1 INTRODUCTIONKnowledge of the basic transport phenomena of ions in an ion exchange membrane isimportant for the application of such a membrane.Various studies on the developmentof mathematical models for predicting a...1 INTRODUCTIONKnowledge of the basic transport phenomena of ions in an ion exchange membrane isimportant for the application of such a membrane.Various studies on the developmentof mathematical models for predicting and correlating membrane transport rate havebeen published in recent years.More exact estimation of the diffusion coefficientshas been the subject of chief concern in many of these papers.For a bi-ionic systemwith the same valence,Sato et al.gave a method for estimating diffusion coefficients展开更多
The diffusion coefficients of CuCl_2 in aqueous solutions of CuCl_2 and CuCl_2-HCl were measured respectively at 298 K with diaphragm cell method. The concentration dependence of CuCl_2 diffusion coefficient in single...The diffusion coefficients of CuCl_2 in aqueous solutions of CuCl_2 and CuCl_2-HCl were measured respectively at 298 K with diaphragm cell method. The concentration dependence of CuCl_2 diffusion coefficient in single CuCl_2 solutions and in mixed CuCl_2 -HCl solutions was discussed on the changes in chemical potential as well as in viscosity.展开更多
The capacity intermittent titration technique (CITT) was developed based on the ratio of potentio-charge capacity to galvano-charge capacity (RPG) method, to continuously determine the solid diffusion coefficient (D) ...The capacity intermittent titration technique (CITT) was developed based on the ratio of potentio-charge capacity to galvano-charge capacity (RPG) method, to continuously determine the solid diffusion coefficient (D) of the intercalary species within insertion-host materials with a small voltage region. The linear equations of D vs the value of ratio of the potentio-charge capacity to the galvano-charge capacity (q) were given. By the CITT technique,the Li+ solid diffusion coefficients within LiMn2 O4 at different voltages were determined. The results show that the values of D varied from 3. 447× 10-9 to 7.60× 10-11 cm2/s in the voltage range of charge from 3.3 to 4.3 V as a function of voltage with "W" shape.展开更多
In this paper, the capacity titration technique （CT technique） was developed on basis of the RPG （ratio of potentio-charge capacity to galvano-charge capacity） method to continuously determine the solid diffusion ...In this paper, the capacity titration technique （CT technique） was developed on basis of the RPG （ratio of potentio-charge capacity to galvano-charge capacity） method to continuously determine the solid diffusion coefficient D of the intercalary species within insertion-host materials with a small voltage region. The linear equations of D vs. q （value of ratio of the potentio-charge capacity to the galvano-charge capacity） were given in different range of q. By the CT technique,the Li^＋ solid diffusion coefficients D within LiMn2O4 at different voltages were determined. The results showed that the values of D varied from 3.447×10^-9 cm^2/s to 7.60×10^-11 cm^2/s in the voltage range of charge from 3.3V to 4.3V as a function of voltage with “W” shape.展开更多
AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included...AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity opened. Forty VX-2 tumor models from them were divided into four groups. DWI was performed periodically and respectively for each group after chemoembolization. All VX-2 tumor samples of each group were studied by pathology. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values. The statistical significance between different time groups, different area groups or different b-value groups was calculated by using SPSS12.0 software. RESULTS: Under b-value of 100 s/mm2, ADC values were lowest at 16 h after chemoembolization in area of VX-2 tumor periphery, central, and normal liver parenchyma around tumor, but turned to increase with further elongation of chemoembolization treatment. The distinction of ADC between different time groups was significant respectively (F = 7.325, P < 0.001; F = 2.496, P < 0.048; F = 6.856, P < 0.001). Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor, increased quickly in sixteen h after chemoembolization but, from the 16th h to the 48th h, cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at, and then increased continually. After chemoembolization, Cellular necrosis in the area of VX-2 tumor periphery was more significantly high than that before chemoembolization. The areas of dead cells in VX-2 tumors manifested low signal and high ADC value, while the areas of viable cells manifested high signal and low ADC value. CONCLUSION: DWI is able to detect and differentiate tumor necrotic areas from viable cellular areas before and after chemoembolization. ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema, tissue cellular death and microcirculation disturbance after chemoembolization.展开更多
AIM： To investigate dynamical and image pathological characteristics of the liver on magnetic resonance （MR） diffusion-weighted imaging （DWI） in the rabbit VX-2 tumor model. METHODS： Forty New Zealand rabbits we...AIM： To investigate dynamical and image pathological characteristics of the liver on magnetic resonance （MR） diffusion-weighted imaging （DWI） in the rabbit VX-2 tumor model. METHODS： Forty New Zealand rabbits were included in the study and VX-2 tumor piece was implanted intrahepatically. Fifteen animals received two intrahepatic implantations while 25 had one intrahepatical implantation. DWI, T1- and T2-weighted of magnetic resonance imaging （MRI） were carried out on the 7th and the 14th d after implantation and DWI was conducted, respectively on the 21th d. Ten VX-2 tumor samples were studied pathologically. RESULTS： The rate of lump detected by DWI, TlWI and T2WI was 78.7%, 10.7% and 53.5% （X^2 =32.61, P 〈 0.001） on the 7th d after implantation and 95.8%, 54.3% and 82.9% （X^2 = 21.50, P 〈 0.001） on the 14th d. The signal of most VX-2 tumors on DWI was uniform and it was equal diffusion coefficient （ADC）. did not decrease on the 7th on the map of apparent The signal of VX tumors d after implantation, most of them slowly growing during the week following implantation without significant cell dying within the tumor. VX-2 tumors grew increasingly within 14 d after implantation but the signal of most VX-2 tumors on DWI or on the map of ADC was uniform or uneven and ADC of VX tumors decreased obscurely or slightly because tumor necrosis was still not obvious. On the 21th d after implantation, the signal of most VX-2 tumors on DWI or on the map of ADC was uneven because tumor necrosis was evident and ADC of VX-2 tumor necrotic areas decreased. The areas of viable cells in VX-2 tumors manifested a high signal on DWI and a low signal on the map of ADC. The areas of dead cells or necrosis in VX-2 tumors manifested low signals on DWI and low, equal or high signals on the map of ADC but they manifested high signals on DWI and on the map of ADC at the same time when the areas of necrotic tumor became liquefied or cystic. The border of tumors on DWI appeared gradually distinct and internal signals of tumor became progressively uneven. CONCLUSION： The manifestations of viable, necrotic and liquefied or cystic areas in VX-2 tumors on DWI are typical and DWI is of significant and potential values in clinical application in both the early detection and diagnosis of liver tumors.展开更多
The adsorption and diffusion of hydrogen atoms on Cu(001)are studied using first-principles calculations.By taking into account the contribution of zero-point energy(ZPE),the originally identical barriers are shown to...The adsorption and diffusion of hydrogen atoms on Cu(001)are studied using first-principles calculations.By taking into account the contribution of zero-point energy(ZPE),the originally identical barriers are shown to be different for H and D,which are respectively calculated to be~158 me V and~139 me V in height.Using the transfer matrix method(TMM),we are able to calculate the accurate probability of transmission across the barriers.The crucial role of quantum tunneling is clearly demonstrated at low-temperature region.By introducing a temperature-dependent attempting frequency prefactor,the rate constants and diffusion coefficients are calculated.The results are in agreement with the experimental measurements at temperatures from~50 K to 80 K.展开更多
