Based on observation data from the mini-type automatic weather station,the evapotranspiration quantity of reference crops from artificial grassland in three river sources areas was estimated by the method of FAO Penma...Based on observation data from the mini-type automatic weather station,the evapotranspiration quantity of reference crops from artificial grassland in three river sources areas was estimated by the method of FAO Penman-Monteith.The actual evapotranspiration quantity of grassland was calculated according to the synthetic crop coefficients referenced by FAQ-56,and the change of the actual evapotranspiration quantity of artificial grassland in three river sources areas as well as the relationship between the evapotranspiration quantity and climatic factors were studied.The results suggested that the seasonal change of actual evapotranspiration quantity in grassland was expressed in a single peak curve with the peak in the middle August,and daily transpiration quantity in summer was significantly larger than that in winter.The evapotranspiration was significantly correlated with air temperature,solar radiation and relative humidity,but not significantly correlated with wind speed.Effects of climatic factors on the evapotranspiration quantity of artificial grassland were ordered as follow:air temperature(T)>solar radiation(Ra)>relative humidity(RH)>wind speed(u2).展开更多
In response to the construction needs of “Real 3D China”, the system structure, functional framework, application direction and product form of block level augmented reality three-dimensional map is designed. Those ...In response to the construction needs of “Real 3D China”, the system structure, functional framework, application direction and product form of block level augmented reality three-dimensional map is designed. Those provide references and ideas for the later large-scale production of augmented reality three-dimensional map. The augmented reality three-dimensional map is produced based on skyline software. Including the map browsing, measurement and analysis and so on, the basic function of three-dimensional map is realized. The special functional module including housing management, pipeline management and so on is developed combining the need of residential quarters development, that expands the application fields of augmented reality three-dimensional map. Those lay the groundwork for the application of augmented reality three-dimensional map. .展开更多
It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A s...It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A soil profile with 2 9 m long and 2 13 2 60 m deep was excavated on a lower slope located at Zigui County, Hubei Province, China. Field observation found that soil pipes were mainly distributed in the transient layer between horizon B with higher degree of granite weathering and horizon C with lower degree of granite weathering. At the foot of the slope, about 5 7 soil pipes per meter were observed along the vertical direction of the slope. The observed results, obtained by continuous observation of soil pipes and pipe flow processes at granite slope for many rainfall events, indicate that the relationship between velocity of pipe flow and hydraulic gradient along the pipe is parabolic rather than linear. Based on the investigated data of soil, landform, and land use etc., combined with observed data of pipe flow derived from many rainfall events, a pipe flow model was developed. For velocity V p, discharge Q p of pipe flow and radius r of soil pipe, great similarity was found between simulated and observed values. Particularly, the simulated length of soil pipes reflects the great difference among soil pipes as a result of its different position in the soil profile. The length values of 4 soil pipes were estimated to be 98 1%, 27 6%, 11 0% and 3 0% of the longest distance of the catchment, respectively. As a special case of water movement, soil pipe flow follows Darcy Weisbach law. Discharge of pipe flow is much greater than infiltration discharge in common. Only when the depth of groundwater is more than the diameter of soil pipe and water layer submerges soil pipes during rainfall, may pipe flow occur. Under these circumstances, discharge of pipe flow is directly proportional to the depth of groundwater.展开更多
A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two ...A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two three-particle non-maximally entangled W states. An arbitrary three-particle state can be perfectly teleported probabilistically if the sender performs three generalized Bell-state measurements and sends to the two receivers the classical result of these measurements, and either one of the two receivers adopts an appropriate unitary transformation conditioned on the suitable measurement outcomes of the other receiver. All kinds of unitary transformations are given in detail.展开更多
