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| 1 | Vibration Absorption Efficiency and Higher Branches Elimination of Variable-Stiffness Nonlinear Energy Sink显示文摘Vibration absorption efficiency of a variable⁃stiffness nonlinear energy sink(NES)was investigated when the main oscillator was subjected to harmonic and impulse excitations.The slow flow equations of the coupled system were derived by using the complexification⁃averaging method,and the nonlinear equations which describe the steady⁃state response were obtained.As the harmonic excitation force increased,the system which comprises constant⁃stiffness NES generated higher branch responses,greatly reducing the vibration absorption efficiency.The influence of nonlinear stiffness on the responses of the system was investigated.Results show that,with the increase of harmonic exciting force,a reduction of NES stiffness can eliminate the higher branch responses and even the frequency band of strongly modulated responses.The vibration absorption efficiency of variable⁃stiffness NES attached to the linear oscillator for different amplitudes of impulse excitation was investigated.Results show that the proper reduction of nonlinear stiffness under increasing impulse excitation can greatly increase the vibration absorption efficiency of NES,and the variable⁃stiffness design can effectively mitigate the negative influences of the increase of the excitation amplitude on the efficiency of constant⁃stiffness NES. | Rui Zhong Jian’en Chen Weimin Ge Jun Liu Xiaofeng Wang | 2020 | Journal of Harbin Institute of Technology(New Series)2020，27，1： | 0 |
| 2 | Blue-Green Electroluminescence of Free-Standing Diamond Thin Films显示文摘Blue-green electroluminescence has been observed in free-standing diamond films which were deposited by microwave plasma assisted CVD on silicon substrates.The electroluminescence device is driven by a 60 Hz power supply.The threshold voltage was about 112 V peak-to-peak.The electroluminescence spectrum at room temperature,showed a blue-green band with the peak centered at 485nm suggesting band A type emission.Electroluminescence was also observed at 77K. | ZHANG Binglin SHEN Shupo WANG Jian’en HE Jintian Howard R.Shanks Moeljanto W.Leksono Robert Girvan | 1994 | Chinese Physics Letters1994，11，4： | 3 |
| 3 | Pediculate Brachiopod Diandongia pista from the Lower Cambrian of South China显示文摘The Chengjiang Lagerstatte has been celebrated for prolific soft-bodied fossils. Based on specimens recentlyexcavated in the Chengjiang Lagerstatte by the Early Life Institute, Northwest University, Diandongiapista Rong, 1974, isdirectly revealed to be a pediculate brachiopod, assigned to the Family Botsfordiidae, as is further confirmed by theexceptionally preserved vascular system including dorsal and ventral mantle canals. These specimens described hereinexhibit some peculiarities, notably the extremely thin and long pedicles, which suggest that Diandongia is epifaunal ratherthan burrowing brachiopod. A study of this group of animals indicates that they may be vital to understand the relationshipbetween the lingulids and the remaining brachiopods, and the character evolution of the early Cambrian brachiopods. | ZHANG Zhifei, HAN Jian, ZHANG Xingliang, LIU Jianni and SHU DeganEarly Life Institute and Key Laboratory for Continental Dynamics of the Ministry of Education,Northwest University, Xi’an, Shaanxi 710069 E-mail: zhangelle@sina.com.cn Wang Si’en and Xie Guanglian | 2003 | Acta Geologica Sinica(English Edition)2003，77，3： | 9 |
| 4 | Quaternary integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas显示文摘The Quaternary strata on the Qinghai-Tibet Plateau contain rich information about the paleoclimate and environmental evolution,record the evolution process of the Quaternary regional tectonics,paleogeography,and geomorphology of the plateau,and are extremely important areas for studying the Quaternary geological events and regional environmental evolution.According to a comprehensive analysis of the regional stratigraphic data and the development and evolution characteristics of the biota,based on the differences in the lithostratigraphic units,sedimentary characteristics,landforms,and drainage systems,the Quaternary strata on the Qinghai-Tibet Plateau and its surrounding areas are divided into five stratigraphic regions:the Tarim region,Loess Plateau region,Qinghai-Tibet Plateau region,Yunnan-Guizhou Plateau region,and India-Ganges region.The Qinghai-Tibet Plateau stratigraphic region is divided into seven stratigraphic sub-regions:the West Kunlun-Karakorum,AltunQilian Mountains,Qaidam-Hehuang,East Kunlun-Bayan Har,Qiangtang,East Xizang-West Yunnan-West Sichuan,and Gangdise-Himalayan sub-regions.This paper briefly describes the lithostratigraphic units of the seven stratigraphic sub-regions of the Qinghai-Tibet Plateau.According to the lithostratigraphic sequence and its sedimentary characteristics,stratigraphic contact relationship,formation age,and evolution of the biota in each stratigraphic sub-region,the Quaternary tectonic paleogeographic evolution of the Qinghai-Tibet Plateau is divided into four stages.