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Influence of strain rate on grain refinement and texture evolution under complex shear stress conditions

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镁合金学报(英文) 2023年第7期11卷 2558-2584页

作者： Zhaocan Li Guoqin Wu Jianmin Yu jiebing wang Jingjing Han Huiyong Cui Zhimin Zhang College of Materials Science and Engineering North University of China3 Xueyuan RoadTaiyuan 030051China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing 100076China

The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were *** increasing strain rate,the average grain size of compression-shear(CS)and compression-torsion(CT)samples are decreased,and the grain size of dynamic recrystallization(DRX)grains is also *** is because that the precipitation number ofβphases is increased,and the hindering effect on grain growth can be significantly *** DRX fractions of CS and CT samples are decreased with increased strain *** low DRX fraction at high strain rate is related to the insufficient time for grains to *** DRX process can be promoted by the PSN mechanism of second phases,and the grain growth can be restricted by the pinning *** the same time,the texture strength is enhanced as the strain rate ***,the kinking degree of lamellar long-period stacking ordered(LPSO)phases is *** complex shear stress conditions,non-basal slip,especially pyramidal slip,is easily activated and the texture is deflected *** with the CS samples,CT samples have smaller average grain size,higher DRX fraction,and lower texture strength for a certain strain *** is because that the equivalent stress of the CT sample is larger,the stress triaxiality is smaller,so more serious dislocations are piled up near grain boundaries and second *** the same time,since CT sample was sheared with torsion,the dislocation movement path can be called“rotational dislocation accumulation”,and the longer distribution path of the CT sample is generated,so more sub-grains and low-angle grain boundaries(LAGBs)are *** with the CS sample,more huge-angle grain boundaries(HAGBs)and DRX grains are formed from grain boundary to grain interior,so better grain refinement effect is achieved.

关键词： Simple shear Compression-shear Compression-torsion Grain refinement Texture evolution ASB

氟比洛芬酯超前镇痛对宫腔镜手术患者术后疼痛、炎症反应指标的影响

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中国计划生育学杂志 2024年第6期32卷 1336-1340页

作者：王学平殷燕妮王结兵蔡小攀陈韬安徽省太湖县人民医院 246000 安徽省安庆市立医院

目的:探究氟比洛芬酯超前镇痛对宫腔镜手术患者术后疼痛、炎症反应指标的影响。方法:选择本院2022年1月-2024年1月收治宫腔镜手术患者138例,随机奇偶数法分为两组各69例,对照组给予全身麻醉,观察组在对照组基础上给予氟比洛芬酯麻醉。... 详细信息

目的:探究氟比洛芬酯超前镇痛对宫腔镜手术患者术后疼痛、炎症反应指标的影响。方法:选择本院2022年1月-2024年1月收治宫腔镜手术患者138例,随机奇偶数法分为两组各69例,对照组给予全身麻醉,观察组在对照组基础上给予氟比洛芬酯麻醉。比较两组术中血流动力学指标、麻醉效果,术后疼痛评分及炎症指标,不良反应。结果:两组扩宫颈时(T1)、术毕前(T2)时心率与平均动脉压均高于麻醉诱导处理前,且观察组T1、T2时HR与MAP均低于对照组;观察组丙泊酚使用量(213.28±2.43 mg)、唤醒时间(3.12±0.75 min)均少于对照组(248.83±2.17 mg、7.53±1.22 min);术后2h、12h、24h时,观察组疼痛评分(1.53±0.36分、2.49±0.74分、1.86±0.53分)均低于对照组(3.72±0.65、4.65±1.18分、3.51±0.62分),血清白介素-6、前列腺素E2、肿瘤坏死因子α、P物质水平均低于对照组(均P0.05)。结论:宫腔镜手术采用氟比洛芬酯超前镇痛有助于减轻患者术后疼痛及炎症反应,提高临床效果,且用药安全。

关键词：宫腔镜手术超前镇痛氟比洛芬酯术后疼痛炎症反应

A microfluidic biosensor for multiplex immunoassay of foodborne pathogens agitated by programmed audio signals

