Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was perfor...Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water (D2O) in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.展开更多
The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) -butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,opt...The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) -butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods.The results indicate that the lamellar,hexagonal and cubic liquid crystals all exist in the above system.Keeping the weight ratio of DAD and C4OH constant,the microphase Structure,2H quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.展开更多
Tremendous research efforts have been aimed at ever-increasing worldwide energy demand. For this purpose, the hybrid supercapacitor power cell were prepared composing 3D porous graphene decorated with Co_3O_4-CeO_2 na...Tremendous research efforts have been aimed at ever-increasing worldwide energy demand. For this purpose, the hybrid supercapacitor power cell were prepared composing 3D porous graphene decorated with Co_3O_4-CeO_2 nano-particles herein by using flower stem as biotemplate. The resulting samples were characterized by field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM), Raman spectra, X-ray diffraction spectroscopy(XRD), nitrogen adsorption and desorption, X-ray photoelectron spectrogram(XPS), and electrochemical test. The 3D graphene acted as an excellent carrier together with Co_3O_4-CeO_2 nano-particles, boosting the specific capacitance of composite(221 F/g), which exceeded the theoretical value limit. This facile biotemplate method of research provided an eco-friendly and cut-price route to obtain high-quality graphene and Co_3O_4-CeO_2nano-composites owing to the unique porous structure derived from original template(flower stem). The finding presented a simple strategy for fabrication of novel energy storage devices.展开更多
Macroscopic spatiotemporal patterns arising in grey matter may explain the clinical manifestations of several functional neurological syndromes (migraine aura, epilepsies). Detailed descriptions of these patterns in c...Macroscopic spatiotemporal patterns arising in grey matter may explain the clinical manifestations of several functional neurological syndromes (migraine aura, epilepsies). Detailed descriptions of these patterns in central grey matter and their physicochemical or pharmacological manipulations can be useful in many scientific fields ranging from drug design to functional brain imaging. These evanescent dynamic structures are electrochemical in nature and show macroscopic tissue polarization due to coupled and macroscopic flow of ions and water across, along and between neuronal and glial membranes. So far the importance of the water flow in the CNS functional syndromes has been examined by manipulations of water channels aquaporines (AQP). In this paper we show the result of substituting H2O for D2O in retinal spreading depression experiments. This inverts the present logic by changing the flow in the water channels in intact tissue and observing the evolution of electrochemical patterns and recording the optical profiles of excitation waves in isolated chick retinas. D2O flow through AQPs is ~20% slower than that of H2O. The slower flux disturbs the tight coupling between ion and water flows across membranes and slowdown the Na-KATPase rate of change with metabolic consequences for the tissue. The whole tissue excitability shifts in a non-stationary manner toward a non-excitable state.展开更多
At thermal ultra-cold neutron (UCN) sources (neutrons in thermal equilibrium with the moderator) only a very small fraction of neutrons have velocities ~6 m/s. Therefore, the UCN production rate cannot be substantiall...At thermal ultra-cold neutron (UCN) sources (neutrons in thermal equilibrium with the moderator) only a very small fraction of neutrons have velocities ~6 m/s. Therefore, the UCN production rate cannot be substantially increased by simply lowering the temperature of the moderator. The new approach is to use the super-thermal principle, i.e., neutrons not in thermal equilibrium with the converter. We want to investigate scattering kernels for a super-thermal UCN source based on a two-layer arrangement of D2O and solid D2. The solid D2 (sD2) at temperature 8 K is kept in close contact with D2O moderator at room temperature. Using the MCNP code, the fast neutron flux on the spallation target, the thermal flux in the D2O near the sD2, and the cold flux in the sD2 are simulated. For a given cold flux, neutron transport equations are calculated. In order to obtain precise neutron scattering kernels, and consequently UCN flux and density, 330 neutron energy groups have been taken. The coupled energy dependent transport equations have been solved by combining MCNPX code with an analytical approach and using implicit method in MATLAB. We have obtained an optimal dimension for the UCN source. A suitable space step has been taken for the numerical stability.展开更多
基金supported by the Beijing Natural Science Foundation,China (6102006)the New-Star of Science and Technology of Beijing Metropolis,China (2011051)
摘要Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water (D2O) in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.
