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In vivo sedative and muscle relaxants activity of Diospyros lotus L 被引量:1
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作者 Abdur Rauf Ghias Uddin +1 位作者 Bina Shaheen Siddiqui Haroon Khan 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2015年第4期277-280,共4页
Objective: To evaluate the sedative effect of Diospyros lotus L(D. lotus) extract in mice using the open field and Rota rod tests.Methods: For the sedative and muscle relaxants activities of extract/fractions of the p... Objective: To evaluate the sedative effect of Diospyros lotus L(D. lotus) extract in mice using the open field and Rota rod tests.Methods: For the sedative and muscle relaxants activities of extract/fractions of the plant, invivo open field and phenobarbitone-induced sleeping time were used, while the Roda rod test was employed in animals for the assessment of muscle relaxant activity.Results: Results from this investigation revealed that the extracts of D. lotus have exhibited significant sedative effect in mice(45.98%) at 100 mg/kg i.p. When the extract was partitioned with different solvents, the n-hexane fraction was inactive whereas the chloroform fraction was the most active with 82.67% sedative effect at 50 and 100 mg/kg i.p. On the other hand,the ethyl acetate and n-butanol fractions displayed significant sedative effects(55.65% and40.87%, respectively) at 100 mg/kg i.p. Among the tested extract/fractions, only chloroform and ethyl acetate fractions showed significant(P < 0.05) muscle relaxant activity in the Rota rod test.Conclusions: In short, our study provided scientific background to the traditional uses of D.lotus as sedative. 展开更多
关键词 DIOSPYROS LOTUS EBENACEAE SEDATIVE MUSCLE relaxants ACTIVITY
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Relaxant Effects of Quercetin and Rutin on Human Isolated Bronchus 被引量:1
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作者 Hanifa Djelili Lekhmici Arrar +1 位作者 Emmanuel Naline Philippe Devillier 《Chinese Medicine》 2012年第2期94-100,共7页
Increasing epidemiological evidence supports the view, that quercetin has protective roles in a multitude of disease states in human who have a high intake of polyphenols. To investigate the ability of quercetin and i... Increasing epidemiological evidence supports the view, that quercetin has protective roles in a multitude of disease states in human who have a high intake of polyphenols. To investigate the ability of quercetin and its rutinoside, rutin, to modulate the relaxation of human airways smooth muscle and to determine the mechanism (s) of such relaxation, isolated human bronchus rings were suspended in individual organ baths, precontracted with acetylcholine or with histamine and the relaxing effects of quercetin and rutin were determined by measurement of isometric tension. Quercetin induced concentration-dependent relaxant responses on acetylcholine or histamine precontracted human bronchial rings and with almost equal effectiveness. In terms of potency (pD2) and efficacy (Emax), quercetin is more potent than rutin on relaxant responses of human bronchus. K+ and Ca2+ concentration-dependent contraction curves were inhibited after incubation with increasing concentrations of quercetin. Quercetin potentiated in a concentration-dependent manner the relaxant effects of isoprenaline or sodium nitroprusside. Rutin had no effect on K+-induced contraction and on relaxant activity of isoprenaline or sodium nitroprusside. Our results suggest that the bronchodilator effects of quercetin are modulated by an increase in cyclic nucleotide levels as well as an alteration in availability of Ca2+ to the contractile machinery. 展开更多
关键词 Calcium Channels Cyclic NUCLEOTIDE HUMAN BRONCHUS QUERCETIN relaxant EFFECTS RUTIN
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Evaluation of the anticonvulsant and muscle relaxant effects of the methanol root bark extracts of Annona senegalensis
