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The principal contribution of this note is to avoid the parametric resonance effect and attenuate the payload oscillations in an overhead-crane system subject to periodic variations in the base support. Considering an appropriate sliding output with relative degree one, we present the sliding mode control design based on the Super-Twisting Algorithm (STA), ensuring finite time convergence to the desired sliding surface for the linear periodic system with Lipschitz continuous matched and unmatched uncertainties bounded together by their gradients by known functions. The suggested approach also provides chattering phenomenon attenuation. Obtained results are verified experimentally.  相似文献   

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After completing the work on mapping chicken genome sequence and chicken genome variation in early March, 2004, two international research consortiums have made significant progress in reading the maps, shedding new light on the studies into the first bird as well as the first agricultural animal that has its genome sequenced and analyzed in the world.  相似文献   

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Following China's announcement of its completion of the draft genome sequence of the rice indica subspecies on October 12,2001 (page 126, Bulletin of the Chinese Academy of Sciences Vol. 15 No.3), Chinese scientists published their findings in the April 5 issue of Science, the journal of the American Association for the Advancement of Science (AAAS). In the same issue, a team of scientists with the Switzerland-based Syngenta company reported a similar achievement for another major rice subspecies,japonica.  相似文献   

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Adetailed analysis of the high-quality sequence of the rice genome was published in the August 11 issue of the journal Nature, marking the completion of a six-year international collaborative effort to unravel the genome of the world's most important food crop that feeds over half of the global population.  相似文献   

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This paper deals with the design and implementation of a nonlinear control algorithm for the attitude tracking of a four-rotor helicopter known as quadrotor. This algorithm is based on the second order sliding mode technique known as Super-Twisting Algorithm (STA) which is able to ensure robustness with respect to bounded external disturbances. In order to show the effectiveness of the proposed controller, experimental tests were carried out on a real quadrotor. The obtained results show the good performance of the proposed controller in terms of stabilization, tracking and robustness with respect to external disturbances.  相似文献   

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合成生物学是利用工程化的思想来设计和构建新的生物基因组,是近年来的研究热点。近年来,对原核细胞支原体天然小基因组进行从头合成并进一步设计与构建最小基因组,对原核模式生物大肠杆菌基因组的不断删减及全基因组密码子简约化设计与人工合成测试,以及对真核模式生物酿酒酵母基因组人工设计与合成测试都取得了很大成功,极大地促进了我们对生命的理解。我国的基因组的设计与工程化构建方面的研究虽然起步较晚,但近年来取得了国际瞩目的成果。基因组的设计与构建为深入了解生命起源与进化,并为进一步构建具有强大应用功能的新型生命体奠定了基础。  相似文献   

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面对人类基因组,我们既是客体,也是主体,这种两重性将深刻影响人类自身.伴随着人类和其他一些生物种属(如模式生物等)基因组测序和作图的初步完成,以功能基因组为中心的探索已经大规模展开.结构和功能基因组学概念的提出,促使人们在全基因组的框架下,以全新的视角研究、认识和理解基因与基因组的生物学涵义及人类学的尊严.其中,人类基因组测序被称为这个时代最具突破性的科学事件.……  相似文献   

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Chinese scientists have recently completed sequencing mitochondrial genome of the Tibetan antelope, an endangered animal on the Qinghai-Tibetan Plateau.  相似文献   

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材料基因组计划及其实施进展研究   总被引:1,自引:0,他引:1  
详细综述美国材料基因组计划( MGI)提出背景及其实施方案(包括实施流程),重点总结MGI近三年来计划实施四个主要联邦机构在基础设施建设(实验工具、计算工具和电子化数据)、教育培训等方面以教育作为计划实施导入点,以“保卫国家安全、造福人类福祉和培育下一代人才资源”为宗旨,从市场需求倒叙研究材料微细观组分与性能,为军方材料基因计划顺利打通实施通道和加速材料研发进程奠定根基。  相似文献   

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We re-conceptualize the role of science policy makers, envisioning and illustrating their move from being simple investors in scientific projects to entrepreneurs who create the conditions for entrepreneurial experiments and initiate them. We argue that reframing science policy around the notion of conducting entrepreneurial experiments - experiments that increase the diversity of technical, organizational and institutional arrangements in which scientific research is conducted - can provide policy makers with a wider repertoire of effective interventions. To illustrate the power of this approach, we analyze the Human Genome Project (HGP) as a set of successful, entrepreneurial experiments in organizational and institutional innovation. While not designed as such, the HGP was an experiment in funding a science project across a variety of organizational settings, including seven public and one private (Celera) research centers. We assess the major characteristics and differences between these organizational choices, using a mix of qualitative and econometric analyses to examine their impact on scientific progress. The planning and direction of the Human Genome Project show that policy makers can use the levers of entrepreneurial experimentation to transform scientific progress, much as entrepreneurs have transformed economic progress.  相似文献   

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Large animals (non-human primates, livestock and dogs) are playing important roles in biomedical research, and large livestock animals serve as important sources of meat and milk. The recently developed programmable DNA nucleases have revolutionized the generation of gene-modified large animals that are used for biological and biomedical research. In this review, we briefly introduce the recent advances in nuclease-meditated gene editing tools, and we outline these editing tools’ applications in human disease modeling, regenerative medicine and agriculture. Additionally, we provide perspectives regarding the challenges and prospects of the new genome editing technology.  相似文献   

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水稻第四号染色体精确测序完成   总被引:1,自引:0,他引:1       下载免费PDF全文
水稻是最重要的粮食作物之一,是世界约一半以上人口的主要口粮。水稻作为禾本科植物基因组研究的模式作物,具有十分重要的意义。中国科学院国家基因研究中心率先完成了国际水稻基因组计划的第4号染色体全长序列的精确测序,该成果已在英国的《自然》杂志发表。本文简要报告水稻基因组测序的意义和目前我国在这一领域已取得的进展,并着重介绍水稻基因组4号染色体精确测序和分析的成果。  相似文献   

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Researchers with the CAS Wuhan Institute of Virology (WHIOV) recently completed the genome sequencing of a mosquitocidal bacterium Bacillus sphaericus C3-41. The feat, first of its kind in China, is expected to further promote the bio-control studies of mosquitoes.  相似文献   

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Creativity is considered a human characteristic; creative endeavors, including automatic story generation, have been a major challenge for artificial intelligences. To understand how humans create and evaluate stories, we (1) construct a story dataset and (2) analyze the relationship between emotions and story interestingness. Given that understanding how to move readers emotionally is a crucial creative technique, we focus on the role of emotions in evaluating reader satisfaction. Although conventional research has highlighted emotions read from a text, we hypothesize that readers’ emotions do not necessarily coincide with those of the characters. The story dataset created for this study describes situations surrounding two characters. Crowdsourced volunteers label stories with the emotions of the two characters and those of readers; we then empirically analyze the relationship between emotions and interestingness. The results show that a story’s score has a stronger relationship to the readers’ emotions than the characters’ emotions.  相似文献   

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<正>DNA is the language of life with the alphabet of four nucleobases–adenine (A), thymine (T), guanine(G), and cytosine (C). Language has the power to define and converse, and so does DNA. DNA stores genetic information and defines what a living thing looks like. DNA can also be interpreted into the molecules of RNAs and proteins that are the two key players to support a life and interact or "converse" with other living things.  相似文献   

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