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Three-dimensional(3D)parametric measurements of individual gravels in the Gobi region using point cloud technique
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作者 JING Xiangyu HUANG Weiyi KAN Jiangming 《Journal of Arid Land》 SCIE CSCD 2024年第4期500-517,共18页
Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materia... Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materials constituting the Gobi result in notable differences in saltation processes across various Gobi surfaces.It is challenging to describe these processes according to a uniform morphology.Therefore,it becomes imperative to articulate surface characteristics through parameters such as the three-dimensional(3D)size and shape of gravel.Collecting morphology information for Gobi gravels is essential for studying its genesis and sand saltation.To enhance the efficiency and information yield of gravel parameter measurements,this study conducted field experiments in the Gobi region across Dunhuang City,Guazhou County,and Yumen City(administrated by Jiuquan City),Gansu Province,China in March 2023.A research framework and methodology for measuring 3D parameters of gravel using point cloud were developed,alongside improved calculation formulas for 3D parameters including gravel grain size,volume,flatness,roundness,sphericity,and equivalent grain size.Leveraging multi-view geometry technology for 3D reconstruction allowed for establishing an optimal data acquisition scheme characterized by high point cloud reconstruction efficiency and clear quality.Additionally,the proposed methodology incorporated point cloud clustering,segmentation,and filtering techniques to isolate individual gravel point clouds.Advanced point cloud algorithms,including the Oriented Bounding Box(OBB),point cloud slicing method,and point cloud triangulation,were then deployed to calculate the 3D parameters of individual gravels.These systematic processes allow precise and detailed characterization of individual gravels.For gravel grain size and volume,the correlation coefficients between point cloud and manual measurements all exceeded 0.9000,confirming the feasibility of the proposed methodology for measuring 3D parameters of individual gravels.The proposed workflow yields accurate calculations of relevant parameters for Gobi gravels,providing essential data support for subsequent studies on Gobi environments. 展开更多
关键词 gobi gravels three-dimensional(3D)parameters point cloud 3D reconstruction Random Sample Consensus(RANSAC)algorithm Density-Based Spatial Clustering of Applications with Noise(DBSCAN)
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Assessment of heavy metal pollution in Laizhou Bay(China)using the ecological risk index and the integrated biomarker response of the goby Acanthogobius ommaturus 被引量:1
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作者 Maosheng LIU Hua XU +7 位作者 Qiang ZOU Fei FANG Shan SUN Yuting ZHAO Xin HE Yonghui BO Lei YAO Yan FANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第4期1519-1536,共18页
We used the Integrated Biological Responses version 2(IBRv2)method to evaluate the biological eff ects of heavy metals in the sediments in Laizhou Bay,China on the benthic goby Acanthogobius ommaturus.In December 2018... We used the Integrated Biological Responses version 2(IBRv2)method to evaluate the biological eff ects of heavy metals in the sediments in Laizhou Bay,China on the benthic goby Acanthogobius ommaturus.In December 2018,gobies and sediments were collected from 15 stations.We measured the activities of defense enzymes and the contents of malondialdehyde(MDA)and metallothionein(MT)in the goby liver as well as the levels of heavy metals in the sediments and goby muscle tissue.Most of the heavy metal concentrations in sediment at each station were below the Class I criteria set by Chinese Standards for Marine Sediment Quality,and the Håkanson ecological risk index suggested low risk for the heavy metals.We found that A.ommaturus could eff ectively accumulate mercury,cadmium,arsenic,and zinc and that the contents of MT and MDA and the activities of glutathione peroxidase and glutathione reductase were suitable biomarkers of heavy metal pollution in this species.The IBRv2 method integrated these four biomarkers and discriminated stations according to heavy metal pollution.Higher IBRv2 values suggested more adverse eff ects in gobies,corroborating more serious heavy metal contamination.The stations with high IBRv2 values and high contents of heavy metals were mainly distributed in the west and northeast parts of the bay.These results show that the IBRv2 approach is a feasible strategy for assessing heavy metal pollution through biological response and biological status and that it can be implemented for environmental monitoring in Laizhou Bay. 展开更多
关键词 integrated biomarker responses heavy metal ASSESSMENT goby Acanthogobius ommaturus Laizhou Bay
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Observation and Study of Land Surface Parameters over Gobi in Typical Arid Region 被引量:15
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作者 张强 曹晓彦 +1 位作者 卫国安 黄荣辉 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2002年第1期121-135,共15页
