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Effects of Al component content on optoelectronic properties of Al_xGa_(1-x)N

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Chinese Physics B 2018年第10期27卷 495-500页

作者： Yan-Jun Ji Jun-Ping Wang you-wen liu College of Science Nanjing University of Aeronautics and AstronauticsNanjing 211106China College of Aeronautical Engineering Bingzhou UniversityBingzhou 256603China

Using density functional theory, the electronic structures, lattice constants, formation energies, and optical properties of AlxGa1-xN are determined with Al component content x in a range from 0 to 1. As x increases, the lattice constants decrease in e-exponential form, and the band gap increases with a band bending parameter b=0.3954. The N–Al interaction force in the（0001） direction is greater than the N–Ga interaction force, while the N–Al interaction force is less than the N–Ga interaction force in the（10ī0） direction. The formation energies under different Al component content are negative and increase with Al component content increasing. The static dielectric function decreases, the absorption edge has a blue shift, and the energy loss spectrum moves to high energy with the Al component content increasing.

关键词： GaN photocathode electronic structure optical properties

Photonic spin Hall effect in PT symmetric metamaterials

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Frontiers of physics 2019年第6期14卷 27-33页

作者： Yang-Yang Fu Yue Fei Da-Xing Dong you-wen liu College of Science Nanjing University of Aeronautics and AstronauticsNanjing 211106China

We proposed and demonstrated that PT symmetric metamaterials could be used to achieve enhanced spin Hall effect(SHE)of *** find that when laser mode is excited in PT symmetric system,the enhanced SHE could be obtained in both transmitted and reflected *** addition,as exceptional points(EPs)of PT symmetric system can happen for both p-and s-polarizations,the enhanced SHE of reflected light can function for both horizontally and vertically polarized incident ***,these EPs can lead to unidirectional reflectionlessness,asymmetric SHE with maximum contrast ratio of 48 is obtained by launching light beams near *** work opens up a new path to obtain enhanced transverse displacement for both reflected and transmitted light and enables more opportunities in manipulating photonic SHE.

关键词： PT symmetry exceptional points laser mode spin Hall effect

Controllably asymmetric beam splitting via gap-induced diffraction channel transition in dual-layer binary metagratings

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Frontiers of physics 2020年第5期15卷 131-136页

作者： Yang-Yang Fu Jia-Qi Tao Ai-Ling Song you-wen liu Ya-Dong Xu College of Science Nanjing University of Aeronautics and AstronauticsNanjing 211106China School of Physical Science and Technology Soochow UniversitySuzhou 215006China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China

In this work,we designed and studied a feasible dual-layer binary metagrating,which can realize cotrollable asymetrie transmission and beam splitting with nearly perfect *** to ingenious geometry configuration,only one meta-atom is required to design for the metagrating *** simply controlling air gap between dual-layer metagratings,high-eficiency beam splitting can be well switched from asymmetrie tranmission to sy mmetric *** working principle lies on gap-induced dffraction channel transition for ineident waves from opposite *** asymmetric/symmetric transmission can work in a certain frequency band and a wide incident *** with previous methods using acoustie metasurfaces,our approuch has the advantages of simple design and tumnable property and shows promise for applications in wavefront manipulation,noise control and one-way propagation.

关键词： beam slittig asymetrie trasmission acoustice metagrating binary design

Low thermal expansion and broad band photoluminescence of Zr0.1Al1.9Mo2.9V0.1O12

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Chinese Physics B 2021年第3期30卷 423-429页

作者： Jun-Ping Wang Qing-Dong Chen Li-Gang Chen Yan-Jun Ji you-wen liu Er-Jun Liang Shandong Engineering Research Center of Aeronautical Materials and Devices Key Laboratory of Aeronautical Optoelectronic Materials and DevicesCollege of Aeronautical EngineeringBinzhou UniversityBinzhou 256603China College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Physical Science&Engineering and Key Laboratory of Materials Physics of Ministry of Education Zhengzhou UniversityZhengzhou 450052China

A new material of Zr0.1Al1.9Mo2.9V0.1O12 is synthesized by the traditional solid state synthesis *** phase transition,coefficient of thermal expansion,and luminescence properties of Zr0.1Al1.9Mo2.9V0.1O12 are explored with Raman spectrometer,dilatometer,and x-ray diffraction(XRD)*** results show that the Zr0.1Al1.9Mo2.9V0.1O12 possesses the strong broad-band luminescence characteristics almost in the whole visible *** sample is crystallized in a monoclinic structure group of P21/a(No.14)crystallized at room temperature(RT).The crystal is changed from monoclinic to orthorhombic structure when the temperature increases to 463 *** material has very low thermal expansion performance in a wide temperature *** excellent low thermal expansion and strong pale green light properties in a wide temperature range suggest its potential applications in light-emitting diode(LED)and other optoelectronic devices.

