The propagation of ring wave packet (composed of carrier waves modulated by an envelope) generated by a water drop was studied experimentally. It is a localized wave packet propagating with constant velocity and low d...The propagation of ring wave packet (composed of carrier waves modulated by an envelope) generated by a water drop was studied experimentally. It is a localized wave packet propagating with constant velocity and low diffusion. The wavelength, the amplitude and the waveform of the carrier waves, the velocity of the carrier waves and the packet have been measured. The measured wavelength λe of the carrier waves and the measured group velocity Cge of the packet are near the minimum point of the dispersion curve of group velocity, which may be the main reason why the packet can propagate with low diffusion.展开更多
Magnetosonic (MS) waves are believed to have the ability to affect the dynamics of ring current protons both inside and outside the plasmasphere. However, previous studies have focused primarily on the effect of high-...Magnetosonic (MS) waves are believed to have the ability to affect the dynamics of ring current protons both inside and outside the plasmasphere. However, previous studies have focused primarily on the effect of high-frequency MS waves (f > 20 Hz) on ring current protons. In this study, we investigate interactions between ring current protons and low-frequency MS waves (< 20 Hz) inside the plasmasphere. We find that low-frequency MS waves can effectively accelerate < 20 keV ring current protons on time scales from several hours to a day, and their scattering efficiency is comparable to that due to high-frequency MS waves (>20 Hz), from which we infer that omitting the effect of low-frequency MS waves will considerably underestimate proton depletion at middle pitch angles and proton enhancement at large pitch angles. Therefore, ring current proton modeling should take into account the effects of both low- and highfrequency MS waves.展开更多
The disadvantages of classic ring type ultrasonic motor were analyzed.To obtain large mechanical output power,a ring type standing wave ultrasonic motor using cantilever type longitudinal transducers was proposed.Ther...The disadvantages of classic ring type ultrasonic motor were analyzed.To obtain large mechanical output power,a ring type standing wave ultrasonic motor using cantilever type longitudinal transducers was proposed.There are four pairs of cantilevers on one side of the ring,and four PZT ceramics are set between each pair of cantilevers.A screw fastened the PZT ceramics and cantilevers together to form a longitudinal transducer.The bending vibration mode of the ring is excited by the stretching vibration of the PZT ceramics.Thus,linear simple harmonic motions are achieved at the particle on the teeth.And the driving force is the frictional force between rotor and stator.The working principle of the proposed motor was analyzed.The ring and the longitudinal transducer were designed with FEM.The sensitive parameters of resonant frequency of the transducer and ring could be gained with modal analysis.The longitudinal vibration modal of transducer and bending vibration modal of ring were degenerated,and the motion trajectories of nodes on the teeth were analyzed.The results of this paper could guide the development of this new type of motor.展开更多
Carbon Nano-Tube Field Effect Transistors (CNTFETS) are the competitor of the conventional MOSFET technology due to their higher current drive capability, ballistic transport, lesser power delay product, higher therma...Carbon Nano-Tube Field Effect Transistors (CNTFETS) are the competitor of the conventional MOSFET technology due to their higher current drive capability, ballistic transport, lesser power delay product, higher thermal stability, and so on. Based on these promising properties of CNTFETs, a CNTFET-based millimeter wave ring oscillator operating around 150 GHz and beyond is introduced here in 32 nm technology node. To prevent overestimation, the CNT interconnects between transistors are also included in simulation, which are assumed to be a single layer of ballistic metallic CNTs in parallel. For the sake of simplicity in RF design, the oscillator is based on CNTFET-based inverters. The inverters with DC gain of 87.5 dB are achieved by proper design with the non-loaded delay around 0.6 ps, which is at least one order of magnitude better than the same 32 nm MOSFET-based inverters. The oscillator’s average power consumption is as low as 40 μW with the fundamental harmonic amplitude of around –6.5 dB. These values are, based on our knowledge, for the first time reported in the literature in CNTFET-based oscillator designs. Also, on the average, the performance of the designed oscillator is 5 - 6 times better than MOSFET-based designs.展开更多
In this paper, we present evolutions of the phase space density(PSD) spectra of ring current(RC) ions based on observations made by Van Allen Probe B during a geomagnetic storm on 23–24 August 2016. By analyzing PSD ...In this paper, we present evolutions of the phase space density(PSD) spectra of ring current(RC) ions based on observations made by Van Allen Probe B during a geomagnetic storm on 23–24 August 2016. By analyzing PSD spectra ratios from the initial phase to the main phase of the storm, we find that during the main phase, RC ions with low magnetic moment μ values can penetrate deeper into the magnetosphere than can those with high μ values, and that the μ range of PSD enhancement meets the relationship: S(O^+) >S(He^+)>S(H^+). Based on simultaneously observed ULF waves, theoretical calculation suggests that the radial transport of RC ions into the deep inner magnetosphere is caused by drift-bounce resonance interactions, and the efficiency of these resonance interactions satisfies the relationship: η(O^+) > η(He^+) > η(H^+), leading to the differences in μ range of PSD enhancement for different RC ions. In the recovery phase,the observed decay rates for different RC ions meet the relationship: R(O^+) > R(He^+) > R(H^+), in accordance with previous theoretical calculations, i.e., the charge exchange lifetime of O^+ is shorter than those of H^+ and He^+.展开更多
