Electromagnetic Performance Analysis of Variable Flux Memory Machines with Series-magnetic-circuit and Different Rotor Topologies

In this paper,the electromagnetic performance of variable flux memory(VFM)machines with series-magnetic-circuit is investigated and compared for different rotor topologies.Based on a V-type VFM machine,five topologies with different interior permanent magnet(IPM)arrangements are evolved and optimized under same constrains.Based on two-dimensional(2-D)finite element(FE)method,their electromagnetic performance at magnetization and demagnetization states is evaluated.It reveals that the iron bridge and rotor lamination region between constant PM(CPM)and variable PM(VPM)play an important role in torque density and flux regulation(FR)capabilities.Besides,the global efficiency can be improved in VFM machines by adjusting magnetization state(MS)under different operating conditions.

Characteristic Analysis and Experimental Study of a Hybrid Permanent Magnet Variable Flux Memory Motor

提出一种混合永磁可变磁通记忆电机，研究了永磁体不同磁化状态下的静态特性。基于有限元法，对施加不同去磁电流时的电机磁场分布进行了分析，并观察永磁体内的磁密变化，计算了不同永磁磁化状态下的气隙磁密、永磁磁链、反电动势及每极气隙磁通等电机主要参数。制作一台样机，并进行实验研究，实验结果与有限元计算结果吻合较好。研究表明，永磁体的充磁比去磁要困难，当磁化电流为2倍的定子额定电流时，能将磁体去磁90％，而仅能充磁到饱和时的30％：与基本结构记忆电机相比，该混合永磁记忆电机具有更高的气隙磁密。该类电机在宽调速驱动系统中具有应用前景。

Hybrid artificial bee colony algorithm with variable neighborhood search and memory mechanism

Artificial bee colony(ABC) is one of the most popular swarm intelligence optimization algorithms which have been widely used in numerical optimization and engineering applications. However, there are still deficiencies in ABC regarding its local search ability and global search efficiency. Aiming at these deficiencies,an ABC variant named hybrid ABC(HABC) algorithm is proposed.Firstly, the variable neighborhood search factor is added to the solution search equation, which can enhance the local search ability and increase the population diversity. Secondly, inspired by the neuroscience investigation of real honeybees, the memory mechanism is put forward, which assumes the artificial bees can remember their past successful experiences and further guide the subsequent foraging behavior. The proposed memory mechanism is used to improve the global search efficiency. Finally, the results of comparison on a set of ten benchmark functions demonstrate the superiority of HABC.

Analytical solution for the time-fractional heat conduction equation in spherical coordinate system by the method of variable separation

In this paper,using the fractional Fourier law,we obtain the fractional heat conduction equation with a time-fractional derivative in the spherical coordinate system.The method of variable separation is used to solve the timefractional heat conduction equation.The Caputo fractional derivative of the order 0 〈 α≤ 1 is used.The solution is presented in terms of the Mittag-Leffler functions.Numerical results are illustrated graphically for various values of fractional derivative.

Variable Stars in the 50BiN Open Cluster Survey.Ⅲ.NGC 884

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.

Recent Advances in Variable Flux Memory Machines for Traction Applications: A Review

This paper overviews the recent advances in variable flux memory machines(VFMMs)for traction applications with particular reference to newly emerged machine topologies and related control strategies.Due to the use of flux memorable low coercive force(LCF)magnets,the air-gap flux of VFMM can be flexibly varied via a magnetizing current pulse.Thus,the copper loss associated with the flux weakening current and high-speed iron loss can be significantly reduced,and hence high efficiency can be achieved over a wide speed and torque/power operation.These merits make VFMM potentially attractive for electric vehicle(EV)applications.Various novel VFMMs are reviewed with particular reference to their topologies,working principle,characteristics and related control techniques.In order to tackle the drawbacks in the existing VFMMs,some new designs are introduced for performance improvement.Then,the electromagnetic characteristics of an exemplified EV-scaled switched flux memory machine and various benchmark traction machine choices,such as induction machine,synchronous reluctance machines,as well as commercially available Prius 2010 interior permanent magnet(IPM)machine are compared.Finally,the key challenges and development trends of VFMM are highlighted,respectively.

