BACKGROUND Laparoscopic low anterior resection(LLAR)has become a mainstream surgical method for the treatment of colorectal cancer,which has shown many advantages in the aspects of surgical trauma and postoperative re...BACKGROUND Laparoscopic low anterior resection(LLAR)has become a mainstream surgical method for the treatment of colorectal cancer,which has shown many advantages in the aspects of surgical trauma and postoperative rehabilitation.However,the effect of surgery on patients'left coronary artery and its vascular reconstruction have not been deeply discussed.With the development of medical imaging technology,3D vascular reconstruction has become an effective means to evaluate the curative effect of surgery.AIM To investigate the clinical value of preoperative 3D vascular reconstruction in LLAR of rectal cancer with the left colic artery(LCA)preserved.METHODS A retrospective cohort study was performed to analyze the clinical data of 146 patients who underwent LLAR for rectal cancer with LCA preservation from January to December 2023 in our hospital.All patients underwent LLAR of rectal cancer with the LCA preserved,and the intraoperative and postoperative data were complete.The patients were divided into a reconstruction group(72 patients)and a nonreconstruction group(74 patients)according to whether 3D vascular reconstruction was performed before surgery.The clinical features,operation conditions,complications,pathological results and postoperative recovery of the two groups were collected and compared.RESULTS A total of 146 patients with rectal cancer were included in the study,including 72 patients in the reconstruction group and 74 patients in the nonreconstruction group.There were 47 males and 25 females in the reconstruction group,aged(59.75±6.2)years,with a body mass index(BMI)(24.1±2.2)kg/m^(2),and 51 males and 23 females in the nonreconstruction group,aged(58.77±6.1)years,with a BMI(23.6±2.7)kg/m^(2).There was no significant difference in the baseline data between the two groups(P>0.05).In the submesenteric artery reconstruction group,35 patients were type Ⅰ,25 patients were type Ⅱ,11 patients were type Ⅲ,and 1 patient was type Ⅳ.There were 37 type Ⅰ patients,24 type Ⅱ patients,12 type Ⅲ patients,and 1 type Ⅳ patient in the nonreconstruction group.There was no significant difference in arterial typing between the two groups(P>0.05).The operation time of the reconstruction group was 162.2±10.8 min,and that of the nonreconstruction group was 197.9±19.1 min.Compared with that of the reconstruction group,the operation time of the two groups was shorter,and the difference was statistically significant(t=13.840,P<0.05).The amount of intraoperative blood loss was 30.4±20.0 mL in the reconstruction group and 61.2±26.4 mL in the nonreconstruction group.The amount of blood loss in the reconstruction group was less than that in the control group,and the difference was statistically significant(t=-7.930,P<0.05).The rates of anastomotic leakage(1.4%vs 1.4%,P=0.984),anastomotic hemorrhage(2.8%vs 4.1%,P=0.672),and postoperative hospital stay(6.8±0.7 d vs 7.0±0.7 d,P=0.141)were not significantly different between the two groups.CONCLUSION Preoperative 3D vascular reconstruction technology can shorten the operation time and reduce the amount of intraoperative blood loss.Preoperative 3D vascular reconstruction is recommended to provide an intraoperative reference for laparoscopic low anterior resection with LCA preservation.展开更多
Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene(UHMWPE)products.Typically,high stretch and shear flow fields are necessary for the formation of shish c...Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene(UHMWPE)products.Typically,high stretch and shear flow fields are necessary for the formation of shish crystals.In this study,UHMWPE gel films with reserved shish crystals were prepared by gel molding,the structural evolution and properties of UHMWPE films stretched at temperatu res of 100,110,120and 130℃were investigated by in situ small-angle X-ray scattering(SAXS)/ultra-small-angle X-ray scattering(USAXS)/wide-angle X-ray diffraction(WAXD)measu rements as well as scanning electron microscopy(SEM)and differential scanning calorimetry(DSC)measurements.Our findings showed that the reserved shish crystals can facilitate the formation and structural evolution of shish-kebab crystals during the hot stretching.Additionally,the reserved shish crystals promote the structu ral evolution of UHMWPE films to a greater extent when stretched at 120 and 130℃,compared to 100 and 110℃,resulting in higher crystallinity,orientation,thermal properties,breaking strength and Young's modulus.Com pared to UHMWPE high-entangled films with reserved shish crystals prepared by compression molding,UHMWPE low-entangled films with reserved shish crystals prepared by gel molding are more effective in inducing the formation and evolution of shish-kebab crystals during the hot stretching,resulting in increased breaking strength and Young's modulus.展开更多
