Background:To assess the edema relief effects of complex decongestive therapy(CDT)in patients with breast cancer associated lymphedema after axillary lymph node dissection(ALND).Methods:58 breast cancer patients with ...Background:To assess the edema relief effects of complex decongestive therapy(CDT)in patients with breast cancer associated lymphedema after axillary lymph node dissection(ALND).Methods:58 breast cancer patients with unilateral arm lymphedema after breast cancer ALND were enrolled.The patients were divided into three groups based on the difference of circumference between the affected and unaffected extremity:group 1,mild lymphedema in circumference difference;group 2,moderate lymphedema,and group 3,severe lymphedema.These patients received four weeks of CDT and self-administered home therapy.Arm circumference was measured before,right after CDT,3 months and 12 months of follow-up.Results:In the first group,the circumference difference was 1.53±0.73 cm prior to CDT,and 0.32±0.59 cm right after CDT,and the difference was statistically significant(P<0.001).At the 1-year-follow-up,we got an even higher value than the pre-CDT one,however,there was no significant difference(P=0.175).At the end of CDT,the circumference difference of the third group was 4.52±2.58 cm,significantly lower than the baseline level(8.76±3.07 cm)(P<0.001).In the third group,the reduction of circumference difference was persisted for 12 months.Conclusion:The effects of CDT were maintained for 12 months,while there were differences in progress of circumference difference among the three groups.The effects of patients with severe initial edema(>5 cm increased)last longer.展开更多
Bulking characteristics of gangue are of great significance for the stability of goafs in mining overburden in the caving zones.In this paper,a particle discrete element method with clusters to represent gangue was ad...Bulking characteristics of gangue are of great significance for the stability of goafs in mining overburden in the caving zones.In this paper,a particle discrete element method with clusters to represent gangue was adopted to explore the bulking coefficient time effect of the broken rock in the caving zone under three-dimensional triaxial compression condition.The phenomena of stress corrosion,deformation,and failure of rock blocks were simulated in the numerical model.Meanwhile,a new criterion of rock fragments damage was put forward.It was found that the broken rock has obvious viscoelastic properties.A new equation based on the Burgers creep model was proposed to predict the bulking coefficient of broken rock.A deformation characteristic parameter of the prediction equation was analyzed,which can be set as a fixed value in the mid-and long-term prediction of the bulking coefficient.There are quadratic function relationships between the deformation characteristic parameter value and Talbot gradation index,axial pressure and confining pressure.展开更多
Through the differentiating and integrating process, a mathematical model for tempering time effect on quenched steel was derived based on the attribute of state function and the general equation of Hollomon parameter...Through the differentiating and integrating process, a mathematical model for tempering time effect on quenched steel was derived based on the attribute of state function and the general equation of Hollomon parameter, which correlates the tempering hardness with the tempering time at different tempering temperature. Using the established model, the linear relationship between the tempering hardness and the tempering time in logarithm was proved theoretically, and the tempering hardness for various tempering time was reduced to the measurement and calculation of a hardness experiment tempered for 1 h at different tempering temperatures. Moreover, the hardness of steel 42CrMo and T8Mn tempered for various times at 200-600℃ was calculated using this method. The predicted results are in good agreement with those of the available experiments.展开更多
This paper presents an investigation of temperature, displacement, stress, and induced magnetic field in a half space perfectly-conductive plate. Finite element equations regarding generalized magneto-thermoelasticity...This paper presents an investigation of temperature, displacement, stress, and induced magnetic field in a half space perfectly-conductive plate. Finite element equations regarding generalized magneto-thermoelasticity problems with two relaxation times (i.e., the G-L theory) are derived using the principle of virtual work. For avoiding numerical complication involved in inverse Laplace and Fourier transformation and low precision thereof, the equations are solved directly in time-domain. As a numerical example, the derived equation is used to investigate the generalized magneto-thermoelastic behavior of a semi-infinite plate under magnetic field and subjecting to a thermal shock loading. The results demonstrate that FEM can faithfully predict the deformation of the plate and the induced magnetic field, and most importantly can reveal the sophisticated second sound effect of heat conduction in two-dimensional generalized thermoelastic solids, which is usually difficult to model by routine transformation methods. A peak can be observed in the distribution of stress and induced front and the magnitude of magnetic field at the heat wave the peak decreases with time, which can not be obtained by transformation methods. The new method can also be used to study generalized piezo-thermoelastic problems.展开更多
The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose ...The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose 1 hour after injections. At the same time, a large increase was observed for triacylglycerols and to a much lesser extent for steroids and phospholipids with 0.1 picomol per bee. By contrast, fatty acids, steroids and triacylglycerols exhibited a depress at the higher dose. Most responses were thus biphasic, showing that much attention should be paid to the effects of very low doses of pesticide.展开更多
