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Estimating the Operation Status of Steam Cracking Furnace Using Numerical Simulation with Combustion Models

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China Petroleum Processing & Petrochemical Technology 2012年第4期14卷 52-63页

作者： Zhou xianfeng Yang Yuanyi Wang Guoqing Zhang Lijun Liu yi College of Chemical Engineering Beijing University of Chemical Technology Beijing Research Institute of Chemical Industry SINOPEC

An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has utilized the standard k-ε model and P1 model. The finite-rate/eddy-dissipation (finite-rate/ED) combustion model and non-premixed combustion model were both used to simulate accurately the combustion and the operation status of the steam cracking furnace. Three different surfaces of the steam cracking furnace were obtained from the simulation, namely:the flue gas temperature field of the entrance surface in long flame burners, the central surface location of tubes, and the crossover section surface. Detailed information on the flue gas temperature and the mass concentration fraction of these different surfaces in the steam cracking furnace can also be obtained by the simulation. This paper analyzed and compared the simulation results with the two combustion models, estimated the operation status of the steam cracking furnace, and reported that the finite-rate/ED model is appropriate to simulate the steam cracking furnace by comparing key simulation data with actual test data. This work has also provided a theoretical basis for simulating and operating the steam cracking furnace.

关键词：蒸汽裂解炉数值模拟燃烧模型运行状态估计温度环境几何模型质量浓度

基于一种标准城市建筑模型的行人高度风环境比较研究

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同济大学学报（自然科学版） 2022年第6期50卷 784-792页

作者：杨易张之远余先锋华南理工大学亚热带建筑科学国家重点实验室广东广州510640

对日本建筑学会(AIJ)提出的标准建筑风环境模型,分别采用风洞试验、基于雷诺平均(RANS)和大涡模拟(LES)的数值模拟方法,开展了考虑不同中央高层建筑高度和来流风向角对周围行人高度风环境影响的详细比较研究。结果表明:RANS和LES模拟得... 详细信息

对日本建筑学会(AIJ)提出的标准建筑风环境模型,分别采用风洞试验、基于雷诺平均(RANS)和大涡模拟(LES)的数值模拟方法,开展了考虑不同中央高层建筑高度和来流风向角对周围行人高度风环境影响的详细比较研究。结果表明:RANS和LES模拟得到各测点风速比的变化趋势与风洞试验整体上一致,相对而言,LES模拟结果与风洞试验结果更接近,平均误差约为RANS的1/2;而RANS方法总体上低估了行人高度风速,无法准确反映建筑背风面的风加速状况。随着中央建筑高度的增加,周边行人高度风速逐渐增大,100 m高度的超高层建筑对局部区域风速的加速达到1.6倍;但当中央建筑高度超过150 m、继续增大至200 m时,行人高度风速不再增大。当风向角在0°~90°范围变化时,在高层建筑背风面和角区附近会产生行人高度风场加速的“文丘里效应”;其中当来流风向角为45°时,风加速情况最为显著,显示出斜风来流工况下会对高层建筑周边行人风环境带来最不利的影响。

关键词：高层建筑行人风环境风洞试验雷诺平均大涡模拟

直接经皮冠状动脉介入治疗在老年急性心肌梗死中的应用

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中华老年心脑血管病杂志 2018年第3期20卷 250-252页

作者：徐争鸣李田昌陈宇李贤峰曹毅裘毅刚张博阳王志超陈星宇海军总医院心内科北京100048

目的评估急诊直接PCI在老年急性心肌梗死患者中应用的可行性、安全性及有效性。方法选择2015年1月~2016年12月在我院心内科住院的急性心肌梗死患者364例,其中≥75岁组90例,<75岁组274例。主要观察指标:手术成功率、围术期相关并发症及... 详细信息

目的评估急诊直接PCI在老年急性心肌梗死患者中应用的可行性、安全性及有效性。方法选择2015年1月~2016年12月在我院心内科住院的急性心肌梗死患者364例,其中≥75岁组90例,<75岁组274例。主要观察指标:手术成功率、围术期相关并发症及住院期间死亡和主要不良心血管事件(MACE)发生率。结果≥75岁组手术成功率94.4%,术后TIMI 3级血流达标率87.8%,围术期手术相关并发症9例(10.0%)。≥75岁组住院期间病死率和MACE发生率明显高于<75岁组(12.2%vs 2.9%,P=0.001;16.7%vs 5.1%,P=0.000)。结论对于年龄≥75岁的急性心肌梗死患者,经桡动脉急诊直接PCI是一种安全、可行、有效的治疗方案。

