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Parallelization strategies for resolved simulations of fluid-structure-particle interactions

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 857-872页

作者： Jianhua QIN fei liao Guodan DONG Xiaolei YANG The State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China Interdisciplinary Center for Fundamental and Frontier Sciences Nanjing University of Science and TechnologyJiangyin 214443Jiangsu ProvinceChina School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100049China

Fluid-structure-particle interactions in three spatial dimensions happen in many environmental and engineering flows.This paper presents the parallel algorithms for the hybrid diffuse and sharp interface immersed boundary(IB)method developed in our previous work.For the moving structure modeled using the sharp interface IB method,a recursive box method is developed for efficiently classifying the background grid nodes.For the particles modeled using the diffuse interface IB method,a‘master-slave’approach is adopted.For the particle-particle interaction(PPI)and particle-structure interaction(PSI),a fast algorithm for classifying the active and inactive Lagrangian points,which discretize the particle surface,is developed for the‘dry’contact approach.The results show that the proposed recursive box method can reduce the classifying time from 52seconds to 0.3 seconds.Acceptable parallel efficiency is obtained for cases with different particle concentrations.Furthermore,the lubrication model is utilized when a particle approaches a wall,enabling an accurate simulation of the rebounding phenomena in the benchmark particle-wall collision problem.At last,the capability of the proposed computational framework is demonstrated by simulating particle-laden turbulent channel flows with rough walls.

关键词： particle-resolved direct numerical simulation particle-laden flow complex geometry resolved fluid-structure-particle interaction(RFSPI) immersed boundary(IB)method

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Practical cloud storage auditing using serverless computing

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Science China(Information Sciences) 2024年第3期67卷 33-47页

作者： fei CHEN Jianquan CAI Tao XIANG Xiaofeng liao College of Computer Science and Software Engineering Shenzhen University College of Computer Science Chongqing University

Cloud storage auditing research is dedicated to solving the data integrity problem of outsourced storage on the cloud. In recent years, researchers have proposed various cloud storage auditing schemes using different techniques. While these studies are elegant in theory, they assume an ideal cloud storage model;that is, they assume that the cloud provides the storage and compute interfaces as required by the proposed schemes. However, this does not hold for mainstream cloud storage systems because these systems only provide read and write interfaces but not the compute interface. To bridge this gap, this work proposes a serverless computing-based cloud storage auditing system for existing mainstream cloud object storage. The proposed system leverages existing cloud storage auditing schemes as a basic building block and makes two adaptations. One is that we use the read interface of cloud object storage to support block data requests in a traditional cloud storage auditing scheme. Another is that we employ the serverless computing paradigm to support block data computation as traditionally required. Leveraging the characteristics of serverless computing, the proposed system realizes economical, pay-as-you-go cloud storage auditing. The proposed system also supports mainstream cloud storage upper layer applications(e.g., file preview) by not modifying the data formats when embedding authentication tags for later auditing. We prototyped and open-sourced the proposed system to a mainstream cloud service, i.e., Tencent Cloud. Experimental results show that the proposed system is efficient and promising for practical use. For 40 GB of data, auditing takes approximately 98 s using serverless computation. The economic cost is 120.48 CNY per year, of which serverless computing only accounts for 46%. In contrast, no existing studies reported cloud storage auditing results for real-world cloud services.

关键词： cloud storage auditing serverless computing object storage usability

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Organic Brønsted Acid-Catalyzed Stereoselective Cationic RAFT Polymerization:The Effect of RAFT Agents

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Chinese Journal of Polymer Science 2024年第6期42卷 711-717页

作者： Zheng-Yi Zhang Zan Yang yun liao Sai-Hu liao Key Laboratory of Molecule Synthesis and Function Discovery(Fujian Province University) College of ChemistryFuzhou UniversityFuzhou350108China State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China Beijing National Laboratory for Molecular Sciences Beijing100190China

The tacticity of vinyl polymers is a key factor affecting the properties of materials.Recently,organic Brønsted acids have been demonstrated as effective catalysts for the development of highly stereoselective cationic reversible addition-fragmentation chain transfer(RAFT)polymerizations of vinyl ethers,in which the use of RAFT agents could allow the control the molecular weight and tacticity of polymer products simultaneously.However,the effect of RAFT agents on the tacticity-regulation remains elusive and lacks of investigation.In this study,we synthesized four types of RAFT agents and evaluated their influence in the stereoselective cationic polymerization of isobutyl vinyl ether in the presence of PADI as a Brønsted acid catalyst,which unveils that the Z group of RAFT agents could not only affect the polydispersity of the products,but also exert a profound effect on the stereoselectivity.After extensive screening of the RAFT agents,high stereoregularity(isotacticity,90%m)was obtained when using dithiocarbonate ester-type RAFT agents with a benzyloxy Z group.

