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Reconstruction and prediction of coherent acoustic field with the combined wave superposition approach

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Chinese Journal of Acoustics 2006年第2期25卷 124-138页

作者： li weibing chen jian yu fei chen xinzhao Institute of sound and vibration research Hefei University of Technology Hefei 230009

The routine wave superposition approach cannot be used in reconstruction and prediction of a coherent acoustic field, because it is impossible to separate the pressures generated by individual sources. According to the superposition theory of the coherent acoustic field , a novel method based on the combined wave superposition approach is developed to reconstruct and predict the coherent acoustic field by building the combined pressure matching matrixes between the hologram surfaces and the sources. The method can reconstruct the acoustic information on surfaces of the individual sources, and it is possible to predict the acoustic field radiated from every source and the total coherent acoustic field can also be calculated spontaneously. The experimental and numerical simulation results show that this method can effectively solve the holographic reconstruction and prediction of the coherent acoustic field and it can also be used as a coherent acoustic field separation technique. The study on this novel method extends the application scope of the acoustic holography technique.

关键词： wave superposition acoustic field holographic reconstruction separation technique acoustic holography simulation results application scope used in

Electro-reductive carboxylation of acyclic C（sp3）–C（sp3） bonds in aromatic hydrocarbons with CO2

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Science China Chemistry 2024年第10期67卷 3366-3372页

作者： Chuan-Kun Ran Quan Qu Yang-Yi Tao Yi-fei chen li-li liao jian-Heng Ye Da-Gang yu Key Laboratory of Green Chemistry & Technology of Ministry of Education College of ChemistrySichuan University West China School of Public Health and West China Fourth Hospital Sichuan University

Despite the recent advances in the selective functionalization of C–C bonds in specific substrates,cleavage and functionalization of C–C bonds in acyclic substrates,such as ethane derivatives,remains *** contrast to the well-developed functionalization of one carbon fragment after C–C bond cleavage,herein,we report a novel electro-reductive carboxylation of C（sp3）–C（sp3） bond in multi-aryl ethanes with carbon dioxide（CO2） by utilizing both carbon ***,this reaction exhibits an atom-,step-economic approach for the synthesis of carboxylic acids,fulfilling principal aspirations of organic ***,this method features mild reaction conditions,broad substrate scope,and good functional group *** and asymmetric substrates bearing primary,secondary,or tertiary C（sp3）–C（sp3） bonds are all amenable to this strategy,enabling one or two structurally different carboxylic acids to be facilely constructed at the same *** investigations indicate that carbanions might be the key intermediates in this reaction,which could be captured by CO2efficiently.

关键词： carbon dioxide electrochemistry C(sp3)–C(sp3) bonds cleavage reductive carboxylation

Efficient micrometer-scale thick-film perovskite solar cells with superior stability

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Rare Metals 2024年第4期43卷 1647-1657页

作者： jian-fei Hu Gang chen Shun-Zhang yu yue-Xin lin Kai-yu Wang Zong-Wei li Guo-Dong Zhang Teng-fei Pan Ya-Jing li Ming-Jie li Ying-Dong Xia Yi-Fan Lv Yong-Hua chen Key Laboratory of Flexible Electronics(KLoFE)and Institute of Advanced Materials(IAM) School of Flexible Electronics(Future Technologies)Nanjing Tech University(NanjingTech)Nanjing211816China Department of Applied Physics The Hong Kong Polytechnic UniversityHong Kong999077China Shenzhen Research Institute The Hong Kong Polytechnic UniversityShenzhen518057China Optics Valley Laboratory Hubei430074China

It is essential to enhance the thickness of the absorber layer for perovskite solar cells(PSCs)to improve device performance and reduce industry ***,thick perovskite films(>1μm)are difficult to be fabricated by employing traditional solvents,such as N,N-dimethylformamide(DMF),dimethyl sulfoxide(DMSO).Besides,it is a challenge to fabricate thick-film perovskite owing to the deteriorated surface morphology and serious defect ***,a simple method was reported to deposit uniform pinhole-free perovskite films with a thickness of more than 2μm utilizing the methylamine acetate(MAAc)ionic liquid as the *** with methylammonium chloride(MACl)as an additive,thick-film perovskite with~2μm in grain size and few grain boundaries(GBs)was prepared,which dramatically improved the perovskite crystal quality and enhanced carrier transport *** final PSCs exhibited a power conversion efficiency(PCE)of 20.16%.The device showed improved stability with 95%of its initial efficiency in a nitrogen environment over 5000 *** work provides an alternative strategy to produce extremely efficient and stable thick-film *** can be believed that this device has great potential in the application of large areas and laminated PSCs.

