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一种基于三角数分解的可配置2-D卷积器优化方法
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作者 黄继业 肖强 +4 位作者 田大海 高明裕 王俊帆 董哲康 黄汐威 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第7期3054-3062,共9页
多尺寸2-D卷积通过特征提取在检测、分类等计算机视觉任务中发挥着重要作用。然而,目前缺少一种高效的可配置2-D卷积器设计方法,这限制了卷积神经网络(CNN)模型在边缘端的部署和应用。该文基于乘法管理以及奇平方数的三角数分解方法,提... 多尺寸2-D卷积通过特征提取在检测、分类等计算机视觉任务中发挥着重要作用。然而,目前缺少一种高效的可配置2-D卷积器设计方法,这限制了卷积神经网络(CNN)模型在边缘端的部署和应用。该文基于乘法管理以及奇平方数的三角数分解方法,提出一种高性能、高适应性的卷积核尺寸可配置的2-D卷积器。所提2-D卷积器包含一定数量的处理单元(PE)以及相应的控制单元,前者负责运算任务,后者负责管理乘法运算的组合,二者结合以实现不同尺寸的卷积。具体地,首先根据应用场景确定一个奇数列表,列表中为2-D卷积器所支持的尺寸,并利用三角数分解得到对应的三角数列表;其次,根据三角数列表和计算需求,确定PE的总数量;最后,基于以小凑大的方法,确定PE的互连方式,完成电路设计。该可配置2-D卷积器通过Verilog硬件描述语言(HDL)设计实现,由Vivado 2 022.2在XCZU7EG板卡上进行仿真和分析。实验结果表明,相比同类方法,该文所提可配置2-D卷积器,乘法资源利用率得到显著提升,由20%~50%提升至89%,并以514个逻辑单元实现1 500 MB/s的吞吐率,具有广泛的适用性。 展开更多
关键词 2-d卷积器 可配置架构 乘法管理 三角数分解
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基于离散2-D小波多级分解的电容器外观缺陷视觉检测方法
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作者 张剑 高云 何栋 《电子器件》 CAS 2024年第5期1255-1260,共6页
电容器外观破损、凸起等缺陷直接影响器件的生产质量。目前电容器微小外观缺陷检测难度较大,导致视觉检测效率较低。为此提出了基于离散2-D小波多层分解的电容器外观缺陷视觉检测方法。采用同态滤波处理去除光照对电容器外观视觉检测结... 电容器外观破损、凸起等缺陷直接影响器件的生产质量。目前电容器微小外观缺陷检测难度较大,导致视觉检测效率较低。为此提出了基于离散2-D小波多层分解的电容器外观缺陷视觉检测方法。采用同态滤波处理去除光照对电容器外观视觉检测结果的影响。利用像素点灰度值确定图像边缘点位置,提取电容器外观缺陷区域。应用离散2-D小波分解的方法对其展开多级分解。再差分统计电容器图像的外观缺陷纹理特征。将特征输入Mahalanobis分类器中,完成电容器外观缺陷视觉检测。仿真结果表明,所提方法可以较好检测电容的各种缺陷,召回率最低值是94.9%,误检率最高值为9.8%,漏检率均在10%以内,电容器缺陷检测效果较好。 展开更多
关键词 多尺度特征 同态滤波处理 2-d小波分解 Mahalanobis分类器 电容缺陷 视觉检测
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Manipulating photogenerated electron flow in nickel single‐atom catalysts for photocatalytic CO_(2) reduction into tunable syngas
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作者 Yida Zhang Qingyu Wang +5 位作者 Lihui Wu Haibin Pan Chengyuan Liu Yue Lin Gongming Wang Xusheng Zheng 《Carbon Energy》 SCIE EI CAS CSCD 2024年第8期205-213,共9页
The key to designing photocatalysts is to orient the migration of photogenerated electrons to the target active sites rather than dissipate at inert sites.Herein,we demonstrate that the doping of phosphorus(P)signific... The key to designing photocatalysts is to orient the migration of photogenerated electrons to the target active sites rather than dissipate at inert sites.Herein,we demonstrate that the doping of phosphorus(P)significantly enriches photogenerated electrons at Ni active sites and enhances the performance for CO_(2) reduction into syngas.During photocatalytic CO_(2) reduction,Ni single‐atom‐anchored P‐modulated carbon nitride showed an impressive syngas yield rate of 85μmol gcat^(−1)h^(−1) and continuously adjustable CO/H_(2) ratios ranging from 5:1 to 1:2,which exceeded those of most of the reported carbon nitride‐based single‐atom catalysts.Mechanistic studies reveal that P doping improves the conductivity of catalysts,which promotes photogenerated electron transfer to the Ni active sites rather than dissipate randomly at low‐activity nonmetallic sites,facilitating the CO_(2)‐to‐syngas photoreduction process. 展开更多
