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高焓湍流边界层直接数值模拟与湍流模型改进研究

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空天技术 2024年第2期2024卷 89-98页

作者：左政玄赵瑞樊宇翔北京理工大学北京理工大学重庆创新中心

随着高超声速飞行器速度的进一步提高，高温化学反应与湍流耦合问题将愈加突出。分别对高焓和低焓流动条件下的平板湍流边界层进行了直接数值模拟（Direct Numerical Simulation,DNS），并将湍流平均量、湍动能生成项、湍流摩擦阻力系... 详细信息

随着高超声速飞行器速度的进一步提高，高温化学反应与湍流耦合问题将愈加突出。分别对高焓和低焓流动条件下的平板湍流边界层进行了直接数值模拟（Direct Numerical Simulation,DNS），并将湍流平均量、湍动能生成项、湍流摩擦阻力系数等物理量与SST湍流模型进行了对比分析。初步研究表明，在低焓来流条件下，SST模型与DNS的计算结果较为吻合，而在高焓条件下，受到化学反应的影响，SST湍流模型预测的湍动能、湍流黏性系数、湍流摩阻系数均高于DNS计算结果。因此，修正了针对高焓流动条件下的SST湍流模型，在k方程湍动能生成项中加入温度限制器，改进后结果与DNS计算结果值吻合较好。

关键词：高焓流动湍流边界层化学非平衡直接数值模拟湍流模型

复方丹参滴丸联合美托洛尔治疗慢性心力衰竭合并阵发性房颤患者的效果

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中国民康医学 2024年第11期36卷 88-91页

作者：范玉香昆山市第二人民医院药学部江苏苏州215000

目的:观察复方丹参滴丸联合美托洛尔治疗慢性心力衰竭(CHF)合并阵发性房颤(PAF)患者的效果。方法:回顾性分析2021年1月至2023年3月该院收治的150例CHF合并PAF患者的临床资料,按照治疗方法不同将其分为研究组与对照组各75例。对照组口服... 详细信息

目的:观察复方丹参滴丸联合美托洛尔治疗慢性心力衰竭(CHF)合并阵发性房颤(PAF)患者的效果。方法:回顾性分析2021年1月至2023年3月该院收治的150例CHF合并PAF患者的临床资料,按照治疗方法不同将其分为研究组与对照组各75例。对照组口服琥珀酸美托洛尔缓释片治疗,研究组在对照组基础上口服复方丹参滴丸治疗。比较两组临床疗效,治疗前后临床症状(心率、房颤发作次数和房颤发作持续时间)、心肌损伤标志物[肌酸激酶同工酶(CK-MB)、生长分化因子15(GDF-15)、N末端脑钠肽前体(NT-proBNP)]水平、血管内皮功能指标[内皮素-1(ET-1)、同型半胱氨酸(Hcy)]水平,以及不良反应发生率。结果:研究组治疗总有效率为92.00%(69/75),高于对照组的80.00%(60/75),差异有统计学意义(P0.05)。结论:复方丹参滴丸联合美托洛尔治疗CHF合并PAF患者效果显著,可减轻房颤症状,降低心率,减轻心肌损伤,保护血管内皮功能,效果优于单用美托洛尔治疗。

关键词：复方丹参滴丸美托洛尔慢性心力衰竭阵发性房颤心肌损伤血管内皮功能

Implantable Electrochemical Microsensors for In Vivo Monitoring of Animal Physiological Information

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Nano-Micro Letters 2024年第3期16卷 183-211页

作者： Jin Zhou Shenghan Zhou Peidi fan Xunjia Li Yibin Ying Jianfeng Ping yuxiang Pan Laboratory of Agricultural Information Intelligent Sensing College of Biosystems Engineering and Food ScienceZhejiang UniversityHangzhou 310058People’s Republic of China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311200People’s Republic of China

