[Objective] The aim was to explore recycling utilization of manure of dairy cattle through returning of manures into fields. [Method] Effects of dairy cattle ma- nure and chemical fertilizer on fertility of soils grow...[Objective] The aim was to explore recycling utilization of manure of dairy cattle through returning of manures into fields. [Method] Effects of dairy cattle ma- nure and chemical fertilizer on fertility of soils grown with Cichorium intybus were in- vestigated through a pot experiment. [Result] After manure of dairy cattle was ap- plied, it can be concluded that organic matter, total N, total P, alkali-hydrolyzable ni- trogen, available P, activities of urease and invertase in soils increased by 0.14-1.28 times, 43.8%-79.7%, 17.4%-30.8%, 147%-188%, 7 times, 17.2%-38.5%, and 1.36%- 3.34%, respectively. Furthermore, organic matter, total N. urease and invertase activi- ties in group of M7F3 increased most; total P and available P achieved the best in group of M3F7. These indicated that the applied manures of dairy cattle would maintain and improve soil fertility, providing better soils for Cichorium intybus. [Conclusion] The research provides reference for recycling of cattle manures and construction of ecological cyclical pattern of ＂grass planting-cattle breeding-methane fermentation-returning of manures into fields＂.展开更多
AIM： To study the prolonged colonic motility under normal conditions with a novel capsule-style microsystem and to assess its clinical significance. METHODS： A single use telemetry capsule （10 mm in diameter, 20 mm...AIM： To study the prolonged colonic motility under normal conditions with a novel capsule-style microsystem and to assess its clinical significance. METHODS： A single use telemetry capsule （10 mm in diameter, 20 mm in length） embedded with a pressure sensor was ingested by the subjects. The sensor is capable of transmitting colonic pressure wirelessly for more than 130 h. The time of capsule entering the segmental colon was detected by ultrasound. The ultrasonic electrodes were mounted on the surface of the ileocecum and navel and at the junction of the left and rectosigmoid colon of the subjects in sequence, which were identified by abdominal X-rays with radiopaque markers. To verify the accuracy and reliability of ultrasonic detection of telemetry capsules at key points of colon, the segmental colonic transit time was simultaneously recorded by using radiopaque markers. RESULTS： The signal lamp showed that all recorders could receive the radio signal transmitted by the telemetry capsule. The X-rays showed that all telemetry capsules were detected successfully when they were passing through the key points of colon. There was a significant correlation between the transit results obtained by ultrasonic detection or by radiopaque markers. Colorectal recording was obtained from 20 healthy subjects during 613 h （411 h during waking, 202 h during sleep）. Compared to waking, the number of pressure contractions and the area under pressure contractions were significantly （P 〈 0.05） decreased during sleep （21 ± 5 h^-vs 15 ± 4 h1, 463 ± 54 mmHg·/min vs 342 ± 45 mmHg·/min）. The colonic motility exhibited significant regional variations both in the circadian behavior and in response to waking and meal. CONCLUSION： The capsule-style micro-system is reliable and noninvasive, and may represent a useful tool for the study of physiology and pathology of colonic motor disorders.展开更多
Northern peatlands store a large amount of carbon and play a significant role in the global carbon cycle. Owing to the presence of waterlogged and anaerobic conditions, peatlands are typically a source of methane (CH4...Northern peatlands store a large amount of carbon and play a significant role in the global carbon cycle. Owing to the presence of waterlogged and anaerobic conditions, peatlands are typically a source of methane (CH4), a very potent greenhouse gas. This paper reviews the key mechanisms of peatland CH4 production, consumption and transport and the major environmental and biotic controls on peatland CH4 emissions. The advantages and disadvantages of micrometeorological and chamber methods in measuring CH4 fluxes from northern peatlands are also discussed. The magnitude of CH4 flux varies considerably among peatland types (bogs and fens) and microtopographic locations (hummocks and hollows). Some anthropogenic activities including forestry, peat harvesting and industrial emission of sulphur dioxide can cause a reduction in CH4 release from northern peatlands. Further research should be conducted to investigate the in fluence of plant growth forms on CH4 flux from northern peatlands, determine the water table threshold at which plant production in peatlands enhances CH4 release, and quantify peatland CH4 exchange at plant community level with a higher temporal resolution using automatic chambers.展开更多
This work discusses the combination of two thermodynamic cycles seeking to improve the overall chemical energy conversion rate into mechanical energy. Here one engine operates according a Rankine cycle in order to use...This work discusses the combination of two thermodynamic cycles seeking to improve the overall chemical energy conversion rate into mechanical energy. Here one engine operates according a Rankine cycle in order to use part of the thermal energy released to the boundary, i.e., the neighboring atmosphere. The analysis of this combined cycle shows that it might, under proper condition, represent a gain of 1.2% in the overall delivered engine power.展开更多