Based on field-survey hydrological series in the Dongting Lake watershed from 1951 to 2011, the variations of lakebed sediment siltation/erosion（S/E） regimes of the Dongting Lake after the operation of the Three Gor...Based on field-survey hydrological series in the Dongting Lake watershed from 1951 to 2011, the variations of lakebed sediment siltation/erosion（S/E） regimes of the Dongting Lake after the operation of the Three Gorges Reservoir（TGR） were analyzed. Significantly positive correlations were found between the flow rate from Zhicheng and the Three Outlets（r^2=0.859, p〈0.0001）, and between the flow rate and sediment delivery rate at the Three Outlets（r^2=0.895, p〈0.0001）. This indicated that the flow rate and sediment delivery rate at the Three Outlets were largely determined by the flow rate from the upstream Yangtze River. Sediment deposition amount in the Dongting Lake basin dropped from ＋4796.4×10^4 t during the period before the operation of TGR（1999–2002） to ＋684.1×10^4 t, ＋449.8×10^4 t and –559.6×10^4 t during the impoundment Phases I, II and III of TGR. The S/E regimes changed from a siltation-dominant to an erosion-dominant state under the pre-discharge, water-storage and water-supplement dispatch over the impoundment from Phase I to III. The sediment deposition amount decreased dramatically under the flood-storage dispatch over the impoundment Phase I to III. The estimated annual mean flow rate, sediment delivery rate and sediment concentration thresholds were respectively 970.81 m3/s, 466.82 kg/s and 0.481 kg/m3 for the upstream Three Outlets to maintain an erosion-dominant state in the downstream linked the Dongting Lake.展开更多
Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is compar...Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is comparatively analyzed. The results are shown as follows. （1） The influence periods are from 25 May to 10 June, from 1 July to 31 August, from 15 September to 31 October and from December to the next April, among which the influence of the water-supplement dispatch in the dry season is not very sensitive. （2） During the period under the pre-discharge dispatch, the runoff volume slightly increases as well as both the average water level and the highest water level rise in the usual year. While in the wet and dry years, the average increase in the runoff volume is 40.25×1 08 m3 and the average rises of the average water level and the highest water level are both 1.06 m. （3） As for the flood-storage dispatch, the flood volume increases slightly, in the dry and wet years, the flood volume, the average water level and the highest water level averagely reduce by 444.02×108 m3, 2.64 m and 1.42 m respectively. （4） Under the water-storage dispatch, the runoff volume slightly in- creases and the water level heightens in a sort in the usual year. And in the dry and wet years the average decreases in the runoff volume, the average water leve/and the highest water levels are respectively 185.27×108 m3, 3.13 m and 2.14 m. （5） During the period under the water-supplement dispatch, the runoff volume, the average water level and the highest water levels averagely decline by 337.7×108 m3, 1.89 m and 2.39 m respectively in the usual and wet years. However, in the dry year, the runoff volume increases as well as the average and highest water levels slightly go up.展开更多
Both the maximal and the total skew information have been studied. For a three-qubit system implemented in three nonlinear interaction models, we give the exact state vector at any time t. Beused on this, we give the ...Both the maximal and the total skew information have been studied. For a three-qubit system implemented in three nonlinear interaction models, we give the exact state vector at any time t. Beused on this, we give the maximal and the total skew information. It is found that they have the same form and their evolution periods are dependent on the energy difference between the ground state and the second excited state in these models. The maximal skew information is always in the （Sx, Sv） plane. We give the condition for the occurrence of IGHZ}sy, in which they can reach the extreme values of 9/4 and 15/4, respectively. In three different decoherence channels, two kinds of information and the concurrence are calculated. We find that the phenomenon of the concurrence of sudden death occurs, but the above two kinds of information do not die suddenly. In the phase-damping channel, the two kinds of information will not be lost completely.展开更多
The calculation of flow and sediment transport is one of the most important tasks in river engineering. The task is particularly difficult because a number of complex physical phenomena should be accounted for more re...The calculation of flow and sediment transport is one of the most important tasks in river engineering. The task is particularly difficult because a number of complex physical phenomena should be accounted for more realistically in a model with a predictive power. Three-dimensional calculations of river flow and suspended sediment transport are performed in this paper with application in the Three Gorges Reservoir in the Yangtze River. A period of 76 years after the dam is built is simulated and the results are compared with laboratory measurements obtained by Tsinghua University whereby the model is verified and calibrated. Generally speaking, the calculated results agree well with the experiments, demonstrating that the present model can be used for flow and sediment transport prediction in rivers.展开更多
