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Spalling characteristics of high-temperature treated granitic rock at different strain rates

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journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： l.F.fan Q.H.Yang X.l.Du The Key laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics High temperature Strain rate Dynamic loading Granite

Material flow analysis and global warming potential assessment of an industrial insect-based bioconversion plant using housefly larvae

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journal of Environmental Sciences 2024年第5期139卷 483-495页

作者： Tao lu fan lü Nanlin liao Honghui Chai Hua Zhang Pinjing He Institute of Waste Treatment and Reclamation Tongji UniversityShanghai 200092China State Key laboratory of Pollution Control and Source Reuse Tongji UniversityShanghai 200092China Zhejiang Qihe Ecological Technology Co. Ltd.Hangzhou 310052China

The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment *** can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food ***,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(lCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per *** lCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,*** greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more *** main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).

关键词： Biomass waste Musca domestica Housefly larvae life cycle assessment Global warming potential

Complete Universal Scaling in First-Order Phase Transitions

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Chinese Physics letters 2024年第10期41卷 8-13页

作者： fan Zhong School of Physics and State Key laboratory of Optoelectronic Materials and Technologies Sun Yat-sen UniversityGuangzhou 510275China

Phase transitions and critical phenomena are among the most intriguing phenomena in nature and *** are classified into first-order phase transitions(FOPTs)and continuous *** the latter shows marvelous phenomena of scaling and universality,whether the former behaves similarly is a long-standing controversial *** we definitely demonstrate complete universal scaling in field driven FOPTs for langevin equations in both zero and two spatial dimensions by rescaling all parameters and subtracting nonuniversal contributions with singular dimensions from an effective temperature and a special field according to an effective *** offers a perspective different from the usual nucleation and growth but conforming to continuous phase transitions to study FOPTs.

关键词： theory. transitions scaling

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

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Acta Mechanica Solida Sinica 2024年第3期37卷 385-395页

作者： Zhiqiang fan Zhihe jin School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering University of MaineOronoME04469USA

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the“wellbore skin zone”,play a pivotal role in determining flow dynamics and the resulting formation *** models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir *** paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic *** solutions are derived using the laplace transform method,addressing both positive and negative skin *** results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a *** results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.

关键词： Poroelastic Graded permeability Analytical solution Wellbore Skin zone

Characterization of geological uncertainties from limited boreholes using copula-based coupled Markov chains for underground construction

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Underground Space 2024年第3期16卷 94-105页

作者： fan Wang Heng li Gang li Zheng-jun You Elton j.Chen National Center of Technology Innovation for Digital Construction Huazhong University of Science and TechnologyWuhan 430074China Department of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Building and Real Estate The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina Shanghai Tunnel Engineering Co. Ltd.Shanghai 200032China Wuhan Metro Group Co.ltd. Wuhan 430070China

This paper proposes an efficient method for quantifying the stratigraphic uncertainties and modeling the geological formations based on *** Markov chains are used to describe the soil transitions along different directions,and the transition probability matrices(TPMs)of the Markov chains are analytically expressed by *** copula expression is efficient since it can represent a large TPM by a few unknown *** to the analytical expression of the TPMs,the likelihood function of the Markov chain model is given in an explicit *** estimation of the TPMs is then re-casted as a multi-objective constrained optimization problem that aims to maximize the likelihoods of two independent Markov chains subject to a set of parameter *** the method which determines the TPMs by counting the number of transitions between soil types,the proposed method is more statistically ***,a random path sampling method is presented to avoid the directional effect problem in *** soil type at a location is inferred from its nearest known neighbors along the cardinal directions.A general form of the conditional probability,based on Pickard’s theorem and Bayes rule,is presented for the soil type *** proposed stratigraphic characterization and simulation method is applied to real borehole data collected from a construction site in Wuhan,*** is illustrated that the proposed method is accurate in prediction and does not show an inclination during simulation.

关键词： Geological stratigraphy Markov chain Transition probability matrix Statistical method Copula

A progressive framework for rotary motion deblurring

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Defence Technology（防务技术） 2024年第2期32卷 159-172页

作者： jinhui Qin Yong Ma jun Huang fan fan You Du School of Electronic Information Wuhan UniversityWuhan430072China

The rotary motion deblurring is an inevitable procedure when the imaging seeker is mounted in the rotating *** rotary motion deblurring methods suffer from ringing artifacts and noise,especially for large blur *** solve the above problems,we propose a progressive rotary motion deblurring framework consisting of a coarse deblurring stage and a refinement *** the first stage,we design an adaptive blur extents factor(BE factor)to balance noise suppression and details *** a novel deconvolution model is proposed based on BE *** the second stage,a triplescale deformable module CNN(TDM-CNN)is designed to reduce the ringing artifacts,which can exploit the 2D information of an image and adaptively adjust spatial sampling *** establish a standard evaluation benchmark,a real-world rotary motion blur dataset is proposed and released,which includes rotary blurred images and corresponding ground truth images with different blur *** results demonstrate that the proposed method outperforms the state-of-the-art models on synthetic and real-world rotary motion blur *** code and dataset are available at https://***/jinhuiQin/RotaryDeblurring.

