17 results on '"Ruibo Li"'
Search Results
2. Alkyl β-D-xyloside synthesis from black liquor xylan using Aureobasidium pullulans CBS 135684 β-xylosidases immobilized on spent expanded perlite
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Hunsa Punnapayak, Sehanat Prasongsuk, Dede Heri Yuli Yanto, Pongtharin Lotrakul, Takashi Watanabe, Ruibo Li, and Wichanee Bankeeree
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chemistry.chemical_classification ,Immobilized enzyme ,biology ,Renewable Energy, Sustainability and the Environment ,020209 energy ,02 engineering and technology ,010501 environmental sciences ,biology.organism_classification ,01 natural sciences ,Xylan ,Hydrolysate ,Xyloside ,Aureobasidium pullulans ,chemistry.chemical_compound ,Glucoside ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,Alkyl ,0105 earth and related environmental sciences ,Nuclear chemistry ,Hexanol - Abstract
The crude β-xylosidase from Aureobasidium pullulans CBS 135684 was immobilized on the surface of the modified spent expanded perlite via (3-aminopropyl) triethoxy-silane and glutaraldehyde cross-linking reaction. Over 80% of the initial free enzyme activity was detected on the bound enzyme. The immobilized β-xylosidase (204.7 ± 6.5 U g-1 of perlite) exhibited transxylosylation activity when sugars from black liquor xylan hydrolysate and a variety of alcohols (C1-6) were used as donor and acceptor molecules, respectively, yielding a number of alkyl xylosides. The synthesized hexyl xyloside exhibited some interesting properties comparable with those of a commercial hexyl glucoside, including an antioxidant activity (IC50 = 8.9 ± 2.0 mg mL-1), wetting time (43 s), and critical micelle concentration value (252 mmol L-1). Optimization for hexyl xyloside synthesis was performed via statistical analysis using a Box and Behnken design. The maximum predicted yield of hexyl xyloside (499.0 ± 1.1 mg g-1 xylan hydrolysate) was obtained with 10% (w/v) xylan hydrolysate, 10 U g-1 immobilized β-xylosidase, and 13% (v/v) hexanol at 70 °C, pH 6.0 for 4 h, and it was validated by the following experimental yield (498.9 ± 4.8 mg g-1 xylan hydrolysate). The maximum production yield remained relatively stable after the immobilized enzyme was reused for 12 cycles with a 471.5 ± 15.1 mg g-1 hexyl xyloside yield (94.4% of the first cycle). Thus, the immobilized β-xylosidase has a high potential as a robust catalyst for application in alkyl xyloside production.
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- 2020
3. An Operational Split-Window Algorithm for Retrieving Land Surface Temperature from Geostationary Satellite Data: A Case Study on Himawari-8 AHI Data
- Author
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Tian Hu, Hua Li, Yikun Yang, Qinhuo Liu, Ruibo Li, Yongming Du, Lin Sun, Biao Cao, and Zunjian Bian
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validation ,Daytime ,010504 meteorology & atmospheric sciences ,Land surface temperature ,Mean squared error ,MODTRAN ,0211 other engineering and technologies ,land surface temperature ,02 engineering and technology ,01 natural sciences ,Advanced Spaceborne Thermal Emission and Reflection Radiometer ,emissivity ,Geostationary orbit ,Emissivity ,Radiance ,General Earth and Planetary Sciences ,Environmental science ,lcsh:Q ,lcsh:Science ,Himawari-8 AHI ,Algorithm ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,operational split-window algorithm - Abstract
An operational split-window (SW) algorithm was developed to retrieve high-temporal-resolution land surface temperature (LST) from global geostationary (GEO) satellite data. First, the MODTRAN 5.2 and SeeBor V5.0 atmospheric profiles were used to establish a simulation database to derive the SW algorithm coefficients for GEO satellites. Then, the dynamic land surface emissivities (LSEs) in the two SW bands were estimated using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Emissivity Dataset (GED), fractional vegetation cover (FVC), and snow cover products. Here, the proposed SW algorithm was applied to Himawari-8 Advanced Himawari Imager (AHI) observations. LST estimates were retrieved in January, April, July, and October 2016, and three validation methods were used to evaluate the LST retrievals, including the temperature-based (T-based) method, radiance-based (R-based) method, and intercomparison method. The in situ night-time observations from two Heihe Watershed Allied