期刊文献+
共找到28,210篇文章
< 1 2 250 >
每页显示 20 50 100
Sandwich structures with tapered tubes as core:A quasi-static investigation
1
作者 Xinmei Xiang Dehua Shao +5 位作者 Xin Zhang Umer Sharif Ngoc San Ha Li Xiang Jing Zhang Jiang Yi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期447-462,共16页
In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to c... In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without corrugations.The results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube sandwich.Furthermore,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their efficiency.Additionally,the tapered corrugated tubes'resistance to oblique impacts was studied.Compared to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical simulations.After conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall thickness.EA and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10. 展开更多
关键词 Sandwich structure Corrugated tube Tapered tube quasi-static Energy absorption
下载PDF
Quasi-static and dynamic compressive behaviour of additively manufactured Menger fractal cube structures
2
作者 Damith Mohotti Dakshitha Weerasinghe +3 位作者 Madhusha Bogahawaththa Hongxu Wang Kasun Wijesooriya Paul JHazell 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第7期39-49,共11页
This paper presents the first-ever investigation of Menger fractal cubes'quasi-static compression and impact behaviour.Menger cubes with different void ratios were 3D printed using polylactic acid(PLA)with dimensi... This paper presents the first-ever investigation of Menger fractal cubes'quasi-static compression and impact behaviour.Menger cubes with different void ratios were 3D printed using polylactic acid(PLA)with dimensions of 40 mm×40 mm×40 mm.Three different orders of Menger cubes with different void ratios were considered,namely M1 with a void ratio of 0.26,M2 with a void ratio of 0.45,and M3with a void ratio of 0.60.Quasi-static Compression tests were conducted using a universal testing machine,while the drop hammer was used to observe the behaviour under impact loading.The fracture mechanism,energy efficiency and force-time histories were studied.With the structured nature of the void formation and predictability of the failure modes,the Menger geometry showed some promise compared to other alternatives,such as foams and honeycombs.With the increasing void ratio,the Menger geometries show force-displacement behaviour similar to hyper-elastic materials such as rubber and polymers.The third-order Menger cubes showed the highest energy absorption efficiency compared to the other two geometries in this study.The findings of the present work reveal the possibility of using additively manufactured Menger geometries as an energy-efficient system capable of reducing the transmitting force in applications such as crash barriers. 展开更多
关键词 Additive manufacturing Fractal geometries Menger cube Energy absorption quasi-static
下载PDF
Experimental crushing behavior and energy absorption of angular gradient honeycomb structures under quasi-static and dynamic compression
3
作者 Jiachen Li Yuchen Wei +2 位作者 Hao Wu Xingyu Shen Mengqi Yuan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第6期47-63,共17页
The high variability of shock in terrorist attacks poses a threat to people's lives and properties,necessitating the development of more effective protective structures.This study focuses on the angle gradient and... The high variability of shock in terrorist attacks poses a threat to people's lives and properties,necessitating the development of more effective protective structures.This study focuses on the angle gradient and proposes four different configurations of concave hexagonal honeycomb structures.The structures'macroscopic deformation behavior,stress-strain relationship,and energy dissipation characteristics are evaluated through quasi-static compression and Hopkinson pressure bar impact experiments.The study reveals that,under varying strain rates,the structures deform starting from the weak layer and exhibit significant interlayer separation.Additionally,interlayer shear slip becomes more pronounced with increasing strain rate.In terms of quasi-static compression,symmetric gradient structures demonstrate superior energy absorption,particularly the symmetric negative gradient structure(SNG-SMS)with a specific energy absorption of 13.77 J/cm~3.For dynamic impact,unidirectional gradient structures exhibit exceptional energy absorption,particularly the unidirectional positive gradient honeycomb structure(UPG-SML)with outstanding mechanical properties.The angle gradient design plays a crucial role in determining the structure's stability and deformation mode during impact.Fewer interlayer separations result in a more pronounced negative Poisson's ratio effect and enhance the structure's energy absorption capacity.These findings provide a foundation for the rational design and selection of seismic protection structures in different strain rate impact environments. 展开更多
