We investigate the decoy state quantum key distribution via the atmosphere channels. We consider the efficient decoy state method with one-signal state and two-decoy states. Our results show that the decoy state metho...We investigate the decoy state quantum key distribution via the atmosphere channels. We consider the efficient decoy state method with one-signal state and two-decoy states. Our results show that the decoy state method works even in the channels with fluctuating transmittance. Nevertheless, the key generation rate will be dra-matically decreased by atmosphere turbulence, which sheds more light on the characterization of atmosphere turbulence in realistic free-space based quantum key distributions.展开更多
Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-con...Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the M-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.展开更多
The failure characteristics of recycled concrete containing brick aggregates are still indistinct,especially how the angular aggregates effect the crack propagation.Based on the concept of modeled concrete,the develop...The failure characteristics of recycled concrete containing brick aggregates are still indistinct,especially how the angular aggregates effect the crack propagation.Based on the concept of modeled concrete,the development of cracks in concrete containing the natural aggregate and brick aggregate under a compression loading was studied.The strain distribution was analyzed with the Digital Image Correlation(DIC).The modeled aggregates include circular and squared ones,and the squared modeled aggregates were placed in different orientations,including 0°,22.5°and 45°.The results show that when the aggregate is placed at 45°,the upper and lower vertices of the aggregate lead to the highest critical strain concentration,therefore,cracks are easy to propagate from these areas and the strength of the corresponding modeled concrete is the lowest.When the modeled natural aggregate is placed at the orientation of 0°,the strain concentration first appears at the interface on both lateral sides of the aggregate.The brick aggregate has a lower elastic modulus and strength than the surrounding mortar.As a result,cracks always propagate through the brick aggregate,which is the primary reason for the low strength of the corresponding concrete.展开更多
We investigate the continuous variable quomtum teleportation in atmosphere channels. The beam-wandering mode/is employed to analyze the teleportation of the unknown single-mode coherent state. Two methods, one is dete...We investigate the continuous variable quomtum teleportation in atmosphere channels. The beam-wandering mode/is employed to analyze the teleportation of the unknown single-mode coherent state. Two methods, one is deterministic by increasing the aperture size of the detecting device and one is probabilistic by entanglement distillation, are proposed to improve the teleportation fidelity in the presence of atmosphere noises.展开更多
Landscape dynamics is a geoecological characteristic that defines changes in a landscape spatial structure and function during an established time scale. In this kind of analysis, geoprocessing is an essential tool, b...Landscape dynamics is a geoecological characteristic that defines changes in a landscape spatial structure and function during an established time scale. In this kind of analysis, geoprocessing is an essential tool, because it combines several technologies that help in this work. However, the majority of landscape dynamic investigations do not consider the dimensionality of the data and the information to be used, which is projected not measured from modeled (real) surface observations, and presents underestimated results, mainly in irregular relief landscapes. Considering that, this paper intends to assess the difference between observations on modeled and planimetric surfaces on the interpretation of landscape dynamics. The study was conducted in the massif of Tijuca, Rio de Janeiro (Brazil) using land use and soil cover maps of different times and a digital elevation models (DEM) generated based on a triangular irregular. The results show an increase of dynamic areas values when observations were carried out on modeled surface, as well as the deforestation rate (17.57% or 0.13 km2/year). This survey showed higher values in comparison with observations on planimetric surface, characterizing more realistic interpretations of how the structural elements and analyses made from these are structured in the landscape.展开更多
The hydrodynamic forces and flow field of artificial reef models in steady flow were numerically investigated using the RNG κ-ε turbulent model. The numerical simulation results are consistent with results observed ...The hydrodynamic forces and flow field of artificial reef models in steady flow were numerically investigated using the RNG κ-ε turbulent model. The numerical simulation results are consistent with results observed by experimental means. A comparative study indicates that the corresponding errors of forces between calculated values and values observed in the experiment vary in the range of2.3%-11.2% and that the corresponding errors of velocities vary in the range of 1.3%-15.8%. The flow field numerical results show that upstream and vortices exist when the current passes over and through the surface of the reef model. This study suggests that the numerical simulation method can be applied to predict the forces and flow field associated with artificial reefs.展开更多