The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave fr...The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave frequency w, and pitch angle diffusion coefficient Daa were calculated at the center location of the symmetrical ring current： r ≈3.5RE with RE the Earth＇s radius. Emin is found to decrease rapidly from 10 MeV to a few keV with the increase in ca in three bands： H^＋-band, He^＋-band and O^＋-band. Moreover, EMIC waves have substantial potential to scatter energetic （～100 keV） ions （mainly H^＋ and He^＋） into the loss cone and yield precipitation loss, suggesting that wave-particle interactions contribute to ring current decay.展开更多
The paper analyzes the principle of positioning of waves by notching at the bottom of the waves in garment draping from the dynamic perspective, and search for the best molding effect under 45° to fabric grain as...The paper analyzes the principle of positioning of waves by notching at the bottom of the waves in garment draping from the dynamic perspective, and search for the best molding effect under 45° to fabric grain as the model baseline. Wavy and ring deformation laws are proved by the sample photographs.展开更多
In the framework of the effective mass theory, this paper calculates the electron energy levels of an InAs/GaAs tyre-shape quantum ring （TSQR） by using the plane wave basis. The results show that the electron energy...In the framework of the effective mass theory, this paper calculates the electron energy levels of an InAs/GaAs tyre-shape quantum ring （TSQR） by using the plane wave basis. The results show that the electron energy levels axe sensitively dependent on the TSQR＇s section thickness d, and insensitively dependent on TSQR＇s section inner radius R1 and TSQR＇s inner radius R2. The model and results provide useful information for the design and fabrication of InAs/GaAs TSQRs.展开更多
The characteristics of coplanar waveguide (CPW) fed ring antennas (such as gain, efficiency and polarization purity) are degraded by the dielectric losses and excitation of surface waves on the substrates. To countera...The characteristics of coplanar waveguide (CPW) fed ring antennas (such as gain, efficiency and polarization purity) are degraded by the dielectric losses and excitation of surface waves on the substrates. To counteract such effects, we propose to remove some portions of the substrate in the vicinity of the metallic patches, which effectively eliminates the conditions for the generation of surface waves. The proposed technique is applied to a CPW-fed ring antenna and a prototype model is fabricated. The measurement data and the computer simulation results agree well and indicate the efficacy of the technique for the improvement of antenna gain and efficiency.展开更多
The motion of organization center of three_dimensional untwisted scroll waves in excitable media with single diffusion is studied by singular perturbation method in this paper. The relation of curvature and the linear...The motion of organization center of three_dimensional untwisted scroll waves in excitable media with single diffusion is studied by singular perturbation method in this paper. The relation of curvature and the linear law are derived for untwisted organization center. These results have explicit physical meaning and are in good agreement with experiments.展开更多
In clinical practice, dentists sometimes encounter phenomena that cannot be explained by modern western medical concepts;for example, the patient’s medical symptoms improve by bringing medicines or dentures close to ...In clinical practice, dentists sometimes encounter phenomena that cannot be explained by modern western medical concepts;for example, the patient’s medical symptoms improve by bringing medicines or dentures close to the body. Although it seems difficult to completely elucidate the mechanism through modern western medicine, it can be explained using quantum mechanics. The quantum, the smallest unit of matter composition, exhibits wave-particle duality. The fact that symptoms can be improved simply by bringing dentures or medicines closer to the body indicates that the waves emitted by dentures or medicines interfere with the pathological waves emitted by the pathological site. Thus, the pathological waves are deformed and lead to a change in symptoms. In this way, quantum theory can explain phenomena that are difficult to elucidate in conventional medicine, which are encountered in clinical practice. So far, the author has presented a case of difficulty in raising the upper limb where the symptoms improved without the need for dentures in the mouth by adjusting the dentures outside the mouth. This time, the author would like to introduce a case which the patient’s knee pain improved by adjusting the dentures outside the mouth.展开更多
基金the State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciencespartially supported by the National Natural Science Foun-dation of China (Grant No. 10674081)
文摘The propagation of ring wave packet (composed of carrier waves modulated by an envelope) generated by a water drop was studied experimentally. It is a localized wave packet propagating with constant velocity and low diffusion. The wavelength, the amplitude and the waveform of the carrier waves, the velocity of the carrier waves and the packet have been measured. The measured wavelength λe of the carrier waves and the measured group velocity Cge of the packet are near the minimum point of the dispersion curve of group velocity, which may be the main reason why the packet can propagate with low diffusion.
