Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its infl...Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation（R_s） and vapor pressure deficit of the air（VPD_（air））. Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in R_s and preceded the changes in VPD_（air） both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize＇s sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and R_s in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPD_（air） in comparison with wet soil and also increase the speed by which sap flow adjusts to R_s. However, sap flow lags that were associated with R_s before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements.展开更多
Vacuum precision seed metering is the key part of vacuum seed planter. Planting performance of planter is affected by vacuum and air flow which are important parameters for choosing fan. Effects of qualification perce...Vacuum precision seed metering is the key part of vacuum seed planter. Planting performance of planter is affected by vacuum and air flow which are important parameters for choosing fan. Effects of qualification percent and miss percent on air chamber vacuum 3, 4, 5 and 6 kPa were studied at different operating speeds. The results showed that operating performance of the seed metering was excellent when air chamber vacuum was 5 and 6 kPa, which air flow was 7.4-8.0 m3·s-1 and 8.0-8.8 m3·s-1 , respectively.展开更多
AIM： To evaluate the efficacy and safety of orbital decomposition （OD） surgery in combination with horse chestnut seed extract （HCSE）, as compared to OD atone, in patients with thyroid-associated ophthalmopathy ...AIM： To evaluate the efficacy and safety of orbital decomposition （OD） surgery in combination with horse chestnut seed extract （HCSE）, as compared to OD atone, in patients with thyroid-associated ophthalmopathy （TAO）. METHODS： Sixty-two orbits from 62 TAO patients were randomly assigned to OD or OD＋HCSE at 1：1 ratio （31 received OD alone, 31 received OD ＋HCSE）. Forty-two orbits from 21 healthy subjects were used as controls. Complete ophthalmic examination and color Doppler flow imaging （CDFI） were performed before surgery and 3mo post-surgery on all 62 orbits from the TAO patients. CDFI were also performed on the 42 control orbits, The effect of OD ＋HCSE and OD alone on TAO orbits was compared on several endpoints, including superior ophthalmic vein blood flow （SOVBF） parameters, subjective assessment, soft tissue involvement, lid retraction, diplopia, eye movement restriction, degree of exophthalmos, and intraocular pressure. The control orbits were used as reference for the SOVBF parameters. RESULTS： OD surgery with or without HCSE improved SOVBF, symptoms and soft tissue involvement, decreased degree of exophthalmos and intraocular pressure in orbits of TAO patients. The OD ＋HCSE combination led to significantly better improvement of SOVBF than OD alone. The differences between the reductions of SOVBF in the two groups are 1.26 cmls in max-volecity and 0.52 cm/s in min-voiecity （P〈0.0001）. CONCLUSION： SOVBF is significantly reduced in the orbits affected with TAO, indicating that congestion may be an important factor contributing to TAO pathogenesis. OD surgery improves the SOVBF, and combination of HCSE medication and OD surgery further improved venous return than OD surgery alone.展开更多
The tracking characteristics of tracer particles for particle image velocimetry（PIV） measurements in supersonic flows were investigated.The experimental tests were conducted at Mach number 4 in Multi-Mach Wind Tunne...The tracking characteristics of tracer particles for particle image velocimetry（PIV） measurements in supersonic flows were investigated.The experimental tests were conducted at Mach number 4 in Multi-Mach Wind Tunnel（MMWT） of Shanghai Jiao Tong University.The motion of tracer particles carried by the supersonic flow across Shockwaves was theoretically modelled,and then their aerodynamic characteristics with compressibility and rarefaction effects were evaluated.According to the proposed selection criterion of tracer particles,the PIV measured results clearly identified that the Shockwave amplitude is in good agreement with theory and Schlieren visualizations.For the tracer particles in nanoscales,their effective aerodynamic sizes in the diagnostic zone can be faithfully estimated to characterize the tracking capability and dispersity performance based on their relaxation motion across oblique Shockwaves.On the other hand,the seeding system enabled the tracer particles well-controlled and repeatable dispersity against the storage and humidity.展开更多
In this paper, research has been conducted to increase the quantity of fiber produced in the enterprise by creating a sorting device for spun seeds, dividing them into fractions by geometric dimensions, and by re-ginn...In this paper, research has been conducted to increase the quantity of fiber produced in the enterprise by creating a sorting device for spun seeds, dividing them into fractions by geometric dimensions, and by re-ginning, separating those with long fibers. A new model was developed for geometric sorting of cotton seeds in the harvest, and experiments determined its effectiveness and the optimal values of the factors affecting the efficiency using mathematical modeling. Based on the results of the study, graphs of the influence of factors on device performance and on device efficiency were constructed.展开更多
基金support from the National Key Basic Research Program of China (2016YFC0400207)the National Natural Science Foundation of China (51439006, 91425302)the 111 Program of Introducing Talents of Discipline to Universities (B14002)
文摘Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation（R_s） and vapor pressure deficit of the air（VPD_（air））. Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in R_s and preceded the changes in VPD_（air） both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize＇s sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and R_s in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPD_（air） in comparison with wet soil and also increase the speed by which sap flow adjusts to R_s. However, sap flow lags that were associated with R_s before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements.
