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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 106-111页

作者： Yuhang Zhang Cong Liu xiyu Zhu Hai-Hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

Recent claim of discovering above-room-temperature superconductivity(Tc≈400 k.at ambient pressure in copper doped apatite Pb10(PO_(4))_(6)O has stimulated world-wide enthusiasm and impulse of motion.A lot of follow-up work. have been carried out with controversial *** check.whether superconductivity is really present or absent in the material,we need samples which should have a rather pure phase of Pb_(10-x)Cux(PO_(4))_(6)*** we report the characterization results from the Pb_(10-x)Cux(PO_(4))_(6)O with a fraction of about 97 wt.%inferred from the fitting to the X-ray diffraction pattern,if assuming Cu2S as the only *** resistivity measurements show that it is a semiconductor characterized roughly by a ln(1/T)temperature dependence in wide temperature region without trace of *** measurements show that it has a general ferromagnetic signal with a weak.superparamagnetic *** grains of the sample show clear interactions with a Nb Fe B *** detected Cu concentration is much lower than the expected nominal *** results show the absence of metallicity and superconductivity in Pb_(10-x)Cux(PO_(4))_(6)O at ambient pressure,and suggest the presence of strong correlation effect.

关键词： superconductivity Pb10(PO4)6O ferromagnetic correlation effect

Modulating Co-Co bonds average length in Co_(0.85)Se_(1-x)S_(x) to enhance conversion reaction for potassium storage

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Journal of Energy Chemistry 2024年第4期91卷 111-121页

作者： Daming Chen Yuchun Liu Pan Feng Xiao Tao Zhiquan Huang xiyu Zhang Min Zhou Jian Chen Jiangsu k.y Laboratory of Advanced Metallic Materials School of Materials Science and EngineeringSoutheast UniversityNanjing 211189JiangsuChina Hefei National Laboratory for Physical Sciences at the Microscale School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still *** this study,we study the influence of dopant concentration on the chemical bonds in TMC and reveal the associated stepwise conversion reaction mechanism for potassium ion *** to density function theory calculations,appropriate S-doping in Co0.85Se(Co_(0.85)Se_(1-x)S_(x))can reduce the average length of Co-Co bonds because of the electronegativity variation,which is thermodynamically favourable to the phase transition *** optimal Se/S ratio(x=0.12)for the conductivity has been obtained from experimental *** assembled as an anode in potassium-ion batteries(PIBs),the sample with optimized Se/S ratio exhibits extraordinary electrochemical *** rate performance(229.2 mA h g^(-1)at 10 A g^(-1))is superior to the state-of-the-art *** assembled with Prussian blue(PB)as a cathode,the pouch cell exhibits excellent performance,demonstrating its great potential for ***,the stepwise k.storage mechanism caused by the coexistence of S and Se is revealed by in-situ X-ray diffraction and ex-situ transmission electron microscopy ***,this work.not only provides an effective strategy to enhance the electrochemical performance of transition metal chalcogenides but also reveals the underlying mechanism for the construction of advanced electrode materials.

关键词： Co_(0.85)Se_(1-x)S_(x) Co-Co bonds Phase transition reactions Optimal Se/s Potassium ion batteries

Signature of Superconductivity in Pressurized La_(4)Ni_(3)O_(10)

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Chinese Physics Letters 2024年第1期41卷 77-84页

作者：李庆张英杰项浙宁张宇航祝熙宇闻海虎 National Laboratory of Solid State Microstructures and Department of Physics Center for Superconducting Physics and MaterialsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

The discovery of high-temperature superconductivity near 80k.in bilayer nick.late La_(3)Ni_(2)O_(7)under high pressures has renewed the exploration of superconducting nick.late in bulk.*** extension of superconductivity in other nick.lates in a broader family is also ***,we report the experimental observation of superconducting signature in trilayer nick.late La_(4)Ni_(3)O_(10)under high *** using a modified solgel method and post-annealing treatment under high oxygen pressure,we successfully obtained polycrystalline La_(4)Ni_(3)O_(10)samples with different transport behaviors at ambient *** we performed high-pressure electrical resistance measurements on these samples in a diamond-anvil-cell ***,the signature of possible superconducting transition with a maximum transition temperature(T_(c))of about 20k.under high pressures is observed,as evidenced by a clear drop of resistance and the suppression of resistance drops under magnetic *** the resistance drop is sample-dependent and relatively small,it appears in all of our measured *** argue that the observed superconducting signal is most lik.ly to originate from the main phase of La_(4)Ni_(3)O_(10).Our findings will motivate the exploration of superconductivity in a broader family of nick.lates and shed light on the understanding of the underlying mechanisms of high-T_(c) superconductivity in nick.lates.