关键词 Negative Poisson's ratio Gradient honeycomb structure quasi-static compression Dynamic impact Titanium alloy
下载PDF
Design,Development and Testing of the JTech Bolt for Use in Static,Quasi-Static and Dynamic Domains
4
作者 Trent Roberts 《Journal of Civil Engineering and Architecture》 2024年第6期282-295,共14页
Designing a rock reinforcement element requires knowledge of:geomechanical behaviour,interaction of the reinforcement element with rock mass and the element’s mechanistic response in static and dynamic environments.U... Designing a rock reinforcement element requires knowledge of:geomechanical behaviour,interaction of the reinforcement element with rock mass and the element’s mechanistic response in static and dynamic environments.Using this knowledge the JTech bolt was developed and subjected to a thorough program to test,gather data and validate the bolt performance in varying domains.By conducting FE(finite element)modeling,the simulation reviews the JTech bolt design evaluating the effects of threadbar geometric variation,threadbar and nut engagement results under high stress,coating friction response and effects of thread tolerance extremes on the failure mode.These results determine safety factors,tolerances and quality management criteria.Once manufactured,in-situ system testing,laboratory and underground short encapsulation testing,resin mixing testing,double shear testing and dynamic testing at varying velocity and mass,determine the system’s capacity and effectiveness in static,quasi-static and dynamic mining environments.In this paper,the process and results are described. 展开更多
关键词 Rock reinforcement geomechanical behavior STATIC quasi-static dynamic domains
下载PDF
Research on Anti-Fluctuation Control of Winding Tension System Based on Feedforward Compensation
5
作者 Yujie Duan Jianguo Liang +4 位作者 Jianglin Liu Haifeng Gao Yinhui Li Jinzhu Zhang Xinyu Wen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1239-1261,共23页
In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tens... In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tension output,this paper proposed a tension fluctuation rejection strategy based on feedforward compensation.In addition to the bias harmonic curve of the unknown state,the tension fluctuation also contains the influence of bounded noise.A tension fluctuation observer(TFO)is designed to cancel the uncertain periodic signal,in which the frequency generator is used to estimate the critical parameter information.Then,the fluctuation signal is reconstructed by a third-order auxiliary filter.The estimated signal feedforward compensates for the actual tension fluctuation.Furthermore,a time-varying parameters fractional-order PID controller(TPFOPID)is realized to attenuate the bounded noise in the fluctuation.Finally,TPFOPID is enhanced by TFO and applied to control a tension control system considering multi-source disturbances.The stability of the method is analyzed by using the Lyapunov theorem.Finally,numerical simulations verify that the proposed scheme improves the tracking ability and robustness of the system in response to tension fluctuations. 展开更多
关键词 Constant tension control anti-fluctuation strategy tension fluctuation observer time-varying parameters fractional-order PID controller feedforward compensate
下载PDF
Atomistic evaluation of tension–compression asymmetry in nanoscale body-centered-cubic AlCrFeCoNi high-entropy alloy
6
作者 邢润龙 刘雪鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期613-622,共10页
The tension and compression of face-centered-cubic high-entropy alloy(HEA) nanowires are significantly asymmetric, but the tension–compression asymmetry in nanoscale body-centered-cubic(BCC) HEAs is still unclear. In... The tension and compression of face-centered-cubic high-entropy alloy(HEA) nanowires are significantly asymmetric, but the tension–compression asymmetry in nanoscale body-centered-cubic(BCC) HEAs is still unclear. In this study,the tension–compression asymmetry of the BCC Al Cr Fe Co Ni HEA nanowire is investigated using molecular dynamics simulations. The results show a significant asymmetry in both the yield and flow stresses, with BCC HEA nanowire stronger under compression than under tension. The strength asymmetry originates from the completely different deformation mechanisms in tension and compression. In compression, atomic amorphization dominates plastic deformation and contributes to the strengthening, while in tension, deformation twinning prevails and weakens the HEA nanowire.The tension–compression asymmetry exhibits a clear trend of increasing with the increasing nanowire cross-sectional edge length and decreasing temperature. In particular, the compressive strengths along the [001] and [111] crystallographic orientations are stronger than the tensile counterparts, while the [110] crystallographic orientation shows the exactly opposite trend. The dependences of tension–compression asymmetry on the cross-sectional edge length, crystallographic orientation,and temperature are explained in terms of the deformation behavior of HEA nanowire as well as its variations caused by the change in these influential factors. These findings may deepen our understanding of the tension–compression asymmetry of the BCC HEA nanowires. 展开更多
