As a promising material in the aircraft industry,2A97 Al-Cu-Li alloy exhibits high corrosion susceptibility that may limit its application.In the present work,to illustrate the influences of precipitate and grain-stor...As a promising material in the aircraft industry,2A97 Al-Cu-Li alloy exhibits high corrosion susceptibility that may limit its application.In the present work,to illustrate the influences of precipitate and grain-stored energy on localized corrosion evolution in 2A97 Al-Cu-Li alloy,cold working and artificial aging were carried out to produce 2A97 Al-Cu-Li alloys under different thermomechanical conditions.Quasi-in-situ analysis,traditional immersion test and electrochemical measurement were then conducted to examine the corrosion behavior of 2A97 alloys.It is revealed that precipitate significantly affects Cu enrichment at corrosion fronts,which determines corrosion susceptibility of alloys,whereas grain-stored energy distribution is closely associated with localized corrosion propagation.It is also indicated that quasi-in-situ analysis exhibits a consistent corrosion evolution with traditional immersion tests,which is regarded as a proper method to explore localized corrosion mechanisms by providing local microstructural information with enhanced time and spatial resolutions.展开更多
The quasi-static and dynamic tensile behaviors in electron beam welded（EBW） Ti-6Al-4V alloy were investigated at strain rates of 10-3 and 103 s-1,respectively,by materials test system（MTS） and reconstructive Hopki...The quasi-static and dynamic tensile behaviors in electron beam welded（EBW） Ti-6Al-4V alloy were investigated at strain rates of 10-3 and 103 s-1,respectively,by materials test system（MTS） and reconstructive Hopkinson bars apparatus.The microstructures of the base metal（BM） and the welded metal（WM） were observed with optical microscope.The fracture characteristics of the BM and WM were characterized with scanning electronic microscope.In Ti-6Al-4V alloy joint,the flow stress of WM is higher than that of BM,while the fracture strain of WM is less than that of BM at strain rates of 103 and 10-3 s-1,respectively.The fracture strain of WM has apparent improvement when the strain rate rises from 10-3 to 103 s-1,while the fracture strain of BM almost has no change.At the same time,the fracture mode of WM alters from brittle to ductile fracture,which causes improvement of the fracture strain of WM.展开更多
Over the past decade,national standard and industry standard of bio-fertilizer have been gradually established in China. Moreover,the microbial fertilizer standard system with Chinese characteristics has been firstly ...Over the past decade,national standard and industry standard of bio-fertilizer have been gradually established in China. Moreover,the microbial fertilizer standard system with Chinese characteristics has been firstly established by China in the world. Development of bio-fertilizer standard,especially the amplification and modification of bio-fertilizer product standard and the construction of bio-fertilizer standard system,etc. were summarized in this paper. Meanwhile,relative suggestions of existing problems were put forward.展开更多
Inflammatory bowel diseases (IBD) are a heterogeneous group of diseases, not always easy to diagnose, even more difficult to classify, and diagnostic criteria are not always uniform. Well done population-based studies...Inflammatory bowel diseases (IBD) are a heterogeneous group of diseases, not always easy to diagnose, even more difficult to classify, and diagnostic criteria are not always uniform. Well done population-based studies are not abundant, and so comparisons among different geographical areas or populations are not always very reliable. In this article, we have reviewed epidemiological studies available on the world’s population while making a critical review of published data.展开更多
The food standardization statusquo and development trend of developedcountries,such as the U.S.,Canada,Japan,etc.are analyzed and researched in this paper.Some practical and effective measuresthat should be taken in t...The food standardization statusquo and development trend of developedcountries,such as the U.S.,Canada,Japan,etc.are analyzed and researched in this paper.Some practical and effective measuresthat should be taken in the food standardizationof China are advised to promote the expeditiousdevelopment of China's food standardization,to improve food quality and safetyand to increase the international competitionof food industry in China.展开更多
