检索结果-南通市图书馆

同方期刊数据库

Influences of Rifle Weight,Weight Distribution and Layout on Aiming Comfort

在线全文

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2019年第2期28卷 248-256页

作者： Yang Yang yaping wang Cheng Xu Liqing Cheng Institute of Technology Anhui Agricultural UniversityHefei 230036China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China

A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of *** study explores how the rifle weight,weight distribution and layout(*** length,position of grip and forestock)affect aiming *** the paper,the upper extremity muscle activity was used to characterize the aiming comfort.A human-rifle musculoskeletal model was developed,which was validated by the surface electromyography(EMG)*** results showed that the design parameters of rifle(weight,distance of gravity center to body and layout)had a significant influence on aiming *** greater the weight was,the stronger the muscle activity *** the distance increasing,first the muscle activity decreased,and then increased when the distance is exceeding a certain *** addition,the combined influences of weight and distance illustrated that there was an optimal distance to make the slightest muscle movements for certain *** designing a rifle’s layout,more muscular exertions were required to maintain the holding posture with the stock length increasing,which was suggested to be in the range of 0.1 8 m to 0.2 7 *** can be used to optimize the ergonomics design of rifle,improving the comfort of the rifle aiming process and the shooting accuracy.

关键词： rifle human-rifle musculoskeletal model weight weight distribution layout

壳体单元与实体单元在大型压力容器吊装分析中的对比分析

在线全文

学校读者我要写书评

暂无评论

现代制造技术与装备 2024年第8期60卷 88-92,102页

作者：赵亚如王亚萍王瑞卿张珺珺山东豪迈机械制造有限公司潍坊261500

研究压力容器各结构在吊装过程是否会发生塑性垮塌至关重要,但压力容器结构复杂,建立的有限元模型网格数量较多,降低了计算效率。基于此,提出用壳体单元模型替代实体单元模型的方法,并对结果的可靠性进行验证。研究结果表明,壳体单元最... 详细信息

研究压力容器各结构在吊装过程是否会发生塑性垮塌至关重要,但压力容器结构复杂,建立的有限元模型网格数量较多,降低了计算效率。基于此,提出用壳体单元模型替代实体单元模型的方法,并对结果的可靠性进行验证。研究结果表明,壳体单元最大Mises当量应力位置、变形趋势与实体单元相同,但由于实体单元存在峰值应力,实体单元的Mises当量应力大于壳体单元;壳体单元的薄膜应力与薄膜加弯曲应力均大于实体单元,实体单元的Mises当量应力大于壳体单元,这是因为壳体单元仅计算了一次应力与二次应力,无峰值应力,但不影响塑性垮塌评定。因此,对于非疲劳工况的压力容器,可采用壳体单元代替实体单元进行分析,以在减少计算量的情况下得到精确的数值解。

关键词：壳体单元实体单元有限元模型压力容器吊装塑性垮塌

The response of sedimentary record to catchment changes induced by human activities in the western intertidal flat of Yalu River Estuary,China

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2017年第4期36卷 54-63页

作者： SHI Yong LIU Zhishuai GAO Jianhua YANG Yang wang yaping National Ocean Technology Center Tianjin 300111 China Ministry of Education Key Laboratory for Coast and Island Development Nanjing University Nanjing 210093 China

The response to the catchment changes of the sedimentary environment of the western intertidal flat of Yalu River Estuary was investigated by analyzing the vertical variations of the grain size of sediment cores,along with the hydrologic data and human activities in the *** results demonstrated a stepwise decreasing trend for the variations of both the sediment load and water discharge into the sea,which could be divided into three stages as 1958–1970,1971–1990 and 1991–*** construction and the changes of catchment vegetation coverage turned out to be the two predominant contributors to the *** are four periods for the variation of the sensitive components of the sediment cores from 1940 to 2010,i.e.,1940–1950,1951–1980,1981–1990 and 1991–*** vertical distribution of grain size in the cores mainly varied with the changes of vegetation coverage in the catchment and reservoir construction from 1960 to 1980,whereas it varied depending on the intensity of water and soil erosion in the catchment from 1980 to *** the further reduction of the water and sediment input into the sea from 1990 to 2009,this period was characterized by coarsening trends for the grain size of sediment in the estuarine intertidal flat and correspondingly,the significantly increased silt contents of the sensitive component.

