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stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

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Acta Mechanica sinica 2015年第4期31卷 558-569页

作者： H.Wu X.W.Chen q.Fang X.Z.Kong L.L.he Institute of systems Engineering China Academy of Engineering Physics state Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact PLA University of Science and Technology

During the high-speed penetration of projectiles into concrete targets （the impact velocity ranges from 1.0 to 1.5 km/s）, important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic tra- jectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differ- ential Area Force Law （DAFL） method and semi-empirical resistance function, a finite differential approach was pro- grammed （PENTRA2D） for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed pene- trators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of ter- minal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

关键词： Projectile Penetration Concrete Massabrasion Terminal ballistic trajectory

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TheRMAL sTREssEs RELAXATION DEsIGN OF Ni/NiFe_(2)O_(4) sYsTEM FUNCTIONALLY GRADED CERMET INERT ANODE

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Acta Metallurgica sinica(English Letters) 2005年第5期18卷 635-641页

作者： J. Li q.s. Zhang Y.q. Lai s.L. Ye Y.X. Liu school of Metallurgy science and Engineering Central South University Changsha 410083 China

The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary condition during high-temp （955℃） electrolysis were calculated using the finite-element software ANsYs, the influence of different parameters on the distribution of the thermal stresses were analyzed. The results showed that, during the process of thermal shock, the thermal hoop tensile stress on the surface of the anode is very large, which is possibly the major cause of anode crack; when the radius of the anode is between 0.05-0.15m, a range that can be realized by recent manufacturing technology, the optimum composition distribution exponent p is 0.25; The hoop tensile stresses reduce with the decrease of anode scale and also decrease with the decrease of the convection coefficient between the electrolyte and the anode.

关键词： functionally graded material (FGM) transient thermal stresses ANsYs inert anode aluminum electrolysis

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A novel friction stir diffusion bonding process using convex-vortex pin tools

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Journal of Materials science & Technology 2020年第13期47卷 23-30页

作者： s.D.Ji q.Wen Z.W.Li College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China state Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

In this work,a novel friction stir diffusion bonding(FsDB)method was proposed to eliminate hook when joining thin *** tools,with several convex-vortex pins were innovatively designed to improve the diffusion bonding effect of the lap *** showed that sound joints,excellently bonded at the lap interface and without hook,were *** lap interfaces on the joints welded using the T-tool and F-tool almost remained intact,thereby indicating that they were formed by diffusion *** material flow behavior was also simulated by FLUENT software and the results showed that the material flow along thickness was significantly enhanced by increasing the pin *** joint welded by the T-tool showed shear fracture *** bonding was formed at the lap interface when using the F-tool and thus the joint showed tensile fracture.

关键词： Friction stir diffusion bonding Convex-vortex pin Hook Material flow Failure

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尿有机酸代谢异常与早产儿视网膜病变的相关性分析

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中华眼底病杂志 2024年第6期40卷 434-442页

作者：何露孙慧清郑州大学附属儿童医院河南省儿童医院新生儿科系郑州450000

目的观察早产儿视网膜病变(ROP)患儿尿代谢产物氨基酸水平变化及其对ROP的影响,初步分析其可能参与ROP发生的氨基酸代谢途径。方法回顾性队列研究。2020年1月至2023年12月于郑州大学附属儿童医院住院治疗且出生胎龄1提示该物质为两组差... 详细信息

目的观察早产儿视网膜病变(ROP)患儿尿代谢产物氨基酸水平变化及其对ROP的影响,初步分析其可能参与ROP发生的氨基酸代谢途径。方法回顾性队列研究。2020年1月至2023年12月于郑州大学附属儿童医院住院治疗且出生胎龄s-DA)模型对尿氨基酸进行代谢组学分析,变量投影重要性(VIP)分值>1提示该物质为两组差异表达氨基酸。采用受试者工作特征(ROC)曲线和曲线下面积比较尿氨基酸对重度ROP的预测价值。对t检验及代谢组学分析两组差异较大的氨基酸归一化后进行对比并行Pearson相关性分析。采用京都基因和基因组百科全书数据库富集分析差异表达氨基酸参与ROP发生的代谢通路。结果与对照组比较,ROP组患儿尿代谢产物中草酸-2、亚硫基二乙酸-2浓度明显降低,4-羟基丁酸-2、3-甲基戊烯二酸-2(1)、2-酮戊二酸-OX-2(2)、3,6-环氧-十二烷二酸-2浓度明显升高,差异有统计学意义(t=0.036、0.005、0.038、0.032、0.022、0.011,Ps-DA分析结果显示,ROP组、对照组受检儿尿代谢产物氨基酸分布于散点图的左右两个区域,两组之间呈现满意分离趋势(R2 Ycum=0.0574,q2cum=0.0257,Ps-plot图显示偏向两极的氨基酸分别是乙醇酸-2、磷酸-3、草酸-2、亚硫基二乙酸-2、4-羟基丁酸-2、3-甲基巴豆酰甘氨酸-1、3-甲基戊烯二酸-2(1)、2-酮戊二酸-OX-2(2)、3,6-环氧-十二烷二酸-2;筛选出VIP分值>1的差异表达氨基酸11个,其中VIP分值最高的是草酸-2、甘油酸-3、磷酸-3、3-甲基巴豆酰甘氨酸-1、尿黑酸-3、亚硫基二乙酸-2。两组氨基酸浓度差异最大的为4-羟基丁酸-2和亚硫基二乙酸-2;草酸-2与甘油酸-3之间相关性最大(r=0.830,P<0.001),多数氨基酸之间表现为正相关。ROC曲线拟合分析结果显示,11个差异表达的氨基酸联合预测ROP的曲线下面积最大(0.816),截断值为0.531,灵敏度和特异性分别为83.1%和70.0%。富集分析提示,11个差异表达的氨基酸涉及的主要通路途径包括丁酯酸代谢、乙醛酸和二羧酸代谢、硫辛酸代谢。结论4-羟基丁酸-2、3-甲基戊烯二酸-2(1)、亚硫基二乙酸-2、2-酮戊二酸-OX-2(2)、3,6-环氧-十二烷二酸-2氨基酸代谢异常可能对ROP的发生有一定影响。