We report recent advances in the experimental and theoretical study of grain size(GS)effects on the thermal and mechanical properties of nanostructured NiTi polycrystalline shape memory alloy(SMA).It is shown that whe...We report recent advances in the experimental and theoretical study of grain size(GS)effects on the thermal and mechanical properties of nanostructured NiTi polycrystalline shape memory alloy(SMA).It is shown that when GS<60 nm,the superelastic stress-strain hysteresis loop area(H)of the polycrystal decreases rapidly with GS and tends to vanish as GS approaches 10 nanometers.At the same time,the temperature dependence of the transition stress also decreases with GS and eventually approaches zero,leading to a wide superelastic temperature window and breakdown of the Clausius-Claperyon relationship.Rate dependence of the stress-strain responses is significantly reduced and the cyclic stability of the material is improved by the nanocrystallization.It is proposed that the emergence of such significant changes in the behavior of the material with GS reduction originate from the large increase in the area-to-volume ratios of the nanometer-thick interfaces(grain boundary and Austenite-Martensite(A-M)interface)in the polycrystal.In particular,with GS reduction,interfacial energy terms will gradually become dominant over the bulk energy of the crystallite,eventually bring fundamental changes in the phase transition responses of the material.Modelling strategy leading to the establishment of quantitative relationships among GS,grain boundary,A-M interfaces and the macroscopic responses of the material are outlined.展开更多
A new model of a quantum heat engine （QHE） cycle is established, in which the working substance consists of an interacting electrons system. One of our purposes is to test the validity of the second law of thermodyn...A new model of a quantum heat engine （QHE） cycle is established, in which the working substance consists of an interacting electrons system. One of our purposes is to test the validity of the second law of thermodynamics by this model, which is more general than the spin-1/2 antiferromagnetic Heisenberg model since it would recover the spin model when the on-site Coulomb interaction U is strong enough. On the basis of quantum mechanics and the first law of thermodynamics, we show no violation of the second law of thermodynamics during the cycle. We further study the performance characteristics of the cycle by investigating in detail the optimal relations of efficiency and dimensionless power output. We find that the efficiency of our engine can be expressed as η = t22/t21 in the large-U limit, which is valid even for a four sites QHE.展开更多
The performance in finite time of a quantum-mechanical Brayton engine cycle is discussed, without intro- duction of temperature. The engine model consists of two quantum isoenergetic and two quantum isobaric processes...The performance in finite time of a quantum-mechanical Brayton engine cycle is discussed, without intro- duction of temperature. The engine model consists of two quantum isoenergetic and two quantum isobaric processes, and works with a single particle in a harmonic trap. Directly employing the finite-time thermodynamics, the efficiency at maximum power output is determined. Extending the harmonic trap to a power-law trap, we find that the efficiency at max/mum power is independent of any parameter involved in the model, but depends on the confinement of the trapping potential.展开更多
基金Supported by National Key Technology Research and Development Program during the Eleventh Five-year University(2006BAD25B08)Programs for Masters and Doctors of Honghe College(XJIS0918)Educational Reform of Honghe University(JYJG1117)~~
文摘[Objective] The aim was to explore recycling utilization of manure of dairy cattle through returning of manures into fields. [Method] Effects of dairy cattle ma- nure and chemical fertilizer on fertility of soils grown with Cichorium intybus were in- vestigated through a pot experiment. [Result] After manure of dairy cattle was ap- plied, it can be concluded that organic matter, total N, total P, alkali-hydrolyzable ni- trogen, available P, activities of urease and invertase in soils increased by 0.14-1.28 times, 43.8%-79.7%, 17.4%-30.8%, 147%-188%, 7 times, 17.2%-38.5%, and 1.36%- 3.34%, respectively. Furthermore, organic matter, total N. urease and invertase activi- ties in group of M7F3 increased most; total P and available P achieved the best in group of M3F7. These indicated that the applied manures of dairy cattle would maintain and improve soil fertility, providing better soils for Cichorium intybus. [Conclusion] The research provides reference for recycling of cattle manures and construction of ecological cyclical pattern of ＂grass planting-cattle breeding-methane fermentation-returning of manures into fields＂.
基金Supported by the High Technology Research and Development Program of China, No. 2004AA404013
文摘AIM： To study the prolonged colonic motility under normal conditions with a novel capsule-style microsystem and to assess its clinical significance. METHODS： A single use telemetry capsule （10 mm in diameter, 20 mm in length） embedded with a pressure sensor was ingested by the subjects. The sensor is capable of transmitting colonic pressure wirelessly for more than 130 h. The time of capsule entering the segmental colon was detected by ultrasound. The ultrasonic electrodes were mounted on the surface of the ileocecum and navel and at the junction of the left and rectosigmoid colon of the subjects in sequence, which were identified by abdominal X-rays with radiopaque markers. To verify the accuracy and reliability of ultrasonic detection of telemetry capsules at key points of colon, the segmental colonic transit time was simultaneously recorded by using radiopaque markers. RESULTS： The signal lamp showed that all recorders could receive the radio signal transmitted by the telemetry capsule. The X-rays showed that all telemetry capsules were detected successfully when they were passing through the key points of colon. There was a significant correlation between the transit results obtained by ultrasonic detection or by radiopaque markers. Colorectal recording was obtained from 20 healthy subjects during 613 h （411 h during waking, 202 h during sleep）. Compared to waking, the number of pressure contractions and the area under pressure contractions were significantly （P 〈 0.05） decreased during sleep （21 ± 5 h^-vs 15 ± 4 h1, 463 ± 54 mmHg·/min vs 342 ± 45 mmHg·/min）. The colonic motility exhibited significant regional variations both in the circadian behavior and in response to waking and meal. CONCLUSION： The capsule-style micro-system is reliable and noninvasive, and may represent a useful tool for the study of physiology and pathology of colonic motor disorders.
