|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Chinese deserts and sand fields in Last Glacial Maximum and Holocene Optimum显示文摘The Last Glacial Maximum (LGM, c. 26-16 ka) and the Holocene Optimum (HO, c. 9-5 ka) were characterized by cold-dry and warm-wet climates respectively in the recently geological Earth. How Chinese deserts and sand fields responded to these distinctive climatic changes is still not clear, however. To reconstruct environments of the deserts and sand fields during the LGM and HO is helpful to understand the forcing mechanisms of environment change in this arid region, and to test paleoclimatic modeling results. Through our long-term field and laboratory investigations, 400 optically stimulated luminescence (OSL) ages and more than 100 depositional records in the Chinese deserts and sand fields were obtained; on the basis of these data, we reconstruct spatial distributions of the deserts and sand fields during the LGM and HO. Our results show that the sand fields of Mu Us, Hunshandake, Horqin and Hulun Buir in northern and northeastern China had expanded 25%, 37%, 38% and 270%, respectively, during the LGM; the sand fields of Gonghe in the northeastern Qinghai-Tibetan Plateau had expanded 20%, and the deserts of Badain Jaran, Tengger in central northern China had expanded 39% and 29% separately during the LGM; the deserts of Taklimakan, Gurbantünggüt and Kumtag in northwestern China had expanded 10%-20% respectively, compared to their modern areas. On the other hand, all of the sand fields were nearly completely covered by vegetation during the HO; the deserts in northwestern and central northern China were reduced by around 5%-20% in area during this time. Lakes in this arid region were probably expanded during the HO but this conclusion needs more investigation. Compared with the geological distributions of deserts and sand fields, human activity has clearly changed (expanded) the area of active sand dunes at the present time. Our observations show that environmental conditions of Chinese deserts and sand fields are controlled by regional climate together with human activity. | LU HuaYu YI ShuangWen XU ZhiWei ZHOU YaLi ZENG Lin ZHU FangYing FENG Han DONG LiNa ZHUO HaiXin YU KaiFeng MASON Joseph WANG XiaoYong CHEN YingYong LU Qi WU Bo DONG ZhiBao QU JianJun WANG XunMing GUO ZhengTang | 2013 | Chinese Science Bulletin2013，58，23： | 40 |
| 2 | Wind tunnel test on the effect of metal net fences on sand flux in a Gobi Desert, China显示文摘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. | WANG Tao QU Jianjun LING Yuquan XIE Shengbo XIAO Jianhua | 2017 | Journal of Arid Land2017，9，6： | 15 |
| 3 | Comprehensive Management of Daily Living Activities,behavioral and Psychological Symptoms,and Cognitive Function in Patients with Alzheimer's Disease:A Chinese Consensus on Alzheimer's Disease显示文摘Alzheimer's disease(AD)is the most common cognitive disorder in the elderly.Its main clinical manifestations are cognitive decline(C),behavioral and psychological symptoms(B),and a decline in the activities of daily living(A),also known as ABC symptoms.Early identification and evaluation of ABC symptoms are helpful for establishing the accurate diagnosis,comprehensive treatment,and prognosis of AD.To guide Chinese clinical practice for optimization of the comprehensive management of AD,in 2018,The Academy of Cognitive Disorder of China gathered 22 neurologists and gerontologists in China to build a consensus on the comprehensive management of AD.Based on a review of the evidence,the consensus summarizes the pathogenesis,pathological changes,clinical manifestations,evaluation,diagnosis,drug and non-drug treatment,and patient care for AD.Focus group discussion was used to establish a flowchart of comprehensive ABC management for AD patients.The new consensus provides a feasible AD management process for clinicians. | Jianjun Jia Jun Xu Jun Liu Yongjun Wang Yanjiang Wang Yunpeng Cao Qihao Guo Qiuming Qu Cuibai Wei Wenshi Wei Junjian Zhang Enyan Yu | 2021 | Neuroscience Bulletin2021，37，7： | 10 |
