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Effect of stress-dependent microannulus aperture on well leakage

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journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 1967-1976页

作者： Meng Meng Luke P.Frash j.William Carey Mohamed Mehana Wenfeng li Bailian Chen Earth and Environmental Sciences Los Alamos National LaboratoryLos AlamosNMUSA

Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in *** detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing ***,the permeability of the microannulus is regarded as a uniform value throughout the ***,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective *** this work,we developed a unique experimental *** equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ *** microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage ***,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and *** observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their *** findings also indicate a distinct behavior when comparing liquid CO_(2) with ***,it is easier for liquid CO_(2) to create the ***,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well *** outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture *** traditional assumption of a constant aperture significantly underestimates fluid leakage risks.

关键词： Microannulus Leakage assessment Aperture size Triaxial experiment Carbon sequestration

Advanced Algorithm for Parameters Estimation of Negative Binomial Distribution with High Dimensional Sparse Group Structure

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journal of Systems Science & Complexity 2024年第5期37卷 2173-2195页

作者： li Meiqi jIN Baisuo School of Management University of Science and Technology of China

Negative binomial regression is a powerful technique for modeling count data, particularly when dealing with overdispersion. However, estimating the parameters for large-dimensional sparse models is challenging due to the complexity of optimizing the mean and dispersion parameter of the negative binomial distribution. To address this issue, the authors propose a novel approach that employs two iterations of the majorize-minimize(MM) algorithm, one for estimating the dispersion parameter and the other for estimating the mean parameters. These approaches improve the convergence speed and stability of the algorithm. The authors also use group penalty for variable selection, which enhances the accuracy and efficiency of the algorithm. The proposed method provides an explicit solution,simplifies the iteration process, and maintains good stability while ensuring algorithm ***, the authors apply the proposed algorithm to the zero-inflated model and demonstrate its promising predictive performance on specific data sets. The research has important implications for count data modeling and analysis in various fields, such as data mining, machine learning, and bioinformatics.

关键词： Group structure majorize-minimize (MM) negative binomial

A Novel Tensor Decomposition-Based Efficient Detector for Low-Altitude Aerial Objects With Knowledge Distillation Scheme

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IEEE/CAA journal of Automatica Sinica 2024年第2期11卷 487-501页

作者： Nianyin Zeng Xinyu li Peishu Wu Han li Xin Luo Department of Instrumental and Electrical Engineering Xiamen UniversityXiamen 361005China IEEE College of Computer and Information Science Southwest UniversityChongqing 400715China

Unmanned aerial vehicles(UAVs) have gained significant attention in practical applications, especially the low-altitude aerial(LAA) object detection imposes stringent requirements on recognition accuracy and computational resources. In this paper, the LAA images-oriented tensor decomposition and knowledge distillation-based network(TDKD-Net) is proposed,where the TT-format TD(tensor decomposition) and equalweighted response-based KD(knowledge distillation) methods are designed to minimize redundant parameters while ensuring comparable performance. Moreover, some robust network structures are developed, including the small object detection head and the dual-domain attention mechanism, which enable the model to leverage the learned knowledge from small-scale targets and selectively focus on salient features. Considering the imbalance of bounding box regression samples and the inaccuracy of regression geometric factors, the focal and efficient IoU(intersection of union) loss with optimal transport assignment(F-EIoU-OTA)mechanism is proposed to improve the detection accuracy. The proposed TDKD-Net is comprehensively evaluated through extensive experiments, and the results have demonstrated the effectiveness and superiority of the developed methods in comparison to other advanced detection algorithms, which also present high generalization and strong robustness. As a resource-efficient precise network, the complex detection of small and occluded LAA objects is also well addressed by TDKD-Net, which provides useful insights on handling imbalanced issues and realizing domain adaptation.

关键词： Attention mechanism knowledge distillation(KD) object detection tensor decomposition(TD) unmanned aerial vehicles(UAVs)

The variation of DOM during long distance water transport by the China South to North Water Diversion Scheme and impact on drinking water treatment

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 85-100页

作者： Hankun yang y.j.an li Hongyu liu Nigel j.D.Graham Xue Wu jiawei Hou Mengjie liu Wenyu Wang Wenzheng yu State Key Laboratory of Environmental Aquatic Chemistry Key Laboratory of Drinking Water Science and TechnologyResearch Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China School of Environment and Municipal Engineering Qingdao Technological UniversityQingdao266033China Colleges of Forestry Northeast Forestry UniversityHarbin150006China Department of Civil and Environmental Engineering Imperial College LondonSouth Kensington CampusLondonSW7 2AZUK School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing100081China State Key Laboratory of Separation Membrane Processes School of Environment Science and EngineeringTiangong UniversityTianjin300387China

