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Influence of cutterhead opening ratio on soil arching effect and face stability during tunnelling through non-uniform soils

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Underground Space 2024年第4期17卷 45-59页

作者： Xue-Jian Chen Pei-Pei Fang Qiu-Nan Chen jun hu Kai Yao Yong Liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China hubei Technology Innovation Center for Smart Hydropower Wuhan 430000China College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China School of Civil Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Civil and Architectural Engineering Hainan UniversityHaikou 570228China School of Qilu Transportation Shandong UniversityJinan 250002China

Tunnelling has increasingly become an essential tool in the exploration of underground space.A typical construction problem is the face instability during tunnelling,posing a great threat to associated *** face instability often occurs with the soil arching *** study investigates the combined effect of cutterhead opening ratio and soil non-uniformity on soil arching effect and face stability,via conducting random finite-element analysis coupled with Monte–Carlo *** results underscore that the face stability is strongly associated with the evolution of stress *** obtained stability factors in the uniform soils can serve as a reference for the design of support pressure in practical tunnelling *** addition,non-uniform soils exhibit a lower stability factor than uniform soils,which implies that the latter likely yields an underestimated probability of face *** tunnel face is found to have a probability of failure more than 50%if the spatial non-uniformity of soil is *** the end,a practical framework is established to determine factor of safety(FOS)corresponding to different levels of probability of face failure considering various opening ratios in non-uniform *** required FOS is 1.70 to limit the probability of face instability no more than 0.1%.Our findings can facilitate the prediction of probability of instability in the conventionally deterministic design of face pressure.

关键词： Tunnel Face stability Soil arching effect Cutterhead opening ratio Non-uniform soil Random field

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NaBH4-induced phase transition of CoSe_(2) with abundant Se deficiency for acidic oxygen reduction to hydrogen peroxide

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Rare Metals 2024年第2期43卷 500-510页

作者： Cai-Di Han Yong-Chao Zhang qian Zhang Jin-Ting Wu Jian Gao Ji-jun Zou Xiao-Dong Zhu State Key Laboratory Base of Eco-Chemical Engineering College of Chemical Engineering Qingdao University of Science and TechnologyQingdao266042China Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive ***,the low activity,insufficient selectivity and high cost of catalysts have been the ***,CoSe_(2) with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH4-induced CoSe_(2) phase transition from orthorhombic to cubic phase with more Se *** cubic phase CoSe_(2) with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of*OOH and*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_(2)O_(2).The onset potential is as low as 0.73 V *** hydrogen electrode(RHE),the H_(2)O_(2) selectivity is 84%(0 V ***),and the average electron transfer number is about ***,the H_(2)O_(2) yield measured using a flow cell is as high as 115.92 mmol·gcat.^(−1)·h^(−1) and the Faradaic efficiency is 70%at 0 V ***,which presents high potential in electrocatalytic acidic ORR to H_(2)O_(2) and organic pollutant degradation using the electron-Fenton process.

关键词： Se defected CoSe_(2) Crystal phase transition Electrocatalysis Acidic oxygen reduction Hydrogen peroxide

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A gas sensing neural circuit for an olfactory neuron

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Communications in Theoretical Physics 2024年第10期76卷 26-40页

作者： Xi-Kui hu Song Zhu Juan Yang Zhao Yao Ping Zhou jun Ma School of Science Chongqing University of Posts and Telecommunications School of Physics and Electronics Central South University Department of Physics Lanzhou University of Technology

A gas sensor can convert external gas concentration or species into electric voltage or current signals by physical adsorption or chemical changes. As a result, a gas sensor in a nonlinear circuit can be used as a sensitive sensor for detecting external gas signals from the olfactory system. In this paper, a gas sensor and a field-effect transistor are incorporated into a simple Fithzhugh–Nagumo neural circuit for capturing and encoding external gas signals. An improved functional neural circuit is obtained, and the effect of gas concentration, gas species and neuronal activity can be discerned as the gate voltage, threshold voltage and activation coefficient of the field-effect transistor, respectively. The gas concentration can affect the neural activities from quiescent to normal working and, finally, to saturation state in bursting, spiking, periodic and chaotic firings with different frequencies. The effects of gas species and neuronal activity on the firing state can also be achieved in this functional neural circuit. In addition, variations in the gate voltage, threshold voltage and activation coefficient can cause switching between different firing modes. These results can be helpful in designing artificial olfactory devices for bionic gas recognition and other coupled systems arising in applied sciences.

