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Performance of double-arch tunnels under internal BLEVE

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Underground Space 2024年第6期19卷 6-25页

作者： Ruishan Cheng Wensu Chen hong Hao Center for Infrastructural Monitoring and Protection School of Civil and Mechanical EngineeringCurtin UniversityPerth 6000Australia Earthquake Engineering Research&Test Center Guangzhou UniversityGuangzhou 510000China

Double-arch tunnels,as one of the popular forms of tunnels,might be exposed to boiling liquid expanding vapour explosions(BLEVEs)associated with transported liquified petroleum gas(LPG),which could cause damage to the tunnel and even catastrophic collapse of the tunnel in extreme ***,very limited study has investigated the performance of double-arch tunnels when exposed to internal BLEVEs and in most analyses of tunnel responses to accidental *** TNT-equivalence method was used to approximate the explosion load,which may lead to inaccurate tunnel response *** study numerically investigates the response of typical double-arch tunnels to an internal BLEVE resulting from the instantaneous rupture of a 20 m^(3) LPG *** of various factors,including in-situ stresses,BLEVE locations,and lining configurations on tunnel responses are *** results show that the double-arch tunnels at their early-operation ages are more vulnerable to severe damage when exposed to the BLEVE due to the low action of in-situ stress of rock mass on the response of early-age *** is also found that directing the LPG tank to different driving lanes inside tunnels can affect the BLEVE-induced tunnel response more significantly than varying the configurations of tunnel ***,installing section-steel arches in the mid-wall can effectively improve the blast resistance of the double-arch tunnels against the internal *** addition,the prediction models based on multi-variate nonlinear regressions and machine learning methods are developed to predict the BLEVE-induced damage levels of the double-arch tunnels without and with section-steel arches.

关键词： Double-arch tunnel BLEVE Lining configuration Section-steel arch Damage prediction

Prospects for green steelmaking technology with low carbon emissions in China

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Carbon Energy 2024年第2期6卷 1-24页

作者： Zhang Fucheng hong Lukuo Xu Ying College of Metallurgy and Energy North China University of Science and TechnologyTangshanHebeiChina Hebei Iron and Steel Laboratory TangshanHebeiChina

The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this *** this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is ***,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment ***,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”***,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is *** conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.

关键词： carbon capture and utilization carbon emission hydrogen metallurgy low-carbon technology steel industry

Rethinking attribute localization for zero-shot learning

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Science China(Information Sciences) 2024年第7期67卷 184-196页

作者： Shuhuang CHEN Shiming CHEN Guo-Sen XIE Xiangbo SHU Xinge you Xuelong LI School of Electronic Information and Communication Huazhong University of Science and Technology School of Computer Science and Engineering Nanjing University of Science and Technology School of Artificial Intelligence Optics and Electronics Northwestern Polytechnical University

Recent advancements in attribute localization have showcased its potential in discovering the intrinsic semantic knowledge for visual feature representations, thereby facilitating significant visual-semantic interactions essential for zero-shot learning(ZSL). However, the majority of existing attribute localization methods heavily rely on classification constraints, resulting in accurate localization of only a few attributes while neglecting the rest important attributes associated with other classes. This limitation hinders the discovery of the intrinsic semantic relationships between attributes and visual features across all *** address this problem, we propose a novel attribute localization refinement(ALR) module designed to enhance the model's ability to accurately localize all attributes. Essentially, we enhance weak discriminant attributes by grouping them and introduce weighted attribute regression to standardize the mapping values of semantic attributes. This module can be flexibly combined with existing attribute localization *** experiments show that when combined with the ALR module, the localization errors in existing methods are corrected, and state-of-the-art classification performance is achieved.