Telemetry Experimental Research (HiWATER) sites and four Terrestrial Ecosystem Research Network (TERN) OzFlux sites were used in the T-based validation, where a mean bias of −0.70 K and a mean root-mean-square error (RMSE) of 2.29 K were achieved. In the R-based validation, the biases were 0.14 and −0.13 K and RMSEs were 0.83 and 0.86 K for the daytime and nighttime, respectively, over four forest sites, four desert sites, and two inland water sites. Additionally, the AHI LST estimates were compared with the Collection 6 MYD11_L2 and MYD21_L2 LST products over southeastern China and the Australian continent, and the results indicated that the AHI LST was more consistent with the MYD21 LST and was generally higher than the MYD11 LST. The pronounced discrepancy between the AHI and MYD11 LST could be mainly caused by the differences in the emissivities used. We conclude that the developed SW algorithm is of high accuracy and shows promise in producing LST data with global coverage using observations from a constellation of GEO satellites.
- Published
- 2020
- Full Text
- View/download PDF
4. Probing the trilinear Higgs boson self-coupling via single Higgs production at the LHeC
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Guohuai Zhu, Bo-Wen Wang, Xiao-Min Shen, Kai Wang, and Ruibo Li
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Physics ,Coupling ,Particle physics ,Luminosity (scattering theory) ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Electroweak interaction ,FOS: Physical sciences ,Computer Science::Digital Libraries ,01 natural sciences ,Vector boson ,Scattering amplitude ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,Higgs boson ,High Energy Physics::Experiment ,Symmetry breaking ,Limit (mathematics) ,010306 general physics - Abstract
The determination of the Higgs self coupling is one of the key ingredients for understanding the mechanism behind the electroweak symmetry breaking. An indirect method for constraining the Higgs trilinear self coupling via single Higgs production at next-to-leading order (NLO) has been proposed in order to avoid the drawbacks of studies with double Higgs production. In this paper we study the Higgs self interaction through the vector boson fusion (VBF) process $e^{-} p \to \nu_{e} h j$ at the future LHeC. At NLO level, we compute analytically the scattering amplitudes for relevant processes, in particular those induced by the Higgs self interaction. A Monte Carlo simulation and a statistical analysis utilizing the analytic results are then carried out for Higgs production through VBF and decay to $b\bar{b}$, which yield for the trilinear Higgs self-coupling rescaling parameter $\kappa_{\lambda}$ the limit [-0.57, 2.98] with $2~\text{ab}^{-1}$ integrated luminosity. If we assume about 10% of the signal survives the event selection cuts, and include all the background, the constraint will be broadened to [-2.11, 4.63]., Comment: 19 pages, 7 figures, 2 tables
- Published
- 2020
5. Retrieving Soil and Vegetation Temperatures From Dual-Angle and Multipixel Satellite Observations
- Author
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Frank-M. Göttsche, Biao Cao, Hua Li, Huazhong Ren, Qinhuo Liu, Yongming Du, Zunjian Bian, Qing Xiao, and Ruibo Li
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land surface temperature (LST) ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Geophysics. Cosmic physics ,soil and vegetation component temperatures ,0211 other engineering and technologies ,02 engineering and technology ,01 natural sciences ,multiangle and multipixel LST retrieval ,Evapotranspiration ,Nadir ,ddc:550 ,Sensitivity (control systems) ,Computers in Earth Sciences ,TC1501-1800 ,Image resolution ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Radiometer ,Pixel ,QC801-809 ,Vegetation ,Ocean engineering ,Earth sciences ,Environmental science ,Satellite ,Bayesian strategy ,sea and land surface temperature radiometer (SLSTR) data - Abstract
