|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | The General Design and Technology Innovations of CAP1400显示文摘行波堆为一次通过式燃料循环反应堆,其利用堆芯自增殖大大降低了对浓缩和后处理的需求。自增殖将次临界换料燃料转化为新的临界燃料,从而使增殖燃烧波得以扩散。该理念建立在增殖燃烧波和燃料的相对移动的基础上。因此,燃料或增殖燃烧波相对于固定的观察器而言是移动的。行波堆最实用的体现就是能够在将核反应保持在同一位置的同时移动燃料——有时行波堆也被称为'驻波堆'。行波堆能够使用换料铀燃料运行,换料铀燃料包括完全贫化铀、天然铀和低浓缩铀燃料(即235U含量为5.5%或更低的燃料),这些燃料通常在快谱中达不到临界状态。轻水反应堆卸出的乏燃料也可以作为行波堆的换料燃料。上述情况均无需后处理即可实现极高的燃料利用率和燃料废物量的显著降低。当换料燃料为贫化铀时,行波堆的最大优势得以实现,即在启动后,无需浓缩设施,就可维持最先启动的反应堆和一连串后续的反应堆的运行。自2006年起,泰拉能源公司(Terra Power)与50多个机构高度协作,开展了概念设计、工程设计和相关技术开发活动,力争到2026年实现将第一个机组投入使用。本文总结了行波堆技术,包括它的发展计划及其进展,分析了行波堆的社会和经济效益。 | Mingguang Zheng Jinquan Yan Jun Shenttu Lin Tian Xujia Wang Zhongming Qiu | 2016 | Engineering2016，2，1： | 27 |
| 2 | Dynamic changes in the expression of matrix metalloproteinases and their inhibitors,TIMPs,during hepatic fibrosis induced by alcohol in rats显示文摘AIM: To determine the dynamic changes in the expression of matrix metalloproteinases (MMPs) and the endogenous tissue inhibitors of MMPs inhibitors (TIMPs) during hepatic fibrosis induced by alcohol.METHODS: Male Sprague-Dawley rats were randomly divided into normal, 4 d, 2 wk, 4 wk, 9 wk and 11 wk groups, and the model rats were fed with a mixture of alcohol by gastric infusion at the designed time, respectively, then decollated and their livers were harvested for the examination of MMP-2, MMP-3, MMP-9, MMP-13, TIMP-1 and TIMP-2 by immunohistochemistry, zymograghy and Western blotting, respectively.RESULTS: Normal rats had moderate expression of MMP-2,which was decreased in the model rats except in the 11 wk group, where MMP-2 expression slightly increased. MMP-3 had the similar changing pattern to MMP-2 despite weaker expression. MMP-9 expression decreased in the 4 d and 2 wk groups, rose in the 4 wk group, decreased again in the 9 wk group and returned to normal levels in the 11 wk group.MMP-13 expression decreased in the 4 d and 2 wk groups,and returned to normal levels in the 4 wk, 9 wk and 11 wk groups. TIMP-1 expression decreased in the 4 d and 2 wk groups, but sharply increased in the 4 wk group and sustained at a high level even after modeling was stopped for 2 wk. In normal rats TIMP-2 expression was strong. However, it decreased as soon as modeling began, and then gradually rose, but remained to a level lower than that in normal rats even after modeling was stopped for 2 wk.CONCLUSION: MMP-2 may not always expresses at a high level during hepatic fibrosis. MMP-13 and MMP-3 are acutely affected by TIMP-1. In this model TIMP-1 is the most powerful factor imposed on capillarization and peri-sinusoidal fibrosis. TIMP-2 is the most effective regulator on the metabolism of type Ⅳ collagen located in the basement of sinus. | Guang-FuXu Peng-TaoLi Xin-YueWang XuJia De-LuTian Liang-DuoJiang Jin-XiangYang | 2004 | World Journal of Gastroenterology2004，10，24： | 24 |
| 3 | Dynamic changes of capillarization and peri-sinusoid fibrosis in alcoholic liver diseases显示文摘AIM:To investigate the dynamic changes of capillarization and peri-sinusoid fibrosis in an alcoholic liver disease model induced by a new method.METHODS:Male SD rats were randomly divided into 6 groups,namely normal,4d,2w,4w,9w and 11w groups.The animals were fed with a mixture of alcohol for designated days and then decollated,and their livers were harvested to examine the pathological changes of hepatocytes, hepatic stellate cells,sinusoidal endothelial cells,sinusoid, perisinusoid.The generation of three kinds of extra cellular matrix was also observed.RESULTS:The injury of hepatocytes became severer as modeling going on.Under electronic microscope,fatty vesicles and swollen mitochondria in hepatocytes,activated hepatic stellate cells with fibrils could been seen near or around it.Fenestrae of sinusoidal endothelial cells were decreased or disappeared,sinusoidal basement was formed.Under light microscopy typical peri-sinusoid fibrosis, griddinglike fibrosis, broaden portal areas, hepatocyte's fatty and balloon denaturation,iron sediment,dot necrosis,congregated lymphatic cells and leukocytes were observed.Type I collagen showed an increasing trend as modeling going on,slightly recovered when modeling stopped for 2 weeks. Meanwhile,type IV collagen decreased rapidly when modeling began and recovered after modeling stopped for 2 weeks.Laminin increased as soon as modeling began and did not recover when modeling stopped for 2 weeks.CONCLUSION:The pathological changes of the model were similar to that of human ALD,but mild in degree.It had typical peri-sinusoid fibrosis, however,capillarization seemed to be instable.It may be related with the reduction of type IV collagen in the basement of sinusoid during modeling. | Guang-FuXu Xin-YueWang Gui-LingGe Peng-TaoLi XuJia De-LuTian Liang-DuoJiang Jin-XiangYang | 2004 | World Journal of Gastroenterology2004，10，2： | 19 |
