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(K_(0.5)Na_(0.5))Nb_(1-x)Ta_(x)O_(3)铁电性的第一性原理研究

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原子与分子物理学报 2025年第4期42卷 138-146页

作者：褚新建雷博程刘晨曦刘纪博新疆科技学院信息科学与工程学院库尔勒841000 新疆大学物理科学与技术学院新疆固体物理与器件重点实验室乌鲁木齐830046 西安工业大学光电工程学院西安710032

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))Nbo_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥... 详细信息

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))Nbo_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥发性使其应用范围受到了极大的限制.基于这样的考虑,本文基于密度泛函理论的第一性原理方法,探究了(K_(0.5)Na_(0.5))Nb_(1-x)TaxO_(3)(x=0.125,0.25,0.375,0.5,0.625,0.75,0.875,1)九种体系的铁电性能,结果表明:随着Ta浓度的增加,晶格常数发生了突变,由此猜测KNN材料随着Ta浓度的增加,发生了正交-单斜的相变;Ta的掺入能够降低KNN材料的烧结难度,且随着Ta浓度的增加,形成难度逐渐降低;掺杂体系中,Ta-4f轨道与Na-3p,K-4p以及O-2s轨道电子发生了杂化,使导带底Nb-4d与Na-3p电子的态密度峰向高能区移动,禁带宽度呈现增加的趋势;在分析KNN材料铁电性作用机理时发现KNN的铁电极化类型是离子位移型极化,且在[001]方向上不具有极化能力.分析掺杂后各个体系的极化强度,发现随着Ta浓度的增加,极化强度逐渐降低,但是在低浓度掺杂时极化有向上增加的趋势,这可能是体系在低浓存在着正交与单斜的准同型相界(Morphotropic phase boundary,MPB)导致的,由此可以判断,低浓度掺杂有利于提高KNN材料的铁电性能.

关键词：第一性原理钙钛矿结果 KNN 铁电性

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Anti-oxidant and Anti-inflammatory Effects of Ethanol Extract from Polygala sibirica *** megalopha *** Lipopolysaccharide-Stimulated RAW264.7 Cells

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Chinese Journal of Integrative Medicine 2023年第10期29卷 905-913页

作者： YANG cheng-liu WANG Shi-bo HE Wen-ping LIU jin-juan Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province School of Life ScienceJiangsu Normal UniversityXuzhouJiangsu Province221116China

Objective To investigate the anti-oxidant and anti-inflammatory effects of ethanol extract of Polygala sibirica *** megalopha Fr.(EEP)on RAW264.7 mouse *** RAW264.7 cells were pretreated with 0–200µg/mL EEP or vehicle for 2 h prior to exposure to 1µg/mL lipopolysaccharide(LPS)for 24 *** oxide(NO)and prostaglandin(PGE2)production were determined by Griess reagent and enzyme-linked immunosorbent assay(ELISA),*** mRNA levels of inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),tumor necrosis factorα(TNF-α),interleukin-1beta(IL-1β),and IL-6 were determined using reverse transcription polymerase chain reaction(RT-PCR).Western blot assay was used to determine the protein expressions of iNOS,COX-2,phosphorylation of extracellular regulated protein kinases(ERK1/2),c-Jun N-terminal kinase(JNK),inhibitory subunit of nuclear factor Kappa B alpha(IκB-α)and *** was used to observe the nuclear expression of nuclear factor-κB p65(NF-κB p65).Additionally,the anti-oxidant potential of EEP was evaluated by reactive oxygen species(ROS)production and the activities of catalase(CAT)and superoxide dismutase(SOD).The 2,2-diphenyl-1-picrylhydrazyl(DPPH),hydroxyl(OH),superoxide anion(O2−)radical and nitrite scavenging activity were also *** The total polyphenol and flavonoid contents of EEP were 23.50±2.16 mg gallic acid equivalent/100 g and 43.78±3.81 mg rutin equivalent/100 *** EEP treatment(100 and 150µg/mL),there was a notable decrease in NO and PGE2 production induced by LPS in RAW264.7 cells by downregulation of iNOS and COX-2 mRNA and protein expressions(P<0.01 or P<0.05).Furthermore,with EEP treatment(150µg/mL),there was a decrease in the mRNA expression levels of TNF-α,IL-1βand IL-6,as well as in the phosphorylation of ERK,JNK and p38 mitogen-activated protein kinase(MAPK,P<0.01 or P<0.05),by blocking the nuclear translocation of NF-κB p65 in LPS-stimulated *** addition,EEP(100 and 150µg/mL)led

