18,790 research outputs found
Solid-state stability of Z′ < 1 and Z′ = 2 polymorphs of N,N,N′,N′-tetrabenzylethylenediamine: a combined experimental and theoretical study
No full textThe synthesis and structural analysis by means of single crystal X-ray diffraction (SC-XRD) and DFT calculations, of two additional new polymorphs of the flexible organic molecule N,N,N′,N′-tetrabenzylethylenediamine (L) which is used as first sphere ligand in outer sphere adducts are reported. Slow crystallization of L in the solution-state yields two polymorphs (Lα-phase and Lβ-phase) with Z′ = 0.5, while fast crystallization by rapid cooling from solution and directly from melt, allows a third, less stable polymorph with Z′ = 2 (Lγ-phase). The latter structure can be seen as a low-density metastable phase obtained by trapping L molecules after they reached high mobility by thermal treatment (i.e., high energy state). The three L polymorphs have been also studied using quantum mechanical (QM) calculations specific for the solid state by comparing the sublimation energy for each polymorph, and by comparing the experimental X-ray structures against the optimized structures from DFT, showing that Lβ-phase is the most stable and Lγ-phase is the least stable phase. The high Z′ structure can be considered as a “crystal on the way” of a more stable form. These results provide insights about crystallization mechanisms and polymorphism in organic crystals. The potential use of conformational polymorphs of flexible ligands to prepare second sphere adducts with marked polymorphism is commented
Comparison of milk oestrone sulphate with rectal palpation, ultrasound and farmers' observation for pregnancy diagnosis in seasonal New Zealand dairy herds
No full textAn Improved Frame Synchronization Method Based on Correlation Window Division
No full textFrame synchronization is susceptible to carrier frequency offset. To solve the problem, the correlation window division method for frame synchronization is presented in this paper. This algorithm divides the correlation window into several sub-sections and calculates the correlation value of each sub-section separately, and then combines these values to detect frame synchronization signal The simulation results show that this method can detect the starting position of frame sequence precisely in presence of large carrier frequency offset. Besides, low complexity of realization and high utilization of hardware resource are achieved.Engineering, Electrical & ElectronicPhysics, AppliedEICPCI-S(ISTP)
Theoretical analyses on effective magnetoelectric coupling coefficients in piezoelectric/piezomagnetic laminates
No full textIn previous theoretical analyses, magnetoelectric (ME) coupling coefficient alpha(ME) of piezoelectric/piezomagnetic laminates for static and dynamic modes is usually regarded as one that is not related to laminates' sizes (length and width). In micrometer or sub-millimeter ME laminates, the decrease in ME coupling was normally attributed to the substrate's clamping effect. Here, we report an effective ME coefficient alpha(ME,eff) including sizes' effect based on magnetic circuit method including the size induced demagnetization effect, which predicted that as sizes of ME laminates decrease from 100 mm to 10(-3) mm, alpha(ME,eff) will dramatically decreases from similar to 5 V/cm-Oe to 0.08 V/cm-Oe. Size decrease in ME laminates will result in a decrease in effective magnetic induction B-mu inside piezomagnetic phase in an applied magnetic field H. Our analyses further disclose a degenerate mode occurred between the longitudinal and transverse resonance modes, which may cause a weakened ME coupling. Finally, our analyses indicate that a thin and long ME laminate will exhibit a stronger ME coupling, which was then confirmed by our experimental results. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3559301]http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000290047000095&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EI7ARTICLE8null10
Digital OFDM Transmitter Architecture and FPGA Design
No full textOFDM technology is an effective multicarrier technology and is the key technology of HiNOC physical layer standard. In this paper, a digital OFDM transmitter architecture is studied and designed. At system level, algorithm model is constructed with MATLAB. At circuit level, the main function modules such as a 256-point IFFT processor are p,resented considering implementation complexity. At last, the OFDM transmitter is implemented with ALTERA StratixII FPGA. The testing result shows that transmitter function is correct and performance meets design requirement perfectly(1).http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000275924100116&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicEICPCI-S(ISTP)
L’evoluzione di pensiero sui costi di produzione nel XX secolo
No full textL’evoluzione di pensiero sui costi di produzione può essere indagata secondo molteplici prospettive; nel lavoro, date per note le nozioni di base in materia di costi aziendali, si ricostruiscono le tappe principali del percorso attraverso cui la letteratura italiana e nord-americana sono pervenute alle teorie affermatesi alla fine del XX secolo