| 4 | Infiltrating lithium into carbon doth decorated with zinc oxide arrays for dendrite-free lithium metal anode显示文摘Lithium metal anode for batteries has attracted extensive attentions, but its application is restricted by the hazardous dendritic Li growth and dead Li formation. To address these issues, a novel Li anode is developed by infiltrating molten Li metal into conductive carbon cloth decorated with zinc oxide arrays. In carbonate-based electrolyte, the symmetric cell shows no short circuit over 1,500 h at 1 mA·cm^-2, and stable voltage profiles at 3 mA cm^-2 for ~ 300 h cycling. A low overpotential of ~ 243 mV over 350 cycles at a high current density of 10 mA·cm^-2 is achieved, compared to the seriously fluctuated voltage and fast short circuit in the cell using bare Li metal. Meanwhile, the asymmetric cell withstands 1,000 cycles at 10 C (1 C = 167 mAh·g^-1) compared to the 210 cycles for the cell using bare Li anode. The excellent performance is attributed to the well-regulated Li plating/stripping drive n from the formation of LiZn alloy on the wavy carb on fibers, resulting in the suppress!on of dendrite growth and pulverization of the Li electrode during cycling. | Xianshu Wang Zhenghui Pan Yang Wu Xiaoyu Ding Xujia Hong Guoguang Xu Meinan Liu Yuegang Zhang Weishan Li | 2019 | Nano Research2019，12，3： | 8 |
| 5 | Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2 complex from photosynthetic bacterium Rhodopseudomonas palustris显示文摘The LH2 complex from Rhodopsudomonas (Rps.) palustris is unique in the heterogeneous carotenoid compositions. The dynamics of triplet excited state Carotenoids (3Car*) has been investigated by means of sub-microsecond time-resolved absorption spectroscopy both at physiological temperature (295 K) and at cryogenic temperature (77 K). Broad and asymmetric Tn←T1 transient absorption was observed at room temperature following the photo-excitation of Car at 532 nm, which suggests the contribution from various carotenoid compositions having different numbers of conjugated C=C double bonds (NC=C). The triplet absorption bands of different carotenoids, which superimposed at room temperature, could be clearly distinguished upon decreasing the temperature down to 77 K. At room temperature the shorter-wavelength side of the main Tn←T1 absorption band decayed rapidly to reach a spectral equilibration with a characteristic time constant of~1 μs, the same spectral dynamics, however, was not observed at 77 K. The aforementioned spectral dynamics can be explained in terms of the triplet-excitation transfer among heterogeneous carotenoid compositions. Global spectral analysis was applied to the time-resolved spectra at room temperature, which revealed two spectral components peaked at 545 and 565 nm, and assignable to the Tn←T1 absorption of Cars with NC=C=11 and NC=C=13, respectively. Surprisingly, the decay time constant of a shorter-con- jugated Car, I.e. 0.72 μs (aerobic) and 1.36 μs (anaerobic), is smaller than that of a longer-con- jugated Car, I.e. 2.12 μs (aerobic) and 3.75 μs (anaerobic), which is contradictory to the general rule of carotenoids and relative polyenes. The results are explained in terms of triplet-excitation transfer among different types of Cars. It is postulated that two Cars with different conjugation lengths coexist in an α,β-subunit in the LH2 complex. | FENG Juan, WANG Qian, ZHANG Xujia, HUANG Youguo, Al Xicheng, ZHANG Xingkang & ZHANG JianpingState Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China | 2004 | Science China Chemistry2004，47，1： | 8 |