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作者 Okoye TC Akah PA Omeke CP 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2010年第1期25-28,共4页
Objective:To investigate the potentials of the root bark of Annona(A.) senegalensis in the control of seizure and related hypnotic and motor incoordination effects in mice using experimental models.Methods:The metha... Objective:To investigate the potentials of the root bark of Annona(A.) senegalensis in the control of seizure and related hypnotic and motor incoordination effects in mice using experimental models.Methods:The methanol extract(ME) of the root bark of A.senegalensis was studied in mice using pentylenetetrazole(PTZ) induced convulsions,phenobarbitone induced sleeping time and motor coordination test on rota-rod performance.Acute toxicity and lethality(LD50) lest as well as phytochemical analysis were also carried out.Results:The extract(200,400,800 mg/ kg) exhibited a non- dose dependent significant(P【0.05) delay in the onset of both tonic and clonic phases of seizure induced by PTZ(60 mg/kg,s.c.) as well as offered a 100%protection (200 mg/kg) in mice from PTZ induced seizures.The extract significantly(P【0.05) decreased the latency and increased the duration of phenobarbitone induced sleeping time.At 200 mg/kg, the extract exhibited a significant(P【0.05) motor incoordination.The acute toxicity test revealed an oral LD<sub>50</sub> of 1 2%mg/kg,while the phytochemical studies showed the presence of alkaloids, resins,glycosides,carbohydrate,reducing sugar,flavonoids,terpenoids,saponins and tannins. Conclusion:The extract of A senegalensis possessed anticonvulsant activity with pronounced hypnotic and muscle relaxant effects. 展开更多
关键词 ANNONA senegalensis HYPNOSIS ANTICONVULSANT MUSCLE relaxant
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THE DESIGN AND APPLICATION OF RELAXANT MONITORING SYSTEM
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作者 Zhou Wei Yang Jieqiu +3 位作者 Lin Shujuan Li Yuejie Wang Yuehua Wang Qiang(Inst. of Biomedical Engineering,CAMS,Tianjin 300192,China)Sun Jialan(Tianjin First Centrol Hospital,Tianjin 300192,China) 《Chinese Journal of Biomedical Engineering(English Edition)》 1998年第1期19-21,共3页
The paper introduces a monitoring system of muscle relaxant actionduring the anaesthesia operation,which is based on measurement of acceleration.The monitor consists of an acceleration transducer,a nerve stimlation an... The paper introduces a monitoring system of muscle relaxant actionduring the anaesthesia operation,which is based on measurement of acceleration.The monitor consists of an acceleration transducer,a nerve stimlation and a microcomputer unit.The transducer can be fastened to the thumb,and the signal of thethumb movement in response to ulnar nerve stimulation is measured and registeredin the computing unit. In daily clinical practice it has proved possible,using this newapparatus, to achieve reliable evaluation of nuromuscular transimission functionand to contribute to improve anesthesia quality and patient care. 展开更多
关键词 MUSCLE relaxant NEUROMUSCULAR TRANSMISSION FUNCTION MONITOR
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Relaxant Effects of Matrine on Aortic Smooth Muscles of Guinea Pigs 被引量:6
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作者 JIE ZHENG PING ZHENG +4 位作者 XU ZHOU LIN YAN RU ZHOU XUE-YAN FU GUI-DONG DAI 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2009年第4期327-332,共6页