Land surface component temperatures (LSCTs), i.e., the temperatures of soil and vegetation, are important parameters in many applications, such as estimating evapotranspiration and monitoring droughts. However, the multiangle algorithm is affected due to different spatial resolution between nadir and oblique views. Therefore, we propose a combined retrieval algorithm that uses dual-angle and multipixel observations together. The sea and land surface temperature radiometer onboard ESA's Sentinel-3 satellite allows for quasi-synchronous dual-angle observations, from which LSCTs can be retrieved using dual-angle and multipixel algorithms. The better performance of the combined algorithm is demonstrated using a sensitivity analysis based on a synthetic dataset. The spatial errors in the oblique view due to different spatial resolution can reach 4.5 K and have a large effect on the multiangle algorithm. The introduction of multipixel information in a window can reduce the effect of such spatial errors, and the retrieval results of LSCTs can be further improved by using multiangle information for a pixel. In the validation, the proposed combined algorithm performed better, with LSCT root mean squared errors of 3.09 K and 1.91 K for soil and vegetation at a grass site, respectively, and corresponding values of 3.71 K and 3.42 K at a sparse forest site, respectively. Considering that the temperature differences between components can reach 20 K, the results confirm that, in addition to a pixel-average LST, the combined retrieval algorithm can provide information on LSCTs. This article demonstrates the potential of utilizing additional information sources for better LSCT results, which makes the presented combined strategy a promising option for deriving large-scale LSCT products.
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- 2020
- Full Text
- View/download PDF
6. Antiviral Activity of Phenolic Derivatives in Pyroligneous Acid from Hardwood, Softwood, and Bamboo
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Ryota Ouda, Ruibo Li, Takashi Watanabe, Shinsuke Marumoto, Mitsuyoshi Yatagai, Seiji P. Yamamoto, Hiroshi Nishimura, Ryo Narita, and Takashi Fujita
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Bamboo ,Catechol ,Softwood ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Pyroligneous acid ,Viral inhibition ,Hardwood ,Environmental Chemistry ,Organic chemistry ,Phenol ,0210 nano-technology ,Methyl group - Abstract
Pyroligneous acids (PA) from hardwood, softwood, and bamboo significantly disinfected encephalomyocarditis virus (EMCV). Twenty-five kinds of phenolic derivatives in the PAs were identified and quantified. The total amounts of phenolic compounds in bamboo PA is higher than those in the PAs from softwood and hardwood. Phenol, 2-methoxyphenol, 2-methoxy-4-methylphenol, and 2-methoxy-4-ethylphenol are the most abundant compounds in the PAs examined. The activities of all the phenolic compounds against the encephalomyocarditis virus were assessed. The number of phenolic hydroxyl groups significantly affects the antiviral activity, and catechol and its derivatives exhibit higher viral inhibition effects than other phenolic derivatives. In addition, substituents affect the antiviral activity of the compounds. Phenolic compounds with a methyl group show higher activities than with a methoxyl group (e.g., 2-methylphenol > 2-methoxyphenol). Moreover, the relative position of functional groups also plays a key role...
- Published
- 2017
7. Analysis of the Temporal and Spatial Variation of Aerosols in the Beijing-Tianjin-Hebei Region with a 1 km AOD Product
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Ruibo Li, Xinpeng Tian, Jing Wei, and Lin Sun
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Pollution ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,Beijing tianjin hebei ,010501 environmental sciences ,Particulates ,01 natural sciences ,Reflectivity ,Aerosol ,Climatology ,Environmental Chemistry ,Environmental science ,Spatial variability ,Retrieval algorithm ,0105 earth and related environmental sciences ,media_common - Abstract
The Beijing-Tianjin-Hebei region is one of the most polluted areas in China, especially in terms of particulate matter pollution. To describe the aerosol distribution of such an area, the aerosol optical depth (AOD) with a 1 km spatial resolution was retrieved from MODIS data based on a new high-resolution aerosol retrieval algorithm with a priori land surface reflectance (LSR) database support (HARLS). Continuous AOD data from 2013 and 2014 retrieved by this algorithm were used to analyze the spatial and temporal distribution of the AOD in the above area. The AOD in the Beijing-Tianjin-Hebei region has obvious regional and seasonal variations. The AOD in the south and east is higher than in the north and west, and the AOD in spring and summer is higher than that in winter and autumn.
