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Analytical solution to incident angle quasi-phase-matching engineering for second harmonic generation in a periodic-poled lithium niobate crystal

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Chinese Physics B 2024年第2期33卷 115-123页

作者：洪丽红邱雅婷李晓霓陈宝琴李志远 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

Phase matching or quasi-phase matching(QPM)is of significant importance to the conversion efficiency of second harmonic generation(SHG)in artificial nonlinear crystals like lithium niobate(LN)crystal or microstructured nonlinear crystals like periodic-poled lithium niobate(PPLN)*** this paper,we propose and show that the incident angle of pump laser light can be harnessed as an alternative versatile tool to engineer QPM for high-efficiency SHG in a PPLN crystal,in addition to conventional means of period adjusting or temperature tuning.A rigorous model is established and analytical solution of the nonlinear conversion efficiency under the small and large signal approximation theory is obtained at different incident *** variation of phase mismatching and walk-off length with incident angle or incident wavelength are also *** simulations for a PPLN crystal with first order QPM structure are used to confirm our theoretical predictions based on the exact analytical solution of the general large-signal *** results show that the narrow-band tunable SHG output covers a range of 532 nm–552.8 nm at the ideal incident angle from 0°to 90°.This theoretical scheme,fully considering the reflection and transmission at the air-crystal interface,would offer an efficient theoretical system to evaluate the nonlinear frequency conversion and help to obtain the maximum SHG conversion efficiency by selecting an optimum incident wavelength and incident angle in a specially designed PPLN crystal,which would be very helpful for the design of tunable narrow-band pulse nanosecond,picosecond,and femtosecond laser devices via PPLN and other microstructured LN crystals.

关键词： nonlinear frequency conversion transmission reflection lithium niobate

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Study on flow characteristics and phase holdup in a slurry bubble column coupled with mild agitation Author links open overlay panel

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Particuology 2024年第8期91卷 226-234页

作者： Qingyuan An Jiantao li Lei Zhang Nailiang Wang Pengfei Zhang Zhenghong Luo Chunxi Lu State Key Laboratory of High-Efficiency Coal Utilization and Green Chemical Engineering Ningxia UniversityYinchuan750021China State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of Petroleum BeijingBeijing102249China Department of Chemical&Biological Engineering Monash UniversityVictoria3800Australia

A pilot-scale experimental setup was constructed to investigate the effect of mild agitation on the bubble characteristics and phase holdup in a slurry bubble *** agitation positively impacts the axial uniform distribution of solid holdup,though it shows insignificant influence on the radial *** homogenous regime,mild agitation promotes the coalescence of bubbles,and the effect becomes stronger with increasing agitator *** mild agitation contributes to a decrease in bubble size in heterogeneous flow *** agitation presents a significant effect on the gas holdup by adjusting the bubble size and bubble motion *** modification was introduced to predict the gas holdup considering the effects of mild agitation,a necessary consideration for applications requiring mild *** adapted model predicts gas holdup with a maximum error of 12.9%.

关键词： Slurry bubble column Mild agitation Phase holdup Bubble characteristics

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Risk Factors of Enternal Nutrition Intolerance in Septic Patients:A Case-control Study

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Current Medical Science 2024年第2期44卷 328-332页

作者： li-zhu WAng Yan XIAng Qian li Yi-rong ZHU Jue FAng Xiao-dan LU Zhao-cai ZHAng Department of Nursing The Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Department of Critical Care Medicine The Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Key Laboratory of the Diagnosis and Treatment for Severe Trauma and Burn of Zhejiang Province Hangzhou 310009China Zhejiang Province Clinical Research Center for Emergency and Critical Care Medicine Hangzhou 310009China

Objective:This study aimed to investigate the incidence of enteral nutrition intolerance(ENI)in patients with sepsis and explore potential risk ***:A case-control study was conducted in patients with sepsis who were receiving enteral nutrition(EN)at a tertiary hospital in *** included patients were divided into the ENI group and the non-ENI *** and multivariate analyses were performed to identify the risk factors for ***:A total of 859 patients were included in the *** them,288(33.53%)patients experienced symptoms of ENI,including diarrhea,vomiting,bloating,and gastric *** regression analysis revealed that the Acute Physiology and Chronic Health Evaluation H(APACHE H)score,thoracocentesis,and usage of cardiotonic drugs(namely,inotropes)were independent predictors of the ***:The incidence of ENI is relatively high in patients with sepsis,especially in those who have higher APACHE H scores,have undergone thoracocentesis,and have received inotropes.