According to the need of popular land surface process models, characteristics and rules of some key land surface process and soil parameters over Gobi in typical arid region of Northwest China are analyzed by using th... According to the need of popular land surface process models, characteristics and rules of some key land surface process and soil parameters over Gobi in typical arid region of Northwest China are analyzed by using the data observed during the intensive observation period of the Dunhuang Land–Surface Process Field Experiment (DLSPFE) (May–June 2000). Using the relative reflection as weighting factor, the weighted mean of the surface albedo over Dunhuang Gobi in typical arid region is calculated and its values are 0.255 ± 0.021. After canceling the interference of the buildings, the mean values of the roughness length averaged with logarithm is 0.0019 ± 0.00071 m. After removing the influence of the oasis, the soil wetness factor computed with data under condition of no precipitation is 0.0045. After removing the influence of the precipitation , the mean values of the soil heat capacity over Dunhuang Gobi in typical arid region is 1.12 × 10<SUP>6</SUP> J m<SUP>&#8722;3</SUP>K<SUP>&#8722;1</SUP>, a bit smaller than the values observed in HEIFE. But the soil heat diffusivity and conductivity are about one of those observed in HEIFE. The soil water content over Dunhuang Gobi in typical synoptic condition is very little and does not exceed 1% basically. 展开更多
关键词 gobi Land surface parameters Restraining factor to evaoration Surface albedo Roughness length Soil heat diffusivity
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Spatial pattern of plant species diversity and the influencing factors in a Gobi Desert within the Heihe River Basin, Northwest China 被引量:15
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作者 ZHANG Pingping SHAO Ming'an ZHANG Xingchang 《Journal of Arid Land》 SCIE CSCD 2017年第3期379-393,共15页
Understanding the spatial pattern of plant species diversity and the influencing factors has important implications for the conservation and management of ecosystem biodiversity. The transitional zone between biomes i... Understanding the spatial pattern of plant species diversity and the influencing factors has important implications for the conservation and management of ecosystem biodiversity. The transitional zone between biomes in desert ecosystems, however, has received little attention in that regard. In this study, we conducted a quantitative field survey (including 187 sampling plots) in a 40-km2 study area to determine the spatial pattern of plant species diversity and analyze the influencing factors in a Gobi Desert within the Heihe River Basin, Northwest China. A total of 42 plant species belonging to 16 families and 39 genera were recorded. Shrub and semi-shrub species generally represented the major part of the plant communities (covering 90% of the land surface), while annual and perennial herbaceous species occupied a large proportion of the total recorded species (71%). Patrick richness index (R), Shannon-Wiener diversity index (H), Simpson's dominance index (D), and Pielou's evenness index (I) were all moderately spadaUy variable, and the variability increased with increasing sampling area. The semivariograms for R and H' were best fitted with Gaussian models while the semivariograms for D andJ were best fitted with exponential models. Nugget-to-still ratios indicated a moderate spatial autocorrelation for R, H', and D while a strong spatial autocorrelation was observed for J. The spatial patterns of R and H' were closely related to the geographic location within the study area, with lower values near the oasis and higher values near the mountains. However, there was an opposite trend for D. R, H', and D were significantly correlated with elevation, soil texture, bulk density, saturated hydraulic conductivity, and total porosity (P〈0.05). Generally speaking, locations at higher elevations tended to have higher species richness and diversity and the higher elevations were characterized by higher values in sand and gravel contents, bulk density, and saturated hydraulic conductivity and also by lower values in total porosity. Furthermore, spatial variability of plant species diversity was dependent on the sampling area. 展开更多
关键词 species diversity spatial heterogeneity environmental factors gobi Desert transitional zone
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A Parameterization Scheme of Surface Turbulent Momentum and Sensible Heat over the Gobi Underlying Surface 被引量:9
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作者 张强 黄荣辉 田辉 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第1期111-118,共8页
The parameterization of surface turbulent fluxes over the Gobi Desert in arid regions is studied by using rationally screened observational data. First, the characteristics of Monin-Obukhov similarity functions are an... The parameterization of surface turbulent fluxes over the Gobi Desert in arid regions is studied by using rationally screened observational data. First, the characteristics of Monin-Obukhov similarity functions are analyzed and their empirical formulae are fitted. The results show that fitted curves of changes of similarity functions of wind speed and temperature with stability parameter differ little from the typical empirical curves and are within the ranges of scatter of the empirical curves, but their values in the neutral condition arc different from the typical values to some extent. Furthermore, average values of momentum and scalar (sensible heat) roughness lengths as well as changes of scalar roughness length with friction velocity are determined by utilizing the data. It is found that the average values of scalar roughness length are about one order smaller than that of the momentum roughness length and decrease with increasing friction velocity, but they are evidently larger than their theoretically forecasted values. 展开更多
