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81.
Application of the Local Boundary Integral Equation Method to Boundary-Value Problems 总被引:5,自引:0,他引:5
A review of the meshless formulations based on local boundary integral equation (LBIE) methods is presented. Physical quantities are approximated by the moving least-squares method. A summary of recent developments in the application of the LBIE method to potential problems, elastostatics, elastodynamics, thermoelasticity, and plate bending problems is given. The efficiency and generality of the present formulation in a wide class of engineering problems are confirmed. 相似文献
82.
A new technique (to our knowledge), for the measurement of residual wedge angle (RWA) of high optical quality transparent nearly parallel plate (PP), using a quasi-monochromatic light source, is presented. Advantages and drawbacks of the technique and the results obtained for a PP, using a filtered white light source, is discussed. A slightly modified optical setup for accurate determination of RWA, using phase shifting interferometry (PSI), has been described. Results obtained, applying PSI, for a validation experiment and for the determination of RWA of a quasi-PP is presented. The PSI based technique does not suffer from any measurement ambiguities due to limitation in effective beam aperture. Hence the technique is suitable for high accuracy measurement of RWA of PP. In both the optical setups, presented in this paper, the respective interfering beams travel the same optical circuit and are thus subject to same perturbation in optical path, due to external mechanical vibration, which finally cancels out. Thus the measurements are much less affected by external vibrations. Since the respective interfering beams undergo identical reflections and transmissions, the visibility or contrast of the interference fringes is very good. 相似文献
83.
Design,Synthesis, and X‐Ray Crystal Structure of a Fullerene‐Linked Metal–Organic Framework
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Dr. Ping Peng Dr. Fang‐Fang Li Venkata S. Pavan K. Neti Dr. Alejandro J. Metta‐Magana Prof. Dr. Luis Echegoyen 《Angewandte Chemie (International ed. in English)》2014,53(1):160-163
Given the unique structural and electronic properties of C60, metal–organic frameworks (MOFs) containing C60 linkers are expected to exhibit interesting characteristics. A new hexakisfullerene derivative possessing two pairs of phenyl pyridine groups attached to two methano‐carbon atoms located at the trans‐1 positions was designed and synthesized. The four pyridyl nitrogen atoms define a perfectly planar rectangle. This new C60 derivative was used to assemble the first fullerene‐linked two‐dimensional MOF by coordination with Cd2+. 相似文献
84.
Chebolu Naga Sesha Sai Pavan Kumar Ejjirothu Srihari Mettu Ravinder Koochana Pranay Kumar U. S. N. Murthy Vaidya Jayathirtha Rao 《Journal of heterocyclic chemistry》2013,50(Z1):E131-E135
Several new thieno[2,3‐b]pyridine and thieno[2,3‐b]quinoline derivatives are synthesized in an efficient manner catalyzed by DBU as a base. Simple workup procedure, good yields, and mild reaction conditions are the salient features of this method. All the synthesized compounds are screened for antimicrobial activity against several organisms. 相似文献
85.
The tripodal ligand N,N′,N″-tri(benzimidazolyl)-methane has been used to synthesize nickel(II) complexes along with an exogeneous
ligand, X(X = Cr−,NO
3
−
,ClO
4
−
, HCOO−, OAc− and CNS−). Electronic absorption spectra reveal that the present nickel(II) complexes have six coordinate tetragonal geometries. The
value of Racah parameter(B), crystal field splitting parameter (Dq) and term,β0 (which is a measure of covalency) have been calculated.1HNMR spectroscopy reveals a dominantσ-delocalization pattern in these complexes. 相似文献
86.
Production of 64Cu on the Sherbrooke TR-PET cyclotron 总被引:1,自引:0,他引:1
S. K. Zeisler R. A. Pavan J. Orzechowski R. Langlois S. Rodrigue J. E. van Lier 《Journal of Radioanalytical and Nuclear Chemistry》2003,257(1):175-177
At energies £15 MeV, 64Cu is most readily produced using the 64Ni(p,n)64Cu reaction. Space restrictions in the TR-PET target selector required a target system of compact design that would still allow the quick and easy removal of the irradiated target. The target consists of a 64Ni-plated rhodium disc held in place by a threaded cooling assembly. For removal, the cooling block is rotated slightly, allowing the disc to fall into a shielding container. The nickel is dissolved and the 64Cu separated by anion exchange or electrochemical deposition. Yields of up to 330 mCi of radiochemically pure 64Cu have been obtained. 相似文献
87.