| 4 | New discoveries on the effects of desertification on the ground temperature of permafrost and its significance to the Qinghai-Tibet Plateau显示文摘The desert and permafrost conditions of the Qinghai-Tibet Plateau are unique.However,the effects of desertification on the ground temperature of permafrost are currently unclear.Recently,understanding this problem has become more urgent because of increasing desertification on the plateau.For this reason,an observational field experiment was undertaken by the authors at Honglianghe on the Qinghai-Tibet Plateau.Thermistor ground temperature probes were used,and synchronized contrasting observations were made in an open area.Observations of the ground temperature of permafrost below sand layers with a range of thicknesses were made from May 2010 to April 2011.The sand layers were found to play a key role in the protection of the underlying permafrost.The ground temperature below a permafrost table overlain by a thick sand layer was lower than that of the average annual temperature for the natural ground surface,and the temperature drop was roughly constant at 0.2°C.During the warmer part of the year (May to September),the maximum temperature drops over the five months were 3.40,3.72,4.85,3.16,and 1.88°C,respectively.The ground temperature near a permafrost table overlain by a thin sand layer was also lower than that of the average annual temperature for the natural ground surface.However,in this case the average of the annual maximum temperature drop was significantly less,0.71°C.The scientific significance of our preliminary conclusions is not only to present an exploration of the interaction between desertification and permafrost,but also to provide new engineering ideas for protecting the permafrost in regions where construction is required on the Qinghai-Tibet Plateau. | XIE ShengBo QU JianJun ZU RuiPing ZHANG KeCun HAN QingJie | 2012 | Chinese Science Bulletin2012，57，8： | 8 |
| 5 | Flame-retardant concentrated electrolyte enabling a Li F-rich solid electrolyte interface to improve cycle performance of wide-temperature lithium–sulfur batteries显示文摘Lithium–sulfur batteries have been regarded as the most promising high-energy electrochemical energy storage device owing to the high energy density, low cost and environmental friendliness. However, traditional lithium–sulfur batteries using ether-based electrolytes often suffer from severe safety risks(i.e. combustion). Herein, we demonstrated a novel kind of flame-retardant concentrated electrolyte(6.5 M lithium bis(trifluoromethylsulphonyl)imide/fluoroethylene carbonate) for highly-safe and widetemperature lithium–sulfur batteries. It was found that such concentrated electrolyte showed superior flame retardancy, high lithium-ion transference number(0.69) and steady lithium plating/stripping behavior(2.5 m Ah cm^(-2) over 3000 h). Moreover, lithium–sulfur batteries using this flame-retardant concentrated electrolyte delivered outstanding cycle performance in a wide range of temperatures(-10 °C, 25 °C and 90 °C). This superior battery performance is mainly attributed to the LiF-rich solid electrolyte interphase formed on lithium metal anode, which can effectively suppress the continuous growth of lithium dendrites. Above-mentioned fascinating characteristics would endow this flame-retardant concentrated electrolyte a very promising candidate for highly-safe and wide-temperature lithium–sulfur batteries. | Zhe Yu Jianjun Zhang Chao Wang Rongxiang Hu Xiaofan Du Ben Tang Hongtao Qu Han Wu Xin Liu Xinhong Zhou Xiaoyan Yang Guanglei Cui | 2020 | Journal of Energy Chemistry2020，29，12： | 7 |
| 6 | Influence of Golmud-Lhasa Section of Qinghai-Tibet Railway on Blown Sand Transport显示文摘The Qinghai-Tibet Railway(QTR) passes through 281 km of sandy land, 11.07 km of which causes serious sand damage to the railway and thus, the control of blown sand is important for the safe operation of the railway. Construction of the railway and sand prevention system greatly changed the blown sand transport of the primary surface. Effective and feasible sand-control measures include stone checkerboard barriers(SCBs), sand fences(SFs), and gravel coverings. This study simulated the embankments, SCBs and SFs of the QTR in a wind tunnel, and analyzed their respective wind profile, sand deposition, and sand-blocking rate(SBR) in conjunction with field data, aiming at studying the influence of Golmud-Lhasa section of the QTR and sand prevention system on blown sand transport. The results of wind tunnel experiments showed that wind speed increased by 