基金Supported by the Youth Science Foundation of Heilongjiang(QC2010119,QC2010028)the Science and Technology Innovation Person with Ability Study Special Foundation Project of Harbin(2011RFQXN054)+1 种基金the Graduate Student Innovative Scientific Research Project of Heilongjiang(YJSCX2011-064JHL)Division of Soybean Machinery,CARS(nycytx-004)
文摘Vacuum precision seed metering is the key part of vacuum seed planter. Planting performance of planter is affected by vacuum and air flow which are important parameters for choosing fan. Effects of qualification percent and miss percent on air chamber vacuum 3, 4, 5 and 6 kPa were studied at different operating speeds. The results showed that operating performance of the seed metering was excellent when air chamber vacuum was 5 and 6 kPa, which air flow was 7.4-8.0 m3·s-1 and 8.0-8.8 m3·s-1 , respectively.
文摘AIM： To evaluate the efficacy and safety of orbital decomposition （OD） surgery in combination with horse chestnut seed extract （HCSE）, as compared to OD atone, in patients with thyroid-associated ophthalmopathy （TAO）. METHODS： Sixty-two orbits from 62 TAO patients were randomly assigned to OD or OD＋HCSE at 1：1 ratio （31 received OD alone, 31 received OD ＋HCSE）. Forty-two orbits from 21 healthy subjects were used as controls. Complete ophthalmic examination and color Doppler flow imaging （CDFI） were performed before surgery and 3mo post-surgery on all 62 orbits from the TAO patients. CDFI were also performed on the 42 control orbits, The effect of OD ＋HCSE and OD alone on TAO orbits was compared on several endpoints, including superior ophthalmic vein blood flow （SOVBF） parameters, subjective assessment, soft tissue involvement, lid retraction, diplopia, eye movement restriction, degree of exophthalmos, and intraocular pressure. The control orbits were used as reference for the SOVBF parameters. RESULTS： OD surgery with or without HCSE improved SOVBF, symptoms and soft tissue involvement, decreased degree of exophthalmos and intraocular pressure in orbits of TAO patients. The OD ＋HCSE combination led to significantly better improvement of SOVBF than OD alone. The differences between the reductions of SOVBF in the two groups are 1.26 cmls in max-volecity and 0.52 cm/s in min-voiecity （P〈0.0001）. CONCLUSION： SOVBF is significantly reduced in the orbits affected with TAO, indicating that congestion may be an important factor contributing to TAO pathogenesis. OD surgery improves the SOVBF, and combination of HCSE medication and OD surgery further improved venous return than OD surgery alone.
基金supported by the National Natural Science Foundation of China(Nos.11672183,91641129 and 91441205)
文摘The tracking characteristics of tracer particles for particle image velocimetry（PIV） measurements in supersonic flows were investigated.The experimental tests were conducted at Mach number 4 in Multi-Mach Wind Tunnel（MMWT） of Shanghai Jiao Tong University.The motion of tracer particles carried by the supersonic flow across Shockwaves was theoretically modelled,and then their aerodynamic characteristics with compressibility and rarefaction effects were evaluated.According to the proposed selection criterion of tracer particles,the PIV measured results clearly identified that the Shockwave amplitude is in good agreement with theory and Schlieren visualizations.For the tracer particles in nanoscales,their effective aerodynamic sizes in the diagnostic zone can be faithfully estimated to characterize the tracking capability and dispersity performance based on their relaxation motion across oblique Shockwaves.On the other hand,the seeding system enabled the tracer particles well-controlled and repeatable dispersity against the storage and humidity.
文摘In this paper, research has been conducted to increase the quantity of fiber produced in the enterprise by creating a sorting device for spun seeds, dividing them into fractions by geometric dimensions, and by re-ginning, separating those with long fibers. A new model was developed for geometric sorting of cotton seeds in the harvest, and experiments determined its effectiveness and the optimal values of the factors affecting the efficiency using mathematical modeling. Based on the results of the study, graphs of the influence of factors on device performance and on device efficiency were constructed.