In this study,samples were taken from three locations,upstream to downstream,along the central route project of the China South to North Water Diversion(SNWD)scheme in summer and *** were used to reveal the variations of dissolved organic matter(DOM)during the water transfer process,and the effects of these variations on drinking water treatment and disinfection by-products formation potential(DBPs-FP).The results showed that polysaccharides accumulate in summer and reduce in winter with flow distance,which has an important effect on the overall properties of DOM,as well as on the performance of coagulation,ultrafiltration,and the formation of *** substances,and their hydrophilic content,also increased in summer and decreased in winter with flow *** contrast,the concentration of small organic substances(MW≤1000 Da)increased in both summer and winter with flow distance,which affected both nanofiltration(NF)membrane fouling and *** results provide a useful case study of spatial and temporal changes in raw water DOM during long distance water transfer and their impact on the treatment and quality of drinking water from the SNWD.

关键词： Long-distance water transfer The China South to North Water Diversion Scheme Coagulation Membrane filtration Disinfection by-products

Boosting High-Voltage Practical lithium Metal Batteries with Tailored Additives

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Nano-Micro Letters 2024年第12期16卷 23-41页

作者： jinhai you Qiong Wang Runhong Wei li Deng yiyang Hu li Niu jingkai Wang Xiaomei Zheng junwei li yao Zhou jun-Tao li College of Energy Xiamen UniversityXiamen 361005People’s Republic of China Magnetism Key Laboratory of Zhejiang Province College of Materials and ChemistryChina Jiliang UniversityHangzhou 310018People’s Republic of China Laboratory for Soft Matter and Biophysics Department of Physics and AstronomyKU Leuven3001 LeuvenBelgium State Key Lab of Physical Chemistry of Solid Surface College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005People’s Republic of China Department of Chemical Engineering KU LeuvenCelestijnenlaan 200F3001 LeuvenBelgium College of Chemistry and Chemical Engineering Northwest Normal UniversityLanzhou 730070GansuPeople’s Republic of China

The lithium(li)metal anode is widely regarded as an ideal anode material for high-energy-density ***,uncontrolled li dendrite growth often leads to unfavorable interfaces and low Coulombic efficiency(CE),limiting its broader ***,an ether-based electrolyte(termed FGN-182)is formulated,exhibiting ultra-stable li metal anodes through the incorporation of liFSI and liNO3 as dual *** synergistic effect of the dual salts facilitates the formation of a highly robust SEI film with fast li+transport ***,li||Cu half cells exhibit an average CE reaching up to 99.56%.In particular,pouch cells equipped with high-loading lithium cobalt oxide(LCO,3 mAh cm^(-2))cathodes,ultrathin li chips(25μm),and lean electrolytes(5 g Ah-1)demonstrate outstanding cycling performance,retaining 80%capacity after 125 *** address the gas issue in the cathode under high voltage,cathode additives 1,3,6-tricyanohexane is incorporated with FGN-182;the resulting high-voltage LCO||li(4.4 V)pouch cells can cycle steadily over 93 *** study demonstrates that,even with the use of ether-based electrolytes,it is possible to simultaneously achieve significant improvements in both high li utilization and electrolyte tolerance to high voltage by exploring appropriate functional additives for both the cathode and anode.

关键词： li metal anode li dendrites liNO_(3) 1,3,6-tricyanohexane Pouch cells

Characterization of squash polysaccharide and the anti-diabetic effect on type 2 diabetic rat revealed by urine metabolomics analysis

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Food Science and Human Wellness 2024年第5期13卷 2937-2946页

作者： li liang Fuming Zhang Quanhong li Baoguo Sun yuyu Zhang Robert j.linhardt Beijing Advanced Innovation Center for Food Nutrition and Human Health Beijing Key Laboratory of Flavor ChemistryBeijing Technology and Business University(BTBU)Beijing 100048China Departments of Chemical and Biological Engineering Chemistry and Chemical BiologyBiomedical Engineering and Biological ScienceCenter for Biotechnology and Interdisciplinary StudiesRensselaer Polytechnic InstituteTroy 12180USA College of Food Science and Nutritional Engineering China Agricultural UniversityBeijing 100083China China National Engineering Research Center for Fruit and Vegetable Processing Beijing 100083China

The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from ***-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were likely to contain HG and RG-I domain of pectic polysaccharide,***-F2(Mw=270.4 kDa)was mainly composed of rhamnose,galactose and *** treatment with SPS decreased body weight gain,glucose and TG levels in type 2 diabetes ***,25 differential metabolites were identified based on urinary metabolomics analysis,which are crucial to the anti-diabetic effect of *** regulation of nicotinamide N-oxide,histamine,cis-aconitate,citrate,L-malic acid,3-(3-hydroxyphenyl)propanoic acid and N-acetyl-L-aspartic acid were mainly associated with energy metabolism,gut microbiota and *** of surface plasmon resonance revealed the binding kinetics with galectin-3(Gal-3)and fibroblast growth factor 2(FGF2).The K_(D)values of SPS-F2 and SPS-F3 to Gal-3 were 4.97×10^(-3)and 1.48×10^(-3)mol/L,indicating a weak binding *** 3 fractions showed moderate binding to FGF2 and the affinity was SPS-F3>SPS-F2>***,the metabolomics and SPR approach were proved to be a promising tool in exploring the anti-diabetes effects of SPS and provided a deep understanding of the mechanisms.