| 6 | Doppler distributed clutter model of airborne radar and its parameters estimation显示文摘To characterize the clutter spectrum center-shift and spread of airborne radar caused by the platform motion, a novel Doppler Distributed Clutter (DDC) model is proposed to describe the clutter covariance matrix in temporal domain. Based on this parametric model, maximum likelihood, subspace based method and other super- resolution methods are introduced into the Doppler parameters estimation, and more excellent performance is obtained than with the conventional approaches in frequency domain. The theoretical derivation and real experimental results are also provided to validate this novel model and methods of parameter estimating. | XUJia PENGYingning WANQun WANGXiutan XIAXianggen | 2004 | Science in China(Series F)2004，47，5： | 7 |
| 7 | An imine-linked covalent organic framework as the host material for sulfur loading in lithium–sulfur batteries显示文摘Lithium–sulfur(Li–S) batteries have high theoretical specific capacity, providing new opportunities for the next generation of secondary battery. Covalent organic framework(COF) as a new porous crystalline material has been used as the host material in Li–S battery to improve the cell's cycling stability. In this paper, an imine-linked TAPB-PDA-COF was applied as the host material for sulfur loading(60%) in Li–S battery. The TAPB-PDA-COF has a beehive-like morphology with high thermal stability(up to 500 ℃).In the electrochemical experiment, the performance of the composite cathode with acetylene black(AB) and super-P(S-P) as the conductive additives was studied individually. The initial discharge capacity under 0.2 A/g current density was 991 mAh/g and 1357 mAh/g for TAPB-PDA-COF/S@A-B and TAPB-PDACOF/S@S-P, respectively. The better result of S-P based cathode than A-B could be due to the better conductivity of the S-P, as proved by the EIS results. When further increased the current density to 2 A/g,the S-P based composite cathode can still deliver a comparable initial discharge capacity of 630 and 274 mAh/g capacity remained after 940 cycles. This results will inspire researchers develop more suitable conductive additives together with the host materials for high performance Li–S battery. | Jianyi Wang Liping Si Qin Wei Xujia Hong Ligui Lin Xin Li Jingyi Chen Peibiao Wen Yuepeng Cai | 2019 | Journal of Energy Chemistry2019，28，1： | 7 |
| 8 | Information security assurance lifecycle research显示文摘This article proposes that problems of information security are mainly caused by the ineffective integration of people, operation, and technology, and not merely by the poor use of technology. Based on the information lifecycle, a model of the information security assurance lifecycle is presented. The crucial parts of the model are further discussed, with the information risk value and protect level, and the solution in each step of the lifecycle is presented with an ensured information risk level, in term of the integration of people, operation, and technology. | XIE Cheng-shan XUJIA Gu-yue WANG Li | 2007 | The Journal of China Universities of Posts and Telecommunications2007，14，4： | 3 |
| 9 | Wind regime for long-ridge yardangs in the Qaidam Basin, Northwest China显示文摘Yardangs are typical aeolian erosion landforms,which are attracting more and more attention of geomorphologists and geologists for their various morphology and enigmatic formation mechanisms.In order to clarify the aeolian environments that influence the development of long-ridge yardangs in the northwestern Qaidam Basin of China,the present research investigated the winds by installing wind observation tower in the field.We found that the sand-driving winds mainly blow from the north-northwest,northwest and north,and occur the most frequent in summer,because the high temperature increases atmospheric instability and leads to downward momentum transfer and active local convection during these months.The annual drift potential and the ratio of resultant drift potential indicate that the study area pertains to a high-energy wind environment and a narrow unimodal wind regime.The wind energy decreases from northwest to southeast in the Qaidam Basin,with the northerly winds in the northwestern basin changing to more westerly in the southeastern basin.The strong and unidirectional wind regime for the long-ridge yardangs in the northwestern Qaidam Basin results from the combined effects of topographic obstacles such as the Altun Mountains and of the interaction between the air stream and the yardang bodies.Present study suggests that yardang evolution needs such strong and unidirectional winds in high-or intermediate-energy wind environments.This differs from sandy deserts or sandy lands,which usually develop at low-or intermediate-energy wind environments.Present study clarifies the wind regime corresponding to the long-ridge yardangs'development,and lays firm foundation to put forward the formation mechanisms for yardangs in the Qaidam Basin. | GAO Xuemin DONG Zhibao DUAN Zhenghu LIU Min CUI Xujia LI Jiyan | 2019 | Journal of Arid Land2019，11，5： | 3 |
