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Experimental investigation of flame propagation characteristics in the in-line crimped-ribbon flame arrester

Science China(Technological Sciences) 2017年第5期60卷 678-691页

作者： SUN ShaoChen DING Chunhui hu xiyu LIU Gang YE Chen BI MingShu School of Chemical Machinery Dalian University of Technology Dalian 116024 China Shenyang Institute of Special Equipment Inspection and Research Shenyang 110179 China

An experimental system that consisted of gas mixing equipment, a sensor detection system, a data acquisition device, and an electric spark ignition device was set up to investigate fuel/air deflagration flame propagation and quenching processes through a crimped-ribbon flame arrester in an enclosed horizontal pipe. Deflagration suppression experiments showed that when the concentration of flammable gas was close to the stoichiometric ratio, the evolution processes of explosion pressure for the propane-air and ethylene-air premixed gases in the pipe diameter （DN32-DN400） were similar and could be divided into four stages： isobaric combustion, slow pressure rise, quick pressure rise, and pressure oscillation. However, the explosion duration of the hydrogen-air premixed gas was relatively short, and the peak explosion pressure was high. The pressure rose quickly after the isobaric combustion stage. Therefore, the process can be divided into three stages in the pipe diameter （DN15-DN150）. Deflagration speed results indicated that the propane-air flame speed initially increased and eventually decreased along with increases in the pipe diameter （DN32-DN400）; however, the ethylene-air flame speed gradually increased with the increase of the pipe diameter （DNS0-DN400）. No notable pattern of change in the hydrogen-air flame speed was observed in the pipe diameter （DN15-DN150）. The maximum propane-air flame speed occurred at 5% concentration. The maximum flame speed for ethylene-air and hydrogen-air happened when the mixture was close to stoichiometric ratio. Under the conditions of the same size of experimental tube configuration and the same ignition distance but different pipe lengths, or the same pipe length but different ignition distances, experimental results showed that the flame arrester successfully stopped the flames at high flame speed and low explosion pressure, but failed at low flame speed and high explosion pressure.

关键词： deflagration flame crimped-ribbon flame arrester explosion pressure flame speed flammable gas concentration

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Ferromagnetism and insulating behavior with a logarithmic temperature dependence of resistivity in Pb_(10-x)Cux(PO_(4))_(6)O

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 106-111页

作者： Yuhang Zhang Cong Liu xiyu Zhu Hai-hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

Recent claim of discovering above-room-temperature superconductivity(Tc≈400 K)at ambient pressure in copper doped apatite Pb10(PO_(4))_(6)O has stimulated world-wide enthusiasm and impulse of motion.A lot of follow-up works have been carried out with controversial *** check whether superconductivity is really present or absent in the material,we need samples which should have a rather pure phase of Pb_(10-x)Cux(PO_(4))_(6)*** we report the characterization results from the Pb_(10-x)Cux(PO_(4))_(6)O with a fraction of about 97 wt.%inferred from the fitting to the X-ray diffraction pattern,if assuming Cu2S as the only *** resistivity measurements show that it is a semiconductor characterized roughly by a ln(1/T)temperature dependence in wide temperature region without trace of *** measurements show that it has a general ferromagnetic signal with a weak superparamagnetic *** grains of the sample show clear interactions with a Nb Fe B *** detected Cu concentration is much lower than the expected nominal *** results show the absence of metallicity and superconductivity in Pb_(10-x)Cux(PO_(4))_(6)O at ambient pressure,and suggest the presence of strong correlation effect.

