The Mg-Ni hydride was prepared by hydriding combustion synthesis under a high magnetic field. The dehydriding kinetics of the hydrides was measured under the isothermal and non-isothermal conditions. A model was appli...The Mg-Ni hydride was prepared by hydriding combustion synthesis under a high magnetic field. The dehydriding kinetics of the hydrides was measured under the isothermal and non-isothermal conditions. A model was applied to analyzing the kinetics behavior of Mg-Ni hydride. The calculation results show that the theoretical value and the experimental data can reach a good agreement, especially in the case of non-isothermal dehydriding. The rate-controlling step is the diffusion of hydrogen atoms in the solid solution. The sample prepared under magnetic field of 6 T under the isothermal condition can reach the best performance. The similar tendency was observed under the non-isothermal condition and the reason was discussed.展开更多
Biomass from SAR data was assimilated into crop growth model to describe relationship between crop biomass and crop growth time to improve estimation accuracy of biomass. In addition, inverse model was established in ...Biomass from SAR data was assimilated into crop growth model to describe relationship between crop biomass and crop growth time to improve estimation accuracy of biomass. In addition, inverse model was established in order to estimate biomass according to relationship between biomass and backscattering coefficients from SAR data. Based on cost function, parameters of growth model were optimized as per conjugate gradient method, minimizing the differences between estimated biomass and inversion values from SAR data. The results indicated that the simulated biomass using the revised growth model with SAR data was consistent with the measured one in time distribution and even higher in accuracy than that without SAR data. Hence, the key parameters of crop growth model could be revised by real-time growth information from SAR data and accuracy of the simulated biomass could be improved accordingly.展开更多
A useful helicobacter pylori-induced gastritis model using BALB/c mice was established for mimicking of human gastritis induced by Helicobacter pylori (H. pylori). The H. pylori isolates were obtained freshly from a...A useful helicobacter pylori-induced gastritis model using BALB/c mice was established for mimicking of human gastritis induced by Helicobacter pylori (H. pylori). The H. pylori isolates were obtained freshly from a human complex ulcer patient. BALB/c mice were fasted for 24 h and then 0.25 mL of 0.2 mol·L -1 NaHCO 3 was administered after by gavage to each mouse and 0.5 mL of 10 9 colonies formation unit per milliliter (CFU/mL) of H. pylori was administered 15 min. On the 3 rd day and 5 th day, the H. pylori inoculations were repeated. The inoculated mice were sacrificed in batch on the 5 th day, in the 2 nd week, 3 rd week and 4 th week. The gastric mucous membrane near pyloric portion was removed, treated and then cultured under microaerobic condition for detection of H.pylori. The remainders of the gastric membrane were fixed by 10% formaldehyde solution for pathological detection. The results showed that the H. pylori could be separated from the gastric membranes of inoculated mice. Obvious invasion of inflammatory cells in the gastric membranes of inoculated mice could be observed from pathological sections. It can be concluded that the inoculating fresh human H. pylori isolates can produce mouse gastritis. This model of BALB/c mice can be used for evaluating the therapeutic agents for the treatment of gastritis induced by H. pylori.展开更多
Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on th...Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research.展开更多
Objective: To apply PS-T in di?erent phases of carcinoma formation and development, and research the mechanism of anti-carcinoma of PS-T in the cytological level. Methods: N-nitrosodiethylamine ...Objective: To apply PS-T in di?erent phases of carcinoma formation and development, and research the mechanism of anti-carcinoma of PS-T in the cytological level. Methods: N-nitrosodiethylamine (DENA) and CCl4 were applied jointly to duplicate the rat hepatocirrhosis and hepatic cancer model. The rats were divided into 7 groups and were administrated via nasal-stomach tube with PS-T in di?erent phases to interfere the cancer genesis and development. All the rats were killed in 20 weeks for pathological observation. Results: The loss of body weight of rats slowed down in the PS-T-treated group, and the carcinogenesis rate was signi?cantly decreased correspondingly. PS-T could also inhibit the carcinogenesis by supressing the hepatocirrhosis, which showed the positive correlation between the curative e?ect and the curative period. Conclusion: Application of PS-T during cancer induction showed a signi?cant e?ect on preventing and supressing cancer. PS-T might be an ideal drug for clinical anti-cancer therapy. And it will be a main drug in both combined and single treatments for tumor.展开更多
