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j.t Characteristics and Optimization of a Cavitation Nozzle for Hydraulic Fracturing Applications

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Fluid Dynamics & Materials Processing 2024年第1期20卷 179-192页

作者： Yu Gao Zhenqiang Xu Kaixiang shen shenzhen South China Sea Oil Economic Development Co. Ltd.Shenzhen518000China Guangzhou Marine Geological Survey China Geological SurveyGuangzhou511458China National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou511458China

Hydraulic j.tting is a form of fracturing that involves using a high-pressure j.t of water to create fractures in the reservoir rock with a nozzle serving as the central component of the hydraulic sandblasting perforation *** this study,the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ωturbulence *** results show that the nozzle structure can significantly influence the j.t performance and related cavitation *** orthogonal experiments,the nozzle geometric parameters are optimized,and the following configuration is found accordingly:contraction angle 20°,contraction segment length 6 mm,cylindrical segment diameter 6 mm,cylindrical segment length 12 mm,spread segment length 10 mm,and spread angle 55°.

关键词： Cavitation j.t angle nozzle hydraulic characteristics nozzle parameters

Study of Turing patterns in a SI reaction-diffusion propagation system based on network and non-network environments

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International j.urnal of Biomathematics 2024年第1期17卷 199-225页

作者： Yuxuan Tang Shuling shen Linhe Zhu School of Mathematical Sciences j.angsu University Zhenjiang212013P.R.China Department of Stomatology Afiliated Hospital of j.angsu University Zhenj.ang 210008P.R.China

The study of rumor propagation dynamics is of great significance to *** news and ensure the authenticity of news *** this paper,a SI reaction-diffusion rumor propagation model with nonlinear saturation incidence is ***,through stability analysis,we obtain the conditions for the existence and local stability of the positive equilibrium *** selecting suitable variable as the control parameter,the critical value of Turing bifurcation and the existence theorem of Turing bifurcation are ***,using the above theorem and multi-scale standard analysis,the expression of amplitude equation around Turing bifurcation point is *** analyzing the amplitude equation,different types of Turing pattern are divided such as uniform steady-state mode,hexagonal mode,stripe mode and mixed structure ***,in the numerical simulation part,by observing different patterns corresponding to different values of control variable,the correctness of the theory is ***,the effects of different network structures on patterns are *** results show that there are significant differences in the distribution of users on different network structures.

关键词： Reaction-diffusion system rumor propagation amplitude equation Turing pattern

Intravitreal conbercept inj.ction with panretinal photocoagulation for high-risk proliferative diabetic retinopathy with vitreous hemorrhage

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International j.urnal of Ophthalmology(English edition) 2024年第6期17卷 1066-1072页

作者： Yao Xu Qing Ye Wei shen Department of Ophthalmology the Fourth Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Ophthalmology Suzhou Kowloon HospitalShanghai Jiao Tong University School of MedcineSuzhou 215000Jiangsu ProvinceChina Department of Ophthalmology the First Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina

AIM:To assess the clinical efficacy and safety of combining panretinal photocoagulation(PRP)with intravitreal conbercept(IVC)inj.ctions for patients with high-risk proliferative diabetic retinopathy(HR-PDR)complicated by mild or moderate vitreous hemorrhage(VH),with or without diabetic macular edema(DME).METHODS:Patients diagnosed with VH with/without DME secondary to HR-PDR and received PRP combined with IVC inj.ctions were recruited in this retrospective *** establishing the patient’s diagnosis,an initial IVC was performed,followed by prompt administration of *** cases who significant bleeding persisted and impeded the laser operation,IVC was sustained before supplementing with *** the completion of PRP,patients were meticulously monitored for a minimum of six *** therapy and IVC inj.ctions were j.diciously adj.sted based on fundus fluorescein angiography(FFA)*** effect and the incidence of adverse events were ***:Out of 42 patients(74 eyes),29 were male and 13 were female,with a mean age of 59.17±12.74y(33-84y).The diabetic history was between 1wk and 26y,and the interval between the onset of visual symptoms and diagnosis of HR-PDR was *** affected eye received 2.59±1.87(1-10)IVC inj.ctions and underwent 5.5±1.02(4-8)sessions of *** these,68 eyes received PRP following 1 IVC inj.ction,5 eyes after 2 IVC inj.ctions,and 1 eye after 3 IVC *** absorption of VH was observed in all 74 eyes 5-50wk after initial treatment,with resolution of DME in 51 eyes 3-48wk after initial treatment.A newly developed epiretinal membrane was noted in one *** acuity significantly improved in 25 *** complications such as glaucoma,retinal detachment,or endophthalmitis were ***:The study suggests that the combination of PRP with IVC inj.ctions is an effective and safe modality for treating diabetic VH in patients with HR-PDR.

