The chain/wire rope/chain combination is a common choice for mooring offshore floating platforms. However, data of the drag coefficients of chain links are rather limited, resulting in uncertainties with the calculati...The chain/wire rope/chain combination is a common choice for mooring offshore floating platforms. However, data of the drag coefficients of chain links are rather limited, resulting in uncertainties with the calculations of the drag force, and hence the damping of the mooring system. In this paper, the importance of the selection of the drag coefficient is first investigated. The computational fluid dynamics(CFD) method is then used to determine the drag coefficients of a studless chain under steady flows. Numerical model validation is first completed by simulating a smooth circular cylinder under steady flows. In particular, the performance of different turbulence models is assessed through the comparisons between the calculations and the experimental results. The large eddy simulation(LES) model is finally selected for the simulation of steady flows past a chain. The effects of the Reynolds number on the drag coefficient of a stud-less chain is also studied. The results show that the calculated drag coefficients of a stud-less chain are fairly consistent with the available experimental data.展开更多
The taut mooring system using synthetic fiber ropes has overcome the shortcomings such as the large self-weight of the mooring lines and provides better mooring performance for the floating structures.The polyester ro...The taut mooring system using synthetic fiber ropes has overcome the shortcomings such as the large self-weight of the mooring lines and provides better mooring performance for the floating structures.The polyester rope has attracted much attention among numerous synthetic fiber rope materials due to its lightweight,low price,corrosion resistance,and high strength.Thus,the mooring characteristics of it are worth studying.Polyester mooring lines are flexible in deep water,when a marine structure is moored by them,the geometric nonlinearity such as large displacement,large stretch,and large bending deformation,and the material nonlinearity like viscoelastic of the polyester ropes become complex integrated problems to be studied.Considering the nonlinear phenomenon,the simulation and calculation of a polyester line were carried out by the absolute nodal coordinate formulation(ANCF)in this paper since the ANCF method has advantages in dealing with the significant deformation problems of the flexible structures.In addition,a chain mooring line was also simulated for comparison,and the results show that the polyester ropes reduce the self-weight of the mooring lines and provide sufficient mooring strength at the same time,and the nonlinear phenomenon of the polyester ropes is different from that of the chain mooring lines.展开更多
The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the targe...The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the target cells. The results showed that the transfection rate of oligonucleotide to the HL-60 was about 90 %—95 % and it had no obvious attenuation within 84 h. However, the plasmid transfection rate was only 5 %—25 % and it was decreased significantly within 60 h. It was suggested that the transfection of oligonucleotide with liposomes was better than that of plasmid.展开更多
Objective To establish a method cloning the exon 3 of eck gene from normal tissue and ZR 75 1 cell line (a human breast cancer cell line)and study whether these genes exist mutant. Methods Designed a pair of s...Objective To establish a method cloning the exon 3 of eck gene from normal tissue and ZR 75 1 cell line (a human breast cancer cell line)and study whether these genes exist mutant. Methods Designed a pair of specific primers and amplified the exon 3 of eck gene fragment from the extracted genomic DNA derived from normal epithelial cells from skin tissue and ZR 75 1 cell line respectively by PCR technique. Transformed the E.coil. JM109 with recombinant plamids constructed by inserting the amplified fragments into medium vector pUCm T and sequenced these amplified fragments after primary screening of endonuclease restriction digestion and PCR amplification. Results ① Obtained the genomic DNA of human normal epithelial cells and ZR 75 1 cell line respectively. ② Obtained the amplified fragments of human exon 3 of eck gene through PCR technique. ③ Obtained the cloning vectors of exon 3 of eck gene of human normal epithelial cells and ZR 75 1 cell line respectively. ④ ZR 75 1 cell line exists mutation of nucleotides. Conclusion Successfully established the method of cloning the human exon 3 of eck gene and found some mutations in the detected samples. This study lays a foundation for further studying the function of eck gene in tumorgenesis.展开更多
Monosomic lines of Nicotiana tabacum are helpful to confirm the location of genes on specific chromosomes. In the cross N. nudicaulis and N. tabacum, hybrid seedlings express lethal symptoms, which are controlled by t...Monosomic lines of Nicotiana tabacum are helpful to confirm the location of genes on specific chromosomes. In the cross N. nudicaulis and N. tabacum, hybrid seedlings express lethal symptoms, which are controlled by the S subgenome of N. tabacum. To identify the responsible chromosome, we needed to produce chromosome lacking lines (CLLs) of N. tabacum L. “Red Russian” and use them to cross with N. nudicaulis. From a cross of (N. tabacum × N. tomentosiformis) × N. tabacum, 380 BC1 individuals were obtained. Using a Haplo-Q line (a monosomic line lacking the single linkage group 11) and N. tabacum, we found that qPCR is a simple and reliable screening method for CLLs of N. tabacum. The marker PT30342 is located on linkage group 11, and the -Ct value (Ct Actin - Ct PT30342) was 2.0 for a disomic line and was 1.097 for a Haplo-Q line. By the use of flow cytometry, qPCR and chromosome counting together as a screening method, we identified 6 CLLs lacking 2 to 6 chromosomes. Compared with conventional methods, our method is a rapid technique for making and screening CLLs ofthe S or S/T subgenome of N. tabacum. Further, these CLLs will be useful to identify the location of two or more factors on chromosomes controlling a variety of genetic problems affecting breeding. Here, we only made CLLs of the S or S/T subgenome of N. tabacum. We will use the method established in this study to produce CLLs of the T subgenome of N. tabacum, and gather a full set of CLLs of N. tabacum. qPCR could also be applied to the identification of chromosome aberrations in other plants.展开更多
基金financial support for the PhD study from GL-Nobel Denton based in London
文摘The chain/wire rope/chain combination is a common choice for mooring offshore floating platforms. However, data of the drag coefficients of chain links are rather limited, resulting in uncertainties with the calculations of the drag force, and hence the damping of the mooring system. In this paper, the importance of the selection of the drag coefficient is first investigated. The computational fluid dynamics(CFD) method is then used to determine the drag coefficients of a studless chain under steady flows. Numerical model validation is first completed by simulating a smooth circular cylinder under steady flows. In particular, the performance of different turbulence models is assessed through the comparisons between the calculations and the experimental results. The large eddy simulation(LES) model is finally selected for the simulation of steady flows past a chain. The effects of the Reynolds number on the drag coefficient of a stud-less chain is also studied. The results show that the calculated drag coefficients of a stud-less chain are fairly consistent with the available experimental data.
