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| 1 | Accumulation of soil organic carbon during natural restoration of desertified grassland in China's Horqin Sandy Land显示文摘China's Horqin Sandy Land,a formerly lush grassland,has experienced extensive desertification that caused considerable carbon(C) losses from the plant-soil system.Natural restoration through grazing exclusion is a widely suggested option to sequester C and to restore degraded land.In a desertified grassland,we investigated the C accumulation in the total and light fractions of the soil organic matter from 2005 to 2013 during natural restoration.To a depth of 20 cm,the light fraction organic carbon(LFOC) storage increased by 221 g C/m2(84%) and the total soil organic carbon(SOC) storage increased by 435 g C/m2(55%).The light fraction dry matter content represented a small proportion of the total soil mass(ranging from 0.74% in 2005 to 1.39% in 2013),but the proportion of total SOC storage accounted for by LFOC was remarkable(ranging from 33% to 40%).The C sequestration averaged 28 g C/(m2·a) for LFOC and 54 g C/(m2·a) for total SOC.The total SOC was strongly and significantly positively linearly related to the light fraction dry matter content and the proportions of fine sand and silt+clay.The light fraction organic matter played a major role in total SOC sequestration.Our results suggest that grazing exclusion can restore desertified grassland and has a high potential for sequestering SOC in the semiarid Horqin Sandy Land. | YuQiang LI XueYong ZHAO FengXia ZHANG Tala AWADA ShaoKun WANG HaLin ZHAO TongHui ZHANG YuLin LI | 2015 | Journal of Arid Land2015,7,3: | 21 |
| 2 | Overview of business innovations and research opportunities in blockchain and introduction to the special issue显示文摘Blockchain has become a new frontier of venture capitals that has attracted the attention of banks,governments,and other business corporations.The recent blockchain related attempts included legal blockchains by Fadada.com and Microsoft and pork tracking blockchains by Walmart and IBM.Blockchain is poised to become the most exciting invention after the Internet;while the latter connects the world to enable new business models based on online business processes,the former will help resolve the trust issue more efficiently via network computing.In this paper,we give an overview on blockchain research and development as well as introduce the papers in this special issue.We show that while blockchain has enabled Bitcoin,the most successful digital currency,its widespread adoption in finance and other business sectors will lead to many business innovations as well as many research opportunities. | J.Leon Zhao Shaokun Fan Jiaqi Yan | 2016 | Financial Innovation2016,2,1: | 17 |
| 3 | Scale dependence of plant species richness and vegetation-environment relationship along a gradient of dune stabilization in Horqin Sandy Land, Northern China显示文摘Ecological patterns and processes in dune ecosystems have been a research focus in recent years, however the information on how dune stabilization influences the spatial scale dependence of plant diversity is still lacking. In this study, we measured the plant species richness, soil properties and altitude across four spatial scales(1, 10, 100 and 1,000 m2) at three different dune stabilization stages(mobile dune, semi-fixed dune and fixed dune) in Horqin Sandy Land, Northern China. We also examined the relationships between plant species richness, community composition and environmental factors along the gradient of dune stabilization. Our results showed that plant species richness increased with the increase of spatial scales in each dune stabilization stage, as well as with the increase of dune stabilization degrees. Canonical correspondence analysis(CCA) showed that plant distribu- tions in the processes of dune stabilization were determined by the combined environmental gradient in relation to soil organic carbon(SOC), total nitrogen(TN), carbon/nitrogen(C/N), pH, electrical conductivity(EC), soil water content(SWC), fine sand(FS), very fine sand(VFS), silt and clay(SC), and altitude. Plant species richness was significantly and positively correlated to SOC and TN in mobile dune, and significantly and positively correlated to SOC, TN, C/N, VFS and SC in semi-fixed dune. However, no significant correlation between plant species richness and environmental factors was observed in fixed dune. In addition, plant species richness in different dune stabili- zation stages was also determined by the combined gradient of soil properties and altitude. These results suggest that plant species richness has obvious scale dependence along the gradient of dune stabilization. Soil resources depending on dune habitats and environmental gradients caused by dune stabilization are important factors to de- termine the scale dependence of species diversity in sand dune ecosystems. | XiaoAn ZUO ShaoKun WANG XueYong ZHAO Jie LIAN | 2014 | Journal of Arid Land2014,6,3: | 13 |