The purpose of this study was to analyze and synthesize a concept of caring in nursing professionals. The Ethnographic Delphi Future Research （EDFR） contained two phases： Phase 1： The analysis and synthesis of the...The purpose of this study was to analyze and synthesize a concept of caring in nursing professionals. The Ethnographic Delphi Future Research （EDFR） contained two phases： Phase 1： The analysis and synthesis of the concept of caring theory in nursing professionals from the literature, research and interviews. The participants were an expert in education, two nurses, two patients and two members of the patients＇ families. The research instrument was a semi-structural questionnaire. The data were analyzed by content analysis and categorized; and Phase 2： The selection of the expressions of caring behavior and guidelines for promotion of caring behavior in new nurses. The participants were two experts in education, eight experts in nursing administration and eight experts in nursing practice. The research instruments were three questionnaires. The data from the first Delphi technique were analyzed by the experts＇ recommendations. The data from the second and third Delphi technique were analyzed by the median and interquartile range of each behavior and consensus. The findings showed the main contents of caring that contained six components as follows： kindness, understanding worth and showing respect, professional relationship, professional competency, professional ethics, and holistic care. The training was a method for promotion of caring behavior. Additionally, in the the first Delphi technique, the experts approved all of the components of caring behavior and the guidelines for promotion of caring behavior as identified in the researchers＇ concepts. However, the researchers＇ concepts were developed 54 caring behaviors while the experts＇ opinion were 50 caring behaviors. In the second and third Delphi technique, all items of caring behaviors get consensus shown by interquartile range not more than 1.5 and the median since 3.5.展开更多
Objective:Cystic lesions of the pancreas have been increasingly recognized.Some lesions exhibit benign behavior,while others have unequivocal malignant potential.Thus,accurate identification of malignancy in patients ...Objective:Cystic lesions of the pancreas have been increasingly recognized.Some lesions exhibit benign behavior,while others have unequivocal malignant potential.Thus,accurate identification of malignancy in patients diagnosed with pancreatic cystic neoplasms(PCNs)remains a major challenge.The aim of this study was to define a combined criterion to better predict malignant lesions in patients with PCNs.Methods:We retrospectively analyzed 165 patients who underwent resection of PCNs from October 2011 to May 2017.The relationship among malignancy and serum carbohydrate antigen 19-9(CA19-9),preoperative neutrophil-to-lymphocyte ratio(NLR),and the presence of enhanced solid component on imaging was analyzed.Results:NLR before surgery in patients with malignant PCNs(2.81±2.14)was significantly higher than that in patients diagnosed with pancreatic neuroendocrine tumor(1.90±0.69,P=0.013)or healthy volunteers(1.40±0.48;P<0.001).Serum CA19-9≥39U/m L,NLR>1.976 and presence of enhanced solid component were independent predictors of PCN malignancy.A combined criterion meeting any two or more of the three elements including CA19-9≥39 U/m L,NLR>1.976,and presence of enhanced solid component on computed tomography imaging is an indicator with a high positive predictive value of 80.5%and a high negative predictive value of 87.9%,and thus,represents a highly accurate test(86.1%).Conclusions:The new combined criterion is an effective predictor of tumor malignancy in patients with PCNs.展开更多
基金supports from the National Natural Science Foundation of China(Nos.52371065,52001128)the Hubei Provincial Natural Science Foundation of China(No.2023AFB637)。
文摘As a promising material in the aircraft industry,2A97 Al-Cu-Li alloy exhibits high corrosion susceptibility that may limit its application.In the present work,to illustrate the influences of precipitate and grain-stored energy on localized corrosion evolution in 2A97 Al-Cu-Li alloy,cold working and artificial aging were carried out to produce 2A97 Al-Cu-Li alloys under different thermomechanical conditions.Quasi-in-situ analysis,traditional immersion test and electrochemical measurement were then conducted to examine the corrosion behavior of 2A97 alloys.It is revealed that precipitate significantly affects Cu enrichment at corrosion fronts,which determines corrosion susceptibility of alloys,whereas grain-stored energy distribution is closely associated with localized corrosion propagation.It is also indicated that quasi-in-situ analysis exhibits a consistent corrosion evolution with traditional immersion tests,which is regarded as a proper method to explore localized corrosion mechanisms by providing local microstructural information with enhanced time and spatial resolutions.
文摘The quasi-static and dynamic tensile behaviors in electron beam welded（EBW） Ti-6Al-4V alloy were investigated at strain rates of 10-3 and 103 s-1,respectively,by materials test system（MTS） and reconstructive Hopkinson bars apparatus.The microstructures of the base metal（BM） and the welded metal（WM） were observed with optical microscope.The fracture characteristics of the BM and WM were characterized with scanning electronic microscope.In Ti-6Al-4V alloy joint,the flow stress of WM is higher than that of BM,while the fracture strain of WM is less than that of BM at strain rates of 103 and 10-3 s-1,respectively.The fracture strain of WM has apparent improvement when the strain rate rises from 10-3 to 103 s-1,while the fracture strain of BM almost has no change.At the same time,the fracture mode of WM alters from brittle to ductile fracture,which causes improvement of the fracture strain of WM.