关键词：早产儿尿代谢早产儿视网膜病变尿氨基酸尿代谢产物

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Influence of Fe Addition on Products of self-Propagating High-Temperature synthesis Reaction in 3Ti-si-2C system

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稀有金属材料与工程 2009年第A3期38卷 113-118页

作者： Guan q L Wang H Y Li s L si W P Jiang q C Key Laboratory of Automobile Materials of Ministry of Education Jilin University Changchun 130025 China

Influence of Fe addition on products of self-propagating high-temperature synthesis (sHs) reaction in 3Ti-si-2C system was investigated in the present study. Without Fe addition, Ti5si3 and TiC are the dominant phases along with a small amount of Ti3siC2 phase and unreacted C left in the final products. As Fe content ranges from 10% to 30%, the products consist of TiC, Ti5si3, Fe2Ti and unreacted C, but no trace of Ti3siC2 phase is detected. Furthermore, the amounts of both Fe2Ti and C phases increase with Fe content increasing. Addition of Fe has a great effect on the reaction route and significantly restrains the formation of Ti3siC2 during the combustion synthesis process, and therefore, the sHs is not an effective fabrication technique to synthesize the ternary Ti3siC2 ceramic in either 3Ti-si-2C or Fe-3Ti-si-2C system. Besides, without Fe addition, Ti5si3 presents as the coarse irregular appearance with an obviously sintered morphology. In contrast, the shape of Ti5si3 exhibits more and more spherical (cobblestone-like) and the surface becomes increasingly smooth, because the amount of liquids formed during the sHs reaction increases with the increase of Fe content. On the other hand, with Fe content increasing from 0 to 30 wt.%, the particulate size of TiC decreases from more than 5 μm to 1 μm or less, mainly due to the fact that the combustion temperature decreases with the increase of Fe content in the preforms.

关键词：复合材料铁含量燃烧过程物理性能

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Two loop low temperature corrections to electron self energy

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Chinese Physics C 2011年第7期35卷 608-611页

作者： Mahnaz q. Haseeb samina s. Masood Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan Department of Physics University of Houston Clear Lake Houston TX 77058

We recalculate the two loop corrections in the background heat bath using real time formalism. The procedure of the integrations of loop momenta with dependence on finite temperature before the momenta without it has been followed. We determine the mass and wavefunction renormalization constants in the low temperature limit of qED, for the first time with this preferred order of integrations. The correction to electron mass and spinors in this limit is important in the early universe at the time of primordial nucleosynthesis as well as in astrophysics.

关键词： renormalization finite temperature field theory electron self energy two-loop corrections

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Influence of previous plane of nutrition on molecular mechanisms regulating the expression of urea and water metabolism related genes in the rumen and kidney of finishing crossbred Angus steers

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Animal Nutrition 2024年第2期17卷 232-243页

作者： Aghata E.Moreira da silva Arturo Macias Franco Bradley s.Ferguson Mozart A.Fonseca College of Agriculture Biotechnology&Natural Resources University of Nevada Department of Animal and Range sciences Clayton Livestock Research Center New Mexico State University

