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排序方式: 共有107条查询结果,搜索用时 15 毫秒
61.
N. K. Zainuddin M. A. Saadiah A. P. P. Abdul Majeed 《International Journal of Polymer Analysis and Characterization》2018,23(4):321-330
The present work deals with the development of carboxymethyl cellulose (CMC) blended with kappa carrageenan (KC) as a host-based polymer electrolyte (PE) system. The CMC/KC films were successfully prepared using solution casting method and were characterized through electrical impedance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) methods, respectively. The FTIR spectrum revealed that the significant region of interaction transpires at wave number 1,057, 1,326, 1,584, and 3,387?cm?1 which correspond to the bending of C–O–C, bending of –OH, asymmetric of –COO? as well as the stretching of –OH, respectively. It has also been demonstrated that the complexation process occurred between CMC and KC. The CMC/KC blend PE system with a ratio of 80:20 achieved an optimum conductivity of 3.91?×?10?7?S?cm?1 and had the lowest crystallinity percentage as suggested by the XRD analysis. 相似文献
62.
Quantum spin Hall and quantum valley Hall effects in trilayer graphene and their topological structures
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The present study pertains to the trilayer graphene in the presence of spin orbit coupling to probe the quantum spin/valley Hall effect. The spin Chern-number C_s for energy-bands of trilayer graphene having the essence of intrinsic spin–orbit coupling is analytically calculated. We find that for each valley and spin, C_s is three times larger in trilayer graphene as compared to single layer graphene. Since the spin Chern-number corresponds to the number of edge states,consequently the trilayer graphene has edge states, three times more in comparison to single layer graphene. We also study the trilayer graphene in the presence of both electric-field and intrinsic spin–orbit coupling and investigate that the trilayer graphene goes through a phase transition from a quantum spin Hall state to a quantum valley Hall state when the strength of the electric field exceeds the intrinsic spin coupling strength. The robustness of the associated topological bulk-state of the trilayer graphene is evaluated by adding various perturbations such as Rashba spin–orbit(RSO) interaction αR, and exchange-magnetization M. In addition, we consider a theoretical model, where only one of the outer layers in trilayer graphene has the essence of intrinsic spin–orbit coupling, while the other two layers have zero intrinsic spin–orbit coupling.Although the first Chern number is non-zero for individual valleys of trilayer graphene in this model, however, we find that the system cannot be regarded as a topological insulator because the system as a whole is not gaped. 相似文献
63.
Nanoparticles of the pure and Ni–Cr co-doped lithium manganese oxides Li[NixCryMn2-x-y]O4 (x = y = 0.01–0.05) have been synthesized by sol–gel method using citric acid as a chelating agent. The effect of low-content doping was noted reflecting the faster ionic movement in the cathode material. The phase structure and morphology of the materials are characterized by XRD, FTIR, SEM and TEM. Electrochemical and impedance measurements established that low-content Ni–Cr substitution substantially improves the structural stability and high rate cycling performance of LiMn2O4. Among all the investigated compositions, LiNi0.01Cr0.01Mn1.98O4 demonstrated the best electrochemical performance. At a substantially high current rate of 5 C, 82% of the initial discharge capacity at 0.1 C is retained. Remarkably, after deep cycling at high rates, a discharge capacity of 104 mAhg?1 is resumed upon reducing the current rate to 0.1 C which is 91% of the specific capacity in the first cycle. 相似文献
64.
Sayed Tayyab Raza Naqvi Bahareh Shirinfar Dilshad Hussain Saadat Majeed Muhammad Naeem Ashiq Yasin Aslam Nisar Ahmed 《Electroanalysis》2019,31(5):851-857
In this research, bimetallic supported CNT modified electrode ( Fe,Ni/CNTs/GCE) has been developed for sensitive, stable and highly elctroactive sensing of glucose, ascorbic acid and hydrogen peroxide. Transition metals such as Iron (Fe) and Nickel (Ni) offer high electrical and thermal conductance, high active surface‐to‐volume ratio and presence of d‐band electrons gives enhanced electrocatalytic behavior. While, CNTs provide high surface area, stability and excellent conductivity. Synthesized material is characterized by SEM, EDS, XRD and FTIR to access morphology, elemental composition and structure. This unique combination is employed for the electrochemical sensing of ascorbic acid, glucose and hydrogen peroxide and different experimental parameters are optimized. Fe,Ni/CNTs/GCE shows good sensing efficiency at pH 7.4 which is ideally suitable for variety of analytes. The modified electrode also show good reproducibility and sensitivity under optimized conditions and can be reused upto 30 cycles without compromising the efficiency. With good linearity, reproducibility and limit of detection, this material possess significant potential as non‐enzymatic biosensor for variety of analytes. 相似文献
65.