After diffusion couples were annealed at 260-360 ℃, the concentration profiles of Zn element were measured by EPMA. It has been first quantitatively determined by Matano method that the interdiffusion coefficient in ...After diffusion couples were annealed at 260-360 ℃, the concentration profiles of Zn element were measured by EPMA. It has been first quantitatively determined by Matano method that the interdiffusion coefficient in A1-Zn fee solid solution containing high Zn contents is remarkably decreased due to the small addition of Cu. Also, the interdiffusion coefficient in A1-Zn fee solid solution clearly increases with the increasing of Zn concentration. The interdiffusion activity energy remarkably decreases with the increasing of Zn contents. On the other hand, the interdiffusion activity energy markedly increases due to the small addition of Cu in the A1 Zn fcc solid solution containing high Zn contents.展开更多
The thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu76.12Al23.88 alloy before and after cryogenic treatment in the heating temperature range of 25℃ to 600℃ ...The thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu76.12Al23.88 alloy before and after cryogenic treatment in the heating temperature range of 25℃ to 600℃ were measured by thermal constant tester and thermal expansion instrument. The effects of cryogenic treatment on the thermal physical properties of CU76,12A123,88 alloy were investigated by comparing the variation of the thermal parameters before and after cryogenic treatment. The results show that the variation trend of the thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of CU76.12Al23.88 alloy after cryogenic treatment was the same as before. The cryogenic treatment can increase the thermal diffusion coefficient, thermal conductivity, and thermal expansion coeffi- cient of Cu76.12Al23.88 alloy and decrease its heat capacity. The maximum difference in the thermal diffusion coefficient between the before and after cryogenic treatment appeared at 400℃. Similarly, thermal conductivity was observed at 200℃.展开更多
采用电解质分子相互作用体积模型eMIVM(Electrolyte Molecular Interaction Volume Model)与它的能量项eMIVM-ET(Energy term of eMIVM)分别对含Cu^(2+)的20个单电解质溶液的活度系数进行拟合,并对含Cu^(2+)的5个两电解质溶液的所有组...采用电解质分子相互作用体积模型eMIVM(Electrolyte Molecular Interaction Volume Model)与它的能量项eMIVM-ET(Energy term of eMIVM)分别对含Cu^(2+)的20个单电解质溶液的活度系数进行拟合,并对含Cu^(2+)的5个两电解质溶液的所有组分活度系数进行预测。结果表明:两个模型对含Cu^(2+)单电解质溶液活度系数的拟合效果均较好,eMIVM模型预测的拟合平均偏差和平均相对误差分别为0.0598和6.4%,eMIVM-ET模型预测的分别为0.0163和3.0%;对含Cu^(2+)的两电解质溶液的所有组分活度系数预测时,eMIVM-ET模型的预测效果要比eMIVM模型的好,eMIVM-ET模型预测时的平均偏差和平均相对误差分别为0.0844和18.2%;在含Cu^(2+)电解质溶液的热力学计算中,与eMIVM模型相比,eMIVM-ET模型更适合作为一个可供选择的预测模型。展开更多
基金Supported by the Post-doctoral Foundation of China
文摘1 INTRODUCTIONKnowledge of the basic transport phenomena of ions in an ion exchange membrane isimportant for the application of such a membrane.Various studies on the developmentof mathematical models for predicting and correlating membrane transport rate havebeen published in recent years.More exact estimation of the diffusion coefficientshas been the subject of chief concern in many of these papers.For a bi-ionic systemwith the same valence,Sato et al.gave a method for estimating diffusion coefficients
文摘The diffusion coefficients of CuCl_2 in aqueous solutions of CuCl_2 and CuCl_2-HCl were measured respectively at 298 K with diaphragm cell method. The concentration dependence of CuCl_2 diffusion coefficient in single CuCl_2 solutions and in mixed CuCl_2 -HCl solutions was discussed on the changes in chemical potential as well as in viscosity.
基金Project (20406024) supported by the National Natural Science Foundation of China project (76600) supported by the Postdoctoral Science Foundation of Central South University
文摘The capacity intermittent titration technique (CITT) was developed based on the ratio of potentio-charge capacity to galvano-charge capacity (RPG) method, to continuously determine the solid diffusion coefficient (D) of the intercalary species within insertion-host materials with a small voltage region. The linear equations of D vs the value of ratio of the potentio-charge capacity to the galvano-charge capacity (q) were given. By the CITT technique,the Li+ solid diffusion coefficients within LiMn2 O4 at different voltages were determined. The results show that the values of D varied from 3. 447× 10-9 to 7.60× 10-11 cm2/s in the voltage range of charge from 3.3 to 4.3 V as a function of voltage with "W" shape.
