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Complementary-Label Adversarial Domain Adaptation Fault Diagnosis Network under Time-Varying Rotational Speed and Weakly-Supervised Conditions
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作者 Siyuan Liu Jinying Huang +2 位作者 Jiancheng Ma Licheng Jing Yuxuan Wang 《Computers, Materials & Continua》 SCIE EI 2024年第4期761-777,共17页
Recent research in cross-domain intelligence fault diagnosis of machinery still has some problems,such as relatively ideal speed conditions and sample conditions.In engineering practice,the rotational speed of the mac... Recent research in cross-domain intelligence fault diagnosis of machinery still has some problems,such as relatively ideal speed conditions and sample conditions.In engineering practice,the rotational speed of the machine is often transient and time-varying,which makes the sample annotation increasingly expensive.Meanwhile,the number of samples collected from different health states is often unbalanced.To deal with the above challenges,a complementary-label(CL)adversarial domain adaptation fault diagnosis network(CLADAN)is proposed under time-varying rotational speed and weakly-supervised conditions.In the weakly supervised learning condition,machine prior information is used for sample annotation via cost-friendly complementary label learning.A diagnosticmodel learning strategywith discretized category probabilities is designed to avoidmulti-peak distribution of prediction results.In adversarial training process,we developed virtual adversarial regularization(VAR)strategy,which further enhances the robustness of the model by adding adversarial perturbations in the target domain.Comparative experiments on two case studies validated the superior performance of the proposed method. 展开更多
关键词 Time-varying rotational speed weakly-supervised fault diagnosis domain adaptation
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Improved Units of Measure in Rotational Mechanics
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作者 Richard James Petti 《World Journal of Mechanics》 2024年第1期1-7,共7页
The SI system of units in rotational mechanics yields correct numerical results, but it produces physically incorrect units of measure in many cases. SI units also violate the principle of general covariance—the gene... The SI system of units in rotational mechanics yields correct numerical results, but it produces physically incorrect units of measure in many cases. SI units also violate the principle of general covariance—the general rule for defining continuous coordinates and units in mathematics and mathematical physics. After 30+ years of wrestling with these problems, the ultimate authority on units of measure has declared that Newton–meter and Joule are not equivalent in rotational mechanics, as they are in the rest of physics. This article proposes a simple modification to SI units called “Nonstandard International units” (“NI units”) until a better name is agreed upon. NI units yield correct numerical results and physically correct units of measure, and they satisfy the principle of general covariance. The main obstacle to the adoption of NI units is the consensus among users that the radius of rotation should have the unit meter because the radius can be measured with a ruler. NI units assigned to radius should have units meter/radian because the radius is a conversion factor between angular size and circumferential length, as in arclength = rθ. To manage the social consensus behind SI units, the author recommends retaining SI units as they are, and informing users who want correct units that NI units solve the technical problems of SI units. 展开更多
关键词 rotational Mechanics Angular Unit TORQUE Moment of Inertia Angular Momentum General Covariance
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Retrospective Case Series on The Enduring Rotational Stability of The AcrySof IQ Toric Intraocular Lens in Cataract Patients Suffering from Myopia
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作者 Jie Luo Yang Liu +2 位作者 Bing Wang Lei Li Junyu Yang 《Journal of Clinical and Nursing Research》 2024年第3期207-214,共8页
Objective:To analyze the enduring rotational steadiness of AcrySof IQ Toric intraocular lens(IOL)in cataract patients suffering from myopia in a long-term study.Methods:A retrospective study was conducted on a case se... Objective:To analyze the enduring rotational steadiness of AcrySof IQ Toric intraocular lens(IOL)in cataract patients suffering from myopia in a long-term study.Methods:A retrospective study was conducted on a case series involving 78 patients.A total of 120 eyes with an axial length(AL)ranging from 24-30 mm and corneal astigmatism≥1.50 D underwent implantation of AcrySof IQ Toric IOL guided by the version navigation system.The eyes were divided into two groups based on AL.Group A included 60 eyes with high myopia(AL≥26 mm),while Group B consisted of eyes with low to moderate myopia(24 mm≤AL<26 mm).Data on the preoperative AL were collected.Measurements were taken for residual astigmatism,the best corrected visual acuity(BCDVA),corneal