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Micro-flow structure at regime transition from bubbling to turbulent fluidization in a fluidized bed

Particuology 2024年第6期89卷 117-130页

作者： Chaoyu Yan Yue Yuan xiaoyang wei Jesse Zhu State Key Laboratory of Heavy Oil Processing Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of PetroleumBeijing 102249China China Beacons Institute The University of NottinghamNingbo315100China Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioN6A 5B9Canada

Gas-solid fluidized beds have found extensive utilization in frontline manufacturing,in particular as low-velocity *** fluidization status,the bubbling or turbulent flow regime and the transition in between,determine the system performance in practical *** the convoluted hydrodynamics are quantitively evaluated through numerous data-processing methodologies,none of them alone can reflect all the critical information to identify the transition from the bubbling to the turbulent ***,this study was to exploit a coupling data processing methodology,in the combination of standard deviation,power spectrum density,probability density function,wavelet transform,and wavelet multiresolution method,to jointly explain the micro-flow structure at the regime transition from bubbling to turbulent *** transient differential pressure fluctuation was measured for the evaluation in a fluidized bed(0.267 m i.d.×2.5 m height)with FCC catalysts(d_(p)=65μm,ρ_(p)=1780kg/m^(3))at different superficial gas velocities(0.02–1.4 m/s).The results show that the onset of turbulent fluidization starts earlier in the top section of the bed than in the bottom *** wavelet decomposition displays that the fluctuation of differential pressure mainly concentrates on the sub-signals with an intermediate frequency *** sub-signals could be synthesized into three types of scales(micro-scale,meso-scale,and macro-scale),representing the multi-scale hydrodynamics in the fluidized *** micro-scale signal has the characteristic information of bubbling fluidization,and the characteristic information of turbulent fluidization is mainly represented by the meso-scale *** work provides a systematic comprehension of fluidization status assessment and serves as an impetus for more coupling analysis in this sector.

关键词： Flow regime transition Bubbling fluidization Turbulent fluidization Micro-flow structure Differential pressure fluctuation

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A novel interpretable multilevel wavelet decomposition deep network for actual heartbeat classification

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Science China(Technological Sciences) 2024年第6期67卷 1842-1854页

作者： JIN YanRui LI ZhiYuan TIAN YuanYuan wei xiaoyang LIU ChengLiang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240China

Arrhythmias may lead to sudden cardiac death if not detected and treated in time.A supraventricular premature beat(SPB)and premature ventricular contraction(PVC)are important categories of arrhythmia ***,deep learning methods have been applied to the PVC/SPB heartbeats ***,most researchers have focused on time-domain information of the electrocardiogram and there has been a lack of exploration of the interpretability of the *** this study,we design an interpretable and accurate PVC/SPB recognition algorithm,called the interpretable multilevel wavelet decomposition deep network(IMWDDN).Wavelet decomposition is introduced into the deep network and the squeeze and excitation(SE)-Residual block is designed for extracting time-domain and frequency-domain ***,inspired by the idea of residual learning,we construct a novel loss function for the constant updating of the multilevel wavelet decomposition ***,the IMWDDN is evaluated on the Third China Physiological Signal Challenge Dataset and the MIT-BIH Arrhythmia *** comparison results show IMWDDN has better detection performance with 98.51%accuracy and a 93.75%F1-macro on average,and its areas of concern are similar to those of an expert diagnosis to a certain ***,the IMWDDN has good application value in the clinical screening of PVC/SPB heartbeats.

关键词： actual heartbeat classification electrocardiogram interpretable deep network multilevel discrete wavelet decomposition layer SE-Residual block

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Towards optimal recovery scheduling for dynamic resilience of networked infrastructure

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Journal of Systems Engineering and Electronics 2018年第5期29卷 995-1008页

作者： WANG Yang FU Shanshan WU Bing HUANG Jinhui wei xiaoyang Intelligent Transportation System Research Center Wuhan University of Technology College of Ocean Science and Engineering Shanghai Maritime University Department of Civil and Environmental Engineering National University of Singapore

Prior research on the resilience of critical infrastructure usually utilizes the network model to characterize the structure of the components so that a quantitative representation of resilience can be obtained. Particularly, network component importance is addressed to express its significance in shaping the resilience performance of the whole system. Due to the intrinsic complexity of the problem, some idealized assumptions are exerted on the resilience-optimization problem to find partial solutions. This paper seeks to exploit the dynamic aspect of system resilience, i.e., the scheduling problem of link recovery in the post-disruption *** aim is to analyze the recovery strategy of the system with more practical assumptions, especially inhomogeneous time cost among links. In view of this, the presented work translates the resilience-maximization recovery plan into the dynamic decisionmaking of runtime recovery option. A heuristic scheme is devised to treat the core problem of link selection in an ongoing *** Monte Carlo simulation, the link recovery order rendered by the proposed scheme demonstrates excellent resilience performance as well as accommodation with uncertainty caused by epistemic knowledge.

