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Study on disc cutter chipping of TBM based on field data and particle flow code simulation

Underground Space 2023年第2期9卷 122-139页

作者： Yadong Xue Yongqiang fan xing Li Kai Shen Jiaxuan Wang Key Laboratory of Geotechnical and Underground Engineering of Education Ministry Tongji UniversityShanghai 200092China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China China State Construction Silkroad Construction Investment Group Co. LTDXi’an 710075China School of Civil Engineering Central South UniversityChangsha 410075China

Using tunnel boring machines to excavate high-strength intact rock masses is becoming more *** to the interactions between disc cutters and rocks,abnormal wear of disc cutters,especially cutter chipping,has become a common *** research has mainly focused on normal wear of disc cutters without addressing abnormal wear *** study used the disc cutter consumption data of a tunnel project in China to investigate the abovementioned problem based on field *** to the fail-ure patterns and fracture surface characteristics,the cutter chipping patterns were mainly categorized into four types:granule chipping,patch chipping,primary collapse,and secondary *** further simulate the evolution of disc cutter chipping,based on the linear plastic bond model,a new contact model called the modified plastic bond(MPB)model was proposed to solve the metal simulation prob-lem in Particle Flow Code *** this end,a set of uniaxial tensile and compressive tests were initially conducted to verify the applicability of the MPB ***,a series of three-dimensional rock-cutting simulation tests were conducted to reflect the evolu-tionary processes involved in each type of cutter *** cutter chipping mechanism and morphological characteristics were clas-sified and summarized in *** results revealed that the cutting speed and penetration growth led to a rising trend in the probability and intensity of the cutter *** presence of initial defects also induced an adverse effect on the service life of the *** results indicated suitable working conditions for the cutter and suggested ways to control tunneling parameters and avoid frequent cutter chipping cases.

关键词： Tunnel boring machine Disc cutter Cutter chipping Particle flow code Modified plastic bond model

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POSS-embedded supramolecular hyperbranched polymers constructed from a 1→7 branching monomer with controllable morphology transitions

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Science China Chemistry 2018年第3期61卷 311-318页

作者： xing Wang Yanyu Yang Linfeng fan Fei Yang Decheng Wu Beijing National Laboratory for Molecular Sciences State Key Laboratory of Polymer Physics & Chemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China College of Materials Science and Engineering Zhengzhou University Zhengzhou 450052 China University of Chinese Academy of Sciences Beijing 100049 China

The research on the supramolecular hyperbranched polymers(SHPs) that combines the advantages of supramolecular polymer and hyperbranched architecture has attracted considerable interests in many applications. Here we demonstrate a simple approach to prepare POSS-embedded supramolecular hyperbranched polymers(POSS-SHPs) with varied morphology and size by controlling monomer concentration and mixed solvents. The SHPs formations can further transfer into the core-shell structured micelles by addition of competitive guests based on the double supramolecular driving forces.

关键词： POSS-embedded polymer supramolecular hyperbranched polymer host-guest interaction morphology transition

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Urban planning construction land standard and its revision based on climate and topography in China

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Journal of Geographical Sciences 2021年第4期31卷 603-620页

作者： XU Yong zhao Shen fan Jie Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land,and it is the basis for drawing up and revising the overall urban planning *** China’s current urban planning construction land standard,many problems exist,such as the gap in the land use control threshold,the lack of regional differences in the climate revision,and failing to consider the topographic *** resolve these problems,this study proposed a step-by-step process framework and quantitative calculation method for the establishment and revision of standards in accordance with the principle of Total-Structure *** setting the conditions,a universal basic standard for construction land was *** analysis was then conducted on the relationship between the basic standard and the selected key indicators,such as urban population size,sunshine spacing coefficient,the width of river valleys or inter-montane basins,and terrain slope,among ***,revised standards were formed for climate conditions,topography,and geomorphologic conditions,which were matched with the basic *** key results are three-fold:(1)The per capita construction land standard of 95 m~2/person can be used as the total indicator of China’s urban planning basic standard,and the corresponding per capita single construction land comprises 32.50%of residential land,7.42%of public management and public service land,22.50%of industrial land,17.50%of transportation facilities,12.50%of green space,and 7.58%of other land-use *** results of the revision of the urban population size indicate that the difference in population size has little effect on the total amount of per capita construction land.(2)The climate revision results of per capita residential land and per capita construction land in major cities reveal that the revised climate value varies greatly between north and south *** revised

