The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper(MMSD) biodynamic model, and the mass damper(TMD) with different op...The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper(MMSD) biodynamic model, and the mass damper(TMD) with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.展开更多
A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined ...A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined by mass detector. The calibration curve of loratadine was linear within the range of 0.4~100 ng·mL -1 with r=0.9995 . The recovery of this method was within 95%~104%, within day and between day RSD were less than 12%. To study the pharmacokinetics and relative bioavailability of loratadine tablets, two formulations of loratadine tablets were given to 18 healthy male volunteers according to a randomized 2 way cross over design. The C max , AUC 0 t and T max values of the two formulations were 51.89±20.18 ng·mL -1 and 52.48±22.35 ng·mL -1 ; 140.75±88.42 ng·h·mL -1 and 147.24±92.33 ng·h·mL -1 ; 0.81±0.35 h and 0.81±0.27 h respectively. Results from statistic analysis showed that there were no significant difference between the C max , AUC 0-t and T max values of the two formulations. The relative bioavailability of tablets I with respect to tablets II was 97%±13% from the AUC 0 t measurement. Bioequivalance was observed between the two tablets.展开更多
The effect of supercooled melt forced laminar flow at low Reynolds Number on dendritic growth perpendicular to melt flow direction was investigated with the phase-field method by incorporating melt convection and ther...The effect of supercooled melt forced laminar flow at low Reynolds Number on dendritic growth perpendicular to melt flow direction was investigated with the phase-field method by incorporating melt convection and thermal noise under non-isothermal condition. By taking the dendritic growth of high pure succinonitrile (SCN) supercooled melt as an example, side-branching shape difference of melts with flow and without flow was analyzed. Relationships among supercooled melt inflow velocity, deflexion angle of dendritic arm and dendritic tip growth velocity were studied. Results show that the melt inflow velocity has few effects on the dendritic tip growth velocity. A formula of relationship between the velocity of the melt in front of primary dendritic tip and the dendritic growth time was deduced, and the calculated result was in quantitative agreement with the simulation result.展开更多
Aim To establish a sensitive and specific liquid chromatography-mass spectrometry (HPLC-MS) method for measuring lovastatin level in human plasma and the relative bioavailability. Methods Lovastatin in the plasma was ...Aim To establish a sensitive and specific liquid chromatography-mass spectrometry (HPLC-MS) method for measuring lovastatin level in human plasma and the relative bioavailability. Methods Lovastatin in the plasma was extracted with acetoacetate. Simvastatin was added as internal standard (IS). Samples were separated on a C_ 18 column with a mobile phase consisting of methanol and 50 mmol·L~ -1 sodium acetate (88 ∶ 12). The flow rate was 1 mL·min~ -1 . Sample was detected using an electrospray ionization (ES...展开更多
Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved ...Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.展开更多
The random distribution problem of dendrite preferred growth direction was settled by random grid method.This method was used to study the influence of forced laminar flow effect on multiple grains during solidificati...The random distribution problem of dendrite preferred growth direction was settled by random grid method.This method was used to study the influence of forced laminar flow effect on multiple grains during solidification.Taking high pure succinonitrile (SCN) undercooled melt as an example,the forced laminar flow effect on multiple grains was studied by phase-field model of single grain which coupled with flow equations at non-isothermal condition.The simulation results show that the random grid method can reasonably settle the problem of random distribution and is more effective.When the solid fraction is relatively low,melt particles flow around the downstream side of dendrite,and the flow velocity between two dendrite arms becomes high.At the stage of solidification time less than 1800Δt,every dendrite grows freely;the upstream dendrites are stronger than the downstream ones.The higher the melt flow rate,the higher the solid fraction.However,when the solid fraction is relatively high,the dendrite arm intertwins and only a little residual melt which is not encapsulated can flow;the solid fraction will gradually tend to equal to solid fraction of melt without flow.展开更多