Objective To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects. Methods... Objective To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects. Methods Phenylephrine or potassium chloride concentration-dependent relaxation response of aortic smooth muscles to matrine was studied in the precontracted guinea pigs. Results Matrine (1×10^-4 mol/L -3.3×10^-3 mol/L) relaxed the endothelium-denuded aortic rings pre-contracted sub-maximally with phenylephrine, in a concentration-dependent manner, and its pre-incubation (3.3× 10^- 3 mol/L) produced a significant rightward shift in the phenylephrine dose-response curve, but had no effects on the potassium chloride-induced contraction. The anti-contractile effect of matrine was not reduced by the highly selective ATP-dependent K^+ channel blocker glibenclamide (10.5 mol/L), either by the non-selective K^+channel blocker tetraethylammonium (10^-3 mol/L), or by the β-antagonist propranolol (10^-5 mol/L). In either "normal" or "Ca^2+-free" bathing medium, the phenylephrine-induced contraction was attenuated by matrine (3.3×10^-3 mol/L), indicating that the vasorelaxation was due to inhibition of intracellular and extracellular Ca^2+ mobilization. Conclusion Matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with the release of intracellular Ca^2+ and the influx of extracellular Ca^2+. 展开更多
关键词 MATRINE AORTA Vascular smooth muscle RELAXATION GUINEA-PIGS CALCIUM
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Relaxant effect and possible mechanism of 17-nor-subincanadine E in rabbit corpora cavernosa
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作者 Otacilio D Benvindo Nilberto RF Nascimento +7 位作者 Claudia F Santos Manasses C Fonteles Edilberto R Silveira Daniel E Uchoa Adriana R Campos Karina MA Cunha Flavia A Santos Vietla S Rao 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第5期747-753,共7页
Compounds with dual action on cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) may be a treatment option for erectile dysfunction, as they not only promote penile erection but also p... Compounds with dual action on cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) may be a treatment option for erectile dysfunction, as they not only promote penile erection but also prevent the upregulation of phosphodiesterase-5. In this study, we examined the possible relaxant effect and mechanism of 17-nor-subincanadine E (SEC, 0.2-200 pmol I^-1), a plant-derived alkaloid, in rabbit corpus cavernosum (RbCC) strips that had been precontracted by exposure to phenylephrine (10 pmol I^- 1) or a high concentration of K+ (60 mmol I^- 1) in vitro. In addition to SEC's effect on cAMP and cGMP levels, electrical field stimulation (EFS) in phenylephrine-precontracted RbCC and calcium chloride (1-100 mmol I^-1) evoked responses in depolarized RbCC were analysed. SEC relaxed the phenylephrine-precontracted RbCCs in a concentration-dependent manner. Atropine, guanethidine and N-co-nitro-L-arginine methyl ester (L-NAME) did not have any effect on the relaxation of RBCCs. When 1H-1,2,4oxadiazole[4,3-a] quinoxalin-1-one (ODQ) was added, it effectively blocked the relaxant response of SEC. Although SEC enhanced the maximal relaxation produced by sodium nitroprusside (SNP) and forskolin in phenylephrine-precontracted cavernosal smooth muscle, it caused a decrease in the maximal contractile response induced by calcium chloride in depolarized RbCCs. The relaxant effect of SEC was paralleled by an increase in the tissue levels of the Cyclic nucleotides cAMP and cGMP. We conclude that SEC promotes the relaxation of RbCC, possibly favouring cAMP and cGMP accumulation and calcium blockade. This novel mechanism could be useful for patients who do not benefit from phosphodiesterase inhibitors and for those with endothelial and nitrergic dysfunction, such as patients with diabetes, hypertension and dyslipidaemias. 展开更多
关键词 17-nor-subincanadine E cyclic nucleotides electrical field stimulation nitric oxide rabbit corpus cavernosum smoothmuscle relaxation
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The relaxant effect of methanolic extract of yohimbe bark (<i>Pausinystalia yohimbe</i>) on rabbit corpus cavernosum smooth muscles
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作者 Mohamed Hassan Hozeifa Imad Eldin Mohamed Taj Eldin +2 位作者 Mohamed Mohamed Ahmed Elhadi Hassan Mohamed Abd Elwahab Sirag Elteyb Nizar 《Health》 2012年第9期656-659,共4页
