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Uncertainty analysis and design optimization of hybrid rocket motor powered vehicle for suborbital flight

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Chinese Journal of Aeronautics 2015年第3期28卷 676-686页

作者： Zhu Hao tian Hui cai Guobiao Bao Weimin School of Astronautics Beihang University China Aerospace Science and Technology Corporation

Abstract In this paper, we propose an uncertainty analysis and design optimization method and its applications on a hybrid rocket motor （HRM） powered vehicle. The multidisciplinary design model of the rocket system is established and the design uncertainties are quantified. The sensitivity anal- ysis of the uncertainties shows that the uncertainty generated from the error of fuel regression rate model has the most significant effect on the system performances. Then the differences between deterministic design optimization （DDO） and uncertainty-based design optimization （UDO） are discussed. Two newly formed uncertainty analysis methods, including the Kriging-based Monte Carlo simulation （KMCS） and Kriging-based Taylor series approximation （KTSA）, are carried out using a global approximation Kriging modeling method. Based on the system design model and the results of design uncertainty analysis, the design optimization of an HRM powered vehicle for suborbital flight is implemented using three design optimization methods： DDO, KMCS and KTSA. The comparisons indicate that the two UDO methods can enhance the design reliability and robustness. The researches and methods proposed in this paper can provide a better way for the general design of HRM powered vehicles.

关键词： Design optimization Hybrid rocket motor Kriging model Uncertainty analysis Uncertainty-based designoptimization

Non-spherical particle mixing behaviors by spherical inert particles assisted in a fluidized bed

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Petroleum Science 2020年第2期17卷 509-524页

作者： An-xing Ren tian-Yu Wang tian-Qi Tang Yu-Rong He School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Heilongjiang Key Laboratory of New Energy Storage Materials and Processes School of Energy Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

Fluidized beds are widely used in many industrial fields such as petroleum,chemical and *** actual industrial processes,spherical inert particles are typically added to the fluidized bed to promote fluidization of non-spherical *** mixing behaviors of binary mixtures in a fluidized bed has specific significance for the design and optimization of related industrial *** this study,the computational fluid dynamic-discrete element method with the consideration of rolling friction was applied to evaluate the mixing behaviors of binary mixtures comprising spherocylindrical particles and spherical particles in a fluidized *** simulation results indicate that the differences between rotational particle velocities were higher than those of translational particle velocities for spherical and non-spherical particles when well ***,as the volume fraction of the spherocylindrical particles increases,translational and rotational granular temperatures gradually *** addition,the addition of the spherical particles makes the spherocylindrical particles preferably distributed in a vertical orientation.

关键词： Non-spherical particle Fluidized bed Discrete element method Binary mixtures

The dynamics of traveling wavefronts for a model describing host tissue degradation by bacteria

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International Journal of Biomathematics 2024年第3期17卷 265-287页

作者： xing-xing Yang Guo-Bao Zhang Ge tian College of Mathematics and Statistics Northwest Normal University Lanzhou Gansu 730070P.R.China

In this paper,we mainly investigate the dynamics of traveling wavefronts for a model describing host tissue degradation by *** first establish the existence of spreading speed,and show that the spreading speed coincides with the minimal wave speed of traveling ***,a lower bound estimate of the spreading speed is ***,we prove that the traveling wavefronts with large speeds are globally exponentially stable,when the initial perturbation around the traveling wavefronts decays exponentially asχ→-∞,but the initial perturbation can be arbitrarily large in other *** adopted methods are the weighted energy and the squeezing technique.

关键词： Host tissue degradation bacterial infection traveling wavefronts minimal wave speed stability

Measurement of gear tooth dynamic deformation using dynamic speckle photography

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Chinese Science Bulletin 1998年第6期43卷 514-518页

作者： Jianfeng Li xing Ai Zhiren tian Shandong Univ Technol Jinan 250061 Peoples R China

A new method of measuring gear tooth dynamic deformation is proposed. Dynamic speckle photographs of the rotating gear tooth have been achieved by combining the pulsed ruby laser with the out-syn-signal. Double speckle patterns of the whole mesh period of gear tooth are obtained by accurate time delay of the ruby laser. Gear tooth dynamic deformation of the whole mesh period is achieved using the automatic image processing. Testing results show that the trends of gear tooth deformation coincides with the calculation by the finite element method. The success of this new trying provides a new technique for the measurement of gear tooth dynamic deformation.

关键词： pulsed ruby laser dynamic speckle photography image process gears deformation.

