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Test and damage assessment of shallow buried RC tunnel under explosion

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Underground Space 2024年第1期14卷 118-137页

作者： Longyun Zhou Xiaojun li Qiushi Yan Shutao li Song chang Pengcheng Ren Beijing University of Technology Beijing 100124China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing 100124China Department of Civil Engineering Tsinghua UniversityBeijing 100084China Research Institute for National Defense Engineering of AMS PLABeijing 100036China

As a major element of the transportation network,tunnels are unavoidably threatened by accidental loads such as vehicle bombs and tank truck *** goal of this research is to explore the dynamic characteristics and damage assessment of tunnel structures under contact blast ***,three scaled-down reinforced concrete tunnel models were made,and the explosion test and static loading test were carried out successively to evaluate the axial residual bearing capacity,axial displacement and failure mechanism of the ***,the finite element model is built by utilizing LS-DYNA,and the reliability of the finite element method is confirmed by comparing the data of the explosion test with the static loading *** the same time,the calculation method for damage coefficient and the classification criteria for damage grade based on axial residual bearing capacity are ***,based on the finite element method,the propagation process of the explosion shock wave in the tunnel and the damage mechanism of the tunnel are ***,seven explosion scenarios are developed,the damage degree of these seven tunnels under the blast load is quantitatively analyzed,and further anti-blast design ideas are put *** study in this article may give an intended reference for the damage assessment,anti-explosion design and strengthening work of reinforced concrete tunnels.

关键词： Shallow buried tunnel Blast location Blast resistance Axial residual bearing capacity Damage assessment

Phase evolution and mechanical properties of low-activation refractory high-entropy alloy Ti_(1.5)ZrV_(0.5)Ta_(0.5)

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Journal of Materials Science & Technology 2024年第7期174卷 145-156页

作者： Yuxiang Chen Ningyu li Yijie Wang Kang liu Yongqin chang Mingyang li School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Xi’an Rare Metal Materials Institute Co.Ltd Xi’an 710016China

A novel low-activation Ti_(1.5)ZrV_(0.5)Ta_(0.5)refractory high-entropy alloy(RHEA)was designed as a potential candidate for nuclear reactor *** room temperature,it had an elongation of 8.4%and a yield strength of 1096 *** phase evolution of this alloy and its effect on properties was *** 400℃,the solid solution bcc 1 transformed into the fcc phase and bcc 2 phase,and theωphase andαphase also *** 600℃,theωphase andαphase disappeared,and the microstructure of the alloy was composed of the fcc phase and bcc 2 *** the temperature was up to 1200℃,the fcc phase and bcc 2 phase re-transformed into solid solution bcc 1 *** precipitation ofωphase andαphase caused a sharp increase in strength and a decrease in ***,the appearance of the fcc phase led to a simultaneous decrease in strength and ductility,due to larger stress concentrations at the fcc/bcc ***,the formation mechanism of each phase in the alloy was discussed in detail.

关键词： Low-activation Refractory high-entropy alloy Phase evolution Phase formation mechanism Strengthening mechanism

Combined Promoting Effects of Specific Organic Functional Groups and Alumina Surface Characteristics for the Design of a Highly Efficient NiMo/Al_(2)O_(3) Hydrodesulfurization Catalyst

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 1-11页

作者： li Huifeng li Mingfeng Zhang Le Wang Wei Nie hong National Energy R&D Center of Petroleum Refining Technology SINOPEC Research Institute of Petroleum Processing Co.Ltd.Beijing 100083China

To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were ***,the correlation between the surface characteristics of four different alumina and the existing Mo species states was *** was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into ***,the Mo-O-Al bonds still exist at the metal-support *** introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on ***,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases.

