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991.
A simple and controllable electrodeposition approach was proposed for one‐step construction of glucose biosensors by in situ co‐deposition of ferrocene‐branched chitosan derivatives (CS‐Fc), multiwalled carbon nanotubes (MWNTs), and glucose oxidase (GOD) onto electrode surface. The formation of CS‐Fc could not only effectively prevent the leakage of Fc and retain its electrochemical activity, but also provide a biocompatible microenvironment for retaining the native activity of the immobilized biomolecules. Further entrapment of MWNTs into the CS matrix improved electronic conductivity of the biocomposite significantly. The facile procedure of immobilizing GOD and the promising feature of biocomposite will offer a versatile platform to fabricate biosensors and bioelectronic devices. 相似文献
992.
Xiuying Wang Feng Zhang Baiying Xia Xingfu Zhu Jiesheng Chen Shilun Qiu Ping Zhang Jixue Li 《Solid State Sciences》2009,11(3):655-659
Multi-walled carbon nanotubes (MWNTs) have been successfully modified with CuO, Cu2O and Cu nanoparticles via a simple method, and the calcination temperature, the amount of NH3·H2O and soaking time play critical roles in controlling the final products. The modified MWNTs have been characterized by X-ray diffraction, infrared spectrum, scanning electron and transmission electron microscopies. Optical absorption of the obtained products has also been investigated, and the quantum confinement effect was illustrated in the absorption spectra. 相似文献
993.
Younan Xia Prof. Yujie Xiong Dr. Byungkwon Lim Dr. Sara E. Skrabalak Dr. 《Angewandte Chemie (International ed. in English)》2009,48(1):60-103
Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape‐controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution‐phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape‐controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take. 相似文献
994.
The rate capability and cyclic performance of the LiNi0.5Mn1.5O4 under high current density have been significantly improved by doping a small amount of ruthenium (Ru). Specifically, Li1.1Ni0.35Ru0.05Mn1.5O4 and LiNi0.4Ru0.05Mn1.5O4 synthesized by solid state reaction can respectively deliver a discharge capacity of 108 and 117 mAh g?1 at 10 C rate between 3 and 5 V. At 10 C charge/discharge rate, Li1.1Ni0.35Ru0.05Mn1.5O4 and LiNi0.4Ru0.05Mn1.5O4 can respectively maintain 91% and 84% of their initial capacity after 500 cycles, demonstrating that Ru-doping could be a way to enhance the electrochemical performance of spinel LiNi0.5Mn1.5O4. 相似文献
995.
Ru‐Song Zhao Xia Wang Jin‐Peng Yuan Xiao‐Dong Wang 《Journal of separation science》2009,32(4):630-636
Bamboo carbon, an inexpensive, readily available material, has attracted great attention in recent years because of adsorptive properties. In this paper, the potential of bamboo carbon as a SPE adsorbent for the determination of phenols, was investigated. Phenols are important environmental contaminants that may adversely affect human health. Parameters influencing extraction efficiency, including type of eluent, eluent volume, amount of adsorbent, as well as sample pH, volume, and flow rate were investigated and optimized. The optimized results exhibited excellent linear relationships between peak area and phenol concentrations over the range of 2.0–100 ng/mL, with precision between 2.2–7.2%. The LODs were 0.06–0.4 ng/mL for the eight phenols tested. The proposed method has been successfully applied to the analysis of several real‐world environmental water samples. These results indicate that bamboo carbon may be used as a novel SPE adsorbent for the concentration and determination of phenols in real environmental water samples. 相似文献
996.
Ya‐Tong Yao Jia Song Jing Yu Xiang‐Feng Wang Feier Hou Ai‐Lan Zhang Yuan Liu Jie Han Meng‐Xia Xie 《Journal of separation science》2009,32(17):2919-2927
A novel approach for differentiation and dating of red ink entries of seals on documents was developed based on ion‐pairing HPLC (IP‐HPLC) and GC/MS. Sixty‐nine red ink pastes of seals were collected and the chromatographic conditions for separation of the dye components by IP‐HPLC and the volatile additives by GC/MS in the ink entries were optimized. According to the dye components and additives, the ink entries were classified by HPLC with a multi‐wavelength UV detector. The volatile components of the inks were identified by GC/MS and the classification of the ink entries was also investigated based on these volatile additives. The results showed that most of the ink entries of the seals can be differentiated by combining HPLC with a multi‐wavelength detector and GC/MS methods. The degradation of the standard dye mixtures and the compositional changes of the ink entries of seals were investigated in light or natural aging conditions. The results indicated that the dye components decomposed in light or natural storage conditions, while the rates of the degradation depended on the structures of the dye components, the aging conditions, even the additives of the ink pastes. The results also showed that there existed good relationships between the compositional changes of the ink entries and the aging time, which can provide scientific evidences and valuable clues for dating of the ink entries. 相似文献
997.
In this note, we prove the existence and uniqueness of the solution to neutral stochastic functional differential equations with infinite delay (INSFDEs in short) in which the initial value belongs to the phase space BC((-∞,0]Rd), which denotes the family of bounded continuous Rd-value functions φ defined on (-∞,0] with norm ||φ||=sup-∞<θ?0|φ(θ)|, under some Carathéodory-type conditions on the coefficients by means of the successive approximation. Especially, we extend the results appeared in Ren et al. [Y. Ren, S. Lu, N. Xia, Remarks on the existence and uniqueness of the solutions to stochastic functional differential equations with infinite delay, J. Comput. Appl. Math. 220 (2008) 364-372], Ren and Xia [Y. Ren, N. Xia, Existence, uniqueness and stability of the solutions to neutral stochastic functional differential equations with infinite delay, Appl. Math. Comput. 210 (2009) 72-79] and Zhou and Xue [S. Zhou, M. Xue, The existence and uniqueness of the solutions for neutral stochastic functional differential equations with infinite delay, Math. Appl. 21 (2008) 75-83]. 相似文献
998.
In this paper, a stage-structured pest management SI model with impulsive perturbations on infected pest is introduced. Sufficient conditions of the global attractivity of pest-extinction periodic solution and permanence of the system are obtained. We also prove that all solutions of system are uniformly ultimately bounded. 相似文献
999.
1000.
Let n > 1 and G be the group SU(n) or Sp(n). This paper constructs compact symplectic manifolds whose symplectic quotient under a Hamiltonian G-action does not inherit the strong Lefschetz property. 相似文献