Polyglycolide (PGA) fibers applied as surgical sutures strongly depend on their microstructure. The structural evolution of PGA nascent fibers during single low-temperature stretching and segmented high-temperature st...Polyglycolide (PGA) fibers applied as surgical sutures strongly depend on their microstructure. The structural evolution of PGA nascent fibers during single low-temperature stretching and segmented high-temperature stretching was analyzed based on a combination of in situ WAXD/SAXS and DSC measurements. The results indicated that the hot stretching was conducive to the crystal perfection and the local fragmentation and recrystallization of the lamellar crystals may occur under stress induction. The single low-temperature stretching of PGA nascent fibers could be divided into three stages: the stretching of amorphous regions, stretch-induced crystallization and the stretching of crystalline regions. The elongation at break of the fibers can be substantially increased by adopting a segmented stretching method, and the high-temperature stretching can also significantly increase the crystallinity and orientation. The amorphous orientation peak appearing in the low-temperature stretching was gradually converted to crystallization peak during the heating process, which greatly improved the crystallinity and orientation of the fibers. High-temperature stretching compared with low-temperature stretching was more favorable for crystal perfection and structural evolution, where lamellar crystals underwent stress-induced fragmentation recrystallization to transform to fibrous crystals as the strain increased.展开更多
Biodegradable poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （PHBV）/graphene nanosheet （GNS） composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscop...Biodegradable poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （PHBV）/graphene nanosheet （GNS） composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscopy revealed that a fine dispersion of GNSs was achieved in the PHBV matrix. The thermal properties of the nanocomposites were investigated by thermogravimetric analysis, and the results showed that the thermal stability of PHBV was significantly improved with a very low loading of GNSs. Nonisothermal melts crystallization behavior, spherulitic morphology and crystal structure of neat PHBV and the PHBV/GNSs nanocomposites were investigated, and the experimental results indicated that crystallization behavior of PHBV was enhanced by the presence of GNSs due to the heterogeneous nucleation effect; however, the two-dimensional （2D） GNSs might restrict the mobility of the PHBV chains in the process of crystal growing. Dynamic mechanical analysis studies showed that the storage modulus of the PHBV/GNSs nanocomposites was greatly improved.展开更多
Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was investigated.In situ small-angle X-ray scattering(SAXS)and ...Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was investigated.In situ small-angle X-ray scattering(SAXS)and wide-angle X-ray diffraction(WAXD)techniques were used to monitor the formation and evolution of shish-kebab structure sheared at low temperature in simple shear mode and low rate.Only the bimodal PE with no branch formed shish-kebab crystals at the shear temperature of 129℃,and the shish length increased with the crystallization time,while bimodal PE with branch has no observable shish under the same conditions.The degree of crystallization for bimodal PE with no branch increased with time up to above 7%,while those with ethyl branch increased continually up to above 23%.Furthermore,bimodal PE's Hermans orientation factor with no branch increased to 0.60,while those with ethyl branch only increased to a value below 0.15.This study indicated that the shish-kebab crystal formed at the low temperature of 129℃is due to the stretch of entangled chains under shear for the bimodal PE with no branch.Only partly oriented lamellar crystals were formed for the bimodal PE with ethyl branch.All the results at the shear temperatures higher,closed to,and lower than the melting point,the modulation of shish crystals formation owing to different mechanisms of the coil-stretch transition and the stretched network by changing shear temperature was achieved in the bimodal PE samples.展开更多