关键词： alumina Mo equilibrium adsorption capacity organic functional groups metal-support interaction hydrodesulfurization

Laser manufacturing of spatial resolution approaching quantum limit

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light(Science & Applications) 2024年第3期13卷 421-428页

作者： Xiao-Jie Wang hong-Hua Fang Zhen-Ze li Dan Wang hong-Bo Sun State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

Atomic and close-to-atom scale manufacturing is a promising avenue toward single-photon emitters,single-electron transistors,single-atom memory,and quantum-bit devices for future communication,computation,and sensing *** manufacturing is outstanding to this end for ease of beam manipulation,batch production,and no requirement for *** is,however,suffering from optical diffraction ***,we report a spatial resolution improved to the quantum limit by exploiting a threshold tracing and lock-in method,whereby the two-order gap between atomic point defect complexes and optical diffraction limit is surpassed,and a feature size oflications.

关键词： quantum limit resolution

Acute Effects of Low Temperatures and Cold Waves on Elderly Infectious Pneumonia Mortality—Jinan City,Shandong Province,China,2014-2022

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China CDC weekly 2024年第5期6卷 77-82,I0002-I0005页

作者： Huiyun chang Mingjun li Ying Wang liangliang Cui Tiantian li Jinan Municipal Center for Disease Control and Prevention Jinan Municipal Center for Disease Control and Prevention Affiliated to Shandong UniversityJinan CityShandong ProvinceChina Chinese Filed Epidemiology Training Program Chinese Center for Disease Control and PreventionBeijingChina China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?The mortality rate due to pneumonia varies depending on the infectious agents present in a low-temperature *** is added by this report?This study aimed to examine the relationship between low temperatures and cold waves and the risk of mortality from infectious pneumonia in the *** findings indicate a significant increase in the risk of infectious pneumonia.

关键词： environment Shandong finding

Prox1 Suppresses Proliferation and Drug Resistance of Retinoblastoma Cells via Targeting Notch1

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Current Medical Science 2024年第1期44卷 223-231页

作者： hong-li ZHANG Na li lin DONG hong-xia MA Mo-chi YANG Department of Ophthalmology General Hospital of Ningxia Medical UniversityYinchuan 750004China

Objective Retinoblastoma(RB)is a prevalent type of eye cancer in *** homeobox 1(Prox1)is a homeobox transcriptional repressor and downstream target of the proneural gene that is relevant in lymphatic,hepatocyte,pancreatic,heart,lens,retinal,and cancer *** goal of this study was to investigate the role of Prox1 in RB cell proliferation and drug resistance,as well as to explore the underlying Notch1 *** Human RB cell lines(SO-RB50 and Y79)and a primary human retinal microvascular endothelial cell line(ACBRI-181)were used in this *** expression of Prox1 and Notch1 mRNA and protein in RB cells was detected using quantitative real time-polymerase chain reaction(RT-qPCR)and Western *** proliferation was assessed after Prox1 overexpression using the Cell Counting Kit-8 and the MTS ***-resistant cell lines(SO-RB50/vincristine)were generated and treated with Prox1 to investigate the role of Prox1 in drug *** employed pcDNA-Notch1 to overexpress Notch1 to confirm the role of Notch1 in the protective function of ***,a xenograft model was constructed to assess the effect of Prox1 on RB in *** Prox1 was significantly downregulated in RB *** of Prox1 effectively decreased RB cell growth while increasing the sensitivity of drug-resistant cells to ***1 was involved in Prox1’s regulatory ***1 was identified as a target gene of Prox1,which was found to be upregulated in RB cells and repressed by increased Prox1 *** pcDNA-Notch1 was transfected,the effect of Prox1 overexpression on RB was ***,by downregulating Notch1,Prox1 overexpression slowed tumor development and increased vincristine sensitivity in *** These data show that Prox1 decreased RB cell proliferation and drug resistance by targeting Notch1,implying that Prox1 could be a potential therapeutic target for RB.

