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The regulation of ferrocene-based catalysts on heat transfer in highpressure combustion of ammonium perchlorate/hydroxyl-terminated polybutadiene/aluminum composite propellants

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Defence Technology（防务技术） 2024年第5期35卷 174-186页

作者： Jinchao Han Songqi Hu linlin liu Science and Technology on Combustion Internal Flow and Thermo-Structure LaboratoryNorthwestern Polytechnical UniversityXi'an 710072ShaanxiChina

The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application in high-pressure solid rocket *** this work,the combustion characteristics of AP/HTPB/Al composite propellants containing ferrocene-based catalysts were investigated,including the burning rate,thermal behavior,the local heat transfer,and temperature profile in the range of 7-28 *** results showed that the exponent breaks were still observed in the propellants after the addition of positive catalysts(Ce-Fc-MOF),the burning rate inhibitor((Ferrocenylmethyl)trimethylammonium bromide,Fc Br)and the mixture of Fc Br/catocene(GFP).However,the characteristic pressure has increased,and the exponent decreased from 1.14 to 0.66,0.55,and 0.48 when the addition of Ce-FcMOF,Fc Br and Fc Br/GFP in the *** addition,the temperature in the first decomposition stage was increased by 7.50℃ and 11.40℃ for the AP/Fc Br mixture and the AP/Fc Br/GFP mixture,respectively,compared to the pure *** the other hand,the temperature in the second decomposition stage decreased by 48.30℃ and 81.70℃ for AP/Fc Br and AP/Fc Br/GFP mixtures,*** was also found that Fc Br might generate ammonia to cover the AP *** this case,a reaction between the methyl in Fc Br and perchloric acid caused more ammonia to appear at the AP surface,resulting in the suppression of ammonia *** addition,the coarse AP particles on the quenched surface were of a concave shape relative to the binder matrix under low and high pressures when the catalysts were *** the process,the decline at the AP/HTPB interface was only exhibited in the propellant with the addition of *** ratio of the gas-phase temperature gradient of the propellants containing catalysts was reduced significantly below and above the characteristic pressure,rather than 3.6 times of the di

关键词： AP/HTPB/Al propellants Heat transfer High-pressure combustion Ferrocene-based catalysts Pressure exponent

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Experimental and numerical study on ignition and combustion characteristics of boron-magnesium composite powders

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Particuology 2024年第1期84卷 12-29页

作者： Shuyuan liu Luyang Han Hongmei liu Yingkai Song linlin liu Songqi Hu Science and Technology on Combustion Internal Flow and Thermo-Structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China School of Mechanical Engineering and Rail Transit Changzhou UniversityChangzhou213164China Shanghai Institute of Space Propulsion Shanghai201112China Shanghai Engineering Research Center of Space Engine Shanghai201112China

A high-pressure laser ignition and combustion system with adjustable oxidizer gas atmosphere is established to investigate the ignition and combustion characteristics of boron-magnesium(BM)com-posite *** ignition and combustion model of BM powders is established and validated in the present *** results show that increasing water content,O_(2) content and Mg content all result in shorter ignition delay time of BM powders,among which the effect of water content is the most ***,ignition delay time increases as pressure *** combustion time decreases with increasing Mg content and ambient pressure but increases with water *** the increase of O_(2) content,combustion time of BM powders first increases and then decreases,which means a critical O_(2) content exists above which combustion time *** results show that there exists a trade-off between ignition and combustion performance of BM composite powders.

关键词： Boron magnesium powder Laser ignition Ignition and combustion model Reaction mechanism Numerical model

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Hierarchical vectorization for facial images

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Computational Visual Media 2024年第1期10卷 97-118页

作者： Qian Fu linlin liu Fei Hou Ying He School of Computer Science and Engineering Nanyang Technological University639798SingaporeSingapore Data61 Commonwealth Scientific and Industrial Research OrganisationSydney2015Australia Interdisciplinary Graduate School Nanyang Technological University and Alibaba Group639798SingaporeSingapore State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

