Novel self cross-linking fluorinated acrylic latex（SCLFAL） has been successfully prepared via starved seeded semi-batch emulsion polymerization.The resultant SCLFAL is characterized by Fourier transform infrared（F...Novel self cross-linking fluorinated acrylic latex（SCLFAL） has been successfully prepared via starved seeded semi-batch emulsion polymerization.The resultant SCLFAL is characterized by Fourier transform infrared（FTIR） spectrometry.Contact angle （CA） and glass transition temperature（T_g） of the film are investigated.Results show that CA and T_g of the film can be improved when the moderate amount of HPMA is introduced into the mixed monomers.展开更多
In order to understand molecular basis of cross-fertilized kernel advantage and heterosis, improved differential display of mRNA was used in this study to analyze alterations in gene expression between cross-fertili...In order to understand molecular basis of cross-fertilized kernel advantage and heterosis, improved differential display of mRNA was used in this study to analyze alterations in gene expression between cross-fertilized and self-fertilized kernels at 2, 4, 6, 8, 10 and 12 days after pollination (DAP) by using 3 wheat hybrids with different level of heterosis. Four patterns of differential expression were observed: (i) bands observed in cross-fertilized kernels but not in self-fertilized kernels (BCnS); (ii) bands occurring in only self-fertilized kernels but not in cross-fertilized kernels (BSnC); (iii) cDNA over-expressed in cross-fertilized kernels compared to self-fertilized kernels (OEC); (iv) cDNA under-expressed in cross-fertilized kernels compared to self-fertilized kernels (UEC). Further analysis showed that BCnS is positively correlated with heterosis, but BSnC is negatively correlated with heterosis. Four differentially expressed cDNA fragments were verified by reverse-northern blot and sequence homology search in GenBank showed that one of them was new sequences; the other exhibited higher similarity to NBS-LRR type resistance protein, 1,6-bisphosphatase and photosystem Ⅱ chlorophyll a-binding protein psbB, respectively, which indicated diverse pathways may be involved in heterosis formation.展开更多
Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the u...Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.展开更多
Self-medication may be associated with side effects and increases the chance of drug interactions and also affects the adherence to treatment and quality of life. This study aims at determining the pattern of self-med...Self-medication may be associated with side effects and increases the chance of drug interactions and also affects the adherence to treatment and quality of life. This study aims at determining the pattern of self-medication, identifying knowledge, attitude and self-reported practices concerning the usage of the drugs and identifying demographic factors that could influence self-medication practices among the general population in El-Minia, Egypt. A community-based cross-sectional study was conducted among 422 randomly selected adults using a multi-stage random sampling technique. Data were collected by using a structured interview questionnaire. Respondents who had practiced some sort of self-medication during the past month were 73% of the sample. The commonest cause of self-medication, illness, was perceived as minor (59.7%). The most common perceived illness for self-medication was common cold (90.6%). Older respondents (>40 years) were about twice more likely to practice self-medication than younger ones. Similarly, professionals in their work were 3.4 times more likely to practice self-medication than unemployed individuals. Self-medication is a relatively frequent problem in Minia and interventions at different levels are required.展开更多
The self-assembly behavior of the amphiphilic block copolymer poly（ methyl methacrylate） -block-poly（ lead dimethacrylate） （PMMA-b-PLDMA） with cross-linked hydrophilic block（PLDMA） in ethanol was investigated....The self-assembly behavior of the amphiphilic block copolymer poly（ methyl methacrylate） -block-poly（ lead dimethacrylate） （PMMA-b-PLDMA） with cross-linked hydrophilic block（PLDMA） in ethanol was investigated. The results show that the size and morphology of the resulting micelle or micellar aggregates are ascribed to the content of ethanol and the nature of the solvent mixture. PbS nanoparticles were formed in the micelle by in situ reaction with H2S gas. The morphology and size of the self-assembly objects were investigated using scanning electron microscopy （SEM） and transmission electron microscopy（TEM）.展开更多
The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone t...The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.展开更多
基金supported by the Science and Technology Department of Zhejiang Province under Grant No. 2010C31040.In additionthe financial support of Zhejiang Provincial Natural Science Foundation of China(No. Y4100152)
文摘Novel self cross-linking fluorinated acrylic latex（SCLFAL） has been successfully prepared via starved seeded semi-batch emulsion polymerization.The resultant SCLFAL is characterized by Fourier transform infrared（FTIR） spectrometry.Contact angle （CA） and glass transition temperature（T_g） of the film are investigated.Results show that CA and T_g of the film can be improved when the moderate amount of HPMA is introduced into the mixed monomers.
