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71.
Iodoplumbates with Tetra‐ and Penta‐coordinated Pb2+ Ions In contrast to all known iodoplumbates with octahedrally coordinated Pb2+ ions, square pyramidal geometry is observed in the iodoplumbate chains of (Pr4N)[PbI3] ( 1 ) and [Mg(dmf)6][PbI3]2 ( 2 ), whereas the isolated anions in (Ph4P)2[Pb2I6] ( 3 ) and [Bu3N–(CH2)3–NBu3][PbI4] ( 4 ) contain tetra‐coordinated lead atoms. (Pr4N)[PbI3] ( 1 ): a = 910.86(6), b = 1221.46(7), c = 1907.7(1) pm, V = 2122.5(2) · 106 pm3, space group P212121; [Mg(dmf)6][PbI3]2 ( 2 ): a = 891.24(9), b = 1025.34(7), c = 1234.82(9) pm, α = 92.938(8), β = 106.457(8), γ = 98.100(7)°, V = 1066.4(2) · 106 pm3, space group P1; (Ph4P)2[Pb2I6] ( 3 ): a = 1174.5(1), b = 722.29(7), c = 3104.8(4) pm, β = 100.50(1)°, V = 2589.8(5) · 106 pm3, space group P21/n; [Bu3N–(CH2)3–NBu3][PbI4] ( 4 ): a = 2178.3(1), b = 1008.63(5), c = 1888.3(1) pm, β = 110.003(5)°, V = 3898.6(4) · 106 pm3, space group P2/c. 相似文献
72.
Artifact Reduction Based on Sinogram Interpolation for the 3D Reconstruction of Nanoparticles Using Electron Tomography
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Kadir Sentosun Ivan Lobato Eva Bladt Yang Zhang Willem Jan Palenstijn Kees Joost Batenburg Dirk Van Dyck Sara Bals 《Particle & Particle Systems Characterization》2017,34(12)
Electron tomography is a well‐known technique providing a 3D characterization of the morphology and chemical composition of nanoparticles. However, several reasons hamper the acquisition of tilt series with a large number of projection images, which deteriorate the quality of the 3D reconstruction. Here, an inpainting method that is based on sinogram interpolation is proposed, which enables one to reduce artifacts in the reconstruction related to a limited tilt series of projection images. The advantages of the approach will be demonstrated for the 3D characterization of nanoparticles using phantoms and several case studies. 相似文献
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Maria Belli Brian Brookman Beatriz de la Calle Vivienne James Michael Koch Nineta Majcen Antonio Menditto Tracey Noblett Roberto Perissi Kees van Putten Piotr Robouch Tommy Šlapokas Philip Taylor Daniel Tholen Annette Thomas Barry Tylee 《Accreditation and quality assurance》2009,14(8-9):507-512
A summary of the working group (WG) discussions on proficiency testing (PT) and external quality assessment (EQA) held at the Eurachem Workshop, Rome, 5–7 October 2008 is provided. The eight WG’s covered a range of issues concerned with current practice and future directions; how frequently should laboratories participate in PT/EQA? (WG1); developments in PT/EQA within the EU—what is required in future? (WG2); what issues do developing countries face with regards to PT/EQA? (WG3), what issues are specific to microbiology PT/EQA? (WG4); what new fields are emerging for PT/EQA? (WG5); what will be the impact of the new ISO/IEC 17043 standard? (WG6); do current PT/EQA schemes meet the needs of participants? (WG7); and what are the issues that affect the quality of proficiency test items? (WG8). Delegates with different backgrounds were on each WG in order to capture a range of views and experience from a number of different sectors. Working group representatives included PT/EQA providers, participants in PT/EQA schemes and end users of PT results such as accreditation bodies and regulatory authorities, from countries around the world. 相似文献
76.
Green's function retrieval by crosscorrelation may suffer from irregularities in the source distribution, asymmetric illumination, intrinsic losses, etc. Multidimensional deconvolution (MDD) may overcome these limitations. A unified representation for Green's function retrieval by MDD is proposed. From this representation, it follows that the traditional crosscorrelation method gives a Green's function of which the source is smeared in space and time. This smearing is quantified by a space-time point-spread function (PSF), which can be retrieved from measurements at an array of receivers. MDD removes this PSF and thus deblurs and deghosts the source of the Green's function obtained by correlation. 相似文献
77.
Simonato S Gröger H Möllmer J Staudt R Puls A Dreisbach F Feldmann C 《Chemical communications (Cambridge, England)》2012,48(6):844-846
The CO(2) uptake on nanoscale AlO(OH) hollow spheres (260 mg g(-1)) as a new material is comparable to that on many metal-organic frameworks although their specific surface area is much lower (530 m(2) g(?1)versus 1500-6000 m(2) g(?1)). Suited temperature-pressure cycles allow for reversible storage and separation of CO(2) while the CO(2) uptake is 4.3-times higher as compared to N(2). 相似文献
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Rob van Asselt Kees Vrieze Cornelis J. Elsevier 《Journal of organometallic chemistry》1994,480(1-2):27-40
Zerovalent complexes of the type Pd(Ar-BIAN)(alkene), i.e. complexes containing the rigid bidentate nitrogen ligands bis(arylimino) acenaphthene (Ar = p-Tol, p-MeOC6H4, o-Tol,o,o′-Me2C6H3, o,o′-iPr2C6H3) and an electron-poor alkene have been shown to react with a variety of (organic) halides RX, including methyl, benzyl, aryl, acyl and allylic halides, to give the corresponding square planar divalent Pd(R)X(Ar-BIAN) or [Pd(η3-allyl)(Ar-BIAN)]X complexes. The new complexes obtained have been fully characterized and their fluxional behaviour in solution studied by 1H NMR spectroscopy. The rate of oxidative addition of iodomethane to Pd(p-Tol-BIAN)(alkene) complexes was found to decrease with increasing Pd-alkene bond strength, i.e. dimethyl fumarate fumaronitrile, but oxidative addition to the fumaronitrile complex was accelerated by irradiation with a mercury lamp. Oxidative addition of allylic ha 相似文献
80.
Octahedral 38-, 44- and 48-electron systems are closed-shells and could be stable. The latter two systems have a high energy and dissociate via a non-symmetric path. (NH)6 in a chair conformation should be stable. 相似文献