In vivo monitoring of animal physiological information plays a crucial role in promptly alerting humans to potential diseases in animals and aiding in the exploration of mechanisms underlying human ***,implantable electrochemical microsensors have emerged as a prominent area of *** microsensors not only fulfill the technical requirements for monitoring animal physiological information but also offer an ideal platform for *** have been extensively studied for their ability to monitor animal physiological information in a minimally invasive manner,characterized by their bloodless,painless features,and exceptional *** development of implantable electrochemical microsensors for in vivo monitoring of animal physiological information has witnessed significant scientific and technological advancements through dedicated *** review commenced with a comprehensive discussion of the construction of microsensors,including the materials utilized and the methods employed for *** this,we proceeded to explore the various implantation technologies employed for electrochemical *** addition,a comprehensive overview was provided of the various applications of implantable electrochemical microsensors,specifically in the monitoring of diseases and the investigation of disease ***,a concise conclusion was conducted on the recent advancements and significant obstacles pertaining to the practical implementation of implantable electrochemical microsensors.

关键词： Electrochemical microsensors Implantable sensors In vivo monitoring Animal physiological information

Enhanced mechanical property by introducing bimodal grains structures in Cu-Ta alloys fabricated by mechanical alloying

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Journal of Materials Science & Technology 2024年第5期172卷 104-112页

作者： Ningyu Li Yongqin Chang Mingyang Li yuxiang Chen Xinrui Luo Shichao Pei fan Yang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Xi’an Rare Metal Materials Institute Co.Ltd Xi’an 710016China

Dispersion-strengthened copper alloys can achieve ultra-high strength,but usually at the expense of *** this study,a strategy for overcoming strength-ductility tradeoffof Cu alloys is realized through the introduction of bimodal grains ***-Ta alloys with only 0.5 at.%Ta content were successfully prepared by mechanical alloying combined with spark plasm *** samples prepared by one-step and two-step ball milling methods are named as Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ),*** microstructural characterizations revealed that ultra-fine equiaxed grains with uniformly dispersed Ta precipitates were obtained in the Cu-Ta *** strength of 377 MPa for yield strength together with elongation of∼8%was obtained in Cu-Ta(Ⅰ).Bimodal grains structures composed of fine-grain zones and coarse-grain zones were successfully introduced into Cu-Ta(Ⅱ)by a two-step ball milling approach,and both yield strength(463 MPa)and elongation(∼15%)were significantly synergistic *** hardness values of both Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ)were almost kept nearly constant with the increase of annealing time,and the softening temperatures of Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ)are 1018 and 1013℃,reaching 93.9%and 93.5%T m of pure Cu(1083℃),*** reveals that the Cu-0.5 at.%Ta alloys exhibit excellent thermal stability and exceptional softening *** nanoclusters with semi-coherent structures play an essential role in enhancing the strength and microstructural stability of *** structures are beneficial to the activation of back stress strengthening and the initiation and propagation of microcracks,thus obtaining the extraordinary combination of strength and *** study provides a new way to fabricate dispersion-strengthened Cu alloys with high strength,high elongation,excellent thermal stability and softening resistance,which have potential application value in the field of the future fusion reactor.

关键词： Cu-Ta alloy Mechanical alloying Ta precipitates Bimodal structures Mechanical property

西双版纳热带森林土壤有机碳积累-分配动态对蚂蚁筑巢活动的响应

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生态环境学报 2024年第1期33卷 35-44页

作者：王郑钧王邵军肖博解玲玲郭志鹏张昆凤张路路樊宇翔郭晓飞罗双夏佳慧李瑞杨胜秋兰梦杰西南林业大学生态与环境学院云南昆明650224

蚂蚁筑巢能够通过影响土壤微生物及理化环境而直接或间接调控土壤有机碳各组分积累及分配动态。以西双版纳崖豆藤热带森林群落为研究样地,测定蚁巢和非巢地土壤碳库组分(总有机碳、易氧化有机碳、微生物生物量碳)含量及分配(易氧化有机... 详细信息

