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Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

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Defence Technology（防务技术） 2024年第2期32卷 55-66页

作者： zhiyuan zhang Hanyu Deng Wenhe Liao Bin Yu Zai Yu Nanjing University of Science and Technology Nanjing 210094China

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano satellite.However,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical application.Adding conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition system.In this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was proposed.The detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were revealed.The ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition combustor.The results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition grain.Moreover,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of flame.As the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,respectively.The rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition positions.Compared to direct injection scheme,swirling injection provided a more favorable flow field

关键词： Micro/nano satellite hybrid propulsion Arc ignition Charring conductive polymer Ignition mechanism Ignition characteristic Repeated ignition

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Spatial transcriptomics reveals that metabolic characteristics define the tumor immunosuppression microenvironment via iCAF transformation in oral squamous cell carcinoma

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International Journal of Oral Science 2024年第1期16卷 110-121页

作者： Zheqi Liu Zhen zhang Yu zhang Wenkai Zhou Xu zhang Canbang Peng Tong Ji Xin Zou zhiyuan zhang Zhenhu Ren Department of Oral and Maxillofacial-Head and Neck Oncology Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of Stomatology&Shanghai Research Institute of StomatologyShanghaiChina Department of Oral and Maxillofacial Surgery Zhongshan HospitalFudan UniversityShanghaiChina School and Hospital of Stomatology Kunming Medical UniversityKunmingChina Center for Tumor Diagnosis&Therapy Jinshan HospitalFudan UniversityShanghaiChina Department of Pathology Jinshan HospitalFudan UniversityShanghaiChina Hainan Western Central Hospital Academician Zhang Zhiyuan Team Innovation CenterDanzhouChina

Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic environment. To clarify the relationship between different metabolic regions and the tumor immune microenvironment (TME) in OSCC, Single cell (SC) and spatial transcriptomics (ST) sequencing of OSCC tissues were performed. The proportion of TME in the ST data was obtained through SPOTlight deconvolution using SC and GSE103322 data. The metabolic activity of each spot was calculated using scMetabolism,and k-means clustering was used to classify all spots into hyper-, normal-, or hypometabolic regions. CD4T cell infiltration and TGF-βexpression is higher in the hypermetabolic regions than in the others. Through CellPhoneDB and NicheNet cell-cell communication analysis, it was found that in the hypermetabolic region, fibroblasts can utilize the lactate produced by glycolysis of epithelial cells to transform into inflammatory cancer-associated fibroblasts (iCAFs), and the increased expression of HIF1A in iCAFs promotes the transcriptional expression of CXCL12. The secretion of CXCL12 recruits regulatory T cells (Tregs), leading to Treg infiltration and increased TGF-β secretion in the microenvironment and promotes the formation of a tumor immunosuppressive microenvironment. This study delineates the coordinate work axis of epithelial cells-iCAFs-Tregs in OSCC using SC, ST and TCGA bulk data, and highlights potential targets for therapy.

关键词： CXCL12 microenvironment squamous

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Design and test of the arc-shaped nail-tooth roller residual film recovery machine from the sowing layer

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 90-98页

作者： zhiyuan zhang Xuegeng Chen Xianfei Wang Shuaikang Xue Jingbin Li College of Mechanical and Electrical Engineering Shihezi UniversityShihezi 832003XinjiangChina Xinjiang Production and Construction Corps Key Laboratory of Modern Agricultural Machinery Shihezi 832003XinjiangChina Key Laboratory of Northwest Agricultural equipment Ministry of Agriculture and Rural AffairsShihezi 832003XinjiangChina

Residual films on the sowing layer produced after mulching in Xinjiang farmland,harm the sowing quality and root growth of crops.In this study,a sowing layer residual film recovery machine based on a radial plate arc-shaped nail-tooth roller structure was designed.Meanwhile,the key device structures were designed and the main working parameters were analyzed.Then,taking the working depth,the forward speed of the machine and the rotation speed of the nail tooth roller as the test factors,and the film collection rate and film intertwining rate as the test indicators,the single factor tests and the Box-Behnken response surface tests were carried out to evaluate the performance of the sowing layer residual film recovery machine.Consequently,the results showed that the order of significant factors was the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller.Besides,the optimal working parameters were determined,which the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller were 100 mm,4.8 km/h,and 49.3 r/min,respectively.Moreover,the predicted value of the film collection rate was 69.20%.Finally,the verification test was taken with the optimal working parameter,and the results showed that the film collection rate was 66.84%,and the film intertwining rate was 1.39%.The relative error between the test value and the predicted value of the film collection rate was 3.40%.It indicated that the machine can perform the collection of sowing layer residual films.This study can provide a theoretical basis and reference for the design of new sowing layer residual film machines.

