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Examination of two-phase behaviors in porous media during pool boiling

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Science China(Technological Sciences) 2024年第6期67卷 1695-1713页

作者： zhang zhihao GUAN ShuYa WU Rui ZHAO ChangYing School of Mechanical Engineering Shanghai Jiao Tong University

The enhancement of pool boiling heat transfer using porous media has been extensively *** the two-phase distribution and evolution in porous media are crucial to the heat transfer performance,including the critical heat flux(CHF)and heat transfer coefficient(HTC),direct observation of the two-phase flow inside the media is limited owing to the blockage of the direct view from the porous *** this study,pool boiling visualization experiments were conducted on porous samples with different throat widths in deionized *** results showed that the HTC increased with the throat ***,the growth-contraction cycle of the vapor region and the formation and drying of the wall liquid film inside the porous media were *** vapor region,including the maximum and minimum areas in the boiling cycle,was quantitatively ***,the relationship between the minimum gas-phase area and HTC peak was identified.A one-dimensional transient model was developed considering solid skeleton heat conduction,liquid film evaporation,and vapor region growth to quantitatively study the influence of heat flux on the internal two-phase *** model successfully captured the maximum gas-phase area,duration of boiling cycles,and HTC trends at specific heat *** results of this quantitative study provide insights into the internal two-phase distribution and evolution induced by pool boiling.

关键词： porous media two-phase behaviors pool boiling

Veratrilla baillonii Franch alleviate the symptoms of diabetes in type 2 diabetic rats induced by high-fat diet and streptozotocin

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Food Science and Human Wellness 2024年第3期13卷 1378-1389页

作者： Chunlan Yan zhihao zhang Liqun Ma Xinyi Xu Muhammad Azhar Xianju Huang Jianxun Shi Jun Li College of Life Sciences South-Central Minzu UniversityWuhan 430074China College of Pharmaceutical Science South-Central Minzu UniversityWuhan 430074China Department of Biosciences COMSATS University IslamabadSahiwal 57000Pakistan Zhejiang Pharmaceutical University Ningbo 315100China Ethnopharmacology Level 3 Laboratory National Administration of Traditional Chinese MedicineSouth-Central Minzu UniversityWuhan 430074China

Our previous research studies have shown that Veratrilla baillonii Franch,a food supplement used by ethnic minorities in Southwest China,has multiple pharmacological activities,such as detoxification,antiinflammatory,antioxidant,and anti-insulin ***,the detailed signal pathways for its salutary effect on damages in multiple organs due to type 2 diabetes mellitus(T2DM)remains *** current study is to evaluate the therapeutic effects of *** on T2DM rats and to explore the underlying *** T2DM rat model was successfully established by a high-sugar and high-fat diet(HFD)combination with intraperitoneal injection of a small dose of streptozotocin(STZ,35 mg/kg).Biochemical analysis and histopatholgical examinations were conducted to evaluate the anti-diabetic potential of water extracts of ***(WVBF).The results showed that the WVBF treatment can improve hyperglycemia and insulin resistance,ameliorate the liver,kidney and pancreas injuries via decreasing inflammatory cytokines such as IL-6 and TNF-α,and oxidative *** investigation suggested that WVBF modulates the signal transductions of the IRS1/PI3K/AKT/GLUT4 and AMPK *** findings demonstrate potentials of WVBF in the treatment of T2DM and possible mechanisms for its hepatoprotective activities.

关键词： Veratrilla baillonii Franch Type 2 diabetes mellitus Liver injury Skeletal muscle GLUT4

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花在笑(十九首)

钟山 2024年第1期 125-130页

作者：张执浩武汉市文联武汉文学院湖北省作协

Photobiomodulation inhibits the expression of chondroitin sulfate proteoglycans after spinal cord injury via the Sox9 pathway

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Neural Regeneration Research 2024年第1期19卷 180-189页

作者： zhihao zhang Zhiwen Song Liang Luo Zhijie Zhu Xiaoshuang Zuo Cheng Ju Xuankang Wang Yangguang Ma Tingyu Wu Zhou Yao Jie Zhou Beiyu Chen Tan Ding Zhe Wang Xueyu Hu Department of Orthopedics Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina

