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Dynamic modeling of cavitation bubble clusters:Effects of evaporation,condensation,and bubble-bubble interaction

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Chinese Physics B 2024年第4期33卷 527-535页

作者：许龙姚昕锐沈阳 College of Science China Jiliang UniversityHangzhou 310018China

We present a dynamic model of cavitation bubbles in a cluster,in which the effects of evaporation,condensation,and bubble-bubble interactions are taken into *** different ultrasound conditions,we examine how the dynamics of cavitation bubbles are affected by several factors,such as the locations of the bubbles,the ambient radius,and the number of *** the variations of bubble radius,energy,temperature,pressure,and the quantity of vapor molecules are *** findings reveal that bubble-bubble interactions can restrict the expansion of bubbles,reduce the exchange of energy among vapor molecules,and diminish the maximum internal temperature and pressure when *** ambient radius of bubbles can influence the intensities of their oscillations,with clusters comprised of smaller bubbles creating optimal conditions for generating high-temperature and high-pressure ***,an increase in the number of bubbles can further inhibit cavitation *** frequency,pressure and waveform of the driving wave can also exert a significant influence on cavitation activities,with rectangular waves enhancing and triangular waves weakening the cavitation of bubbles in the *** results provide a theoretical basis for understanding the dynamics of cavitation bubbles in a bubble cluster,and the factors that affect their behaviors.

关键词： bubble dynamics bubble-bubble interaction mass exchange ultrasound waveform

Advancing flood susceptibility modeling using stacking ensemble machine learning: A multi-model approach

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Journal of Geographical Sciences 2024年第8期34卷 1513-1536页

作者： YANG Huilin yao rui DONG Linyao SUN Peng ZHANG Qiang WEI Yongqiang SUN Shao AGHAKOUCHAK Amir School of Geography and Tourism Anhui Normal UniversityWuhu 241002AnhuiChina Changjiang River Scientific Research Institute Wuhan 430015China Advanced Interdisciplinary Institute of Environment and Ecology Beijing Normal UniversityZhuhai 519087GuangdongChina Hunan Institute of Water Resources and Hydropower Research Changsha 410007China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Department of Civil and Environmental Engineering University of California IrvineIrvineCA 92697USA

Flood susceptibility modeling is crucial for rapid flood forecasting, disaster reduction strategies, evacuation planning, and decision-making. Machine learning(ML) models have proven to be effective tools for assessing flood susceptibility. However, most previous studies have focused on individual models or comparative performance, underscoring the unique strengths and weaknesses of each model. In this study, we propose a stacking ensemble learning algorithm that harnesses the strengths of a diverse range of machine learning models. The findings reveal the following:(1) The stacking ensemble learning, using RF-XGBCB-LR model, significantly enhances flood susceptibility simulation.(2) In addition to rainfall,key flood drivers in the study area include NDVI, and impervious surfaces. Over 40% of the study area, primarily in the northeast and southeast, exhibits high flood susceptibility, with higher risks for populations compared to cropland.(3) In the northeast of the study area,heavy precipitation, low terrain, and NDVI values are key indicators contributing to high flood susceptibility, while long-duration precipitation, mountainous topography, and upper reach vegetation are the main drivers in the southeast. This study underscores the effectiveness of ML, particularly ensemble learning, in flood modeling. It identifies vulnerable areas and contributes to improved flood risk management.

关键词： flood susceptibility assessment machine learning stacking ensemble learning flood drivers XiangjiangRiverBasin

Amorphous NiMo_(3)S_(13)/nickel foam integrated anode for lithium-ion batteries

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Tungsten 2024年第2期6卷 438-446页

作者： Ming-Xin Shi Min Wu Shan-Shan Xiao Shan-Ping Liu rui-Qi yao Ying-Qi Li Yong-Hui Wang Yang-Guang Li Hua-Qiao Tan Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Faculty of ChemistryNortheast Normal UniversityChangchun 130024China School of Materials Science and Engineering Jilin Jianzhu UniversityChangchun 130118China Institute Charles Gerhardt Montpellier Universite de MontpellierCentre National de la Recherche Scientifi quePlace E.Bataillon34095 Montpellier Cedex 05France

Although crystalline anode materials with long-range ordered lattice structure are in favor of facilitating the electron transfer,their structures are easily disrupted during long-term cycling due to the continuous embedding/de-embedding of lithium *** contrast,the amorphous materials have abundant defects and lithium ion storage sites,refl ecting a superior reaction kinetics and long-term cycling ***,we synthesize an integrated hybrid anode by in-situ loading amorphous NiMo_(3)S_(13)nanosheets on nickel foam *** ting from the introduction of Ni^(2+)that amorphizes the molybdenumsulfur clusters,the assembled lithium ion battery based on the integrated NiMo_(3)S_(13)/nickel foam anode delivers a specifi c capacity up to 1659 mA·h·g^(−1)at a current density of 0.6 A·g^(−1)and exhibits superior rate/cycling performance.