| 4 | The first airborne scalar gravimetry system based on SINS/DGPS in China显示文摘China has developed an airborne gravimetry system based on SINS/DGPS named SGA-WZ,the first system in which a strapdown inertial navigation system(SINS)has been used for airborne gravimetry in China.This gravity measurement system consists of a strap-down inertial navigation system and a differential global positioning system(DGPS).In April 2010,a flight test was carried out in Shandong Province of China to test the accuracy of this system.The test was designed to assess the repeatability and accuracy of the system.Two repeated flights and six grid flights were made.The flying altitude was about 400 m.The average flying speed was about 60 m/s,which corresponds to a spatial resolution of 4.8 km when using 160-s cutoff low-pass filter.This paper describes the data processing of the system.The evaluation of the internal precision is based on repeated flights and differences in crossover points.Gravity results in this test from the repeated flight lines show that the repeatability of the repeat lines is 1.6 mGal with a spatial resolution of 4.8 km,and the internal precision of grid flight data is3.2 mGal with a spatial resolution of 4.8 km.There are some systematic errors in the gravity results,which can be modeled using trigonometric function.After the systematic errors are compensated,the precision of grid flight data can be better than1 mGal. | CAI ShaoKun WU MeiPing ZHANG KaiDong CAO JuLiang | 2013 | Science China Earth Sciences2013,56,12: | 12 |
| 5 | Wideband electromagnetic characteristics modeling and analysis of missile targets in ballistic midcourse显示文摘The wideband electromagnetic characteristics of missile targets in midcourse are the foundation of midcourse attack-defense confrontation.This paper proposes a novel electromagnetic scattering modeling method for midcourse targets based on a precise scattering center model,in which the nonideal scattering phenomenon,shielding effect and micro-motion are taken into consideration for the first time.Firstly,a precise scattering center model incorporating both the sliding scattering and anisotropic scattering is established.Then the change rule of the target attitude is generalized,and a checking method of the scattering center shielding effect is proposed for rotationally symmetric targets.Afterwards,a novel dynamic electromagnetic scattering model is presented,where the scattering center model updates along with the variation of the target attitude and can characterize the change of the electromagnetic characteristics of midcourse targets exactly.Finally,in light of the established model,the dynamic electromagnetic characteristics within different attitude angle bounds are analyzed by stages,and some useful conclusions are obtained.Experiment results from the measured data in anechoic chamber verify the validity of the proposed modeling method and relevant analysis. | XU ShaoKun LIU JiHong WEI XiZhang LI Xiang GUO GuiRong | 2012 | Science China(Technological Sciences)2012,55,6: | 11 |
| 6 | A state-of-the-art review on passivation and biofouling of Ti and its alloys in marine environments显示文摘High strength-to-weight ratio, commendable biocompatibility and excellent corrosion resistance make Ti alloys widely applicable in aerospace, medical and marine industries. However, these alloys suffer from serious biofouling, and may become vulnerable to corrosion attack under some extreme marine conditions. The passivating and biofouling performance of Ti alloys can be attributed to their compact,stable and protective films. This paper comprehensively reviews the passivating and biofouling behavior,as well as their mechanisms, for typical Ti alloys in various marine environments. This review aims to help extend applications of Ti alloys in extremely harsh marine conditions. | Shaokun Yan Guang-Ling Song Zhengxian Li Haonan Wang Dajiang Zheng Fuyong Cao Miroslava Horynova Matthew S.Dargusch Lian Z-hou | 2018 | Journal of Materials Science & Technology2018,34,3: | 11 |