From 1981 to 2010, the effects of climate change on evapotranspiration of the alpine ecosystem and the regional difference of effects in the Tibetan Plateau （TP） were studied based on the Lund-Potsdam-Jena dynamic v...From 1981 to 2010, the effects of climate change on evapotranspiration of the alpine ecosystem and the regional difference of effects in the Tibetan Plateau （TP） were studied based on the Lund-Potsdam-Jena dynamic vegetation model and data from 80 meteorological stations. Changes in actual evapotranspiration （AET） and water balance in TP were analyzed. Over the last 30 years, climate change in TP was characterized by significantly increased temperature, slightly increased precipitation, and decreased potential evapotranspiration （PET）, which was significant before 2000. AET exhibited increasing trends in most parts of TP. The difference between precipitation and AET decreased in the southeastern plateau and increased in the northwestern plateau. A decrease in atmospheric water demand will lead to a decreased trend in AET. However, AET in most regions increased because of increased precipitation. Increased precipitation was observed in 86% of the areas with increased AET, whereas decreased precipitation was observed in 73% of the areas with decreased AET.展开更多
Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(...Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_(2))since 2014.In this study,the OCO-2 XCO_(2)products were compared between in-situ data from the Total Carbon Column Network(TCCON)and Global Monitoring Division(GMD),and modeling data from CarbonTracker2019 over global ocean and land.Results showed that the OCO-2 XCO_(2)data are consistent with the TCCON and GMD in situ XCO_(2)data,with mean absolute biases of 0.25×10^(-6)and 0.67×10^(-6),respectively.Moreover,the OCO-2 XCO_(2)data are also consistent with the CarbonTracker2019 modeling XCO_(2)data,with mean absolute biases of 0.78×10^(-6)over ocean and 1.02×10^(-6)over land.The results indicated the high accuracy of the OCO-2 XCO_(2)product over global ocean which could be applied to estimate the air-sea CO_(2)flux.展开更多
Permafrost thickness under identical climates in cold regions can vary significantly because it is severely affected by climate change, topography, soil physical and thermal properties, and geothermal conditions. This...Permafrost thickness under identical climates in cold regions can vary significantly because it is severely affected by climate change, topography, soil physical and thermal properties, and geothermal conditions. This study numerically in- vestigates the response of ground thermal regime and talik development processes to permafrost with different thicknesses under a thermokarst lake on the Qinghai-Tibet Plateau. On the basis of observed data and information from a representative monitored lake in the Beiluhe Basin, we used a heat transfer model with phase change under a cylindrical coordinate system to conduct three simulation cases with permafrost thicknesses of 45 m, 60 m, and 75 m, respectively. The simulated results indicate that increases in permafrost thickness not only strongly retarded the open talik formation time, but also delayed the permafrost lateral thaw process after the formation of open talik. Increasing the permafrost thickness by 33.3% and 66.7% led to open talik formation time increases of 83.66% and 207.43%, respectively, and resulted in increases in the lateral thaw duration of permafrost under the modeled thermokarst lake by 28.86% and 46.54%, respectively, after the formation of the open taliks.展开更多
Simplified wave models- such as kinematic,diffusion and quasi-steady- are widely employed as a convenient replacement of the full dynamic one in the analysis of unsteady open-channel flows,and especially for flood rou...Simplified wave models- such as kinematic,diffusion and quasi-steady- are widely employed as a convenient replacement of the full dynamic one in the analysis of unsteady open-channel flows,and especially for flood routing.While their use may guarantee a significant reduction of the computational effort,it is mandatory to define the conditions in which they may be confidently applied.The present paper investigates the applicability conditions of the kinematic,diffusion and quasisteady dynamic shallow wave models for mud flows of power-law fluids.The power-law model describes in an adequate and convenient way fluids that at low shear rates fluids do not posses yield stress,such as clay or kaolin suspensions,which are frequently encountered in Chinese rivers.In the framework of a linear analysis,the propagation characteristics of a periodic perturbation of an initial steady uniform flow predicted by the simplified models are compared with those of the full dynamic one.Based on this comparison,applicability criteria for the different wave approximations for mud flood of power-law fluids are derived.The presented results provide guidelines for selecting the appropriate approximation for a given flow problem,and therefore they may represent a useful tool for engineering predictions.展开更多