关键词： residual film recycling machine mulching film pick-up device seedbed preparation

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Effect of catalyst diesel particulate filter aging and catalyst loadings on particulate emission characteristics from a diesel vehicle

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Journal of Environmental Sciences 2024年第2期136卷 35-44页

作者： Yunhua zhang Diming Lou Piqiang Tan zhiyuan Hu Liang Fang School of Automotive Studies Tongji UniversityShanghai 201804China

In this study,the effect of new and used catalyzed diesel particulate filter(CDPF)with different catalyst loadings on the particulate emissions including the particle mass(PM),particle number(PN),particle size distribution(PSD)and geometric mean diameter(GMD)from a diesel vehicle were investigated based on a heavy chassis dynamometer.Results showed that more than 97.9%of the PN and 95.4%of the PM were reduced by the CDPF,and the reduction efficiency was enhanced by the catalyst loading.After using the CDPF,the PSD transformed from bimodal to trimodal with the peak shifting towards smaller particle size,more nucleation mode particles were reduced compared with accumulation mode ones,but the reduction effect on the accumulation mode particles was more significantly influenced by the catalyst loading.Notably,the CDPF increased the accumulation mode particles proportion,producing a larger GMD.For the used CDPF,its reduction effect on the particulate emissions enhanced,especially for the PM in accumulation mode.The PSD returned to bimodal,but the peak at accumulation mode began to be higher than that at nucleation mode,illustrating that more nucleation mode particles was removed.The aging of the CDPF resulted in greater effect on the PN-based PSD than that of PM-based PSD,but the effect of catalyst loading on the PN and PM emission factors was weakened.The used CDPF further increased the GMD,and the effect of catalyst loading on the GMD was strengthened,a higher catalyst loading led to a reduction in the GMD.

关键词： Catalyzed diesel particulate filter (CDPF) Catalyst loading Aging Particle Particle size distribution Geometric mean diameter

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Indefinite metacavities coupled to a mirror:bound states in the continuum with anomalous resonance scaling

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Photonics Research 2024年第3期12卷 598-607页

作者： QIANG zhang PEIXIANG LI zhiyuan GU SHAODING LIU ZEJUN DUAN College of Electronic Information and Optical Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

Indefinite metacavities(IMCs)made of hyperbolic metamaterials show great advantages in terms of extremely small mode volume due to large wave vectors endowed by the unique hyperbolic dispersion.However,quality(Q)factors of IMCs are limited by Ohmic loss of metals and radiative loss of leaked waves.Despite the fact that Ohmic loss of metals is inevitable in IMCs,the radiative loss can be further suppressed by leakage engineering.Here we propose a mirror coupled IMC structure which is able to operate at Fabry–Pérot bound states in the continuum(BICs)while the hyperbolic nature of IMCs is retained.At the BIC point,the radiative loss of magnetic dipolar cavity modes in IMCs is completely absent,resulting in a considerably increased Q factor(>90).Deviating from the BIC point,perfect absorption bands(>0.99)along with a strong near-field intensity enhancement(>1.8×10^(4))appear when the condition of critical coupling is almost fulfilled.The proposed BICs are robust to the geometry and material composition of IMCs and anomalous scaling law of resonance is verified during the tuning of optical responses.We also demonstrate that the Purcell effect of the structure can be significantly improved under BIC and quasi-BIC regimes due to the further enhanced Q factor to mode volume ratio.Our results provide a new train of thought to design ultra-small optical nanocavities that may find many applications benefitting from strong light–matter interactions.