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- 2017
8. Dynamic Monitoring of the Strong Sandstorm Migration in Northern and Northwestern China via Satellite Data
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Shangfeng Jia, Qinghua Su, Yikun Yang, Ruibo Li, Xueying Zhou, and Lin Sun
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010504 meteorology & atmospheric sciences ,0211 other engineering and technologies ,Storm ,02 engineering and technology ,Vegetation ,Spatial distribution ,01 natural sciences ,Pollution ,Dynamic monitoring ,Remote sensing (archaeology) ,Climatology ,Satellite data ,Environmental Chemistry ,Environmental science ,Moderate-resolution imaging spectroradiometer ,China ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
Sand and dust storms (hereafter, "sandstorms") not only damage the ecological environment in northern and northwestern China but also influence the economic and social development of the affected regions and constitute a threat to human health. This study focuses on monitoring sandstorms and analyzing the sandstorm migration process in northern and northwestern China. These sandstorms are characterized by their high frequency occurrences, strong dust intensity, long durations and highly destructive effects. The dry climate conditions and low degree of vegetation coverage in this region increase the difficulty of sandstorm monitoring. This paper proposes a remote sensing monitoring method for sandstorms in northern and northwestern China based on Moderate Resolution Imaging Spectroradiometer (MODIS) data and the radiation characteristics of the research region and of the sandstorms. A strong sandstorm that occurred on April 23–25, 2014, is analyzed to illustrate the proposed monitoring method. Information on the sandstorm is validated and analyzed through visual interpretation and comparison with Meteorological Information Comprehensive Analysis and Process System (MICAPS) ground measurements. The spatial distribution of the sandstorm is highly consistent with the true-color MODIS data. The comparison of the results of the remote sensing monitoring of the sandstorm with the MICAPS measurements yields a high coincidence rate of 96.3%. Additionally, the migration process of the sandstorm can be clearly recognized in 6 MODIS images captured during the 3-day sandstorm. Based on the above results, we conclude that the proposed method can be used for dynamic remote sensing monitoring of sandstorms in northern and northwestern China.
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- 2017
9. High Temporal Resolution Land Surface Temperature Retrieval from Global Geostationary Satellite Data
- Author
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Biao Cao, Yongming Du, Hua Li, Qinhuo Liu, Zunjian Bian, Lin Sun, and Ruibo Li
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010504 meteorology & atmospheric sciences ,Land surface temperature ,MODTRAN ,0211 other engineering and technologies ,02 engineering and technology ,01 natural sciences ,Cross-validation ,Term (time) ,Advanced Spaceborne Thermal Emission and Reflection Radiometer ,Geostationary orbit ,Emissivity ,Environmental science ,High temporal resolution ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing - Abstract
In this paper, in order to produce long term fully global land surface temperature (LST) product, the generalized split-window (GSW) algorithm and dual-window (DW) algorithm was used to retrieve LST from different geostationary (GEO) satellite data, including the FY-2E/4A, MTSAT-2/Himawari-8, MSG2, and GOES13/15. First, the coefficients of the GSW and DW algorithm were obtained from a simulation database constructed using the MODTRAN 5.2 and the SeeBor V5.0 atmospheric profile database. Second, the emissivity was estimated using the vegetation cover method, with the bare soil component emissivity derived from the ASTER global emissivity dataset (GED). Finally, the LST results of FY-4A AGRI and Himawari-8 AHI were retrieved and cross-validated. The results show that the LST algorithms developed in this work are capable of generating accurate high temporal resolution LST retrieval from global GEO satellite data.