| 7 | Effect of spatial scale and topography on spatial heterogeneity of soil seed banks under grazing disturbance in a sandy grassland of Horqin Sand Land, Northern China显示文摘Soil seed banks play an important role in the distribution and composition of plant communities in semiarid grassland ecosystems.However,information on how spatial scale influences the spatial heterogeneity of soil seed banks in a grassland under grazing disturbance is still lacking.Based on field sampling and greenhouse germination,we measured the species composition and seed density of soil seed banks at different spatial scales (30 m×30 m,30 m×60 m and 30 m×90 m)along a topographical gradient in a sandy grassland in Horqin Sand Land, Northern China.By applying geostatistical methods,we examined how spatial scale and topography affected the spatial distribution of soil seed banks in the study area.Our results showed that the total number of species in soil seed banks,as well as the number of dominant annuals,increased with the increase of spatial scales.Seed density in soil seed banks decreased with the increase of spatial scales due to an increase in the slopes and relative heights of the sampling points.Geostatistical analysis showed that the relative structural variance(C/(C0+C))of seed density and species richness were over 65%for all spatial scales,indicating that these variables had an obvious spatial autocorrelation and the spatial structured variance accounted for the largest proportion of the total sample variance.Spatial autocorrelation of seed density in soil seed banks increased with the increase of measured scales,while that of species richness showed a reverse trend.These results suggest that the total number of species in soil seed banks is spatial scale dependent and lower topography may accommodate more seeds.Spatial distribution of seed density in soil seed banks is also scale dependent due to topographic variation.Grassland management,therefore,needs to consider local grazing disturbance regime,spatial scale and topography. | XiaoAn ZUO ShaoKun WANG XueYong ZHAO WenJin LI Johannes KNOPS Amy KOCHSlEK | 2012 | Journal of Arid Land2012,4,2: | 9 |
| 8 | Deep neural network algorithm for estimating maize biomass based on simulated Sentinel 2A vegetation indices and leaf area index显示文摘Accurate estimation of biomass is necessary for evaluating crop growth and predicting crop yield.Biomass is also a key trait in increasing grain yield by crop breeding.The aims of this study were(i)to identify the best vegetation indices for estimating maize biomass,(ii)to investigate the relationship between biomass and leaf area index(LAI)at several growth stages,and(iii)to evaluate a biomass model using measured vegetation indices or simulated vegetation indices of Sentinel 2A and LAI using a deep neural network(DNN)algorithm.The results showed that biomass was associated with all vegetation indices.The three-band water index(TBWI)was the best vegetation index for estimating biomass and the corresponding R2,RMSE,and RRMSE were 0.76,2.84 t ha−1,and 38.22%respectively.LAI was highly correlated with biomass(R2=0.89,RMSE=2.27 t ha−1,and RRMSE=30.55%).Estimated biomass based on 15 hyperspectral vegetation indices was in a high agreement with measured biomass using the DNN algorithm(R2=0.83,RMSE=1.96 t ha−1,and RRMSE=26.43%).Biomass estimation accuracy was further increased when LAI was combined with the 15 vegetation indices(R2=0.91,RMSE=1.49 t ha−1,and RRMSE=20.05%).Relationships between the hyperspectral vegetation indices and biomass differed from relationships between simulated Sentinel 2A vegetation indices and biomass.Biomass estimation from the hyperspectral vegetation indices was more accurate than that from the simulated Sentinel 2A vegetation indices(R2=0.87,RMSE=1.84 t ha−1,and RRMSE=24.76%).The DNN algorithm was effective in improving the estimation accuracy of biomass.It provides a guideline for estimating biomass of maize using remote sensing technology and the DNN algorithm in this region. | Xiuliang Jin Zhenhai Li Haikuan Feng Zhibin Ren Shaokun Li | 2020 | The Crop Journal2020,8,1: | 9 |
| 9 | Parameter Estimation and Performance Analysis of Coherent Polarization Attributed Scattering Center Model显示文摘 | XU Shaokun WEI Xizhang LI Xiang GUO Guirong | 2013 | Chinese Journal of Electronics2013,22,1: | 9 |
