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转学
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作者 詹亦慕 李秀华 《小学生作文》 2016年第7期118-119,共2页
来南京上学已经快一个月了.今天做完作业,我不由得又想起转学的那一天。记得当时我们正在上数学课,班主任陈老师突然走进教室,有些闷闷不乐地对我说:“詹亦慕,把书包整理好,跟我出来。”
关键词 小学教育 语文 作文 《转学
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转学
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作者 詹亦慕 李秀华 《小学生作文》 2011年第2期11-12,共2页
来南京上学已经快一个月了,今天做完作业,我不由得又想起转学的那一天。记得当时我正在上数学课,班主任陈老师突然走进教室,有些闷闷不乐地对我说:“詹亦慕,把书包整理好,跟我出来。”全班同学都觉得很奇怪,
关键词 《转学 小学生 作文 语文学习
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齿轮耦合的转子-轴承系统非线性动力特性的研究 被引量:31
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作者 张锁怀 李忆平 丘大谋 《机械工程学报》 EI CAS CSCD 北大核心 2001年第9期53-57,61,共6页
在考虑齿轮时变啮合刚度、齿侧间隙、脱齿、挤齿及齿背接触 等因素的情况下,建立了齿轮耦合的转子—滑动轴承系统的多自由度动力学模型。用数值方 法研究了该系统的质量不平衡响应,结果发现,由于齿轮时变啮合刚度的影响,随着转速的... 在考虑齿轮时变啮合刚度、齿侧间隙、脱齿、挤齿及齿背接触 等因素的情况下,建立了齿轮耦合的转子—滑动轴承系统的多自由度动力学模型。用数值方 法研究了该系统的质量不平衡响应,结果发现,由于齿轮时变啮合刚度的影响,随着转速的 增加,系统动力学响应首先由周期运动向准周期运动变化,当转速超过某一值时,系统的响应将由准周期运动发展为混沌运动;由于混沌运动,转子将沿齿轮中心线方向产生很大的变 形,脱齿、齿背接触及挤齿现象也将发生,可能导致系统产生破坏。 展开更多
关键词 齿侧间隙 时变啮合刚度 分岔 混沌 非线性动力学 齿轮耦合 转子-轴承系统
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Advances and applications in spatial transcriptomics
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作者 SUN Yueqiu YU Nianzuo ZHANG Junhu 《分子科学学报》 CAS 2024年第2期95-106,共12页
Spatial transcriptomics is an organizational study done on tissue sections that preserves the spatial information of the sample.Spatial transcriptomics aims to combine spatial information with gene expression data to ... Spatial transcriptomics is an organizational study done on tissue sections that preserves the spatial information of the sample.Spatial transcriptomics aims to combine spatial information with gene expression data to quantify the mRNA expression of a large number of genes in the spatial context of tissues and cells.As a paradigm shift in biological research,spatial transcriptomics can provide both spatial location information and transcriptome-level cellular gene expression data,elucidating the interactions between cells and the microenvironment.From the understanding of the entire functional life cycle of RNA to the characterization of molecular mechanisms to the mapping of gene expression in various tissue regions,by choosing the appropriate spatial transcriptome technology,researchers can achieve a deeper exploration of biological developmental processes,disease pathogenesis,etc.In recent years,the field of spatial transcriptomics has ushered in several challenges along with its rapid development,such as the dependence on sample types,the resolution of visualized genes,the difficulty of commercialization,and the ability to obtain detailed single-cell information.In this paper,we summarize and review the four major categories of spatial transcriptome technologies and compare and analyze the technical advantages and major challenges of multiple research strategies to assist current experimental design and research analysis.Finally,the importance of spatial transcriptomics in the integration of multi-omics analysis and disease modeling as well as the future development prospects are summarized and outlined. 展开更多
关键词 spatial transcriptomics spatial position omics technology multi-omics
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转学外星球
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作者 李志伟 《少先队员(成长树)》 2009年第11期42-44,共3页
学校里流传着一条爆炸性新闻:五(2)班的李大奇要转到鳄鱼星球去上学啦!