astigmatism,and IOL rotation occurring between 24-and 48-months post-surgery.The percentage of eyes with an IOL rotation of under 5°and 10°was analyzed.Results:The mean length of follow-up times was recorded as 34.27±4.98,and the average rotation was 2.73±1.29°.Group A exhibited a slightly higher average rotation of 2.87±1.31°,compared to the rotation of 2.59±1.27°observed in Group B.At both the 24-36 month and 26-48 month post-operation marks,the degree of IOL rotation did not show a statistically significant difference between the two groups,with none of the patients experiencing a rotation exceeding 10°(P>0.05).The percentage of rotation degrees under 5°was recorded as 98.22%.After the procedure,the BCDVA was 0.1322±0.03 LogMAR.There was a substantial increase in theχvalue after the operation as compared to the pre-operativeχ^(2) value(χ^(2)=76.79).The standard deviation of preoperative corneal astigmatism was statistically significant(P<0.05)at 2.17±1.08 D.Following the surgical procedure,the remaining astigmatism was measured at 0.41±0.26 D.The data showed a notable gap in statistical significance(t=4.281,P<0.05).Conclusion:The AcrySof Toric IOL was a reliable solution for managing corneal astigmatism in cataract patients with myopia,demonstrating excellent long-term rotational stability. 展开更多
关键词 ASTIGMATISM Long-term MYOPIA rotational stability
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Preheating-assisted solid-state friction stir repair of Al-Mg-Si alloy plate at different rotational speeds
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作者 Hui Wang Yidi Li +3 位作者 Ming Zhang Wei Gong Ruilin Lai Yunping Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第4期725-736,共12页
Additive friction stir deposition(AFSD)is a novel structural repair and manufacturing technology has become a research hotspot at home and abroad in the past five years.In this work,the microstructural evolution and m... Additive friction stir deposition(AFSD)is a novel structural repair and manufacturing technology has become a research hotspot at home and abroad in the past five years.In this work,the microstructural evolution and mechanical performance of the Al-Mg-Si alloy plate repaired by the preheating-assisted AFSD process were investigated.To evaluate the tool rotation speed and substrate preheating for repair quality,the AFSD technique was used to additively repair 5 mm depth blind holes on 6061 aluminum alloy substrates.The results showed that preheat-assisted AFSD repair significantly improved joint bonding and joint strength compared to the control non-preheat substrate condition.Moreover,increasing rotation speed was also beneficial to improve the metallurgical bonding of the interface and avoid volume defects.Under preheating conditions,the UTS and elongation were positively correlated with rotation speed.Under the process parameters of preheated substrate and tool rotation speed of 1000 r/min,defect-free specimens could be obtained accompanied by tensile fracture occurring in the substrate rather than the repaired zone.The UTS and elongation reached the maximum values of 164.2MPa and 13.4%,which are equivalent to 99.4%and 140%of the heated substrate,respectively. 展开更多
关键词 additive friction stir deposition structural repair tool rotation speed Al alloy
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Dual-Fields Rotational Total Skin Electron Therapy: Investigation and Implementation
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作者 M. Ming Xu Iris Rusu Richard P. Garza 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2024年第1期1-15,共15页
Purpose: To present a protocol of a dual-field rotational (DFR) total skin electron therapy (TSET) and to provide an assessment of clinical implementation, dosimetry properties, and skin dose evaluation. Methods and M... Purpose: To present a protocol of a dual-field rotational (DFR) total skin electron therapy (TSET) and to provide an assessment of clinical implementation, dosimetry properties, and skin dose evaluation. Methods and Materials: The DFR-TSET combined the Stanford 6-field and McGill rotational methods. Dual 6 MeV electron beams in high dose total skin electron mode were used for DFR-TSET on a commercial linac. Beam profiles and dosimetric properties were measured using solid phantoms. The dose rate at expanded source-to-surface distance (SSD) was a combination of static rate and rotational rate. In vivo dosimetry of patient skin was performed on patients’ skin using film, metal oxide semiconductor field-effect transistors (MOSFET), and optically stimulated luminescent dosimeters (OSLD). Results: Dual field rotational total skin electron therapy exhibited good (≤±10%) uniformity in the beam profiles in the vertical direction at an extended SSD of 332 cm with a gantry angulation of ±20˚ deviated from the horizontal direction. In-vivo measurements confirmed acceptable uniformity of the patients’ total body surfaces and revealed anatomically self-blocked or shielded areas where underdosing occurred. Conclusions: The clinical implementation of DFR-TSET effectively utilizes the special mode on a linac. This technique provides short beam-on times, uniform dose distribution, large treatment field, and reduced dose of x-ray contamination to the patients. In-vivo measurements indicate satisfactory delivery and dose uniformity of the prescribed dose. Electron boost fields are recommended at normal SSDs to address underdosed areas. 展开更多