Global warming has been being a serious issue since 1980, and it impacts environment and biosphere. Here, we reviewed the physiological and ecological responses of marine zooplankton which is an important component of...Global warming has been being a serious issue since 1980, and it impacts environment and biosphere. Here, we reviewed the physiological and ecological responses of marine zooplankton which is an important component of biosphere to the global warming. Much research on physiological changes in response to different temperature is given to discuss this issue. Furthermore, we focused on ecological changes of zooplankton to global warming and several indices such as abundance, biomass, biodiversity and biogeographic boundary are enumerated. Phenological changes of zooplankton were presented, followed by the prospects of this subject, viz. observing more functional groups, more concerning on zooplankton in tropical region and investigation on a species-level zooplankton system.展开更多
In order to optimize the design of a 12.5 m deepwater channel project and protect the ecological environment, it is necessary to study the habitat evaluation of species in the engineered area. A coupled eco-hydrodynam...In order to optimize the design of a 12.5 m deepwater channel project and protect the ecological environment, it is necessary to study the habitat evaluation of species in the engineered area. A coupled eco-hydrodynamic model, which combines a hydrodynamic model (ADCIRC) and a habitat suitability index (HSI) model is developed for target fish (Coilia nasus) and benthos (Corbicula fluminea) in the Yangtze River in order to predict the ecological changes and optimize the regulation scheme. Based on the existing research concerning the characteristics of Coilia nasus and Corbicula fluminea, the relationship between the target species and water environment factors is established. The verification results of tidal level, velocity and biological density show that the proposed coupling model performs well when predicting ecological suitability in the studied region. The results indicate a slight improvement in the potential habitat availability for the two species studied as the natural hydraulic conditions change after the deep-water channel regulation works.展开更多
We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference...We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference and tolerance of these lizards correspond with their latitudinal distributions.Overall,selected body temperature(Tsel)and viable temperature range(VTR)were both highest in E.brenchleyi and lowest in E.multiocellata,with E.argus in between;critical thermal minimum(CTMin)was highest in E.multiocellata and lowest in E.brenchleyi,with E.argus in between;critical thermal maximum(CTMax)was lower in E.multiocellata than in other two species.Lizards acclimated to 28℃ and 38℃ overall selected lower body temperatures than those acclimated to 33℃;lizards acclimated to high temperatures were less tolerant of low temperatures,and vice versa;lizards acclimated to 28℃ were less tolerant of high temperatures but had a wider VTR range than those acclimated to 33℃ and 38℃.Lizards of three species acclimated to the three temperatures always differed from each other in CTMin,but not in Tsel,CTMax and VTR.Our results show that:temperature acclimation plays an important role in influencing thermal preference and tolerance in the three Eremias lizards,although the degrees to which acclimation temperature affects thermal preference and tolerance differ among species;thermal preference rather than tolerance of the three Eremias lizards corresponds with their latitudinal distributions.展开更多
Fermentation of bioflocculant with Corynebacterium glutamicum was studied by way of kinetic modeling.Lorentzian modified Logistic model, time-corrected Luedeking–Piret and Luedeking–Piret type models were proposed a...Fermentation of bioflocculant with Corynebacterium glutamicum was studied by way of kinetic modeling.Lorentzian modified Logistic model, time-corrected Luedeking–Piret and Luedeking–Piret type models were proposed and applied to describe the cell growth, bioflocculant synthesis and consumption of substrates, with the correlation of initial biomass concentration and initial glucose concentration, respectively. The results showed that these models could well characterize the batch culture process of C. glutamicum at various initial glucose concentrations from 10.0 to 17.5 g·L-1. The initial biomass concentration could shorten the lag time of cell growth,while the maximum biomass concentration was achieved only at the optimal initial glucose concentration of16.22 g·L-1. A novel three-stage fed-batch strategy for bioflocculant production was developed based on the model prediction, in which the lag phase, quick biomass growth and bioflocculant production stages were sequentially proceeded with the adjustment of glucose concentration and dissolved oxygen. Biomass of2.23 g·L-1was obtained and bioflocculant concentration was enhanced to 176.32 mg·L-1, 18.62% and403.63% higher than those in the batch process, respectively, indicating an efficient fed-batch culture strategy for bioflocculant production.展开更多