关键词： runoff and sediment load human activities sediment record sensitive component Yalu River

Baicalin influences the dendritic morphology of newborn neurons in the hippocampus of chronically stressed rats

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2013年第6期8卷 496-505页

作者： Xinghua Jiang Junmei Xu Dingquan Zou Lin Yang yaping wang Department of Anesthesiology the Second Xiangya Hospital of Central South University

Chronic stress models, established in adult Sprague-Dawley rats through a 14-day subcutaneous injection of 40 mg/kg corticosterone, once per day, were given a daily oral feeding of 50 mg/kg baicalin. The study was an attempt to observe the effect of baicalin on neurogenesis in chronically stressed rats. Results showed that subcutaneous injection of corticosterone significantly decreased the total number of doublecortin-positive neurons in the hippocampus. The reduced cell number caused by corticosterone was mainly due to the decrease of class II doublecortin-positive neurons, but the class I doublecortin-positive neurons were unaffected. Baicalin treatment increased the number of both class I and class II doublecortin-positive neurons. In addition, doublecortin-positive neurons showed less complexity in dendritic morphology after corticosterone injection, and this change was totally reversed by baicalin treatment. These findings suggest that baicalin exhibits a beneficial effect on adult neurogenesis.

关键词： neural regeneration traditional Chinese medicine neurogenesis neurodegenerative disease baicalin stress hippocampus neurons doubiecortin dendrites cognition mood regulation grants-supported paper photographs-containing paper neuroregeneration

新工科背景下大学生创新创业教育培养模式研究与探索

在线全文

学校读者我要写书评

暂无评论

创新创业理论研究与实践 2024年第17期7卷 161-163+194页

作者：丁志鹏王雅萍潘刚合肥工业大学宣城校区

新工科背景下大学生创新创业教育培养模式在实践教学方面仍有所缺乏，在理论教学方面偏重专业知识讲授，在一定程度上限制了学生创新思维和实践能力的培养。该文分析创新创业教育培养模式现状及存在的问题，基于高校“双创”教育改革与... 详细信息

新工科背景下大学生创新创业教育培养模式在实践教学方面仍有所缺乏，在理论教学方面偏重专业知识讲授，在一定程度上限制了学生创新思维和实践能力的培养。该文分析创新创业教育培养模式现状及存在的问题，基于高校“双创”教育改革与发展要求，提出在创新创业课程体系及师资配套完善的基础上，探索构建“一实验室、一研究中心、一实践基地、一孵化平台”阶梯式实践教学平台，强化培养模式中的实践教学。该方案使大学生创新创业教育更加贴近实际，提高学生的实践能力和创新意识，同时也有助于学生在未来的工作和创业中更具竞争力。

关键词：创新创业培养模式新工科阶梯式实践教育教学平台

Necklace-like Si@C nano?bers as robust anode materials for high performance lithium ion batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2019年第4期64卷 261-269页

作者： Xiangzhong Kong Yuchao Zheng yaping wang Shuquan Liang Guozhong Cao Anqiang Pan School of Materials Science & Engineering Central South University Department of Materials Science & Engineering University of Washington Key Laboratory of Nonferrous Metal Materials and Engineering Ministry of Education Central South University

Silicon is believed to be a promising anode material for lithium ion batteries because of its highest theoretical capacity and low discharge potential. However, severe pulverization and capacity fading caused by huge volume change during cycling limits its practical application. In this work, necklace-like N-doped carbon wrapped mesoporous Si nanofibers(NL-Si@C) network has been synthesized via electrospinning method followed by magnesiothermic reduction reaction process to suppress these issues. The mesoporous Si nanospheres are wrapped with N-doped carbon shells network to form yolk-shell ***, the distance of adjacent Si@C nanospheres can be controllably adjusted by different addition amounts of SiO_2 nanospheres. When used as an anode material for lithium ion batteries, the NL-Si@C-0.5 exhibits best cycling stability and rate capability. The excellent electrochemical performances can be ascribed to the necklace-like network structure and N-doped carbon layers, which can ensure fast ions and electrons transportation, facilitate the electrolyte penetration and provide finite voids to allow large volume expansion of inner Si nanoparticles. Moreover, the protective carbon layers are also beneficial to the formation of stable solid electrolyte interface film.