- Published
- 2019
10. Evaluation of the Musyq Land Surface Temperature Product in an Arid Area of Northwest China
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Hua Li, Qinhuo Liu, Yongming Du, Ruibo Li, Biao Cao, and Zunjian Bian
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Daytime ,Watershed ,010504 meteorology & atmospheric sciences ,Land surface temperature ,Arid area ,Soil component ,0211 other engineering and technologies ,02 engineering and technology ,01 natural sciences ,Advanced Spaceborne Thermal Emission and Reflection Radiometer ,Product (mathematics) ,Emissivity ,Environmental science ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing - Abstract
In this study, we present an operational algorithm to retrieve the land surface temperature (LST) from MODIS thermal infrared data using physically retrieved emissivity product. This algorithm was implemented in the MUlti-source data SYnergized Quantitative (MuSyQ) remote sensing product system. First, the emissivity in the MODIS two split-window channels was estimated using the vegetation cover method, with the bare soil component emissivity derived from the ASTER global emissivity dataset. Then, the LST was retrieved using a modified generalized split-window algorithm. The MuSyQ MODIS LST product and the C6 MxD11 LST product were evaluated using ground measurements collected from four barren surface sites in Northwest China during the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) experiment. The evaluation results indicate that the MuSyQ LST products provide better accuracy than the C6 MxD11 product during both daytime and nighttime at all four sites. This study demonstrates that physically retrieved emissivity products are a useful source for LST retrieval over barren surfaces.
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- 2019
11. Photo-production of Higgs Boson at the LHeC
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Tao Xu, Bo-Wen Wang, Ruibo Li, Xiang Lv, and Kai Wang
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Nuclear and High Energy Physics ,Particle physics ,Photon ,FOS: Physical sciences ,Computer Science::Digital Libraries ,01 natural sciences ,law.invention ,Vector boson ,High Energy Physics - Phenomenology (hep-ph) ,law ,0103 physical sciences ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,Rapidity ,010306 general physics ,Collider ,Particle Physics - Phenomenology ,Boson ,Physics ,Neutral current ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Yukawa potential ,hep-ph ,High Energy Physics - Phenomenology ,Higgs boson ,lcsh:QC770-798 ,High Energy Physics::Experiment - Abstract
As one category of vector boson fusion, photo-production is one important production mechanism at $e$-$p$ colliders. A future $e$-$p$ collider -- Large Hadron-electron Collider (LHeC) has been discussed as a "Higgs factory" candidate where the Higgs boson produced via weak boson fusion (WBF) at the LHeC plays an important role in precision measurement of Yukawa couplings. On the other hand, a measurement of photo-production of the Higgs boson, if possible, might be complementary to the measurement of Higgs to di-photon partial decay width $\Gamma({h\to\gamma\gamma})$. In this paper, we study the possibility of measuring this production process at the LHeC with the help of the photon PDFs published in recent years. This process has a clean final state without additional colored particles in the detectable region other than the decay products of the Higgs. We compute the cross sections of all related processes and find that the production rate is at the same order as the neutral current WBF production of Higgs boson with missing forward jets. However, a detailed phenomenological study of various Higgs decay channels shows that even in the most promising semi-leptonic $WW$ channel, the feasibility of identifying such photo-production is negative due to an irreducible photo-production of $W^{+}W^{-}$., Comment: 19pages, 6figures
- Published
- 2019
12. Searching for the light Higgsinos in the MSSM at future e−p colliders
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Ren-Qi Pan, Chengcheng Han, Kai Wang, and Ruibo Li
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Physics ,Particle physics ,Large Hadron Collider ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Supersymmetry ,01 natural sciences ,Future Circular Collider ,law.invention ,law ,0103 physical sciences ,High Energy Physics::Experiment ,Production (computer science) ,Higgsino ,010306 general physics ,Collider ,Minimal Supersymmetric Standard Model ,Lepton - Abstract
The search for the light Higgsino in the minimal supersymmetric standard model is a crucial test of the naturalness criteria in supersymmetry. On the other hand, the direct production of light Higgsinos is also known as one of the most challenging supersymmetry searches at the LHC. The lack of visible leptons due to the compressed spectrum and their small production rates limit their discovery potential in both monojet plus ET events and weak boson fusion (WBF) production. The signal-to-background ratio prediction is usually within the background systematic uncertainties at the LHC. Without color exchange between the beams, e−p colliders are well known to exhibit WBF. Therefore, we search for light Higgsinos at two future e−p colliders at CERN: the Large Hadron electron Collider (LHeC) and the Future Circular Collider in hadron-electron mode (FCC-eh). The light Higgsinos will be produced in pairs through weak boson fusion with controlled background at these colliders. We find that a 95/145 GeV Higgsino can be reached at the 2σ level at the future LHeC/FCC-eh with a luminosity of 3 ab−1, respectively.