关键词 gobi surface turbulent flux PARAMETERIZATION similarity functions scalar roughness length
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Characteristics of Hydrologic Transfer between Soil and Atmosphere over Gobi near Oasis at the End of Summer 被引量:7
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作者 张强 宋连春 +3 位作者 黄荣辉 卫国安 王胜 田辉 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第3期442-452,共11页
By utilizing the data observed at Dunhuang during August and September 2000 in the 'Field Experiment on Interaction between Land and Atmosphere in the Arid Region of Northwest China (FEILARNC)', the characteri... By utilizing the data observed at Dunhuang during August and September 2000 in the 'Field Experiment on Interaction between Land and Atmosphere in the Arid Region of Northwest China (FEILARNC)', the characteristics of the soil moisture, temperature, and atmospheric humidity are analyzed. It is found that the thickness of the soil temperature active layer is about 5 cm and much thinner than is typical, that not only the atmospheric humidity gradient is often inverted but also the soil moisture gradient in the shallow layer in the Gobi near oasis, that the diurnal variation of soil moisture can be divided into the four stages that are called the wet stage, the losing-water stage, the dry stage, and the attaining-water stage. It is shown that in soil moisture profiles, the depth of the soil moisture active layer is about 10 cm and soil moisture inversion is the main feature in the shallow layer during the wet stage. Such a feature as soil moisture inversion indicates that soil in the shallow layer can inhale moisture from the air through condensation in the nighttime and exhale moisture to the air through evaporation in the daytime. The condensation and evaporation constitute together the full respiration process of moisture on the ground. The formation of soil moisture inversion is related with the state of soil temperature and moisture, the intensity of atmospheric humidity inversion, and the atmospheric thermodynamic stability. 展开更多
关键词 gobi soil active layer atmosphere specific humidity inversion soil moisture inversion RESPIRATION
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Application of otolith shape analysis for stock discrimination and species identification of five goby species(Perciformes: Gobiidae) in the northern Chinese coastal waters 被引量:3
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作者 于鑫 曹亮 +3 位作者 刘金虎 赵博 单秀娟 窦硕增 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第5期1060-1073,共14页
We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias... We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices(83.7%), elliptic Fourier coefficients(98.6%), or the combination of both methods(94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks(Liaodong Bay, LD; Bohai Bay, BH; Huanghe(Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta(50%–54%) and C. stigmatias(65.7%–75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone(70.2%) or in combination with shape indices(75.8%) than using only shape indices(65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species. 展开更多
关键词 gobiES inter- and intra-specific identification otolith morphology elliptic Fourier analysis shape indices
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Wind tunnel test on the effect of metal net fences on sand flux in a Gobi Desert, China 被引量:20
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作者 WANG Tao QU Jianjun +2 位作者 LING Yuquan XIE Shengbo XIAO Jianhua 《Journal of Arid Land》 SCIE CSCD 2017年第6期888-899,共12页
The Lanzhou-Xinjiang High-speed Railway runs through an expansive windy area in a Gobi Desert, and sand-blocking fences were built to protect the railway from destruction by wind-blown sand. However, the shielding eff... The Lanzhou-Xinjiang High-speed Railway runs through an expansive windy area in a Gobi Desert, and sand-blocking fences were built to protect the railway from destruction by wind-blown sand. However, the shielding effect of the sand-blocking fence is below the expectation. In this study, effects of metal net fences with porosities of 0.5 and 0.7 were tested in a wind tunnel to determine the effectiveness of the employed two kinds of fences in reducing wind velocity and restraining wind-blown sand. Specifically, the horizontal wind velocities and sediment flux densities above the gravel surface were measured under different free-stream wind velocities for the following conditions: no fence at all, single fence with a porosity of 0.5, single fence with a porosity of 0.7, double fences with a porosity of 0.5, and double fences with a porosity of 0.7. Experimental results showed that the