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通井机液压泵接合器的改进与应用
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作者 位志斌 张保国 +1 位作者 王汝涛 刘平震 《机械工程师》 2011年第2期138-138,共1页
介绍了一种提高通井机液压泵转速的液压泵变速结合转换器装置,从而降低了油耗,延长了工具的使用寿命,提高了工作效率。
关键词 作业设备 通井机液压泵 接合装置
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8-Weighted-Type Fractional Fourier Transform Based Three-Branch Transmission Method 被引量:3
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作者 Jing Li Xuejun Sha +1 位作者 Xiaojie Fang Lin Mei 《China Communications》 SCIE CSCD 2018年第9期147-159,共13页
To improve the bit error rate(BER) performance of multiple input multiple output(MIMO) systems with low complexity, a three-branch transmission scheme employing 8-weighted-type fractional Fourier transform(8-WFRFT) mo... To improve the bit error rate(BER) performance of multiple input multiple output(MIMO) systems with low complexity, a three-branch transmission scheme employing 8-weighted-type fractional Fourier transform(8-WFRFT) module is proposed. In the proposed scheme, the original signal is first decomposed into eight sub-signals and then merged into three component signals by the same carrier pattern. The three signals have mathematical constraint relations among themselves that can counteract the channel fading. They are simultaneously transmitted via three independent antennas after delay regulating. At the receiver, an inverse 8-WFRFT module is employed to obtain the estimated original signal by processing the received signal. Then, the bit error rate(BER) performance, transmitting power, transmission rate, power spectrum and computational complexity of the proposed scheme are analysed in detail. Numerical results show that the proposed scheme has a superior performance compared to STBC based three-antenna transmission scheme, in terms of BER performance. 展开更多
关键词 8-weighted-type fractional Fourier transform (8-WFRFT) bit error rate (BER) low complexity multiple input multiple output (MIMO)
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English Connector as Binding Term for Conjunction and Relative Pronoun
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作者 Japen Sarage 《Sino-US English Teaching》 2015年第9期660-666,共7页
As grammatical words, conjunction and relative pronoun play a similar role. They join clauses, phrases, and even words. The terms independent and dependent clauses have become popular for quite a long time. When the c... As grammatical words, conjunction and relative pronoun play a similar role. They join clauses, phrases, and even words. The terms independent and dependent clauses have become popular for quite a long time. When the concept of clause and sentence meets at the presence of NP (Noun Phrase) and VP (Verb Phrase), there is a right to consider construction as an S or a sentence leaving the conjunction and relative pronoun as means of uniting device and leaving every NP-VP construction as equal units. By employing an embedding theory, we can see hidden parts of a sentence and their roles in other sentences. This article tries to see if it is still necessary to distinguish between dependent and independent clauses. 展开更多
关键词 CONNECTOR CONJUNCTION relative pronoun
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