关键词：心肌梗死手术中并发症桡动脉

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紫色象草在我国南方地区的种植表现(英文)

农业科学与技术：英文版 2016年第3期17卷 667-671页

作者：易显凤赖志强姚娜蔡小艳韦锦益赖大伟梁永良广西畜牧研究所广西南宁530001

[目的]研究紫色象草(Pennisetum purpureum Schumab ***)的产量、品质特性及适应性,为其新品种审定及饲草开发提供参考依据。[方法]以紫色象草为研究对象,20072009年在广西南宁、凌云和天等参加品种比较试验,2011～2013年在海南澹州、... 详细信息

[目的]研究紫色象草(Pennisetum purpureum Schumab ***)的产量、品质特性及适应性,为其新品种审定及饲草开发提供参考依据。[方法]以紫色象草为研究对象,20072009年在广西南宁、凌云和天等参加品种比较试验,2011～2013年在海南澹州、福建福州和广东湛江参加品种区域性试验,测定其株高、干草产量、茎叶比、营养成分等综合性状,并与热研4号王草(***×*** *** No.4)和桂闽引象草(*** Schum ***)进行对比分析。[结果]紫色象草的平均株高706.54 cm,比热研4号王草、桂闽引象草分别低5.92%和8.44%;2007～2009年在广西南宁、凌云和天等3个试验点的平均十草产量为32.74±3.28 t/ha,2011-2013年在海南澹州、福建福州和广东湛江3个区域性试验点的平均十草产量为22.41±2.23 t/hm2,干草产量虽然比两个对照品种低,但差异均不显著(P>0.05);紫色象草的茎叶比0.98:1。与热研4号王草和桂闽引象草相比,其干物质中的粗纤维分别降低4.76%和2.78%,中性洗涤纤维降低5.07%和2.22%,酸性洗涤纤维降低2.54%和1.99%;而粗脂肪分别提高64.29%和43.75%,钙含量提高28.00%和33.33%,磷含量提高9.68%和22.73%,氨基酸总量提高43.23%和68.41%,叶片花青素含量显著提高400.00%和216.90%(P<0.05)。[结论]紫色象草的适应性强,产草量高,营养丰富,适口性好,是饲养草食动物的优质牧草新品种,适合在我国南方地区综合开发利用。

关键词：紫色象草株高十草产量茎叶比营养成分南方地区

Microstructure of premixed propane/air flame in the transition from laminar to turbulent combustion

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Chinese Science Bulletin 2007年第5期52卷 685-691页

作者： CHEN xianfeng SUN JinHua LIU yi LIU XuanYa CHEN SiNing LU ShouXiang State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China

In order to explore the flame structure and propagation behavior of premixed propane/air in the transi-tion from laminar to turbulent combustion, the high speed camera and Schlieren images methods were used to record the photograph of flame propagation process in a semi-vented pipe. Meanwhile, the super-thin thermocouple and ionization current probe methods were applied to detect the temperature distribution and reaction intensity of combustion reaction. The characteristics of propane/air flame propagation and microstructure were analyzed in detail by the experimental results coupled with chemical reaction thermodynamics. In the test, the particular tulip flame behavior and the formation process in the laminar-turbulent transition were disclosed clearly. From the Schlieren images and iron current results, one conclusion can be drawn that the small-scale turbulent combustion also appeared in laminar flame, which made little influence on the flame shape, but increased the flame thickness obviously.

关键词：丙烷/空气预混火焰火焰结构层流焰紊流燃烧过渡可燃气体爆炸

Broadband quasi-phase matching in a MgO:PPLN thin film

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Photonics Research 2018年第10期6卷 954-958页

作者： LICHENG GE YUPING CHEN HAOWEI JIANG GUANGZHEN LI BING ZHU yi'AN LIU xianfeng CHEN State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China

Future quantum information networks operated on telecom channels require qubit transfer between different wavelengths while preserving quantum coherence and entanglement. Qubit transfer is a nonlinear optical process,but currently the types of atoms used for quantum information processing and storage are limited by the narrow bandwidth of upconversion available. Here we present the first experimental demonstration of broadband and high-efficiency quasi-phase matching second-harmonic generation(SHG) in a chip-scale periodically poled lithium niobate thin film. We achieve a large bandwidth of up to 2 THz for SHG by satisfying quasi-phase matching and group-velocity matching simultaneously. Furthermore, by changing the film thickness, the central wavelength of the quasi-phase matching SHG bandwidth can be modulated from 2.70 μm to 1.44 μm. The reconfigurable quasi-phase matching lithium niobate thin film provides a significant on-chip integrated platform for photonics and quantum optics.

