Efficient quantum circuits for Schur and Clebsch-Gordan transforms

The Schur basis on n d-dimensional quantum systems is a generalization of the total angular momentum basis that is useful for exploiting symmetry under permutations or collective unitary rotations. We present efficient {size poly[n,d,log(1/epsilon)] for accuracy epsilon} quantum circuits for the Schur transform, which is the change of basis between the computational and the Schur bases. Our circuits provide explicit efficient methods for solving such diverse problems as estimating the spectrum of a density operator, quantum hypothesis testing, and communicating without a shared reference frame. We thus render tractable a large series of methods for extracting resources from quantum systems and for numerous quantum information protocols.     

Controlling hydrogel properties by tuning non-covalent interactions in a charge complementary multicomponent system

Mixing small molecule gelators is a promising route to prepare useful and exciting materials that cannot be accessed from any of the individual components. Here, we describe pH-triggered hydrogelation by mixing of two non-gelling amphiphiles. The intermolecular interactions among the molecules can be tuned either by controlling the degree of ionization of the components or by a preparative pathway, which enables us to control material properties such as gel strength, gel stiffness, thermal stability, and an unusual shrinking/swelling behaviour.

The properties of a charge complementary multicomponent gel can be tuned either by pH change or by varying the preparative pathway.     

Influence of Naphthalene Moiety on Mesomorphism

Compounds containing naphthalene moiety are synthesized and the liquid crystalline properties studied by texture observations. The mesomorphic properties of these compounds are compared with related compounds to understand the influence of broad units such as naphthalene on mesomorphism. It is observed that there is a limit to which the end alkoxy group can be extended in a mesogen. The method of preparation, and properties of these compounds are given.     

Rapidly converging approximations and regularity theory

We consider distributions on a closed compact manifold $M$ as maps on smoothing operators. Thus spaces of maps between ${{\Psi }^{\!-\!\infty }}(M)$ and $\mathcal{C ^{\infty }}(M)$ are considered as generalized functions. For any collection of regularizing processes we produce various algebras of generalized functions and equivariant embeddings of distributions into such algebras. The regularity for such generalized functions is provided in terms of a certain tameness of maps between graded Frechét spaces. This also recovers the singularity behaviour of distributions (singular support/wavefront sets) in terms of certain subalgebras of the algebra of generalized functions. This notion of regularity is compared with the regularity in Colombeau algebras in the $\mathcal{G }^{\infty }$ sense.     

Characterisation of sol-gel prepared (HfO2)x(SiO2)1-x (x=0.1, 0.2 and 0.4) by 1H, 13C, 17 O and 29Si MAS NMR, FTIR and TGA

The HfO2-SiO2 system is attracting interest as a possible new dielectric material in semiconductor devices. Knowledge of the location of hafnium within the silica network and the effect hafnium has on the structure will be central to the successful use of this material system in this application. Here, sol-gel techniques have been used to manufacture (HfO2)x(SiO2)1-x samples (x=0.1, 0.2 and 0.4, each heat treated at 250, 500 and 750 degrees C) and these have been characterised by magic angle spinning (MAS) NMR (1H, 13C, 17 O, 29Si), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. 29Si MAS NMR showed that increasing the hafnia content decreases the connectivity of the silicate network, i.e. increases the range of differently connected SiO4 (Qn) units with more having increased numbers of non-bridging oxygens (i.e. lower n). FTIR and 17 O MAS NMR showed unequivocally that the x=0.4 sample phase-separated at higher temperatures, while in the x=0.1 sample the hafnium was homogeneously mixed into the SiO2 phase without any phase separation.     

Hybrid ceramic nanosieves: stabilizing nanopores with organic links

Unprecedented hydrothermal stability in functional membranes has been obtained with hybrid organic-inorganic nanoporous materials, enabling long-term application in energy-efficient molecular separation, including dehydration up to at least 150 degrees C.     

Chemistry of 2,2,6,6,-tetramethyl-3,5-heptanedione (Hthd) modification of zirconium and hafnium propoxide precursors

The modification of different zirconium propoxide and hafnium propoxide precursors with 2,2,6,6,-tetramethyl-3,5-heptanedione (Hthd) was investigated by characterization of the isolated modified species. The complexes [Zr(OnPr)3(thd)](2), [Zr(OnPr)(OiPr)2(thd)]2, Zr(OiPr)(thd)3, [Hf(OnPr)3(thd)]2, and Hf(OiPr)(thd)3 were isolated and characterized. The structure of the n-propoxide analogue of Zr(OiPr)(thd)3 could not be refined, but its existence was clearly demonstrated by XRD and 1H NMR. The modification of the propoxide precursors involves mono- and trisubstituted intermediate compounds and does not involve a disubstituted compound; thus, the commercial product that is claimed to be "Zr(OiPr)2(thd)2" and is most commonly used for the MOCVD preparation of ZrO2 does not exist. No evidence was found for the presence of such a compound in either zirconium- or hafnium-based systems. Formation of the dimeric hydroxo-di-thd-substituted complex, [Hf(OH)(OiPr)(thd)2]2, which could be isolated only for hafnium-based systems, occurs on microhydrolysis. All heteroleptic intermediates are eventually transformed to the thermodynamically stable Zr(thd)4 or Hf(thd)4) The compounds obtained from isopropoxide precursors showed a higher stability than those with n-propoxide ligands or a combination of both types. In addition, it is important to note that residual alcohol facilitates the transformation and strongly enhances its rate. The unusually low solubility and volatility of MIV(thd)4 has been shown to be due to close packing and strong van der Waals interactions in the crystal structures of these compounds.     

Implementation of garlic cryopreservation techniques in the national plant germplasm system

The USDA-ARS National Plant Germplasm System (NPGS) maintains more than 200 Allium sativum (garlic) accessions at the Western Regional Plant Introduction Station in Pullman, WA. All accessions must be grown out in the field annually since garlic plants from these accessions do not reliably produce seeds and bulbs do not store well. Shoot tips excised from garlic cloves can be successfully cryopreserved using either Plant Vitrification Solution 2 (PVS2; 15 percent v/v DMSO, 15 percent v/v ethylene glycol, 30 percent v/w glycerol, 0.4 M sucrose) or Plant Vitrification Solution 3 (PVS3; 50 percent v/w sucrose, 50 percent v/w glycerol). We compared regrowth of shoot tips representing diverse garlic germplasm after exposure to either PVS2 or PVS3 during the cryopreservation procedure. At the USDA-ARS National Center for Genetic Resources Preservation, a component of the NPGS, we consider accessions successfully preserved if a minimum of 40 percent of explants exhibit regrowth after liquid nitrogen exposure and at least 60 viable shoot tips remain in long-term storage. Ten of twelve diverse garlic accessions were successfully cryopreserved using either PVS2 or PVS3 as cryoprotectants. Five genotypes had the best post liquid nitrogen regrowth after exposure to PVS2, four genotypes had the best regrowth after exposure to PVS3, and three genotypes performed equally well using either cryoprotectant solution. This project is part of an ongoing program to cryopreserve accessions of NPGS clonal crop collections.     

Dipeptide hydrogelation triggered via ultraviolet light

UV irradiation of a dipeptide gelator in solution with a photoacid generator (PAG) results in the formation of a hydrogel. We demonstrate that photopatterning of these gels using a UV mask is possible.