关键词： urban planning construction land standard climate revision standard topography revision standard

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In situ FT-IR investigation on the reaction mechanism of visible light photocatalytic NO oxidation with defective g-C_3N_4

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Science Bulletin 2018年第2期63卷 117-125页

作者： Hong Wang Wenjie He xing’an Dong Haiqiang Wang fan Dong Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and Resources Chongqing Technology and Business University Department of Environmental Engineering Key Laboratory of Polluted Environment Remediation and Ecological Health of Ministry of Education Zhejiang University

The g-C_3N_4 with different structures was prepared by heat treatment using urea(CN-U) and thiourea(CN-T) as precursors under the same conditions. The microstructure and optical properties of the photocatalyst were analyzed with advanced tools. The results showed that the CN-U has a porous structure, a high specific surface area and a wide band gap in comparison with CN-T. The in situ FT-IR technique was used to monitor the adsorption and reaction process of visible photocatalytic NO oxidation on g-C_3N_4. The corresponding reaction mechanism was proposed based on the results of reaction intermediate observation and electron paramagnetic resonance(EPR) radical scavenging. It was revealed that(1) the presence of defective sites favored the adsorption of gas molecules and electronically compensated it leading to promoted formation of the final products;(2) the high separation efficiency of photogenerated electron-hole pairs enhanced the production of radicals during the photocatalytic reaction;(3) the hydroxyl radicals(-OH) are not selective for the decomposition of pollutants, which are favorable to the complete oxidation of the reaction intermediates. The above three aspects are the main reasons for the CN-U possessing the efficient visible light photocatalytic activity. The present work could provide new insights and methods for understanding the mechanism of photocatalysis.

关键词： g-C3N4 Visible light photocatalysis Defects In situ FT-IR Reaction mechanism

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Effect of low-speed waterjet pressure on the rock-breaking performance of unsubmerged cavitating abrasive waterjet

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Petroleum Science 2024年第4期21卷 2638-2649页

作者： Chen-xing fan Deng Li Yong Kang Hai-Tao Zhang Hubei Key Laboratory of Waterjet Theory and New Technology Wuhan UniversityWuhan430072HubeiChina School of Power and Mechanical Engineering Wuhan UniversityWuhan430072HubeiChina

Unsubmerged cavitating abrasive waterjet(UCAWJ)has been shown to artificially create a submerged environment that produces shear cavitation,which effectively enhances rock-breaking *** shear cavitation generation and collapse intensity depend on the pressure difference between the intermediate high-speed abrasive waterjet and the coaxial low-speed ***,the effect of the pressure of the coaxial low-speed waterjet is *** this purpose,the effect of low-speed waterjet pressure on rock-breaking performance at different standoff distances was experimentally investigated,and the effects of erosion time and ruby nozzle diameter on erosion performance were ***,the micromorphology of the sandstone was observed at different *** results show that increased erosion time and ruby nozzle diameter can significantly improve the rock-breaking *** different standoff distances,the mass loss increases first and then decreases with the increase of low-speed waterjet pressure,the maximum mass loss is 10.4 g at a low-speed waterjet pressure of0.09 *** surface morphology of cavitation erosion was measured using a 3D profiler,the increase in both erosion depth and surface roughness indicated a significant increase in the intensity of the shear cavitation *** a low-speed waterjet pressure of 0.18 MPa,the cavitation erosion surface depth can reach 600μm with a roughness of 127μm.