The correlation between ring-opening polymerization （ROP） of cyclic butylene terephthalate （CBT） and crystallization of polymerized CBT （pCBT） strongly affected the final properties of pCBT and its composites. T...The correlation between ring-opening polymerization （ROP） of cyclic butylene terephthalate （CBT） and crystallization of polymerized CBT （pCBT） strongly affected the final properties of pCBT and its composites. The major objective of this contribution is to pinpoint the threshold temperature between them and the interrelation is successfully disclosed. That is, crystallization during polymerization occurs below 204 ℃ and the crystallization properties of pCBT are determined by this isothermal ROP stage; polymerization and crystallization are gradually separated with the increase of temperature of ROP （Tp） from 204 ℃, and the crystallization properties of pCBT are dominated by cooling stage; only polymerization is performed above 212 ℃. Moreover, quantitative analysis suggests that uniform crystal size distributions and thicker lamellar crystals derive from the stage of crystallization during polymerization. On the contrary, the crystal size distributions become wider above 204 ℃ of Tp and lead to obvious double melting peaks during heating scan. These efforts provide a very useful guide for the related investigation and application of CBT.展开更多
Subgrade construction is frequently interrupted due to precipitation,soil shortage,and environmental protection.Therefore,increasing the thickness layer is required to reduce construction costs and to allow highways t...Subgrade construction is frequently interrupted due to precipitation,soil shortage,and environmental protection.Therefore,increasing the thickness layer is required to reduce construction costs and to allow highways to be placed into service earlier.This paper presents a series of full-scale field experiments evaluating the compaction quality of gravel subgrade with large-thickness layers of 65 cm and 80 cm using heavy vibratory rollers.An improved sand cone method was first proposed and calibrated to investigate the distribution of soil compaction degree across the full subgrade depth.Results showed that dynamic soil stresses caused by the heavy vibratory rollers were 2.4–5.9 times larger than those of traditional rollers,especially at deeper depths,which were large enough to densify the soils to the full depth.A unified empirical formula was proposed to determine the vertical distribution of dynamic soil stresses caused by roller excitation.It was demonstrated that soils were effectively compacted in a uniform fashion with respect to the full depth to 96.0%–97.2%and 94.1%–95.4%for the large-thickness layers of 65 cm and 80 cm within 6 or 7 passes,respectively.Empirically,linear formulae were finally established between soil compaction degree and the subgrade reaction modulus,dynamic modulus of deformation,dynamic deflection,and relative difference of settlement to conveniently evaluate the compaction qualities.It is demonstrated that increasing the thickness layer by means of heavy rollers can significantly reduce the cost and time burdens involved in construction while ensuring overall subgrade quality.展开更多
The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed...The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed by differential scanning calorimetry(DSC),and the evolutions of crystal structure and lamellar morphology in the heating and melting process were tracked by in situ synchrotron wide angle X-ray diffraction(WAXD)and small angle X-ray scattering(SAXS)techniques.The emergence of asymmetric features of both the diffraction peaks and scattering curves indicates the coexistence of different lamellar crystals with varied unit cell parameters.Based on the in situ WAXD and SAXS measurements,we calculated the evolutions of the unit cell parameters a and b as well as the long period and lamellar thickness upon heating.The comparative analysis of WAXD and SAXS data confirms that the multiple endothermic peaks of P(HB-co-19.4%HV)and P(HB-co-28.7%HV)result from the melting of different lamellae rather than the melting/recrystallization.The thinner,unstable uniform lamellae with HV counits total inclusion melt first and the thicker,stable sandwich lamellae with HV counits partial inclusion melt last.In addition,the large second melting peak in P(H B-co-19.4%HV),differing from that of samples with HV content of 28.7 mol%and 36.2 mol%,is due to the unique state of HV content leading to a transition of sandwich lamellae to uniform lamellae.The present study establishes the relationship between the different lamellae structure and multiple melting behaviors of isomorphous copolymer.展开更多
