This study applies the diatonic chord in music theory,utilization rate,and the close relationship between the main chord system,the dominant chord system,and the subordinate chord system.From the perspective of music ...This study applies the diatonic chord in music theory,utilization rate,and the close relationship between the main chord system,the dominant chord system,and the subordinate chord system.From the perspective of music theory,the computer can automatically and quickly analyze the music,and establish a set of algorithms for configuring the chord accompaniment for the main melody,called the symmetrical circle offifths algorithm,SCFA(Symmetrical Circle of Fifths Algorithm).SCFA can immediately confirm the key,perform harmony analysis,configure chord accompaniment for the main melody,and effectively and correctly complete any given melody or interval.It can also quickly analyze and correctly configure the chord accompaniment for any MIDI(Musical Instrument Digital Interface)music,enriching the musicality of the music.It can also allow scorers or computer music creators to quickly deconstruct the harmony configuration of the melody.Through the measurement of bio-feedback sensor HRV(Heart Rate Variability),it can achieve a relaxing music healing effect.展开更多
Based on the EDRF(endothelium derived relaxing factor)-like effects for polyarginine Arg-Arg-oH was selected as the lead compound and its derivatives Arg-Arg- OCH_3.Arg Arg-Arg-OH,HO-ArgCOCH_2CH_2COArg-OH,HO-ArgCOCH_2...Based on the EDRF(endothelium derived relaxing factor)-like effects for polyarginine Arg-Arg-oH was selected as the lead compound and its derivatives Arg-Arg- OCH_3.Arg Arg-Arg-OH,HO-ArgCOCH_2CH_2COArg-OH,HO-ArgCOCH_2COArg-OH,were synthesized.These substances showed on bioassay various degrees of vasorelaxant activities. With protection for the C-terminal of Arg-Arg-OH with a methyl ester.the vasorelaxing ac- tivitv was decreased.In contrast.when the N-terminal of Arg-OH was protected with mal- onic acid or butane diacid.the biological activites were lower than those of Arg-Arg-OH due to the lowered metabolic rate.With protection of N-terminal of Arg-Arg-OH with L-Arg residue.Arg-Arg-Arg-OH was obtained,which showed a vasorelaxing activity better than that of Arg-Arg-OH.The bioactivities observed on the Wister's rats for the former com- pound become the experimental basis for prodrug design of EDRF.展开更多
Objective: To analyze the effectiveness and safety of corneal relaxing incisions (CRI) in correcting keratometric astigmatism during cataract surgery. Methods: A prospective study of two groups: control group and trea...Objective: To analyze the effectiveness and safety of corneal relaxing incisions (CRI) in correcting keratometric astigmatism during cataract surgery. Methods: A prospective study of two groups: control group and treatment group. A treatment group included 25 eyes of 25 patients who had combined clear corneal phacoemulsification, IOL implantation and CRI. A control group included 25 eyes of 25 patients who had clear corneal phacoemulsification and IOL implantation.Postoperative keratometric astigmatism was measured at 1 week, 1 month, 3 months and 6 months. Results: CRI signifi-cantly decreased keratometric astigmatism in patients with preexisting astigmatism compared with astigmatic changes in the control group. In eyes with CRI, the mean keratometric astigmatism was 0.29±0.17 D(range 0 to 0.5 D) at 1 week, 0.41±0.21 D (range 0 to 0.82 D) at 1 month, respectively reduced by 2.42 D and 2.30 D at 1 week and 1 month postoperatively (P=0.000, P=0.000), and postoperative astigmatism was stable until 6 months follow-up. The keratometric astigmatism of all patients decreased to less than 1.00 D postoperatively. Conclusions: CRI is a practical, simple, safe and effective method to reduce preexisting astigmatism during cataract surgery. A modified nomogram is proposed. The long-term effect of CRI should be investigated.展开更多
ONE child or two? This is the question soon to be pondered by more than 15 million couples across China's mainland. They will become eligible later this year to have two children if one of the parents is an only chi...ONE child or two? This is the question soon to be pondered by more than 15 million couples across China's mainland. They will become eligible later this year to have two children if one of the parents is an only child. The new population policy, issued in November 2013, has already seen the choice given to couples in 22 provincial-level regions by the end of April this year.展开更多
A process has been developed recently to fabricate a structure com- prising,from top to bottom,a SiGe thin film,a glass layer,and a Si wafer.The SiGe film is a perfect crystal,and is under biaxial compression.The SiGe...A process has been developed recently to fabricate a structure com- prising,from top to bottom,a SiGe thin film,a glass layer,and a Si wafer.The SiGe film is a perfect crystal,and is under biaxial compression.The SiGe film is patterned into islands.On annealing,the glass flows and the islands relax.The resulting strain-free islands are used as substrates,to grow epitaxial optoelectronic devices.This article describes a series of studies on the annealing process,combining experiment and theory.A small island relaxes by expansion,starting at the edges and diffusing to the center.A large island wrinkles before the expansion reaches the center.After some time,the wrinkles either disappear,or cause the island to fracture. We model the island as an elastic plate,and the glass layer as a viscous liquid.The strains in the islands are measured by X-ray diffraction and Raman spectroscopy,and the wrinkle amplitudes by atomic force microscope.The data are compared with the theoretical predictions.We determine the conditions under which the islands relax by expansion without significant wrinkling,and demonstrate that a cap layer suppresses wrinkles,relaxing a large island crack-free.展开更多
