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91.
Iain J McGaw 《Microscopy and microanalysis》2005,11(1):18-36
Historically, the decapod crustacean circulatory system has been classed as open. However, recent work on the blue crab, Callinectes sapidus, suggests the circulatory system may be more complex than previously described. Corrosion casting techniques were refined and used to map the circulatory system of a variety of crab species (order: Decapoda; family: Cancridae) to determine if the complexity observed in the blue crab was present in other species. Seven arteries arose from the single chambered heart. The anterior aorta, the paired anterolateral arteries, and the paired hepatic arteries exited from the anterior aspect of the heart. The small-diameter posterior aorta exited posteriorly from the heart. Exiting from the ventral surface of the heart, the sternal artery branched to supply the legs and mouthparts of the crab. These arteries were more complex than previously described, with arterioles perfusing all areas of the body. The arterioles split into fine capillary-like vessels. Most of these capillaries were blind ending. However, in several areas (antennal gland, supraesophageal ganglion) complete capillary beds were present. After passing through the capillary-like vessels, blood drained into a series of sinuses. However, rather than being arbitrary spaces as previously described, scanning electron micrographs showed the sinuses to be distinct units. Most of the sinuses formed a series of flattened membrane-bound lacunae. This complexity may qualify the decapod crustacean circulatory system as one that is "partially closed" rather than open. 相似文献
92.
The non-singlet quark structure function is calculated in the leading logarithm approximation in an axial gauge with n2 = 0, the light-cone gauge. The choice n2 = 0 leads to a simple identity for loop integrals involving the extra n · k denominators. We compare the results graph by graph with both Feynman gauge QCD and a scalar gluon theory. The leading diagrams are the same “rainbow” diagrams as for the case of the scalar theory.The techniques are also applied to quark-quark scattering at large transverse momentum. The leading diagrams have the same dressed ladder-form factor structure. 相似文献
93.
94.
J.P. Boucher L.P. Regnault J. Rossat-Mignod J.P. Renard J. Bouillot W.G. Stirling 《Solid State Communications》1980,33(2):171-174
It is shown that magnetic solitons are expected to occur when a magnetic field is applied to a planar antiferromagnetic chain. Neutron inelastic scattering measurements have been performed at low energy on the one dimensional antiferromagnetic compound TMMC. A new fluctuation is observed, around q = π and ω = 0 which is well interpreted in terms of magnetic solitons. 相似文献
95.
96.
Jonathan R. Gaunt Chun-Hay Kom Anna Kulesza W. James Stirling 《The European Physical Journal C - Particles and Fields》2010,69(1-2):53-65
We study the production of same-sign W boson pairs at the LHC in double parton interactions. Compared with simple factorised double parton distributions (dPDFs), we show that the recently developed dPDFs, GS09, lead to non-trivial kinematic correlations between the W bosons. A numerical study of the prospects for observing this process using same-sign dilepton signatures, including W ± W ± jj, diboson and heavy flavour backgrounds, at 14 TeV centre-of-mass energy is then performed. It is shown that a small excess of same-sign dilepton events from double parton scattering over a background dominated by single scattering W ± Z(γ *) production could be observed at the LHC. 相似文献
97.
Mpamhanga CP Chen B McLay IM Willett P 《Journal of chemical information and modeling》2006,46(2):686-698
A new method for the postprocessing of docking outputs has been developed, based on encoding putative 3D binding modes (docking solutions) as ligand-protein interactions into simple bit strings, a method analogous to the structural interaction fingerprint. Instead of employing traditional scoring functions, the method uses a series of new, knowledge-based scores derived from the similarity of the bit strings for each docking solution to that of a known reference binding mode. A GOLD docking study was carried out using the Bissantz estrogen receptor antagonist set along with the new scoring method. Superior recovery rates, with up to 2-fold enrichments, were observed when the new knowledge-based scoring was compared to the GOLD fitness score. In addition, top ranking sets of molecules (actives and potential actives or decoys) were structurally diverse with low molecular weights and structural complexities. Principal component analysis and clustering of the fingerprints permits the easy separation of active from inactive binding modes and the visualization of diverse binding modes. 相似文献
98.
Copping R Gaunt AJ May I Sharrad CA Collison D Helliwell M Fox OD Jones CJ 《Chemical communications (Cambridge, England)》2006,(36):3788-3790
(NH4)14Na4[(Np3W4O15)(H2O)3(BiW9O33)3].62H2O (1) and (NH4)14.5Na3.5[(Np3W4O15)(H2O)3(SbW9O33)3].40.5H2O (2) each contain three neptunyl(v) moieties encapsulated within heteropolyoxotungstate frameworks in which axial {NpO2}+ oxygens form one face of a WO6 octahedron. 相似文献
99.
Benjamin M. O’Brien Emilio P. Calius Tokushu Inamura Sheng Q. Xie Iain A. Anderson 《Applied Physics A: Materials Science & Processing》2010,100(2):385-389
Some of the most exciting possibilities for dielectric elastomer artificial muscles consist of biologically inspired networks
of smart actuators working towards common goals. However, the creation of these networks will only be realised once intelligence
and feedback can be fully distributed throughout an artificial muscle device. Here we show that dielectric elastomer artificial
muscles can be built with intrinsic sensor, control, and driver circuitry, bringing them closer in capability to their natural
analogues. This was achieved by exploiting the piezoresistive behaviour of the actuator’s highly compliant electrodes using
what we have called the dielectric elastomer switch. We developed suitable switching material using carbon loaded silicone
grease and experimentally demonstrated the primitives required for self-sensing actuators and digital computation, namely
compliant electromechanical NAND gates and oscillator circuits. We anticipate that dielectric elastomer switches will reduce
the need for bulky and rigid external circuitry as well as provide the simple distributed intelligence required for soft,
biologically inspired networks of actuators. Examples include many-degree-of-freedom robotic hearts, intestines, and manipulators;
wearable assistive devices; smart sensor skins and fabrics; and ultimately new types of artificial muscle embedded, electromechanical
computers. 相似文献
100.
Abstract The stability of travelling waves which occur when a nematic liquid crystal is subjected to crossed electric and magnetic fields has been studied previously where conditions on a control parameter q for stability to occur have been given. This article is concerned with the behaviour of the stable perturbations as time increases. For each of the three travelling wave solutions we can determine the long-term monotonic or oscillatory behaviour of the perturbations using knowledge of the spectrum of the operator governing the perturbation equation. 相似文献