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| 1 | MICROWAVE-ASSISTED EXTRACTION OF GLYCYRRHIZIC ACID FROM LICORICE ROOT-EFFECT OF THE PROPERTY OF SOLUTION ON EXTRACTION OF GA显示文摘The property of extraction solution is an important factor influencing the extraction efficiency. In the present work, the effect of the property of solution on extraction of GA was studied, which including the concentration of ethanol, ammonia and cation (M+), pH of extraction solution, different kinds of organic solvent etc. The results show that 50%-60%(v/v) ethanol can reach high percentage extraction of GA. If 1% (v/v) ammonia solution was added into 60%(v/v) ethanol, the percentage extraction can be increased from 2.0% to 2.31%. Without ammonia, 50mmol/L [M+] (M+ = K+, NH4+) was added into 60%(v/v) ethanol, percentage extraction of GA can reach about 2.26%. If pH of solution (60% ethanol) was adjust to pH=4.0, it can reach high percentage extraction. If pH of solution (60% ethanol + 50mmol [M+], pH=6.1) was adjust tO PH=4.0, especially M+ is K+ or NH4+, it can reach almost same extraction efficiency as that of 1% ammonia solution + 60% ethanol, and the operation environment can be greatly improved. | Pan Xuejun and Liu Huizhou (Young Scienctist Laboratory of Separation Science & Engineering, State Key Laboratory of Biochemical Engineering, Instigate of Chemical Metallurgy, Chinese Academy of Sciepces, Beijing 100080) | 2000 | 化工学报2000，51，S1： | 52 |
| 2 | Research on the slope spectrum of the Loess Plateau显示文摘A new concept dealing with digital analysis of loess terrain,slope spectrum,is presented and discussed in this paper,by introducing its characteristic,represen-tation and extracting method from DEMs. Using 48 geomorphological units in dif-ferent parts of the loess as test areas and 5 m-resolution DEMs as original test data,the quantitative depiction and spatial distribution of slope spectrum in China's Loess Plateau have been studied on the basis of a series of carefully-designed experiments. In addition,initial experiment indicates a strong relationship between the slope spectrum and the loess landform types,displaying a potential importance of the slope spectrum in geomorphological studies. Based on the slope spectrums derived from the 25 m-resolution DEM data in whole loess terrain in northern part of Shaanxi,13 slope spectrum indices were extracted and integrated into a compre-hensive layer with image integration method. Based on that,a series of unsuper-vised classifications was applied in order to make a landform classification in northern Shaanxi Loess Plateau. Experimental results show that the slope spec-trum analysis is an effective method in revealing the macro landform features. A continuous change of slope spectrum from south to north in northern Shaanxi Loess Plateau shows an obvious spatial distribution of different loess landforms. This also proves the great significance of the slope spectrum method in describing the terrain roughness and landform evolution as well as a further understanding on landform genesis and spatial distribution rule of different landforms in the Loess Plateau. | TANG GuoAn,LI FaYuan,LIU XueJun,LONG Yi & YANG Xin Key Laboratory of Virtual Geographic Environment,Nanjing Normal University,Ministry of Education,Nanjing 210046,China | 2008 | Science China(Technological Sciences)2008，51，S1： | 22 |
| 3 | Collision free 4D path planning for multiple UAVs based on spatial refined voting mechanism and PSO approach显示文摘In this paper, a four-dimensional coordinated path planning algorithm for multiple UAVs is proposed, in which time variable is taken into account for each UAV as well as collision free and obstacle avoidance. A Spatial Refined Voting Mechanism(SRVM) is designed for standard Particle Swarm Optimization(PSO) to overcome the defects of local optimal and slow convergence.For each generation candidate particle positions are recorded and an adaptive cube is formed with own adaptive side length to indicate occupied regions. Then space voting begins and is sorted based on voting results, whose centers with bigger voting counts are seen as sub-optimal positions. The average of all particles of corresponding dimensions are calculated as the refined solutions. A time coordination method is developed by generating specified candidate paths for every UAV, making them arrive the same destination with the same time consumption. A spatial-temporal collision avoidance technique is introduced to make collision free. Distance to destination is constructed to improve the searching accuracy and velocity of particles. In addition, the objective function is redesigned by considering the obstacle and threat avoidance, Estimated Time of Arrival(ETA), separation maintenance and UAV self-constraints. Experimental results prove the effectiveness and efficiency of the algorithm. | Yang LIU Xuejun ZHANG Yu ZHANG Xiangmin GUAN | 2019 | Chinese Journal of Aeronautics2019，32，6： | 20 |