67.7%–77.3% at the upwind shoulder of the embankment and decreased by 50.0%–83.3% at upwind foot of embankment. Wind speed decreased by 50.0%–100.0% after passing through the first SF, and 72.2%–100.0% after the first row of stones within the first SCB grid. In the experiment of sand deposition, the higher the wind speed, the lower the SBR of SCB and SF. From field investigation, the amount of sand blocked by the four SFs decreased exponentially and its SBR was about 50.0%. By contrast, SCB could only block lower amounts of sand, but had a higher SBR(96.7%) than SF. Although, results show that SFs and SCBs along the Golmud-Lhasa section of the QTR provide an obvious sand blocking effect, they lead to the deposition of a large amount of sand, which forms artificial dunes and becomes a new source of sand damage. | XIAO Jianhua YAO Zhengyi QU Jianjun | 2015 | Chinese Geographical Science2015，25，1： | 6 |
| 7 | Experimental definition and its significance on the minimum safe distance of blown sand between the proposed Qinghai-Tibet Expressway and the existing Qinghai-Tibet Railway显示文摘The Qinghai-Tibet Expressway is a major strategic project planned by China that will be built along the Qinghai-Tibet Engineering Corridor. At present,important traffic line projects,such as the Qinghai-Tibet Railway,have been built within this narrow corridor,particularly at the blown sand sections. How to ensure that the wind speed and its flow field between the new expressway and existing railway subgrades are not affected by each other is a priority to prevent breaking the dynamic balance of the blown sand movement of the existing subgrade,thereby avoiding aggravating or inducing new blown sand hazards and ensure the safe operation of the existing Qinghai-Tibet Railway. Therefore,defining the minimum distance of the wind speed and its flow field,which are not affected by each other,between the subgrades become a scientific problem that should be solved immediately to implement the construction of the Qinghai-Tibet Expressway. For this purpose,the minimum safe distance between the subgrades of the Qinghai-Tibet Expressway and Qinghai-Tibet Railway was investigated from the perspective of blown sand by making subgrade models for conducting wind tunnel experiments and combining the observation data of the local field. Results indicated that the minimum safe distance between the two subgrades is 45–50 times the subgrade height when the Qinghai-Tibet Expressway is located at the downwind direction of the Qinghai-Tibet Railway,and 50 times the subgrade height when the former is located at the upwind direction of the latter. These results have guiding significance for the route selection,survey,and design of the Qinghai-Tibet Expressway at the blown sand sections and for the traffic line projects in other similar sandy regions. | XIE ShengBo QU JianJun HAN QingJie PANG YingJun | 2020 | Science China(Technological Sciences)2020，63，12： | 5 |
| 8 | Anatomical variation of infra-pyloric artery origination: A prospective multicenter observational study (IPA-Origin)显示文摘Objective: Infra-pyloric artery(IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA.Methods: We did this prospective, multicenter, open-label, observational study at gastric surgery departments of34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ~2 tests and Fisher's tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov(No. NCT03071237).Results: Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419(97.7%) patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398(95.0%) patients, including gastroduodenal artery(GDA) in154(36.8%) patients, anterior superior pancreaticoduodenal artery(ASPDA) in 130(31.0%) patients, and right gastroepiploic artery(RGEA) in 114(27.2%) patients. Fifteen(3.6%) patients were identified with multiple IPA and 6(1.4%) patients were identified as IPA absence. The differences in the distribution of surgical approach(P=0.003) and geographic area(P=0.030) were statistically significant. No difference was shown in sex, age,gastrectomy type, tumor location, and clinical T, N and M stage.Conclusions: Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions.Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery. | Rulin Miao Jianjun Qu Zhengrong Li Daguang Wang Jiang Yu Weidong Zang Yong Li Fenglin Liu Jian Zhang Wu Song Kai Ye Su Yan Wei Wang Shuangyi Ren Lu Zang Changqing Jing Li Zhang Kuan Wang Weihua Fu Lin Fan Bin Liang Gang Zhao Jun Cai Li Yang Jiaming Zhu Jun You Kun Yang Qingxing Huang Zhaojian Niu Ning Ning Xingfeng Qiu Gang Ji Feng Liang Hua Huang Chao Gao Fei Shan Shuangxi Li Yongning Jia Lianhai Zhang Xiangji Ying Yan Zhang Zhaode Bu Xiangqian Su Gang Zhao Ziyu Li Jiafu Ji | 2018 | Chinese Journal of Cancer Research2018，30，5： | 5 |
