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51.
Salah S. Massoud Febee R. Louka Masahiro Mikuriya Hideaki Ishida Franz A. Mautner 《Inorganic chemistry communications》2009,12(5):420-425
The reaction of Cu(ClO4)2, 2-pyridylcarbonyl-N,N-bis(2-pyridylmethyl)amine (DPA-CO-py) and sodium dicyanamide (Nadca) in aqueous medium led to the isolation of three complexes: {[Cu(DPA)(μ1,5-dca)]ClO4}n (1), [Cu2(pic)2(μ1,3-H2NCO–N–CN)2(H2O)2] · 2H2O (2) and Cu(pic)2 · H2O (3). The Cu2+ ion, during its complex formation with DPA-CO-py and dca not only assisted the hydrolysis of DPA-CO-py to the corresponding di(2-methylpyridyl)amine (DPA) and picolinic acid (Hpic) but also resulted in partial hydrolysis of one of the two nitrile groups of the dicyanamide, NC–N–CN? (dca) to amidocynamide, H2NCO–NH–CN. The complexes were structurally characterized and the single X-ray structures for 1 and 2 reveal their identity. Complex 1 forms a 1D polymeric chain with the dca acting as a μ1,5-bridging ligand via the terminal nitrile nitrogen atoms. A distorted SP geometry around the Cu2+ centers was achieved by the three N-atoms of the DPA and by the two nitrile groups of the bridging dca ligands. Complex 2 consists of a dimeric unit with CuN3O2 chromophore in coordination polyhedron that has a distorted SP geometry. The amidocyanamide ion, H2NCO–N–CN? acts as bis(monodentate) μ1,3-bridging ligand via the central amido and terminal nitrile nitrogen atoms whereas the picolinate anion forms a six-membered chelate ring through its pyridyl nitrogen and an oxygen atom of the carboxylate group, and the aqua water occupies the apical position of the structure. Complex 1 exhibits very weak antiferromagnetic coupling (J = ?0.31 cm?1) whereas 2 shows a significant antiferromagnetic interaction between the two copper centers (J = ?13.6 cm?1). 相似文献
52.
53.
Low power DCVSL circuits employing AC power supply 总被引:2,自引:0,他引:2
In view of changing the type of energy conversion in CMOS circuits, this paper investigates low power CMOS circuit design, which adopts a gradually changing power clock. First, we discuss the algebraic expressions and the corresponding properties of clocked power signals. Then the design procedure is summed up for converting complementary CMOS logic gates employing DC power to the power-clocked CMOS gates employing AC power. On this basis, the design of differential cas-code voltage switch logic (DCVSL) circuits employing AC power clocks is proposed. The PSPICE simulations using a sinusoidal power-clock demonstrate that the designed power-clocked DCVSL circuit has a correct logic function and low power characteristics. Finally, an interface circuit to convert clocked signals into the standard logic levels of a CMOS circuit is proposed, and its validity is verified by computer simulations. 相似文献
54.
In 2006, Zhao et al. proposed a practical verifiable multi-secret sharing based on Yang et al.’s and Feldman’s schemes. In this paper we propose two efficient, computationally secure (t,n), and verifiable multi-secret sharing schemes based on homogeneous linear recursion. The first scheme has the advantage of better performance, a new simple construction and various techniques for the reconstruction phase. The second scheme requires fewer public values with respect to Zhao et al.’s and Shao and Cao schemes. These schemes are easy to implement and provide great capabilities for many applications. 相似文献
55.
PROMETHEE with Precedence Order in the Criteria (PPOC) as a New Group Decision Making Aid: An Application in Urban Water Supply Management 总被引:2,自引:2,他引:0
In this paper, a new group Multi-Criteria-Decision-Making (MCDM) method is introduced by combining two ??Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE)?? and ??Multi-attribute decision making with dominance in the criteria?? methods. PROMETHEE family of outranking methods is among the recently developed MCDM methods which have received lots of attention in the recent years because of its capacity in ranking finite set of alternative actions based on conflicting criteria. The second method helps the decision makers to consider ambiguity and imprecision of relative importance of each objective (criterion) without allocating importance weights to them. The proposed method of PROMETHEE with Precedence Order in the Criteria (PPOC) not only can address capabilities of PROMETHEE method just with determination of precedence order of criteria, but also can make it possible to have a group decision making environment with conflicting objectives. Operational management of an urban water supply system is a good example of a set of decision making problems with several objectives and Decision Makers (DMs). In this paper, PPOC method has been applied to the case study of Melbourne water supply system, previously analyzed in the literature, to assess a number of operation rules with respect to eight criteria evaluated under single or group decision-making situations. The satisfaction degree of each DM and the overall group ranking results have also been provided in the paper. The proposed method is applicable for different decision making problems in urban water supply management. 相似文献
56.