关键词： low thermal expansion phase transition x-ray diffraction(XRD) Raman spectrum luminescence

Phase transition and near-zero thermal expansion of Zr_(0.5)Hf_(0.5)VPO_7

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Chinese Physics B 2018年第6期27卷 350-354页

作者： Jun-Ping Wang Qing-Dong Chen Sai-Lei Li Yan-Jun Ji wen-Ying Mu Wei-Wei Feng you-wen liu Gao-Jie Zeng Er-Jun Liang College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Aeronautics and Engineering Binzhou College Binzhou 256603 China Key Laboratory of Materials Physics of Ministry of Education School of Physical Science and Engineering Zhengzhou University Zhengzhou 450052 China

The Zr（0.5）Hf（0.5）VPO7 is successfully synthesized by the solid-state method with near-zero thermal expansion. Powder x-ray diffraction（XRD）, Raman spectroscopy, thermal dilatometry, and scanning electron microscopy（SEM） are used to investigate the structure, the phase transition, and the coefficient of thermal expansion（CTE） of Zr（0.5）Hf（0.5）VPO7. The investigation results show that the samples are of the single cubic type with a space group of Pa3ˉ at room temperature（RT）.It can be inferred that the superstructure is transformed from the 3 × 3 × 3 superstructure to the 1 × 1 × 1 ideal crystal in a temperature range between 310 K and 323 K. The CTE is measured by a dilatometer to be 0.59 × 10^（-6） K^（-1）（310 K–673 K）. The values of intrinsic（XRD） and extrinsic（dilatometric） thermal expansion are both near zero. The results show that Zr（0.5）Hf（0.5）VPO7 has near-zero thermal expansion behavior over a wide temperature range.

关键词： near-zero thermal expansion phase transition x-ray diffraction (XRD) Raman spectrum

高分辨率太阳吸收光谱二氧化碳反演中参数的敏感性分析

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光谱学与光谱分析 2017年第7期37卷 1997-2003页

作者：单昌功刘诚王薇孙友文刘文清田园杨维中国科学技术大学环境科学与光电技术学院安徽合肥230031 中国科学技术大学地球与空间科学学院安徽合肥230031 中国科学院安徽光学精密机械研究所环境光学与技术重点实验室安徽合肥230031

基于高分辨率傅里叶变换红外太阳吸收光谱可以准确测量大气中二氧化碳的柱总量。基于光谱反演算法中的前向模型,分析了改变前向模型中不同参数和不同天顶角情况下对反演结果的影响及其原因。选取具有代表性的两天的测量光谱,改变前向模... 详细信息

基于高分辨率傅里叶变换红外太阳吸收光谱可以准确测量大气中二氧化碳的柱总量。基于光谱反演算法中的前向模型,分析了改变前向模型中不同参数和不同天顶角情况下对反演结果的影响及其原因。选取具有代表性的两天的测量光谱,改变前向模型中连续体倾斜量值、内部视场角、零偏置和多普勒效应四个模型参数,观察不同先验模型参数的扰动对二氧化碳测量结果的影响。结果表明,不同模型参数的扰动引起反演的二氧化碳柱平均干空气混合比(XCO_2)相对偏差并不一样;不同的测量时间,相同参数扰动引起的二氧化碳含量相对偏差也不同。其中连续体倾斜量值的变化对反演结果的影响最大,其变化引起的相对偏差波动范围在0.1%~0.2%之间;内部视场角、零偏置和多普勒效应的变化对反演结果影响较小,引起的二氧化碳的相对偏差分别在-0.045%~0.02%,-0.045%~0.015%和-0.03%~0.04%之间。最后用二氧化碳反演平均核解释了反演误差来源。研究结果对光谱反演算法中模型参数的设定和提高测量的准确度提供了理论依据。

关键词：模型参数傅里叶变换红外光谱敏感性分析二氧化碳

Total anterior displacement of the vertebra of C2 without C2-3 locked joint and neurological deficit in Hangman＇s fracture

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Chinese Medical Journal 2009年第8期122卷 992-995页

作者： WANG Bing LV Guo-hua MA Ze-min KANG Yi-jun LI Jing CHEN Fei DENG you-wen liu Wei-dong KUANG Lei Department of Spine Surgery Second Xiangya Hospital of Central South University Changsha Hunan 410011 China

Hangman＇s fracture means bilateral pedicle fractures of the axis accompanying displacement and angulations between the body of C2 and C3. The injury is often caused as a result of falling down or being involved in a vehicular accident. In 1985, based on the classification of Effendi et al, Levine and Edwards proposed a new classification of Hangman＇s fracture according to the mechanism, morphology and stability. The Hangman＇s fracture was classified as type I, II, IIA and III, with type II being the most common of the four types.