关键词： Rock-breaking Coaxial low-speed waterjet pressure Abrasive waterjet Cavitation Unsubmerged environment

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Molecular imprinted polymer with positively charged assistant recognition polymer chains for adsorption/enrichment of low content target protein

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Chinese Science Bulletin 2008年第17期53卷 2617-2623页

作者： LONG Yi SUN Yang WANG Ying xing XiaoCui zhao Zhuo WANG ChunHong fan YunGe MI HuaiFeng Key Laboratory of Functional Polymer Materials of Ministry of Education Institute of Polymer Chemistry Nankai University Tianjin 300071 China

Here, we introduce a new type of molecular imprinted polymer (MIP) with immobilized assistant recognition polymer chains (ARPCs) to create effective recognition sites and with bacterial cloned protein as template for adsorbing the low content target protein from cell extract. In this work, cloned pig cyclophilin 18 (pCyP18), a peptidyl-prolyl cis/trans-isomerase, was used as template. The template protein was selectively assembled with ARPCs from their library, which consists of numerous limited length polymer chains with randomly distributed recognition sites of positively charged amino groups and immobilizing sites. These assemblies were adsorbed by porous microsphers and immobilized on them. After removing the template, binding sites complementary to the target protein in size, shape and the position of recognition groups were exposed, and their confirmation was preserved by the cross-linked structure. The synthesized MIP was used to adsorb the cellular pCyP18, and its proportional content was enriched more than hundred times. The extended experiment on imprinting bovine serum albumin (BSA) with ARPCs shows that this method is also suitable for large protein.

关键词：分子印迹聚合体蛋白质生物化学聚合物链

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Dynamic Active Sites in Bi_(5)O_(7)I Promoted by Surface Tensile Strain Enable Selective Visible Light CO_(2)Photoreduction

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Research 2023年第1期2022卷 301-311页

作者： Xian Shi xing'an Dong Yanjuan Sun Shihan Zhang fan Dong Research Center for Environmental and Energy Catalysis Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province College of EnvironmentZhejiang University of TechnologyHangzhou 310014China

Surface defects with abundant localized electrons on bismuth oxyhalide catalysts are proved to have the capability to capture and activate CO_(2).However,bismuth oxyhalide materials are susceptible to photocorrosion,making the surface defects easily deactivated and therefore losing their function as active *** of deactivation-resistant surface defects on catalyst is essential for stable CO_(2)photoreduction,but is a universal *** this work,the Bi_(5)O_(7)I nanotubes with surface tensile strain are synthesized,which are favorable for the visible light-induced dynamic I defects *** CO_(2)molecules absorbed on I defects are constantly reduced by the incoming photogenerated electrons from I-deficient Bi_(5)O_(7)I nanotubes and the successive protonation of CO_(2)molecules is thus highly promoted,realizing the selective CO_(2)conversion process via the route of CO_(2)-COOH^(-)-*** efficient and stable photoreduction of CO_(2)into CO with 100%selectivity can be achieved even under visible light(>420 nm)irradiation benefited from the dynamic I defects as active *** results presented herein demonstrate the unique action mechanism of light-induced dynamic defects during CO_(2)photoreduction process and provide a new strategy into rational design of deactivation-resistant catalysts for selective CO_(2)photoreduction.

关键词： visible bismuth rational

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Dual-Wavelength Laser Flash Raman Spectroscopy Method for In-Situ Measurements of the Thermal Diffusivity: Principle and Experimental Verification

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Journal of Thermal Science 2019年第2期28卷 159-168页

作者： fan Aoran HU Yudong MA Weigang WANG Haidong ZHANG xing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University

This paper presents an in-situ, non-contact, non-destructive "dual-wavelength laser flash Raman spectroscopy method" for measuring the thermal diffusivity. In this method, a heating pulse is used to heat the sample and another pulsed laser with a different wavelength and negligible heating effect is used as a probe to measure the sample temperature changes during the heating and cooling periods from the Raman peak shifts. The sample temperature rise and fall curves are measured by changing the delay between the heating pulse and the probing pulse with the thermal diffusivity then characterized by fitting the temperature curves. The time delay between the heating and probing pulses can be precisely controlled with a minimum step of 100 ps. Hence, the temperature variation can be scanned with an ultra-high temporal resolution of up to 100 ps, which significantly improves the measurement accuracy of transient thermal parameters. The measurement accuracy of this method has been verified using a bulk material model and experiments. The measured thermal diffusivity of a silicon sample has been obtained to be 8.8×10^(-5 )m^2/s with a 3% difference between the measured value and the average result for bulk silicon in the literature which verifies the reliability and accuracy of this method.