Multiple sequence alignments can be used in the template-based modelling of protein structures to build fragment-based assembly models. Therefore, useful functional information on the 3D structure of the anti-MCF-7 sc...Multiple sequence alignments can be used in the template-based modelling of protein structures to build fragment-based assembly models. Therefore, useful functional information on the 3D structure of the anti-MCF-7 scFv protein can be obtained using available bioinformatics tools. This paper utilises several commonly-used bioinformatics tools and databases, including BLAST (Basic Local Alignment Search Tool), GenBank, PDB (Protein Data Bank), KABAT numbering and SWISS-MODEL, to gain specific functional insights into the anti-MCF-7 scFv protein and the assembly of single-chain fragment variable (scFv) antibodies, which consist of a variable heavy chain (VH) and a variable light chain (VL) connected by the linker (Gly4-Ser)3. The linker has been built as a loop structure using the Insight II software. The accuracy of the loop structure has been evaluated using Root Mean Square Deviation (RMSD). The accuracies of the VL and VH template-based structures are enhanced by using the evaluation methods Verify3D, ERRAT and Ramchandran plotting, which measure the error in the residues. In the results, 100% of the light-chain residues scored above 0.2, whereas 88.5% of the heavy-chain residues’ scored above 0.15 in the Verify3D evaluation method. Meanwhile, using ERRAT, the alignments of both chains scored more than 70% in space. Additionally, the Ramchandran plot evaluation method showed large numbers of residues in the favoured areas in both chains;these findings demonstrated that all of the chosen templates were the best candidates.展开更多
The dry deposition process refers to the flux loss of an atmospheric pollutant due to uptake of the pollutant by the earth’s surfaces.Dry deposition flux of a chemical species is typically calculated as the product o...The dry deposition process refers to the flux loss of an atmospheric pollutant due to uptake of the pollutant by the earth’s surfaces.Dry deposition flux of a chemical species is typically calculated as the product of its surface-layer concentration and its dry deposition velocity(V_(d)).Field measurement based V_(d) data are very scarce or do not exist for many chemical species considered in chemistry transport models.In the present study,gaseous and particulate dry deposition schemes were applied to generate a database of hourly V_(d) for 45 gaseous species and three particle size ranges for two years(2016–2017)at a 15 kmby 15 km horizontal resolution across North America.Hourly V_(d) of the 45 gaseous species ranged from<0.001 to 4.6 cm/sec across the whole domain,with chemical species-dependentmedian(mean)values being in the range of 0.018–1.37 cm/sec(0.05–1.43 cm/sec).The spatial distributions of the two-year average V_(d) showed values higher than 1–3 cm/sec for those soluble and reactive species over certain land types.Soluble species have the highest V_(d) over water surfaces,while insoluble but reactive species have the highest V_(d) over forests.Hourly V_(d) of PM_(2.5) across the whole domain ranged from 0.039 to 0.75 cm/sec with median(mean)value of 0.18(0.20)cm s^(−1),while the mean V_(d) for PM_(2.5)–10 is twice that of PM_(2.5).Uncertainties in the modeled V_(d) are typically on the order of a factor of 2.0 or larger,which needs to be considered when applying the dataset in other studies.展开更多
Under different conditions,gene regulatory networks(GRNs)of the same gene set could be similar but different.The differential analysis of GRNs under different conditions is important for understanding condition-specif...Under different conditions,gene regulatory networks(GRNs)of the same gene set could be similar but different.The differential analysis of GRNs under different conditions is important for understanding condition-specific gene regulatory relationships.In a naive approach,existing GRN inference algorithms can be used to separately estimate two GRNs under different conditions and identify the differences between them.However,in this way,the similarities between the pairwise GRNs are not taken into account.Several joint differential analysis algorithms have been proposed recently,which were proved to outperform the naive approach apparently.In this paper,we model the GRNs under different conditions with structural equation models(SEMs)to integrate gene expression data and genetic perturbations,and re-parameterize the pairwise SEMs to form an integrated model that incorporates the differential structure.Then,a Bayesian inference method is used to make joint differential analysis by solving the integrated model.We evaluated the performance of the proposed re-parametrization-based Bayesian differential analysis(ReBDA)algorithm by running simulations on synthetic data with different settings.The performance of the ReBDA algorithm was demonstrated better than another state-of-the-art joint differential analysis algorithm for SEMs ReDNet obviously.In the end,the ReBDA algorithm was applied to make differential analysis on a real human lung gene data set to illustrate its applicability and practicability.展开更多
