5,588 research outputs found
3-Chloro-N′-(4-hydroxybenzylidene)benzohydrazide
The title compound, C14H11ClN2O2, was prepared by the reaction of 4-hydroxybenzaldehyde with 3-chlorobenzohydrazide in methanol. The dihedral angle between the two benzene rings is 38.2 (2)°. In the crystal, molecules are linked through intermolecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming layers lying parallel to the bc plane
Estimation of the optical quality after implanting Acrysof ReSTOR multifocal intraocular lenses with corneal incision to correct astigmatism in cataract patients
AIM: To compare the postoperative vision performance of multifocal intraocular lens implantation combined with corneal incision to correct astigmatism and that of monofocal intraocular lenses implantation.<p>METHODS: Eighty patients(100 eyes)with age-related cataract and low cornea astigmatism were divided into control group and intervention group. Intervention group received limbal relaxing incisions at the steepest meridian axis during phacoemulsification with temporal corneal incision and implanting multifocal intraocular; the control group only received phacoemulsifieation with temporal corneal incision and implanting monofocal intraocular lenses. Uncorrected distance visual acuity(UCDVA), uncorrected near visual acuity(UCNVA)and cornea astigmatism were observed 1 week, 1 month and 3 months postoperatively. Best corrected near visual acuity(BCNVA), best corrected distance visual acuity(BCDVA), distant corrected near visual acuity(DCNVA), were observed 3 months postoperatively. <p>RESULTS: UCDVA and UCNVA in intervention group were higher than that in control group 1 week, 1 month and 3 months postoperatively while the cornea astigmatism in intervention group was lower than that in control group. BCNVA, BCDVA and DCNVA in both groups showed obvious improvement 3d after the surgery. There was no significant difference between the two groups in UCDVA and UCNVA 1 week, 1 month and 3 months postoperatively and in BCDVA and BCNVA 3 months postoperatively.<p>CONCLUSION:Multifocal intraocular lens implantation combined with transparency cornea relaxing incisions can effectively rectify preoperative cornea astigmatism in cataract patients, and it can provide good visual acuity of entire range, thus to extend the target users of multifocal intraocular lens
Clinical effects of using rigid gas permeable contact lens for refractoriness amblyopia
AIM:To explore the clinical effects of using rigid gas permeable contact lens(RGP)for refractoriness amblyopia patients. <p>METHODS: Ninety-eight cases(98 eyes)were voluntarily divided into RGP group and frame glasses group, and the two groups were received the regularity combined training to treat amblyopia for 6mo. We overviewed the corrected vision(on that day, 1, 3, 6mo)and the complication in RGP group. <p>RESULTS: The corrected vision in RGP group was obviously better than that in control group during the same time. The therapeutic efficacy in RGP group was better than that in frame glasses group, without serious complications at 6mo after treatment.<p>CONCLUSION: RGP groups could get better corrected visual acuity. It is safe and effective to improve corrected vision for refractoriness amblyopia patients
Cascading failures in coupled networks with both inner-dependency and inter-dependency links
We study the percolation in coupled networks with both inner-dependency and
inter-dependency links, where the inner- and inter-dependency links represent
the dependencies between nodes in the same or different networks, respectively.
We find that when most of dependency links are inner- or inter-ones, the
coupled networks system is fragile and makes a discontinuous percolation
transition. However, when the numbers of two types of dependency links are
close to each other, the system is robust and makes a continuous percolation
transition. This indicates that the high density of dependency links could not
always lead to a discontinuous percolation transition as the previous studies.
More interestingly, although the robustness of the system can be optimized by
adjusting the ratio of the two types of dependency links, there exists a
critical average degree of the networks for coupled random networks, below
which the crossover of the two types of percolation transitions disappears, and
the system will always demonstrate a discontinuous percolation transition. We
also develop an approach to analyze this model, which is agreement with the
simulation results well.Comment: 9 pages, 4 figure
Fire resistance of circulat steel tubes infilled with ultra-high strength concrete with external fire protection
In this paper, a non-linear three-dimensional finite element model is presented in order to study the behaviour of axially loaded ultra-high strength concrete filled circular hollow tubular columns exposed to fire. Ultra-high strength concrete with compressive strength greater than 180 N/mm2 has been developed for concrete filled tubes for use in high–rise buildings. This paper studies the structural performance of fire protected ultra-high strength concrete filled tubular columns exposed to the standard ISO fire. The aim of this work is to understand and represent the behaviour of axially loaded ultra-high strength concrete filled circular hollow tubular columns in fire situations and to compare calculation results with experiment. The numerical analyses are carried out using a general finite element analysis package ABAQUS and the results are validated against the test results in terms of heat distribution and mechanical behavior. Comparison with the test results showed a reasonable agreement with finite element results in terms of temperature prediction and load displacement behavior during the fire
Design of Ultra-compact Graphene-based Superscatterers
The energy-momentum dispersion relation is a fundamental property of
plasmonic systems. In this paper, we show that the method of dispersion
engineering can be used for the design of ultra-compact graphene-based
superscatterers. Based on the Bohr model, the dispersion relation of the
equivalent planar waveguide is engineered to enhance the scattering cross
section of a dielectric cylinder. Bohr conditions with different orders are
fulfilled in multiple dispersion curves at the same resonant frequency. Thus
the resonance peaks from the first and second order scattering terms are
overlapped in the deepsubwavelength scale by delicately tuning the gap
thickness between two graphene layers. Using this ultra-compact graphene-based
superscatterer, the scattering cross section of the dielectric cylinder can be
enhanced by five orders of magnitude.Comment: This paper has been accepted by IEEE Journal of Selected topics in
Quantum Electronic
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