关键词： Molybdenum-sulfur clusters Amorphous Integrated anode Crystalline Lithium-ion batteries

Testicular volume is a noninvasive predictor of sperm retrieval failure in idiopathic nonobstructive azoospermia

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Asian Journal of Andrology 2024年第4期26卷 421-425页

作者： Hong Xiao Song-Xi Tang rui-Jie yao Yi-Lang Ding Peng Yang Qiang Chen Hai-Lin Huang Xi Chen Hui-Liang Zhou Department of Andrology and Sexual Medicine First Affiliated Hospital of Fujian Medical UniversityFuzhou 350005China.

We investigated the prognostic importance of noninvasive factors in predicting sperm retrieval failure in idiopathic nonobstructive azoospermia(iNOA).We studied 193 patients with nonobstructive azoospermia who underwent microsurgical testicular sperm *** Chi-square test and Mann–Whitney U tests for clinical parameters and seminiferous tubule distribution were used for between-group comparisons.A logistic regression analysis was conducted to identify predictors of retrieval *** under the receiver operating characteristic curve for each variable was evaluated,and the net clinical benefit was calculated using a clinical decision *** with iNOA had a lower sperm retrieval rate than those with known ***,testicular volume was an independent factor affecting sperm extraction outcomes(odds ratio=0.79,P<0.05).The testicular volume cut-off value was 6.5 ml(area under the curve:0.694).The patients with iNOA were categorized into two groups on the basis of the distribution of seminiferous tubules *** sperm retrieval rate and testicular volume were significantly different between the groups with a uniform or heterogeneous tubule *** was also a significant association between a uniform tubule distribution and testicular *** conclusion,a testicular volume of more than 6.5 ml effectively predicts microsurgical testicular sperm extraction failure due to a uniform tubule distribution in patients with iNOA.

关键词： idiopathic nonobstructive azoospermia microsurgical testicular sperm extraction sperm retrieval failure testicular volume

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基于神经网络的粒子输运问题高效计算方法

物理学报 2024年第7期73卷 114-123页

作者：马锐垚王鑫李树勇珩上官丹骅北京应用物理与计算数学研究所北京100094 中物院高性能数值模拟软件中心北京100088

蒙特卡罗方法是求解粒子输运问题的有力工具之一,其局限性在于为达到精度要求需模拟大量粒子,计算耗时长,这阻碍了该方法的进一步应用,尤其在需快速响应的情形.本文结合神经网络和若干蒙特卡罗方法基本原理发展了一种计算方法,能够实现... 详细信息

蒙特卡罗方法是求解粒子输运问题的有力工具之一,其局限性在于为达到精度要求需模拟大量粒子,计算耗时长,这阻碍了该方法的进一步应用,尤其在需快速响应的情形.本文结合神经网络和若干蒙特卡罗方法基本原理发展了一种计算方法,能够实现源分布可变,几何、材料和目标计数不变的中子输运问题的快速准确求解.首先,为高效生成用于神经网络训练的数据,利用重要性原理实现在同样模拟次数基础上有效扩充训练数据集容量,在一定程度上克服了使用蒙特卡罗计算获取训练数据耗时长的缺点.进而,基于目标计数是源分布与重要性函数乘积积分的事实,设计了利用神经网络实现快速输运计算的策略.该网络的输入是中子源项,输出是目标计数,在几何、材料和目标计数固定的情况下,该神经网络可重复使用,根据新的源项快速准确得到目标计数.本文所提出方法的原理和框架同样适用于其他种类粒子的同类型输运问题.基于若干基准模型的验证表明,训练得到的神经网络能在不到1 s的时间内得到目标计数,且与蒙特卡罗大样本模拟得到基准结果的平均相对偏差均低于5%.

关键词：蒙特卡罗方法神经网络粒子输运重要性原理

某化工厂项目配套罐区SIS系统改造实践研究

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山西化工 2024年第2期44卷 134-137页

作者：姚瑞国家能源集团煤制油化工有限公司鄂尔多斯煤制油分公司内蒙古鄂尔多斯017209

针对化工厂自建罐区并没有专门安全仪表系统,全部依靠DCS系统实现连锁及保护的问题,从自控水平到罐区安全要求等与现有要求相差甚远的现状,对存在安全缺陷的储罐逐步改造为液位仪表联锁及阀门快速切断控制系统。本次改造实现油品罐区内... 详细信息

针对化工厂自建罐区并没有专门安全仪表系统,全部依靠DCS系统实现连锁及保护的问题,从自控水平到罐区安全要求等与现有要求相差甚远的现状,对存在安全缺陷的储罐逐步改造为液位仪表联锁及阀门快速切断控制系统。本次改造实现油品罐区内一二级重大危险源能按照有关规范设置独立SIS系统,建立安全屏障,保障安全生产。

关键词：安全仪表系统分散控制系统储罐

“超星学习通”在公共选修课《民间文学》中的应用

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办公自动化 2024年第14期29卷 48-50页

作者：姚锐山东华宇工学院德州253034

随着信息化时代的快速发展,教育教学模式也发生翻天覆地的变化,“互联网+教育”得到越来越广泛的应用,超星学习通在远程教学中的应用效果较好,体现翻转课堂教学的价值。文章通过阐述“超星学习通”在公共选修课《民间文学》中的应用,发... 详细信息

