目的制备具有不同官能团(-CH3、-COOH、-OH、两性基团)的聚对苯二甲酸丁二醇酯(PBT)平板膜,并了解其对血浆蛋白吸附情况与对白细胞、血小板的黏附效果。方法利用紫外改性的方法,将不同单体接枝到PBT表面,得到PBT-AA(-COOH)、PBT-HEMA(-...目的制备具有不同官能团(-CH3、-COOH、-OH、两性基团)的聚对苯二甲酸丁二醇酯(PBT)平板膜,并了解其对血浆蛋白吸附情况与对白细胞、血小板的黏附效果。方法利用紫外改性的方法,将不同单体接枝到PBT表面,得到PBT-AA(-COOH)、PBT-HEMA(-OH)、PBT-SMDB(两性基团)并进行表征。采用ELISA测定吸附的人血清白蛋白(HSA)、纤维蛋白原(Fgn)含量,扫描电镜(SEM)观察黏附白细胞、血小板数量。结果 HSA吸附量(μg/cm2),PBT、PBT-AA分别为:15.05±4.51vs 35.61±6.91(P<0.01);Fgn吸附量(μg/cm2),PBT、PBT-HEMA、PBT-SMDB分别为:19.85±1.93 vs 14.93±4.05 vs 17.04±2.10(P<0.05)。4种材料在吸附HSA、Fgn前后,黏附的WBC、Plt均发生明显变化(P<0.01)。结论 Fgn对2种血小板和白细胞的黏附均有促进作用,而HSA对白细胞的黏附有一定抑制性。通过四种材料的比较发现,PBT-AA滤除白细胞及保留血小板的效果更好。展开更多
This paper presents a new type of base isolation system, i. e. , slide-limited friction (S-LF) base isolation system . Based on this system, the harmonic and subharmonic periodic response of S-LF subjected to harmonic...This paper presents a new type of base isolation system, i. e. , slide-limited friction (S-LF) base isolation system . Based on this system, the harmonic and subharmonic periodic response of S-LF subjected to harmonic motions is investigated by using Fourier-Galerkin-Newton (FGN) method with Flo-quet theory. The dynamic response of S-LF subjected to earthquake ground motions is calculated with a high order precision direct integration method, and the numerical results are presented in maximum acceleration response spectra of superstructure and maximum sliding displacement response spectrum form. The comparison of isolating effects of S-LF, pure-friction base isolation system (P-F) and resilient-friction base isolation system (R-FBI) shows that the isolating property of S-LF is superior to those of P-F and R-FBI. Finally, by analyzing an engineering example, it is observed that the distribution of the maximum shear between floors and absolute acceleration of S-LF to earthquake ground motion is very different from that of traditional structures.展开更多
The self similarity of the network traffic has great influences on the performance. But there are few analytical or even numerical solutions for such a model. So simulation becomes the most efficient method for resear...The self similarity of the network traffic has great influences on the performance. But there are few analytical or even numerical solutions for such a model. So simulation becomes the most efficient method for research. Fractal Gaussian noise (FGN) is the most popularly used self similar model. This paper presented an FGN generator based on fast Fourier transform (FFT). The study indicates that this algorithm is fairly fast and accurate.展开更多
Although the encryption of network packets significantly increases privacy, the density of the traffic can still provide useful information to the observer, and maybe results in the breach of confidentiality. In this ...Although the encryption of network packets significantly increases privacy, the density of the traffic can still provide useful information to the observer, and maybe results in the breach of confidentiality. In this paper, we address issues related to hiding information in self-similar network, which is proved to be similar with modern communication network. And a statistical hiding algorithm is proposed for traffic padding. The figures and the comparison of Hurst Parameters before and after traffic padding, show the effective performance of the algorithm.展开更多
Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious ...Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious material were then investigated. The results indicate that the addition of FGN decreases the fluidity slightly and improves mechanical properties of cement-based composites significantly. The highest strength is obtained with FGN content of 0.02% where the flexural strength and compressive strength at 28 days are 12.917 MPa and 52.42 MPa, respectively. Besides, scanning electron micrographs show that FGN can regulate formation of massive compact cross-linking structures and thermo gravimetric analysis indicates that FGN can accelerate the hydration reaction to increase the function of the composite effectively.展开更多