| 10 | Immunogenicity and protective efficacy of a recombinant protein subunit vaccine and an inactivated vaccine against SARS-CoV-2 variants in non-human primates显示文摘Emerging SARS-CoV-2 variants and the gradually decreasing neutralizing antibodies over time post vaccination have led to an increase in incidents of breakthrough infection across the world.To investigate the potential protective effect of the recombinant protein subunit COVID-19 vaccine targeting receptor-binding domain(RBD)(PS-RBD)and whole inactivated virus particle vaccine(IV)against the variant strains,in this study,rhesus macaques were immunized with PS-RBD or IV vaccine,followed by a Beta variant(B.1.351)challenge.Although neutralizing activity against the Beta variant was reduced compared with that against the prototype,the decreased viral load in both upper and lower respiratory tracts,milder pathological changes,and downregulated inflammatory cytokine levels in lung tissues after challenge demonstrated that PS-RBD and IV still provided effective protection against the Beta variant in the macaque model.Furthermore,PS-RBD-induced macaque sera possessed general binding and neutralizing activity to Alpha,Beta,Delta,and Omicron variants in our study,though the neutralizing antibody(NAb)titers declined by varying degrees,demonstrating potential protection of PS-RBD against current circulating variants of concern(VOCs).Interestingly,although the IV vaccine-induced extremely low neutralizing antibody titers against the Beta variant,it still showed reduction for viral load and significantly alleviated pathological change.Other correlates of vaccine-induced protection(CoP)like antibody-dependent cellular cytotoxicity(ADCC)and immune memory were both confirmed to be existing in IV vaccinated group and possibly be involved in the protective mechanism. | Qian He Qunying Mao Xiaozhong Peng Zhanlong He Shuaiyao Lu Jialu Zhang Fan Gao Lianlian Bian Chaoqiang An Wenhai Yu Fengmei Yang Yanan Zhou Yun Yang Yanyan Li Yadi Yuan Xujia Yan Jinghuan Yang Xing Wu Weijin Huang Changgui Li Junzhi Wang Zhenglun Liang Miao Xu | 2022 | Signal Transduction and Targeted Therapy2022，7，4： | 2 |
| 11 | Mesh Smoothing Method Based on Local Wave Analysis显示文摘As the mesh models usually contain noise data,it is necessary to eliminate the noises and smooth the mesh.But existed methods always lose geometric features during the smoothing process.Hence,the noise is considered as a kind of random signal with high frequency,and then the mesh model smoothing is operated with signal processing theory.Local wave analysis is used to deal with geometric signal,and then a novel mesh smoothing method based on the local wave is proposed.The proposed method includes following steps:Firstly,analyze the principle of local wave decomposition for 1D signal,and expand it to 2D signal and 3D spherical surface signal processing;Secondly,map the mesh to the spherical surface with parameterization,resample the spherical mesh and decompose the spherical signals by local wave analysis;Thirdly,propose the coordinate smoothing and radical radius smoothing methods,the former filters the mesh points' coordinates by local wave,and the latter filters the radical radius from their geometric center to mesh points by local wave;Finally,remove the high-frequency component of spherical signal,and obtain the smooth mesh model with inversely mapping from the spherical signal.Several mesh models with Gaussian noise are processed by local wave based method and other compared methods.The results show that local wave based method can obtain better smoothing performance,and reserve more original geometric features at the same time. | QIN Xujia ZHENG Hongbo CHENG Shiwei LIU Shishuang XU Xiaogang | 2012 | Chinese Journal of Mechanical Engineering2012，25，3： | 2 |
