Pot experiments were conducted to evaluate the effect of water management,namely continuous flooding(CF),intermittent flooding(IF)and non-flooding(NF),on Cd phytoavailaility in three paddy soils that differed in p H a...Pot experiments were conducted to evaluate the effect of water management,namely continuous flooding(CF),intermittent flooding(IF)and non-flooding(NF),on Cd phytoavailaility in three paddy soils that differed in p H and in Cd concentrations.Diffusive gradients in thin films(DGT)technique was employed to monitor soil labile Cd and Fe concentrations simultaneously at three growth stages(tillering,heading and mature stage)of rice.The Cd phytoavailability were generally in the order of NF>IF>CF,and higher rice Cd(over permitted level,0.2 mg/kg)were only found in neutral and acidic soils under NF conditions.DGT measured soil labile Cd rather than total Cd was the most reliable predictor for Cd accumulation in rice.CF enhanced the formation of root plaques,which related to oxidation of large quantities of available Fe on root surfaces due to the O2 secretion of rice root.The Cd concentration in root plaques shared the same trend with DGT-Cd.Generally,root plaques would inhibit Cd uptake by rice under CF conditions,while under IF and NF conditions,root plaques act as a temporarily store of Cd,and soil labile Cd is the key factor that controls the transfer of Cd from soil to rice.The results of principle component analysis revealed that water management had the greatest effect on soil Cd lability and rice Cd in acidic soil.Thus,it is important to consider the availability of Cd and soil p H when assessing current agricultural practices of contaminated soil in China.展开更多
Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The...Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of L0C and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands （pine forest （PF） on slope land, barren hill （BH） on slope land, citrus orchard （C0） on terrace land and Cinnarnornum Camphora （CC） on terrace land） at a sampling depth of 20 cm. Soil nutrients, soil organic carbon （SOC）, L0C and CMI were measured. Results showed that the L0C and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC 〉 PF 〉 CO 〉 BH at the upper- slope, while CO 〉 CC 〉 BH 〉 PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order： upper-slope 〉 down-slope 〉 mid- slope. As whole, the mean values of LOC and CMI in different lands followed the order CC 〉 CO 〉 PF 〉 BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a high~ quality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.展开更多
This study examines nine dynamical and three emotional aspects of behavior in depression and anxiety, singly and comorbidly. The study employs the Structure of Temperament Questionnaire Compact (STQ 77), whose 12 scal...This study examines nine dynamical and three emotional aspects of behavior in depression and anxiety, singly and comorbidly. The study employs the Structure of Temperament Questionnaire Compact (STQ 77), whose 12 scales assess the energetic, lability and sensitivity aspects of behavior in the physical, social, mental and emotional domains. The STQ 77 was administered to 86 patients with Major Depression, 85 patients with an anxiety disorder, 43 patients with comorbid depression and anxiety, and 71 subjects without depression or anxiety disorder all presenting to a private outpatient clinical practice. Results: 1) Depression was associated with self-reports of increased impulsivity and rigidity of behavior;2) Depressed patients reported significantly lower physical energy, tempo of physical activity and plasticity of behavior. The presence of comorbid anxiety further worsened these effects;3) The ability to sustain attention on a mental task and to learn new information was lower in depressed patients than in other groups. Conclusions: comorbid depression and anxiety might be associates, decreasing adaptivity and the self-regulatory balance of behavior, leading to the de- velopment of extremes in behavioral reactivity (impulsivity and rigidity).展开更多
Considering the flexibility and controllability of heat exchanger networks (HENs), bypasses are widely used for effective control of process stream target temperatures. However, the optimal location for the bypass is ...Considering the flexibility and controllability of heat exchanger networks (HENs), bypasses are widely used for effective control of process stream target temperatures. However, the optimal location for the bypass is generally difficult to design with the trade-off between controllability and capital investments. In this paper, based on the steady-state model of heat exchanger networks the optimal bypass location was firstly selected by iteratively calculating the non-square Relative Gain Array (ns-RGA). To simplify the calculation process, rules of bypass selection were also proposed. In order to evaluate this method, then, the structural controllability of heat exchanger networks was analyzed. With both the consideration of the controllability and capital investments, the bypasses locations were finally selected. A case study on the HEN in Crude Distillation Unit was presented in which the ns-RGA and structural controllability were used to select bypasses and also to evaluate the results.展开更多
It is known that patients infected with H pylori can spontaneously become free from infection, and that the reverse change can occur. The time-scale of these conversions is expressed as percentages per year. Since the...It is known that patients infected with H pylori can spontaneously become free from infection, and that the reverse change can occur. The time-scale of these conversions is expressed as percentages per year. Since they have been investigated in terms of serology, the changes are called sero-reversion and sero-conversion respectively. Using serological evidence to investigate these phenomena is open to the criticisms that positive serology can be present in the absence of all other evidence of infection, and that a time-lag of 6-12 mo or longer can occur between eradication of the infection and sero-reversion. Investigations using direct evidence of current infection are sparse. The few that exist suggest that some individuals can seroconvert or sero- revert within six to twelve weeks. If these findings are confirmed, it means that some patients have an ability that is variable in time to resist, or spontaneously recover from, H pylori infection. Evidence suggests that the deciding factor of susceptibility is the level of gastric secretion of acid.展开更多
Ⅰ. PROBLEM AND ASSUMPTIONS In 1978 J. Henry first discussed the globe controllability problem on a semilinear parabolic system with a distributed control. The author obtained the approximate control lability theory o...Ⅰ. PROBLEM AND ASSUMPTIONS In 1978 J. Henry first discussed the globe controllability problem on a semilinear parabolic system with a distributed control. The author obtained the approximate control lability theory on a semilinear abstract control system unifying finited-dimen-展开更多
基金supported by the National Natural Science Foundation of China(Nos.41601533 and U1401234)the Guangdong Natural Science Foundation(No.2017A030313241)
文摘Pot experiments were conducted to evaluate the effect of water management,namely continuous flooding(CF),intermittent flooding(IF)and non-flooding(NF),on Cd phytoavailaility in three paddy soils that differed in p H and in Cd concentrations.Diffusive gradients in thin films(DGT)technique was employed to monitor soil labile Cd and Fe concentrations simultaneously at three growth stages(tillering,heading and mature stage)of rice.The Cd phytoavailability were generally in the order of NF>IF>CF,and higher rice Cd(over permitted level,0.2 mg/kg)were only found in neutral and acidic soils under NF conditions.DGT measured soil labile Cd rather than total Cd was the most reliable predictor for Cd accumulation in rice.CF enhanced the formation of root plaques,which related to oxidation of large quantities of available Fe on root surfaces due to the O2 secretion of rice root.The Cd concentration in root plaques shared the same trend with DGT-Cd.Generally,root plaques would inhibit Cd uptake by rice under CF conditions,while under IF and NF conditions,root plaques act as a temporarily store of Cd,and soil labile Cd is the key factor that controls the transfer of Cd from soil to rice.The results of principle component analysis revealed that water management had the greatest effect on soil Cd lability and rice Cd in acidic soil.Thus,it is important to consider the availability of Cd and soil p H when assessing current agricultural practices of contaminated soil in China.