关键词： dual-wavelength laser flash Raman spectroscopy method thermal diffusivity Raman spectroscopy nanomaterials bulk materials

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Modifying glass fiber surface with grafting acrylamide by UV-grafting copolymerization for preparation of glass fiber reinforced PVDF composite membrane

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Journal of Environmental Sciences 2016年第1期28卷 208-217页

作者： Nan Luo Hui Zhong Min Yang xing Yuan Yaobo fan Group of Membrane Separation Technique Department of Water Pollution Control Technology Research Center for Eco-Environmental Sciences (RCEES) Chinese Academy of Sciences (CAS) State Key Joint Laboratory of Environmental Simulation and Pollution Control Research Center for Eco-Environmental Sciences (RCEES)Chinese Academy of Sciences (CAS)

Experimental design and response surface methodology（RSM） were used to optimize the modification of conditions for glass surface grafting with acrylamide（AM） monomer for preparation of a glass fiber reinforced poly（vinylidene fluoride）（PVDF） composite membrane（GFRP-CM）. The factors considered for experimental design were the UV（ultraviolet）-irradiation time, the concentrations of the initiator and solvent, and the kinds and concentrations of the silane coupling agent. The optimum operating conditions determined were UV-irradiation time of 25 min, an initiator concentration of 0–0.25 wt.%,solvent of N-Dimethylacetamide（DMAC）, and silane coupling agent KH570 with a concentration of 7 wt.%. The obtained optimal parameters were located in the valid region and the experimental confirmation tests conducted showed good accordance between predicted and experimental values. Under these optimal conditions, the water absorption of the grafted modified glass fiber was improved from 13.6% to 23%; the tensile strength was enhanced and the peeling strength of the glass fiber reinforced PVDF composite membrane was improved by 23.7% and 32.6% with an AM concentration at 1 wt.% and 2 wt.%. The surface composition and microstructure of AM grafted glass fiber were studied via several techniques including Field Emission Scanning Electron Microscopy（FESEM）, Fourier transform infrared spectroscopy-attenuated total reflectance（FTIR-ATR） and energy dispersive X-ray spectroscopy（EDX）. The analysis of the EDX and FTIR-ATR results confirmed that the AM was grafted to the glass fiber successfully by detecting and proving the existence of nitrogen atoms in the GFRP-CM.

关键词： Glass fibers Polymer-matrix composites Coupling agents UV-grafting copolymerization Interfacial strength

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ROS-Responsive Berberine Polymeric Micelles Effectively Suppressed the Inflammation of Rheumatoid Arthritis by Targeting Mitochondria

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Nano-Micro Letters 2020年第6期12卷 138-151页

作者： xing-xing fan Meng-ze Xu Elaine Lai-Han Leung Cai Jun Zhen Yuan Liang Liu State Key Laboratory of Quality Research in Chinese Medicine Macao Institute For Applied Research in Medicine and HealthMacao University of Science and TechnologyAvenida Wai LongTaipaMacao SARChina Faculty of Health Sciences University of MacaoTaipaMacao SARChina

Rheumatoid arthritis(RA)is an autoimmune disease,which attacks human joint system and causes lifelong inflammatory *** date,no cure is available for RA and even the ratio of achieving remission is very ***,to enhance the efficacy of RA treatment,it is essential to develop novel approaches specifically targeting pathological *** this study,we discovered that RA synovial fibroblasts exhibited higher reactive oxygen species(ROS)and mitochondrial superoxide level,which were adopted to develop ROS-responsive nano-medicines in inflammatory microenvironment for enhanced RA treatment.A selenocystamine-based polymer was synthesized as a ROS-responsive carrier nanoplatform,and berberine serves as a tool *** assembling,ROS-responsive berberine polymeric micelles were fabricated,which remarkably increased the uptake of berberine in RA fibroblast and improved in vitro and in vivo efficacy ten times ***,the anti-RA effect of micelles was blocked by the co-treatment of AMPK inhibitor or palmitic acid,indicating that the mechanism of micelles was carried out through targeting mitochondrial,suppressing lipogenesis and finally inhibiting cellular *** together,our ROS-responsive nano-medicines represent an effective way of preferentially releasing prodrug at the inflammatory microenvironment and improving RA therapeutic efficacy.

关键词： Rheumatoid arthritis Reactive oxygen species Nanoparticles Berberine Oxygen consumption rate

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