| 4 | T cell–associated immunoregulation and antiviral effect of oxymatrine in hydrodynamic injection HBV mouse model显示文摘Although oxymatrine(OMT) has been shown to directly inhibit the replication of hepatitis B virus(HBV) in vitro, limited research has been done with this drug in vivo. In the present study, the antiviral effect of OMT was investigated in an immunocompetent mouse model of chronic HBV infection.The infection was achieved by tail vein injection of a large volume of DNA solution. OMT(2.2, 6.7 and20 mg/kg) was administered by daily intraperitoneal injection for 6 weeks. The efficacy of OMT was evaluated by the levels of HBV DNA, hepatitis B surface antigen(HBs Ag), hepatitis B e antigen(HBe Ag)and hepatitis B core antigen(HBc Ag). The immunoregulatory activity of OMT was evaluated by serum ELISA and flow cytometry. Results shows that OMT at 20 mg/kg inhibited HBV replication, and it was more efficient than entecavir(ETV) in the elimination of serum HBs Ag and intrahepatic HBc Ag. Inaddition, OMT accelerated the production of interferon-γ(IFN-γ) in a dose-dependent manner in CD4^+T cells. Our findings demonstrate the beneficial effects of OMT on the enhancement of immunological function and in the control of HBV antigens. The findings suggest this drug to be a good antiviral therapeutic candidate for the treatment of HBV infection. | Xiuxiu Sang Ruilin Wang Yanzhong Han Cong’en Zhang Honghui Shen Zhirui Yang Yin Xiong Huimin Liu Shijing Liu Ruisheng Li Ruichuang Yang Jiabo Wang Xuejun Wang Zhaofang Bai Xiaohe Xiao | 2017 | Acta Pharmaceutica Sinica B2017，7，3： | 20 |
| 5 | Research on heart sound identification technology显示文摘In this article,both the basic principles and the experimental methods of identity recognition technology based on heart sounds are addressed.First,the characteristics of heart sounds and the feasibility of heart sounds as a biometric were analyzed.A synthetic model of heart sounds was then developed based on a family of wavelets;Finally,the characteristic parameters of heart sounds were extracted by using the heart sounds linear band frequency cepstra(HS-LBFC)with a specified configuration,and the similarity distance was adopted for heart sound identification.To highlight the difference in two heart sound signals between the time and frequency domains,a construction method of the heart sound wavelet,a calculation method of the parameters of a synthetic model,selection of the characteristic parameters of heart sounds and the corresponding data processing technology were examined.The experimental results showed that the proposed method exhibited excellent performance and practicability. | CHENG XieFeng MA Yong LIU Chen ZHANG XueJun GUO YuFeng | 2012 | Science China(Information Sciences)2012，55，2： | 20 |
| 6 | Impact of nitrogen addition on plant community in a semi-arid temperate steppe in China显示文摘Increased nitrogen (N) deposition will often lead to a decline in species richness in grassland ecosystems but the shifts in functional groups and plant traits are still poorly understood in China.A field experiment was conducted at Duolun,Inner Mongolia,China,to investigate the effects of N addition on a temperate steppe ecosystem.Six N levels (0,3,6,12,24,and 48 g N/(m 2 a)) were added as three applications per year from 2005 to 2010.Enhanced N deposition,even as little as 3 g N/(m 2 a) above ambient N deposition (1.2 g N/(m 2 a)),led to a decline in species richness of the whole community.Increasing N addition can significantly stimulate aboveground biomass of perennial bunchgrasses (PB) but decrease perennial forbs (PF),and induce a slight change in the biomass of shrubs and semi-shrubs (SS).The biomass of annuals (AS) and perennial rhizome grasses (PR) accounts for only a small part of the total biomass.Species richness of PF decreased significantly with increasing N addition rate but there was a little change in the other functional groups.PB,as the dominant functional group,has a relatively higher height than others.Differences in the response of each functional group to N addition have site-specific and species-specific characteristics.We initially infer that N enrichment stimulated the growth of PB,which further suppressed the growth of other functional groups. | Ling SONG XueMei BAO XueJun LIU FuSuo ZHANG | 2012 | Journal of Arid Land2012，4，1： | 18 |