In this paper, we develop a design optimization methodology for switchable multi-port spiral inductors in fully integrated
wireless systems. The methodology simultaneously maximizes the inductor’s performance for multiple inductance values and operating
frequencies. We utilize multi-level optimization techniques to efficiently design the geometry of the switchable inductor
structure. The methodology can produce designs with significantly larger quality factors than those obtained by optimizing
the inductor design for a single inductance value and operating frequency. 相似文献
57.
Dusan Prelog Massoud Momeni Bogomir Horvat Manfred Glesner 《Analog Integrated Circuits and Signal Processing》2007,51(3):201-206
A low-power, multi-stage delta-sigma modulator with comparator-based switched-capacitor (CBSC) gain stages is presented. The
presented design eliminates the need for operational amplifiers and replaces them by comparators with current sources at their
outputs to alleviate the effects of continued technology scaling on analog and mixed-signal circuits. The proposed technique
significantly reduces power consumption and can be applied to switched-capacitor delta-sigma modulators of arbitrary order.
Based on the proposed methodology, a 2-1 cascade, single-bit, pseudo-differential switched-capacitor delta-sigma modulator
is developed and achieves a SNDR of 76.8 dB with an oversampling ratio of 64 at a clock frequency of 8 MHz. 相似文献
58.
Mastrototaro J.J. Massoud H.Z. Pilkington T.C. Ideker R.E. 《IEEE transactions on bio-medical engineering》1992,39(3):271-279
Thin-film transmural cardiac multielectric arrays were fabricated using integrated-circuit processing techniques. Several substantial improvements were achieved over conventional handmade arrays such as a smaller cross-sectional area, a larger number of recording sites per needle, more accurately controlled size and spacing of the recording sites, smaller bipolar spacings, and higher throughout yield. These advantages allow for a higher density of closely spaced bipolar electrodes capable of monitoring complex voltage and gradient fields present during ventricular fibrillation and defibrillation. Both rigid and flexible arrays were fabricated and used in the acquisition of transmural electrical signals. The rigid multielectrode arrays were made of gold electrodes on a molybdenum substate, and the flexible arrays of silver and gold electrodes on a polyimide substrate. In vitro and in vivo testing of the thin-film transmural cardiac multielectrode arrays indicates that there are no adhesion or delamination problems observed during acute studies, no implantation difficulties, and that unipolar and bipolar recordings during normal sinus rhythm and injury potentials in unipolar recordings are similar to those obtained using the handmade electrodes. 相似文献
59.
The dependence of oxide thickness, and oxide thickness variation within a wafer and wafer-to-wafer on process variables was studied in rapid-thermal processing systems that differed in chamber configuration and construction, incoherent light source, and pyrometers used for temperature measurement. Mechanisms for oxide growth and oxide thickness variation in rapid-thermal oxidation are discussed. Thermally induced stress, lamp configuration, and convective cooling affected the oxide thickness variation within a wafer. Wafer-to-wafer oxide thickness variation depended on the material of chamber construction, quartz or metal, and was related to residual heating for longer oxidations. For the same processing conditions, the oxide thickness was different for different systems, due to temperature error and a photonic component to rapid-thermal oxidation. Analysis of empirical oxide thickness models revealed a silicon orientation effect and a mechanism related to oxidant transport that was common to rapid-thermal oxidation in different systems 相似文献
60.
Oxygen reduction electrodes, containing non-noble metal catalysts supported on high surface area carbon and wet-proofed with PTFE were tested under reaction conditions for the chlor-alkali electrolysis. Double-layer gas diffusion electrodes were prepared by rolling of an active layer and diffusion layer on a nickel wire screen, compressed and sintered at 300 °C. Electrochemical measurements for substantiating the activity and stability of the half-cells were conducted in 8 M NaOH by supplying oxygen at a cell temperature of 70 °C and a constant current load of 300 mA cm−2. An electrolysis cell with a dimensionally stable anode (DSA) and double-layered cathode was assembled, where 4.8 M NaCl and oxygen were supplied, respectively, for the production of chlorine and NaOH. The cell performances as well as stability of the electrodes were investigated at about 80 °C. This study shows that by replacing the high voltage consuming hydrogen-evolving reaction and by adopting highly active electrocatalysts as cathode materials, energy savings of more than 30% could be realized. 相似文献