关键词： bifurcation field-effect transistor gas sensor olfactory neural circuit

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Degradation of warm permafrost and talik formation on the Qinghai-Tibet Plateau in 2006-2021

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Advances in Climate Change Research 2024年第2期15卷 275-284页

作者： Qi-Hang MEI Ji CHEN You-qian LIU Shou-Hong ZHANG Jing-Yi ZHAO Tian-Chun DONG jun-Cheng WANG Yao-jun ZHAO Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment Key Laboratory of Cryospheric Science and Frozen Soil EngineeringNorthwest Institute of Eco-Environmental and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co.Ltd Xining 810007China University of Chinese Academy of Sciences Beijing 100049China

Permafrost is degrading globally,particularly those with low thermal stability on the Qinghai-Tibet Plateau,owing to climate ***,the inadequacy of direct research on permafrost degradation based on in-situ monitoring limits the prediction of permafrost degradation and engineering *** study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai-Tibet Plateau from 2006 to *** results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom *** rate of permafrost degradation from the top down and bottom up increase during the degradation process,but the increase of the former is more drastic after the formation of thawed ***,the construction of the Qinghai-Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer,particularly after through talik formation under the *** findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more *** evaluating the thermal impact of projects in warm permafrost regions,special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik.

关键词： Warm permafrost Degradation Talik Qinghai-Tibet Plateau Climate change

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Establishment of a humanized ST6GAL1 mouse model for influenza research

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Animal Models and Experimental Medicine 2024年第3期7卷 337-346页

作者： Lyu Chao Han Feng Gao qian Lv Limin Lu Ziwei Lu Shuangshuang Li Xiaoyan hu Yuechao Yang Mengjie Zhao Yingze Liu jun Lu Xuancheng Duo Shuguang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Chinese Center for Disease Control and PreventionBeijingChina Institute of Zoology Chinese Academy of SciencesBeijingChina NHC Key Laboratory of Biosafety National Key Laboratory of Intelligent Tracking and Forecasting for Infectious DiseasesNational Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina Zhejiang Provincial Key Laboratory of Medical Genetics Key Laboratory of Laboratory MedicineMinistry of EducationSchool of Laboratory Medicine and Life SciencesWenzhou Medical UniversityWenzhouChina

Background:This study aimed to construct and characterize a humanized influenza mouse model expressing ***:humanized fragments,consisting of the endothelial cell-specific K18 promoter,human ST6GAL1-encoding gene,and luciferase gene,were microinjected into the fertilized eggs of *** manipulated embryos were transferred into the oviducts of pseudopregnant female *** offspring were identified using *** exhibiting elevated expression of the hST6GAL1 gene were selectively bred for propagation,and in vivo analysis was performed for *** of the humanized gene was tested by performing immunohistochemical(IHC)*** and biochemical analyses using the whole blood and serum of humanized hST6GAL1 mice were ***:Successful integration of the human ST6GAL1 gene into the mouse genome led to the overexpression of human SiaT *** mice were identified as carrying copies of the humanized gene,and the in vivo analysis indicated that hST6GAL1gene expression in positive mice mirrored influenza virus infection *** IHC results revealed that hST6GAL1 was expressed in the lungs of humanized ***,the hematologic and biochemical parameters of the positive mice were within the normal ***:A humanized influenza mouse model expressing the hST6GAL1 gene was successfully established and characterized.