| 7 | Agriculture Green Development: a model for China and the world显示文摘Realizing sustainable development has become a global priority.This holds,in particular,for agriculture.Recently,the United Nations launched the Sustainable Development Goals(SDGs),and the Nineteenth National People’s Congress has delivered a national strategy for sustainable development in China—realizing green development.The overall objective of Agriculture Green Development(AGD)is to coordinate'green'with'development'to realize the transformation of current agriculture with high resource consumption and high environmental costs into a green agriculture and countryside with high productivity,high resource use efficiency and low environmental impact.This is a formidable task,requiring joint efforts of government,farmers,industry,educators and researchers.The innovative concept for AGD will focus on reconstructing the whole crop-animal production and food production-consumption system,with the emphasis on high thresholds for environmental standards and food quality as well as enhanced human well-being.This paper addresses the significance,challenges,framework,pathways and potential solutions for realizing AGD in China,and highlights the potential changes that will lead to a more sustainable agriculture in the future.Proposals include interdisciplinary innovations,whole food chain improvement and regional solutions.The implementation of AGD in China will provide important implications for the countries in developmental transition,and contribute to global sustainable development. | Jianbo SHEN Qichao ZHU Xiaoqiang JIAO Hao YING Hongliang WANG Xin WEN Wen XU Tingyu LI Wenfeng CONG Xuejun LIU Yong HOU Zhenling CUI Oene OENEMA William JDAVIES Fusuo ZHANG | 2020 | Frontiers of Agricultural Science and Engineering2020，7，1： | 18 |
| 8 | Imaging 3-D crustal P-wave velocity structure of western Yunnan with bulletin data显示文摘Western Yunnan is a region with intensive tectonic activity and serious earthquake risk.It is of significant importance to study three dimensional crustal structure of this region to understand the tectonic setting and disaster mechanism.Densification and digitalization of seismic networks in this region provides an opportunity to study the velocity structure with bulletin data.In this study,we collect P-wave data of 10 403 regional earthquakes recorded by 79 seismic stations from January 2008 to December 2010.In addition to first arrivals data (Pg with epicentral distance less than 200 km and Pn),the Pg (or P) data with epicentral distance more than 200 km are also considered as later direct arrivals in the tomographic inversion.We also compare the quantity and the quality of the seismic data before 2010 and after 2010.The test results show that adding the follow-up Pg phase can effectively improve the inversion ability of crustal imaging,and quantity and the data quality are significantly improved since 2010.The tomographic results show that:(1) The Honghe fault zone,which is the major fault systems in this region,may cut through the entire crust,and the velocity contrasts between two sides at lower crust beneath the Honghe fault are estimated at higher than 10%,while the velocity difference below Nujiang fault zone extends only in the upper crust;(2) Most of the earthquakes in the region occurred at the interface of high-velocity media and low-velocity media,i.e.,the areas with high velocity gradient,which has been validated in other areas. | Jing Huang Xuejun Liu Youjin Su Baoshan Wang | 2012 | Earthquake Science2012，25，2： | 16 |
| 9 | Nitrogen deposition as an important nutrient from the environment and its impact on ecosystems in China显示文摘As an example of atmospheric nitrogen(N) deposition,the paper summarizes the definition,form and amount of nutrient from the environment(NFE) and the relationship between NFE and anthro-pogenic reactive N emission.Based on our own study and published articles,we find that N wet and dry deposition has been an important nutrient resource in agricultural and natural ecosystems in China.The total amount of N deposition and other environment-derived N in China was up to 18 Tg N/a,equal to ap-proximately 60% of the national N fertilizer consumption.Nitrogen deposition is expected to contribute substantially to nutrient cycling and net primary productivity in various ecosystems.Therefore,it is crucial to utilize this environment-derived nutrient resource by integrated nutrient resource management in order to realize the sustainable development of both agricultural and non-agricultural ecosystems. | Liu, XueJun Song, Ling He, ChunE Zhang, FuSuo | 2010 | Journal of Arid Land2010，2，2： | 15 |
