Floquet engineering of a dynamical Z2 lattice gauge field with ultracold atoms

Gauge field theory is a fundamental concept in modern physics,attracting many theoretical and experimental efforts towards its simulation.In this paper we propose that a simple model,in which fermions coupled to a dynamical lattice gauge field,can be engineered via the Floquet approach.The model possesses both an independent Maxwell term and local Z_(2) gauge symmetry.Our proposal relies on a species-dependent optical lattice,and can be achieved in one,two or three dimensions.By a unitary transformation,this model can be mapped into a non-interacting composite fermion system with fluctuating background charge.With the help of this composite fermion picture,two characteristic observations are predicted.One is radio-frequency spectroscopy,which exhibits no dispersion in all parameter regimes.The second is dynamical localization,which depends on the structure of the initial states.

Monitoring absolute vertical land motions and absolute sea-level changes from GPS and tide gauges data over French Polynesia

In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as ancillary results,estimates of the absolute changes in sea level at the same locations.To verify our processing approach to determining vertical motion,we first modeled vertical motion at the International GNSS Service(IGS)THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations,with a good agreement.We obtained the following estimates for the vertical land motions at the tide gauges:Tubuai island,Austral Archipelago-0.92±0.17 mm/yr,Vairao village,Tahiti Iti:-0.49±0.39 mm/yr,Rikitea,Gambier Archipelago-0.43±0.17 mm/yr.The absolute variations of the sea level are:Tubuai island,Austral Archipelago 5.25±0.60 mm/yr,Vairao village,Tahiti Iti:3.62±0.52 mm/yr,Rikitea,Gambier Archipelago 1.52±0.23 mm/yr.We discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia.

Unification of Gravitational and Strong Interaction Fields Using Partial Gauge Symmetry

We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms like the well-type potential where a particle behaves almost freely but is very hard to escape without external energy, which can be interpreted as local confinement and asymptotic freedom. By assuming a 2-dimensional metric tensor in 4-dimensional space-time, we suggest the existence of 3 kinds of particles that resemble QCD with 3 color charges. We also show that the mass term exists but comes to zero and derive the charge and spin values. We can regard the particle with this new potential as a gluon, and the interaction in this well-type potential as a strong interaction for the properties of mass, charge, spin, and its behavior. We suggest the eight-fold way with this new particle, which is similar to the existing method based on SU (3) symmetry. Even though the strong interaction has been analyzed in the standard model and string theory, we build a new consistent model based on the theory of relativity including Riemann geometry, and show the unification of gravitational and strong interactional field.

Research on the strain gauge mounting scheme of track wheel force measurement system based on high-speed wheel/rail relationship test rig

Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system.

Observation about the Classical Electromagnetic Gauge Transformation and Its Quantum Correspondence

Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.

新型25-Gauge与传统20-Gauge玻璃体切除术后干眼对比

目的:对比25-Gauge与20-Gauge玻璃体切除术后患者干眼症状的严重程度。方法:在玻璃体切除手术的患者中,20-Gauge手术26例26眼,25-Gauge手术21例21眼,于手术前及术后3,7及30d,做干眼症状评分、泪液分泌试验、泪膜破裂时间及角膜荧光素钠染色评分比较。结果:与25G手术后患者相比,术后3,7d,20G手术患者干眼症状明显(P<0.05)、泪液分泌量增多(P<0.05)、泪膜破裂时间缩短(P<0.05)、角膜荧光素钠着色明显(P<0.05),上述差异具有统计学意义;术后30d,两组泪液分泌量无统计学差异,其他指标仍具有统计学差异(P<0.05)。结论:25G手术与20G手术相比,对眼表创伤较小,患者术后干眼的情况相对较轻。

再谈“strain gauge”等若干名词术语的译意

为了进一步规范应变片技术的学术名词术语,现把常容易出错的一些学术用语的翻译和释义做一些介绍。并用相应的图示加以进一步说明,以供从事应变片、传感器技术研究及应用人员参考。

Gauge积分在HOL4中的形式化

积分是许多数学理论的基础,如实数分析、信号与系统中微分方程的求解等等。Gauge积分是黎曼积分在闭区间上的推广,应用更加方便。将Gauge积分的运算性质在HOL4(Higher-Order Logic 4)中形式化,包括积分的线性运算性质、积分不等式、分部积分、积分分裂定理、子区间的可积性、对特殊函数的积分的形式化及积分极限定理、柯西可积准则,并根据相关性质对反相积分器进行了验证。

基于FusionWidgets Gauges开发高职院校人才培养工作状态数据仪表盘

提出使用FusionWidgets Gauges仪表盘套件展示高职院校人才培养工作状态数据量化指标的仪表盘方法,给出了实现原理,文末给出实现实例。

关于Gauge积分的注记

在[1]中Armstrong和Lamoreaux定义了一种新型的积分,即Gauge积分和参导数 本文则证明了[1]中一些未证明的结论,并首次提出了Gauge积分的一些性质,对[1]作了一些补充;进一步,本文还系统讨论了Riemann,Lebesgue,Gauge三种积分之间的关系.

