The performance of engineered wood products is highly associated with proper bonding and an efficient cutting method.This paper investigates the influence of CO_(2) laser cutting on the wetting properties,the modified ch...The performance of engineered wood products is highly associated with proper bonding and an efficient cutting method.This paper investigates the influence of CO_(2) laser cutting on the wetting properties,the modified che-mical component of the laser-cut surface,and the strength and adhesive penetration near the bondline.Beech-wood is cut by the laser with varying processing parameters,cutting speeds,gas pressures,and focal point positions.The laser-cut samples were divided into two groups,sanded and non-sanded samples.Polyvinyl acetate adhesive(PVAc)was used to bond the groups of laser-cut samples.After assembly with cold pressing,the tensile shear test was carried out.Numerical modelling was carried out to determine the partial elongation and shear strain of the glue line.Based on this,the shear modulus and linear elasticity of the glue line were estimated.Scan-ning electron microscopy was used to assess the adhesive penetration into the porosity structure of the laser-cut samples,and the depth of the heat-affected zone.The laser-cut surface was analysed by Fourier transform infrared spectroscopy.The wetting properties of the laser-cut surface were investigated by using a contact angle goni-ometer.The numerical model of the strain-stress curve confirmed the experimental model.The highest modulus of the linear elasticity of the glue in the numerical calculation belongs to the joint containing laser-cut samples at a gas pressure of 21(bar).The penetration depth of PVAc adhesive into the porosity structure of the laser-cut sam-ples was similar to that of sawn samples.The deepest heat-affected zone in the laser-cut samples was 150µm.A PVAc drop disappeared immediately on the laser-cut surface without sanding,but gradually on the sanded surface.In contrast,the drop on the sawn surface remained with an angle of 32°–48°.The degradation of hemi-cellulose and lignin was proven by the lower intensity of the C=O and C-O Bonds,compared to the sawn surface.展开更多
In this paper, the eigen function expansions of displacements and stresses of bi-metal laminates with interface cracks are obtained. Furthermore, the stress intensity factors are determined by the variational method t...In this paper, the eigen function expansions of displacements and stresses of bi-metal laminates with interface cracks are obtained. Furthermore, the stress intensity factors are determined by the variational method to satisfy the boundary conditions and there are only line integrals in the variational equations due to the previous satisfaction of all basic equations. The computations show that this method of solution has the advantages of rapid convergency and time-saving. The results obtained by this method for homogeneous material agree with the known ones very well.展开更多
The use of glued bamboo(GB)in structural engineering is growing interest in the construction industry,as it is a kind of natural material with strong regenerative ability.In addition,the utilizing of GB can reduce the...The use of glued bamboo(GB)in structural engineering is growing interest in the construction industry,as it is a kind of natural material with strong regenerative ability.In addition,the utilizing of GB can reduce the demand for concrete,a possible way to decrease the destruction to natural environment and the consumption of fossil energy.This paper presents a comprehensive analysis on the properties of GB based on the experimental data available in the published researches.Some important physical,mechanical,and chemical properties of GB are discussed.It can be concluded that,at present,more emphasis has been given to study the mechanical property and gluing performance of GB.By analyzing existing research results,this paper provides some recommendations for future research.展开更多