关键词 Total Skin Electron Therapy Stanford 6 Field McGill Rotation Therapy In-Vivo Dosimetry
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NCCT for Micropolar Solid and Fluid Media Based on Internal Rotations and Rotation Rates with Rotational Inertial Physics: Model Problem Studies
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作者 Karan S. Surana Jacob K. Kendall 《Applied Mathematics》 2023年第9期612-651,共40页
This paper presents model problem studies for micropolar thermoviscoelastic solids without memory and micropolar thermoviscous fluid using micropolar non-classical continuum theories (NCCT) based on internal rotations... This paper presents model problem studies for micropolar thermoviscoelastic solids without memory and micropolar thermoviscous fluid using micropolar non-classical continuum theories (NCCT) based on internal rotations and rotation rates in which rotational inertial physics is considered in the derivation of the conservation and balance laws (CBL). The dissipation mechanism is due to strain rates as well as rotation rates. Model problems are designed to demonstrate and illustrate various significant aspects of the micropolar NCCT with rotational inertial physics considered in this paper. In case of micropolar solids, the translational and rotational waves are shown to coexist. In the absence of microconstituents (classical continuum theory, CCT) the internal rotations are a free field, hence have no influence on CCT. Absence of gradients of displacements and strains in micropolar thermoviscous fluid medium prohibits existence of translational waves as well as rotational waves even though the appearance of the mathematical model is analogous to the solids, but in terms of strain rates. It is shown that in case of micropolar thermoviscous fluids the BAM behaves more like time dependent diffusion equation i.e., like heat conduction equation in Lagrangian description. The influence of rotational inertial physics is demonstrated using BLM as well as BAM in the model problem studies. 展开更多
关键词 MICROPOLAR Internal Rotations Internal Rotation Rates Translational Waves rotational Waves DISSIPATION Thermoviscous rotational Inertial Physics
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Theoretical analysis of the optical rotational Doppler effect under atmospheric turbulence by mode decomposition 被引量:1
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作者 马圣杰 徐世龙 +3 位作者 董骁 张鑫源 陈友龙 胡以华 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期459-467,共9页
The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotatio... The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotational Doppler effect.First,we deduce the generalized formula of the rotational Doppler shift in atmospheric turbulence by mode decomposition.It is found that the rotational Doppler signal frequency spectrum will be broadened,and the bandwidth is related to the turbulence intensity.In addition,as the propagation distance increases,the bandwidth also increases.And when C_(n)^(2)≤5×10^(-15)m^(-2/3)and 2z≤2 km,the rotational Doppler signal frequency spectrum width d and the spiral spectrum width d_(0)satisfy the relationship d=2d_(0-1).Finally,we analyze the influence of mode crosstalk on the rotational Doppler effect,and the results show that it destroys the symmetrical distribution of the rotational Doppler spectrum about 2l·Ω/2π.This theoretical model enables us to better understand the generation of the rotational Doppler frequency and may help us better analyze the influence of the complex atmospheric environment on the rotational Doppler frequency. 展开更多
关键词 optical rotational Doppler effect atmospheric turbulence vortex beam mode decomposition mode crosstalk
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Local Rotational Jamming and Multi-Stage Hyperuniformities in an Active Spinner System 被引量:1
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作者 刘锐 巩建晓 +1 位作者 杨明成 陈科 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第12期104-108,共5页
An active system consisting of many self-spinning dimers is simulated, and a distinct local rotational jamming transition is observed as the density increases. In the low density regime, the system stays in an absorbi... An active system consisting of many self-spinning dimers is simulated, and a distinct local rotational jamming transition is observed as the density increases. In the low density regime, the system stays in an absorbing state,in which each dimer rotates independently subject to the applied torque;while in the high density regime,a fraction of the dimers become rotationally jammed into local clusters, and the system exhibits microphaseseparation like two-phase morphologies. For high enough densities, the system becomes completely jammed in both rotational and translational degrees of freedom. Such a simple system is found to exhibit rich and multiscale disordered hyperuniformities among the above phases: the absorbing state shows a critical hyperuniformity of the strongest class and subcritically preserves the vanishing density fluctuation scaling up to some length scale;the locally jammed state shows a two-phase hyperuniformity conversely beyond some length scale with respect to the phase cluster sizes;the totally jammed state appears to be a monomer crystal, but intrinsically loses large-scale hyperuniformity. These results are inspiring for designing novel phase-separation and disordered hyperuniform systems through dynamical organization. 展开更多
