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Evaluation and prediction of earth pressure balance shield performance in complex rock strata:A case study in Dalian,China

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1491-1505页

作者： Xiang Shen Dajun Yuan Xing-Tao Lin xiangsheng Chen Yuansheng Peng College of Civil and Transportation Engineering Shenzhen UniversityShenzhen518060China Key Laboratory for Resilient Infrastructures of Coastal Cities of Ministry of Education Shenzhen UniversityShenzhen518060China shenzhen Key Laboratory of Green Efficient and Intelligent Construction of Underground Metro StationShenzhen518060China Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing100044China

This research explores the potential for the evaluation and prediction of earth pressure balance shield performance based on a gray system model.The research focuses on a shield tunnel excavated for Metro Line 2 in Dalian,China.Due to the large error between the initial geological exploration data and real strata,the project construction is extremely difficult.In view of the current situation regarding the project,a quantitative method for evaluating the tunneling efficiency was proposed using cutterhead rotation(R),advance speed(S),total thrust(F)and torque(T).A total of 80 datasets with three input parameters and one output variable(F or T)were collected from this project,and a prediction framework based gray system model was established.Based on the prediction model,five prediction schemes were set up.Through error analysis,the optimal prediction scheme was obtained from the five schemes.The parametric investigation performed indicates that the relationships between F and the three input variables in the gray system model harmonize with the theoretical explanation.The case shows that the shield tunneling performance and efficiency are improved by the tunneling parameter prediction model based on the gray system model.

关键词： Evaluation of earth pressure balance shield performance Gray system model Metro construction Rock strata Field data prediction

Tuning the Stability of the Polyplex Nanovesicles of Oligonucleotides via a Zinc(Ⅱ)-Coordinative Strategy

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Chinese Journal of Polymer Science 2022年第9期40卷 1034-1042页

作者： Quan Zhou xiang Li Jia-Jia xiang You-Qing shen Zhejiang Key Laboratory of Smart Biomaterials and Center for Bionanoengineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Department of Cell Biology School of Basic Medical SciencesZhejiang UniversityHangzhou 310058China The Forth Affiliated Hospital Zhejiang University School of MedicineYiwu 322000China Hangzhou Global Scientific and Technological Innovation Center Hangzhou 311215China

Oligonucleotide therapeutics have great potential to target the currently undruggable genes and to generate entirely new therapeutic paradigms in multiple types of disease,thus having attracted much attention in recent years.However,their applications are greatly hindered by a lack of safe and efficient oligonucleotide-delivery vectors.Polyplex nanovesicles formed from oligonucleotides and the cationic block have shown exceptional features for the delivery of therapeutic oligonucleotides and other biopharmaceuticals.Nevertheless,these polyplex nanovesicles are deeply fraught with difficulty in tolerating physiological ionic strength.Inspired by the high binding ability between the dipicolylamine(DPA)/zinc(Ⅱ)complex and the phosphodiester moieties of oligonucleotides,herein,we designed a coordinative cationic block to solve the intrinsic stability dilemma.Moreover,we found the stability of the resulted polyplex nanovesicles could be easily tuned by the content of coordinated zinc ions.In vitro cellular studies implied that the prepared zinc(Ⅱ)-coordinative polyplex nanovesicles preferred to retain in the lysosomes upon internalization,making them ideal delivery candidates for the lysosome-targeting oligonucleotide therapeutics.

关键词： Oligonucleotide therapeutics Polyplex nanovesicles Coordinative cationic block Lysosome-targeting

Temperature-Dependent Mechanical Properties of Graphene/Cu Nanocomposites with In-Plane Negative Poisson’s Ratios

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Research 2020年第1期2020卷 902-913页

作者： Yin Fan Yang xiang Hui-shen shen School of Engineering Western Sydney UniversityLocked Bag 1797PenrithNSW 2751Australia School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China School of Ocean and Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Negative Poisson’s ratio(NPR),also known as“auxetic”,is a highly desired property in a wide range of future industry applications.By employing molecular dynamics(MD)simulation,metal matrix nanocomposites reinforced by graphene sheets are studied in this paper.In the simulation,single crystal copper with crystal orientation絵110is selected as the matrix and an embeddedatom method(EAM)potential is used to describe the interaction of copper atoms.An aligned graphene sheet is selected as reinforcement,and a hybrid potential,namely,the Erhart-Albe potential,is used for the interaction between a pair of carbon atoms.The interaction between the carbon atom and copper atom is approximated by the Lennard-Jones(L-J)potential.The simulation results showed that both graphene and copper matrix possess in-plane NPRs.The temperature-dependent mechanical properties of graphene/copper nanocomposites with in-plane NPRs are obtained for the first time.