基金Project supported by the Canadian Carbon Program (Fluxnet-Canada Research Network) funded by the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS)a Natural Sciences and Engineering Research Councilof Canada (NSERC) Discovery Grant to Nigel Roulet
文摘Northern peatlands store a large amount of carbon and play a significant role in the global carbon cycle. Owing to the presence of waterlogged and anaerobic conditions, peatlands are typically a source of methane (CH4), a very potent greenhouse gas. This paper reviews the key mechanisms of peatland CH4 production, consumption and transport and the major environmental and biotic controls on peatland CH4 emissions. The advantages and disadvantages of micrometeorological and chamber methods in measuring CH4 fluxes from northern peatlands are also discussed. The magnitude of CH4 flux varies considerably among peatland types (bogs and fens) and microtopographic locations (hummocks and hollows). Some anthropogenic activities including forestry, peat harvesting and industrial emission of sulphur dioxide can cause a reduction in CH4 release from northern peatlands. Further research should be conducted to investigate the in fluence of plant growth forms on CH4 flux from northern peatlands, determine the water table threshold at which plant production in peatlands enhances CH4 release, and quantify peatland CH4 exchange at plant community level with a higher temporal resolution using automatic chambers.
文摘This work discusses the combination of two thermodynamic cycles seeking to improve the overall chemical energy conversion rate into mechanical energy. Here one engine operates according a Rankine cycle in order to use part of the thermal energy released to the boundary, i.e., the neighboring atmosphere. The analysis of this combined cycle shows that it might, under proper condition, represent a gain of 1.2% in the overall delivered engine power.
基金supported by the Hong Kong Research Grant Council(RGC)(Grant No.619113)the National Natural Science Foundation of China(Grant No.11128204)the State Key Lab of Water Resources and Hydropower Engineering of WHU,China
文摘We report recent advances in the experimental and theoretical study of grain size(GS)effects on the thermal and mechanical properties of nanostructured NiTi polycrystalline shape memory alloy(SMA).It is shown that when GS<60 nm,the superelastic stress-strain hysteresis loop area(H)of the polycrystal decreases rapidly with GS and tends to vanish as GS approaches 10 nanometers.At the same time,the temperature dependence of the transition stress also decreases with GS and eventually approaches zero,leading to a wide superelastic temperature window and breakdown of the Clausius-Claperyon relationship.Rate dependence of the stress-strain responses is significantly reduced and the cyclic stability of the material is improved by the nanocrystallization.It is proposed that the emergence of such significant changes in the behavior of the material with GS reduction originate from the large increase in the area-to-volume ratios of the nanometer-thick interfaces(grain boundary and Austenite-Martensite(A-M)interface)in the polycrystal.In particular,with GS reduction,interfacial energy terms will gradually become dominant over the bulk energy of the crystallite,eventually bring fundamental changes in the phase transition responses of the material.Modelling strategy leading to the establishment of quantitative relationships among GS,grain boundary,A-M interfaces and the macroscopic responses of the material are outlined.
基金supported by the National Natural Science Foundation of China (Grant Nos.50971011,11174022 and 10974011)the Beijing Natural Science Foundation (Grant No.1102025)+1 种基金the State Key Laboratory of Software Development Environment (Grant No.SKLSDE-2011ZX-19)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20091102110038)
文摘A new model of a quantum heat engine （QHE） cycle is established, in which the working substance consists of an interacting electrons system. One of our purposes is to test the validity of the second law of thermodynamics by this model, which is more general than the spin-1/2 antiferromagnetic Heisenberg model since it would recover the spin model when the on-site Coulomb interaction U is strong enough. On the basis of quantum mechanics and the first law of thermodynamics, we show no violation of the second law of thermodynamics during the cycle. We further study the performance characteristics of the cycle by investigating in detail the optimal relations of efficiency and dimensionless power output. We find that the efficiency of our engine can be expressed as η = t22/t21 in the large-U limit, which is valid even for a four sites QHE.
基金Supported by the National Natural Science Foundation of China under Grant No. 11265010, the Jiangxi Provincial Natural Science Foundation under Grant No. 20132BAB212009, University Young Teacher Training Program of the SMEC under Grant No. egdll005, and by Innovation Program of the SMEC under Grant No. 12YZ177
文摘The performance in finite time of a quantum-mechanical Brayton engine cycle is discussed, without intro- duction of temperature. The engine model consists of two quantum isoenergetic and two quantum isobaric processes, and works with a single particle in a harmonic trap. Directly employing the finite-time thermodynamics, the efficiency at maximum power output is determined. Extending the harmonic trap to a power-law trap, we find that the efficiency at max/mum power is independent of any parameter involved in the model, but depends on the confinement of the trapping potential.