Hamilton-Jacobi equation appears frequently in applications, e.g., in differential games and control theory, and is closely related to hyperbolic conservation laws[3, 4, 12]. This is helpful in the design of differenc...Hamilton-Jacobi equation appears frequently in applications, e.g., in differential games and control theory, and is closely related to hyperbolic conservation laws[3, 4, 12]. This is helpful in the design of difference approximations for Hamilton-Jacobi equation and hyperbolic conservation laws. In this paper we present the relaxing system for HamiltonJacobi equations in arbitrary space dimensions, and high resolution relaxing schemes for Hamilton-Jacobi equation, based on using the local relaxation approximation. The schemes are numerically tested on a variety of 1D and 2D problems, including a problem related to optimal control problem. High-order accuracy in smooth regions, good resolution of discontinuities, and convergence to viscosity solutions are observed.展开更多
This paper continues to study the central relaxing schemes for system of hyperbolic conservation laws, based on the local relaxation approximation. Two classes of relaxing systems with stiff source term are introduced...This paper continues to study the central relaxing schemes for system of hyperbolic conservation laws, based on the local relaxation approximation. Two classes of relaxing systems with stiff source term are introduced to approximate system of conservation laws in curvilinear coordinates. Based on them, the semi-implicit relaxing schemes are con- structed as in [6, 12] without using any linear or nonlinear Riemann solvers. Numerical experiments for one-dimensional and two-dimensional problems are presented to demon- strate the performance and resolution of the current schemes.展开更多
The distribution of data has a significant impact on the results of classification.When the distribution of one class is insignificant compared to the distribution of another class,data imbalance occurs.This will resu...The distribution of data has a significant impact on the results of classification.When the distribution of one class is insignificant compared to the distribution of another class,data imbalance occurs.This will result in rising outlier values and noise.Therefore,the speed and performance of classification could be greatly affected.Given the above problems,this paper starts with the motivation and mathematical representing of classification,puts forward a new classification method based on the relationship between different classification formulations.Combined with the vector characteristics of the actual problem and the choice of matrix characteristics,we firstly analyze the orderly regression to introduce slack variables to solve the constraint problem of the lone point.Then we introduce the fuzzy factors to solve the problem of the gap between the isolated points on the basis of the support vector machine.We introduce the cost control to solve the problem of sample skew.Finally,based on the bi-boundary support vector machine,a twostep weight setting twin classifier is constructed.This can help to identify multitasks with feature-selected patterns without the need for additional optimizers,which solves the problem of large-scale classification that can’t deal effectively with the very low category distribution gap.展开更多
Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal...Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal astigmatism.Cataract surgery used to cause a progressive increase in the pre-exisiting corneal astigmatism because of creating a surgically induced astigmatism,for example,a large size surgery incision.The development of surgical techniques during last decades has made cataract surgery interchange to treat preoperative corneal astigmatism at time of surgery.Nowadays,three surgical approaches can be used.By placing a sutureless clear corneal incision on the steep meridian of the cornea,a preoperative corneal astigmatism less than 1.0 D can be corrected.Single or paired peripheral corneal relaxing incisions(PCRIs)provide 1.0-3.0 D corneal astigmatism correction.PCRIs are typically used for treating 1.0-1.5 D of regular corneal astigmatism,if more than 2.0 D,the risk of overcorrection and irregular astigmatism is increased.When toric intraocular lenses(IOLs)are unavailable in markets,PCRIs are still a reasonable option for patients with up to 3.0 D of pre-existing corneal astigmatism.Toric IOLs implantation can correct 1.0-4.5 D of corneal astigmatism.Several IOLs are approved to correct a high degree of corneal astigmatism with cylinder power up to 12.0 D.These approaches can be used alone or in combination.展开更多
With the continuous advancement of science and technology,our lifestyles are undergoing significant changes,with wearable technology emerging as a captivating trend.In this digital era,there is a growing demand for so...With the continuous advancement of science and technology,our lifestyles are undergoing significant changes,with wearable technology emerging as a captivating trend.In this digital era,there is a growing demand for solutions that cater to people’s needs for health and comfort.The wearable inflatable massage chair represents one such innovation designed to meet these evolving needs.This project is focused on creating a“wearable and portable massage chair”that is both convenient and lightweight.It serves as a massage solution particularly beneficial for the elderly and sedentary individuals.This innovative chair can be used by the elderly during outings or errands,as well as by office workers on business trips,while driving,or commuting via subway.Users can simply lean against the seat or a wall,enjoying moments of relaxation amid the busy and fast-paced modern era.展开更多
