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Numerical and experimental investigation into the evolution of the shock wave when a muzzle jet impacts a constrained moving body

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Defence Technology（防务技术） 2024年第3期33卷 317-326页

作者： Zijie li hao Wang Changshun Chen Kun Jiang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing 210016China

The gun-track launch system is a new special launch device that connects the track outside the *** it is constrained by the track,the characteristics of development of the muzzle jet differ from those of the traditional muzzle ***,it changes from freely developing to doing so in a constrained manner,where this results in an asymmetric direction of flow as well as spatio-temporal coupling-induced interference between various shock waves and the formation of *** this background,the authors of this article formulate and consider the development and characteristics of evolution of the muzzle jet as it impacts a constrained moving *** designed simulations to test the gun-track launch system,and established a numerical model based on the dynamic grid method to explore the development and characteristics of propagation of disturbances when the muzzle jet impacted a constrained moving *** also considered models without a constrained track for the sake of *** results showed that the muzzle jet assumed a circumferential asymmetric shape,and tended to develop in the area above the *** the test platform was close to the ground,the muzzle jet was subjected to reflections from it that enhanced the development and evolution of various forms of shock waves and vortices in the muzzle jet to exacerbate its rate of distortion and asymmetric *** in turn led to significant differences in the changes in pressure at symmetric points that would otherwise have been *** results of a comparative analysis showed that the constrained track could hinder the influence of reflections from the ground on the muzzle jet to some extent,and could reduce the velocity of the shock waves inducing the motion of the muzzle as well as the Mach number of the moving *** work here provides a theoretical basis and the requisite technical support for applications of the gun-track launch *** also sheds light on the

关键词： Shock wave/vortex interference Muzzle jet Constrained boundary Dynamic grid

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Delving into high-quality SVBRDF acquisition: A new setup and method

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Computational Visual Media 2024年第3期10卷 523-541页

作者： Chuhua xian Jiaxin li hao Wu Zisen lin Guiqing li School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China Guangdong Shidi Intelligence Technology Ltd.Guangzhou 510000China

In this study, we present a new andinnovative framework for acquiring high-qualitySVBRDF maps. Our approach addresses the limitations of the current methods and proposes a newsolution. The core of our method is a simple hardwaresetup consisting of a consumer-level camera, LEDlights, and a carefully designed network that canaccurately obtain the high-quality SVBRDF propertiesof a nearly planar object. By capturing a ﬂexiblenumber of images of an object, our network usesdifferent subnetworks to train different property mapsand employs appropriate loss functions for each ofthem. To further enhance the quality of the maps, weimproved the network structure by adding a novel skipconnection that connects the encoder and decoder withglobal features. Through extensive experimentation usingboth synthetic and real-world materials, our resultsdemonstrate that our method outperforms previousmethods and produces superior results. Furthermore,our proposed setup can also be used to acquire physicallybased rendering maps of special materials.

关键词： acquisition setup SVBRDF acquisition material capture global skip connection

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Probabilistic seismic inversion based on physics-guided deep mixture density network

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Petroleum Science 2024年第3期21卷 1611-1631页

作者： Qian-hao Sun Zhao-Yun Zong Xin li National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Laoshan Laboratory Qingdao266580ShandongChina CNOOC Research Institute Ltd. Beijing100028China

Deterministic inversion based on deep learning has been widely utilized in model parameters *** by logging data,seismic data,wavelet and modeling operator,deterministic inversion based on deep learning can establish nonlinear relationships between seismic data and model ***,seismic data lacks low-frequency and contains noise,which increases the non-uniqueness of the *** conventional inversion method based on deep learning can only establish the deterministic relationship between seismic data and parameters,and cannot quantify the uncertainty of *** order to quickly quantify the uncertainty,a physics-guided deep mixture density network(PG-DMDN)is established by combining the mixture density network(MDN)with the deep neural network(DNN).Compared with Bayesian neural network(BNN)and network dropout,PG-DMDN has lower computing cost and shorter training time.A low-frequency model is introduced in the training process of the network to help the network learn the nonlinear relationship between narrowband seismic data and low-frequency *** addition,the block constraints are added to the PG-DMDN framework to improve the horizontal continuity of the inversion *** illustrate the benefits of proposed method,the PG-DMDN is compared with existing semi-supervised inversion *** synthetic data examples of Marmousi II model are utilized to quantify the influence of forward modeling part,low-frequency model,noise and the pseudo-wells number on inversion results,and prove the feasibility and stability of the proposed *** addition,the robustness and generality of the proposed method are verified by the field seismic data.