基金Supported by Guangdong Provincial Science and Technology Project(2007B080401018)~~
文摘Over the past decade,national standard and industry standard of bio-fertilizer have been gradually established in China. Moreover,the microbial fertilizer standard system with Chinese characteristics has been firstly established by China in the world. Development of bio-fertilizer standard,especially the amplification and modification of bio-fertilizer product standard and the construction of bio-fertilizer standard system,etc. were summarized in this paper. Meanwhile,relative suggestions of existing problems were put forward.
文摘Inflammatory bowel diseases (IBD) are a heterogeneous group of diseases, not always easy to diagnose, even more difficult to classify, and diagnostic criteria are not always uniform. Well done population-based studies are not abundant, and so comparisons among different geographical areas or populations are not always very reliable. In this article, we have reviewed epidemiological studies available on the world’s population while making a critical review of published data.
文摘The food standardization statusquo and development trend of developedcountries,such as the U.S.,Canada,Japan,etc.are analyzed and researched in this paper.Some practical and effective measuresthat should be taken in the food standardizationof China are advised to promote the expeditiousdevelopment of China's food standardization,to improve food quality and safetyand to increase the international competitionof food industry in China.
文摘The purpose of this study was to analyze and synthesize a concept of caring in nursing professionals. The Ethnographic Delphi Future Research （EDFR） contained two phases： Phase 1： The analysis and synthesis of the concept of caring theory in nursing professionals from the literature, research and interviews. The participants were an expert in education, two nurses, two patients and two members of the patients＇ families. The research instrument was a semi-structural questionnaire. The data were analyzed by content analysis and categorized; and Phase 2： The selection of the expressions of caring behavior and guidelines for promotion of caring behavior in new nurses. The participants were two experts in education, eight experts in nursing administration and eight experts in nursing practice. The research instruments were three questionnaires. The data from the first Delphi technique were analyzed by the experts＇ recommendations. The data from the second and third Delphi technique were analyzed by the median and interquartile range of each behavior and consensus. The findings showed the main contents of caring that contained six components as follows： kindness, understanding worth and showing respect, professional relationship, professional competency, professional ethics, and holistic care. The training was a method for promotion of caring behavior. Additionally, in the the first Delphi technique, the experts approved all of the components of caring behavior and the guidelines for promotion of caring behavior as identified in the researchers＇ concepts. However, the researchers＇ concepts were developed 54 caring behaviors while the experts＇ opinion were 50 caring behaviors. In the second and third Delphi technique, all items of caring behaviors get consensus shown by interquartile range not more than 1.5 and the median since 3.5.
文摘Objective:Cystic lesions of the pancreas have been increasingly recognized.Some lesions exhibit benign behavior,while others have unequivocal malignant potential.Thus,accurate identification of malignancy in patients diagnosed with pancreatic cystic neoplasms(PCNs)remains a major challenge.The aim of this study was to define a combined criterion to better predict malignant lesions in patients with PCNs.Methods:We retrospectively analyzed 165 patients who underwent resection of PCNs from October 2011 to May 2017.The relationship among malignancy and serum carbohydrate antigen 19-9(CA19-9),preoperative neutrophil-to-lymphocyte ratio(NLR),and the presence of enhanced solid component on imaging was analyzed.Results:NLR before surgery in patients with malignant PCNs(2.81±2.14)was significantly higher than that in patients diagnosed with pancreatic neuroendocrine tumor(1.90±0.69,P=0.013)or healthy volunteers(1.40±0.48;P<0.001).Serum CA19-9≥39U/m L,NLR>1.976 and presence of enhanced solid component were independent predictors of PCN malignancy.A combined criterion meeting any two or more of the three elements including CA19-9≥39 U/m L,NLR>1.976,and presence of enhanced solid component on computed tomography imaging is an indicator with a high positive predictive value of 80.5%and a high negative predictive value of 87.9%,and thus,represents a highly accurate test(86.1%).Conclusions:The new combined criterion is an effective predictor of tumor malignancy in patients with PCNs.
