Pb1−x Bi x /Bi/Pb1−x Bi x Josephson junction

A superconductor/semimetal/superconductor (S/SM/S) Josephson junction has been developed. We have used an alloy of Pb_1–x Bi _x (0x 0.6) as the superconductor and Bi as the semimetal. By irradiating at X-band microwave of 10 GHz, Shapiro steps were observed for various bismuth barrier thicknesses inÅ and bismuth weight ratiosx. Finally, we obtained the empirical relationship for barrier thickness, below which microwaves could be detected for various bismuth weight ratiosx at the temperature of 4.2 K.     

Rain attenuation from log-normal and Weibull raindrop-size distributions

The rain attenuation from 1 to 1000 GHz was calculated by using both log-normal and Weibull distributions for raindrop size. The results were compared with the recent microwave measurements from 8.4 to 312.5 GHz at the rain rateR = 50mm/h. The log-normal distribution leads to a higher estimate of attenuation than both the Weibull distribution and the experimental data.     

FM eliminated CH4locked frequency stabilization of 3.39 µm He-Ne laser in dual feedback control

The frequency of the 3.39 μm He-Ne laser was locked to the CH4saturated absorption line by means of integral-proportional feedback control, i.e., dual feedback control. The frequency modulation was applied by a vibrating mirror placed outside a laser cavity, obtaining a modulation-free laser beam with a stabilized frequency. The long-term stability achieved under integral feedback control was aboutpm1.1 times 10^{-11}, which was further improved topm1.35 times 10^{-12}under dual feedback control. The Allan variance measured by the photomixing technique was1.77 times 10^{-12}at an averaging time 100 s.     

Electrodeposition of amorphous gold alloy films

The process for electroplating amorphous gold-nickel-tungsten alloy that we developed previously based on the addition of a gold salt to a known amorphous Ni-W electroplating solution was investigated further using the X-ray diffraction (XRD) method for the purpose of quickly surveying the effects of various experimental variables on the microstructure of the alloy. In this system the gold concentration in the plating bath was found to be critical; i.e., when it is either very low or very high, the deposit becomes crystalline to XRD. The deposit composition varies linearly with the mole ratio of Au to Ni in solution, and the alloy deposit is amorphous to XRD when the atomic ratio of Au/Ni in the deposit is between 0.5 and 1.5. At suitable concentrations of the metal ions, the deposit contains essentially no tungsten. By extending the work on the Au-Ni-W system, an amorphous Au-Co alloy plating process was also developed.     

A CMOS image sensor module applied for a digital still camerautilizing the TAB on glass (TOG) bonding method

The world's smallest (105×55×20 mm) and lightest (130 g) digital still camera has been developed, in which a 330 K pixel complementary metal-oxide-semiconductor (CMOS) image sensor chip is used as an image sensor. The authors have developed a new thinner and smaller image sensor module, called tape automated bonding (TAB) on glass (TOG) module, using the anisotropic conductive paste (ACP) interconnection method. The TOG production process was established by obtaining optimum bonding conditions for both optical glass bonding and CMOS chip bonding to the TAB tape. The bonding conditions including sufficient bonding margins, were mainly studied. The TOG module obtained good imaging properties, It also has a high reliability such as thermal cycle test (-40 to +110°C/30 min, 2000 cycles) and the high temperature storage test (60°C, 90% RH, 3000 h). The stable production process was confirmed by fabricating an automatic bonding machine     

Maximum value of the pulse energy of a passively Q-switched laser as a function of the pump power

The finite recovery time Ts of the bleached absorber is presented as one of the possible mechanisms accounting for the increase-maximum-decrease in pulse energy E with the pumping rate Wp in cw-pumped passively Q-switched solid-state lasers, by analytically evaluating the sign of the derivative partial differentialE/ partial differentialWP. The results show that, in the low pump regime (T>Ts, T is the interpulse period), the initial population density ni remains constant, the final population density nf decreases with Wp, and this results in a monotonic increase of E with Wp. In the high pump regime (T相似文献   

新疆煤矿大数据智能管理平台建设规划的研讨

为推动新疆煤矿企业升级传统管理模式至大数据智能模式,在研讨当前煤矿大数据智能管理建设的必要性和存在的主要问题基础上,系统性提出在矿井各生产作业子系统、管理部门多源化实时采集和共享大数据,在矿井调度指挥中心搭建生产执行管理系统（Manufacturing Execution System,MES）平台,统领大数据、使用大数据的智能管理平台建设规划,为企业现代化转型升级提供参考。     

Imaging flaws in soldered joints of integrated circuits using an ultrasound electronic scanning technique

An electronic scanning c-scopic 25-MHz ultrasonic imaging system has been developed for high-speed precise testing of electronic parts such as ICs. Two-dimensional scanning is performed, one axis being electronic and the other mechanical. A focused beam is formed so as to be a longitudinal wave in solid samples. Voids equal to or larger than 0.2 mm in diameter in the solder are accurately detected and their sizing data agree within 0.1 mm with those measured visually through an optical microscope after destruction. The imaging performance was examined for fatigue cracks in soldered joints. In 1000 heat cycles between -55 and +150 degrees C, cracks resulted in the soldered joints of most samples, and their growth was clearly visible. By comparing the images with those observed by a scanning electron microscope, minimum cracks of 1-mum separation were found to be detectable. The c-scan imaging of a 14x14 mm area of the joints was completed in 1.2 s by the system.     

Tribological Action and Cutting Performance of MQL Media in Machining of Aluminum

The tribological action of MQL media and atmospheric carrier gases was investigated using controlled atmosphere cutting apparatus. The investigation demonstrated their adsorption behavior onto metal surfaces was in close connection with the cutting performance of a lubricant synthetic ester and carrier gases in practical MQL machining. In particular, the presence of oxygen resulted in unfavorable cutting phenomena in MQL machining of aluminum. A unique technique of MQL media treatment was further proposed to prepare oil mist sprays containing microdroplets of water. This advanced technique provided some possibilities of improving the tribological action of MQL media in machining of aluminum.     

Approximating dipoles from human EEG activity: the effect of dipolesource configuration on dipolarity using single dipole models

Dipolarity is the goodness-of-fit of the observed potential distribution with one calculated using specific assumptions about the source of the electrical potential distribution. The authors used computer simulations to examine the effect of different distributions of sources on their resulting dipolarity values. Electric dipoles were placed in a head-shaped model with uniform conductivity using four different dipole configurations (randomly oriented dipoles, a uniform dipole disk layer, a dipole disk layer with uniformly distributed holes, or one with randomly oriented dipoles). The best-fitting single dipole for each configuration was calculated and the dipolarity was computed as the mean squared error of the electrical potential distributions generated by the actual dipole configuration and by the best-fitting single dipole. The simulations show that: 1) a smooth dipole layer with or without holes gives dipolarities above 99.5% even when extended over areas as large as 1256 mm²; 2) randomly oriented dipoles under a smooth dipole layer also give dipolarities above 99.5%; and 3) randomly oriented and distributed dipoles, even if contained in a small portion of the total area, give dipolarities below 93.0%. These simulations show that inhomogeneity (holes) within a dipole disk layer per se do not lower dipolarity; rather, it is the random orientation and distribution of these dipoles which lowers dipolarity. Furthermore, dipolarity is not lowered by such randomly oriented and distributed dipoles when they are beneath a dipole disk layer