关键词 初等教育 作文 语文教育 《转学外星球》
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转学,转变,转过头
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作者 大葱头 马开峰(图) 《中国少年儿童》 2010年第3期18-20,共3页
转学的尴尬 三年级之前,我生性活泼,是班里的优等生,那时我最爱干的事情就是抢答老师的提问。三年级以后,由于父母工作变动,我也被迫转学,从此我的性格也陡然走向另一个极端。
关键词 小学 课外阅读 阅读材料 《转学 转变 转过头》
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Role of inclination angle on columnar-to-equiaxed transition in the eutectic Al-5Mg-2Si alloy fabricated by laser powder bed fusion
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作者 YANG Fei-peng WEN Tao +4 位作者 ZHANG Lei WANG Jian-ying HUANG Shi-long JI Shou-xun YANG Hai-lin 《Journal of Central South University》 SCIE EI CAS 2024年第7期2150-2166,共17页
In this study,the effect of inclination angles relative to the building direction in the additively manufactured eutectic Al-5Mg-2Si alloy was investigated through the laser powder bed fusion(LPBF).The microstructures... In this study,the effect of inclination angles relative to the building direction in the additively manufactured eutectic Al-5Mg-2Si alloy was investigated through the laser powder bed fusion(LPBF).The microstructures and mechanical properties of the Al-5Mg-2Si alloy manufactured with different inclination angles(0°,30°,45°,60°and 90°)were reported and discussed.It is found that the“semicircular”melt pool(MP)in the load bearing face of 0°sample was eventually transformed into“stripe-like”MP in the 90°sample,accompanied by an increased fraction of melt pool boundaries(MPBs).Moreover,the microstructural analysis revealed that the columnar-to-equiaxed transition(CET)of theα-Al grains and eutectic Mg2Si was completed in the 90°sample,which were significantly refined with the average size of 10.6μm and 0.44μm,respectively.It is also found that the 90°sample exhibited good combination of strength and elongation(i.e.yield strength of 393 MPa,ultimate tensile strength of 483 MPa and elongation of 8.1%).The anisotropic mechanical properties were highly associated with the refined microstructures,thermal stress,and density of MPBs.Additionally,the CET driven by inclination angles was attributed to the variation of thermal conditions inside the local MPs. 展开更多
关键词 additive manufacturing aluminium alloys columnar-to-equiaxed transition anisotropy mechanical property
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Thermochemical recycling of waste disposable facemasks in a non-electrically powered system
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作者 Kingsley O.Iwuozor Ebuka Chizitere Emenike +3 位作者 Agbana Abiodun Stephen Otoikhian Shegun Kevin Joy Adeleke Adewale George Adeniyi 《Low-carbon Materials and Green Construction》 2023年第1期146-156,共11页
The COVID-19 pandemic encouraged the use of plastic-based personal protective equipment (PPE), which aidedgreatly in its management. However, the increased production and usage of these PPEs put a strain on the enviro... The COVID-19 pandemic encouraged the use of plastic-based personal protective equipment (PPE), which aidedgreatly in its management. However, the increased production and usage of these PPEs put a strain on the environment,especially in developing and underdeveloped countries. This has led various researchers to study low-costand effective technologies for the recycling of these materials. One such material is disposable facemasks. However,previous studies have only been able to engage electrically powered reactors for their thermochemical conversion,which is a challenge as these reactors cannot be used in regions with an insufficient supply of electricity. In thisstudy, the authors utilized a biomass-powered reactor for the conversion of waste disposable facemasks and almondleaves into hybrid biochar. The reactor, which is relatively cheap, simple to use, environmentally friendly, and modifiedfor biochar production, is biomass-powered. The co-carbonization process, which lasted 100 min, produced a 46%biochar yield, which is higher than previously obtained biochar yields by other researchers. The biochar thus obtainedwas characterized to determine its properties. FTIR analysis showed that the biochar contained functional groupssuch as alkenes, alkynes, hydroxyls, amines, and carbonyls. The EDX analysis revealed that the biochar was primarilymade of carbon, tellurium, oxygen, and calcium in the ratios of 57%, 19%, 9%, and 7%, respectively. The inclusion ofthe facemask decreased the surface area and porosity of the biochar material, as evidenced by its surface area andpore characteristics. 展开更多
关键词 Biochar Biomass Covid-19 Facemask Thermochemical conversion
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