关键词： Polygala sibirica L.var megalopha Fr. anti-inflammatory anti-oxidant RAW264.7 cells lipopolysaccharide Chinese medicine

Improving cleanliness of 30Cr2Ni4MoV low-pressure rotor steel by CaO-SiO_(2)-MgO-Al_(2)O_(3) slag refining

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Journal of Iron and Steel Research International 2022年第9期29卷 1434-1445页

作者： Yong-bo Peng cheng-song Liu Ling Yang Song-wei Hou Ri-jin cheng Hua Zhang Hong-wei Ni The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Huangshi Product Quality Supervision and Inspection Institute Huangshi 435000HubeiChina

The optimal composition of a CaO-SiO_(2)-Al_(2)O_(3)-MgO slag in the ladle furnace refining process was investigated to precisely control the contents of[0]and[Si]and improve the cleanliness of 30Cr2Ni4MoV *** iso-[O]lines and iso-[Si] lines of the equilibrium between the CaO-SiO_(2)-Al_(2)O_(3)-MgO refining slag and 30Cr2Ni4MoV steel at 1873 K were calculated by the thermodynamic software FactSage 7.3,and the activities of SiO_(2),Al_(2)O_(3)and CaO in the refining slag were discussed to achieve the optimal composition range of the refining ***,combined with high-temperature"slag-steel"equilibrium experiments,the effects of different refining slags on the oxygen contents,chemical composi-tions,quantities and sizes of inclusions in steels were studied,and then the thermody namic formation mechanism of MgAl_(2)O_(4) inclusions in 30Cr2Ni4MoV steel was *** results showed that the contents of dissolved[O]nd[Si]in steel can be controlled below 10 × 10^(-6)and 0.05%.respectively;when the slag basicity is above *** CaO/Al_(2)O_(3)ratio is above *** the mass fraction of SiO_(2)in the slag docs not cxcced 7%.The chemical composition of the slag has a great influence on the removal and composition of *** assessed stability phase diagrams of ***_(2)O_(3)and MgOAl_(2)O_(3) inclusion formation in the Fe-Al-Mg-O system calculated by FactSage 7.3 show good agreement with the experimental results.

关键词： 30Cr2Ni4MoV steel Non metallic inclusion Refining slag Basicity CaO/Al_(2)O_(3) ratio

The Important Roles of Water in Protein Folding:an Approach by Single Molecule Force Spectroscopy

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Chinese Journal of Polymer Science 2018年第3期36卷 379-384页

作者： bo cheng Shu-Xun Cui School of Mechanical Engineering North University of ChinaTaiyuan 030051China Key Lab of Advanced Technologies of Materials Ministry of Education of ChinaSouthwest Jiaotong UniversityChengdu 610031China

The single-chain elasticity of a completely unfolded protein （027）8, modules of human cardiac titin） is studied in different liquid environments by the atomic force microscopy （AFM）-based single molecule force spectroscopy （SMFS）. The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments. Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded （I27）s chain upon stretching in aqueous solution, which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein. Through the analysis of the free energy changes involved in protein folding, we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions. We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution.