关键词： conbercept panretinal photocoagulation high-risk proliferative diabetic retinopathy vitreous hemorrhage

BreedingAIDB: A database integrating crop genome-to-phenotype paired data with machine learning tools applicable to breeding

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Plant Communications 2024年第7期5卷 12-15页

作者： Zij.e shen Enhui shen Kun Yang Zuoqian Fan Qian-Hao Zhu Longj.ang Fan Chu-Yu Ye Hainan Institute Zhejiang UniversitySanya 572025China Institute of Crop Science&Institute of Bioinformatics College of Agriculture&BiotechnologyZhejiang UniversityHangzhou 310058China CSIRO Agriculture and Food CanberraACT 2601Australia

Machine learning(ML)is one of the key technologies for next-generation breeding,and“big data”is the cornerstone for development of ML algorithms that are applicable to crop breeding ***,there is a shortage of databases containing phenotype data and corresponding genomic data,i.e.,genome-to-phenotype(G2P)paired data,that can be used in the development of ML algorithms for *** fill this gap,we constructed a user-friendly database named the BreedingAIDB(http://***/BreedingAIDB)to provide breeders and ML experts with easily accessible G2P paired data for crops,as well as ML tools.

关键词： database learning breeding

Flexible ultrasound arrays with embossed polymer structures for medical imaging

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j.urnal of Semiconductors 2024年第8期45卷 1-3页

作者： Zhongming Chen Qilin Hua Guozhen shen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China Institute of Flexible Electronics Beijing Institute of TechnologyBeijing 102488China

In recent years,the application of flexible electronic technology[1−3]combined with ultrasonic imaging[4]has blossomed,resulting in a shift in the application place of ultrasonic imaging technology from medical institutions to *** utilization of this application has expanded from the physician’s positioning and guidance to real-time patient monitoring[5],while the range of application scenarios continues to *** transformative changes have made possible through the development of flexible transducer arrays[6,7].*** Xu's team at the University of California San Diego has pioneered the development of various flexible transducer arrays based on island-bridge structures[8]and serpentine electrodes[9].These transducer arrays incorporate rigid 1−3 composite piezoelectric transducers on an island,featuring thin electrodes between the islands to provide mechanical flexibility,metallic electrodes of serpentine structure to provide stretchability of the device,and elastomer materials are used to encapsulate the overall structure,ensuring structural stability and impedance matching to the skin tissue[10].These flexible transducer arrays have found extensive applications in human blood pressure detection[11],cardiac imaging[12],blood flow doppler imaging[13],tissue modulus detection[14],and tissue deep hemoglobin detection[15].

关键词： island matching expanded

Artificial hawk-eye camera for foveated, tetrachromatic, and dynamic vision

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j.urnal of Semiconductors 2024年第9期45卷 1-3页

作者： Wenhao Ran Zhuoran Wang Guozhen shen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China Institute of Flexible Electronics Beijing Institute of TechnologyBeijing 102488China

With the rapid development of drones and autonomous vehicles, miniaturized and lightweight vision sensors that can track targets are of great interests. Limited by the flat structure, conventional image sensors apply a large number of lenses to achieve corresponding functions, increasing the overall volume and weight of the system.

关键词： awk vision system.

Sparse Adversarial Learning for FDIA Attack Sample Generation in Distributed Smart

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2095-2115页

作者： Fengyong Li Weicheng shen Zhongqin Bi Xiangj.ng Su College of Computer Science and Technology Shanghai University of Electric PowerShanghai201306China College of Electrical Engineering Shanghai University of Electric PowerShanghai201306China