关键词： Polysaccharide Metabolomics Type 2 diabetes Surface plasmon resonance

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Efflcient machining of a complex blisk channel using a disc cutter

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Chinese journal of Aeronautics 2024年第1期37卷 414-437页

作者： Xiangyu li Zhaoyu li Dong HE junxue REN Qian FENG Kai TANG Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong Kong 999077China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Xi’an Sanhang Power Technology Co. LtdXi’an 710000China HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute FutianShenzhen 518057China HKUST Shenzhen Research Institute Shenzhen 518057China

For rough machining of a complex narrow cavity,e.g.,a complex blisk channel on an aero-engine,the typically used cutting tools are the slender cylindrical cutter and conical ***,as neither of the two is particularly suited for rough machining,wherein the main purpose is to remove a large volume as quickly as possible,the machining efficiency is low,especially when the part materials are of hard-to-cut types(e.g.,Titanium-alloy)for which it often takes days to rough machine a ***,disc machining provides a new and efficient roughing solution,since a disc cutter with a large radius enables a much larger cutting speed and thus a larger material removal ***,due to the large radius of the disc cutter,its potential collision with narrow and twisted channels becomes a serious *** this paper,we propose a novel twophase approach for efficiently machining a complex narrow cavity workpiece using a disc-shaped cutter,i.e.,3+2-axis disc-slotting of the channel by multiple layers(rough machining)+five-axis disc-milling of the freeform channel side surfaces(semi-finish machining).Both simulation and physical cutting experiments are conducted to assess the effectiveness and advantages of the proposed *** experimental results show that,with respect to a same cusp-height threshold on the channel side surfaces,the total machining time of the tested part by the proposed method is about only 36%of that by the conventional approach of plunging-milling(for roughing)plus milling by a slender cylindrical cutter(for semi-finishing).

关键词： Blisk channel CNC machining Disc cutter Roughing efficiency Tool path planning

Two-way shape memory effect in a Ti-Zr-Nb-Ta high-temperature shape memory alloy

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Rare Metals 2024年第3期43卷 1257-1262页

作者： Cheng-yang Xiong Tuo li jun Wang yan li School of Materials Science and Engineering Beihang UniversityBeijing100191China

The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta ***α"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of *** alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 *** maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.

关键词： Ti-Zr Shape memory alloys Two-way shape memory effect

Quantitative Applications of Weather Satellite Data for Nowcasting:Progress and Challenges

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journal of Meteorological Research 2024年第3期38卷 399-413页

作者： jun li jing ZHENG Bo li Min MIN yanan liU Chian-yi liU Zhenglong li WPaul MENZEL Timothy.j.SCHMIT john L.CINTINEO Scott liNDSTROM Scott BACHMEIER yunheng XUE yayu MA Di DI Han liN Innovation Centre for Fengyun Meteorological Satellite(FySIC) National Satellite Meteorological CentreChina Meteorological AdministrationBeijing100081China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai519082China Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai200241China Research Center for Environmental Changes Academia SinicaTaipei11529China Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-MadisonMadisonWI53706USA Sensors and Calibration Branch STAR/NESDISMadisonWI53706USA Wuxi University Wuxi214105China School of Computer Science Chengdu University of Information TechnologyChengdu610225China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education National and Local Joint Engineering Research Center of Satellite Geospatial Information TechnologyFuzhou UniversityFuzhou350108China

Monitoring and predicting highly localized weather events over a very short-term period,typically ranging from minutes to a few hours,are very important for decision makers and public *** these events usually relies on radar observations through monitoring and *** advanced high-resolution imaging and sounding observations from weather satellites,nowcasting can be enhanced by combining radar,satellite,and other data,while quantitative applications of those data for nowcasting are advanced through using machine learning *** applications include monitoring the location,impact area,intensity,water vapor,atmospheric instability,precipitation,physical properties,and optical properties of the severe storm at different stages(pre-convection,initiation,development,and decaying),identification of storm types(wind,snow,hail,etc.),and predicting the occurrence and evolution of the *** observations can provide information on the environmental characteristics in the preconvection stage and are very useful for situational awareness and storm *** paper provides an overview of recent progress on quantitative applications of satellite data in nowcasting and its challenges,and future perspectives are also addressed and discussed.

关键词： weather satellite quantitative applications nowcasting pre-convection