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An Improved Machine Learning Model for Pure Component Property Estimation

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Engineering 2024年第8期39卷 61-73页

作者： Xinyu Cao Ming Gong Anjan Tula Xi Chen Rafiqul Gani Venkat Venkatasubramanian state Key Laboratory of Industrial Control Technology College of Control Science and EngineeringZhejiang UniversityHangzhou 310027China Department of Physics Bard College at Simon’s RockGreat BarringtonMA 01230USA PsE for sPEED Company Charlottenlund DK-2920Denmark sustainable Energy and Environment Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 510000China Department of Applied sustainability Széchenyi István UniversityGyör 9026Hungary Complex Resilient Intelligent systems Laboratory Department of Chemical EngineeringColumbia UniversityNew YorkNJ 10027USA

Information on the physicochemical properties of chemical species is an important prerequisite when performing tasks such as process design and product ***,the lack of extensive data and high experimental costs hinder the development of prediction techniques for these ***,accuracy and predictive capabilities still limit the scope and applicability of most property estimation *** paper proposes a new Gaussian process-based modeling framework that aims to manage a discrete and high-dimensional input space related to molecular structure representation with the group-contribution approach.A warping function is used to map discrete input into a continuous domain in order to adjust the correlation between different *** selection techniques,including prior elicitation and prior predictive checking,are also applied during the building procedure to provide the model with more information from previous research *** framework is assessed using datasets of varying sizes for 20 pure component *** 18 out of the 20 pure component properties,the new models are found to give improved accuracy and predictive power in comparison with other published models,with and without machine learning.

关键词： Group contribution Gaussian process Warping function Prior predictive checking

A modified 3D mean strain energy density criterion for predicting shale mixed-mode Ⅰ/Ⅲ fracture toughness

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Journal of rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2411-2428页

作者： Kun Zheng Chaolin Wang Yu Zhao Jing Bi Haifeng Liu college of Civil Engineering Guizhou UniversityGuiyang550025China state Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

The fracture toughness of rocks is a critical fracturing parameter in geo-energy exploitation playing a significant role in fracture mechanics and hydraulic *** edge-notched disk bending(ENDB)specimens are employed to measure the entire range of mixed-modeⅠ/Ⅲfracture toughness of Longmaxi *** theoretically interpret the fracture mechanisms,this research first introduces the detailed derivations of three established fracture *** distinguishing the volumetric and distortional strain energy densities,an improved three-dimensional mean strain energy density(MsED)criterion is *** the critical volumetric to distortional MsED ratio decreases,the transition from tensiondominated fracture to shear-dominated fracture is *** results indicate that both peak load and applied energy increase significantly with the transition from pure mode I(i.e.,tension)to pure modeⅢ(i.e.,torsion or tearing)since mode-Ⅲcracking happens in a twisted manner and mode-Ⅰcracking occurs in a coplanar *** macroscopic fracture signatures are consistent with those of triaxial hydraulic *** average ratio of pure mode-Ⅲfracture toughness to pure mode-Ⅰfracture toughness is 0.68,indicating that the obtained mode-Ⅲfracture resistance for a tensionbased loading system is apparent rather than *** to the three mainstream fracture criteria,the present fracture criterion exhibits greater competitiveness and can successfully evaluate and predict mixed-modeⅠ/Ⅲfracture toughness of distinct materials and loading methods.

