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Transfer-free chemical vapor deposition graphene for nitride epitaxy: challenges, current status and future outlook

Science China Chemistry 2024年第3期67卷 824-840页

作者： xiang Gao Senlin Li Jingfeng Bi Kaixuan Zhou Meng Li Zhongfan liu Jingyu Sun College of Energy Soochow Institute for Energy and Materials InnovationsSUDA-BGI Collaborative Innovation CenterKey Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006China Beijing Graphene Institute Beijing 100095China Xiamen Silan Advanced Compound Semiconductor Co.Ltd. Xiamen 361026China

Graphene, a two-dimensional material with outstanding electrical and mechanical properties, has attracted considerable attention in the field of semiconductor technologies due to its potential use as a buffer layer for the epitaxial Ⅲ-nitride growth. In recent years, significant progress has been made in the chemical vapor deposition growth of graphene on various insulating substrates for the nitride epitaxy, which offers a facile, inexpensive, and easily scalable methodology. However, certain challenges are still present in the form of producing high-quality graphene and achieving optimal interface compatibility with Ⅲ-nitride *** this review, we provide an overview of the bottlenecks associated with the transferred graphene fabrication techniques and the state-of-the-art techniques for the transfer-free graphene growth. The present contribution highlights the current progress in the transfer-free graphene growth on different insulating substrates, including sapphire, quartz, SiO_(2)/Si, and discusses the potential applications of transfer-free graphene in the Ⅲ-nitride epitaxy. Finally, it includes the prospects of the transfer-free graphene growth for the Ⅲ-nitride epitaxy and the challenges that should be overcome to realize its full potential in this field.

关键词： Transfer-free chemical vapor deposition graphene for nitride epitaxy challenges current status and future outlook graphene

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Estimation-free spatial-domain image reconstruction of structured illumination microscopy

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Journal of Innovative Optical Health Sciences 2024年第2期17卷 45-58页

作者： Xiaoyan Li Shijie Tu Yile Sun Yubing Han xiang Hao Cuifang kuang Xu liu State Key Laboratory of Extreme Photonics and Instrumentation College of Optical Science and Engineering Zhejiang University Hangzhou 310027P.R.China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou 311200 P.R.China Collaborative Innovation Center of Extreme Optics Shanxi University TaiyuanShanxi 030006P.R.China A dvanced Biomedical Imaging Facility-Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology WuhanHubei 430074P.R.China

Structured illumination microscopy(SIM)achieves super-resolution(SR)by modulating the high-frequency information of the sample into the passband of the optical system and subsequent image *** traditional Wiener-filtering-based reconstruction algorithm operates in the Fourier domain,it requires prior knowledge of the sinusoidal illumination patterns which makes the time-consuming procedure of parameter estimation to raw datasets necessary,besides,the parameter estimation is sensitive to noise or aberration-induced pattern distortion which leads to reconstruction ***,we propose a spatial-domain image reconstruction method that does not require parameter estimation but calculates patterns from raw datasets,and a reconstructed image can be obtained just by calculating the spatial covariance of differential calculated patterns and differential filtered datasets(the notch filtering operation is performed to the raw datasets for attenuating and compensating the optical transfer function(OTF)).Experiments on reconstructing raw datasets including nonbiological,biological,and simulated samples demonstrate that our method has SR capability,high reconstruction speed,and high robustness to aberration and noise.

关键词： Structured illumination microscopy image reconstruction spatial domain digital micromirror device(DMD)

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Oxidation behavior of low-grade vanadiferous titanomagnetite concentrate with high titanium

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Journal of Iron and Steel Research International 2024年第2期31卷 329-341页

作者： Jin-sheng liu Zhen-xing Xing Gong-jin Cheng Xue-yong Ding xiang-xin Xue School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina Liaoning Key Laboratory of Recycling Science for Metallurgical Resources Shenyang110819LiaoningChina Innovation Research Institute of Vanadium and Titanium Resource Industry Technology Northeastern UniversityShenyang110819LiaoningChina