The behavior of variable transparency glass is studied, and the response time analyzed and measured aimed at applications to welding goggles. Detection apparatus for goggle testing is involved in the design and develo...The behavior of variable transparency glass is studied, and the response time analyzed and measured aimed at applications to welding goggles. Detection apparatus for goggle testing is involved in the design and development. Charac-teristics of the apparatus are discussed based on experiments. The definition of nominal response time and effective response time are presented based on the analysis and calculation with experimental data.展开更多
The effect of reduced glutathione (GSH) on fresh and pre-proofed frozen dough rheological properties were investigated using dynamic stress rheometry and small scale extensibility with the addition of three levels (80...The effect of reduced glutathione (GSH) on fresh and pre-proofed frozen dough rheological properties were investigated using dynamic stress rheometry and small scale extensibility with the addition of three levels (80×10-6, 160× 10-6 and 240×10-6 GSH) and six storage times (0 and 1 day, 2, 4, 6 and 8 weeks). Three relaxation times (1, 13 and 26min) after loading the dough in the rheometer were used to determine storage (G’) and loss (G”) moduli. Correlations for G’ (r=0.678 and 0.622 at 0.05, and 10Hz, respectively) and G” (r=0.699, and 0.690 at 0.05, and 10Hz, respectively) were observed with the area under the extension curve at 26 min relaxation time. The addition of GSH to fresh dough reduced G’ (16.4% to 55.9%) and G” (13.7% to 52.2%). Freezing and frozen storage caused increase in G’ and G”. The addition of GSH reduced dough strength indicated by the reduction in maximum resistance to extension (Rmax) and the ratio of maximum resistance to extensibility (Rmax/E). The reduction in Rmax across all relaxation times ranged from 16.2% to 59.4%. An increase in dough extension (E) was observed with 240×10-6 GSH at all frozen storage and rest period times. Addition of GSH caused an increase of liquid phase (30.6% to 35.3%) in fresh dough and frozen dough (10.3% to 20.7%) after one day frozen storage. Negative correlations of water content in the solid phase with dough extensibility and area under the extensibility curve were found (r=-0.594 and-0.563, respectively, p<0.001). This suggests a loss of dough extensibility and strength as the water holding capacity of the dough components changes during frozen storage.展开更多
Biological soil crusts (BSCs) are an important type of land cover in arid desert landscapes and play an important role in the carbon source-sink exchange within a desert system. In this study, two typical BSCs, moss...Biological soil crusts (BSCs) are an important type of land cover in arid desert landscapes and play an important role in the carbon source-sink exchange within a desert system. In this study, two typical BSCs, moss crusts and algae crusts, were selected from a revegetated sandy area of the Tengger Desert in northern China, and the experiment was carried out over a 3-year period from January 2010 to November 2012. We obtained the effec- tive active wetting time to maintain the physiological activity of BSCs basing on continuous field measurements and previous laboratory studies on BSCs photosynthesis and respiration rates. And then we developed a BSCs carbon fixation model that is driven by soil moisture. The results indicated that moss crusts and algae crusts had significant effects on soil moisture and temperature dynamics by decreasing rainfall infiltration. The mean carbon fixation rates of moss and algae crusts were 0.21 and 0.13 g C/(m2.d), respectively. The annual carbon fixations of moss crusts and algae crusts were 64.9 and 38.6 g C/(m2.a), respectively, and the carbon fixation of non-rainfall water reached 11.6 g C/(m2.a) (30.2% of the total) and 8.8 g C/(m2.a) (43.6% of the total), respectively. Finally, the model was tested and verified with continuous field observations. The data of the modeled and measured CO2 fluxes matched notably well. In desert regions, the carbon fixation is higher with high-frequency rainfall even the total amount of seasonal rainfall was the same.展开更多
Throughout the service life, underground structures are subjected to transient and sustained hydrostatic pressures. The reservoir impoundment results in an increase in water level, as well as hydraulic gradient,which ...Throughout the service life, underground structures are subjected to transient and sustained hydrostatic pressures. The reservoir impoundment results in an increase in water level, as well as hydraulic gradient,which can endanger the uplift performance of infrastructure. In uplift design, a reduction factor is often suggested for buoyant force acting on underground structures in clays due to the time lag effect.However, the mechanism of pore pressure generation in clays is not fully understood. This investigation presents a novel U-shaped test chamber to assess the pore pressure generation with time in the horizontal branch subjected to an increase in reservoir level in the left vertical branch. A mathematical model is developed to explain the time lag effect of pore pressure generation. The test program also involves the evaluation of uplift pressure acting on foundation model in the right vertical branch due to adjacent reservoir impoundment. It is found that the time lag effect of pore pressure generation in clays can be observed irrespective of hydraulic gradient, but a higher hydraulic gradient can lead to a faster response in pore pressure sensors. A reduction factor of 0.84-0.87 should be considered to reduce the conservatism of uplift design.展开更多
