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1.
Heavily doped diamond films are quite actively studied for their promising applications in industrial as well as in fundamental electrochemistry (both for physicochemical studies and in the field of electroanalysis), because of their very high stability toward chemical and electrochemical oxidative attacks. Fluorinated diamond electrodes exhibit an exceptionally lower electrocatalytic activity toward reactions involving adsorbed intermediates, as a result of the F-termination of the surface dangling bonds. This feature allows the investigation of the widest range of potentials for an electrode material in aqueous solution, being limited only by the formation of free hydrogen [E degrees (H*/H2) = -2.3 V(SHE)] and hydroxyl [E degrees (*OH,H+/H2O) = 2.74 V(SHE)] radicals, at the two boundaries of the approximately 5-V polarization window.  相似文献   
2.
Calixto S 《Applied optics》2003,42(2):259-263
It is shown that a relief is generated when spatial distributions of infrared light (lambda = 10.6 microm) are recorded on albumen films. The relief can be applied to the fabrication of microelements, such as diffraction gratings and microlenses. Examples are shown.  相似文献   
3.
We describe a method to characterize spatial or temporal changes in the optical properties of turbid media using diffuse reflectance images acquired under broad-beam illumination conditions. We performed experiments on liquid phantoms whose absorption (mu(a)) and reduced scattering (mu(s)') coefficients were representative of those of biological tissues in the near infrared. We found that the relative diffuse reflectance R depends on mu(a) and mu(s)' only through the ratio mu(a)/mu(s)' and that dependence can be well described with an analytical expression previously reported in the literature [S. L. Jacques, Kluwer Academic Dordrecht (1996)]. We have found that this expression for R deviates from experimental values by no more than 8% for various illumination and detection angles within the range 0 degrees-30 degrees. Therefore, this analytical expression for R holds with good approximation even if the investigated medium presents curved or irregular surfaces. Using this expression, it is possible to translate spatial or temporal changes in the relative diffuse reflectance from a turbid medium into quantitative estimates of the corresponding changes of (mu(a)/mu(s)')(1/2). In the case of media with optical properties similar to those of tissue in the near infrared, we found that the changes mu(a)/mu(s)' should occur over a volume approximately 2 mm deep and 4 mm x 4 mm wide to apply this expression.  相似文献   
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This paper presents a mixed-signal system-on-chip (SOC) for sensing capacitance variations, enabling the creation of pressure-sensitive fabric. The chip is designed to sit in the corner of a smart fabric such as elastic foam overlaid with a matrix of conductive threads. When pressure is applied to the matrix, an image is created from measuring the differences in capacitance among the rows and columns of fibers patterned on the two opposite sides of the elastic substrate. The SOC approach provides the flexibility to accommodate for different fabric sizes and to perform image enhancement and on-chip data processing. The chip has been designed in a 0.35-/spl mu/m five-metal one-poly CMOS process working up to 40 MHz at 3.3 V of power supply, in a fully reconfigurable arrangement of 128 I/O lines. The core area is 32 mm/sup 2/.  相似文献   
6.
The mitochondrial proteome, meant as the collection of proteins localized in the mitochondrion, whose fundamental function is the energy production for the life of the cell, is estimated to be constituted by at least 1000 proteins. Since the mitochondrial genome codes only for 13 polypeptides, in practice all of them are coded by nuclear genes and are imported in the mitochondrion by means of a sophisticated mechanism of sorting that is not completely known. Most classified mitochondrial proteins are synthesized as precursors with an amino-terminal extension (leader peptide), provided with peculiar physical and structural characteristics that are responsible for the recognition and import system. However, there is experimental evidence that complementary or alternative import systems exist. In particular, the 3' UnTranslated Regions (UTRs) of the mRNAs may be involved, through their secondary structure, in the mechanisms of recognition and localization. In this paper, the information content of different human mRNA sequences has been analyzed, and the results show that a significative short-term correlation exists in the 3' UTR sequences of the mRNA's coding for the proteins provided with leader peptides, probably representing the structural constraints that are necessary to the sorting machinery.  相似文献   
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8.
Integrated Aquifers Management (IAM) demands innovative tools and methods that are able to consider as much perspectives as possible. This research is aimed to design, apply and provide an indicator named Social Sustainable Aquifer Yield (SSAY), expressed in units of time that includes pure hydrological variables as well as social ones. The indicator is defined as the relation between the Residence Time, which is the relation between aquifer Storage (S) and Recharge (R) (S/R), and the relation between the aquifer Pumping (P) and the new variable named Aquifer Social Yield (ASY). The whole indicator is defined by this formula: (S/R)/(P/ASY). The assessment of the residence time is essential in aquifers with at least one of the following features: i) high hydraulic diffusivity, and ii) small volume of reserves. Finally, the variable ASY is defined as the average perception from the stakeholders about the maximum acceptable aquifer exploitation. This indicator has been successfully applied in the aquifers located in southern Jaen province (South Spain) belonging to the Water System SE4-Jaén Water Supply. The results probe the high utility of the indicator, especially in regards to the public participation processes.  相似文献   
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10.
In wireless power transfer (WPT) systems with more than two coils, the intermediary or relay circuits are used to extend the link distance. Thus, to achieve this extension efficiently in terms of power transfer, these relay circuits must have low losses. However, there are several instances in which there are restrictions in reducing the ohmic losses in all the relay circuits of the system. This is the case of biomedical applications where commonly there are size and access restrictions since one of the circuits can be implanted and also in applications using high-temperature superconductor (HTS) coils due to the difficulty in implementing the necessary cooling system for all the coils of the system. Therefore, in these situations, the designer need to choose which relay circuit will be optimized. In this work, it is presented an analysis on the impact that losses in individual relay circuits have on efficiency, and power transfer, of typical four-coil wireless power transfer systems consisting of circuit 1 (transmitter), relay circuits 2 and 3, and circuit 4 (load). It is shown that the losses on relay circuit 2 have greater impact on efficiency, while the losses of relay circuit 3 have a greater impact on power transfer for a given condition. Practical experiments confirm the developed analysis.  相似文献   
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