horizontal wind velocity was more significantly decreased by the fence with a porosity of 0.5, especially for the double fences. The horizontal wind velocity decreased approximately 65% at a distance of 3.25 m(i.e., 13 H, where H denotes the fence height) downwind the double fences, and no reverse flow or vortex was observed on the leeward side. The sediment flux density decreased exponentially with height above the gravel surface downwind in all tested fences. The reduction percentage of total sediment flux density was higher for the fence with a porosity of 0.5 than for the fence with a porosity of 0.7, especially for the double fences. Furthermore, the decreasing percentage of total sediment flux density decreased with increasing free-stream wind velocity. The results suggest that compared with metal net fence with a porosity of 0.7, the metal net fence with a porosity of 0.5 is more effective for controlling wind-blown sand in the expansive windy area where the Lanzhou-Xinjiang High-speed Railway runs through. 展开更多
关键词 wind-blown sand wind tunnel experiment porous fence flow field sediment flux density Lanzhou-Xinjiang High-speed Railway gobi Desert
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Folk nomenclature of plants in Cistanche deserticola-associated community in South Gobi, Mongolia 被引量:2
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作者 Urtnasan Mandakh Munkhjargal Battseren +4 位作者 Danzanchadav Ganbat Turuutuvshin Ayanga Zolzaya Adiya Almaz Borjigidai Chunlin Long 《Plant Diversity》 SCIE CAS CSCD 2020年第6期434-442,共9页
Cistanche deserticola is an important medicinal plant in Mongolia.Despite its significant role in local healing systems,little traditional knowledge had been reported.The present study investigated folk names of C.des... Cistanche deserticola is an important medicinal plant in Mongolia.Despite its significant role in local healing systems,little traditional knowledge had been reported.The present study investigated folk names of C.deserticola and other species of the same community in Umnugobi Province,South Gobi region of Mongolia,based on ethnobotanical approaches.The high correspondence between folk names and scientific names of plant species occurring in Cistanche-associated community shows the scientific meaning of folk nomenclature and classification in Mongolia.The Mongolian and folk names of plants were formed on the basis of observations and understanding of wild plants including their morphology,phenology and traditional uses as well.Results from this study will support the conservation of C.deserticola itself,a rare and endangered plant species listed in the Monglian Red Data Book.Our documentation of folk nomenclature based on 96 plant species in the Cistanche community,as a part of traditional knowledge associated with biodiversity,will be very helpful for making strategy of plant biodiversity conservation in Mongolia. 展开更多
关键词 Cistanche deserticola Plant community ETHNOBOTANY Folk nomenclature Conservation strategy South gobi of Mongolia
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The slope creep law for a soft rock in an open-pit mine in the Gobi region of Xinjiang, China 被引量:2
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作者 Hongze Zhao Yu Tian +2 位作者 Qingyong Guo Meijie Li Jianwen Wu 《International Journal of Coal Science & Technology》 EI 2020年第2期371-379,共9页
The lithology of the strata in the Gobi region of the Xinjiang autonomous region of China is mainly composed of mudstone,silty mudstone,and other soft rocks.Because of the low strength of the rock mass and the serious... The lithology of the strata in the Gobi region of the Xinjiang autonomous region of China is mainly composed of mudstone,silty mudstone,and other soft rocks.Because of the low strength of the rock mass and the serious effects of physical weathering in this area,the slope stability in open-pit mines is poor,and creep deformation and instability can readily occur.Taking the Dananhu No.2 open-pit mine as a typical example,the creep test of a mudstone sample under different stress levels was studied.Then,based on a bottom friction experiment and a FLAC3D numerical simulation,the deformation and failure processes of the slope were analyzed.The stress–displacement curve and the displacement–time curve for the monitoring points were plotted to obtain the relationship between the stress and displacement for the slope of the soft rock.The results showed that the long-term strength of the mudstone was between 8.0 and 8.8 MPa,and that stable creep occurred when the slope was under low stress.The potential failure mode for this type of slope is that the front edge creeps along the weak layer and then a crack is formed at the trailing edge of the slope.When the crack penetrates the weak layer,cutting bedding and bedding sliding occur.The deformation process of the stable creep slope includes an initial deformation stage,an initial creep stage,a constant velocity creep stage and a deceleration creep stage. 展开更多
关键词 gobi region Soft rock slope Numerical simulation Creep deformation Creep experiment
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Effect of stones on the sand saltation threshold during natural sand and dust storms in a stony desert in Tsogt-Ovoo in the Gobi Desert,Mongolia 被引量:1