A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and...A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and strength degradation and pinching effects, and hysteretic damping are taken into account in a simple manner by utilizing plastic energy and seismic input energy modification factors. Having a pre-selected yield mechanism, energy balance of structure in inelastic range is considered. P-delta effects are included in derived equation by adding the external work of gravity loads to the work of equivalent inertia forces and equating the total external work to the modified plastic energy. Earthquake energy input to multi degree of freedom(MDOF) system is approximated by using the modal energy-decomposition. Energybased base shear coefficients are verified by means of both pushover analysis and nonlinear time history(NLTH) analysis of several RC frames having different number of stories. NLTH analyses of frames are performed by using the time histories of ten scaled ground motions compatible with elastic design acceleration spectrum and fulfilling duration/amplitude related requirements of Turkish Seismic Design Code. The observed correlation between energy-based base shear force coefficients and the average base shear force coefficients of NLTH analyses provides a reasonable confidence in estimation of nonlinear base shear force capacity of frames by using the derived equation.展开更多
This paper proposes a mechanism theory on regional development by using a modified Logistic model. It reveals regional evolution is an integration of fluctuation in temporal dimension and disparity in spatial dimensio...This paper proposes a mechanism theory on regional development by using a modified Logistic model. It reveals regional evolution is an integration of fluctuation in temporal dimension and disparity in spatial dimension. T = S model is established by using Logistic model to simulate the growth of per capita GDP in China from 1990 to 1999. The result shows that T=S model accurately simulates the tracks of economic growth.展开更多
Purpose: To evaluate the performance of a phacoemulsification system in terms of effective (EPT) and total phaco time (TPT) using 20G and 21G phaco tips. Methods: Retrospective comparative study including 143 consecut...Purpose: To evaluate the performance of a phacoemulsification system in terms of effective (EPT) and total phaco time (TPT) using 20G and 21G phaco tips. Methods: Retrospective comparative study including 143 consecutive cataractous eyes undergoing phacoemulsification cataract surgery with the Visalis 500 device. The 20G and 21G phaco tips were used in 46 and 97 eyes, respectively. The EPT and TPT values were evaluated. Results: Median TPT was 11.25 s and 17.50 s in the 20G and 21G groups, respectively (p = 0.0011). Median EPT values were 3.15 s and 5.00 s in the 20G and 21G groups, respectively (p = 0.0032). TPT and EPT were significantly lower in 3/3+ cataract eyes compared to 4/4+ using both tips (p < 0.001). Conclusions: The Visalis 500 allows cataract surgery with reduced TPT and EPT, even in hard cataracts. The use of the 20G phaco tip provides an additional benefit in terms of reduction of phaco time.展开更多
This study is to utilize the heat-absorbing and releasing capabilities of phase change materials(PCM)to regulate the surface temperature fluctuations of batteries during charging and discharging.The goal is to keep th...This study is to utilize the heat-absorbing and releasing capabilities of phase change materials(PCM)to regulate the surface temperature fluctuations of batteries during charging and discharging.The goal is to keep the battery within the optimal operating temperature range.The impact of PCM thickness and phase change temperature on battery temperature is investigated by encircling a cylindrical battery with a PCM ring.To improve the thermal conductivity of PCM,expanded graphite(EG) is added to make a composite phase change material(CPCM),and the effects of various EG mass ratios on battery surface temperature and CPCM utilization level are investigated.The findings indicate that increasing PCM thickness effectively extends temperature control time,but its impact is limited.The difference in phase change temperature of PCM controls the battery temperature in different temperature ranges.Lower phase change temperatures are unsuitable for controlling battery temperature in high temperature environments.The addition of EG enhances the thermal conductivity of PCM,leading to further control of battery temperature.The results show that the addition of 6%(mass ratio) EG to CPCM extends the effective temperature control time by 11 min and improves by 28% compared to a single PCM.The CPCM utilization is also more satisfactory and achieved a balance between heat storage and thermal conductivity in a battery thermal management system(BTMS) based on PCM.展开更多
Under internal blast loading,the response of a beam or plate is highly correlated with the phenomenon of saturated impulse,which governs the deflection of the structure.This paper aims to investigate the phenomenon of...Under internal blast loading,the response of a beam or plate is highly correlated with the phenomenon of saturated impulse,which governs the deflection of the structure.This paper aims to investigate the phenomenon of saturated impulse for fully clamped rectangular plates subjected to internal blast loading.Based on the rigid,perfectly plastic assumption,the relationship between saturation duration and saturation deflection is derived.Influences of the peak shock wave,the duration of shock wave and the peak quasi-static pressure loading on saturation duration and saturation deflection are discussed.It is found that there is a critical duration for the internal blast impulse to reach saturation,and beyond this duration,the deflection of plate will no longer increase as the loading increases further.The saturation deflection and saturation duration both exhibit regular variation patterns with the changes of the dimensionless peak shock wave,the duration of shock wave and the peak quasi-static pressure loading.展开更多