| 9 | Quantitative analysis on the dynamic characteristics of megadunes around the Crescent Moon Spring, China显示文摘The Crescent Moon Spring is a precious natural heritage. However, the dynamic characteristics of megadunes around the Crescent Moon Spring are not well known. This paper quantitatively studied the character- istics and changes of megadunes around the Crescent Moon Spring by interpreting aerial photographs taken in 1985 and 2004 and analysing the dune crestlines and the wind data collected from 2011 to 2012. Results revealed that pyramid dunes were formed by a complex wind regime. The Crescent Moon Spring was not buried by shifting sands because of the stable wind regime and relative stability of pyramid dunes. The crestlines of the dunes around the spring moved northward between 1985 and 2004. The south-facing slip faces were also exposed to wind ero- sion, whereas the other faces were under deposition, thus indicating that the southerly wind was relatively en- hanced. Limiting the scale of tall windbreaks and architectures in the Dunhuang oasis at the north of the spring was necessary to maintain the dynamic equilibrium of the wind regime and sand transport. | YingJun PANG JianJun QU KeCun ZHANG ZhiShan AN QingHe NIU | 2014 | Journal of Arid Land2014，6，3： | 4 |
| 10 | Computational fluid dynamics evaluation of the effect of different city designs on the wind environment of a downwind natural heritage site显示文摘Disturbance in wind regime and sand erosion deposition balance may lead to burial and eventual vanishing of a site.This study conducted 3D computational fluid dynamics(CFD)simulations to evaluate the effect of a proposed city design on the wind environment of the Crescent Spring,a downwind natural heritage site located in Dunhuang,Northwestern China.Satellite terrain data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)Digital Elevation Model(DEM)were used to construct the solid surface model.Steady-state Reynolds Averaged Navier-Stokes equations(RANS)with shear stress transport(SST)k-ωturbulence model were then applied to solve the flow field problems.Land-use changes were modeled implicitly by dividing the underlying surface into different areas and by applying corresponding aerodynamic roughness lengths.Simulations were performed by using cases with different city areas and building heights.Results show that the selected model could capture the surface roughness changes and could adjust wind profile over a large area.Wind profiles varied over the greenfield to the north and over the Gobi land to the east of the spring.Therefore,different wind speed reduction effects were observed from various city construction scenarios.The current city design would lead to about 2 m/s of wind speed reduction at the downwind city edge and about 1 m/s of wind speed reduction at the north of the spring at 35-m height.Reducing the city height in the north greenfield area could efficiently eliminate the negative effects of wind spee.By contrast,restricting the city area worked better in the eastern Gobi area compared with other parts of the study area.Wind speed reduction in areas near the spring could be limited to 0.1 m/s by combining these two abatement strategies.The CFD method could be applied to simulate the wind environment affected by other land-use changes over a large terrain. | BenLi LIU JianJun QU QingHe NIU JunZhan WANG KeCun ZHANG | 2014 | Journal of Arid Land2014，6，1： | 4 |
