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Normalization in Riemann Tensor Polynomial Ring

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Journal of Systems Science & Complexity 2018年第2期31卷 569-580页

作者： liu jiang Department of Systems Science University of Shanghai for Science and Technology Glorious Sun School of Business and Management Donghua University

It is one of the oldest research topics in computer algebra to determine the equivalence of Riemann tensor indexed polynomials. However, it remains to be a challenging problem since Grbner basis theory is not yet powerful enough to deal with ideals that cannot be finitely generated. This paper solves the problem by extending Grbner basis theory. First, the polynomials are described via an infinitely generated free commutative monoid ring. The authors then provide a decomposed form of the Grbner basis of the defining syzygy set in each restricted ring. The canonical form proves to be the normal form with respect to the Grbner basis in the fundamental restricted ring, which allows one to determine the equivalence of polynomials. Finally, in order to simplify the computation of canonical form, the authors find the minimal restricted ring.

关键词： Canonical form Einstein summation convention monoid ring nD symbolic computation,Riemann tensor.

X射线透视引导下不同方式建立兔椎间盘退变模型的结果对比

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中国组织工程研究 2025年第5期29卷 995-1002页

作者：丁至立黄杰蒋强李土胜刘江丁宇安徽医科大学海军临床学院北京市100048 安徽医科大学第五临床医学院安徽省合肥市230032 解放军总医院第六医学中心中医医学部骨伤科北京市100048

背景:国内外学者认为新西兰大白兔腰椎解剖形态与人类腰椎更为相似,是理想的模型动物。在X射线引导下采用不同方式建立兔椎间盘退变模型目前尚缺乏系统性比较。目的:基于X射线引导采用针刺法、终板注射法以及改良终板注射法建立兔腰椎... 详细信息

背景:国内外学者认为新西兰大白兔腰椎解剖形态与人类腰椎更为相似,是理想的模型动物。在X射线引导下采用不同方式建立兔椎间盘退变模型目前尚缺乏系统性比较。目的:基于X射线引导采用针刺法、终板注射法以及改良终板注射法建立兔腰椎间盘退变模型,比较3种方法造模的效果。方法:6月龄新西兰大白兔16只随机分为4组,分别为针刺组、终板注射组、改良终板注射组及空白对照组,针刺组对3个连续节段(L2/3、L3/4、L4/5)椎间盘进行针刺造模,终板注射组在3个连续节段终板单点注射50μL无水乙醇,改良终板注射组对3个连续节段椎间盘进行针刺并在相应节段终板4个方位点注射50μL无水乙醇,空白对照组不进行干预。术后2,4,8周进行X射线检查,测量椎间隙高度指数,然后取椎间盘组织进行解剖学观察、病理学检查。结果与结论:①解剖学观察显示,针刺组以纤维环破溃为主要表现,终板注射组主要以髓核退变为主要表现,改良终板注射组以全椎间盘结构紊乱为主要表现;②与空白对照组相比,针刺组术后2周椎间隙高度指数降低最明显,终板注射组术后2,4周椎间隙高度指数降低明显,改良终板注射组术后2,4,8周椎间隙高度指数均显著降低;③病理学检查显示,针刺组纤维环结构出现破损,内层纤维环向内凸入,终板注射组表现为终板裂隙、排列混乱及细胞核丢失,改良终板注射组表现为整体椎间盘结构紊乱,髓核失水皱缩,与破损的纤维环无明显边界。结果表明,针刺法、终板注射法及改良终板注射法均能建立兔椎间盘退变模型,改良终板注射法较单一方法可大幅加快并加重椎间盘退变,可有效缩短实验周期。

关键词：组织工程椎间盘退变纤维环穿刺法终板注射法 X射线新西兰大白兔

GNSS Fault Detection and Exclusion Based on Virtual Pseudorange-Based Consistency Check Method

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Chinese Journal of Electronics 2020年第1期29卷 41-48页

作者： liu jiang ZHAO Xiaolin School of Electronic and Information Engineering Beijing Jiaotong University Beijing Engineering Research Center of EMC and GNSS Technology for Rail Transportation

Although there have been many implementations of Global navigation satellite system(GNSS)in rail transport systems, the integrity assurance of GNSS positioning is still not highly concerned by the *** is a significant issue for specific safety-relevant GNSS railway applications, especially the railway signaling system which requires a critical safety level. Classical integrity monitoring solutions require an acceptable satellite visibility level to carry out Fault detection and exclusion(FDE), and this restriction leads to a degraded availability of FDE and final position computation. In order to break the limitation by satellite visibility, a consistency check method for FDE is proposed based on the virtual satellite pseudorange data, which is established based on the track database. Results from simulations show that the presented method can detect and exclude different types of faults effectively. Compared with classical residualbased GNSS integrity monitoring algorithm, the presented method achieves a higher FDE availability and makes better use of the satellite measurements even under the limited GNSS observing conditions.