关键词： Longmaxi shale Hydraulic fracturing Fracture mechanisms Fracture criteria Mixed-modeⅠ/Ⅲfracture toughness Edge-notched disk bending

Does Foreign Direct Investment Provide Desirable Development Finance? The Case of China

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China & World Economy 2007年第2期15卷 104-120页

作者： Yan Liang simon＇s rock college of bard USA

Foreign direct investment （FDI） is ofen considered as a cost-effective and risk-reducing source for development finance. This paper, however, shows that FDI finance often entails underestimated risks and costs. FDI might react sensitively to business cycles and might not be as ＂permanent＂ as conventionally believed. FDI might also accelerate other forms of capital flow in times of financial difficulties and, hence, destabilize ftnancial order. In addition to the risks, compensations to FDI and the high import-dependency of FDI-related trade lead to a considerable drain on the balance of payments. Moreover, the reliance on foreign capital for development finance is equivalent to building a Ponzi financing scheme and, therefore, is unsustainable. Given the fact that FDI financing is risky and costly and China does not lack savings, it is suggested in the present paper that China ＇s efforts in attracting FDI should not aim at external capital provisioning.

关键词： development finance foreign direct investment portfolio investment

Numerical and theoretical study of load transfer behavior during cascading pillar failure

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Journal of rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3014-3033页

作者： Hangyu Dong Wancheng Zhu Leilei Niu Chen Hou Xige Liu college of Geosciences and Engineering North China University of Water Resources and Electric PowerZhengzhou450046China Center for rock Instability and seismicity Research School of Resource and Civil EngineeringNortheastern UniversityShenyang110819China

To further study the load transfer mechanism of roofemulti-pillarefloor system during cascading pillar failure(CPF),numerical simulation and theoretical analysis were carried out to study the three CPF modes according to the previous experimental study on treble-pillar specimens,*** failure mode(sFM),domino failure mode(DFM)and compound failure mode(CFM).Based on the finite element code rock failure process analysis(RFPA^(2D)),numerical models of treble-pillar specimen with different mechanical properties were established to reproduce and verify the experimental results of the three CPF *** results show that the elastic rebound of roofefloor system induced by pillar instability causes dynamic disturbance to adjacent pillars,resulting in sudden load increases and sudden jump displacement of adjacent *** phenomena of load transfer in the roofemulti-pillarefloor system,as well as the induced accelerated damage behavior in adjacent pillars,were discovered and *** addition,based on the catastrophe theory and the proposed mechanical model of treble-pillar specimen edisc spring group system,a potential function that characterizes the evolution characteristics of roof emulti-pillarefloor system was *** analytical expressions of sudden jump and energy release of treble-pillar specimenedisc spring group system of the three CPF modes were derived according to the potential *** numerical and theoretical results show good agreement with the experimental *** study further reveals the physical essence of load transfer during CPF of roof emulti-pillarefloor system,which provides references for mine design,construction and disaster prevention.

关键词： Cascading pillar failure(CPF) Load transfer Multi-pillar Numerical simulation

Do Vacuoles Obscure the Evidence for Auxin Homeostasis？

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Molecular Plant 2016年第1期9卷 4-6页

作者： EricM. Kramer EthanM. Ackelsberg bard college at simon's rock Great Barrington MA 01230 USA

The plant hormone auxin （indole-3-aectic acid [IAA]） has a role in nearly every aspect of plant growth and development. The last two decades have seen rapid progress in the identifi- cation of gene families involved... 详细信息

关键词： ARABIDOPsIs ROOT APEX INDOLEACETIC-ACID TRANsPORT

Effects of thawing-induced softening on fracture behaviors of frozen rock

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Journal of rock Mechanics and Geotechnical Engineering 2024年第3期16卷 979-989页

作者： Ting Wang Hailiang Jia Qiang sun Xianjun Tan Liyun Tang college of Geology and Environment Xi’an University of Science and TechnologyXi’an710054China college of Architecture and Civil Engineering Xi’an University of Science and TechnologyXi’an710054China state Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430064China