关键词： superconductivity Pb10(PO4)6O ferromagnetic correlation effect

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Pressure-induced color change arising from transformation between intra-and inter-band transitions in LuH_(2±x)N_(y)

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 161-166页

作者： Zhe Liu Yingjie Zhang Shenyang huang Xue Ming Qing Li Chenghao Pan Yaomin Dai Xiaoxiang Zhou xiyu Zhu hugen Yan Hai-hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano-Photonic Structures of the Ministry of EducationDepartment of PhysicsFudan UniversityShanghai 200433China

The pressure-induced color change in the nitrogen-doped lutetium hydride has triggered extensive discussions about the underlying physics and potential ***,we study the optical response of LuH_(2±x)N_(y)in a broad frequency range at ambient pressure and its evolution with pressure in the visible spectral *** broad-band optical spectra at ambient pressure reveal a Drude component associated with intra-band electronic transitions and two Lorentz components(L1 and L2)arising from inter-band electronic *** application of pressure causes a spectral weight transfer from L1 to the Drude component,leading to a blue shift of the plasma edge in the reflectivity spectrum alongside a reduction of the high-frequency *** results suggest that the pressure-induced color change in LuH_(2±x)N_(y)is closely related to the transformation between intra-and inter-band electronic transitions,providing new insights into the mechanism of the pressure-induced color change in LuH_(2±x)N_(y).

关键词： nitrogen-doped lutetium hydride optical spectroscopy high-pressure technique color change

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Encapsulated ferric pyrophosphate improves intestinal inflammation and gut flora disorder in suckling rats with iron deficiency anemia

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Food Science and human Wellness 2024年

作者： Mengxiao hu Lili Qiu Rui Song xiyu Qin Xiaoxue Liu Zidi Tan Rong Liu Xiaoyu Wang College of Food Science & Nutritional Engineering， China Agricultural University Key Laboratory of Precision Nutrition and Food Quality， Department of Nutrition and Health， China Agricultural University Food Laboratory of Zhongyuan Luohe

The prevalence of iron deficiency anemia （IDA） remains high in infants， resulting in growth retardation， neurodevelopmental impairment， immunodeficiency and other irreversible injuries. Efficient and safe iron supplementation for infants has been the goal of recent research. This study aims to investigate the effect of encapsulated ferric pyrophosphate （FePP） on intestinal inflammation and gut microbiota in IDA suckling rats. Newborn Sprague Dawley rats were gavaged with low and high doses of FePP and FeSO4（2 and 10 mg Fe/kg BW， respectively） during postnatal days 2-14. Results showed that FePP supplementation was as effective as FeSO4in promoting growth， alleviating anemia and restoring body iron levels. Both low and high doses of FePP could significantly down-regulate the expression of pro-inflammatory cytokines in the colon to the level similar to that in the Ctrl group （P > 0.05）. However， the high dose of FeSO4did not show a down-regulation effect. Compared with the Ctrl group， IDA caused a disturbance of gut microbiota composition in suckling rats， and FePP could restore this dysbiosis. Besides， FePP was more beneficial than FeSO4in increasing the abundance of beneficial bacteria such as Bacteroides and Akkermansia. Spearman's correlation analysis showed a correlation between gut microbiota and biochemical indicators such as iron status， pro-inflammatory cytokine expression， and oxidative stress level. Overall， these findings suggested that FePP could effectively improve IDA， and is more effective than FeSO4in alleviating intestinal inflammation and regulating gut microbiota， which provides a basis for the application of new iron fortificant in infant formula.

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热处理对Q245R/06Cr19Ni10复合钢板性能的影响

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金属热处理 2019年第6期44卷 159-161页

作者：王大伟胡熙玉郝延平沈阳特种设备检测研究院

采用分段冷却(淬火+空冷)方式对Q245R/06Cr19Ni10复合钢板进行热处理。利用扫描电镜、EDS和显微硬度等方法分别对热处理前、后复合钢板试样的微观结构和性能进行了研究。结果表明:在真空和高温条件下,施加一定的压力可以较好实现Q245R/0... 详细信息

采用分段冷却(淬火+空冷)方式对Q245R/06Cr19Ni10复合钢板进行热处理。利用扫描电镜、EDS和显微硬度等方法分别对热处理前、后复合钢板试样的微观结构和性能进行了研究。结果表明:在真空和高温条件下,施加一定的压力可以较好实现Q245R/06Cr19Ni10两种材料复合,复合界面上生成Fe-Cr金属间化合物,靠近界面的不锈钢侧析出大量含Cr的碳化物,导致复合板的力学性能较差。经过热处理后,不锈钢侧Cr的碳化物数量减少,界面上的金属间化合物消失,大幅提高了复合钢板的力学性能。最终热处理后的复合板剪切强度达到349.3 MPa,拉伸强度达到456.9 MPa,冲击吸收能量达到138.8 J。