In order to clarify the oxidation mechanisms and make better use of the low-grade vanadiferous titanomagnetite concentrate with high titanium(LVTC),the oxidation behavior of LVTC was *** results showed that oxidation degree was achieved within 90 min when temperature was not lower than 700°C,and the main phases of the oxidized LVTC consisted of Fe9TiO15,Fe2O3,CaSiTiO5 and a small amount of *** temperature is favorable to the formation of *** surface of LVTC gradually becomes rough,with fine particles of needle-like and granular shape appearing on the surface,which finally turn from laminar to creamy,spread out,and are interspersed with many tiny *** phase oxidation paths in LVTC were as follows:(1)Fe2.75Ti0.25O4→Fe9TiO15+Fe2O3;(2)Fe2.75Ti0.25O4→Fe2O3+FeTiO3→Fe2TiO5;(3)FeTiO3→Fe2O3+Fe2Ti3O9→*** is predominantly mesoporous whether oxidized or not,with the pores mainly distributed in the range of 2–40 nm,and the specific surface area of LVTC decreases significantly with increasing temperature.

关键词： Low-grade vanadiferous titanomagnetite concentrate Oxidation degree Phase transformation Micromorphology Oxidation path Pore structure

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Special electromyographic features in a child with paramyotonia congenita: A case report and review of literature

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World Journal of Clinical Cases 2024年第3期12卷 587-595页

作者： Hui Yi Chen-xiang liu Shu-Xin Ye Yu-Lin liu Department of Neuroelectrophysiology Qilu Children’s Hospital of Shandong UniversityJinan 250000Shandong ProvinceChina Department of Neuroelectrophysiology University of Health and Rehabilitation Sciences(Qingdao Municipal Hospital)Qingdao 266000Shandong ProvinceChina

BACKGROUND Paramyotonia congenita(PMC)stands as a rare sodium channelopaty of skeletal muscle,initially identified by *** identification of PMC often relies on electromyography(EMG),a diagnostic *** child’s needle EMG unveiled trains of myotonic discharges with notably giant amplitudes,alongside irregular wave trains of myotonic *** distinctive observation had not surfaced in earlier *** SUMMARY We report the case of a 3-year-old female child with PMC,who exhibited la-ryngeal stridor,muffled speech,myotonia from ***,exposure to cool water,crying,and physical activity exacerbated the myotonia,which was relieved in warmth,yet never *** myotonia was observable in bilateral *** symptoms remained unchanged after potassium-rich food consumption like *** periodic paralysis was *** magnetic resonance imaging yielded normal *** potassium remained within normal range,while creatine kinase showed slight ***-wide genetic testing pinpointed a heterozygous mutation on chromosome SCN4A:c.3917G>A(p.G1306E).After a six-month mexiletine regimen,symptoms *** In this case revealed the two types of myotonic discharges,and had not been documented in other *** underscore two distinctive features:Giant-amplitude potentials and irregular waves.

关键词： Paramyotonia congenita Channelopathy Electromyography Child Case report

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circRNA3669 promotes goat endometrial epithelial cells proliferation via miR-26a/RCN2 to activate PI3K/AKT-mTOR and MAPK pathways

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Journal of Integrative Agriculture 2024年第3期23卷 960-974页

作者： Xiaorui liu Jiuzeng Cui Mengyao Wei Xiaofei Wang Yuexia liu Zhongshi Zhu Min Zhou gui Ba Langda Suo Yuxuan Song Lei Zhang Division of Laboratory Safety and Services Northwest A&F UniversityYangling 712100China College of Animal Science and Technology Northwest A&F UniversityYangling 712100China Institute of Animal Sciences Tibet Academy of Agricultural and Animal Husbandry SciencesLhasa 850009China