关键词： SMFS Protein Folding Water

Experimental Study on the Wavelengths of Two-Dimensional and Three-Dimensional Freak Waves

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China Ocean Engineering 2023年第1期37卷 154-164页

作者： CUI cheng PAN Wen-bo National Engineering Research Center for Port Hydraulic Construction Technology M.O.T.Tianjin Research Institute of Water Transport EngineeringTianjin 300456China

Freak waves are commonly characterized by strong-nonlinearity, and the wave steepness, which is calculated from the wavelength, is a measure of the degree of the wave nonlinearity. Moreover, the wavelength can describe the locally spatial characteristics of freak waves. Generally, the wavelengths of freak waves are estimated from the dispersion relations of Stokes waves. This paper concerns whether this approach enables a consistent estimate of the wavelength of freak waves. The two-(unidirectional, long-crested) and three-dimensional(multidirectional, shortcrested) freak waves are simulated experimentally through the dispersive and directional focusing of component waves, and the wavelengths obtained from the surface elevations measured by the wave gauge array are compared with the results from the linear, 3rd-order and 5th-order Stokes wave theories. The comparison results suggest that the 3rd-order theory estimates the wavelengths of freak waves with higher accuracy than the linear and 5th-order theories. Furthermore, the results allow insights into the dominant factors. It is particularly noteworthy that the accuracy is likely to depend on the wave period, and that the wavelengths of longer period freak waves are overestimated but the wavelengths are underestimated for shorter period ones. In order to decrease the deviation, a modified formulation is presented to predict the wavelengths of two-and three-dimensional freak waves more accurately than the 3rd-order dispersion relation, by regression analysis. The normalized differences between the predicted and experimental results are over 50% smaller for the modified model suggested in this study compared with the 3rd-order dispersion relation.

关键词： freak wave rogue wave wavelength three-dimension directional spread multidirectional wave

Fullerene bisadduct stabilizers:The effect of different addition positions on inhibiting the autocatalytic decomposition of nitrocellulose absorbed nitroglycerin

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Defence Technology（防务技术） 2021年第6期17卷 1944-1953页

作者： Ling Liao bo jin Zhi-cheng Guo Fei Xian Chen-jie Hou Ru-fang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologySichuanMianyang621010China

To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose(NC)/nitroglycerine(NG),we synthesized N-(4-methoxy)phenylpyrrolidine-C_(60) and four different of bis(N-(4-methoxy)phenylpyrrolidine)-C_(60) compounds through Prato *** structures were characterized by UVevis,^(1)H NMR,^(13)C NMR,high-resolution mass spectroscopy,and single-crystal X-ray *** stabilization effect to NC/NG were investigated using differential scanning calorimetry,methyl violet,vacuum stabilization effect,weight loss,and accelerating rate calorimeter *** results indicated these compounds had excellent stabilization effect to NC/*** stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C_(60).Moreover,the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different,and its stabilization effect to NC is also *** stabilization effect order of different bisadduct isomers to nitrocellulose is as follows:e-edge>trans-2>cis-2>*** paramagnetic resonance(EPR)and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/*** EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide,and their ability is better than that of the monoadduct and C_(60),which is consistent with the results of stabilization effect performance test.

关键词： Fulleropyrrolidine bisadducts Stabilization effect Nitrocellulose/nitroglycerine

Design and test of 2ZYM-2 potted vegetable seedlings transplanting machine

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International Journal of Agricultural and Biological Engineering 2020年第1期13卷 101-110页

作者： Xin jin Qun cheng bo Zhao Jiangtao Ji Mingyong Li College of Agricultural Equipment Engineering Henan University of Science and TechnologyLuoyang 471003China Collaborative Innovation Center of Machinery Equipment Advanced Manufacturing of Henan Province Luoyang 471003China Chinese Academy of Agricultural Mechanization Sciences Beijing 100083China