关键词：电信信道信息网络通讯技术发展现状

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紫色象草及其高效栽培与利用

草学 2021年第1期 52-58页

作者：赖大伟赖志强易显凤姚娜蔡小艳邓素媛史静丘金花黄一龙广西壮族自治区畜牧研究所广西南宁530001 宁夏大学宁夏银川750021

紫色象草是新近通过全国草品种审定登记的新型象草类品种,紫色象草的产草量与热研4号王草和桂闽引象草差异不显著,但其叶量多,质量好,粗蛋白含量高,粗纤维含量低,特别是花青素和胡萝卜素含量高,花青素分别比热研4号王草、桂闽引象草提高... 详细信息

紫色象草是新近通过全国草品种审定登记的新型象草类品种,紫色象草的产草量与热研4号王草和桂闽引象草差异不显著,但其叶量多,质量好,粗蛋白含量高,粗纤维含量低,特别是花青素和胡萝卜素含量高,花青素分别比热研4号王草、桂闽引象草提高了172.73%~400.00%和36.36%~216.90%,胡萝卜素比热研4号王草提高15.49%~461.45%,比桂闽引象草提高33.33%~56.6%,差异显著。紫色象草是具有开发利用价值的新品种。本文从紫色象草的植物学特征、生物学特性、适应区域、栽培技术、生产应用、动物利用效果等方面进行了较系统的介绍,帮助广大农牧民和草牧业科技工作者掌握紫色象草栽培利用技术难点和重点,以便更好地在热带亚热带地区推广应用。

关键词：紫色象草栽培利用花青素胡萝卜素

Flame propagation characteristics and flame structures of zirconium particle cloud in a small-scale chamber

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Chinese Science Bulletin 2010年第34期55卷 3954-3959页

作者： DING yiBin SUN JinHua HE XueChao WANG QiuHong yiN yi XU Yao Chen xianfeng State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China Anhui Province Academy of Safety Science And Technology Hefei 230001 China Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001 China School of Resources and Environmental Engineering Wuhan University of Technology Wuhan 430070 China

Flame propagating through zirconium particle cloud in a small-scale vertical rectangle chamber was investigated *** the experiments,the zirconium quoted 99% purity was used and the diameter of particles was distributed 1-22 μ*** zirconium dust was dispersed into the chamber by air flow and ignited by an electrode spark.A high-speed video camera was used to record the images of the propagating ***-thermocouples,schlieren optical system and microscopic lens were used to obtain temperature profiles and flame structure,*** on the experimental results,flame propagation characteristics and flame structure of zirconium particle cloud were *** propagation velocity of the flame is quite slow in the initial 14 ms and then accelerates to maximum ***,the propagation velocity of the flame almost keeps *** combustion zone width of zirconium particle cloud is 5-6 *** particles burn mainly at the leading edge of combustion zone in the width of 1.4 mm followed by larger particles burning 1.4-6 mm behind the leading edge of the combustion *** phase flame is not seen in zirconium particle cloud and the combustion time of single zirconium particle is 1-5 ms,which depends on its original *** preheated zone is 7-8 mm thickness ahead of the combustion zone and intensive chemical reaction takes place at 490 *** maximum flame temperature increases at lower concentrations,reaches the maximum value,and then decreases slightly at higher concentrations.

关键词：火焰结构传播特性小规模粒子火焰传播速度会议厅锆纹影光学系统

Characterization of Annealed, Proton Exchange Optical Waveguides in Y-cut MgO∶LiNbO3 Crystal

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Chinese Journal of Lasers 2000年第3期9卷 47-51页

作者： CAO Xia XIA Yuxing YANG yi WANG Pinghe CHEN xianfeng (Department of Applied Physics, Shanghai Jiao Tong University, Shanghai 200030, China) 上海交通大学上海

It is reported the results of a systematic study on planar w aveguides fabricated in Y-cut MgO∶LiNbO 3 crystal. The index profile of the as-exchanged waveguide can be modeled as a step-like one. It is deduced the diffusion coefficient and the activation energy for the proton exchange process. The surface index increases Δn e of around 0.127 after proton exchange can be reduced by post thermal annealing. The effects of the annealing on the index profile and guide depth were found not as fast as it does on a pure LiNbO 3 crystal.

关键词： proton exchange MgO∶LiNbO 3 crystal optical waveguides refractive index profile