| 12 | Preservation Effect of Prochloraz-manganese Chloride Complex on Postharvest ‘Shatangju'( Citrus reticulata)Fruits显示文摘[Objective]The paper was to solve the weakness of heavy postharvest diseases and non-endurable storage of‘Shatangju',to improve the preservation effect of‘Shatangju'. [Method] Fruits were dipped in different concentrations of prochloraz-manganese chloride complex solutions. The postharvest weight loss rate,soluble solids content and decay rate of fruits were determined,and the safety of chemical agents was observed and evaluated. [Result]Prochloraz-manganese chloride complex had significant preservation effect on postharvest‘Shatangju'fruits,and the appropriate concentration was 0. 15%-0. 20%( effective content);the decay rates of fruits stored at room temperature for 15,30,45,60 and 90 d were 0,5%,< 10%,< 10% and < 30%; there was no specific changes in smell and flavor of non-decayed fruits. [Conclusion] Prochloraz-manganese chloride complex solution had significant preservation effect on ‘Shatangju'by inhibiting and reducing the growth and development of pathogenic bacteria,and the effect was much better under refrigeration condition. | Xu Chengxiang Zheng Fuqing Ma Yanping Zhang Xujia | 2016 | Plant Diseases and Pests2016，7，5： | 2 |
| 13 | Effects of a novel bimetallic catalytic biofilter-based pretreatment technique on the form of ultrafiltration membrane fouling显示文摘Pretreatments of influents using bimetallic catalytic biofilter(BC-biofilter)can help reduce transmembrane pressures.For ultrafiltration membranes coupled with a conventional biofilter pretreatment,the cake layer resistance accounts for 25.0%of the total resistance.However,for those coupled with BC-biofilter pretreatment,the cake layer resistance accounts only for 12.5%of the total resistance.Confocal laser scanning microscopy is employed to determine the porosity of cake layer.It is found that ultrafiltration membranes with BC-biofilter pretreatment show a cake layer porosity of up to 0.56 or greater,whereas those with a conventional biofilter pretreatment exhibit a cake layer porosity of only 0.36.This is because micro-flocculation occurs in the effluents of BC-biofilter.The flocs generated through flocculation deposit on membrane surfaces to create highly porous cake layer.Moreover,catalytic reduction can increase the zeta potentials of the biofilter effluents.This makes the deposition of colloidal particles and flocs on membrane surfaces difficult under electrostatic repulsion.Simultaneously,micro-flocculation after BC-biofilter pretreatment can remove colloidal particles with particle sizes of200–350 nm in water.This can effectively prevent the blockage of ultrafiltration membrane pores.Furthermore,compared to conventional biofilter,BC-biofilter pretreatment can more effectively reduce the number of colloidal particles and the van der Waals forces of ultrafiltration membranes.They can also change the action directions of electric double layers and thereby mitigate ultrafiltration membrane fouling. | Songze Hao Xuehui Zhao Hongwei Zhang Yun Wu Cheng Fang Xujia Wang | 2020 | Chinese Journal of Chemical Engineering2020，28，10： | 2 |
| 14 | LIC color texture enhancement algorithm for ocean vector field data based on HSV color mapping and cumulative distribution function显示文摘Texture-based visualization method is a common method in the visualization of vector field data.Aiming at adding color mapping to the texture of ocean vector field and solving the ambiguity of vector direction in texture image,a new color texture enhancement algorithm based on the Line Integral Convolution(LIC)for the vector field data is proposed,which combines the HSV color mapping and cumulative distribution function calculation of vector field data.This algorithm can be summarized as follows:firstly,the vector field data is convoluted twice by line integration to get the gray texture image.Secondly,the method of mapping vector data to each component of the HSV color space is established.And then,the vector field data is mapped into HSV color space and converted from HSV to RGB values to get the color image.Thirdly,the cumulative distribution