蚂蚁筑巢能够通过影响土壤微生物及理化环境而直接或间接调控土壤有机碳各组分积累及分配动态。以西双版纳崖豆藤热带森林群落为研究样地,测定蚁巢和非巢地土壤碳库组分(总有机碳、易氧化有机碳、微生物生物量碳)含量及分配(易氧化有机碳/总有机碳、微生物生物量碳/总有机碳)的时空动态,分析蚂蚁筑巢引起热带森林土壤性质改变对有机碳组分积累与分配的影响特征。结果表明,1)蚂蚁筑巢显著促进土壤总有机碳及各组分含量的积累(P<0.01)。相较于非巢地,蚁巢土壤总有机碳、微生物生物量碳、易氧化有机碳含量分别提高了19.7%、35.4%和153.3%。2)蚂蚁筑巢显著影响土壤碳库各组分含量的时空变化(P<0.050)。其中,相较于非蚁巢,蚁巢土壤总有机碳、易氧化有机碳、微生物生物量碳含量季节变化的增幅分别为11.4%-30.1%、13.6%-72.3%、53.4%-212.2%;蚁巢土壤总有机碳、微生物生物量碳、易氧化有机碳含量沿土层降幅(43.1%-422.4%)显著高于非蚁巢(38.1%-111.4%)。3)蚁巢土壤微生物生物量碳(15.2%)和易氧化有机碳(36.9%)在总有机碳中分配均值均显著高于非巢地(7.5%-31.6%),蚁巢土壤微生物生物量碳分配沿土层降幅(63.1%)小于非蚁巢(75.2%),易氧化有机碳分配(277.2%)则大于非蚁巢(53.4%)。4)主成分分析表明,温湿度、pH、氨氮是调控蚁巢土壤有机碳组分积累的主要协同因子,温度和容重是蚁巢土壤有机碳组分分配的主控因子。蚂蚁筑巢主要通过改变土壤物理环境(微气候、酸碱性、通气性)和土壤氮库(铵氮)的状况,进而对土壤有机碳组分积累及组分分配产生重要影响。

关键词：蚂蚁筑巢活性碳组分碳积累碳分配西双版纳热带森林

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Journal of Systems Science and Information 2018年第2期9卷 134-151页

作者： Xiaoyu ZHU yuxiang fan Junguang GAO School of Economics and Management Beihang University Beijing International Science and Technology Cooperation Base for City Safety Operation and Emergency Support Business School Beijing Technology and Business University

As the pace of urbanization is accelerating, increasing amount of floodplain has been projected as the future cities. Subsequently, urban flooding is being studied by global emergency management exports due to its increasingly significant impact on us. Some existing research on flooding emergency management based on the case-based reasoning(CBR) method have made tremendous progress, but the urban flooding case with its stratified data characteristics is required a new methodology which is different from the ones applied to flash floods. So, based on the case-based reasoning(CBR) method, this paper proposed a CPIE-CBR model with four layers, classification filtration, punctiform similarity, interval similarity and entropy weight method, to calculate the case similarity among the urban flooding case with stratified data characteristics. Then we carry out the numerical simulation with the real data about China and conduct some comparison with original ways so that we observe the validity and efficiency of our model in the end.

关键词： urban flooding CBR case similarity emergency management

数据要素新动能对制造业高质量发展的影响研究

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统计与信息论坛 2023年第8期38卷 55-66页

作者：田时中许玉久范宇翔安徽大学经济学院安徽合肥230601 中国科学技术大学马克思主义学院安徽合肥230026 合肥学院经济与管理学院安徽合肥230601

研究数据要素新动能对制造业高质量发展的影响效应及作用机理,对于突破传统动力弱化所导致的发展约束,推进经济社会高质量发展具有重要现实意义。基于制造业高质量发展的“驱动力—压力—状态—影响—响应”(DPSIR)评价指标体系,对2008... 详细信息

