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901.
Inorganic-organic hybrid materials have been obtained at room temperature in aqueous solution without using the templates of surfactants. The materials are carefully characterized by anion-exchange measurement, elements analysis, X-ray diffraction, and infrared spectroscopy. Notably, the anion-exchange capacity of the samples (3.9mmol.g^-1) is even higher than anion-exchangeable resins. Interestingly, both small and large anions could be easily exchanged into the samples due to the plasticity of the samples, along with the phase transition.  相似文献   
902.
The advance in first generation Bi-2223 HTS wire has enabled the demonstration of superconducting power cables, magnetic energy-storage devices, transformers,fault current limiters and motors. However, the low irreversibility field (H^*) prevents application of Bi-2223 at 77 Kin any significant field. Worldwide activities are therefore,focused on developing a second-generation HTS technology based on YBCO, for which H^* (77K)-7 T. In this paper, we discuss the status and commercial prospects of second generation HTS wire technologies. In addition, we review the recent results and discuss the prospects of future applications.  相似文献   
903.
The general idea of holographic optical data storage (HODS) is briefly introduced. Based on the recent advances of HODS, the key techniques and the challenges of HODS are discussed. Some new techniques are proposed to improve the system. A miniaturized volume holographic data storage and correlation system is presented. It can achieve a density of 10 Gb/cm^3 and a fast correlation recognition rate of more than 2000 images per second. It shows the attracting potential advantages over other conventional storage methods in the information storage as well as information processing.  相似文献   
904.
The China foot-and-mouth virus (FMDV) isolate OH/CHA/99 was isolated from swine, which was unable to infect bovine thyroid cells in vitro or to cause typical disease in bovines following intradermal inoculation in the tongue. To enhance antigenicity, replication, maturation and pathogenicity studies of OH/CHA/99, an infectious fulllength cDNA clone, designated pBIFMDV, was prepared. The in vitro and in vivo biological properties of the virus derived from pBIFMDV were studied by analyzing antigenicity, plaque morphology and virulence in pigs. The results showed that the virus derived from pBIFMDV had the same biological properties as the parent strain OH/CHA/99; the fulllength infections cDNA clone, pBIFMDV, will be very useful in studies of the antigenicity, virulence, pathogenesis, maturation and replication of FMDV.  相似文献   
905.
906.
In this paper, a new model to analyze laminar forced convective enhanced heat transfer in latent functionally thermal fluid is developed. The main characteristics of the model are- i) a new formula of the specific heat at constant pressure is used; ii ) a real heat transfer process is considered; that is, heat transfer processes occur not only between working fluid and microcapsules, but also between the mixture and tube wall; iii) the new method, which combines the newly developed axisymmetrical dual reciprocity boundary element method (DRBEM) with finite difference method (FDM), is used to solve the control equations of this problem. The new model is validated by experimental data. Some new physical results on the variational characteristics of the specific heat at constant pressure with space and time during phase-change process, the time-marching history of the phase-change interfaces and so on are obtained. Several main physical factors that affect enhanced heat transfer in latent functionally thermal fluid are numerically analyzed. Some new understandings for the mechanism of enhanced heat transfer in the functionally fluid are obtained.  相似文献   
907.
Permeation study of the potassium channel from streptomyces Lividans   总被引:1,自引:0,他引:1  
A three-state hopping model is established according to experiments to study permeation of an open-state potassium channel from Streptomyces Lividans (KcsA potassium channel). The master equations are used to characterize the dynamics of the system. In this model, ion conduction involves transitions of three states, with one three-ion state and two two-ion states in the selectivity filter respectively. In equilibrium, the well-known Nernst equation is deduced. It is further shown that the current follows Michaelis-Menten kinetics in steady state. According to the parameters provided by Nelson, the current-voltage relationship is proved to be ohmic and the current-concentration relationship is also obtained reasonably. Additional validation of the model in the characteristic time to reach the steady state for the potassium channel is also discussed. This model lays a possible physical basis for the permeation of ion channel, and opens an avenue for further research.  相似文献   
908.
The neural stem cells in the anterior subventricular zone (SVZa) mainly generate the progenitors that will differentiate into neurons, and along a highly circumscribed migratory access Rostral migratory stream (RMS), they migrate to the olfactory bulbs (OB). To understand the effects of BMPs on SVZa neural stem cells, in this study BMP4 at various concentrations was used to induce SVZa neural stem cells, and the living cell labeling using BMP4 promotor conjugated with red fluorescence protein showed the expression of BMP4 dynamically. The results demonstrated that low BMP4 doses (1-5 ng/mL) promoted while high doses (10-100 ng/mL) inhibited the proliferation of SVZa neural stem cells, and BMP4 promotedneuron differentiation in the early stage (1-3 d), howeverm, it inhibited the neuron commitment after 4 d. Noggin, the antagonist of BMP4, blocked the physiological effects of BMP4. In OB, BMP4 is mainly to accelerate the progenitors to withdraw from the cell cycle and trigger the differentiation, and in RMS, it promotes the proliferation of committed progenitors and not differentiation, further in SVZa, BMP4 enhances astrocyte commitment.  相似文献   
909.
It is important to find some developing high-density magnetic recording materials in magnetic recording field with the development of information and technique, in which vertical magnetic recording is a very important way and has received considerable attention[1—3]. The vertical magnetic recording materials require high squareness, suitable coercivity, and small size of storage element[4]. Someone used nanoporous anodic aluminum oxide as templates to fabricate uniform arrays of multi magneti…  相似文献   
910.
Metallabenzenes are metallacyclohexatriene complexes that are derived by replacement of one of the CH groups in benzene with a transition-metal fragment. Their synthesis and aromatic properties have recently attracted considerable attention. This paper summarizes the progress in the synthesis, aromatic property, and reactivity studies of metallabenzenes. We will describe the synthesis and reactivity of typical metallabenzenes with various metals (e.g. osmium, iridium, and ruthenium, etc.), the synthesis and structure of a recent reported example of metallanaphthalene and several rare examples of novel and stable metallabenzynes. Finally, the possible future developments in this field have also been suggested.  相似文献   
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