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Efficient placement technology of proppants based on structural stabilizers
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作者 GUO Jianchun REN Shan +3 位作者 ZHANG Shaobin DIAO Su LU Yang ZHANG Tao 《Petroleum Exploration and Development》 SCIE 2024年第3期706-714,共9页
Fiber is highly escapable in conventional slickwater,making it difficult to form fiber-proppant agglomerate with proppant and exhibit limited effectiveness.To solve these problems,a novel structure stabilizer(SS)is de... Fiber is highly escapable in conventional slickwater,making it difficult to form fiber-proppant agglomerate with proppant and exhibit limited effectiveness.To solve these problems,a novel structure stabilizer(SS)is developed.Through microscopic structural observations and performance evaluations in indoor experiments,the mechanism of proppant placement under the action of the SS and the effects of the SS on proppant placement dimensions and fracture conductivity were elucidated.The SS facilitates the formation of robust fiber-proppant agglomerates by polymer,fiber,and quartz sand.Compared to bare proppants,these agglomerates exhibit reduced density,increased volume,and enlarged contact area with the fluid during settlement,leading to heightened buoyancy and drag forces,ultimately resulting in slower settling velocities and enhanced transportability into deeper regions of the fracture.Co-injecting the fiber and the SS alongside the proppant into the reservoir effectively reduces the fiber escape rate,increases the proppant volume in the slickwater,and boosts the proppant placement height,conveyance distance and fracture conductivity,while also decreasing the proppant backflow.Experimental results indicate an optimal SS mass fraction of 0.3%.The application of this SS in over 80 wells targeting tight gas,shale oil,and shale gas reservoirs has substantiated its strong adaptability and general suitability for meeting the production enhancement,cost reduction,and sand control requirements of such wells. 展开更多
关键词 hydraulic fracturing PROPPANT structure stabilizer placement mechanism CONDUCTIVITY proppant backflow rate
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Enhanced stability of FA-based perovskite:Rare-earth metal compound EuBr_(2) doping
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作者 候敏娜 郭旭 +6 位作者 韩梅斗雪 赵均陶 王志元 丁毅 侯国付 张宗胜 韩小平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期669-675,共7页
It is highly desirable to enhance the long-term stability of perovskite solar cells(PSCs)so that this class of photovoltaic cells can be effectively used for the commercialization purposes.In this contribution,attempt... It is highly desirable to enhance the long-term stability of perovskite solar cells(PSCs)so that this class of photovoltaic cells can be effectively used for the commercialization purposes.In this contribution,attempts have been made to use the two-step sequential method to dope EuBr_(2)into FAMAPbI_(3)perovskite to promote the stability.It is shown that the device durability at 85℃in air with RH of 20%-40%is improved substantially,and simultaneously the champion device efficiency of 23.04%is achieved.The enhancement in stability is attributed to two points:(ⅰ)EuBr_(2)doping effectively inhibits the decomposition andα-δphase transition of perovskite under ambient environment,and(ⅱ)EuBr_(2)aggregates in the oxidized format of Eu(BrO_(3))_(3)at perovskite grain boundaries and surface,hampering humidity erosion and mitigates degradation through coordination with H_(2)O. 展开更多
关键词 EuBr_(2) doping inhibited phase transition and decomposition stabilITY perovskite solar cell
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Study on Compound Stabilizer Formulation for Mango Juice with Skin
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作者 Ziyi YANG Yurong WANG +2 位作者 Licheng LIU Zijing WANG Jiamei LIU 《Agricultural Biotechnology》 2024年第1期78-83,共6页
[Objectives]The effects of stabilizers such as sodium carboxymethyl cellulose,pectin,sodium alginate and xanthan gum on the stability of mango juice with skin were discussed using mango as the raw material.[Methods]Th... [Objectives]The effects of stabilizers such as sodium carboxymethyl cellulose,pectin,sodium alginate and xanthan gum on the stability of mango juice with skin were discussed using mango as the raw material.[Methods]The formula and stability of mango beverage with skin were studied using mango juice with skin as the raw material.Four stabilizers,including pectin,sodium alginate and sodium carboxymethyl cellulose,were added to improve the stability of the juice.Based on single factor experiments and a response surface experiment,the stability model of mango juice was established to determine the best compound stabilizer.