The objective of this paper is to identify time lag effect in the relationship between supply chain management and financial performance.We hypothesize that firms with higher supply chain management capability are ass...The objective of this paper is to identify time lag effect in the relationship between supply chain management and financial performance.We hypothesize that firms with higher supply chain management capability are associated with higher financial performance and the impact would last longer.In addition,we introduce two contextual variables,ownership and market orientation,to detect the moderating effect of ownership structure and organizational culture,respectively.We use firm-level empirical data from 1,131 public Chinese manufacturing firms for the 2010–2019 period to investigate the effect and the result shows that there is a two-year time lag effect in the relationship,which means the positive impact of current supply chain management would last for three years.Furthermore,we find evidence that supply chain management in non-state-owned firms is more efficient and its positive financial impact would last longer than that in state-owned enterprises.Finally,we indicate that market-orientation can’t moderate the relationship between supply chain management and financial performance.展开更多
Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy with tile use of a pulsed lapser transmitter and streak tube receiver to produce 3D range inlages. This work investigates t...Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy with tile use of a pulsed lapser transmitter and streak tube receiver to produce 3D range inlages. This work investigates the effect of tile time bin size oil the range accuracy of STIL systems based on the peak detection algorithm. The nunlerical simulation indicates that the time bin size has a significant effect on the range aceuracy, resulting in a modified analytical estimate of the range error. An indoor experilnent with a planar target is carried out to validate the theory that shows the linear relationship between tile range error and the time bin size. Finer 3D depth iinages of a fist model are acquired by using a smaller time bin size and the best range error of 0.003 In is achieved with the optimal time bin size of 0.07 ns.展开更多
The accuracy of information network partition is not high and the characteristics of metapath cannot represent the attributes of network nodes in the existing academic citation recommendation algorithms.In order to so...The accuracy of information network partition is not high and the characteristics of metapath cannot represent the attributes of network nodes in the existing academic citation recommendation algorithms.In order to solve the problems,a similarity measurement algorithm,community merging and time effect PathSim(CMTE-PathSim),based on community merging and time effect is proposed.On the premise of dividing heterogeneous information network(HIN)effectively,the algorithm considers the influence of node information on the characteristics of metapath.The results of Top-k query verify the effectiveness of CMTE-PathSim on real datasets and improve the quality of citation recommendation.展开更多
Background 131Ⅰ therapy is recognized as the simplest, safest, least expensive, and most effective treatment, and accepted by more and more patients. However its curative effect is influenced by many factors, therefo...Background 131Ⅰ therapy is recognized as the simplest, safest, least expensive, and most effective treatment, and accepted by more and more patients. However its curative effect is influenced by many factors, therefore there are some difficulties for doctors to establish individual treatment strategy. The aims of this study were to determine the incidence of early and late hypothyroidism after 131Ⅰ treatment for Graves' disease (GD) and to compare their correlation, to observe and analyze the influential factors and to understand the predictabilities of them.Methods Five hundred GD patients (144 males, 356 females; age (41.2±12.3) years) received 131Ⅰ treatment for the first time. The therapeutic procedure was carried out as the following: undergoing 131Ⅰ uptake test to obtain maximum of thyroid uptake value and effective half-life (EHL) time; estimating the thyroid's weight by ultrasonography; determination of thyroid hormones and correlative antibodies; pre-therapy physical examination; thyroid imaging; calculating 131Ⅰtherapeutic dosage; per os uptake of the determined 131Ⅰ dosage; follow-up appraisal of curative effect. The observing parameters included age, gender, thyroid weight, GD duration, condition of onset, state of disease, course of treatment, EHL time, maximum of thyroid uptake value, 131Ⅰ dosage and titer of correlative antibodies. We sorted out the data and used both univariate and multivariate analysis to evaluate them statistically.Results The incidence rates of early and late hypothyroidism were 33.2% and 6.6% respectively after 131Ⅰ treatment and approximately 22.2% cases of late hypothyroidism developed from early hypothyroidism. The influential factors of early hypothyroidism included course of GD, the highest thyroid uptake ratio of 131Ⅰ, EHL time and thyroid microsome antibody (TMAb), etc. A multivariate analysis on late hypothyroidism showed that female patients, with recurrence after anti-thyroid drug treatment and higher thyroid weight, had lower possibility of late hypothyroidism after 131Ⅰ therapy.Conclusions The incidence of early hypothyroidism is higher than that of late hypothyroidism. The highest thyroid uptake ratio of 131Ⅰ, EHL and TMAb will increase the possibility of early hypothyroidism, while GD course is the protective factor. Higher 131Ⅰ dosage, longer EHL and higher TMAb titer will also increase the possibility of late hypothyroidism. The multi-perspective and multi-factor analysis has the benefit to establish individualized treatment strategy.展开更多
