Quantum fluctuations of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling

Based on the scheme of damped harmonic oscillator quantization and thermo-field dynamics （TFD）, the quantization of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling is proposed. The quantum fluctuations of charge and current of each loop in a squeezed vacuum state are studied in the thermal excitation case. It is shown that the fluctuations not only depend on circuit inherent parameters, but also rely on excitation quantum number and squeezing parameter. Moreover, due to the finite environmental temperature and damped resistance, the fluctuations increase with the temperature rising, and decay with time.

Imaging changes in neural circuits in patients with depression using 1 H-magnetic resonance spectroscopy and diffusion tensor imaging

1 H-magnetic resonance spectroscopy imaging and diffusion tensor imaging were performed in 19 patients with mild depression and in 13 controls.The mean age of the patients was 31 years.The mean Hamilton depression score of the patients was 22.5±13.2.N-acetylaspartate,choline and creatine concentrations and the average diffusion coefficient and fractional anisotropy values were measured in the bilateral hippocampus,striatum,thalamus and prefrontal deep white matter. Compared with the control group,the mild depressed patients had：（1）a higher choline/creatine ratio and a negative correlation between the choline/creatine ratio and the average diffusion coefficient in the hippocampus;（2）a lower choline/creatine ratio and a higher fractional anisotropy in the striatum;（3）a lower fractional anisotropy and a positive correlation between the fractional anisotropy and the choline/creatine ratio in the prefrontal deep white matter;and（4）a higher average diffusion coefficient and a positive correlation between the choline/creatine ratio and the N-acetylaspartate/creatine ratio in the thalamus,as well as positive correlation between the choline/creatine ratio and Hamilton depression scores.These data suggest evidence of abnormal connectivity in neurofibrotic microstructures and abnormal metabolic alterations in the limbic-cortical-striatal-pallidal-thalamic neural circuit in patients with mild depression.

Coupled Electromagnetic Circuits and Their Connection to Quantum Mechanical Resonance Interactions and Biorhythms

The existence of specific biorhythms and the role of geomagnetic and/or solar magnetic activities are well-established by appropriate correlations in chronobiology. From a physical viewpoint, there are two different accesses to biorhythms to set up connections to molecular processes: quantum mechanical perturbation theoretical methods and their resonance dominators to characterize specific interactions between constituents. These methods permit the treatment of molecular processes by circuits with characteristic resonances and “beat-frequencies”, which result from primarily fast physical processes. As examples, the tunneling processes between DNA base pairs (H bonds), the ATP decomposition and the irradiation of tumor cells are accounted for.

Wireless Power Transfer Experiment by Using Magnetic Coupling Resonance

Wireless power transfer experiment by using magnetic coupling resonance can be used for electric vehicles,portable electronic equipment,etc.It is clear that this technology will bring convenience and productivity.So how can we do the wireless power transfer experiment?This thesis will show the experiment from two aspects:the first is to understand and explore the theory of this experiment.The second is to raise the questions I met and the utility of this technology.By studying the knowledge[1]of the theory,I have the fundamental understanding of alternating current,resonance circuit,and electro-magnetic induction[2].After the experiment,I also collect analyze the data.

A Method for Measuring LC Resonance Frequency by Impulse Response

LC circuit resonance frequency measurement often requires the use of professional analysis instruments such as LCR meters,vector network analyzers,but currently such instruments on the market are expensive,and it is difficult for non-professional institute personnel to access.Here comes unnecessary trouble.In view of this situation,a test method for measuring the resonance frequency using only a digital storage oscilloscope is proposed.Using the impulse signal to obtain the system response,the response waveform period can be observed through the oscilloscope.

Features and Prototypes of HTS High Q Resonant Circuit

High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.

Electrode Location Efficiency and Equivalent Circuit for Flexure Vibration of Piezoelectric Beam

Aim To provide technical parameters for development of quartz gyro. Methods Theory of elastic beam was applied to piezoelectric beam. Based on the concept of equivalent volume force and energy conservation, the formula of electrode location efficiency was derived. And the electric system was compared with the dynamic one according to the principle of equivalent circuit for piezoelectric crystal, and the general formulae of the parameters for the equivalent circuit, R n L n C n , were derived. Results and Conclusion Optimum electrode location is chosen, and the derived equivalent circuit parameters are the theoretical base of the circuit design for quartz gyro.

