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Two-layer autonomous intelligence dynamic trajectory planning method based on shield-tunnel ring-geology interactions

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Underground Space 2024年第6期19卷 227-250页

作者： Min Hu Bingjian wu Huiming wu Liefeng pei SILC Business School Shanghai UniversityShanghai 201800China SHU-SUCG Research Centre for Building Industrialization Shanghai 201800China Shanghai Tunnel Engineering Co. Ltd.Shanghai 200032China

To solve the problem that current attitude planning methods do not fully consider the interaction and constraints among the shield,segmental tunnel ring,and geology,and cannot adapt to the changes in the actual engineering environment,or provide feasible long-term and short-term attitude planning,this paper proposes autonomous intelligent dynamic trajectory planning(AI-DTP)to provide tunnel ring and centimeter-layer planning targets for a self-driving shield to meet long-term accuracy and short-term ***-DTP introduces the Frenet coordinate system to solve the problem of inconsistent spatial representation of tunnel data,segmental tunnel ring location,and surrounding geological conditions,designs the long short-term memory attitude prediction model to accurately predict shield attitude change trend based on shield,tunnel,and geology,and uses a heuristic algorithm for trajectory ***-DTP provides ring-layer and centimeter-layer planning objectives that meet the needs of long-term accuracy and short-term correction of shield attitude *** the Hangzhou-Shaoxing Intercity Railroad Tunnel Project in China,the “Zhiyu”shield equipped with the AI-DTP system was faster and more accurate than the manually controlled shield,with a smoother process and better quality of the completed tunnel.

关键词： Shield tunnel Trajectory planning Attitude control Self-driving Machine learning

Effects of N source and nitrification pretreatment on growth of Arthrospira platensis in human urine

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第11期8卷 1846-1852页

作者： FENG dao-lun wu Zu-cheng WANG Da-hui Department of Environmental Science and Engineering Zhejiang University Hangzhou 310027 China

Culture ofArthrospiraplatensis （Spirulinaplatens） in human urine was investigated to get valuable biomass. NO3-N was the proper N source, in comparison with other N source, including urea, NH4-N and NO2-N. As a result, aerobic nitrification of human urine was performed, with above 93.6% nitrification percentage finally achieved with total-N （TN） load of 46.52 mg/（L.d）, in which Arthrospira platensis was successfully grown. The main compositions of the obtained biomass are close to those in Zarrouk medium. Thus, it is possible to culture Arthrospiraplatensis in nitrified human urine for food production within bioregenerative life support systems （BLSSs）.

关键词： Arthrospira platensis Human urine N source Nitrification Bioregenerative life support system (BLSS)

Substrate concentration effect on gene expression in genetic circuits with additional positive feedback

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Science China(Technological Sciences) 2018年第8期61卷 1175-1183页

作者： wu LuLu WANG pei Lü JinHu Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences School of Mathematics and Statistics Henan University School of Automation Science and Electrical Engineering State Key Laboratory of Software Development Environment and Beijing Advanced Innovation Center for Big Data and Brain Machine Intelligence Beihang University

In gene regulatory networks, gene regulation loops often occur with multiple positive feedback, multiple negative feedback and coupled positive and negative feedback forms. In above gene regulation loops, auto-activation loops are ubiquitous regulatory motifs. This paper aims to investigate a two-component dual-positive feedback genetic circuit, which consists of a double negative feedback circuit and an additional positive feedback loop(APFL). We study effect of substrate concentration on gene expression in the single and the networked systems with APFLs, respectively. We find that substrate concentration can tune stochastic switch behavior in the signal system and then we explore relationship of substrate concentration with positive feedback strength in aspect of stochastic switch behavior. Furthermore, we also discuss gene expression and stochastic switch behavior in the networked systems with APFLs. Based on analysis in the networked systems, we discover that genes express in some specific cells and do not express in the other cells when the expression achieves its steady state. These results can be used to well explain the character of regionalization in the expression of genes and the phenomenon of gene differentiation.