| 10 | Chinese progress in geomorphometry显示文摘Geomorphometry,the science of digital terrain analysis(DTA),is an important focus of research in both geomorphology and geographical information science(GIS).Given that 70% of China is mountainous,geomorphological research is popular among Chinese scholars,and the development of GIS over the last 30 years has led to significant advances in geomorphometric research.In this paper,we review Chinese progress in geomorphometry based on the published literature.There are three major areas of progress:digital terrain modelling methods,DTA methods,and applications of digital terrain models(DTMs).First,traditional vector-and raster-based terrain modelling methods,including the assessment of uncertainty,have received widespread attention.New terrain modelling methods such as unified raster and vector,high-fidelity,and real-time dynamic geographical scene modelling have also attracted research attention and are now a major focus of digital terrain modelling research.Second,in addition to the popular DTA methods based on topographical derivatives,geomorphological features,and hydrological factors extracted from DTMs,DTA methods have been extended to include analyses of the structure of underlying strata,ocean surface features and even socioeconomic spatial structures.Third,DTMs have been applied to fields including global climate change,analysis of various typical regions,lunar surface and other related fields.Clearly,Chinese scholars have made significant progress in geomorphometry.Chinese scholars have had the greatest international impact in areas including high-fidelity digital terrain modelling and DTM-based regional geomorphological analysis,particularly in the Loess Plateau and the Tibetan Plateau regions. | LV Guonian XIONG Liyang CHEN Min TANG Guoan SHENG Yehua LIU Xuejun SONG Zhiyao LU Yuqi YU Zhaoyuan ZHANG Ka WANG Meizhen | 2017 | Journal of Geographical Sciences2017，27，11： | 14 |
| 11 | Ductile deformation within Upper Himalaya Crystalline Sequence and geological implications,in Nyalam area,Southern Tibet显示文摘The South Tibet Detachment System(STDS) is a flat normal fault that separates the Upper Himalaya Crystalline Sequence(UHCS) below from the Tethyan Sedimentary Sequence(TSS) above.Timing of deformations related to the STDS is critical to understand the mechanism and evolution of the Himalaya collision zone.The Nyalam detachment(ND)(~86°E) locates in the middle portion of STDS(81°-89°E).Dating of deformed leucocratic dykes that are most probably syntectonic at different depth beneath the ND,allow us to constrain the timing of deformation.(1) Dyke T11N37 located ~3500 m structurally below the ND emplaced at 27.4± 0.2 Ma;(2) Dyke T11N32 located ~1400 m structurally below the ND emplaced at 22.0±0.3 Ma;(3) T11N25 located within the top to the north STD shear zone,~150 m structurally below the ND,emplaced at 17.1±0.2 Ma.Combining ND footwall cooling history and T11N25 deformation temperature,we indicate a probable onset of top to the north deformation at ~16 Ma at this location.These results show an upward younging of the probable timing of onset of the deformation at different structural distance below the ND.We then propose a new model for deformation migration below the ND with deformation starting by pure shear deformation at depth prior to ~27.5 Ma that migrates upward at a rate of ~ 0.3 mm/a until ~18 Ma when deformation switches to top to the north shearing in the South Tibet Detachment shear zone(STDsz).As deformation on the ND stops at 14-13 Ma this would imply that significant top to the North motion would be limited to less than 5 Ma and would jeopardize the importance of lower channel flow. | LIU XiaoBing LIU XiaoHan LELOUP P.H. MAHEO G. PAQUETTE J.L. ZHANG XinGang ZHOU XueJun | 2012 | Chinese Science Bulletin2012，57，26： | 14 |
| 12 | Antimony smelting process generating solid wastes and dust:Characterization and leaching behaviors显示文摘A large amount of solid waste has been produced by the antimony smelting process in the'World Capital of Antimony', Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag,arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 104 and 3.16 × 105mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste. | Xuejun Guo Kunpeng Wang Mengchang He Ziwei Liu Hailin Yang Sisi Li | 2014 | Journal of Environmental Sciences2014，26，7： | 13 |
| 13 | Aircraft conflict resolution method based on hybrid ant colony optimization and artificial potential field显示文摘Dear editor, With the significant growth of the civil aviation industry and especially its rapid development in booming economies such as that of China,air traffic flow is drastically increasing,leading to greater congestion around airport terminal areas and in busy airspace [i].The substantial increase in air traffic flow has intensified the risk of violating safe separation regulations,endangering the airspace operational safety.Furthermore,as the result of this significant growth has resulted in problems such as longer delays,which increase fuel consumption and cost the airline industry billions of dollars every year [2,3]. | Huaxian LIU Feng LIU Xuejun ZHANG Xiangmin GUAN Jun CHEN Pascal SAVINAUD | 2018 | Science China(Information Sciences)2018，61，12： | 11 |
