Einfluß der Probengeometrie auf die Ergebnisse von Bruchmechanik-Untersuchungen an dem Stahl StE 47

Untersuchung an Kompakt-Zug-(CT-)Proben zum Einfluß der Probendicke und -breite auf die Rißzähigkeit des Stahls StE 47 in Abhängigkeit von der Prüftemperatur. Auswirkungen auf die Ausbildung der plastischen Zone und das Bruchaussehen. Vergleich der Rißzähigkeit mit den bruchmechanischen Kenngrößen Rißaufweitung und J-Integral.     

Epidemiological comparisons of problems and positive qualities reported by adolescents in 24 countries.

In this study, the authors compared ratings of behavioral and emotional problems and positive qualities on the Youth Self-Report (T. M. Achenbach & L. A. Rescorla, 2001) by adolescents in general population samples from 24 countries (N = 27,206). For problem scales, country effect sizes (ESs) ranged from 3% to 9%, whereas those for gender and age ranged from less than 1% to 2%. Scores were significantly higher for girls than for boys on Internalizing Problems and significantly higher for boys than for girls on Externalizing Problems. Bicountry correlations for mean problem item scores averaged .69. For Total Problems, 17 of 24 countries scored within one standard deviation of the overall mean of 35.3. In the 19 countries for which parent ratings were also available, the mean of 20.5 for parent ratings was far lower than the self-report mean of 34.0 in the same 19 countries (d = 2.5). Results indicate considerable consistency across 24 countries in adolescents' self-reported problems but less consistency for positive qualities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of Power Converters for AC-Fed Traction Drives and Microcomputer-Aided On-Line Optimization of Their Line Response

The analysis of sector-controllable bridges shows the dependence of line responses on special circuit parameters and control methods. The line response of a line current is calculated in terms of the corresponding harmonic spectrum and the magnitudes of the power factor X and the psophometric current Ip4. Referring to the case of a drive model, it is shown how a microcomputer control system optimizes the line response of a particular power converter. This system evaluates the harmonics of line current and line voltage, using a fast FFT-computer. These harmonics are then expressed in terms of certain quantities which represent the line response of the system. A control algorithm makes use of these quantities to calculate a combination of firing angles for an optimum power factor, the minimum psophometric current or the suppression of certain harmonics. In this way, a traction drive can be operated by automatic control, causing little influence on the line side.     

On the Development of the Mental Number Line: More, Less, or Never Holistic With Increasing Age?

Magnitude is assumed to be represented along a holistic mental number line in adults. However, the authors recently observed a unit-decade compatibility effect for 2-digit numbers that is inconsistent with this "holisticness" assumption (H.-C. Nuerk, U. Weger, & K. Willmes, 2001). This study used the compatibility effect to examine whether the mental number line representation of magnitude changes toward greater or less holisticness in children from Grades 2-5. The results indicate that decades and units of 2-digit numbers are processed separately rather than holistically from Grade 2 on. However, this separate processing seems to develop from a more sequential (left-to-right) to a more parallel processing mode. Moreover, children may use different strategies depending on task demands. The results are interpreted in the framework of Siegler's overlapping waves model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

喷油率形状可变的增压式压电共轨喷射系统

柴油机的低排放与经济性是相互矛盾的，为降低制造成本和运行费用，必须进一步采取机内净化措施降低柴油机的原始排放和燃油耗，其中燃油喷射系统依然起着十分重要的作用。Bosch公司正在研制的一种增压式压电共轨喷射系统(APCRS)，不但能以较低的共轨压力获得比一般共轨系统高得多的喷油压力，而且除能进行多次预喷射和后喷射外，还能使主喷射的喷油率形状从矩形变化到斜坡形直至靴形，与柴油机的运转工况达到最佳的匹配，在宽广的发动机特性曲线范围内显示出明显降低排放和燃油耗的潜力。     

Methods of pattern recognition in the synthesis and identification of thin film optical systems

A layered medium is regarded as an input-output system in which the system structure is given by a parameter vector a. The output (e.g. reflectivity) is a computable function F(x,a) of the input x (e.g. wavelength, angle of incidence) and a. In synthesis a is to be determined such that F(x,a) is (in a certain sense) the best approximation of a prescribed behaviour; in the identification of the system the prescribed behaviour is replaced by a set of measurements. We consider a synthesis method based on a direct exploration of the frequency function F(x,a) without constructing a merit function. The parameter space is subjected to discretization. For each parameter vector a of this finite set we check the waveform y = F(x,a) for relevant phenomena. This method consumes a large amount of computation time and therefore requires efficient pattern recognition procedures; linguistic structure analysis is of special interest. We report algorithms for plateau detection, including numerical experiments.