Microbleeds in fronto-subcortical circuits are predictive of dementia conversion in patients with vascular cognitive impairment but no dementia

Cerebral small vessel disease（CSVD） is a common etiology of vascular cognitive impairment with no dementia（V-CIND）. Studies have revealed that cerebral microbleeds（CMBs）, a feature of CSVD, contribute to cognitive impairment. However, the association between CMBs and dementia conversion in individuals with V-CIND is still unclear. Here, we analyzed the predictive role of CMBs in the conversion from V-CIND to dementia in CSVD patients. We recruited and prospectively assessed 85 patients with CSVD and V-CIND. V-CIND was evaluated using a series of comprehensive neuropsychological scales, including the Chinese version of the Montreal Cognitive Assessment and the Clinical Dementia Rating. MRI assessments were used to quantify lacunar infarcts, white matter hyperintensities, CMBs, and medial temporal lobe atrophy. Eighty-two of the 85 patients completed the assessment for dementia conversion at a 1-year follow-up assessment. Multivariate logistic regression analyses were conducted to examine independent clinical and MRI variables associated with dementia conversion. Twenty-four patients（29.3%） had converted to dementia at the 1-year follow-up, and these individuals had significantly more CMBs in the fronto-subcortical circuits. Multivariate logistic regression analyses revealed that the patients with CMBs in the fronto-subcortical circuits（odds ratio = 4.4; 95% confidence interval： 1.602-12.081, P = 0.004） and 5 or more CMBs overall（odds ratio = 17.6, 95% confidence interval： 3.23-95.84, P = 0.001） had a significantly increased risk of dementia at the 1-year follow-up. These findings indicate that CMBs in the fronto-subcortical circuits may be predictive of dementia conversion in CSVD patients with V-CIND, and thus extend the clinical significance of CMBs.

Novel method to measure unloaded quality factor of resonant cavities at room temperature

We demonstrated a novel method to measure the unloaded quality factor(Q factor) of high-Q resonant cavities. This method was used to obtain data with low errors and calculate the unloaded Q factor. This procedure was more reliable than traditional methods. The data required for the method were near the resonant frequency,not at the half-power points of the reflection coefficient curve or Smith chart. We applied the new method to measure a resonant cavity with an unloaded Q factor of^100,000, obtaining good agreement between the measured and theoretical results.

Analysis and Design of Planar Tunable Inner-Coupling Step Impedance Resonator

A full planar tunable band pass resonator is introduced, which is constructed by using novel symmetric step impedance resonator （SIR） and hyperabrupt varactors for wide bandwidth tuning and size reduction. The equivalent circuit model of the proposed resonator is set up. Theoretical analysis based on transmission line as well as odd and even-mode method is completed. The attractiveness of the approach presented lies in its simplicity. Based on the detailed analysis, a 6 GHz to 10 GHz varactor tuned resonator is designed, fabricated, and measured. It shows wideband tuning ability of 37%. The experimental results of the resonator have a good agreement with the analysis results.

Tunable optical filter using second-order micro-ring resonator

In this paper, we design and fabricate a silicon integrated optical filter consisting of two cascaded micro-ring resonators and two straight waveguides. Two micro-heaters are fabricated on the top of two micro-rings respectively, which are employed to modulate the micro-rings to perform the function of a tunable optical filter by the thermo–optic effect. The static response test indicates that the extinction ratio and 3-d B bandwidth are 29.01 d B and 0.21 nm respectively, the dynamic response test indicates that the 10%–90% rise and 90%–10% fall time of the filter are 16 μs and 12 μs, respectively,which can meet the requirements of optical communication and information processing. Finally, the power consumption of the device is also characterized, and the total power consumption is about 9.43 m W/nm, which has been improved efficiently.

Complete eigenmode analysis of a ladder-type multiple-gap resonant cavity

A theoretical model is developed for calculating the eigenmodes of the multi-gap resonant cavity. The structure of concern is a kind of ladder-type circuit, offering the advantages of easy fabrication, high characteristic impedance （R/Q）, and thermal capacity in the millimeter wave to THz regime. The eigenfunction expansion method is used to establish the field expressions for the gaps and the coupling region. Then, the match conditions at the interface are employed, which leads to a group of complicate boundary equations in the form of an infinite series. To facilitate the mathematical treatments and perform a highly efficient calculation, these boundary equations are transformed into the algebraic forms through the matrix representations. Finally, the concise dispersion equation is obtained. The roots of the dispersion equation include both the axial modes in the gaps, which include the fundamental and the high-order modes, and the cavity modes in the coupling region. Extensive numerical results are presented and the behaviors of the multi-gap resonant cavity are examined.