关键词： materials superconductivity signature

基于不同涡黏模型的三心拱巷道风流数值模拟研究

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矿业安全与环保 2024年第3期51卷 97-106页

作者：程熙宇周春山陈鹏燕太原理工大学安全与应急管理工程学院山西晋中030600 山西省矿井通风与火灾防治工程技术研究中心山西太原030000

为了研究不同湍流模型在预测U形钢支护三心拱巷道截面风速分布的差异性,选取相同边界条件下风洞实测风速与基于标准k.epsilon模型、标准k.omega模型、Spalart-Allmaras模型等3种湍流模型的仿真风速进行比较。结果表明,上述3种湍流模型... 详细信息

为了研究不同湍流模型在预测U形钢支护三心拱巷道截面风速分布的差异性,选取相同边界条件下风洞实测风速与基于标准k.epsilon模型、标准k.omega模型、Spalart-Allmaras模型等3种湍流模型的仿真风速进行比较。结果表明,上述3种湍流模型均能大致描述巷道风流特征,巷道截面处风速实测值与仿真值的绝对误差与入口风速呈正相关关系,与壁面距离呈负相关关系;以绝对误差平均值和均方根误差为评判准则,标准k.epsilon模型在模拟巷道风速时与现场实测风速数据的拟合度较高,Spalart-Allmaras模型次之,标准k.omega模型拟合度较低。

关键词：三心拱巷道 U形钢支护计算流体力学数值模拟涡黏模型风流特征

Critical size limit of biodegradable nanopartides for enhanced lymph node traffick.ng and paracortex penetration

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Nano Research 2019年第4期12卷 837-844页

作者： Gregory P. Howard Garima Verma xiyu k. Winter M. Thayer Timothy Hamerly Victoria k. Baxter John E. Lee Rhoel R. Dinglasan Hai-Quan Mao Department of Biomedical Engineering Johns Hopkins School of Medicine Baltimore MD 21218 USA Institute for NanoBioTechnology Johns Hopkins University Baltimore MD 2121 & USA W. Harry Feinstone Department of Molecular Microbiology & Immunology and the Malaria Research Institute Johns Hopkins Bloomberg School of Public Health Baltimore MD 21205 USA Emerging Pathogens Institute Department of Infectious Diseases & Immunology College of Veterinary Medicine University of Florida Gainesville FL 32611 USA Department of Materials Science and Engineering Whiting School of Engineering Johns Hopkins University Baltimore MD 21218 USA Johns Hopk.ns School of Nursing Baltimore MD 21205 USA Department of Molecular and Comparative Pathobiology Johns Hopkins School of Medicine Baltimore MD 21205 USA Department of Biomedical Engineering Yale University New Haven CT 06520 USA Translational Tissue Engineering Center Johns Hopkins University School of Medicine Baltimore MD 21231 USA

Lymph node (LN) targeti ng through interstitial drain age of nan oparticles (NPs) is an attractive strategy to stimulate a pote nt immune respo nse, as LNs are the primary site for lymphocyte priming by antigen presenting cells (APCs) and triggering of an adaptive immune response. NP size has been shown to influence the efficiency of LN-targeting and retention after subcutaneous injection. For clinical translation, biodegradable NPs are preferred as carrier for vaccine delivery. However, the selective "size gateM for effective LN-drainage, particularly the k.netics of LN traffick.ng, is less well defined. This is partly due to the challenge in generating size-controlled NPs from biodegradable polymers in the sub-100-nm range. Here, we report the preparation of three sets of poly(lactic-co-glycolic)-b-poly(ethylene-glycol)(PLGA-b-PEG) NPs with number average diameters of 20-, 40-, and 100-nm and narrow size distributions using flash nanoprecipitation. Using NPs labeled with a near-infrared dye, we showed that 20-nm NPs drain rapidly across proximal and distal LNs following subcutaneous inoculation in mice and are retai ned in LNs more effectively than NPs with a nu mber average diameter of 40-nm. The drain age of 100-nm NPs was n egligible. Furthermore, the 20-nm NPs showed the highest degree of penetration around the paracortex region and had enhanced access to dendritic cells in the LNs. Together, these data confirmed that small, size-controlled PLGA-b-PEG NPs at the lower threshold of about 30-nm are most effective for LN traffick.ng, retention, and APC uptak. after s.c. administration. This report could inform the design of LN-targeted NP carrier for the delivery of therapeutic or prophylactic vaccines.

