|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Infrared radiation characteristics of a hypersonic vehicle under time-varying angles of attack显示文摘Hypersonic vehicles emit strong infrared(IR) radiation signatures that can be treated as a detecting source for object identification and routine diagnosis. This paper is aimed at examining the intrinsic radiation characteristics of a Boost-Glide Vehicle(BGV) under the condition of various Angles of Attack(AOAs). A two-temperature model considering the thermal and chemical nonequilibrium effects is coupled with Navier-Stokes equations solved by the finite volume technique.A gas–solid conjunction heat transfer model is also added into the fluid solver to simulate the surface temperature of the vehicle. The radiative transfer equation is solved with Line of Sight(LOS)algorithm. The computational results for a Hypersonic Technology Vehicle-2(HTV-2) type vehicle show that radiances of the vehicle are strongly dependent on the surface temperature. The presence of AOA results in the significant difference of the surface temperature. Infrared radiation characteristics are also changed in intensity and spectral band due to the AOA. Simulations are performed with two time-varying AOAs. Transient results indicate that the variation of AOA does have a great effect on the infrared radiance and is closely related to observation angle, spectral band, angle size,angular velocity and time history. | Qinglin NIU Zhichao YUAN Biao CHEN Shikui DONG | 2019 | Chinese Journal of Aeronautics2019，32，4： | 10 |
| 2 | IR radiation characteristics of rocket exhaust plumes under varying motor operating conditions显示文摘The infrared(IR) irradiance signature from rocket motor exhaust plumes is closely related to motor type,propellant composition,burn time,rocket geometry,chamber parameters and flight conditions.In this paper,an infrared signature analysis tool(IRSAT) was developed to understand the spectral characteristics of exhaust plumes in detail.Through a finite volume technique,flow field properties were obtained through the solution of axisymmetric Navier-Stokes equations with the Reynolds-averaged approach.A refined 13-species,30-reaction chemistry scheme was used for combustion effects and a k-e-Rtturbulence model for entrainment effects.Using flowfield properties as input data,the spectrum was integrated with a line of sight(LOS) method based on a single line group(SLG) model with Curtis-Godson approximation.The model correctly predicted spectral distribution in the wavelengths of 1.50–5.50 lm and had good agreement for its location with imaging spectrometer data.The IRSAT was then applied to discuss the effects of three operating conditions on IR signatures:(a) afterburning;(b) chamber pressure from ignition to cutoff;and(c) minor changes in the ratio of hydroxyl-terminated polybutadiene(HTPB) binder to ammonium perchlorate(AP) oxidizer in propellant.Results show that afterburning effects can increase the size and shape of radiance images with enhancement of radiation intensity up to 40%.Also,the total IR irradiance in different bands can be characterized by a non-dimensional chamber pressure trace in which the maximum discrepancy is less than 13% during ignition and engine cutoff.An increase of chamber pressure can lead to more distinct diamonds,whose distance intervals are extended,and the position of the first diamond moving backwards.In addition,an increase in HTPB/AP causes a significant jump in spectral intensity.The incremental rates of radiance intensity integrated in each band are linear with the increase of HTPB,and the growth rates of radiance intensities in some bands reach up to 50% as HTPB weight increases by 3%. | Qinglin NIU Zhihong HE Shikui DONG | 2017 | Chinese Journal of Aeronautics2017，30，3： | 10 |
| 3 | Heavy metals in Changjiang estuarine and offshore sediments:responding to human activities显示文摘The Changjiang (Yangtze) estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions.Distributions of heavy metals show typical banded diffusion pattern,with high concentrations near the river mouth and following a decreasing trend in the offshore direction.According to chemical fractions,Fe/Mn oxide fraction is the major non-residual fraction in the Changjiang estuarine and offshore sediments.Higher percentage of non-residual fraction of Pb implies that,the industrial contaminations transported via the atmosphere and river input,may affect the non-residual fraction of heavy metals.Over past fifteen years,the concentration of Pb normalizing to Al presents significant increasing trend,corresponding to the effect of human activities.By comparison of heavy metals fractions in 2003 to 2006,it has been realized that increasing water and sediment may cause a higher percentage non-residual fraction of Cu in the southern part of offshore muddy sediments. | DONG Aiguo ZHAI Shikui Matthias Zabel YU Zenghui ZHANG Huaijing LIU Feifei | 2012 | Acta Oceanologica Sinica2012，31，2： | 8 |