Background:The commonly used intraocular lens(IOL)implantation modalities when there is a rent in a posterior capsule or lack of posterior capsular support includes iris fixated IOL,anterior chamber(AC)IOL,sutured and...Background:The commonly used intraocular lens(IOL)implantation modalities when there is a rent in a posterior capsule or lack of posterior capsular support includes iris fixated IOL,anterior chamber(AC)IOL,sutured and suture less trans-scleral fixated IOL.This work was planned to evaluate the safety and efficacy of trans-scleral glued IOL implantation.Methods:Retrospective study was undertaken with 28 patients of glued IOL fixation,performed by a single surgeon over a period of 4 years.Relevant pre-operative and post-operative data including visual acuity,intraocular pressures,associated ocular conditions and complications were collected and statistically analyzed.Results:The mean age of males in our study group was 39.1±4.6 years and mean age of females were 37.9±7.5 years.Glued IOL was implanted in 13 eyes with traumatic cataract with subluxation of 46.4%.The most common associated ocular condition was found to be a penetrating ocular trauma with corneal tear in three patients(10.6%).The mean pre-operative and post-operative Log MAR acuity was found to be 1.18 and 0.55 respectively,which was found to be statically significant with P value of 0.00.Twenty five out of 28 patients(89%)of the study population had no postoperative complications.Conclusions:Glued IOL implantation technique has 89%of success rate and statistically significant improvement in visual acuity with no significant change in intraocular pressure.展开更多
为探究脯氨酸(Proline,Pro)、谷氨酸(Glutamic Acid,Glu)二肽与鲜味受体分子相互作用,该研究合成了12个Pro、Glu二肽,以感官评价为基础,利用同源建模、分子对接技术研究Pro、Glu二肽与味觉受体第一家族亚型1(Taste Receptor Type 1 Memb...为探究脯氨酸(Proline,Pro)、谷氨酸(Glutamic Acid,Glu)二肽与鲜味受体分子相互作用,该研究合成了12个Pro、Glu二肽,以感官评价为基础,利用同源建模、分子对接技术研究Pro、Glu二肽与味觉受体第一家族亚型1(Taste Receptor Type 1 Member 1,T1R1)、味觉受体第一家族亚型3(Taste Receptor Type 1 Member 3,T1R3)和钙敏感受体(Calcium Sensitive Receptor,CaSR)的构效关系。结果表明:除脯氨酸-丝氨酸(Proline-serine,Pro-Ser)、缬氨酸-脯氨酸(Valine-proline,Val-Pro)和亮氨酸-谷氨酸(Leucine-glutamic Acid,Leu-Glu)不呈鲜,其余二肽的呈鲜阈值均低于谷氨酸钠阈值(0.3 mg/mL),其中γ-谷氨酸-蛋氨酸(γ-Glutamic Acid-methionine,γ-Glu-Met)和甘氨酸-谷氨酸(Glycine-glutamic Acid,Gly-Glu)的呈鲜阈值最低,为0.07 mg/mL。二肽与T1R1的关键结合位点为Asp147、Thr149、Ser172和Arg277,T1R1是Glu二肽呈鲜的重要受体;与T1R3的关键结合位点为Glu45、Ser147、Val277和His278,Ser147是N-γ-Glu二肽与T1R3受体的关键结合位点;与CaSR的关键结合位点为Leu173、Asn176、Gln179、Arg220、Ser244和Asp275,Glu二肽比Pro二肽更易与CaSR受体结合。二肽与受体主要通过氢键与疏水相互作用结合,呈味较强的二肽在对接时多嵌于受体结合口袋深处;呈味较弱的二肽有的位于结合口袋较浅的位置,有的其疏水区或亲水区暴露于受体表面。该研究有助于阐明鲜味肽与鲜味受体相互作用机制,为深入研究鲜味肽呈鲜机理奠定基础。展开更多
文摘The performance of engineered wood products is highly associated with proper bonding and an efficient cutting method.This paper investigates the influence of CO_(2) laser cutting on the wetting properties,the modified che-mical component of the laser-cut surface,and the strength and adhesive penetration near the bondline.Beech-wood is cut by the laser with varying processing parameters,cutting speeds,gas pressures,and focal point positions.The laser-cut samples were divided into two groups,sanded and non-sanded samples.Polyvinyl acetate adhesive(PVAc)was used to bond the groups of laser-cut samples.After assembly with cold pressing,the tensile shear test was carried out.Numerical modelling was carried out to determine the partial elongation and shear strain of the glue line.Based on this,the shear modulus and linear elasticity of the glue line were estimated.Scan-ning electron microscopy was used to assess the adhesive penetration into the porosity structure of the laser-cut samples,and the depth of the heat-affected zone.The laser-cut surface was analysed by Fourier transform infrared spectroscopy.The wetting properties of the laser-cut surface were investigated by using a contact angle goni-ometer.The numerical model of the strain-stress curve confirmed the experimental model.The highest modulus of the linear elasticity of the glue in the numerical calculation belongs to the joint containing laser-cut samples at a gas pressure of 21(bar).The penetration depth of PVAc adhesive into the porosity structure of the laser-cut sam-ples was similar to that of sawn samples.The deepest heat-affected zone in the laser-cut samples was 150µm.A PVAc drop disappeared immediately on the laser-cut surface without sanding,but gradually on the sanded surface.In contrast,the drop on the sawn surface remained with an angle of 32°–48°.The degradation of hemi-cellulose and lignin was proven by the lower intensity of the C=O and C-O Bonds,compared to the sawn surface.