关键词： Proxl Notch1 retinoblastoma cells proliferation drug resistance

Palladium-catalyzed multi components oxy-aminofluorination and aminofluorination of gem-difluoroalkenes

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Chinese Chemical Letters 2024年第2期35卷 420-425页

作者： Fen Wu Xin li Junbiao chang Dachang Bai State Key Laboratory of Antiviral Drugs NMPA Key Laboratory for Research and Evaluation of Innovative DrugKey Laboratory of Green Chemical Media and ReactionsMinistry of EducationSchool of Chemistry and Chemical EngineeringPingyuan LaboratoryHenan Normal UniversityXinxiang 453007China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Organofluorine compounds are widely used in the realm of drug discovery and material ***,we developed palladium catalyzed intermolecular aminofluorination and oxy-aminofluorination of gem‑difluoroalkenes with N-fluorobenzenesulfonimide(NFSI),in which NFSI was used as the nitrogen source and *** reaction provides an efficient and straightforward synthesis route of a series ofα-trifluoromethyl benzylic ***,three/four components oxy-aminofluorination processes were realized to giveα-trifluoromethyl benzylic ether with a terminal amino group,which proceed through C(sp^(3))-O bond cleavage of easily available ether and simultaneous introduced a fluorine,an amino and an oxy substituent in one pot with excellent *** divergent reactivity not only included the incorporation of one ether molecular,but also much more challenged two ether insertion with excellent selectivity through succession C(sp^(3))-O bonds *** protocol allows for concise synthesis of high value amines with fluoroalkyl-substituents and selectively transformation of easily available ethers by high-valent palladium catalysis.

关键词： Palladium Multi components Aminofluorination Oxy-aminofluorination C(sp^(3))-O bond cleavage

Opportunities and challenges in studies of mammalian hybrid speciation

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Science China(life Sciences) 2024年第3期67卷 614-617页

作者： hong Wu Yuxing Zhang li Yu State Key Laboratory for Conservation and Utilization of Bio-Resource in Yunnan School of Life SciencesYunnan UniversityKunming 650091China

Revealing the mechanisms of speciation remains one of the most attractive and challenging issues in the field of evolutionary biology, and is also key to understanding the biodiversity present in nature.

关键词： biodiversity attractive evolutionary

Tetrahedral framework nucleic acids promote the proliferation and differentiation potential of diabetic bone marrow mesenchymal stem cell

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Chinese Chemical Letters 2024年第9期35卷 284-288页

作者： Yanjing li Jiayin li Yuqi chang Yunfeng lin Lei Sui Department of Prosthodontics Tianjin Medical University School and Hospital of StomatologyTianjin 300070China State Key Laboratory of Oral Diseases West China Hospital of StomatologySichuan UniversityChengdu 610041China

Diabetes mellitus considerably affects bone marrow mesenchymal stem cells(BMSCs),for example,by inhibiting their proliferation and differentiation potential,which enhances the difficulty in endogenous bone ***,effective strategies for enhancing the functions of BMSCs in diabetes have farreaching consequences for bone healing and regeneration in diabetes *** framework nucleic acids(tFNAs)are nucleic acid nanomaterials that can autonomously enter cells and regulate their *** this study,we evaluated the effects of tFNAs on BMSCs from diabetic *** found that tFNAs could promote the proliferation,migration,and osteogenic differentiation of BMSCs from rats with type 2 diabetes mellitus,and inhibited cell senescence and ***,tFNAs effectively scavenged the accumulated reactive oxygen species and activated the suppressed protein kinase B(Akt)signaling ***,we show that tFNAs can recover the proliferation and osteogenic potential of diabetic BMSCs by alleviating oxidative stress and activating Akt *** study provides a strategy for endogenous bone regeneration in diabetes and also paves the way for exploiting DNA-based nanomaterials in regenerative medicine.

关键词： Bone marrow mesenchymal stem cell Diabetes mellitus DNA-based nanomaterial Tetrahedral framework nucleic acids Endogenous bone regeneration