关键词 high-entropy alloys body-centered-cubic NANOWIRE tension–compression asymmetry atomistic simulations
下载PDF
Impact of Tension-Type Headaches in the Workplace in Brazzaville
7
作者 Happhia Dinah Boubayi Motoula Latou Josué Euberma Diatewa +4 位作者 Ghislain Armel Mpandzou Prince Eliot Galieni Sounga Bandzouzi Jean Brice Mouendenguia Karen Lise Obondzo Aloba Paul Macaire Ossou-Nguiet 《Neuroscience & Medicine》 2024年第2期77-91,共15页
Introduction: Tension-type headaches are the most widespread of the primary headache disorders. Due to their high prevalence, tension-type headaches represent a major public health problem with an enormous socio-econo... Introduction: Tension-type headaches are the most widespread of the primary headache disorders. Due to their high prevalence, tension-type headaches represent a major public health problem with an enormous socio-economic burden. Determining their impact remains a challenge. Objective: To assess the impact of occupational tension-type headache in Brazzaville and identify associated factors. Population and Methods: This was an analytical case-control study conducted in public and private companies in the city of Brazzaville over a period of four (04) months. The case population consisted of cephalalgic employees;the control population was drawn from the same companies and was free of tension-type headaches. Study variables were divided into socio-professional, clinical and individual impact variables. Individual impact variables were represented by: the HIT-6 score, which incorporates a very broad conception of disability, covering several domains, namely: severity of pain during attacks and the restrictive and limiting nature of attacks. Results: Individual impact was severe in 18 (62.1%) men and 11 (37.9%) women. Mean age was 36.3 6.14 years for cases with severe impact. The mean duration of headache was 40.3 32.7 months for cases with severe impact. Tension headache evolved in attacks in 22 (75.9%) cases with severe impact, and continuously in seven (24.1%) cases. The average number of attacks per month was 2.52 1.04 for cases with severe impact. Cases with severe impact included 14 (48.3%) with chronic headache and 15 (51.7%) with episodic headache. Pain of severe intensity present in 48.3% of cases was associated with a severe impact of tension-type headache: OR = 151.66 [2.36 - 44245.95] and p-value = 0.037. At least one days absence from work per year was observed in 47.4% of our cases. The number of days off work per year due to tension-type headache had an interquartile range between 0 and 3 days and extremes from 0 to 14 days. It was the consequence of a severe impact on daily and/or professional activities. Conclusion: The high frequency of tension-type headaches in the workplace and its impact on the condition of workers in Brazzaville represent a real public health problem. It was found that the number of days absent from work per year due to tension headaches was the consequence of a severe impact on daily and/or professional activities. An awareness-raising program in this environment seems necessary, as well as an assessment of working conditions. 展开更多
关键词 IMPACT tension Headache WORKPLACE
下载PDF
Eudragit®-PEG Nanoparticles: Physicochemical Characterization and Interfacial Tension Measurements
8
作者 Papa Mady Sy Sidy Mouhamed Dieng +4 位作者 Alphonse Rodrigue Djiboune Louis Augustin Diaga Diouf Boucar Ndong Gora Mbaye Mounibé Diarra 《Open Journal of Biophysics》 2024年第2期121-131,共11页