关键词： Bronsted acid catalysis Stereoselective cationic polymerization RAFT polymerization Chain transfer agents Tacticity

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RNA modifications in cellular metabolism:implications for metabolism-targeted therapy and immunotherapy

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1565-1594页

作者： Wei-Wei Liu Si-Qing Zheng Tian Li yun-fei fei Chen Wang Shuang Zhang fei Wang Guan-Min Jiang Hao Wang Department of Laboratory Medicine The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina School of Clinical Medicine Shandong UniversityJinanChina Core Unit of National Clinical Research Center for Laboratory Medicine HefeiChina Neurosurgical Department The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina Department of Clinical Laboratory The Fifth Affiliated HospitalSun Yat-sen UniversityZhuhaiChina

Cellular metabolism is an intricate network satisfying bioenergetic and biosynthesis requirements of cells.Relevant studies have been constantly making inroads in our understanding of pathophysiology,and inspiring development of therapeutics.As a crucial component of epigenetics at post-transcription level,RNA modification significantly determines RNA fates,further affecting various biological processes and cellular phenotypes.To be noted,immunometabolism defines the metabolic alterations occur on immune cells in different stages and immunological contexts.In this review,we characterize the distribution features,modifying mechanisms and biological functions of 8 RNA modifications,including N6-methyladenosine(m6A),N6,2'-O-dimethyladenosine(m6Am),N1-methyladenosine(m1A),5-methylcytosine(m5C),N4-acetylcytosine(ac4C),N7-methylguanosine(m7G),Pseudouridine(V),adenosine-to-inosine(A-to-l)editing,which are relatively the most studied types.Then regulatory roles of these RNA modification on metabolism in diverse health and disease contexts are comprehensively described,categorized as glucose,lipid,amino acid,and mitochondrial metabolism.And we highlight the regulation of RNA modifications on immunometabolism,further influencing immune responses.Above all,we provide a thorough discussion about clinical implications of RNA modification in metabolism-targeted therapy and immunotherapy,progression of RNA modification-targeted agents,and its potential in RNAtargeted therapeutics.Eventually,we give legitimate perspectives for future researches in this field from methodological requirements,mechanistic insights,to therapeutic applications.

关键词： metabolism targeted alterations

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Idiopathic mesenteric phlebosclerosis missed by a radiologist at initial diagnosis: A case report

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World Journal of Clinical Cases 2024年第10期12卷 1810-1816页

作者： Min Wang Yu-Xia Wan Jin-Wen liao fei Xiong Department of Gastroenterology Changning County People’s HospitalYibin 644300Sichuan ProvinceChina Department of Gastroenterology Qianwei People’s HospitalLeshan 614400Sichuan ProvinceChina Department of Gastroenterology The People’s Hospital of Jianyang CityChengdu 641400Sichuan ProvinceChina Department of Gastroenterology Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengdu 610000Sichuan ProvinceChina

BACKGROUND Idiopathic mesenteric phlebosclerosis(IMP)is a rare type of ischemic colitis characterized by thickening of the wall of the right hemicolon and calcification,sclerosis,and fibrosis of mesenteric veins.The diagnosis of IMP is based on typical clinical features and imaging findings.We report a case of IMP that was initially missed by the radiologist.CASE SUMMARY A 77-year-old woman was admitted to the hospital due to chronic diarrhea for over 2 months.She had been consuming Chinese patent medicines(CPM)containing fructus gardeniae for more than 15 years.Colonoscopy revealed an edematous mucosa,bluish-purple discoloration,erosions,and ulcerations throughout the colorectal area.Abdominal computed tomography(CT)showed diffuse mural thickening of the entire colorectum,with tortuous thread-like calcifications in the right hemicolon,left hemicolon,and rectum.Most of the calcifications were located in the mesenteric vein.The diagnosis of IMP was established based on medical history,colonoscopy,CT findings,and histopathological examination.The patient was treated conservatively with papaverine and rifaximin,and CPM was stopped.Her diarrhea symptoms improved,indicating the effectiveness of the treatment.Over the next several years,she took opium alkaloids for an extended period and did not require hospitalization for the aforementioned gastrointestinal disorder.CONCLUSION IMP is a rare gastrointestinal disease affecting Asian populations,possibly related to long-term herbal medicine intake.Accurate imaging analysis is crucial for diagnosis,but insufficient understanding of the disease can lead to misdiagnosis or missed diagnosis.Treatment strategies should be personalized.