关键词 carbon nitride CO_(2) photoreduction electron flow Ni single atoms SYNGAS
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Transforming liquid flow fuel cells to controllable reactors for highlyefficient oxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid at low temperature
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作者 Ye Qiang Xi Liu +2 位作者 Denghao Ouyang Zhao Jiang Xuebing Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期621-631,I0014,共12页
Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport cha... Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild conditions.This LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to air.The reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of electrons.For a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism. 展开更多
关键词 5-HYDROXYMETHYLFURFURAL 2 5-Furandicarboxylic acid ELECTRODEPOSITION Electron transport chain Liquid flow fuel cell
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Comparison of the precision of glacier flow rates derived from offset-tracking using Sentinel-2 and Landsat-8/9 imagery
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作者 YANG Zhibin CHEN Zhuoqi +3 位作者 LI Gang MAO Yanting FENG Xiaoman CHENG Xiao 《Advances in Polar Science》 CSCD 2024年第2期238-251,共14页
Offset-tracking is an essential method for deriving glacier flow rates using optical imagery.Sentinel-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial ... Offset-tracking is an essential method for deriving glacier flow rates using optical imagery.Sentinel-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial resolution with relatively short revisit time,wide swath width,and free accessibility.To evaluate and compare the precision of offset-tracking results yielded with these two kinds of data,in this study S2 and L8/9 imagery observed in Petermann Glacier in Greenland,Karakoram in High-Mountains Asia,and Amery Ice Shelf in the Antarctic are analyzed.Outliers and various systematic error sources in the offset-tracking results including orbital and strip errors were analyzed and eliminated at the pre-process stage.Precision at the off-glacier(bare rock)region was evaluated by presuming that no deformation occurred;then for both glacierized and the off-glacier regions,precision of velocity time series was evaluated based