Utilization-Aware Data Variable Allocation on NVM- Based SPM in Real-Time Embedded Systems

With the development of the nonvolatile memory(NVM),using NVM in the design of the cache and scratchpad memory(SPM)has been increased.This paper presents a data variable allocation(DVA)algorithm based on the genetic algorithm for NVM-based SPM to prolong the lifetime.The lifetime can be formulated indirectly as the write counts on each SPM address.Since the differences between global variables and stack variables,our optimization model has three constraints.The constraints of the central processing unit(CPU)utilization and size are used for all variables,while no-overlay constraint is only used for stack variables.To satisfy the constraints of the optimization model,we use the greedy strategy to generate the initial population which can determine whether data variables are allocated to SPM and distribute them evenly on SPM addresses.Finally,we use the Mälardalen worst case executive time(WCET)benchmark to evaluate our algorithm.The experimental results show that the DVA algorithm can not only obtain close-to-optimal solutions,but also prolong the lifetime by 9.17% on average compared with SRAM-based SPM.

G328: A Small-Amplitude Red Variable with a Period Near One Day

G328 = A65 = L3314 （V = 13.83, B - V = 1.91） is a field star in the direction of the globular cluster M4. If we take E（B - V） = 0.40, then its （B - V）0 = 1.51, corresponding to a spectral type of K5Ⅲ if it is a giant star; or of dM2 if it is a dwarf. Observations at both the MSSSO and Yunnan Observatory have shown that G328 is a new variable with peak to peak amplitude ≌ 0.05 mag in V. While it is not unusual for so red a star to be a variable, special attention must be paid to its short period of about one day. If the variability is due to pulsation, the spectral type and luminosity as well as effective temperature should be determined in order to compare it with Xiong＇s theory.

New Variable Stars Discovered as By-product of the Beijing Astronomical Observatory Supernova Survey

The Beijing Astronomical Observatory (BAO) 0.6 m telescope has been used for nearby supernova survey in more than 3000 fields, covering a total area of 235 deg2. More than 260000 CCD images have been collected since April 1996, with 45 supernovae discovered. We searched for variables in about 90000 images taken during 1996-1998. For the fields in which long period variables (LPVs) were discovered, we reduced further images taken from 1999 to 2000, for the period estimation. Among the 280000 stars selected from the survey fields, i.e., brighter than 18 mag, we discovered seven new LPVs and reconfirmed three known LPVs. Additionally, we found 146 variable star candidates, and reconfirmed about 20 previously known or suspected objects.

Associations between IL-1RN variable number of tandem repeat, IL-1β (-511) and IL-1β (+3954) gene polymorphisms and urolithiasis in Uighur children of China

Objective:Interleukin-1(IL-1)is a pro-inflammatory cytokine which may be related to urolithiasis.Genetic polymorphisms of the interleukin-1beta(IL-1β)have been proposed as markers for urolithiasis in some areas.Due to the high incidence of urolithiasis in Uighur children(Xinjiang,China)and existence of ethnic difference,our aim is to explore the potential of IL-1 gene polymorphisms and urolithiasis among these children.Methods:Genomic DNA extracted from peripheral blood of 115 patients and 98 controls were used for genotype polymorphisms analyses.IL-1 receptor antagonist(IL-1RN)gene variable number of tandem repeat(VNTR)gene polymorphisms were analyzed by PCR method.PCR-based restriction analysis was done for the IL-1β(-511)and IL-1β(+3954)gene polymorphisms by endonucleases Ava I and Taq I,respectively.The genotype distribution,allele frequencies,carriage rate,and haplotype frequencies were statistically analyzed.Results:No significant differences were observed in genotypic frequencies between pediatric urolithiasis patients and control group for IL-1RN gene(χ^(2)=1.906,p=0.605),IL-1β(-511)gene(χ^(2)=0.105,p=0.949),or IL-1β(+3954)gene(χ^(2)=3.635,p=0.169).There were yet no significant differences of the allele frequencies of IL-1RN VNTR gene(p=0.779),IL-1β(-511)gene(p=0.941),and IL-1β(+3954)gene(p=0.418)in the case and control groups,as well as the carriage rate and haplotype of them(all p>0.05).Conclusions:The associations between IL-1RN VNTR,IL-1β(-511)and IL-1β(+3954)genes polymorphisms and urolithiasis were not significant in Uighur children.The results need to be confirmed in studies with larger population sample size,as well as in other ethnic groups.