基金This work was supported by the State Key Basic Research and Development Plan of China(2001CB1088)the National Science Fund for Distinguished Young Scholars(39925026)the National Natural Science Foundation of China(30270824).
文摘In order to understand molecular basis of cross-fertilized kernel advantage and heterosis, improved differential display of mRNA was used in this study to analyze alterations in gene expression between cross-fertilized and self-fertilized kernels at 2, 4, 6, 8, 10 and 12 days after pollination (DAP) by using 3 wheat hybrids with different level of heterosis. Four patterns of differential expression were observed: (i) bands observed in cross-fertilized kernels but not in self-fertilized kernels (BCnS); (ii) bands occurring in only self-fertilized kernels but not in cross-fertilized kernels (BSnC); (iii) cDNA over-expressed in cross-fertilized kernels compared to self-fertilized kernels (OEC); (iv) cDNA under-expressed in cross-fertilized kernels compared to self-fertilized kernels (UEC). Further analysis showed that BCnS is positively correlated with heterosis, but BSnC is negatively correlated with heterosis. Four differentially expressed cDNA fragments were verified by reverse-northern blot and sequence homology search in GenBank showed that one of them was new sequences; the other exhibited higher similarity to NBS-LRR type resistance protein, 1,6-bisphosphatase and photosystem Ⅱ chlorophyll a-binding protein psbB, respectively, which indicated diverse pathways may be involved in heterosis formation.
基金Supported by National Natural Science Foundation of China(No.0 5 1730 0 3) Beijing Science and Technology New StarProgram(No.H0 10 4 10 0 10 112 ) and Important Natural Science Foundation of Beijing(No.2 0 310 0 1) .
文摘Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.
文摘Self-medication may be associated with side effects and increases the chance of drug interactions and also affects the adherence to treatment and quality of life. This study aims at determining the pattern of self-medication, identifying knowledge, attitude and self-reported practices concerning the usage of the drugs and identifying demographic factors that could influence self-medication practices among the general population in El-Minia, Egypt. A community-based cross-sectional study was conducted among 422 randomly selected adults using a multi-stage random sampling technique. Data were collected by using a structured interview questionnaire. Respondents who had practiced some sort of self-medication during the past month were 73% of the sample. The commonest cause of self-medication, illness, was perceived as minor (59.7%). The most common perceived illness for self-medication was common cold (90.6%). Older respondents (>40 years) were about twice more likely to practice self-medication than younger ones. Similarly, professionals in their work were 3.4 times more likely to practice self-medication than unemployed individuals. Self-medication is a relatively frequent problem in Minia and interventions at different levels are required.
基金Suppored by the National Natural Science Foundation of China ( Nos 20374024 and 20534040) and the Program forChangjiang Scholars and Innovative Research Team in Universities(No IRT0422)
文摘The self-assembly behavior of the amphiphilic block copolymer poly（ methyl methacrylate） -block-poly（ lead dimethacrylate） （PMMA-b-PLDMA） with cross-linked hydrophilic block（PLDMA） in ethanol was investigated. The results show that the size and morphology of the resulting micelle or micellar aggregates are ascribed to the content of ethanol and the nature of the solvent mixture. PbS nanoparticles were formed in the micelle by in situ reaction with H2S gas. The morphology and size of the self-assembly objects were investigated using scanning electron microscopy （SEM） and transmission electron microscopy（TEM）.
基金financially supported by the Director Fund of National Energy Deepwater Oil and Gas Engineering Technology Research and Development Center(Grant No.KJQZ-2024-2103)。
文摘The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.