| 10 | 基于体波有限频层析成像的青藏高原南部和中部下方印度大陆岩石层俯冲和撕裂的三维图像显示文摘使用TIBET-31N无源地震台阵以及以前临时地震台阵记录到的远震体波数据进行了有限频层析成像反演,对青藏高原南部及中部的三维速度结构成像。在喜马拉雅和拉萨地块下方存在向北倾角40°的高速体。我们把这些高速异常区域解释为俯冲的印度大陆岩石层(ICL)。印度大陆岩石层似乎在青藏高原中部比东部向北延伸更多——沿85°E在31°N到达350km深处,而沿91°E则是在30°N到达350km深度。P波和S波低速异常区在当惹雍错裂谷、亚东—谷露裂谷和错那裂谷下方从下地壳延伸至≥180km深度,这表明青藏高原南部的裂谷可能包含了整个岩石层的变形。当惹雍错裂谷下方的异常区向下延伸到约180km,而亚东—谷露裂谷西部和错那裂谷东部的异常延伸到了超过300km的深度。亚东—谷露裂谷西部的低速区上地幔延伸至最北,并且似乎与青藏高原中部下方广阔的上地幔低速区相连。于是,北向俯冲的印度板块沿着南北走向的裂缝撕裂。这些裂缝允许或者导致的软流层上涌同青藏高原北部上地幔相类似。 | Xiaofeng Liang Yun Chen Xiaobo Tian Yongshun John Chen James Ni Andrea Gallegos Simon L.Klemperer Minling Wang Tao Xu Changqing Sun Shaokun Si Haiqiang Lan Jiwen Teng 左思成 | 2016 | 世界地震译丛2016,47,6: | 8 |
| 11 | Impending HRT wave precursors to the Wenchuan M_s8.0 earthquake and methods of earthquake impending prediction by using HRT wave显示文摘We deployed four geo-electric monitoring stations in Sichuan and Yunnan provinces from 2004, using the new generation of equipment (PS-100) and technologies to capture the HRT wave earthquake precursor. Before the Wenchuan Ms8.0 earthquake, we recorded the HRT wave precursor at the only operating station in Hongge (HG, Δ=465 km) and found that significant impending signal had been recorded at the station in the early morning ( 0―5 am) of 12th of May, 2008. The precursor for this earthquake is consistent with precursors recorded for other strong earthquakes. The measured physical properties (geo-resistivity and telluric-current) show tidal wave period oscillations from several days to several months before the earthquakes and the amplitude of such HT oscillation increases significantly towards the occurrence of an earthquake. These HT and RT waves from the epicenter have a causal relationship with the earthquakes that happened several days later. The arrival time of two RT waves is proportional to the distance from the station to the epicenter. The estimated natural decay of the amplitude is correlated with the natural period (T0) of the earthquake fault, which is proportional to the fault length. From this relationship, we can predict the earthquake magnitude. For magnitude 6―9 earthquakes, the natural period is about 1―6 hours. Such oscillation comes from the epicenter area and they can propagate several thousand kilometers in the Earth's crust. Before a strong earthquake in the shallow crust, the conductive pore fluid will experience major changes before the fault rapture. Such fluid change will emit an oscillation in the pore fluid pressure. This is the mechanism for the HRT wave generation. Since the China Earthquake Administration funded the HRT wave short-term earth-quake prediction project in 2003, the first record of HRT precursor wave has been recorded from the 2004-12-26 Sumatra Mw9.0 earthquake with the largest epicentre distance Δ=2900 km. Thereafter, we have captured HRT waves from more than twenty strong earthquakes, which are well-matched and show repeatability, consistency and regularity. All our observation with the HRT waves demonstrate that HRT wave precursors to earthquakes indeed exist. Strong earthquakes can be predicted and short-term and impending earthquake prediction is achievable in the very near future. From all the observations, including the ones at HG station from Wenchuan Ms8.0 earthquake, we conclude that using HRT wave to predict earthquakes is feasible. | QIAN FuYe ZHAO BiRu QIAN Wei ZHAO Jian HE ShiGen ZHANG HongKui LI ShiYu LI ShaoKun YAN GuLiang WANG ChengMin SUN ZhenKai ZHANG DongNing LU Jun ZHANG Ping YANG GuoJun SUN JiaLin GUO ChunSheng TANG YuXiong XU JianMing XIA KunTao JU Hang YIN BangHong LI Ming YANG DongSheng QI WeiLuo HE TaiMing GUAN HuaPing ZHAO YuLin | 2009 | Science China Earth Sciences2009,52,10: | 8 |
| 12 | Variation in soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land显示文摘In order to investigate the spatio-temporal variability of soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land,a plot of 25 m × 25 m,where there were 6 shrub canopies of C. microphylla,was sited for measuring soil water content at two soil layers of 0-20 cm (top layer) and 20-40 cm (lower layer). Soil water content was measured on the 1st,5th,10th and 15th day after a 42 mm rainfall in Naiman of Inner Mongolia. The results showed that soil water contents at both layers under C. microphylla shrub were gradually decreased after the rain. Soil water content at the top layer outside the shrub canopy was higher than that inside the shrub canopy within 5 days,and became similar inside and outside the shrub canopy on the 10th day after the 42 mm rainfall,and it was lower outside than that inside the shrub canopy on the 15th day. The soil water content at lower layer in the area without shrubs was higher than that under shrub canopy all along. All the measured values of soil water content can be fitted to a variogram model. There was significant autocorrelation of the values of soil water content between top layer and lower layer,except for the fourth measured values of soil water content at top layer. The range and spatial dependence of soil water content at top layer were lower than that at lower layer. | Wang, ShaoKun Zhao, XueYong Qu, Hao Luo, YaYong Yun, JianYing | 2010 | Journal of Arid Land2010,2,3: | 8 |