The main objective of this study is the control of the agricultural greenhouse in view of the economic interest generated by such an activity. A simulation model is developed, gathering all the external and internal c...The main objective of this study is the control of the agricultural greenhouse in view of the economic interest generated by such an activity. A simulation model is developed, gathering all the external and internal climatic conditions that influence the microclimate of the greenhouse to predict the temporal evolution of the state variables characterizing this microclimate. The fuzzy control is an alternative to the approaches proposed by the automatic for the control of complex systems. The performance objectives of the looped systems and the corresponding actions are summarized in the form of rules of expertise, which are spelled out in plain language. This technique thus makes it possible to dispense with the use of mathematical models which are sometimes difficult to obtain. Our objective is the multivariable strategy synthesis and the fuzzy application to a multivariate system （MIMO ~ such as the agricultural greenhouse.） First, the principles of fuzzy logic and fuzzy control are recalled. The origins of non-Linearitys of the command are explained. One of the practical problems of this technique is the combinatorial explosion of the rule base when the number of variables involved becomes large. A solution to simplify the complexity of the system is presented together with an optimization algorithm to automatically adjust the parameters of the fuzzy controller. The last part is devoted to the synthesis of an optimal control of the greenhouse in order to compare it to the fuzzy control implemented.展开更多
In this paper, we developed a new continuous block method by the method of interpolation and collocation to derive new scheme. We adopted the use of power series as a basis function for approximate solution. We evalua...In this paper, we developed a new continuous block method by the method of interpolation and collocation to derive new scheme. We adopted the use of power series as a basis function for approximate solution. We evaluated at off grid points to get a continuous hybrid multistep method. The continuous hybrid multistep method is solved for the independent solution to yield a continuous block method which is evaluated at selected points to yield a discrete block method. The basic properties of the block method were investigated and found to be consistent, zero stable and convergent. The results were found to compete favorably with the existing methods in terms of accuracy and error bound. In particular, the scheme was found to have a large region of absolute stability. The new method was tested on real life problem namely: Dynamic model.展开更多
The flow around an axisymmetric body of revolution(DARPA SUBOFF bare model)at Re=1.2×10^(7)is numerically investigated using the wall-modeled large eddy simulation(WMLES).To evaluate the capabilities of WMLES in ...The flow around an axisymmetric body of revolution(DARPA SUBOFF bare model)at Re=1.2×10^(7)is numerically investigated using the wall-modeled large eddy simulation(WMLES).To evaluate the capabilities of WMLES in such wall-bounded turbulent flows,the effects of the wall stress model and sampling distance are systematically studied.The numerical results of the non-equilibrium wall stress model with an appropriate sampling distance are in good agreement with the experiments in terms of pressure coefficient,skin-friction coefficient,and drag coefficient.On this basis,the thickening of the turbulent boundary layer and the expansion of the wake can be clearly observed through flow visualization,especially using the Liutex vortex identification method.展开更多
Considering the demanding of grid requirements for high-Reynolds-number wall-bounded flow,the wall-modeled large-eddy simulation(WMLES)is an attractive method to deal with near wall turbulence.However,the effect of su...Considering the demanding of grid requirements for high-Reynolds-number wall-bounded flow,the wall-modeled large-eddy simulation(WMLES)is an attractive method to deal with near wall turbulence.However,the effect of subgrid-scale(SGS)models for wall-bounded turbulent flow in combination with wall stress models is still unclear.In this paper,turbulent channel flow at Reτ=1000 are numerically simulated by WMLES in conjunction with four different SGS models,i.e.,the wall-adapting local eddy-viscosity model,the dynamic Smagorinsky model,the dynamic SGS kinetic energy model and the dynamic Lagrangian model.The mean velocity profiles are compared with the law of the wall,and the velocity fluctuations are compared with direct numerical simulation data.The energy spectrum of velocity and wall pressure fluctuations are presented and the role of SGS models on predicting turbulent channel flow with WMLES is discussed.展开更多
Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microgl...Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574400,U1304613,11204197,11204379 and 11074244the National Basic Research Program of China under Grant No 2011CBA00200the Doctor Foundation of the Ministry of Education of China under Grant No 20113402110059
文摘We investigate the decoy state quantum key distribution via the atmosphere channels. We consider the efficient decoy state method with one-signal state and two-decoy states. Our results show that the decoy state method works even in the channels with fluctuating transmittance. Nevertheless, the key generation rate will be dra-matically decreased by atmosphere turbulence, which sheds more light on the characterization of atmosphere turbulence in realistic free-space based quantum key distributions.