Presents a study which examined a cell entropy inequality for a class of local relaxation approximation relaxing scheme for scalar conservation laws. Way to obtain the scheme; Use of numerical entropy condition for th...Presents a study which examined a cell entropy inequality for a class of local relaxation approximation relaxing scheme for scalar conservation laws. Way to obtain the scheme; Use of numerical entropy condition for the approximation.展开更多
Direct observation was made by using the patch-clamp technique with a specially designed microperfusion system to investigate the effect of acetylcholine (Ach 10^(-6) mol/L) elicited endothelium-derived relaxing facto...Direct observation was made by using the patch-clamp technique with a specially designed microperfusion system to investigate the effect of acetylcholine (Ach 10^(-6) mol/L) elicited endothelium-derived relaxing factor (EDRF) on the calcium-activated potassium channel (IK(Ca))in the smooth muscle cells of mesenteric resistance vessels in Wistar rats. Activation of IK(Ca) was firstly observed by inducing the elicited EDRF or sodium nitroprusside (SNP 10^(-8) mol/L) under various clamping voltages in cell-attached configuration. While the pipette solution contained KCl 126 mmol/L and the bath solution contained KCl 5.9 mmol/L, two types of conductances of calcium-activated potassium current being 76.4±2.3 pS(mean±S.E. n = 7) and 160.3±7.5 pS (mean±S.E. n= 7) were recorded during the EDRF activation, one type of conductance being 100.5±2.8 pS (mean±S.E. n = 6) was activated by nitric oxide (NO) which is an effective component from SNP. Differences in kinetic characteristics of these channels between EDRF and NO activation were found, particularly the probability of the channel being open in EDRF activation was obviously greater than that in NO stimulation. It has been shown that the potassium channel mechanisms involved in the EDRF and NO actions might be different.展开更多
Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,...Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.展开更多
The buried interface in the perovskite solar cell(PSC)has been regarded as a breakthrough to boost the power conversion efficiency and stability.However,a comprehensive manipulation of the buried interface in terms of...The buried interface in the perovskite solar cell(PSC)has been regarded as a breakthrough to boost the power conversion efficiency and stability.However,a comprehensive manipulation of the buried interface in terms of the transport layer,buried interlayer,and perovskite layer has been largely overlooked.Herein,we propose the use of a volatile heterocyclic compound called 2-thiopheneacetic acid(TPA)as a pre-buried additive in the buried interface to achieve cross-layer all-interface defect passivation through an in situ bottom-up infiltration diffusion strategy.TPA not only suppresses the serious interfacial nonradiative recombination losses by precisely healing the interfacial and underlying defects but also effectively enhances the quality of perovskite film and releases the residual strain of perovskite film.Owing to this versatility,TPA-tailored CsPbBr3 PSCs deliver a record efficiency of 11.23% with enhanced long-term stability.This breakthrough in manipulating the buried interface using TPA opens new avenues for further improving the performance and reliability of PSC.展开更多
We study the interfacial Dzyaloshinskii-Moriya interactions(i-DMI)of Fe/Pt bilayers grown on Si substrates with MgO,SiO_(2),or Ta each as a buffer layer on the basis of wave-vector-resolved Brillouin light scattering(...We study the interfacial Dzyaloshinskii-Moriya interactions(i-DMI)of Fe/Pt bilayers grown on Si substrates with MgO,SiO_(2),or Ta each as a buffer layer on the basis of wave-vector-resolved Brillouin light scattering(BLS)measurement.The obtained i-DMI energy values for Fe/Pt on MgO,Ta,and SiO_(2) buffer layers are 0.359,0.321,and 0.274 mJ/m~2,respectively.The large i-DMI value observed in Fe/Pt system on the MgO buffer layer can be attributed to the good interfacial quality and the Rshaba effect at the MgO/Fe interface.Moreover,the MgO/Fe/Pt system,benefiting from better sample quality,exhibits a lower damping factor.Furthermore,layer-resolved first-principles calculations are carried out to gain a more in-depth understanding of the origin of the i-DMI in the Fe/Pt system.The results indicate that in the Fe(110)/Pt(111)system,the substantial DMI energy between Fe spins at the interface is related to a significant change in spin-orbit coupling(SOC)energy in the neighboring Pt layer.In contrast,for the MgO(002)/Fe(002)system,both the DMI and its related SOC energy are concentrated at the interfacial Fe layer.Our investigation will provide a valuable insight into the spintronic community in exploring novel devices with chirality dependence.展开更多