| 13 | Harnessing Internet finance with innovative cyber credit management显示文摘In the last two decades,Internet technologies,such as cloud computing,mobile communications,social media,and big data analytics,have brought tremendous changes to our society and reshaped the business in various industries.Specifically,the mushrooming innovations in the financial area fertilized by information and communication technologies indicates the advent of the Internet finance era.Applying the exploratory research approach,we investigate major innovative Internet-based financial services and classify them into five categories,as of e-commerce,e-payment,e-money market,online loan services,and digital currencies.Then we propose a market structure of Internet finance extended from the traditional financial market.We claim that credit management is the key issue in the marketplace of Internet finance,characterized by big data analytics,in which cyber credit appears as whole-process,multi-dimensional,and holographic.We further suggest that cyber credit be represented in the form of vector to overcome the limits of traditional single-value measure in cyber credit management.Based on this framework,we raise main research issues in Internet finance from the perspectives of theory,technology,and governance. | Zhangxi Lin Andrew B.Whinston Shaokun Fan | 2015 | Financial Innovation2015,1,1: | 7 |
| 14 | Toward sustainable desertification reversion:A case study in Horqin Sandy Land of northern China显示文摘Desertification reversion is an interactive process involving climate, land use change, and water processes. In order to reveal the relationship between desertification reversion and these factors, we analyzed historical data on precipitation, air temperature, desertified land changes, underground water tables, and water body changes in Naiman County in the central part of Horqin Sandy Land. Our analysis showed that during 1961-2010 the annual precipitation fluctuated dramatically and has decreased fairly consistently in recent years. The air temperature increased by 0.50-1.25 °C, and the minimum temperature increased more obviously. The desertified land area increased from 42,300 km2 in 1959 to 62,000 km2 in 1985, and then declined to about 50,000 km2 in 2010. The underground water tables have been lowered by about 10 m in the past 30 years, and declined more rapidly in recent years. Desertified land is significantly related to the amount of total cropland, and underground water tables are significantly correlated with annual precipitation and the amount of irrigated cropland. Therefore, it is necessary to pursue sustainable desertification reversion without compromising the capacity for local development and restoration of degraded land, through application of appropriate management measures for improving water availability in this region. | XueYong Zhao ShaoKun Wang YaYong Luo WenDa Huang Hao Qu Jie Lian | 2015 | Research in Cold and Arid Regions2015,7,1: | 6 |
| 15 | Prevalent thickening and local thinning of the mantle transition zone beneath the Baikal rift zone and its dynamic implications显示文摘The Baikal rift is the most seismically active continental rift in the world and is significant for studying the dynamics of continental rifts, although its precise dynamic mechanisms remain controversial. We calculated receiver functions (1748) from Global Seismographic Network seismic stations TLY and ULN and stacked receiver functions in different bins. Here we present discontinuities at depths of 410km and 660km and thickness of the mantle transition zone (MTZ) beneath the study area. The MTZ structure shows an obvious thickening (292km) in the Baikal rift zone except for an area of limited thinning (230km), whereas it is basically normal (250km) beneath the Mongolian area, to the southeast of the Baikal rift. Combining these results with previous findings, we propose that the large-scale thickening beneath the Baikal rift zone is likely to be caused by the Mesozoic collision between the Siberian Platform and the Mongolia-North China Block or magmatic intrusion into the lower crust, which would result in crust and lithosphere thickening. Thus, the lower crust becomes eclogitized and consequently