Quantum communication via controlled holes in the statistical distribution of excitations in a nanoresonator coupled to a Cooper pair box

We propose a scheme to transmit information via the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a Cooper pair box. The success probability and the fidelity are calculated and compared with those obtained in an atom-field system in different regimes. Addtionaly, the scheme can also be applied to prepare low excited Fock states.

Power Management Integrated Circuit with 90Plus Efficiency Used in AC/DC Converter

Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of-art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specific suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.

Prior Somatic Stimulation Improves Performance of Acquired Motor Skill by Facilitating Functional Connectivity in Cortico-Subcortical Motor Circuits

Once people have a well-trained motor skill, their performance becomes stabilized and achieving substantial improvement is difficult. Recently, we have shown that even a plateaued hand motor skill can be upgraded with short-period electrical stimulation to the hand prior to the task. Here, we identify the neuronal substrates underlying the improvement of the plateaued skill by examining the enhanced functional connectivity in the sensory-motor regions that are associated with motor learning. We measured brain activity using functional magnetic resonance imaging and performed psychophysiological interaction analysis. We recruited seven right-handed very-well trained participants, whose motor performance of continuously rotating two balls with their right hands became stabilized at higher performance levels. We prepared two experiments, in each of which they repeated an experimental run 16 times. In each run, they performed this cyclic rotation as many times as possible in 16 s. In the thenar-stimulation experiment, we applied 60-s stimulation to the thenar muscle before each of the 5th - 12th runs, and the others were preceded by ineffective sham stimulation. In the control experiment, the sham was always provided. Thenar stimulation enabled the participants to perform the movements at higher cycles. In association with this performance improvement, we found enhanced activity couplings between the primary motor cortex and the sensorimotor territory of the putamen and between the cerebellum and the primary sensorimotor cortices, without any quantitative activity increase. Neither behavioral change nor these increased activity couplings were observed in the control.Thus, in contrast to the stable neuronal states in the cortico-subcortical motor circuits when the well-learned task is repeated at the later stages of motor skill learning, plastic changes in the motor circuits seem to be required when the plateaued skill is upgraded, and the stimulation may entail a state of readiness for the plastic change that allows subsequent performance improvement.

SWITCHING CHARACTERISTICS AND ANALYSIS OF RESONANT TUNNELING DIODES

Resonant tunneling diode （RTD） of AlAs/InGaAs/AlAs double barrier-single well structure was designed and fabricated. The devices showed current-voltage characteristics with peak-valley current ratio of 4 ： 1 at room temperature. The scattering parameter of RTD was measured by using an HP8510（C） network analyzer. Equivalent circuit parameters were obtained by curve fitting and optimized. The RTD switching time was estimated using the measured capacitance and average negative differential resistance. The minimum rise time of the sample was estimated to be 21 ps.

A novel design of power management integrated circuit with 90 plus efficiency used in AC/DC converter

Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.

ANALYSIS OF ZERO-VOLTAGE QUASI-RESONANT BOOST DC-DC CONVERTER

The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small signal characteristics of the converter are also given.

一种基于锁相放大的谐振式密度传感器谐振频率测量系统设计

谐振式密度传感器测量密度的关键在于谐振频率的测量。现有的测频法、测周期法、FFT法等谐振频率测量方法因噪声、脉冲误差等因素限制了其精度。为了解决该问题,设计了一种以锁相放大器为核心的谐振频率测量系统,其检测电路将交流振动信号的测量转换为直流恒定电压的测量。利用实验中发现的谐振区域内该直流电压与激励频率呈近似线性关系,基于扫频思想提出并实现了一种谐振频率自动测量算法。在(20±0.05)℃环境下进行了密度标定实验,对密度传感器进行了温度补偿。实验结果表明,在密度为700 kg/m^(3)~1000 kg/m^(3)的测量范围内,测得谐振频率稳定性可达到0.002%,传感器的密度测量最大误差为0.48 kg/m^(3),最大综合测量误差为0.069%,验证了所提谐振频率测量方法的有效性、精确性。

典型压电材料在液氮低温环境下的压电性能

对压电材料进行阻抗测试可以获取压电振子等效电路的谐振频率和模型参数。对压电材料在室温及液氮低温下的性能进行测试。结果表明:不同压电材料在室温与液氮低温下的谐振频率、介电常数、机电耦合系数、介质损耗等参数存在较大的差异;在液氮低温环境下,压电材料的谐振电阻、谐振频率、介质损耗都存在不同程度的增大,介电常数、平面机电耦合系数均存在不同程度的减小,液氮低温环境会对BaTiO3及钛酸锶钡的介质损耗造成不可逆的影响。