低压电弧短路电流计算

根据大量低压电弧短路实验的结果，用概率统计方法导出低压电弧短路时的电弧电压模型及电弧短路电流的计算公式。用这些公式计算的最小电弧短路电流与实验结果吻合。因此，这些公式可用于低压继电保护装置的整定计算，以确保在发生电弧短路时继电保护能可靠动作。     

Controlled multiplex PCR of enterotoxigenic Clostridium perfringens strains in food samples

Developing rats between 5 and 44 days of age as well as rats about 2 months old were anesthetized with urethane. Spontaneous activities and muscle potentials to sciatic stimuli were recorded from their exposed medial gastrocnemius muscles using concentric electrodes. Neostigmine of 0.12-0.40 mg/kg was injected into the contralateral muscles. Regardless of age, spontaneous activities were not observed and muscle potentials were evoked by single stimuli primarily in a biphasic wave (main component) before the drug treatment. Developmental differences were revealed in the presence of the drug. 1) Spontaneous activities were detected only in single spikes around postnatal 10 days. Single or double spikes were often found in rats of about two weeks. Burst discharges such as seen in adult rats were observed immediately before weaning. 2) In rats of 2 weeks or so, one or more components were observed obscurely following the main component of muscle potentials, which appeared definitely at the preweaning period. 3) When double shocks with the interval of 2 sec were delivered in the presence of the drug, the second potential was greatly depressed in rats older than two weeks as well as in adult rats. The potential was only slightly reduced in rats around 10 days. Thus, an adult pattern as to impulse transmission was observed immediately before weaning. These alterations would, at least in part, reflect the maturation of acetylcholine receptors at neuromuscular junctions.     

Analysis of a Liquid Metal Current Limiter

A liquid metal fault current limiter (LMFCL) was investigated as a tool for improving the power quality and reliability of power service. The LMFCL is a newly developed current limiter for low-voltage power systems. It can effectively limit the fault current by taking advantage of the pinch effect and arcs in the LMFCL. A multiphysics simulation of magneto-fluid in the LMFCL was performed based on the 3-D finite element method for analysis of the pinch effect. The magnetic forces were calculated, and the turbulence driven by the magnetic forces was simulated. The results of the turbulent simulation coincide with those of the experiments. Several characteristics of the LMFCL are described based on analysis of the results of experiments with single-phase power sources of 253, 440, and 725-V.     

Edge-connected, crossed-electrode array for two-dimensionalprojection and beamforming

A novel geometry for planar structures which allows simpler implementation and construction while trading off higher signal processing costs and possible reduced performance is introduced. A geometry for array construction which uses two sets of orthogonal striped electrodes is discussed. The basic operation principles of the geometry are given. While obtaining N² intersecting points in a two-dimensional structure, only 2N control points are required. Thus, N² active elements are controlled with 2N degrees of freedom, which simplifies both implementation and data handling. This gain in simplicity is traded off against reduced performance when used as a projector and increased signal processing when used in beamforming if the process is carried out in a two-step process. The limitations of the crossed-electrode geometry and discussed, and a theory for operation as a projector and a receiver is presented     

Impact of gender characteristics of instructional materials: An integration of the research literature.

Discusses the influence of gender characteristics of instructional materials on children. Recent reviews indicate that most instructional materials are still sexist. Definitions of sexist and sex equitable that incorporate both language form and gender content are included in the present article. Generalizations synthesized from research regarding the effects of gender characteristics of instructional materials on students are presented. It is suggested that the following generalizations apply to students from preschool through college age: (1) The use of gender-specified language forms explicitly including both sexes yields gender-balanced associations, while use of male generic language frequently results in male associations. (2) Exposure to sex-equitable materials results in more flexible sex role attitudes for both males and females, with degree of attitude change being directly related to the amount of exposure. (3) Students often prefer materials with same-sex main characters but do not reject sex-equitable materials. (4) The patterns for comprehension are not as clear, but sex-equitable materials do not decrease comprehension. (63 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ejection of a rear facing,golf cart passenger

The following report details the findings of a series of experiments and simulations performed on a commercially available, shuttle style golf cart during several maneuvers involving rapid accelerations of the vehicle. It is determined that the current set of passive restraints on these types of golf carts are not adequate in preventing ejection of a rear facing passenger during rapid accelerations in the forward and lateral directions. Experimental data and simulations show that a hip restraint must be a minimum of 13 in. above the seat in order to secure a rear facing passenger during sharp turns, compared to the current restraint height of 5 in. Furthermore, it is determined that a restraint directly in front of the rear facing passenger is necessary to prevent ejection. In addressing these issues, golf cart manufacturers could greatly reduce the likelihood of injury due to ejection of a rear facing, golf cart passenger.     

Hygienic problems of air moistening in children''s facilities]

Advances in understanding genetic disorders have been rapid in the last few years and with them the need and desire for genetic counselling have grown. Almost simultaneously, particularly in the USA, several large screening programmes have been initiated to screen large numbers of people who may be carriers of such deleterious genes as those of Tay-Sachs disease and sickle cell anaemia. The authors of this paper, clinical medical students at University College Hospital, London, spent some time studying the ethical issues raised. The first part of their study, which is not published here, relates to the biochemistry of certain genetic disorders, so leading up to the aspect of the subject which must concern readers of this journal, genetic counselling. At present genetic counselling is generally the province of the medical practitioner working with clinical biochemists, and in this paper their function is described and how programmes of screening for carriers are designed. Whether the subjects of the screening tests are found to be 'innocent' or 'guilty' psychological problems confront them, and of these the genetic counsellor must be aware. In fact the range of ethical problems raised by such counselling is wide and can only be sketched in this article.     

Adaptive abilities of hospitalized alcoholics and matched controls. The brain-age quotient

1 The effect of a series of antidepressant drugs on noradrenaline accumulation was studied in the isolated anococcygeus muscle of the rat. 2 The most potent inhibitors of noradrenaline accumulation were nortriptyline, desipramine and protriptyline. Opipramol, trimipramine and iprindole were active only in high concentrations. 3 Contractions of the anococcygeus muscle produced by noradrenaline were strongly potentiated by nortriptyline, desipramine and protriptyline. Other uptake inhibitors were less active in potentiating the noradrenaline response. 4 Nortriptyline, in concentrations that potentiated the action of noradrenaline, reduced or abolished the response to tyramine.     

Active‐matrix and flexible liquid‐crystal displays with carbon‐nanotube pixel electrodes

Abstract— The necessary processes to use random carbon‐nanotube networks as transparent conductors in twisted‐nematic liquid‐crystal displays have been developed, replacing indium tin oxide. Because the nanotubes are deposited vacuum‐free from suspension, the potential advantages are lower costs for material, equipment, and production. Nanotube networks are also much better suited for flexible displays than the commonly used metal oxides. With the developed processes, the world's first full‐color active‐matrix LCDs as well as directly addressed flexible displays on plastic substrates with carbon‐nanotube pixel electrodes, have been realized.