Background: Development and maintenance of penile erection requires the relaxation of corpus cavernosum smooth muscle (CCSM) cells and it is essentially mediated by nitric oxide (NO). Pausinystalia yohimbe bark is tra... Background: Development and maintenance of penile erection requires the relaxation of corpus cavernosum smooth muscle (CCSM) cells and it is essentially mediated by nitric oxide (NO). Pausinystalia yohimbe bark is traditionally used for the treatment of erectile dysfunction (ED). Objectives and Methods: This study aimed to evaluate the effects of the methanolic extract of P. yohimbe bark (10 mg/ml) on isolated rabbit corpus cavernosum smooth muscle (CCSM). Results: Methanolic extract of P. yohimbe bark blocked contractions in CCSM induced by adrenergic agonists, through facilitating NO release from the endothelial cells. Conclusion: The obtained results revealed that, methanolic extract of P. yohimbe bark caused relaxation of CCSM that validates its traditional aphrodisiac property, thus it could be used to initiate and maintain erection in cases of erectile dysfunction. 展开更多
关键词 P. yohimbe BARK CORPUS Cavernosum Relaxation NITRIC Oxide APHRODISIAC Erectile Dysfunction
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A Kind of Fast Iterative Methods With the Application Based on Diagonal Matrix Splitting 被引量:1
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作者 XU Qiuyan 《宁夏大学学报(自然科学版中英文)》 2026年第1期1-13,共13页
The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix sp... The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix splitting methods.Taking the decomposition of the diagonal elements for coefficient matrix as the key point,some new preconditioners are constructed.Taking the tri-diagonal coefficient matrix as an example,the convergence domains and optimal relaxation factor of the new method are analyzed theoretically.The presented new iteration methods are applied to solve linear algebraic equations,even 2D and 3D diffusion problems with the fully implicit discretization.The results of numerical experiments are matched with the theoretical analysis,and show that the iteration numbers are reduced greatly.The superiorities of presented iteration methods exceed some classical iteration methods dramatically. 展开更多
关键词 ITERATION matrix splitting diffusion equation CONVERGENCE optimal relaxation factor
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Contribution of Water and Lipid Soluble Substances in the Relaxant Effects of Tymus Vulgaris Extract on Guinea Pig Tracheal Smooth Muscle in Vitro
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作者 Rana Keyhanmanesh Mohammad Hossien Boskabady +1 位作者 Mohammad Ali Ebrahimi Saadatloo Morteza Boskabady 《Chinese Journal of Integrative Medicine》 SCIE CAS CSCD 2016年第5期377-383,共7页
Objective: To examine the relaxant effects of hydro-ethanolic, macerated aqueous (MA) and lipid- free macerated aqueous (LFMA) extract of Tymus vulgaris on tracheal chains of guinea pigs. Methods: The relaxant e... Objective: To examine the relaxant effects of hydro-ethanolic, macerated aqueous (MA) and lipid- free macerated aqueous (LFMA) extract of Tymus vulgaris on tracheal chains of guinea pigs. Methods: The relaxant effects of five cumulative concentrations of each extract (0.4, 0.8, 1.2, 1.6 and 2.0 g/100 mL) were compared with saline as negative control and five cumulative concentrations of theophylline (0.1, 0.2, 0.4, 0.6 and 0.8 mmol/L) on precontracted tracheal smooth muscle of guinea pig with 60 mmol/L KCl (group 1) and 10 μmol/L methacholine (group 2, n=6 for each group). Results: In group 1 all concentrations of theophylline, three higher concentrations of hydro-ethanolic, two concentrations of LFMA and last concentration of MA extracts showed significant relaxant effects compared with