Surface acoustic wave(SAW)is a powerful technique for investigating quantum phases appearing in twodimensional electron systems.The electrons respond to the piezoelectric field of SAW through screening,attenuating its...Surface acoustic wave(SAW)is a powerful technique for investigating quantum phases appearing in twodimensional electron systems.The electrons respond to the piezoelectric field of SAW through screening,attenuating its amplitude,and shifting its velocity,which is described by the relaxation model.In this work,we systematically study this interaction using orders of magnitude lower SAW amplitude than those in previous studies.At high magnetic fields,when electrons form highly correlated states such as the quantum Hall effect,we observe an anomalously large attenuation of SAW,while the acoustic speed remains considerably high,inconsistent with the conventional relaxation model.This anomaly exists only when the SAW power is sufficiently low.展开更多
By using muon spin relaxation(μSR)measurements,we perform a comparative study of the microscopic magnetism in the parent compounds of infinite-layer nickelate superconductors RNiO_(2)(R=La,Nd).In either compound,the ...By using muon spin relaxation(μSR)measurements,we perform a comparative study of the microscopic magnetism in the parent compounds of infinite-layer nickelate superconductors RNiO_(2)(R=La,Nd).In either compound,the zero-fieldμSR spectra down to the lowest measured temperature reveal no long-range magnetic order.In LaNiO_(2),short-range spin correlations appear below T=150 K,and spins fully freeze below T∼10 K.NdNiO_(2)exhibits a more complex spin dynamics driven by the Nd 4f and Ni3d electron spin fluctuations.Further,it shows features suggesting the proximity to a spin-glass state occurring below T=5 K.In both compounds,the spin behavior with temperature is further confirmed by longitudinal-field μSR measurements.These results provide new insight into the magnetism of the parent compounds of the superconducting nickelates,crucial to understanding the microscopic origin of their superconductivity.展开更多
The occurrence of geological hazards and the instability of geotechnical engineering structures are closely related to the time-dependent behavior of rock.However,the idealization boundary condition for constant stres...The occurrence of geological hazards and the instability of geotechnical engineering structures are closely related to the time-dependent behavior of rock.However,the idealization boundary condition for constant stress in creep or constant strain in relaxation is not usually attained in natural geological systems.Therefore,generalized relaxation tests that explore the simultaneous changes of stress and strain with time under different stress levels with constant pore-water pressure are conducted in this study.The results show that in area Ⅰ,area Ⅱ,and area Ⅲ,the stress and strain both change synchronously with time and show similar evolutionary laws as the strain-time curve for creep or the stress-time curve for relaxation.When the applied stress level surpasses the δ_(ci) or δ_(cd) threshold,the variations in stress and strain and their respective rates of change exhibit a significant increase.The radial deformation and its rate of change exhibit greater sensitivity in response to stress levels.The apparent strain deforms homogeneously at the primary stage,and subsequently,gradually localizes due to the microcrack development at the secondary stage.Ultimately,interconnection of the microcracks causes the formation of a shear-localization zone at the tertiary stage.The strain-time responses inside and outside the localization zone are characterized by local strain accumulation and inelastic unloading during the secondary and tertiary stages,respectively.The width of the shear-localization zone is found to range from 4.43 mm to 7.08 mm and increased with a longer time-to-failure.Scanning electron microscopy(SEM)reveals a dominant coalescence of intergranular cracks on the fracture surface,and the degree of physiochemical deterioration caused by water-rock interaction is more severe under a longer lifetime.The brittle sandstone’s time-dependent deformation is essentially controlled by microcrack development during generalized relaxation,and its expectancy-life is determined by its initial microstructural state and the rheological path.展开更多
The growth of high-quality germanium tin(Ge_(1–y)Sn_(y))binary alloys on a Si substrate using chemical vapor deposition(CVD)techniques holds immense potential for advancing electronics and optoelectronics application...The growth of high-quality germanium tin(Ge_(1–y)Sn_(y))binary alloys on a Si substrate using chemical vapor deposition(CVD)techniques holds immense potential for advancing electronics and optoelectronics applications,including the development of efficient and low-cost mid-infrared detectors and light sources.However,achieving precise control over the Sn concentration and strain relaxation of the Ge_(1–y)Sn_(y)epilayer,which directly influence its optical and electrical properties,remain a significant challenge.In this research,the effect of strain relaxation on the growth rate of Ge_(1–y)Sn_(y)epilayers,with Sn concentration>11at.%,is investigated.It is successfully demonstrated that the growth rate slows down by~55%due to strain relaxation after passing its critical thickness,which suggests a reduction in the incorporation of Ge into Ge_(1–y)Sn_(y)growing layers.Despite the increase in Sn concentration as a result of the decrease in the growth rate,it has been found that the Sn incorporation rate into Ge_(1–y)Sn_(y)growing layers has also decreased due to strain relaxation.Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge_(1–y)Sn_(y)epilayers with tuned Sn concentration and strain relaxation.展开更多
基金The Ministry of Science and Technology project of Taiwan:MOST 108-2511-H-424-001-MY3.