on error propagation theory.The least squares method based on connected components was used to solve flow rates time series based on multi-pair images offset-tracking.The results indicated that S2 achieved slightly higher precision than L8/9 in terms of both single-pair derived displacements and least square solved daily flow rates time series.Generally,the RMSE of daily velocity is 26%lower for S2 than L8/9.Moreover,S2 provided higher temporal resolution for monitoring glacier flow rates. 展开更多
关键词 Sentinel-2 LANDSAT glacier flow rates offset-tracking PRECISION
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基于二萘并[2,3-B∶2′,3′-D]呋喃基团的高效窄发射蓝光OLED器件
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作者 王小伟 袁江波 +4 位作者 马佩兰 闫自强 崔志远 孙军 彭其明 《发光学报》 EI CAS CSCD 北大核心 2024年第9期1503-1510,共8页
高效率窄光谱蓝色有机电致发光器件(OLED)是柔性显示领域的研究重点之一。本文以二萘并[2,3-B∶2′,3′-D]呋喃为弱电子受体、N-(4-联苯基)-1-萘胺作为电子给体设计合成了一种D-A-D型蓝光分子DPF-NA,其在正己烷溶液中的发射峰位于441 n... 高效率窄光谱蓝色有机电致发光器件(OLED)是柔性显示领域的研究重点之一。本文以二萘并[2,3-B∶2′,3′-D]呋喃为弱电子受体、N-(4-联苯基)-1-萘胺作为电子给体设计合成了一种D-A-D型蓝光分子DPF-NA,其在正己烷溶液中的发射峰位于441 nm。理论计算与光物理测试结果显示DPF-NA具有杂化局域电荷转移激发态(HLCT)特性,兼具局域态(LE)高发光效率与电荷转移态(CT)高激子利用率特征,在二氯甲烷溶液中的光致发光量子效率(PLQY)为81.2%。基于质量分数3%DPF-NA掺杂浓度的OLED器件电致发光(EL)峰位于455 nm,半峰宽(FWHM)仅为26 nm,CIE(x,y)坐标为(0.14,0.08),最大外量子效率(EQEmax)为6.76%。 展开更多
关键词 有机电致发光器件 二萘并[2 3-B∶2 3′-d]呋喃 蓝光 激子利用 外量子效率
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New 4-imino-4H-Chromeno[2,3-d]Pyrimidin-3(5H)-Amine: Synthesis, Cytotoxic Effects on Tumoral Cell Lines and in Silico ADMET Properties
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作者 Marwa Dhiabi Sirine Karoui +7 位作者 Mehdi Fakhfakh Souhir Abid Emmanuelle Limanton Rémy Le Guével Thierry Charlier Ludovic Paquin Jean-Pierre Bazureau Houcine Ammar 《International Journal of Organic Chemistry》 2024年第3期107-122,共16页
The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was establishe... The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR and mass spectroscopy. These new compounds were tested for their antiproliferative activities on seven representative human tumoral cell lines (Huh7 D12, Caco2, MDA-MB231, MDA-MB468, HCT116, PC3 and MCF7) and also on fibroblasts. Among them, only the compounds 6c showed micromolar cytotoxic activity on tumor cell lines (1.8 50 50 > 25 μM). Finally, in silico ADMET studies ware performed to investigate the possibility of using of the identified compound 6c as potential anti-tumor compound. 展开更多
关键词 2-Amino-4H-Chromene 4H-Chromeno[2 3-d]Pyrimidin-3(5H)-Amine Microwave Irradiation Tumoral Cell Line in Silico ADMET
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2-D Modeling and Calculations of Stratospheric Ozone and Influences of Convection, Diffusion, and Time