关键词： Satellite navigation Integrity monitoring Fault detection Fault exclusion Railway train control

Isolation and characterization of ferrous-and sulfur-oxidizing bacteria from Tengchong solfataric region,China

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Journal of Environmental Sciences 2009年第9期21卷 1247-1252页

作者： jiang Chengying liu Ying liu Yanyang GUO Xu liu Shuang-jiang State Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of Sciences Beijing 100101 China. Biomaterial & Biocatalyst Group Temasek Life Sciences Laboratory National University of Singapore Singapore 117604 Singapore.

Microbial oxidation and reduction of iron and sulfur are important parts of biogeochemical cycles in acidic environments such as geothermal solfataric regions. Species of Acidithiobacillus and Leptospirillum are the common ferrous-iron and sulfur oxidizers from such environments. This study focused on the Tengchong sofataric region, located in Yunnan Province, Southwest China. Based on cultivation, 9 strains that grow on ferrous-iron and sulfuric compounds were obtained. Analysis of 16S rRNA genes of the 9 strains indicated that they were affiliated to AcidithiobaciUus, Alicyclobacillus, Sulfobacillus, Leptospirillum and Acidiphilium. Physiological and phylogenetic studies indicated that two strains （TC-34 and TC-71） might represent two novel members of Alicyclobacillus. Strain TC-34 and TC-71 showed 94.8%-97.1% 16S rRNA gene identities to other species of Alicyclobacillus. Different from the previously described Alicyclobacillus species, strains TC-34 and TC-71 were mesophilic and their cellular fatty acids do not contain w-cyclic fatty acids. Strain TC-71 was obligately dependent on ferrous-iron for growth. It was concluded that the ferrous-iron oxidizers were diversified and Alicyclobacillus species were proposed to take part in biochemical geocycling of iron in the Tengchong solfataric region.

关键词： ferrous-iron oxidation sulfur oxidation biogeochemical cycle Alicyclobacillus, solfataric region

Reconsideration on the role of the specific heat ratio in Arrhenius law applications

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Acta Mechanica Sinica 2008年第3期24卷 261-266页

作者： Yunfeng liu Zonglin jiang Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of SciencesBeijing 100080 China

Arrhenius law implicates that only those molecules which possess the internal energy greater than the activation energy Ea can react. However, the internal energy will not be proportional to the gas temperature if the specific heat ratio y and the gas constant R vary during chemical reaction processes. The varying y may affect significantly the chemical reaction rate calculated with the Arrhenius law under the constant γ assumption, which has been widely accepted in detonation and combustion simulations for many years. In this paper, the roles of variable γ and R in Arrhenius law applications are reconsidered, and their effects on the chemical reaction rate are demonstrated by simulating one- dimensional C-J and two-dimensional cellular detonations. A new overall one-step detonation model with variable γ and R is proposed to improve the Arrhenius law. Numerical experiments demonstrate that this improved Arrhenius law works well in predicting detonation phenomena with the numerical results being in good agreement with experimental data.

关键词： Arrhenius law Detonation Specific heat ratio

Quantum Chemistry Calculation of Quercetin-silver Complex

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Chinese Journal of Structural Chemistry 2005年第11期24卷 1340-1346页

作者： jiang liu-Yun liu Yu-Ming Analytical and Testing Center of Sichuan University Chengdu 610064 China

Three possible molecular structures of quercetin-silver complexes obtained from the reaction of quercetin and Ag^＋ in equivalent molar ratio were designed and optimized by using Gaussian 98 program at the B3LYP/LanL2DZ basis set. Through theoretical analysis, one of the three designed structures is discovered to have the most stable coordination position. Then its geometry structure, natural bond orbital analyses, vibrational frequency and biological activity were performed. The results show that it has good stability and relatively stronger antioxidative activity because it is favorably attacked by O2^-. Therefore theoretical foundation is provided for the development of new quercetin metal complexes with higher activity antioxidants.