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- 2018
13. Structure-dependent antiviral activity of catechol derivatives in pyroligneous acid against the encephalomycarditis virus
- Author
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Chihiro Kimura, Ryo Narita, Ruibo Li, Hiroshi Nishimura, Takashi Fujita, Takashi Watanabe, Ryota Ouda, and Mitsuyoshi Yatagai
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chemistry.chemical_classification ,Reactive oxygen species ,Catechol ,Chemistry ,Stereochemistry ,General Chemical Engineering ,Substituent ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Virus ,0104 chemical sciences ,chemistry.chemical_compound ,Immune system ,Viral life cycle ,Pyroligneous acid ,0210 nano-technology ,IC50 - Abstract
The pyrolysis product, wood vinegar (WV), from Japanese larch exhibited strong antiviral activity against the encephalomycarditis virus (EMCV). Catechol, 3-methyl-, 4-methyl-, 4-ethyl-, and 3-methoxycatechol, and 2-methyl-1,4-benzenediol were identified as the major antiviral compounds. The viral inhibition ability of these compounds was affected by the structure and position of the substituent group attached to the aromatic skeleton. The IC50 of catechol was 0.67 mg mL−1 and those of its derivatives were
- Published
- 2018
14. Monocular Relative Depth Perception with Web Stereo Data Supervision
- Author
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Zhenbo Luo, Hao Lu, Yang Xiao, Ruibo Li, Ke Xian, Zhiguo Cao, and Chunhua Shen
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Monocular ,Computer science ,business.industry ,02 engineering and technology ,Image segmentation ,010501 environmental sciences ,01 natural sciences ,Set (abstract data type) ,Metric (mathematics) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Computer vision ,Segmentation ,Artificial intelligence ,Focus (optics) ,business ,0105 earth and related environmental sciences - Abstract
In this paper we study the problem of monocular relative depth perception in the wild. We introduce a simple yet effective method to automatically generate dense relative depth annotations from web stereo images, and propose a new dataset that consists of diverse images as well as corresponding dense relative depth maps. Further, an improved ranking loss is introduced to deal with imbalanced ordinal relations, enforcing the network to focus on a set of hard pairs. Experimental results demonstrate that our proposed approach not only achieves state-of-the-art accuracy of relative depth perception in the wild, but also benefits other dense per-pixel prediction tasks, e.g., metric depth estimation and semantic segmentation.
