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High Voltage 2017年第1期2卷 25-31页

作者： Jun-Wei Zha Na Huang Kang-Qiang He Zhi-Min Dang Chang-Yong Shi robert kwokyiu li Department of Physics and Materials Science City University of Hong KongTat Chee AvenueKowloonHong KongPeople’s Republic of China Department of Polymer Science and Engineering School of Chemistry and Biological EngineeringUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China State Key Laboratory of Electrical System Department of Electrical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Department of Elements Beijing Institute of Fashion TechnologyBeijing 100029People’s Republic of China

Solid polymer electrolytes(SPEs)have great potential to address the safety issues of lithium(li)-ion batteries when compared with conventional liquid electrolytes,which makes them a promising alternative for next-generation high-energy *** this work,poly(ethylene oxide)-lithium perchlorate(PEO–liClO4)polymer electrolytes for li-ion batteries were prepared using *** crystallinity,ionic conductivity as well as mechanical properties were *** conductivities and mechanical properties of PEO–liClO4 based SPE have been obviously increased by incorporating modified TiO2 nanofibres(TNFs)than TiO2 nanoparticles(TNPs),due to that both TNFs and TNPs can decrease the crystalline phase concentration of PEO and increase segmental flexibility of *** SPE with 3 wt%TNFs exhibits the highest conductivity of 5.308×10−5 S cm−1 at 20°C and higher tensile strength of 13.8 *** results highlight the potential of utilising the electrospinning method to improve the ionic conductivity of SPEs.

关键词： conductivity ionic polymer

Towards geospatial semantic search:exploiting latent semantic relations in geospatial data

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International Journal of Digital Earth 2014年第1期7卷 17-37页

作者： Wenwen li Michael FGoodchild robert Raskin GeoDa Center for Geospatial Analysis and Computation School of Geographical Science and Urban PlanningArizona State UniversityTempeAZUSA Center for Spatial Studies(Spatial@UCSB) University of CaliforniaSanta BarbaraCAUSA NASA Jet Propulsion Laboratory PasadenaCAUSA

This paper reports our efforts to address the grand challenge of the Digital Earth vision in terms of intelligent data discovery from vast quantities of geo-referenced *** propose an algorithm combining LSA and a Two-Tier Ranking(LSATTR)algorithm based on revised cosine similarity to build a more efficient search engine-Semantic Indexing and Ranking(SIR)-for a semantic-enabled,more effective data *** addition to its ability to handle subject-based search,we propose a mechanism to combine geospatial taxonomy and Yahoo!GeoPlanet for automatic identification of location information from a spatial query and automatic filtering of datasets that are not spatially *** metadata set,in the format of ISO19115,from NASA's SEDAC(Socio-Economic Data Application Center)is used as the corpus of *** show that our semantic search engine SIR built on LSATTR methods outperforms existing keyword-matching techniques,such as Lucene,in terms of both recall and ***,the semantic associations among all existing words in the corpus are *** associations provide substantial support for automating the population of spatial *** expect this work to support the operationalization of the Digital Earth vision by advancing the semantic-based geospatial data discovery.

关键词： ontology geospatial semantics search engine Digital Earth similarity search effectiveness

Characteristics of Water Infiltration in Layered Water-Repellent Soils

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Pedosphere 2018年第5期28卷 775-792页

作者： li Yi REN Xin robert HILL robert MALONE ZHAO Ying College of Water Resources and Architecture Engineering Northwest A&F University Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F University Department of Environmental Science and Technology University of Maryland USDA-ARS National Laboratory for Agriculture and the Environment Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of AgricultureNorthwest A&F University