关键词 UNIFORM SYSTEM rotational
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Rotational stability of plate haptic toric intraocular lenses after combined 25-gauge vitrectomy and cataract surgery 被引量:1
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作者 Lara Buhl Julian Langer +3 位作者 Stefan Kassumeh Thomas C.Kreutzer Wolfgang J.Mayer Siegfried G.Priglinger 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第8期1231-1236,共6页
AIM:To evaluate the postoperative intraocular lens(IOL)rotational stability and residual refractive astigmatism following combined 25-gauge vitrectomy and cataract surgery with implantation of a plate haptic toric IOL... AIM:To evaluate the postoperative intraocular lens(IOL)rotational stability and residual refractive astigmatism following combined 25-gauge vitrectomy and cataract surgery with implantation of a plate haptic toric IOL.METHODS:In this retrospective case series,32 eyes of 32 patients underwent a combined 25-gauge vitrectomy and phacoemulsification for vitreoretinal diseases and cataract with regular corneal astigmatism of at least 1 diopter(D).A plate haptic toric IOL(AT Torbi 709M,Carl Zeiss Meditec AG)was implanted in all eyes.The outcome measures were rotational stability and refractive astigmatism up to 6mo postoperatively as well as the best corrected visual acuity(BCVA).RESULTS:Preoperative refractive astigmatism was 2.14±1.17 D,which was significantly reduced to 0.77±0.37 D six to eight weeks postoperatively and remained stable throughout the observation period(0.67±0.44 D at three months and 0.75±0.25 D at six months;for all groups:P<0.0001 compared to baseline).BCVA improved significantly from 0.36±0.33 logMAR preoperatively to 0.10±0.15 logMAR following surgery(P=0.02).Mean IOL axis deviation from the target axis was 3.4°±2.9°after six to eight weeks and significantly decreased over time(2.4°±2.6°six months after surgery;P=0.04).In one patient IOL,re-alignment was performed.CONCLUSION:Corneal astigmatism is significantly reduced following combined 25-gauge vitrectomy and cataract surgery.The plate haptic toric IOL position and axis remain stable during the observation period of six months. 展开更多
关键词 combined phaco-vitrectomy toric intraocular lens rotational stability corneal astigmatism CATARACT vitreoretinal disease
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Does nature-based solution sustain grassland quality? Evidence from rotational grazing practice in China
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作者 LI Dong-qing ZHANG Ming-xue +1 位作者 Lü Xin-xin HOU Ling-ling 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第8期2567-2576,共10页
Rotational grazing is considered as one of the nature-based solutions(NbS)to grassland protection by natural scientists.However,its effects on improving grassland quality are still unclear when it is adopted by herder... Rotational grazing is considered as one of the nature-based solutions(NbS)to grassland protection by natural scientists.However,its effects on improving grassland quality are still unclear when it is adopted by herders.Using a householdlevel panel data from field survey in two main pastoral provinces of China,empirical results from fixed-effect model and instrumental approach show that rotational grazing practices have insignificant short-term effects on grassland quality,but have positive long-term effects.In addition,rotational grazing practices can improve grassland quality when villages invest public infrastructure or herders have private supporting measures for more efficiency livestock production.Further analysis shows that herders adopting rotational grazing have higher grazing intensity,higher supplementary intensity and more livestock-house-feeding days,which indicate herders can utilize more efficient livestock management without increasing pressure on natural grassland.We also find that herders with pastoral income are more likely to adopt rotational grazing practice.These insightful findings offer policy implications on promoting grassroot NbS for ecosystem protection and resource utilization in developing pastoral countries. 展开更多
关键词 grassroots nature-based solutions rotational grazing grassland quality pastoral region China
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Performance evaluation of a novel rotational damper for structural reinforcement steel frames subjected to lateral excitations 被引量:7