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作者 Batjargal BUYANTOGTOKH Yasunori KUROSAKI +7 位作者 Atsushi TSUNEKAWA Mitsuru TSUBO Batdelger GANTSETSEG Amarsaikhan DAVAADORJ Masahide ISHIZUKA Tsuyoshi T SEKIYAMA Taichu Y TANAKA Takashi MAKI 《Journal of Arid Land》 SCIE CSCD 2021年第7期653-673,共21页
Non-erodible elements such as stones and vegetation are key to controlling wind erosion and dust emission in drylands.Stony deserts are widely distributed in the Gobi Desert,but the effect of stones on wind erosion an... Non-erodible elements such as stones and vegetation are key to controlling wind erosion and dust emission in drylands.Stony deserts are widely distributed in the Gobi Desert,but the effect of stones on wind erosion and dust emission have not been well studied,except under artificial conditions.In this study,we evaluated the effect of stones on wind erosion and dust emission by measuring the sand saltation threshold in a stony desert in Tsogt-Ovoo in the Gobi Desert,Mongolia,under natural surface conditions during sand and dust storms.We quantified the amount of stones by measuring the roughness density,and determined the threshold friction velocity for sand saltation by measuring wind speed and sand saltation count.Our results showed that the threshold friction velocity increased with the roughness density of stones.In the northern part of the study area,where neither a surface crust nor vegetation was observed,the roughness density of stones was 0.000 in a topographic depression(TD),0.050 on a northern slope(N.SL),and 0.160 on the northern mountain(N.MT).The mean threshold friction velocity values were 0.23,0.41,and 0.57 m/s at the TD,N.SL,and N.MT sites,respectively.In the southern part of the study area,the roughness density values of stones were 0.000 and 0.070-0.320 at the TD and southern slope sites,respectively,and the mean threshold friction velocities were 0.23 and 0.45-0.71 m/s,respectively.We further compared the observed threshold friction velocities with simulated threshold friction velocities using Raupach's theoretical roughness correction and the measured roughness density values,and found that Raupach's roughness correction worked very well in the simulation of threshold friction velocity in the stony desert.This means that the results of our stone measurement can be applied to a numerical dust model. 展开更多
关键词 arid region threshold friction velocity roughness density shear stress sand saltation threshold roughness correction gobi Desert
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Separating emitted dust from the total suspension in airflow based on the characteristics of PM10 vertical concentration profiles on a Gobi surface in northwestern China
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作者 ZHANG Chunlai WANG Xuesong +2 位作者 CEN Songbo ZHENG Zhongquan Charlie WANG Zhenting 《Journal of Arid Land》 SCIE CSCD 2022年第6期589-603,共15页
During aeolian processes,the two most critical factors related to dust emissions are soil particle and aggregate saltation,which greatly affect the vertical profiles of near-surface dust concentrations.In this study,w... During aeolian processes,the two most critical factors related to dust emissions are soil particle and aggregate saltation,which greatly affect the vertical profiles of near-surface dust concentrations.In this study,we measured PM10 concentrations at four different heights(0.10,0.50,1.00 and 2.00 m)with and without continuous and simultaneous aeolian saltation processes on a Gobi surface in northwestern China from 31 March to 10 April,2017.We found that the vertical concentration profiles of suspended PM10 matched the log-law model well when there was no aeolian saltation.For the erosion process with saltation,we divided the vertical concentration profiles of PM10 into the saltation-affected layer and the airflow-transport layer according to two different dust sources(i.e.,locally emitted PM10 and upwind transported PM10).The transition height between the saltation-affected layer and the airflow-transport layer was not fixed and varied with saltation intensity.From this new perspective,we calculated the airflow-transport layer and the dust emission rate at different times during a wind erosion event occurred on 5 April 2017.We found that dust emissions during wind erosion are primarily controlled by saltation intensity,contributing little to PM10 concentrations above the ground surface compared to PM10 concentrations transported from upwind directions.As erosion progresses,the surface supply of erodible grains is the most crucial factor for saltation intensity.When there was a sufficient amount of erodible grains,there was a significant correlation among the friction velocity,saltation intensity and dust emission rate.However,when supply is limited by factors such as surface renewal or an increase in soil moisture,the friction velocity will not necessarily correlate with the other two factors.Therefore,for the Gobi surface,compared to limiting dust emissions from upwind directions,restricting the transport of suspended dust in its path is by far a more efficient and realistic option for small areas that are often exposed to dust storms.This study provides some theoretical basis for correctly estimating PM10 concentrations in the Gobi areas. 展开更多