Manufacturing of ship piping systems is one of the major production activities in shipbuilding. The schedule of pipe production has an important impact on the master schedule of shipbuilding. In this research, the ITO...Manufacturing of ship piping systems is one of the major production activities in shipbuilding. The schedule of pipe production has an important impact on the master schedule of shipbuilding. In this research, the ITOC concept was introduced to solve the scheduling problems of a piping factory, and an intelligent scheduling system was developed. The system, in which a product model, an operation model, a factory model, and a knowledge database of piping production were integrated, automated the planning process and production scheduling. Details of the above points were discussed. Moreover, an application of the system in a piping factory, which achieved a higher level of performance as measured by tardiness, lead time, and inventory, was demonstrated.展开更多
The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH (1-34)] in Rhesus monkeys after single and multiple subcutaneous administration....The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH (1-34)] in Rhesus monkeys after single and multiple subcutaneous administration. An immunoradiometric assay (IRMA) was used to determine the plasma drug concentration of rhFFH (1-34) after giving single dose of 10, 20 and 40 ug/kg and daily dose of 40 ug/kg for 7 d by subcutaneous administration, and intravenous injection of 20 ug/kg in Rhesus monkeys. The pharmacokinetic parameters were calculated by noncompartmental analysis. The drug plasma level quantitation range was from 0.027 to 2.22 ng/mL. The intra- and inter-assay precision (CV) of analysis were less than 15%, and the average recovery was about 93.0% ± 8.6% - 116.5% ± 14.0%. After subcutaneous administration of rhPTH(1-34) at dose of 10, 20 and 40 ug/kg, the average Tmax was 0.67, 0.5 and 0.83 h, Cmax were 1.85 ± 0.05, 3.23 ± 0.25 and 7.15 ± 1.19 ng/mL, the AUC(0-∞) were 3.4 ± 0.6, 10.7 ± 1.3 and 12.6 ± 1.5 ng/h/mL, and terminal-phase elimination T1/2 were 0.72 ± 0.10, 1.15 ± 0.10 and 1.03 ± 0.06 h, respectively. The absolute bioavailability of rhPTH (1-34) was 46.96% after subcutaneous administration of 20 ug/kg. There was no evidence of accumulation during systemic exposure of rhPTH (1-34) upon multiple dosing in Rhesus monkeys. The IRMA assay method provide reasonable sensitivity and specificity for the pharrnacokinetic study of rhPTH (1-34) after subcutaneous or intravenous administration in Rhesus monkeys. The pharmacokinetic characteristic of rhPTH (1-34) in monkeys shows linear relationship with the dose administered subcutaneously.展开更多
Automotive surface coating manufacturing is one of the most sophisticated and expensive steps in automotive assembly. This step involves generating multiple thin layers of polymeric coatings on the vehicle surface thr...Automotive surface coating manufacturing is one of the most sophisticated and expensive steps in automotive assembly. This step involves generating multiple thin layers of polymeric coatings on the vehicle surface through paint spray and curing in a multistage, dynamically changing environment. Traditionally, the quality control is solely post-process inspection based, and process operational adjustment is only experience based, thus the manufacturing may not be (highly) sustainable. In this article, a multiscale system modeling and analysis methodology is introduced for achieving a sustainable application of polymeric materials through paint spray and film curing in automotive surface coating manufacturing. By this methodology, the correlations among paint material, application processes and coating performance can be identified. The model-based analysis allows a comprehensive and deep study of the dynamic behaviors of the material, process, and product in a wide spectrum of length and time. Case studies illustrate the efficacy of the methodology for sustainable manufacturing.展开更多
AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. Methods...AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. MethodsThe concentrations of Cyclo-D4G in rat (Sprague-Dawley male rats) plasma and urine were analyzed by high performance liquid chromatography (HPLC). ResultsFollowing intravenous adm inistration to rats, concentrations of Cyclo-D4G in plasma declined with a term inal phase half-life of 0 78±0 14 h (±s). Total clearance was 0 90±0 21 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximately 20% of total clearance. Steady state volume of distr ibution was 0 91±0 07 L·kg -1 . After oral administration to rats, conce ntrations of Cyclo-D4G in plasma declined with a terminal phase half-life of 0 83±0 13 h (±s). Total clearance was 3 81±2 03 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximat ely 9% of total clearance. Oral bioavailability of Cyclo-D4G in rat was 26 9%. ConclusionThe favorable pharmacokinetic profiles and lower to xicity provide support for further development of Cyclo-D4G clinical trials.展开更多
