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41.
罗立祝 《机械工业高教研究》2008,(2):106-110
从高校招生的演变历史看,中国在1978年以前对工农阶层子女实行高校入学优惠政策主要源于国家对这一阶层的特殊偏好而实行平均主义分配政策所致。国家通过报考资格政策、优先录取政策和免试推荐入学政策人为地大幅度提高了工农阶层子女在高校大学生中所占的比例。从公平视角看,这项政策不仅违背了公平原则,而且降低了人才选拔的质量。 相似文献
42.
W. Shang B. Robrahn F. Golding M. H. J. Koch 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2004,530(3):513-520
A data acquisition system for time resolved X-ray scattering experiments using linear, quadrant or area gas proportional detectors with delay line readout based on commercially available hardware (National Instruments) is described. The system can easily be configured for recording data from point detectors (e.g. photomultipliers and photodiodes) and/or ancillary data only. Applications involving measurements with two different types of time to digital converters illustrate the features and performances of the system. 相似文献
43.
D. P. Phillips, T. E. Ruth, and L. M. Wagner (1993) reported that 1969-1990 California mortality data show that Chinese Americans are particularly vulnerable to diseases that Chinese astrology and traditional Chinese medicine associate with their birth years. For example, because fire is associated with the heart, a Chinese person born in a fire year (such as 1937) is more likely to die of heart disease than is a Chinese person born in a nonfire year. However, many diseases were excluded from this study, some diseases that were included have ambiguous links to birth years, and the statistical tests were indirect. A more complete statistical analysis and independent California mortality data for the years 1960-1968 and 1991-2002 did not replicate the original results. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
No authorship indicated 《Canadian Metallurgical Quarterly》2003,58(11):931
Provides the biography of David W. Johnson and announces that he has won the Award for Distinguished Contributions of Applications of Psychology to Education and Training for programmatic research, comprehensive research reviews, and revision of theory over four decades of persistence that have provided the knowledge foundation for cooperative learning, constructive controversy, conflict resolution, and peer mediation training. A selected bibliography is also provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
45.
Seog Geun Kang 《ETRI Journal》2006,28(2):235-238
In this letter, a block code that minimizes the peak‐to‐average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals is proposed. It is shown that peak envelope power is invariant to cyclic shift and codeword inversion. The systematic encoding rule for the proposed code is composed of searching for a seed codeword, shifting the register elements, and determining codeword inversion. This eliminates the look‐up table for one‐to‐one correspondence between the source and the coded data. Computer simulation confirms that OFDM systems with the proposed code always have the minimum PAPR. 相似文献
46.
47.
对小型中间下料预焙电解槽技术条件摆布的原则和具体数据进行了探讨,提出了尽可能利用从大型预焙槽上得出的先进经验,并消化吸收,掌握好各种条件的平衡,以取得好经济技术指标的观点。 相似文献
48.
Per Hovstad Liching Sung 《International Journal of Satellite Communications and Networking》2005,23(2):91-110
The 1977 Broadcasting‐Satellite Service (BSS) Plan for Region 1 & 3 had been widely acknowledged to be out‐of‐date by the late 1980s. Development of digital modulation in the early 1990s provided an opportunity to update the technical provisions of the Plan to make it more economically viable. After a decade of work and three World Radiocommunication Conferences (WRCs), the revision of Region 1 & 3 BSS Plan was finally completed in 2003. The new Plan increased channel assignments from 5 to 10 analog‐equivalent channels for each country in Region 1, and from 4 to 12 channels for each country in Region 3. Yet, despite the increase in capacity, the new Plan is surprisingly similar to the original one in terms of the technical parameters. It is still based on national coverage, and the channel plan, orbital location, orbital spacing, and polarization are also the same. As a result, the new Plan is no more economically viable to implement than the old. To create economically viable BSS systems would most likely require modifications to the assignment in the Plan. Yet, modification procedures were made more difficult to apply after replanning. Less future implementation of BSS networks than would otherwise have occurred can be expected, and an inefficient usage of these frequency bands will likely result. On the other hand, less implemented systems will mean more capacity set aside for future use. This is important for countries that currently do not have satellite operations. In the end, BSS replanning reflects the eternal conflict between efficient usage and guaranteed future access. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
49.
李桂敏 《中国材料科技与设备》2007,4(4):92-93
本文介绍了一种作业效率高、省时省力新型的转炉炉底车,其特点是转盘转动灵活,炉底车上项盘径向任意方向均能平稳倾斜一定角度,以保证炉底圆周所受项力均匀可靠,满足炉底安装要求。 相似文献
50.
In many legal proceedings, fact finders scrutinize the demeanor of a defendant or witness, particularly his or her nonverbal behavior, for indicators of deception. This meta-analysis investigated directly observable nonverbal correlates of deception as a function of different moderator variables. Although lay people and professionals alike assume that many nonverbal behaviors are displayed more frequently while lying, of 11 different behaviors observable in the head and body area, only 3 were reliably associated with deception. Nodding, foot and leg movements, and hand movements were negatively related to deception in the overall analyses weighted by sample size. Most people assume that nonverbal behaviors increase while lying; however, these behaviors decreased, whereas others showed no change. There was no evidence that people avoid eye contact while lying, although around the world, gaze aversion is deemed the most important signal of deception. Most effect sizes were found to be heterogeneous. Analyses of moderator variables revealed that many of the observed relationships varied as a function of content, motivation, preparation, sanctioning of the lie, experimental design, and operationalization. Existing theories cannot readily account for the heterogeneity in findings. Thus, practitioners are cautioned against using these indicators in assessing the truthfulness of oral reports. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献