- Published
- 2018
15. Probing anomalous WWγ triple gauge bosons coupling at the LHeC
- Author
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Tao Xu, Guohuai Zhu, Xiao-Min Shen, Ruibo Li, Liangliang Zhang, and Kai Wang
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Physics ,Gauge boson ,Particle physics ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Hadron ,Parton ,Electron ,Lambda ,Computer Science::Digital Libraries ,01 natural sciences ,Vertex (geometry) ,Nuclear physics ,Distribution function ,0103 physical sciences ,010306 general physics ,Charged current - Abstract
The precision measurement of the WWγ vertex at the future Large Hadron electron Collider (LHeC) at CERN is discussed in this paper. We propose to measure this vertex in the e−p→e−W±j channel as a complement to the conventional charged current νeγj channel. In addition to the cross section measurement, χ2 method studies of angular variables provide powerful tools to probe the anomalous structure of triple gauge boson couplings. We study the distribution of the well-known azimuthal angle between the final state forward electron and jet in this vector-boson fusion process. On the other hand, full reconstruction of leptonic W decay opens a new opportunity to measure W polarization that is also sensitive to the anomalous triple gauge boson couplings. Taking into consideration the superior determination of parton distribution functions based on future LHeC data, the constraints of λγ and Δκγ might reach up to O(10−3) level in the most ideal case with the 2–3 ab−1 data set, which shows a potential advantage compared to those from LHC and Large Electron-Positron Collider (LEP) data.
- Published
- 2018
16. A high-resolution global dataset of aerosol optical depth over land from MODIS data
- Author
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Yikun Yang, Jing Wei, Lin Sun, Fangwei Liu, Chen Jia, Ruibo Li, Shangfeng Jia, Xueying Zhou, and Ping Gan
- Subjects
010504 meteorology & atmospheric sciences ,Resolution (electron density) ,Environmental science ,Atmospheric model ,010502 geochemistry & geophysics ,AOD measurements ,01 natural sciences ,Image resolution ,Reflectivity ,0105 earth and related environmental sciences ,Aerosol ,Remote sensing ,AERONET - Abstract
To improve the spatial resolution of the global aerosol optical depth (AOD) distribution, a new method for AOD retrieval is proposed over land in this paper. A monthly Global Land Surface Reflectance Database (GLSRD) was constructed using the long time serious of MODIS surface reflectance product (MOD09A1) and used for the surface reflectance estimation over land for AOD retrieval. A seasonal Global Land Aerosol Type Database (GLATD) was also built based on the MODIS aerosol product (MOD04) and used for providing the aerosol types over land in AOD retrieval. Thus, the AOD global dataset with 1 km resolution was produced and was validated against with the AERONET ground-based AOD measurements located in the global 172 stations over land. Results showed that the AOD retrievals are highly consistent with AERONET AODs and showed an overall better precision over both dark and bright areas.
- Published
- 2016
17. Dynamic threshold cloud detection algorithms for MODIS and Landsat 8 data
- Author
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Yikun Yang, Chen Jia, Ruibo Li, Ping Gan, Fangwei Liu, Xueying Zhou, Jing Wei, Lin Sun, and Shangfeng Jia
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Earth observation ,010504 meteorology & atmospheric sciences ,Pixel ,business.industry ,Cloud top ,media_common.quotation_subject ,Cloud fraction ,0211 other engineering and technologies ,Cloud computing ,02 engineering and technology ,Atmospheric model ,01 natural sciences ,Sky ,Environmental science ,A priori and a posteriori ,business ,Algorithm ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,media_common - Abstract
Cloud detection is a key processing step before extracting information of earth surface from the earth observation data. Lots of schemes have been developed for cloud detection, static threshold method is the main method that is widely used in cloud detection. However, for the huge difference between different land objects, it is much difficult to find a proper threshold to detect the cloudy pixel from clear sky, especially, when the land covered by the thin or broken cloud. Therefore, a dynamic threshold cloud detection algorithm was proposed in this paper to improve the cloud detection. A priori monthly surface reflectance database was constructed using MODIS surface reflectance products and used to estimate the surface reflectance for dynamic threshold determination. Dynamic thresholds were determined by the simulation relationships between the apparent reflectance and the surface reflectance under clear conditions with 6S model. MODIS and Landsat 8 OLI data were selected to perform the experiments. Results showed that this new algorithm demonstrated better detection results of different cloud types over different land types.
- Published
- 2016
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