The priority of management factors for reducing the yield gap of summer maize in the north of Huang-Huai-Hai region, China

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Journal of Integrative Agriculture 2021年第2期20卷 450-459页

作者： LIU Yue-e LI Yu-xin LU tian-fang xing Jin-feng XU tian-jun cai Wan-tao ZHANG Yong ZHAO Jiuran WANG Rong-huan Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding Maize Research CenterBeijing Academy of Agriculture&Forestry SciencesBeijing 100097P.R.China

Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. In this study, we conducted field experiments using different planting modes, which were basic productivity(CK), farmer practice(FP), high yield and high efficiency(HH), and super high yield(SH), to estimate the yield gap. Different factorial experiments(fertilizer, planting density, hybrids, and irrigation) were also conducted to evaluate the priority of individual management factors for reducing the yield gap between the different planting modes. We found significant differences between the maize yields of different planting modes. The treatments of CK, FP, HH, and SH achieved 54.26, 58.76, 65.77, and 71.99% of the yield potential, respectively. The yield gaps between three pairs: CK and FP, FP and HH, and HH and SH, were 0.76, 1.23 and 0.85 t ha^(–1), respectively. By further analyzing the priority of management factors for reducing the yield gap between FP and HH, as well as HH and SH, we found that the priorities of the management factors(contribution rates) were plant density(13.29%)>fertilizer(11.95%)>hybrids(8.19%)>irrigation(4%) for FP to HH, and hybrids(8.94%)>plant density(4.84%)>fertilizer(1.91%) for HH to SH. Therefore, increasing the planting density of FP was the key factor for decreasing the yield gap between FP and HH, while choosing hybrids with density and lodging tolerance was the key factor for decreasing the yield gap between HH and SH.

关键词： maize yield gap management factors priority hybrid plant density fertilizer irrigation

First-principle study of Ba isotopic fractionation during ion exchange processes

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Acta Geochimica 2022年第1期41卷 121-131页

作者： Xin-Yue Ji Yan-Fang Wang Le-cai xing Jian Liu Peng-Dong Wang tian-Di Zhang Hao-Nan Zhao School of Earth Science and Engineering Hebei University of EngineeringHandan 056038China Key Laboratory of Resource Survey and Research of Hebei Province Hebei University of EngineeringHandan 056038China

The potential utilization and development of the Ba isotope tool depend on an accurateδ^(137/134)Ba determination of the *** the chemical purification,whether the adsorption process on the surface of the ionexchange resin could lead to the Ba isotopic fractionation and the degree of fractionation directly influence the accurateδ^(137/134)Ba *** the present work,first-principles calculations based on the density functional theory were used to quantify the Ba isotopic equilibrium fractionation factor between the aqueous solution and the resin in the acid leaching *** constructing and optimizing the geometric configurations of Ba-containing species,Ba(H_(2)O)_(n)^(2+),Ba(H_(2)O)_(n)Cl_(2),Ba(H_(2)O)_(n)(NO_(3))2,and the adsorbed Ba^(2+)on the surface of the resin,extracting the harmonic vibrational frequencies,we finally at 298 K obtained the fractionations,Δ^(137/134)Ba_(soln-ads)=0.07‰,Δ^(137/134)Ba_(Ba(H_(2)O)_(n)Cl_(2)-ads)=0.05‰,andΔ^(137/134)-Ba^(Ba(H_(2)O)_(n)(NO_(3))2-ads)=0.02‰.Overall,there were almost no Ba isotope fractionations during *** the Ba isotope fractionation can be magnified by the Rayleigh fractionation process in purification,the difference inδ137/134Ba between the initial and final stages did not exceed0.060‰(or 0.045‰)when leaching the standard sample with HCl or HNO_(3),which is equal to or less than the accuracy of Ba isotopic *** a common yield of89.75%,Ba isotopic fractionation induced by incomplete recovery was 0.015‰for HCl(or 0.011‰for HNO_(3)).Finally,if the influence of an incomplete recovery on theδ137/134Ba determination needs to be ignored,the recovery is suggested to be not less than 67%for HCl(or 46%for HNO_(3)).

