538 research outputs found
Reaction of [(mu-RE)(mu-CO)Fe-2(CO)(6)](-) (E = S, Se) with N2CHCO2Me. Synthesis and characterisation of (mu-RE)[mu-eta(2)-N=NCH(R ')CO2Me]Fe-2(CO)(6) and (mu-PhSe)[mu-eta(1)-N=NCH(Me)CO2Me]Fe-2(CO)(6)
No full textReaction of [M][(mu-RE)(mu-CO)Fe-2(CO)(6)] (E = S, Se; M = Et3NH, Na) with N2CHCO2Me give the intermediate [M][(mu-RE)(mu-N2CHCO2Me)Fe-2(CO)(6)] Action of LI with counterion Et3NH+ yields neutral complexes (mu-RE)(mu-eta(2-)N=NCH2CO2Me)Fe-2(CO)(6) (1, RE=Bu'S; 2, RE=PhS; 3, RE=PhSe). Treatment of II (M=Na) with Mel affords (mu-RE)[mu-eta(2)-N=NCH(Me)CO2Me]Fe-2(CO)(6) (4, RE = Bu'S; 5, RE = PhS). In the case of RE = PhSe, the reaction of II with Mel gives two isomers, (mu-PhSe)[mu-eta 2-N=NCH(Me)CO2Me]Fe-2(CO)(6) (6) and (mu-PhSe)[mu-eta(1)-N=NCH(Me)CO2Me]Fe-2(CO)(6) (7). The structure of complex 7 has been determined by single-crystal X-ray diffraction technique. (C) 2000 Elsevier Science S.A. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000088590600012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Chemistry, Inorganic & NuclearChemistry, OrganicSCI(E)2ARTICLE2214-21860
Effect of Porous Microstructures on the Biomechanical Characteristics of a Root Analogue Implant: An Animal Study and a Finite Element Analysis
No full textBackground: Full ceramic or metal custom-made root analogue implants (RAIs) are made by replicating the natural tooth geometry. However, it may lead to the stress shielding of the surrounding bone, and an RAI is unable to easily achieve primary stability. Therefore, to improve primary stability and reduce stress shielding, RAI porous structures are proposed. The purpose of this study was to evaluate the effect of porous microstructures on the biomechanical characteristics of the custom-made RAT. Methods: Porous and bulk titanium cylinders and porous RAI and conventional implants for in vivo tests were fabricated using a selective laser melting (SLM) technology. The elastic modulus and the compressive strength of porous titanium cylinders were evaluated. These samples were then implanted into rabbit femurs (cylinders) and beagle dog mandibles (RAI and conventional implants). A simplified three-dimensional geometry of the anterior maxilla of a patient was constructed. Then, based on the extracted standard template library (STL) data, five different RAI models were constructed: (A) smooth surface, (B) pit surface, (C) bulb surface, (D) threaded surface, and (E) porous surface. A conventional implant model was also constructed. A static load of 100 N was applied to the crown in the multivectoral direction. Results: The results of the in vivo experiment confirmed that the porous structure decreased the elastic modulus of Ti6AI4V. Additionally, the implantation of the porous custom-made RAIs resulted in increased new bone ingrowth and decreased bone resorption compared to conventional implants. Moreover, the 3D finite element analysis suggested that the bone surrounding porous custom-made RAIs was subjected to a more uniform stress distribution, and the strain values of the surrounding bone were more conducive to bone formation. Conclusion: Based on these findings, a custom-made RAI with a porous surface accelerates bone formation and might reduce the stress-shielding effect
Superdense Coding with GHZ and Quantum Key Distribution with W in the ZX-calculus
No full textQuantum entanglement is a key resource in many quantum protocols, such as quantum teleportation and quantum cryptography. Yet entanglement makes protocols presented in Dirac notation difficult to verify. This is why Coecke and Duncan have introduced a diagrammatic language for quantum protocols, called the ZX-calculus. This diagrammatic notation is both intuitive and formally rigorous. It is a simple, graphical, high level language that emphasises the composition of systems and naturally captures the essentials of quantum mechanics. In the author's MSc thesis it has been shown for over 25 quantum protocols that the ZX-calculus provides a relatively easy and more intuitive presentation. Moreover, the author embarked on the task to apply categorical quantum mechanics on quantum security; earlier works did not touch anything but Bennett and Brassard's quantum key distribution protocol, BB84. Superdense coding with the Greenberger-Horne-Zeilinger state and quantum key distribution with the W-state are presented in the ZX-calculus in this paper
Hydraulic conductivity of whole root system is better than hydraulic conductivity of single root in correlation with the leaf water status of maize
No full textUnder hydroponic culture conditions, we studied the relationship between two different types of root hydraulic conductivity of maize (Zea mays L.) and its leaf water status. The results have proved the inaccuracy of the single root hydraulic conductivity (Lp(sr)) to describe the ability of water uptake by maize roots, which can be better described by the whole root systems hydraulic conductivity (Lp(wr)). Moreover, Lp(wr) can be measured easier. Although the whole roots surface area (WRA), which integrated all the root characters, such as root dry weight, volume and length, represent the interaction between root and soil (or water in soil solutions) better, there is no significant relationship between WRA and Lp(wr), and leaf water potential because part of the roots has no activity for water uptake. However, active root surface area (ARA) truly reflects the level of root metabolic activity and root function efficiency, i.e., the ratio of the active roots to the whole roots. Hence, ARA has a significant linear correlation with Lp(wr). Because of the high plasticity of plant root systems architecture and metabolism under changed water and nutrition conditions, the relationship between single root Lp(sr) and whole root Lp(wr) and between WRA and ARA are not positively linear correlated. Results demonstrate that the whole root Lp(wr) described by ARA can reflect more accurately both the water uptake by plant roots and the leaf water status than the single root Lp(sr)