基金supported by the Science and Technology Development Fund of Macao SAR (FDCT) through grants 039/2013/A2supports from the National Natural Science Foundation of China (NSFC) through grants 41525015 and 41774186
文摘Magnetosonic (MS) waves are believed to have the ability to affect the dynamics of ring current protons both inside and outside the plasmasphere. However, previous studies have focused primarily on the effect of high-frequency MS waves (f > 20 Hz) on ring current protons. In this study, we investigate interactions between ring current protons and low-frequency MS waves (< 20 Hz) inside the plasmasphere. We find that low-frequency MS waves can effectively accelerate < 20 keV ring current protons on time scales from several hours to a day, and their scattering efficiency is comparable to that due to high-frequency MS waves (>20 Hz), from which we infer that omitting the effect of low-frequency MS waves will considerably underestimate proton depletion at middle pitch angles and proton enhancement at large pitch angles. Therefore, ring current proton modeling should take into account the effects of both low- and highfrequency MS waves.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50875057)the State Key Laboratory of Robotics and Systems (HIT No.SKLRS200901A04)
文摘The disadvantages of classic ring type ultrasonic motor were analyzed.To obtain large mechanical output power,a ring type standing wave ultrasonic motor using cantilever type longitudinal transducers was proposed.There are four pairs of cantilevers on one side of the ring,and four PZT ceramics are set between each pair of cantilevers.A screw fastened the PZT ceramics and cantilevers together to form a longitudinal transducer.The bending vibration mode of the ring is excited by the stretching vibration of the PZT ceramics.Thus,linear simple harmonic motions are achieved at the particle on the teeth.And the driving force is the frictional force between rotor and stator.The working principle of the proposed motor was analyzed.The ring and the longitudinal transducer were designed with FEM.The sensitive parameters of resonant frequency of the transducer and ring could be gained with modal analysis.The longitudinal vibration modal of transducer and bending vibration modal of ring were degenerated,and the motion trajectories of nodes on the teeth were analyzed.The results of this paper could guide the development of this new type of motor.
文摘Carbon Nano-Tube Field Effect Transistors (CNTFETS) are the competitor of the conventional MOSFET technology due to their higher current drive capability, ballistic transport, lesser power delay product, higher thermal stability, and so on. Based on these promising properties of CNTFETs, a CNTFET-based millimeter wave ring oscillator operating around 150 GHz and beyond is introduced here in 32 nm technology node. To prevent overestimation, the CNT interconnects between transistors are also included in simulation, which are assumed to be a single layer of ballistic metallic CNTs in parallel. For the sake of simplicity in RF design, the oscillator is based on CNTFET-based inverters. The inverters with DC gain of 87.5 dB are achieved by proper design with the non-loaded delay around 0.6 ps, which is at least one order of magnitude better than the same 32 nm MOSFET-based inverters. The oscillator’s average power consumption is as low as 40 μW with the fundamental harmonic amplitude of around –6.5 dB. These values are, based on our knowledge, for the first time reported in the literature in CNTFET-based oscillator designs. Also, on the average, the performance of the designed oscillator is 5 - 6 times better than MOSFET-based designs.
基金supported by the National Natural Science Foundation of China (41925018, 41874194)
文摘In this paper, we present evolutions of the phase space density(PSD) spectra of ring current(RC) ions based on observations made by Van Allen Probe B during a geomagnetic storm on 23–24 August 2016. By analyzing PSD spectra ratios from the initial phase to the main phase of the storm, we find that during the main phase, RC ions with low magnetic moment μ values can penetrate deeper into the magnetosphere than can those with high μ values, and that the μ range of PSD enhancement meets the relationship: S(O^+) >S(He^+)>S(H^+). Based on simultaneously observed ULF waves, theoretical calculation suggests that the radial transport of RC ions into the deep inner magnetosphere is caused by drift-bounce resonance interactions, and the efficiency of these resonance interactions satisfies the relationship: η(O^+) > η(He^+) > η(H^+), leading to the differences in μ range of PSD enhancement for different RC ions. In the recovery phase,the observed decay rates for different RC ions meet the relationship: R(O^+) > R(He^+) > R(H^+), in accordance with previous theoretical calculations, i.e., the charge exchange lifetime of O^+ is shorter than those of H^+ and He^+.
