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61.
62.
Molecular electronics is, relatively speaking, a young field. Even so, there have been many significant advances and a much greater understanding of the types of materials that will be useful in molecular electronics, and their properties. The purpose of this review is to provide a broad basis for understanding the areas where new advances might arise, and to provide introduction to the subdisciplines of molecular electronics. This review is divided into two major parts; an historical examination of the development of conventional electronics, which should provide some understanding of the push towards molecular electronics. The problems associated with continuing to shrink conventional systems are presented, along with references to some of the efforts to solve them. This section is followed by an in-depth look at the most important research into the types of behaviors that molecular systems have been found to display. 相似文献
63.
[reaction:see text] During the total synthesis of the novel cyclic depsipeptide callipeltin A (1), the unit (3S,4R)-3,4-dimethylglutamine, was successfully synthesized by asymmetric Michael addition and subsequent electrophilic azidation. The key feature of this approach is the generation of three adjacent stereogenic centers using the same camphorsultam chiral auxiliary. 相似文献
64.
M.A. Nasser M.M. Gazzaly J.V. Geaga B. Höistad G. Igo J.B. McClelland A.L. Sagle H. Spinka J.B. Carroll V. Perez-Mendez E.T.B. Whipple 《Nuclear Physics A》1978,312(3):209-216
The p-4He elastic differential cross section has been measured at a kinetic energy of 2.68 GeV. The momentum transfer region studied is t = 0.15–0.66 (GeV/c)2. The cross section displays a shallow first minimum and shape very similar to recent data at 1 GeV. 相似文献
65.
P.J. Bussey C. Raine J.G. Rutherglen P.S.L. Booth L.J. Carroll G.R. Court P.R. Daniel A.W. Edwards R. Gamet C.J. Hardwick P.J. Hayman J.R. Holt J.N. Jackson W.H. Range F.H. Combley W. Galbraith V.H. Rajaratnam C. Sutton 《Nuclear Physics B》1979,154(3):492-502
The polarisation parameters Σ, P and T have been measured for the process γp→π0p in the photon energy range 1300–2100 MeV and c.m. angles between 30° and 110°, in an experiment with a polarised beam and polarised target. The results are compared with a recent theoretical analysis which fits data from threshold to 16 GeV. The new data are in general agreement with the analysis, but with some significant discrepancies in detail. 相似文献
66.
67.
R. Daniel Little George W. Muller Manuel G. Venegas Gary L. Carroll Ahmed Bukhari Larry Patton Keith Stone 《Tetrahedron》1981,37(25):4371-4383
A comparison of the inter- and intramolecular diyl trapping routes to linearly fused tricyclopentanoids is presented. In addition, several of the factors which are responsible for the stereoselectivity which is associated with the intramolecular process are examined and it is concluded that conformational rather than electronic (secondary orbital) factors play the dominant role. It is shown that gem methyl groups located on the acyclic chain which joins the diyl and diylophile (in reference to 32 and 35, but not to 47) have no practical effect upon the outcome of the trapping reaction. The intramolecular process is stereospecific with respect to diylophile geometry, and highly stereoselective with respect to the ring junction stereochemistry. Finally, an abortive attempt to synthesize the marine natural product Δ9(12)-capnellene (19) as well as a successful synthesis of the mold metabolite d,l- hirsutene (18) is presented. 相似文献
68.
Carroll TL 《Chaos (Woodbury, N.Y.)》2005,15(1):13109
In a radar system, it is necessary to measure both range and velocity of a target. The movement of the target causes a Doppler shift of the radar signal, and the size of the Doppler shift is used to measure the velocity of the target. In this work, a chaotic drive-response system is simulated that detects a Doppler shift in a chaotic signal. The response system can detect Doppler shifts in more than one signal at a time. 相似文献
69.
Carroll TL 《Chaos (Woodbury, N.Y.)》2005,15(3):33103
Radiofrequency signals can disrupt the operation of low frequency circuits. A digital inverter circuit would seem to be immune to such disruption, because its output state usually jumps abruptly between 0 and 5 V. Nevertheless, when driven with a high frequency signal, the inverter can have two coexisting stable states (which are not at 0 and 5 V). Slow switching between these states (by changing the rf signal) will produce a low frequency signal. I demonstrate the bistability in a circuit experiment and in a simple model of the circuit. 相似文献
70.
Adams J Adler C Aggarwal MM Ahammed Z Amonett J Anderson BD Anderson M Arkhipkin D Averichev GS Badyal SK Balewski J Barannikova O Barnby LS Baudot J Bekele S Belaga VV Bellwied R Berger J Bezverkhny BI Bhardwaj S Bhaskar P Bhati AK Bichsel H Billmeier A Bland LC Blyth CO Bonner BE Botje M Boucham A Brandin A Bravar A Cadman RV Cai XZ Caines H Calderón de la Barca Sánchez M Carroll J Castillo J Castro M Cebra D Chaloupka P Chattopadhyay S Chen HF Chen Y Chernenko SP Cherney M Chikanian A Choi B 《Physical review letters》2004,92(17):171801
Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider. 相似文献