随着信息化时代的快速发展,教育教学模式也发生翻天覆地的变化,“互联网+教育”得到越来越广泛的应用,超星学习通在远程教学中的应用效果较好,体现翻转课堂教学的价值。文章通过阐述“超星学习通”在公共选修课《民间文学》中的应用,发现其中的问题,并提出一些切实可行的方案,为同类课程的建设提供一些经验。

关键词：超星学习通公共选修课线上教学

基于稀疏表示剪枝集成建模的烧结终点位置智能预测

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控制理论与应用 2024年第3期41卷 436-446页

作者：周平吴忠卫张瑞垚吴永建东北大学流程工业综合自动化国家重点实验室辽宁沈阳110819 中国矿业大学煤炭加工与高效洁净利用教育部重点实验室江苏徐州221116

烧结终点位置(BTP)是烧结过程至关重要的参数,直接决定着最终烧结矿的质量.由于BTP难以直接在线检测,因此,通过智能学习建模来实现BTP的在线预测并在此基础上进行操作参数调节对提高烧结矿质量具有重要意义.针对这一实际工程问题,首先... 详细信息

烧结终点位置(BTP)是烧结过程至关重要的参数,直接决定着最终烧结矿的质量.由于BTP难以直接在线检测,因此,通过智能学习建模来实现BTP的在线预测并在此基础上进行操作参数调节对提高烧结矿质量具有重要意义.针对这一实际工程问题,首先提出一种基于遗传优化的Wrapper特征选择方法,可选取使后续预测建模性能最优的特征组合;在此基础上,为了解决单一学习器容易过拟合的问题,提出了基于随机权神经网络(RVFLNs)的稀疏表示剪枝(SRP)集成建模算法,即SRP-ERVFLNs算法.所提算法采用建模速度快、泛化性能好的RVFLNs作为个体基学习器,采用对基学习器基函数与隐层节点数等参数进行扰动的方式来增加集成学习子模型间的差异性;同时,为了进一步提高集成模型的泛化性能与计算效率,引入稀疏表示剪枝算法,实现对集成模型的高效剪枝;最后,将所提算法用于烧结过程BTP的预测建模.工业数据实验表明,所提方法相比于其他方法具有更好的预测精度、泛化性能和计算效率.

关键词：智能预测特征选择集成学习稀疏表示剪枝烧结终点位置随机权神经网络(RVFLNs)

燕麦sHSP基因家族的鉴定及其响应高温及老化的表达分析

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草业学报 2024年第8期33卷 145-158页

作者：马圆刘欢赵桂琴王敬龙张然姚瑞瑞甘肃农业大学草业学院草业生态系统教育部重点实验室甘肃兰州730070 西藏自治区农牧科学院草业科学研究所西藏拉萨850000 中国林业科学研究院生态保护与修复研究所国家林业和草原局草原研究中心北京100091

小热激蛋白(sHSPs)是植物体中普遍存在的由核基因编码的一类蛋白,具有保守的ACD结构域,能够在高温、干旱以及老化等胁迫刺激中发挥重要作用。本研究利用生物信息学方法在燕麦基因组中鉴定得到24个HSP20(AsHSP20.1~AsHSP20.24)基因,并对A... 详细信息

小热激蛋白(sHSPs)是植物体中普遍存在的由核基因编码的一类蛋白,具有保守的ACD结构域,能够在高温、干旱以及老化等胁迫刺激中发挥重要作用。本研究利用生物信息学方法在燕麦基因组中鉴定得到24个HSP20(AsHSP20.1~AsHSP20.24)基因,并对AsHSP20家族成员的理化性质、蛋白结构、亚细胞定位、系统进化、保守基序和保守结构域、基因染色体位置以及响应高温及老化基因的表达等进行系统分析。研究发现AsHSP20基因分布在17条染色体上。编码氨基酸数目136~529 aa,分子量大小14.9~58.1 kDa,理论等电点5.30~8.79。HSP20成员多定位在核、胞质和叶绿体上,部分定位在质膜、线粒体、过氧化物酶体以及胞外。蛋白质二级结构和三级结构分析表明AsHSP20成员确定有β-折叠结构。根据保守基序组成与系统发育关系分析,AsHSP20基因家族被分为11个亚组,同一亚组成员之间具有相似或相同的保守基序,表明这些蛋白之间具有功能的相似性。进一步分析自然老化和人工老化处理下AsHSP20基因的表达情况,结果表明AsHSP20.20、AsHSP20.24基因在自然老化处理与人工老化处理下共同下调表达,推测AsHSP20.20和AsHSP20.24在两种老化方法下共同参与调控燕麦种子活力降低的过程,可作为燕麦种子寿命及抗老化种质育种研究的候选基因。研究为AsHSP20基因家族在燕麦种质老化过程中的调控机制提供了有价值的信息,也为进一步探究燕麦HSP20基因的功能及种子抗衰老分子机制提供了理论支撑。

关键词：燕麦种子老化 HSP20基因家族系统进化表达分析

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