that of saline (P〈0.05 or P〈0.01). Two lower concentrations of LFMA and all concentrations of MA except higher one caused contraction compared with saline (P〈0.05 or 0.01). In group 2 experiments, all concentrations of theophylline, hydro-ethanolic, MA and LFMA extracts showed significant relaxant effects compared to that of saline (P〈0.05 or P〈0.01). In both groups, the relaxant effect of all concentrations of hydro-ethanolic extract were significantly higher than most concentrations of others (P〈0.05 or P〈0.01). The relaxant effect of different concentrations of three extracts were significantly greater in group 2 compared with group 1 experiments (all P〈0.01). There were significantly positive correlations between the relaxant effects and concentrations for theophylline and all extracts in both groups (P〈0.05 or P〈0.01). Conclusion: Hydro-ethanolic extract has a potent weaker relaxant effect for other extracts from Tymus vulgaris on tracheal chains of guinea pigs. 展开更多
关键词 Tymus vulgaris hydro-ethanolic extract macerated aqueous extract lipid-free macerated aqueous extract relaxant effect guinea pig TRACHEAL
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Relaxant Effect of Bioactive Component Compatibility of San-ao Decoction on In vitro Guinea Pig Airway Smooth Muscle:A Dose-Response Relationship Study
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作者 Wen-Jie Song Yan-Ling Fu +3 位作者 Sheng-Lou Ni Jia-Jia Fan Qian Du Hao Zheng 《World Journal of Traditional Chinese Medicine》 CAS 2022年第2期262-272,共11页
Background:Component compatibility is important to the modernization of traditional Chinese medicine.Studies have shown that San-ao decoction(SAD)can treat respiratory diseases by relaxing airway smooth muscle(ASM)and... Background:Component compatibility is important to the modernization of traditional Chinese medicine.Studies have shown that San-ao decoction(SAD)can treat respiratory diseases by relaxing airway smooth muscle(ASM)and reducing airway hyper-responsiveness.However,whether its bioactive components and compatibility also present with similar relaxant effects remains unknown.This study aims to explore the potential relaxant property,dose-response relationship,and underlying mechanisms of the bioactive component compatibility in SAD.Methods:Network pharmacology was primarily used to identify the bioactive components of SAD and uncover its underlying mechanisms.ASM tension force measuring technique was utilized to verify the relaxant and dose-response effects on in vitro guinea pig ASM.Results:We postulated pseudoephedrine hydrochloride(PH),amygdalin(AM),and diammonium glycyrrhizate(DG)to be the bioactive components of SAD,which could effectively relax ASM in a dose-dependent manner on both acetylcholine-induced and spontaneous contraction.Both PH and AM could lead to DG dose–response curve shift.The regression equation of these three bioactive components was Y=-2.048×X_(1)+0.411×X_(2)+14.052×X_(3)(X_(1),X_(2),X_(3)representing PH,AM,and DG,respectively).The underlying mechanisms of these components might be associated with the regulation of smooth muscle contraction.Conclusions:PH,AM,and DG are the bioactive components of SAD,which can relax ASM in a dose–response manner and exert a synergistic effect.Clinically,compatibility of these three bioactive components may serve as a new complementary and alternative treatment for respiratory diseases. 展开更多
关键词 Airway smooth muscle bioactive component compatibility dose–response manner relaxant effect San-ao decoction
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Relax,Refresh,and Reset in Guizhou
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作者 LU YONGZHENG 《China Today》 2026年第1期52-55,共4页
It’s never too early in the year to start planning a break from the stress of city life,and southwest China’s charming Guizhou Province is a destination that should be right at the top of your list.