The objectives of this study are to understand the mechanisms involved in the stabilization of water/oil interfaces by polymeric nanoparticles (NPs) (Eudragit®). Eudragit L100 NPs of various sizes and Zeta potent... The objectives of this study are to understand the mechanisms involved in the stabilization of water/oil interfaces by polymeric nanoparticles (NPs) (Eudragit®). Eudragit L100 NPs of various sizes and Zeta potentials were studied and compared at a water/cyclohexane model interface using a droplet tensiometer (Tracker Teclis, Longessaigne, France). The progressive interfacial adsorption of the NPs in the aqueous phase was monitored by tensiometry. The model interface was maintained and observed in a drop tensiometer, analyzed via axisymmetric drop shape analysis (ADSA), to determine the interfacial properties. Given the direct relationship between the stability of Pickering emulsions (emulsions stabilized by solid nanoparticles) and the interfacial properties of these layers, different nanoparticle systems were compared. Specifically, Eudragit NPs of different sizes were examined. Moreover, the reduction of the Zeta potential with PEG-6000 induces partial aggregation of the NPs (referred to as NP flocs), significantly impacting the stability of the interfacial layer. Dynamic surface tension measurements indicate a significant decrease in interfacial tension with Eudragit® nanoparticles (NPs). This reduction correlates with the size of the NPs, highlighting that this parameter does not operate in isolation. Other factors, such as the contact angle and wettability of the nanoparticles, also play a critical role. Notably, larger NPs further diminished the interfacial tension. This study enhances our understanding of the stability of Pickering emulsions stabilized by Eudragit® L100 polymeric nanoparticles. 展开更多
关键词 NANOPARTICLES Eudragit® PEG Interfacial tension Pickering Emulsion
下载PDF
Adaptive RISE Control of Winding Tension with Active Disturbance Rejection
9
作者 Junjie Mi Jianyong Yao Wenxiang Deng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第4期135-145,共11页
A winding system is a time-varying system that considers complex nonlinear characteristics,and how to control the stability of the winding tension during the winding process is the primary problem that has hindered de... A winding system is a time-varying system that considers complex nonlinear characteristics,and how to control the stability of the winding tension during the winding process is the primary problem that has hindered development in this field in recent years.Many nonlinear factors affect the tension in the winding process,such as friction,structured uncertainties,unstructured uncertainties,and external interference.These terms severely restrict the tension tracking performance.Existing tension control strategies are mainly based on the composite control of the tension and speed loops,and previous studies involve complex decoupling operations.Owing to the large number of calculations required for this method,it is inconvenient for practical engineering applications.To simplify the tension generation mechanism and the influence of the nonlinear characteristics of the winding system,a simpler nonlinear dynamic model of the winding tension was established.An adaptive method was applied to update the feedback gain of the continuous robust integral of the sign of the error(RISE).Furthermore,an extended state observer was used to estimate modeling errors and external disturbances.The model disturbance term can be compensated for in the designed RISE controller.The asymptotic stability of the system was proven according to the Lyapunov stability theory.Finally,a comparative analysis of the proposed nonlinear controller and several other controllers was performed.The results indicated that the control of the winding tension was significantly enhanced. 展开更多
关键词 Winding tension Continuous robust integral of the sign of the error(RISE)control Adaptive control Disturbance compensation Extended state observer(ESO) tension control
下载PDF
Membrane tension evolution and mechanical regulation of melittin-induced membrane poration
10
作者 Wanting Zhang Rong Xu +3 位作者 Wendong Ma Zhao Lin Kai Yang Bing Yuan 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期465-475,共11页
Membrane tension plays a crucial role in various fundamental cellular processes,with one notable example being the T cell-mediated elimination of tumor cells through perforin-induced membrane perforation by amplifying... Membrane tension plays a crucial role in various fundamental cellular processes,with one notable example being the T cell-mediated elimination of tumor cells through perforin-induced membrane perforation by amplifying cellular force.However,the mechanisms governing the regulation of biomolecular activities at the cell interface by membrane tension remain elusive.In this study,we investigated the correlation between membrane tension and poration activity of melittin,a prototypical pore-forming peptide,using dynamic giant unilamellar vesicle leakage assays combined with flickering tension analysis,molecular dynamics simulations,and live cell assays.The results demonstrate that an increase in membrane tension enhances the activity of melittin,particularly near its critical pore-forming concentration.Moreover,peptide actions such as binding,insertion,and aggregation in the membrane further influence the evolution of membrane tension.Live cell experiments reveal that artificially enhancing membrane tension effectively enhances melittin’s ability to induce pore formation and disrupt membranes,resulting in up to a ten-fold increase in A549 cell mortality when exposed to a concentration of 2.0-μg·mL^(-1)melittin.Our findings elucidate the relationship between membrane tension and the mechanism of action as well as pore-forming efficiency of melittin,while providing a practical mechanical approach for regulating functional activity of molecules at the cell-membrane interface. 展开更多