文摘This study applies the diatonic chord in music theory,utilization rate,and the close relationship between the main chord system,the dominant chord system,and the subordinate chord system.From the perspective of music theory,the computer can automatically and quickly analyze the music,and establish a set of algorithms for configuring the chord accompaniment for the main melody,called the symmetrical circle offifths algorithm,SCFA(Symmetrical Circle of Fifths Algorithm).SCFA can immediately confirm the key,perform harmony analysis,configure chord accompaniment for the main melody,and effectively and correctly complete any given melody or interval.It can also quickly analyze and correctly configure the chord accompaniment for any MIDI(Musical Instrument Digital Interface)music,enriching the musicality of the music.It can also allow scorers or computer music creators to quickly deconstruct the harmony configuration of the melody.Through the measurement of bio-feedback sensor HRV(Heart Rate Variability),it can achieve a relaxing music healing effect.
基金This project was supported by the National Natural Science Foundation of China
文摘Based on the EDRF(endothelium derived relaxing factor)-like effects for polyarginine Arg-Arg-oH was selected as the lead compound and its derivatives Arg-Arg- OCH_3.Arg Arg-Arg-OH,HO-ArgCOCH_2CH_2COArg-OH,HO-ArgCOCH_2COArg-OH,were synthesized.These substances showed on bioassay various degrees of vasorelaxant activities. With protection for the C-terminal of Arg-Arg-OH with a methyl ester.the vasorelaxing ac- tivitv was decreased.In contrast.when the N-terminal of Arg-OH was protected with mal- onic acid or butane diacid.the biological activites were lower than those of Arg-Arg-OH due to the lowered metabolic rate.With protection of N-terminal of Arg-Arg-OH with L-Arg residue.Arg-Arg-Arg-OH was obtained,which showed a vasorelaxing activity better than that of Arg-Arg-OH.The bioactivities observed on the Wister's rats for the former com- pound become the experimental basis for prodrug design of EDRF.
文摘Objective: To analyze the effectiveness and safety of corneal relaxing incisions (CRI) in correcting keratometric astigmatism during cataract surgery. Methods: A prospective study of two groups: control group and treatment group. A treatment group included 25 eyes of 25 patients who had combined clear corneal phacoemulsification, IOL implantation and CRI. A control group included 25 eyes of 25 patients who had clear corneal phacoemulsification and IOL implantation.Postoperative keratometric astigmatism was measured at 1 week, 1 month, 3 months and 6 months. Results: CRI signifi-cantly decreased keratometric astigmatism in patients with preexisting astigmatism compared with astigmatic changes in the control group. In eyes with CRI, the mean keratometric astigmatism was 0.29±0.17 D(range 0 to 0.5 D) at 1 week, 0.41±0.21 D (range 0 to 0.82 D) at 1 month, respectively reduced by 2.42 D and 2.30 D at 1 week and 1 month postoperatively (P=0.000, P=0.000), and postoperative astigmatism was stable until 6 months follow-up. The keratometric astigmatism of all patients decreased to less than 1.00 D postoperatively. Conclusions: CRI is a practical, simple, safe and effective method to reduce preexisting astigmatism during cataract surgery. A modified nomogram is proposed. The long-term effect of CRI should be investigated.
文摘ONE child or two? This is the question soon to be pondered by more than 15 million couples across China's mainland. They will become eligible later this year to have two children if one of the parents is an only child. The new population policy, issued in November 2013, has already seen the choice given to couples in 22 provincial-level regions by the end of April this year.
基金The project supported by NSF (CMS-9820713)DARPA (N66001-00-1-8957)+1 种基金ARO (DAA655-98-1-ff270)New Jersey Science and Technology Commission
文摘A process has been developed recently to fabricate a structure com- prising,from top to bottom,a SiGe thin film,a glass layer,and a Si wafer.The SiGe film is a perfect crystal,and is under biaxial compression.The SiGe film is patterned into islands.On annealing,the glass flows and the islands relax.The resulting strain-free islands are used as substrates,to grow epitaxial optoelectronic devices.This article describes a series of studies on the annealing process,combining experiment and theory.A small island relaxes by expansion,starting at the edges and diffusing to the center.A large island wrinkles before the expansion reaches the center.After some time,the wrinkles either disappear,or cause the island to fracture. We model the island as an elastic plate,and the glass layer as a viscous liquid.The strains in the islands are measured by X-ray diffraction and Raman spectroscopy,and the wrinkle amplitudes by atomic force microscope.The data are compared with the theoretical predictions.We determine the conditions under which the islands relax by expansion without significant wrinkling,and demonstrate that a cap layer suppresses wrinkles,relaxing a large island crack-free.