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作者 M.Sanati S.E.Khadem +2 位作者 S.Mirzabagheri H.Sanati M.Y.Khosravieh 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2014年第1期75-84,共10页
In this study,a novel rotational damper called a Rotational Friction Viscoelastic Damper(RFVD) is introduced.Some viscoelastic pads are added to the Rotational Friction Damper(RFD) in addition to the friction discs us... In this study,a novel rotational damper called a Rotational Friction Viscoelastic Damper(RFVD) is introduced.Some viscoelastic pads are added to the Rotational Friction Damper(RFD) in addition to the friction discs used in this conventional device.Consequently,the amount of energy dissipated by the damper increases in low excitation frequencies.In fact,the input energy to the structure is simultaneously dissipated in the form of friction and heat by frictional discs and viscoelastic pads.In order to compare the performance of this novel damper with the earlier types,a set of experiments were carried out.According to the test results,the RFVD showed a better performance in dissipating input energy to the structure when compared to the RFD.The seismic behavior of steel frames equipped with these dampers was also numerically evaluated based on a nonlinear time history analysis.The numerical results verifi ed the performance of the dampers in increasing the energy dissipation and decreasing the energy input to the structural elements.In order to achieve the maximum dissipated energy,the dampers need to be installed in certain places called critical points in the structure.An appropriate approach is presented to properly fi nd these points.Finally,the performance of the RFVDs installed at these critical points was investigated in comparison to some other confi gurations and the validity of the suggested method in increasing the energy dissipation was confi rmed. 展开更多
关键词 seismic excitations rotational friction-viscoelastic damper rotational damper friction pad viscoelastic material energy dissipation
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Intensity Evolution of Zonal Shear Line over the Tibetan Plateau in Summer:A Perspective of Divergent and Rotational Kinetic Energies 被引量:2
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作者 Xiaohong BAO Xiuping YAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第7期1021-1033,共13页
Based on the ERA5 reanalysis datasets during 1980-2019,a total of eleven zonal shear lines(ZSLs)that caused heavy precipitation and lasted more than 60 hours over the Tibetan Plateau in summer are selected for composi... Based on the ERA5 reanalysis datasets during 1980-2019,a total of eleven zonal shear lines(ZSLs)that caused heavy precipitation and lasted more than 60 hours over the Tibetan Plateau in summer are selected for composite analysis.By decomposing the kinetic energy(K)near the ZSL into divergent and rotational kinetic energies(K_(D)and K_(R))and the kinetic energy of interaction between the divergent wind and the rotational wind(K_(R)D),the influence of the rotational and divergent winds on the evolution of the ZSL intensity is investigated from the perspective of K_(D)and K_(R).The main results are as follows.The ZSL is a comprehensive reflection of rotation and convergence.The intensity evolution of ZSL is essentially synchronized with those of K,K_(R),and K_(RD)but lags behind K_(D)by about three hours.The enhancement of K is mainly contributed by K_(R),which is governed by the conversion from K_(D)to K_(R).Furthermore,the increase in the conversion from K_(D)to K_(R)is controlled by the geostrophic effect term Af,which is determined by the joint enhancement of the zonal rotational and meridional divergent wind components(u_(R)and v_(D)).Therefore,the joint enhancement of u_(R)and v_(D)controls the increase of the ZSL intensity,leading to increased precipitation. 展开更多
关键词 zonal shear line over the Tibetan Plateau intensity evolution divergent and rotational kinetic energies joint action of the zonal rotational and meridional divergent wind components
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Effects of Rotational Isomerism and Bond Length Alternation on Optical Spectra of FTC Chromophore in Solution
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作者 赵珂 韩广超 +1 位作者 张立立 贾海洪 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第1期75-81,I0004,共8页
Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-... Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran (FTC) in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra. 展开更多
关键词 rotational isomerism Bond length alternation One-photon absorption Po-larizable continuum model
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Differential Interference Angle of Collision-induced Rotational Energy Transfer in Na_2(A^1∑_u^+,v=8-b^3∏_(0u),v=14)-Na System
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作者 李健 李永庆 +1 位作者 王伟丽 马凤才 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第6期469-472,共4页
Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study t... Here wc report calculation of the differential interference angles (including b≤p gild b≥p ) for singlet-triplet mixed states of Na2(A^1∑u^+,ν=8-b^3∏0u,ν=14) system in collision with Na, in order to study the collision- induced quantum interference on rotational energy transfer in an atom-diatom system. The calculation is based on the first-order Born approximation of time-dependent perturbation theory, and the anisotropic Lennard-Jones intcraction potentials are also employed, The relationships between differential interference angle and impact parameter, including collision diameter and velocity, are obtained, 展开更多
关键词 rotational energy transfer Collision induced quantum interference Interference angle
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A 3-Node Co-Rotational Triangular Finite Element for Non-Smooth,Folded and Multi-Shell Laminated Composite Structures 被引量:1
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作者 Zhongxue Li Jiawei Ji +2 位作者 Loc Vu-Quoc Bassam A.Izzuddin Xin Zhuo 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第11期485-518,共34页
Based on the first-order shear deformation theory,a 3-node co-rotational triangular finite element formulation is developed for large deformation modeling of non-smooth,folded and multi-shell laminated composite struc... Based on the first-order shear deformation theory,a 3-node co-rotational triangular finite element formulation is developed for large deformation modeling of non-smooth,folded and multi-shell laminated composite structures.The two smaller components of the mid-surface normal vector of shell at a node are defined as nodal rotational variables in the co-rotational local coordinate system.In the global coordinate system,two smaller components of one vector,together with the smallest or second smallest component of another vector,of an orthogonal triad at a node on a non-smooth intersection of plates and/or shells are defined as rotational variables,whereas the two smaller components of the mid-surface normal vector at a node on the smooth part of the plate or shell(away from non-smooth intersections)are defined as rotational variables.All these vectorial rotational variables can be updated in an additive manner during an incremental solution procedure,and thus improve the computational efficiency in the nonlinear solution of these composite shell structures.Due to the commutativity of all nodal variables in calculating of the second derivatives of the local nodal variables with respect to global nodal variables,and the second derivatives of the strain energy functional with respect to local nodal variables,symmetric tangent stiffness matrices in local and global coordinate systems are obtained.To overcome shear locking,the assumed transverse shear strains obtained from the line-integration approach are employed.The reliability and computational accuracy of the present 3-node triangular shell finite element are verified through modeling two patch tests,several smooth and non-smooth laminated composite shells undergoing large displacements and large rotations. 展开更多
关键词 Co-rotational approach 3-node triangular finite element laminated composite shells folded and multi-shell structures vectorial rotational variable line integration approach large deformation analysis
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Effect of Nonlinear Geometric Behavior on Random Response of Rotational Shell
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作者 高世桥 Niemann H J 《Journal of Beijing Institute of Technology》 EI CAS 2001年第1期23-28,共6页
Aimed at the large deformation problem of industry cooling tower shell, the mathematical model for the random response of rotational shell under the external random excitation is established by statistic perturbation ... Aimed at the large deformation problem of industry cooling tower shell, the mathematical model for the random response of rotational shell under the external random excitation is established by statistic perturbation method. The effect of nonlinear geometric behavior on the response of rotational shell is analyzed. 展开更多
关键词 nonlinear behavior random response rotational shell cooling tower
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Nonlinear Stochastic Response of Rotational Shell Under the Action of Stationary Strong Wind Loads
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作者 高世桥 Niemann H J 《Journal of Beijing Institute of Technology》 EI CAS 2001年第1期29-33,共5页
Based on the theoretical analysis of nonlinear random response of structure, for the engineering practical problem, that is, the large deformation of industry cooling tower shell structure under the action of strong w... Based on the theoretical analysis of nonlinear random response of structure, for the engineering practical problem, that is, the large deformation of industry cooling tower shell structure under the action of strong wind loads, the statistic perturbation method is also used to analyze some statistic characteristics of the nonlinear random response of rotational shell with geometric nonlinearity and stationary strong wind load considered. Through computation, some average values of nornal displacements and the nonlinear effect factor of the cooling tower shell are given. 展开更多