关键词： composites copper interaction

Catalytic enantioselective synthesis of β-amino alcohols by nitrene insertion

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Science China Chemistry 2021年第3期64卷 452-458页

作者： Zijun Zhou Yuqi Tan Xiang Shen Sergei Ivlev Eric Meggers Fachbereich Chemie Philipps-Universitat MarburgHans-Meerwein-Strasse 435043 MarburgGermany

Chiral β-amino alcohols are important building blocks for the synthesis of drugs, natural products, chiral auxiliaries, chiral ligands and chiral organocatalysts. The catalytic asymmetric β-amination of alcohols offers a direct strategy to access this class of molecules. Herein, we report a general intramolecular C(sp^(3))–H nitrene insertion method for the synthesis of chiral oxazolidin-2-ones as precursors of chiral β-amino alcohols. Specifically, the ring-closing C(sp^(3))–H amination of N-benzoyloxycarbamates with 2 mol% of a chiral ruthenium catalyst provides cyclic carbamates in up to 99% yield and with up to 99% ee.The method is applicable to benzylic, allylic, and propargylic C–H bonds and can even be applied to completely non-activated C(sp^(3))–H bonds, although with somewhat reduced yields and stereoselectivities. The obtained cyclic carbamates can subsequently be hydrolyzed to obtain chiral β-amino alcohols. The method is very practical as the catalyst can be easily synthesized on a gram scale and can be recycled after the reaction for further use. The synthetic value of the new method is demonstrated with the asymmetric synthesis of a chiral oxazolidin-2-one as intermediate for the synthesis of the natural product aurantioclavine and chiral β-amino alcohols that are intermediates for the synthesis of chiral amino acids, indane-derived chiral Box-ligands, and the natural products dihydrohamacanthin A and dragmacidin A.

关键词： asymmetric catalysis nitrene amination chiral-at-metal ruthenium

Kinetics and capacities of non-reactive phosphorus (NRP) sorption to crushed autoclaved aerated concrete (CAAC)

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Journal of Environmental Sciences 2023年第5期127卷 799-810页

作者： Shuting shen xiang Li Zhuofan Geng Xiwu Lu School Energy and Environment Southeast UniversityNanjing 210096China ERC Taihu Lake Water Environment Wuxi Wuxi 214135China

With growing interest in resource recovery and/or reuse,wastematerials have been considered a promising alternative for phosphorus(P)adsorption because they are low-cost and easily accessible.Crushed autoclaved aerated concrete(CAAC),as representative construction waste,has been extensively studied for P removal in ecological technologies such as treatment wetlands.However,most of the previous studies focused on the adsorption of orthophosphate,namely reactive phosphorus,and lacked attention to non-reactive phosphorus(NRP)which is widely present in sewage.This study presents the first investigation on the potential and mechanism of CAAC removing four model NRP compounds.Adsorption isotherm and kinetics of NRP onto CAAC indicate that the removal of NRP was a chemisorption process and also involved a two-step pore diffusion process.The desorption experiment shows that different NRP species showed varying degrees of desorption.Most NRP was irreversibly adsorbed on CAAC.Among the model compounds considered in this study,the adsorption capacity and hydrolysis rate of organophosphorus were much less than that of inorganic phosphorus.Moreover,the adsorption of different NRP species by CAAC in the mesocosm study was different from the results of laboratory adsorption experiments,and the possible biodegradation was essential for the conversion and removal of NRP.The findings confirmed the validity of CAAC for NRP removal and the potential advantages of CAAC in terms of costs and environmental impact.This study will contribute to a better understanding of NRP conversion and environmental fate and that can be the basis for a refined risk assessment.

关键词： Non-reactive phosphorus Crushed autoclaved aerated concrete Phosphorus removal Sorption Wastewater treatment

Adaptive Simplified Chicken Swarm Optimization Based on Inverted S-Shaped Inertia Weight

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Chinese Journal of Electronics 2022年第2期31卷 367-386页

作者： GU Yanchun LU Haiyan xiang Lei shen Wanqiang School of Science Jiangnan University Wuxi Engineering Technology Research Center for Biological Computing Jiangnan University

Considering the issues of premature convergence and low solution accuracy in solving high-dimensional problems with the basic chicken swarm optimization algorithm, an adaptive simplified chicken swarm optimization algorithm based on inverted S-shaped inertia weight(ASCSO-S) is proposed. Firstly, a simplified chicken swarm optimization algorithm is presented by removing all the chicks from the chicken swarm. Secondly, an inverted S-shaped inertia weight is designed and introduced into the updating process of the roosters and hens to dynamically adjust their moving step size and thus to improve the convergence speed and solution accuracy of the algorithm. Thirdly, in order to enhance the exploration ability of the algorithm, an adaptive updating strategy is added to the updating process of the hens.Simulation experiments on 21 classical test functions show that ASCSO-S is superior to the other comparison algorithms in terms of convergence speed, solution accuracy, and solution stability. In addition, ASCSO-S is applied to the parameter estimation of Richards model, and the test results indicate that ASCSO-S has the best fitting results compared with other three algorithms.