[Results]According to an orthogonal experiment on the stability of mango juice with skin,the optimum technical parameters were as follows:sodium carboxymethyl cellulose 0.20%,xanthan gum 0.08%,sodium alginate 0.18%,and pectin 0.14%,with which the optimal suspension stability was 69.12%.The optimum technical parameters from the response surface experiment were as follows:sodium carboxymethyl cellulose 0.199%,pectin 0.1185%,sodium alginate 0.163%,and xanthan gum 0.077%,with which the suspension stability was 70.32%.It was found that the stability of mango juice with skin obtained by the response surface experiment was better than that by the orthogonal experiment,and the order of factors affecting the stability of mango was sodium alginate(C)>sodium carboxymethyl cellulose(A)>pectin(D)>xanthan gum(B).[Conclusions]The formula of compound stabilizer for mango juice was optimized by the orthogonal experiment and the response surface method,providing a theoretical basis for the actual production of mango juice with skin. 展开更多
关键词 MANGO stability of fruit juice Response surface experiment Optimization
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Assessment of Cement-Lime as Stabilizer on Mud Bricks
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作者 Chrisdel Chancelice Ndjeumi Djonga Paul Nestor Djomou +2 位作者 George Elambo Nkeng Fatoumata Adda Souaibou Soulemane Anong 《Journal of Materials Science and Chemical Engineering》 2024年第7期1-13,共13页
The aim of this study was to evaluate the compressive strength of clay bricks and their stability to water absorption by inserting stabilizers such as lime and cement of 0%, 4%, 6%, 8%, 10%, 12% to 14%. Spectrometric ... The aim of this study was to evaluate the compressive strength of clay bricks and their stability to water absorption by inserting stabilizers such as lime and cement of 0%, 4%, 6%, 8%, 10%, 12% to 14%. Spectrometric analysis was used to characterize the various stabilizers and the clay used, and tests of resistance and water absorption were also carried out. The clay was found to be an aluminosilicate (15.55% to 17.17% Al2O3 and 42.12% to 44.15% SiO2). The lime contains 90.84% CaO and the cement has 17.80% SiO2, 3.46% Al2O3, 2.43% Fe2O3 and 58.47% CaO in the combined form of tricalcium silicate, dicalcium silicate, tricalcium aluminate and ferro-tetra calcium aluminate. The results showed that the insertion of locally available stabilizers (lime and cement) improved the strength of the material by almost 80% when the lime was increased from 0% to 14% for 14 days. For compressed cement, a 65% increase in strength was observed under the same conditions. Strength increases with drying time, with a 52% increase in strength at 28 days compared to 14 days. Furthermore, compressed cement bricks have a more compact structure, absorbing very little water (32%). In view of all these results, cement appears to be the best stabilizer, and compression improves compressive strength and reduces water absorption. 展开更多
关键词 Cement-stabilized Earth Lime-stabilized Earth Compressed Earth Brick Compressive Strength Water Absorption Test
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Synthesis,crystallographic characterization,and potential application of fullerene anisole derivatives as nitrocellulose stabilizer
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作者 Jie Xiong Bo Jin +2 位作者 Xue-mei Yu Ling Liao Ru-fang Peng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期164-172,共9页
A series of fullerene anisole derivative stabilizers was synthesized by nucleophilic substitution reaction using hexachlorofullerene and benzyl alcohol as raw materials to extend the service duration of nitrocellulose... A series of fullerene anisole derivative stabilizers was synthesized by nucleophilic substitution reaction using hexachlorofullerene and benzyl alcohol as raw materials to extend the service duration of nitrocellulose(NC)-based propellants.Single-crystal X-ray diffraction,nuclear magnetic resonance,highresolution mass spectrometry,Fourier transform infrared(FT-IR)spectroscopy,and UV-Vis spectroscopy were used to characterize the structures of the synthesized fullerene anisole derivative stabilizers.Methyl violet,differential scanning calorimetry test,isothermal weight loss,vacuum stability test,and adiabatic accelerated test were used to study their compatibility with NC and their ability to stabilize NC.The results show that the designed and synthesized novel fullerene anisole derivative stabilizer has good compatibility with NC,and their overall stabilizing effects on NC are better than those of the traditional stabilizers,diphenylamine(DPA),and N,N’-dimethyl-N,N’-diphenylurea(C2).The stabilizing effects was ranked as:3b>2d>2a>2c>C2>2b>DPA>NC.In addition,FT-IR analysis and electron spin resonance spectroscopy were applied to explore the stability mechanism of fullerene-based stabilizers to NC.The results reveal that the new fullerene stabilizer can adsorb and effectively eliminate the nitrogen oxide free radicals generated by NC degradation;therefore,it can forbid the autocatalytic degradation of NC and stabilize NC. 展开更多
关键词 FULLERENE NITROCELLULOSE stability PROPELLANT Mechanism