关键词 membrane tension mechanical regulation membrane poration giant unilamellar vesicle leakage assay
下载PDF
Neuroimaging in atypical normal tension glaucoma:debating routine implementation in the absence of classic neurological findings
11
作者 Umay Güvenç Gülizar Demirok +1 位作者 Güner Üney Selma Uzman 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期509-517,共9页
●AIM:To assess the necessity of neuroimaging in patients with neurological or atypical findings of normal tension glaucoma(NTG)who do not exhibit typical glaucoma manifestations.●METHODS:A retrospective analysis was... ●AIM:To assess the necessity of neuroimaging in patients with neurological or atypical findings of normal tension glaucoma(NTG)who do not exhibit typical glaucoma manifestations.●METHODS:A retrospective analysis was conducted on 90 atypical NTG patients who underwent cranial magnetic resonance imaging(MRI)due to atypical symptoms.The demographic characteristics,clinical parameters,and radiological findings were recorded.●RESULTS:Among the patients,66.7%had abnormal radiology results,with the most common findings being gliosis(34.4%),sequelae of cerebrovascular events and vascular malformations(14.4%),and benign intracranial mass lesions(11%).Non-glaucomatous visual field defects were more frequently observed in patients with abnormal neuroimaging results.However,there were no significant differences in intraocular pressure,optic disc parameters,retinal nerve fiber layer thickness,and visual field indices between patients with normal and abnormal radiological results.The mean age of the patients was 58.74y.Interestingly,there was a significant age difference,with the abnormal radiology group having a higher median age(P=0.021).●CONCLUSION:The study highlights the importance of cranial imaging in older NTG patients to detect underlying pathologies and prevent misdiagnosis.It suggests that neuroimaging may be warranted in NTG patients with atypical visual field defects incompatible with glaucoma.However,routine neuroimaging in all NTG patients without classic neurological signs may not be necessary. 展开更多
关键词 normal tension glaucoma NEUROIMAGING atypical visual field defects
下载PDF
Mechanical behavior of rock under uniaxial tension:Insights from energy storage and dissipation
12
作者 Guanshuang Tan Chunde Ma +3 位作者 Junjie Zhang Wenyuan Yang Guiyin Zhang Zihao Kang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2466-2481,共16页
Many rock engineering projects show that the growth of tensile cracks is often an important cause of engineering disasters,and the mechanical behavior of rocks is essentially the transmission,storage,dissipation and r... Many rock engineering projects show that the growth of tensile cracks is often an important cause of engineering disasters,and the mechanical behavior of rocks is essentially the transmission,storage,dissipation and release of energy.To investigate the tensile behavior of rock from the perspective of energy,uniaxial tension tests(UTTs)and uniaxial compression tests(UCTs)were carried out on three typical rocks(granite,sandstone and marble).Different unloading points were set before the peak stress to separate elastic energy and dissipated energy.The input energy density ut,elastic energy density ue,and dissipated energy density ud at each unloading point were calculated by integrating stress-strain curves.The results show that there is a strong linear relationship between the three energy parameters and the square of the unloading stress in UCT,but this linear relationship is weaker in UTT.The ue and ud increase linearly with the increase in ut in UCT and UTT.Based on the phenomenon that ue and ud increase linearly with ut,the applicability of W_(et)^(p) index in UTT was proved and the relative energy storage capacity and absolute energy distribution characteristics of three rocks in UCT and UTT were evaluated.The tensile behavior of marble and sandstone in UTT can be divided into two stages vaguely according to the energy distribution,but granite is not the case.In addition,based on dissipated energy,the damage evolution of three types of rocks in UCT and UTT was discussed.This study provides some new insights for understanding the tensile behavior of rock. 展开更多