| 14 | Using the EMD Method to Determine Fault Criterion for Medium-low Pressure Gas Regulators显示文摘By extracting the outlet pressure data of gas regulators,this paper uses the EMD toolbox of the MATLAB software,which can perform data decomposition and the Hilbert-Huang Transform to find the rules with fault data.Eventually,the medium-low pressure gas regulator fault criterion can be established. | HAO Xuejun LIU Qiang YANG Guobin DU Yi | 2015 | Journal of Thermal Science2015，24，6： | 11 |
| 15 | A new hybrid aerodynamic optimization framework based on differential evolution and invasive weed optimization显示文摘Since many aerodynamic optimization problems in the area of aeronautics contain highly nonlinear objectives and multiple local optima, it is still a challenge for most of the traditional optimization methods to find the global optima. In this paper, a new hybrid optimization framework based on Differential Evolution and Invasive Weed Optimization(IWO_DE/Ring) is developed, which combines global and local search to improve the performance, where a Multiple-Output Gaussian Process(MOGP) is used as the surrogate model. We first use several test functions to verify the performance of the IWO_DE/Ring method, and then apply the optimization framework to a supercritical airfoil design problem. The convergence and the robustness of the proposed framework are compared against some other optimization methods. The IWO_DE/Ringbased approach provides much quicker and steadier convergence than the traditional methods.The results show that the stability of the dynamic optimization process is an important indication of the confidence in the obtained optimum, and the proposed optimization framework based on IWO_DE/Ring is a reliable and promising alternative for complex aeronautical optimization problems. | Zijing LIU Xuejun LIU Xinye CAI | 2018 | Chinese Journal of Aeronautics2018，31，7： | 9 |
| 16 | Effects of Unbalance Location on Dynamic Characteristics of High-speed Gasoline Engine Turbocharger with Floating Ring Bearings显示文摘For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings(FRBs), the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers. | WANG Longkai BIN Guangfu LI Xuejun LIU Dingqu | 2016 | Chinese Journal of Mechanical Engineering2016，29，2： | 9 |
| 17 | In situ plasmonic optical fiber detection of the state of charge of supercapacitors for renewable energy storage显示文摘In situ and continuous monitoring of electrochemical activity is key to understanding and evaluating the operation mechanism and efficiency of energy storage devices.However,this task remains challenging.For example,the present methods are not capable of providing the real-time information about the state of charge(SOC)of the energy storage devices while in operation.To address this,a novel approach based on an electrochemical surface plasmon resonance(SPR)optical fiber sensor is proposed here.This approach offers the capability of in situ comprehensive monitoring of the electrochemical activity(the electrode potential and the SOC)of supercapacitors(used as an example).The sensor adopted is a tilted fiber Bragg grating imprinted in a commercial single-mode fiber and coated with a nanoscale gold film for high-efficiency SPR excitation.Unlike conventional“bulk”detection methods for electrode activity,our approach targets the“localized”(sub-μm-scale)charge state of the ions adjacent to the electrode interface of supercapacitors by monitoring the properties of the SPR wave on the fiber sensor surface located adjacent to the electrode.A stable and reproducible correlation between the real-time charge–discharge cycles of the supercapacitors and the optical transmission of the optical fiber has been found.Moreover,the method proposed is inherently immune to temperature cross-talk because of the presence of environmentally insensitive reference features in the optical transmission spectrum of the devices.Finally,this particular application is ideally suited to the fundamental qualities of optical fiber sensors,such as their compact size,flexible shape,and remote operation capability,thereby opening the way for other opportunities for electrochemical monitoring in various hard-to-reach spaces and remote environments. | Jiajie Lao Peng Sun Fu Liu Xuejun Zhang Chuanxi Zhao Wenjie Mai Tuan Guo Gaozhi Xiao Jacques Albert | 2018 | Light(Science & Applications)2018，7，1： | 8 |