摘要The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) -butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods.The results indicate that the lamellar,hexagonal and cubic liquid crystals all exist in the above system.Keeping the weight ratio of DAD and C4OH constant,the microphase Structure,2H quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.
基金supported by the National Natural Science Foundation of China(51478285,21407111)Natural Science Foundation of Jiangsu Province(BK20140280,BK20151198)+2 种基金Collegiate Natural Science Fund of Jiangsu Province(14KJA430004,16KJA430008)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Collaborative Innovation Center of Technology and Material for Water Treatment,Excellent Innovation Team in Science and Technology of Education Department of Jiangsu Province
摘要Tremendous research efforts have been aimed at ever-increasing worldwide energy demand. For this purpose, the hybrid supercapacitor power cell were prepared composing 3D porous graphene decorated with Co_3O_4-CeO_2 nano-particles herein by using flower stem as biotemplate. The resulting samples were characterized by field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM), Raman spectra, X-ray diffraction spectroscopy(XRD), nitrogen adsorption and desorption, X-ray photoelectron spectrogram(XPS), and electrochemical test. The 3D graphene acted as an excellent carrier together with Co_3O_4-CeO_2 nano-particles, boosting the specific capacitance of composite(221 F/g), which exceeded the theoretical value limit. This facile biotemplate method of research provided an eco-friendly and cut-price route to obtain high-quality graphene and Co_3O_4-CeO_2nano-composites owing to the unique porous structure derived from original template(flower stem). The finding presented a simple strategy for fabrication of novel energy storage devices.
摘要Macroscopic spatiotemporal patterns arising in grey matter may explain the clinical manifestations of several functional neurological syndromes (migraine aura, epilepsies). Detailed descriptions of these patterns in central grey matter and their physicochemical or pharmacological manipulations can be useful in many scientific fields ranging from drug design to functional brain imaging. These evanescent dynamic structures are electrochemical in nature and show macroscopic tissue polarization due to coupled and macroscopic flow of ions and water across, along and between neuronal and glial membranes. So far the importance of the water flow in the CNS functional syndromes has been examined by manipulations of water channels aquaporines (AQP). In this paper we show the result of substituting H2O for D2O in retinal spreading depression experiments. This inverts the present logic by changing the flow in the water channels in intact tissue and observing the evolution of electrochemical patterns and recording the optical profiles of excitation waves in isolated chick retinas. D2O flow through AQPs is ~20% slower than that of H2O. The slower flux disturbs the tight coupling between ion and water flows across membranes and slowdown the Na-KATPase rate of change with metabolic consequences for the tissue. The whole tissue excitability shifts in a non-stationary manner toward a non-excitable state.
摘要At thermal ultra-cold neutron (UCN) sources (neutrons in thermal equilibrium with the moderator) only a very small fraction of neutrons have velocities ~6 m/s. Therefore, the UCN production rate cannot be substantially increased by simply lowering the temperature of the moderator. The new approach is to use the super-thermal principle, i.e., neutrons not in thermal equilibrium with the converter. We want to investigate scattering kernels for a super-thermal UCN source based on a two-layer arrangement of D2O and solid D2. The solid D2 (sD2) at temperature 8 K is kept in close contact with D2O moderator at room temperature. Using the MCNP code, the fast neutron flux on the spallation target, the thermal flux in the D2O near the sD2, and the cold flux in the sD2 are simulated. For a given cold flux, neutron transport equations are calculated. In order to obtain precise neutron scattering kernels, and consequently UCN flux and density, 330 neutron energy groups have been taken. The coupled energy dependent transport equations have been solved by combining MCNPX code with an analytical approach and using implicit method in MATLAB. We have obtained an optimal dimension for the UCN source. A suitable space step has been taken for the numerical stability.