The explosive growth of social media means portrait editing and retouching are in high *** portraits are commonly captured and stored as raster images,editing raster images is non-trivial and requires the user to be highly *** at developing intuitive and easy-to-use portrait editing tools,we propose a novel vectorization method that can automatically convert raster images into a 3-tier hierarchical *** base layer consists of a set of sparse diffusion curves(DCs)which characterize salient geometric features and low-frequency colors,providing a means for semantic color transfer and facial expression *** middle level encodes specular highlights and shadows as large,editable Poisson regions(PRs)and allows the user to directly adjust illumination by tuning the strength and changing the shapes of *** top level contains two types of pixel-sized PRs for high-frequency residuals and fine details such as pimples and *** train a deep generative model that can produce high-frequency residuals *** to the inherent meaning in vector primitives,editing portraits becomes easy and *** particular,our method supports color transfer,facial expression editing,highlight and shadow editing,and automatic *** quantitatively evaluate the results,we extend the commonly used FLIP metric(which measures color and feature differences between two images)to consider *** new metric,illumination-sensitive FLIP,can effectively capture salient changes in color transfer results,and is more consistent with human perception than FLIP and other quality measures for portrait *** evaluate our method on the FFHQR dataset and show it to be effective for common portrait editing tasks,such as retouching,light editing,color transfer,and expression editing.

关键词： face editing vectorization Poisson editing color transfer illumination editing expression editing

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Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

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Food Science and Human Wellness 2024年第4期13卷 2090-2101页

作者： Dengyu Wang linlin liu Bing Wang Wenjian Xie Yanguo Shi Na Zhang Hongchen Fan Key Laboratory of Food Science and Engineering of Heilongjiang Ordinary Higher Colleges Key Laboratory of Grain Food and Comprehensive Processing of Heilongjiang ProvinceCollege of Food EngineeringHarbin University of CommerceHarbin 150076China

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter *** results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice *** particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice ***,the gelatinization enthalpy of the fermented samples increased *** frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control *** results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

关键词： Glutinous rice flour Glutinous rice dough Lactic acid bacteria compound starter cultures Pasting properties Viscoelasticity

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Ten ring-B aromatized ergosterols from Aspergillus spectabilis

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Chinese Journal of Natural Medicines 2024年第7期22卷 654-662页

作者： WEI Mengsha SUN Weiguang liu linlin LI Yongqi LI Lanqin LI Qin CHEN Yu GUO Jieru GU Lianghu ZHU Hucheng CHEN Chunmei ZHANG Yonghui Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation School of PharmacyTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Tongji Hospital Affiliated to Tongji Medical College Huazhong University of Science and TechnologyWuhan 430030China

Spectasterols F−O(1−10),ten interesting ergosterols with an aromatized B ring,were obtained from Aspergillus *** structures and absolute configurations were determined using a combination of high-resolution electrospray ionization mass spectrometry(HR-ESI-MS),nuclear magnetic resonance(NMR)spectroscopy,single-crystal X-ray diffraction analyses,and electronic circular dichroism(ECD)***,these aromatic ergosterols feature versatile side ***,compound aromatic ergosterols featured versatile side chains,and compound 4 is an unusual C23 ergosterol characterized by a shorter side chain due to oxidative cleavage between C-23 and *** compounds were evaluated for their neuroprotective activities,with compound 8 showing a dose-dependent ability to reduce apoptosis and protect mitochondrial function in glutamate-induced SH-SY5Y cells.

关键词： Steroids Aspergillus spectabilis Aromatic ergosterols Neuroprotective activities Structure elucidation

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全球气候变化多层次治理下的城市参与

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城市发展研究 2024年第4期031卷 70-73页

作者：刘林琳胡苑上海财经大学法学院

后巴黎时代，全球气候治理主体呈现多元化趋势。城市在全球气候变化治理中实现主体化转型，有力补充了这一过程中国家行为的不足。以城市气候治理经验跨国传播为基础的主动型治理(横向)、以城市与气候变化国际组织上下贯通为主导的互动... 详细信息

后巴黎时代，全球气候治理主体呈现多元化趋势。城市在全球气候变化治理中实现主体化转型，有力补充了这一过程中国家行为的不足。以城市气候治理经验跨国传播为基础的主动型治理(横向)、以城市与气候变化国际组织上下贯通为主导的互动性治理(纵向)和以中央权威命令下城市气候实验为主的强制性治理(科层)是城市参与全球气候变化治理的三种主要形态。然而，这一行为可能受到上级治理主体的权力限制和城市内部治理主体异质性的困境。对此，我国需要依托超大特大城市气候实验，结合规划法整合城市气候治理措施，推进城市气候治理的国际互动，以系统性优化城市参与全球气候变化治理的具体路径。

关键词：全球气候变化城市治理跨国城市气候网络城市外交

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外部监督对上市民营企业信用风险的影响研究——基于媒体关注视角

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投资研究 2024年第6期43卷 95-108页

作者：庄云蓓刘琳琳山东理工大学经济学院

媒体关注作为外部监督的一种方式,对企业经营与发展的影响日益显著。因此,本文选取上市民营企业媒体关注和财务数据,研究媒体关注对上市民营企业信用风险的影响及其作用路径。研究表明:(1)媒体关注有助于降低上市民营企业信用风险;(2)... 详细信息