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Chinese Chemical Letters 2024年第10期35卷 370-374页

作者： Gaowa Xing Yuting Shang Xiaorui wang Zengnan Wu Qiang Zhang jiebing Ai Qiaosheng Pu Ling Lin Key Laboratory of Ecology-Toxicological Effects and Control for Emerging Contaminants of Fujian Province College of Environmental&Biological EngineeringPutian UniversityPutian351100China Xining Urban Vocational&Technical College Xining 810000China Department of Bioengineering Beijing Technology and Business UniversityBeijing 100048China Department of Chemistry Beijing Key Laboratory of Microanalytical Methods and InstrumentationTsinghua UniversityBejing 100084China College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China

Foods are often contaminated by multiple foodborne pathogens,which threatens human *** this work,we developed a microfluidic biosensor for multiplex immunoassay of foodborne bacteria with agitation driven by programmed audio *** agitation,powered by the vibration of a speaker cone during music playing,accelerated the mass transport in the incubation process to form bacterial complexes within 10 *** reagents of the two target bacteria(Escherichia coli O157:H7 and Salmonella typhimurium)were preloaded into the corresponding fore-vacuum storage chamber on the chip,and released to participate in the subsequent immune analysis process by piercing the *** the detection processes were integrated into a single microfluidic chip and controlled by a smartphone through *** selected conditions,wide linear ranges and low limits of detection(LODs<2CFU/m L)were obtained,and real food samples were successfully determined within 30 *** biosensing method can be extended to wide-ranging applications by loading different recognizing reagents.

关键词： Multiplex immunoassay Microfluidic biosensor Audio signals Foodborne bacteria Smartphone

Model Test Study on Response of Weathered Rock Slope to Rainfall Infiltration under Different Conditions

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Journal of Earth Science 2024年第4期35卷 1316-1333页

作者： Cong Li Rongtang Zhang jiebing Zhu Bo Lu Xiaowei wang Fangling Xu Xiaoke Shen Jiesheng Liu Weizhen Cai School of Civil Engineering and Architecture Wuhan Polytechnic UniversityWuhan430023China Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources Yangtze River Scientific Research InstituteWuhan430010China Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China

Weathered rock(especially granite)slopes are prone to failure under the action of rainfall,making it necessary to study the response of weathered rock slope to rainfall infiltration for landslide *** this study,a series of model tests of weathered rock slope under different conditions were *** matric suction,volumetric water content,earth pressure and deformation of slope were monitored in real time during *** response of the slope to rainfall infiltration,failure process and failure mode of slope under different conditions were analyzed,and the early warning criterion for the failure of weathered rock slope caused by rainfall was *** results show that the slope deformation evolution process under rainfall condition was closely related to the dissipation of matric *** the distribution of the matrix suction(or water content)of slope met the condition that the resistance to sliding of the slip-mass was overcome,the displacement increased sharply and landslide *** factors including rainfall process,lithologic condition and excavation condition significantly affect the response of weathered rock slope to *** can be found from the test results under different conditions that compared with intermittent rainfall condition,the rainfall intensity and infiltration depth were smaller when the slope entering accelerated deformation stage under the condition of incremental *** accumulated rainfall when weathered clastic landslide occurring was greater than that of weathered granite,which results in greater disaster *** excavation angle and moisture distribution of a slope were the main factors affecting the stability of a *** addition,the evolution processes and critical displacement velocities of slopes were studied by combining the deformation curves and matrix suction curves,which can be used as reference for early warning of rainfall-induced weathered rock landslide.