基金Supported by the National Basic Research Program of China under Grant No 2014CB643902the Key Program of Natural Science Foundation of China under Grant No 61334004+3 种基金the National Natural Science Foundation of China under Grant No 61404152the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDA5-1the Foundation of National Laboratory for Infrared Physics,the Key Research Program of the Chinese Academy of Sciences under Grant No KGZDEW-804the Creative Research Group Project of Natural Science Foundation of China under Grant No 61321492
文摘Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the M-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.
基金the National Natural Science Foundation of China(Nos.52078358,51325802)China Postdoctoral Science Foundation(No.2018M642079)are highly acknowledged.
文摘The failure characteristics of recycled concrete containing brick aggregates are still indistinct,especially how the angular aggregates effect the crack propagation.Based on the concept of modeled concrete,the development of cracks in concrete containing the natural aggregate and brick aggregate under a compression loading was studied.The strain distribution was analyzed with the Digital Image Correlation(DIC).The modeled aggregates include circular and squared ones,and the squared modeled aggregates were placed in different orientations,including 0°,22.5°and 45°.The results show that when the aggregate is placed at 45°,the upper and lower vertices of the aggregate lead to the highest critical strain concentration,therefore,cracks are easy to propagate from these areas and the strength of the corresponding modeled concrete is the lowest.When the modeled natural aggregate is placed at the orientation of 0°,the strain concentration first appears at the interface on both lateral sides of the aggregate.The brick aggregate has a lower elastic modulus and strength than the surrounding mortar.As a result,cracks always propagate through the brick aggregate,which is the primary reason for the low strength of the corresponding concrete.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574400,U1304613,11204197,11204379and 11074244
文摘We investigate the continuous variable quomtum teleportation in atmosphere channels. The beam-wandering mode/is employed to analyze the teleportation of the unknown single-mode coherent state. Two methods, one is deterministic by increasing the aperture size of the detecting device and one is probabilistic by entanglement distillation, are proposed to improve the teleportation fidelity in the presence of atmosphere noises.
基金supported by a grant from the CNPq(National Council for Developing Science and Technol-ogy)FAPERJ(Carlos ChagasFilho Foundation for Research Development of the Rio de Janeiro State).
文摘Landscape dynamics is a geoecological characteristic that defines changes in a landscape spatial structure and function during an established time scale. In this kind of analysis, geoprocessing is an essential tool, because it combines several technologies that help in this work. However, the majority of landscape dynamic investigations do not consider the dimensionality of the data and the information to be used, which is projected not measured from modeled (real) surface observations, and presents underestimated results, mainly in irregular relief landscapes. Considering that, this paper intends to assess the difference between observations on modeled and planimetric surfaces on the interpretation of landscape dynamics. The study was conducted in the massif of Tijuca, Rio de Janeiro (Brazil) using land use and soil cover maps of different times and a digital elevation models (DEM) generated based on a triangular irregular. The results show an increase of dynamic areas values when observations were carried out on modeled surface, as well as the deforestation rate (17.57% or 0.13 km2/year). This survey showed higher values in comparison with observations on planimetric surface, characterizing more realistic interpretations of how the structural elements and analyses made from these are structured in the landscape.
基金Supported by the National High Technology Research and Development Program of China(863 Programs)(No.2006AA100301)Science and Technology Development Program of Shandong Province(No.2005GG3205102)
文摘The hydrodynamic forces and flow field of artificial reef models in steady flow were numerically investigated using the RNG κ-ε turbulent model. The numerical simulation results are consistent with results observed by experimental means. A comparative study indicates that the corresponding errors of forces between calculated values and values observed in the experiment vary in the range of2.3%-11.2% and that the corresponding errors of velocities vary in the range of 1.3%-15.8%. The flow field numerical results show that upstream and vortices exist when the current passes over and through the surface of the reef model. This study suggests that the numerical simulation method can be applied to predict the forces and flow field associated with artificial reefs.