关键词 PM10 vertical concentration profiles dust emission rate saltation intensity suspensions gobi surface
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Distribution and Characteristics of Nitraria sphaerocarpa nebkhas in a Gobi habitat outside an oasis in Hexi Corridor region,China
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作者 YongZhong Su Rong Yang +1 位作者 ZhiHui Zhang MingWu Du 《Research in Cold and Arid Regions》 2012年第4期288-295,共8页
Nitraria sphaerocarpa Maxim., a typical desert plant which often appears in nebkha form, is widely distributed along the periph- ery of oasis in arid regions of Northwest China, and plays an important role in desertif... Nitraria sphaerocarpa Maxim., a typical desert plant which often appears in nebkha form, is widely distributed along the periph- ery of oasis in arid regions of Northwest China, and plays an important role in desertification control around oases. In this paper, the characteristics and distribution patterns ofN. sphaerocarpa nebkhas were investigated in a Gobi environment outside an oasis. Results shows that about 200 N. sphaerocarpa nebkhas per hectare was recorded and total sand sediments was 25 m3/ha. Nebkhas vary in size, and the mean height (H) and horizontal composition (L) were 15 cm and 80 cm, respectively. There exists a signifi- cant linear relationship between H and L, suggesting that the investigated nebkhas are mostly in the growth stage. The numbers, height and sand deposit ofnebkhas decreased with increasing distance away from the oasis. Grain-size analysis indicates that the mean grain size of sediments at the crests of nebkhas increased with increasing nebkha height. Organic C and total N concentra- tions were related to the mean grain size. It was concluded that N. sphaerocarpa shrubs are efficient horizontal sand traps for wind-driven sediments. A better understanding of the development of nebkha can provide information for the design of biological sand control measures around oases in add regions. 展开更多
关键词 N. sphaerocarpa nebkha SEDIMENTS gobi OASIS Northwest China
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The Expanding Earth: Indisputable Evidences of the Gobi Desert
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作者 Alexey Ju. Retejum 《Open Journal of Geology》 2020年第1期1-12,共12页
The most striking contrasts that are found on the continents in paleogeographic reconstructions of the end of the Mesozoic era are the occurrence on the place of the disappeared humid subtropics of the largest Gobi De... The most striking contrasts that are found on the continents in paleogeographic reconstructions of the end of the Mesozoic era are the occurrence on the place of the disappeared humid subtropics of the largest Gobi Desert in Eurasia with air temperatures falling below 50&#176;from the freezing point and annual precipitation totals at the level of 100 mm. Science does not know the processes that can lead to a cooling of the atmosphere at 70&#176;and other equally radical changes in nature with a stable position of the blocks of the earth’s crust in space. Changes in the environment of this magnitude can only be the result of land moving northward for a distance equal to about half the radius of the Earth. Titanosaurs, described by the remains in the Gobi deposits, had a body volume, which at modern gravity corresponds to a mass of 10 to 30 ton. However, animals with such a mass and such growth could not exist now. To create the necessary pressure in the vessels and provide energy to the body, Mongolian sauropods would need a heart of 2 - 3 m in diameter. Known types of muscle tissue are unable to maintain an elongated neck and head with a mass of more than a ton. The femur bones of four-legged dinosaurs had strength sufficient to move on land only animals weighing no more than 5 - 7 tons. The bones of giant bipedal dinosaurs at a constant gravitational field would have to be subjected to specific loads, several times greater than the bones of modern elephants, which is excluded. The natural conclusion about the action of a lesser gravity in the Mesozoic provides a solution to the mystery of the truly global spread in that era of bipedal mode of movement as the most energy efficient. 展开更多
关键词 EXPANDING EARTH GOBY DESERT CRETACEOUS FOSSILS Giant Dinosaurs Gravity Atmospheric Circulation
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Study of Caspian Goby Neogobius sp. Karyotype Flexibility from Several Biotops
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作者 Aithazha Bigaliev Saidina Kobegenova +3 位作者 Viktor Vasil'ev Elena Vasil'eva Aiman Imentai Ashan Shametov 《Journal of Life Sciences》 2014年第5期442-446,共5页
The karyotype of Caspian goby was studied, which has been identified as Caspian bighead goby-Neogobius gorlap before. The results of cytogenetic analyses have shown that the diploid set of goby varies from 38 to 40 ch... The karyotype of Caspian goby was studied, which has been identified as Caspian bighead goby-Neogobius gorlap before. The results of cytogenetic analyses have shown that the diploid set of goby varies from 38 to 40 chromosomes, which is different from bighead goby (2n = 43-46). We assumed that Caspian goby has independence as a species. 展开更多
关键词 Caspian goby diploid number of chromosomes KARYOTYPE CYTOGENETIC chromosomal mutation evolution.