关键词： Ion exchange Barium Equilibrium isotopic fractionation First-principles calculations Rayleigh fractionation

Staged dendrite suppression for high safe and stable lithium-sulfur batteries

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Journal of Energy Chemistry 2025年第1期100卷 674-683页

作者： Jun Jiang Zhenjie Lu Yanwen Ding Shujun Liu Zhijie Qi tian Tang Yunfan Zhang Zhiyuan Ma Jingwen Sun Liang Xue Wenyao Zhang Pan Xiong Xin Wang Junwu Zhu Yongsheng Fu Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education Nanjing University of Science and Technology Jiangsu Pylon Battery Co.Ltd

The unavoidable dendrite growth and shuttle effect have long been stranglehold challenges limiting the safety and practicality of lithium-sulfur ***,we propose a dual-action strategy to address the lithium dendrite issue in stages by constructing a multifunctional surface-negatively-charged nanodiamond layer with high ductility and robust puncture resistance on polypropylene （PP） *** uniformly loaded compact negative layer can not only significantly enhance electron transmission efficiency and promote uniform lithium deposition,but also reduce the formation of dendrite during early deposition *** importantly,under the strong puncture stress encountered during the deterioration of lithium dendrite growth under limiting current,the high ductility and robust puncture resistance（145.88 MPa） of as-obtained nanodiamond layer can effectively prevent short circuits caused by unavoidable lithium *** Li||Li symmetrical cells assembled with nanodiamond layer modified PP demonstrated a stable cycle of over 1000 h at 2 mA cm-2with a polarization voltage of only 29.3 ***,the negative charged layer serves as a physical barrier blocking lithium polysulfide ions,effectively mitigating capacity *** improved cells achieved a capacity decay of only 0.042%per cycle after 700 cycles at 3 C,demonstrating effective suppression of dendrite growth and capacity attenuation,showing promising prospect.

关键词： Ductility

Dopamine Switches Affective States Under Acute Sleep Deprivation

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Neuroscience Bulletin 2024年第8期40卷 1205-1208页

作者： Zhou-cai Luo tian-Ming Gao State Key Laboratory of Organ Failure Research Key Laboratory of Mental Health of the Ministry of EducationGuangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired IntelligenceGuangdong-Hong Kong Joint Laboratory for Psychiatric DisordersGuangdong Province Key Laboratory of Psychiatric DisordersGuangdong Basic Research Center of Excellence for Integrated Traditional and Western Medicine for Qingzhi DiseasesDepartment of NeurobiologySchool of Basic Medical SciencesSouthern Medical UniversityGuangzhou 510515China

The transition of affective states manifests affective regulation,wherein individuals adaptively adjust their emotional states to cope with changes in the external environment,reflecting their sensitivity and adaptability to environmental *** process of affective state transition is complex,involving both instantaneous and persistent changes influenced by environmental,behavioral,and pharmacological *** underlying neural mechanisms encompass alterations in neurotransmitter release,neural circuit activity,and the plasticity of brain structures[1].

关键词： alterations Dopamine neural

Design high-performance narrowband emitters for blue light-emitting diodes through manipulating resonance structure of aromatic heterocycles

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Science China Chemistry 2025年

作者： Yue Yu Lei Xu Wenle Tan Yuyu Pan Jiyin Xiao Bohan Wang Guangjun tian Yuguang Ma Lei Ying Institute of Polymer Optoelectronic Materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials State Key Laboratory of Luminescent Materials and Devices South China University of Technology School of Petrochemical Engineering Shenyang University of Technology Key Laboratory for Microstructural Material Physics of Hebei Province School of Science Yanshan University

Narrowband light-emitting materials play critical roles in improving the color gamut and energy consumption of electroluminescence. Herein we demonstrated that by regulating the ground state resonance structure form of emitters with polycyclic aromatic heterocycles, the high-energy vibration of the C–C bond can be effectively suppressed, resulting in narrow emission like classical cyanine dyes. The designed compounds consist of twist and planar conformation, while having differences in the orientation of the positioning electron-donating(nitrogen) and electron-accepting(carbonyl) groups in the polycyclic aromatic hydrocarbon skeleton. The resulting compound Ac-Ph-Ac with a dominated zwitterionic resonance structure exhibits a relatively wide electroluminescent profile with the full width at half maximum(FWHM) of 42 nm and moderate device performance. In contrast, the “soliton transition” of 2AcPh based on the cyanine limit character effectively suppresses C–C stretching vibration in the polycyclic aromatic heterocycle skeleton, leading to a narrow electroluminescent profile with FWHM of 30 nm(0.16 eV)associated with an impressively high external quantum efficiency of 28.52%, which is among the highest efficiencies of so far reported non-sensitized organic light-emitting diodes.

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