On-top pair-correlation function in the homogeneous electron liquid
No full textThe ladder theory, in which the Bethe-Goldstone equation for the effective potential between two scattering particles plays a central role, is well known for its satisfactory description of the short-range correlations in the homogeneous electron liquid. By solving exactly the Bethe-Goldstone equation in the limit of large transfer momentum between two scattering particles, we obtain accurate results for the on-top pair-correlation function g(0), in both three dimensions and two dimensions. Furthermore, we prove, in general, that the ladder theory satisfies the cusp condition for the pair-correlation function g(r) at zero distance r=0.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000235009500047&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, Condensed MatterSCI(E)8ARTICLE3null7
Silicon-glass wafer bonding with silicon hydrophilic fusion bonding technology
No full textSilicon-glass wafer bonding is realized with silicon hydrophilic fusion bonding technology. Tensile strength testing shows that the bonding strength is large enough for most applications of integrated circuits and transducers. The bonding strengths of 4 in. 575 mu m thick #7740 glass-4 in. 525 mu m thick silicon and of 1.5 in. 1000 mu m thick #7740 glass-2 in. 380 mu m thick silicon are larger than 9 MPa both with an annealing temperature of 450 degrees C. (C) 1999 Elsevier Science S.A. All rights reserved.Engineering, Electrical & ElectronicInstruments & InstrumentationSCI(E)EI25ARTICLE146-487
Improved fifth-order geometric aberration coeincients of electron lenses
No full textIn this paper, fifth-order geometric aberrations of round electron lenses have been restudied. Improved analytical formulae of the aberration coefficients were derived by the computer algebra software-Mathematica-and their correctness verified by cross-checking with numerical integration and differential algebraic techniques for a given electromagnetic lens.Physics, AppliedSCI(E)EI3ARTICLE5653-6593
Integrated acousto-optic polarization converter in a ZX-cut LiNbO3 waveguide superlattice
No full textInternational audienceWe report an integrated acousto-optic polarization converter exploiting a novel surface acoustic superlattice (S-ASL) transducer. The S-ASL transducer is made of a ZX-cut periodically poled lithium niobate (PPLN) crystal with uniform coplanar electrodes for surface acoustic wave (SAW) generation. For a PPLN period of 20 mu m the SAW is excited at an rf of about 190 MHz, while the phase matching occurs at an optical wavelength of around 1456 nm. The measured mode conversion efficiency of 90% at an input rf power of 1 W and the 3 dB optical bandwidth of 2.5 nm confirm the confinement of the SAW between the electrode gap and the constructive interaction along the whole 10 mm electrode length
Long-wavelength behavior of the dynamical spin-resolved local-field factor in a two-dimensional electron liquid
No full textThe high-frequency limits of the singular component A(omega) of the small wave-vector expansion of the longitudinal (L) and transverse (T) components of the spin-resolved exchange-correlation kernel tensor f(xc,sigmasigma)('L,T)(q,omega)=-v(q)G(sigmasigma)('L,T)(q,omega) in a two-dimensional isotropic electron liquid with arbitrary spin polarization are studied. Here G(sigmasigma)('L,T)(q,omega) is the spin-resolved local-field factor, v(q) is the Coulomb interaction in momentum space, and sigma denotes spin. Particularly, the real part of A(omega) is found to be logarithmically divergent at large omega. The large wave-vector structure of the corresponding spin-resolved static structure factor is also established.Physics, Condensed MatterSCI(E)1ARTICLE23null7
Molecular Analysis of Chinese Celastrus and Tripterygium and Implications in Medicinal and Pharmacological Studies.
No full textCelastrus and Tripterygium species, which are used in traditional Chinese medicine, have attracted much attention due to their anti-tumor promoting and neuroprotective activities, in addition to their applications in autoimmune disorders. However, systematic relationships between them and among species are unclear, and it may disturb their further medicinal utilization. In the present study, the molecular analysis of combined chloroplast and nuclear markers of all Chinese Celastrus and Tripterygium was performed, and clear inter- and intra-genus relationships were presented. The result suggests that Tripterygium constitute a natural monophyletic clade within Celastrus with strong support value. Fruit and seed type are better than inflorescence in subgeneric classification. Chinese Celastrus are classified for three sections: Sect. Sempervirentes (Maxim.) CY Cheng & TC Kao, Sect. Lunatus XY Mu & ZX Zhang, sect. nov., and Sect. Ellipticus XY Mu & ZX Zhang, sect. nov. The phylogenetic data was consistent with their chemical components reported previously. Owing to the close relationship, several evergreen Celastrus species are recommended for chemical and pharmacological studies. Our results also provide reference for molecular identification of Chinese Celastrus and Tripterygium
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