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211.
Irena Ban Janja StergarMiha Drofenik Gregor FerkDarko Makovec 《Journal of magnetism and magnetic materials》2011,323(17):2254-2258
Mechanical alloying of a mixture of copper and nickel powders has been applied for the preparation of copper-nickel alloy particles in the nanometer range. The particles were designed to be used for controlled magnetic hyperthermia applications. The milling conditions were optimized using the desired alloy composition. Utilizing a ball-to-powder mass ratio of 20, we could obtain a nanocrystalline Cu27.5Ni72.5 (at%) alloy with a crystallite size of around 10 nm and a Curie temperature of 45 °C.Thermal demagnetization in the vicinity of the Curie temperature of the nanoparticles was determined by thermomagnetic measurements using an adapted TGA-SDTA apparatus. The size and morphology of the particles were determined by XRD measurements and TEM analyses. The magnetic properties were also examined with a VSM. The magnetic heating effects were measured for the powdered material. 相似文献
212.
S. Ban X.X. Liang 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,5(1):153-158
The interface polaron states in a heterojunction are discussed by considering an energy-band bending near the interface and
the influence of an image potential. The ground state energy and the effective mass of a polaron are variationally calculated.
The numerical results for the GaAs/
heterojunction are given. It is shown that even though the influences from bulk longitudinal optical (LO) phonons are more
important for the heterojunctions with lower Al composition, the contributions from two branches of interface optical (IO)
phonons are not negligible. For the heterojunctions with higher Al composition, both the influences from LO phonons and two
branches of IO phonons are important. The band-bending plays an important role for the interface localization of polarons,
but the influence of the image potential is not essential.
Received: 4 November 1997 / Revised and Accepted: 9 March 1998 相似文献
213.
A solvable model of quantum-statistical mechanical frequency modulation is proposed and is solved for the cases of boson and two-state irrelevant subsystems to obtain the intensity distribution for a certain operator of the relevant subsystem. The damping theoretical approach, which is based on the time-independent projection operator method, to the model is also investigated. 相似文献
214.
An oligomer or low polymer, polysulfonyldiphenylene thiophenylphosphonate (PSTPP), was synthesized from phenylphosphonothioic dichloride (PPTD) and 4,4′-sulfonyldiphenol (SDP) by polycondensation reaction. Its structures and thermal behaviors were studied using infrared spectrophotometer and thermal gravimetric analysis, respectively. This novel oligomer can be used as the flame retardant for poly(ethylene terephthalate) (PET). PET samples containing PSTPP can reach an oxygen index (OI) of 29 and a UL-94 V-0 rating when the phosphorus content of the sample is 2.5 wt%. No melting dripping was observed during the UL-94 flame test. 相似文献
215.
针对目前一些企业与建筑工程项目盲目上马,建成后出现经营不景、亏本倒闭、关停并转、滞销积压等情况,文章提出重视可行性研究决择意义的建议。 相似文献
216.
217.
Hoang The Ban Yasuo Tsunogae Takeshi Shiono 《Journal of polymer science. Part A, Polymer chemistry》2005,43(6):1188-1195
This article reports a new methodology for preparing highly stereoregular styrene (ST)/1,3‐butadiene (BD) block copolymers, composed of syndiotactic polystyrene (syn‐PS) segments chemically bonded with cis‐polybutadiene (cis‐PB) segments, through a stereospecific sequential block copolymerization of ST with BD in the presence of a C5Me5TiMe3/B(C6F5)3/Al(oct)3 catalyst. The first polymerization step, conducted in toluene at ?25 °C, was attributed to the syndiospecific living polymerization of ST. The second step, conducted at ?40 °C, was attributed to the cis‐specific living polymerization of BD. The livingness of the whole polymerization system was confirmed through a linear increase in the weight‐average molecular weights of the copolymers versus the polymer yields in both steps, whereas the molar mass distributions remained constant. The profound cross reactivity of the styrenic‐end‐group active species with BD toward ST led to the production of syn‐PS‐b‐cis‐PB copolymers with extremely high block efficiencies. Because of the presence of crystallizable syn‐PS segments, this copolymer exhibited high melting temperatures (up to 270 °C), which were remarkably different from those of the corresponding anionic ST–BD copolymers, for which no melting temperatures were observed. Scanning electron microscopy pictures of a binary syn‐PS/cis‐PB blend with or without the addition of the syn‐PS‐b‐cis‐PB copolymers proved that it could be used as an effective compatibilizer for noncompatibilized syn‐PS/cis‐PB binary blends. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1188–1195, 2005 相似文献
218.
Masashi Ban Keiko Kurokawa Rei Momose Osamu Hirota 《International Journal of Theoretical Physics》1997,36(6):1269-1288
An optimum quantum measurement that minimizes the average probability of error is considered for symmetric quantum states.
The positive operator-valued measure (POM) which satisfies the necessary and sufficient condition for the minimization of
the average probability of error is derived by using the quantum Bayes strategy. It is also shown that the mutual information
obtained in the optimum quantum measurement becomes extremum. Furthermore, an optimum quantum measurement for parameter estimation
is found for symmetric quantum states by applying the maximum-likelihood estimation. The optimum POM for the parameter estimation
has the same structure as that for the quantum state discrimination. 相似文献
219.
通过电沉积方法 ,以气 /液界面上形成的硬脂酸单分子膜为模板诱导沉积金属银膜 .考察了镀液 pH值、单分子膜表面压及沉积电位对银膜形貌及结构的影响 .实验发现 ,酸性镀液的气 /液界面上形成的单分子膜不能诱导沉积银 ,而在中性和碱性镀液的气 /液界面上可以诱导银膜的生长 .当单分子膜处于液态或固态时 ,气 /液界面有银膜形成 ;液态单分子膜上的银膜生长速度较快 ,且银膜的结构一致 .随着电极电位的升高 ,银膜沉积的速度加快 ,呈环状向外生长的圆形银膜逐渐变得不规则 .将不同实验条件下的银膜转移出来 ,采用扫描电镜 (SEM )、透射电镜 (TEM )对银膜的结构与形貌进行了表征 .研究表明 ,银首先在单分子膜上异相成核 ,由八面体构型逐渐发展成星型 ,最终在气 /液界面形成具有松枝状微观结构的光亮银膜 . 相似文献
220.
We establish the connection between the standard intertwining operators for a square integrable representation and its Aubert involution. In the cases of special orthogonal groups and symplectic groups, we define the R-group for a nontempered unitary representation, under the assumption that the Aubert involution of the representation is square-integrable. 相似文献