The energy-conserving performance of dividing wall column(DWC) is discussed in this paper. The heat transfer through the dividing wall is considered and the results are compared with that of common heat insulation div...The energy-conserving performance of dividing wall column(DWC) is discussed in this paper. The heat transfer through the dividing wall is considered and the results are compared with that of common heat insulation dividing wall column(HIDWC). Based on the thermodynamic analysis of heat transfer dividing wall column(HTDWC) and HIDWC, both computer simulation and experiments are employed to analyze the energyconserving situation. Mixtures of n-hexane, n-heptane and n-octane are chosen as the example for separation.The results show that the energy consumption of HTDWC is 50.3% less than that of conventional distillation column, while it is 46.4% less than that of HIDWC. It indicates that DWC is efficient on separating threecomponent mixtures and HTDWC can save more energy than HIDWC. Thus it is necessary to consider the heat transfer while applying DWC to industry.展开更多
For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the war...For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.展开更多
A three-node triangular element fitted to numerical manifold method with continuous nodal stress, called Trig_3-CNS(NMM)element, was recently proposed for linear elastic continuous problems and linear elastic simple c...A three-node triangular element fitted to numerical manifold method with continuous nodal stress, called Trig_3-CNS(NMM)element, was recently proposed for linear elastic continuous problems and linear elastic simple crack problems. The Trig_3-CNS(NMM) element can be considered as a development of both the Trig_3-CNS element and the numerical manifold method(NMM).Inheriting all the advantages of Trig_3-CNS element, calculations using Trig_3-CNS(NMM) element can obtain higher accuracy than Trig_3 element without extra degrees of freedom(DOFs) and yield continuous nodal stress without stress smoothing. Inheriting all the advantages of NMM, Trig_3-CNS(NMM) element can conveniently treat crack problems without deploying conforming mathematical mesh. In this paper,complex problems such as a crucifix crack and a star-shaped crack with many branches are studied to exhibit the advantageous features of the Trig_3-CNS(NMM) element. Numerical results show that the Trig_3-CNS(NMM) element is prominent in modeling complex crack problems.展开更多
Objective:To construct a novel non-viral vector loaded with growth and differentiation factor-5(GDF-5) plasmid using chitosan,hyaluronic acid,and chondroitin sulfate for osteoarthritis (OA)gene therapy.Methods: Nano-m...Objective:To construct a novel non-viral vector loaded with growth and differentiation factor-5(GDF-5) plasmid using chitosan,hyaluronic acid,and chondroitin sulfate for osteoarthritis (OA)gene therapy.Methods: Nano-microspheres (NMPs)were prepared by mixing chitosan,hyaluronic acid,and chondreitin sulfate.GDF-5 plasmid was encapsulated in the NMPs through electrostatic adsorption.The basic characteristics of the NMPs were observed,and then they were co-cultured with chondrocytes to observe their effects on extracellular matrix (ECM) protein expression.Finally,NMPs loaded with GDF-5were inje.cted into the articular cavities of rabbits to observe their therapeutic effects on OA in vivo.Results:NMPs exhibited good physicochemical properties and low cytotoxicity.Their average diameter was (0.61±0.20)μm,and encapsulation efficiency was (38.19±0.36)%.According to Cell Counting Kit-8(CCK-8)assay,relative cell viability was 75%-99%when the total weight of NMPs was less than 560μg. Transfection efficiency was (62.0±2.1)% in a liposome group,and (60.0±1.8)% in the NMP group.There was no sig- nificant difference between the two groups (P>0.05).Immunohistochemical staining results suggested that NMPs can successfully transfect chondrocytes and stimulate ECM protein expression in vitro.Compared with the control groups, the NMP group significantly promoted the expression of chondrocyte ECM in vivo (P<0.05),as shown by analysis of the biochemical composition of chondrocyte ECM.When NMPs were injected into OA model rabbits,the expression of ECM proteins in chondrocytes was significantly promoted and the progression of OA was slowed down.Conclusions: Based on these data,we think that these NMPs with excellent physicochemical and biological properties could be promising non-viral vectors for OA gene therapy.展开更多
基金Supported by the National Natural Science Foundation of China(21306036)Science&Technology Research Fund Project for Outstanding Youth in Colleges and Universities of Hebei province(Y2012040)the Joint Specialized Research Fund for the Doctoral Program of Higher Education of China(20131317120014)
文摘The energy-conserving performance of dividing wall column(DWC) is discussed in this paper. The heat transfer through the dividing wall is considered and the results are compared with that of common heat insulation dividing wall column(HIDWC). Based on the thermodynamic analysis of heat transfer dividing wall column(HTDWC) and HIDWC, both computer simulation and experiments are employed to analyze the energyconserving situation. Mixtures of n-hexane, n-heptane and n-octane are chosen as the example for separation.The results show that the energy consumption of HTDWC is 50.3% less than that of conventional distillation column, while it is 46.4% less than that of HIDWC. It indicates that DWC is efficient on separating threecomponent mixtures and HTDWC can save more energy than HIDWC. Thus it is necessary to consider the heat transfer while applying DWC to industry.