研究数据要素新动能对制造业高质量发展的影响效应及作用机理,对于突破传统动力弱化所导致的发展约束,推进经济社会高质量发展具有重要现实意义。基于制造业高质量发展的“驱动力—压力—状态—影响—响应”(DPSIR)评价指标体系,对2008—2019年中国31个省份的制造业高质量发展指数进行熵值处理,运用面板Tobit模型,检验数据要素新动能对制造业高质量发展的影响效应。结果显示:中国制造业高质量发展指数呈现“稳步提升”的发展趋势,子系统差异显著;制造业高质量发展指数呈现“东部地区>西部地区>中部地区”的分布格局,东部地区领先优势较为明显,地区差异呈现“先升后降”的演变趋势。数据要素对中国制造业高质量发展具有显著的促进作用,但区域异质性特征明显,西部地区数据要素新动能对制造业高质量发展具有显著的促进作用,而东部地区和中部地区的影响不显著。全国视角下的财政投入、城镇化发展、外商投资、电力消耗对制造业高质量发展具有正向作用,而工业化水平、技术市场规模、地区开放和科技改进的作用相反。分地区视角下,城镇化水平和电力消耗对东部、中部及西部地区的制造业高质量发展均有正向作用,工业化水平则对三大地区的制造业高质量发展均存在抑制效应,技术市场规模、企业信息化、外商投资、地区开放和科技改进对三大地区的影响皆不相同。最后,从数据要素的权属界定、要素流动、高效利用和安全保护等方面,围绕深化数据要素新动能对制造业高质量发展的促进效应提出相关政策建议。

关键词：数据资源数字经济经济新动能数据生产要素制造业

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火箭整流罩脉动压力环境数值模拟与优化设计

空气动力学学报 2022年第6期40卷 29-37页

作者：樊宇翔于洋席柯赵瑞任方北京理工大学宇航学院北京100081 北京强度环境研究所可靠性与环境工程技术重点实验室北京100076 中国兵器工业导航与控制技术研究所北京100089

采用雷诺平均N-S方程(RANS)求解流场与非线性噪声方程(NLAS)求解声场相结合的方法(RANS/NLAS),对跨声速条件下火箭整流罩外部的脉动压力环境进行数值模拟与气动外形优化设计研究。通过与国内外文献及风洞试验结果对比发现,使用NLAS方法... 详细信息

采用雷诺平均N-S方程(RANS)求解流场与非线性噪声方程(NLAS)求解声场相结合的方法(RANS/NLAS),对跨声速条件下火箭整流罩外部的脉动压力环境进行数值模拟与气动外形优化设计研究。通过与国内外文献及风洞试验结果对比发现,使用NLAS方法能够利用较少的网格量准确模拟脉动压力的传播历程。同时,结果表明:跨声速流动中,在火箭整流罩的头锥肩部会出现激波/边界层干扰,而在后部倒锥部位会产生大分离区,因此在肩部和倒锥区域脉动压力环境最为恶劣;随着迎角的增加,背风面头锥肩部的脉动压力环境更加恶劣,倒锥区域减缓。为抑制倒锥区域的脉动压力,新设计了直线外形、正弦曲线外形、“切线弧+圆弧”外形三种倒锥轮廓线方案,对比分析了不同方案的倒锥区域时均摩擦力系数、分离区、均方根脉动压力系数,得出了“切线弧+圆弧”外形最有利于优化其脉动压力环境的结论。

关键词：脉动压力环境非线性声学求解器优化设计火箭整流罩计算流体力学

Theoretical Predictions on Superconducting Phase above Room Temperature in Lutetium-Beryllium Hydrides at High Pressures

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Chinese Physics Letters 2023年第9期40卷 82-86页

作者：李斌杨业迁范雨香朱聪刘胜利施智祥 School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Electronic and Optical Engineering Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Physics Southeast UniversityNanjing 211189China

High-pressure structural search was performed on the hydrogen-rich compound LuBeH8at pressures up to 200 *** found an Fm3m structure that exhibits stability and superconductivity above 100 *** phonon dispersion,electronic band structure,and superconductivity analyses in the 100–200 GPa pressure range reveal a strong electron–phonon coupling in Lu Be H8,while the superconducting critical temperature Tcshows a decreasing trend as the pressure increases,with T_(c)=255 K at 200 GPa and maximal T_(c)=355 K at 100 *** study demonstrated the room-temperature superconductivity in Fm3m thus enriching the family of ternary *** findings provide valuable guidance for identifying new high-temperature superconducting hydrides.

关键词： superconductivity structure Phase