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A New Method for Monitoring Scattered Stray light of an Inner-occulted Coronagraph

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Research in Astronomy and Astrophysics 2024年第2期24卷 216-227页

作者： Da-Yang liu Hong-Xin Zhang Ming-Zhe Sun Zheng-Hua Huang li-dong xia Wei-Xin liu Hui Fu Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

The scattered stray light of a coronagraph is a type of stray light that is generated by the objective lens as its surface defects are irradiated by *** defects mainly include dust and blemishes on the lens surface,microroughness of the lens surface,and impurity and inhomogeneity of the *** the other types of relatively stable defects introduced when the objective lens is being manufactured,the scattered stray light caused by dusts on the lens surface is difficult to quantify accurately due to the disorder and randomness of the dust *** contribution of this type of stray light to the overall stray light level is difficult to determine through simulations and *** can result in continuous deterioration of the stray light level of a coronagraph and thus affect the observation capabilities of the *** solve this issue,through analyzing the forming mechanism of scattered stray light and ghost image generated by the inner-occulted coronagraph,we propose a novel method to monitor the scattered stray light from dusts by utilizing different stray light correlation *** this method,we first simulate and measure the level of stray light from the ghost image of the objective lens,and then determine the flux ratio of scattered light and ghost image on the conjugate *** the flux ratio varies with the accumulation of dusts on the lens surface,it remains constant on the image ***,the level of dust scattering light on the image plane can be obtained by using this ratio together with the level of ghost image stray *** accuracy of this method has been validated in a laboratory by applying the objective lens with numerous surface cleanliness levels.

关键词： Sun corona-Sun atmosphere-instrumentation miscellaneous-methods analytical-techniques image processing

Period ratios for standing kink and sausage modes in magnetized structures with siphon flow on the Sun

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Research in Astronomy and Astrophysics 2016年第6期16卷 69-84页

作者： Hui Yu Shao-xia Chen Bo li li-dong xia Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong University

Standing oscillations with multiple periods have been found in a number of atmospheric struc- tures on the Sun. The ratio of the period of the fundamental to twice the one of its first overtone, P1/2192, is important in applications of solar magneto-seismology. We examine how field-aligned flows impact P1/2P2 of standing modes in solar magnetic cylinders. For coronal loops, the flow effects are significant for both fast kink and sausage modes. For kink modes, they reduce P1/2P2 by up to 17% relative to the static case even when the density contrast between the loop and its surroundings approaches infinity. For sausage modes, the reduction in P1/2P2 due to flow is typically ≤ 5.5% compared with the static case. However, the threshold aspect ratio, only above which can trapped sausage modes be supported, may increase dramatically with the flow magnitude. For photospheric tubes, the flow effect on P1/2P2 is not as strong. However, when applied to sausage modes, introducing field-aligned flows offers more possibilities in interpreting the multiple peri- ods that have recently been measured. We conclude that field-aligned flows should be taken into account to help better understand what causes the departure of P1/2P2 from unity.

关键词： magnetohydrodynamics (MHD) -- Sun: corona -- Sun: magnetic fields -- waves

Experimental and theoretical analysis of equilibrium segregation and radiation-induced segregation of Cr at grain boundariesin a reduced activation ferritic/martensitic(RAFM)steel

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Journal of Iron and Steel Research International 2021年第4期28卷 445-452页

作者： li-dong xia Hao Chen Zhi-gang Yang Chi Zhang Key Laboratory of Advanced Materials of Ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Helium ion irradiation at 350℃was performed to study equilibrium segregation and radiation-induced segregation(RIS)of Cr at grain boundaries in reduced activation ferritic/martensitic *** concentration at grain boundary was measured by scanning transmission electron microscopy with an energy-dispersive *** measured Cr concentration at grain boundaries in heat treated zone was 11.7 and 12.8 wt.%in irradiated zone,respectively,which matched well to the calculated results from Mclean and modified Perk *** segregation and RIS of Cr mechanisms were theoretically *** analysis indicates that as temperature rises,equilibrium Cr segregation decreases monotoni-cally,while RIS of Cr has a bell-shape profile,which increases first and then *** is also shown that at low and high temperatures,equilibrium segregation of Cr is higher than that of RIS;at intermediate temperatures,equilibrium Cr segregation is lower than RIS.