关键词： weathered rock slope model test rainfall early warning unsaturated soil

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抗氧化碳/碳复合材料螺钉设计方法研究

哈尔滨工程大学学报 2022年第7期43卷 1006-1012页

作者：常园园王捷冰董耀军王乾冯韶伟北京宇航系统工程研究所北京100076 空间物理重点实验室北京100076

针对C/C复合材料紧固件失效模式多、承载低且无设计标准的特点,本文对影响沉头螺钉承力的公称直径D、钉头高度H、钉头角度α、螺纹啮合深度h等4个设计变量进行分析,结合抗氧化C/C复合材料力学性能特点,提出抗氧化C/C复合材料螺钉的设计... 详细信息

针对C/C复合材料紧固件失效模式多、承载低且无设计标准的特点,本文对影响沉头螺钉承力的公称直径D、钉头高度H、钉头角度α、螺纹啮合深度h等4个设计变量进行分析,结合抗氧化C/C复合材料力学性能特点,提出抗氧化C/C复合材料螺钉的设计方法,分析涂层对螺钉承载的影响,给出设计变量与材料性能之间关系:H>D×σ_(t)/(4×ζ)、α>ctan(ζ/σ_(c))、h>3H(螺牙进行抗氧化涂层处理后可稍微减小h,但也需大于2H)。该设计方法消除螺纹拉脱、钉头拉脱/压溃等C/C复合材料螺钉的失效模式,大幅度提升螺钉承载能力。设计验证实验,通过实验考核螺钉结构形式及设计方法的正确性,验证抗氧化涂层工艺对螺钉承载的影响。

关键词： C/C复合材料抗氧化涂层螺纹连接件设计方法设计变量螺纹拉脱钉头拉脱失效模式

基于不同类型溶液蒸气压特性的太阳能界面蒸发实验研究

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化工学报 2022年第2期73卷 663-671页

作者：王洁冰高金彤徐震原上海交通大学制冷与低温工程研究所上海200240

太阳能界面蒸发可实现高效太阳能海水淡化和蒸发式污水处理,但目前的研究大多局限于纯水或NaCl溶液。实际脱盐或废水处理中溶质会与此不同,导致溶液蒸气压变化并影响蒸发性能。本文首先分析了溶液表面蒸气压曲线类型,将其分为上凸型、... 详细信息

太阳能界面蒸发可实现高效太阳能海水淡化和蒸发式污水处理,但目前的研究大多局限于纯水或NaCl溶液。实际脱盐或废水处理中溶质会与此不同,导致溶液蒸气压变化并影响蒸发性能。本文首先分析了溶液表面蒸气压曲线类型,将其分为上凸型、下凹型和直线型。针对这几种蒸气压曲线进一步选取[EMIM][OTf]、[EMIM][Ac]和NaCl水溶液作为代表溶液,在不同辐照强度和浓度下进行了实验研究,并与纯水的蒸发作对比。实验结果表明:低浓度下[EMIM][OTf]水溶液展现出了良好的蒸发性能,主要原因是由于其蒸气压处于上凸区间;当溶液浓度升高或辐照强度提升时,[EMIM][OTf]溶液的蒸发速率提升较NaCl水溶液小,主要原因在于蒸发过程的浓度极化导致气液界面处的[EMIM][OTf]浓度升高,蒸气压相差较小;不同工况下[EMIM][Ac]水溶液的蒸发速率均较慢,纯水的蒸发速率最快,体现了蒸气压对蒸发性能的关键影响,原因是低蒸气压导致高蒸发温度,并带来更多的能量损失。

关键词：汽液平衡蒸发界面蒸发溶液太阳能水处理

基于LiCl溶液太阳能界面蒸发的连续式空气取水

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化工学报 2021年第S1期72卷 70-76页

作者：安美燕王洁冰徐震原王如竹上海交通大学制冷与低温工程研究所上海200240

太阳能吸收式空气取水利用广泛存在的太阳能和空气获取淡水,是解决淡水短缺的有效方法,然而传统技术的水分吸收和解吸收集需要分开运行,效率较低且需要人工操作。为解决该问题,提出基于吸湿盐溶液太阳能界面蒸发的连续式空气取水,一方... 详细信息