On the basis of the quantization of mesoscopic biological cell equivalent circuit,we studied the quantum fluctuations of voltage and current of mesoscopic biological cell equivalent circuit as finite temperature by Bo...On the basis of the quantization of mesoscopic biological cell equivalent circuit,we studied the quantum fluctuations of voltage and current of mesoscopic biological cell equivalent circuit as finite temperature by Bogoliuov transformation.The result shows that the quantum fluctuations of voltage and current not only relate with the parameters of equivalent circuit,temperature,but also decay with time.This result may have significant value on the design and application of the bio-electronic apparatus.展开更多
Application of pneumatic separators in coal beneficiation is increasing rapidly over the last decade primarily due to their low capital and operating costs, and waste handling problems associated with traditional wet ...Application of pneumatic separators in coal beneficiation is increasing rapidly over the last decade primarily due to their low capital and operating costs, and waste handling problems associated with traditional wet processing methods. Large amount of shale/rock that is extracted in coal production can be removed prior to transportation at the mine face by using this methodology. Due to the limited washing facilities in India, most of the thermal power plants burn raw coal from run-of-mine (ROM) to generate electricity. This practice causes poor utilization efficiency, high operating and maintenance costs, and high emission rates for the power plants. One potential method that can be utilized is the air-fluidized inclined vibrating deck technology. The technology was demonstrated on a pilot-scale at different coal washeries in India at a feed rate of 5-ton per hour. The pilot-scale evaluation showed that 20 %-25 % high-ash incombustible material can be eliminated from ROM feed with only minor losses in energy content (〈10 %) from respective ROM coal. Furthermore, a feasibility analysis showed significant economic gains in terms of transportation cost, improving power-plant efficiency, and reducing emissions rates by using the technology.展开更多
In 70 years since the founding of the People’s Republic of China,China has successfully transitioned from a closed economy to an open economy with the watershed year of reform and opening up in 1978 and modernized it...In 70 years since the founding of the People’s Republic of China,China has successfully transitioned from a closed economy to an open economy with the watershed year of reform and opening up in 1978 and modernized its social security system accordingly.This paper divides the transition of China’s social security system into seven stages before and after 1978.The traditional social security system was predicated on the dominant public ownership,a highly centralized economy,and“full employment.”It was congruous with the ownership structure,income distribution,and labor systems under the closed economy.The modern social security system is developed to meet the needs of an open economy and promotes economic development by giving play to consumption and investment,facilitating labor flow,and boosting productivity.The modern social security system requires further supply-side structural reforms to promote the high-quality development of the open economy.展开更多
基金The National Natural Science Foundation of China(No.51508257,51668042,51578274)the Yangtze River Scholar and the Innovation Team of M inistry of Education(No.IRT13068)the Scientific Research Project of Gansu Higher Education(No.2015B-34)
文摘The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper(MMSD) biodynamic model, and the mass damper(TMD) with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.
文摘A new HPLC MS method to determine loratadine in human plasma was established. The method involved extracting drug with organic solvent under basic conditions. The samples were seperated by ODS column and determined by mass detector. The calibration curve of loratadine was linear within the range of 0.4~100 ng·mL -1 with r=0.9995 . The recovery of this method was within 95%~104%, within day and between day RSD were less than 12%. To study the pharmacokinetics and relative bioavailability of loratadine tablets, two formulations of loratadine tablets were given to 18 healthy male volunteers according to a randomized 2 way cross over design. The C max , AUC 0 t and T max values of the two formulations were 51.89±20.18 ng·mL -1 and 52.48±22.35 ng·mL -1 ; 140.75±88.42 ng·h·mL -1 and 147.24±92.33 ng·h·mL -1 ; 0.81±0.35 h and 0.81±0.27 h respectively. Results from statistic analysis showed that there were no significant difference between the C max , AUC 0-t and T max values of the two formulations. The relative bioavailability of tablets I with respect to tablets II was 97%±13% from the AUC 0 t measurement. Bioequivalance was observed between the two tablets.
