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Thermal conductivity of systems with a gap in the phonon spectrum

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Chinese Physics B 2018年第7期27卷 424-430页

作者： e Salamatov Udmurt Federal Research Center Ural Branch of the Russian Academy of Sciences

An original theoretical model for describing the low-temperature thermal conductivity in systems with a region of forbidden values （a gap） in the phonon spectrum is proposed. The model is based on new experimental results on the temperature dependence of the phonon diffusion coefficient in nanoceramics and dielectric glasses which showed a similar anomalous behavior of the diffusion coefficient in these systems that may be described under the assumption of a gap in the phonon spectrum. In this paper, the role of the gap in low-temperature behavior of the thermal conductivity, ~＇（T）, is analyzed. The plateau in the temperature dependence of the thermal conductivity is shown to correlate with the position and the width of the gap. The temperature dependence of thermal conductivity of such systems when changing the scat- tering parameters related to various mechanisms is studied. It is found that the umklapp process （U-processes） involving low-frequency short-wavelength phonons below the gap forms the behavior of the temperature dependence of thermal con- ductivity in the plateau region. A comparison of the calculated and experimental results shows considerable possibilities of the model in describing the low-temperature thermal conductivity in glass-like systems.

关键词： phononic band gap phonon diffusion coefficient thermal conductivity glassy crystals

Paired eye-control study of unilateral opaque bubble layer in femtosecond laser assisted laser in situ keratomileusis

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International Journal of Ophthalmology(english edition) 2019年第4期12卷 654-659页

作者： Cheng-Hua Wei Qiao-yun Dai Li-Xin Mei yao ge Peng-Fei Zhang e Song Department of Ophthalmology the Second Affiliated Hospital of Soochow University Department of Ophthalmology the First Affiliated Hospital of Wannan Medical College Department of Ophthalmology Lixiang Eye Hospital of Soochow University

AIM: To investigate the predictive factors of the opaque bubble layer(OBL) compared to the fellow eye of same patients in FS200 femtosecond laser assisted laser in situ keratomileusis(FS-LASIK).MeTHODS: This study consisted of 60 consecutive patients(120 eyes) with unilateral OBL during FS-LASIK. eyes were divided into OBL(the OBL eyes) and OBL-free groups(the fellow eyes) based on the occurrence of OBL. The preoperative demographic data, refraction, keratometry, corneal astigmatism, pachymetry, intraocular pressure and intraoperative data including the outlet location of gas diffusing canal were collected. Conditional logistic regression analysis was performed to find the associated factors with OBL in the two groups by determining odds ratios(OR) and 95%***: The preoperative demographic data, mean spherical errors, mean K value, suction time, intraocular pressure and central cornea thickness were not significantly different between the two groups. The outlet location of gas diffusing canal(Pe corneal astigmatism(P=0.013, OR 0.13, 95%CI 0.03-0.65) were significantly associated with the incidence of OBL by multivariate logistic regression analysis. Visual acuity, efficacy, and safety were comparable between the two groups two months after surgery except for a slightly lower predictability value for the hard OBL ***: The reduction of the incidence of OBL is obvious when the outlet of gas diffusing canal located at the posterior border of the corneoscleral limbus. This is probably consequent to more effectiveness of gas diffusing canal. Corneal astigmatism is also an independent protective factor for OBL formation.

关键词： opaque bubble layer femtosecond laser LASIK location of gas diffusing canal

Magnetophotothermal interaction in a rotating solid cylinder of semiconductor silicone material with time dependent heat flow

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Applied Mathematics and Mechanics(english edition) 2021年第1期42卷 39-52页

作者： A.e.ABOUeLReGAL Department of Mathematics College of Science and ArtsJouf UniversityAl-Qurayyat 77423Saudi Arabia Department of Mathematics Faculty of ScienceMansoura UniversityMansoura 35516Egypt

A mathematical model linking thermoelasticity to photothermal experiments is proposed with the consideration of the photothermal *** system equations for coupled plasma,heat conduction with phase-lags(PLs),and motion equations are introduced and solved by using the Laplace transform *** photothermal,thermal,and elastic waves in a rotating solid cylinder of semiconductor material are analyzed with the proposed *** cylinder surface is constrained and subjected to a time-dependent pulse heat *** sensitivity of the physical fields for the angular velocity,PLs,and thermal vibration parameters is *** addition,the effects of the effective parameters on the physical quantities are graphically illustrated and discussed in detail.

关键词： photothermal phase-lag(PL) solid cylinder rotation semiconductor carrier concentration

Size-dependent thermoelastic initially stressed micro-beam due to a varying temperature in the light of the modified couple stress theory

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Applied Mathematics and Mechanics(english edition) 2020年第12期41卷 1805-1820页

The bending of the euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)*** many models have been incorporated into the literature,there is still room for introducing an improved model in this *** this work,we investigate the thermoelastic vibration of a micro-beam exposed to a varying temperature due to the application of the initial stress employing the MCS theory and generalized *** MCS theory is used to investigate the material length scale *** the Laplace transform,the temperature,deflection,displacement,flexure moment,and stress field variables of the micro-beam are *** effects of the temperature pulse and couple stress on the field distributions of the micro-beam are obtained numerically and graphically *** numerical results indicate that the temperature pulse and couple stress have a significant effect on all field variables.