Assimilated Tidal Results of Tide Gauge and TOPEX/POSEIDON Data over the China Seas Using a Variational Adjoint Approach with a Nonlinear Numerical Model

In order to obtain an accurate tide description in the China Seas, the 2-dimensional nonlinear numerical Princeton Ocean Model （POM） is employed to incorporate in situ tidal measurements both from tide gauges and TOPEX/POSEIDON （T/P） derived datasets by means of the variational adjoint approach in such a way that unknown internal model parameters, bottom topography, friction coefficients and open boundary conditions, for example, are adjusted during the process. The numerical model is used as a forward model. After the along-track T/P data are processed, two classical methods, i.e. harmonic and response analysis, are implemented to estimate the tide from such datasets with a domain covering the model area extending from 0° to 41°N in latitude and from 99°E to 142°E in longitude. And the results of these two methods are compared and interpreted. The numerical simulation is performed for 16 major constituents. In the data assimilation experiments, three types of unknown parameters （water depth, bottom friction and tidal open boundary conditions in the model equations） are chosen as control variables. Among the various types of data assimilation experiments, the calibration of water depth brings the most promising results. By comparing the results with selected tide gauge data, the average absolute errors are decreased from 7.9 cm to 6.8 cm for amplitude and from 13.0° to 9.0° for phase with respect to the semidiurnal tide M2 constituent, which is the largest tidal constituent in the model area. After the data assimilation experiment is performed, the comparison between model results and tide gauge observation for water levels shows that the RMS errors decrease by 9 cm for a total of 14 stations, mostly selected along the coast of China's Mainland, when a one-month period is considered, and the correlation coefficients improve for most tidal stations among these stations.

Clinical outcomes of 25-gauge vitrectomy surgery for vitreoretinal diseases: comparison of vitrectomy alone and phaco-vitrectomy

AIMTo compare the clinical outcomes of combined 25-gauge pars plana vitrectomy (PPV) and phacoemulsification/posterior chamber intraocular lens (PC-IOL) implantation with vitrectomy alone surgery in patients with various vitreoretinal diseases.METHODSA total of 306 eyes (145 with PPV alone and 161 with phaco-vitrectomy) were enrolled in this retrospective analysis. The surgical approach was 25-gauge PPV combined with phacoemulsification and PC-IOL implantation at the same time in eyes in phaco-vitrectomy group and only PPV in eyes in vitrectomy alone surgery group. The main outcome measures were postoperative clinical outcomes included anterior chamber inflammation, changes in intraocular pressure (IOP) and best corrected visual acuity (BCVA).RESULTSThe most common postoperative complication was anterior chamber reaction which has higher incidence in phaco-vitrectomy group (P<0.001). The mean postoperative 1st day IOP of vitrectomy alone group was significantly lower than that of phaco-vitrectomy group (16.3±5.8 mm Hg vs 17.8±8.1 mm Hg, respectively, P=0.02). Hypotony (IOP≤8 mm Hg) was not different between groups in the postoperative 1st day (P>0.05). The mean preoperative visual acuity was not different between groups (1.6±0.9 logMAR vs 1.8±0.9 logMAR, respectively, P>0.05). However, the mean visual acuity was decreased in vitrectomy alone group at the final visit compared to phaco-vitrectomy group (1.2±0.8 logMAR, 0.9±0.7 logMAR, respectively P<0.05).CONCLUSIONTwenty-five gauge PPV combined with phacoemulsification surgery is a safe and efficient procedure, which can be preferred in phacic patients with a variety of vitreoretinal diseases compared to vitrectomy alone. Despite improved outcomes, this approach is not free of limitations as anterior chamber complications especially with combined surgery.

粉砂土路基施工质量GeoGauge检测有效性分析

为了深入研究GeoGauge使用的有效性,以常见的粉砂土公路路基结构为模拟对象,基于室内模型试验和三维有限元数值模拟,研究分析GeoGauge的检测影响深度以及含水率、压实度变化对测试结果的影响。结果表明:GeoGauge在粉砂土路基中的影响深度在25cm左右;GeoGauge检测刚度值随着含水率的增大,呈现出先增大后减小的变化趋势,且最大刚度值在最优含水率附近;GeoGauge检测刚度值随着压实度的增加而增大,且刚度和压实度之间存在良好的指数关系。

Evaluation of high-resolution satellite precipitation products with surface rain gauge observations from Laohahe Basin in northern China