| 4 | Prediction of shock-layer ultraviolet radiation for hypersonic vehicles in near space显示文摘A systemic and validated model was developed to predict ultraviolet spectra features from the shock layer of near-space hypersonic vehicles in the ‘‘solar blind' band region. Computational procedures were performed with 7-species thermal non-equilibrium fluid mechanics, finite rate chemistry, and radiation calculations. The thermal non-equilibrium flow field was calculated with a two-temperature model by the finite volume technique and verified against the bow-shock ultra-violet(BSUV) flight experiments. The absorption coefficient of the mixture gases was evaluated with a line-by-line method and validated through laboratory shock tube measurements. Using the line of sight(LOS) method, radiation was calculated from three BSUV flights at altitudes of 38,53.5 and 71 km. The investigation focused on the level and structure of ultraviolet spectra radiated from a NO band system in wavelengths of 200–400 nm. Results predicted by the current model show qualitative spatial agreement with the measured data. At a velocity of 3.5 km/s(about Mach11), the peak absolute intensity at an altitude of 38 km is two orders of magnitude higher than that at 53.5 km. Under the same flight conditions, the spectra structures have quite a similar distribution at different viewing angles. The present computational model performs well in the prediction of the ultraviolet spectra emitted from the shock layer and will contribute to the investigation and analysis of radiative features of hypersonic vehicles in near space. | Niu Qinglin He Zhihong Dong Shikui | 2016 | Chinese Journal of Aeronautics2016，29，5： | 4 |
| 5 | Environmental risks of shale gas exploitation and solutions for clean shale gas production in China显示文摘Shale gas is a relatively clean-burning fossil fuel,produced by hydraulic fracturing.This technology may be harmful to the environment;therefore,environmentally friendly methods to extract shale gas have attracted considerable attention from researchers.Unlike previous studies,this study is a comprehensive investigation that uses systematic analyses and detailed field data.The environmental challenges associated with shale gas extraction,as well as measures to mitigate environmental impacts from the source to end point are detailed,using data and experience from China’s shale gas production sites.Environmental concerns are among the biggest challenges in practice,mainly including seasonal water shortages,requisition of primary farmland,leakage of drilling fluid and infiltration of flowback fluid,oil-based drill cuttings getting buried underground,and induced seismicity.China’s shale gas companies have attempted to improve methods,as well as invent new materials and devices to implement cleaner processes for the sake of protecting the environment.Through more than 10-year summary,China’s clean production model for shale gas focuses on source pollution prevention,process control,and end treatment,which yield significant results in terms of resource as well as environmental protection,and can have practical implications for shale gas production in other countries,that can be duplicated elsewhere. | Shikui GAO Quanzhong GUAN Dazhong DONG Fang HUANG | 2021 | Frontiers of Earth Science2021，15，2： | 3 |
| 6 | Landscape Network Approach to Assess Ecological Impacts of Road Projects on Biological Conservation显示文摘Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats.In this study,we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province,China.The results showed landscape connectivity levels(Probability of Connectivity(PC))decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation.First level roads affected landscape connectivity most significantly.At a distance of 100 m,the PC index decreased more than 50%.Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis.In addition,we conducted a graph theory and a least-cost modeling discussion,it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement.Network analysis offers a quantitative and simple but effective tool for ecological process assessment and biological conservation on large scales. | LIU Shiliang DENG Li CHEN Liding LI Junran DONG Shikui ZHAO Haidi | 2014 | Chinese Geographical Science2014，24，1： | 3 |