基金the National Natural Science Foundation of China (Grant No. 19901031)and the foundation of National Laboratory of Computationa
文摘Hamilton-Jacobi equation appears frequently in applications, e.g., in differential games and control theory, and is closely related to hyperbolic conservation laws[3, 4, 12]. This is helpful in the design of difference approximations for Hamilton-Jacobi equation and hyperbolic conservation laws. In this paper we present the relaxing system for HamiltonJacobi equations in arbitrary space dimensions, and high resolution relaxing schemes for Hamilton-Jacobi equation, based on using the local relaxation approximation. The schemes are numerically tested on a variety of 1D and 2D problems, including a problem related to optimal control problem. High-order accuracy in smooth regions, good resolution of discontinuities, and convergence to viscosity solutions are observed.
基金This project supported partly by National Natural Science Foundation of China (No.19901031), the specialFunds for Major State
文摘This paper continues to study the central relaxing schemes for system of hyperbolic conservation laws, based on the local relaxation approximation. Two classes of relaxing systems with stiff source term are introduced to approximate system of conservation laws in curvilinear coordinates. Based on them, the semi-implicit relaxing schemes are con- structed as in [6, 12] without using any linear or nonlinear Riemann solvers. Numerical experiments for one-dimensional and two-dimensional problems are presented to demon- strate the performance and resolution of the current schemes.
基金Hebei Province Key Research and Development Project(No.20313701D)Hebei Province Key Research and Development Project(No.19210404D)+13 种基金Mobile computing and universal equipment for the Beijing Key Laboratory Open Project,The National Social Science Fund of China(17AJL014)Beijing University of Posts and Telecommunications Construction of World-Class Disciplines and Characteristic Development Guidance Special Fund “Cultural Inheritance and Innovation”Project(No.505019221)National Natural Science Foundation of China(No.U1536112)National Natural Science Foundation of China(No.81673697)National Natural Science Foundation of China(61872046)The National Social Science Fund Key Project of China(No.17AJL014)“Blue Fire Project”(Huizhou)University of Technology Joint Innovation Project(CXZJHZ201729)Industry-University Cooperation Cooperative Education Project of the Ministry of Education(No.201902218004)Industry-University Cooperation Cooperative Education Project of the Ministry of Education(No.201902024006)Industry-University Cooperation Cooperative Education Project of the Ministry of Education(No.201901197007)Industry-University Cooperation Collaborative Education Project of the Ministry of Education(No.201901199005)The Ministry of Education Industry-University Cooperation Collaborative Education Project(No.201901197001)Shijiazhuang science and technology plan project(236240267A)Hebei Province key research and development plan project(20312701D)。
文摘The distribution of data has a significant impact on the results of classification.When the distribution of one class is insignificant compared to the distribution of another class,data imbalance occurs.This will result in rising outlier values and noise.Therefore,the speed and performance of classification could be greatly affected.Given the above problems,this paper starts with the motivation and mathematical representing of classification,puts forward a new classification method based on the relationship between different classification formulations.Combined with the vector characteristics of the actual problem and the choice of matrix characteristics,we firstly analyze the orderly regression to introduce slack variables to solve the constraint problem of the lone point.Then we introduce the fuzzy factors to solve the problem of the gap between the isolated points on the basis of the support vector machine.We introduce the cost control to solve the problem of sample skew.Finally,based on the bi-boundary support vector machine,a twostep weight setting twin classifier is constructed.This can help to identify multitasks with feature-selected patterns without the need for additional optimizers,which solves the problem of large-scale classification that can’t deal effectively with the very low category distribution gap.
基金Supported by Independent Research Foundation of the 305 Hospital of PLA(No.24ZZJJLW-010).
文摘Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal astigmatism.Cataract surgery used to cause a progressive increase in the pre-exisiting corneal astigmatism because of creating a surgically induced astigmatism,for example,a large size surgery incision.The development of surgical techniques during last decades has made cataract surgery interchange to treat preoperative corneal astigmatism at time of surgery.Nowadays,three surgical approaches can be used.By placing a sutureless clear corneal incision on the steep meridian of the cornea,a preoperative corneal astigmatism less than 1.0 D can be corrected.Single or paired peripheral corneal relaxing incisions(PCRIs)provide 1.0-3.0 D corneal astigmatism correction.PCRIs are typically used for treating 1.0-1.5 D of regular corneal astigmatism,if more than 2.0 D,the risk of overcorrection and irregular astigmatism is increased.When toric intraocular lenses(IOLs)are unavailable in markets,PCRIs are still a reasonable option for patients with up to 3.0 D of pre-existing corneal astigmatism.Toric IOLs implantation can correct 1.0-4.5 D of corneal astigmatism.Several IOLs are approved to correct a high degree of corneal astigmatism with cylinder power up to 12.0 D.These approaches can be used alone or in combination.
