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Mechanical behaviors of warm and ice-rich frozen soil stabilized with sulphoaluminate cement

Journal of Mountain Science 2024年第1期21卷 335-345页

作者： WANG Honglei ZHANG Hu ZHANG Jianming ZHANG qi yin Zhenhua State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China School of Civil Engineering and Transportation Northeast Forestry UniversityHarbin 150040China National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment CCCC First Highway Consultants Co.LtdXi'an 710065China Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China

The warm and ice-rich frozen soil is characterized by high unfrozen water content, low shear strength and large compressibility, which is unreliable to meet the stability requirements of engineering infrastructures and foundations in permafrost regions. In this study, a novel approach for stabilizing the warm and ice-rich frozen soil with sulphoaluminate cement was proposed based on chemical stabilization. The mechanical behaviors of the stabilized soil, such as strength and stress-strain relationship, were investigated through a series of triaxial compression tests conducted at -1.0℃, and the mechanism of strength variations of the stabilized soil was also explained based on scanning electron microscope test. The investigations indicated that the strength of stabilized soil to resist failure has been improved, and the linear Mohr-Coulomb criteria can accurately reflect the shear strength of stabilized soil under various applied confining pressure. The increase in both curing age and cement mixing ratio were favorable to the growth of cohesion and internal friction angle. More importantly, the strength improvement mechanism of the stabilized soil is attributed to the formation of structural skeleton and the generation of cementitious hydration products within itself. Therefore, the investigations conducted in this study provide valuable references for chemical stabilization of warm and ice-rich frozen ground, thereby providing a basis for in-situ ground improvement for reinforcing warm and ice-rich permafrost foundations by soil-cement column installation.

关键词： Permafrost regions Frozen soil Mechanical behavior Chemical stabilization Ground improvement Ground modification

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Intelligent Reflecting Surface Assisted Transmission Optimization Strategies in Wireless Networks

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China Communications 2024年第4期21卷 120-135页

作者： He Xinxin qi Xuan Meng Wei Liu Wei yin Changchuan School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Wireless Power Transfer(WPT)technology can provide real-time power for many terminal devices in Internet of Things(IoT)through millimeterWave(mmWave)to support applications with large capacity and low *** the intelligent reflecting surface(IRS)can be adopted to create effective virtual links to address the mmWave blockage problem,the conventional solutions only adopt IRS in the downlink from the Base Station(BS)to the users to enhance the received signal *** practice,the reflection of IRS is also applicable to the uplink to improve the spectral *** is a challenging to jointly optimize IRS beamforming and system resource allocation for wireless energy acquisition and information *** this paper,we first design a Low-Energy Adaptive Clustering Hierarchy(LEACH)clustering protocol for clustering and data ***,the problem of maximizing the minimum system spectral efficiency is constructed by jointly optimizing the transmit power of sensor devices,the uplink and downlink transmission times,the active beamforming at the BS,and the IRS dynamic *** solve this non-convex optimization problem,we propose an alternating optimization(AO)-based joint solution *** results show that the use of IRS dynamic beamforming can significantly improve the spectral efficiency of the system,and ensure the reliability of equipment communication and the sustainability of energy supply under NLOS link.

关键词： intelligent reflecting surface(IRS) joint optimization millimeter wave wireless information transmission(WIT) wireless power transfer(WPT)

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Alkylene-functionality in bridged and fused nitrogen-rich poly-cyclic energetic materials:Synthesis,structural diversity and energetic properties

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Defence Technology（防务技术） 2024年第5期35卷 18-46页

作者： Man Xu Nanxi Xiang Ping yin qi Lai Siping Pang School of Materials Science&Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open *** the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark *** methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich ***,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic *** this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.

关键词： Energetic materials Alkyl bridge strategy Nitrogen-rich azoles Fused heterocycles Azoles

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Deep learning to estimate ocean subsurface salinity structure in the Indian Ocean using satellite observations

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Journal of Oceanology and Limnology 2024年第2期42卷 377-389页

作者： Jifeng qi Guimin SUN Bowen XIE Delei LI Baoshu yin CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China School of Mathematics and Physics Qingdao University of Science and TechnologyQingdao 266061China CAS Engineering Laboratory for Marine Ranching Institute of OceanologyChinese Academy of SciencesQingdao 266071China

Accurately estimating the ocean subsurface salinity structure(OSSS)is crucial for understanding ocean dynamics and predicting climate *** present a convolutional neural network(CNN)model to estimate the OSSS in the Indian Ocean using satellite data and Argo *** evaluated the performance of the CNN model in terms of its vertical and spatial distribution,as well as seasonal variation of OSSS *** demonstrate that the CNN model accurately estimates the most significant salinity features in the Indian Ocean using sea surface data with no significant differences from Argo-derived ***,the estimation accuracy of the CNN model varies with depth,with the most challenging depth being approximately 70 m,corresponding to the halocline *** of the CNN model’s accuracy in estimating OSSS in the Indian Ocean are also conducted by comparing Argo observations and CNN model estimations along two selected sections and four selected *** results show that the CNN model effectively captures the seasonal variability of salinity,demonstrating its high performance in salinity estimation using sea surface *** analysis reveals that sea surface salinity has the strongest correlation with OSSS in shallow layers,while sea surface height anomaly plays a more significant role in deeper *** preliminary results provide valuable insights into the feasibility of estimating OSSS using satellite observations and have implications for studying upper ocean dynamics using machine learning techniques.