| 7 | Filling of the Three Gorges Reservoir to the 135-m Level: Instant Effects on the Yangtze Discharge and Suspended Sediment Concentration Entering the Estuary显示文摘Via the valuable opportunity of the Three Gorges Reservoir (TGR) 135-m filling in June 2003, the Yangtze discharge and suspended sediment concentration (SSC) entering the estuary during the period from 15 May to 15 July 2003 were analyzed to examine the instant effects of the filling on them. The Yangtze discharge and SSC entering the estuary in the periods before, during and after the filling clearly indicated three phases: 1) the pre-storage phase characterized by natural conditions, in which the SSC increased with increasing water discharge; 2) the storage phase, during which the SSC decreased dramatically with decreasing water discharge; and 3) the post-storage phase, during which both the SSC and water discharge remained at relatively low levels first until the end of June, then the SSC increased gradually with increasing water discharge. It seems that the times for the instant effects of the decreasing discharge downstream from the upper Yangtze on the Yangtze discharge and SSC entering the estuary due to the TGR 135-m filling to take place were about 5 d and 1 d respectively, while both were about 18 d for those of the increasing discharge. This probably reflects the buffering and resultantly hysteresis of the 1800-km stretch from the upper Yangtze to the estuary. The results are helpful for scientific and hydrological investigation of the Yangtze mainstream downstream from the TGR Dam and of the estuarine and adjacent coastal waters. | CHU Zhongxin ZHAI Shikui ZHANG Jing DING Dong | 2009 | Journal of Ocean University of China2009，8，3： | 2 |
| 8 | Vegetation distribution pattern in the dam areas along middle-low reach of Lancang-Mekong River in Yunnan Province, China显示文摘Lancang 湄公河河盆在世界上是有富有的生物多样性和高生态的价值的 ecoregions 之一。盆被人的活动强烈影响了,特别地由水坝建设。这研究被进行在中国的云南省沿着 Lancang 湄公河河的中间低的活动范围在水坝区域调查植被分发模式,在八个串联水坝被计划了或被构造的地方。识别植被作文和结构,我们沿着从 2004 ~ 2010 的一年垂直地穿到河隧道的双方的横断取样了 126 空铅。我们发现森林,灌木和草社区广泛地沿着河边被散布。在 Lancang 湄公河河的低活动范围分水岭,统治植被是被人的活动严重地扰乱的草和灌木。在 Lancang 湄公河河的中间的活动范围,干燥热的山谷植被在低山谷被发现。在高高度,松森林和半常绿树的季节的森林被发现。由于水坝建设和操作,河边的植被的结构和作文强烈被改变。一些工厂由于他们的产地的改变衰退了或消失。保护或恢复干预着急地被需要减轻沿着 Lancang 湄公河河的中间、低的活动范围与水坝工程联系的植被损坏的风险[出版摘要] | Jinpeng LI Shikui DONG Mingchun PENG Xiaoyan LI Shiliang LIU | 2012 | Frontiers of Earth Science2012，6，3： | 2 |
| 9 | Spatial variation and contamination assessment of heavy metals in sediments in the Manwan Reservoir, Lancang River显示文摘 | Cong Wang Shiliang Liu Qinghe Zhao Li Deng Shikui Dong | 2012 | Ecotoxicology and Environmental Safety2012，，： | 2 |
| 10 | Study on the effect of highway construction on photosynthetic rate of roadsides plant in Longitudinal Range-Gorge Region显示文摘 | LIU Jie CUI Baoshan DONG Shikui ZHU Jianjun YAO Weike | 2006 | Chinese Science Bulletin2006，51，B11： | 2 |
| 11 | Excessive plant compensatory growth:a potential endogenous driver of meadow degradation on the Qinghai-Tibetan Plateau显示文摘Degradation of meadow ecosystems in the largest alpine region of the world,i.e.,the Qinghai-Tibetan Plateau(QTP),is a crucial ecological issue that has ardently discussed in recent years.Many factors,such as livestock overgrazing,climate change and overpopulation of small mammals are treated as important factors that cause the degradation of meadow ecosystems in the QTP.However,there are few hypotheses focus on the potential role of plant compensatory growth on meadow degradation.We proposed a compensatory growth-related hypothesis to understand the potential degradation process of meadow ecosystems in the QTP.We discussed that there are two stages of meadow degradation,i.e.the beginning stage of meadow degradation that is triggered by high-strength overcompensation;and the intensification stage of meadow degradation,which are driven by external factors such as climate warming,small mammals and thawing of permafrost.The mechanism of meadow degradation driven by plant compensatory growth is the asynchronism of plant consumption and the availability of soil nutrients.Our hypothesis that plant compensatory growth drives meadow degradation under the overgrazing condition requires re-examination and modification by testing the balance between soil nutrient cycling rates and the strength of plant compensatory growth in alpine regions. | Yong Zhang Hasbagan Ganjurjav Shikui Dong Qingzhu Gao | 2020 | Ecosystem Health and Sustainability2020，6，1： | 1 |
| 12 | Ecological security assessment of Yuan River watershed based on landscape pattern and soil erosion显示文摘 | Zhang Zhaoliang Liu Shiliang Dong Shikui | 2010 | Procedia Environmental Sciences2010，32，2： | 1 |
| 13 | Procedia Environmental Science 显示文摘 | Zhaoling Zhang Shiliang Liu Shikui Dong Ecollgical security assessment of Yuan River watershed based on landscape pattern and soil erosion | 2010 | (2) : 613-6182010，，2： | 1 |