关键词： biodegradable nano particle lymph node traffick.ng vaccine delivery nanoparticle size an tigen presenting cells in vivo imaging

Bi_(2)Fe_(4)O_(9)纳米片制备及其压电催化性能实验设计

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实验技术与管理 2024年第7期41卷 80-86页

作者：罗海健苏闯建魏熙宇柯丁宁孙飞云哈尔滨工业大学(深圳)实验与创新实践教育中心广东深圳518055 广东省环境科学研究院广东广州510045 哈尔滨工业大学(深圳)土木与环境工程学院广东深圳518055

压电催化是由压电晶体的应力诱导电效应驱动的催化过程。为进一步提高压电材料的压电催化性能,对制备铁酸铋压电材料Bi_(2)Fe_(4)O_(9)的传统水热法进行了优化改进,并探索了其压电催化降解性能及相关机理。利用XRD、SEM、XPS等表征手段... 详细信息

压电催化是由压电晶体的应力诱导电效应驱动的催化过程。为进一步提高压电材料的压电催化性能,对制备铁酸铋压电材料Bi_(2)Fe_(4)O_(9)的传统水热法进行了优化改进,并探索了其压电催化降解性能及相关机理。利用XRD、SEM、XPS等表征手段分析了Bi_(2)Fe_(4)O_(9)样品的形貌尺寸和元素分布,利用FPM、压电瞬间电流等测试了其压电性能,以罗丹明B模拟废水考察了基于Bi_(2)Fe_(4)O_(9)压电催化的高级氧化体系。结果表明,通过改进水热法制备的Bi_(2)Fe_(4)O_(9)样品是具有光滑表面、单分散性、平均尺寸为910 nm×82 nm的薄片状形态纳米片结构。XRD及XPS结果表明,Bi_(2)Fe_(4)O_(9)样品纯度高,且Bi、Fe、O元素均匀分布。PFM及压电电流测试发现,Bi_(2)Fe_(4)O_(9)纳米片具有很好的压电催化性能。超声波空化诱导Bi_(2)Fe_(4)O_(9)纳米片压电催化S_(2)O_(8)^(2-)体系(US/Bi_(2)Fe_(4)O_(9)/S_(2)O_(8)^(2-))的罗丹明B(RhB)去除率达97.8%,表明超声活化压电和压电催化多场耦合系统具有显著的协同促进作用。

关键词：压电催化 Bi_(2)Fe_(4)O_(9) 纳米片状超声空化水热制备

Coal-based transformation of cities in Shandong Province,China

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Chinese Journal of Population,Resources and Environment 2015年第4期13卷 358-364页

作者： Zheng Xiang xiyu Liu College of Management Science and Engineering Shandong Normal University

This article primarily discusses the issue of realizing sustainable development in Shandong Province,China through *** compares the global energy structure to China's,as well as among regions and provinces within *** article tak.s six cities in Shandong Province as typical objectives,and then using principal component analysis it calculates their flexibility in regard to city shift and *** main purpose was to quantify the impact of economic activities triggered by the coal industry,a.k.a the energy economic nexus,and to assess the flexibility and sustainability in transformation among the observed coal-based cities.