Due to the presence of ice and unfrozen water in pores of frozen rock,the rock fracture behaviors are susceptible to *** this study,the potential thawing-induced softening effects on the fracture behaviors of frozen rock is evaluated by testing the tension fracture toughness(KIC)of frozen rock at different temperatures(i.e.-20℃,-15℃,-12℃,-10℃,-8℃,-6℃,-4℃,-2℃,and 0℃).Acoustic emission(AE)and digital image correlation(DIC)methods are utilized to analyze the microcrack propagation during *** melting of pore ice is measured using nuclear magnetic resonance(NMR)*** results indicate that:(1)The KIC of frozen rock decreases moderately between-20℃ and-4℃,and rapidly between-4℃ and 0℃.(2)At-20℃ to-4℃,the fracturing process,deduced from the DIC results at the notch tip,exhibits three stages:elastic deformation,microcrack propagation and microcrack ***,at-4℃e0℃,only the latter two stages are observed.(3)At-4℃e0℃,the AE activities during fracturing are less than that at-20℃ to-4℃,while more small events are reported.(4)The NMR results demonstrate a reverse variation trend in pore ice content with increasing temperature,that is,a moderate decrease is followed by a sharp decrease and-4℃ is exactly the critical ***,we interpret the thawing-induced softening effect by linking the evolution in microscopic structure of frozen rock with its macroscopic fracture behaviors as follow:from-20℃ to-4℃,the thickening of the unfrozen water film diminishes the cementation strength between ice and rock skeleton,leading to the decrease in fracture ***-4℃ to 0℃,the cementation effect of ice almost vanishes,and the filling effect of pore ice is reduced significantly,which facilitates microcrack propagation and thus the easier fracture of frozen rocks.

关键词： Frozen sandstone Different thawing temperature Fracture toughness Microcrack propagation process Unfrozen water content

The delivery of N-myc downstream-regulated gene 2(NDRG2)self-amplifying mRNA via modified lipid nanoparticles as a potential treatment for drug-resistant and metastatic cancers

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Medical Review 2024年第3期4卷 235-238页

作者： sandra E.Reznik Amit K.Tiwari Vivek Chavda Charles R.Ashby Jr. Department of Pharmaceutical sciences College of Pharmacy and Health SciencesSt.John’s UniversityQueensUSA Departments of Pathology and Obstetrics and Gynecology and Women’s Health Montefiore Medical Center/Albert Einstein College of MedicineBronxUSA Department of Pharmaceutical sciences College of Pharmacy University of Arkansas for Medical Sciences Little RockUSA Department of Pharmaceutics and Pharmaceutical Technology L.M.college of Pharmacy AhmedabadIndia Department of Pharmaceutical sciences College of Pharmacy and Health SciencesSt.John’s UniversityQueensNY 11439USA

The protein,N-myc downstream-regulated gene 2(NDRG2),a tumor suppressor,is significantly decreased or absent in many types of *** is a significant negative correlation between the levels of NDRG2 and the development and progression of cancer tumor recurrence and tumor invasion,in different *** contrast,the in vitro and in vivo overexpression of the NDRG2 protein decreases the proliferation,growth,adhesion and migration of many types of cancer *** in vitro overexpression of NDRG2 increases the efficacy of certain anticancer drugs in specific types of cancer *** hypothesize that the delivery of the mRNA of the NDRG2 protein,encapsulated by lipid nanoparticles,could represent a potential treatment of metastatic and drug-resistant *** would be accomplished using a self-amplifying mRNA that encodes the NDRG2 protein and an RNA-dependent-RNA polymerase,obtained from an in vitrotranscribed(IVT)*** IVT mRNA would be encapsulated in a lipid *** efficacy of the nanoformulation would be determined in cultured cancer cells and if the results are positive,nude mice transplanted with either drug-resistant or metastatic drug-resistant cancer cells,would be treated with the nanoformulation and monitored for efficacy and adverse *** the appropriate preclinical studies indicate this formulation is efficacious and safe,it is possible it could be evaluated in clinical trials.