关键词： Deep learning Probabilistic inversion Physics-guided Deep mixture density network

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Evaluation of UAV spraying quality based on 1D-CNN model and wireless multi-sensors system

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Information Processing in Agriculture 2024年第1期11卷 65-79页

作者： Ziyuan hao Minzan li Wei Yang Xinze li Key Laboratory of Smart Agriculture Systems Ministry of EducationChina Agricultural UniversityBeijing 100083PR China

The droplet deposition is a key index to evaluate the quality of unmanned aerial vehicle(UAV)*** detection of the droplet deposition is time-consuming and costly,therefore,it is difficult to achieve large-scale and rapid acquisition in the *** solve the above problems,a droplet deposition acquisition system(DDAS)was *** was composed of the multiple sensors,processing units,remote server database and Android-based software.A droplet deposition prediction model based on field experimental data was established by using a one-dimensional convolutional neural network(1D-CNN)algorithm,and the effects of different inputs on the prediction ability of the model were *** results showed that adding temperature and humidity data to the inputs can achieve higher prediction accuracy than only using UAV spraying operation parameters and wind speed data as the inputs to the *** addition,the prediction accuracy of the 1D-CNN model was the highest when compared with other models such as back propagation neural network,multiple correlation vector machine,and multiple linear *** 1D-CNN model was embedded into the DDAS,and the evaluation experiments were carried out in the *** correlation analysis was conducted between two datasets of the droplet deposition obtained by the DDAS and water sensitive paper(WSP),*** R2 was 0.924,and the RMSE was 0.026μL/*** is proved that the droplet deposition values obtained by the DDAS and WSP have high consistency,and the DDAS developed can provide an auxiliary solution for the intelligent evaluation of UAV spraying quality.

关键词： UAV Spraying quality Droplet deposition 1D-CNN model Sensor

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A new integrated model of deformation resistance and its application in prediction of rolling force of a thick plate

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Journal of Iron and Steel Research International 2024年第4期31卷 882-893页

作者： Shun-hu Zhang Yan li li-zhi Che Wen-hao Tian Shagang School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

The prediction accuracy of existing models of the rolling force of a thick plate is always very *** address this problem,a high-precision genetic algorithm-backpropagation network(GA-BP)model of deformation resistance was built,and its integration with the traditional fitted model was further ***,a novel rolling force model was obtained by embedding the integration model of deformation resistance in the original model of rolling *** to this research idea,the industrial data are normalized at *** this basis,the interactions among the process parameters were disclosed through the variance analysis,and then described by various virtual *** factors are set as part of input ***,the optimal structure of the GA-BP model of deformation resistance was determined and an integration model of deformation resistance was ***,a novel rolling force model is obtained by substituting the traditional fitted deformation resistance into the Sims model with the integration model of the deformation *** results proves that the introduction of virtual factors can increase the hit rate of±5%from 75.8%to 78%and can reduce the root mean square error from 4.72%to 4.48%.Besides,it is found that the mean relative error of the traditional fitted deformation resistance is 0.142,while that of the modified deformation resistance is only *** addition,the mean relative error in the original rolling force model is 0.145,while that of the present model is only 0.03.

关键词： Integration model-Deformation resistance Variance analysis Virtual factor Genetic algorithm-backpropagation network model

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Recent Advances in Deuteration Reactions

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Chinese Journal of Chemistry 2024年第10期42卷 1145-1156页

作者： hao li Muhammad Shabbir Wu li Aiwen Lei Institutefor Advanced Studies(IAS) Collegeof Chemistry and Molecular SciencesWuhan UniversityWuhanHubei 430072China

The deuteration of organic compounds has attracted more attentions in recent years for the potential applications in new drug discovery and synthetic *** this purpose,many efficient deuterium labeling methodologies have been developed,including hydrogen isotope exchange(HIE),reductive deuteration,and dehalogenative deuteration that allow for the synthesis of selectively deuterated *** the last few years,great breakthroughs in selective isotope labeling have been achieved and the interest in new methodologies for the deuteration of organic molecules is *** this review,we summarized the recent developments in the selective deuteration of organic molecules since *** types of key processes in deuterium incorporation reactions,including H/D exchange,reductive deuteration and dehalogenative deuteration,are introduced and discussed.