The error propagation for general numerical method in ordinarydifferential equations ODEs is studied. Three kinds of convergence, theoretical, numerical and actual convergences, are presented. The various components o...The error propagation for general numerical method in ordinarydifferential equations ODEs is studied. Three kinds of convergence, theoretical, numerical and actual convergences, are presented. The various components of round-off error occurring in floating-point computation are fully detailed. By introducing a new kind of recurrent inequality, the classical error bounds for linear multistep methods are essentially improved, and joining probabilistic theory the “normal” growth of accumulated round-off error is derived. Moreover, a unified estimate for the total error of general method is given. On the basis of these results, we rationally interpret the various phenomena found in the numerical experiments in part I of this paper and derive two universal relations which are independent of types of ODEs, initial values and numerical schemes and are consistent with the numerical results. Furthermore, we give the explicitly mathematical expression of the computational uncertainty principle and expound the intrinsic relation between two uncertainties which result from the inaccuracies of numerical method and calculating machine.展开更多
文摘Background:To assess the edema relief effects of complex decongestive therapy(CDT)in patients with breast cancer associated lymphedema after axillary lymph node dissection(ALND).Methods:58 breast cancer patients with unilateral arm lymphedema after breast cancer ALND were enrolled.The patients were divided into three groups based on the difference of circumference between the affected and unaffected extremity:group 1,mild lymphedema in circumference difference;group 2,moderate lymphedema,and group 3,severe lymphedema.These patients received four weeks of CDT and self-administered home therapy.Arm circumference was measured before,right after CDT,3 months and 12 months of follow-up.Results:In the first group,the circumference difference was 1.53±0.73 cm prior to CDT,and 0.32±0.59 cm right after CDT,and the difference was statistically significant(P<0.001).At the 1-year-follow-up,we got an even higher value than the pre-CDT one,however,there was no significant difference(P=0.175).At the end of CDT,the circumference difference of the third group was 4.52±2.58 cm,significantly lower than the baseline level(8.76±3.07 cm)(P<0.001).In the third group,the reduction of circumference difference was persisted for 12 months.Conclusion:The effects of CDT were maintained for 12 months,while there were differences in progress of circumference difference among the three groups.The effects of patients with severe initial edema(>5 cm increased)last longer.
基金This work was supported by the National Natural Science Foundation of China,NSFC(Nos.U1803118 and 51974296)and the China Scholarship Council(CSC)(award to Fanfei Meng for PhD period at Kyushu University).
文摘Bulking characteristics of gangue are of great significance for the stability of goafs in mining overburden in the caving zones.In this paper,a particle discrete element method with clusters to represent gangue was adopted to explore the bulking coefficient time effect of the broken rock in the caving zone under three-dimensional triaxial compression condition.The phenomena of stress corrosion,deformation,and failure of rock blocks were simulated in the numerical model.Meanwhile,a new criterion of rock fragments damage was put forward.It was found that the broken rock has obvious viscoelastic properties.A new equation based on the Burgers creep model was proposed to predict the bulking coefficient of broken rock.A deformation characteristic parameter of the prediction equation was analyzed,which can be set as a fixed value in the mid-and long-term prediction of the bulking coefficient.There are quadratic function relationships between the deformation characteristic parameter value and Talbot gradation index,axial pressure and confining pressure.
文摘Through the differentiating and integrating process, a mathematical model for tempering time effect on quenched steel was derived based on the attribute of state function and the general equation of Hollomon parameter, which correlates the tempering hardness with the tempering time at different tempering temperature. Using the established model, the linear relationship between the tempering hardness and the tempering time in logarithm was proved theoretically, and the tempering hardness for various tempering time was reduced to the measurement and calculation of a hardness experiment tempered for 1 h at different tempering temperatures. Moreover, the hardness of steel 42CrMo and T8Mn tempered for various times at 200-600℃ was calculated using this method. The predicted results are in good agreement with those of the available experiments.
基金The project supported by the National Natural Science Foundation of China(10132010 and 10472089)
文摘This paper presents an investigation of temperature, displacement, stress, and induced magnetic field in a half space perfectly-conductive plate. Finite element equations regarding generalized magneto-thermoelasticity problems with two relaxation times (i.e., the G-L theory) are derived using the principle of virtual work. For avoiding numerical complication involved in inverse Laplace and Fourier transformation and low precision thereof, the equations are solved directly in time-domain. As a numerical example, the derived equation is used to investigate the generalized magneto-thermoelastic behavior of a semi-infinite plate under magnetic field and subjecting to a thermal shock loading. The results demonstrate that FEM can faithfully predict the deformation of the plate and the induced magnetic field, and most importantly can reveal the sophisticated second sound effect of heat conduction in two-dimensional generalized thermoelastic solids, which is usually difficult to model by routine transformation methods. A peak can be observed in the distribution of stress and induced front and the magnitude of magnetic field at the heat wave the peak decreases with time, which can not be obtained by transformation methods. The new method can also be used to study generalized piezo-thermoelastic problems.
文摘The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose 1 hour after injections. At the same time, a large increase was observed for triacylglycerols and to a much lesser extent for steroids and phospholipids with 0.1 picomol per bee. By contrast, fatty acids, steroids and triacylglycerols exhibited a depress at the higher dose. Most responses were thus biphasic, showing that much attention should be paid to the effects of very low doses of pesticide.