基金The "Strategic Priority Research Program" of the Chinese Academy of Sciences,No.XDA05090304Project for Public Service from Ministry of Environmental Protection of China,No.201009056National Key Technology Research and Development Program,No.2009BAC61B05
文摘From 1981 to 2010, the effects of climate change on evapotranspiration of the alpine ecosystem and the regional difference of effects in the Tibetan Plateau （TP） were studied based on the Lund-Potsdam-Jena dynamic vegetation model and data from 80 meteorological stations. Changes in actual evapotranspiration （AET） and water balance in TP were analyzed. Over the last 30 years, climate change in TP was characterized by significantly increased temperature, slightly increased precipitation, and decreased potential evapotranspiration （PET）, which was significant before 2000. AET exhibited increasing trends in most parts of TP. The difference between precipitation and AET decreased in the southeastern plateau and increased in the northwestern plateau. A decrease in atmospheric water demand will lead to a decreased trend in AET. However, AET in most regions increased because of increased precipitation. Increased precipitation was observed in 86% of the areas with increased AET, whereas decreased precipitation was observed in 73% of the areas with decreased AET.
基金The National Key Research and Development Programme of China under contract No.2017YFA0603004the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(Zhanjiang Bay Laboratory)under contract No.ZJW-2019-08+1 种基金the National Natural Science Foundation of China under contract Nos 41825014,41676172 and 41676170the Global Change and Air-Sea Interaction Project of China under contract Nos GASI-02-SCS-YGST2-01,GASI-02-PACYGST2-01 and GASI-02-IND-YGST2-01。
文摘Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_(2))since 2014.In this study,the OCO-2 XCO_(2)products were compared between in-situ data from the Total Carbon Column Network(TCCON)and Global Monitoring Division(GMD),and modeling data from CarbonTracker2019 over global ocean and land.Results showed that the OCO-2 XCO_(2)data are consistent with the TCCON and GMD in situ XCO_(2)data,with mean absolute biases of 0.25×10^(-6)and 0.67×10^(-6),respectively.Moreover,the OCO-2 XCO_(2)data are also consistent with the CarbonTracker2019 modeling XCO_(2)data,with mean absolute biases of 0.78×10^(-6)over ocean and 1.02×10^(-6)over land.The results indicated the high accuracy of the OCO-2 XCO_(2)product over global ocean which could be applied to estimate the air-sea CO_(2)flux.
基金supported by the National Natural Science Foundation of China (NSFC) (No.41271076)the National Key Basic Research Program of China (No.2010CB951402)the Open Fund Project of the Institute of Plateau Meteorology, China Meteorological Administration (No.LPM2008019)
文摘Permafrost thickness under identical climates in cold regions can vary significantly because it is severely affected by climate change, topography, soil physical and thermal properties, and geothermal conditions. This study numerically in- vestigates the response of ground thermal regime and talik development processes to permafrost with different thicknesses under a thermokarst lake on the Qinghai-Tibet Plateau. On the basis of observed data and information from a representative monitored lake in the Beiluhe Basin, we used a heat transfer model with phase change under a cylindrical coordinate system to conduct three simulation cases with permafrost thicknesses of 45 m, 60 m, and 75 m, respectively. The simulated results indicate that increases in permafrost thickness not only strongly retarded the open talik formation time, but also delayed the permafrost lateral thaw process after the formation of open talik. Increasing the permafrost thickness by 33.3% and 66.7% led to open talik formation time increases of 83.66% and 207.43%, respectively, and resulted in increases in the lateral thaw duration of permafrost under the modeled thermokarst lake by 28.86% and 46.54%, respectively, after the formation of the open taliks.