Solstice: An Electronic Journal of Geography and Mathematics, Volume XX, Number 1
No full textThis document was delivered over the internet. The .zip file contains all static images, animated images, and text files.The purpose of Solstice is to promote interaction between geography and mathematics. Articles in which elements of one discipline are used to shed light on the other are particularly sought. Also welcome, are original contributions that are purely geographical or purely mathematical. These may be prefaced (by editor or author) with commentary suggesting directions that might lead toward the desired interaction. Contributed articles will be refereed by geographers and/or mathematicians. Invited articles will be screened by suitable members of the editorial board. IMaGe is open to having authors suggest, and furnish material for, new regular features.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63017/1/Solstice Volume XX Number 1.ziphttp://deepblue.lib.umich.edu/bitstream/2027.42/63017/3/sum09.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/63017/5/SolsticeVolXXNo1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/63017/7/SolsticeVolXIXNo1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/63017/8/SolsticeVolXXNo1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/63017/10/KML.ziphttp://deepblue.lib.umich.edu/bitstream/2027.42/63017/11/Kerry Ard's Submission- Environmental Toxicity in Wayne County, Michigan.kmzDescription of SolsticeVolXXNo1.pdf : Cover of JournalDescription of Solstice Volume XX Number 1.zip : Solstice, June 2009. Full JournalDescription of sum09.pdf : Full Journal, pdf, attached animated graphicsDescription of SolsticeVolXIXNo1.pdf : Cover fileDescription of SolsticeVolXXNo1.pdf : Cover fil
A NOVEL ODOR SENSOR COATED WITH A LIPID-MEMBRANE
No full textIn this paper, an interdigital electrode lipid film odour sensor (ILOS) is designed, fabricated and tested. It is made from a microfabricated chemiresistor coated with a synthetic multibilayer film. Nine odorants in gas phase at room temperature have been detected using the odour sensor. For most of the odorants, the relation between the response of the ILOS and odorant concentration obeys Stevens' power law, and there is a good correlation between the minimum odorant concentrations that give rise to a change of the sensor's conductance and human olfactory thresholds
Opere del XX secolo e formazione di nuovi contesti
No full textCon riferimento al titolo «Architettura del XX secolo e nuovi contesti», si rinvia a una serie consistente di rimandi teorici, di progetti e di architetture realizzate. Tutti i possibili esempi mantengono la loro validità a prescindere dalle scale. Con immediatezza si potrebbe fare riferimento al rapporto tra architettura e città e, contemporaneamente, si potrebbe riflettere sul rapporto tra la città e il suo intorno e, dalla parte opposta, tra una sedia, un tavolo e lo spazio interno di una abitazione. Oppure, ancora, tra un particolare luogo eminente della chiesa (battistero, ambone e altare) e lo spazio dell’aula.
In modo diverso i contesti, sono la somma di luoghi e architetture ma, sempre e in ogni caso e per tutti gli esempi, si conferma il contesto come insieme e rapporto fra gli elementi che costituiscono l’insieme.
Nell’approfondire oltre questo tema è necessario stabilire una data di inizio, una linea dalla quale proporre delle altre considerazioni. Riferendocisi ancora al titolo, questo limita il campo d’azione al XX secolo, e, all’interno di tale intervallo cronologico, si decide di stabilire un ambito ancora più limitato; un nuovo incipit a partire dal quale muta il senso di alcune acquisizioni raggiunte nella prima metà del ’900.
Per alcune questioni dibattute tra architettura e città, tra progettazione architettonica e urbanistica, resta centrale, all’interno del XX secolo, il momento in cui il Team X esprime alcune critiche ai modelli del Movimento Moderno, dopo che il tema delle preesistenze ambientali, posto da Ernesto N. Rogers, aveva già contribuito a modificare il rapporto tra antico e nuovo
An Improved Narrow-Band Interference Suppression Method for HINOC System
No full textNarrowband interference has serious impact on the signal synchronization in communication system and suppression of narrow-band interference is one of the key techniques to improve system performance. An improved narrow-band interference suppression method associate time-domain notch filter with frequency-domain processing is proposed in this paper for HINOC system. The chip test result shows that the associated narrow-band interference suppression method can restrain the decline of system throughput efficiently in the condition that NSR is greater than 30dB.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000319824700465&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicPhysics, AppliedEICPCI-S(ISTP)
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