In order to improve the efficiency and quality of transplanting vegetables in dry land,based on the seedling technology,transplanting effect and analysis of the planting process,a potted vegetable seedlings transplanting machine was *** mainly comprised rotary disc type feeding mechanism,five-bar duckbill type planting mechanism(simulated duckbill mechanism,disc cam,connecting rod,crank,fork,cable)and power transmission *** on the physical parameters of the seedlings and design requirements,it was determined that the diameter of the duckbill was D=90 mm,the opening and closing angle was 25°,and the taper angle was 17°.A test bench with adjustable parameters was built by analyzing the structure of the planting mechanism and the motion of the working *** digital speckle technique was used to optimize the parameters,so that the length of the crankshaftΙwas S1=100 mm,the length of the crankshaftΙΙwas S2=80 mm,the length of the connecting rodΙwas S3=140 mm,the length of the connecting rodΙΙwas S4=260 mm,the length of rod to connecting the rack was S6=314 mm,and the height of planting track was H=450 *** to the above parameters and the control requirements of the duckbill mechanism,the cam stroke was determined to be S=15 *** the initial phase difference between the two cams was 180°.The experiment was carried out with pepper seedlings as transplanting *** results showed that when the planting frequency was 50-70 plants/min,the seedling upright rate was 93%-91.1%,the planting depth qualified rate was 96%-92%.The leakage rate was 0-0.26%,the variation coefficient of plant spacing was 0.37%-0.67%,the injury rate was 0%,and the mechanical damage degree of the mining surface was 2.43-3.77 mm/*** machine can effectively improve the quality of transplanting,which can meet the production needs and design requirements of the mechanism.

关键词： seedling transplanting planting mechanism digital speckle parameter optimization test analysis

Adversarial robustness analysis of LiDAR-included models in autonomous driving

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High-Confidence Computing 2024年第1期4卷 60-69页

作者： bo Yang Zizhi jin Yushi cheng Xiaoyu Ji Wenyuan Xu College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Hangzhou Zhuoxi Institute of Brain and Intelligence Hangzhou 311100China

In autonomous driving systems,perception is pivotal,relying chiefly on sensors like LiDAR and cameras for environmental ***,celebrated for its detailed depth perception,is being increasingly integrated into autonomous *** this article,we analyze the robustness of four LiDAR-included models against adversarial points under physical *** first introduce an attack technique that,by simply adding a limited number of physically constrained adversarial points above a vehicle,can make the vehicle undetectable by the LiDAR-included *** reveal that adversarial points adversely affect the detection capabilities of both LiDAR-only and LiDAR–camera fusion models,with a tendency for more adversarial points to escalate attack success ***,voxel-based models are more susceptible to deception by these adversarial *** also investigated the impact of the distance and angle of the added adversarial points on the attack success ***,the farther the victim object to be hidden and the closer to the front of the LiDAR,the higher the attack success ***,we have experimentally proven that our generated adversarial points possess good cross-model adversarial transferability and validated the effectiveness of our proposed optimization method through ablation ***,we propose a new plug-and-play,modelagnostic defense method based on the concept of point *** ROC curve of this defense method shows an AUC value of approximately 0.909,demonstrating its effectiveness.

关键词： Autonomous driving LiDAR Adversarial example Defense

Multiple Positive Solutions for Semi-positone m-point boundary Value Problems

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 419-426页

作者： cheng-bo Zhai cheng Yang School of Mathematical Science Shanxi University Shanxi 030006 China Business College of Shanxi University Shanxi 030031 China

In this article, we establish the existence of at least two positive solutions for the semi-positone m-point boundary value problem with a parameter u （t）＋ λf （t, u） = 0, t ∈ （0, 1）, u （0） = sum （biu （ξ i ）） from i=1 to m-2, u（1）= sum （aiu（ξ i ）） from i=1 to m-2, where λ 〉 0 is a parameter, 0 〈 ξ 1 〈 ξ 2 〈 ··· 〈 ξ m 2 〈 1 with 0 〈sum ai from i=1 to m-2 〈 1, sum bi from i=1 to m-2 =1 b i 〈 1, a i , b i ∈ [0, ∞） and f （t, u） ≥ M with M is a positive constant. The method employed is the Leggett-Williams fixed-point theorem. As an application, an example is given to demonstrate the main result.

关键词： Multiple positive solutions cone semi-positone m-point boundary value problem,concave functional parameter