文摘BACKGROUND Laparoscopic low anterior resection(LLAR)has become a mainstream surgical method for the treatment of colorectal cancer,which has shown many advantages in the aspects of surgical trauma and postoperative rehabilitation.However,the effect of surgery on patients'left coronary artery and its vascular reconstruction have not been deeply discussed.With the development of medical imaging technology,3D vascular reconstruction has become an effective means to evaluate the curative effect of surgery.AIM To investigate the clinical value of preoperative 3D vascular reconstruction in LLAR of rectal cancer with the left colic artery(LCA)preserved.METHODS A retrospective cohort study was performed to analyze the clinical data of 146 patients who underwent LLAR for rectal cancer with LCA preservation from January to December 2023 in our hospital.All patients underwent LLAR of rectal cancer with the LCA preserved,and the intraoperative and postoperative data were complete.The patients were divided into a reconstruction group(72 patients)and a nonreconstruction group(74 patients)according to whether 3D vascular reconstruction was performed before surgery.The clinical features,operation conditions,complications,pathological results and postoperative recovery of the two groups were collected and compared.RESULTS A total of 146 patients with rectal cancer were included in the study,including 72 patients in the reconstruction group and 74 patients in the nonreconstruction group.There were 47 males and 25 females in the reconstruction group,aged(59.75±6.2)years,with a body mass index(BMI)(24.1±2.2)kg/m^(2),and 51 males and 23 females in the nonreconstruction group,aged(58.77±6.1)years,with a BMI(23.6±2.7)kg/m^(2).There was no significant difference in the baseline data between the two groups(P>0.05).In the submesenteric artery reconstruction group,35 patients were type Ⅰ,25 patients were type Ⅱ,11 patients were type Ⅲ,and 1 patient was type Ⅳ.There were 37 type Ⅰ patients,24 type Ⅱ patients,12 type Ⅲ patients,and 1 type Ⅳ patient in the nonreconstruction group.There was no significant difference in arterial typing between the two groups(P>0.05).The operation time of the reconstruction group was 162.2±10.8 min,and that of the nonreconstruction group was 197.9±19.1 min.Compared with that of the reconstruction group,the operation time of the two groups was shorter,and the difference was statistically significant(t=13.840,P<0.05).The amount of intraoperative blood loss was 30.4±20.0 mL in the reconstruction group and 61.2±26.4 mL in the nonreconstruction group.The amount of blood loss in the reconstruction group was less than that in the control group,and the difference was statistically significant(t=-7.930,P<0.05).The rates of anastomotic leakage(1.4%vs 1.4%,P=0.984),anastomotic hemorrhage(2.8%vs 4.1%,P=0.672),and postoperative hospital stay(6.8±0.7 d vs 7.0±0.7 d,P=0.141)were not significantly different between the two groups.CONCLUSION Preoperative 3D vascular reconstruction technology can shorten the operation time and reduce the amount of intraoperative blood loss.Preoperative 3D vascular reconstruction is recommended to provide an intraoperative reference for laparoscopic low anterior resection with LCA preservation.
基金financially supported by the National Natural Science Foundation of China(Nos.52173021 and 52373038)Key Research and Development Programme of Zhejiang Province(No.2023C01209)S&T Innovation 2025 Major Special Programme of Ningbo(No.2023Z079)。
文摘Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene(UHMWPE)products.Typically,high stretch and shear flow fields are necessary for the formation of shish crystals.In this study,UHMWPE gel films with reserved shish crystals were prepared by gel molding,the structural evolution and properties of UHMWPE films stretched at temperatu res of 100,110,120and 130℃were investigated by in situ small-angle X-ray scattering(SAXS)/ultra-small-angle X-ray scattering(USAXS)/wide-angle X-ray diffraction(WAXD)measu rements as well as scanning electron microscopy(SEM)and differential scanning calorimetry(DSC)measurements.Our findings showed that the reserved shish crystals can facilitate the formation and structural evolution of shish-kebab crystals during the hot stretching.Additionally,the reserved shish crystals promote the structu ral evolution of UHMWPE films to a greater extent when stretched at 120 and 130℃,compared to 100 and 110℃,resulting in higher crystallinity,orientation,thermal properties,breaking strength and Young's modulus.Com pared to UHMWPE high-entangled films with reserved shish crystals prepared by compression molding,UHMWPE low-entangled films with reserved shish crystals prepared by gel molding are more effective in inducing the formation and evolution of shish-kebab crystals during the hot stretching,resulting in increased breaking strength and Young's modulus.