关键词： Necklace-like Carbon shells network N-doped Mesoporous silicon Lithium ion batteries

QB/T 2673《鞋类产品标识》新旧标准比对分析

在线全文

学校读者我要写书评

暂无评论

中国纤检 2024年第8期 88-91页

作者：王亚萍关頔侯景燕北京市产品质量监督检验研究院北京100025

为了准确理解和运用新标准,本文介绍了QB/T 2673《鞋类产品标识》国家推荐性标准的制修订目的与依据,采用对比分析的方法,比较并解读了新旧标准在标识内容要求和标识要素要求的主要差异。重点阐述了标准制修订的内容与依据,以期为国内... 详细信息

为了准确理解和运用新标准,本文介绍了QB/T 2673《鞋类产品标识》国家推荐性标准的制修订目的与依据,采用对比分析的方法,比较并解读了新旧标准在标识内容要求和标识要素要求的主要差异。重点阐述了标准制修订的内容与依据,以期为国内相关检测机构和生产销售企业正确理解及运用标准、准确明示产品信息提供帮助与指导。

关键词：鞋类产品 QB/T 2673 标识对比分析差异

Transgene for growth hormone in common carp(Cyprinus carpio L.)promotes thymus development

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2003年第16期48卷 1764-1770页

作者： GUO Qionglin wang yaping JIA Weizhang ZHU Zuoyan State Key Laboratory of Freshwater Ecology and Biotechnology Insti-tute of HydrobiologyChinese Academy of SciencesWuhan 430072China

The transgenic carp were produced by micro-injection of CAgcGHc into the fertilized eggs. Observation of the thymus development between the transgenics and non- transgenic controls was carried out. The thymus of one-year- old transgenics F1 showed a great increase in both size and weight. The unilateral thymus of the transgenics weighed from 190 to 295 mg with average 218.6 mg, whereas the uni-lateral thymus of the controls weighed 20—81 mg with av-erage 42.5 mg; i.e. the thymus weight in the transgenics was 5.14 fold over that in the controls. The index of thymus/body weight in the transgenics was 2.97 fold over the controls. Light microscopy observation indicated that the thymus of the transgenics well developed with the thickened outer re-gion and compactly arranged thymocytes, while the thymus in the controls were degenerating with the thinned outer region, scattered thymocytes and groups of fatty cells. Fur-ther analysis with the electron microscopy revealed that pro-liferous cells in the transgenics were mainly small lympho-cytes and no pathological changes were found. The results confirmed that the 揂ll-fish?GH-transgene promotes thy-mus development and thymocyte proliferation, and retards thymus degeneration. The study has laid a foundation for further analysis of the immunobiological function in GH- transgenic carp.

关键词：生长激素转基因鲤鱼受精卵胸腺发育显微镜观察方法胸腺细胞电子显微镜淋巴细胞变化病态变化

Turbidity maximum formation and its seasonal variations in the Zhujiang(Pearl River)Estuary,southern China

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2016年第8期35卷 22-31页

作者： LIU Runqi wang yaping GAO Jianhua WU Ziyin GUAN Weibing Collaborative Innovation Center of South China Sea Studies Nanjing 210093China Ministry of Education Key Laboratory for Coast and Island Development Nanjing UniversityNanjing 210023China Key Laboratory of Submarine Geosciences State Oceanic AdministrationHangzhou 310012China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic AdministrationHangzhou 310012China

Real-time observations in the field and numerical simulations（with Delft3D） were combined to study the formation, distribution and the relevant influencing factors of turbidity maximum（TM） in the Zhujiang（Pearl River） Estuary（ZE）. The spatial distribution pattern of the TM varies with the longitudinal distributions of salinity and suspended sediment concentration（SSC）. The SSC is enhanced and the TM is intensified during dry seasons,whereas the center of the TM moves upstream by a distance of 10 km during wet seasons. The formation of the TM is influenced by a complex combination of numerous factors, including tides, river discharges and topography, wherein sediment resuspension and vertical circulation dominate the formations and variability of the TM.

关键词： sediment resuspension vertical circulation turbidity maximum Delft3D Zhujiang(Pearl River) Estuary