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Mechanisms of the formation of wind-blown sand hazards and the sand control measures in Gobi areas under extremely strong winds along the Lanzhou-Xinjiang high-speed railway 被引量:2
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作者 Jianjun QU Tao WANG +5 位作者 Qinghe NIU Benli LIU Lihai TAN Qingjie HAN Yang GAO Jianhua XIAO 《Science China Earth Sciences》 SCIE EI CAS CSCD 2023年第2期292-302,共11页
The Lanzhou-Xinjiang high-speed railway(HSR)traverses areas of the Gobi Desert where extremely strong winds are frequent.These strong winds cause sand/gravel hazards,an unaddressed issue that often seriously compromis... The Lanzhou-Xinjiang high-speed railway(HSR)traverses areas of the Gobi Desert where extremely strong winds are frequent.These strong winds cause sand/gravel hazards,an unaddressed issue that often seriously compromises the safe operation of the HSR.This paper studies the mechanisms leading to wind-blown sand hazards and the outcomes of sand control projects in these areas.The main findings are as follows:(1)Cold northern airflows over the Tian Shan mountain range are accelerated by the wind tunnels and downslope effect as they pass over complex terrain comprising passes,gullies,and proluvial fans.Consequently,the wind intensity often increases two-to threefold,creating frequent high-speed winds that lead to severe sand damage along the HSR.(2)In the Gobi areas with extremely strong winds,sand grains can be lifted as high as 9 m from the ground into the air,far higher than in other areas of the desert.The sand transport rate decreases exponentially with increasing height.Both wind speed and particle size determine saltation height.Coarser particles and stronger winds provide the particles with a higher kinetic energy as they collide with the ground.In the wind zones of Baili and Yandun,the analysed study areas,the saltation layer height of wind-blown sand/gravel exceeds 3 and 2 m,respectively.(3)Based on the above findings,recently emerging sand control materials,suitable for the areas of interest,were screened and developed.Furthermore,under the proposed principle of‘supplementing blocking with trapping’,a comprehensive sand control measure was established,featuring sandblocking belts comprised of multiple rows,and high,vertical sand-trapping installations with a large grids size.The installed system showed a high efficacy,reducing sand transport rate by 87.87%and significantly decreasing the deposition of sand along a trial section of the HSR. 展开更多
关键词 gobi areas with extremely strong winds Wind-blown sand hazards Complex terrain Sand/gravel flow Wind-blown sand control
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Aeolian sediment transport over sandy gobi:Field studies in the Nanhu gobi along the Hami-Lop Nor Railway 被引量:1
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作者 Tao Wang Jianjun Qu Lihai Tan 《International Soil and Water Conservation Research》 SCIE CSCD 2023年第1期125-134,共10页
Wind-blown sand over sandy gobi with an abundant sediment supply can cause severe sand hazards.However,compared with the study of aeolian transport over gravel gobi with a limited sediment supply,less attention has be... Wind-blown sand over sandy gobi with an abundant sediment supply can cause severe sand hazards.However,compared with the study of aeolian transport over gravel gobi with a limited sediment supply,less attention has been devoted to sandy gobi,and thus,our understanding of wind-blown sand movement on sandy gobi is still poor.Here,we report the results of observations of three transport events on a sandy gobi along the Hami-Lop Nor Railway based on high-frequency saltation particle count and horizontal sediment flux measurements coupled with instantaneous wind velocity measurements.The results reveal that,unlike the notably intermittent aeolian saltation over gravel gobi,continuous transport occurred on the sandy gobi.The mean saltation layer height was 0.23±0.07 m,and it was positively related to both the grain size of surface particles and the wind velocity regardless of the gobi type.The sediment transport rates could be expressed as the power function Q=ap/g[u^(*)(u^(*2)-u^(*)t^(2))]b,and the scaling parameter(b)reached to 2.5,which is much larger than that of other gobi areas(b=1).Our findings suggest that the wind-blown sand over sandy gobi is much more severe than that over gravel gobi,and the Nanhu sandy gobi is the major sand source for sand hazards of the Hami-Lop Nor Railway.Sand-fixation measures such as checkerboard sand barriers with enhanced checkerboard size and barrier height should be the main subject of sand control systems for the Hami-Lop Nor Railway in sandy gobi. 展开更多