关键词： coal transformation principal component analysis sustainability

Contrasting physical properties of the trilayer nick.lates Nd4Ni3O10 and Nd4Ni3O8

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Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 98-104页

作者： Qing Li ChengPing He xiyu Zhu Jin Si XinWei Fan Hai-Hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China

We report the crystal structures and physical properties of trilayer nick.lates Nd4Ni3O10and *** of magnetization and electrical resistivity display contrasting behaviors in the two ***4Ni3O10shows a paramagnetic metallic behavior with a metal-to-metal phase transition(T^*)at about 162 k.as revealed by both magnetic susceptibility and *** magnetoresistance and Hall coefficient results show a negative magnetoresistance at low temperatures and the carrier type of Nd4Ni3O10is dominated by hole-type charge *** significant enhancement of Hall coefficient and resistivity below T*suggests that effective charge carrier density decreases when cooling through the transition *** contrast,Nd4Ni3O8 shows an insulating *** addition,this compound shows a paramagnetic behavior with the similar magnetic moment as that of Nd4Ni3O10derived from the Curie-Weiss *** may suggest that the magnetic moments in both systems are contributed by Nd^3+ *** applying pressures up to about 49 GPa,the insulating behavior is still present and becomes even stronger under a high *** results suggest that the different Ni configurations(Ni^1+/2+ or Ni^2+/3+)and the changes of coordination environment of Ni sites may account for the contrasting behaviors in trilayer nick.lates Nd4Ni3O10and Nd4Ni3O8.

关键词： trilayer nick.late Nd4Ni3O10 and Nd4Ni3O8 high-pressure study

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基于深度学习的住院部口服药分类模型的构建

护理研究 2024年第6期38卷 948-954页

作者：王茜玉李南欣向凡李杨唐良友向军莲张俊然四川大学电气工程学院四川610065 德阳市人民医院

目的:基于深度学习法构建针对住院部的口服药分类模型。方法:模拟实际应用场景,采集95类药丸图片构建数据集,并对其进行图片预处理操作;以MobileNet V2网络为基础架构建立药丸分类模型,并在模型中嵌入注意力机制以增强网络特征通道间的... 详细信息

目的:基于深度学习法构建针对住院部的口服药分类模型。方法:模拟实际应用场景,采集95类药丸图片构建数据集,并对其进行图片预处理操作;以MobileNet V2网络为基础架构建立药丸分类模型,并在模型中嵌入注意力机制以增强网络特征通道间的依赖关系;融合迁移学习的方法,利用自建药丸数据集对模型进行训练和测试,通过模型分类准确率和模型参数量指标检测模型性能。结果:本研究构建的模型在自然环境中采集的口服药丸图片分类方面表现卓越,通过使用包含95类药丸、总计728张图片的自建数据集进行训练和测试,模型分类准确率为95.8%,分别比MobileNet V2、ShuffleNet V2、ResNet50高11.6%、14.3%、11.3%。模型参数量为2.55 M,约为ResNet50的1/10。结论:本研究构建的模型可以较好地平衡模型的复杂度和分类准确率,为药房等场景下涉及的药丸自动分类系统提供技术路线和效果验证,对于提升药房发药、病房分药等具体情形的护理自动化水平具有一定的理论和实际应用价值。

关键词：药房口服药图像处理分类模型深度学习 MobileNet V2网络

Superconductivity in Li OHFe S single crystals with a shrunk.c-axis lattice constant

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Science China(Physics,Mechanics & Astronomy) 2017年第2期Mechanics & Astronomy) .卷 50-54页

作者： Hai Lin Rui Zhe k.ng Lu k.ng xiyu Zhu Hai-Hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced Microstructures Nanjing University

By using a hydrothermal ion-exchange method, we have successfully grown superconducting crystals of Li OHFe S with Tcof about 2.8 k. Being different from the sister sample(Li1-xFex)OHFe Se, the energy dispersion spectrum analysis on Li OHFe S shows that the Fe/S ratio is very close to 1:1, suggesting an almost charge neutrality and less electron doping in the Fe S planes of the system. Comparing with the non superconducting Li OHFe S crystal, each peak.of the X-ray diffraction pattern of the superconducting crystal splits into two, and the diffraction peak. locating at lower reflection angles are consistent with that of non-superconducting ones. The rest set of diffraction peak. with higher reflection angles is corresponding to the superconducting phase, suggesting that the superconducting phase may has a shrunk.c-axis lattice constant. Magnetization measurements indicate that the magnetic shielding due to superconductivity can be quite high under a weak.magnetic field. The resistivity measurements under various magnetic fields show that the upper critical field is quite low, which is similar to the tetragonal Fe S superconductor.

关键词： iron chalcogenides magnetic properties transport properties