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| 1 | 查看详情显示文摘 | Minofar B Jungwirth P R.Das M | | 0，，23： | 1 |
| 2 | 抵御“杀手小行星” 可能让地球更安全的科技显示文摘美国宇航局(以下简称NASA)的科学家们成功地让一颗小行星偏离其运行轨道,让我们的星球又安全了一点儿。2022年9月26日,烘干机大小的“双小行星重定向测试”任务飞船(以下简称DART),撞上了一个没有威胁性的小行星Dimorphos。此举证明:万一有朝一日有“杀手小行星”朝我们而来,人类或许在地球就能组织开展保卫战。 | Saswato R.Das | 2023 | 空中英语教室(高级版.彭蒙惠英语)2023，，4： | 0 |
| 3 | 铁和硫用量对煤液化的影响——模型建立与最佳条件选择显示文摘在温度为450℃、H_2压强稳定在24.5±0.2MPa的间歇式高压釜里,用Samla,Kottadih煤与低温煤焦油(230~330℃)在不同铁、硫浓度下进行了加氢反应试验。非线性参数估计和统计分析显示出,通过一种简单的二次回归模型,可以相当满意地解释随铁和硫用量的不同,总量、煤、苯可溶性产物(BSP)和沥青烯转化率的变化情况。此外,在各种不同的非线性约束集下,多变量的、非线性目标函数的最优化表明,在铁和硫的特定用量下,油的产率随非需要产物的产率降至最小而变得最大。 | R.Das Gupta 李雷 | 1992 | 煤化工1992，，4： | 0 |
| 4 | Closed-Form Solutions of Stress Intensity Factors for Semi-elliptical Surface Cracks in a Cylindrical Bar Under Pure Tension显示文摘In this work,the stress intensity factors(SIFs)for a wide range of semi-elliptical surface cracks with different inclination angles in a cylindrical bar subjected to pure tension were investigated numerically.The main parameters considered to evaluate the SIFs were the crack size ratio(a/d),the crack aspect ratio(a/c),and the crack inclination angle(0).The dual-boundary element met hod implemented in software BEASY was used to compute the SIF values for cracks.Furt her more,the general closed-form solutions were proposed to evaluate the corresponding SIFs for Mode I,Mode II and Mode III types of fracture through curve fitting approaches.These solutions can provide accurate and reliable values of stress intensity factors for a crack on a cylindrical bar under pure tension in a rapid way compared to those obtained using computational models.In addition,these results can be used as inputs for failure studies and life evaluations of cracked cylinder under working conditions. | M.K.Ramezani S.Ramesh J.Purbolaksono R.Das | 2022 | Acta Mechanica Solida Sinica2022，35，2： | 0 |
| 5 | Ultralight,ductile metal mechanical metamaterials with super elastic admissible strain(0.1)显示文摘Mechanical metamaterials are architectured cellular materials with unusual properties.Herein we report another type of metal mechanical metamaterials-their elastic admissible strain(EAS)is on the order of 0.1,compared to about 0.01 for common metallic materials.Four conditions are required for a metal mechanical metamaterial to achieve this super EAS:(i)bending-dominated deformation;(ii)low density;(iii)an appropriate lattice topology,and(iv)an intrinsically high EAS for the lattice strut constituent material.The findings of this work extend perspectives on metal mechanical metamaterials. | H.Z.Zhong T.Song R.Das C.W.Li J.F.Gu M.Qian | 2023 | Journal of Materials Science & Technology2023，，31： | 0 |
| 6 | SYNTHESIS AND CHARACTERIZATION OF COMPLEX FERROELECTRIC OXIDE显示文摘The polycrystalline sample of Li_(2)Pb_(2)Pr_(2)W_(2)Ti_(4)V_(4)O_(30) was prepared by a solid-state reaction technique.The preparation conditions of the compound have been optimized using thermal analysis(DTA and TGA)technique.Room temperature structural analysis confirms the formation of single phase compound in orthorhombic crystal system.The surface morphology of the sample,recorded by scanning electron microscope,shows uniform grain distribution on the surface of the sample.The observation of hysteresis loop confirmed that the material has ferroelectric properties at room temperature.Electrical properties of the material were studied by complex impedance spectroscopic technique.Temperature dependence of electrical parameters(impedance,modulus,etc.)is strongly correlated to the micro-structural characteristics(bulk,grain boundary,etc.)of the sample.A typical temperature-dependent resistive characteristic of the sample(i.e.,negative temperature coe±cient of resistance(NTCR))exhibits its semiconducting properties.The temperature dependence of dc conductivity shows a typical Arrhenius behavior.A signature of ionic conductivity in the system was observed in ac conductivity spectrum.The sample obeys Jonscher's universal power law.The hopping mechanism for electrical transport properties of the system with nonexponential-type conductivity relaxation was suggested from the electrical modulus analysis. | PIYUSH R.DAS B.N.PARIDA R.PADHEE R.N.P.CHOUDHARY | 2012 | Journal of Advanced Dielectrics2012，2，4： | 0 |
| 7 | Synthesis of RNA-Amphiphiles via Atom Transfer Radical Polymerization in the Organic Phase显示文摘The combination of hydrophobic polymers with nucleic acids is a fascinating way to engineer the self-assembly behavior of nucleic acids into diverse nanostructures such as micelles,vesicles,nanosheets,and worms.Here we developed a robust route to synthesize a RNA macroinitiator with protecting groups on the 2′-hydroxyl groups in the solid phase using an oligonucleotide synthesizer.The protecting groups successfully solubilized the RNA macroinitiator,enabling atom transfer radical polymerization(ATRP)of hydrophobic monomers.As a result,the RNA−polymer hybrids obtained by ATRP exhibited enhanced chemical stability by suppressing cleavage.In addition,we demonstrated evidence of controlled polymerization behavior as well as control over the molecular weight of the hydrophobic polymers grown from RNA.We envision that this methodology will expand the field of RNA−polymer conjugates while vastly enhancing the possibility to alter and engineer the properties of RNA-based polymeric materials. | Jaepil Jeong Grzegorz Szczepaniak Subha R.Das Krzysztof Matyjaszewski | 2023 | Precision Chemistry2023，1，5： | 0 |