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作者 Ibraheem Alelmi Laurie Wei Sen Nieh 《Atmospheric and Climate Sciences》 2024年第2期250-276,共27页
An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical react... An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone D<sub>O3</sub> and active atomic oxygen D<sub>O</sub> on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen D<sub>O</sub> was found to be more sensitive and important than that of ozone D<sub>O3</sub> on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. . 展开更多
关键词 Stratospheric Ozone 2-d Model Ozone Layer Ozone Depletion CONVECTION DIFFUSION
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CO_(2)分注井气嘴节流特性及矿场应用 被引量:1
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作者 蔡萌 朱振坤 +2 位作者 刘云 刘钰川 李海成 《大庆石油地质与开发》 CAS 北大核心 2024年第1期119-127,共9页
为了解决CO_(2)分注井节流压差建立困难,气嘴易冲蚀的技术难题,通过构建CO_(2)物性变化的流动-传热耦合模型,揭示2级和3级节流气嘴的流场演化机制,优化设计气嘴结构、建立了绕流气嘴节流图版并开展现场应用。结果表明:流量为10 m3/d时,... 为了解决CO_(2)分注井节流压差建立困难,气嘴易冲蚀的技术难题,通过构建CO_(2)物性变化的流动-传热耦合模型,揭示2级和3级节流气嘴的流场演化机制,优化设计气嘴结构、建立了绕流气嘴节流图版并开展现场应用。结果表明:流量为10 m3/d时,2级嘴径1.4 mm和3级嘴径1.6 mm的绕流气嘴分别能产生将近6 MPa和8 MPa的节流压差,证明绕流气嘴结构合理、性能可靠、能够达到调整层间压差的技术要求;参照气嘴图版优选的节流气嘴,现场应用20口井,节流压差可达4 MPa左右,调整后注入压力上升2.4 MPa,加强层相对吸气比例由9.7%上升至50.7%,有效调整了层间差异,解决了分注井小层吸气不均的问题。研究结果指导现场测调,为CO_(2)分注规模化应用提供技术支撑。 展开更多
关键词 CO_(2)分注 绕流气嘴 节流机理 气嘴图版 节流压差
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进气流量对滑动电弧放电分解CO_(2)的瞬态电-光-热特性和转化性能的影响
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作者 刘洋 章子潇 +2 位作者 赵贤根 杜亚平 何俊佳 《电工技术学报》 EI CSCD 北大核心 2024年第23期7616-7627,共12页
进气流量作为影响滑动电弧放电特性的关键操作参数,直接关系到滑动电弧分解CO_(2)的转化性能。该文拟通过实验研究进气流量对滑动电弧放电分解CO_(2)的电-光-热特性及其对转化性能的影响。为此搭建了滑动电弧放电的瞬态电-光-热特性同... 进气流量作为影响滑动电弧放电特性的关键操作参数,直接关系到滑动电弧分解CO_(2)的转化性能。该文拟通过实验研究进气流量对滑动电弧放电分解CO_(2)的电-光-热特性及其对转化性能的影响。为此搭建了滑动电弧放电的瞬态电-光-热特性同步原位诊断平台,其中,热特性通过高速纹影技术表征。借助搭建的诊断平台,开展了不同进气流量(1.5~10 L/min)下滑动电弧放电分解CO_(2)的实验,并对比分析进气流量对滑动电弧运动特征(即放电周期和电弧短路事件)、等离子体发光区和高温气流区面积、注入能量和CO_(2)转化性能参数的影响规律。实验结果表明:滑动电弧的放电周期随着进气流量的增大而减小,且变化趋势近似服从指数衰减;等离子体发光区和高温气流区的面积均与进气流量呈正相关,表明进气流量的增大有利于扩大活性粒子分布区域并强化对流换热过程,从而提升CO_(2)的转化性能;过高的进气流量(10L/min)会引发两类电弧短路事件,而短路事件的频繁发生会抑制滑动电弧的作用区域和对流换热过程,导致CO_(2)转化性能劣化。最后,提出了进气流量对滑动电弧放电分解CO_(2)的影响机制,将有助于理解反应器内气流与等离子体之间的相互作用关系,为反应器操作参数的调控提供指导。 展开更多
关键词 CO_(2)分解 滑动电弧放电 进气流量 纹影技术 电-光-热特性
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不同流向上小流道加热管内超临界CO_(2)的压降特性
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作者 王磊 曹雄金 +2 位作者 罗凯 王艳 费华 《化工进展》 EI CAS CSCD 北大核心 2024年第2期830-843,共14页
