In May 2006, a high intensity wildfire occurred in Songling forest region in Daxing＇an Mountains, China. The concentration changes of eight ions （K^＋, Na^＋, Ca^2＋, Mg^2＋, Cl^-, Br^-, NO3^- and SO4^2-） were meas...In May 2006, a high intensity wildfire occurred in Songling forest region in Daxing＇an Mountains, China. The concentration changes of eight ions （K^＋, Na^＋, Ca^2＋, Mg^2＋, Cl^-, Br^-, NO3^- and SO4^2-） were measured in burned and tmbumed streams after fire from May to Oct., 2006. Results show that the most ions flux were higher in burned stream than that in unburned stream during the sampling period, and the greatest concentrations of most ions transported from burned stream occurred in July. After fire, the most amplitude chemical ion was Ca^2＋, whose average concentration was 5.50 mg·L^-1 higher than that in unburned stream, and the total concentration of every chemical ion presents a trend Ca^2＋〉SO4^2- 〉Na^＋〉Mg^2＋〉NO3^- . The average concentrations of Ca^2＋, SO4^2- , Na^＋＇Mg^2＋,NO3^- showed an increase trend, but those of K^＋, Cl^- , Br had a decreased trend. SO4^2- had the largest loss among these anions, followed by NO3^-. Overall, the increase degree of cation was greater than that of anion after burning.展开更多
The research explored growth and development, economic profits, and eco- logical benefits of released black carps on basis of 21 group ecological data on 52 365 fish within 6 months. The results indicated that the age...The research explored growth and development, economic profits, and eco- logical benefits of released black carps on basis of 21 group ecological data on 52 365 fish within 6 months. The results indicated that the age and growth index of released black carp were normal and body length and size were coordinated; 88.89% released black carps exceeded theoretical weight, with an average of 25.15%, which indicated that black carps are hardly to reproduct naturally. In 2013, 310 000 black carps were released in the Reservoir, and 123 tons black carps were obtained, with direct economic value of 2.46 million yuan and indirect econom- ic value of 3.84 million yuan. It can be concluded based on averages that 123 tons black carps can be produced in 2013 and 3 690 kg nitrogen and 740 kg phospho- rus can be removed. The releasing of fish has shown much more economic, ecological and social benefits in Yantan Reservoir, but the hidden dangers still exist on fishery environment. Therefore, it is necessary to further increase the number of re- leased black carps in the Reservoir.展开更多
To improve the separation efficiency of a conventional Teetered Bed Separator(TBS) in beneficiation of fine coal with a wide size range,an Aeration TBS(A-TBS) was proposed in this investigation.The bubbles were introd...To improve the separation efficiency of a conventional Teetered Bed Separator(TBS) in beneficiation of fine coal with a wide size range,an Aeration TBS(A-TBS) was proposed in this investigation.The bubbles were introduced to A-TBS by a self-priming micro-bubble generator.This study theoretically analyzed the effect of bubbles on the difference in hindered settling terminal velocity between different density particles,investigated the impact of superficial water velocity(V_(SW)) and superficial gas velocity(V_(Sg)) on bed fluidization,and compared the performance of the TBS and A-TBS in treating 1-0.25 mm size fraction particles.The results show that the expansion degree of fluidized bed which was formed by different size particles or has different initial height,is increased by the introduction of bubbles.Compared with the TBS,at the same level of clean coal ash content,the A-TBS shows an increase in the combustible recovery of clean coal,ash content of tailings,and practical separation density by 5.26%,6.56%,and 0.088 g/cm3 respectively,while it shows a decrease in the probable error(E_p) and V_(SW) by 0.031 and 3.51 mm/s,respectively.The addition of bubbles at a proper amount not only improves the separation performance of TBS,but also reduces the upward water velocity.展开更多
The aim of this paper is to collect information about dairy cow＇s behaviour connected to different environmental conditions. During summer 2009 and winter 2010 experimental trials were arranged to verify the behaviou...The aim of this paper is to collect information about dairy cow＇s behaviour connected to different environmental conditions. During summer 2009 and winter 2010 experimental trials were arranged to verify the behaviour of dairy cows in a farm located in Po Plain （Italy）. The barn was provided with an air-water cooling system, based on the use of fans and sprinklers placed only in the feeding alley. Two different trials were carried out. The first experiment was targeted on verifying the use of the cubicles by the cows in relation to the availability of the cooling system only in feeding