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Atom substitution of the solid-state electrolyte Li_(10)GeP_(2)S_(12)for stabilized all-solid-state lithium metal batteries 被引量:1
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作者 Zijing Wan Xiaozhen Chen +3 位作者 Ziqi Zhou Xiaoliang Zhong Xiaobing Luo Dongwei Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期28-38,I0002,共12页
Solid-state electrolyte Li_(10)GeP_(2)S_(12)(LGPS)has a high lithium ion conductivity of 12 mS cm^(-1)at room temperature,but its inferior chemical stability against lithium metal anode impedes its practical applicati... Solid-state electrolyte Li_(10)GeP_(2)S_(12)(LGPS)has a high lithium ion conductivity of 12 mS cm^(-1)at room temperature,but its inferior chemical stability against lithium metal anode impedes its practical application.Among all solutions,Ge atom substitution of the solid-state electrolyte LGPS stands out as the most promising solution to this interface problem.A systematic screening framework for Ge atom substitution including ionic conductivity,thermodynamic stability,electronic and mechanical properties is utilized to solve it.For fast screening,an enhanced model Dop Net FC using chemical formulas for the dataset is adopted to predict ionic conductivity.Finally,Li_(10)SrP_(2)S_(12)(LSrPS)is screened out,which has high lithium ion conductivity(12.58 mS cm^(-1)).In addition,an enhanced migration of lithium ion across the LSr PS/Li interface is found.Meanwhile,compared to the LGPS/Li interface,LSrPS/Li interface exhibits a larger Schottky barrier(0.134 eV),smaller electron transfer region(3.103?),and enhanced ability to block additional electrons,all of which contribute to the stabilized interface.The applied theoretical atom substitution screening framework with the aid of machine learning can be extended to rapid determination of modified specific material schemes. 展开更多
关键词 Atom substitution Solid-state electrolyte Machine learning stabilized interface
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Production of Corn (Zea mays) Starch and Cassava (Manihot esculenta) Starch and Their Application as Yogurt Stabilizer
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作者 Fabien Nsanzabera Alexis Manishimwe +1 位作者 Aimable Mwiseneza Evangeline Irakoze 《Food and Nutrition Sciences》 2023年第7期589-600,共12页
The present study evaluated the stabilizing effect of starch produced from corns and cassava on the stability of cow milk yogurt. A sample of both corn and cassava starch was selected and used in the yogurt making as ... The present study evaluated the stabilizing effect of starch produced from corns and cassava on the stability of cow milk yogurt. A sample of both corn and cassava starch was selected and used in the yogurt making as stabilizers. The yogurt samples have been analyzed for their WHC, syneresis and protein content. The yogurt with no added starch has found to have very low WHC and high syneresis compared to other samples. The yogurt made with the addition of corn starch as a stabilizer was highly accepted than the yogurt with cassava starch and the yogurt without starch. The findings from this study provide an alternative to add the value of local corns and cassava. 展开更多
关键词 Corn Starch Cassava Starch Cow Milk Yogurt stabilizer SYNERESIS
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Gouge stability controlled by temperature elevation and obsidian addition in basaltic faults and implications for moonquakes 被引量:1
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作者 Shutian Cao Fengshou Zhang +4 位作者 Mengke An Derek Elsworth Manchao He Hai Liu Luanxiao Zhao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第9期1273-1282,共10页
Basalt is a major component of the earth and moon crust.Mineral composition and temperature influence frictional instability and thus the potential for seismicity on basaltic faults.We performed velocitystepping shear... Basalt is a major component of the earth and moon crust.Mineral composition and temperature influence frictional instability and thus the potential for seismicity on basaltic faults.We performed velocitystepping shear experiments on basalt gouges at a confining pressure of 100 MPa,temperatures in the range of 100-400℃ and with varied obsidian mass fractions of 0-100%under wet/dry conditions to investigate the frictional strength and stability of basaltic faults.We observe a transition from velocity-neutral to velocity-weakening behaviors with increasing obsidian content.The frictional stability response of the mixed obsidian/basalt gouges is characterized by a transition from velocitystrengthening to velocity-weakening at 200℃ and another transition to velocity-strengthening at temperatures>300℃.Conversely,frictional strengths of the obsidian-bearing gouges are insensitive to temperature and wet/dry conditions.These results suggest that obsidian content dominates the potential seismic response of basaltic faults with the effect of temperature controlling the range of seismogenic depths.Thus,shallow moonquakes tend to occur in the lower lunar crust due to the corresponding anticipated higher glass content and a projected temperature range conducive to velocity-weakening behavior.These observations contribute to a better understanding of the nucleation mechanism of shallow seismicity in basaltic faults. 展开更多
