2,796 research outputs found
catena-Poly[[chloridocobalt(II)]-μ-5-(8-quinolyloxymethÂyl)tetraÂzolato-κ4 N 5,O,N 1:N 4]
In the title compound, [Co(C11H8N5O)Cl]n, the CoII atom is pentaÂcoordinated by one O atom and two N atoms from a 5-(8-quinolyloxymethÂyl)tetraÂzolate ligand, one N atom from another symmetry-related ligand, and a Cl atom. The coordination geometry can be described as slightly distorted trigonal–bipyramidal. Adjacent Co atoms are connected by the bridging tetraÂzole groups into a chain. The dihedral angle between the quinoline and tetraÂzole planes is 21.2 (1)°. The structure involves intra- and interÂchain C—H⋯N hydrogen bonds
Generalized bioinspired approach to a daytime radiative cooling "skin"
Energy-saving cooling materials with strong operability are desirable towards
sustainable thermal management. Inspired by the cooperative thermo-optical
effect in fur of polar bear, we develop a flexible and reusable cooling skin
via laminating a polydimethylsiloxane film with a highly-scattering
polyethylene aerogel. Owing to its high porosity of 97.9% and tailored pore
size of 3.8 +- 1.4 micrometers, superior solar reflectance of 0.96 and high
transparency to irradiated thermal energy of 0.8 can be achieved at a thickness
of 2.7 mm. Combined with low thermal conductivity of 0.032 W/m/K of the
aerogel, the cooling skin exerts midday sub-ambient temperature drops of 5-6
degrees in a metropolitan environment, with an estimated limit of 14 degrees
under ideal service conditions. We envision that this generalized bilayer
approach will construct a bridge from night-time to daytime radiative cooling
and pave the way for economical, scalable, flexible and reusable cooling
materials.Comment: 15 pages, 4 figures, of which another version has been accepted by
ACS ami but not published ye
Cloud Resource Management With Turnaround Time Driven Auto-Scaling
Cloud resource management research and techniques have received relevant attention in the last years. In particular, recently numerous studies have focused on determining the relationship between server-side system information and performance experience for reducing resource wastage. However, the genuine experiences of clients cannot be readily understood only by using the collected server-side information. In this paper, a cloud resource management framework with two novel turnaround time driven auto-scaling mechanisms is proposed for ensuring the stability of service performance. In the first mechanism, turnaround time monitors are deployed in the client-side instead of the more traditional server-side, and the information collected outside the server is used for driving a dynamic auto-scaling operation. In the second mechanism, a schedule-based auto scaling preconfiguration maker is designed to test and identify the amount of resources required in the cloud. The reported experimental results demonstrate that using our original framework for cloud resource management, stable service quality can be ensured and, moreover, a certain amount of quality variation can be handled in order to allow the stability of the service performance to be increased
Vertices with the Second Neighborhood Property in Eulerian Digraphs
The Second Neighborhood Conjecture states that every simple digraph has a
vertex whose second out-neighborhood is at least as large as its first
out-neighborhood, i.e. a vertex with the Second Neighborhood Property. A cycle
intersection graph of an even graph is a new graph whose vertices are the
cycles in a cycle decomposition of the original graph and whose edges represent
vertex intersections of the cycles. By using a digraph variant of this concept,
we prove that Eulerian digraphs which admit a simple dicycle intersection graph
have not only adhere to the Second Neighborhood Conjecture, but have a vertex
of minimum outdegree that has the Second Neighborhood Property.Comment: fixed an error in an earlier version and made structural change
Contralateral seventh cervical nerve transfer for central spastic arm paralysis: a systematic review and meta-analysis
ObjectivesThe specific benefits of a contralateral cervical 7 nerve transplant in people with spastic paralysis of the upper extremity caused by cerebral nerve injury are unclear. To evaluate the efficacy and safety of contralateral C7 nerve transfer for central spastic paralysis of the upper extremity, we conducted a comprehensive literature search and meta-analysis.Materials and methodsPRISMA guidelines were used to search the databases for papers comparing the efficacy of contralateral cervical 7 nerve transfer vs. rehabilitation treatment from January 2010 to August 2022. The finishing indications were expressed using SMD ± mean. A meta-analysis was used to assess the recovery of motor function in the paralyzed upper extremity.ResultsThe meta-analysis included three publications. One of the publications offers information about RCTs and non-RCTs. A total of 384 paralyzed patients were included, including 192 who underwent CC7 transfer and 192 who received rehabilitation. Results from all patients were combined and revealed that patients who had CC7 transfer may have regained greater motor function in the Fugl-Meyer score (SMD 3.52, 95% CI = 3.19–3.84, p < 0.00001) and had superior improvement in range of motion compared to the rehabilitation group (SMD 2.88, 95% CI = 2.47–3.29, p < 0.00001). In addition, the spasticity in the paralyzed upper extremity significantly improved in patients with CC7 transfer (SMD −1.42, 95% CI = −1.60 to −1.25, p < 0.00001).ConclusionOur findings suggested that a contralateral C7 nerve transfer, which has no additional adverse effects on the healthy upper limb, is a preferable method to restore motor function
Quantum correlations in spin models
Bell nonlocality, entanglement and nonclassical correlations are different
aspects of quantum correlations for a given state. There are many methods to
measure nonclassical correlations. In this paper, nonclassical correlations in
two-qubit spin models are measured by use of measurement-induced disturbance
(MID) [Phys. Rev. A, 77, 022301 (2008)] and geometric measure of quantum
discord (GQD) [Phys. Rev. Lett. 105, 190502 (2010)]. Their dependencies on
external magnetic field, spin-spin coupling, and Dzyaloshinski-Moriya (DM)
interaction are presented in detail. We also compare Bell nonlocality,
entanglement measured by concurrence, MID and GQD and illustrate their
different characteristics.Comment: 1 text and 5 eps figures, accepted by Annals of Physic
Modelling the evaporation of aluminum in Ti–6Al–4V alloy melted with electron beam and laser
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