针对不同流动方向上超临界CO_(2)流体在小流道加热管径为0.75mm内的压降特性进行了实验研究。结果表明,不同流动(水平流动、垂直向上流动以及垂直向下流动)方向上,实验总压降、摩擦压降以及加速度压降均随着系统压力的升高而逐渐减小,... 针对不同流动方向上超临界CO_(2)流体在小流道加热管径为0.75mm内的压降特性进行了实验研究。结果表明,不同流动(水平流动、垂直向上流动以及垂直向下流动)方向上,实验总压降、摩擦压降以及加速度压降均随着系统压力的升高而逐渐减小,而随着质量流量的增大、加热功率以及进口温度的升高而增大。然而,在垂直流动方向上重力压降随着系统压力的升高以及质量流量的增大而逐渐增大,但随着加热功率以及进口温度的升高而逐渐减小。当系统压力、质量流量、加热功率以及进口温度保持恒定时,不同流动方向上超临界CO_(2)流体的摩擦压降均在实验总压降中所占有的比例最大,而重力压降在实验总压降中所占有的比例最小。通过两种测试管径的压降数据比较可知,超临界CO_(2)流体在不同流动方向上实验总压降的变化趋势始终保持一致,并且小管径的实验总压降远大于大管径的实验总压降,从而说明测试管径的尺寸大小对实验总压降的变化有着显著影响。 展开更多
关键词 超临界CO_(2) 不同流动方向 总压降 摩擦压降 加速度压降 重力压降
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基于夹点的带喷射器CO_(2)热泵系统性能分析
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作者 杨俊兰 张鑫 +2 位作者 王林秀 韩一飞 杜雨帆 《暖通空调》 2024年第3期92-97,171,共7页
为了研究带喷射器的跨临界CO_(2)内部过冷热泵系统(TCISE),基于夹点建立了TCISE的热力学模型,分析了冷却水进出水温度及流量对系统性能的影响。研究表明:冷却水进水温度从25℃降低到15℃时,最优高压压力从9.3 MPa降至8.8 MPa,降低了5.4%... 为了研究带喷射器的跨临界CO_(2)内部过冷热泵系统(TCISE),基于夹点建立了TCISE的热力学模型,分析了冷却水进出水温度及流量对系统性能的影响。研究表明:冷却水进水温度从25℃降低到15℃时,最优高压压力从9.3 MPa降至8.8 MPa,降低了5.4%,最大COP从3.83提升至4.27,提高了11.49%;TCISE存在临界冷却水出水温度和临界冷却水质量流量,当冷却水进水温度一定时,在出水温度低于临界出水温度或质量流量高于临界质量流量时,系统COP保持不变。 展开更多
关键词 CO_(2)热泵 喷射器 夹点 内部过冷 冷却水 进水温度 出水温度 流量
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Synergistic regulation of hydrophobicity and basicity for copper hydroxide-derived copper to promote the CO_(2)electroreduction reaction 被引量:3
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作者 Limin Zhou Chenghang Li +8 位作者 Jing-Jing Lv Wei Wang Shaojun Zhu Jun Li Yifei Yuan Zheng-Jun Wang Qingcheng Zhang Huile Jin Shun Wang 《Carbon Energy》 SCIE CSCD 2023年第6期72-81,共10页
A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutrali... A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutralization reaction between Cu(OH)_(2)and Nafion in aqueous solution induces the exposing of vast anions which can exclude the in-situ-formed hydroxides and raise the local basicity.Remarkably,the optimal Nafionactivated Cu(OH)_(2)-derived Cu can efficiently suppress the hydrogen evolution reaction(HER)and improve the selectivity for multi-carbon products in the CO_(2)electroreduction reaction(eCO_(2)RR).The H2 Faradaic efficiency(FE)decreased to 11%at a current density of 300 mA/cm2(−0.76 V vs.RHE)in a flow cell,while the bare one with H2 had an FE of 40%.The total eCO_(2)RR FE reaches as high as 83%,along with an evidently increased C2H4 FE of 44%as compared with the bare one(24%),and good stability(8000 s),surpassing that of most of the reported Cu(OH)_(2)-derived Cu.The experimental and theoretical results both show that the strong hydrophobicity and high local basicity jointly boosted the eCO_(2)RR as acquired by felicitously introducing ionomer on the Cu(OH)_(2)-derived Cu surface. 展开更多
关键词 CO_(2)electroreduction reaction Cu(OH)_(2)@Nafion flow cell IONOMERS multi-carbon products
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急性冠脉综合征患者血清sST2及NLRP3水平与介入术后无复流-慢血流的相关性分析