关键词 nonlinear behavior random response rotational shell cooling tower
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Stochastic Responses of a Shell of Rotational Symmetry Haing Physically Nonlinear Behavior
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作者 高世桥 《Journal of Beijing Institute of Technology》 EI CAS 1994年第1期25+19-25,共8页
Concrete is considered as an elastic body when subjected to compressive stress butas a brittle body when subjected to tensile stress. That is, after the elastic extremum it cannotcontinue to bear the stress. Based on ... Concrete is considered as an elastic body when subjected to compressive stress butas a brittle body when subjected to tensile stress. That is, after the elastic extremum it cannotcontinue to bear the stress. Based on this.'cracked' physical model, for stochastic extemalwind loads, nonlinear stochastic constitutive equations have been established. To solve equations of nonlinear stochastic vibration, an iterative statistic linearization method (ISLM) hasbeen developedb. Some statistic characteristics were foundd out. 展开更多
关键词 NON-LINEAR stochastic processes/rotational shell
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Collisional Quantum Interference on Rotational Energy Transfer: Relation Between Integral Interference Angle and Rotational Quantum Number in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14)-Na System
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作者 WANG Wei-Li SONG Peng +2 位作者 LI Yong-Qing MIAO Gang MA Feng-Cai 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期123-129,共7页
Collisional quantum interference (CQI) on rotational energy transfer was observed in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14) system in collision with Na [Chem. Phys. Lett. 318 (2000) 107], and the degree of the inter... Collisional quantum interference (CQI) on rotational energy transfer was observed in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14) system in collision with Na [Chem. Phys. Lett. 318 (2000) 107], and the degree of the interference was measured. The integral interference angle was obtaJned through theoretical calculation. We will research the factors that have effect on collisional quantum interference on rotational energy transfer in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14)-Na system. Basing on the time-dependent first order Born approximation, and taking into account the anlsotroplc Lennard Jones interaction potentials and "straight-line" trajectory approximation, we obtain the factors that have effect on CQI in Na2-Na system, and obtain the relation between the integral interference angle and rotational quantum number. 展开更多
关键词 rotational energy transfer interference angle rotational quantum number
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Type Synthesis and Characteristic Analysis of a Family of 2-DOF Rotational Decoupled Parallel Mechanisms 被引量:14
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作者 ZENG Daxing Hou Yulei HUANG Zhen LU Wenjuan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第6期833-840,共8页
It is widely used for the rotational parallel mechanism in the field of spatial orientation. While owing to the existence of coupling, the forward kinematic solution and the control of the general rotational parallel ... It is widely used for the rotational parallel mechanism in the field of spatial orientation. While owing to the existence of coupling, the forward kinematic solution and the control of the general rotational parallel mechanism are especially difficult. If decoupling can be realized, the kinematic analysis of the mechanism will be very simple. Presently, the research of the parallel mechanism is focused on the inverse solution and structure optimization, and there is a lack of rotation decoupled parallel mechanisms (DPMs). So this paper proposes a family of 2 degree of freedom (DOF) rotational DPMs based on the four-bar linkage mechanism, and performs a characteristic analysis. This family of DPMs is composed of a moving platform, a fixed base and three limbs. Taking U_RRU SPU DPM as an example, the motion feature of this DPM is analyzed with the constraint screw method, and its mobility is calculated by using the Modified Kutzbach-Grtibler criterion. The inverse and forward displacement problems of the proposed parallel mechanism are solved. The decoupled feature of the proposed parallel mechanism is validated by the deduction of the expression of the Jaeobian matrix. Three kinds of singularity conditions of this DPM are discussed, and the atlases of the output parameter concerning different geometric parameters are plotted with the theory of the physical model of the solution space. The proposition and characteristic analysis of the novel rotational DPMs in this paper should be useful for further research and application of the parallel mechanisms. 展开更多
关键词 parallel mechanism rotational decoupled constraint screw method ATLASES
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