文摘Simplified wave models- such as kinematic,diffusion and quasi-steady- are widely employed as a convenient replacement of the full dynamic one in the analysis of unsteady open-channel flows,and especially for flood routing.While their use may guarantee a significant reduction of the computational effort,it is mandatory to define the conditions in which they may be confidently applied.The present paper investigates the applicability conditions of the kinematic,diffusion and quasisteady dynamic shallow wave models for mud flows of power-law fluids.The power-law model describes in an adequate and convenient way fluids that at low shear rates fluids do not posses yield stress,such as clay or kaolin suspensions,which are frequently encountered in Chinese rivers.In the framework of a linear analysis,the propagation characteristics of a periodic perturbation of an initial steady uniform flow predicted by the simplified models are compared with those of the full dynamic one.Based on this comparison,applicability criteria for the different wave approximations for mud flood of power-law fluids are derived.The presented results provide guidelines for selecting the appropriate approximation for a given flow problem,and therefore they may represent a useful tool for engineering predictions.
文摘Multiple sequence alignments can be used in the template-based modelling of protein structures to build fragment-based assembly models. Therefore, useful functional information on the 3D structure of the anti-MCF-7 scFv protein can be obtained using available bioinformatics tools. This paper utilises several commonly-used bioinformatics tools and databases, including BLAST (Basic Local Alignment Search Tool), GenBank, PDB (Protein Data Bank), KABAT numbering and SWISS-MODEL, to gain specific functional insights into the anti-MCF-7 scFv protein and the assembly of single-chain fragment variable (scFv) antibodies, which consist of a variable heavy chain (VH) and a variable light chain (VL) connected by the linker (Gly4-Ser)3. The linker has been built as a loop structure using the Insight II software. The accuracy of the loop structure has been evaluated using Root Mean Square Deviation (RMSD). The accuracies of the VL and VH template-based structures are enhanced by using the evaluation methods Verify3D, ERRAT and Ramchandran plotting, which measure the error in the residues. In the results, 100% of the light-chain residues scored above 0.2, whereas 88.5% of the heavy-chain residues’ scored above 0.15 in the Verify3D evaluation method. Meanwhile, using ERRAT, the alignments of both chains scored more than 70% in space. Additionally, the Ramchandran plot evaluation method showed large numbers of residues in the favoured areas in both chains;these findings demonstrated that all of the chosen templates were the best candidates.
文摘The dry deposition process refers to the flux loss of an atmospheric pollutant due to uptake of the pollutant by the earth’s surfaces.Dry deposition flux of a chemical species is typically calculated as the product of its surface-layer concentration and its dry deposition velocity(V_(d)).Field measurement based V_(d) data are very scarce or do not exist for many chemical species considered in chemistry transport models.In the present study,gaseous and particulate dry deposition schemes were applied to generate a database of hourly V_(d) for 45 gaseous species and three particle size ranges for two years(2016–2017)at a 15 kmby 15 km horizontal resolution across North America.Hourly V_(d) of the 45 gaseous species ranged from<0.001 to 4.6 cm/sec across the whole domain,with chemical species-dependentmedian(mean)values being in the range of 0.018–1.37 cm/sec(0.05–1.43 cm/sec).The spatial distributions of the two-year average V_(d) showed values higher than 1–3 cm/sec for those soluble and reactive species over certain land types.Soluble species have the highest V_(d) over water surfaces,while insoluble but reactive species have the highest V_(d) over forests.Hourly V_(d) of PM_(2.5) across the whole domain ranged from 0.039 to 0.75 cm/sec with median(mean)value of 0.18(0.20)cm s^(−1),while the mean V_(d) for PM_(2.5)–10 is twice that of PM_(2.5).Uncertainties in the modeled V_(d) are typically on the order of a factor of 2.0 or larger,which needs to be considered when applying the dataset in other studies.
基金supported by grants from National Natural Science Foundation of China(Nos.61502198,61572226,61472161,61876069)。
文摘Under different conditions,gene regulatory networks(GRNs)of the same gene set could be similar but different.The differential analysis of GRNs under different conditions is important for understanding condition-specific gene regulatory relationships.In a naive approach,existing GRN inference algorithms can be used to separately estimate two GRNs under different conditions and identify the differences between them.However,in this way,the similarities between the pairwise GRNs are not taken into account.Several joint differential analysis algorithms have been proposed recently,which were proved to outperform the naive approach apparently.In this paper,we model the GRNs under different conditions with structural equation models(SEMs)to integrate gene expression data and genetic perturbations,and re-parameterize the pairwise SEMs to form an integrated model that incorporates the differential structure.Then,a Bayesian inference method is used to make joint differential analysis by solving the integrated model.We evaluated the performance of the proposed re-parametrization-based Bayesian differential analysis(ReBDA)algorithm by running simulations on synthetic data with different settings.The performance of the ReBDA algorithm was demonstrated better than another state-of-the-art joint differential analysis algorithm for SEMs ReDNet obviously.In the end,the ReBDA algorithm was applied to make differential analysis on a real human lung gene data set to illustrate its applicability and practicability.