基金the Science and Technology Commission of Shanghai Municipality (Grant No.052912015)
文摘The behavior of variable transparency glass is studied, and the response time analyzed and measured aimed at applications to welding goggles. Detection apparatus for goggle testing is involved in the design and development. Charac-teristics of the apparatus are discussed based on experiments. The definition of nominal response time and effective response time are presented based on the analysis and calculation with experimental data.
基金Financial Support of Oklahorna Wheat Foundation, Oklahome Wheat Commission and Oklahoma Experiment Station of Oklahoma State University.
文摘The effect of reduced glutathione (GSH) on fresh and pre-proofed frozen dough rheological properties were investigated using dynamic stress rheometry and small scale extensibility with the addition of three levels (80×10-6, 160× 10-6 and 240×10-6 GSH) and six storage times (0 and 1 day, 2, 4, 6 and 8 weeks). Three relaxation times (1, 13 and 26min) after loading the dough in the rheometer were used to determine storage (G’) and loss (G”) moduli. Correlations for G’ (r=0.678 and 0.622 at 0.05, and 10Hz, respectively) and G” (r=0.699, and 0.690 at 0.05, and 10Hz, respectively) were observed with the area under the extension curve at 26 min relaxation time. The addition of GSH to fresh dough reduced G’ (16.4% to 55.9%) and G” (13.7% to 52.2%). Freezing and frozen storage caused increase in G’ and G”. The addition of GSH reduced dough strength indicated by the reduction in maximum resistance to extension (Rmax) and the ratio of maximum resistance to extensibility (Rmax/E). The reduction in Rmax across all relaxation times ranged from 16.2% to 59.4%. An increase in dough extension (E) was observed with 240×10-6 GSH at all frozen storage and rest period times. Addition of GSH caused an increase of liquid phase (30.6% to 35.3%) in fresh dough and frozen dough (10.3% to 20.7%) after one day frozen storage. Negative correlations of water content in the solid phase with dough extensibility and area under the extensibility curve were found (r=-0.594 and-0.563, respectively, p<0.001). This suggests a loss of dough extensibility and strength as the water holding capacity of the dough components changes during frozen storage.
基金supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX2-EW-301-3)the National Program on Key Basic Research Project (2013CB429905)+1 种基金the National Natural Scientific Foundation of China (41201084 31170385)
文摘Biological soil crusts (BSCs) are an important type of land cover in arid desert landscapes and play an important role in the carbon source-sink exchange within a desert system. In this study, two typical BSCs, moss crusts and algae crusts, were selected from a revegetated sandy area of the Tengger Desert in northern China, and the experiment was carried out over a 3-year period from January 2010 to November 2012. We obtained the effec- tive active wetting time to maintain the physiological activity of BSCs basing on continuous field measurements and previous laboratory studies on BSCs photosynthesis and respiration rates. And then we developed a BSCs carbon fixation model that is driven by soil moisture. The results indicated that moss crusts and algae crusts had significant effects on soil moisture and temperature dynamics by decreasing rainfall infiltration. The mean carbon fixation rates of moss and algae crusts were 0.21 and 0.13 g C/(m2.d), respectively. The annual carbon fixations of moss crusts and algae crusts were 64.9 and 38.6 g C/(m2.a), respectively, and the carbon fixation of non-rainfall water reached 11.6 g C/(m2.a) (30.2% of the total) and 8.8 g C/(m2.a) (43.6% of the total), respectively. Finally, the model was tested and verified with continuous field observations. The data of the modeled and measured CO2 fluxes matched notably well. In desert regions, the carbon fixation is higher with high-frequency rainfall even the total amount of seasonal rainfall was the same.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51878185, 52078506, and 52178321)
文摘Throughout the service life, underground structures are subjected to transient and sustained hydrostatic pressures. The reservoir impoundment results in an increase in water level, as well as hydraulic gradient,which can endanger the uplift performance of infrastructure. In uplift design, a reduction factor is often suggested for buoyant force acting on underground structures in clays due to the time lag effect.However, the mechanism of pore pressure generation in clays is not fully understood. This investigation presents a novel U-shaped test chamber to assess the pore pressure generation with time in the horizontal branch subjected to an increase in reservoir level in the left vertical branch. A mathematical model is developed to explain the time lag effect of pore pressure generation. The test program also involves the evaluation of uplift pressure acting on foundation model in the right vertical branch due to adjacent reservoir impoundment. It is found that the time lag effect of pore pressure generation in clays can be observed irrespective of hydraulic gradient, but a higher hydraulic gradient can lead to a faster response in pore pressure sensors. A reduction factor of 0.84-0.87 should be considered to reduce the conservatism of uplift design.