| 18 | Fluxes of methane,carbon dioxide and nitrous oxide in an alpine wetland and an alpine grassland of the Tianshan Mountains,China显示文摘Methane(CH4), carbon dioxide(CO2) and nitrous oxide(N2O) are known to be major greenhouse gases that contribute to global warming. To identify the flux dynamics of these greenhouse gases is, therefore, of great significance. In this paper, we conducted a comparative study on an alpine grassland and alpine wetland at the Bayinbuluk Grassland Eco-system Research Station, Chinese Academy of Sciences. By using opaque, static, manual stainless steel chambers and gas chromatography, we measured the fluxes of CH4, N2O and CO2 from the grassland and wetland through an in situ monitoring study from May 2010 to October 2012. The mean flux rates of CH4, N2O and CO2 for the experimental alpine wetland in the growing season(from May to October) were estimated at 322.4 μg/(m2?h), 16.7 μg/(m2?h) and 76.7 mg/(m2?h), respectively; and the values for the alpine grassland were –88.2 μg/(m2?h), 12.7 μg/(m2?h), 57.3 mg/(m2?h), respectively. The gas fluxes showed large seasonal and annual variations, suggesting weak fluxes in the non-growing season. The relationships between these gas fluxes and environmental factors were analyzed for the two alpine ecosystems. The results showed that air temperature, precipitation, soil temperature and soil moisture can greatly influence the fluxes of CH4, N2O and CO2, but the alpine grassland and alpine wetland showed different feedback mechanisms under the same climate and environmental conditions. | GuiXiang HE KaiHui LI XueJun LIU YanMing GONG YuKun HU | 2014 | Journal of Arid Land2014，6，6： | 7 |
| 19 | Contribution of atmospheric nitrogen deposition to diffuse pollution in a typical hilly red soil catchment in southern China显示文摘Atmospheric nitrogen(N) deposition is currently high and meanwhile diffuse N pollution is also serious in China. The correlation between N deposition and riverine N export and the contribution of N deposition to riverine N export were investigated in a typical hilly red soil catchment in southern China over a two-year period. N deposition was as high as 26.1 to55.8 kg N/(ha·yr) across different land uses in the studied catchment, while the riverine N exports ranged from 7.2 to 9.6 kg N/(ha·yr) in the forest sub-catchment and 27.4 to30.3 kg N/(ha·yr) in the agricultural sub-catchment. The correlations between both wet N deposition and riverine N export and precipitation were highly positive, and so were the correlations between NH4+-N or NO3--N wet deposition and riverine NH4+-N or NO3--N exports except for NH4+-N in the agricultural sub-catchment, indicating that N deposition contributed to riverine N export. The monthly export coefficients of atmospheric deposited N from land to river in the forest sub-catchment(with a mean of 14%) presented a significant positive correlation with precipitation, while the monthly contributions of atmospheric deposition to riverine N export(with a mean of 18.7% in the agricultural sub-catchment and a mean of 21.0% in the whole catchment) were significantly and negatively correlated with precipitation. The relatively high contribution of N deposition to diffuse N pollution in the catchment suggests that efforts should be done to control anthropogenic reactive N emissions to the atmosphere in hilly red soil regions in southern China. | Jianlin Shen Jieyun Liu Yong Li Yuyuan Li Yi Wang Xuejun Liu Jinshui Wu | 2014 | Journal of Environmental Sciences2014，26，9： | 7 |
| 20 | On developing data-driven turbulence model for DG solution of RANS显示文摘High-order Discontinuous Galerkin(DG) methods have been receiving more and more attentions in the area of Computational Fluid Dynamics(CFD) because of their high-accuracy property. However, it is still a challenge to obtain converged solution rapidly when solving the Reynolds Averaged Navier–Stokes(RANS) equations since the turbulence models significantly increase the nonlinearity of discretization system. The overall goal of this research is to develop an Artificial Neural Networks(ANNs) model with low complexity acting as an algebraic turbulence model to estimate the turbulence eddy viscosity for RANS. The ANN turbulence model is off-line trained using the training data generated by the widely used Spalart–Allmaras(SA) turbulence model before the Optimal Brain Surgeon(OBS) is employed to determine the relevancy of input features.Using the selected relevant features, a fully connected ANN model is constructed. The performance of the developed ANN model is numerically tested in the framework of DG for RANS, where the‘‘DG+ANN' method provides robust and steady convergence compared to the ‘‘DG+SA' method. The results demonstrate the promising potential to develop a general turbulence model based on artificial intelligence in the future given the training data covering a large rang of flow conditions. | Liang SUN Wei AN Xuejun LIU Hongqiang LYU | 2019 | Chinese Journal of Aeronautics2019，32，8： | 7 |
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