A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence...A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence was attributed to ^5D3→^7F5, ^5D3→^7F4, ^5D3→^7F3, ^5D4→^7F6, ^5D4→^7F5, ^5D4→^7F4, and ^5D4→^7F3 transitions of Tb^3＋. The relationship between upconversion luminescence intensity and the pump power indicated that a three-photon simultaneous absorption process was dominant in this upconversion luminescence. The intense red, green, and blue upconversion luminescence of Tb^3＋-doped CaO-Al2O3-SiO2 glass may be potentially useful in developing three-dimensional display applications.展开更多
In this paper, the definition of three-order form invariance is given. Then the relation between the three-order form invariance and the three-order Lie symmetry is discussed and the sufficient and necessary condition...In this paper, the definition of three-order form invariance is given. Then the relation between the three-order form invariance and the three-order Lie symmetry is discussed and the sufficient and necessary condition of Lie symmetry, which comes from the three-order form invariance, is obtained. Finally a three-order Hojman conserved quantity is studied and an example is given to illustrate the application of the obtained results.展开更多
The spatial composition of natural environment and settlement in the Three Gorges region along the Yangtze River was analyzed from a macro perspective,which emphasized its characteristics of the interdependence among ...The spatial composition of natural environment and settlement in the Three Gorges region along the Yangtze River was analyzed from a macro perspective,which emphasized its characteristics of the interdependence among its buildings,landform and waterscape,between buildings and landscape,and integration of nature and human culture.Then the spatial features of folk houses were analyzed,while special attention was paid to its "upward","grey",and dynamic characteristics.The courtyard-type residence and stilted building in South China were taken as examples in order to explain their exterior spatial characteristics,and the interior spatial features were analyzed from the pursuit of courtyard layout,the preference of courtyard space and the emphasis of central room space.The paper exposed the builders' rational thinking about natural environment and living place conveyed through the traditional folk houses,as well as the practical value of this architectural style in the special natural environment of the Three Gorges region,and explained the artistic achievements from the integration of architecture and environment,aiming to provide references for the urban and living environment construction in this region during the "Post Three-Gorges Project Era".展开更多
The semidiagnostic and prognostic models are used to compute the current in the Taiwan Strait with wind and hydrographic data collected during August, 1984 and September 1 ~ 6, 1988. This calculation can be divided in...The semidiagnostic and prognostic models are used to compute the current in the Taiwan Strait with wind and hydrographic data collected during August, 1984 and September 1 ~ 6, 1988. This calculation can be divided into two stages, i. e. (1 ) the adjustable stage; (2) prognostic calculation. The computed result shows tha the density and velocity fields etc. have been adjusted when t = 2. 5 d, namely the solution of semidignostic calculation is obtained,and the quasi-steady state solution have been reached after about 40 d. Comparing the results of diagncotic calculation with those of semidiagnortic and prognostic calculations indicates that they agree qualitatively. For example, they all have the following common features: (1 ) there is a persistent northward fiow with a volume transport of 0. 8 × 10 6 m3/s through the Taiwan Strait in summer; (2 ) the current near the western coas of Taiwan is stronger than that in other regiona; (3) the upweiling occurs near the Fujian coast and so on. However, there is a quantitative difference between them as follows. For example, the horizotal velocity near the westem cot of Taiwan and the upwelling speed near the Fujian aret both are underestimaed in the diagnestic calculation, because the data used in which is smoothed, and they both are intensified in the solutions of semidiagnostic and prognostic calculations. For example, the maximum velocity near the western coast of Taiwan at t = 0 d (diagnostic), 2. 5 d (semidiagnostic) and 300 d (prognostic) is 59.1, 62. 1 and 62. 0 cm/s, respectively. From the above comparison we see it is quite necessary that a semidiagnostic model be used to compute the currents when the data have been smoothed.展开更多