关键词： Reduced activation ferritic/martensitic steel Equilibrium Cr segregation Radiation-induced segregation Grain boundary Rate theory Mclean equation

“岗课赛证”融合育人背景下的“仪器分析”教学改革

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教育教学论坛 2024年第14期 69-72页

作者：杨巍李冬霞王芳苏州农业职业技术学院食品科技学院江苏苏州215008

“仪器分析”课程主要培养学生应用仪器分析技术对食品中的质量安全指标进行检测分析的综合技能,具有测定原理抽象、操作流程复杂等特点,高职学生在学习过程中存在一定的困难。为提高教学效果,课程团队融合“岗课赛证”,优化教学内容;... 详细信息

“仪器分析”课程主要培养学生应用仪器分析技术对食品中的质量安全指标进行检测分析的综合技能,具有测定原理抽象、操作流程复杂等特点,高职学生在学习过程中存在一定的困难。为提高教学效果,课程团队融合“岗课赛证”,优化教学内容;整合优质教学资源,解决重点难点。借助视频动画、虚拟仿真,以“学赛融合”的方式探索实施“岗课赛证”融合育人路径,一体化培养能从事食品质量安全分析检测与管理等工作的高素质技术技能人才。

关键词：岗课赛证仪器分析教学改革

不同供磷水平对椰枣幼苗生长、生理指标和营养元素含量的影响

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南方农业学报 2024年第5期55卷 1424-1435页

作者：李东霞马卫能符海泉张宁徐中亮中国热带农业科学院椰子研究所/国家热带棕榈种质资源圃海南文昌571339 云南农业大学热带作物学院云南普洱665099

【目的】通过分析不同供磷水平对椰枣幼苗生长、生理指标和营养元素含量的影响,为构建椰枣幼苗平衡施肥技术提供理论依据。【方法】以椰枣幼苗为试验材料,采用盆栽试验,设4个供磷水平处理,浓度分别为5(CK)、100、1000和5000μmol/L,培养... 详细信息

【目的】通过分析不同供磷水平对椰枣幼苗生长、生理指标和营养元素含量的影响,为构建椰枣幼苗平衡施肥技术提供理论依据。【方法】以椰枣幼苗为试验材料,采用盆栽试验,设4个供磷水平处理,浓度分别为5(CK)、100、1000和5000μmol/L,培养7个月后,观察测定幼苗的生长、生理指标和营养元素含量。【结果】5μmol/L供磷水平下,椰枣幼苗长势弱;100μmol/L供磷水平下椰枣幼苗的根部鲜重显著低于1000μmol/L供磷水平(P<0.05,下同);1000μmol/L供磷水平下椰枣幼苗长势好,其根部鲜重、地上部干重、株高增加量、植株磷含量、植株磷累积量、第3叶和第6叶片中的可溶性蛋白含量均显著大于CK;5000μmol/L供磷水平下,新抽叶片密集,根部磷利用效率和植株磷利用效率最低。同一供磷水平下,椰枣幼苗茎尖中的磷含量高于叶片和根尖。不同供磷水平对地上部和根部氮、钾、钙、镁、钠、铝元素的含量影响不同。随着供磷水平的增加,地上部和根部的钾、铝含量,以及地上部钙含量均先增加后降低,地上部镁含量逐渐增加,根部钙、镁含量逐渐降低;5000μmol/L供磷水平下,地上部和根部的钠含量达最高。1000μmol/L供磷水平下,椰枣幼苗地上部的氮、钾、镁、钠、铝的累积量,地上部氮利用效率,以及地上部和根部的钙利用效率显著大于CK。【结论】营养液中的供磷水平会影响椰枣幼苗的长势、生理指标及营养元素的含量、累积量和利用效率。过低或者过高供磷水平均不利于椰枣幼苗的生长,1000μmol/L供磷水平下,椰枣幼苗长势良好。

关键词：椰枣磷幼苗生长生理指标营养元素

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Influence of lactic acid bacteria, cellulase, cellulase-producing Bacillus pumilus and their combinations on alfalfa silage quality

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Journal of Integrative Agriculture 2018年第12期17卷 2768-2782页

作者： li dong-xia NI Kui-kui ZHANG Ying-chao liN Yan-li YANG Fu-yu College of Animal Science and Technology China Agricultural UniversityBeijing 100193P.R.China Beijing Sure Academy of Biosciences Beijing 100085P.R.China