| 8 | Dielectric response and pyroelectric properties of lead-free ferroelectric Ba_(3)(VO_(4))_(2)显示文摘The current paper presents results of dielectric response,pyroelectric behavior and conductivity study of lead-free ferroelectric barium orthovanadate(Ba_(3)(VO_(4))_(2)or Ba_(3)V_(2)O_(8))ceramic,for a wide range of temperature and frequency.An X-ray diffraction study suggests the formation of a single-phase compound in trigonal crystal system.The SEM micrograph of gold-coated pellet sample shows well-defined and homogeneous morphology.Detailed studies of dielectric parameters(ε_(r)and tanδ)of the compound as a function of temperature and frequency reveal their independence over a wide range of temperature and frequency.The nature of Polarization versus electric field(P-E)hysteresis loop of Ba_(3)V_(2)O_(8)at room temperature suggests its ferroelectric nature.The temperature dependence of pyroelectric coefficient and figure of merits of the sample support its dielectric response.The nature of variation of dc conductivity with temperature confirms the Arrhenius and negative temperature coefficient of resistance(NTCR)behavior of the material. | Biswajit Pati R.N.P.Choudhary Piyush R.Das B.C.Sutar | 2015 | Journal of Advanced Dielectrics2015，5，1： | 0 |
| 9 | Electrical properties of Na_(2)Pb_(2)R_(2)W_(2)Ti_(4)V_(4)O_(30)(R=Dy,Pr)ceramics显示文摘The polycrystalline samples of complex tungsten bronze(TB)Na_(2)Pb_(2)R_(2)W_(2)Ti_(4)V_(4)O_(30)(R=Dy,Pr)compounds were prepared by solid-state reaction technique.Room-temperature preliminary structural studies confirm the formation of the compounds in the orthorhombic crystal system.Detailed studies of electrical properties of the materials using complex impedance spectroscopy technique exhibit that the impedance and related parameters are strongly dependent upon temperature and microstructure(bulk,grain boundary,etc).An observation of negative temperature coefficient of resistance(NTCR)suggests the materials have semiconducting properties.The variation of AC conductivity with temperature shows a typical Arrhenius behavior of the materials.Both the samples obey Jonscher’s universal power law.The existence of hopping mechanism in the electrical transport processes in the system with non-exponential type of conductivity relaxation is confirmed by electrical modulus analysis. | Piyush R.DAS B.N.PARIDA R.PADHEE R.N.P.CHOUDHARY | 2013 | Journal of Advanced Ceramics2013，2，2： | 0 |
| 10 | Saint-Venant torsion analysis of bars with rectangular cross-section and effective coating layers显示文摘This paper investigates the torsion analysis of coated bars with a rectangular cross-section. Two opposite faces of a bar are coated by two isotropic layers with different materials of the original substrate that are perfectly bonded to the bar. With the SaintVenant torsion theory, the governing equation of the problem in terms of the warping function is established and solved using the finite Fourier cosine transform. The state of stress on the cross-section, warping of the cross-section, and torsional rigidity of the bar are evaluated. Effects of thickness of the coating layers and material properties on these quantities are investigated. A set of graphs are provided that can be used to determine the coating thicknesses and material properties so as to keep the maximum von Mises stress on the cross-section below an allowable value for effective use of the coating layer. | H.TEIMOORI R.T.FAAL R.DAS | 2016 | Applied Mathematics and Mechanics(English Edition)2016，37，2： | 0 |
| 11 | Studies of electrical conductivity and magnetic properties of Bi_(1-x)Gd_(x)FeO_(3) multiferroics显示文摘The polycrystalline samples of Bi_(1-x)Gd_(x)FeO_(3)(x=0,0.1,and 0.2)muliferroic oxides have been synthesized by a solid-state reaction/mixed oxide technique.The preliminary X-ray structural analysis with room temperature diffraction data confirmed the formation of single-phase systems.Study of room temperature scanning electron micrograph(SEM)of the surface of the above samples exhibits a uniform distribution of plate-and rod shaped grains throughout the sample surface with less porosity.The dielectric behavior of the materials was studied in a wide range of frequency(1 kHz-1 MHz)and temperature(30-400℃).The nature of temperature dependence of de conductivity confirms the Arrhenius behavior of the materials.The frequency-temperature dependence of ac conductivity suggests that the material obeys Jonscher's universal power law.An increase in Gd-content results in the enhancement of spontaneous magnetization BiFeO_(3)(BFO)due to the collapse of spin cycloid structure.The magnetoelectric coupling coefficient of BFO has been enhanced on Gd-substitution. | Samita Pattanayak R.N.P.Choudhary Piyush R.Das | 2014 | Journal of Advanced Dielectrics2014，4，2： | 0 |
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