| 11 | Morphology and formation mechanism of sand shadow dunes on the Qinghai-Tibet Plateau显示文摘The formation and development of dunes depend on wind-blown sand movement which is affected by the characteristics of sand material, topography, wind regimes and other factors. In this paper, we investigated two sand shadow dune groups in Shigatse and Za'gya Zangbo of Tibet and an individual dune in Da Qaidam of Qinghai, and analyzed their topographies and morphologies, and the physical characteristics of the sand, wind regime and sand transport. Formed under harsh conditions behind hills, these mature sand shadow dunes are hundreds of meters long, have significant ridges and crescent dunes downwind, and have a hill pass on one or both sides. Wind tunnel experiments revealed that the hill gap and wind velocity are important factors in the formation of these dunes. Sand shadow dunes formed only when the gap spacing is two-thirds of the hill height. When wind velocities are 20 m/s, the sand body is divided into two parts. The hill pass allows the transport of sand by wind, creating a 'narrow-pipe effect', which causes the transported material to gradually accumulate in the center of the shadow zone. We observed that the following are needed for sand shadow dunes to form:(1) strong winds, sufficient sand, suitable obstacles and a dry climate;(2) one or both sides of the obstacle forming the shadow zone must have a hill pass; and(3) the windward side of the obstacle must have a wide, flat area, providing adequate spacing for wind flow and transport of material and the leeward side must have a sufficiently broad, flat area to allow the release of the transported material. Research results on these newly discovered dunes on the Qinghai-Tibet Plateau could contribute to the understanding of dune geomorphology. | JianHua XIAO JianJun QU ZhengYi YAO YingJun PANG KeCun ZHANG | 2015 | Journal of Arid Land2015，7，1： | 4 |
| 12 | Effects of oxygen and carbon on the magnetic properties and microstructure of Sm_2Co_(17) permanent magnets显示文摘The research on the sintered Sm2Co17 permanent magnets prepared by metal injection molding is still at the ex- ploratory stage. Carbon and oxygen are two key factors that influence the magnetic properties. In this article, the effects of oxygen and carbon on the properties and microstructure of the magnets have been studied. The results indicate that oxygen consumes the effective Sm content of the magnets and forms Sm2O3–the non-magnetism phase, which result in the dete- rioration of the magnetic properties. Besides, the magnetic properties decrease in evidence with increasing carbon content. The main factor that affects the magnetic properties is the deterioration of the microstructure of the magnets. The Sm(Co, Cu)5 phase decreases, whereas the cell size increases with the increase of the carbon content. When the carbon content is above 0.43 wt.%, the Sm(Co, Cu)5 phase is not enough to form a uniform cellular microstructure. Thus the magnetic properties disappear. ZrC is detected in the magnets by XRD when the carbon content is above 0.21 wt.%. ZrC also re- duces the properties of the magnets. | TIAN Jianjun ZHANG Shengen QU Xuanhui | 2007 | Rare Metals2007，26，4： | 4 |
| 13 | Methods for calculating glacier area and length in a mountainous area based on remote-sensing data and a digital elevation model显示文摘In a mountainous region, the glacier area and length extracted form the satellite imagery data is the projected area and length of the land surface, which can't be representative of the reality; there are always some errors. In this paper, the methods of calculating glacier area and length calculation were put forward based on satellite imagery data and a digital elevation model (DEM). The pure pixels and the mixed pixels were extracted based on the linear spectral un-mixing approach, the slop of the pixels was calculated based on the DEM, then the area calculation method was presented. The projection length was obtained from the satellite imagery data, and the elevation differences was calculated from the DEM. The length calculation method was presented based on the Pythagorean theorem. For a glacier in the study area of western Qilian Mountain, northwestern China, the projected area and length were 140.93 km2 and 30.82 km, respectively. This compares with the results calculated by the methods in this paper, which were 155.16 km2 and 32.11 km respectively, a relative error of the projected area and length extracted from the LandSat Thematic Mapper (TM) image directly reach to -9.2 percent and -4.0 percent, respectively. The calculation method is more in accord with the practicality and can provide reference for some other object's area and length monitoring in a mountainous region. | JunZhan Wang YouJing Zhang WeiMin Zhang JianJun Qu Chen Chen | 2010 | Research in Cold and Arid Regions2010，2，4： | 4 |