文摘目的制备具有不同官能团(-CH3、-COOH、-OH、两性基团)的聚对苯二甲酸丁二醇酯(PBT)平板膜,并了解其对血浆蛋白吸附情况与对白细胞、血小板的黏附效果。方法利用紫外改性的方法,将不同单体接枝到PBT表面,得到PBT-AA(-COOH)、PBT-HEMA(-OH)、PBT-SMDB(两性基团)并进行表征。采用ELISA测定吸附的人血清白蛋白(HSA)、纤维蛋白原(Fgn)含量,扫描电镜(SEM)观察黏附白细胞、血小板数量。结果 HSA吸附量(μg/cm2),PBT、PBT-AA分别为:15.05±4.51vs 35.61±6.91(P<0.01);Fgn吸附量(μg/cm2),PBT、PBT-HEMA、PBT-SMDB分别为:19.85±1.93 vs 14.93±4.05 vs 17.04±2.10(P<0.05)。4种材料在吸附HSA、Fgn前后,黏附的WBC、Plt均发生明显变化(P<0.01)。结论 Fgn对2种血小板和白细胞的黏附均有促进作用,而HSA对白细胞的黏附有一定抑制性。通过四种材料的比较发现,PBT-AA滤除白细胞及保留血小板的效果更好。
文摘This paper presents a new type of base isolation system, i. e. , slide-limited friction (S-LF) base isolation system . Based on this system, the harmonic and subharmonic periodic response of S-LF subjected to harmonic motions is investigated by using Fourier-Galerkin-Newton (FGN) method with Flo-quet theory. The dynamic response of S-LF subjected to earthquake ground motions is calculated with a high order precision direct integration method, and the numerical results are presented in maximum acceleration response spectra of superstructure and maximum sliding displacement response spectrum form. The comparison of isolating effects of S-LF, pure-friction base isolation system (P-F) and resilient-friction base isolation system (R-FBI) shows that the isolating property of S-LF is superior to those of P-F and R-FBI. Finally, by analyzing an engineering example, it is observed that the distribution of the maximum shear between floors and absolute acceleration of S-LF to earthquake ground motion is very different from that of traditional structures.
文摘The self similarity of the network traffic has great influences on the performance. But there are few analytical or even numerical solutions for such a model. So simulation becomes the most efficient method for research. Fractal Gaussian noise (FGN) is the most popularly used self similar model. This paper presented an FGN generator based on fast Fourier transform (FFT). The study indicates that this algorithm is fairly fast and accurate.
基金Sponsored by the Program for New Excellent Talents in University(Grant No.NZCT2004-0332)
文摘Although the encryption of network packets significantly increases privacy, the density of the traffic can still provide useful information to the observer, and maybe results in the breach of confidentiality. In this paper, we address issues related to hiding information in self-similar network, which is proved to be similar with modern communication network. And a statistical hiding algorithm is proposed for traffic padding. The figures and the comparison of Hurst Parameters before and after traffic padding, show the effective performance of the algorithm.
基金Project(51102035)supported by the National Natural Science Foundation of China
文摘Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious material were then investigated. The results indicate that the addition of FGN decreases the fluidity slightly and improves mechanical properties of cement-based composites significantly. The highest strength is obtained with FGN content of 0.02% where the flexural strength and compressive strength at 28 days are 12.917 MPa and 52.42 MPa, respectively. Besides, scanning electron micrographs show that FGN can regulate formation of massive compact cross-linking structures and thermo gravimetric analysis indicates that FGN can accelerate the hydration reaction to increase the function of the composite effectively.