Two mono iron complexes Fe(CO)2PR3(NN) (R = Cy (3), Ph (4), NN = o-phenylenediamine dianion ligand, N2H2Ph2-) derived from the ligand substitution of Fe(CO)3hPR3 by the NN ligand were isolated and structur...Two mono iron complexes Fe(CO)2PR3(NN) (R = Cy (3), Ph (4), NN = o-phenylenediamine dianion ligand, N2H2Ph2-) derived from the ligand substitution of Fe(CO)3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.展开更多
Aim To investigate the anti-atherosclerotic mechanisms of the novel compoundpivanampeta in the early and later stages of atherosclerosis evolution. Methods Rats or rabbits wererandomly assigned to the control, the mod...Aim To investigate the anti-atherosclerotic mechanisms of the novel compoundpivanampeta in the early and later stages of atherosclerosis evolution. Methods Rats or rabbits wererandomly assigned to the control, the model and the pivanampeta-treated groups. The rats or rabbitsin the model group and the pivanampeta-treated group were fed with hypercholesterol diet. Thecarotids of rabbits were cut into pieces and stained with HE. The rat or rabbit serum levels of TC,LDL-CHO, HDL-CHO, IL-8, ET-1, PGI_2, TXA_2, and NO were assayed. The expressions of MCP-1 and IL-8mRNA on rabbit carotid were determined by semi-quantitative RT-PCR. Results Pivanampeta exerted aninhibitory effect on TXA_2 formation without PGI_2 production in the early and later stages ofatherosclerosis. The significantly increased release of NO and the decreased release of IL-8 in theanimals in pivanampeta-treated group were both detected in the rat atherosclerosis model. In therabbit atherosclerosis model the expressions of IL-8 and MCP-1 mRNA in pivanampeta-treated groupwere decreased significantly. However, the treatment with pivanampeta had no effect on the levels ofplasma cholesterol, MDA and SOD. Conclusion The increase of serum NO contents and the decrease ofplasma TXA_2 level, as well as its inhibition of expression of IL-8 and MCP-1 are probably involvedin the mechanisms underlying the anti-atherosclerotic effects of pivanampeta.展开更多
The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total...The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).展开更多
Based on the structure of glass (or liquid) polymers consisting of α-domain, β-co-domain, and entanglement constituent chain networks, and the nonexponentially viscoelastic behavior, a “heterophase fluctuation” ...Based on the structure of glass (or liquid) polymers consisting of α-domain, β-co-domain, and entanglement constituent chain networks, and the nonexponentially viscoelastic behavior, a “heterophase fluctuation” model was proposed. It was found that the dynamics of cooperative rearrangement on the “fluidized domain” has a great shear rate, domain size, and temperature dependences. When the shear rate, domain size, and temperature dependences were taken account into the cooperatively localized rearrangement on the fluidized domain by the degradation of primary α-domain and the reformation of secondary β-co-domain constituent chains. A new dynamic theory of cooperatively localized rearrangement on the fluidized domain constituent chains with different size and different network chain length during physical and mechanical aging was established. The total viscoelastic free en-ergy of deformation resulting from the change in conformations of α-domain, β-co-domain, crytallite, crosslinked, and trapped entanglement constituent chains during aging processes was calculated by the combining method of kinetics and statistical mechanics. The constitu- tive equations and reduced stress relaxation modulus and creep compliances for three types of polymers were also derived. Finally, two reduced universal equations on creep compliance and stress relaxation modulus with a non-linear and two nonexponential parameters α and β were theoretically derived from the dynamic theory and a statistically extended mode coupling theory for double aging effects of polymers was developed. Results show that the two reduced universal equations have the same form as Kohlraush-Williams-Watts (K-W-W) stretched exponential function. The nonlinearity and the nonexponentiality are, respectively, originated from the memory effects of nonthermal and thermal history. The correlation of nonlinearity, α and β to the aging time, aging temperature, and the mesomorphic structure of fluidized domains was also established.展开更多
The terminal velocity of a liquid droplet settling in a sulfactant solution has been studied for the non-linear adsorption Langmuir frameworks accounting for monolayer saturation and non-ideal surfactant interactions....The terminal velocity of a liquid droplet settling in a sulfactant solution has been studied for the non-linear adsorption Langmuir frameworks accounting for monolayer saturation and non-ideal surfactant interactions. Most prior research uses a linear adsorption model which cannot capture these effects, The Maragoni migration of a liquid drop settling through a surfactant solution is examined by using Langmuir framework. The solution concentration Ceq is assumed large enough for the surfactant mass transfer to be adsorption-controlled. Langmuir model generates non-linear Marangoni stresses which diverge in the limit of approaching ∝, strongly retarding U'.展开更多