文摘A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and strength degradation and pinching effects, and hysteretic damping are taken into account in a simple manner by utilizing plastic energy and seismic input energy modification factors. Having a pre-selected yield mechanism, energy balance of structure in inelastic range is considered. P-delta effects are included in derived equation by adding the external work of gravity loads to the work of equivalent inertia forces and equating the total external work to the modified plastic energy. Earthquake energy input to multi degree of freedom(MDOF) system is approximated by using the modal energy-decomposition. Energybased base shear coefficients are verified by means of both pushover analysis and nonlinear time history(NLTH) analysis of several RC frames having different number of stories. NLTH analyses of frames are performed by using the time histories of ten scaled ground motions compatible with elastic design acceleration spectrum and fulfilling duration/amplitude related requirements of Turkish Seismic Design Code. The observed correlation between energy-based base shear force coefficients and the average base shear force coefficients of NLTH analyses provides a reasonable confidence in estimation of nonlinear base shear force capacity of frames by using the derived equation.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences and National Key Technologies R &D Program in the 10th Five-Ycar Plan of china(2001BA901A40)
文摘This paper proposes a mechanism theory on regional development by using a modified Logistic model. It reveals regional evolution is an integration of fluctuation in temporal dimension and disparity in spatial dimension. T = S model is established by using Logistic model to simulate the growth of per capita GDP in China from 1990 to 1999. The result shows that T=S model accurately simulates the tracks of economic growth.
文摘Purpose: To evaluate the performance of a phacoemulsification system in terms of effective (EPT) and total phaco time (TPT) using 20G and 21G phaco tips. Methods: Retrospective comparative study including 143 consecutive cataractous eyes undergoing phacoemulsification cataract surgery with the Visalis 500 device. The 20G and 21G phaco tips were used in 46 and 97 eyes, respectively. The EPT and TPT values were evaluated. Results: Median TPT was 11.25 s and 17.50 s in the 20G and 21G groups, respectively (p = 0.0011). Median EPT values were 3.15 s and 5.00 s in the 20G and 21G groups, respectively (p = 0.0032). TPT and EPT were significantly lower in 3/3+ cataract eyes compared to 4/4+ using both tips (p < 0.001). Conclusions: The Visalis 500 allows cataract surgery with reduced TPT and EPT, even in hard cataracts. The use of the 20G phaco tip provides an additional benefit in terms of reduction of phaco time.
文摘This study is to utilize the heat-absorbing and releasing capabilities of phase change materials(PCM)to regulate the surface temperature fluctuations of batteries during charging and discharging.The goal is to keep the battery within the optimal operating temperature range.The impact of PCM thickness and phase change temperature on battery temperature is investigated by encircling a cylindrical battery with a PCM ring.To improve the thermal conductivity of PCM,expanded graphite(EG) is added to make a composite phase change material(CPCM),and the effects of various EG mass ratios on battery surface temperature and CPCM utilization level are investigated.The findings indicate that increasing PCM thickness effectively extends temperature control time,but its impact is limited.The difference in phase change temperature of PCM controls the battery temperature in different temperature ranges.Lower phase change temperatures are unsuitable for controlling battery temperature in high temperature environments.The addition of EG enhances the thermal conductivity of PCM,leading to further control of battery temperature.The results show that the addition of 6%(mass ratio) EG to CPCM extends the effective temperature control time by 11 min and improves by 28% compared to a single PCM.The CPCM utilization is also more satisfactory and achieved a balance between heat storage and thermal conductivity in a battery thermal management system(BTMS) based on PCM.
基金The authors would like to thank the support from the National Natural Science Foundation of China under Grant No.11802030.
文摘Under internal blast loading,the response of a beam or plate is highly correlated with the phenomenon of saturated impulse,which governs the deflection of the structure.This paper aims to investigate the phenomenon of saturated impulse for fully clamped rectangular plates subjected to internal blast loading.Based on the rigid,perfectly plastic assumption,the relationship between saturation duration and saturation deflection is derived.Influences of the peak shock wave,the duration of shock wave and the peak quasi-static pressure loading on saturation duration and saturation deflection are discussed.It is found that there is a critical duration for the internal blast impulse to reach saturation,and beyond this duration,the deflection of plate will no longer increase as the loading increases further.The saturation deflection and saturation duration both exhibit regular variation patterns with the changes of the dimensionless peak shock wave,the duration of shock wave and the peak quasi-static pressure loading.
基金This work was supported by the National Natural Science Foundation of China(NSFC),under Grant 71871114.
文摘The objective of this paper is to identify time lag effect in the relationship between supply chain management and financial performance.We hypothesize that firms with higher supply chain management capability are associated with higher financial performance and the impact would last longer.In addition,we introduce two contextual variables,ownership and market orientation,to detect the moderating effect of ownership structure and organizational culture,respectively.We use firm-level empirical data from 1,131 public Chinese manufacturing firms for the 2010–2019 period to investigate the effect and the result shows that there is a two-year time lag effect in the relationship,which means the positive impact of current supply chain management would last for three years.Furthermore,we find evidence that supply chain management in non-state-owned firms is more efficient and its positive financial impact would last longer than that in state-owned enterprises.Finally,we indicate that market-orientation can’t moderate the relationship between supply chain management and financial performance.