关键词 Sandy gobi Saltation threshold salcation layer height Sediment transport rates Wind-blown sand control
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青藏高原戈壁生境中一株链霉菌新种Streptomyces haixigobicum sp.nov.Qhu-G9的多相分类学鉴定及其次级代谢产物的基因组挖掘
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作者 向信 殷恒霞 +5 位作者 樊嘉凯 邓佳文 朱肇宇 邱庆辉 柳宇睿 张本印 《微生物学通报》 CAS CSCD 北大核心 2023年第5期1872-1886,共15页
【背景】青藏高原极端生境具有丰富的微生物资源,同时也是微生物药物的重要来源,但是大量微生物新资源尚待开发利用。【目的】对从青藏高原戈壁土壤中分离得到的一株链霉菌Qhu-G9进行多相分类鉴定及次级代谢产物生物合成潜力分析。【方... 【背景】青藏高原极端生境具有丰富的微生物资源,同时也是微生物药物的重要来源,但是大量微生物新资源尚待开发利用。【目的】对从青藏高原戈壁土壤中分离得到的一株链霉菌Qhu-G9进行多相分类鉴定及次级代谢产物生物合成潜力分析。【方法】通过16S rRNA基因扩增、测序和系统发育分析,结合形态、生理生化、细胞化学组分及基因组测序等多相分类特征,确定链霉菌Qhu-G9的分类地位。【结果】Qhu-G9与链霉菌Streptomyces dioscori A217T和Streptomyces auranttiiacus NBRC 13017T相似度最高,均为99.22%,结合形态观察,说明该菌是一株链霉菌。基于16S rRNA基因序列构建的系统发育树显示Qhu-G9独立成支,并且其生理生化和细胞化学成分特征与最相似模式菌存在较大差异。通过基因组测序评估了与最相似模式菌的数字DNA-DNA杂交值(digital DNA-DNA hybridization,dDDH)和平均核苷酸一致性(average nucleotide identity,ANI),发现Qhu-G9与最相似菌S.auranttiiacus NBRC 13017T的dDDH与ANI值最高,分别为36.65%和88.21%,但是均低于判定新菌的阈值,进一步表明Qhu-G9为一株链霉菌属新种,并命名为Streptomyces haixigobicum sp.nov.Qhu-G9。此外,通过antiSMASH分析发现Qhu-G9基因组中存在大量编码已知和未知次级代谢产物的生物合成基因簇。【结论】从青藏高原戈壁土壤中分离得到的Qhu-G9是一株链霉菌新种,并且具有进一步挖掘活性次级代谢产物的潜力。 展开更多
关键词 青藏高原 戈壁 链霉菌 多相分类学 生物合成基因簇
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Ecological Functions of PV Power Plants in the Desert and Gobi 被引量:17
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作者 常兆丰 刘世增 +3 位作者 朱淑娟 韩福贵 仲生年 段晓峰 《Journal of Resources and Ecology》 CSCD 2016年第2期130-136,共7页
Photovoltaic (PV) power generation is an emerging energy industry that is developing rapidly. A number of PV power plants have been established in the desert and Gobi areas in northwest China in recent years. Is the... Photovoltaic (PV) power generation is an emerging energy industry that is developing rapidly. A number of PV power plants have been established in the desert and Gobi areas in northwest China in recent years. Is there any ecological significance to the establishment of PV power plants? If yes, what is it? This paper tries to find the answer by analyzing meteorological data from the Hexi Corridor as well as the observational data of light and vegetation in the Minqin desert area. The results show that the solar energy converted from 1 m2 of PV panels is equivalent to the solar energy that is utilized by 260.75 m2 of desert plants in the desert area. In China, there is vast area of desert and Gobi, with frequent dust storms and aeolian sand, as well as rich sunlight resources. Therefore, to develop the PV industry in the desert and Gobi regions will not only create considerable economic benefits, but will also be of great ecological significance. On the one hand, PV can effectively regulate thermodynamic equilibrium on the surface, helping to prevent sandstorms and reduce aeolian sand. The development of the PV industry is a win-win that generates economic returns and provides ecological protection by combating desertification. On the other hand, the PV industry can be developed without taking up arable land or other types of land. There are frequently high winds in the desert and Gobi region. PV power plants, together with wind power generation, are useful to transform and consume the power source that creates duststorms and aeolian sandflow in the desert and Gobi areas. This results in fewer sandstorms and reduced aeolian sandflow. 展开更多
关键词 DESERT gobi photovoltaic power plant ecological significance Hexi Corridor
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椰糠型生态保育基质栽培对辣椒品质及产量的影响 被引量:1
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作者 王之君 王志伟 黄磊 《北方园艺》 CAS 北大核心 2024年第13期1-9,共9页
以‘甘科4号’辣椒为试材,以当地常规栽培作为对照(CK),采用温室大棚栽培的试验方法,研究椰糠、风沙土、人造泥炭、有机肥配比分别为5∶2∶1∶3(T1)、4∶3∶1∶3(T2)、3.5∶3.5∶1∶3(T3)、3∶4∶1∶3(T4)、2∶5∶1∶3(T5)、1∶6∶1∶3(... 以‘甘科4号’辣椒为试材,以当地常规栽培作为对照(CK),采用温室大棚栽培的试验方法,研究椰糠、风沙土、人造泥炭、有机肥配比分别为5∶2∶1∶3(T1)、4∶3∶1∶3(T2)、3.5∶3.5∶1∶3(T3)、3∶4∶1∶3(T4)、2∶5∶1∶3(T5)、1∶6∶1∶3(T6)、0∶7∶1∶3(T7)复混形成的模块化生态保育基质对辣椒生长特性及产量的影响,以期为探索西部荒漠戈壁工业化土壤改良及特色生态农业发展提供新路径。结果表明:不同生育期下,T2~T5处理可促进辣椒长势(株高、茎粗、株幅),根系、品质和产量亦显著提高,且各项指标均随椰糠含量增加呈现先增大后降低的趋势;相较CK,T5处理下单株结果数和单株产量分别增加了9.47%、19.65%。利用VIKOR法对各处理的品质及产量进行综合评价显示,T5处理下辣椒品质及产量最优,利益比率最小,为0.019。研究结果进一步证明椰糠型生态保育基质(椰糠含量占比30%~55%)适合荒漠化土地上的辣椒种植。 展开更多
关键词 椰糠型生态保育基质 辣椒种植 生长特性 戈壁生态农业 土壤改良
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