Both glial cells and glia scar greatly affect the development of spinal cord injury and have become hot spots in research on spinal cord injury *** cellular deposition of dense extracellular matrix proteins such as chondroitin sulfate proteoglycans inside and around the glial scar is known to affect axonal growth and be a major obstacle to autogenous *** proteins are thus candidate targets for spinal cord injury *** previous studies demonstrated that 810 nm photo biomodulation inhibited the formation of chondroitin sulfate proteoglycans after spinal cord injury and greatly improved motor function in model ***,the specific mechanism and potential targets involved remain to be *** this study,to investigate the therapeutic effect of photo biomodulation,we established a mouse model of spinal cord injury by T9 clamping and irradiated the injury site at a power density of 50 mW/cm~2 for 50 minutes once a day for 7 consecutive *** found that photobiomodulation greatly restored motor function in mice and down regulated chondroitin sulfate proteoglycan expression in the injured spinal *** analysis revealed that photobiomodulation inhibited the expression of proteoglycan-related genes induced by spinal cord injury,and versican,a type of proteoglycan,was one of the most markedly changed *** staining showed that after spinal cord injury,versican was present in astrocytes in spinal cord *** expression of versican in primary astrocytes cultured in vitro increased after inflammation induction,whereas photobiomodulation inhibited the expression of ve ***,we found that the increased levels of p-Smad3,p-P38 and p-Erk in inflammatory astrocytes were reduced after photobiomodulation treatment and after delivery of inhibitors including FR 180204,(E)-SIS3,and SB *** suggests that Sma d 3/Sox9 and MAP K/Sox9 pathways may be involved in the effects of photobiomodulatio

关键词： chondroitin sulfate proteoglycans Erk MAPK P38 photobiomodulation principal component analysis Smad3 Sox9 spinal cord injury versican

基于水电解制氢的梯度多孔传输层中气液流动可视化实验研究

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化工学报 2024年第2期75卷 520-530页

作者：刘志鹏赵长颖吴睿张智昊上海交通大学机械与动力工程学院上海200240

在电解水制氢的过程中,多孔电极内的孔隙会发生气泡阻塞现象,这会妨碍气体扩散以及电解液在多孔电极内的流动,从而导致电极传质电阻的增加,进而影响电解水制氢的速率和能耗。采用3D金属打印技术制备了LSL-PTL、MMM-PTL和SLS-PTL三种规... 详细信息

在电解水制氢的过程中,多孔电极内的孔隙会发生气泡阻塞现象,这会妨碍气体扩散以及电解液在多孔电极内的流动,从而导致电极传质电阻的增加,进而影响电解水制氢的速率和能耗。采用3D金属打印技术制备了LSL-PTL、MMM-PTL和SLS-PTL三种规则的镍铁合金电极扩散层,进行了可视化的水电解实验,定量地记录了不同电流密度下梯度多孔传输层中气液两相流动的变化,包括气泡形态、孔隙含气率和气泡脱离速率等参数,研究扩散层梯度对气液传质过程的影响,并分析了不同电极梯度结构对电解过程中阻抗和过电位的影响。实验结果显示,与SLS-PTL和MMM-PTL相比,LSL-PTL的梯度结构从催化层即逐渐增大孔隙尺寸,始终保持较低的容积含气率,可以加速气泡在扩散层中的迁移,使气液交换更加频繁,有效减小气液传质阻力,并获得更低的传质阻抗和电解过电位,三种梯度电极在相同电流密度下的电解电势关系为ELSL

关键词：水电解多孔传输层梯度结构制氢气液两相流

基于WNN参数整定的ADRC在火箭炮伺服系统中的应用

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兵工自动化 2024年第4期43卷 14-18,53页

作者：廖华侯润民张志豪南京理工大学机械工程学院南京210094

针对多管火箭炮交流伺服系统存在变负载、强耦合和不确定性扰动等非线性问题,提出一种优化型小波神经网络自抗扰控制器(WNN-ADRC)。简化电流环节得到被控系统的数学模型,将小波神经网络(waveletneural network,WNN)嵌入自抗扰控制器中... 详细信息

针对多管火箭炮交流伺服系统存在变负载、强耦合和不确定性扰动等非线性问题,提出一种优化型小波神经网络自抗扰控制器(WNN-ADRC)。简化电流环节得到被控系统的数学模型,将小波神经网络(waveletneural network,WNN)嵌入自抗扰控制器中进行参数整定,利用分层调整学习速率的方法优化小波神经网络的学习算法得到WNN-ADRC,采用WNN-ADRC控制火箭炮伺服系统,实现对非线性特性的精准估计和补偿。数值仿真结果表明:相对于传统的自抗扰控制器,WNN-ADRC能改善伺服系统的静态响应和动态性能,具有响应速度快、控制精度高的优点。

关键词：交流伺服系统小波神经网络自抗扰控制器

昆仑山北坡两种优势荒漠灌木的生物量预测模型

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干旱区研究 2024年第2期41卷 284-292页

作者：张元梅孙桂丽鲁艳李利张志浩张栋栋新疆农业大学林学与风景园林学院新疆乌鲁木齐830052 干旱区林业生态与产业技术重点实验室新疆乌鲁木齐830052 中国科学院新疆生态与地理研究所新疆荒漠植物根系生态与植被修复重点实验室新疆乌鲁木齐830011 新疆策勒荒漠草地生态系统国家野外科学观测研究站新疆策勒848300 石河子大学生命科学学院新疆石河子832003