关键词： dynamic resilience network model component importance recovery scheduling epistemic uncertainty

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Sustainable nitrogen fixation by bubble discharge plasma:Performance optimization and mechanism

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Journal of Energy Chemistry 2024年第11期98卷 692-701页

作者： Yuankun Ye xiaoyang wei Li Zhang Sen Wang Zhi Fang College of Electrical Engineering and Control Science Nanjing Tech UniversityNanjing 211816JiangsuChina

Sustainable nitrogen fixation driven by renewable energy sources under mild conditions has been widely sought to replace the industrial Haber-Bosch *** fixation of nitrogen in the form of NO_(x)^(-)and NH_4^(+)into aqueous solutions using electricity-driven gas-liquid discharge plasma is considered a promising *** this paper,a scalable bubble discharge excited by nanosecond pulse power is employed for nitrogen fixation in the liquid *** nitrogen fixation performance and the mechanisms are analyzed by varying the power supply parameters,working gas flow rate and *** results show that an increase in voltage and frequency can result in an enhanced NO_(3)^(-)*** in the gas flow rate can result in inadequate activation of the working gas,which together with more inefficient mass transfer efficiencies can reduce the *** addition of O_(2) effectively elevates NO_(3)^(-)production while simultaneously inhibiting NH_4^(+) *** addition of H_(2)O vapor increases the production of OH and H,thereby promoting the generation of reactive nitrogen and enhancing the yield of nitrogen ***,the excessive addition of O_(2) and H_(2)O vapor results in negative effect on the yield of nitrogen fixation,due to the significant weakening of the discharge *** optimal nitrogen fixation yield was up to 16.5 μmol/min,while the optimal energy consumption was approximately 21.3 MJ/mol in this ***,the mechanism related to nitrogen fixation is discussed through the optical emission spectral(OES) information in conjunction with the simulation of energy loss paths in the plasma by BOLSIG+.The work advances knowledge of the effect of parameter variations on nitrogen fixation by gas-liquid discharge for higher yield and energy production.

关键词： Nitrogen fixation Gas-liquid discharge plasma Bubble discharge Mechanism

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Contrast-enhanced ultrasonographic imaging diagnosis on assessment of vascularity in liver metastatic lesions

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World Journal of Gastroenterology 2005年第23期11卷 3610-3613页

作者： Wen-HuaDu wei-xiaoyang Xiu-QinXiong XiangWang YiZhou HuiWang DepartmentofUltrasonograpfiy DapingHospitalandResearchInstituteofSurgerytheThirdMilitaryMedicalUniversityChongqing400042China

AIM: To investigate the vasculature of rabbit liver metastatic lesions by color Doppler imaging and power Doppler imaging (PDI) ***: Eight New Zealand rabbits with implanted VX2 liver tumors were used. All ultrasound examinations were performed with a HP 5500 color Doppler ultrasound scanner. Before and after the injection of contrast agent, the changes of gray scale and the periphery and intralesional blood flow of the liver metastatic lesion were carefully observed by B mode ultrasound, color Doppler flow imaging (CDFI)and ***: Twelve lesions were found in the eight rabbits with implanted VX2 liver tumors, whose diameter rangedfrom 1.6 to 4.8 cm. Echoes of these lesions were not characterized and has lack of specificity. After the injectionof contrast agent, the numbers of dot or strip-like flow messages increased both at the periphery and inside of these lesions under the mode of CDFI and PDI, and were more pronounced under PDI. Morphology of intralesional vessels extended, even branched and some signals were clearly found encircling the lesion. And some vessels were found penetrating into the center of the ***: PDI after injection of self-made echo contrast agent can show a pronounced sensitivity than that of B mode ultrasound and CDFI in diagnosis of vascularity of a metastatic lesion.

关键词： Doppter imaging Vasculature Color Doppler imaging

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Freestanding macroscopic metal-oxide nanotube films derived from carbon nanotube film templates

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Nano Research 2015年第6期8卷 2024-2032页

作者： He Ma Yang wei Jiangtao Wang xiaoyang Lin WenyunWu Yang Wu Ling Zhang Peng Liu Jiaping Wang Qunqing Li Shoushan Fan Kaili Jiang State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics & Tsinghua-Foxconn Nanotechnology Research Center Tsinghua University Beijing 100084 China

Aligned carbon nanotube films coated with amorphous carbon were developed into novel templates by atomic layer deposition. Freestanding macroscopic metal-oxide nanotube films were then successfully synthesized by using these templates. The reactive amorphous carbon layer greatly improved the nuclei density, which ensured the high quality of the films and allowed for precise control of the wall thickness of the nanotubes. Using template-synthesized alumina nanotube films, we demonstrate a humidity sensor with a high response speed, a transmission electron microscopy （TEM） grid, and a catalyst support. The cross- stacked assembly, ultrathin thickness, chemical inertness, and high thermal stability of the alumina nanotube films contributed to the excellent performance of these devices. In addition, it is expected that the metal-oxide nanotube films would have significant potential owing to their material richness, macroscopic appearance, flexibility, compatibility with the semiconducting technologies, and the feasibility of mass production.