关键词： displacement locked joint neurological deficit Hangman's fracture

Real-world evidence on the efficacy and safety of vonoprazanamoxicillin dual therapy for Helicobacter pylori treatment in elderly patients

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World Journal of Gastroenterology 2025年第1期31卷 68-78页

作者： wen Gao Jing-wen Li Hui Ye Xue-Zhi Zhang Jian-Xiang liu Hong Cheng Department of Gastroenterology Peking University First HospitalBeijing 100034China School of Medicine Tsinghua MedicineTsinghua UniversityBeijing 100034China Department of Traditional Chinese Medicine and Integrative Medicine Peking University First HospitalBeijing 100034China

BACKGROUND A dual therapy regimen containing amoxicillin is a common treatment option for the eradication of Helicobacter pylori(***).While substantial research supports the efficacy and safety of vonoprazan and amoxicillin(VA)dual therapy in the general population,there is still a lack of studies specifically focusing on its safety in elderly *** To evaluate efficacy and safety of VA dual therapy as first-line or rescue treatment for *** in elderly *** As a real-world retrospective study,data were collected from elderly patients aged 60 years and above who accepted VA dual therapy(vonoprazan 20 mg twice daily+amoxicillin 1000 mg thrice daily for 14 days)for *** eradication in the Department of Gastroenterology at Peking University First Hospital between June 2020 and January *** status was evaluated by^(13)C-urease breath test 6 weeks after *** adverse events(AEs)during treatment were *** In total,401 cases were ***-one cases were excluded due to loss to follow-up,lack of re-examination,or unwillingness to take *** total of 380 included cases comprised 250 who received VA dual therapy as first-line treatment and 130 who received VA dual therapy as rescue *** was successfully eradicated in 239 cases(95.6%)in the first-line treatment group and 116 cases(89.2%)in the rescue treatment *** overall incidence of AEs was 9.5%for both ***,9.2%of patients experienced an AE in the first-line treatment group and 10.0%in the rescue treatment *** patients discontinued treatment due to AE,with a discontinuation rate of 1.3%.No serious AE *** The VA dual therapy regimen as a first-line treatment and a rescue therapy was effective and safe for elderly patients aged 60 and older.

关键词： Helicobacter pylori Vonoprazan Amoxicillin Dual therapy Elderly

PI3K/AKT signaling and neuroprotection in ischemic stroke:molecular mechanisms and therapeutic perspectives

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Neural Regeneration Research 2025年第10期20卷 2758-2775页

作者： Tianlong liu Xiaolin Li Xiaowei Zhou Wei Chen Aidong wen Minna liu Yi Ding Department of Pharmacy Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina Department of Pharmacy The 940 Hospital of Joint Logistics Support Forces of Chinese PLALanzhouGansu ProvinceChina Department of Pharmacy The 944 Hospital of Joint Logistics Support Forces of Chinese PLAJiuquanGansu ProvinceChina Department of Nephrology The 940 Hospital of Joint Logistics Support Forces of Chinese PLALanzhouGansu ProvinceChina

It has been reported that the PI3K/AKT signaling pathway plays a key role in the pathogenesis of ischemic *** a result,the development of drugs targeting the PI3K/AKT signaling pathway has attracted increasing attention from *** article reviews the pathological mechanisms and advancements in research related to the signaling pathways in ischemic stroke,with a focus on the PI3K/AKT signaling *** key findings include the following:(1)The complex pathological mechanisms of ischemic stroke can be categorized into five major types:excitatory amino acid toxicity,Ca^(2+)overload,inflammatory response,oxidative stress,and apoptosis.(2)The PI3K/AKT-mediated signaling pathway is closely associated with the occurrence and progression of ischemic stroke,which primarily involves the NF-κB,NRF2,BCL-2,mTOR,and endothelial NOS signaling pathways.(3)Natural products,including flavonoids,quinones,alkaloids,phenylpropanoids,phenols,terpenoids,and iridoids,show great potential as candidate substances for the development of innovative anti-stroke medications.(4)Recently,novel therapeutic techniques,such as electroacupuncture and mesenchymal stem cell therapy,have demonstrated the potential to improve stroke outcomes by activating the PI3K/AKT signaling pathway,providing new possibilities for the treatment and rehabilitation of patients with ischemic *** investigations should focus on the direct regulatory mechanisms of drugs targeting the PI3K/AKT signaling pathway and their clinical translation to develop innovative treatment strategies for ischemic stroke.

关键词： apoptosis autophagy inflammation ischemic stroke neuroprotection oxidative stress pathogenesis phosphatidylinositol 3-kinase protein kinase B therapeutics