关键词： substrate concentration additional positive feedback loop stochastic switch behavior gene expression gene differ-entiation

‘Hide-then-hit’to explain the importance of genotypic polymorphism of DNA repair genes in determining susceptibility to cancer

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Journal of Molecular Cell Biology 2011年第1期3卷 59-65页

作者： pei-Ei wu Chen-Yang Shen Institute of Biomedical Sciences Academia SinicaTaipei 11529 Graduate Institute of Environmental Science China Medical UniversityTaichong 40402

have been suggested to account for different risk of developing *** this review article,on the basis of breast cancer formation as a model,we propose a‘hide-then-hit’hypothesis indicating the importance of escaping checkpoint surveillance for sub-optimal DNA repair variants to cause ***,only cells with subtle defects in repair capacity arising from low-penetrance variants of DNA repair genes would have the opportunity to grow and accumulate the genetic changes needed for cancer formation,without triggering cell-cycle checkpoint ***,distinct from high-penetrance alleles,these polymorphic alleles of DNA repair genes would predispose carriers to a higher risk of developing cancer but would not necessarily cause *** examine this,we simultaneously genotyped multiple SNPs of cell-cycle checkpoint genes and the DNA repair *** for the hypothesis came from observations that breast cancer risk associated with variant genotypes of DNA repair genes became more significant in the subgroups of women with specific genotypic statuses of checkpoint ***‘hide-then-hit’hypothesis is certainly needed to be confirmed by biological evidence in which a cause–effect relationship has to be ***,based on this,possible gene–gene interaction is considered to play an important role in modifying the cancer risk associated with genotypic polymorphism of DNA repair gene in different study populations.

关键词： DNA repair genotype polymorphism

Friction and Wear Behaviors of MoS_2/Zr Coated HSS in Sliding Wear and in Drilling Processes

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1218-1223页

作者： DENG Jianxin YAN pei wu Ze Department of Mechanical Engineering Shandong UniversityJinan 250061China

MoS2 metal composite coatings have been successful used in dry turning, but its suitability for dry drilling has not been yet established. Therefore, it is necessary to study the friction and wear behaviors of MoS2/Zr coated HSS in sliding wear and in drilling processes. In the present study, MoS2/Zr composite coatings are deposited on the surface of W6Mo5Cr4V2 high speed steel（HSS）. Microstructural and fundamental properties of these coatings are examined. Ball-on-disc sliding wear tests on the coated discs are carried out, and the drilling performance of the coated drills is tested. Test results show that the MoS2/Zr composite coatings exhibit decreases friction coefficient to that of the uncoated HSS in sliding wear tests. Energy dispersive X-ray（EDX） analysis on the wear surface indicates that there is a transfer layer formed on the counterpart ball during sliding wear processes, which contributes to the decreasing of the friction coefficient between the sliding couple. Drilling tests indicate that the MoS2/Zr coated drills show better cutting performance compared to the uncoated HSS drills, coating delamination and abrasive are found to be the main flank and rake wear mode of the coated drills. The proposed research founds the base of the application of MoS2 metal composite coatings on dry drilling.

关键词： cutting tools coating MoS2 wear mechanisms

CFD simulation of a gas-solid fluidized bed with two vertical jets

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Particuology 2010年第5期8卷 425-432页

作者： pei pei Kai Zhang Jintian Ren Dongsheng Wen Guiying wu State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China School of Engineering and Materials Science Queen Mary University of London Mile End Road London E1 4NS UK National Engineering Laboratory for Biomass Power Generation Equipment North China Electric Power University Beijing 102206 China

A computational fluid dynamics （CFD） model is used to investigate the hydrodynamics of a gas-solid fluidized bed with two vertical jets. Sand particles with a density of 2660 kg/m3 and a diameter of 5.0 × 10^-4 m are employed as the solid phase. Numerical computation is carried out in a 0.57 m ×1.00 m two-dimensional bed using a commercial CFD code, CFX 4.4, together with user-defined Fortran subroutines. The applicability of the CFD model is validated by predicting the bed pressure drop in a bubbling fluidized bed, and the jet detachment time and equivalent bubble diameter in a fluidized bed with a single jet. Subsequently, the model is used to explore the hydrodynamics of two vertical jets in a fluidized bed. The computational results reveal three flow patterns, isolated, merged and transitional jets, depending on the nozzle separation distance and jet gas velocity and influencing significantly the solid circulation pattern. The jet penetration depth is found to increase with increasing jet gas velocity, and can be predicted reasonably well by the correlations of Hong et al. （2003） for isolated jets and of Yang and Keairns （1979） for interacting jets.