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作者 雷锐 殷实 李志 《现代检验医学杂志》 CAS 2024年第4期121-125,154,共6页
目的探讨急性冠脉综合征(acute coronary syndrome,Acs)患者血清可溶性生长刺激表达基因蛋白2(soluble growth stimulation expression gene 2 protein,sST2),核苷酸寡聚化结构域样受体热蛋白结构域相关蛋白3(nucleotide oligomerizatio... 目的探讨急性冠脉综合征(acute coronary syndrome,Acs)患者血清可溶性生长刺激表达基因蛋白2(soluble growth stimulation expression gene 2 protein,sST2),核苷酸寡聚化结构域样受体热蛋白结构域相关蛋白3(nucleotide oligomerization domain like receptor heat protein domain associated protein 3,NLRP3)水平与经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)术后无复流-慢血流的关系。方法选择2020年1月~2022年12月佳木斯市中心医院收治的97例急性冠脉综合征患者,所有患者均接受PCI治疗,根据术后无复流-慢血流发生情况分为无复流-慢血流组(n=20)和对照组(n=77)。术前检测血清sST2及NLRP3水平,分析影响急性冠脉综合征患者PCI术后无复流-慢血流的因素以及sST2,NLRP3预测急性冠脉综合征患者PCI术后无复流-慢血流的价值。结果无复流-慢血流组血清sST2(14.32±2.65 ng/ml vs 11.02±2.13 ng/ml),NLRP3(68.23±10.17 pg/ml vs 42.05±8.23 pg/ml)水平高于对照组,差异具有统计学意义(t=5.860,12.055,均P<0.05)。多因素Logistic回归分析显示高血栓负荷(OR:7.791,95%CI:2.834~21.421)、高水平sST2(OR=2.071,95%CI:1.146~3.743)、高水平NLRP3(OR=2.008,95%CI:1.228~3.284)是急性冠脉综合征患者PCI术后无复流-慢血流的危险因素(均P<0.05)。sST2,NLRP3诊断急性冠脉综合征患者PCI术后无复流-慢血流的临界值分别为12.91ng/ml,55.39 pg/ml,曲线下面积分别为0.737,0.686,联合sST2,NLRP3诊断急性冠脉综合征患者PCI术后无复流-慢血流的曲线下面积为0.907,高于单独诊断(Z=2.662,2.856,均P<0.05)。结论急性冠脉综合征患者血清sST2,NLRP3水平增高与PCI术后无复流-慢血流的发生有关,联合检测sST2和NLRP3可提高对术后无复流-慢血流的诊断效能。 展开更多
关键词 急性冠脉综合征 经皮冠状动脉介入术 无复流-慢血流 可溶性生长刺激表达基因蛋白2 核苷酸寡聚化结构域样受体热蛋白结构域相关蛋白3
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超临界CO_(2)管道输送流动保障分析要点探讨 被引量:1
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作者 陈俊文 关沛丰 +6 位作者 汤晓勇 史博会 昝林峰 张则鹏 宫敬 郭艳林 彭伟 《天然气与石油》 2024年第2期8-15,共8页
近年来,随着碳捕集与封存的需求不断提高,CO_(2)管道成为关键支撑,大规模发展趋势明显。CO_(2)管道可采用气相、超临界相或密相输送的方式。相比气相输送,长距离CO_(2)管道采用超临界输送模式具有更好的经济性。与常规油品输送相比,超临... 近年来,随着碳捕集与封存的需求不断提高,CO_(2)管道成为关键支撑,大规模发展趋势明显。CO_(2)管道可采用气相、超临界相或密相输送的方式。相比气相输送,长距离CO_(2)管道采用超临界输送模式具有更好的经济性。与常规油品输送相比,超临界CO_(2)在输送过程中存在水击超压、热膨胀超压、降压相变、相变低温等问题,受超临界CO_(2)物性特点、输送工艺等影响,超临界CO_(2)流动保障值得系统性探讨。基于超临界CO_(2)输送工艺与运行特点,识别了超临界CO_(2)管道输送流动保障分析要点,探讨了超临界CO_(2)与常规油品的水击超压、热膨胀超压问题,具体开展了超临界CO_(2)计划性放空管体相态与温度分布研究。研究表明:超临界CO_(2)管道水击超压影响相对较小,但存在水击点下游降压相变风险;超临界CO_(2)管道停输后存在热膨胀超压风险;受地形影响,超临界CO_(2)管道计划性放空时存在不均匀相变与不均匀温度分布等问题;超临界CO_(2)管道计划性放空宜同步开展数值模拟分析,泄放过程温度监测方案还需进一步研究。研究成果可为超临界CO_(2)管道设计与运行提供相关借鉴。 展开更多
关键词 超临界CO_(2) 管道 流动保障 计划性放空
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Simulation of Cavitating Flow around a 2-D Hydrofoil 被引量:7
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作者 黄胜 何苗 +1 位作者 王超 常欣 《Journal of Marine Science and Application》 2010年第1期63-68,共6页
