuous track system has obviously changed dynamic characteristics of bridge structure.The bridge system and CRTS-II track system form a complex nonlinear system.To investigate the seismic response of high speed railway(HSR)simply supported bridge-track system,nonlinear models of three-span simply supported bridge with piers of different height and CRTS-II slab ballastless track system are established.By seismic analysis,it is found that shear alveolar in CRTS-II track system is more prone to be damaged than bridge components,such as piers,girders and bearings.The result shows that the inconsistent displacement of bridge girders is the main cause of the CRTS-II track system’s damage.Then the rotational friction damper(RFD)is adopted,which utilizes the device’s rotation and friction to dissipate seismic energy.The hysteretic behavior of RFD is studied by numerical and experimental methods.Results prove that RFD can provide good hysteretic energy dissipation ability with stable performance.Furthermore,the analysis of RFD’s influence on seismic response of HSR bridge-track system shows that RFD with larger sliding force is more effective in controlling excessive inconsistent displacement where RFD is installed,though response of other bridge spans could slightly deteriorated.展开更多
目的:采用ICF康复组合(ICF-RS)评价非特异性下腰痛(nonspecific low back pain,NLBP)患者的功能状况,初步分析水中太极治疗NLBP的康复疗效。方法:74例NLBP患者随机分配入治疗组(水中太极)和对照组(核心肌力训练),每组各37例。按照预定...目的:采用ICF康复组合(ICF-RS)评价非特异性下腰痛(nonspecific low back pain,NLBP)患者的功能状况,初步分析水中太极治疗NLBP的康复疗效。方法:74例NLBP患者随机分配入治疗组(水中太极)和对照组(核心肌力训练),每组各37例。按照预定的治疗方案进行为期8周的集中康复训练,通过ICF-RS评估NLBP患者的功能改善情况。结果:NLBP患者存在明显身体功能障碍的类目依次为:b152情感功能、b280痛觉、b455运动和耐受能力、b710关节活动能力、b730肌肉力量;存在明显活动与参与功能障碍依次为:d230进行日常事务、d410改变身体基本姿势、d415保持一种身体姿势、d640做家务、d660帮助别人、d710基本的人际交往、d770亲密关系、d850有报酬的就业、d920娱乐与休闲。2组NLBP患者治疗前后通过ICF-RS进行疗效评估,2组患者治疗后30条类目中14条明显改善(b152、b280、b455、b710、b730、d230、d410、d415、d640、d660、d710、d770、d850、d920),治疗组改善类目评分均较对照组改善明显,具有显著性差异(P<0.05)。结论:水中太极对NLBP痛患者有明显的临床疗效。ICF-RS可以用于评估NLBP患者的功能状况,指导康复治疗和进行疗效评价。展开更多
基金funded by the National Key R&D Program of China(2020YFD0900900)。
文摘The quality and flavor of scallops changes during the fresh dry rehydration process.In order to control the changes after rehydration,a scallop pretreatment method was adopted.The pretreatment method involved impregnating fresh scallops with 0.2 g/100 m L konjac glucomannan(KGM),carrageenan(CA),and sodium alginate(SA)before the drying and rehydration process.After rehydration,the KGM treated samples had better water retention and the highest betaine content.The CA treated samples had a deepened yellow color and the highest content of flavoring amino acids(FAA)and inosine monophosphate(IMP).What’s more,a total of 77 volatile compounds were detected,with a maximum of 15 esters.The highest proportion in the four groups was eugenol,followed by n-hexadecanoic acid,methyl hexadecanoate etc.The SA group had no significant contribution in terms of quality and taste.The samples pretreated with KGM had the best quality,and those pretreated by CA had the best flavor.