D. Bazzacco F. Brandolini K. Löwenich P. Pavan C. Rossi Alvarez M. De Poli A. M. I. Haque 《Hyperfine Interactions》1990,59(1-4):133-136
The g-factor of the octupole vibrational state 3− at 1810 keV in144Sm has been measured to be 0.76(9) by means of the transient field technique. The state has been Coulomb excited by 217 MeV58Ni beam. The obtained value agrees with the predictions of RPA calculations and confirms the dominance of the proton particle-hole
configuration π(1h11/2−2d5/2
−1) 相似文献
88.
E. Amaldi C. Cosmelli S. Frasca I. Modena G. V. Pallottino G. Pizzella F. Ricci P. Bonifazi F. Bordoni V. Ferrari U. Giovanardi V. Iafolla B. Pavan S. Ugazio G. Vannaroni 《Il Nuovo Cimento C》1978,1(6):497-509
Summary The intermediate gravitational-wave antenna ofM=390 kg and ν0=1795 Hz has been operated at 4.2 K in the Laboratorio Plasma Spazio of CNR from June 10 to July 18, 1978. The data collected
during more than 50% of the time show an effective temperature of 1.5 K on the average, with periods of the order of a few
hours during which it goes below 1 K. This corresponds to an instrumental sensitivity of 2 GPU=200 J/m2·Hz. The observed difference between observed and computed equivalent temperature is due to disturbances of mechanical and
thermal origin which we believe can be further reduced.
Riassunto L'antenna gravitazionale intermedia di massaM=390 kg e frequenza ν0=1795 Hz è stata posta e mantenuta in funzione a 4.2 K nel Laboratorio del Plasma nello Spazio del CNR dal 10 Giugno al 18 Luglio 1978. I dati, raccolti per più del 50% del tempo, corrispondono in media ad una temperatura efficace di 1.5 K, con periodi dell'ordine di alcune ore durante i quali essa scende al di sotto di 1 K. Questa corrisponde a una sensibilità strumentale di 2 GPU-200 J/m2·Hz. La differenza fra il valore osservato e quello calcolato della temperatura efficace è dovuto a disturbi di origine meccanica e termica che noi riteniamo di poter ulteriormente ridurre.
Резюме Промежуточная антенна гравитационных волн сM=390 кг и ν0=1795 Гц действовала при 4.2 К в лаборатории плазмы Национального Исследовательского Центра с 10 июня по 18 июля 1978 г. Данные, полученные в течение более 50% времени, указывают эффективную температуру 1.5 К в среднем, с периодами порядка нескольких часов, в течение которЫх эффективная температура опускалась ниже 1 К. Это соответствует инструментальной чувствительности 2 GPU=200 Дж/м2·Гц. Обнаруженная разница между наблюденной и вычисленной эквивалентной температурой обусловлена возмущениями механическиой и тепловой природы, которые, как мы считаем, могут быть в дальнейшем уменьшены.相似文献
89.
Holographic superconductors containing a non-minimal derivative coupling for the scalar field in a regular phantom plane symmetric black hole have been considered. We show that the parameter of the regular black hole b as well as the non-minimal derivative coupling parameter η affect the formation of the condensate as well as the conductivity in the superconductor. Moreover, b has a critical value in which the critical temperature Tc increases without a bound. 相似文献
90.
Fabian M. Steudel Dr. Ernest Ubasart Luigi Leanza Míriam Pujals Dr. Teodor Parella Prof. Giovanni M. Pavan Prof. Xavi Ribas Prof. Max von Delius 《Angewandte Chemie (International ed. in English)》2023,62(42):e202309393
The addition of two unsymmetric malonate esters to the Buckminster fullerene C60 can lead to 22 spectroscopically distinguishable isomeric products and therefore represents a formidable synthesis challenge. In this work, we achieve 87 % selectivity for the formation of a single (in,out-trans-3) isomer by combining three approaches: (i) we use a starting material, in which the two malonates are covalently connected (tether approach); (ii) we form the strong supramolecular complex of C60 with the shape-persistent [10]CPP macrocycle (template approach) and (iii) we embed this complex further within a self-assembled nanocapsule (shadow mask approach). Variation of the spacer chain shed light on the limitations of the approach and the ring dynamics in the unusual [2]catenanes were studied in silico with atomistic resolution. This work significantly widens the scope of mechanically interlocked architectures comprising cycloparaphenylenes (CPP). 相似文献