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Experimental methods for determination of mechanical behaviors of materials at high temperatures via the split Hopkinson bars

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Acta Mechanica Sinica 2020年第6期36卷 1275-1293,I0003页

作者： Q.B.Dou K.R.Wu T.suo C.z.ang X.Guo Y.z.Guo W.G.Guo Y.L.Li School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China Joint International Research Laboratory of Impact Dynamics and its Engineering Application Xi’an710072China Shaanxi Key Laboratory of Impact Dynamics and its Engineering Application Xi’an710072China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an710049China

Full understanding of the thermomechanical behaviors of materials at high strain rates and high temperatures are of great importance from not only scientific meaning but also practical value in engineering structure design and safety *** efforts have been made for abilities of operation the split Hopkinson bars,the most popular technique for experimental determination of mechanical behaviors of materials over the strain rates from 10^2 to 10^4 s^−1 over the past 70 years,at high temperatures since 1960s.A review of experiment work is presented in this paper to give an overview of the development of experimental techniques at high temperatures based on Hopkinson bar *** principles of the split Hopkinson bar requires the loading bars avoiding temperature gradient or keeping relatively low temperature when performing high temperature *** such as performing temperature gradient corrections,rapid heating or using special designed automatically assembled systems were proposed by researchers to enable the operation of the split Hopkinson bars at temperature as high as ***,to the application of high speed photographic technique for capturing the dynamic deformation process of the specimen in high temperature Hopkinson bar testing,some key issues of eliminating the strong thermal radiation induced lights oversaturation and de-blurring of images due to insufficient exposure at high temperature and high strain rate condition,as well as fabrication of high contrast speckle pattern for high temperature digital image correlation measurement were also *** technique can now enable the split Hopkinson bar testing to be performed at high temperature up to 1873 K under the loading conditions of compression or tension with the in situ observation and full field measurement of deformation as *** paper concludes with summaries of the most important achievements and highlighting of the prospects,trends and remaining challenge

关键词： Mechanical behaviors Split Hopkinson bar High strain rate High temperature

Fast In-Situ Triaxial Remanent Magnetic Field Measurement for Single-Beam SERF Atomic Magnetometer Based on Trisection Algorithm

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Photonic Sensors 2023年第3期13卷 77-89页

作者： Tengyue LONG Bangcheng HAN Xinda SONG Yuchen suo Le JIA Department of Instrumentation Science and Opto-Electronics Engineering Beihang UniversityBeijing 100191China Hangz.ou Extremely Weak Magnetic Field Major Science and Technology Infrastructure Research Institute Hangzhou 310051China

We demonstrate a method for quickly and automatically detecting all three components of a remanent magnetic field around a shielded spin-exchange relaxation-free(SERF)atomic magnetometer(AM)using the trisection algorithm(TSA)for z.ro-field resonance(z.R).To satisfy the measurement of AMs,a resonance light of the ^(87)Rb D1 line with a spectral width of less than 1 MHz.is converted to circular polariz.tion by a linear polariz.r and a quarter-wave *** the light beam has passed through the alkali metal vapor cell,the residual magnetic field can be measured by searching for triaxial z.R optical *** TSA stably reduces the measurement time to 2.41 s on average and improves the measurement accuracy,significantly outpacing existing *** weighted averages of all measurements with corresponding uncertainties are(–15.437±0.022)nT,(6.062±0.021)nT,and(–14.158±0.052)nT on the x-,y-,and z.axes,*** improvements could facilitate more extremely weak magnetic studies in real time,such as magnetoencephalography(MEG)and magnetocardiography(MCG)measurements.

关键词： Atomic magnetometer remanent magnetic field measurement spin-exchange relaxation free trisection algorithm

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钻井液侵入纹层状页岩的模型

工程科学学报 2024年第3期46卷 547-555页

作者：索彧李芬芬何文渊付晓飞潘哲君冯福平赵万春东北石油大学石油工程学院大庆163311 提高油气采收率教育部重点实验室大庆163311 大庆油田博士后科研工作站大庆163458 黑龙江省油气藏压裂改造与评价重点实验室大庆163311 中国石油国际勘探开发有限公司北京100034 东北石油大学非常规天然气研究院大庆163311

井壁失稳一直是钻井工程中的世界性技术难题,纹层状页岩弱面发育以及黏土矿物含量较高,导致井眼坍塌的风险增加,极大地制约了页岩水平井的高效开发.为了研究钻井液在纹层状页岩中的侵入规律,开展了驱替实验和核磁扫描,确定了不同驱替时... 详细信息

井壁失稳一直是钻井工程中的世界性技术难题,纹层状页岩弱面发育以及黏土矿物含量较高,导致井眼坍塌的风险增加,极大地制约了页岩水平井的高效开发.为了研究钻井液在纹层状页岩中的侵入规律,开展了驱替实验和核磁扫描,确定了不同驱替时间下钻井液侵入纹层状页岩的深度,基于实验结果建立了新的包含纹层侵入的纹层状页岩的流体侵入数学模型,在总吸水量一定的情况下,可以根据侵入时间求得钻井液在纹层的侵入深度以及侵入量,基于实验结果验证了模型的准确性,采用有限元-离散元法描述钻井液侵入过程并进行敏感性分析.研究结果表明:在钻井液使用量一定的条件下,钻井液沿纹层状页岩油的侵入深度与侵入时间呈正向对数关系,随着侵入时间、纹层张开度的增大,侵入深度逐渐变大,但后期增长缓慢最终趋于不变;随着纹层数量的增加,侵入深度逐渐减小.