function of the RGB color components of the gray texture image and the color image is constructed to enhance the gray texture and RGB color values.Finally,both the gray texture image and the color image are fused to get the color texture.The experimental results show that the proposed LIC color texture enhancement algorithm is capable of generating a better display of vector field data.Furthermore,the ambiguity of vector direction in the texture images is solved and the direction information of the vector field is expressed more accurately. | Hongbo Zheng Qin Shao Jie Chen Yangyang Shan Xujia Qin Ji Ma Xiaogang Xu | 2022 | Acta Oceanologica Sinica2022，41，10： | 1 |
| 15 | Spatio-temporal Evolution Characteristics and Driving Mechanism of the New Infrastructure Construction Development Potential in China显示文摘With the advent of the era of big data and artificial intelligence, new infrastructure construction(NIC) has attracted the attention of many countries. The development of NIC provides an opportunity to bridge the digital divide and narrow the regional gap,providing continuous impetus to further promote economic development. Here, we considered 31 provincial-level administrative units in China(not including Hong Kong, Macao, and Taiwan of China due to data unavailable) and established comprehensive evaluation indicators for the development potential of NIC. Afterward, we used the entropy-weight TOPSIS model to determine the development potential of NIC and analyze its spatio-temporal evolution characteristics. Furthermore, the GeoDetector model was applied to explore the driving mechanism of the NIC development potential. The conclusions were as follows: (1) The Chinese NIC development potential is generally low. The eastern China was the region with the highest development potential year by year, while the development potential in the central China was found to be in an accelerating phase. (2) The evolution of the Chinese NIC development potential’s spatial pattern has been characterized by an inland extension and coastal agglomeration. Moreover, we identified a superior development zone, a rising development zone, an inferior development zone, and a declining development zone. (3) The scope of Chinese NIC development potential agglomeration areas has gradually expanded and its degree has gradually deepened. The range of high-value agglomeration in eastern area gradually expanded and its degree gradually deepened. (4) Investment in innovative talents appears as the core factor affecting the Chinese NIC development potential. Whether acting alone or synergistically with other factors, its promoting effect on Chinese NIC development potential is the strongest. | GU Tianshi ZHANG Peng ZHANG Xujia | 2021 | Chinese Geographical Science2021，31，4： | 1 |
| 16 | Regulation of RAW 264.7 macrophages behavior on anodic TiO2 nanotubular arrays显示文摘 | Shenglian YAO Xujia FENG Wenhao LI Lu-Ning WANG Xiumei WANG | 2017 | Frontiers of Materials Science2017，11，4： | 1 |
| 17 | Deformation field and crack analyses of concrete using digital image correlation method显示文摘The study on the deformation distribution and crack propagation of concrete under axial compression was conducted by the digital image correlation (DIC) method. The main parameter in this test is the water-cement (fT/C) ratio. The novel analysis process and numerical program for DIC method were established. The displacements and strains of coarse aggregate, and cement mortar and interface transition zone (ITZ) were obtained and verified by experimental results. It was found that the axial displacement distributed non-uniformly during the loading stage, and the axial displacements of ITZs and cement mortar were larger than that of coarse aggregates before the occurrence of macrocracks. The effect of W/C on the horizontal displacement was not obvious. Test results also showed that the transverse and shear deformation concentration areas (DCAs) were formed when stress reached 30%-40% of the peak stress. The transverse and shear DCAs crossed the cement mortar, and ITZs and coarse aggregates. However, the axial DCA mainly surrounded the coarse aggregate. Generally, the higher W/C was, the more size and number of DCAs were. The crack propagations of specimens varied with the variation of W/C. The micro-crack of concrete mainly initiated in the ITZs, irrespective of the W/C. The number and distribution range of cracks in concrete with high W/C were larger than those of cracks in specimen adopting low W/C. However, the value and width of eraeks in high W/C specimen were relatively small. The W/C had an obvious effect on the characteristics of concrete deterioration. Finally, the characteristics of crack was also evaluated by comparing the calculated results. | Yijie HUANG Xujia HE Qing WANG Jianzhuang XIAO | 2019 | Frontiers of Structural and Civil Engineering2019，13，5： | 1 |
