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91.
A surface of epoxy-impregnated hardened cement paste was investigated using a novel atomic force microscopy (AFM) imaging mode that allows for the quantitative mapping of the local elastic modulus. The analyzed surface was previously prepared using focussed ion beam milling. The same surface was also characterized by electron microscopy and energy-dispersive X-ray spectroscopy.We demonstrate the capability of this quantitative nanomechanical mapping to provide information on the local distribution of the elastic modulus (from about 1 to about 100 GPa) with a spatial resolution in the range of decananometers, that corresponds to that of low-keV back-scattered electron imaging. Despite some surface roughness which affects the measured nanomechanical properties it is shown that topography, adhesion and Young's modulus can be clearly distinguished.The quantitative mapping of the local elastic modulus is able to discriminate between phases in the cement paste microstructure that cannot be distinguished from the corresponding back-scattered electron images. 相似文献
92.
We describe annotation of multiword expressions (MWEs) in the Prague dependency treebank, using several automatic pre-annotation steps. We use subtrees of the tectogrammatical tree structures of the Prague dependency treebank to store representations of the MWEs in the dictionary and pre-annotate following occurrences automatically. We also show a way to measure reliability of this type of annotation. 相似文献
93.
The design and analysis of a silicon nanowire inverter with a wrap-around-gate nMOS is presented and its performance is compared with that of a conventional inverter. The analysis shows that the nano-channel structure design can improve carrier mobility by suppressing the transverse component of the electric field. This results in an enhancement in the current drive of the nMOS, and contributes to lowering power consumption and the switching delay. Simulated power consumption and rise time of the proposed design was found to be about 20 μW and 0.5 ns, respectively, compared with 2.5 mW and 1.5 ns achievable with conventional planar MOSFETs. Investigation of the gate length shows that a nMOS with shorter gates have an improved switching response compared with long channel devices. 相似文献
94.
Partition coefficients of phenol, salicylic acid, and several environmentally important chloro- and nitrophenols in a supercritical CO2-water system were measured using direct cocurrent extraction of aqueous solutions of the individual solutes with CO2. Partitioning data on the nitrophenols and salicylic acid were obtained for the first time. To bypass the troublesome and error-prone analysis of the CO2-rich phase, the present method employed only the solute concentrations in the aqueous phase before and after extraction to determine the partition coefficient. Unlike most previous engineering studies of phenol partitioning in a CO2-water system, the concentrations of phenolic solutes approached infinite dilution in both phases. This makes the results relevant to analytical-scale SFE of environmental water samples with CO2. Because of effective infinite dilution of the solutes, the partition coefficients provide a direct measure of relative CO2-philicity/hydrophilicity of the individual phenols. Compared to the octanol-water partition coefficients of substituted phenols, the CO2-water partition coefficients are more sensitive to substitution in the position neighboring the hydroxyl group. 相似文献
95.
Abbott AP Barker GW Davies DL Griffiths GA Walter AJ Kocovský P 《Analytical chemistry》2002,74(16):4002-4006
The use of ephedrine-substituted quaternary ammonium binaphthyl salts as molecular receptors is demonstrated. The electrochemical oxidation of the receptor is affected by the binding of an analyte in solution. The binding site on the binaphthyl salt has been determined using computer modeling and confirmed using 1D and 2D NMR studies. It is shown that the sensitivity of the receptor is related to the size of the analyte. Axially chiral binaphthyl salts are shown to bind chiral analytes in a different manner and this is demonstrated using lactic and mandelic acid. The presence of a polar functional group on the analyte is also shown to have an effect on the guest-host interaction. 相似文献
96.
97.
Enterprise Architecture (EA) is a relatively new domain that is rapidly developing. “The primary reason for developing EA
is to support business by providing the fundamental technology and process structure for an IT strategy” [TOGAF]. EA models
have to model enterprises facets that span from marketing to IT. As a result, EA models tend to become large. Large EA models
create a problem for model management. Concern-based design methods (CBDMs) aim to solve this problem by considering EA models
as a composition of smaller, manageable parts—concerns. There are dozens of different CBDMs that can be used in the context
of EA: from very generic methods to specific methods for business modeling or IT implementations. This variety of methods
can cause two problems for those who develop and use innovative CBDMs in the field of Enterprise Architecture (EA). The first
problem is to choose specific CBDMs that can be used in a given EA methodology: this is a problem for researchers who develop
their own EA methodology. The second problem is to find similar methods (with the same problem domain or with similar frameworks)
in order to make a comparative analysis with these methods: this is a problem of researchers who develop their own CBDMs related
to a specific problem domain in EA (such as business process modeling or aspect oriented programming). We aim to address both
of these problems by means of a definition of generic Requirements for CBDMs based on the system inquiry. We use these requirements
to classify twenty CBDMs in the context of EA. We conclude with a short discussion about trends that we have observed in the
field of concern-based design and modeling. 相似文献
98.
Pavel Grigorenko Ando Saabas Enn Tyugu 《Electronic Notes in Theoretical Computer Science》2005,141(4):137
A compiler-compiler for visual languages is presented. It has been designed as a framework for building visual programming environments that translate schemas into textual representation as well as into programs representing the deep meaning of schemas. The deep semantics is implemented by applying attribute grammars to schema languages; attribute dependencies are implemented as methods of Java classes. Unlike compiler-compilers of textual languages, a large part of the framework is needed for support of interactive usage of a visual language. 相似文献
99.
Improved pump-beam distribution in a diode side-pumped solid-state laser with a highly diffuse, cross-axis beam delivery system 总被引:1,自引:0,他引:1
A new cavity for diode side-pumped solid-state lasers was designed, built, and tested. The results were efficient absorption of pumped light in the media and homogeneous pumped-beam distribution under various pump-power levels, which generated Nd:YAG active media of different radii and concentrations and shifts of the diode wavelength. Full-multimode quasi-continuous pump operation with a slope efficiency of 40.5% was obtained from a plane-plane resonator equipped with two Nd:YAG rods. At a maximum average pump power of 1.33 kW, the optical-to-optical efficiency was 31.4%. Single-transverse-mode operation (M(2) factor of less than 1.1) of 163 W was demonstrated. 相似文献
100.