基金financially supported by the National Natural Science Foundation of China (41271294)the Program for New Century Excellent Talents in University (NCET-09-330)the Natural Science Foundation of Hunan Province of China (11JJ3041)
文摘Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of L0C and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands （pine forest （PF） on slope land, barren hill （BH） on slope land, citrus orchard （C0） on terrace land and Cinnarnornum Camphora （CC） on terrace land） at a sampling depth of 20 cm. Soil nutrients, soil organic carbon （SOC）, L0C and CMI were measured. Results showed that the L0C and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC 〉 PF 〉 CO 〉 BH at the upper- slope, while CO 〉 CC 〉 BH 〉 PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order： upper-slope 〉 down-slope 〉 mid- slope. As whole, the mean values of LOC and CMI in different lands followed the order CC 〉 CO 〉 PF 〉 BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a high~ quality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.
文摘This study examines nine dynamical and three emotional aspects of behavior in depression and anxiety, singly and comorbidly. The study employs the Structure of Temperament Questionnaire Compact (STQ 77), whose 12 scales assess the energetic, lability and sensitivity aspects of behavior in the physical, social, mental and emotional domains. The STQ 77 was administered to 86 patients with Major Depression, 85 patients with an anxiety disorder, 43 patients with comorbid depression and anxiety, and 71 subjects without depression or anxiety disorder all presenting to a private outpatient clinical practice. Results: 1) Depression was associated with self-reports of increased impulsivity and rigidity of behavior;2) Depressed patients reported significantly lower physical energy, tempo of physical activity and plasticity of behavior. The presence of comorbid anxiety further worsened these effects;3) The ability to sustain attention on a mental task and to learn new information was lower in depressed patients than in other groups. Conclusions: comorbid depression and anxiety might be associates, decreasing adaptivity and the self-regulatory balance of behavior, leading to the de- velopment of extremes in behavioral reactivity (impulsivity and rigidity).
基金Supported by the National Natural Science Foundation of China （21006127）, the National Basic Research Program of China （2012CB720500） and the Science Foundation of China University of Petroleum, Beijing （YJRC-2011-11）.
文摘Considering the flexibility and controllability of heat exchanger networks (HENs), bypasses are widely used for effective control of process stream target temperatures. However, the optimal location for the bypass is generally difficult to design with the trade-off between controllability and capital investments. In this paper, based on the steady-state model of heat exchanger networks the optimal bypass location was firstly selected by iteratively calculating the non-square Relative Gain Array (ns-RGA). To simplify the calculation process, rules of bypass selection were also proposed. In order to evaluate this method, then, the structural controllability of heat exchanger networks was analyzed. With both the consideration of the controllability and capital investments, the bypasses locations were finally selected. A case study on the HEN in Crude Distillation Unit was presented in which the ns-RGA and structural controllability were used to select bypasses and also to evaluate the results.
文摘It is known that patients infected with H pylori can spontaneously become free from infection, and that the reverse change can occur. The time-scale of these conversions is expressed as percentages per year. Since they have been investigated in terms of serology, the changes are called sero-reversion and sero-conversion respectively. Using serological evidence to investigate these phenomena is open to the criticisms that positive serology can be present in the absence of all other evidence of infection, and that a time-lag of 6-12 mo or longer can occur between eradication of the infection and sero-reversion. Investigations using direct evidence of current infection are sparse. The few that exist suggest that some individuals can seroconvert or sero- revert within six to twelve weeks. If these findings are confirmed, it means that some patients have an ability that is variable in time to resist, or spontaneously recover from, H pylori infection. Evidence suggests that the deciding factor of susceptibility is the level of gastric secretion of acid.
文摘Ⅰ. PROBLEM AND ASSUMPTIONS In 1978 J. Henry first discussed the globe controllability problem on a semilinear parabolic system with a distributed control. The author obtained the approximate control lability theory on a semilinear abstract control system unifying finited-dimen-
