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Evasion guidance algorithms for air-breathing hypersonic vehicles in three-player pursuit-evasion games

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Chinese Journal of Aeronautics 2020年第12期33卷 3423-3436页

作者： tian YAN Yuanli cai Bin XU School of Electronic and Information Engineering Xi'an Jiaotong UniversityXi'an 710049China School of Automation Northwestern Polytechnical UniversityXi'an 710072China

In practical combat scenario,the cooperative intercept strategies are often carefully designed,and it is challenging for the hypersonic vehicles to achieve successful *** on the analysis,it can be found that if several Successive Pursuers come from the Same Direction(SPSD)and flight with a proper spacing,the evasion difficulty may increase *** address this problem,we focus on the evasion guidance strategy design for the Air-breathing Hypersonic Vehicles(AHVs)under the SPSD combat *** order to avoid the induced influence on the scramjet,altitude and speed of the vehicle,the lateral maneuver and evasion are *** guarantee the remnant maneuver ability,the concept of specified miss distance is introduced and utilized to generate the guidance command for the *** the framework of constrained optimal control,the analytical expression of the evasion command is derived,and the constraints of the overload can be ensured to be never *** fact,by analyzing the spacing of the pursers,it can be classified whether the cooperative pursuit is *** the coordination-unformed multiple pursers,the evasion can be achieved lightly by the proposed *** the coordination is formed,the proposed method will generate a large reverse direction maneuver,and the successful evasion can be maintained as a *** performance of the proposed algorithms is tested in numerical simulations.

关键词： Differential game theory Game theory Hypersonic vehicles Optimal control Pursuit-evasion strategy

PICRUSt2 functionally predicts organic compounds degradation and sulfate reduction pathways in an acidogenic bioreactor

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Frontiers of Environmental Science & Engineering 2022年第4期16卷 81-93页

作者： Jun Li Aimin Li Yan Li Minhui cai Gan Luo Yaping Wu Yechao tian Liqun xing Quanxing Zhang State Key Laboratory of Pollution Control and Resources Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing 210094China

For comprehensive insights into the influences of sulfate on performance,microbial community and metabolic pathways in the acidification phase of a two-phase anaerobic system,a laboratory-scale acidogenic bioreactor was continuously operated to treat wastewater with elevated sulfate concentrations from 2000 to 14000 mg/*** results showed that the acidogenic bioreactor could achieve sulfate reduction efficiency of greater than 70%for influent sulfate content less than 12000 mg/*** sulfate induced the accumulation of volatile fatty acids(VPAs),especially propionate and butyrate,which was the primary negative effects to system performance under the high-sulfate ***-throughput sequencing coupled with PICRUSt2 uncovered that the accumulation of VFAs was triggered by the decreasing of genes encoding short-chain acyl-CoA dehydrogenase(EC:1.***.8.1),regulating the transformation of propanoyl-CoA to propenoyl-CoA and butanoyl-CoA to crotonyl-CoA of propionate and butyrate oxidation pathways,which made these two process hardly ***,genes encoding(EC:1.***.8.1)were mainly carried by order *** was the most abundant sulfate-reducing bacteria and identified as the primary host of dissimilatory sulfate reduction ftinctional *** analysis indicated the dissimilatory sulfate reduction process predominated under a low sulfate environment,but was not favored under the circumstance of *** the increase of sulfate,the assimilatory sulfate reduction process finally overwhelmed dissimilatory as the dominant sulfate reduction pathway in acidogenic bioreactor.

关键词： Acidogenic phase reactor High-sulfate wastewater Sulfate reduction Acidogenic fermentation PICRUSt2

Pulp health and calcific healing of a complicated crown–root fracture with additional root fracture in a maxillary incisor: A case report

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World Journal of Clinical Cases 2025年第3期13卷 42-49页

作者： Na Li Yue-Yue Ren Ying Tang Qi Yang tian-tian Meng Song Li Jing Zhang Stomatological Hospital and College Anhui Medical UniversityHefei 230032Anhui ProvinceChina Department of Endodontics The Affiliated Stomatological Hospital of Xuzhou Medical UniversityXuzhou 221000Jiangsu ProvinceChina

BACKGROUND Complicated crown–root fracture (CRF) involves severe injury to the crown, root,and pulp, and may be accompanied by multiple root fractures. The loss of a toothhas lifelong consequences for children and teenagers, but the maintenance of pulphealth and the calcific healing of multiple root fractures are rarely reported in *** SUMMARY This case reports healing of a permanent tooth with complicated crown–root andadditional root fractures, in which pulp health was maintained. A 10-year-old girlfell and fractured the root of her maxillary left central incisor at the cervical *** the coronal fragment was repositioned, the tooth was splinted until thetooth was no longer mobile, 2 years later. Eight years after treatment, the toothhas remained asymptomatic with vital pulp and localized gingival ***-beam computed tomography revealed not only calcified healing of the CRFbut also spontaneous healing in an additional undiagnosed root fracture. Thefracture line on the enamel could not be healed by hard tissue and formed agroove in the cervical crown. It was speculated that the groove was related to thelocalized gingival *** This case provides a clinical perspective of the treatment of a tooth with acomplicated CRF and an additional root fracture.