文摘With the continuous advancement of science and technology,our lifestyles are undergoing significant changes,with wearable technology emerging as a captivating trend.In this digital era,there is a growing demand for solutions that cater to people’s needs for health and comfort.The wearable inflatable massage chair represents one such innovation designed to meet these evolving needs.This project is focused on creating a“wearable and portable massage chair”that is both convenient and lightweight.It serves as a massage solution particularly beneficial for the elderly and sedentary individuals.This innovative chair can be used by the elderly during outings or errands,as well as by office workers on business trips,while driving,or commuting via subway.Users can simply lean against the seat or a wall,enjoying moments of relaxation amid the busy and fast-paced modern era.
文摘Presents a study which examined a cell entropy inequality for a class of local relaxation approximation relaxing scheme for scalar conservation laws. Way to obtain the scheme; Use of numerical entropy condition for the approximation.
基金Project supported by the National Natural Science Foundation of China.
文摘Direct observation was made by using the patch-clamp technique with a specially designed microperfusion system to investigate the effect of acetylcholine (Ach 10^(-6) mol/L) elicited endothelium-derived relaxing factor (EDRF) on the calcium-activated potassium channel (IK(Ca))in the smooth muscle cells of mesenteric resistance vessels in Wistar rats. Activation of IK(Ca) was firstly observed by inducing the elicited EDRF or sodium nitroprusside (SNP 10^(-8) mol/L) under various clamping voltages in cell-attached configuration. While the pipette solution contained KCl 126 mmol/L and the bath solution contained KCl 5.9 mmol/L, two types of conductances of calcium-activated potassium current being 76.4±2.3 pS(mean±S.E. n = 7) and 160.3±7.5 pS (mean±S.E. n= 7) were recorded during the EDRF activation, one type of conductance being 100.5±2.8 pS (mean±S.E. n = 6) was activated by nitric oxide (NO) which is an effective component from SNP. Differences in kinetic characteristics of these channels between EDRF and NO activation were found, particularly the probability of the channel being open in EDRF activation was obviously greater than that in NO stimulation. It has been shown that the potassium channel mechanisms involved in the EDRF and NO actions might be different.
基金National Natural Science Foundation of ChinaLaboratory of Computational Physics of Beijing IAPCM
文摘Presents a central relaxing scheme for scalar conservation laws. Details on the preliminary equations; Properties of the relaxed schemes; Conclusions.
文摘Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.
基金This work was supported by the National Natural Science Foundation of China(62104136,22179051)the National Key Research and Development Program of China(2021YFE0111000)+3 种基金Project of Shandong Province Higher Educational Young Innovative Team(2022KJ218)China Postdoctoral Science Foundation(2023M732104)Qingdao Postdoctoral Funding Program(QDBSH20220201002)Postdoctoral Innovation Project of Shandong Province(SDCX-ZG-202303032).
文摘The buried interface in the perovskite solar cell(PSC)has been regarded as a breakthrough to boost the power conversion efficiency and stability.However,a comprehensive manipulation of the buried interface in terms of the transport layer,buried interlayer,and perovskite layer has been largely overlooked.Herein,we propose the use of a volatile heterocyclic compound called 2-thiopheneacetic acid(TPA)as a pre-buried additive in the buried interface to achieve cross-layer all-interface defect passivation through an in situ bottom-up infiltration diffusion strategy.TPA not only suppresses the serious interfacial nonradiative recombination losses by precisely healing the interfacial and underlying defects but also effectively enhances the quality of perovskite film and releases the residual strain of perovskite film.Owing to this versatility,TPA-tailored CsPbBr3 PSCs deliver a record efficiency of 11.23% with enhanced long-term stability.This breakthrough in manipulating the buried interface using TPA opens new avenues for further improving the performance and reliability of PSC.