关键词： Deuterated compounds H/D exchange Reductive deuterations Dehalogenative deuterations Deuterium C-Hactivation Synthetic methods

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Reduced expression of semaphorin 3A in osteoclasts causes lymphatic expansion in a Gorham-Stout disease(GSD)mouse model

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第1期25卷 38-50页

作者： Dongfang ZHANG hao XU Chi QIN Kangming CAI Jing ZHANG Xinqiu xia Jingwen BI li ZHANG lianping XING Qianqian liANG Wensheng WANG Laboratory of Molecular Medicine College of Life Science and State Key Laboratory of Cell Differentiation and RegulationHenan Normal UniversityXinxiang453007China Longhua Hospital&Spine Institute Shanghai University of Traditional Chinese MedicineShanghai200032China Key Laboratory of Theory and Therapy of Muscles and Bones Ministry of Education(Shanghai University of Traditional Chinese Medicine)Shanghai201203China Department of Pathology and Laboratory Medicine University of Rochester Medical CenterRochester14642USA

Gorham-Stout disease(GSD)is a sporadic chronic disease characterized by progressive bone dissolution,absorption,and disappearance along with lymphatic vessel infiltration in bone-marrow *** the osteolytic mechanism of GSD has been widely studied,the cause of lymphatic hyperplasia in GSD is rarely *** this study,by comparing the RNA expression profile of osteoclasts(OCs)with that of OC precursors(OCPs)by RNA sequencing,we identified a new factor,semaphorin 3A(Sema3A),which is an osteoprotective factor involved in the lymphatic expansion of *** to OCPs,OCs enhanced the growth,migration,and tube formation of lymphatic endothelial cells(LECs),in which the expression of Sema3A is low compared to that in *** the presence of recombinant Sema3A,the growth,migration,and tube formation of LECs were inhibited,further confirming the inhibitory effect of Sema3A on LECs in *** an LEC-induced GSD mouse model,the effect of Sema3A was examined by injecting lentivirus-expressing Sema3A into the tibiae in *** found that the overexpression of Sema3A in tibiae suppressed the expansion of LECs and alleviated bone loss,whereas the injection of lentivirus expressing Sema3A short hairpin RNA(shRNA)into the tibiae caused GSD-like *** staining further demonstrated that OCs decreased and osteocalcin increased after Sema3A lentiviral treatment,compared with the *** on the above results,we propose that reduced Sema3A in OCs is one of the mechanisms contributing to the pathogeneses of GSD and that expressing Sema3A represents a new approach for the treatment of GSD.

关键词： Semaphorin 3A Gorham-Stout disease Osteoclast Osteolysis Lymphatic endothelial cell

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Structural variations of a new fertility restorer gene,Rf20,underlie the restoration of wild abortive-type cytoplasmic male sterility in rice

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Molecular Plant 2024年第8期17卷 1272-1288页

作者： Shufeng Song Yixing li Mudan Qiu Na Xu Bin li Longhui Zhang Lei li Weijun Chen Jinglei li Tiankang Wang Yingxin Qiu Mengmeng Gong Dong Yu hao Dong Siqi xia Yi Pan Dingyang Yuan li li State Key Laboratory of Hybrid Rice Hunan Hybrid Rice Research CenterHunan Academy of Agricultural SciencesChangsha 410125China College of Agronomy Hunan Agricultural UniversityChangsha 410128China College of Plant Protection Hunan Agricultural UniversityChangsha 410128China College of Tropical Crops Hainan UniversityHaikou 570228China Longping Branch College of BiologyHunan UniversityChangsha 410125China

The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food ***,the molecular mechanisms underlyingfertility abortion and the restoration of CMs-WA lines remain largely *** this study,we cloned a restorer gene,Rf2o,following a genome-wide association study analysis of the core parent lines of three-line hybrid *** found that Rf20 was present in all core parental lines,but different haplotypes and structural variants of its gene resulted in differences in Rf2o expression levels between sterileand restored ***20 could restorepollen fertility in the CMS-WA line and was found to be responsible for fertility restoration in some CMs lines under high *** addition,we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with *** interaction enhances Cox11's function as a scavenger of reactive oxygen species,which in turn restores ***,ourstudysuggestsanewactionmodeforpentatricopeptide repeatproteins inthe fertilityrestorationofCMs lines,providing an essential theoretical basisforbreedingrobustrestorer lines and for overcoming high temperature-induced fertility recovery of some CMS lines.