Water-repellent(WR) soil greatly influences infiltration behavior. This research determined the impacts of WR levels of silt loam soil layer during infiltration. Three column scenarios were utilized, including homogeneous wettable silt loam or sand, silt loam over sand(silt loam/sand), and sand over silt loam(sand/silt loam). A 5-cm thick silt loam soil layer was placed either at the soil surface or 5 cm below the soil surface. The silt loam soil used had been treated to produce different WR levels, wettable, slightly WR, strongly WR, and severely WR. As the WR level increased from wettable to severely WR, the cumulative infiltration decreased. Traditional wetting front-related equations did not adequately describe the infiltration rate and time relationships for layered WR soils. The Kostiakov equation provided a good fit for the first infiltration stage. Average infiltration rates for wettable, slightly WR, strongly WR, and severely WR during the 2 nd infiltration stage were 0.126, 0.021, 0.002, and 0.001 mm min^(-1) for the silt loam/sand scenario,respectively, and 0.112, 0.003, 0.002, and 0.000 5 mm min^(-1) for the sand/silt loam scenario, respectively. Pseudo-saturation phenomena occurred when visually examining the wetting fronts and from the apparent changes in water content(?θ_(AP)) at the slightly WR,strongly WR, and severely WR levels for the silt loam/sand scenario. Much larger ?θAPvalues indicated the possible existence of finger flow. Delayed water penetration into the surface soil for the strongly WR level in the silt loam/sand scenario suggested negative water heads with infiltration times longer than 10 min. The silt loam/sand soil layers produced sharp transition zones of water content. The WR level of the silt loam soil layer had greater effects on infiltration than the layer position in the column.

关键词： infiltration model layered soils ponded infiltration experiment pseudo-saturation soil water content soil water move-ment soil water repellency water drop penetration time

Accurate Identification of Mass Peaks for Tandem Mass Spectra Using MCMC Model

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Tsinghua Science and Technology 2015年第5期20卷 453-459页

作者： Hui li Chunmei liu Mugizi robert Rwebangira Legand Burge the Department of Computer Science Howard University

In proteomics, many methods for the identification of proteins have been developed. However, because of limited known genome sequences, noisy data, incomplete ion sequences, and the accuracy of protein identification,it is challenging to identify peptides using tandem mass spectral data. Noise filtering and removing thus play a key role in accurate peptide identification from tandem mass spectra. In this paper, we employ a Bayesian model to identify proteins based on the prior information of bond cleavages. A Markov Chain Monte Carlo（MCMC）algorithm is used to simulate candidate peptides from the posterior distribution and to estimate the parameters for the Bayesian model. Our simulation and computational experimental results show that the model can identify peptide with a higher accuracy.

关键词： mass spectrometry Fourier transform noise filtering Markov Chain Monte Carlo(MCMC)

Research on encoding and decoding of non-binary polar codes over GF(2m)

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Digital Communications and Networks 2022年第3期8卷 359-372页

作者： Shufeng li Mingyu Cai robert Edwards Yao Sun libiao Jin The State Key Laboratory of Media Convergence and Communication School of Information and EngineeringCommunication University of ChinaBeijing100024China The Wolfson School of Mechanical Electrical and Manufacturing Engineering Loughborough UniversityLeicestershireLE113TEUK James Watt School of Engineering University of GlasgowG128QQScotlandUK

Binary Polar Codes (BPCs) have advantages of high-efficiency and capacity-achieving but suffer from large latency due to the Successive-Cancellation list (SCL) decoding. Non-Binary Polar Codes (NBPCs) have been investigated to obtain the performance gains and reduce latency under the implementation of parallel architectures for multi-bit decoding. However, most of the existing works only focus on the Reed-Solomon matrix-based NBPCs and the probability domain-based non-binary polar decoding, which lack flexible structure and have a large computation amount in the decoding process, while little attention has been paid to general non-binary kernel-based NBPCs and Log-likelihood Ratio (LLR) based decoding methods. In this paper, we consider a scheme of NBPCs with a general structure over GF(2m). Specifically, we pursue a detailed Monte-Carlo simulation implementation to determine the construction for proposed NBPCs. For non-binary polar decoding, an SCL decoding based on LLRs is proposed for NBPCs, which can be implemented with non-binary kernels of arbitrary size. Moreover, we propose a Perfect Polarization-Based SCL (PPB-SCL) algorithm based on LLRs to reduce decoding complexity by deriving a new update function of path metric for NBPCs and eliminating the path splitting process at perfect polarized (i.e., highly reliable) positions. Simulation results show that the bit error rate of the proposed NBPCs significantly outperforms that of BPCs. In addition, the proposed PPB-SCL decoding obtains about a 40% complexity reduction of SCL decoding for NBPCs.