基金Project (10964004) supported by the National Natural Science Foundation of ChinaProject (096RJZA104) supported by the Natural Science Foundation of Gansu Province, China
文摘The effect of supercooled melt forced laminar flow at low Reynolds Number on dendritic growth perpendicular to melt flow direction was investigated with the phase-field method by incorporating melt convection and thermal noise under non-isothermal condition. By taking the dendritic growth of high pure succinonitrile (SCN) supercooled melt as an example, side-branching shape difference of melts with flow and without flow was analyzed. Relationships among supercooled melt inflow velocity, deflexion angle of dendritic arm and dendritic tip growth velocity were studied. Results show that the melt inflow velocity has few effects on the dendritic tip growth velocity. A formula of relationship between the velocity of the melt in front of primary dendritic tip and the dendritic growth time was deduced, and the calculated result was in quantitative agreement with the simulation result.
文摘Aim To establish a sensitive and specific liquid chromatography-mass spectrometry (HPLC-MS) method for measuring lovastatin level in human plasma and the relative bioavailability. Methods Lovastatin in the plasma was extracted with acetoacetate. Simvastatin was added as internal standard (IS). Samples were separated on a C_ 18 column with a mobile phase consisting of methanol and 50 mmol·L~ -1 sodium acetate (88 ∶ 12). The flow rate was 1 mL·min~ -1 . Sample was detected using an electrospray ionization (ES...
文摘Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.
基金Project(10964004) supported by the National Natural Science Foundation of ChinaProject(20070731001) supported by Research Fund for the Doctoral Program of China+1 种基金 Project(096RJZA104) supported by the Natural Science Foundation of Gansu Province,ChinaProject(SB14200801) supported by the Doctoral Fund of Lanzhou University of Technology,China
文摘The random distribution problem of dendrite preferred growth direction was settled by random grid method.This method was used to study the influence of forced laminar flow effect on multiple grains during solidification.Taking high pure succinonitrile (SCN) undercooled melt as an example,the forced laminar flow effect on multiple grains was studied by phase-field model of single grain which coupled with flow equations at non-isothermal condition.The simulation results show that the random grid method can reasonably settle the problem of random distribution and is more effective.When the solid fraction is relatively low,melt particles flow around the downstream side of dendrite,and the flow velocity between two dendrite arms becomes high.At the stage of solidification time less than 1800Δt,every dendrite grows freely;the upstream dendrites are stronger than the downstream ones.The higher the melt flow rate,the higher the solid fraction.However,when the solid fraction is relatively high,the dendrite arm intertwins and only a little residual melt which is not encapsulated can flow;the solid fraction will gradually tend to equal to solid fraction of melt without flow.
文摘Global warming has been being a serious issue since 1980, and it impacts environment and biosphere. Here, we reviewed the physiological and ecological responses of marine zooplankton which is an important component of biosphere to the global warming. Much research on physiological changes in response to different temperature is given to discuss this issue. Furthermore, we focused on ecological changes of zooplankton to global warming and several indices such as abundance, biomass, biodiversity and biogeographic boundary are enumerated. Phenological changes of zooplankton were presented, followed by the prospects of this subject, viz. observing more functional groups, more concerning on zooplankton in tropical region and investigation on a species-level zooplankton system.
基金The National Natural Science Foundation of China(No.51209040,51279134)the Natural Science Foundation of Jiangsu Province(No.BK2012341)
文摘In order to optimize the design of a 12.5 m deepwater channel project and protect the ecological environment, it is necessary to study the habitat evaluation of species in the engineered area. A coupled eco-hydrodynamic model, which combines a hydrodynamic model (ADCIRC) and a habitat suitability index (HSI) model is developed for target fish (Coilia nasus) and benthos (Corbicula fluminea) in the Yangtze River in order to predict the ecological changes and optimize the regulation scheme. Based on the existing research concerning the characteristics of Coilia nasus and Corbicula fluminea, the relationship between the target species and water environment factors is established. The verification results of tidal level, velocity and biological density show that the proposed coupling model performs well when predicting ecological suitability in the studied region. The results indicate a slight improvement in the potential habitat availability for the two species studied as the natural hydraulic conditions change after the deep-water channel regulation works.