基金Supported by the Specialized Research Project for LS17-2 Semi-submersible Production Platform(LSZX-2020-HN-05-0405).
文摘The taut mooring system using synthetic fiber ropes has overcome the shortcomings such as the large self-weight of the mooring lines and provides better mooring performance for the floating structures.The polyester rope has attracted much attention among numerous synthetic fiber rope materials due to its lightweight,low price,corrosion resistance,and high strength.Thus,the mooring characteristics of it are worth studying.Polyester mooring lines are flexible in deep water,when a marine structure is moored by them,the geometric nonlinearity such as large displacement,large stretch,and large bending deformation,and the material nonlinearity like viscoelastic of the polyester ropes become complex integrated problems to be studied.Considering the nonlinear phenomenon,the simulation and calculation of a polyester line were carried out by the absolute nodal coordinate formulation(ANCF)in this paper since the ANCF method has advantages in dealing with the significant deformation problems of the flexible structures.In addition,a chain mooring line was also simulated for comparison,and the results show that the polyester ropes reduce the self-weight of the mooring lines and provide sufficient mooring strength at the same time,and the nonlinear phenomenon of the polyester ropes is different from that of the chain mooring lines.
基金This project was supported by a grant from National Natu ral Sciences Foundation of China (No. 39800149).
文摘The transfection efficiency of oligonucleotide and plasmid to the HL-60 cell line with lipofectaminePLUS was compared through observing the transfection rate and the expression duration of exogenous gene in the target cells. The results showed that the transfection rate of oligonucleotide to the HL-60 was about 90 %—95 % and it had no obvious attenuation within 84 h. However, the plasmid transfection rate was only 5 %—25 % and it was decreased significantly within 60 h. It was suggested that the transfection of oligonucleotide with liposomes was better than that of plasmid.
文摘Objective To establish a method cloning the exon 3 of eck gene from normal tissue and ZR 75 1 cell line (a human breast cancer cell line)and study whether these genes exist mutant. Methods Designed a pair of specific primers and amplified the exon 3 of eck gene fragment from the extracted genomic DNA derived from normal epithelial cells from skin tissue and ZR 75 1 cell line respectively by PCR technique. Transformed the E.coil. JM109 with recombinant plamids constructed by inserting the amplified fragments into medium vector pUCm T and sequenced these amplified fragments after primary screening of endonuclease restriction digestion and PCR amplification. Results ① Obtained the genomic DNA of human normal epithelial cells and ZR 75 1 cell line respectively. ② Obtained the amplified fragments of human exon 3 of eck gene through PCR technique. ③ Obtained the cloning vectors of exon 3 of eck gene of human normal epithelial cells and ZR 75 1 cell line respectively. ④ ZR 75 1 cell line exists mutation of nucleotides. Conclusion Successfully established the method of cloning the human exon 3 of eck gene and found some mutations in the detected samples. This study lays a foundation for further studying the function of eck gene in tumorgenesis.
文摘Monosomic lines of Nicotiana tabacum are helpful to confirm the location of genes on specific chromosomes. In the cross N. nudicaulis and N. tabacum, hybrid seedlings express lethal symptoms, which are controlled by the S subgenome of N. tabacum. To identify the responsible chromosome, we needed to produce chromosome lacking lines (CLLs) of N. tabacum L. “Red Russian” and use them to cross with N. nudicaulis. From a cross of (N. tabacum × N. tomentosiformis) × N. tabacum, 380 BC1 individuals were obtained. Using a Haplo-Q line (a monosomic line lacking the single linkage group 11) and N. tabacum, we found that qPCR is a simple and reliable screening method for CLLs of N. tabacum. The marker PT30342 is located on linkage group 11, and the -Ct value (Ct Actin - Ct PT30342) was 2.0 for a disomic line and was 1.097 for a Haplo-Q line. By the use of flow cytometry, qPCR and chromosome counting together as a screening method, we identified 6 CLLs lacking 2 to 6 chromosomes. Compared with conventional methods, our method is a rapid technique for making and screening CLLs ofthe S or S/T subgenome of N. tabacum. Further, these CLLs will be useful to identify the location of two or more factors on chromosomes controlling a variety of genetic problems affecting breeding. Here, we only made CLLs of the S or S/T subgenome of N. tabacum. We will use the method established in this study to produce CLLs of the T subgenome of N. tabacum, and gather a full set of CLLs of N. tabacum. qPCR could also be applied to the identification of chromosome aberrations in other plants.