关键词： sepsis enteral nutrition intolerance influencing factor

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国内森林地下火研究进展

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林业勘查设计 2024年第1期53卷 45-50页

作者：李存宇赵南黑龙江省森林保护研究所哈尔滨150081

森林地下火多发生于高温干燥且生物量充足的枯落物底层,枯落物与泥炭混合后在缺氧环境下持续阴燃。森林地下火燃烧不明显,但其破坏森林根系与土壤、产生大量有害气体,对森林生态系统和生态安全产生重大影响。长时间的地底燃烧形成的大... 详细信息

森林地下火多发生于高温干燥且生物量充足的枯落物底层,枯落物与泥炭混合后在缺氧环境下持续阴燃。森林地下火燃烧不明显,但其破坏森林根系与土壤、产生大量有害气体,对森林生态系统和生态安全产生重大影响。长时间的地底燃烧形成的大量灰烬可随风传送至其他森林区域,导致更大的火灾。从理论与应用2个研究方向总结阐述森林地下火的研究进展,包括森林地下火燃烧特性、森林地下火影响因子、森林地下火预防扑救技术和识别森林地下火的技术装备。对上述研究进展进行梳理与综述,对未来地下火的防控手段、扑救应对及灾后管理恢复工作给予有价值的参考,为森林地下火研究提供新的思路与方向。

关键词：森林保护森林地下火综述

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Pseudorabies virus manipulates mitochondrial tryptophanyl-tRNA synthetase 2 for viral replication

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Virologica Sinica 2024年第3期39卷 403-413页

作者： Xiu-Qing li Meng-Pan Cai Ming-Yang Wang Bo-Wen Shi Guo-Yu Yang Jiang Wang Bei-Bei Chu Sheng-li Ming College of Veterinary Medicine Henan Agricultural UniversityZhengzhou 450046China Key Laboratory of Animal Biochemistry and Nutrition Ministry of Agriculture and Rural AffairsZhengzhou 450046China Key Laboratory of Veterinary Biotechnology of Henan Province Henan Agricultural UniversityZhengzhou 450046China Longhu Advanced Immunization Laboratory Zhengzhou 450046China International Joint Research Center of National Animal Immunology Henan Agricultural UniversityZhengzhou 450046China Ministry of Education Key Laboratory for Animal Pathogens and Biosafety Zhengzhou 450046China School of Basic Medicine Chongqing Medical UniversityChongqing 400016China

The pseudorabies virus(PRV)is identified as a double-helical DNA virus responsible for causing Aujeszky's disease,which results in considerable economic impacts *** enzyme tryptophanyl-tRNA synthetase 2(WARS2),a mitochondrial protein involved in protein synthesis,is recognized for its broad expression and vital role in the translation *** findings of our study showed an increase in both mRNA and protein levels of WARS2 following PRV infection in both cell cultures and animal *** WARS2 expression via RNA interference in PK-15 cells led to a reduction in PRV infection rates,whereas enhancing WARS2 expression resulted in increased infection ***,the activation of WARS2 in response to PRV was found to be reliant on the cGAS/STIng/TBK1/IRF3 signaling pathway and the interferon-alpha receptor-1,highlighting its regulation via the type I interferon signaling *** analysis revealed that reducing WARS2 levels hindered PRV's ability to promote protein and lipid *** research provides novel evidence that WARS2 facilitates PRV infection through its management of protein and lipid levels,presenting new avenues for developing preventative and therapeutic measures against PRV infections.