基金supported by the National Key Scientific Instrument and Equipment Development Projects of China under Grant No.2012YQ040164
文摘Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy with tile use of a pulsed lapser transmitter and streak tube receiver to produce 3D range inlages. This work investigates the effect of tile time bin size oil the range accuracy of STIL systems based on the peak detection algorithm. The nunlerical simulation indicates that the time bin size has a significant effect on the range aceuracy, resulting in a modified analytical estimate of the range error. An indoor experilnent with a planar target is carried out to validate the theory that shows the linear relationship between tile range error and the time bin size. Finer 3D depth iinages of a fist model are acquired by using a smaller time bin size and the best range error of 0.003 In is achieved with the optimal time bin size of 0.07 ns.
基金Supported by the Scientific Research Fund of Liaoning Provincial Education Department(L2019048)Talent Scientific Research Rund of LSHU(2016XJJ-033)of China.
文摘The accuracy of information network partition is not high and the characteristics of metapath cannot represent the attributes of network nodes in the existing academic citation recommendation algorithms.In order to solve the problems,a similarity measurement algorithm,community merging and time effect PathSim(CMTE-PathSim),based on community merging and time effect is proposed.On the premise of dividing heterogeneous information network(HIN)effectively,the algorithm considers the influence of node information on the characteristics of metapath.The results of Top-k query verify the effectiveness of CMTE-PathSim on real datasets and improve the quality of citation recommendation.
文摘Background 131Ⅰ therapy is recognized as the simplest, safest, least expensive, and most effective treatment, and accepted by more and more patients. However its curative effect is influenced by many factors, therefore there are some difficulties for doctors to establish individual treatment strategy. The aims of this study were to determine the incidence of early and late hypothyroidism after 131Ⅰ treatment for Graves' disease (GD) and to compare their correlation, to observe and analyze the influential factors and to understand the predictabilities of them.Methods Five hundred GD patients (144 males, 356 females; age (41.2±12.3) years) received 131Ⅰ treatment for the first time. The therapeutic procedure was carried out as the following: undergoing 131Ⅰ uptake test to obtain maximum of thyroid uptake value and effective half-life (EHL) time; estimating the thyroid's weight by ultrasonography; determination of thyroid hormones and correlative antibodies; pre-therapy physical examination; thyroid imaging; calculating 131Ⅰtherapeutic dosage; per os uptake of the determined 131Ⅰ dosage; follow-up appraisal of curative effect. The observing parameters included age, gender, thyroid weight, GD duration, condition of onset, state of disease, course of treatment, EHL time, maximum of thyroid uptake value, 131Ⅰ dosage and titer of correlative antibodies. We sorted out the data and used both univariate and multivariate analysis to evaluate them statistically.Results The incidence rates of early and late hypothyroidism were 33.2% and 6.6% respectively after 131Ⅰ treatment and approximately 22.2% cases of late hypothyroidism developed from early hypothyroidism. The influential factors of early hypothyroidism included course of GD, the highest thyroid uptake ratio of 131Ⅰ, EHL time and thyroid microsome antibody (TMAb), etc. A multivariate analysis on late hypothyroidism showed that female patients, with recurrence after anti-thyroid drug treatment and higher thyroid weight, had lower possibility of late hypothyroidism after 131Ⅰ therapy.Conclusions The incidence of early hypothyroidism is higher than that of late hypothyroidism. The highest thyroid uptake ratio of 131Ⅰ, EHL and TMAb will increase the possibility of early hypothyroidism, while GD course is the protective factor. Higher 131Ⅰ dosage, longer EHL and higher TMAb titer will also increase the possibility of late hypothyroidism. The multi-perspective and multi-factor analysis has the benefit to establish individualized treatment strategy.
基金This work was supported by the Knowledge Innovation Key Project of Chinese Academy of Sciences inthe Resource Environment Field (KZCX1-203) Outstanding State Key Laboratory Project (Grant No. 49823002) the National Natural Science Foundation of C
文摘The error propagation for general numerical method in ordinarydifferential equations ODEs is studied. Three kinds of convergence, theoretical, numerical and actual convergences, are presented. The various components of round-off error occurring in floating-point computation are fully detailed. By introducing a new kind of recurrent inequality, the classical error bounds for linear multistep methods are essentially improved, and joining probabilistic theory the “normal” growth of accumulated round-off error is derived. Moreover, a unified estimate for the total error of general method is given. On the basis of these results, we rationally interpret the various phenomena found in the numerical experiments in part I of this paper and derive two universal relations which are independent of types of ODEs, initial values and numerical schemes and are consistent with the numerical results. Furthermore, we give the explicitly mathematical expression of the computational uncertainty principle and expound the intrinsic relation between two uncertainties which result from the inaccuracies of numerical method and calculating machine.