基金Project(2017YFC0804201)supported by the National Key Research and Development Program of ChinaProject(51574246)supported by the National Natural Science Foundation of China+1 种基金Project(2011QZ01)supported by Fundamental Research Funds for the Central Universities,ChinaProject(C201911362)supported by the National Training Program of Innovation and Entrepreneurship for Undergraduates,China。
文摘Rockburst is a dynamic phenomenon accompanied by acoustic emission(AE)activities.It is difficult to predict rockburst accurately.Based on the fast Fourier transform(FFT)method and the information entropy theory,the evolution model of dominant frequency entropy was established.The AE energy,frequency and stress were synthetically considered to predict rockburst.Under the triaxial and the single-face unloading tests,the relationship between AE energy and the development of internal cracks was analyzed.Using the FFT method,the distribution characteristics of AE dominant frequency values were obtained.Based on the information entropy theory,the dominant frequencies evolved patterns were ascertained.It was observed that the evolution models of the dominant frequency entropy were nearly the same and shared a characteristic“undulation-decrease-rise-sharp decrease”pattern.Results show that AE energy will be released suddenly before rockburst.The density of intermediate frequency increased prior to rockburst.The dominant frequency entropy reached a relative maximum value before rockburst,and then decreased sharply.These features could be used as a precursory information for predicting rockburst.The proposed relative maximum value could be as a key point to predict rockburst.This is a meaningful attempt on predicting rockburst.
基金The authors are grateful for the financial support from the Fundamental Research Funds for the Central Universities of Central South University(Project No.502221804)the National Natural Science Foundation of China(Project Nos.51878674,51878563)+1 种基金the Foundation for Key Youth Scholars in Hunan Province(Project No.150220077)the Project of Yuying Plan in Central South University(Project No.502034002).Any opinions,findings,and conclusions or recommendations expressed in this paper are those of the authors.
文摘CRTS-II slab ballastless track on bridge is a unique system in China high speed railway.The application of longitudinal continuous track system has obviously changed dynamic characteristics of bridge structure.The bridge system and CRTS-II track system form a complex nonlinear system.To investigate the seismic response of high speed railway(HSR)simply supported bridge-track system,nonlinear models of three-span simply supported bridge with piers of different height and CRTS-II slab ballastless track system are established.By seismic analysis,it is found that shear alveolar in CRTS-II track system is more prone to be damaged than bridge components,such as piers,girders and bearings.The result shows that the inconsistent displacement of bridge girders is the main cause of the CRTS-II track system’s damage.Then the rotational friction damper(RFD)is adopted,which utilizes the device’s rotation and friction to dissipate seismic energy.The hysteretic behavior of RFD is studied by numerical and experimental methods.Results prove that RFD can provide good hysteretic energy dissipation ability with stable performance.Furthermore,the analysis of RFD’s influence on seismic response of HSR bridge-track system shows that RFD with larger sliding force is more effective in controlling excessive inconsistent displacement where RFD is installed,though response of other bridge spans could slightly deteriorated.
文摘目的:采用ICF康复组合(ICF-RS)评价非特异性下腰痛(nonspecific low back pain,NLBP)患者的功能状况,初步分析水中太极治疗NLBP的康复疗效。方法:74例NLBP患者随机分配入治疗组(水中太极)和对照组(核心肌力训练),每组各37例。按照预定的治疗方案进行为期8周的集中康复训练,通过ICF-RS评估NLBP患者的功能改善情况。结果:NLBP患者存在明显身体功能障碍的类目依次为:b152情感功能、b280痛觉、b455运动和耐受能力、b710关节活动能力、b730肌肉力量;存在明显活动与参与功能障碍依次为:d230进行日常事务、d410改变身体基本姿势、d415保持一种身体姿势、d640做家务、d660帮助别人、d710基本的人际交往、d770亲密关系、d850有报酬的就业、d920娱乐与休闲。2组NLBP患者治疗前后通过ICF-RS进行疗效评估,2组患者治疗后30条类目中14条明显改善(b152、b280、b455、b710、b730、d230、d410、d415、d640、d660、d710、d770、d850、d920),治疗组改善类目评分均较对照组改善明显,具有显著性差异(P<0.05)。结论:水中太极对NLBP痛患者有明显的临床疗效。ICF-RS可以用于评估NLBP患者的功能状况,指导康复治疗和进行疗效评价。