关键词 Uniaxial tension Energy density Mechanical behavior Energy storage coefficient Energy dissipation coefficient
下载PDF
Geometry and formation mechanism of tension gashes and their implication on the hydrocarbon accumulation in the deep-seated strata of sedimentary basin:A case from Shunnan area of Tarim Basin
13
作者 Yan-Nan Du Kong-You Wu +4 位作者 Yin Liu Yan-Ying Li Zi-Cheng Cao You-Wei Cui Jun Liu 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期87-99,共13页
With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic ... With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic movements,the strike-slip faults have controlled the distribution of hydrocarbon resources owing to the special fault characteristics and fault-related structures.In contrast,the kinematics and formation mechanism of strike-slip faults in buried sedimentary basins are difficult to investigate,limiting the discussion of these faults and hydrocarbon accumulation.In this study,we identified the characteristics of massive sigmoidal tension gashes(STGs)that formed in the Shunnan area of the Tarim Basin.High-resolution three-dimensional seismic data and attribute analyses were used to investigate their geometric and kinematic characteristics.Then,the stress state of each point of the STGs was calculated using seismic curvature attributes.Finally,the formation mechanism of the STGs and their roles in controlling hydrocarbon migration and accumulation were discussed.The results suggest that:(1)the STGs developed in the Shunnan area have a wide distribution,with a tensile fault arranged in an enéchelon pattern,showing an S-shaped bending.These STGs formed in multiple stages,and differential rotation occurred along the direction of strike-slip stress during formation.(2)Near the principal displacement zone of the strike-slip faults,the stress value of the STGs was higher,gradually decreasing at both ends.The shallow layer deformation was greater than the deep layer deformation.(3)STGs are critical for connecting source rocks,migrating oil and gas,sealing horizontally,and developing efficient reservoirs.This study not only provides seismic evidence for the formation and evolution of super large STGs,but also provides certain guidance for oil and gas exploration in this area. 展开更多
关键词 Tarim Basin Sigmoidal tension gashes Seismic attributes Shear stress calculation Formation mechanism Reservoir control
下载PDF
Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia
14
作者 Shan Hua Qiu-Xia Xie +1 位作者 Hu Wang Jing-Xiang Zhong 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期499-508,共10页
●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical tria... ●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical trial was conducted.Totally 98 eyes(74 patients)who underwent femtosecond laser-assisted cataract surgery(FLACS)with trifocal IOLs were enrolled in the study and followed up for 2y after surgery:46 eyes(33 patients)with capsular tension ring implantation in the long axial lengths(AL)group(26<AL<29 mm)and 52 eyes(41 patients)in the normal AL group(22<AL<24.5 mm).Postoperative outcomes about effectivity and safety,including the subjective and objective visual quality,and postoperative complications were assessed.●RESULTS:Uncorrected distance visual acuity at 5 m and uncorrected intermediate visual acuity at 60 and 80 cm in the long AL group were significantly worse than those in the normal AL group at 3mo postoperatively(P<0.05).The differences in reading speed,spectacle independence and potential visual complaints between the two groups were not statistically significant(P>0.05).The dysfunctional lens index and total modulation transfer function(MTF)average height were similar between the two groups.The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group(P<0.05).The total satisfaction score in the long AL group(91.32±2.76)was slightly higher than that in the normal AL group(90.36±3.47),but there was no difference(P=0.136).A statistically negative correlation was found between corrected distance visual acuity(CDVA)and dysfunctional lens index(r=-0.382,P=0.009),and between CDVA and the total MTF average height(r=-0.374,P=0.01).But there was no significant correlation between CDVA and total satisfaction score(r=0.059,P=0.696).Postoperative complications mainly presented as posterior capsular opacity(PCO),retinal detachment and cystoid macular edema.There was no difference in the incidence of fundus disease(6.5%vs 3.8%,P=0.663)or PCO(17.4%vs 7.7%,P=0.217)between the two groups at two years.●CONCLUSION:The utilization of trifocal IOL and capsular tension ring implantation is beneficial for cataract patients with axial high myopia undergoing FLACS.This approach not only ensures excellent subjective feelings and objective visual quality,but also does not increase the incidence of postoperative complications. 展开更多