基金financially supported by the National Natural Science Foundation of China (Nos. 51973097 and 52173021)the Open Fund of State Key Laboratory of Biobased Fiber Manufacturing Technology (No. SKL202207)
文摘Polyglycolide (PGA) fibers applied as surgical sutures strongly depend on their microstructure. The structural evolution of PGA nascent fibers during single low-temperature stretching and segmented high-temperature stretching was analyzed based on a combination of in situ WAXD/SAXS and DSC measurements. The results indicated that the hot stretching was conducive to the crystal perfection and the local fragmentation and recrystallization of the lamellar crystals may occur under stress induction. The single low-temperature stretching of PGA nascent fibers could be divided into three stages: the stretching of amorphous regions, stretch-induced crystallization and the stretching of crystalline regions. The elongation at break of the fibers can be substantially increased by adopting a segmented stretching method, and the high-temperature stretching can also significantly increase the crystallinity and orientation. The amorphous orientation peak appearing in the low-temperature stretching was gradually converted to crystallization peak during the heating process, which greatly improved the crystallinity and orientation of the fibers. High-temperature stretching compared with low-temperature stretching was more favorable for crystal perfection and structural evolution, where lamellar crystals underwent stress-induced fragmentation recrystallization to transform to fibrous crystals as the strain increased.
基金supported by the Ningbo Natural Science Foundation (Nos. 2010A610193 and 2011A610116)the Program for Ningbo Innovative Research Team (2009B21008)the Ningbo Key Lab of Polymer Materials(No. 2010A22001)
文摘Biodegradable poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （PHBV）/graphene nanosheet （GNS） composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscopy revealed that a fine dispersion of GNSs was achieved in the PHBV matrix. The thermal properties of the nanocomposites were investigated by thermogravimetric analysis, and the results showed that the thermal stability of PHBV was significantly improved with a very low loading of GNSs. Nonisothermal melts crystallization behavior, spherulitic morphology and crystal structure of neat PHBV and the PHBV/GNSs nanocomposites were investigated, and the experimental results indicated that crystallization behavior of PHBV was enhanced by the presence of GNSs due to the heterogeneous nucleation effect; however, the two-dimensional （2D） GNSs might restrict the mobility of the PHBV chains in the process of crystal growing. Dynamic mechanical analysis studies showed that the storage modulus of the PHBV/GNSs nanocomposites was greatly improved.
基金the National Natural Science Foundation of China(Nos.51773101 and 51973097).
文摘Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was investigated.In situ small-angle X-ray scattering(SAXS)and wide-angle X-ray diffraction(WAXD)techniques were used to monitor the formation and evolution of shish-kebab structure sheared at low temperature in simple shear mode and low rate.Only the bimodal PE with no branch formed shish-kebab crystals at the shear temperature of 129℃,and the shish length increased with the crystallization time,while bimodal PE with branch has no observable shish under the same conditions.The degree of crystallization for bimodal PE with no branch increased with time up to above 7%,while those with ethyl branch increased continually up to above 23%.Furthermore,bimodal PE's Hermans orientation factor with no branch increased to 0.60,while those with ethyl branch only increased to a value below 0.15.This study indicated that the shish-kebab crystal formed at the low temperature of 129℃is due to the stretch of entangled chains under shear for the bimodal PE with no branch.Only partly oriented lamellar crystals were formed for the bimodal PE with ethyl branch.All the results at the shear temperatures higher,closed to,and lower than the melting point,the modulation of shish crystals formation owing to different mechanisms of the coil-stretch transition and the stretched network by changing shear temperature was achieved in the bimodal PE samples.