关键词： COX11 cytoplasmic male sterility rf20 WA352 wild abortion

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Solid solution strategy modulated defects engineering of(Cr_(1-x)V_(x))_(2)AlC MAX phase toward superior electromagnetic wave absorption

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Rare Metals 2024年第7期43卷 3205-3219页

作者： Ji-lin Gou Yu-Kai Chang Shu liu Peng-Hui li Ping-hao Cui Qian-Ku Hu li-Bo Wang Xin Zhang Jun-Kai Wang Qi-Xun xia Ai-Guo Zhou School of Materials Science and Engineering Henan Polytechnic UniversityJiaozuo 454003China Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

Defects engineering is an effective strategy for manipulating electromagnetic parameters and enhancing electromagnetic wave(EMW)absorption ***,the relationship between them is not clear,especially in solid solution *** this work,a series of(Cr_(1-x)V_(x))_(2)AlC MAX phase solid solutions with layered structure were prepared via tuning the ratio of Cr and V to explore their EMW absorption *** experimental results indicated that the doping of V atoms at the M-site could effectively regulate its impedance matching and EMW absorption properties by introducing appropriate numbers of defects in the crystal,such as twin boundaries,dislocations and lattice *** them,if Cr:V=3:1,Cr_(1.5)V_(0.5)AlC,as radar absorption materials,could reach a strong reflection loss of-51.8 dB at the frequency of 12.8 GHz under an ultra-thin thickness of 1.3 *** reflection loss value could attain-10 dB in a wide frequency range of 2.7-18 GHz and thickness range of 1-5 *** addition,after high temperature and acid-alkali immersion treatment,this sample still had good EMW absorption capability,and the effective absorption bandwidth was enhanced from 2.3 to 2.6 GHz after concentrated acid immersion or 3.1 GHz after concentrated alkali *** work has great reference significance for the research and development of high-performance MAX-based EMW absorption materials in harsh environments.

关键词： MAX phases Solid solution Defects engineering Electromagnetic wave absorption Harsh environments

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How to achieve energy efficiency in buildings without compromising indoor air quality:A case study on enthalpy exchangers

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Science China(Technological Sciences) 2024年第9期67卷 2648-2658页

作者： li hao ZHANG Tao liU xiaoHua Department of Building Science Tsinghua UniversityBeijing 100084China

As a representative heat recovery device,the fixed-plate enthalpy exchanger possesses the advantages of high recovery effectiveness,low pressure drop,and small space ***,indoor contaminants may transfer to fresh air through the enthalpy exchanger simultaneously,causing cross-contamination ***,the cross-contamination risk of the fixed-plate enthalpy exchanger has been under-researched in previous *** a result,this study experimentally investigates the energy performance,formaldehyde and ammonia transfer rates of paper-based and membrane-based enthalpy *** results illustrate that the enthalpy recovery effectiveness of the plate exchangers ranges from 60%–85%.The formaldehyde transfer rate through the exchangers varies from 5%–23%,and the ammonia transfer rate is 0–15%.The high effectiveness and low contaminant transfer rates are conducive to the promising application of the fixed-plate enthalpy *** addition,the energy reclaimed increases with the increase of the absolute indoor-outdoor enthalpy *** formaldehyde and ammonia transfer rates and cross-contamination risk slightly decrease with increasing temperature but significantly increase with increasing ***,the experimental results demonstrate that the contaminant transfer rates through the membranebased exchanger are lower than those of the paper-based *** study provides a reference for the fixed-plate enthalpy exchanger design in practical applications.

关键词： building energy efficiency enthalpy recovery heat recovery effectiveness cross-contamination

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