基金supported by a grant from Natural Science Foundation of China(Project No.30670281)
文摘We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference and tolerance of these lizards correspond with their latitudinal distributions.Overall,selected body temperature(Tsel)and viable temperature range(VTR)were both highest in E.brenchleyi and lowest in E.multiocellata,with E.argus in between;critical thermal minimum(CTMin)was highest in E.multiocellata and lowest in E.brenchleyi,with E.argus in between;critical thermal maximum(CTMax)was lower in E.multiocellata than in other two species.Lizards acclimated to 28℃ and 38℃ overall selected lower body temperatures than those acclimated to 33℃;lizards acclimated to high temperatures were less tolerant of low temperatures,and vice versa;lizards acclimated to 28℃ were less tolerant of high temperatures but had a wider VTR range than those acclimated to 33℃ and 38℃.Lizards of three species acclimated to the three temperatures always differed from each other in CTMin,but not in Tsel,CTMax and VTR.Our results show that:temperature acclimation plays an important role in influencing thermal preference and tolerance in the three Eremias lizards,although the degrees to which acclimation temperature affects thermal preference and tolerance differ among species;thermal preference rather than tolerance of the three Eremias lizards corresponds with their latitudinal distributions.
基金Supported by the National Natural Science Foundation of China(21206143,51378444)the program for New Century Excellent Talents of Education Ministry of China(ncet-13-0501)
文摘Fermentation of bioflocculant with Corynebacterium glutamicum was studied by way of kinetic modeling.Lorentzian modified Logistic model, time-corrected Luedeking–Piret and Luedeking–Piret type models were proposed and applied to describe the cell growth, bioflocculant synthesis and consumption of substrates, with the correlation of initial biomass concentration and initial glucose concentration, respectively. The results showed that these models could well characterize the batch culture process of C. glutamicum at various initial glucose concentrations from 10.0 to 17.5 g·L-1. The initial biomass concentration could shorten the lag time of cell growth,while the maximum biomass concentration was achieved only at the optimal initial glucose concentration of16.22 g·L-1. A novel three-stage fed-batch strategy for bioflocculant production was developed based on the model prediction, in which the lag phase, quick biomass growth and bioflocculant production stages were sequentially proceeded with the adjustment of glucose concentration and dissolved oxygen. Biomass of2.23 g·L-1was obtained and bioflocculant concentration was enhanced to 176.32 mg·L-1, 18.62% and403.63% higher than those in the batch process, respectively, indicating an efficient fed-batch culture strategy for bioflocculant production.
文摘Manufacturing of ship piping systems is one of the major production activities in shipbuilding. The schedule of pipe production has an important impact on the master schedule of shipbuilding. In this research, the ITOC concept was introduced to solve the scheduling problems of a piping factory, and an intelligent scheduling system was developed. The system, in which a product model, an operation model, a factory model, and a knowledge database of piping production were integrated, automated the planning process and production scheduling. Details of the above points were discussed. Moreover, an application of the system in a piping factory, which achieved a higher level of performance as measured by tardiness, lead time, and inventory, was demonstrated.
文摘The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH (1-34)] in Rhesus monkeys after single and multiple subcutaneous administration. An immunoradiometric assay (IRMA) was used to determine the plasma drug concentration of rhFFH (1-34) after giving single dose of 10, 20 and 40 ug/kg and daily dose of 40 ug/kg for 7 d by subcutaneous administration, and intravenous injection of 20 ug/kg in Rhesus monkeys. The pharmacokinetic parameters were calculated by noncompartmental analysis. The drug plasma level quantitation range was from 0.027 to 2.22 ng/mL. The intra- and inter-assay precision (CV) of analysis were less than 15%, and the average recovery was about 93.0% ± 8.6% - 116.5% ± 14.0%. After subcutaneous administration of rhPTH(1-34) at dose of 10, 20 and 40 ug/kg, the average Tmax was 0.67, 0.5 and 0.83 h, Cmax were 1.85 ± 0.05, 3.23 ± 0.25 and 7.15 ± 1.19 ng/mL, the AUC(0-∞) were 3.4 ± 0.6, 10.7 ± 1.3 and 12.6 ± 1.5 ng/h/mL, and terminal-phase elimination T1/2 were 0.72 ± 0.10, 1.15 ± 0.10 and 1.03 ± 0.06 h, respectively. The absolute bioavailability of rhPTH (1-34) was 46.96% after subcutaneous administration of 20 ug/kg. There was no evidence of accumulation during systemic exposure of rhPTH (1-34) upon multiple dosing in Rhesus monkeys. The IRMA assay method provide reasonable sensitivity and specificity for the pharrnacokinetic study of rhPTH (1-34) after subcutaneous or intravenous administration in Rhesus monkeys. The pharmacokinetic characteristic of rhPTH (1-34) in monkeys shows linear relationship with the dose administered subcutaneously.