detached into the deep mantle because of negative buoyancy. The detachment not only induces asthenosphere upwelling but also accelerates mantle convection of water detached from the subducted slab, which would increase mantle melting, while both processes promote the development of the rift. Our preliminary results indicate that the detachment and the consequent hot upwelling have an important influence on the development of the Baikal rift, and a small-scale mantle upwelling indicated by the located thinning may have destroyed the lithosphere and promoted this development. | SI ShaoKun TIAN XiaoBo ZHANG HongShuang TENG JiWen | 2013 | Science China Earth Sciences2013,56,1: | 6 |
| 16 | Influence of plastic film mulching and planting density on yield,leaf anatomy,and root characteristics of maize on the Loess Plateau显示文摘In rainfed areas of northwestern China,maize production is constrained mainly by low temperature during early growth and water limitation during the entire growth period.Plastic film mulching is commonly used to increase maize yield in this area,because it increases topsoil temperature and moisture content as well as water use efficiency.However,the physiological and anatomical bases of maize yield improvement with plastic film mulching are not well understood.The effects of plastic film mulching and planting density on maize yield,photosynthetic characteristics,respiration,leaf anatomy,and root growth were studied in a two-year field experiment conducted on the Loess Plateau of China in 2017 and 2018.The experiment used a split-split plot design with two mulching treatments(plastic film mulching and no mulching),two planting densities(7.5×104 and10.5×104 plants ha-1),and two maize cultivars,Zhengdan 958 and Xianyu 335.Compared with no mulching,plastic film mulching increased maize yields by 31.1%–46.4%in 2017 and3.6%–34.7%in 2018.Compared with low planting density,high planting density significantly increased and slightly reduced yields of both cultivars in the dry year 2017 and the rainy year 2018,respectively.Plastic film mulching increased photosynthesis and respiration as well as leaf stomatal density and aperture.Photosynthetic rate,dark respiration,and stomatal conductance and aperture were lower at high planting than at low planting density.Maize yield was positively correlated with photosynthesis,dark respiration,and stomatal aperture.Mulching increased root dry weight and length in the 0–20 cm soil layer and root activity at maturity.Overall,the changes in root growth and leaf anatomy resulted in increased photosynthesis and dark respiration,and the increased photosynthesis contributed to the increase in grain yield and biomass production under plastic film mulching conditions.Our results increase understanding of the physiological mechanisms by which plastic film mulching increases maize yield in water-and temperature-limited areas. | Li Niu Yanyan Yan Peng Hou Wenbo Bai Rulang Zhao Yonghong Wang Shaokun Li Taisheng Du Ming Zhao Jiqing Song Wenbin Zhou | 2020 | The Crop Journal2020,8,4: | 6 |
| 17 | Elevated 8-oxo-7,8-dihydro-2'-deoxyguanosine in genome of T24 bladder cancer cells induced by halobenzoquinones显示文摘Halobenzoquinones(HBQs) are an emerging class of halogenated disinfection byproducts(DBPs) in drinking water, which raised public concerns due to potential carcinogenic effects to human bladder. Our previous work demonstrated that HBQs and hydrogen peroxide(H_2O_2)together generated oxidative DNA damage via a metal-independent and intercalationenhanced oxidation mechanism in vitro. This study further investigated the efficiency of various HBQs to induce oxidative DNA damage in T24 bladder cancer cells. Compared with T24 cells without treatment(3.1 lesions per 10~6 d G), the level of 8-oxo-7,8-dihydro-2′-deoxyguanosine(8-oxod G) significantly increased by 1.4, 3.2, 8.8, and 9.2 times after treatment with tetrabromo-1,4-benzoquinone(TBBQ), terachloro-1,4-benzoquinone(TCBQ),2,6-dichloro-1,4-benzoquinone(2,6-DCBQ) and 2,5-dichloro-1,4-benzoquinone(2,5-DCBQ) for24 hr, respectively. Interestingly, we found that the oxidative potency of HBQs in T24 cells(2,5-DCBQ ≈ 2,6-DCBQ > TCBQ > TBBQ) is inconsistent with that of in vitro ds DNA oxidation(TCBQ > TBBQ > 2,5-DCBQ > 2,6-DCBQ), suggesting HBQs induce oxidative lesions in cellular genomic DNA probably involved with a complex mechanism. | Tian Xu Junfa Yin Shaokun Chen Dapeng Zhang Hailin Wang | 2018 | Journal of Environmental Sciences2018,30,1: | 5 |