关键词： zero-shot learning attention mechanism attribute localization image classification

Numerical manifold method for steady-state nonlinear heat conduction using Kirchhoff transformation

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Science China(Technological Sciences) 2024年第4期67卷 992-1006页

作者： ZHANG LiMei KONG Heng ZHENG hong Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China Beijing Municipal Construction Co. Ltd.Beijing 100048China

The numerical manifold method(NMM)introduces the mathematical and physical cover to solve both continuum and discontinuum problems in a unified *** this study,the NMM for solving steady-state nonlinear heat conduction problems is presented,and heat conduction problems consider both convection and radiation boundary ***,the nonlinear governing equation of thermal conductivity,which is dependent on temperature,is transformed into the Laplace equation by introducing the Kirchhoff *** transformation reserves linearity of both the Dirichlet and the Neumann boundary conditions,but the Robin and radiation boundary conditions remain ***,the NMM is employed to solve the Laplace equation using a simple iteration procedure because the nonlinearity focuses on parts of the problem domain ***,the temperature field is retrieved through the inverse Kirchhoff *** examples are analyzed,demonstrating the advantages of the Kirchhoff transformation over the direct solution of nonlinear equations using the NewtonRaphson *** study provides a new method for calculating nonlinear heat conduction.

关键词： numerical manifold method nonlinear heat conduction temperature-dependent thermal conductivity Kirchhoff transformation convection and radiation boundary conditions

MCS-based quantile value approach for reliability-based design of tunnel face support pressure

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Underground Space 2024年第5期18卷 187-198页

作者： Bin Li Changxing Wang hong Li Department of Road and Bridge Engineering School of Transportation and Logistics EngineeringWuhan University of TechnologyWuhan 430063China Hubei Highway Engineering Research Center Wuhan 430063China

This paper develops a new approach for reliability-based design(RBD)of tunnel face support pressure from a quantile value perspective.A surrogate model is constructed to calculate the collapse pressures of the random samples generated by a single run of Monte Carlo simulation(MCS).The cumulative distribution function(CDF)of the collapse pressure is then obtained and the support pressure aiming at a target failure probability is chosen as the upper quantile value of the collapse *** proposed approach does not require repetitive reliability analyses compared to the existing ***,a direct relationship between the target failure probability and the required support pressure is *** illustrative example is used to demonstrate the implementation *** accuracy of the reliability-based support pressures is verified by direct MCS incorporating with three-dimensional numerical ***,the influencing factors,including the sample size of MCS,the correlation coefficient between random variables,the choice of experimental points,and the surrogate model,are *** method can play a complementary role to available approaches due to its advantages of simplicity and efficiency.

关键词： Tunnel face stability Support pressure Reliability-based design Response surface method Monte Carlo simulation

Thermal performance of cast-in-place piles with artificial ground freezing in permafrost regions

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Journal of Mountain Science 2024年第4期21卷 1307-1328页

作者： WANG Xinbin CHEN Kun YU Qihao GUO Lei you Yanhui JIN Mingyang 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

During the construction of cast-in-place piles in warm permafrost,the heat carried by concrete and the cement hydration reaction can cause strong thermal disturbance to the surrounding *** the bearing capacity of the pile is quite small before the full freeze-back,the quick refreezing of the native soils surrounding the cast-in-place pile has become the focus of the infrastructure construction in *** solve this problem,this paper innovatively puts forward the application of the artificial ground freezing(AGF)method at the end of the curing period of cast-in-place piles in permafrost.A field test on the AGF was conducted at the Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment(34°51.2'N,92°56.4'E)in the Qinghai Tibet Plateau(QTP),and then a 3-D numerical model was established to investigate the thermal performance of piles using AGF under different engineering ***,the long-term thermal performance of piles after the completion of AGF under different conditions was *** experiment results demonstrate that AGF is an effective method to reduce the refreezing time of the soil surrounding the piles constructed in permafrost terrain,with the ability to reduce the pile-soil interface temperatures to below the natural ground temperature within 3 *** results further prove that AGF still has a good cooling effect even under unfavorable engineering conditions such as high pouring temperature,large pile diameter,and large pile ***,the application of this method is meaningful to save the subsequent latency time and solve the problem of thermal disturbance in pile construction in *** research results are highly relevant for the spread of AGF technology and the rapid building of pile foundations in permafrost.

关键词： Permafrost engineering Cast-in-place pile Artificial ground freezing Thermal performance.

Pre-MASLD:Should it be defined separately?

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 1-3页

作者： Hang-Kai Huang you-Ming Li Cheng-Fu Xu Department of Gastroenterology Zhejiang Provincial Clinical Research Center for Digestive Diseasesthe First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases,yet it has not received sufficient attention[1].Over the past two decades,the overall global prevalence of NAFLD has risen from 25%to 37%[2].The disease burden of NAFLD is fueled by the epidemic of obesity and diabetes[3].It is estimated that more than half of patients with diabetes have NAFLD.