关键词： Pseudorabies virus WARS2 Innate immunity Protein synthesis lipid synthesis

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Drought shifts soil nematode trophic groups and mediates the heterotrophic respiration

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Journal of Plant Ecology 2024年第2期17卷 100-109页

作者： Cancan Zhao Yuanhu Shao Huijie Lu Aimée T.Classen Zuyan Wang Ying li Yanchun liu Zhongling Yang Guoyong li Shenglei Fu International Joint Research Laboratory for Global Change Ecology School of Life SciencesHenan UniversityKaifeng 475004China Henan Dabieshan National Field Observation and Research Station of Forest Ecosystem Zhengzhou 450046China Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions Ministry of EducationCollege of Environment and PlanningHenan UniversityKaifeng 475004China Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security Kaifeng 475004China Department of Ecology and Evolutionary Biology University of MichiganAnn ArborMI 48109USA South China Botanical Garden Chinese Academy of SciencesGuangzhou 510650China Department of Natural Resource of Henan Province Institute of Natural Resources Survey and PlanningZhengzhou 450000China

As the most diverse metazoan taxa,soil nematodes serve a diversity of functions in soil food webs and thus can regulate microbial community composition and affect organic matter decomposition and nutrient turnover *** nematodes depend on water flms to access food resources,drought can negatively affect nematode-microbial food webs,yet the impacts of drought on nematode diversity and abundance and how these changes may infuence food web members and their functions are hardly ***,we coupled research along a drought gradient in arid and semiarid grasslands with a detailed intact plant-soil microcosm experiment to explore the patterns and mechanisms of how drought impacts nematode abundance and carbon footprint,microbial phospholipid fatty acid(PLFA)and heterotrophic soil ***,in the feld and the microcosm experiments,we found that nematode abundance,carbon footprint and diversity,microbial PLFA and heterotrophic respiration were reduced under drier *** addition,drought altered nematode and microbial community composition,through reducing the nematode channel ratio and increasing the relative fungivorous nematode abundance and the fungal to bacterial *** soil decomposition channel shifted from a bacterial to a fungal pathway in response to drought,indicating decelerated heterotrophic respiration under *** results highlight the important contribution of soil nematodes and their associated microbial food web to soil carbon *** fndings underscore the need to incorporate key soil fauna into terrestrial ecosystem model evaluation.

关键词： soil biota fungal energy channel bacterial energy channel carbon footprint arid grassland

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Synthesis and electrochemical properties of li FePO_(4) cathode material by ionic thermal method using eutectic mixture of tetramethyl ammonium chloride-urea

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Rare Metals 2021年第12期40卷 3477-3484页

作者： Si-nan li Shao-Hua Luo liu Yang Qing Wang Ya-Hui Zhang Xin liu School of Materials Science and Engineering Northeastern UniversityShenyang 110819China School of Resources and Materials Northeastern University At QinhuangdaoQinhuangdao 066004China Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province Qinhuangdao 066004China

In this study, the liFePO_(4) cathode was synthesized by the ionic thermal method using the deep eutectic mixture of tetramethyl ammonium chloride and urea. The synthetic conditions were systematically investigated by orthogonal experiments, which indicate that the optimal reaction time, reaction temperature, molar ratio of li to DES and rotate speed are 96 h, 220 ℃, 1:14 and20 r·min^(-1), respectively. X-ray diffraction(XRD), scanning electron microscope(SEM) and transmission electron microscope(TEM) were characterized to investigate the crystalline structure and morphology of the obtained materials, indicating well-crystallized liFePO_(4) with olivine structure. And the physical properties of liFePO_(4) were explored through Fourier transform infrared spectroscopy(FTIR),57 Fe Mo¨ ssbauer absorption spectra and Raman spectra. An initial discharge capacity can reach 151 m Ah·g^(-1) at 0.1 C rate for liFePO_(4) following by calcining at 600 ℃ under the optimal conditions, and it retains 125.1 m Ah·g^(-1) after 100 cycles. These results demonstrated that the addition of ionic liquids can improve the rate performance, cycle performance and ion diffusion rate of liFePO_(4).