| 18 | Novel imaging methods of stepped frequency radar based on compressed sensing显示文摘The theory of compressed sensing (CS) provides a new chance to reduce the data acquisition time and improve the data usage factor of the stepped frequency radar system. In light of the sparsity of radar target reflectivity, two imaging methods based on CS, termed the CS-based 2D joint imaging algorithm and the CS-based 2D decoupled imaging algorithm, are proposed. These methods incorporate the coherent mixing operation into the sparse dictionary, and take random measurements in both range and azimuth directions to get high resolution radar images, thus can remarkably reduce the data rate and simplify the hardware design of the radar system while maintaining imaging quality. Experiments from both simulated data and measured data in the anechoic chamber show that the proposed imaging methods can get more focused images than the traditional fast Fourier transform method. Wherein the joint algorithm has stronger robustness and can provide clearer inverse synthetic aperture radar images, while the decoupled algorithm is computationally more efficient but has slightly degraded imaging quality, which can be improved by increasing measurements or using a robuster recovery algorithm nevertheless. | Jihong Liu Shaokun Xu Xunzhang Gao Xiang Li | 2012 | Journal of Systems Engineering and Electronics2012,23,1: | 4 |
| 19 | Using irrigation intervals to optimize water-use efficiency and maize yield in Xinjiang,northwest China显示文摘Worldwide, scarce water resources and substantial food demands require efficient water use and high yield.This study investigated whether irrigation frequency can be used to adjust soil moisture to increase grain yield and water use efficiency(WUE) of high-yield maize under conditions of mulching and drip irrigation.A field experiment was conducted using three irrigation intervals in 2016: 6, 9, and 12 days(labeled D6, D9, and D12) and five irrigation intervals in 2017: 3, 6, 9, 12, and 15 days(D3, D6, D9, D12, and D15).In Xinjiang, an optimal irrigation quota is 540 mm for high-yield maize.The D3, D6, D9, D12, and D15 irrigation intervals gave grain yields of 19.7, 19.1–21.0, 18.8–20.0, 18.2–19.2, and 17.2 Mg ha^-1 and a WUE of 2.48, 2.53–2.80, 2.47–2.63, 2.34–2.45, and 2.08 kg m-3, respectively.Treatment D6 led to the highest soil water storage, but evapotranspiration and soil-water evaporation were lower than other treatments.These results show that irrigation interval D6 can help maintain a favorable soil-moisture environment in the upper-60-cm soil layer, reduce soilwater evaporation and evapotranspiration, and produce the highest yield and WUE.In this arid region and in other regions with similar soil and climate conditions, a similar irrigation interval would thus be beneficial for adjusting soil moisture to increase maize yield and WUE under conditions of mulching and drip irrigation. | Guoqiang Zhang Dongping Shen Bo Ming Ruizhi Xie Xiuliang Jin Chaowei Liu Peng Hou Jun Xue Jianglu Chen Wanxu Zhang Wanmao Liu Keru Wang Shaokun Li | 2019 | The Crop Journal2019,7,3: | 4 |
| 20 | New discoveries from the classic Quaternary mammalian fossil area of Yanjinggou,Chongqing,and their chronological explanations显示文摘Yanjinggou in Wanzhou District of Chongqing is one of the earliest reported and most famous Quaternary mammalian fossil areas in China.The fauna from this area used to be taken as a benchmark for the biochronological comparison of Quaternary paleontology of South China,but the chronology of this fauna has many controversies for the lack of exact locational and stratigraphical records.The present article,on the basis of recent investigations and discoveries,discusses and explains the distribution and biochronology of the mammalian faunas in the Yanjinggou area.The newly discovered Dayakou fissure fauna,including Rhizomys troglodytes,Homotherium sp.,Panthera pardus,Stegodon orientalis,Dicerorhinus sumatrensis,Hesperotherium sinense,Sus sp.,Cervavitus fenqii,Cervus sp.and Muntiacus sp.,is correlated to the middle Early Pleistocene.The presence of Early Pleistocene mammalian fauna in the Yanjinggou area is therefore confirmed.The'Wanhsien fauna'or'Yenchingkou(=Yanjinggou)fauna'as a Mid-Late Pleistocene biostratigraphical datum should be abandoned.The Dayakou fauna and the Upper Cave fauna of Pingba,both in the Yanjinggou area,are correlated to the middle Early Pleistocene and the early Middle Pleistocene in age,respectively. | CHEN ShaoKun PANG LiBo HE CunDing WEI GuangBiao HUANG WanBo YUE ZongYing ZHANG XiaoHu ZHANG Hua QIN Li | 2013 | Chinese Science Bulletin2013,58,31: | 4 |