关键词： Non-binary polar code Log-likelihood ratio Successive-cancellation list Perfect polarization based-SCL Decoding complexity

Highly enantioselective construction of CF_(3) -bearing all-carbon quaternary stereocenters: Chiral spiro-fused bisoxazoline ligands with 1,1'-binaphthyl sidearm for asymmetric Michael-type Friedel-Crafts reaction

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Chinese Chemical Letters 2022年第5期33卷 2415-2419页

作者： robert li-Yuan Bao Lei Shi Kang Fu School of Science Harbin Institute of TechnologyShenzhen 518055China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was *** developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields(up to 99%) and good to excellent enantioselectivies(up to> 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF_(3)-β-disubstituted nitroalkene was favorable.

关键词： Chiral bisoxazoline ligand Chiral pocket Chiral spiro ligand Friedel-Crafts reaction Trifluoromethylated all-carbon quaternary stereocenter

Surgical outcome of carcinosarcoma of the gall bladder:A review

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World Journal of Gastroenterology 2009年第39期15卷 4877-4882页

作者： Takehiro Okabayashi Zhao-li Sun robert A Montgomery Kazuhiro Hanazaki Department of Surgery Kochi Medical School Kohasu-Okocho Nankoku- City Kochi 783-8505 Japan Department of Surgery Johns Hopkins University School of Medicine 720 Rutland Ave. Ross 771 Baltimore MD 21205 Japan

Carcinosarcoma,which comprises less than one percent of all gall bladder neoplasms,is characterized by the presence of variable proportions of carcinomatous and sarcomatous ***,several reports have described patients suffering from carcinosarcoma of the gall ***,there are no large studies regarding the clinicopathologic features,therapeutic management,and surgical outcome of this disease because the number of patients who undergo resection of gall bladder carcinosarcoma at a single institution is limited.A Medline search was performed using the keywords 'gall bladder' and 'carcinosarcoma'.Additional articles were obtained from references within the papers identified by the Medline *** adjuvant chemotherapy and/or radiotherapy protocols for carcinosarcoma of the gall bladder have not been *** surgical resection offers the only chance for long-term survival from this *** outcome of 36 patients who underwent surgical resection for carcinosarcoma of the gall bladder was poor;the 3-year overall survival rate was only 31.0% and the median survival time was 7.0 *** the postoperative prognosis of carcinosarcoma of the gall bladder is worse than that of adenocarcinoma,new adjuvant chemotherapies and/or radiation techniques are essential for improvement of surgical outcome.

关键词： Gall bladder Carcinosarcoma Spindle cell carcinoma Surgery Outcome

Mono-isotope Prediction for Mass Spectra Using Bayes Network

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Tsinghua Science and Technology 2014年第6期19卷 617-623页

作者： Hui li Chunmei liu Mugizi robert Rwebangira Legand Burge Department of Systems and Compute Science Howard University Washington DC 20059 USA

Mass spectrometry is one of the widely utilized important methods to study protein functions and components. The challenge of mono-isotope pattern recognition from large scale protein mass spectral data needs computational algorithms and tools to speed up the analysis and improve the analytic results. We utilized na¨？ve Bayes network as the classifier with the assumption that the selected features are independent to predict monoisotope pattern from mass spectrometry. Mono-isotopes detected from validated theoretical spectra were used as prior information in the Bayes method. Three main features extracted from the dataset were employed as independent variables in our model. The application of the proposed algorithm to public Mo dataset demonstrates that our na¨？ve Bayes classifier is advantageous over existing methods in both accuracy and sensitivity.