关键词： Complicated crown-root fracture Multiple root fracture Spontaneous healing Cone-beam computed tomography Long-term follow-up Case report

Cloud detection from visual band of satellite image based on variance of fractal dimension

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Journal of Systems Engineering and Electronics 2019年第3期30卷 485-491页

作者： tian Pingfang GUANG Qiang LIU xing School of Computer Science and Technology Wuhan University of Science and Technology Wuhan 430065 China Key Laboratory of Intelligent Information Processing and Real-Time Industrial System in Hubei Province Wuhan 430065 China Institute of Big Data Science and Engineering Wuhan University of Science and Technology Wuhan 430065 China Key Laboratory of Rich-Media Knowledge Organization and Service of Digital Publishing Content National Press and Publication Administration Beijing 100038 China

Cover ratio of cloud is a very important factor which affects the quality of a satellite image, therefore cloud detection from satellite images is a necessary step in assessing the image quality. The study on cloud detection from the visual band of a satellite image is developed. Firstly, we consider the differences between the cloud and ground including high grey level, good continuity of grey level, area of cloud region, and the variance of local fractal dimension (VLFD) of the cloud region. A single cloud region detection method is proposed. Secondly, by introducing a reference satellite image and by comparing the variance in the dimensions corresponding to the reference and the tested images, a method that detects multiple cloud regions and determines whether or not the cloud exists in an image is described. By using several Ikonos images, the performance of the proposed method is demonstrated.

关键词： cloud detection visual image satellite image variance of local fractal dimension (VLFD)

Bionic Flexible Texture Design Based on Bio-Fouling Suppression Effect for Protection of Marine Structures

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China Ocean Engineering 2023年第5期37卷 842-848页

作者： YI Peng WU Yu-peng cai Bao-ping tian xing-hui Javad MOSTAGHIMI YANG Xiao-shuang LYU Ming-li College of Mechanical and Electrical Engineering China University of PetroleumQingdao 266580China Department of Mechanical and Industrial Engineering University of TorontoToronto ONM5S3G8Canada Qingdao Yongzhao New Material Science&Technology Co.Ltd. Qingdao 266061China

Marine equipments such as marine risers and oil pipelines operate in complex underwater environments and are usually attached by animals,plants and *** attachment of marine fouling organisms will accelerate the corrosion damage of offshore structure and greatly reduce the service *** have shown that non-smooth bionic surfaces with specific microstructures can inhibit fouling *** on the idea of bionics,this paper proposes a new type of underwater flexible fretting texture,which is a composite material prepared by mixing graphene and silicone rubber,and modified by pulsed laser to construct a hexagonal bionic surface *** the impact of specific water flow,the flexible texture can produce an angular displacement around 8°and a linear displacement in the amplitude range of 165μm,and the inhibition rate of fouling biological diatoms up to 97.5%,which can effectively avoid the occurrence of marine biological *** results provide a new idea for the surface protection of marine structures,which is of great significance for the development of marine industry.

关键词： flexible microstructure marine antifouling algae attachment laser-induced texture

Hybrid uncertainty-based design optimization and its application to hybrid rocket motors for manned lunar landing

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Chinese Journal of Aeronautics 2017年第2期30卷 719-725页

作者： Zhu Hao tian Hui cai Guobiao School of Aeronautics Science and Engineering Beihang University Beijing 100083 China

Design reliability and robustness are getting increasingly important for the general design of aerospace systems with many inherently uncertain design *** paper presents a hybrid uncertainty-based design optimization（UDO） method developed from probability theory and interval *** of the uncertain design parameters which have sufficient information or experimental data are classified as random variables using probability theory,while the others are defined as interval variables with interval *** a hybrid uncertainty analysis method based on Monte Carlo simulation and Taylor series interval analysis is developed to obtain the uncertainty propagation from the design parameters to system *** design optimization strategies,including deterministic design optimization（DDO）,probabilistic UDO and hybrid UDO,are applied to the conceptual design of a hybrid rocket motor（HRM） used as the ascent propulsion system in Apollo lunar *** comparison,the hybrid UDO is a feasible method and can be effectively applied to the general design of aerospace systems.