Physical parameters and orbital period variation of a newly discovered cataclysmic variable GSC 4560-02157

GSC 4560-02157 is a new eclipsing cataclysmic variable with an orbital period of 0.265359 days. By using the published V- and R-band data together with our observations, we discovered that the O - C curve of GSC 4560-02157 may show a cyclic variation with a period of 3.51 years and an amplitude of 1.40 min. If this variation is caused by a light travel-time effect via the existence of a third body, then its mass can be derived as M3 sin i1≈ 91.08 Mjup, and it should be a low-mass star. In addition, several physical parameters were measured. The color of the secondary star was determined to be V - R = 0.77（±0.03） which corresponds to a spectral type of K2-3. The secondary star＇s mass was estimated as M2 = 0.73（±0.02） Mo by combing the derived V - R value around phase 0 with the assumption that it obeys the mass-luminosity relation for main sequence stars. This mass is consistent with the mass-period relation for CV donor stars. For the white dwarf, the eclipse durations and contacts of the white dwarf yield an upper limit on the white dwarf＇s radius corresponding to a lower limit on mass of M1 ≈ 0.501 M⊙. The overestimated radius and previously published spectral data indicate that the boundary layer may have a very high temperature.

Force-displacement characteristics of simply supported beam laminated with shape memory alloys

As a preliminary step in the nonlinear design of shape memory alloy（SMA） composite structures,the force-displacement characteristics of the SMA layer are studied.The bilinear hysteretic model is adopted to describe the constitutive relationship of SMA material.Under the assumption that there is no point of SMA layer finishing martensitic phase transformation during the loading and unloading process,the generalized restoring force generated by SMA layer is deduced for the case that the simply supported beam vibrates in its first mode.The generalized force is expressed as piecewise-nonlinear hysteretic function of the beam transverse displacement.Furthermore the energy dissipated by SMA layer during one period is obtained by integration,then its dependencies are discussed on the vibration amplitude and the SMA＇s strain（Ms-Strain） value at the beginning of martensitic phase transformation.It is shown that SMA＇s energy dissipating capacity is proportional to the stiffness difference of bilinear model and nonlinearly dependent on Ms-Strain.The increasing rate of the dissipating capacity gradually reduces with the amplitude increasing.The condition corresponding to the maximum dissipating capacity is deduced for given value of the vibration amplitude.The obtained results are helpful for designing beams laminated with shape memory alloys.

Effect of Panax notoginseng saponins on the expression of beta-amyloid protein in the cortex of the parietal lobe and hippocampus, and spatial learning and memory in a mouse model of senile dementia

BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.

Optogenetics-induced activation of glutamate receptors improves memory function in mice with Alzheimer’s disease

Optogenetics is a combination of optics and genetics technology that can be used to activate or inhibit specific cells in tissues. It has been used to treat Parkinson’s disease, epilepsy and neurological diseases, but rarely Alzheimer’s disease. Adeno-associated virus carrying the CaMK promoter driving the optogenetic channelrhodopsin-2 (CHR2) gene (or without the CHR2 gene, as control) was injected into the bilateral dentate gyri, followed by repeated intrahippocampal injections of soluble low-molecular-weight amyloid-β1–42 peptide (Aβ1–42). Subsequently, the region was stimulated with a 473 nm laser (1–3 ms, 10 Hz, 5 minutes). The novel object recognition test was conducted to test memory function in mice. Immunohistochemical staining was performed to analyze the numbers of NeuN and synapsin Ia/b-positive cells in the hippocampus. Western blot assay was carried out to analyze the expression levels of glial fibrillary acidic protein, NeuN, synapsin Ia/b, metabotropic glutamate receptor-1a (mGluR-1a), mGluR-5, N-methyl-D-aspartate receptor subunit NR1, glutamate receptor 2, interleukin-1β, interleukin-6 and interleukin-10. Optogenetic stimulation improved working and short-term memory in mice with Alzheimer’s disease. This neuroprotective effect was associated with increased expression of NR1, glutamate receptor 2 and mGluR-5 in the hippocampus, and decreased expression of glial fibrillary acidic protein and interleukin-6. Our results show that optogenetics can be used to regulate the neuronal-glial network to ameliorate memory functions in mice with Alzheimer’s disease. The study was approved by the Animal Resources Committee of Jinan University, China (approval No. LL-KT-2011134) on February 28, 2011.

Searching for Variable Stars in the Field of NGC 7789

We present the results of a time-series CCD photometric survey of variable stars in the field of the open cluster NGC 7789. In a field of about one degree centering on the cluster, a total of 28 new variable stars are discovered (14 W UMa systems, nine EA-type eclipsing binaries, one RR Lyr star, and four unclassified). In addition, we recovered 11 old variables previously discovered by other authors. Preliminary parameters are given for some of these variables.