基金National Natural Science Foundation of China (Nos.40874076,40774078,40774079 and 40536029)the Special Fund for Public Welfare Industry (meteorology)GYHY200806072the Visiting Scholar Foundation of State Key Laboratory for Space Weather,Chinese Academy of Sciences
文摘The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave frequency w, and pitch angle diffusion coefficient Daa were calculated at the center location of the symmetrical ring current： r ≈3.5RE with RE the Earth＇s radius. Emin is found to decrease rapidly from 10 MeV to a few keV with the increase in ca in three bands： H^＋-band, He^＋-band and O^＋-band. Moreover, EMIC waves have substantial potential to scatter energetic （～100 keV） ions （mainly H^＋ and He^＋） into the loss cone and yield precipitation loss, suggesting that wave-particle interactions contribute to ring current decay.
基金This work was supported by the Dong Hua University and the corporation foundation
文摘The paper analyzes the principle of positioning of waves by notching at the bottom of the waves in garment draping from the dynamic perspective, and search for the best molding effect under 45° to fabric grain as the model baseline. Wavy and ring deformation laws are proved by the sample photographs.
基金Project supported by the National Natural Science Foundation of China (Grant No 60521001)
文摘In the framework of the effective mass theory, this paper calculates the electron energy levels of an InAs/GaAs tyre-shape quantum ring （TSQR） by using the plane wave basis. The results show that the electron energy levels axe sensitively dependent on the TSQR＇s section thickness d, and insensitively dependent on TSQR＇s section inner radius R1 and TSQR＇s inner radius R2. The model and results provide useful information for the design and fabrication of InAs/GaAs TSQRs.
文摘The characteristics of coplanar waveguide (CPW) fed ring antennas (such as gain, efficiency and polarization purity) are degraded by the dielectric losses and excitation of surface waves on the substrates. To counteract such effects, we propose to remove some portions of the substrate in the vicinity of the metallic patches, which effectively eliminates the conditions for the generation of surface waves. The proposed technique is applied to a CPW-fed ring antenna and a prototype model is fabricated. The measurement data and the computer simulation results agree well and indicate the efficacy of the technique for the improvement of antenna gain and efficiency.
文摘The motion of organization center of three_dimensional untwisted scroll waves in excitable media with single diffusion is studied by singular perturbation method in this paper. The relation of curvature and the linear law are derived for untwisted organization center. These results have explicit physical meaning and are in good agreement with experiments.
文摘针对移相器和功分器的功能融合设计,提出了一种基于慢波基片集成波导(Slow-Wave Substrate Integrated Waveguide,SW-SIW)的小型化移相功分器,两个输出分支等长带宽,可实现30°相移量.其中一个输出分支通过基片集成波导(Substrate Integrated Waveguide,SIW)实现,而另一个输出分支将互补开口谐振环(Complementary SplitRing Resonator,CSRR)加载在上层金属表面,代替传统SIW连续的金属表面,该CSRR由经典CSRR结构演变而来,同时为了降低由CSRR加载所造成的相位上的不稳定,在CSRR内部添加金属化通孔,实现SW-SIW,使得截止频率和相速度降低.测试结果表明,移相功分器在9.0~11.8 GHz频带范围内反射系数|S11|小于-10 d B,相对工作带宽为26.9%,插入损耗小于1.3 d B.两个输出端口的相位差稳定在30°±3°,幅度差小于1.4 d B,实现了等功率分配.所设计的移相功分器具有较小的尺寸和低制造成本,适合应用在相控阵天线中.
文摘In clinical practice, dentists sometimes encounter phenomena that cannot be explained by modern western medical concepts;for example, the patient’s medical symptoms improve by bringing medicines or dentures close to the body. Although it seems difficult to completely elucidate the mechanism through modern western medicine, it can be explained using quantum mechanics. The quantum, the smallest unit of matter composition, exhibits wave-particle duality. The fact that symptoms can be improved simply by bringing dentures or medicines closer to the body indicates that the waves emitted by dentures or medicines interfere with the pathological waves emitted by the pathological site. Thus, the pathological waves are deformed and lead to a change in symptoms. In this way, quantum theory can explain phenomena that are difficult to elucidate in conventional medicine, which are encountered in clinical practice. So far, the author has presented a case of difficulty in raising the upper limb where the symptoms improved without the need for dentures in the mouth by adjusting the dentures outside the mouth. This time, the author would like to introduce a case which the patient’s knee pain improved by adjusting the dentures outside the mouth.