关键词： Idiopathic mesenteric phlebosclerosis Computed tomography Colonoscopy Chinese patent medicines Fructus gardeniae Case report

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Calcium-based polymers for suppression of soil acidification by improving acid-buffering capacity and inhibiting nitrification

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Journal of Environmental Sciences 2024年第5期139卷 138-149页

作者： fei Kang yunshan Meng Yanning Ge yun Zhang Haixiang Gao Xueqin Ren Jie Wang Shuwen Hu Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China Department of Applied Chemistry China Agricultural UniversityBeijing 100193China

Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil acidity.However,their effectiveness in inhibiting soil acidification has not been studied.This study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,respectively.For comparison,Ca(OH)_(2)and lignin were used as the inorganic and organic controls,respectively.Among the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange processes.Under acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation.Furthermore,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS application.Therefore,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect acidification.Overall,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification.In conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.

关键词： Calcium-based polymer Soil acidification pH buffering capacity Nitrification inhibition

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Effects of the sand content of muddy water content on one-dimensional vertical infiltration characteristics and dense layer formation characteristics

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 172-179页

作者： Shouxuan Kang Liangjun fei yun Zhong Lihua Liu State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi’an University of TechnologyXi’an 710048China Institute of Water Resources and Hydro-electric Engineering Xi’an University of TechnologyXi’an 710048China Engineering Research Center of Eco-environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges UniversityYichang 443002HubeiChina School of Water Conservancy and Hydroelectric Power Hebei University of EngineeringHandan 056038HebeiChina

Muddy water irrigation,an effective water-saving irrigation method,has been widely used in the Yellow River Basin in China.To investigate the effect of sand content on water infiltration and dense layer formation under one-dimensional vertical infiltration of muddy water,muddy water infiltration experiments were performed in the laboratory,and five sand contents of muddy water(S=0%,3%,6%,9%,and 12%)were used.Models were established to describe the relationship between the cumulative infiltration amount[I(t)]and the infiltration duration(t);the relationship among the migration distance of the wetting front(Z),S,and t;the thickness of the sedimentary layer[H(t)];and the relationship between S and t.The results revealed that I(t)and Z decreased significantly with the increase of sand contents,while H(t)increased significantly with the increase of sand contents.I(t)and Z were in the range of 7 cm and 20 cm for each treatment,respectively.The variation in I(t)with t fitted Kostiakov and Philip models,and the coefficients of determination were all greater than 0.99.With the increase in S,the infiltration coefficient gradually decreased,the infiltration index gradually increased,and the sorptivity gradually decreased.The particle composition of the sedimentary layer was similar to that of the argillaceous sediment,and the content of particles with a size of less than 2 mm in the sedimentary layer was lower than that of the argillaceous sediment.Compared with the original soil,the content of particles with a size of less than 0.05 mm and physical clay particles(diameter less than 0.01 mm)in the soil with an infiltration depth of 0-2 cm increased.The retention layer was from the topsoil to the infiltration depth of approximately 2 cm.This study can provide a scientific basis for further research on soil infiltration mechanisms under muddy water.

关键词： muddy water sand content dense layer cumulative infiltration wetting front transport deposit layer thickness

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MPI/OpenMP-Based Parallel Solver for Imprint Forming Simulation

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 461-483页

作者： Yang Li Jiangping Xu yun Liu Wen Zhong fei Wang School of Mechanical Engineering Jiangsu UniversityZhenjiang212016China School of Mechanical Engineering Wuhan Polytechnic UniversityWuhan430023China Shenyang Mint Company Limited Shenyang110092China