The development of receptive endometrium(RE) from pre-receptive endometrium(PE) for successful embryo implantation is a complex dynamic process in which the morphology and physiological states of the endometrial epithelium undergo a series of significant changes, including cell proliferation and apoptosis. However, the molecular mechanisms are not yet fully understood. In this study, a higher circRNA3669 level was observed in PE than in RE of goats. Functional assays revealed that this overexpression promoted the proliferation of goat endometrial epithelial cells(GEECs) by activating the expression of genes related to the PI3K/AKT-mTOR and MAPK pathways,thereby inhibiting apoptosis in vitro. Furthermore, circRNA3669 functioned as a competing endogenous RNA(ceRNA) to upregulate Reticulocalbin-2(RCN2) expression at the post-transcriptional level by interacting with and downregulating miR-26a in GEECs. In addition, RCN2, which is highly expressed in the PE of goats, was found to be regulated by β-estradiol(E2) and progesterone(P4). Our results demonstrated that RCN2 also affected the key proteins PI3K, AKT, mTOR, JNK, and P38 in the PI3K/AKT-mTOR and MAPK pathways, thereby facilitating GEECs proliferation and suppressing their apoptosis in vitro. Collectively, we constructed a new circRNA3669-miR-26aRCN2 regulatory network in GEECs, which further provides strong evidence that circRNA could potentially play a crucial regulatory role in the development of RE in goats.

关键词： circRNA3669 RCN2 miR-26a goat endometrial epithelial cells(GEECs) proliferation

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Numerical investigation on compressible flow around a cylinder in proximity to the heated wall

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Journal of Hydrodynamics 2024年第3期36卷 519-533页

作者： Yu-lu liu Jun-wang Qu Yi-zhou Tao Yong-guang Lyu xiang Qiu Shanghai Institute of Technology School of ScienceShanghai201418China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China

In this study,direct numerical simulations were conducted to investigate the compressible flow around a circular cylinder near a heated wall at a Reynolds number(Re)of 500 and a Mach number(Ma)of *** heating ratio T^(*)ranging from 1.0 to 1.6 represents the different situations of a heated wall,whereas the gap ratio ranges from 0.3 to *** study analyzed the impact of heating effect and wall proximity on flow characteristics and aerodynamic *** results indicated that the stability of the flow was enhanced as the gap ratio decreased or the heating ratio *** the calculation of enstrophy,it was found that the strength of shedding vortices weakens with a decrease in gap ratio or an increase in heating ***,the mean drag coefficient decreases as the heating ratio increases or the gap ratio *** contrast,the mean lift coefficient initially decreases and then increases as the gap ratio ***,the drag reduction mechanism was analyzed by examining the pressure distribution on the surface of the cylinder.

关键词： Compressible flow wall proximity heating effect stability enstrophy

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Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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Science China Chemistry 2024年第3期67卷 1017-1027页

作者： Bei liu Fan Wang Xiaomeng Dou Pengfei Li Hongwei xiang Yong Yang Peng He State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Department of Chemistry Tsinghua UniversityBeijing 100084China National Energy R&D Center for Coal to Liquid Fuels Synfuels China Technology Co.Ltd.Beijing 101407China University of Chinese Academy of Sciences Beijing 101408China Leibniz-Institut für Katalyse e.V.an der Universitat Rostock Rostock 18059Germany

The co-aromatization of methane with higher hydrocarbons represents a promising route to valorize methane, an abundant but underexploited carbon resource. In this study, we elucidate a novel approach to enhance the catalytic co-aromatization of hexane and methane by confining Pt within zeolite catalysts and modulating its electron density. Our findings show that encapsulating Pt within MFI structure is pivotal for activating the feedstock and fostering the formation of aromatic products. Interaction between K atoms and the silanol nest forms siloxy groups which are critical for the stabilization of Pt species. Tuning the K content in PtSn@MFI catalysts adeptly alters the electronic configuration of Pt clusters. This modification is corroborated by infrared and X-ray photoelectron spectroscopy analysis, and density functional theory calculations. Remarkably, the catalyst with 0.8 wt% K exhibits an optimal Pt electron density, driving its superior efficacy in the co-aromatization reaction, converting 0.78 mol of methane for each mole of hexane processed. By employing ~(13)C isotopic labeling and solid-state NMR studies, we demonstrate the participation of methane in the adsorbed species inside the zeolite channel and its incorporation to the benzyl site of the substitute group and phenyl rings in aromatic compounds, underscoring the importance of Pt encapsulation.