Summary： This study sought to evaluate the contribution of two-dimensional ultrasound （2D-US） and three-dimensional skeletal imaging ultrasound （3D-SUIS） in the prenatal diagnosis of sirenomelia. Be- tween Septem...Summary： This study sought to evaluate the contribution of two-dimensional ultrasound （2D-US） and three-dimensional skeletal imaging ultrasound （3D-SUIS） in the prenatal diagnosis of sirenomelia. Be- tween September 2010 and April 2014, a prospective study was conducted in a single referral center using 3D-SU1S performed after 2D-US in 10 cases of sirenomelia. Diagnostic accuracy and detailed findings were compared with postnatal three-dimensional helical computed tomography （3D-HCT）, radiological findings and autopsy. Pregnancy was terminated in all 10 sirenomelia cases, including 9 singletons and I conjoined twin pregnancy, for a total of 5 males and 5 females. These cases of sirenomelia were deter- mined by autopsy and/or chromosomal examination. Initial 2D-US showed that there were 10 cases of oligohydranmios, bilateral renal agenesis, bladder agenesis, single umbilical artery, fusion of the lower limbs and spinal abnormalities; 8 cases of dipus or monopus; 2 cases of apus; and 8 cases of cardiac abnormalities. Subsequent 3D-SUIS showed that there were 9 cases of scoliosis, l0 cases of sacrococ- cygeal vertebra dysplasia, 3 cases of hemivertebra, 1 case of vertebral fusion, 3 cases of spina bifida, and 5 cases of rib abnormalities. 3D-SUIS identified significantly more skeletal abnormalities than did 2D-US, and its accuracy was 79.5% （70/88） compared with 3D-HCT and radiography. 3D-SUIS seems to be a useful complementary method to 2D-US and may improve the accuracy of identifying prenatal skeletal abnormalities related to sirenomelia.展开更多
In this paper, we study the existence of positive solutions for a class of third-order three-point boundary value problem. By employing the fixed point theorem on cone, some new criteria to ensure the three-point boun...In this paper, we study the existence of positive solutions for a class of third-order three-point boundary value problem. By employing the fixed point theorem on cone, some new criteria to ensure the three-point boundary value problem has at least three positive solutions are obtained. An example illustrating our main result is given. Moreover, some previous results will be improved significantly in our paper.展开更多
Based on the meteorological data from 33 stations of Three Gorges Reservoir from 1960 to 2008,climate yield of rice,corn and winter wheat and the changes of climatic potential productivity after water storage in Three...Based on the meteorological data from 33 stations of Three Gorges Reservoir from 1960 to 2008,climate yield of rice,corn and winter wheat and the changes of climatic potential productivity after water storage in Three Gorges Reservoir were calculated by the dynamic statistic model of crop growth.The results showed that the temperature in Three Gorges Reservoir was fluctuant decreased before late 1980s,and warmed rapidly after the late 1980s.The precipitation had little change before the late 1990s and had a slight decrease after the late 1990s.Sunshine hours were more in 1960s and 1970s,and then it changed little after 1980s.After water storage,the temperature increased in Three Gorges Reservoir as a whole.The precipitation decreased in the south of Three Gorges Reservoir,while it increased in the northwest of Three Gorges Reservoir.The sunshine hours were reduced except that in the vicinity of Dianjiang.After water storage,climatic potential productivity of rice decreased in the northwest and the northeast,while it increased in the south of Three Gorges Reservoir.The climatic potential productivity of corn decreased in the northeast and the southwest,but increased in the rest of Three Gorges Reservoir.The climatic potential productivity of winter wheat increased almost in total.展开更多
This paper firstly defined the concept of folk culture block,and then analyzed the significance and planning principle of landscape design in folk culture block,and at last expounded landscape planning and design of f...This paper firstly defined the concept of folk culture block,and then analyzed the significance and planning principle of landscape design in folk culture block,and at last expounded landscape planning and design of folk culture block based on theory of three elements of landscape.展开更多
Through the introduction of disaster situation of Qiang Culture after Wenchuan Earthquake, the paper emphasized that carriers of Qiang Culture had been seriously damaged, the inheritance of Qiang Culture had been affe...Through the introduction of disaster situation of Qiang Culture after Wenchuan Earthquake, the paper emphasized that carriers of Qiang Culture had been seriously damaged, the inheritance of Qiang Culture had been affected, and the environment for Qiang Culture was difficult to recover. It highlighted that three-dimensional reconstruction of Qiang Culture should stress the core task and timely and effectively rescue endangered cultural heritages of Qiang Nationality from the perspectives of material and spiritual life. It had explained focuses of three-dimensional pattern construction in detail. In terms of spatial reconstruction, it should reconstruct native culture and history while material culture was constructed, and reconstruct Qiang culture highland by depending on aborigines; in terms of cluster reconstruction, it should give support to large tourism enterprises and perfect tourism chain; in terms of ecological reconstruction, it should enhance construction and demonstration of "ecological protection pilot area of Qiang culture"; in terms of development reconstruction, it should realize coordinated unity between protection and development according to classification protection, characteristic protection and key protection, so as to form the virtuous circle of post-disaster recovery protection and sustainable development.展开更多
