1,151 research outputs found
INVARIANT ALGEBRAIC SURFACES OF THE CHEN SYSTEM
No full textIn this paper, enlightened by the idea of the weight of a polynomial introduced by Swinnerton-Dyer [2002], we find all the invariant algebraic surfaces of the Chen system x′ = a(y - x), y′ = (c - a)x + cy - xz, z′ = xy - bz.</jats:p
Quantum memory for photonic packets
No full textNumerical simulations of the trapping and the retrieval processes of three different types of single-pulse photonic packets in a medium with electromagnetically induced transparency (EIT) are performed, and the simulation results for a single-Gaussian-pulse photonic packet correspond to the results of a recent well-known experiment. According to the simulation results, in spite of the fact that all three types of photonic packets, in general, experience a shape-preserving storage process, the single-Gaussian-pulse photonic packet suffers the least distortion. Also, based on our numerical simulation, we present, for the first time to the best of our knowledge, a shape- and quantum-state-preserving propagation of a multiple-Gaussian-pulse photonic packet in a medium with EIT. According to the simulations, attainment of a quantum random access memory (RAM) for photonic packets is within the bounds of possibility
The sequences of cDNA and amino acids from the susceptible SS strain and resistant XZ populations.
No full text<p>The sequences XZ1 and XZ2 come from cloning <i>An. sinensis</i> individuals from the XZ population. The sequence of the SS strain amino acid was translated from the DNA sequence of the <i>An. sinensis</i> SS strains. XZ1 and XZ2 amino acid sequences were translated from XZ cDNA sequences by cloning.</p
Growth Strategy and Physical Properties of the High Mobility P-Type CuI Crystal
No full textAcquiring stable binary wide band-gap semiconductor (WBS) materials with high p-type mobility is essential for the development of WBS optoelectronic devices. CuI is-a p-type WBS material with a large band gap (3.1 eV) and high exciton binding energy (62 meV). However, the semiconductor-characteristics of the CuI single crystal are unknown due to the lack of a large sized and high quality crystal. Our approach focuses on the design of the mineralizer for the hydrothermal method to effectively control the growth habit and the impurity concentration in the crystal. A large size (15 mm x 10 mm x 1 mm) and high quality CuI single crystal is obtained by using a new mineralizer (NH4I + KI). The crystal shows high p-type mobility (43.9 cm(2).V-1.S1-). The strong and sharp band-edge emission at 410 nm indicates that the interband excitonic transition dominates the optical response in the spectrum. Such a binary crystalline material may open the way to new applications in optoelectronic devices
Probing the alkyl ligands on silylated mesoporous MCM-41 using hyperpolarized Xe-129 NMR spectroscopy
No full textStable carbon and hydrogen isotopic fractionations of alkane compounds and crude oil during aerobically microbial degradation
No full textNorm inequalities for cartesian decompositions
No full textAbstractLet the Cartesian decomposition of a complexn × n matrixT beT = A + iB withA, B Hermitian. Letαj andβj be the eigenvalues ofA andB respectively ordered so that|α1|⩾ … ⩾ |αn|and|β1|⩾ … ⩾ |βn|. We prove that∥diag(α1+iβ1,…αn+iβn)∥⩽2∥T∥ for every unitarily invariant norm this settles affirmatively a conjecture of Ando and Bhatia (T. Ando, R. Bhatia, Eigenvalue inequalities associated with the cartesian decomposition, Linear and Multilinear Algebra 22 (1987) 133)
Shared compliant control of teleoperation based on stiffness feedback
No full textIn teleoperation tasks, communication delays between master and slave sides negatively affect the stability and transparency of closed loop system, and make it difficult to maintain a desired contact force. In order to improve the performance of contact force control in teleoperation under large time delays, a shared compliant control method is proposed in this paper. On the master side, the operator issues a desired contact force command according to the feedback of the contact stiffness identified on line besides motion commands. And on the slave side, a local contact force controller is designed using an adaptive Smith predictor, so as to shares control load with the operator. Experimental results show that this method can improve the force control performance, lower the difficulty of operation, and help the operator complete contact tasks with proper forces. © (2013) Trans Tech Publications, Switzerland
Gastrochilus xizangensis W. S. Chen, M. Lei & X. L. Wang 2022, sp. nov.
No full textGastrochilus xizangensis W.S.Chen, M.Lei & X.L.Wang, sp. nov. (Fig.1 and 2) (ƱAEfiffiż) Type: CHINA. Xizang Autonomous Region, Cuona county, on branch of tree, elevation 2300 m, 2021, W.S. Chen, M. Lei, X.L.Wang, 2021001 (holotype XZ!, isotype, XZ!) Epiphytic herbs. Stems clustered, pendulous, rarely branched; 3–10 cm long, rooting. Leaves distichous, twisted at bases, leathery, narrowly elliptic, 10–12 × 3–5 mm, apex acute and with three short awns or not, smooth surface with purplish red speckles. Inflorescence lateral, 5–30 mm long, subumbellate, 1-8 flowered; peduncle 2–5 mm long, with a sterile bract, 1–3 mm long; floral bracts deltoid, 1 × 1.5–2.0 mm, apex acute; ovary and pedicel 6–7 mm long, with purple-red stripes; flowers not open widely, 4.5–5 mm long, 3.6–4.6 mm wide, yellow-green with sparse purple-red speckles, with sparse short hairs. Sepals and petals subequal, elliptic-oblong, slightly concave, 2.3–2.7 × ca. 1.0 mm, glabrous, abaxially slightly ridged, purple stripes on the ridges, margin entire or minutely erose. Lip composed by a saccate hypochile and a flat epichile of 3–3.5 mm long; hypochile conical, ca. 2 mm long, ca. 1.5 mm in diam., apex obtuse to round; epichile oblong or reniform, ca. 1.5 mm × 2.2 mm, consisting of a central cushion and a marginal part; central cushion thickened and green with purple-red spots, thickest at the edges as a ridge, densely with short hairs along the ridges; marginal part membranous and white, sparsely short hairs, apices broadly obtuse; column short and stout, ca. 1.3 mm long, 0.5 mm wide, footless; rostellum forked at apex; anther cap pentagonal, ca. 0.8 × 0.8 mm, apex pointed and upturned; pollinarium ca. 1 mm long; pollinia 2, yellow, waxy, ellipsoid, on a slender stipe; stipe slender, ca. 0.7 mm long; viscidium elliptic. Distribution and habitat: —Known so far only from Cuona County, Southeast of Xizang Autonomous Region, as epiphytic plants on tree barks in a broad-leaved forest at elevation of 2300 m. Phenology: —Flowering in April. Etymology: —In reference to the type-locality of the new species. Conservation status: —There are two populations of the new species, which consists of no more than 50 individuals (clumps). According to the IUCN categories (2022), G. xizangensis should be treated as Data Deficient.Published as part of Chen, Wen-Shuai, Lei, Ming, Ma, Chong-Bo, Jin, Xiao-Hua & Wang, Xi-Long, 2022, Gastrochilus xizangensis (Aeridinae, Vandeae, Orchidaceae), a new species from Xizang, China, pp. 219-226 in Phytotaxa 566 (2) on pages 222-224, DOI: 10.11646/phytotaxa.566.2.6, http://zenodo.org/record/711920
Simultaneous determination of endocrine-disrupting phenols and steroid estrogens in sediment by gas chromatography-mass spectrometry
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