The Fifth Edition of the General Catalogue of Variable Stars:experiences in the constellation Centaurus

We have recently announced that the General Catalogue of Variable Stars enters the stage of its fifth, purely electronic edition （GCVS 5.1）. We have included 1408 variable stars in the constellation Centaurus in this new version, GCVS 5.1. Working on this revision, we applied current possibilities from data mining, suggested new variability types for many variable stars and found new light elements for a large number of periodic variables. This paper describes the work completed during the preparation of GCVS 5.1 for Centaurus and discusses in detail a number of the most astrophysically significant cases.

An investigation of a magnetic cataclysmic variable with a period of 14.1 ks

Magnetic cataclysmic variables （CVs） contain a white dwarf （WD） with a magnetic field strong enough to control the accretion flow from a late type secondary. In this paper, we identify a magnetic CV （CXOGSG J215544.4＋380116） from the Chandra archive data. The X-ray light curves show a significant period of 14.1 ks, and the X-ray spectra can be described by a multi-temperature hot thermal plasma, suggesting the source is a magnetic CV. The broad dip in the X-ray light curve is due to the eclipse of the primary magnetic pole, and the additional dip in the bright phase of the soft and medium bands may be caused by the accretion stream crossing our line of sight to the primary pole. Follow-up optical spectra show features of an M2-M4 dwarf dominating the red band and a WD which is responsible for the weak upturn in the blue band. The mass （~ 0.4 34⊙） and radius （~0.4 R⊙） for the M dwarf are obtained using CV evolution models and empirical relations between the orbital period and the mass/radius. The estimated low X-ray luminosity and accretion rate may suggest the source is a low-accretion-rate polar. In addition, Very Large Array observations reveal a possible radio counterpart to the X-ray source, but with a low significance. Further radio observations with high quality are needed to confirm the radio counterpart and explore the properties of this binary system.

Enabling Variability-Aware Design-Technology Co-Optimization for Advanced Memory Technologies

This paper presents a TCAD-based methodology to enable Design-Technology Co-Optimization(DTCO)of advanced semiconductor memories.After reviewing the DTCO approach to semiconductor devices scaling,we introduce a multi-stage simulation flow to study the deviceto-circuit performance of advanced memory technologies in presence of statistical and process variability.We present a DRAM example to highlight the DTCO enablement for both memory and periphery.Our analysis demonstrates how the evaluation of different possible technology improvements and design combinations can be carried out to maximize the benefits of continuous technology scaling for a given set of manufacturing equipment.

Imperatorin alleviates Aβ-induced spatial learning memory impairment and neuroinflam⁃mation in model mice of Alzheimer disease

OBJECTIVE To investigate the effects of imperatorin on the spatial learning memory impairment and neuroinflammation in model mice of Alzheimer disease(AD)induced by intracerebroventricular injection of Aβ1-42.METHODS Mouse model of AD was established by injection of Aβ1-42 into the lateral ventricles.Im⁃peratorin(2.5 and 5.0 mg·kg-1,daily)was inject⁃ed by intraperitoneally 1 h after intracerebroven⁃tricular injection for 13 d.The effect of imperato⁃rin on the spatial learning and memory impair⁃ment was assessed by eight arm maze tests.The levels of cytokines TNF-α,IL-1β,IL-6,IL-18 and chemokines MCP-1 in mouse cortex and hip⁃pocampus were detected by ELISA.The protein expression of NF-κB P65,TLR4,MyD88,p-P38,p-ERK,and p-JNK were detected by Western blotting.RESULTS As compared with the AD model group,imperatorin treatment significantly attenuated Aβ1-42-induced spatial learning and memory impairment assessed by eight arm maze tests.In addition,imperatorin significantly reduced the levels of cytokines TNF-α,IL-1β,IL-6,IL-18 and chemokines MCP-1 in the cerebral cortex and hippocampus.Meanwhile,Western blotting results showed that imperatorin treat⁃ment significantly down-regulated the protein expression of NF-κB P65,TLR4,MyD88,p-P38,p-ERK,and p-JNK.CONCLUSION Imperatorin has neuroprotective effects in the Aβ1-42 induced AD model mice and its mechanism may be partially associated with the inhibition of inflam⁃matory response in the cortex and hippocampus.

Discovery of Four Peculiar Variable Stars

Four stars, GSC 1258–0143, GSC 1986–1665, GSC 3045–0892 and GSC 2983–1597 were found to be new variables during a campaign of CCD photometric monitoring of short-period eclipsing binary stars. The variabilities of these new variables are reported. The main characteristics and probable classifications of the variables are discussed through a preliminary analysis on their light curves. Among these stars, GSC 1258–0143 is classified as a RR Lyr star of sub-type a. Its pulsation period is determined to be about 0.5206 days. The other three stars, are definite variables, but their periods and types of light variations remain unknown.