关键词： liFePO_(4) Deep eutectic solvents Ionic thermal method Orthogonal experiments Electrochemical performance

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基于局部空间特征引导的表情识别算法

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信息对抗技术 2024年第1期3卷 46-56页

作者：李剑鹏苏楠清华大学电子工程系北京100084

面部表情识别在计算机视觉任务中受到越来越多的关注,由于真实场景中的表情往往包含着大量由姿态、年龄、图像质量、标注等因素带来的噪声,大大增加了类内变化,给表情的分类任务带来了很大的困难。现有的基于此类问题的研究往往聚焦于... 详细信息

面部表情识别在计算机视觉任务中受到越来越多的关注,由于真实场景中的表情往往包含着大量由姿态、年龄、图像质量、标注等因素带来的噪声,大大增加了类内变化,给表情的分类任务带来了很大的困难。现有的基于此类问题的研究往往聚焦于数据本身,通过对数据进行筛选或者扩大模型接受的数据类型的形式提高识别能力,没有考虑到卷积网络本身对图像特征关注的局限性。针对该问题,提出了一种基于局部空间特征引导的卷积神经网络,对于特征图的某部分像素点进行强调,引导卷积网络的深层特征图能够关注到多个对分类有效的局部面部区域,同时使用对数据重标记的形式抑制由标签错误导致的噪声问题。经过在多个公开的表情识别数据集中测试,并与多个同类方法对比,所提方法具有较好的识别效果。

关键词：面部表情识别卷积神经网络特征图可视化空间特征聚合

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Research and development of a 0.5-m-long helical superconducting undulator prototype

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-10页

作者： Yang, Xiang-Chen Yu, Xiao-Wu Wei, Jun-Hao Zhang, Xiang-Zhen Chen, Zi-lin Bian, Xiao-Juan li, He-Ting Feng, Guang-Yao li, Yu-Hui Univ Sci & Technol China Natl Synchrotron Radiat Lab Hefei 230029 Peoples R China Chinese Acad Sci Inst High Energy Phys Beijing 100049 Peoples R China Chinese Acad Sci Inst High Energy Phys China Spallat Neutron Source Dongguan 523000 Peoples R China Chinese Acad Sci Inst Plasma Phys ASIPP Hefei 230031 Peoples R China

The helical undulator is in high demand in synchrotron radiation facilities for circular polarization generation. Owing to the higher field strength provided by the superconducting undulator compared to the conventional permanent-magnet undulator, greater research efforts should be directed toward this area. The helical superconducting undulator holds great potential in synchrotron radiation facilities, especially in low-energy storage rings that seek circularly polarized radiation with the highest possible radiation flux. Following the successful development of planar superconducting undulators, the Institute of High Energy Physics conducted research and development for the helical superconducting undulator. A 0.5-m-long Delta-type superconducting undulator prototype was developed and tested. Detailed information on the design, fabrication, and cryogenic testing of the prototype is presented and discussed.

关键词： Helical Superconducting undulator Delta DESIGN

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电视剧《风起陇西》男子首服设计考

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武汉纺织大学学报 2024年第3期37卷 27-33页

作者：吴隽言李楠中国传媒大学戏剧影视学院北京100024

电视剧《风起陇西》的男子首服设计种类丰富,具有表意、象征、隐喻等功能,是串联全剧内容的重要线索,因其精良的制作水准而备受关注。文章以电视剧《风起陇西》的首服制作实物为研究对象,主要采用文献研究法,结合考古实物和其他艺术形... 详细信息

电视剧《风起陇西》的男子首服设计种类丰富,具有表意、象征、隐喻等功能,是串联全剧内容的重要线索,因其精良的制作水准而备受关注。文章以电视剧《风起陇西》的首服制作实物为研究对象,主要采用文献研究法,结合考古实物和其他艺术形式的图像,梳理、考辨、比对首服形态。研究认为电视剧《风起陇西》男子首服的结构、形制与运用基本符合历史依据,在追求历史之真的基础上进行了艺术化再创作,重视首服设计在视觉语言层面发挥的重要作用。

关键词：《风起陇西》男子首服设计人物造型服饰语言

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