关键词： NAFLD liver diseases

Sustainable, thermoplastic and hydrophobic coating from natural cellulose and cinnamon to fabricate eco-friendly catering packaging

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Green Energy & Environment 2024年第5期9卷 927-936页

作者： Rumeng Xu Chunchun Yin Jingxuan you Jinming Zhang Qinyong Mi Jin Wu Jun Zhang CAS Key Laboratory of Engineering Plastics Institute of ChemistryChinese Academy of Sciences(CAS)Beijing100190China University of Chinese Academy of Sciences Beijing100049China

Non-degradable polymers cause serious environmental pollution problem,such as the widely-used while unrecyclable coatings which signiﬁcantly affect the overall degradation performance of *** is imperative and attractive to develop biodegradable functional ***,we proposed a novel strategy to successfully prepare biodegradable,thermoplastic and hydrophobic coatings with high transparence and biosafety by weakening the interchain interactions between cellulose *** natural cellulose and cinnamic acid were as raw *** reducing the degree of polymerization(DP)of cellulose and regulating the degree of substitution(DS)of cinnamate moiety,the obtained cellulose cinnamate(CC)exhibited not only the thermalﬂow behavior but also good biodegradability,which solves the conﬂict between the thermoplasticity and biodegradability in cellulose-based *** glass transition temperature(T_(g))and thermalﬂow temperature(T_(f))of the CC could be adjusted in a range of 150–200℃ and 180–210℃,*** CC with DS<1.2 and DP≤100 degraded more than 60%after an enzyme treatment for 7 days,and degraded more than 80%after a composting treatment for 42 ***,CC had no toxicity to human epidermal cells even at a high concentration(0.5 mg mL^(-1)).In addition,CC could be easily fabricated into multifunctional coating with high hydrophobicity,thermal adhesion and high ***,after combining with cellophane and paperboard,CC coating with low DP and DS could be used to prepare fully-biodegradable heat-sealing packaging,art paper,paper cups,paper straws and food packaging boxes.

关键词： Thermoplastic coating Bio-degradable adhesive Natural products Cellulose Eco-friendly packaging

Spatial diversion and coordination of flood water for an urban flood control project in Suzhou, China

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Water Science and Engineering 2024年第2期17卷 108-117页

作者： Yu Xu you-peng Xu Qiang Wang Yue-feng Wang Chao Gao Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratoryof Hydology Water Resources and Hydraulic Enginering Nanjing Hydraulic Research InstitueNanjing 210029China Laboratory of Sustainable Urban Drainage Ningbo UniversityNingbo 31521lChina Schol of Gegraphical and Oceanographic Sciences Nanjing UniversiyNanjing 210023China School of Geography and Tourism Chongqing Normal UniversityChongqing 401331China

Suzhou City,located in the Yangtze River Delta in China,is prone to flooding due to a complex combination of natural factors,including its monsoon climate,low elevation,and tidally influenced position,as well as intensive human *** Large Encirclement Flood Control Project(LEFCP)was launched to cope with serious floods in the urban *** project changed the spatiotemporal pattern of flood processes and caused spatial diversion of floods from the urban area to the outskirts of the ***,this study developed a distributed flood simulation model in order to understand this transition of flood *** results revealed that the LEFCP effectively protected the urban areas from floods,but the present scheduling schemes resulted in the spatial diversion of floods to the outskirts of the *** rainstorm frequencies of 10.0%to 0.5%,the water level differences between two representative water level stations(Miduqiao(MDQ)and Fengqiao(FQ))located inside and outside the LEFCP area,ranged from 0.75 m to 0.24 m and from 1.80 m to 1.58 m,*** addition,the flood safety margin at MDQ and the duration with the water level exceeding the warning water level at FQ ranged from 0.95 m to 0.43 m and from 4 h to 22 h,*** scheduling schemes for the hydraulic facilities of the LEFCP in extreme precipitation cases were developed ac-cording to food simulations under seven scheduling *** helps to regulate the spatial flood diversion caused by the LEFCP during extreme precipitation.

关键词： Urban flooding Urban flood control project Rainstorm fregue ncy Flood simulation model Suzhou City