关键词： N-myc downstream-regulated gene 2(NDRG2) cancer self-amplifying mRNA nanoparticle

Effects of fracture evolution and non-Darcy flow on the thermal performance of enhanced geothermal system in 3D complex fractured rock

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International Journal of Mining science and Technology 2024年第4期34卷 443-459页

作者： Yachen Xie Jianxing Liao Pengfei Zhao Kaiwen Xia Cunbao Li Department of Civil and Mineral Engineering University of TorontoToronto M5S1A4Canada college of Water Resources and Hydropower Sichuan UniversityChengdu 610225China state Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsWuhan 430071China college of Civil Engineering Guizhou UniversityGuiyang 550025China Institute of Geosafety School of Engineering and TechnologyChina University of GeosciencesBeijing 100083China state Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen 518060China

In fractured geothermal reservoirs,the fracture networks and internal fluid flow behaviors can significantly impact the thermal *** this study,we proposed a non-Darcy rough discrete fracture network(NR-DFN)model that can simultaneously consider the fracture evolution and non-Darcy flow dynamics in studying the thermo-hydro-mechanical(THM)coupling processes for heat extraction in geothermal *** further employed the model on the Habanero enhanced geothermal systems(EGs)project located in ***,our findings illustrate a clear spatial-temporal variation in the thermal stress and pressure perturbations,as well as uneven spatial distribution of shear failure in 3D fracture *** shear failure is mainly concentrated in the first fracture ***,channeling flow have also been observed in DFNs during heat extraction and are further intensified by the expansion of fractures driven by thermal ***,the combined effect of non-Darcy flow and fracture evolution triggers a rapid decline in the resulting heat rate and *** NR-DFN model framework and the Habanero EGs's results illustrate the importance of both fracture evolution and non-Darcy flow on the efficiency of EGs production and have the potential to promote the development of more sustainable and efficient EGs operations for stakeholders.

关键词： Coupled THM model Non-Darcy flow Deformable DFN Enhanced geothermal systems

Disc-cutter induced rock breakage mechanism for TBM excavation in rock masses with different joint shear strengths

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Underground space 2024年第6期19卷 119-137页

作者： Bolong Liu Bo Li Liang Zhang Rui Huang Huicai Gao shilin Luo Tao Wang Key Laboratory of rock Mechanics and Geohazards of Zhejiang Province Shaoxing UniversityShaoxing 312000China college of Civil Engineering Tongji UniversityShanghai 200092China college of Civil and Architectural Engineering Xi’an University of Science and TechnologyXi’an 710054China college of Civil Engineering Changsha UniversityChangsha 410022China school of Transportation science and Engineering Harbin Institute of TechnologyHarbin 150040China Chongqing Research Institute of Harbin Institute of Technology Harbin Institute of TechnologyChongqing 401151China

When tunnel boring machines(TBMs)excavate through jointed rock masses,the cutting efficiency is strongly affected by the shear strength of joints,the mechanism of which,however,remains poorly *** this study,a series of disc-cutter indentation tests were conducted on granite rock mass specimens with different joint shear *** the indentation,the cracking process was recorded by a digital image correlation(DIC)*** deformation and strength of specimens,cracking behavior,rock breakage mode and cutting efficiency were quantitatively *** addition,to investigate the combined effects of joint shear strength,orientation and spacing on the rock breakage mechanism,numerical rock mass models were established based on a particle flow code *** results reveal that the cracking of primary and secondary cracks changes from the mixed shear-tensile to tensile mode in the initial stage,while the joint shear strength does not affect the cracking mode in the subsequent propagation *** rock breakage mode is classified to an internal block breakage mode,a cross-joint breakage mode and a cutters-dependent breakage *** cross-joint breakage mode is optimal for improving the cutting *** simulation results reveal that the increase in the joint shear strength changes the internal block breakage mode to cross-joint breakage mode for rock masses of particular ranges of joint orientation and *** findings provide basis for improving the TBM cutting efficiency through jointed rock masses.

关键词： Indentation test Joint shear strength Disc cutter rock breakage mechanism Cutting efficiency