关键词： quercetin,silver-complex quantum chemistry

Gut microbial interactions based on network construction and bacterial pairwise cultivation

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Science China(Life Sciences) 2024年第8期67卷 1751-1762页

作者： Min-Zhi jiang Chang liu Chang Xu He jiang Yulin Wang Shuang-jiang liu State Key Laboratory of Microbial Technology Shandong UniversityQingdao 266000China State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center(EMRC)Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Association networks are widely applied for the prediction of bacterial interactions in studies of human gut ***,the experimental validation of the predicted interactions is challenging due to the complexity of gut microbiomes and the limited number of cultivated *** this study,we addressed this challenge by integrating in vitro time series network(TSN)associations and cocultivation of TSN taxon *** samples were collected and used for cultivation and enrichment of gut microbiome on YCFA agar plates for 13 *** cells were harvested for DNA extraction and metagenomic sequencing.A total of 198 metagenome-assembled genomes(MAGs)were *** dynamics of bacteria growing on the YCFA agar were used to infer microbial association *** experimentally validate the interactions of taxon pairs in networks,we selected 24 and 19 bacterial strains from this study and from the previously established human gut microbial biobank,respectively,for pairwise *** co-culture experiments revealed that most of the interactions between taxa in networks were identified as neutralism(51.67%),followed by commensalism(21.67%),amensalism(18.33%),competition(5%)and exploitation(3.33%).Genome-centric analysis further revealed that the commensal gut bacteria(helpers and beneficiaries)might interact with each other via the exchanges of amino acids with high biosynthetic costs,short-chain fatty acids,and/or *** also validated 12 beneficiaries by adding 16 additives into the basic YCFA medium and found that the growth of 66.7%of these strains was significantly *** approach provides new insights into the gut microbiome complexity and microbial interactions in association *** work highlights that the positive relationships in gut microbial communities tend to be overestimated,and that amino acids,short-chain fatty acids,and vitamins are contributed to the positive relationships.

关键词： human gut microbiome gut microbial pairwise interaction co-culture association network microbial community

Robust fault detection for a class of nonlinear network control system with communication delay

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Journal of Systems Engineering and Electronics 2009年第5期20卷 1024-1030页

作者： Ai Qiangyu liu Chunsheng jiang Bin Coll. of Automation Engineering Nanjing Univ. of Aeronautics and Astronautics Nanjing 210016 P. R. China

To investigate a class of nonlinear network control system, a robust fault diagnosis method is presented based on the robust state observer. To access the objective that the designed robust filter is maximally tolerant to disturbances and sensitive to fault, the robustness and stability properties of the fault diagnosis scheme are established rigorously. Using the residual vector, a fault tolerant controller is established in order to guarantee the stability of the closed-loop system, and the controller law can be obtained by solving a set of linear matrix inequalities. Then, some relevant sufficient conditions for the existence of a solution are given by applying Lyapunov stability theory. Finally, a simulation example is performed to show the effectiveness of the proposed approach.

关键词： nonlinear network control systems robust fault detection observer linear matrix inequality.

Temperature action and effect of concrete-filled steel tubular bridges:A review

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第2期7卷 174-191页

作者： jiang liu Yongjian liu Chenyu Zhang Qiuhong Zhao Yi Lyu Lei jiang School of Highway Chang'an UniversityXi'an 710064China Department of Civil Engineering Tianjin UniversityTianjin 300072China Department of Civil Engineering Queen's UniversityKingstonON K7L 3N6Canada

Concrete-filled steel tube(CFST)has been widely applied in bridges due to its excellent structural and constructional *** CFST bridges,temperature action is not only an important but also a special load that must be considered in bridge design,construction and structural *** paper presents an overview on current researches of the temperature action and effect of CFST *** historical and spatial characteristics as well as corresponding influencing factors of temperature distributions are summarized,and classifications of temperature actions are also *** show that in-depth investigations of the contributions of temperature influencing factors can help to effectively reduce the adverse temperature effects on CFST bridges in the design *** to the lack of long-term measurements and insufficient use of historical meteorological data,research on the representative value along with correlation analysis of CFST temperature actions and meteorological parameters have to be further carried *** the meanwhile,a decomposition method of temperature distribution is proposed based on structural effects of CFST bridges in this *** decomposed temperature actions can be used for more accurate effect calculation than traditional temperature action classification method,especially for CFST truss *** last,specific temperature action patterns still need to be investigated in some of the special problems,such as longitudinal temperature differences along the CFST arch rib and thermal debonding in the CFST *** investigations are required on the accurate simulation of temperature distribution of CFST bridges considering the shading effects of components and terrain.

关键词： Bridge engineering CFST bridge Temperature action Temperature effect Thermal debonding