基金Supported by the National Key Technology R&D Program(2006BAC01A02)the CAS Action-Plan for West Developmert(KZCX2XB20601)~~
文摘Based on observation data from the mini-type automatic weather station,the evapotranspiration quantity of reference crops from artificial grassland in three river sources areas was estimated by the method of FAO Penman-Monteith.The actual evapotranspiration quantity of grassland was calculated according to the synthetic crop coefficients referenced by FAQ-56,and the change of the actual evapotranspiration quantity of artificial grassland in three river sources areas as well as the relationship between the evapotranspiration quantity and climatic factors were studied.The results suggested that the seasonal change of actual evapotranspiration quantity in grassland was expressed in a single peak curve with the peak in the middle August,and daily transpiration quantity in summer was significantly larger than that in winter.The evapotranspiration was significantly correlated with air temperature,solar radiation and relative humidity,but not significantly correlated with wind speed.Effects of climatic factors on the evapotranspiration quantity of artificial grassland were ordered as follow:air temperature(T)>solar radiation(Ra)>relative humidity(RH)>wind speed(u2).
文摘In response to the construction needs of “Real 3D China”, the system structure, functional framework, application direction and product form of block level augmented reality three-dimensional map is designed. Those provide references and ideas for the later large-scale production of augmented reality three-dimensional map. The augmented reality three-dimensional map is produced based on skyline software. Including the map browsing, measurement and analysis and so on, the basic function of three-dimensional map is realized. The special functional module including housing management, pipeline management and so on is developed combining the need of residential quarters development, that expands the application fields of augmented reality three-dimensional map. Those lay the groundwork for the application of augmented reality three-dimensional map. .
文摘It is well known that, in most cases, soil water doesn't move in the form of laminar flow as described by Darcy law. Only when Reynolds number ( Re ) is no more than 10, does water movement follow Darcy law. A soil profile with 2 9 m long and 2 13 2 60 m deep was excavated on a lower slope located at Zigui County, Hubei Province, China. Field observation found that soil pipes were mainly distributed in the transient layer between horizon B with higher degree of granite weathering and horizon C with lower degree of granite weathering. At the foot of the slope, about 5 7 soil pipes per meter were observed along the vertical direction of the slope. The observed results, obtained by continuous observation of soil pipes and pipe flow processes at granite slope for many rainfall events, indicate that the relationship between velocity of pipe flow and hydraulic gradient along the pipe is parabolic rather than linear. Based on the investigated data of soil, landform, and land use etc., combined with observed data of pipe flow derived from many rainfall events, a pipe flow model was developed. For velocity V p, discharge Q p of pipe flow and radius r of soil pipe, great similarity was found between simulated and observed values. Particularly, the simulated length of soil pipes reflects the great difference among soil pipes as a result of its different position in the soil profile. The length values of 4 soil pipes were estimated to be 98 1%, 27 6%, 11 0% and 3 0% of the longest distance of the catchment, respectively. As a special case of water movement, soil pipe flow follows Darcy Weisbach law. Discharge of pipe flow is much greater than infiltration discharge in common. Only when the depth of groundwater is more than the diameter of soil pipe and water layer submerges soil pipes during rainfall, may pipe flow occur. Under these circumstances, discharge of pipe flow is directly proportional to the depth of groundwater.
文摘A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two three-particle non-maximally entangled W states. An arbitrary three-particle state can be perfectly teleported probabilistically if the sender performs three generalized Bell-state measurements and sends to the two receivers the classical result of these measurements, and either one of the two receivers adopts an appropriate unitary transformation conditioned on the suitable measurement outcomes of the other receiver. All kinds of unitary transformations are given in detail.
基金National Natm＇al Science Foundation of China, No.41071067 Program of the Key Discipline Con- struction of the Physical Geography in Hunan Province.Acknowledgements The authors would like to thank Changjiang （Yangtze） Water Resources Committee and Hunan Hydro ＆ Power Institute for their help in providing the data presented in this work.