area. The second trial aimed at testing the effectiveness of zone cooling systems placed in the front of cubicles. For this purpose three cubicles in the barn were provided with cooling systems, based on the input of high velocity conditioned air streams. The results clearly remark that the behaviour of the animals is greatly influenced by the environmental conditions. With high temperatures the use of the cubicles is deeply reduced and the animals prefer to stay in feeding area, thus benefiting from the cooling effect of water sprinkled by the showers and of the air streams created by the fans. With air temperatures increasing from 21℃ to 33 ℃ the cows reduce the staying in the cubicles, which gets down from 540 to 32% （r2 = 0.2608）. As regards the efficacy of zone cooling system in the cubicles, the results are not particularly encouraging. The cows continue to use the cubicles without changing the behaviour in relation to the presence of conditioned air flow.展开更多
Field topography or microtopography plays an important role in achieving acceptable performance in border irrigation. Extension of conservation tillage across the North China Plain has resulted in change in field bott...Field topography or microtopography plays an important role in achieving acceptable performance in border irrigation. Extension of conservation tillage across the North China Plain has resulted in change in field bottom configuration. This study defined regular bottom configuration for border irrigation, and introduced three regular bottom configurations： border-strip irrigation （BSI）, border-furrow irrigation （BFI） and rill irrigation （RI）. The effects of regular bottom configuration on the hydraulic process and irrigation performance were evaluated by field experiments and a WinSRFR3.1 model. Results suggest that the WinSRFR3.1 model was capable of the simulation of BFI and RI, and that the hydraulic process and irrigation performance were diverse among BSI, BFI, and RI. BSI had the highest infiltration rate while BFI had the lowest infiltration rate; BSI took the most time to complete the water advance while BFI took the least time. As a result, BSI showed the worst irrigation performance while BFI gave the best irrigation performance. Different field bottom configurations mainly accounted for differences. We conclude that regular field bottom configuration is an important factor for acceptable performance in border irrigation.展开更多
基金This research was supported by National Coopera-tion Project of Japan and China.
文摘In May 2006, a high intensity wildfire occurred in Songling forest region in Daxing＇an Mountains, China. The concentration changes of eight ions （K^＋, Na^＋, Ca^2＋, Mg^2＋, Cl^-, Br^-, NO3^- and SO4^2-） were measured in burned and tmbumed streams after fire from May to Oct., 2006. Results show that the most ions flux were higher in burned stream than that in unburned stream during the sampling period, and the greatest concentrations of most ions transported from burned stream occurred in July. After fire, the most amplitude chemical ion was Ca^2＋, whose average concentration was 5.50 mg·L^-1 higher than that in unburned stream, and the total concentration of every chemical ion presents a trend Ca^2＋〉SO4^2- 〉Na^＋〉Mg^2＋〉NO3^- . The average concentrations of Ca^2＋, SO4^2- , Na^＋＇Mg^2＋,NO3^- showed an increase trend, but those of K^＋, Cl^- , Br had a decreased trend. SO4^2- had the largest loss among these anions, followed by NO3^-. Overall, the increase degree of cation was greater than that of anion after burning.
基金Supported by Guangxi Natural Science Foundation(2013GXNSFEA053003)Special Fund for Agro-scientific Research in the Public Interest(201303048)Germplasm Resource Protection Project of Ministry of Agriculture([2013]75)~~
文摘The research explored growth and development, economic profits, and eco- logical benefits of released black carps on basis of 21 group ecological data on 52 365 fish within 6 months. The results indicated that the age and growth index of released black carp were normal and body length and size were coordinated; 88.89% released black carps exceeded theoretical weight, with an average of 25.15%, which indicated that black carps are hardly to reproduct naturally. In 2013, 310 000 black carps were released in the Reservoir, and 123 tons black carps were obtained, with direct economic value of 2.46 million yuan and indirect econom- ic value of 3.84 million yuan. It can be concluded based on averages that 123 tons black carps can be produced in 2013 and 3 690 kg nitrogen and 740 kg phospho- rus can be removed. The releasing of fish has shown much more economic, ecological and social benefits in Yantan Reservoir, but the hidden dangers still exist on fishery environment. Therefore, it is necessary to further increase the number of re- leased black carps in the Reservoir.