False data inj.ction attack(FDIA)is an attack that affects the stability of grid cyber-physical system(GCPS)by evading the detecting mechanism of bad *** FDIA detection methods usually employ complex neural networkmodels to detect FDIA ***,they overlook the fact that FDIA attack samples at public-private network edges are extremely sparse,making it difficult for neural network models to obtain sufficient samples to construct a robust detection *** address this problem,this paper designs an efficient sample generative adversarial model of FDIA attack in public-private network edge,which can effectively bypass the detectionmodel to threaten the power grid system.A generative adversarial network(GAN)framework is first constructed by combining residual networks(ResNet)with fully connected networks(FCN).Then,a sparse adversarial learning model is built by integrating the time-aligned data and normal data,which is used to learn the distribution characteristics between normal data and attack data through iterative ***,we introduce a Gaussian hybrid distributionmatrix by aggregating the network structure of attack data characteristics and normal data characteristics,which can connect and calculate FDIA data with normal ***,efficient FDIA attack samples can be sequentially generated through interactive adversarial *** simulation experiments are conducted with IEEE 14-bus and IEEE 118-bus system data,and the results demonstrate that the generated attack samples of the proposed model can present superior performance compared to state-of-the-art models in terms of attack strength,robustness,and covert capability.

关键词： Distributed smart grid FDIA adversarial learning power public-private network edge

The Completeness of Accreting Neutron Star Binary Candidates from the Chinese Space Station Telescope

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Research in Astronomy and Astrophysics 2024年第9期24卷 28-36页

作者： Hao shen Shun-Yi Lan Xiang-Cun Meng Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China

A neutron star(NS)has many extreme physical conditions,and one may obtain some important information about an NS via accreting neutron star binary(ANSB)*** upcoming Chinese Space Station Telescope(CSST)provides an opportunity to search for a large sample of ANSB *** goal is to check the completeness of the potential ANSB samples from CSST *** this paper,we generate some ANSBs and normal binaries under the CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification *** the Precision(94.56%)of our machine learning model is as high as before study,the Recall is only about 63.29%.The Precision/Recall is mainly determined by the mass transfer rate between the NSs and their *** addition,we also find that the completeness of ANSB samples from CSST photometric data by the machine learning method also depends on the companion mass and the age of the *** candidates with a low initial mass companion star(0.1 M_(⊙)to 1 M_(⊙))have a relatively high Precision(94.94%)and high Recall(86.32%),whereas ANSB candidates with a higher initial mass companion star(1.1 M_(⊙)to 3 M_(⊙))have similar Precision(93.88%)and quite low Recall(42.67%).Our results indicate that although the machine learning method may obtain a relatively pure sample of ANSBs,a completeness correction is necessary for one to obtain a complete sample.

关键词： stars:neutron X-rays:binaries methods:analytical

Numerical investigation on the flow and thermal behaviors of the volumetric solar receivers with different morphologies

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Science China(Technological Sciences) 2024年第9期67卷 2749-2757页

作者： DU shen LI Dong LI Mengj.e HE YaLing National Innovation Platform(Center)for Industry-Education Integration of Energy Storage Technology Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of EducationXi’an Jiaotong UniversityXi’an 710049China

Morphologies of the porous materials influence the processes of solar radiation transport, flow, and thermal behaviors within volumetric solar receivers. A comprehensive comparative study is conducted by applying pore scale numerical simulations on volumetric solar receivers featuring various morphologies, including Kelvin, Weaire-Phelan, and foam configurations. The idealized unit cell and X-ray computed tomography scan approaches are employed to reconstruct pore scale porous *** Carlo ray tracing and pore scale numerical simulations are implemented to elucidate the radiative, flow, and thermal behaviors of distinct receivers exposed to varying thermal boundary conditions and real irradiation situations. The findings demonstrate that the foam structure exhibits greater solar radiation absorptivity, while Kelvin and Weaire-Phelan structures enhance the penetration depth under non-perpendicular solar irradiation. In comparison with Kelvin and Weaire-Phelan configurations, the foam structure presents efficient convective heat transfer, with the Weaire-Phelan structure showing pronounced thermal non-equilibrium phenomena. The variance in convective heat transfer coefficient between Kelvin and Weaire-Phelan configurations is approximately 8.4%. The foam structure exhibits higher thermal efficiency and flow resistance under nonperpendicular irradiation compared to Kelvin and Weaire-Phelan structures, attributed to its smaller pore size and intricate flow channels. An increase of 1.3% in thermal efficiency is observed with a substantial rise in pressure drop of 32.2%.

关键词： volumetric solar receiver porous morphology pore scale method solar radiation absorption thermal performance flow resistance