文摘Based on field-survey hydrological series in the Dongting Lake watershed from 1951 to 2011, the variations of lakebed sediment siltation/erosion（S/E） regimes of the Dongting Lake after the operation of the Three Gorges Reservoir（TGR） were analyzed. Significantly positive correlations were found between the flow rate from Zhicheng and the Three Outlets（r^2=0.859, p〈0.0001）, and between the flow rate and sediment delivery rate at the Three Outlets（r^2=0.895, p〈0.0001）. This indicated that the flow rate and sediment delivery rate at the Three Outlets were largely determined by the flow rate from the upstream Yangtze River. Sediment deposition amount in the Dongting Lake basin dropped from ＋4796.4×10^4 t during the period before the operation of TGR（1999–2002） to ＋684.1×10^4 t, ＋449.8×10^4 t and –559.6×10^4 t during the impoundment Phases I, II and III of TGR. The S/E regimes changed from a siltation-dominant to an erosion-dominant state under the pre-discharge, water-storage and water-supplement dispatch over the impoundment from Phase I to III. The sediment deposition amount decreased dramatically under the flood-storage dispatch over the impoundment Phase I to III. The estimated annual mean flow rate, sediment delivery rate and sediment concentration thresholds were respectively 970.81 m3/s, 466.82 kg/s and 0.481 kg/m3 for the upstream Three Outlets to maintain an erosion-dominant state in the downstream linked the Dongting Lake.
基金National Natural Science Foundation of China, No.41071067 Program of the Key Discipline Construction of the Physical Geography in Hunan Province
文摘Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is comparatively analyzed. The results are shown as follows. （1） The influence periods are from 25 May to 10 June, from 1 July to 31 August, from 15 September to 31 October and from December to the next April, among which the influence of the water-supplement dispatch in the dry season is not very sensitive. （2） During the period under the pre-discharge dispatch, the runoff volume slightly increases as well as both the average water level and the highest water level rise in the usual year. While in the wet and dry years, the average increase in the runoff volume is 40.25×1 08 m3 and the average rises of the average water level and the highest water level are both 1.06 m. （3） As for the flood-storage dispatch, the flood volume increases slightly, in the dry and wet years, the flood volume, the average water level and the highest water level averagely reduce by 444.02×108 m3, 2.64 m and 1.42 m respectively. （4） Under the water-storage dispatch, the runoff volume slightly in- creases and the water level heightens in a sort in the usual year. And in the dry and wet years the average decreases in the runoff volume, the average water leve/and the highest water levels are respectively 185.27×108 m3, 3.13 m and 2.14 m. （5） During the period under the water-supplement dispatch, the runoff volume, the average water level and the highest water levels averagely decline by 337.7×108 m3, 1.89 m and 2.39 m respectively in the usual and wet years. However, in the dry year, the runoff volume increases as well as the average and highest water levels slightly go up.
基金Project supported by the College Young Talents Foundation of Anhui Province,China(Grant No.2010SQRL107)the Natural Science Foundation of the Education Department of Anhui Province,China(Grant No.KJ2008B83ZC)the Natural Science Foundation of Anhui Province,China(Grant No.KJ2011Z234)
文摘Both the maximal and the total skew information have been studied. For a three-qubit system implemented in three nonlinear interaction models, we give the exact state vector at any time t. Beused on this, we give the maximal and the total skew information. It is found that they have the same form and their evolution periods are dependent on the energy difference between the ground state and the second excited state in these models. The maximal skew information is always in the （Sx, Sv） plane. We give the condition for the occurrence of IGHZ}sy, in which they can reach the extreme values of 9/4 and 15/4, respectively. In three different decoherence channels, two kinds of information and the concurrence are calculated. We find that the phenomenon of the concurrence of sudden death occurs, but the above two kinds of information do not die suddenly. In the phase-damping channel, the two kinds of information will not be lost completely.
