| 1 | High-static-low-dynamic stiffness isolator based on an electromagnetic negative stiffness spring with long linear stroke显示文摘Negative stiffness mechanisms can improve low-frequency vibration isolation performance and have been widely used in the vibration isolation of precision equipment. However, the negative stiffness mechanism usually introduces a nonlinear stiffness,resulting in a nonlinear response and worsening the vibration isolation performance, especially under large amplitude vibration.In this paper, an electromagnetic spring with linear negative stiffness(ESLNS) is proposed, in which the antagonistic ampere forces of the energized coils are used to generate negative stiffness within a long linear stroke. The magnetic field distribution is improved through the design of the magnetic circuit, thereby increasing the stiffness generation efficiency. The stiffness can be adjusted bidirectionally by current within the range of positive and negative stiffness. An electromagnetic stiffness model was established based on the equivalent magnetic circuit method. Experimental measurements verified the accuracy of the model and proved the linearity of the electromagnetic spring. A vibration isolator with high static and low dynamic stiffness(HSLDS) based on the ESLNS is designed and tested. The experimental results prove that the introduction of the ESLNS can effectively expand the isolation frequency band without changing the equilibrium position. Moreover, the vibration isolator with ESLNS does not produce nonlinear response. The proposed electromagnetic spring with linear negative stiffness extends the application range of HSLDS isolators to a large amplitude vibration environment. | YUAN ShuJin WU YaJun SONG DaiPing PU HuaYan MOU LiSheng HOU Lei ZHAO JingLei LI XuePing LUO Jun WU Jie HUANG XiaoXu | 2024 | Science China(Technological Sciences)2024，67，3： | 0 |
| 2 | The Records of Anatomy in Ancient China显示文摘Through long-term observations and repeated practices of human body structure,anatomical knowledge in ancient China has gradually developed from the sprouting period when ancient Chinese hunted animals for survival,to anatomical exploration,which breaks the shackles of fear and religious rites.For example,Hua Tuo(华佗),a famous doctor in the period of The Three Kingdoms,did exquisite abdominal surgery;Yan Luozi(烟萝子),a Taoist priest in the period of The Five Dynasties,drew a map of human anatomy;Wang Weiyi(王唯一),a medical official in Northern Song dynasty,was responsible for casting acupuncture bronze figures,an anatomical mold for practicing acupuncture;Song Ci(宋慈),a forensic expert in Southern Song Dynasty,wrote Xi Yuan Ji Lu(《洗冤集录》Collected Cases of Injustice Rectified);Wang Qingren(王清任),a physician in Qing Dynasty wrote Yi Lin Gai Cuo(《医林改错》Correction on Errors in Medical Works).Ancient Chinese anatomy is far ahead of Western anatomy in understanding and describing human body structures.It has made great contributions to the emergence of Huang Di Nei Jing(《黄帝内经》Huangdi's Internal Classic)and laid a solid foundation for the establishment of visceral manifestation theory and meridian and collateral theory.Even now,it has served the basic theory of traditional Chinese medicine and clinical practices.Anatomical knowledges,such as relevant operation records,books,Atlas,models in ancient China,especially the names of Zangorgan and Fu-organ,bones and five sense organs,are still used in modern anatomy and modern medicine,making indelible contributions to the development of modern anatomy in China. | Shuijin Shao Haidong Guo Fangfang Mou Chunxia Guo Lisheng Zhang | 2020 | Chinese Medicine and Culture2020，3，4： | 0 |
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