关键词： thermoelectricity micro-beam initial stress temperature pulse modified couple stress(MCS)theory

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer M.Colón-Mercado Aranza I.Torrado-Tapias Iris K.Salgado Jose M.Santiago Samuel e.Ocasio Rivera Dina P.Bracho-Rincon Luis H.Pagan Rivera Jorge D.Miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain eAAT-1/GLAST eAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

Collapse assessment of steel moment frames using endurance time method

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earthquake engineering and engineering Vibration 2015年第2期14卷 347-360页

作者： e.Rahimi H.e.estekanchi Department of Civil engineering Sharif University of Technology (SUT)

In endurance time(eT) method structures are subjected to a set of predesigned intensifying excitations. These excitations are produced in a way that their response spectrum, while complying with a specifi ed spectrum, intensifi es with time so they can be used approximately to simulate the average effects of several ground motions scaled to different intensities. In this paper applicability of the eT method for evaluating collapse potential of buildings is investigated. A set of four steel moment frames is used for collapse assessment. The process of using eT method in collapse evaluation is explained and the results are compared with incremental dynamic analysis(IDA) results. It is shown that although the computational effort using the eT method is much less than the IDA analysis, the results of both methods are consistent. Finally collapse fragility curves using eT and IDA methods are produced and it is shown that the probabilities of collapse in different hazard levels are also consistent.

关键词： endurance time method collapse analysis incrementa

Chromomagnetic dipole moments of light quarks in the bestest little Higgs model

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Chinese Physics C 2024年第10期48卷 125-136页

作者： T.Cisneros-Pérez e.Cruz-Albaro A.y.Ojeda-Castañeda S.e.Solís-Núñez Unidad Académica de Ciencias Químicas Universidad Autónoma de ZacatecasApartado Postal C-58598060 ZacatecasMexico Facultad de Física Universidad Autónoma de ZacatecasApartado Postal C-58098060 ZacatecasMexico

In this study,we investigated the anomalous Chromomagnetic Dipole Moment(CMDM),denoted as μ_(q)^(BLHM),of light quarks q=(u,c,d,s,b) within the framework of the Bestest Little Higgs Model(BLHM)as an extension of the Standard Model(SM).Our investigation encompassed novel interactions among the light quarks,heavy quark B,and heavy bosons (W'^(±),H^(±),φ^(±),η^(±))incorporating the extended Cabibbo-Kobayashi-Maskawa(CKM)matrix characteristic of the *** thoroughly explored the permissible parameter space,yielding a spectrum of CMDM values ranging from 10^(-10) to 10^(-3).

关键词： beyond standard model flavor physics chromomagnetic dipole light quarks

基于马尔可夫链的COVID-19流行病患病区域变化趋势预测

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陕西科技大学学报 2025年第1期43卷 211-218页

作者：王鑫王令戈师鹏柔陕西科技大学电子信息与人工智能学院陕西西安710021

在COVID-19疫情环境下,为精准预测不同症状状态的人群人数和区域级别的发展趋势,以SIR传染病模型为基础,基于马尔可夫链预测时空相关的特性,设计了感染人群状态与管控措施相关的K-SIRD传染病预测模型.根据COVID-19疫情人群之间传染性的... 详细信息

在COVID-19疫情环境下,为精准预测不同症状状态的人群人数和区域级别的发展趋势,以SIR传染病模型为基础,基于马尔可夫链预测时空相关的特性,设计了感染人群状态与管控措施相关的K-SIRD传染病预测模型.根据COVID-19疫情人群之间传染性的特征及受距离影响造成有效传染数R e的变化而导致不同的症状状态改变的转移规律,实时精准预测了不同状态的人员人数变化,并根据同一区域人群症状状态分布情况不同,针对不同级别的区域采用不同等级的管控措施.

关键词： K-SIRD模型 COVID-19 马尔可夫链有效繁殖数

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Primary pancreatic hydatid disease associated with acute pancreatitis

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Hepatobiliary & Pancreatic Diseases International 2010年第4期9卷 441-442页

作者： Karakas e Tuna y Basar  Kklü S Department of Radiology Sanllurfa education and Research Hospital Sanllurfa Turkey Department of Gastroenterology Akdeniz University Faculty of Medicine Department of Gastroenterology Dlskapl education and Research Hospital Department of Gastroenterology Ankara education and Research Hospital

The editor welcomes submissions for possible publication in the Letters to the editor section. Letters commenting on an article published in the Journal or other interesting pieces will be considered if they are received within 6 weeks of the time the article was published. Authors of the article being commented on will be given an opportunity to offer a timely response to the letter. Authors of letters will be notified that the letter has been received. Unpublished letters cannot be returned.

关键词： Primary pancreatic hydatid disease associated with acute pancreatitis