基金The project supported by the National Natural Science Foundation of China (50009004)
文摘The calculation of flow and sediment transport is one of the most important tasks in river engineering. The task is particularly difficult because a number of complex physical phenomena should be accounted for more realistically in a model with a predictive power. Three-dimensional calculations of river flow and suspended sediment transport are performed in this paper with application in the Three Gorges Reservoir in the Yangtze River. A period of 76 years after the dam is built is simulated and the results are compared with laboratory measurements obtained by Tsinghua University whereby the model is verified and calibrated. Generally speaking, the calculated results agree well with the experiments, demonstrating that the present model can be used for flow and sediment transport prediction in rivers.
基金supported by the Education Department of Zhejiang Province (20050359)
文摘A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence was attributed to ^5D3→^7F5, ^5D3→^7F4, ^5D3→^7F3, ^5D4→^7F6, ^5D4→^7F5, ^5D4→^7F4, and ^5D4→^7F3 transitions of Tb^3＋. The relationship between upconversion luminescence intensity and the pump power indicated that a three-photon simultaneous absorption process was dominant in this upconversion luminescence. The intense red, green, and blue upconversion luminescence of Tb^3＋-doped CaO-Al2O3-SiO2 glass may be potentially useful in developing three-dimensional display applications.
文摘In this paper, the definition of three-order form invariance is given. Then the relation between the three-order form invariance and the three-order Lie symmetry is discussed and the sufficient and necessary condition of Lie symmetry, which comes from the three-order form invariance, is obtained. Finally a three-order Hojman conserved quantity is studied and an example is given to illustrate the application of the obtained results.
基金Supported by Humanities Fund of Ministry of Education (09YJAZH047)Scientific Research and Development Program of Yichang City (A09302-27)~~
文摘The spatial composition of natural environment and settlement in the Three Gorges region along the Yangtze River was analyzed from a macro perspective,which emphasized its characteristics of the interdependence among its buildings,landform and waterscape,between buildings and landscape,and integration of nature and human culture.Then the spatial features of folk houses were analyzed,while special attention was paid to its "upward","grey",and dynamic characteristics.The courtyard-type residence and stilted building in South China were taken as examples in order to explain their exterior spatial characteristics,and the interior spatial features were analyzed from the pursuit of courtyard layout,the preference of courtyard space and the emphasis of central room space.The paper exposed the builders' rational thinking about natural environment and living place conveyed through the traditional folk houses,as well as the practical value of this architectural style in the special natural environment of the Three Gorges region,and explained the artistic achievements from the integration of architecture and environment,aiming to provide references for the urban and living environment construction in this region during the "Post Three-Gorges Project Era".
文摘The semidiagnostic and prognostic models are used to compute the current in the Taiwan Strait with wind and hydrographic data collected during August, 1984 and September 1 ~ 6, 1988. This calculation can be divided into two stages, i. e. (1 ) the adjustable stage; (2) prognostic calculation. The computed result shows tha the density and velocity fields etc. have been adjusted when t = 2. 5 d, namely the solution of semidignostic calculation is obtained,and the quasi-steady state solution have been reached after about 40 d. Comparing the results of diagncotic calculation with those of semidiagnortic and prognostic calculations indicates that they agree qualitatively. For example, they all have the following common features: (1 ) there is a persistent northward fiow with a volume transport of 0. 8 × 10 6 m3/s through the Taiwan Strait in summer; (2 ) the current near the western coas of Taiwan is stronger than that in other regiona; (3) the upweiling occurs near the Fujian coast and so on. However, there is a quantitative difference between them as follows. For example, the horizotal velocity near the westem cot of Taiwan and the upwelling speed near the Fujian aret both are underestimaed in the diagnestic calculation, because the data used in which is smoothed, and they both are intensified in the solutions of semidiagnostic and prognostic calculations. For example, the maximum velocity near the western coast of Taiwan at t = 0 d (diagnostic), 2. 5 d (semidiagnostic) and 300 d (prognostic) is 59.1, 62. 1 and 62. 0 cm/s, respectively. From the above comparison we see it is quite necessary that a semidiagnostic model be used to compute the currents when the data have been smoothed.