关键词： machine learning convolutional neural network(CNN) ocean subsurface salinity structure(OSSS) Indian Ocean satellite observations

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Insensitizing Controls for the Parabolic Equation with Equivalued Surface Boundary Conditions

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Acta Mathematica Sinica,English Series 2012年第12期28卷 2373-2394页

作者： Zhong qi yin School of Mathematics Sichuan University Department of Mathematics Sichuan Normal University

This paper is devoted to the study of the existence of insensitizing controls for the parabolic equation with equivalued surface boundary conditions. The insensitizing problem consists in finding a control function such that some energy functional of the equation is locally insensitive to a perturbation of the initial data. As usual, this problem can be reduced to a partially null controllability problem for a cascade system of two parabolic equations with equivalued surface boundary conditions. Compared the problems with usual boundary conditions~ in the present case we need to derive a new global Carleman estimate, for which, in particular one needs to construct a new weight function to match the equivalued surface boundary conditions.

关键词： Insensitizing controls parabolic equation equivalued boundary conditions

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A robust viscoelastic surfactant tolerating 20% HCl up to 150℃ for oil well stimulation

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Petroleum Science 2024年第3期21卷 1865-1874页

作者： Ji Wang Ning qi Hong-Yao yin Yu-Jun Feng Polymer Research Institute State Key Laboratory of Polymer Materials Engineering Sichuan University Tianfu Yongxing Laboratory New Theory and Technology of CO School of Petroleum Engineering China University of Petroleum (East China)

Viscoelastic surfactants（VES） are often used as viscous diverters in acidizing stimulation to prolong the acid consumption time and maximize zonal coverage of the acid for improving well ***, the ceiling temperature of commercial VES cannot exceed 120℃ in practical use because of the poor thermal stability and fragile molecular structure, hindering their implementation in hightemperature oil reservoirs, i.e., ≥150℃. Here we synthesized a novel C22-tailed diamine, N-erucaminopropyl-N,N-dimethylamine（EDPA）, and examined comparatively its rheological behavior, assemblies morphology and molecular stability in 20 wt% HCl with a commercial VES, erucyl dimethyl amidopropyl betaine（EDAB）. The feasibility of EDPA for acidizing stimulation was assessed by acid etching of carbonate rock with its HCl solution at 150℃. Rheological results showed that the 2.5 wt% EDPA—20 wt%HCl solution maintains stable viscosity of 90 m Pa s at 150℃ for 60 min, while that of 2.0 wt% EDAB HCl solution is just 1 m Pa s under identical conditions.1H NMR spectra and cryo-TEM observations revealed that the chemical structure and self-assembled architectures of EDPA remained intact in such context,but the EDAB suffered from degradation due to the hydrolysis of the amide group, accounting for the poor heat-resistance and acid-tolerance. The reaction rate of 2.5 wt% EDPA HCl solution with carbonate rock was one order of magnitude lower than that of 20 wt% HCl solution at 150℃, underpinning the potential of EDPA to be used in the high-temperature reservoirs acidizing. This work improved the thermal tolerance of VES in highly concentrated HCl solution, paving a feasible way for the acidization of high-temperature reservoir environments（～150℃）.

关键词： Viscoelastic surfactants Thermal stability Self-diverting acid Wormlike micelles Acidizing stimulation

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Local failure mechanism of sand-blocking fence in latticed dune along desert roads

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Journal of Mountain Science 2024年第2期21卷 526-537页

作者： LI Liangying LV Lele LI qi WANG Zhenqiang YANG Youhai yin Wenhua School of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730070China Ningxia Highway Survey and Design Institute Co Ltd Yinchuan 750001China

The latticed dunes in the Tengger Desert are widely distributed,and the sand-blocking fence placed here are highly susceptible to local failure due to complex wind-sand activities,posing a serious threat to the safe operation of the *** explore the local failure mechanism of sand-blocking fence in the latticed dune area,the local failure of sand-blocking fence in the latticed dune areas along the Wuhai-Maqin Highway in China was *** the first main ridge of the latticed dune as the placement location,the structure of the wind-sand flow field of sand-blocking fence placed at top,the bottom and the middle of windward slope was analyzed by Computational Fluid Dynamics(CFD).The results show that when placed at top of the first main ridge,the wind speed near the sand-blocking fence is the highest,up to 15.23 m/***,the wind load strength on the sand barrier is correspondingly larger,up to 232.61 N∙*** the strength of material continues to decrease,the nylon net is prone to *** roots of the angle steel posts are susceptible to hollowing by vortex action,which can cause sand-blocking fence to fall over in strong wind *** placed at the bottom of windward slope,wind speed drop near sand-blocking fence is greatest,with the decrease of 12.48-14.32 m/s compared to the original wind *** is highly likely to lead to large-scale deposition of sand particles and burial of the sand-blocking *** placed in the middle of windward slope,sand-blocking fence is subjected to less wind load strength(168.61N∙m-2)and sand particles are mostly deposited at the bottom of windward slope,with only a small amount of sand accumulating at the root of sand-blocking *** on field observations and numerical modelling results,when the sand-blocking fence is placed in latticed dune area,it should be placed in the middle of the windward slope of the first main ridge as a matter of *** the sand-blocking fence should be placed