基金Supported in part by US NSF (CBET 0647113 and 0730383, CMMI 0700178, and DUE 0736739)the Institute of Manufacturing Research of Wayne State University.
文摘Automotive surface coating manufacturing is one of the most sophisticated and expensive steps in automotive assembly. This step involves generating multiple thin layers of polymeric coatings on the vehicle surface through paint spray and curing in a multistage, dynamically changing environment. Traditionally, the quality control is solely post-process inspection based, and process operational adjustment is only experience based, thus the manufacturing may not be (highly) sustainable. In this article, a multiscale system modeling and analysis methodology is introduced for achieving a sustainable application of polymeric materials through paint spray and film curing in automotive surface coating manufacturing. By this methodology, the correlations among paint material, application processes and coating performance can be identified. The model-based analysis allows a comprehensive and deep study of the dynamic behaviors of the material, process, and product in a wide spectrum of length and time. Case studies illustrate the efficacy of the methodology for sustainable manufacturing.
文摘AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. MethodsThe concentrations of Cyclo-D4G in rat (Sprague-Dawley male rats) plasma and urine were analyzed by high performance liquid chromatography (HPLC). ResultsFollowing intravenous adm inistration to rats, concentrations of Cyclo-D4G in plasma declined with a term inal phase half-life of 0 78±0 14 h (±s). Total clearance was 0 90±0 21 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximately 20% of total clearance. Steady state volume of distr ibution was 0 91±0 07 L·kg -1 . After oral administration to rats, conce ntrations of Cyclo-D4G in plasma declined with a terminal phase half-life of 0 83±0 13 h (±s). Total clearance was 3 81±2 03 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximat ely 9% of total clearance. Oral bioavailability of Cyclo-D4G in rat was 26 9%. ConclusionThe favorable pharmacokinetic profiles and lower to xicity provide support for further development of Cyclo-D4G clinical trials.
基金Supported by the Natural Science Foundation of Shandong Prov-ince ,China(No.Y2002A05)
文摘On the basis of the quantization of mesoscopic biological cell equivalent circuit,we studied the quantum fluctuations of voltage and current of mesoscopic biological cell equivalent circuit as finite temperature by Bogoliuov transformation.The result shows that the quantum fluctuations of voltage and current not only relate with the parameters of equivalent circuit,temperature,but also decay with time.This result may have significant value on the design and application of the bio-electronic apparatus.
文摘Application of pneumatic separators in coal beneficiation is increasing rapidly over the last decade primarily due to their low capital and operating costs, and waste handling problems associated with traditional wet processing methods. Large amount of shale/rock that is extracted in coal production can be removed prior to transportation at the mine face by using this methodology. Due to the limited washing facilities in India, most of the thermal power plants burn raw coal from run-of-mine (ROM) to generate electricity. This practice causes poor utilization efficiency, high operating and maintenance costs, and high emission rates for the power plants. One potential method that can be utilized is the air-fluidized inclined vibrating deck technology. The technology was demonstrated on a pilot-scale at different coal washeries in India at a feed rate of 5-ton per hour. The pilot-scale evaluation showed that 20 %-25 % high-ash incombustible material can be eliminated from ROM feed with only minor losses in energy content (〈10 %) from respective ROM coal. Furthermore, a feasibility analysis showed significant economic gains in terms of transportation cost, improving power-plant efficiency, and reducing emissions rates by using the technology.
文摘In 70 years since the founding of the People’s Republic of China,China has successfully transitioned from a closed economy to an open economy with the watershed year of reform and opening up in 1978 and modernized its social security system accordingly.This paper divides the transition of China’s social security system into seven stages before and after 1978.The traditional social security system was predicated on the dominant public ownership,a highly centralized economy,and“full employment.”It was congruous with the ownership structure,income distribution,and labor systems under the closed economy.The modern social security system is developed to meet the needs of an open economy and promotes economic development by giving play to consumption and investment,facilitating labor flow,and boosting productivity.The modern social security system requires further supply-side structural reforms to promote the high-quality development of the open economy.