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141.
Victor L. Pérez 《Information & Management》1984,7(1):29-38
The organizational Information Management System is identified, analyzed and evaluated. In order to identify it, the objectives and functional components of such a system are described; then, the different levels of sophistication of the alternatives implementing each one of the system components are presented. A proposed “upgrading approach” is applied to analyze the information management activities within the organization. 相似文献
142.
Michael Bommer Fay Blair Gilbert Goodgion Victor Pease 《Computers, Environment and Urban Systems》1980,5(1-2)
This paper describes the development of a zero base budgeting process as part of an integral planning-budgeting-control system relating client needs with service programs. Particular attention is focused on designing, gaining acceptance for and implementing a new budgeting system for the human services agencies of a rural county government. The relationship of the zero base budgeting process to the client case management and evaluation system are explored. Problems encountered in implementing the system and an evaluation of the results are discussed. 相似文献
143.
Lehtonen S Plessky VP Hartmann CS Salomaa MM 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2004,51(12):1697-1703
Filters based on using single-phase, unidirectional transducers (SPUDT) consisting of lambda/4 and wider electrodes are presented. The design variants exploit the significant difference between the reflectivity of short-circuited lambda/4 electrodes and that of floating wide electrodes on 128 degree lithium niobate (LiNbO3). The surface acoustic wave (SAW) devices operating at 2.45 GHz have critical dimensions of about 0.3-0.4 microm, accessible to standard optical lithography. When matched, the fabricated SPUDT filters exhibit minimum insertion losses of 5.5-7.9 dB together with 3 dB passbands of 89-102 MHz. The majority of the insertion loss can be attributed to the attenuation on free surface and inside the grating, and to the resistivity of the electrodes. 相似文献
144.
Superconductivity and magnetism are two antagonistic cooperative phenomena, and the intriguing problem of their coexistence has been studied for several decades. Recently, artificial hybrid superconductor-ferromagnet systems have been commonly used as model systems to reveal the interplay between competing superconducting and magnetic order parameters, and to verify the existence of new physical phenomena, including the predicted domain-wall superconductivity (DWS). Here we report the experimental observation of DWS in superconductor-ferromagnet hybrids using a niobium film on a BaFe(12)O(19) single crystal. We found that the critical temperature T(c) of the superconductivity nucleation in niobium increases with increasing field until it reaches the saturation field of BaFe(12)O(19). In accordance with the field-shift of the maximum value of T(c), pronounced hysteresis effects have been found in resistive transitions. We argue that the compensation of the applied field by the stray fields of the magnetic domains as well as the change in the domain structure is responsible for the appearance of the DWS and the coexistence of superconductivity and magnetism in the superconductor-ferromagnet hybrids. 相似文献
145.
Quantum mechanical calculations based on density functional theory and the generalised gradient approximation show that the equilibrium lattice parameter of a carbon polymorph with space group symmetry
would be 3.08 Å, and hence very different from that of diamond. No local minimum in the dependence of the total energy on the lattice parameter has been found. Such a polymorph would be approximately 5 eV atom−1 less stable than diamond, suggesting that its synthesis is very unlikely. This finding is consistent with older density functional calculations and contradicts recent results of LCAO calculations, which have been used to support the interpretation of experimental data as showing the existence of a metallic carbon polymorph with space group symmetry
. 相似文献
146.
Rafael García Victor H. López Andrew R. Kennedy Gabriel Arias 《Journal of Materials Science》2007,42(18):7794-7800
An Al-based composite reinforced with 20%SiCp was welded using the MIG welding process with direct and indirect application of the electric arc (DEA and IEA respectively).
The welds were made on 12.5 mm thick plates in three welding passes for the DEA joint whereas only one pass was required for
the IEA joint. Microstructural examination of the joints revealed DEA welds with light signs of matrix/reinforcement reaction
whilst in the IEA welds the SiC particles remained with their initial angular morphology. Mechanical failure occurred consistently
and independently of the type of joint in the weld zone and the measured strengths were 209 and 234 MPa for DEA and IEA welds
respectively. The greater strength measured for the IEA weld was due to reduced porosity and good incorporation and dispersion
of the SiC particles into the weld pool. 相似文献
147.
Aline Bruna da Silva Celio Wisniewski Jo?o Victor Almeida Esteves Rinaldo Gregorio 《Journal of Materials Science》2010,45(15):4206-4215
Poly(vinylidene fluoride), PVDF, samples containing exclusively the polar β phase were obtained by crystallization from N,N-dimethylformamide (DMF) solution at 60 °C and subsequent pressing. Some of these samples were uniaxially drawn at 120 °C
at draw ratio of 4, resulting in oriented films. Oriented and unoriented samples were characterized as to relative fraction
of β phase, degree of crystallinity and orientation by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC),
and wide-angle X-ray diffraction (WAXD). The dependence on frequency of the real (
e\textr¢ \varepsilon_{\text{r}}^{\prime} ) and imaginary (
e\textr¢¢ \varepsilon_{\text{r}}^{\prime\prime} ) components of the relative permittivity of the samples was determined between 104 and 1.7 × 107 Hz. The coercive field and stable and metastable remanent ferroelectric polarization were determined from the hysteresis
loop obtained by the ramp voltage technique, described in detail in this work. The results allowed verification of the effect
of drawing on structure and of the resulting structure on the dielectric properties, remanent polarization, and coercive field
of β-PVDF. A possible effect of the crystal–amorphous interphase region on the metastable remanent polarization is suggested.
The results obtained with the oriented and unoriented samples were compared with those obtained for films commercialized by
Piezotech S.A. 相似文献
148.
Ana C.F. Ribeiro Susana M.N. Simões Victor M.M. Lobo Artur J.M. Valente M.A. Esteso 《Food chemistry》2010
A Taylor dispersion method is used to measure ternary mutual diffusion coefficients (D11, D22, D12 and D21) for aqueous solutions of CuCl2 (1) + caffeine (2) + H2O-(3) at 25 °C and 37 °C at carrier concentrations from (0.000 to 0.020 mol dm−3), for each solute, respectively. The results are compared with these obtained for the binary systems, that is, CuCl2 (1) + H2O (2) and caffeine (1) + H2O (2), also reported here. From these data it is possible to make conclusions about the influence of the caffeine solutes in diffusion of copper chloride. 相似文献
149.
Weibing Dong Huining He Junbo Gong Victor C. Yang 《Frontiers of Chemical Engineering in China》2010,4(1):87-90
Amino-modified silica hydrogel (N-MSHG) was prepared by a simple sol-gel processing via the co-condensation of commercial silica sol with 3-aminopropyltrieoxysilane. Penicillin G acylase (PGA), a model enzyme, was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin. The samples were characterized by Nitrogen sorption analysis, FT-IR and thermal gravimetric analysis (TGA). The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17 nm. The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency. The yield of the synthesis of amoxicillin in aqueous media was 38% for 2.5 h. This sol-gel preparation is simple and shows prominent potential value in industrial processing. 相似文献
150.