文摘Summary： This study sought to evaluate the contribution of two-dimensional ultrasound （2D-US） and three-dimensional skeletal imaging ultrasound （3D-SUIS） in the prenatal diagnosis of sirenomelia. Be- tween September 2010 and April 2014, a prospective study was conducted in a single referral center using 3D-SU1S performed after 2D-US in 10 cases of sirenomelia. Diagnostic accuracy and detailed findings were compared with postnatal three-dimensional helical computed tomography （3D-HCT）, radiological findings and autopsy. Pregnancy was terminated in all 10 sirenomelia cases, including 9 singletons and I conjoined twin pregnancy, for a total of 5 males and 5 females. These cases of sirenomelia were deter- mined by autopsy and/or chromosomal examination. Initial 2D-US showed that there were 10 cases of oligohydranmios, bilateral renal agenesis, bladder agenesis, single umbilical artery, fusion of the lower limbs and spinal abnormalities; 8 cases of dipus or monopus; 2 cases of apus; and 8 cases of cardiac abnormalities. Subsequent 3D-SUIS showed that there were 9 cases of scoliosis, l0 cases of sacrococ- cygeal vertebra dysplasia, 3 cases of hemivertebra, 1 case of vertebral fusion, 3 cases of spina bifida, and 5 cases of rib abnormalities. 3D-SUIS identified significantly more skeletal abnormalities than did 2D-US, and its accuracy was 79.5% （70/88） compared with 3D-HCT and radiography. 3D-SUIS seems to be a useful complementary method to 2D-US and may improve the accuracy of identifying prenatal skeletal abnormalities related to sirenomelia.
文摘In this paper, we study the existence of positive solutions for a class of third-order three-point boundary value problem. By employing the fixed point theorem on cone, some new criteria to ensure the three-point boundary value problem has at least three positive solutions are obtained. An example illustrating our main result is given. Moreover, some previous results will be improved significantly in our paper.
基金Supported by Operation and Improvement Program of Climate Monitoring,Warning and Assessment Services in Three Gorges Reservoir AreaNational Key Technology R&D Program (2007BAC29B06)+1 种基金Major State Basic Research Development 973 Program (2006CB400503)National Natural Science Foundation of China (40705031)
文摘Based on the meteorological data from 33 stations of Three Gorges Reservoir from 1960 to 2008,climate yield of rice,corn and winter wheat and the changes of climatic potential productivity after water storage in Three Gorges Reservoir were calculated by the dynamic statistic model of crop growth.The results showed that the temperature in Three Gorges Reservoir was fluctuant decreased before late 1980s,and warmed rapidly after the late 1980s.The precipitation had little change before the late 1990s and had a slight decrease after the late 1990s.Sunshine hours were more in 1960s and 1970s,and then it changed little after 1980s.After water storage,the temperature increased in Three Gorges Reservoir as a whole.The precipitation decreased in the south of Three Gorges Reservoir,while it increased in the northwest of Three Gorges Reservoir.The sunshine hours were reduced except that in the vicinity of Dianjiang.After water storage,climatic potential productivity of rice decreased in the northwest and the northeast,while it increased in the south of Three Gorges Reservoir.The climatic potential productivity of corn decreased in the northeast and the southwest,but increased in the rest of Three Gorges Reservoir.The climatic potential productivity of winter wheat increased almost in total.
文摘This paper firstly defined the concept of folk culture block,and then analyzed the significance and planning principle of landscape design in folk culture block,and at last expounded landscape planning and design of folk culture block based on theory of three elements of landscape.
文摘Through the introduction of disaster situation of Qiang Culture after Wenchuan Earthquake, the paper emphasized that carriers of Qiang Culture had been seriously damaged, the inheritance of Qiang Culture had been affected, and the environment for Qiang Culture was difficult to recover. It highlighted that three-dimensional reconstruction of Qiang Culture should stress the core task and timely and effectively rescue endangered cultural heritages of Qiang Nationality from the perspectives of material and spiritual life. It had explained focuses of three-dimensional pattern construction in detail. In terms of spatial reconstruction, it should reconstruct native culture and history while material culture was constructed, and reconstruct Qiang culture highland by depending on aborigines; in terms of cluster reconstruction, it should give support to large tourism enterprises and perfect tourism chain; in terms of ecological reconstruction, it should enhance construction and demonstration of "ecological protection pilot area of Qiang culture"; in terms of development reconstruction, it should realize coordinated unity between protection and development according to classification protection, characteristic protection and key protection, so as to form the virtuous circle of post-disaster recovery protection and sustainable development.
