用于战术制导与导航应用的一种微机械振梁多敏感器的研制

基尔福特(Kearfott)制导与导航公司已经开发出用于战术惯性制导与导航应用的一种微机械振梁多敏感器(MVBM).这种MVBM是一种固态石英(硅Si)器件,它测量运动共轴的线加速度和角速率.这是通过单个柔性放置的检测质量来实现的,其中检测质量起到一种耦合模式的哥里奥利(Coriolis-哥氏)敏感器和加速度计的作用.位置敏感器是固定的,以使这两种测量在双级输出中有所不同,这样增加了标度因数,且相对于单极器件而言降低了共模而引起的热、振动以及老化误差.     

Plasma concentrations of prolactin, growth hormone, and luteinizing hormone in steers administered ergotamine or ergonovine

This research investigated whether ergot alkaloids associated with endophyte-infected tall fescue could alter plasma concentrations of pituitary hormones that regulate biological processes related to cattle performance. Seven Angus yearling steers received single i.v. injections of ergotamine tartrate, ergonovine maleate, or saline vehicle in a simple cross-over design. Each steer was given a different compound each week. Blood samples were collected at 15-min intervals for 45 min before and 240 min after treatments to assess plasma concentrations of prolactin, growth hormone, and LH. Respiratory rates were measured hourly to ascertain a systemic effect. Ambient temperature averaged 34 degrees C during data collection. Treatment x time was a significant source of variation for respiration rate and plasma concentrations of each hormone evaluated. Respiration rates were higher for ergonovine than for saline (P < .02) and ergotamine (P < .07) 30 min after treatment, but they were higher (P < .05) for ergotamine than for ergonovine and saline by 210 min after treatment. Both alkaloids transiently elevated (P < .01) plasma growth hormone concentrations compared with before alkaloid treatment and after saline treatment. Ergotamine reduced (P < .01) plasma concentrations of prolactin and LH throughout the 120-min period after treatment compared with concentrations before ergotamine treatment and after saline treatment. Ergonovine lowered (P < .01) prolactin concentrations for a shorter time than ergotamine and did not affect mean LH concentrations. Results indicated that ergot alkaloids implicated as contributing agents to fescue toxicosis can alter plasma concentrations of pituitary hormones important to cattle production.     

A 300 GHz quasioptical schottky frequency doubler

A monolithically integrated frequency multiplier based on a planar antenna providing impedance matching has been realized and measured at 300 GHz. Each of the two circuits comprises a Schottky varactor, slot antenna, MIM-capacitor and microstrip bias feed. The theoretical design aspects, the technological approach and the RF performance are addressed.     

Self-adjusting anode power supply for a gyrotron

Sydney University's tunable cw gyrotrons use a simplified power supply arrangement to provide the voltages on the gun electrodes. The cathode supply is conventional, but the anode voltage is provided by a single highvalue resistor connected between the anode and ground. A small fraction of the electrons in the beam are reflected and the anode automatically finds an optimum operating potential. This arrangement is shown to have lower starting currents. Two advantages follow. It becomes easier to operate low-power gyrotrons with modest power supplies and it becomes easier to achieve higher frequencies by exciting harmonics of the electron cyclotron frequency.     

Individual perceptions of stress by dentists

This paper is concerned with individual responses of four dental practitioners to stress. The subjects were chosen on the basis of age, sex, length of time in practice and whether or not they practised solo or in a group. Responses were measured against ten stressor variables that were previously found to have occurred commonly among dentists. From these responses stressor ratings of the four subjects were obtained and compared. These ratings, which seem to be idiosyncratic and unpredictable, reflect wide differences between the respondents. The findings suggest the possibility that these differences may be attributable to personality factors and differences in coping styles, and tend to support the hypothesis that stress is a unique, perceptual and experimental phenomenon.     

Intraperitoneal chemo-hyperthermia with mitomycin C in cancer of the stomach with peritoneal carcinosis

We report 42 cases of gastric cancer with peritoneal carcinosis treated with intraperitoneal chemohyperthermia. Intraperitoneal chemohyperthermia was achieved with a closed sterile circuit containing mitomycin C, 10 mg/l producing an input temperature varying from 46 to 49 degrees C for 90 minutes. There were three postoperative deaths: one pulmonary embolism at day 4, one multiple organ failure et day 4, and one septic shock at day 25 due to a colonic fistula. Two patients suffered complications: one opening of the duodenal stump requiring reoperation on day 5, and one prolonged postoperative ileus lasting to day 10. Of the 12 patients with ascites, resorption was achieved in 8. In patients with early-stage peritoneal carcinosis (granulations less than 5 mm) survival at 1, 2 and 3 years was 90%, 61% and 41% respectively. For those with more extensive carcinosis, survival at 1 year was 10%. Five patients survived more than 30 months, three have survived to 34, 43 and 73 months. Intraperitoneal chemohyperthermia is a new treatment for carcinosis of gastric origin. These early results must be assessed further with larger controlled.     

Changes in epoxy-coated aluminium due to exposure to water

An investigation was performed of the changes that occur in a typical epoxy-coated aluminium system due to exposure to water. The adhesion of the epoxy coating upon exposure to water was evaluated for different exposure temperatures and periods. The adhesion test results showed an initial loss of adhesion of the coating but after this the adhesion improved again and even significantly exceeded adhesion prior to exposure. The amount of adhesion improvement and the speed with which adhesion improvement occurred was found to be larger for higher exposure temperatures. The changes that occur in the epoxy-coated aluminium system due to exposure to water were investigated using a number of different analytical techniques. Based on this, a model was proposed for the processes that take place during exposure and which can explain the adhesion test results. First, the adhesion of the epoxy coating is lost upon exposure due to the accumulation of a significant amount of water at the interface. The water at the interface causes formation and growth of a thin oxyhydroxide layer underneath the epoxy coating. After some time, this oxyhydroxide layer re-establishes contact with the epoxy coating and forms a new, water-stable bond, hence explaining the improvement of the adhesion after its initial loss.

The temperature-dependence observed in the adhesion test results is explained by the fact that at a higher exposure temperature, more water accumulates at the interface, the oxyhydroxide layer grows faster and also attains a larger limiting thickness.     

Digital station protection

A homogeneous and uniform protective system for all protected units in a substation, which uses the processing capabilites of modern microprocessors, is presented. The basic idea is to split protective tasks into processing and data communication. The processing units are located at each boundary of the protection zones, each of which always comprises phasor representation for currents and voltages, fault type, and fault direction are evaluated. The selective tripping command for each protection zone is produced by collective merging allows bridging of faulty components. The required communication can be adapted to both requested protective functions and availability, reliability, and maintainability. Cooperation with other protective devices, especially with stand-alone relays, further protection-related functions and other substation tasks are supported. Laboratory tests and field experience obtained so far have proved the feasibility of this digital station protection     

Can pluralism be intolerant?

Comments on the article by R. E. Redding (see record 2001-00465-001) which discusses pluralism and sociopolitical diversity in psychology. The current author agrees with Redding's stance that the discipline of psychology is liberally biased and presents his opinions in support of Redding's argument. It is stated that taking Redding's analysis seriously, along with addressing its implications for psychological theory, research, practice, and education, would improve the discipline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)