基金This work was supported by NNSF of China(No.20406024)the Postdoctoral Science Foundation of Central South University(No.76600).
文摘In this paper, the capacity titration technique （CT technique） was developed on basis of the RPG （ratio of potentio-charge capacity to galvano-charge capacity） method to continuously determine the solid diffusion coefficient D of the intercalary species within insertion-host materials with a small voltage region. The linear equations of D vs. q （value of ratio of the potentio-charge capacity to the galvano-charge capacity） were given in different range of q. By the CT technique,the Li^＋ solid diffusion coefficients D within LiMn2O4 at different voltages were determined. The results showed that the values of D varied from 3.447×10^-9 cm^2/s to 7.60×10^-11 cm^2/s in the voltage range of charge from 3.3V to 4.3V as a function of voltage with “W” shape.
基金the National Natural Science Foundation of China, No. 30070235, 30470508
文摘AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity opened. Forty VX-2 tumor models from them were divided into four groups. DWI was performed periodically and respectively for each group after chemoembolization. All VX-2 tumor samples of each group were studied by pathology. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values. The statistical significance between different time groups, different area groups or different b-value groups was calculated by using SPSS12.0 software. RESULTS: Under b-value of 100 s/mm2, ADC values were lowest at 16 h after chemoembolization in area of VX-2 tumor periphery, central, and normal liver parenchyma around tumor, but turned to increase with further elongation of chemoembolization treatment. The distinction of ADC between different time groups was significant respectively (F = 7.325, P < 0.001; F = 2.496, P < 0.048; F = 6.856, P < 0.001). Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor, increased quickly in sixteen h after chemoembolization but, from the 16th h to the 48th h, cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at, and then increased continually. After chemoembolization, Cellular necrosis in the area of VX-2 tumor periphery was more significantly high than that before chemoembolization. The areas of dead cells in VX-2 tumors manifested low signal and high ADC value, while the areas of viable cells manifested high signal and low ADC value. CONCLUSION: DWI is able to detect and differentiate tumor necrotic areas from viable cellular areas before and after chemoembolization. ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema, tissue cellular death and microcirculation disturbance after chemoembolization.
基金The National Natural Science Foundation of China, No. 30070235, 30470508The Natural Science Foundation of Hunan Province, No. 08JJ5043+1 种基金The Science and Technolgy Foundation of Hunan Province, No. 06FJ3120, 2007SK3072the Medical Science and Technology Foundation of Hunan Province, No. B2006-159
文摘AIM： To investigate dynamical and image pathological characteristics of the liver on magnetic resonance （MR） diffusion-weighted imaging （DWI） in the rabbit VX-2 tumor model. METHODS： Forty New Zealand rabbits were included in the study and VX-2 tumor piece was implanted intrahepatically. Fifteen animals received two intrahepatic implantations while 25 had one intrahepatical implantation. DWI, T1- and T2-weighted of magnetic resonance imaging （MRI） were carried out on the 7th and the 14th d after implantation and DWI was conducted, respectively on the 21th d. Ten VX-2 tumor samples were studied pathologically. RESULTS： The rate of lump detected by DWI, TlWI and T2WI was 78.7%, 10.7% and 53.5% （X^2 =32.61, P 〈 0.001） on the 7th d after implantation and 95.8%, 54.3% and 82.9% （X^2 = 21.50, P 〈 0.001） on the 14th d. The signal of most VX-2 tumors on DWI was uniform and it was equal diffusion coefficient （ADC）. did not decrease on the 7th on the map of apparent The signal of VX tumors d after implantation, most of them slowly growing during the week following implantation without significant cell dying within the tumor. VX-2 tumors