基金financially supported by the National Natural Science Foundation of China(No.21364004)Gansu Province University Fundamental Research FundsDoctor Research Fund of Lanzhou University of Technology,China
文摘The correlation between ring-opening polymerization （ROP） of cyclic butylene terephthalate （CBT） and crystallization of polymerized CBT （pCBT） strongly affected the final properties of pCBT and its composites. The major objective of this contribution is to pinpoint the threshold temperature between them and the interrelation is successfully disclosed. That is, crystallization during polymerization occurs below 204 ℃ and the crystallization properties of pCBT are determined by this isothermal ROP stage; polymerization and crystallization are gradually separated with the increase of temperature of ROP （Tp） from 204 ℃, and the crystallization properties of pCBT are dominated by cooling stage; only polymerization is performed above 212 ℃. Moreover, quantitative analysis suggests that uniform crystal size distributions and thicker lamellar crystals derive from the stage of crystallization during polymerization. On the contrary, the crystal size distributions become wider above 204 ℃ of Tp and lead to obvious double melting peaks during heating scan. These efforts provide a very useful guide for the related investigation and application of CBT.
基金the National Natural Science Foundation for Young Scientists of China(No.51608306)the Shandong Provincial Natural Science Foundation of China(Nos.ZR2021ME103 and ZR2021QE254)+1 种基金the Shandong Transportation Science and Technology Foundation(Nos.2020-MS1-044,2021B63,and 202060804178)the Young Scholar Future Plan Funds of Shandong University,China。
文摘Subgrade construction is frequently interrupted due to precipitation,soil shortage,and environmental protection.Therefore,increasing the thickness layer is required to reduce construction costs and to allow highways to be placed into service earlier.This paper presents a series of full-scale field experiments evaluating the compaction quality of gravel subgrade with large-thickness layers of 65 cm and 80 cm using heavy vibratory rollers.An improved sand cone method was first proposed and calibrated to investigate the distribution of soil compaction degree across the full subgrade depth.Results showed that dynamic soil stresses caused by the heavy vibratory rollers were 2.4–5.9 times larger than those of traditional rollers,especially at deeper depths,which were large enough to densify the soils to the full depth.A unified empirical formula was proposed to determine the vertical distribution of dynamic soil stresses caused by roller excitation.It was demonstrated that soils were effectively compacted in a uniform fashion with respect to the full depth to 96.0%–97.2%and 94.1%–95.4%for the large-thickness layers of 65 cm and 80 cm within 6 or 7 passes,respectively.Empirically,linear formulae were finally established between soil compaction degree and the subgrade reaction modulus,dynamic modulus of deformation,dynamic deflection,and relative difference of settlement to conveniently evaluate the compaction qualities.It is demonstrated that increasing the thickness layer by means of heavy rollers can significantly reduce the cost and time burdens involved in construction while ensuring overall subgrade quality.
基金the National Natural Science Foundation of China(Nos.51973097 and 51773101).
文摘The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed by differential scanning calorimetry(DSC),and the evolutions of crystal structure and lamellar morphology in the heating and melting process were tracked by in situ synchrotron wide angle X-ray diffraction(WAXD)and small angle X-ray scattering(SAXS)techniques.The emergence of asymmetric features of both the diffraction peaks and scattering curves indicates the coexistence of different lamellar crystals with varied unit cell parameters.Based on the in situ WAXD and SAXS measurements,we calculated the evolutions of the unit cell parameters a and b as well as the long period and lamellar thickness upon heating.The comparative analysis of WAXD and SAXS data confirms that the multiple endothermic peaks of P(HB-co-19.4%HV)and P(HB-co-28.7%HV)result from the melting of different lamellae rather than the melting/recrystallization.The thinner,unstable uniform lamellae with HV counits total inclusion melt first and the thicker,stable sandwich lamellae with HV counits partial inclusion melt last.In addition,the large second melting peak in P(H B-co-19.4%HV),differing from that of samples with HV content of 28.7 mol%and 36.2 mol%,is due to the unique state of HV content leading to a transition of sandwich lamellae to uniform lamellae.The present study establishes the relationship between the different lamellae structure and multiple melting behaviors of isomorphous copolymer.