基金Supported by the Key Program of National Natural Science Foundation of China(11432003)the Key Research Project for Henan Universities(15A430009)
文摘For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.
基金the National Natural Science Foundation of China(Grant Nos 51609240,11572009&51538001)and the National Basic Research Program of China(Grant No 2014CB047100)
文摘A three-node triangular element fitted to numerical manifold method with continuous nodal stress, called Trig_3-CNS(NMM)element, was recently proposed for linear elastic continuous problems and linear elastic simple crack problems. The Trig_3-CNS(NMM) element can be considered as a development of both the Trig_3-CNS element and the numerical manifold method(NMM).Inheriting all the advantages of Trig_3-CNS element, calculations using Trig_3-CNS(NMM) element can obtain higher accuracy than Trig_3 element without extra degrees of freedom(DOFs) and yield continuous nodal stress without stress smoothing. Inheriting all the advantages of NMM, Trig_3-CNS(NMM) element can conveniently treat crack problems without deploying conforming mathematical mesh. In this paper,complex problems such as a crucifix crack and a star-shaped crack with many branches are studied to exhibit the advantageous features of the Trig_3-CNS(NMM) element. Numerical results show that the Trig_3-CNS(NMM) element is prominent in modeling complex crack problems.
基金Project supported by the National Natural Science Foundation of China(No.81201407)the Bureau of Science&Technology and Intellectual Property Nanchong City(Nos.NSMC20170203 and NSMC20170310)+1 种基金the Health and Family Planning Commission of Sichuan Province(No.17JP496)the Research Projects of North Sichuan Medical College(No.CBY13-A-ZD09),China
文摘Objective:To construct a novel non-viral vector loaded with growth and differentiation factor-5(GDF-5) plasmid using chitosan,hyaluronic acid,and chondroitin sulfate for osteoarthritis (OA)gene therapy.Methods: Nano-microspheres (NMPs)were prepared by mixing chitosan,hyaluronic acid,and chondreitin sulfate.GDF-5 plasmid was encapsulated in the NMPs through electrostatic adsorption.The basic characteristics of the NMPs were observed,and then they were co-cultured with chondrocytes to observe their effects on extracellular matrix (ECM) protein expression.Finally,NMPs loaded with GDF-5were inje.cted into the articular cavities of rabbits to observe their therapeutic effects on OA in vivo.Results:NMPs exhibited good physicochemical properties and low cytotoxicity.Their average diameter was (0.61±0.20)μm,and encapsulation efficiency was (38.19±0.36)%.According to Cell Counting Kit-8(CCK-8)assay,relative cell viability was 75%-99%when the total weight of NMPs was less than 560μg. Transfection efficiency was (62.0±2.1)% in a liposome group,and (60.0±1.8)% in the NMP group.There was no sig- nificant difference between the two groups (P>0.05).Immunohistochemical staining results suggested that NMPs can successfully transfect chondrocytes and stimulate ECM protein expression in vitro.Compared with the control groups, the NMP group significantly promoted the expression of chondrocyte ECM in vivo (P<0.05),as shown by analysis of the biochemical composition of chondrocyte ECM.When NMPs were injected into OA model rabbits,the expression of ECM proteins in chondrocytes was significantly promoted and the progression of OA was slowed down.Conclusions: Based on these data,we think that these NMPs with excellent physicochemical and biological properties could be promising non-viral vectors for OA gene therapy.