关键词：页岩纹层状钻井液侵入模型影响因素

The Folded(2D+1)-cube and Its Uniform Posets

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Acta Mathematicae Applicatae Sinica 2018年第2期34卷 281-292页

作者： Li-hang HOU BO HOU suo-gang GAO College of Mathematics and Information Science Hebei Normal University

Let F denote the folded （2D ＋ 1）-cube with vertex set X and diameter D ≥ 3. Fix x∈ X. We first define a partial order ≤ on X as follows. For y,z.∈ X let y ≤ z.whenever （x,y）＋（y,z. =- （x, z.. Let R （resp. L） denote the raising matrix （resp. lowering matrix） of P. Next we show that there exists a certain linear dependency among RL2, LRL, L2R and L for each given Q-polynomial structure of F. Finally, we determine whether the above linear dependency structure gives this poser a uniform structure or strongly uniform structure.

关键词： distance-regular graph the folded (2D + 1)-cube uniform poset

Shoot Apex Demand Determines Assimilate and Nutrients Partitioning and Nutrient-uptake Rate in Tobacco Plants

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Journal of Integrative Plant Biology 2007年第11期49卷 1654-1661页

作者： Huai-Yu Yang Chun-Jian Li Fu-suo z.ang The Key Laboratory of Plant Nutrition Ministry of Agriculture Key Laboratory of Plant-Soil Interactions Ministry of Education Department of Plant Nutrition China Agricultural University Beijing 100094 China

Our previous experiment revealed that apex-removed plants have larger root systems but a lower K＋-uptake rates than intact tobacco plants. Since the apex is not only a center of growth and metabolism, but also an important place of auxin synthesis and export, the aims of this study were to distinguish whether the apex demand or auxin synthesiz.d in the apex regulates assimilate and nutrients partitioning within plant, and to explain the reason for the lower K＋-uptake rate of the apex-removed plant. In comparison with the control plant, covering the shoot apex with a black transparent plastic bag reduced net increases in dry matter and nutrients; however, the distribution of the dry matter and nutrients between shoot and roots and nutrient-uptake rates were not changed. Removal of the shoot apex shifted the dry mass and nutrients distributions to roots, and reduced the rate of nutrient uptake. Application of 1-naphthylacetic acid （NAA） could partly replace the role of the removed apex, stimulated assimilate and nutrient deposition into the treated tissue, and enhanced the reduced plasma membrane ATPase activity of roots to the control level. However, treatment of the apex-removed plants with NAA could not rescue the reduced nutrient uptake rate and the shifted assimilates and nutrients partitioning caused by excision of the apex. Higher nutrient uptake rate of the intact plants could not be explained by root growth parameters, such as total root surface area and number of root tips. The results from the present study indicate that strong apex demand determined assimilates and nutrients partitioning and nutrient-uptake rate in tobacco （Nicotiana tabacum） plants.

关键词： assimilate and nutrient partitioning auxin nutrient uptake removal of the shoot apex shoot apex demand tobacco (Nicotiana tabacum).

Differentiation renders susceptibility to excitotoxicity in HT22 neurons

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Neural Regeneration Research 2013年第14期8卷 1297-1306页

作者： Minchao He Jun Liu haowu Cheng Yigang Xing William z.suo Department of Neurology Sun Yat-sen Memorial HospitalSun Yat-sen University Laboratory for Alz.eimer's Disease & Aging Research Veterans Affairs Medical Center Department of Neurology University of Kansas Medical Center Molecular & Integrative Physiology University of Kansas Medical Center

HT22 is an immortaliz.d mouse hippocampal neuronal cell line that does not express cholinergic and glutamate receptors like mature hippocampal neurons in vivo. This in part prevents its use as a model for mature hippocampal neurons in memory-related studies. We now report that HT22 cells were appropriately induced to differentiate and possess properties similar to those of mature hippocampal neurons in vivo, such as becoming more glutamate-receptive and excitatory. Results showed that sensitivity of HT22 cells to glutamate-induced toxicity changed dramatically when comparing undifferentiated with differentiated cells, with the half-effective concentration for differentiated cells reducing approximately two orders of magnitude. Moreover, glutamate-induced toxicity in differentiated cells, but not undifferentiated cells, was inhibited by the N-methyi-D- aspartate receptor antagonists MK-801 and memantine. Evidently, differentiated HT22 cells expressed N-methyI-D-aspartate receptors, while undifferentiated cells did not. Our experimental findings indicated that differentiation is important for immortaliz.d cell lines to render post-mitotic neuronal properties, and that differentiated HT22 neurons represent a better model of hippocampal neurons than undifferentiated cells.