关键词： metal-oxide nanotube film atomic layer deposition carbon nanotube humidity sensor catalyst support

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Synthesis of Fe3O4 Nanoparticles and their Magnetic Properties

Synthesis of Fe3O4 Nanoparticles and their Magnetic Properti...

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2011中国材料研讨会

作者： Yan wei,Bing Han,xiaoyang Hu

＜正＞Fe3O4 magnetic nanoparticles （MNPs） were synthesized by a co-precipitation method using odiumcitrate and oleic acid as *** composition and microstructure analysis indicate that the sodium citrate

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日本文化法治及其对中国的启示

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北京大学学报（哲学社会科学版） 2017年第1期54卷 142-149页

作者：魏晓阳中国传媒大学文化研究院北京100024

当代日本文化法治最早可以追溯到明治维新时期。随着西方法律的移植,当代意义的"文化"以及"法治"的概念进入日本,日本从此开始了文化行政的有限建构。第二次世界大战至今,文化权在日本上升为宪法所保护的基本权利,日本也由此发展了比较... 详细信息

当代日本文化法治最早可以追溯到明治维新时期。随着西方法律的移植,当代意义的"文化"以及"法治"的概念进入日本,日本从此开始了文化行政的有限建构。第二次世界大战至今,文化权在日本上升为宪法所保护的基本权利,日本也由此发展了比较成熟和完备的文化法治体系。与日本相似,中国的文化法治也起始于19世纪末,但是中国比日本经历了更多的历史曲折。时至今日,中国文化法治体系当前在立法、行政、司法等不同层次都存在一定的问题,不仅文化立法体制尚有待完善,而且文化领域政策法治化及依法行政尚需健全。要实现文化法治,中国必须同时完善文化领域的立法、行政与司法体制,让宪法保障的公民权利真正落到实处。

关键词：日本文化法治文化产业

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基于时间效用模型的大型展会游客时空行为模式——以2014青岛世园会为例

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旅游学刊 2019年第1期34卷 73-81页

作者：朱玮魏晓阳同济大学建筑与城市规划学院城市规划系

游客的时空活动路径因其高度异质性一直以来是研究其模式和规律的难点。该研究提出一个归纳游客时空行为模式的方法,挖掘形成这些模式背后的机理。文章以2014年青岛世界园艺博览会为例,基于问卷调查得到624位游客的参观行为数据,建构基... 详细信息

游客的时空活动路径因其高度异质性一直以来是研究其模式和规律的难点。该研究提出一个归纳游客时空行为模式的方法,挖掘形成这些模式背后的机理。文章以2014年青岛世界园艺博览会为例,基于问卷调查得到624位游客的参观行为数据,建构基于相对时空位置对准的路径相似度算法,采用吸引子传播算法对参观路径进行聚类,归纳出5种路径模式;构建展馆选择的时间效用模型来对不同路径模式进行解释,发现几种模式对应的模型系数差异明显,验证了模型的有效性。用时间效用模型对游客路径进行聚类,归纳得出6类具有明显差异的参观行为偏好模式。偏好差异是决定游客参观时空路径模式的内在因素,通过时间效用模型可以得到游客时空行为的更一般规律。此方法具有进一步应用于解释其他情景下个人时空行为的潜力。

关键词：游客时空行为路径模式偏好模式时间效用模型青岛世园会

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宪政文化与制度建构刍议

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华东政法大学学报 2008年第5期11卷 12-21页

作者：魏晓阳中国传媒大学

宪政制度的建构和文化转变之间存在着复杂关系。在一个变动的社会中,制度通常先于文化而发生变化,但如果文化不能及时发生相应的变化,那么新制度就不能确立下来,而最终将在旧势力的围剿下销声匿迹。新制度的引入也可能破坏传统社会的道... 详细信息

宪政制度的建构和文化转变之间存在着复杂关系。在一个变动的社会中,制度通常先于文化而发生变化,但如果文化不能及时发生相应的变化,那么新制度就不能确立下来,而最终将在旧势力的围剿下销声匿迹。新制度的引入也可能破坏传统社会的道德文化资源,在新文化建立不起来的情况下产生社会失序,或最终建立一个比旧秩序更糟糕的制度。因此,宪政制度的改革者必须重视文化的革新,塑造与新制度相适应的宪政文化。

关键词：宪政文化制度建构

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