关键词 Fault stability Basaltic fault Temperature elevation Obsidian content Shallow moonquakes
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Impact of spatially varying rock disturbance on rock slope stability 被引量:1
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作者 Dowon Park Radoslaw L.Michalowski 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期3907-3923,共17页
Degradation of rock mass produced by rock blasting,stress relief,and other causes is an important factor in the assessment of rock strength.Quantified as a disturbance factor,such degradation varies depending on blast... Degradation of rock mass produced by rock blasting,stress relief,and other causes is an important factor in the assessment of rock strength.Quantified as a disturbance factor,such degradation varies depending on blasting control,stress state and stress relief,and rock mass quality.This study focuses on the impact of disturbance on the safety of slopes.The disturbance in the rock mass is characterized by the geometry of the disturbed zone,its size,the magnitude,and the decaying rate with the distance away from the slope surface.A method accounting for decay of rock disturbance is presented.A study of the impact of rock disturbance characteristics on the quantitative stability measures of slopes was carried out.These characteristics included disturbed zone geometry,its thickness,the maximum magnitude of the disturbance factor,and the rate of disturbance decaying.The thickness of the disturbed zone and the maximum factor of disturbance were found to have the greatest impact.For example,the factor of safety for a 45slope in low-quality rock mass can decrease from 1.96 to 1.09 as the thickness of the disturbed zone increases from 1/4 of slope height H to the double of H and the maximum disturbance factor increases from 0.5 to 1.Uniform thickness of a disturbed zone was found to yield more conservative outcomes than the triangular zones did.The critical failure surfaces were found to be shallow for high rates of disturbance decay,and they were the deepest for spatially uniform disturbance factors. 展开更多
关键词 Disturbance decaying Blast damage Limit analysis Damage zone stability number
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Mechanical Modeling and Analysis of Stability Deterioration of Production Well During Marine Hydrate Depressurization Production 被引量:1
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作者 SUN Huan-zhao CHANG Yuan-jiang +4 位作者 SUN Bao-jiang WANG Kang CHEN Guo-ming LI Hao DAI Yong-guo 《China Ocean Engineering》 SCIE EI CSCD 2024年第2期338-351,共14页
Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence d... Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production well.However,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during production.To fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate decomposition.Based on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is developed.The analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability deterioration.The higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even instability.This work can provide a theoretical reference for the stability maintaining of the production well. 展开更多
关键词 natural gas hydrate production well depressurization production formation deformation stability deterioration
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Influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel 被引量:1
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作者 N.HUMNEKAR D.SRINIVASACHARYA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第3期563-580,共18页
The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dyn... The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented. 展开更多
关键词 NANOFLUID inclined channel variable viscosity linear stability double dif-fusion porous medium
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Probabilistic analysis of tunnel face seismic stability in layered rock masses using Polynomial Chaos Kriging metamodel 被引量:2
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作者 Jianhong Man Tingting Zhang +1 位作者 Hongwei Huang Daniel Dias 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2678-2693,共16页