grew increasingly within 14 d after implantation but the signal of most VX-2 tumors on DWI or on the map of ADC was uniform or uneven and ADC of VX tumors decreased obscurely or slightly because tumor necrosis was still not obvious. On the 21th d after implantation, the signal of most VX-2 tumors on DWI or on the map of ADC was uneven because tumor necrosis was evident and ADC of VX-2 tumor necrotic areas decreased. The areas of viable cells in VX-2 tumors manifested a high signal on DWI and a low signal on the map of ADC. The areas of dead cells or necrosis in VX-2 tumors manifested low signals on DWI and low, equal or high signals on the map of ADC but they manifested high signals on DWI and on the map of ADC at the same time when the areas of necrotic tumor became liquefied or cystic. The border of tumors on DWI appeared gradually distinct and internal signals of tumor became progressively uneven. CONCLUSION： The manifestations of viable, necrotic and liquefied or cystic areas in VX-2 tumors on DWI are typical and DWI is of significant and potential values in clinical application in both the early detection and diagnosis of liver tumors.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474285 and 12074382)。
文摘The adsorption and diffusion of hydrogen atoms on Cu(001)are studied using first-principles calculations.By taking into account the contribution of zero-point energy(ZPE),the originally identical barriers are shown to be different for H and D,which are respectively calculated to be~158 me V and~139 me V in height.Using the transfer matrix method(TMM),we are able to calculate the accurate probability of transmission across the barriers.The crucial role of quantum tunneling is clearly demonstrated at low-temperature region.By introducing a temperature-dependent attempting frequency prefactor,the rate constants and diffusion coefficients are calculated.The results are in agreement with the experimental measurements at temperatures from~50 K to 80 K.
文摘After diffusion couples were annealed at 260-360 ℃, the concentration profiles of Zn element were measured by EPMA. It has been first quantitatively determined by Matano method that the interdiffusion coefficient in A1-Zn fee solid solution containing high Zn contents is remarkably decreased due to the small addition of Cu. Also, the interdiffusion coefficient in A1-Zn fee solid solution clearly increases with the increasing of Zn concentration. The interdiffusion activity energy remarkably decreases with the increasing of Zn contents. On the other hand, the interdiffusion activity energy markedly increases due to the small addition of Cu in the A1 Zn fcc solid solution containing high Zn contents.
文摘The thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu76.12Al23.88 alloy before and after cryogenic treatment in the heating temperature range of 25℃ to 600℃ were measured by thermal constant tester and thermal expansion instrument. The effects of cryogenic treatment on the thermal physical properties of CU76,12A123,88 alloy were investigated by comparing the variation of the thermal parameters before and after cryogenic treatment. The results show that the variation trend of the thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of CU76.12Al23.88 alloy after cryogenic treatment was the same as before. The cryogenic treatment can increase the thermal diffusion coefficient, thermal conductivity, and thermal expansion coeffi- cient of Cu76.12Al23.88 alloy and decrease its heat capacity. The maximum difference in the thermal diffusion coefficient between the before and after cryogenic treatment appeared at 400℃. Similarly, thermal conductivity was observed at 200℃.
文摘采用电解质分子相互作用体积模型eMIVM(Electrolyte Molecular Interaction Volume Model)与它的能量项eMIVM-ET(Energy term of eMIVM)分别对含Cu^(2+)的20个单电解质溶液的活度系数进行拟合,并对含Cu^(2+)的5个两电解质溶液的所有组分活度系数进行预测。结果表明:两个模型对含Cu^(2+)单电解质溶液活度系数的拟合效果均较好,eMIVM模型预测的拟合平均偏差和平均相对误差分别为0.0598和6.4%,eMIVM-ET模型预测的分别为0.0163和3.0%;对含Cu^(2+)的两电解质溶液的所有组分活度系数预测时,eMIVM-ET模型的预测效果要比eMIVM模型的好,eMIVM-ET模型预测时的平均偏差和平均相对误差分别为0.0844和18.2%;在含Cu^(2+)电解质溶液的热力学计算中,与eMIVM模型相比,eMIVM-ET模型更适合作为一个可供选择的预测模型。