| 14 | Mechanical tests on the reconstructed anterior cruciate ligament fixed with allogenetic cortical bone cross-pin on the femoral side显示文摘 | Liu Chang Liu Yujie Zhang Yingze Qu Feng Li Shuyuan Wang Junliang Qi Wei Wang Aiyuan Wang Xin Liang Jianjun Liang Dongqi Zhu Juanli Liu Yang | 2014 | Chinese Medical Journal2014，，15： | 3 |
| 15 | Sheltering effect of punched steel plate sand fences for controlling blown sand hazards along the Golmud-Korla Railway:Field observation and numerical simulation studies显示文摘Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studies have assessed the protective effect of PSP sand fences,especially through field observations.This study analyzes the effects of double-row PSP sand fences on wind and sand resistance using field observations and a computational fluid dynamics(CFD)numerical simulation.The results of field observations showed that the average windproof efficiencies of the first-row and second-row sand fences were 79.8%and 70.8%,respectively.Moreover,the average windproof efficiencies of the numerical simulation behind the first-row and second-row sand fences were 89.8%and 81.1%,respectively.The sand-resistance efficiency of the double-row PSP sand fences was 65.4%.Sand deposition occurred close to the first-row sand fence;however,there was relatively little sand on the leeward side of the second-row sand fence.The length of sand accumulation near PSP sand fences obtained by numerical simulation was basically consistent with that through field observations,indicating that field observations combined with numerical simulation can provide insight into the complex wind-blown sand field over PSP sand fences.This study indicates that the protection efficiency of the double-row PSP sand fences is sufficient for effective control of sand hazards associated with extremely strong wind in the Gobi areas.The output of this work is expected to improve the future application of PSP sand fences. | ZHANG Kai TIAN Jianjin QU Jianjun ZHAO Liming LI Sheng | 2022 | Journal of Arid Land2022，14，6： | 3 |
| 16 | Wind tunnel simulation experiment and investigation on the electrification of sandstorms显示文摘Electric discharge phenomenon is often observed during the passage of sandstorms over desert regions and sometimes does great damage to human beings. Based on previous researches on the electrification of sandstorms by the scholars both at home and aboard,the authors conducted the simulation experiments on the electric fields of sandstorm-triggered creeping-saltating sand, suspending sand and watered suspending sand in the large-scale wind tunnel. According to the experimental results the electric field structure and its formation mechanism were analysed and discussed, the quantity of electric charges and electric field strengthwere measured and calculated, and finally several conclusions were drawn. | QU Jianjun YAN Muhong DONG Guangrong ZHANG Hongfa ZU Ruiping TUO Wanquan ZHAO Aiguo XIAO Zhenghua LI Fang YANG Bao | 2004 | Science China Earth Sciences2004，47，6： | 2 |
| 17 | Desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China显示文摘Environmental heterogeneity significantly affects the structure of ecological communities.Exploring vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mechanism(s)driving vegetation succession,especially in the ecologically fragile areas.In this study,based on the quantitative analysis of plant community and environmental factors in 68 plots at 10 different transects in the Minqin oasis-desert ecotone(ODE)of northwestern China,we investigated desert vegetation distribution and species-environment relationships using multivariate analysis.Two-way indicator species analysis(TWINSPAN),detrended correspondence analysis(DCA),and canonical correspondence analysis(CCA)methods were used.A total of 28 species,belonging to 27 genera in 8 families,were identified.Chenopodiaceae,Zygophyllaceae,Gramineae,and Leguminosae were the largest families.Annual and perennial herbs accounted for 28.60%of the total number of plants,while shrubs(42.90%)were the most dominant.Nitraria tangutorum was the constructive species of the desert plant community.We divided the 68 plots surveyed in