关键词： neural regeneration brain injury HT22 differentiation N-methyI-D-aspartate receptor glutamateexcitatory neurotoxicity mitosis hippocampus neurons MK-801" memantine grants-supportedpaper neuroregeneration

激光预热温度对铣削GH4169切削力及表面粗糙度的影响

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工具技术 2024年第10期58卷 103-108页

作者：孔宪俊宋一平锁聪刘明刚王兴超沈阳航空航天大学机电工程学院沈阳飞机工业(集团)有限公司中国航发沈阳黎明航空发动机有限责任公司

采用单因素法,通过ABAQUS仿真与试验研究了激光预热温度与切削参数对铣削GH4169高温合金的铣削力和表面粗糙度的影响规律,进一步分析了激光加热产生的热影响区深度与切削参数对切削力及表面粗糙度的影响。结果表明:本研究仿真模型与试... 详细信息

采用单因素法,通过ABAQUS仿真与试验研究了激光预热温度与切削参数对铣削GH4169高温合金的铣削力和表面粗糙度的影响规律,进一步分析了激光加热产生的热影响区深度与切削参数对切削力及表面粗糙度的影响。结果表明:本研究仿真模型与试验结果高度吻合,最大误差值16.5%,具有一定的准确性与指导意义。激光加热辅助可明显地降低切削力,比常规铣削方式降低15%~30%。低进给量配合相对较小的切削深度能明显改善切削力,激光加热辅助铣削加工表面粗糙度皆低于常规铣削加工表面,且粗糙度值下降率与切削力下降率变化较吻合,说明表面粗糙度与切削力之间密切相关。当预热温度增加到一定程度时,激光加热对加工表面的改善作用减弱。研究发现,预热温度800℃,切削速度60m/min,进给量0.03mm/z.切削深度0.3mm时,切削力与表面粗糙度值最佳。

关键词： ABAQUS 热影响区切削力预热温度表面粗糙度

Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz.wave detection

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Light(Science & Applications) 2021年第4期10卷 600-609页

作者： Jinchao Tong Fei suo Tianning z.ang z.iming Huang Junhao Chu Dao Hua z.ang School of Electrical and Electronic Engineering Nanyang Technological UniversityNanyang Avenue639798 SingaporeSingapore State Key Laboratory of Infrared Physics Shanghai Institute of Technical

High-performance uncooled millimnetre and terahertz.wave detectors are required as a building block for a wide range of *** state-of-the art technologies,however,are plagued by low sensitivity,narrow spectral bandwidth,and complicated ***,we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz.wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature *** making a nanogroove array in the grown InSb layer,strong millimetre and terahertz.wave surface plasmon polaritons can be generated at the InSb-air interfaces,which results in significant improvement in detecting performance.A noise equivalent power(NEP)of 2.2× 10^(-14)WHz.(-1/2) or a detectivity(D)of 2.7× 10^(12)cmHz.(1/2) W^(-1) at 1.75 mm(0.171 THz.is achieved at room *** lowering the temperature to the thermoelectric cooling available 200 K,the corresponding NEP and D'of the nanogroove device can be improved to 3.8× 10^(-15)WHz.(-1/2) and 1.6× 10^(13) cm Hz.(-1/2) w^(-1),*** addition,such a single device can perform broad spectral band detection from 0.9 mm(0.330 THz.to 9.4 mm(0.032 THz..Fast responses of 3.5μs and 780 ns are achieved at room temperature and 200 K,*** high-performance millimnetre and terahertz.wave photodetectors are useful for wide applications such as high capacity communications,walk-through security,biological diagnosis,spectroscopy,and remote *** addition,the integration of plasmonic semiconductor nanostructures paves a way for realiz.ng high performance and multifunctional long-wavelength optoelectrical devices.

关键词： wave spectral terahertz

Time evolution of angular momentum coherent state derived by virtue of entangled state representation and a new binomial theorem

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Chinese Physics B 2019年第10期28卷 253-256页

作者： Ji-suo Wang Xiang-Guo Meng Hong-Yi Fan Shandong Provincial Key Laboratory of Laser Polariz.tion and Information Technology College of Physics and EngineeringQufu Normal UniversityQufu 273165China Shandong Provincial Key Laboratory of Optical Communication Science and Technology School of Physical Science and Information EngineeringLiaocheng UniversityLiaocheng 252059China Department of Material Science and Engineering University of Science and Technology of ChinaHefei 230026China

We study how can an angular momentum coherent state |τ> keeps its form-invariant during time evolution governed by the Hamiltonian H = f(t)J++ f^*(t)J-+ g(t)Jz. We discuss this topic in the context of boson realiz.tion of |τ>. By employing the entangled state representation |ζ> and deriving a new binomial theorem involving two-subscript Hermite polynomials, we derive the wave function , which turns out to be a single-subscript Hermite polynomial. Based on this result the maintenance of angular momentum coherent state during time evolution is examined, and the value of τ(t) is totally determined by the parameters involved in the Hamiltonian.

关键词： invariance of angular momentum coherent state entangled state representation new binomial theorem time evolution