文摘The main objective of this study is the control of the agricultural greenhouse in view of the economic interest generated by such an activity. A simulation model is developed, gathering all the external and internal climatic conditions that influence the microclimate of the greenhouse to predict the temporal evolution of the state variables characterizing this microclimate. The fuzzy control is an alternative to the approaches proposed by the automatic for the control of complex systems. The performance objectives of the looped systems and the corresponding actions are summarized in the form of rules of expertise, which are spelled out in plain language. This technique thus makes it possible to dispense with the use of mathematical models which are sometimes difficult to obtain. Our objective is the multivariable strategy synthesis and the fuzzy application to a multivariate system （MIMO ~ such as the agricultural greenhouse.） First, the principles of fuzzy logic and fuzzy control are recalled. The origins of non-Linearitys of the command are explained. One of the practical problems of this technique is the combinatorial explosion of the rule base when the number of variables involved becomes large. A solution to simplify the complexity of the system is presented together with an optimization algorithm to automatically adjust the parameters of the fuzzy controller. The last part is devoted to the synthesis of an optimal control of the greenhouse in order to compare it to the fuzzy control implemented.
文摘In this paper, we developed a new continuous block method by the method of interpolation and collocation to derive new scheme. We adopted the use of power series as a basis function for approximate solution. We evaluated at off grid points to get a continuous hybrid multistep method. The continuous hybrid multistep method is solved for the independent solution to yield a continuous block method which is evaluated at selected points to yield a discrete block method. The basic properties of the block method were investigated and found to be consistent, zero stable and convergent. The results were found to compete favorably with the existing methods in terms of accuracy and error bound. In particular, the scheme was found to have a large region of absolute stability. The new method was tested on real life problem namely: Dynamic model.
基金Project supported by the National Natural Science Foundation of China(Grant No.52131102)the National Key Research and Development Program of China(Grant Nos.2022YFC2806705,2019YFB1704200).
文摘The flow around an axisymmetric body of revolution(DARPA SUBOFF bare model)at Re=1.2×10^(7)is numerically investigated using the wall-modeled large eddy simulation(WMLES).To evaluate the capabilities of WMLES in such wall-bounded turbulent flows,the effects of the wall stress model and sampling distance are systematically studied.The numerical results of the non-equilibrium wall stress model with an appropriate sampling distance are in good agreement with the experiments in terms of pressure coefficient,skin-friction coefficient,and drag coefficient.On this basis,the thickening of the turbulent boundary layer and the expansion of the wake can be clearly observed through flow visualization,especially using the Liutex vortex identification method.
基金supported by the National Natural Science Foundation of China(Grant No.52131102)the National Key Research and Development Program of China(Grant No.2022YFC2806705)。
文摘Considering the demanding of grid requirements for high-Reynolds-number wall-bounded flow,the wall-modeled large-eddy simulation(WMLES)is an attractive method to deal with near wall turbulence.However,the effect of subgrid-scale(SGS)models for wall-bounded turbulent flow in combination with wall stress models is still unclear.In this paper,turbulent channel flow at Reτ=1000 are numerically simulated by WMLES in conjunction with four different SGS models,i.e.,the wall-adapting local eddy-viscosity model,the dynamic Smagorinsky model,the dynamic SGS kinetic energy model and the dynamic Lagrangian model.The mean velocity profiles are compared with the law of the wall,and the velocity fluctuations are compared with direct numerical simulation data.The energy spectrum of velocity and wall pressure fluctuations are presented and the role of SGS models on predicting turbulent channel flow with WMLES is discussed.
基金supported by the Natural Science Foundation of Yunnan Province,No.202401AS070086(to ZW)the National Key Research and Development Program of China,No.2018YFA0801403(to ZW)+1 种基金Yunnan Science and Technology Talent and Platform Plan,No.202105AC160041(to ZW)the Natural Science Foundation of China,No.31960120(to ZW)。
文摘Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.