关键词： Perovskite solar cells Thick-film Stability Ionic liquid

Interaction mechanism between BaZrO_(3)/Y_(2)O_(3) refractory and Ti_(2)Ni alloy melts

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Journal of Iron and Steel Research International 2024年第6期31卷 1376-1388页

作者： Xiao Hou Guang-yao chen jian liu Ming-rui Lv fei-hai yu Qi-sheng Feng Rong-bin li Xiong-gang Lu Chong-he li State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferromeallurgy and School of Materials Science and Engineering Shanghai UniversityShanghai 200072China Shanghai Special Casting Engineering Technology Research Center Shanghai 201605China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100ZhejiangChina School of Materials Science and Engineering Shanghai DianJi UniversityShanghai 201306China

The titanium alloys with highly chemical activity require stable crucible refractories that can withstand the erosion of alloy *** phase composition and microstructure are crucial factors that affect the stability of the refractory *** effect of Y_(2)O_(3) on the composition and microstructure of BaZrO_(3) crucible was systematically investigated,and the improved mechanism of the stability of BaZrO_(3)/Y_(2)O_(3) crucible was clarified in comparison with the BaZrO_(3) *** results showed that the erosion layer thickness of the BaZrO_(3)/Y_(2)O_(3) crucible was only 63μm,which was far less than that in the BaZrO_(3) crucible(485μm),and the erosion layer in the BaZrO_(3)/Y_(2)O_(3) crucible also exhibited a higher density than that in the BaZrO_(3) *** the sintering,Y_(2)O_(3) could improve the densification of the BaZrO_(3) crucible due to the solid solution effect between Y_(2)O_(3) and ZrO_(2),which also caused the evaporation of BaO,resulting in the generation of a Y_(2)O_(3)(ZrO_(2))film on the surface of the ***,the Y_(2)O_(3)(ZrO_(2))had higher thermodynamic stability than Y_(2)O_(3),confirming that the BaZrO_(3)/Y_(2)O_(3) crucible with high density exhibited a superior erosion resistance to titanium *** dual-phase structure provides a strategy to design a long-life and stable refractory for melting titanium alloys.

关键词： Barium zirconate Yttrium oxide Dual-phase refractory Titanium alloy Interaction

Treatment of bilateral developmental dysplasia of the hip joint with an improved technique:A case report

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World Journal of Clinical Cases 2024年第7期12卷 1320-1325页

作者： Xing-Xing yu jian-Ye chen Hong-Sheng Zhan Ming-Da liu yun-fei li yu-Yan Jia College of Traditional Chinese Medicine Changchun University of Traditional Chinese MedicineChangchun 130117Jilin ProvinceChina Shi's Traumatology Medical Center Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese MedicineShanghai 201203China College of Traditional Chinese Medicine The Affiliated Hospital of Changchun University of Chinese MedicineChangchun 130021Jilin ProvinceChina

BACKGROUND Developmental dysplasia of the hip(DDH)is a common osteoarticular deformity in pediatric orthopedics.A patient with bilateral DDH was diagnosed and treated using our improved technique"(powerful overturning acetabuloplasty)"combined with femoral rotational shortening *** SUMMARY A 4-year-old girl who was diagnosed with bilateral DDH could not stand normally,and sought surgical treatment to solve the problem of double hip extension and *** this child had high dislocation of the hip joint and the acetabular index was high,we changed the traditional acetabuloplasty to"powerful turnover acetabuloplasty"combined with femoral rotation shortening *** the short-term postoperative follow-up(1,3,6,9,12,and 15 months),the child had no discomfort in her lower *** the braces and internal fixation plates were removed,formal rehabilitation training was actively carried *** Our"powerful overturning acetabuloplasty"combined with femoral rotational shortening osteotomy is feasible in the treatment of DDH in *** technology may be widely used in the clinic.