关键词：高温压力成形复合钢板热处理组织性能

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真空绝热低温容器安全泄放装置应用探讨

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压力容器 2020年第10期37卷 70-78页

作者：吴全龙胡熙玉上海华理安全装备有限公司上海201108 沈阳特种设备检测研究院沈阳110079

由于介质和设备的特殊性,国内外标准对充装冷冻液化气体的真空绝热低温容器用安全泄放装置设置有诸多专项规定。以相关标准为基础,从真空绝热低温容器失效模式及安全泄放装置类型选择、结构设置、设定压力和排放压力的确定等方面进行分... 详细信息

由于介质和设备的特殊性,国内外标准对充装冷冻液化气体的真空绝热低温容器用安全泄放装置设置有诸多专项规定。以相关标准为基础,从真空绝热低温容器失效模式及安全泄放装置类型选择、结构设置、设定压力和排放压力的确定等方面进行分析比较,为工程人员和标准编制人员提供参考。

关键词：冷冻液化气体安全泄放装置火灾工况设定压力安全泄放量

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水产养殖中水质与鱼类行为双向映射模型研究

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农业机械学报 2024年第3期55卷 290-299页

作者：魏天娇胡祝华范习禹海南大学信息与通信工程学院海口570228

在水产养殖中,水质参数与鱼类活动之间有着密不可分的相互映射关系。过去的监测更多偏向于单向映射,一般都是通过鱼类的行为表明水质的情况。针对仅仅通过鱼类行为反映水质情况会产生误判和滞后的问题,本文构建一种基于随机森林的鱼类... 详细信息

在水产养殖中,水质参数与鱼类活动之间有着密不可分的相互映射关系。过去的监测更多偏向于单向映射,一般都是通过鱼类的行为表明水质的情况。针对仅仅通过鱼类行为反映水质情况会产生误判和滞后的问题,本文构建一种基于随机森林的鱼类行为与水质情况双向映射模型。双向映射模型不仅可以提供更多的信息从而提高预测的准确性,而且也可以通过相互验证提高模型的可靠性。首先,通过引入可变形卷积模块对YOLO v7进行改进,利用改进模型检测出视频中鱼类的位置再通过前后帧的坐标量化出鱼的游动参数。随后,将采集到的鱼类游动参数及对应的水质参数作为输入,使用随机森林模型进行分类、回归,分别完成鱼类游动参数和水质参数具体数值的预测以及指标异常级别的预测,从而得到双向映射关系。为了表明模型的泛化能力,分别在黎安港和新村港渔场2个数据集下进行实验。实验结果表明:提出的方法可以较好地实现鱼类行为与水质关系的双向映射,其中,分类实验平均准确率可以达到90.947%,回归实验决定系数R^(2)的平均值可以达到0.801。

关键词：智慧养殖鱼类行为水质深度学习随机森林双向映射模型

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Signature of Superconductivity in Pressurized La_(4)Ni_(3)O_(10)

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Chinese Physics Letters 2024年第1期41卷 77-84页

作者：李庆张英杰项浙宁张宇航祝熙宇闻海虎 National Laboratory of Solid State Microstructures and Department of Physics Center for Superconducting Physics and MaterialsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

The discovery of high-temperature superconductivity near 80K in bilayer nickelate La_(3)Ni_(2)O_(7)under high pressures has renewed the exploration of superconducting nickelate in bulk *** extension of superconductivity in other nickelates in a broader family is also ***,we report the experimental observation of superconducting signature in trilayer nickelate La_(4)Ni_(3)O_(10)under high *** using a modified solgel method and post-annealing treatment under high oxygen pressure,we successfully obtained polycrystalline La_(4)Ni_(3)O_(10)samples with different transport behaviors at ambient *** we performed high-pressure electrical resistance measurements on these samples in a diamond-anvil-cell ***,the signature of possible superconducting transition with a maximum transition temperature(T_(c))of about 20K under high pressures is observed,as evidenced by a clear drop of resistance and the suppression of resistance drops under magnetic *** the resistance drop is sample-dependent and relatively small,it appears in all of our measured *** argue that the observed superconducting signal is most likely to originate from the main phase of La_(4)Ni_(3)O_(10).Our findings will motivate the exploration of superconductivity in a broader family of nickelates and shed light on the understanding of the underlying mechanisms of high-T_(c) superconductivity in nickelates.