In order to predict the effects of cavitation on a hydrofoil, the state equations of the cavitation model were combined with a linear viscous turbulent method for mixed fluids in the computational fluid dynamics (CFD)... In order to predict the effects of cavitation on a hydrofoil, the state equations of the cavitation model were combined with a linear viscous turbulent method for mixed fluids in the computational fluid dynamics (CFD) software FLUENT to simulate steady cavitating flow. At a fixed attack angle, pressure distributions and volume fractions of vapor at different cavitation numbers were simulated, and the results on foil sections agreed well with experimental data. In addition, at the various cavitation numbers, the vapor fractions at different attack angles were also predicted. The vapor region moved towards the front of the airfoil and the length of the cavity grew with increased attack angle. The results show that this method of applying FLUENT to simulate cavitation is reliable. 展开更多
关键词 2-d hydrofoil cavitation model cavitation flow
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井筒流压快速分析方法及其在CO_(2)井中的应用
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作者 何邦超 次惠岭 +4 位作者 白冰 刘建锋 邹炎 雷宏武 崔银祥 《石油机械》 北大核心 2024年第8期108-117,共10页
井筒作为井筒内工质流体和地下储层发生物质和能量交换的主要通道,其内部流体温度场和压力场的准确预测是深部流体注采工程中至关重要的内容,控制工程生产效率与安全性评估。通过总结前人研究工作,发现井筒内流体压力随深度近似线性变... 井筒作为井筒内工质流体和地下储层发生物质和能量交换的主要通道,其内部流体温度场和压力场的准确预测是深部流体注采工程中至关重要的内容,控制工程生产效率与安全性评估。通过总结前人研究工作,发现井筒内流体压力随深度近似线性变化的特征,在此基础上,提出一种关于井筒内流压的快速分析方法;建立了基于井筒内流体的质量守恒方程、动量守恒方程和能量守恒方程的井筒内流体温度、压力耦合计算模型,并利用该耦合模型就所提快速分析方法中待定参数与流体工况、井筒参数、地层物性等参数变化的敏感性进行分析;针对CO_(2)井,给出了井筒内流压快速分析表达式,结合工程现场数据进行验证,压力解精度在工程应用许可的范围内。所提井筒内流压快速分析方法基于文献统计得出,适用于气井、液井、生产井、注入井等,覆盖范围较广,具有计算参数少、方便快捷的特点,针对某指定工质流体的快速分析表达式中的待定参数可由室内研究人员给出。研究结果对现场工程师具有极大的便利性。 展开更多
关键词 井筒流动模型 快速分析方法 一维稳态流动 流体压力 敏感性分析 CO_(2)井
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一种高速2-D滑动FFT的设计实现
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作者 许丁鸿 张多利 +2 位作者 陶相颖 韩帅鹏 宋宇鲲 《合肥工业大学学报(自然科学版)》 CAS 北大核心 2023年第7期912-918,共7页
文章介绍了采用2-D快速傅里叶变换(fast Fourier transform,FFT)算法的滑动窗FFT的基本特性原理和硬件实现过程,完成了窗长256点、步长16点的2-D滑动窗FFT的专用集成电路(application specific integrated circuit,ASIC)设计。传统FFT... 文章介绍了采用2-D快速傅里叶变换(fast Fourier transform,FFT)算法的滑动窗FFT的基本特性原理和硬件实现过程,完成了窗长256点、步长16点的2-D滑动窗FFT的专用集成电路(application specific integrated circuit,ASIC)设计。传统FFT算法受序列完整性的制约,时滞较大,无法满足某些高实时性信号分析领域的处理速度要求。该文采用滑动FFT算法,克服了传统FFT对序列完整性的依赖,设计的滑动FFT处理器使用2-D FFT压缩新序列计算时间,以基16蝶形运算器为核心,采用系数复用和高基Booth方法优化系数编码技术压缩乘法器的数量,减少电路面积。所设计的2-D滑动FFT完成单次滑动窗长的计算时间比传统算法节约了16.1%,变换结果与MATLAB的运算结果相比,信噪比(signal-to-noise ratio,SNR)大于130 dB。在TSMC 28 nm的工艺下,工作主频为600 MHz,面积为1980μm×2060μm。 展开更多
关键词 快速傅里叶变换(FFT) 滑动FFT 2-d FFT算法 高基Booth编码
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Simulation of dilatancy-controlled gas migration processes in saturated bentonite using a coupled multiphase flow and elastoplastic H2 M model