基金Project(51464008) supported by the National Natural Science Foundation of ChinaProject(KY[2012]004) supported by the Key Laboratory Item of Education Office in Guizhou Province,China
文摘The Mg-Ni hydride was prepared by hydriding combustion synthesis under a high magnetic field. The dehydriding kinetics of the hydrides was measured under the isothermal and non-isothermal conditions. A model was applied to analyzing the kinetics behavior of Mg-Ni hydride. The calculation results show that the theoretical value and the experimental data can reach a good agreement, especially in the case of non-isothermal dehydriding. The rate-controlling step is the diffusion of hydrogen atoms in the solid solution. The sample prepared under magnetic field of 6 T under the isothermal condition can reach the best performance. The similar tendency was observed under the non-isothermal condition and the reason was discussed.
基金Supported by National High-tech R & D Program of China (863 Program)(2007AA12Z174)~~
文摘Biomass from SAR data was assimilated into crop growth model to describe relationship between crop biomass and crop growth time to improve estimation accuracy of biomass. In addition, inverse model was established in order to estimate biomass according to relationship between biomass and backscattering coefficients from SAR data. Based on cost function, parameters of growth model were optimized as per conjugate gradient method, minimizing the differences between estimated biomass and inversion values from SAR data. The results indicated that the simulated biomass using the revised growth model with SAR data was consistent with the measured one in time distribution and even higher in accuracy than that without SAR data. Hence, the key parameters of crop growth model could be revised by real-time growth information from SAR data and accuracy of the simulated biomass could be improved accordingly.
文摘A useful helicobacter pylori-induced gastritis model using BALB/c mice was established for mimicking of human gastritis induced by Helicobacter pylori (H. pylori). The H. pylori isolates were obtained freshly from a human complex ulcer patient. BALB/c mice were fasted for 24 h and then 0.25 mL of 0.2 mol·L -1 NaHCO 3 was administered after by gavage to each mouse and 0.5 mL of 10 9 colonies formation unit per milliliter (CFU/mL) of H. pylori was administered 15 min. On the 3 rd day and 5 th day, the H. pylori inoculations were repeated. The inoculated mice were sacrificed in batch on the 5 th day, in the 2 nd week, 3 rd week and 4 th week. The gastric mucous membrane near pyloric portion was removed, treated and then cultured under microaerobic condition for detection of H.pylori. The remainders of the gastric membrane were fixed by 10% formaldehyde solution for pathological detection. The results showed that the H. pylori could be separated from the gastric membranes of inoculated mice. Obvious invasion of inflammatory cells in the gastric membranes of inoculated mice could be observed from pathological sections. It can be concluded that the inoculating fresh human H. pylori isolates can produce mouse gastritis. This model of BALB/c mice can be used for evaluating the therapeutic agents for the treatment of gastritis induced by H. pylori.
基金Supported by National Basic Research Program of China (973 Program) (Grant No. 2007CB714101)~~
文摘Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research.
文摘Objective: To apply PS-T in di?erent phases of carcinoma formation and development, and research the mechanism of anti-carcinoma of PS-T in the cytological level. Methods: N-nitrosodiethylamine (DENA) and CCl4 were applied jointly to duplicate the rat hepatocirrhosis and hepatic cancer model. The rats were divided into 7 groups and were administrated via nasal-stomach tube with PS-T in di?erent phases to interfere the cancer genesis and development. All the rats were killed in 20 weeks for pathological observation. Results: The loss of body weight of rats slowed down in the PS-T-treated group, and the carcinogenesis rate was signi?cantly decreased correspondingly. PS-T could also inhibit the carcinogenesis by supressing the hepatocirrhosis, which showed the positive correlation between the curative e?ect and the curative period. Conclusion: Application of PS-T during cancer induction showed a signi?cant e?ect on preventing and supressing cancer. PS-T might be an ideal drug for clinical anti-cancer therapy. And it will be a main drug in both combined and single treatments for tumor.