关键词： materials superconductivity signature

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波纹管道阻火器内火焰传播的实验与数值模拟研究

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爆炸与冲击 2017年第2期37卷 353-364页

作者：孙少辰毕明树丁春辉胡熙玉刘刚封宇大连理工大学化工机械学院辽宁大连116024 沈阳特种设备检测研究院辽宁沈阳110035

对乙烯-空气预混火焰在波纹管道阻火器中的传播与淬熄过程进行了实验和数值模拟研究,实验结果显示:当乙烯接近当量浓度时,预混气体爆炸压力变化过程可分为4个阶段,等压燃烧阶段、缓慢上升阶段、快速上升阶段和压力振荡阶段;在爆炸过程中... 详细信息

对乙烯-空气预混火焰在波纹管道阻火器中的传播与淬熄过程进行了实验和数值模拟研究,实验结果显示:当乙烯接近当量浓度时,预混气体爆炸压力变化过程可分为4个阶段,等压燃烧阶段、缓慢上升阶段、快速上升阶段和压力振荡阶段;在爆炸过程中,由于反射压力波和火焰相互作用的影响,超压值出现多次振荡,压力振荡阶段一般可以持续数十毫秒;乙烯-空气火焰传播速度随管径增加、阻火单元波纹高度减小呈递增趋势,而且随着阻火单元厚度的增加,阻火器的阻火能力明显提高,可以更有效地使火焰淬熄。数值模拟结果显示:在管道封闭端点火后,火焰面呈半球形并以层流扩散的方式向四周传播;当火焰传播到管道壁面时,在管道壁面的约束作用下,火焰面发生变形,壁面附近的火焰逐渐超过了管道轴线附近的火焰,最后形成了"郁金香"状的火焰结构;当爆燃火焰经过阻火单元时,高温已燃气体被其吸收大量热量,同时在反应区产生的稀疏波作用下,气体温度逐渐降低、化学反应速率迅速减小,最终导致火焰被熄灭。通过模拟计算结果可以看出,在整个爆炸过程中,火焰传播速度与爆炸压力波动均较为明显。并提出了孔隙率和阻火单元厚度对火焰传播的影响机制。基于传热学理论模型,并结合实验数据,得出了爆燃火焰速度与爆炸压力之间的关系,为工业装置阻火器的设计和选型提供更为准确的参考依据。

关键词：波纹阻火器淬熄 “郁金香”火焰爆燃火焰速度爆炸压力

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稻谷水分含量的测量不确定度评定

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现代食品 2022年第17期28卷 170-172,178页

作者：胡溪育漳州市粮油质量监测站福建漳州363000

为提高稻谷水分含量测定的准确度和可靠性,减少实验误差,本文依据直接干燥法对稻谷的水分含量进行测定,并结合《测量不确定度评定与表示》(JJF 1059.1—2012)对测量过程中的不确定度来源、影响因素进行系统分析,通过测定的各不确定度分... 详细信息

为提高稻谷水分含量测定的准确度和可靠性,减少实验误差,本文依据直接干燥法对稻谷的水分含量进行测定,并结合《测量不确定度评定与表示》(JJF 1059.1—2012)对测量过程中的不确定度来源、影响因素进行系统分析,通过测定的各不确定度分量计算得到扩展不确定度。本次实验所测定稻谷水分含量可表示为(11.80±0.10)g/100 g,进一步分析结果表明样品的测量重复性和恒重是稻谷水分含量测量不确定度的主要来源,有助于在后续的实验过程中减少误差,保证检验结果的准确性和可靠性。

关键词：稻谷水分含量不确定度

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