关键词： Chicken swarm optimization algorithm Inverted S-shaped inertia weight Random learning Function optimization Richards model

Current status of hair analysis in forensic toxicology in China

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Forensic Sciences Research 2021年第4期6卷 240-249页

作者： Hui Yan Ping xiang Min shen Department of Forensic Toxicology academy of Forensic scienceshanghai Key Laboratory of Forensic Medicineshanghaichina

Hair analysis has been mainly used to document drug use history in abusers,drug-facilitated crime cases,doping control analysis and postmortem toxicology in the fields of forensic toxicology,clinical toxicology,and doping control.Hair analysis has also gained more attention in the last 30 years in China.Relevant technology has been promoted as more research has appeared concerning hair analysis,and consensus has been sought among forensic toxicologists regarding aspects such as hair decontamination treatment,detection of abused substances in hair,segmental hair analysis and interpretation of analytical results.However,there are still some limitations in the estimation of drug intake time and frequency by segmental hair analysis due to the different growth cycles evident within a bundle of hairs,the drug incorporation mechanism and sampling errors.Microsampling and imaging mass spectrometry(iMS)technology based on a single hair may be a good choice to estimate drug intake time more accurately.Analysis of hair root samples may also be used to document acute poisoning in postmortem toxicology,and the analysis of the hair shaft can document long-term use of drugs depending on the length of the hair being evaluated.

关键词： Forensic sciences forensic toxicology hair analysis black hair drug abuse microsampling imaging mass spectrometry

Alternating nitrogen feeding strategy induced aerobic granulation:Influencing conditions and mechanism

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Journal of Environmental Sciences 2021年第11期33卷 135-147页

作者： Chunli Wan Zhengwen Li Yanggui shen xiang Liu Department of Environmental Science and Engineering Fudan UniversityShanghai 200438China College of Materials Science and Chemical Engineering Harbin Engineering UniversityHarbin 150001China

Effective cultivation of stable aerobic granular sludge(AGS)is a crucial step in the successful application of this technology,and the formation of AGS could be facilitated by some environmental stress conditions.Four identical sequencing batch reactors(SBRs)were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions(inorganic carbon source,temperature,N/COD).Although various superimposed conditions induced a significant difference in the size,settling velocity,mechanic strength of AGS,mature aerobic granules could be successfully obtained in all four reactors after 70 days’operation,indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation.Based on the results of redundancy analysis,the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function,while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS.In addition,superimposed stress conditions could result in the difference in the microbial population between four reactors,but the population diversity and abundance of microorganisms were not the determinants of AGS formation.This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.

关键词： Aerobic granule sludge Granulation Alternating nitrogen feeding Cultivation

Evaluation of 1,4-naphthoquinone derivatives as antibacterial agents:activity and mechanistic studies

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Frontiers of Environmental Science & Engineering 2023年第3期17卷 49-61页

作者： Zhizhuo Liu Zhemin shen Shouyan xiang Yang sun Jiahua Cui Jinping Jia School of Environmental Science&Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The diverse and large-scale application of disinfectants posed potential health risks and caused ecological damage during the 2019-nCoV pandemic,thereby increasing the demands for the development of disinfectants based on natural products,with low health risks and low aquatic toxicity.In the present study,a few natural naphthoquinones and their derivatives bearing the 1,4-naphthoquinone skeleton were synthesized,and their antibacterial activity against selected bacterial strains was evaluated.In vitro antibacterial activities of the compounds were investigated against Escherichia coli and Staphylococcus aureus.Under the minimum inhibitory concentration(MIC)of≤0.125μmol/L for juglone(1a),5,8-dimethoxy-1,4-naphthoquinone(1f),and 7-methyl-5-acetoxy-1,4-naphthoquinone(3),a strong antibacterial activity against S.aureus was observed.All 1,4-naphthoquinone derivatives exhibited a strong antibacterial activity,with MIC values ranging between 15.625 and 500μmol/Land ECso values rangingbetween10.56 and248.42μmol/L.Most of the synthesized compounds exhibited strong antibacterial activities against S.aureus.Among these compounds,juglone(la)showed the strongest antibacterial activity.The results from mechanistic investigations indicated that juglone,a natural naphthoquinone,caused cell death by inducing reactive oxygen species production in bacterial cells,leading to DNA damage.In addition,juglone could reduce the self-repair ability of bacterial DNA by inhibiting RecA expression.In addition to having a potent antibacterial activity,juglone exhibited low cytotoxicity in cell-based investigations.In conclusion,juglone is a strong antibacterial agent with low toxicity,indicating that its application as a bactericidal agent may be associated with low health risks and aquatic toxicity.

关键词： 1,4-naphthoquinone derivatives Antibacterial Actionmechanism RecA