this study into 7 community types,according to the results of TWINSPAN.The distribution of these 7 communities in the DCA ordination graph showed that species with a similar ecotype were clustered together.Results of CCA indicated that groundwater was the dominant factor influencing vegetation distribution,while distance between plot and oasis(Dis)and soil electrical conductivity(EC)were the local second-order factors.Our study suggests that optimizing the utilization of groundwater in oases is key to controlling the degradation of desert vegetation.The favorable topographic conditions of sand dunes should be fully utilized for vegetal dune stabilization,and the influence of soil salinity on the selection of afforestation tree species should be considered. | ZHAO Peng QU Jianjun XU Xianying YU Qiushi JIANG Shengxiu ZHAO Heran | 2019 | Journal of Arid Land2019，11，3： | 2 |
| 18 | Feathered sand ridges in the Kumtagh Desert and their position in the classification system显示文摘Feathered sand ridges in the northeastern Kumtagh Desert in China cover an area of 4016 km 2 and consist of crescent sand ridges and interridge tongue-shaped dunes.Differences in grain size,mineral composition and albedo between crescent sand ridges and tongue-shaped dunes,and between windward and leeward slopes of tongue-shaped dunes,result in their feathery appearance in aerial and satellite imagery.Measurements of the sand drift potential in the region show that the sand-moving wind for feathered sand ridges can be divided into three sectors;i.e.north-northeasterly,easterly and east-northeasterly sectors roughly corresponding to the southeast,northwest and southwest slip faces.Our findings suggests that the crescent sand ridges resulting from the connection of barchan dunes along the prevailing wind direction are longitudinal dune ridges rather than transverse ones.Tongue-shaped dunes and quasi-dune shapes have obvious distinctions and are new transverse dune types.According to McKee's dune shape classification,the feathered sand ridges are not a deformation dune type but a complex one.According to Wu's dune morphological and genetic classification,they are not dune ridges or compound dune ridges that form under the action of unidirectional winds or two winds intersecting at an acute angle,but are complex dune ridges that form under the action of three winds intersecting at an acute angle. | QU JianJun LIAO KongTai DONG GuangRong NIU QingHe JING ZheFan HAN QinJie | 2011 | Science China Earth Sciences2011，54，8： | 2 |
| 19 | Model test of stone columns as liquefaction countermeasure in sandy soils显示文摘 | Mengfei QU Qiang XIE Xinwen CAO Wen ZHAO Jianjun HE Jiang JIN | 2016 | Frontiers of Structural and Civil Engineering2016，10，4： | 2 |
| 20 | Overall efficiency of a V-shaped nylon net fence in preventing sand damage to the Mogao Grottoes显示文摘A V-shaped nylon net fence installed in 1990 on top of the Mogao Grottoes is shown to be effectively resisting aeolian sand damage to the grottoes.The structure guides and causes deposition of sand from westerly wind(the primary hard wind),but to some extent hinders the inverse function of easterly wind carrying sand away from the grottoes toward Mount Mingsha.The gobi side by the fence experiences higher wind speed,so that on which are easily formed undercutting pits,and the deposited sands on it generally form double-peak structures due to abundant sand sources.If the earth surface characteristics in gobi areas by both sides of the fence are quite varied,the erosion and deposition features of the accumulating sand section are similar in different seasons;however,if the earth surface characteristics are similar,the features become irregular in different seasons.Sand depositions with long slope feet are formed along the south and north sides of V-shaped nylon net fence.Disrupted by strong westerly wind and northwesterly wind,sand accumulations by north of the fence are in form of single peaks.Although the operation duration of the V-shaped nylon net fence has exceeded its design life(10 years),our observations indicate that it is still effective in reducing wind-driven sand damages to the Mogao Grottoes,so it should not be withdrawn. | GuoShuai Li JianJun Qu WanFu Wang Wei Yang | 2012 | Research in Cold and Arid Regions2012，4，2： | 2 |
您所在的机构暂未开通此部分的功能，请联系管理员