关键词： Hybrid rocket motor Hybrid uncertainty-based design optimization Manned lunar landing Uncertainty analysis

Puerarin, an isoflavone compound extracted from Gegen (Radix Puerariae Lobatae), modulates sclera remodeling caused by extremely low frequency electromagnetic fields

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Journal of Traditional Chinese Medicine 2016年第5期36卷 678-682页

作者： tian tian cai Xiaojing Zhu Huang Department of Ophthalmology Xinhua Hospital Shanghai Jiao Tong University School of Medicine

OBJECTIVE: To evaluate the protective effect of puerarin [an isoflavone compound extracted from Gegen(Radix Puerariae Lobatae)] in scleral remodeling induced by extremely low frequency electromagnetic fields(ELF-EMFs).METHODS: Human fetal scleral fibroblasts(HFSFs)were divided into 5 groups:(a) untreated controls;(b) cells treated with ELF-EMFs;(c) cells treated with ELF-EMFs and puerarin 0.1 μM;(d) cells treated with ELF-EMFs and puerarin 1 μM;(e) cells treated with ELF-EMFs and puerarin 10 μM. Cell proliferation activity was measured by the cell-counting kit-8 assay. Matrix metalloproteinase-2(MMP-2) activity was measured by gelatin ***-2 and collagenⅠ(COL1A1) m RNA, protein expression were measured by Real-Time polymerase chain reaction, Western blot analysis, ***: Puerarin reduced the inhibition in cell proliferation, MMP-2 activity, m RNA, protein expression of HFSFs exposed to ELF-EMFs and enhanced the COL1A1 m RNA and protein ***: Puerarin was found to participate in the matrix remodeling process. It might be a potential agent for the treatment of extracellular matrix degradation of sclera associated with ocular conditions.

关键词： Puerarin Pueraria lobata Sclera Fibroblast Matrix metalloproteinase 2 Collagen type Ⅰ Electromagnetic fields

Carbon Sequestration in Two Alpine Soils on the Tibetan Plateau

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Journal of Integrative Plant Biology 2009年第9期51卷 900-905页

作者： Yu-Qiang tian xing-Liang Xu Ming-Hua Song cai-Ping Zhou Qiong Gao Hua Ouyang College of Resources Science & Technology State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing 100875 China Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources Research the Chinese Academy of Sciences Beijing 100101 China

Soil carbon sequestration was estimated in a conifer forest and an alpine meadow on the Tibetan Plateau using a carbon- 14 radioactive label provided by thermonuclear weapon tests （known as bomb-^14C）. Soil organic matter was physically separated into light and heavy fractions. The concentration spike of bomb-^14C occurred at a soil depth of 4 cm in both the forest soil and the alpine meadow soil. Based on the depth of the bomb-^14C spike, the carbon sequestration rate was determined to be 38.5 g C/m^2 per year for the forest soil and 27.1 g C/m^2 per year for the alpine meadow soil. Considering that more than 60% of soil organic carbon （SOC） is stored in the heavy fraction and the large area of alpine forests and meadows on the Tibetan Plateau, these alpine ecosystems might partially contribute to ＂the missing carbon sink＂.

关键词： alpine soils bomb carbon carbon sequestration soil organic carbon.

Investigating the mechanisms of glyphosate resistance in goosegrass(Eleusine indica) population from South China

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Journal of Integrative Agriculture 2015年第5期14卷 909-918页

作者： ZHANG Chun FENG Li HE Ting-ting YANG cai-hong CHEN Guo-qi tian xing-shan Guangdong Provincial Key Laboratory of High Technology for Plant Protection Institute of Plant ProtectionGuangdong Academy of Agricultural Sciences

Glyphosate has been used worldwide for nearly 40 years,and 30 types of resistant weeds have been *** is mass-produced and widely used in China,but few studies and reports on glyphosate-resistant weeds and resistance mechanisms *** studies found a goosegrass species with high glyphosate resistance from orchards in South China and its glyphosate resistant mechanism was described in this *** cDNAof 5-enolpyruvylshikimate-3-phosphate synthase（EPSPS,EC 2.***.1.19）,the target enzyme of glyphosate,was cloned from the glyphosate-resistant and-susceptible goosegrass,respectively,and referred as EPSPS-R and *** Pro106 residue was known to be involved in the glyphosate resistance in most goosegrass ***,sequence analysis did not find the mutation at the Pro106 residue in the R biotype EPSPS amino acid *** residue 133 and 382 was mutated in the R biotype EPSPS amino acid sequence instead,but it did not affect the EPSPS-S and EPSPS-R genes sensitivities to ***-PCR and Western blot analyses suggested that EPSPS mRNA and protein are mainly present in the shoot tissues both in the R and S goosegrass *** EPSPS-R rapidly responds to the glyphosate in R-biotype goosegrass and the induced expression was detected at 12 h post glyphosate *** mRNA and protein expression of EPSPS-R increased constantly as the increasing concentration of ***,the expression of the EPSPS-S was not induced significantly by glyphosate in the S goosegrass *** of real-time PCR results showed that the copy number of the EPSPS in R-biotype goosegrass was 4.7 times higher than that in the S goosegrass *** the results implied that EPSPS gene amplification might mainly caused the glyphosate resistance of a goosegrass population collected from orchards in South China.

关键词： populations shoot residue susceptible constantly translocation instead implied confer chlorophyll