关键词： hyperbolic mirror definite

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Rational Design of Cost-Effective Metal-Doped ZrO_(2)for Oxygen Evolution Reaction

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Nano-Micro Letters 2024年第9期16卷 385-396页

作者： Yuefeng zhang Tianyi Wang Liang Mei Ruijie Yang Weiwei Guo Hao Li zhiyuan Zeng Department of Materials Science and Engineering and State Key Laboratory of Marine PollutionCity University of Hong Kong83 Tat Chee AvenueKowloon 999077Hong KongPeople’s Republic of China Advanced Institute for Materials Research(WPI‑AIMR) Tohoku UniversitySendai 980‑8577Japan Shenzhen Research Institute City University of Hong KongShenzhen 518057People’s Republic of China Shanxi Supercomputing Center Lvliang 033000ShanxiPeople’s Republic of China

The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction(OER)due to the“stable-oractive”dilemma.Zirconium dioxide(ZrO_(2)),a versatile and low-cost material that can be stable under OER operating conditions,exhibits inherently poor OER activity from experimental observations.Herein,we doped a series of metal elements to regulate the ZrO_(2)catalytic activity in OER via spin-polarized density functional theory calculations with van der Waals interactions.Microkinetic modeling as a function of the OER activity descriptor(G_(O*)-G_(HO*))displays that 16 metal dopants enable to enhance OER activities over a thermodynamically stable ZrO_(2)surface,among which Fe and Rh(in the form of single-atom dopant)reach the volcano peak(i.***.the optimal activity of OER under the potential of interest),indicating excellent OER performance.Free energy diagram calculations,density of states,and ab initio molecular dynamics simulations further showed that Fe and Rh are the effective dopants for ZrO_(2),leading to low OER overpotential,high conductivity,and good stability.Considering cost-effectiveness,single-atom Fe doped ZrO_(2)emerged as the most promising catalyst for OER.This finding offers a valuable perspective and reference for experimental researchers to design cost-effective catalysts for the industrial-scale OER production.

关键词： Oxygen evolution reaction Metal oxide Electrocatalysis Surface Pourbaix analysis Doping

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Multi-blade rubbing characteristics of the shaft-disk-blade-casing system with large rotation

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 111-136页

作者： zhiyuan WU Linchuan ZHAO Han YAN Ge YAN Ao CHEN Wenming zhang State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Aerospace Systems Engineering Shanghai 201108China

Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.

关键词： shaft-disk-blade-casing(SDBC) large rotation spin and whirl multi-blade rubbing rotational effect

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Highly efficient catalyzed by imidazolium-based dual-sulfonic acid functionalized ionic liquids for liquid phase Beckmann rearrangement:experiments and COSMO-RS calculations

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Green Chemical Engineering 2024年第1期5卷 108-118页

作者： Xin Guo zhiyuan Wang Ye Yang Jiahui zhang Yanduo Liu zhiyuan Mu Siqi Jiang Chunxiao Ren Dan Lv Yufeng Hu Zhichang Liu State Key Laboratory of Heavy Oil Processing and High Pressure Fluid Phase Behavior&Property Research Laboratory China University of PetroleumBeijing102249China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei230026China School of Light Industry and Engineering South China University of TechnologyGuangzhou510641China

A production technique with the high yield and environmentally friendly process need be developed forε-Caprolactam(CPL)in the chemical industry.This technology is highly desired to design and synthesize high--performance catalysts for liquid phase Beckmann rearrangement of cyclohexanone oxime(CHO)to CPL.In this work,3-methyl-1-(propyl-4-sulfonyl)imidazolium methanesulfonate([PHSO_(3)MIM][MSA])with highly efficient and excellent yield is synthesized successfully.When the optimum molar ratio of ZnCl_(2)over[PHSO_(3)MIM][MSA]was 0.02,it exhibits the high selectivity(94%)of CPL at 90℃for 1 h.Interestingly,Fourier-transform infrared(FT-IR)investigations show that the functional Br∅nsted-Lewis acidic types of ionic liquids(ILs)are formed by the uniformly distributed ZnCl_(2)and[PHSO_(3)MIM][MSA].In addition,the hydrogen bond(H-bond)is formed between CHO and ILs.After ten reaction cycles,no significant structure changes are observed in the recovered[PHSO_(3)MIM][MSA]-ZnCl_(2).The solubilities of ILs are predicted by using COSMO-RS model,the results show that[PHSO_(3)MIM][MSA]is a promising candidate for the liquid phase Beckmann rearrangement of CHO into CPL.Finally,a theoretical model of the H-bond interactions between ILs and CHO is further confirmed to support the advance of reaction mechanism.A feasible way is provided for the CPL production technique in the liquid phase Beckmann rearrangement reaction.