关键词： Pt encapsulation MFI zeolite methane activation co-aromatization ^(13)C solid-state NMR

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Effect of Humidity on Formaldehyde Oxidation over Ce_(0.8)Zr_(0.2)O_(y)Catalyst

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1108-1115页

作者： TANG Ruijiu YANG Zonglin liu xiang JIA Lijuan WANG Fang DUAN Kaijiao liu Tiancheng College of Chemistry and Environment Yunnan Minzu UniversityTechnology Innovation Team of Green Purification Technology for Industrial Waste GasEducation Department of YunnanKey Laboratory of Environmental Functional Materials of Yunnan Province Education DepartmentKunming 650504China

In the preparation of a series of Ce_(0.8)Zr_(0.2)O_(y)catalysts catalyzing the removal of formaldehyde,BET,H2-TPR,IR,SEM,XPS,and XRD were used to characterize the catalyst,and the influence of humidity on the catalyst activity was studied by adjusting the humidity during the *** experimental results showed that the formaldehyde removal rate increased with the increase of *** the humidity was higher than 50%,the formaldehyde removal rate decreased by 3%over that when the humidity was 50%.The characterization results showed that humidity facilitated the activation of oxygen and the formation of hydroxyl groups,which both promoted the formation and oxidative decomposition of intermediates and prevented the deposition of intermediates that clogged the pores,allowing more formaldehyde to be adsorbed and oxidized,which increased the activity of the *** provides new mechanistic evidence for the oxidation of formaldehyde and helps in the development of relatively low-cost materials for formaldehyde purification.

关键词： formaldehyde humidity Ce_(0.8)Zr_(0.2)O_(y) catalytic oxidation

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Efficient and precise genomic deletion in rice using enhanced prime editing

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aBIOTECH 2024年第2期5卷 214-218页

作者： Mengyuan liu xiang Zhang Wen Xu guiting Kang Ya liu Xinxiang liu Wen Ren Jiuran Zhao Jinxiao Yang Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China

Efficient and precise genomic deletion shows promise for investigating the function of proteins in plant research and enhancing agricultural *** this study,we tested the PRIME-Del(PDel)strategy using a pair of prime editing guide RNAs(pegRNAs)that targeted opposite DNA strands and achieved an average deletion efficiency of 55.8%for 60 bp fragment deletions at six endogenous ***,as high as 84.2%precise deletion efficiency was obtained for a 2000 bp deletion at the OsGS1 site in transgenic rice *** add the bases that were unintentionally deleted between the two nicking sequences,we used the PDel/Syn strategy,which introduced multiple synonymous base mutations in the region that had to be patched in the RT *** PDel/Syn strategy achieved an average of 58.1%deletion efficiency at six endogenous targets,which was higher than the PDel *** strategies presented in this study contribute to achieving more accurate and flexible deletions in transgenic rice plants.

关键词： Prime editing Precise genomic deletion CRISPR Cas9

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Assessment of the Influence of Tunnel Settlement on Operational Performance of Subway Vehicles

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Structural Durability & Health Monitoring 2024年第1期18卷 55-71页

作者： Gang Niu Guangwei Zhang Zhaoyang Jin Wei Zhang xiang liu China Communications Construction Rail Transit Subsidiary Beijing100000China China Communications Construction Strait Construction Investment Development Co. Ltd.Fuzhou350000China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

In the realm of subway shield tunnel operations,the impact of tunnel settlement on the operational performance of subway vehicles is a crucial *** study introduces an advanced analytical model to investigate rail geometric deformations caused by settlement within a vehicle-track-tunnel coupled *** model integrates the geometric deformations of the track,attributed to settlement,as track irregularities.A novel“cyclic model”algorithm was employed to enhance computational efficiency without compromising on precision,a claim that was rigorously *** model’s capability extends to analyzing the time-history responses of vehicles traversing settlement-affected *** research primarily focuses on how settlement wavelength,amplitude,and vehicle speed influence operational *** findings indicate that an increase in settlement wavelength can improve vehicle performance,whereas a rise in amplitude can degrade *** study also establishes settlement thresholds,based on vehicle operation comfort and *** insights are pivotal for maintaining and enhancing the safety and efficiency of subway systems,providing a valuable framework for urban infrastructure management and long-term maintenance strategies in metropolitan transit systems.

关键词： Settlement running performance subway tunnel dynamic analysis track irregularity threshold

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