| 18 | Contribution of underlying terrain to sand dunes: evidence from the Qaidam Basin, Northwest China显示文摘Underlying terrain strongly influences dune formation.However,the impacts of underlying terrain on the dune formation are poorly studied.In the present research,we focused on dunes that formed in the alluvial fans and dry salt flats in the Qaidam Basin,Northwest China.We quantified the dunes'sediment characteristics on different types of underlying terrain and the terrain's effects on the surface quartz grains by analyzing grain-size distribution,soluble salt contents and grain surface micro-textures.Results showed that barchan dunes were dominated by medium sands with a unimodal frequency distribution,whose peak corresponded to the saltation load.Linear dunes were mainly composed of fine sands with a bimodal frequency distribution,whose main peak represented the saltation load,and whose secondary peak represented the modified saltation or suspension load.Sand was transported from source area by running water(inland rivers)over short distances and by wind over relatively longer distances.Thus,quartz grains had poor roundness and were dominated by sub-angular and angular shapes.Surface micro-textures indicated that dune sands were successively transported by exogenic agents(glaciation,fluviation and wind).Soluble salt contents were low in dunes that developed in the alluvial fans,which represented a low-energy chemical environment,so the grain surface micro-textures mainly resulted from mechanical erosion,with weak micro-textures formed by SiO2 solution and precipitation.However,soluble salt contents were much higher in dunes that developed in the dry salt flats,which indicated a high-energy chemical environment.Therefore,in addition to micro-structures caused by mechanical erosion,micro-textures formed by SiO2 solution and precipitation also well developed.Our results improve understanding of the sediment characteristics of dune sands and the effects of underlying terrain on dune development in the Qaidam Basin,China. | LI Jiyan QU Xin DONG Zhibao CAI Yingying LIU Min REN Xiaozong CUI Xujia | 2021 | Journal of Arid Land2021，13，12： | 1 |
| 19 | The Monge - Ampere equation and its geometric application显示文摘 | Trudinger N S Wang Xujia | 2008 | Handbook of Geometric A- nalysis Adv Lect Math (ALM) 7 Higher Euducation Press Beijing2008，，： | 1 |
| 20 | Novel parametric optimum processing method for airborne radar显示文摘In radar target detection, an optimum processor needs to automatically adapt its weights to the environment change. Conventionally, the optimum weights are obtained by substantial independently and identically distributed (i.i.d.) interference samplings, which is not always realistic in an inhomogeneous clutter background of airborne radar. The lack of i.i.d, samplings will inevitably lead to performance deterioration for optimum processing. In this paper, a novel parametric adaptive processing method is proposed for airborne radar target detection based on the modified Doppler distributed clutter (DDC) model with contribution of clutter's internal motion. It is different from the conventional methods in that the adaptive weights are determined by two parameters of DDC model, i.e., angular center and spread. A low-complexity nonlinear operators approach is also proposed to estimate these parameters. Simulation and performance analysis are also provided to show that the proposed method can remarkably reduce the dependence of i.i.d, samplings and it is computationally efficient for practical use. | XUJia PENGYingning WANQun ZHANGLiping LINYan XIAXianggen | 2004 | Science in China(Series F)2004，47，6： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员