关键词 stress southwest China PROVINCE city life BREAK relax GUIZHOU REFRESH
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Fluid-structure coupling characteristics of membrane under supersonic conditions
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作者 Zexuan YANG Jiandong HUANG +3 位作者 Chao YANG Yifan WANG Zhigang WU Bing Feng NG 《Chinese Journal of Aeronautics》 2026年第2期283-300,共18页
In order to enable wing morphing(e.g.change in camber or folds)without incurring additional weight to the aircraft,lightweight flexible materials such as membrane are needed.However,the research on fluid-structure cou... In order to enable wing morphing(e.g.change in camber or folds)without incurring additional weight to the aircraft,lightweight flexible materials such as membrane are needed.However,the research on fluid-structure coupling of membranes has mainly focused on parachutes in low-speed conditions,while that in supersonic flow conditions is lacking.Here,the degraded shell method is proposed to study membrane deformation by using shell element,which is more effective than using membrane elements directly.A fluid-structure interaction computational framework is proposed,whereby the aerodynamic module is composed of either the piston theory or computational fluid dynamics.A rectangular membrane of length 0.4 m and width 0.6 m is investigated in supersonic conditions.The characteristics of the limit cycle and steady deformation are analyzed,considering the effects of angle of attack and dynamic pressure.It is found that the structural response exhibits significant differences under various angles of attack.Furthermore,initial relaxation of membrane has significant influence on the structural deformation.Finally,the aeroelastic scaling method for membrane structures is derived,providing guidance for the design of wind tunnel models.This study provides a theoretical foundation for the analysis and application of membrane structures under supersonic conditions in future research. 展开更多
关键词 Aeroelasticity Fluid-structure interaction Initial relaxation Limit cycle oscillation Membranes Similarity criterion
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Unlocking Wavelength-Selective Modulations of Open-Circuit Voltage in Metal Halide Perovskite Solar Cells
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作者 Younsuk Hu Jibeom Hong +3 位作者 Kyounguk Cho Wanseung Yoo Doo Hyun Ko Inchan Hwang 《Energy & Environmental Materials》 2026年第1期329-340,共12页
The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet... The photovoltaic performance of metal halide perovskite solar cells often respond divergently to environmental conditions during storage.In particular,light exposure can either enhance or degrade device efficiency,yet the mechanisms underlying these antithetical behaviors are still under investigation.In this study,we explore the modulation of the open-circuit voltage(Voc)in triple-cation mixed-halide perovskite solar cells by systematically controlling storage environments.While light intensity exhibits minimal impact during storage,the spectral composition of illumination selectively enhances Voc comprising reversible and irreversible contributions.Structural characterization reveals that prolonged storage degrades the quality of perovskite crystals in the upper region of the perovskite layer,whereas light storage promotes the relaxation of microstrain at the buried interface with a p-type organic layer.This structural reorganization at the interface,accompanied by lattice expansion,accounts for suppressed nonradiative recombination and a corresponding increase in quasi-Fermi level splitting.Consequently,devices fabricated without chemical defect passivation achieve a power conversion efficiency of higher than 40%under indoor lighting conditions after preconditioned by continuous exposure to ambient light during storage.These findings highlight the critical role of controlled light exposure during storage not only in enhancing efficiency,but also in ensuring reproducibility of perovskite solar cell characterization. 展开更多
关键词 indoor photovoltaics light-induced modulations perovskite solar cells REPRODUCIBILITY strain relaxation
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Strain localization and time-dependent deformation in granodiorite characterized by distributed optical fiber sensing
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作者 Shuting Miao Arno Zang +3 位作者 Guido Blöcher Yinlin Ji Hannes Hofmann Pengzhi Pan 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期166-178,共13页
A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relax... A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions. 展开更多
关键词 Distributed optical fiber sensing Stress relaxation Strain localization Time-dependent deformation
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Radar Beampattern Gain Maximization for MIMO Integrated Sensing and Communication Systems
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作者 Ren Hong Zhang Ruoyu +2 位作者 Chen Guangyi Lin Xu Wu Wen 《China Communications》 2026年第2期268-284,共17页