关键词： Bayes network tandem mass spectrum mono-isotope prediction

Mesenchymal stem cells and immune disorders: from basic science to clinical transition

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Frontiers of Medicine 2019年第2期13卷 138-151页

作者： Shihua Wang Rongjia Zhu Hongling li Jing li Qin Han robert Chunhua Zhao Institute of Basic Medical Sciences Chinese Academy of Medical SciencesSchool of Basic MedicinePeking Union Medical CollegePeking Union Medical College HospitalCenter of Excellence in Tissue EngineeringChinese Academy of Medical SciencesBeijing 100005China

As a promising candidate seed cell type in regenerative medicine, mesenchymal stem cells (MSCs) have attracted considerable attention. The unique capacity of MSCs to exert a regulatory effect on immunity in an autologous/allergenic manner makes them an attractive therapeutic cell type for immune disorders. In this review, we discussed the current knowledge of and advances in MSCs, including its basic biological properties, i.e., multilineage differentiation, secretome, and immunomodulation. Specifically, on the basis of our previous work, we proposed three new concepts of MSCs, i.e.,“subtotipotent stem cell” hypothesis, MSC system, and “Yin and Yang” balance of MSC regulation, which may bring new insights into our understanding of MSCs. Furthermore, we analyzed data from the Clinical Trials database (http://***) on registered clinical trials using MSCs to treat a variety of immune diseases, such as graft-versus-host disease, systemic lupus erythematosus, and multiple sclerosis. In addition, we highlighted MSC clinical trials in China and discussed the challenges and future directions in the field of MSC clinical application.

关键词： mesenchymal stem cell clinical transition immune disorders

Cleavage of the Carboxyl-Terminus of LEACS2, a Tomato 1-Aminocyclopropane-l-Carboxylic Acid Synthase Isomer, by a 64-kDa Tomato Metalloprotease Produces a Truncated but Active Enzyme

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Journal of Integrative Plant Biology 2005年第11期47卷 1352-1363页

作者： Jian-Feng li robert QI liang-Hu QU Autar K Mattoo Ning li Department of Biology The Hong Kong University of Science and Technology Hong Kong SAR China Key Laboratory of Gene Engineering of the Ministry of Education Zhongshan University Guangzhou 510275 China Department of Biochemistry The Hong Kong University of Science and Technology Hong Kong SAR China Sustainable Agricultural Systems Laboratory United States Department of Agriculture-Agriculture Research Service Beltsville Maryland 20705-2350 USA

1-Aminocyclopropane-1-carboxylic acid （ACC） synthase （ACS） is the principal enzyme in phytohormone ethylene biosynthesis. Previous studies have shown that the hypervariable C-terminus of ACS is proteolytically processed in vivo. However, the protease responsible for this has not yet been identified. In the present study, we investigated the processing of the 55-kDa full-length tomato ACS （LeACS2） into 52-, 50- and 49-kDa truncated isoforms in ripening tomato （Lycopersicon esculentum Mill. cv. Cooperation 903） fruit using the sodium dodecyl sulfate-boiling method. Meanwhile, an LeACS2-processing protease was purified via multi-step column chromatography from tomato fruit. Subsequent biochemical analysis of the 64-kDa purified protease revealed that it is a metalloprotease active at multiple cleavage sites within the hypervariable C-terminus of LeACS2. N-terminal sequencing and matrix-assisted laser desorption/ionization time-of-flight analysis indicated that the LeACS2-processing metalloprotease cleaves at the C-terminal sites Lys^438, Glu^447, Lys^448, Asn^456, Ser^460, Ser^462, Lys^463, and Leu^474, but does not cleave the N- terminus of LeACS2. Four C-terminus-deleted （26-50 amino acids） LeACS2 fusion proteins were overproduced and subjected to proteolysis by this metalloprotease to identify the multiple cleavage sites located on the N-terminal side of the phosphorylation site Ser^460. The results indisputably confirmed the presence of cleavage sites within the region between the α-helix domain （H14） and Ser^460 for this metalloprotease. Furthermore, the resulting C-terminally truncated LeACS2 isoforms were active enzymatically. Because this protease could produce LeACS2 isoforms in vitro similar to those detected in vivo, it is proposed that this metalloprotease may be involved in the proteolysis of LeACS2 in vivo.

关键词： 1-aminocyclopropane-1-carboxylic acid synthase cleavage sites metalloprotease proteolytic processing.