文摘In this paper, the eigen function expansions of displacements and stresses of bi-metal laminates with interface cracks are obtained. Furthermore, the stress intensity factors are determined by the variational method to satisfy the boundary conditions and there are only line integrals in the variational equations due to the previous satisfaction of all basic equations. The computations show that this method of solution has the advantages of rapid convergency and time-saving. The results obtained by this method for homogeneous material agree with the known ones very well.
基金The authors gratefully acknowledge the help and support from Pro.Xiao Yan,International Campus Zhejiang University and Dr.JJ Xu,Nanjing Tech University.
文摘The use of glued bamboo(GB)in structural engineering is growing interest in the construction industry,as it is a kind of natural material with strong regenerative ability.In addition,the utilizing of GB can reduce the demand for concrete,a possible way to decrease the destruction to natural environment and the consumption of fossil energy.This paper presents a comprehensive analysis on the properties of GB based on the experimental data available in the published researches.Some important physical,mechanical,and chemical properties of GB are discussed.It can be concluded that,at present,more emphasis has been given to study the mechanical property and gluing performance of GB.By analyzing existing research results,this paper provides some recommendations for future research.
基金The study was approved by scientific committee and ethical committee clearance of our institution(Ethical approval ID:011/AFEH/2016).
文摘Background:The commonly used intraocular lens(IOL)implantation modalities when there is a rent in a posterior capsule or lack of posterior capsular support includes iris fixated IOL,anterior chamber(AC)IOL,sutured and suture less trans-scleral fixated IOL.This work was planned to evaluate the safety and efficacy of trans-scleral glued IOL implantation.Methods:Retrospective study was undertaken with 28 patients of glued IOL fixation,performed by a single surgeon over a period of 4 years.Relevant pre-operative and post-operative data including visual acuity,intraocular pressures,associated ocular conditions and complications were collected and statistically analyzed.Results:The mean age of males in our study group was 39.1±4.6 years and mean age of females were 37.9±7.5 years.Glued IOL was implanted in 13 eyes with traumatic cataract with subluxation of 46.4%.The most common associated ocular condition was found to be a penetrating ocular trauma with corneal tear in three patients(10.6%).The mean pre-operative and post-operative Log MAR acuity was found to be 1.18 and 0.55 respectively,which was found to be statically significant with P value of 0.00.Twenty five out of 28 patients(89%)of the study population had no postoperative complications.Conclusions:Glued IOL implantation technique has 89%of success rate and statistically significant improvement in visual acuity with no significant change in intraocular pressure.
文摘为探究脯氨酸(Proline,Pro)、谷氨酸(Glutamic Acid,Glu)二肽与鲜味受体分子相互作用,该研究合成了12个Pro、Glu二肽,以感官评价为基础,利用同源建模、分子对接技术研究Pro、Glu二肽与味觉受体第一家族亚型1(Taste Receptor Type 1 Member 1,T1R1)、味觉受体第一家族亚型3(Taste Receptor Type 1 Member 3,T1R3)和钙敏感受体(Calcium Sensitive Receptor,CaSR)的构效关系。结果表明:除脯氨酸-丝氨酸(Proline-serine,Pro-Ser)、缬氨酸-脯氨酸(Valine-proline,Val-Pro)和亮氨酸-谷氨酸(Leucine-glutamic Acid,Leu-Glu)不呈鲜,其余二肽的呈鲜阈值均低于谷氨酸钠阈值(0.3 mg/mL),其中γ-谷氨酸-蛋氨酸(γ-Glutamic Acid-methionine,γ-Glu-Met)和甘氨酸-谷氨酸(Glycine-glutamic Acid,Gly-Glu)的呈鲜阈值最低,为0.07 mg/mL。二肽与T1R1的关键结合位点为Asp147、Thr149、Ser172和Arg277,T1R1是Glu二肽呈鲜的重要受体;与T1R3的关键结合位点为Glu45、Ser147、Val277和His278,Ser147是N-γ-Glu二肽与T1R3受体的关键结合位点;与CaSR的关键结合位点为Leu173、Asn176、Gln179、Arg220、Ser244和Asp275,Glu二肽比Pro二肽更易与CaSR受体结合。二肽与受体主要通过氢键与疏水相互作用结合,呈味较强的二肽在对接时多嵌于受体结合口袋深处;呈味较弱的二肽有的位于结合口袋较浅的位置,有的其疏水区或亲水区暴露于受体表面。该研究有助于阐明鲜味肽与鲜味受体相互作用机制,为深入研究鲜味肽呈鲜机理奠定基础。