基金Project supported by the National Basic Research Program of China (Grant Nos.12074220,12304151,12204355,and 12204356)the Natural Science Foundation of Shandong Province,China (Grant No.ZR2022QA085)。
文摘We study the interfacial Dzyaloshinskii-Moriya interactions(i-DMI)of Fe/Pt bilayers grown on Si substrates with MgO,SiO_(2),or Ta each as a buffer layer on the basis of wave-vector-resolved Brillouin light scattering(BLS)measurement.The obtained i-DMI energy values for Fe/Pt on MgO,Ta,and SiO_(2) buffer layers are 0.359,0.321,and 0.274 mJ/m~2,respectively.The large i-DMI value observed in Fe/Pt system on the MgO buffer layer can be attributed to the good interfacial quality and the Rshaba effect at the MgO/Fe interface.Moreover,the MgO/Fe/Pt system,benefiting from better sample quality,exhibits a lower damping factor.Furthermore,layer-resolved first-principles calculations are carried out to gain a more in-depth understanding of the origin of the i-DMI in the Fe/Pt system.The results indicate that in the Fe(110)/Pt(111)system,the substantial DMI energy between Fe spins at the interface is related to a significant change in spin-orbit coupling(SOC)energy in the neighboring Pt layer.In contrast,for the MgO(002)/Fe(002)system,both the DMI and its related SOC energy are concentrated at the interfacial Fe layer.Our investigation will provide a valuable insight into the spintronic community in exploring novel devices with chirality dependence.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1401900 and 2019YFA0308403)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33030000)+1 种基金the National Natural Science Foundation of China(Grant Nos.92065104,12074010,and 12141001)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302602)for sample fabrication and measurement。
文摘Surface acoustic wave(SAW)is a powerful technique for investigating quantum phases appearing in twodimensional electron systems.The electrons respond to the piezoelectric field of SAW through screening,attenuating its amplitude,and shifting its velocity,which is described by the relaxation model.In this work,we systematically study this interaction using orders of magnitude lower SAW amplitude than those in previous studies.At high magnetic fields,when electrons form highly correlated states such as the quantum Hall effect,we observe an anomalously large attenuation of SAW,while the acoustic speed remains considerably high,inconsistent with the conventional relaxation model.This anomaly exists only when the SAW power is sufficiently low.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1402203)the National Natural Science Foundation of China(Grant No.12174065)supported by the Shenzhen Fundamental Research Program(Grant Nos.JCYJ20220818100405013 and JCYJ20230807093204010)。
文摘By using muon spin relaxation(μSR)measurements,we perform a comparative study of the microscopic magnetism in the parent compounds of infinite-layer nickelate superconductors RNiO_(2)(R=La,Nd).In either compound,the zero-fieldμSR spectra down to the lowest measured temperature reveal no long-range magnetic order.In LaNiO_(2),short-range spin correlations appear below T=150 K,and spins fully freeze below T∼10 K.NdNiO_(2)exhibits a more complex spin dynamics driven by the Nd 4f and Ni3d electron spin fluctuations.Further,it shows features suggesting the proximity to a spin-glass state occurring below T=5 K.In both compounds,the spin behavior with temperature is further confirmed by longitudinal-field μSR measurements.These results provide new insight into the magnetism of the parent compounds of the superconducting nickelates,crucial to understanding the microscopic origin of their superconductivity.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52304099,52172625)Shenzhen Science and Technology Program(Grant No.RCYX20221008092903013).
文摘The occurrence of geological hazards and the instability of geotechnical engineering structures are closely related to the time-dependent behavior of rock.However,the idealization boundary condition for constant stress in creep or constant strain in relaxation is not usually attained in natural geological systems.Therefore,generalized relaxation tests that explore the simultaneous changes of stress and strain with time under different stress levels with constant pore-water pressure are conducted in this study.The results show that in area Ⅰ,area Ⅱ,and area Ⅲ,the stress and strain both change synchronously with time and show similar evolutionary laws as the strain-time curve for creep or the stress-time curve for relaxation.When the applied stress level surpasses the δ_(ci) or δ_(cd) threshold,the variations in stress and strain and their respective rates of change exhibit a significant increase.The radial deformation and its rate of change exhibit greater sensitivity in response to stress levels.The apparent strain deforms homogeneously at the primary stage,and subsequently,gradually localizes due to the microcrack development at the secondary stage.Ultimately,interconnection of the microcracks causes the formation of a shear-localization zone at the tertiary stage.The strain-time responses inside and outside the localization zone are characterized by local strain accumulation and inelastic unloading during the secondary and tertiary stages,respectively.The width of the shear-localization zone is found to range from 4.43 mm to 7.08 mm and increased with a longer time-to-failure.Scanning electron microscopy(SEM)reveals a dominant coalescence of intergranular cracks on the fracture surface,and the degree of physiochemical deterioration caused by water-rock interaction is more severe under a longer lifetime.The brittle sandstone’s time-dependent deformation is essentially controlled by microcrack development during generalized relaxation,and its expectancy-life is determined by its initial microstructural state and the rheological path.
文摘The growth of high-quality germanium tin(Ge_(1–y)Sn_(y))binary alloys on a Si substrate using chemical vapor deposition(CVD)techniques holds immense potential for advancing electronics and optoelectronics applications,including the development of efficient and low-cost mid-infrared detectors and light sources.However,achieving precise control over the Sn concentration and strain relaxation of the Ge_(1–y)Sn_(y)epilayer,which directly influence its optical and electrical properties,remain a significant challenge.In this research,the effect of strain relaxation on the growth rate of Ge_(1–y)Sn_(y)epilayers,with Sn concentration>11at.%,is investigated.It is successfully demonstrated that the growth rate slows down by~55%due to strain relaxation after passing its critical thickness,which suggests a reduction in the incorporation of Ge into Ge_(1–y)Sn_(y)growing layers.Despite the increase in Sn concentration as a result of the decrease in the growth rate,it has been found that the Sn incorporation rate into Ge_(1–y)Sn_(y)growing layers has also decreased due to strain relaxation.Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge_(1–y)Sn_(y)epilayers with tuned Sn concentration and strain relaxation.