关键词： hST6GAL1 humanized mice influenza animal model

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Research progress of slippage characteristic and gas film stability enhancement methods on biomimetic hydrophobic surfaces

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Journal of Hydrodynamics 2024年第1期36卷 87-101页

作者： Meng-zhuo Zhang Hai-bao hu Liu-zhen Ren Lu-yao Bao jun Wen Luo Xie School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518063China

The biomimetic hydrophobic surface is a potentially efficient underwater drag reduction method and the drag reduction mechanism of this kind of surface comes from the interfacial *** now,it is a hotspot to grasp the slippage characteristic and explore slippage enhancement *** paper not only summarizes our numerical simulation and experimental results of slippage characteristic at the solid-liquid interface(SLI)of hydrophobic surfaces(HS)and the gas-liquid interface(GLI)of superhydrophobic surfaces(SHS)in recent years,but also introduces some innovative methods that can effectively improve the gas film stability and drag reduction effect of ***,we used the molecular dynamics(MD)simulation method to figure out the effect of the solid-liquid interaction strength,the system temperature and the shear rate on the slippage of SLI,and expound their action mechanism from molecular ***,by MD and multibody dissipative particle dynamics(MDPD)method,the slippage behavior at the GLI was studied under the influence of the microstructure size and the flow driving *** proposed a new kind of hybrid slip boundary condition model to describe the slippage characteristic on *** addition,we found through experiment that a three-dimensional backflow will appear on the GLI under the interfacial adsorption of surfactants,and the backflow direction will reverse with the change of GLI ***,we put forward the wettability step structure and gas injection method to enhance the stability and drag reduction effect of the gas film on SHS.

关键词： Hydrophobic surface superhydrophobic surface interfacial slip underwater drag reduction

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Improving chitosan-based composite membrane by introducing a novel hybrid functional nano-hydroxyapatite with carboxymethyl cellulose and phytic acid

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 1-15页

作者： Liuyun Jiang Yingjun Ma Shuo Tang Yuqing Wang Yan Zhang Shengpei Su Xiang hu jun He National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources Key Laboratory of Chemical Biology&Traditional Chinese Medicine Research(Ministry of Education)College of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha 410081China State Key Laboratory Developmental Biology of Freshwater Fish School of Life ScienceHunan Normal UniversityChangsha 410081China hunan Provincial Key Laboratory of Regional Hereditary Birth Defects Prevention and Control Changsha Hospital for Matemal&Child Health Care Aiffiliated to Hunan Normal UniversityChangsha 410081China

A functional hybrid nano-hydroxyapatite(carboxymethyl cellulose-phytic acid-n-HA,CMC-PA-n-HA)was prepared by adding CMC and *** results of Fourier transformation infrared spectra,X-ray diffraction,thermal gravimetric analysis and dispersion experiments indicated that the addition of CMC and PA affected the morphology,crystallinity and crystal size of hybrid n-HA,and CMC endowed hybrid n-HA with excellent *** electron microscope results showed that CMC-PA-n-HA nanoparticle could be uniformly dispersed in chitosan(CS)matrix to obtain composite membrane by casting technology,so that the highest tensile strength of CMC-PA-n-HA/CS composite membrane was 69.64%and 144.45%higher than that of CS membrane and n-HA/CS composite membrane,*** angle test showed that CMC-PA-n-HA effectively improved hydrophilicity of the CS *** simulated body fluid immersion results indicated that the CMC-PA-n-HA/CS composite membrane not only exhibited good degradability but also promoted bone-like apatite *** cell proliferation experiments proved that the introduction of PA made the composite membrane have better cell adhesion and proliferation *** tests demonstrated that PA could effectively improve the antibacterial properties of the composite membrane,which is expected to be applied as guide bone tissue regeneration membrane.

关键词： nano-hydroxyapatite chitosan dispersion guide bone tissue regeneration membrane

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Surface quality investigation in high-speed dry milling of Ti-6Al-4V by using 2D ultrasonic-vibration-assisted milling platform

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Advances in Manufacturing 2024年第2期12卷 349-364页

作者： Jin Zhang Li Ling qian-Yue Wang Xue-Feng huang Xin-Zhen Kang Gui-Bao Tao hua-jun Cao College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing400044People’s Republic of China State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing400044People’s Republic of China Aerospace Research Institute of Materials and Processing Technology Beijing100076People’s Republic of China