太阳能吸收式空气取水利用广泛存在的太阳能和空气获取淡水,是解决淡水短缺的有效方法,然而传统技术的水分吸收和解吸收集需要分开运行,效率较低且需要人工操作。为解决该问题,提出基于吸湿盐溶液太阳能界面蒸发的连续式空气取水,一方面采用LiCl溶液吸收空气中的水分,另一方面利用太阳能界面蒸发实现溶液解吸与水蒸气冷凝收集,由于太阳能界面蒸发可以实现局部加热与解吸,吸收和解吸两个过程可以同时进行。进一步对LiCl溶液的太阳能界面蒸发与连续空气取水分别进行了试验研究,试验结果显示:质量分数为30%的LiCl溶液可以进行高效的吸收/解吸工作,在一个太阳光照强度下达到0.44 kg/(m^(2)·h)的蒸发速率和39.3%的能量效率,并能实现连续太阳能空气取水,取水速率达到2 L/(m^(2)·d)。

关键词：空气取水吸收界面解吸连续

典型连接结构螺栓的附加弯矩形成机理与承载能力研究及结构优化设计

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力学学报 2022年第5期54卷 1303-1321页

作者：范刚张宏宇王捷冰薛铮刘晓华中国运载火箭技术研究院空间物理重点实验室北京100076

针对典型连接结构中,高强螺栓在受拉工况下因产生附加弯矩而极大削弱其承载能力的问题,开展了螺栓附加弯矩产生的机理研究,并提出了一种有效降低螺栓附加弯矩的结构优化设计方法.首先,建立典型连接结构的等效力学模型,推导出螺栓附加弯... 详细信息

针对典型连接结构中,高强螺栓在受拉工况下因产生附加弯矩而极大削弱其承载能力的问题,开展了螺栓附加弯矩产生的机理研究,并提出了一种有效降低螺栓附加弯矩的结构优化设计方法.首先,建立典型连接结构的等效力学模型,推导出螺栓附加弯矩的解析解,进一步开展数值仿真分析,验证了解析方法的正确性.考虑螺栓同时承受拉弯耦合载荷工况,引入梁塑性弯曲理论,研究了不同拉弯组合下的螺栓截面各类应力分布的交互关系,并给出了考虑轴力影响的弯矩塑性折减系数.基于最大应力破坏准则,开展了考虑附加弯矩和弯曲塑性影响的螺栓载荷失效判据研究,该判据更加具有工程应用价值.从机理出发,开展典型连接结构优化设计以降低螺栓的附加弯矩进而提高其承载能力,进一步采用解析方法,阐述了铰支球头的工作机理.采用数值仿真方法,开展了螺栓附加弯矩灵敏度分析,验证了优化设计方法的有效性.进一步开展试验研究,获得不同连接状态下螺栓的附加弯矩,验证了优化设计方法的正确性和可行性.该方法能够极大降低高强螺栓的附加弯矩,最大程度发挥螺栓的承载能力,提高连接结构的可靠性.

关键词：高强螺栓附加弯矩塑性折减系数结构优化设计试验研究

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航天飞行器铸件舱段结构快速设计方法

北京航空航天大学学报 2022年第1期48卷 87-94页

作者：郑成成王捷冰吴曼乔许大帅杨晨陈爽空间物理实验室北京100076

为提高航天飞行器铸件舱段在方案论证阶段的结构设计效率、设计质量和迭代效率,基于航天飞行器复杂曲面结构特点对铸件舱段结构特征参数进行研究,提出曲线比率法以描述纵筋参数化布局;定义骨架模型发布元素,以实现铸件舱段的Top-Down设... 详细信息

为提高航天飞行器铸件舱段在方案论证阶段的结构设计效率、设计质量和迭代效率,基于航天飞行器复杂曲面结构特点对铸件舱段结构特征参数进行研究,提出曲线比率法以描述纵筋参数化布局;定义骨架模型发布元素,以实现铸件舱段的Top-Down设计。提出航天飞行器铸件舱段结构快速参数化设计方法,通过定义特征命名规则和创建特征集合实现建模规范化,通过封装舱段设计知识实现设计快速化,通过创建特征参数和公式实现特征参数化。通过建立交互式铸件舱段结构快速设计环境,实现铸件舱段结构的快速实例化、快速修改,并以航天飞行器铸件舱段为例验证了所提方法的可行性和有效性。

关键词：复杂曲面骨架模型参数化设计快速设计快速修改建模规范化