Three high-resolution satellite precipitation products, the Tropical Rainfall Measuring Mission （TRMM） standard precipitation products 3B42V6 and 3B42RT and the Climate Precipitation Center＇s （CPC） morphing technique precipitation product （CMORPH）, were evaluated against surface rain gauge observations from the Laohahe Basin in northern China. Widely used statistical validation indices and categorical statistics were adopted. The evaluations were performed at multiple time scales, ranging from daily to yearly, for the years from 2003 to 2008. The results show that all three satellite precipitation products perform very well in detecting the occurrence of precipitation events, but there are some different biases in the amount of precipitation. 3B42V6, which has a bias of 21%, fits best with the surface rain gauge observations at both daily and monthly scales, while the biases of 3B42RT and CMORPH, with values of 81% and 67%, respectively, are much higher than a normal receivable threshold. The quality of the satellite precipitation products also shows monthly and yearly variation： 3B42RT has a large positive bias in the cold season from September to April, while CMORPH has a large positive bias in the warm season from May to August, and they all attained their best values in 2006 （with 10%, 50%, and -5% biases for 3B42V6, 3B42RT, and CMORPH, respectively）. Our evaluation shows that, for the Laohahe Basin, 3B42V6 has the best correspondence with the surface observations, and CMORPH performs much better than 3B42RT. The large errors of 3B42RT and CMORPH remind us of the need for new improvements to satellite precipitation retrieval algorithms or feasible bias adjusting methods.

Monitor automatic gauge control strategy with a Smith predictor for steel strip rolling

The simplified transfer function diagram block for a monitor automatic gauge control （Mon-AGC） system of strip steel rolling process was investigated. The new notion of strip sample length was given. In this way, the delay time varying with the rolling speed was evaded. After a Smith predictor was used to monitor the AGC system, the control laws were deduced for both proportional and integral regulators. The control strategies showed that by choosing the controller parameter P=∞ for both control algo- rithms each regulator could compensate the whole strip gage error in the first control step. The result shows that the integral algo- rithm is more controllable for the system regulating process and has a better steady-state precision than the proportional regulator. Compared with the traditional control strategy, the new control laws have a faster response speed and a hieher steadv-state precision.

Study on Measurement Methods of Multi-Directional Waves—Wave Gauge Array Method

Measuring multi-directional waves with the wave gauge array is one of the fundamental and easily realised methods. In this paper, the wave gauge array is described and the effects of the gauge spacing, the array orientations, etc. of the three array arrangements, i. e., linear array, T-type array and pentagon array, on the resolution of the directional spreading of waves, are investigated experimentally. This study can be used as a reference in the experimental study and the field measurement of directional waves.

Runoff Simulation Using Radar and Rain Gauge Data

The conceptual rainfall-runoff model TOPMODEL is used to simulate runoffs of the Meishan and Nianyushan catchments during the summers of 1998 and 1999 in the GAME/HUBEX (GEWEX Asia Monsoon Experiment /HUAIHE River Basin Experiment) project. The rainfall distributions are estimated by weather radar and rain gauge networks according to different methods. Observed and simulated runoffs are compared and analyzed for both catchments. Results show that (1) the runoff of the catchment is best simulated by radar data combined with rain gauge network data from inside the catchment, and (2) the rainfall estimated by radar adjusted by a few rain gauges outside the catchment can be used to simulate runoff equally as well as using the dense rain gauge network alone.

New gauge boson and spin correction of top quark pair production at ILC

Based on the SU(3) simple group model , we study the spin correction of the top quark pair production at the high energy linear e+e- collider (ILC) with a center-of-mass energy =800GeV. Our numerical results show that the gauge boson ZH exchange generates very small corrections to the spin correction observable in all the parameter space, which can not be detected in the future ILC experiments.

Gauge-meter model building based on the effect of elastic deformation of rolls in a plate mill

The calculation error of the gauge-meter model will affect the gap setting precision and the self-learn precision of rolling force. The precision of the gauge-meter model is strongly influenced by plate width, working roll radius, backup roll radius, working roll crown, backup roll crown, and rolling force. The influence rules are hard to get by measuring. Taking a conventional 4-h plate mill as the research subject, these influences were transferred into the calculation of roll deflection and flattening deformation. To calculate these deformations, the theory of the influence function method was adopted. By modifying the traditional gauge-meter model, a novel model of the effect of roll elastic deformation on the gap setting was built by data fitting. By this model, it was convenient to analyze the variation caused by the rolling condition. Combining the elastic deformation model of rolls with the kiss-rolls method, a gauge-meter model was put forward for plate thickness prediction. The prediction precision of thickness was greatly improved by the new gauge- meter model.

Effect of Testing Conditions on Fibre-Bundle Tensile Properties-Part Ⅱ: the Gauge Length and Elongation Speed in Wool Fibre Bundle Measurement

The testing conditions of a fibre bundle tensile tester (TENSOR) are elongation speed (ES), gauge length (GL), pretension, jaw pressure, environmental temperature and relative humidity, instrument linearity and sensitivity. The effects on fibre-bundle tensile properties at different GL and ES have been discussed in detail and compared with Peirce’s theories on the weaklinks and the breaking time effect. The experimental results indicate that the tensile properties of fibre bundles are strongly affected by GL and vary with different GL. The reasonable GL should be 5 15 mm rather than 3.2 mm for wool bundle measurements. The ES ranging from 20 mm/min to 40 mm/min is beneficial for obtaining comparatively stable and accurate tensile values, whereas 20 mm/min used in current testing for wool fibre bundles is at the lower limit of the suggested range. For bundle modulus measurement, the sampling interval must be selected appropriately. The new calculation of the sampling interval has been established.