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4篇 您的检索式:作者名="Pengchang Li"
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1Comparison of dominant frequency attenuation of blasting vibration for different charge structures显示文摘Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration control.It is necessary to develop a concise and practical prediction equation describing dominant frequency attenuation.In this paper,a prediction equation of dominant frequency that accounts for primary parameters influencing the dominant frequency was proposed based on theoretical and dimensional analyses.Three blasting experiments were carried out in the Chiwan parking lot for collecting blasting vibration data used to conduct regression analysis of the proposed prediction equation.The fitting equations were further adopted to compare the reliability of three different types of dominant frequencies in the proposed equation and to explore the effects of different charge structures on the dominant frequency attenuation.The apparent frequency proved to be more reliable to express the attenuation law of the dominant frequency.The reliability and superiority of the proposed equation employing the apparent frequency were verified by comparison with the other five prediction equations.The smaller blasthole diameter or decoupling ratio leads to the higher initial value and corresponding faster attenuation of the dominant frequency.The blasthole diameter has a greater influence on the dominant frequency attenuation than the decoupling ratio does.Among the charge structures applied in the experiments,the charge structure with decoupling ratio of 1.5 and blasthole diameter of 48 mm results in the greatest initial value and corresponding fastest attenuation of the dominant frequency.Pengchang Sun Wenbo Lu Junru Zhou Xincheng Huang Ming Chen Qi Li 2022Journal of Rock Mechanics and Geotechnical Engineering2022,14,2:2
2显示文摘Xue Pengchang LU Ran LI Dongmei 2004Langmuir2004,20,25:1
3Spontaneous Self-healing Bio-inspired Lubricant-infused Coating on Pipeline Steel Substrate with Reinforcing Anti-corrosion,Anti-fouling,and Anti-scaling Properties显示文摘Superhydrophobic surfaces(SHS)and slippery lubricant-infused porous surfaces(SLIPS)attract great attention due to their multiple properties in both industries and our daily lives.Here,we first fabricated the SHS with micro-scale flower-like structures composed of nano-sheets on pipeline steel substrate.Then,we obtained the SLIPS by spin-coating lubricant into gaps of micro-scale flower-like structures,with the air still trapped among gaps of nano-sheets.The SLIPS shows excellent liquid repellency as the SHS.The SLIPS also shows stability after the scour of flowing water.These results of polarization curves(Tafel)and electrochemical impedance spectroscopies deduced the SLIPS with better and more stable anti-corrosion property than the SHS.Compared with the SHS,the lack of attachment and CaCO_(3) on the SLIPS indicates that the SLIPS demonstrates better anti-fouling and anti-scaling properties than the SHS.Moreover,the SLIPS shows promising wear resistance under the abrasion simulated by sandpaper compared with the SHS.Notably,the air trapped among nano-sheets is conducive to the lubricant flowing to the surface quickly,exhibiting spontaneous self-healing in atmosphere,even if part flower-like structures of the SLIPS subject to damage with the lubricant consumed after scratched.Hao Li Yujie Peng Kai Zhang Pengchang Li Lei Xin Xiaoli Yin Sirong Yu 2022Journal of Bionic Engineering2022,19,6:0
4Epidemiologic Features, Radiological Findings and Clinical Outcomes of 19 Patients with COVID-19 in a Single Center in Beijing, China显示文摘Objective To describe the epidemiologic,clinical,laboratory,and radiological characteristics and prognoses of COVID-19 confirmed patients in a single center in Beijing,China.Methods The study retrospectively included 19 patients with nucleic acid-confirmed SARS-CoV^2 infection at our hospital from January 20 to March 5,2020.The final follow-up date was March 14,2020.The epidemiologic and clinical information was obtained through direct communication with the patients or their family members.Laboratory results retrieved from medical records and radiological images were analyzed both qualitatively by two senior chest radiologists as well as quantitatively via an artificial intelligence software.Results We identified 5 family clusters(13/19,68.4%)from the study cohort.All cases had good clinical prognoses and were either mild(3/19)or moderate(16/19)clinical types.Fever(15/19,78.9%)and dry cough(11/19,57.9%)were common symptoms,Two patients received negative results for more than three consecutive viral nucleic acid tests.The longest interval between an initial CT abnormal finding and a confirmed diagnosis was 30 days.One patient's nucleic acid test turned positive on the follow-up examination after discharge.The presence of radiological abnormalities was non-specific for the diagnosis of COVID-19.Conclusions COVID-19 patients with mild or no clinical symptoms are common in Beijing,China.Radiological abnormalities are mostly non-specific and massive CT examinations for COVID-19 screening should be avoided.Analyses of the contact histories of diagnosed cases in combination with clinical,radiological and laboratory findings are crucial for the early detection of COVID-19.Close monitoring after discharge is also recommended.Lan Song Zhenchen Zhu Ruijie Zhao Pengchang Li Duxue Tian Tiekuan Du Yan Xu Qiwen Yang Wei Cao Wei Song Zhengyu Jin 2021Chinese Medical Sciences Journal2021,36,2:0
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