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951.
Arup Chattopadhyay B. Krishna Das Jaydeb Sarkar S. Sarkar 《Integral Equations and Operator Theory》2014,79(4):567-577
Doubly commuting invariant subspaces of the Bergman space and the Dirichlet space over the unit polydisc \({\mathbb{D}^n}\) (with \({n \geq 2}\) ) are investigated. We show that for any non-empty subset \({\alpha=\{\alpha_1,\ldots,\alpha_k\}}\) of \({\{1,\ldots,n\}}\) and doubly commuting invariant subspace \({\mathcal{S}}\) of the Bergman space or the Dirichlet space over \({\mathbb{D}^n}\) , restriction of the multiplication operator tuple on \({\mathcal{S}, M_{\alpha}|_\mathcal{S}:=(M_{z_{\alpha_1}}|_\mathcal{S},\ldots, M_{z_{\alpha_k}}|_\mathcal{S})}\) , always possesses generating wandering subspace of the form $$\bigcap_{i=1}^k(\mathcal{S}\ominus z_{\alpha_i}\mathcal{S})$$ . 相似文献
952.
B. Krishna Das Jaydeb Sarkar Santanu Sarkar 《Complex Analysis and Operator Theory》2014,8(6):1325-1339
Maximality of a contractive tuple of operators is considered. A characterization for a contractive tuple to be maximal is obtained. The notion of maximality for a submodule of the Drury–Arveson module on the \(d\) -dimensional unit ball \({\mathbb {B}}_d\) is defined. For \(d=1\) , it is shown that every submodule of the Hardy module over the unit disc is maximal. But for \(d\ge 2\) we prove that any homogeneous submodule or submodule generated by polynomials is not maximal. A characterization of maximal submodules is obtained. 相似文献
953.
Qian Cheng Weiheng Xu Shiyi Qin Subhabrata Das Tianwei Jin Aijun Li Alex Ceng Li Boyu Qie Pengcheng Yao Haowei Zhai Changmin Shi Xin Yong Yuan Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5613-5617
The lithium–sulfur battery is an attractive option for next‐generation energy storage owing to its much higher theoretical energy density than state‐of‐the‐art lithium‐ion batteries. However, the massive volume changes of the sulfur cathode and the uncontrollable deposition of Li2S2/Li2S significantly deteriorate cycling life and increase voltage polarization. To address these challenges, we develop an ?‐caprolactam/acetamide based eutectic‐solvent electrolyte, which can dissolve all lithium polysulfides and lithium sulfide (Li2S8–Li2S). With this new electrolyte, high specific capacity (1360 mAh g?1) and reasonable cycling stability are achieved. Moreover, in contrast to conventional ether electrolyte with a low flash point (ca. 2 °C), such low‐cost eutectic‐solvent‐based electrolyte is difficult to ignite, and thus can dramatically enhance battery safety. This research provides a new approach to improving lithium–sulfur batteries in aspects of both safety and performance. 相似文献
954.
Solid-supported nano and microparticles of Pd(0) (SS-Pd) were prepared and used as heterogeneous catalysts for Suzuki-Miyaura cross coupling reactions of aryl halides (chloro, bromo and iodo) and phenyl boronic acid under mild and ligand-free conditions. Scanning electron microscope (SEM) and UV-vis based studies were performed to observe the distribution of nano and microparticles of palladium over solid surface and their oxidation states. In addition, the catalyst could be reused up to seven runs without significant loss of activity and stable enough under moist conditions. 相似文献
955.
Sayantani Das Alo Dutta Binita Ghosh Sourish Banerjee T.P. Sinha 《Journal of Physics and Chemistry of Solids》2014
Nanoparticles of cadmium selenide (CdSe) have been synthesized by soft chemical route using mercaptoethanol as a capping agent. X-ray diffraction and transmission electron microscope measurements show that the prepared sample belongs to sphalerite structure with the average particle size of 25 nm. The band gap of the material is found to be 2.1 eV. The photoluminescence (PL) emission spectra of the sample are measured at various excitation wavelengths. The PL spectra appear in the visible region, and the emission feature depends on the wavelength of the excitation. Impedance spectroscopy is applied to investigate the dielectric relaxation of the sample in a temperature range from 323 to 473 K and in a frequency range from 42 Hz to 1.1 MHz. The complex impedance plane plot has been analyzed by an equivalent circuit consisting of two serially connected R-CPE units, each containing a resistance (R) and a constant phase element (CPE). The dielectric relaxation of the sample is investigated in the electric modulus formalism. The temperature dependent relaxation times obey the Arrhenius law. The Havriliak–Negami model is used to investigate the dielectric relaxation mechanism in the sample. The frequency dependent conductivity spectra are found to obey the power law. 相似文献
956.
Vinod Kumar Vashistha Kumar Anuj Tevatia Prashant Das Deepak Kumar 《Russian Journal of Electrochemistry》2021,57(4):348-356
Russian Journal of Electrochemistry - Herein, we synthesized [12] membered pyridine based transition metal macrocyclic complexes [MIILCl2] (M = Fe(II) and Ni(II), L = 6,12,5,11-tetraphenyl... 相似文献
957.
Kinetics of polymerization of methyl methacrylate initiated by Mn3+/1,2-propanedlol has been investigated in aqueous sulfuric acid at the temperature range of 25–35°C. The rate of polymerization (Rp) and the rate of manganic ion disappearance (-RMn) have been computed. The effects of organic solvents, certain cationic and anionic detergents, added electrolytes on the initial rate of polymerization, and maximum conversion have been examined. Depending on the kinetic results, a reaction scheme has been suggested involving the formation of a complex between Mn3+ and the alcohol, which subsequently decomposed in an unimolecular step to generate the initiating free-radical which initiates polymerization and termination of the growing polymer chain by metal ion. 相似文献
958.
H. A. Das M. Dejkumhang H. J. Van Nieuwkerk J. J. Peeters 《Journal of Radioanalytical and Nuclear Chemistry》1983,77(1):223-233
The precision and accuracy of the peak energy allocation in γ-ray spectrometry govern the subsequent computer processing of
the data. By applying the main procedures for peak energy determination to a well-defined case, it is possible to define the
minimal statistical uncertainties to be expected. The systematic bias of the energies obtained is caused mainly by changes
in the total count rate. A correction can be applied based on the pulser peak. From the precision and the accuracy of the
peak energy determination, the scanning width for automatic peak indexing follows. 相似文献
959.
960.