This study aimed to understand how molecular mechanisms controlling water and urea metabolism at the finishing phase can be affected by previous plane of nutrition of crossbred Angus beef steers. Twentyfour(n = 24) animals were randomly distributed into either a moderate(MP) or high plane of nutrition during the background phase for 85 d. Animals were then blocked by their previous plane and were moved onto a 105-d finishing phase in a 2 × 2 factorial arrangement. The forage-finished group received only high-quality alfalfa hay, whereas the grain-fed group received a high grain diet(80% whole corn and20% alfalfa hay). By the end of the finishing phase, animals were harvested and tissue samples from the rumen and kidney were collected. Changes in gene expression of aquaporins(AqP)-2,-3,-4,-7, ATP1A1,ATP1B1, sGK1, CLIC1(kidney and rumen), UT-A1(kidney only) and UT-B(rumen only), were assayed via real-time q PCR; 18s r RNA was used as an endogenous control. One-way ANOVA followed by Tukey's post hoc analysis was conducted. When animals were from MP, forage-finishing increased the relative abundance of AqP3(P ≤ 0.05), AqP7(P ≤ 0.05), ATP1B1(P ≤ 0.05), and sGK1(P ≤ 0.05) in the kidney when compared to grain-fed animals. In the rumen, for the MP group, AqP7 was differentially expressed in both treatments at the finishing phase(P ≤ 0.01), with forage-finished steers having the highest expression of AqP7. For the MP group, UT-B had a tendency of presenting a higher expression on grainfed animals(P = 0.075). Overall, these results suggest that previous plane can impact expression of genes associated with water and urea metabolism during the finishing phase, namely AqP3, AqP7, ATP1B1, and sGK1 in the kidney, and AqP7 and UT-B in the rumen. The greatest impact observed on gene expression changes of investigated genes at the finishing phase was reflective of animals backgrounded on the moderate previous plane.

关键词： Gene expression Aquaporin sodium channel Urea transporter

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A reliability assessment method based on support vector machines for CNC equipment

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science China(Technological sciences) 2009年第7期52卷 1849-1857页

作者： WU Jun DENG Chao sHAO XinYu XIE s q school of Naval Architecture and Ocean Engineering Huazhong University of Science and TechnologyWuhan 430074China state Key Laboratory of Digital Manufacturing Equipment&Technology Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of AucklandAucklandNew Zealand

With the applications of high technology,a catastrophic failure of CNC equipment rarely occurs at normal operation *** it is difficult for traditional reliability assessment methods based on time-to-failure distributions to deduce the reliability *** paper presents a novel reliability assessment methodology to estimate the reliability level of equipment with machining performance degradation data when only a few samples are *** least squares support vector machines(Ls-sVM) are introduced to analyze the performance degradation process on the equipment.A two-stage parameter optimization and searching method is proposed to improve the Ls-sVM regression performance and a reliability assessment model based on the Ls-sVM is built.A machining performance degradation experiment has been carried out on an OTM650 machine tool to validate the effectiveness of the proposed reliability assessment methodology.

关键词： reliability assessment least squares support vector machines performance degradation radial basis function parameter optimization

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Template-free Fabrication and Luminescent Characterization of Highly Uniform and Monodisperse Y_2O_2s:sm^(3+) Hollow submicrospheres

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Journal of Materials science & Technology 2012年第7期28卷 666-672页

作者： s.q. Deng Z.P. Xue Y.H. Yang q. Yang Y.L. Liu Department of Chemistry Jinan University Guangzhou 510632 China

Well dispersed and homogeneous Y2O2s：sm3＋ hollow submicrospheres were successfully achieved by a template- free solvothermal method combining with a postcalcining process. The crystalstructure and particle morphology were investigated by the X-ray diffraction （XRD）, Fourier transform infrared （FT-IR） spectra, scanning and transmission electron microscopy （sEM and TEM）, respectively. A possible growth mechanism was proposed to reveal the formation process. Luminescence properties of the Y202s：sm3＋ long-lasting phosphor were an- alyzed by measuring the excitation spectra, emission spectra, afterglow decay curve and thermoluminescence curve. The excitation spectra indicated that the phosphor could be excited effectively by the ultraviolet-light emitting diode （UV-LED） or blue LED, and the emission spectra showed that the phosphor could emit red light from 600 to 650 nm.

关键词： Yttrium oxysulfide Hollow submicrosphere Luminescence Long-lasting phosphor

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EMBRITTLEMENT OF A Cr-Mo LOW-ALLOY sTEEL DUE TO LOW-TEMPERATURE NEUTRON IRRADIATION

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Acta Metallurgica sinica(English Letters) 2006年第1期19卷 20-26页

作者： s.H. song L. q. Weng Department of Materials science and Engineering Shenzhen Graduate School HarbinInstitute of Technology Shenzhen 518055 China

Embrittlement of a Cr-Mo2.25CrlMo steel stemming from neutron irradiation at 270℃ is studied by virtue of small punch testing in conjunction with scanning electron microscopy. The ductile-brittle transition temperature determined by the small punch test is much lower than that determined by the standard Charpy test. There is some irradiation-induced embrittlement effect after the steel is irradiated for 46 days with a neutron dose rate of 1.05×10^18dpa/s （displacement per atom per second）.

关键词： irradiation embrittlement segregation low alloy steels pressure vessel

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