| 14 | Land cover classification in a mixed forest-grassland ecosystem using LResU-net and UAV imagery显示文摘Using an unmanned aerial vehicle (UAV) paired with image semantic segmentation to classify land cover within natural vegetation can promote the development of forest and grassland field. Semantic segmentation normally excels in medical and building classification, but its usefulness in mixed forest-grassland ecosystems in semi-arid to semi-humid climates is unknown. This study proposes a new semantic segmentation network of LResU-net in which residual convolution unit (RCU) and loop convolution unit (LCU) are added to the U-net framework to classify images of different land covers generated by UAV high resolution. The selected model enhanced classification accuracy by increasing gradient mapping via RCU and modifying the size of convolution layers via LCU as well as reducing convolution kernels. To achieve this objective, a group of orthophotos were taken at an altitude of 260 m for testing in a natural forest-grassland ecosystem of Keyouqianqi, Inner Mongolia, China, and compared the results with those of three other network models (U-net, ResU-net and LU-net). The results show that both the highest kappa coefficient (0.86) and the highest overall accuracy (93.7%) resulted from LResU-net, and the value of most land covers provided by the producer’s and user’s accuracy generated in LResU-net exceeded 0.85. The pixel-area ratio approach was used to calculate the real areas of 10 different land covers where grasslands were 67.3%. The analysis of the effect of RCU and LCU on the model training performance indicates that the time of each epoch was shortened from U-net (358 s) to LResU-net (282 s). In addition, in order to classify areas that are not distinguishable, unclassified areas were defined and their impact on classification. LResU-net generated significantly more accurate results than the other three models and was regarded as the most appropriate approach to classify land cover in mixed forest-grassland ecosystems. | Chong Zhang Li Zhang Bessie Y.J.Zhang Jingqian Sun Shikui Dong Xueyan Wang Yaxin Li Jian Xu Wenkai Chu Yanwei Dong Pei Wang | 2022 | Journal of Forestry Research2022，33，3： | 1 |
| 15 | Establishment of Elymus natans improves soil quality of a heavily degraded alpine meadow in Qinghai-Tibetan Plateau, China显示文摘 | Ruizhang Feng Ruijun Long Zhanhuan Shang Yushou Ma Shikui Dong Yanlong Wang | 2010 | Plant and Soil (-)2010，，1： | 1 |
| 16 | Reproducing kernel particle method for radiative heat transfer in 1D participating media 显示文摘 | Mu Lei He Zhihong Dong Shikui | 2015 | Mathetatical Problems in Engineering2015，2015，： | 1 |
| 17 | Heat Transfer and Flow Characteristics Predictions with a Refined k-ε-f_u Turbulent Model in Impinging Jet显示文摘Local heat transfer and flow characteristics in a round turbulent impinging jet for Re≈23 000 is predicted numerically with the RANS approach and a k-ε-fu turbulence model. The heat transfer predictions and turbulence parameters are verified against the axis-symmetric free jet impingement measurements and compared with previous other turbulence models, and results show the k-ε-fu model has a good performance in predictions of the local wall heat transfer coefficient, and in agreement with measurements in mean velocity profiles at different radial positions as well. The numerical model is further used to examine the effect of the fully confined impingement jet on the local Nusselt number. Local Nusselt profiles in x and y-centerlines for the target plate over three separation distances are predicted. Compared with the experimental data, the numerical results are accurate in the central domain around the stagnation region and present a consistent structure distribution. | Qinglin Niu Biao Chen Zhihong He Jianfei Tong Shikui Dong | 2019 | Journal of Harbin Institute of Technology(New Series)2019，26，4： | 1 |
| 18 | Analysis of rocket plume base heating by using backward Monte-Carlo method显示文摘 | Tan Heping Shuai Yong Dong Shikui | 2005 | AIAA J of Thermophysics and Heat Transfer2005，19，1： | 1 |
| 19 | Landscape connectivity dynamics based on network analysis in the Xishuangbanna Nature Reserve, China显示文摘 | Shiliang Liu Li Deng Shikui Dong Qinghe Zhao Juejie Yang Cong Wang | 2014 | Acta Oecologica2014，，： | 1 |
| 20 | Effects of cascade hydropower dams on the structure and distribution of riparian and upland vegetation along the middle-lower Lancang-Mekong River显示文摘 | LI Jinpeng DONG Shikui YANG Zhifeng | 2012 | Forest Ecology and Management2012，284，15： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员