基金supported by the National Natural Science Foundation of China(No.51474213)the National Natural Science Foundation of China(No.51374205)+1 种基金the Fundamental Research Funds for the Central Universities(No.2014XT05)A Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘To improve the separation efficiency of a conventional Teetered Bed Separator(TBS) in beneficiation of fine coal with a wide size range,an Aeration TBS(A-TBS) was proposed in this investigation.The bubbles were introduced to A-TBS by a self-priming micro-bubble generator.This study theoretically analyzed the effect of bubbles on the difference in hindered settling terminal velocity between different density particles,investigated the impact of superficial water velocity(V_(SW)) and superficial gas velocity(V_(Sg)) on bed fluidization,and compared the performance of the TBS and A-TBS in treating 1-0.25 mm size fraction particles.The results show that the expansion degree of fluidized bed which was formed by different size particles or has different initial height,is increased by the introduction of bubbles.Compared with the TBS,at the same level of clean coal ash content,the A-TBS shows an increase in the combustible recovery of clean coal,ash content of tailings,and practical separation density by 5.26%,6.56%,and 0.088 g/cm3 respectively,while it shows a decrease in the probable error(E_p) and V_(SW) by 0.031 and 3.51 mm/s,respectively.The addition of bubbles at a proper amount not only improves the separation performance of TBS,but also reduces the upward water velocity.
文摘The aim of this paper is to collect information about dairy cow＇s behaviour connected to different environmental conditions. During summer 2009 and winter 2010 experimental trials were arranged to verify the behaviour of dairy cows in a farm located in Po Plain （Italy）. The barn was provided with an air-water cooling system, based on the use of fans and sprinklers placed only in the feeding alley. Two different trials were carried out. The first experiment was targeted on verifying the use of the cubicles by the cows in relation to the availability of the cooling system only in feeding area. The second trial aimed at testing the effectiveness of zone cooling systems placed in the front of cubicles. For this purpose three cubicles in the barn were provided with cooling systems, based on the input of high velocity conditioned air streams. The results clearly remark that the behaviour of the animals is greatly influenced by the environmental conditions. With high temperatures the use of the cubicles is deeply reduced and the animals prefer to stay in feeding area, thus benefiting from the cooling effect of water sprinkled by the showers and of the air streams created by the fans. With air temperatures increasing from 21℃ to 33 ℃ the cows reduce the staying in the cubicles, which gets down from 540 to 32% （r2 = 0.2608）. As regards the efficacy of zone cooling system in the cubicles, the results are not particularly encouraging. The cows continue to use the cubicles without changing the behaviour in relation to the presence of conditioned air flow.
基金the Knowledge Innovation Program,Chinese Academy of Sciences (No.KSCX2-EW-B-1andKSCX1-YW-09-06)
文摘Field topography or microtopography plays an important role in achieving acceptable performance in border irrigation. Extension of conservation tillage across the North China Plain has resulted in change in field bottom configuration. This study defined regular bottom configuration for border irrigation, and introduced three regular bottom configurations： border-strip irrigation （BSI）, border-furrow irrigation （BFI） and rill irrigation （RI）. The effects of regular bottom configuration on the hydraulic process and irrigation performance were evaluated by field experiments and a WinSRFR3.1 model. Results suggest that the WinSRFR3.1 model was capable of the simulation of BFI and RI, and that the hydraulic process and irrigation performance were diverse among BSI, BFI, and RI. BSI had the highest infiltration rate while BFI had the lowest infiltration rate; BSI took the most time to complete the water advance while BFI took the least time. As a result, BSI showed the worst irrigation performance while BFI gave the best irrigation performance. Different field bottom configurations mainly accounted for differences. We conclude that regular field bottom configuration is an important factor for acceptable performance in border irrigation.