Reetika Mahajan Sajad Majeed Zargar Ravinder Singh Romesh Kumar Salgotra Sufia Farhat Humaira Sonah 《Applied biochemistry and biotechnology》2017,182(1):16-28
Understanding the genetic diversity of a crop is useful for its effective utilization in breeding programmes. For better understanding of the genetic variability in common bean, the first and foremost step is to study its genetic diversity. In the present investigation, 138 genotypes of common bean collected from various regions of Jammu and Kashmir, India, representing major common bean growing areas of this region, were evaluated using 23 SSRs. These SSRs were found highly polymorphic and possess high values for various parameters indicating their high discriminatory power. The average PIC value observed was 0.692, with 0.730 as average gene diversity value, and 0.267 as heterozygosity. Twenty-three SSRs produced a total of 251 alleles. The dendrogram generated with un-weighted neighbour joining cluster analysis grouped genotypes into three main clusters with various degrees of sub-clustering within the clusters. The model-based STRUCTURE analysis using 23 SSR markers identified a population with 3 sub-populations which corresponds to distance-based groupings with average F ST value and expected heterozygosity of 0.1497 and 0.6696, respectively, within the sub-population, as such high level of genetic diversity was observed within the population. Further, Core Hunter II was used to identify a core set of 96 diverse genotypes. This core set of diverse 96 genotypes is a potential resource for association mapping studies and can be used by breeders as a material to make desirable genetic crosses to generate elite varieties for the fulfilling global market needs. These findings have further implications in common bean breeding as well as conservation programs. 相似文献
66.
Burhan Hamid Zaffar Bashir Ali Mohd Yatoo Fayaz Mohiddin Neesa Majeed Monika Bansal Peter Poczai Waleed Hassan Almalki R. Z. Sayyed Ali A. Shati Mohammad Y. Alfaifi 《Molecules (Basel, Switzerland)》2022,27(18)
More than 70% of our planet is covered by extremely cold environments, nourishing a broad diversity of microbial life. Temperature is the most significant parameter that plays a key role in the distribution of microorganisms on our planet. Psychrophilic microorganisms are the most prominent inhabitants of the cold ecosystems, and they possess potential cold-active enzymes with diverse uses in the research and commercial sectors. Psychrophiles are modified to nurture, replicate, and retain their active metabolic activities in low temperatures. Their enzymes possess characteristics of maximal activity at low to adequate temperatures; this feature makes them more appealing and attractive in biotechnology. The high enzymatic activity of psychrozymes at low temperatures implies an important feature for energy saving. These enzymes have proven more advantageous than their mesophilic and thermophilic counterparts. Therefore, it is very important to explore the efficiency and utility of different psychrozymes in food processing, pharmaceuticals, brewing, bioremediation, and molecular biology. In this review, we focused on the properties of cold-active enzymes and their diverse uses in different industries and research areas. This review will provide insight into the areas and characteristics to be improved in cold-active enzymes so that potential and desired enzymes can be made available for commercial purposes. 相似文献
67.
Journal of Solid State Electrochemistry - We have deposited pure SnO2 and SnO2:Pd nanostructure films on the quartz and porous silicon PSi substrates using chemical spray pyrolysis technique to... 相似文献
68.
69.
Polyimide (PI) and Fluorinated Ethylene Propylene (FEP) samples (15 mm×15 mm×50 μm ) were exposed to atomic oxygen ions of average energy ~12 eV and flux ~5×1013 ions cm ?2 s ?1, produced in the Electron Cyclotron Resonance (ECR) plasma. The energy and the flux of the oxygen ions at different positions in the plasma were measured by a retarding field analyzer. The fluence of the oxygen ions was varied from sample to sample in the range of ~5×1016 to 2×1017 ions cm ?2 by changing the irradiation period. The pre- and the post-irradiated samples were characterized by the weight loss, Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transform Infrared (FTIR) techniques. The weight of the PI and FEP samples decreased with increasing the ion fluence. However, the erosion yield for the PI is found to be higher, by almost a factor five, when compared with that of FEP. On the surface region of irradiated samples, the concentrations of the carbon, fluorine, and oxygen and their corresponding chemical bonds have changed appreciably. Moreover, blisters and nanoglobules were also observed even at a fluence of ~1017 ions cm ?2. This oxygen ion fluence is almost two orders of magnitude lower than that of the 5 eV atomic oxygen, which a satellite encounters in the space, at the low Earth orbit, during its mission period of about 7 years. 相似文献
70.