关键词： Developmental dysplasia of the hip Improved technique Case report

Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

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Petroleum Science 2024年第4期21卷 2830-2838页

作者： Yi-jian Zhu Xiao-Mei Yang Xing Huang Hao li Xiao-Hui Wang Yi-fei Sun Peng Xiao Chang-yu Sun Guang-Jin chen State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： gas hydrate bentonite illite P-wave velocity amplitude

Nomogram for predicting the risk of anxiety and depression in patients with non-mild burns

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World Journal of Psychiatry 2024年第8期14卷 1233-1243页

作者： Jie chen jian-fei Zhang Xia Xiao yu-Jun Tang He-Jin Huang Wen-Wen Xi li-Na liu Zheng-Zhou Shen jian-Hua Tan Feng Yang Department of Burns and Plastic Surgery The Second Affiliated HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421001Hunan ProvinceChina Department of Beauty Surgery Nantong Shenmei Medical Beauty ClinicNantong 226001Jiangsu ProvinceChina Department of Respiratory and Critical Care Medicine The Second Affiliated HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421001Hunan ProvinceChina

BACKGROUND Post-burn anxiety and depression affect considerably the quality of life and recovery of patients;however,limited research has demonstrated risk factors associated with the development of these *** To predict the risk of developing post-burn anxiety and depression in patients with non-mild burns using a nomogram *** We enrolled 675 patients with burns who were admitted to The Second Affiliated Hospital,Hengyang Medical School,University of South China between January 2019 and January 2023 and met the inclusion *** patients were randomly divided into development(n=450)and validation(n=225)sets in a 2:1 *** and multivariate logistic regression analyses were conducted to identify the risk factors associated with post-burn anxiety and depression dia-gnoses,and a nomogram model was *** Female sex,agelidation sets,respectively,and good predictive *** and decision curve analyses confirmed the clinical utility of the *** The nomogram model predicted the risk of post-burn anxiety and depression in patients with non-mild burns,facilitating the early identification of high-risk patients for intervention and treatment.

关键词： Burn Post-burn anxiety Depression Risk prediction Nomogram model

Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-13 tandem accelerator

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Nuclear Science and Techniques 2024年第4期35卷 136-143页

作者： Yang Zhang Sheng-Quan Yan Ming He Qing-Zhang Zhao Wen-Hui Zhang Chao-Xin Kan jian-Ming Zhou Kang-Ning li Xiao-fei Wang jian-cheng liu Zhao-Hua Peng Zhuo liang Ai-ling li jian Zheng Qi-Wen Fan yun-Ju li You-Bao Wang Zhi-Hong li Yang-Ping Shen Ding Nan Wei Nan yu-Qiang Zhang Jia-Ying-Hao li Jun-Wen Tian jiang-lin Hou Chang-Xin Guo Zhi-cheng Zhang Ming-Hao Zhu yu-Wen chen yu-chen jiang Tao Tian Jin-Long Ma Yi-Hui liu Jing-yu Dong Run-Long liu Mei-yue-Nan Ma Yong-Shou chen Wei-Ping liu Bing Guo China Institute of Atomic Energy P.O.Box 275(10)Beijing 102413China College of Science Southern University of Science and TechnologyShenzhen 518055China School of Physics Xi’an Jiaotong UniversityXi’an 710049China

The Moon provides a unique environment for investigating nearby astrophysical events such as *** samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)*** this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy *** particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the ***,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS *** results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)*** sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

关键词： Accelerator mass spectrometry Wien filter Isobar separation Supernovae Chang'e-5 lunar samples

A robust technique to reconstruct sound field for all wave-numbers

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Science China(Technological Sciences) 2004年第5期47卷 505-517页

作者： yu fei chen jian li weibing chen xinzhao School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China

A robust technique has been proposed for reconstructing sound field for all wave-numbers, which is suitable for the radiation analysis on an arbitrarily-shaped body. According to the wave superposition formulation, the spatial sound field of an actual radiator can be represented equivalently by superposing the fields generated by some fictitious sources interior to the actual radiator. Meanwhile, the strength density on the fictitious sources can be obtained by matching the sound pressures of a finite number of field points. Once the strength density is calculated, the acoustic information at any field point can be obtained subsequently. Finally, some typical numerical examples are given to validate the theoretical analysis, and some investigations are made to analyze the influence of sound frequency and the fictitious source position on the reconstruction precision, which are helpful to the application of the proposed technique to real industrial measurements.

关键词： sound field reconstruction, wave superposition, hybrid layer potential theory, non-uniqueness,robustness.