铝电解电容器标准中的阻抗比初探

本文针对铝电解电容器的阻抗比问题比较了国家标准与国际标准的不同之处，我国铝电解电容器国家标准是等同采用国际标准，但现行的国家标准中的阻抗比明显不同于国际标准中的阻抗比，本文提出了作者对国际标准中阻抗比的理解，指出了国家标准中阻抗比的不当之处。     

A New Approach to Measurement of Heating Rate of Trapped Ions

We propose a new scheme to estimate the heating rate of trapped ions in thermal states. By applying a controlled-U gate between the internal and the motional states of one of the trapped ions, we could obtain the mean phonon number from the population of the internal state of the ion. The imperfection due to fluctuations of the relevant parameters in real experiments is considered and we anaiyze the experimental feasibility of our scheme with sophisticated ion trap techniques.     

Scheme to measure the expectation value of a physical quantity in weak coupling regime

In quantum mechanics, the expectation value of an operator can be measured by using the projective measurement, ifthe coupling between the measured system and pointer is strong enough. However in the weak coupling regime, the pointercan not show all the eigenvalue of the physical quantity directly due to the overlapping among the pointer states, whichmakes the measurement of the expectation value difficult. In this paper, we propose an expectation value measurementmethod in the weak coupling regime inspired by the weak measurement scheme. Compared to the projective measurement,our scheme has two obvious advantages. Experimentally we use the internal state and motional state of a single trapped40Ca+ to establish the measurement scheme and realize the proof of principle demonstration of the scheme.     

Irreversibility of a quantum walk induced by controllable decoherence employing random unitary operations

Quantum walk is different from random walk in reversibility and interference. Observation of the reduced re- versibility in a realistic quantum walk is of scientific interest in understanding the unique quantum behavior. We propose an idea to experimentally investigate the decoherence-induced irreversibility of quantum walks with trapped ions in phase space via the average fidelity decay. By introducing two controllable decoherence sources, i.e., the phase damping channel (i.e., dephasing) and the high temperature amplitude reservoir (i.e., dissipation), in the intervals between the steps of quantum walk, we find that the high temperature amplitude reservoir shows more detrimental effects than the phase damping channel on quantum walks. Our study also shows that the average fidelity decay works better than the position variance for characterizing the transition from quantum walks to random walk. Experimental feasibility to monitor the irreversibility is justified using currently available techniques.     

铝电解电容器的温度加速因子

采用温度作为铝电解电容器寿命加速因子,通常根据“１０℃法则”或“７℃法则”计算。作者通过对６３Ｖ－４７μＦ铝电解电容器在四种不同温度下的负荷试验（＋８５℃、＋９５℃、＋１０５℃、＋１１５℃）后对数百只样品、数万个测量数据进行了处理分析。认为单纯地使用“１０℃法则”或“７℃法则”不能准确地描述温度加速因子。作者结合铝电解电容器的结构,分析了铝电解电容器的失效因素,给出了负荷试验中温度与铝电解电容器寿命的关系。     

非密封超小型中高压固体钽电解电容器的研制

采用较高比容钽粉,改进工艺,研制成了电性能优良的超小型中高压(40V、50V)钽电解电容器。     

75V、100V全密封固体钽电解电容器的研制

研制成功的７５Ｖ、１００Ｖ工作电压全密封固体钮电解电容器性能达到了ＧＢ９５８３－８８标准，可靠性达到了五级失效率。本文分析了该产品的制造工艺，叙述了制造工艺对产品性能的影响，分析了产品的性能。     

铝电解电容器用电解纸

从铝电解电容器用电解纸的材料组成和制造方式入手，全面分析了各种电解纸的性能，给出铝电解电容器电解纸的选用方法。     

固体钽电容器损耗变化的原因及工艺改进

作者在研制非密封超小型固体钽电解电容器中,发现试制的50V/2.2μF样品在常温储存一段时间后,损耗明显上升,损耗角正切值变化极大,已影响产品的使用。经过一系列试验和分析,找出了损耗角正切值变大的内在原因。改进生产工艺后,试制出的50V/2.2μF样品的损耗角正切值不变,电性能稳定。     

Control of a Cloud of Laser-Cooled 40Ca+ in a Linear Ion Trap

A cloud of laser-cooled ^40Ca^＋ is successfully trapped and manipulated under well control in our home-built linear ion trap, which is designed and constructed solely for studying quantum information processing. By exploring the variation of the ion cloud with respect to the trap parameters, we have optimized the trapping condition and obtained very good fluorescence spectra. We observe the dynamics of the ion cloud, and estimate the temperature of the ion cloud to be of the order of milli-Kelvin.