Integrated sensing and communication(ISAC)is an appealing approach to address spectrum congestion and beamforming is an effective method to realize ISAC.In this paper,we investigate the beamforming design problem for ... Integrated sensing and communication(ISAC)is an appealing approach to address spectrum congestion and beamforming is an effective method to realize ISAC.In this paper,we investigate the beamforming design problem for multiple-input multipleoutput(MIMO)ISAC systems and propose to maximize the radar beampattern gain of the target direction while ensuring the signal-to-interference-plus-noise ratio(SINR)constraints of communication users.Particularly,we discuss two cases of ISAC transmit beamforming,i.e.,Case-Ⅰand Case-Ⅱ,which do not have and do have the dedicated probing signal,respectively.For these two cases of transmit beamforming design problems,we start from the single-user scenario and provide the closed-form solutions for MIMO ISAC beamforming vectors.Then,we consider the multiuser scenario and utilize the semidefinite relaxation technique to convert the beamforming design problems into convex semidefinite programming problems.Furthermore,we investigate the impact of the channel correlation between radar and communication on the performance gain of MIMO ISAC systems and characterize the performance tradeoff.Numerical results validate that the dedicated probing signal is unnecessary in the single-user scenario,whereas it has a slight improvement in target detection performance at low SINR thresholds in the multi-user scenario.It is also shown that the stronger the correlation between radar and communication channels,the greater the performance gain of the system. 展开更多
关键词 integrated sensing and communication multiple-input multiple-output performance tradeoff radar beampattern gain semidefinite relaxation
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A Hybrid Experimental-Numerical Framework for Identifying Viscoelastic Parameters of 3D-Printed Polyurethane Samples:Cyclic Tests,Creep/Relaxation and Inverse Finite Element Analysis
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作者 Nikita Golovkin Olesya Nikulenkova +4 位作者 Vsevolod Pobezhimov Alexander Nesmelov Sergei Chvalun Fedor Sorokin Arthur Krupnin 《Computers, Materials & Continua》 2026年第3期519-536,共18页
This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens ... This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens manufactured using extrusion-based 3D printing.Through comprehensive testing,including cyclic compression at strain rates ranging from 0.12 to 120 mm/min(0%-15%strain)and creep/relaxation experiments(10%-30%strain),the lumped parameters were independently determined using both analytical and numerical solutions of the models’differential equations,followed by cross-verification in additional experiments.Numerical solutions for creep and relaxation problems were obtained using finite element analysis,with the three-parameter Mooney-Rivlin model and Prony series employed to simulate elastic and viscous stress components,respectively.Energy dissipation per cycle was quantified during cyclic compression tests.The results demonstrate that all three models adequately describe material behavior within the 0%-15%strain range across various strain rates.Comparative analysis revealed the Burgers model’s superior performance in characterizing creep and stress relaxation at low strain levels.While Zener and Burgers model parameters from uniaxial compression showed limited applicability for energy dissipation calculations,the generalized Maxwell model effectively captured viscoelastic properties across different strain rates.Notably,parameters derived from creep tests provided a more universal assessment of dissipative properties due to optimization based on characteristic curve regions.Both parameter sets described polyurethane’s elastic-hysteretic behavior with approximately 20%error,proving significantly more accurate than the linear strain-time dependence hypothesis.Finite element analysis(FEA)complemented numerical modeling by demonstrating that while the generalized Maxwell model effectively describes initial rapid stress-strain changes,FEA provides superior characterization of steady-state processes.This computational approach yields more physically representative results compared to simplified analytical solutions,despite certain limitations in transient analysis. 展开更多
关键词 VISCOELASTICITY cyclic compression HYSTERESIS CREEP stress relaxation finite element method optimization 3D printing structural rheological models Prony series
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Global Optimization Algorithm for Minimizing Linear Fractional Programming
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作者 ZHAO Peng SHEN Pei-ping ZHONG Zhe-wei 《Chinese Quarterly Journal of Mathematics》 2026年第1期50-59,共10页
In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,w... In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,we convert the problem(LFP)to the equivalent problem(EP2).Secondly,by applying the linear relaxation technique to the problem(EP2),the linear relaxation programming problem(LRP2Y)was obtained.Then,the overall framework of the algorithm is given,and the convergence and complexity of the algorithm are analyzed.Finally,experimental results are listed to illustrate the effectiveness of the algorithm. 展开更多