关键词 trifocal intraocular lenses capsular tension ring axial high myopia CATARACT visual quality
下载PDF
Hubble Tension Explanation from This Cosmological Model AΛΩ (Slow Bang Model, SB)
15
作者 Jean Perron 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期106-125,共20页
In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of t... In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of the evolution of space-time as well as an equation of state that retains all the infinitesimal terms. We find an explanation of the Hubble tension H<sub>0</sub>. Indeed, we have seen that this constant depends on the transceiver pair which can vary from the lowest observable value, from photons of the CMB (theoretical [km/s/Mpc]) to increasingly higher values depending on the earlier origin of the formation of the observed galaxy or cluster (ETG ~0.3 [Gy], ~74 [km/s/Mpc]). We have produced a theoretical table of the values of the constant according to the possible pairs of transmitter/receiver in the case where these galaxies follow the Hubble flow without large disturbance. The calculated theoretical values of the constant are in the order of magnitude of all values mentioned in past studies. Subsequently, we applied the models to 9 galaxies and COMA cluster and found that the models predict acceptable values of their distances and Hubble constant since these galaxies mainly follow the Hubble flow rather than the effects of a galaxy cluster or a group of clusters. In conclusion, we affirm that this Hubble tension does not really exist and it is rather the understanding of the meaning of this constant that is questioned. 展开更多
关键词 Model of the Universe Cosmological Constant Hubble Constant Hubble’s tension Hubble-Lemaître Law Hubble’s Flow
下载PDF
Unveiling the silent link:Normal-tension glaucoma's enigmatic bond with cardiac blood flow
16
作者 Prasanna Venkatesh Ramesh Arvind Kumar Morya +5 位作者 Ajanya K Aradhya Pavithra Pannerselvam Sai Thaejesvi Gopalakrishnan Shruthy Vaishali Ramesh Aji Kunnath Devadas Navaneeth Krishna 《World Journal of Cardiology》 2024年第1期10-15,共6页
This comprehensive review embarks on a captivating journey into the complex relationship between cardiology and normal-tension glaucoma(NTG),a condition that continues to baffle clinicians and researchers alike.NTG,ch... This comprehensive review embarks on a captivating journey into the complex relationship between cardiology and normal-tension glaucoma(NTG),a condition that continues to baffle clinicians and researchers alike.NTG,characterized by optic nerve damage and visual field loss despite normal intraocular pressure,has long puzzled clinicians.One emerging perspective suggests that alterations in ocular blood flow,particularly within the optic nerve head,may play a pivotal role in its pathogenesis.While NTG shares commonalities with its high-tension counterpart,its unique pathogenesis and potential ties to cardiovascular health make it a fascinating subject of exploration.It navigates through the complex web of vascular dysregulation,blood pressure and perfusion pressure,neurovascular coupling,and oxidative stress,seeking to uncover the hidden threads that tie the heart and eyes together in NTG.This review explores into the intricate mechanisms connecting cardiovascular factors to NTG,shedding light on how cardiac dynamics can influence ocular health,particularly in cases where intraocular pressure remains within the normal range.NTG's enigmatic nature,often characterized by seemingly contradictory risk factors and clinical profiles,underscores the need for a holistic approach to patient care.Drawing parallels to cardiac health,we examine into the shared vascular terrain connecting the heart and the eyes.Cardiovascular factors,including systemic blood flow,endothelial dysfunction,and microcirculatory anomalies,may exert a profound influence on ocular perfusion,impacting the delicate balance within the optic nerve head.By elucidating the subtle clues and potential associations between cardiology and NTG,this review invites clinicians to consider a broader perspective in their evaluation and management of this elusive condition.As the understanding of these connections evolves,so too may the prospects for early diagnosis and tailored interventions,ultimately enhancing the quality of life for those living with NTG. 展开更多
关键词 Normal tension glaucoma Vascular dysregulation Ocular blood flow Blood pressure Perfusion pressure Oxidative stress
下载PDF
The Tension Cosmology, Largest Cosmic Structures and Explosions of Supernovae from SST
17
作者 Sylwester Kornowski 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1029-1044,共16页
Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter lea... Here, using the Scale-Symmetric Theory (SST) we explain the cosmological tension and the origin of the largest cosmic structures. We show that a change in value of strong coupling constant for cold baryonic matter leads to the disagreement in the galaxy clustering amplitude, quantified by the parameter S8. Within the same model we described the Hubble tension. We described also the mechanism that transforms the gravitational collapse into an explosion—it concerns the dynamics of virtual fields that lead to dark energy. Our calculations concern the Type Ia supernovae and the core-collapse supernovae. We calculated the quantized masses of the progenitors of supernovae, emitted total energy during explosion, and we calculated how much of the released energy was transferred to neutrinos. Value of the speed of sound in the strongly interacting matter measured at the LHC confirms that presented here model is correct. Our calculations show that the Universe is cyclic. 展开更多
关键词 Scale-Symmetric Theory tension Cosmology Coupling Constants Parameters σ8 and S8 Largest Cosmic Structures Dark Energy Supernova Explosion Cyclic Universe
下载PDF
In-situ study of the microstructure evolution during tension of a Mg-Y-Zn-Al alloy processed by rapidly solidified ribbon consolidation technique
18
作者 Jeno Gubicza Kristián Máthis +7 位作者 Péter Nagy Péter Jenei Zoltán Hegedus Andrea Farkas Jozef Vesely Shin-ichi Inoue Daria Drozdenko Yoshihito Kawamura 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期2024-2040,共17页
Mg-Y-Zn-Al alloys processed by rapidly solidified ribbon consolidation(RSRC)technique exhibit an exceptional mechanical performance indicating promising application potential.This material has a bimodal microstructure... Mg-Y-Zn-Al alloys processed by rapidly solidified ribbon consolidation(RSRC)technique exhibit an exceptional mechanical performance indicating promising application potential.This material has a bimodal microstructure consisting of fine recrystallized and coarse non-recrystallized grains with solute-rich stacking faults forming cluster arranged layers(CALs)and nanoplates(CANaPs),or complete long period stacking ordered(LPSO)phase.In order to reveal the deformation mechanisms,in-situ synchrotron X-ray diffraction line profile analysis was employed for a detailed study of the dislocation arrangement created during tension in Mg-0.9%Zn-2.05%Y-0.15%Al(at%)alloy.For uncovering the effect of the initial microstructure on the mechanical performance,additional samples were obtained by annealing of the as-consolidated specimen at 300 and 400℃ for 2 h.The heat treatment at 300℃ had no significant effect on the initial microstructure,its evolution during tension and,thus,the overall deformation behavior under tensile loading.On the other hand,annealing at 400℃ resulted in a significant increase of the recrystallized grains fraction and a decrease of the dislocation density,leading to only minor degradation of the mechanical strength.The maximum dislocation density at the failure of the samples corresponding to the plastic strain of 10-25% was estimated to be about 16-20×10^(14)m^(-2).The diffraction profile analysis indicated that most dislocations formed during tension were of non-basal and pyramidal types,what was also in agreement with the Schmid factor values revealed independently from orientation maps.It was also shown that the dislocation-induced Taylor hardening was much lower below the plastic strain of 3% than above this value,which was explained by a model of the interaction between prismatic dislocations and CANaPs/LPSO plates. 展开更多
关键词 Mg-Zn-Y-Al alloy Long period stacking ordered(LPSO)phase Cluster arranged nanoplates(CANaPs) Annealing tension Dislocation density Hardening
下载PDF
A Comment on the Hubble Expansion Parameter Tension
19
作者 Bruce Hoeneisen 《International Journal of Astronomy and Astrophysics》 2024年第1期61-64,共4页
We point out that the recent baryon acoustic oscillation measurement by the Dark Energy Survey collaboration relieves the Hubble expansion parameter tension.
关键词 Hubble Parameter H0 tension
下载PDF
Crealet presents its innovative warp tension solutions at Techtextil 2024
20
《China Textile》 2024年第2期43-43,共1页
Crealet is the world leader in sophisticated warp feeding technology and tailored solutions.Controlled warp tension stands also for controlled fabric quality.The Swiss firm presents its latest developments for technic... Crealet is the world leader in sophisticated warp feeding technology and tailored solutions.Controlled warp tension stands also for controlled fabric quality.The Swiss firm presents its latest developments for technical textile applications at Techtextil 2024 in Frankfurt,Germany. 展开更多
关键词 tension WARP GERMANY
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部