This study assessed the effects of lactic acid bacteria(LAB), cellulase, cellulase-producing Bacillus pumilus and their combinations on the fermentation characteristics, chemical composition, bacterial community and in vitro digestibility of alfalfa silage. A completely randomized design involving a 8(silage additives)×3 or 2(silage days) factorial arrangement of treatments was adopted in the present study. The 8 silage additive treatments were: untreated alfalfa(control); two commercial additives(GFJ and Chikuso-1); an originally selected LAB(Lactobacillus plantarum a214) isolated from alfalfa silage; a cellulase-producing Bacillus(CB) isolated from fresh alfalfa; cellulase(C); and the combined additives(a214+C and a214+CB). Silage fermentation characteristics, chemical composition and microorganism populations were analysed after 30, 60 and 65 days(60 days followed by exposure to air for five additional days). In vitro digestibility was analysed for 30 and 60 days. Compared with the other treatments, selected LAB a214, a214 combined with either C or CB, and Chikuso-1 had the decreased(Pling process, and there were no differences(P>0.05) among them. Fiber degradation was not significant(P≥0.054) in any C or CB treatments. The a214 treatment showed the highest(P=0.009) in vitro digestibility of dry matter(595.0 g kg–1DM) after ensiling and the highest abundance of Lactobacillus(69.42 and 79.81%, respectively) on days 60 and 65, compared to all of other treatments. Overall, the silage quality of alfalfa was improved with the addition of a214, which indicates its potential as an alfalfa silage inoculant.

关键词： alfalfa silage cellulase fermentation quality invitro digestibility lactic acid bacteria

Damping and power spectra of quasi-periodic intensity disturbances above a solar polar coronal hole

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Research in Astronomy and Astrophysics 2016年第6期16卷 85-92页

作者： Fang-Ran Jiao li-dong xia Zheng-Hua Huang Bo li Hui Fu Ding Yuan Kalugodu Chandrashekhar Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space Sciences Shandong University Weihai 264209 Shandong China Jeremiah Horrocks Institute University of Central Lancashire Preston PR1 2HE UK

We study intensity disturbances above a solar polar coronal hole that can be seen in the AIA 171 and 193 ＆ passbands, aiming to provide more insights into their physical nature. The damping and power spectra of the intensity disturbances with frequencies from 0.07 mHz to 10.5 mHz are investigated. The damping of the intensity disturbances tends to be stronger at lower frequencies, and their damping behavior below 980＂（for comparison, the limb is at 945＂） is different from what happens above. No significant difference is found between the damping of the intensity disturbances in the AIA 171 ~ and that in the AIA 193 ]k. The indices of the power spectra of the intensity disturbances are found to be slightly smaller in the AIA 171/~ than in the AIA 193 ~, but the difference is within one standard deviation. An additional enhanced component is present in the power spectra in a period range of 8-40 min at lower heights. The power spectra of a spicule is highly correlated with its associated intensity disturbance, which suggests that the power spectra of the intensity disturbances might be a mixture of spicules and wave activities. We suggest that each intensity disturbance in the polar coronal hole is possibly a series of independent slow magnetoacoustic waves triggered by spicular activities.

关键词： Sun: corona- Sun: waves -- Sun: turbulence -- method: observational

Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

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International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao liang dong Wang Guanghe li Guangyu Sun Mingyu Yu dong xia Chunjian Ding College of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua Coal Industry Co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy Co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability ***,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical ***,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope *** the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding *** integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is ***,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is *** analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear *** spatial form equation of the sliding mass comprises an ellipsoid and weak plane *** analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite ***,the3D stability coefficient of the composite slope exhibits an exponential co

关键词： Composite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability Coordinated development distance

Effect of Bimodal Quasicrystal Phase on the Dynamic Recrystallization of Mg–Zn–Gd Alloy during High-Pressure Torsion

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1128-1134页

作者： Ping li Shuangwu xia Junfu dong liangwei Dai Zhicheng Luo Kemin Xue School of Material Science and Engineering Hefei University of TechnologyHefei230009China

The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. The results showed that the block I-phase can stimulate obvious particle-stimulated nucleation and dynamic recrystallization (DRX) grains were preferentially formed after HPT for 5 turns, while the granular I-phase only promoted the generation of sub-grains. The orientation relationship was determined as twofold//[1210] and fivefold//(0002)_(Mg). Moreover, after HPT for 9 turns, the DRX grains induced by block I-phase appeared to grow up and coarsened. Compared with block I-phase, the grains induced by granular I-phase presented much smaller size and distributed more homogeneous due to the strong pinning effect.

关键词： High-pressure torsion(HPT)-Quasicrystal phase Dynamic recrystallization Particle-stimulated nucleation Orientation relationship