关键词 Global optimization Linear Fractional Programming Branch and bound algorithm Linear relaxation
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Temperature dependence of two or more water species in delignified wood and lignocellulosic,tracked by LFNMR relaxometry
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作者 Long Zhou Wenjing Liu +5 位作者 Zhihong Zhao Rui Tan Xiaofeng Zhu Shen Wang Zonghai Harry Xie Minghui Zhang 《Magnetic Resonance Letters》 2026年第1期13-24,共12页
Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delig... Distributions of nuclear magnetic resonance(NMR)relaxation times provide detailed information about the water in wood.This study documents the water dynamics analysis of T_(2)and T_(1)distributions for saturated delignified sapwood(DSW),delignified heartwood(DHW)and lignocellulose(LC)samples at different temperatures.Results indicate that below the freezing point of bulk water,free water freezes,causing its signal to disappear from the distribution.Then,the low temperature distributions of the unfrozen bound water contain more information about its components,with DSW,DHW and LC containing two distinct states of bound water(OH bound water(B-water)and more freely bound water(C-water)).Furthermore,it was observed that within the temperature range of−3°C to−60°C,B-water in DSW,DHW and LC maintained a higher unfrozen water content(UWC)value than C-water,and the T_(1)/T_(2)ratios for B-water were consistently higher than that for C-water,indicating that B-water has a greater antifreeze capacity.T_(2)and T_(1)distributions offer different kinds of information about water components,and all peaks within the distribution have been assigned. 展开更多
关键词 Low-field nuclear magnetic resonance (LFNMR) Delignified wood and lignocellulosic Water species Relaxation characteristics Bound water Temperature dependence
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Pressure-Modulated Activation Energy as a Unified Descriptor of Mechanical Behavior in Metallic Glass
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作者 Huanrong Liu Jian Li +1 位作者 Shan Zhang Pengfei Guan 《Chinese Physics Letters》 2026年第1期71-82,共12页
The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ... The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework. 展开更多
关键词 pressure modulated activation energy predicting mechanical properties metallic glass relaxation processes functional properties mechanical behavior simulations varied protocols structural configurational descriptors
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Tailoringα-MnO_(2) gas diffusion electrodes for enhanced oxygen reduction in aluminum-air batteries
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作者 Alexander Rampf Robert Leiter +2 位作者 Simon Fleischmann Giuseppe Antonio Elia Roswitha Zeis 《Journal of Energy Chemistry》 2026年第3期473-484,共12页
α-MnO_(2) is a promising,inexpensive,and readily producible catalyst for the oxygen reduction reaction(ORR)in alkaline media,but its application is limited by low electronic conductivity.In this study,we enhance the ... α-MnO_(2) is a promising,inexpensive,and readily producible catalyst for the oxygen reduction reaction(ORR)in alkaline media,but its application is limited by low electronic conductivity.In this study,we enhance the performance ofα-MnO_(2) electrodes by systematically varying theα-MnO_(2)-to-Vulcan ratio within the catalyst layer.Electrodes are evaluated in a gas diffusion electrode(GDE)half-cell,where an optimized catalyst layer composition leads to significantly improved ORR performance.By finetuning both theα-MnO_(2)-to-Vulcan ratio and theα-MnO_(2) loading,the electrode outperforms a commercial MnO_(2)-based electrode and approaches the performance of the Pt/C benchmark.The improvement is attributed to the presence of a three-dimensional(3D)Vulcan network electronically connecting catalytically activeα-MnO_(2) sites with the substrate.Additionally,the optimized electrodes are employed in a prototype Al-O_(2) flow cell.Under constant oxygen flow,power densities exceed 250 mW cm^(-2),which is significantly higher than that of conventional Al-air batteries.Electrochemical impedance spectroscopy combined with distribution of relaxation times(DRT)analysis enables the separation of anode and cathode charge transfer impedances without the need for an additional reference electrode.The analysis reveals that the anode contributes more than twice as much impedance as the cathode,highlighting the need for further anode optimization.This work demonstrates a transferable approach for catalyst layer screening under technically relevant conditions in the GDE half-cell.Subsequent measurements in an Al-O_(2) flow cell validate the approach.The methodology is widely applicable to the development of advanced electrodes for a variety of metal-air battery technologies. 展开更多
关键词 Manganese dioxide Oxygen reduction reaction(ORR) Aluminum-air battery Gas diffusion electrode half-cell Electrochemical impedance spectroscopy(EIS) Distribution of relaxation times(DRT)
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