In this research,we present the pure open multi-processing(OpenMP),pure message passing interface(MPI),and hybrid MPI/OpenMP parallel solvers within the dynamic explicit central difference algorithm for the coining process to address the challenge of capturing fine relief features of approximately 50 microns.Achieving such precision demands the utilization of at least 7 million tetrahedron elements,surpassing the capabilities of traditional serial programs previously developed.To mitigate data races when calculating internal forces,intermediate arrays are introduced within the OpenMP directive.This helps ensure proper synchronization and avoid conflicts during parallel execution.Additionally,in the MPI implementation,the coins are partitioned into the desired number of regions.This division allows for efficient distribution of computational tasks across multiple processes.Numerical simulation examples are conducted to compare the three solvers with serial programs,evaluating correctness,acceleration ratio,and parallel efficiency.The results reveal a relative error of approximately 0.3%in forming force among the parallel and serial solvers,while the predicted insufficient material zones align with experimental observations.Additionally,speedup ratio and parallel efficiency are assessed for the coining process simulation.The pureMPI parallel solver achieves a maximum acceleration of 9.5 on a single computer(utilizing 12 cores)and the hybrid solver exhibits a speedup ratio of 136 in a cluster(using 6 compute nodes and 12 cores per compute node),showing the strong scalability of the hybrid MPI/OpenMP programming model.This approach effectively meets the simulation requirements for commemorative coins with intricate relief patterns.

关键词： Hybrid MPI/OpenMP parallel computing MPI OpenMP imprint forming

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Distributed Secondary Control Based on Dynamic Diffusion Algorithm for Current Sharing and Average Voltage Regulation in DC Microgrids

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 597-607页

作者： Dawei liao fei Gao Daniel J.Rogers Wentao Huang Dong Liu Houjun Tang Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghaiChina Department of Engineering Science University of OxfordOxford OX12JDU.K. IEEE

This paper introduces a distributed secondary control scheme for achieving current sharing and average voltage regulation objectives in a DC microgrid.The proposed scheme employs a dynamic diffusion algorithm(DDA)instead of the consensus algorithm to enable distributed communication among converters.To help understand DDA,the relation of DDA and other diffusion algorithms is discussed in detail and its superiority is shown by comparison with diffusion and consensus algorithms.Furthermore,considering the discrete nature and different sampling time of the digital controller and communication network,a z-domain model of the entire DC microgrid is established.The influence of communication and secondary control parameters on the system stability is investigated.Based on the established model,the tolerable communication rates are obtained.Real-time simulations conducted on the OPAL-RT platform validate the effectiveness of the proposed scheme,showcasing its advantages in terms of convergence speed and stability.

关键词： Cooperative control DC microgrid diffusion algorithm discrete-time modeling distributed secondary control

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Appendiceal intussusception complicated by adenocarcinoma of the cecum:A case report

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World Journal of Clinical Cases 2024年第8期12卷 1461-1466页

作者： Yu Long Yi-Ning Xiang fei Huang Lei Xu Xiao-yun Li yun-Huan Zhen Department of Colorectal Surgery The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550001Guzihou ProvinceChina Department of Colorectal Surgery Guizhou Medical UniversityGuiyang 550001Guizhou ProvinceChina Department of Pathology The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550001Guizhou ProvinceChina

BACKGROUND Appendiceal intussusception is a pathological condition in which the appendix is inverted into the cecum,which may cause symptoms that resemble those of other gastrointestinal disorders and may induce intestinal obstruction.The rarity of this case presentation is the co-occurrence of appendiceal intussusception and cecal adenocarcinoma,a combination that to our knowledge has not previously been reported in the medical literature.This case provides new insights into the complexities of diagnosing and managing overlapping pathologies.CASE SUMMARY A 25-year-old woman presented with persistent periumbilical pain and bloody stools.An initial biopsy showed cecal cancer;however,subsequent colonoscopy and computed tomography findings raised the suspicion of appendiceal intussus-ception,which was later confirmed postoperatively.This unique case was charac-terized by a combination of intussusception and adenocarcinoma of the cecum.The intervention included a laparoscopic right hemicolectomy,which led to the histopathological diagnosis of mucinous adenocarcinoma with appendiceal intussusception.The patient recovered well postoperatively and was advised to initiate adjuvant chemotherapy.This case highlights not only the importance of considering appendiceal intussusception in the differential diagnosis,but also the possibility of appendicitis and the atypical presentation of neoplastic lesions.CONCLUSIONS Physicians should consider the possibility of appendiceal intussusception in cases of atypical appendicitis,particularly when associated with neoplastic presentation.

关键词： Appendiceal intussusception Appendicitis Cecal cancer Target signs Misdiagnosis Case report

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