Face stability is an essential issue in tunnel design and construction.Layered rock masses are typical and ubiquitous;uncertainties in rock properties always exist.In view of this,a comprehensive method,which combines... Face stability is an essential issue in tunnel design and construction.Layered rock masses are typical and ubiquitous;uncertainties in rock properties always exist.In view of this,a comprehensive method,which combines the Upper bound Limit analysis of Tunnel face stability,the Polynomial Chaos Kriging,the Monte-Carlo Simulation and Analysis of Covariance method(ULT-PCK-MA),is proposed to investigate the seismic stability of tunnel faces.A two-dimensional analytical model of ULT is developed to evaluate the virtual support force based on the upper bound limit analysis.An efficient probabilistic analysis method PCK-MA based on the adaptive Polynomial Chaos Kriging metamodel is then implemented to investigate the parameter uncertainty effects.Ten input parameters,including geological strength indices,uniaxial compressive strengths and constants for three rock formations,and the horizontal seismic coefficients,are treated as random variables.The effects of these parameter uncertainties on the failure probability and sensitivity indices are discussed.In addition,the effects of weak layer position,the middle layer thickness and quality,the tunnel diameter,the parameters correlation,and the seismic loadings are investigated,respectively.The results show that the layer distributions significantly influence the tunnel face probabilistic stability,particularly when the weak rock is present in the bottom layer.The efficiency of the proposed ULT-PCK-MA is validated,which is expected to facilitate the engineering design and construction. 展开更多
关键词 Tunnel face stability Layered rock masses Polynomial Chaos Kriging(PCK) Sensitivity index Seismic loadings
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A frequency servo SoC with output power stabilization loop technology for miniaturized atomic clocks 被引量:1
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作者 Hongyang Zhang Xinlin Geng +3 位作者 Zonglin Ye Kailei Wang Qian Xie Zheng Wang 《Journal of Semiconductors》 EI CAS CSCD 2024年第6期13-22,共10页
A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL... A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time. 展开更多
关键词 CMOS technology atomic clock phase-locked loop output power stabilization 1PPS
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Robust adaptive precision motion control of tank horizontal stabilizer based on unknown actuator backlash compensation
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作者 Shu-Sen Yuan Wen-Xiang Deng +1 位作者 Jian-Yong Yao Guo-Lai Yang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第2期72-83,共12页
Backlash nonlinearity inevitably exists in the actuator of tank horizontal stabilizer and has adverse effect on the system control performance,however,how to effectively eliminate its effect remains a pending issue.To... Backlash nonlinearity inevitably exists in the actuator of tank horizontal stabilizer and has adverse effect on the system control performance,however,how to effectively eliminate its effect remains a pending issue.To solve this problem,a robust adaptive precision motion controller is presented in this paper to address uncertainties and unknown actuator backlash of tank horizontal actuator.The controller handles the modeling uncertainties including parameter uncertainties and unmodeled disturbances by integrating adaptive feedforward compensation and continuous nonlinear robust law.Based on the backstepping method,a smooth backlash inverse model is constructed by combining the adaptive idea.Meanwhile,the unknown backlash parameters of the system can be approximated through the parameter adaptation,and the impact of the actuator backlash nonlinearity is effectively compensated via the inverse operation,which can availably improve the tracking performance.Moreover,the adaptive law can update the disturbance ranges of tank horizontal stabilizer online in real time,which enhances the feasibility in practical engineering applications.Furthermore,the stability analysis based on Lyapunov function shows that with the existence of unmodeled disturbances and unknown actuator backlash,the designed controller guarantees excellent asymptotic output tracking performance.Extensive comparative results verify the effectiveness of the proposed control strategy. 展开更多
关键词 TANK Horizontal stabilizer Adaptive control Robust control Backlash inverse
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Evaluation of slope stability through rock mass classification and kinematic analysis of some major slopes along NH-1A from Ramban to Banihal, North Western Himalayas 被引量:1
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作者 Amit Jaiswal A.K.Verma T.N.Singh 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期167-182,共16页