基金supported by the National Natural Science Foundation of China(21103121,21276187)Tianjin Municipal Natural Science Foundation(13JCQNJC05800)the Specialized Research Fund for the Doctoral Program of Higher Education(20121317110009)~~
文摘Two mono iron complexes Fe(CO)2PR3(NN) (R = Cy (3), Ph (4), NN = o-phenylenediamine dianion ligand, N2H2Ph2-) derived from the ligand substitution of Fe(CO)3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.
文摘Aim To investigate the anti-atherosclerotic mechanisms of the novel compoundpivanampeta in the early and later stages of atherosclerosis evolution. Methods Rats or rabbits wererandomly assigned to the control, the model and the pivanampeta-treated groups. The rats or rabbitsin the model group and the pivanampeta-treated group were fed with hypercholesterol diet. Thecarotids of rabbits were cut into pieces and stained with HE. The rat or rabbit serum levels of TC,LDL-CHO, HDL-CHO, IL-8, ET-1, PGI_2, TXA_2, and NO were assayed. The expressions of MCP-1 and IL-8mRNA on rabbit carotid were determined by semi-quantitative RT-PCR. Results Pivanampeta exerted aninhibitory effect on TXA_2 formation without PGI_2 production in the early and later stages ofatherosclerosis. The significantly increased release of NO and the decreased release of IL-8 in theanimals in pivanampeta-treated group were both detected in the rat atherosclerosis model. In therabbit atherosclerosis model the expressions of IL-8 and MCP-1 mRNA in pivanampeta-treated groupwere decreased significantly. However, the treatment with pivanampeta had no effect on the levels ofplasma cholesterol, MDA and SOD. Conclusion The increase of serum NO contents and the decrease ofplasma TXA_2 level, as well as its inhibition of expression of IL-8 and MCP-1 are probably involvedin the mechanisms underlying the anti-atherosclerotic effects of pivanampeta.
文摘The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).
基金ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China (No.50973007).
文摘Based on the structure of glass (or liquid) polymers consisting of α-domain, β-co-domain, and entanglement constituent chain networks, and the nonexponentially viscoelastic behavior, a “heterophase fluctuation” model was proposed. It was found that the dynamics of cooperative rearrangement on the “fluidized domain” has a great shear rate, domain size, and temperature dependences. When the shear rate, domain size, and temperature dependences were taken account into the cooperatively localized rearrangement on the fluidized domain by the degradation of primary α-domain and the reformation of secondary β-co-domain constituent chains. A new dynamic theory of cooperatively localized rearrangement on the fluidized domain constituent chains with different size and different network chain length during physical and mechanical aging was established. The total viscoelastic free en-ergy of deformation resulting from the change in conformations of α-domain, β-co-domain, crytallite, crosslinked, and trapped entanglement constituent chains during aging processes was calculated by the combining method of kinetics and statistical mechanics. The constitu- tive equations and reduced stress relaxation modulus and creep compliances for three types of polymers were also derived. Finally, two reduced universal equations on creep compliance and stress relaxation modulus with a non-linear and two nonexponential parameters α and β were theoretically derived from the dynamic theory and a statistically extended mode coupling theory for double aging effects of polymers was developed. Results show that the two reduced universal equations have the same form as Kohlraush-Williams-Watts (K-W-W) stretched exponential function. The nonlinearity and the nonexponentiality are, respectively, originated from the memory effects of nonthermal and thermal history. The correlation of nonlinearity, α and β to the aging time, aging temperature, and the mesomorphic structure of fluidized domains was also established.
文摘The terminal velocity of a liquid droplet settling in a sulfactant solution has been studied for the non-linear adsorption Langmuir frameworks accounting for monolayer saturation and non-ideal surfactant interactions. Most prior research uses a linear adsorption model which cannot capture these effects, The Maragoni migration of a liquid drop settling through a surfactant solution is examined by using Langmuir framework. The solution concentration Ceq is assumed large enough for the surfactant mass transfer to be adsorption-controlled. Langmuir model generates non-linear Marangoni stresses which diverge in the limit of approaching ∝, strongly retarding U'.