媒体关注作为外部监督的一种方式,对企业经营与发展的影响日益显著。因此,本文选取上市民营企业媒体关注和财务数据,研究媒体关注对上市民营企业信用风险的影响及其作用路径。研究表明:(1)媒体关注有助于降低上市民营企业信用风险;(2)融资约束是媒体关注对上市民营企业信用风险发挥影响作用的重要渠道,即融资约束可以通过改善市场中信息透明度、约束高管机会主义行为进而降低上市民营企业信用风险。

关键词：外部监督媒体关注信用风险

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碳排放权交易政策与中国“双碳”目标实现——基于碳中和进程的测度与分析

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南开经济研究 2024年第1期 115-130页

作者：王道平刘琳琳刘杨婧卓南开大学金融学院 300350 南开大学中国式现代化发展研究院 300071 北京大学经济学院 100871

“双碳”目标是党中央作出的重大战略决策,是实现我国高质量发展的内在要求。为科学量化我国碳中和进程,并考察相关政策效果,总结分析碳中和目标实现路径,本文首先从区域总体、人均和能源消耗三个维度出发,构建了能够反映我国各省份碳... 详细信息

“双碳”目标是党中央作出的重大战略决策,是实现我国高质量发展的内在要求。为科学量化我国碳中和进程,并考察相关政策效果,总结分析碳中和目标实现路径,本文首先从区域总体、人均和能源消耗三个维度出发,构建了能够反映我国各省份碳中和进程的指数体系,总结了其时空动态演化特征,并以碳排放权交易政策试点作为准自然实验,基于我国省级经验数据,深入分析了碳排放权交易政策对我国碳中和目标实现的影响。研究发现,碳排放权交易政策能够推进我国各地区碳中和目标的实现,并通过碳排放和碳吸收(即碳汇)两端产生积极的政策效果;进一步的机制分析表明,碳排放权交易政策通过改善能源结构和提升能源效率两个渠道促进了碳中和目标的实现。本文研究为实现“双碳”目标、建设健全中国碳市场和推动中国经济高质量发展,提供了科学的实证证据和政策支持。

关键词：碳中和碳排放权交易能源效率碳排放碳汇

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农田水利规划设计与灌溉技术措施

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水利技术监督 2024年第5期 114-116页

作者：刘淋淋山东省水利勘测设计院有限公司山东济南250000

农田水利工程是影响农村经济发展及农业生产的重要因素之一。为推进农业基础建设,需要对农田水利进行科学的规划。文章首先指出了农田水利规划中存在的问题,包括设计规划准备不足、机械设备问题、与农村发展不协调,并对水利设施的灌溉... 详细信息

农田水利工程是影响农村经济发展及农业生产的重要因素之一。为推进农业基础建设,需要对农田水利进行科学的规划。文章首先指出了农田水利规划中存在的问题,包括设计规划准备不足、机械设备问题、与农村发展不协调,并对水利设施的灌溉技术优缺点进行了分析,提出了农田水利设计标准和设计原则,同时对取水方式进行了规划设计。为推动水利建设的可持续发展以及农村农业的现代化提供参考。

关键词：农田水利规划灌溉技术

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地铁车辆可清洁式均匀送风道数值仿真分析

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城市轨道交通研究 2024年第5期27卷 167-170,174页

作者：刘林林孙方李泉中车南京浦镇车辆有限公司南京210031

[目的]随着乘客对地铁车内空气品质和空调均匀送风的追求越来越高,有必要研究提高地铁车辆可清洁式送风的均匀性。[方法]采用CFD(计算流体动力学)法对送风道内气流组织进行数值模拟,优化风道内部结构,并制作了一套全尺寸送风道,进行空... 详细信息

[目的]随着乘客对地铁车内空气品质和空调均匀送风的追求越来越高,有必要研究提高地铁车辆可清洁式送风的均匀性。[方法]采用CFD(计算流体动力学)法对送风道内气流组织进行数值模拟,优化风道内部结构,并制作了一套全尺寸送风道,进行空调与风道配套试验。[结果及结论]各出风口数值模拟预测风量和试验实测风量整体变化趋势一致;增加隔板后,送风均匀性有较大改善,80%以上的出风口预测风量与试验风量之间偏差在15%之内,其余在15%~20%之间;同时,缓解了入风口相邻出风口的倒吸问题,从而验证了数值仿真计算的可靠性。

关键词：地铁车辆可清洁式均匀送风道数值仿真

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