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作者 Eike Radeisen Hua Shao +3 位作者 Jürgen Hesser Olaf Kolditz Wenjie Xu Wenqing Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第4期803-813,共11页
Dilatancy-controlled gas flow in preferential pathways plays a key role in the safety analysis of radioactive waste repositories.This is particularly the case for bentonite,an often-preferred barrier material.Gas flow... Dilatancy-controlled gas flow in preferential pathways plays a key role in the safety analysis of radioactive waste repositories.This is particularly the case for bentonite,an often-preferred barrier material.Gas flow in preferential pathways is characterized by localization and spontaneous behavior,which is challenging to simulate in numerical models due to strong hydro-mechanical coupling.To analyze a laboratory experiment in the framework of the DECOVALEX-2023 project,this study introduced a new approach of combining continuous modelling methods with spatial material properties derived from material heterogeneities and experimental observations.The proposed model utilized hydro-mechanical spatial distributions,namely Young’s modulus and gas entry pressure,and elastoplasticity combined with a linear swelling model.A conceptual strain-dependent permeability approach simulated dilatancycontrolled gas flow based on hydro-mechanical coupling.To test the effectiveness of the presented approach,a gas injection test in a compacted,saturated bentonite sample was simulated using the opensource code OpenGeoSys 5.8 and compared with experimental observations.The presented methodology is capable of simulating localized gas flow in preferential pathways.The spatial distributions of Young’s modulus and gas entry pressure affect the swelling pressure,relative permeability and,in combination with the strain-dependent permeability model,also the intrinsic permeability. 展开更多
关键词 H^(2)M coupling Gas migration Dilatancy-controlled flow Continuous approach Geomaterial heterogeneity OPENGEOSYS
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超临界CO_(2)管输首站增压方式优选
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作者 马启钊 张瑛 +5 位作者 李淼 李林 于徽 陈廷鑫 史瑶 马宇航 《石油化工设备》 CAS 2024年第5期48-54,共7页
超临界CO_(2)管输增压方式的优选对CO_(2)捕集、利用与封存技术的经济性评价具有重要影响。以将常温、常压下输量为500万t/a的CO_(2)在首站增压至14 MPa为例,应用Aspen HYSYS软件建立了2种n+1多级增压工艺流程进行过程模拟,对比了不同... 超临界CO_(2)管输增压方式的优选对CO_(2)捕集、利用与封存技术的经济性评价具有重要影响。以将常温、常压下输量为500万t/a的CO_(2)在首站增压至14 MPa为例,应用Aspen HYSYS软件建立了2种n+1多级增压工艺流程进行过程模拟,对比了不同增压方式以及不同增压级数下的总费用现值。结果表明,取首站运行时间为30 a,基准折现率为8%,在n取值4、5、6的增压级数下,压缩机+泵组合增压工艺流程相较于压缩机多级增压工艺流程能分别降低新建首站总费用现值5.51%、5.85%和6.03%。研究结果可为超临界CO_(2)管输首站增压方式选择提供参考。 展开更多
关键词 CO_(2) 输送 超临界 增压 工艺流程 优选
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