(1)The inherited differential uplift stage since the Pliocene(2.6-1.8/1.5 Ma):the regional sedimentary differences were significant,and the stratigraphic distribution was limited,the alluvial-proluvial sandy conglomerate was widely developed along the piedmont,and fluvial and lacustrine deposits were developed in the low-lying areas between the mountains.(2)The mountain range flattening stage(1.8/1.5-1.2/0.8 Ma):the erosion unconformity surfaces around the plateau were widely distributed,large rivers were formed,and lake sediments developed in the intermountain basins and the hinterland of the plateau.(3)1.2/0.8-0.128 Ma:the plateau continued to rise in a large range,with significant topographic differences and intensified mountain erosion.At about 0.8 Ma,the plateau uplifted above the snow line and entered the cryosphere,mountain glaciers developed,and the alpine arid environment gradually formed.(4)0.128 Ma-:the mountains rose and erosion intensified,and intermountain basins and lakes were widely distributed.There were significant differences in the regional sedimentary characteristics,and the sedimentary types developed toward diversification.The modern plateau landform pattern was basically formed. | Yong WANG Mianping ZHENG Yuan LING Shuyuan XIANG Zhaogang SHAO Kexin ZHANG Xue KE Xiao LIN Fang HAN Jian’en HAN | 2024 | Science China Earth Sciences2024，67，4： | 0 |
| 5 | Expert consensus on prevention and cardiopulmonary resuscitation for cardiac arrest in COVID-19显示文摘Background:Cardiopulmonary resuscitation(CPR)strategies in COVID-19 patients differ from those in patients suffering from cardiogenic cardiac arrest.During CPR,both healthcare and non-healthcare workers who provide resuscitation are at risk of infection.The Working Group for Expert Consensus on Prevention and Cardiopulmonary Resuscitation for Cardiac Arrest in COVID-19 has developed this Chinese Expert Consensus to guide clinical practice of CPR in COVID-19 patients.Main recommendations:1)A medical team should be assigned to evaluate severe and critical COVID-19 for early monitoring of cardiac-arrest warning signs.2)Psychological counseling and treatment are highly recommended,since sympathetic and vagal abnormalities induced by psychological stress from the COVID-19 pandemic can induce cardiac arrest.3)Healthcare workers should wear personal protective equipment(PPE).4)Mouth-to-mouth ventilation should be avoided on patients suspected of having or diagnosed with COVID-19.5)Hands-only chest compression and mechanical chest compression are recommended.6)Tracheal-intubation procedures should be optimized and tracheal-intubation strategies should be implemented early.7)CPR should be provided for 20-30 min.8)Various factors should be taken into consideration such as the interests of patients and family members,ethics,transmission risks,and laws and regulations governing infectious disease control.Changes in management:The following changes or modifications to CPR strategy in COVID-19 patients are proposed:1)Healthcare workers should wear PPE.2)Hands-only chest compression and mechanical chest compression can be implemented to reduce or avoid the spread of viruses by aerosols.3)Both the benefits to patients and the risk of infection should be considered.4)Hhealthcare workers should be fully aware of and trained in CPR strategies and procedures specifically for patients with COVID-19. | Wei Song Jie Wei Xiangdong Jian Deren Wang Yanhong Ouyang Yuanshui Liu Xianjin Du Ying Chen Yingqi Zhang Heping Xu Shuming Xianyu Qiong Ning Xiang Li Xiaotong Han Feng Zhan Tao Yu Wenteng Chen Jun Zhang Wenwei Cai Sheng’ang Zhou Shengyang Yi Yu Cao Xiaobei Chen Shunjiang Xu Zong’an Liang Duohu Wu Fen Ai Zhong Wang Qingyi Meng Yuhong Mi Sisen Zhang Rongjia Yang Shouchun Yan Wenbin Han Yong Lin Chuanyun Qian Wenwu Zhang Yan Xiong Jun Lv Baochi Liu Yan Cao Xiaojun He Xuelian Sun Yufang Cao Tian’en Zhou | 2021 | Asian Pacific Journal of Tropical Medicine2021，14，6： | 0 |
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