构建数学模型是估算灌木生物量的重要方法之一。本研究以中昆仑山北坡山前荒漠带常见的两种荒漠灌木红砂(Reaumuria soongarica)和合头草(Sympegma regelii)为研究对象。采用全株收获法采集植株,分别以株高(H)、冠幅面积(S)、植株体积(V... 详细信息

构建数学模型是估算灌木生物量的重要方法之一。本研究以中昆仑山北坡山前荒漠带常见的两种荒漠灌木红砂(Reaumuria soongarica)和合头草(Sympegma regelii)为研究对象。采用全株收获法采集植株,分别以株高(H)、冠幅面积(S)、植株体积(V)为自变量,植株地上生物量(W_(1))、地下生物量(W_(2))、全株生物量(W_(3))为因变量,建立函数模型,选取决定系数(R^(2))、估计标准差(SEE)、回归检验显著水平(P值)为评价指标,以P<0.001为前提,选取R^(2)尽量大、SEE尽量小的模型为红砂和合头草生物量最优预测模型。结果显示:红砂和合头草的生物量最优预测模型均为二次函数模型,合头草全株最优预测模型为一次函数模型除外。红砂植株体积(V)与生物量的相关性最高,生物量最优预测模型R^(2)为0.820~0.920。合头草冠幅面积(S)与生物量相关性最高,生物量最优预测模型R^(2)为0.935~0.973。红砂和合头草生物量最优预测模型均通过(P<0.001)显著性检验,拟合率在84.1%~95.6%之间,可用于生物量估算,本研究为预测荒漠生态系统碳储量和评价碳汇潜力提供科学依据。

关键词：荒漠灌木生物量预测模型昆仑山

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数字服务税的可税性研究

武汉冶金管理干部学院学报 2024年第2期34卷 16-20页

作者：张之浩中南财经政法大学法学院湖北武汉430073

数字服务税的可税性应从经济与税法两个层面进行考量:经济层面,数字服务性收益需得以被具体量化与识别;税法层面,应分别分析数字服务税主、客体的可税性,具体为对其征税范围、征税权、纳税主体的可税性分析。对数字服务税而言,经济可税... 详细信息

数字服务税的可税性应从经济与税法两个层面进行考量:经济层面,数字服务性收益需得以被具体量化与识别;税法层面,应分别分析数字服务税主、客体的可税性,具体为对其征税范围、征税权、纳税主体的可税性分析。对数字服务税而言,经济可税性仅属技术范畴,认定其具有可税性的关键在于证成其征税范围的收益性与征税权赋予的正当性。审视之下,“用户参与”理论与反垄断理论的互补将保证征税范围的收益性,基于“新联结度规则”与“经济忠诚”理论的征税权赋予具备充分的正当性。

关键词：数字服务税可税性收益性征税权

Cu对Al-Ti-B梯形连铸坯微观组织的影响

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稀有金属材料与工程 2024年第6期53卷 1749-1760页

作者：李振亮王鑫凌思涵张志豪赵帆内蒙古科技大学内蒙古包头014010 北京科技大学新材料技术研究院材料先进制备技术教育部重点实验室北京100083

以梯形连铸坯Al-5Ti-1B-0.2Cu中间合金为研究对象,进行不同温度的固溶处理,然后在不同变形温度、应变速率和变形方向进行热压缩变形。研究Cu元素加入、固溶处理、热压缩对第二相粒子微观组织及尺寸不均匀变形的影响。结果表明:Al-5Ti-1B... 详细信息

以梯形连铸坯Al-5Ti-1B-0.2Cu中间合金为研究对象,进行不同温度的固溶处理,然后在不同变形温度、应变速率和变形方向进行热压缩变形。研究Cu元素加入、固溶处理、热压缩对第二相粒子微观组织及尺寸不均匀变形的影响。结果表明:Al-5Ti-1B-0.2Cu中间合金经固溶处理600℃/4 h后第二相粒子共有4类:(Ti,Al)B_(2)、Al_(7)Cu_(2)Fe、TiB_(2)和TiAl_(3)。当Cu存在时,Al-Cu-Fe相生成有利于增多第二相粒子数目。在相同变形程度和变形温度下随变形速率(0.01、0.1、1 s^(-1))增大,TiAl_(3)平均粒子尺寸逐渐减小而TiB_(2)粒子更趋于弥散分布。第二相粒子TiAl_(3)在横向压缩变形后更加均匀,纵向压缩变形后更加细小,横向压缩与纵向压缩后TiB_(2)粒子尺寸、分布情况则基本相同,梯形连铸坯的尺寸不均匀塑性变形更有利于第二相粒子TiAl_(3)和Ti B_(2)的尺寸与分布。

关键词： Al-5Ti-1B-0.2Cu 第二相粒子固溶处理