Ultrasonic-vibration-assisted milling(UVAM)is an advanced method for the efficient and precise machining of difficult-to-machine materials in modern ***,the milling efficiency is limited because the ultrasonic vibration toolholder ER16 collet has a critical cutting ***,a 2D UVAM platform is built to ensure precision machining efficiency and improve the surface quality without changing the milling *** evaluate this 2D UVAM platform,ultrasonic-vibration-assisted high-speed dry milling(UVAHSDM)is performed to process a titanium alloy(Ti-6Al-4V)on the platform,and the milling temperature,surface roughness,and residual stresses are selected as the important indicators for performance *** results show that the intermittent cutting mechanism of UVAHSDM combined with the specific spindle speed,feed speed,and vibration amplitude can reduce the milling temperature and improve the texture of the machined *** with conventional milling,UVAHSDM reduces surface roughness and peak-groove surface profile values and extends the range of residual surface compressive stresses from−413.96 MPa to−600.18 *** excellent processing performance demonstrates the feasibility and validity of applying this 2D UVAM platform for investigating surface quality achieved under UVAHSDM.

关键词： 2D ultrasonic-vibration-assisted milling(UVAM)platform Ultrasonic-vibration-assisted high-speed dry milling(UVAHSDM) Milling temperature Surface roughness Residual stress

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CRISPR/Cas9-mediated NlInR2 mutants:Analyses of residual mRNA and truncated proteins

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Journal of Integrative Agriculture 2024年第6期23卷 2006-2017页

作者： jun Lü Jingxiang Chen Yutao hu Lin Chen Shihui Li Yibing Zhang Wenqing Zhang State Key Laboratory of Biocontrol/School of Life Sciences Sun Yat-sen UniversityGuangzhou 510275China Development of Food Science and Engineering Moutai InstituteRenhuai 564507China

CRISPR/Cas9 technology is a powerful genome manipulation tool in ***,little is known about whether mRNA and protein of a target gene are completely cleared in homozygous *** study generated homozygous mutants of the insulin receptor gene 2(NlInR2)in the brown planthopper(Nilaparvata lugens)using CRISPR/Cas9 genome *** frameshift mutants,E5_D17 and E6_I7,differentiated towards long wings,but there were differences in wing morphology,with E5_D17 showing wing *** investigations revealed the presence of residual expression of NlInR2 mRNA in both mutants,as well as the occurrence of spliceosomes featuring exon skipping splicing in E5_***,the E5_D17 exhibited the detection of N-terminally truncated NlInR2 *** interference experiments indicated that the knockdown of NlInR2 expression in the E5_D17 mutant line increased the proportion of wing deformities from 11.1 to 65.6%,suggesting that the residual NlInR2 mRNA of the E5_D17 mutant might have retained some genetic *** results imply that systematic characterization of residual protein expression or function in CRISPR/Cas9-generated mutant lines is necessary for phenotypic interpretation.

关键词： CRISPR/Cas9 Nilaparvata lugens residual mRNA skipping exon truncated protein

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Molecular Mechanism of Polysaccharides Extracted from Chinese Medicine Targeting Gut Microbiota for Promoting Health

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Chinese Journal of Integrative Medicine 2024年第2期30卷 171-180页

作者： ZHAO Wen-xiao WANG Tong ZHANG Ya-nan CHEN qian WANG Yuan XING Yan-qing ZHENG jun DUAN Chen-chen CHEN Lijun ZHAO Hai-jun WANG Shijun School of Nursing Shandong University of Traditional Chinese MedicineShandong University of Traditional Chinese MedicineJi'nan(250355)China Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula Shandong University of Traditional Chinese MedicineJi'nan(250355)China College of Traditional Chinese Medicine Shandong University of Traditional Chinese MedicineJinan(250355)China

The accumulating evidence revealed that gut microbiota plays an important role in pathological process of disease including obesity,type 2 diabetes mellitus,heart failure,and non-alcoholic fatty liver *** extracted from Chinese medicine(CM)can not only alleviate pathological status but also promote health by anti-inflammatory,regulating immunity,lowering blood glucose and lipids,anti-cancer,and *** alterations of gut microbiota composition and metabolism pathways are the potential mechanisms of CM polysaccharides *** addition,they exert functions through gut-organ axis or play an indirect role by synergistic actions with other drugs or components mediated by gut *** review summarizes the molecular mechanisms of CM polysaccharides interacted with intestinal microbial inhabitants as potential prebiotics forpromoting health.

关键词： Chinese medicine polysaccharides gut microbiota short-chain fatty acids lipopolysaccharides gut-organaxis synergistic actions

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