关键词： Rotary motion deblurring Progressive framework Blur extents factor TDM-CNN

Seismic response of pile-supported structures considering the coupling of inertial and kinematic interactions in different soil sites

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Frontiers of Structural and Civil Engineering 2024年第9期18卷 1350-1361页

作者： Huiling ZHAO fan ZHANG Department of Civil Engineering Shanghai UniversityShanghai 200444China

Dynamic soil−pile−superstructure interaction is crucial for understanding pile behavior in earthquake-prone *** the safety of piles requires determining the seismic bending moment caused by combined inertial and kinematic interactions,which is *** paper addresses this problem through numerical simulations of piles in different soil sites,considering soil *** reveal that the period of the soil site significantly affects the interaction among soil,piles,and *** moments in soft and hard soil sites exceed those in medium soil sites by more than *** modes of piles exhibit distinct characteristics between hard and soft soil *** soil sites exhibit a singular inflection point,while hard soil sites show two inflection *** soft soil sites,pile-soil kinematic interaction gradually increases bending moment from tip to head,with minor influence from superstructure’s inertial *** hard soil sites,significant inertial effects from soil,even surpassing pile-soil kinematic effects near the tip,lead to reversed superposition bending ***’s inertial interaction notably impacts pile head in hard soil sites.A simplified coupling method is proposed using correlation coefficient to represent inertial and kinematic *** findings provide insights into complex seismic interactions among soil,piles,and structures.

关键词： pile seismic response soft soil inertial interaction kinematic interaction

Impact of non-ideal UE hardware on cell-free massive MIMO network with centralized operation

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Science China(Information Sciences) 2024年第4期67卷 255-271页

作者： Ning lI Pingzhi fan Institute of Mobile Communications Southwest jiaotong University

This paper investigates the impact of non-ideal user equipment(UE) hardware on a cell-free(CF) massive MIMO(mMIMO) network with centralized operation under spatially correlated channels. The minimum mean-squared error(MMSE) estimator can be derived with the help of the generic non-ideal UE hardware model. It is demonstrated that even if the effective signal-to-noise ratio approaches infinity, pilot contamination and imperfect hardware can cause a non-zero estimation error floor. After that, a lower bound is determined for the ergodic uplink capacity of the centralized CF mMIMO network under non-ideal UE hardware. Moreover, the optimal receive combining vector is obtained to maximize the uplink spectral efficiency(SE). The maximum ratio(MR) and regularized zero-forcing(RZF) combining schemes are offered as alternatives in light of the computational complexity of the MMSE receiver. Comparing the RZF to the MMSE scheme under different levels of hardware impairments, our findings indicate that the RZF receiver suffers a negligible loss in total SE. For MR combining, a novel closed-form uplink achievable SE expression is obtained based on the MMSE estimator and the use-and-then-forget bounding technique. This expression gives vital insights into the achievable uplink performance with UE hardware impairments. Besides, for various hardware impairment factors, the impact of pilot sequence length on average sum SE is disclosed for different receive combining schemes. To increase the overall SE of the max-min fairness scheme, a heuristic fractional power control scheme with UE hardware impairments is developed, which can essentially avoid sacrificing the SE of other UEs while maximizing the SE of the unluckiest UE in the whole network. Finally,our theoretical performance analysis and power control algorithm are validated by simulation results, and fundamental design guidelines are provided for selecting hardware satisfying the practical UE requirements.

关键词： cell-free massive MIMO centralized operation spatially correlated channels hardware impairments channel estimation uplink spectral efficiency optimal receive combining pilot length design fractional power control

Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction:Efficient photodegradation of organic pollutant and toxicity evaluation

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journal of Materials Science & Technology 2024年第3期170卷 200-211页

作者： Yanyan Zhao Xu fan Hongxing Zheng Enzhou liu jun fan Xuejun Wang College of Biology Pharmacy and Food Engineering Shangluo UniversityShangluo 726000China Qinling-Bashan Mountains Bioresources Comprehensive Development C.I.C. Shaanxi University of TechnologyHanzhong 723001China School of Chemical Engineering Northwest UniversityXi’an 710069China

Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of *** this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants *** Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and *** study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,*** improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation ***,a S-scheme charge transfer mechanism including multiple charge transfer channels was *** work could provide an effective strategy for organic pollutants degradation in wastewater.

关键词： Photocatalysis S-scheme heterojunction AgInS_(2) Bi_(2)WO_(6) Toxicity experiments