The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabil... The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabilities along the networks has been increasing over last few decades.Assessment of stability of natural and artificial slopes due to construction of these connecting road networks is significant in safely executing these roads throughout the year.Several rock mass classification methods are generally used to assess the strength and deformability of rock mass.This study assesses slope stability along the NH-1A of Ramban district of North Western Himalayas.Various structurally and non-structurally controlled rock mass classification systems have been applied to assess the stability conditions of 14 slopes.For evaluating the stability of these slopes,kinematic analysis was performed along with geological strength index(GSI),rock mass rating(RMR),continuous slope mass rating(CoSMR),slope mass rating(SMR),and Q-slope in the present study.The SMR gives three slopes as completely unstable while CoSMR suggests four slopes as completely unstable.The stability of all slopes was also analyzed using a design chart under dynamic and static conditions by slope stability rating(SSR)for the factor of safety(FoS)of 1.2 and 1 respectively.Q-slope with probability of failure(PoF)1%gives two slopes as stable slopes.Stable slope angle has been determined based on the Q-slope safe angle equation and SSR design chart based on the FoS.The value ranges given by different empirical classifications were RMR(37-74),GSI(27.3-58.5),SMR(11-59),and CoSMR(3.39-74.56).Good relationship was found among RMR&SSR and RMR&GSI with correlation coefficient(R 2)value of 0.815 and 0.6866,respectively.Lastly,a comparative stability of all these slopes based on the above classification has been performed to identify the most critical slope along this road. 展开更多
关键词 Rock mass classification Kinematic analysis Slope stability Himalayan road Static and dynamic conditions
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Reliability analysis of slope stability by neural network,principal component analysis,and transfer learning techniques 被引量:1
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作者 Sheng Zhang Li Ding +3 位作者 Menglong Xie Xuzhen He Rui Yang Chenxi Tong 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4034-4045,共12页
The prediction of slope stability is considered as one of the critical concerns in geotechnical engineering.Conventional stochastic analysis with spatially variable slopes is time-consuming and highly computation-dema... The prediction of slope stability is considered as one of the critical concerns in geotechnical engineering.Conventional stochastic analysis with spatially variable slopes is time-consuming and highly computation-demanding.To assess the slope stability problems with a more desirable computational effort,many machine learning(ML)algorithms have been proposed.However,most ML-based techniques require that the training data must be in the same feature space and have the same distribution,and the model may need to be rebuilt when the spatial distribution changes.This paper presents a new ML-based algorithm,which combines the principal component analysis(PCA)-based neural network(NN)and transfer learning(TL)techniques(i.e.PCAeNNeTL)to conduct the stability analysis of slopes with different spatial distributions.The Monte Carlo coupled with finite element simulation is first conducted for data acquisition considering the spatial variability of cohesive strength or friction angle of soils from eight slopes with the same geometry.The PCA method is incorporated into the neural network algorithm(i.e.PCA-NN)to increase the computational efficiency by reducing the input variables.It is found that the PCA-NN algorithm performs well in improving the prediction of slope stability for a given slope in terms of the computational accuracy and computational effort when compared with the other two algorithms(i.e.NN and decision trees,DT).Furthermore,the PCAeNNeTL algorithm shows great potential in assessing the stability of slope even with fewer training data. 展开更多
关键词 Slope stability analysis Monte Carlo simulation Neural network(NN) Transfer learning(TL)
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Insights into ionic association boosting water oxidation activity and dynamic stability 被引量:1
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作者 Zanling Huang Shuqi Zhu +8 位作者 Yuan Duan Chaoran Pi Xuming Zhang Abebe Reda Woldu Jing-Xin Jian Paul K.Chu Qing-Xiao Tong Liangsheng Hu Xiangdong Yao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期99-109,I0004,共12页
There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to i... There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to identify the activity improvement and discover that Ni sites act as a host to attract Fe(Ⅲ)to form Fe(Ni)(Ⅲ)binary centres,which serve as the dynamic sites to promote OER activity and stability by cyclical formation of intermediates(Fe(Ⅲ)→Fe(Ni)(Ⅲ)→Fe(Ni)-OH→Fe(Ni)-O→Fe(Ni)OOH→Fe(Ⅲ))at the electrode/electrolyte interface to emit O_(2).Additionally,some ions(Co(Ⅱ),Ni(Ⅱ),and Cr(Ⅲ))can also be the active sites to catalyze the OER process on a variety of electrodes.The Fe(Ⅲ)-catalyzed overall water-splitting electrolyzer comprising bare Ni foam as the anode and Pt/Ni-Mo as the cathode demonstrates robust stability for 1600 h at 1000 mA cm^(-2)@~1.75 V.The results provide insights into the ioncatalyzed effects boosting OER performance. 展开更多
