Fractional Modeling and Analysis of Coupled MR Damping System

The coupled magnetorheological(MR) damping system addressed in this paper contains rubber spring and magnetorheological damper. The device inherits the damping merits of both the rubber spring and the magnetorheological damper.Here a fractional-order constitutive equation is introduced to study the viscoelasticity of the combined damper. An introduction to the definitions of fractional calculus, and the transfer function representation of a fractional-order system are given. The fractional-order system model of a magnetorheological vibration platform is set up using fractional calculus, and the function of displacement is presented. It is indicated that the fractional-order constitutive equation and the transfer function are feasible and effective means for investigating of magnetorheological vibration device.

Gait speed and hospitalization among ambulatory hemodialysis patients: USRDS special study data

AIM:To assess the association of measured gait speed with hemodialysis(HD)patients’hospitalization,in conjunction with,and apart from,recent fall history.METHODS:Gait speed was measured by a standard protocol and falls during the past 12 mo were ascertained for a prevalent multi-center HD cohort(n=668)aged 20-92.Hospitalization during the past 12 mo was identified in the patient’s clinic records,and the first hospitalization after gait speed assessment(or the competing event of death)was identified in the 2013 United States Renal Data System Standard Analysis Files.RESULTS:Slow gait speed,defined as<0.8 m/s,characterized 34.7%of the patients,and 27.1%had experienced a recent fall.Patients with slow gait speed but without a history of recent falls were 1.79 times more likely to have been hospitalized during the past12 mo(OR=1.79,95%CI:1.11-2.88,P=0.02),and patients with slow gait speed and a history of recent falls were over two times more likely to have been hospitalized(OR=2.10,95%CI:1.19-3.73,P=0.01),compared with patients having faster gait speed and no recent fall history.Prospective examination of gait speed/fall history status in relation to first hospitalization(or death)incurred by the end of follow-up December 31,2011 also showed that slow gait speed was associated with these events in conjunction with a history of falls(HR=1.54,95%CI:1.04-2.30,P=0.03).CONCLUSION:The International Task Force on Nutrition and Aging reported that gait speed is a powerful predictor for older adults of adverse outcomes such as hospitalization.In our data,gait speed--apart from,as well as in conjunction with,recent fall history--was associated with HD patients’hospitalization for multiple causes.Gait speed may be a sensitive health indicator among HD patients across the age spectrum.

Liquid modified photonic crystal fiber for simultaneous temperature and strain measurement

A liquid modified photonic crystal fiber(PCF)integrated with an embedded directional coupler and multi-mode interferometer is fabricated by infiltrating three adjacent air holes of the innermost layer with standard 1.48 refractive index liquids.The refractive index of the filled liquid is higher than that of background silica,which can not only support the transmitting rod modes but also the"liquid modified core"modes propagating between the PCF core and the liquid rods.Hence,the light propagating in the liquid modified core can be efficiently coupled into the satellite waveguides under the phase-matching conditions,resulting in a dramatic decrease of the resonant wavelength intensity.Furthermore,there is a multi-mode interference produced by modified core modes and rod modes.Such a compact(~0.91 cm)device integrated with an embedded coupler and interferometer is demonstrated for high-sensitivity simultaneous temperature(~14.72 nm∕℃)and strain(~13.01 pm∕με)measurement.

Cenozoic Fault Distribution Characteristics and Evolution in Qikou Sag of Bohai Basin, China

Qikou sag, located in north-center of Huanghua depression in Bohai Basin, is a Cenozoic sag with rich hydrocarbon. As a microcosm of Bohai Basin, the fault characteristics of Cenozoic structural layers in Qikou sag could indicate and record the evolution of Cenozoic stress field in Bohai Basin. Based on the latest 3-D seismic data, the study takes statistics on the fault system of Cenozoic structural layers and analyzes the fault throws of major large faults along the strikes in different periods in Qikou sag, then the fault distribution regularities and the fault direction characteristics in each structural layer are summarized. The result shows that during Cenozoic, the fault activity strength migrates from southwest to northeast and the strikes of faults changes from northwestward in Sha-3 period to nearly east-westward since Sha-1 period.

Two-micron all-fiberized passively mode-locked fiber lasers with high-energy nanosecond pulse

We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses,relying on the transmission in a semiconductor saturable absorber(SESA)and a carbon nanotube(CNTs-PVA)film separately.A section of an SMF-MMF-SMF structure multimode interferometer with a transmission peak wavelength of^2003 nm was used as a wavelength selector to fix the laser wavelength.When the SESA acted as a saturable absorber(SA),the mode-locked fiber laser had a maximum output power of^461 mW with a pulse energy of^0.14µJ and a pulse duration of^9.14 ns.In a CNT-film-based mode-locked fiber laser,stable mode-locked pulses with the maximum output power of^46 mW,pulse energy of^26.8 nJ and pulse duration of^9.3 ns were obtained.To the best of our knowledge,our experiments demonstrated the first 2µm region‘real’SA-based dissipative soliton resonance with the highest mode-locked pulse energy from a‘real’SA-based all-fiberized resonator.

Improving the Efficiency and Orthogonality of Genetic Code Expansion

The site-specific incorporation of the noncanonical amino acid(ncAA)into proteins via genetic code expansion(GCE)has enabled the development of new and powerful ways to learn,regulate,and evolve biological functions in vivo.However,cellular biosynthesis of ncAA-containing proteins with high efficiency and fidelity is a formidable challenge.In this review,we summarize up-to-date progress towards improving the efficiency and orthogonality of GCE and enhancing intracellular compatibility of introduced translation machinery in the living cells by creation and optimization of orthogonal translation components,constructing genomically recoded organism(GRO),utilization of unnatural base pairs(UBP)and quadruplet codons(four-base codons),and spatial separation of orthogonal translation.