关键词： Liquid phase Beckmann rearrangement Imidazolium-based ionic liquids COSMO-RS calculations H-bond

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Comparative study on the hydrogen storage performance of as-milled MgRENi rapid quenched alloy catalyzed by metal sulfides

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Journal of Magnesium and Alloys 2024年第5期12卷 2010-2023页

作者： Xiaoping Dong Zhaoqing zhang Liying Yang Shenghai Xin Dandan Su zhiyuan Li Department of Mechanical Design and Manufacture and Automation Hebei University Baoding New Energy Vehicle Power Engineering Technology Research Center Hebei University Hebei Technology Innovation Center for Lightweight of New Energy Vehicle Power System(Preparation) Hebei University

The composites of Mg20Pr1Sm3Y1Ni10as-quenched alloy and 3 wt.% M（M = CoS, CoS2, MoS2） catalyst were prepared by high-speed vibration ball mill. The effects of metal sulfides on the hydrogenation and dehydrogenation dynamics of alloys were compared. The results show that the as-milled composites contain a large number of amorphous embedded by a small amount of nanocrystals, and there are many point defects. After ball milling, the crystal grain size in the composites containing CoS is relatively larger, followed by CoS2and MoS2again. After hydrogenation, the amorphous phase is crystallized to form Mg2NiH4, YH3, Pr8H18.96, Sm3H7, Mg, Co or Mo phases, however,Mg2Ni, YH2, PrH2and Ni3Y phases appeared after dehydrogenation. The maximum hydrogenation capacity of the composites containing CoS, CoS2and MoS2are 3.939, 4.265 and 4.507 wt.%, respectively. The hydrogenation saturation ratio of composite containing MoS2is higher than that of the composites containing CoS and CoS2. The dehydrogenation activation energy of the composites containing CoS, CoS2and MoS2is 107.76, 68.43 and 63.28 kJ.mol-1.H2. On the improvement of hydrogen storage performance of Mg20Pr1Sm3Y1Ni10alloy, the catalytic effect of MoS2sulfide is better than that of CoS2sulfide, and which is better than CoS sulfide.

关键词： Mg 20 Pr 1 Sm 3 Y 1 Ni 10 as-quenched alloy CoS CoS 2 and MoS 2 sulfide Milling Activation energy Hydrogen storage dynamics

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Spatiotemporal variations of parameters of internal solitary waves in the northern South China Sea

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Journal of Oceanology and Limnology 2024年第2期42卷 421-438页

作者： Yu’ang LIU Yifei JIANG Xiaojiang zhang zhiyuan WANG Yu CAO Huizan WANG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China

The dynamic parameters for internal solitary waves(ISWs)derived from the extended Korteweg-de Vries(eKdV)equation play an important role in the understanding and prediction of ISWs.The spatiotemporal variations of the dynamic parameters of the ISWs in the northern South China Sea(SCS)were studied based on the reanalysis of long-term temperature and salinity datasets.The results for spectrum analysis show that there are definite geographical differences for the periodic variation of the parameters:in shallow water,all parameters vary with a wave period of one year,while in deep water wave components of the parameters at other frequencies exist.Using wavelet analysis,the wavelet power spectral densities in deep water exhibited an inter-annual variation pattern.For example,the wave component of the dispersion coefficient with a wave period of about half a year reached its power peak once every two years.Based on previous work,this inter-annual variation pattern was deduced to be caused by dynamic processes.In further work on the regulatory mechanisms,empirical orthogonal function(EOF)decomposition was performed.It was found that the modes of the dispersion coefficient have different geographical distributions,explaining the reason why the wave components in different frequencies appeared in different locations.The numerical simulation results confirm that the variations in the parameters of the ISWs derived from the eKdV equation could affect the waveforms significantly because of changes in the polarity of the ISWs.Therefore,the periodic variations of the dynamic parameters are related to the geographical location because of dynamic processes operating.

关键词： internal solitary waves(ISWs) dynamic parameters eKdV equation spatiotemporal variation polarity empirical orthogonal function(EOF)decomposition

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