关键词 Oxygen evolution reaction Fe(Ⅲ)-catalysis Ni-Fe binary active centers Ion-catalyzed effects Robust stability
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基于COMPASS iStability的浮船坞稳性计算 被引量:1
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作者 于峰 《船海工程》 北大核心 2024年第1期72-76,共5页
为比对分段建模与整体建模工作量及稳性计算结果,选取某浮船坞,采用命令流方法,对坞墙无开口,做5分段建模和整体建模稳性计算,对坞墙有开口,做7分段建模和借助体过渡整体建模稳性计算,结果表明,无论坞墙有无开口,整体建模比分段建模节... 为比对分段建模与整体建模工作量及稳性计算结果,选取某浮船坞,采用命令流方法,对坞墙无开口,做5分段建模和整体建模稳性计算,对坞墙有开口,做7分段建模和借助体过渡整体建模稳性计算,结果表明,无论坞墙有无开口,整体建模比分段建模节省约一半工作量,两种建模方式稳性计算精度相同,建模过程表明,命令流方法整体建模计算稳性,高效快捷。 展开更多
关键词 浮船坞 三维建模 命令流 稳性
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Effect and mechanism of reductive polyaniline on the stability of nitrocellulose
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作者 Wenjiang Li Binbin Wang +5 位作者 Huimin Chen Aoao Lu Chenguang Li Qiang Li Fengqiang Nan Ping Du 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第8期217-225,共9页
The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, ... The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, reduced polyaniline(r-PANI), which has a similar functional structure to diphenylamine(DPA) but is non-toxic, was prepared from PANI based on the action with N_(2)H_(4) and NH_(3)-H_(2)O, and used for the first time as a potential stabilizer for NC. XPS, FTIR, Raman, and SEM were used to characterize the reduced chemical structure and surface morphology of r-PANI. In addition, the effect of r-PANI on the stabilization of NC was characterized using DSC, VST, isothermal TG, and MMC. Thermal weight loss was reduced by 83% and 68% and gas pressure release by 75% and 49% compared to pure NC and NC&3%DPA, respectively.FTIR and XPS were used to characterize the structural changes of r-PANI before and after reaction with NO_(2). The 1535 cm^(-1) and 1341 cm^(-1) of the FTIR and the 404.98 eV and 406.05 eV of the XPS showed that the -NO_(2) was generated by the absorption of NO_(2). Furthermore, the quantum chemical calculation showed that NO_(2) was directly immobilized on r-PANI by forming -NO_(2) in the neighboring position of the benzene ring. 展开更多
关键词 NITROCELLULOSE Green stabilizer POLYANILINE Mechanism of stability
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Effects of connected automated vehicle on stability and energy consumption of heterogeneous traffic flow system
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作者 申瑾 赵建东 +2 位作者 刘华清 姜锐 余智鑫 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期291-301,共11页
With the development of intelligent and interconnected traffic system,a convergence of traffic stream is anticipated in the foreseeable future,where both connected automated vehicle(CAV)and human driven vehicle(HDV)wi... With the development of intelligent and interconnected traffic system,a convergence of traffic stream is anticipated in the foreseeable future,where both connected automated vehicle(CAV)and human driven vehicle(HDV)will coexist.In order to examine the effect of CAV on the overall stability and energy consumption of such a heterogeneous traffic system,we first take into account the interrelated perception of distance and speed by CAV to establish a macroscopic dynamic model through utilizing the full velocity difference(FVD)model.Subsequently,adopting the linear stability theory,we propose the linear stability condition for the model through using the small perturbation method,and the validity of the heterogeneous model is verified by comparing with the FVD model.Through nonlinear theoretical analysis,we further derive the KdV-Burgers equation,which captures the propagation characteristics of traffic density waves.Finally,by numerical simulation experiments through utilizing a macroscopic model of heterogeneous traffic flow,the effect of CAV permeability on the stability of density wave in heterogeneous traffic flow and the energy consumption of the traffic system is investigated.Subsequent analysis reveals emergent traffic phenomena.The experimental findings demonstrate that as CAV permeability increases,the ability to dampen the propagation of fluctuations in heterogeneous traffic flow gradually intensifies when giving system perturbation,leading to enhanced stability of the traffic system.Furthermore,higher initial traffic density renders the traffic system more susceptible to congestion,resulting in local clustering effect and stop-and-go traffic phenomenon.Remarkably,the total energy consumption of the heterogeneous traffic system exhibits a gradual decline with CAV permeability increasing.Further evidence has demonstrated the positive influence of CAV on heterogeneous traffic flow.This research contributes to providing theoretical guidance for future CAV applications,aiming to enhance urban road traffic efficiency and alleviate congestion. 展开更多
关键词 heterogeneous traffic flow CAV linear stability nonlinear stability energy consumption
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