关键词： Latticed dune Sand-blocking fence Local failure Numerical simulation Desert roads

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Research on Fiber Optic Surface Plasmon R ***:A Review

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Photonic Sensors 2024年第2期14卷 1-30页

作者： qi WANG Dianyun ZHANG Yizhuo qiAN Xiangyu yin Lei WANG Shushuai ZHANG Yuyang WANG State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China College of Information Science and Engineering Northeastern UniversiyShenyang 110819China Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology Qinhuangdao 066004China State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan UniversityChangsha 410082China

Due to the benefits of the high sensitivity,real-time response,no labeling requirement,and good selectivity,fiber optic sensors based on surface plasmon resonance(SPR)have gained popularity in biochemical sensing in recent *** current research on such sensors is hot in enhancing sensitivity,improving detection accuracy,and achieving the detection of biochemical *** goal of this work is to present a thorough overview of recent developments in the optical fiber SPR biosensor ***,it explores the basic principles and sensing structures of optical fiber SPR biosensors,focusing on four ***,this paper introduces three fiber optic surface plasmon biosensors:SPR,localized surface plasmon resonance(LSPR),and long-range surface plasmon resonance(LRSPR).Each concept is explained from the perspective of the basic principles of fiber optic SPR ***,a classification of fiber optic SPR biosensors in health monitoring,food safety,environmental monitoring,marine detection,and other applications is introduced and ***,this paper summarizes the current research directions of SPR ***,it provides a prospective outlook on how fiber optic SPR sensors will develop in the future.

关键词： Surface plasmon resonance biosensors optical fiber sensors sensitivity

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Solubility of iron(Ⅲ) and nickel(Ⅱ) acetylacetonates in supercritical carbon dioxide

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Chinese Journal of Chemical Engineering 2024年第1期65卷 29-34页

作者： Haixin Sun Jianlei qi Jianfei Sun Lin Li Kunpeng Yu Jintao Wu Jianzhong yin State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China College of Chemical Engineering Inner Mongolia University of TechnologyHohhot 010051China

As a common precursor for supercritical CO_(2)(scCO_(2))deposition techniques,solubility data of organometallic complexes in scCO_(2)is crucial for the preparation of ***,metal acetylacetonates have shown great potential for the preparation of single-atom catalytic *** this study,the solubilities of iron(Ⅲ)acetylacetonate(Fe(acac)3)and nickel(Ⅱ)acetylacetonate(Ni(acac)2)were measured at the temperature from 313.15 to 333.15 K and in the pressure range of 9.5–25.2 MPa to accumulate new solubility *** was measured using a static weight loss *** semi-empirical models proposed by Chrastil and Sung et *** used to correlate the solubility data of Fe(acac)3 and Ni(acac)*** equations obtained can be used to predict the solubility of the same system in the experimental range.

关键词： Iron(III)acetylacetonate Nickel(II)acetylacetonate Supercritical carbon dioxide Solubility measurement Correlation model Phase equilibrium

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Influence of natural deposition plane orientation on oedometric consolidation behavior of three typical clays from southeast coast of China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第11期14卷 767-777页

作者： qi-yin ZHU yin-fu JIN Zhen-yu yin Pierre-Yves HICHER Department of Civil Engineering Shanghai Jiao Tong University LUNAM University Ecole Centrale de NantesGeM UMR CNRS 6183 Nantes France

The parameters obtained from oedometric consolidation tests are commonly used in the development of constitutive modeling and for engineering practice. This paper focuses on the influence of the natural deposition plane orientation on oedometric consolidation behavior of three natural clays from the southeast coast of China. Oedometer tests were conducted on intact specimens prepared by sampling at a series of angles relative to the natural deposition plane. For each specimen, yield stress,compressibility indexes, secondary compression, and permeability coefficients were determined. The influence of the sampling angle on these properties was investigated, revealing that yield stress, compression index, swelling index, creep index, ratio of secondary compression coefficient to compression index(Cae/Cc) and permeability coefficient were all dependent to some extent on the sampling angle. These findings indicate the role of the anisotropy due to the natural deposition on the oedometric consolidation behavior.

关键词： Clay Compressibility Consolidation Creep Permeability Natural deposition

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