关键词： Gas-solid fluidized bedTwo vertical jetsFluid dynamicsCFD model

Origin of Modulus Improvement for Epoxide-terminated Hyperbranched Poly(ether sulphone)/DGEBA/TETA Systems

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Chinese Journal of Polymer Science 2018年第8期36卷 991-998页

作者： Xue-pei Miao dao-Jian Cheng Ya-Dong Dai Yan Meng Xiao-Yu Li Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology Beijing 100029 China Neo Trident Technology Ltd (Beijing) Beijing 100190 China

It has been experimentally shown that epoxide-terminated hyperbranched polyether sulphone （EHBPES） can significantly improve the mechanical properties of traditional diglycidyl ether of bisphenol A/triethylenetetramine （DGEBA/TETA） systems, but the origin of the improvement is still unclear. In this work, we used molecular dynamics （MD） simulations to gain a thorough understanding of the origin of modulus improvement for EHBPES/DGEBA/TETA systems. It is found that the modulus of EHBPES/DGEBA/TETA systems increases with the increase of EHBPES loading. In addition, the crosslinking density, cohesive energy density （CED）, and free volume can be used to understand the modulus for EHBPES/DGEBA/TETA systems. It is shown that the highest modulus is achieved at 7 wt% EHBPES loading due to the highest crosslinking density and CED. When EHBPES loading is below 7 wt%, the higher CED and crosslinking density are responsible for the higher modulus. At higher loadings （〉 7 wt%）, the decreased modulus is closely related to the decreased crosslinking density and increased fractional free volume. It is expected that our results could be of great implications for designing high-performance epoxy materials.

关键词： Modulus Molecular simulation Epoxy resin

Flavonoids rather than alkaloids as the diagnostic constituents to distinguish Sophorae Flavescentis Radix from Sophorae Tonkinensis Radix et Rhizoma: an HPLC fingerprint study

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Chinese Journal of Natural Medicines 2018年第12期16卷 951-960页

作者： DING pei-Lan HE Chang-Ming CHENG Zhi-Hong CHEN dao-Feng Department of Pharmacognosy School of Pharmacy Fudan University

Sophorae Flavescentis Radix(Sophora flavescens Ait., SFR) and Sophorae Tonkinensis Radix et Rhizoma(S. tonkinensis Gapnep., STR) are two commonly used traditional Chinese medicines from Sophora(Leguminosae) plants, which are believed to possess similar bioactive components with entirely different clinical applications. In order to find out the characteristic chemical constituents potentially leading to the unique medicinal properties claimed for each of the two closely related TCMs, an HPLC fingerprint method was developed for analyses of the alkaloid and flavonoid constituents of SFR and STR, respectively, which were further evaluated and compared through similarity calculation and hierarchical clustering analysis(HCA). The results from the present study showed that the alkaloid fingerprints of the two herbs were similar, with many components co-existing in both drugs and various batches of samples from different species being mixed together in the HCA dendrogram. However, their flavonoid constituents were totally different with specific fingerprints being yielded for each herb, and further HCA analysis showed that the tested samples could almost be clearly divided into two groups based on their origins of species. The results from the present study indicated that the flavonoid constituents could serve as the differentially diagnostic constituents of SFR and STR and might potentially attributed to their distinct therapeutic effects.

关键词： Sophoraflavescens Sophora tonkinensis Alkaloids Flavonoids HPLC fingerprint Hierarchical clustering analysis

Constructing the barley model for genetic transformation in Triticeae

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Journal of Integrative Agriculture 2015年第3期14卷 453-468页

作者： Lü Bo wu Jia-jie FU dao-lin State Key Laboratory of Crop Biology/Shandong Key Laboratory of Crop Biology Shandong Agricultural University

Barley（Hordeum vulgare L.） is one of the oldest domesticated crops, showing dramatic adaptation to various climate and environmental conditions. As a major cereal crop, barley ranks the 4th after wheat, maize and rice in terms of planting area and production all over the world. Due to its diploid nature, the cultivated barley is considered as an ideal model to study the polyploid wheat and other Triticeae species. Here, we reviewed the development, optimization, and application of transgenic approaches in barley. The most efficient and robust genetic transformation has been built on the Agrobacterium-mediated transfer in conjunction with the immature embryo-based regeneration. We then discussed future considerations of using more practical technologies in barley transformation, such as the T-DNA/transposon tagging and the genome editing. As a cereal crop amenable to genetic transformation, barley will serve as the most valuable carrier for global functional genomics in Triticeae and is becoming the most practical model for generating value-added products.

关键词： Agrobacterium-mediated transfer genetically modified organism Hordeum vulgare immature embryos