检索结果-南通市图书馆

The Local Structure and Luminescence property of(M, Ba)3Eu2(BO3)4(M=Ca, Sr) Red Phosphors

在线全文

学校读者我要写书评

暂无评论

The Local Structure and Luminescence property of(M, Ba)3Eu2(...

Viscosity and structure relationship with equimolar substitution of CaO with MgO in the CaO–MgO–Al_(2)O_(3)–siO_(2)slag melts

中国稀土学会2021学术年会

作者： Gui-Hua Li Nian Yang jia-yong si Ge-Mei Cai School of Materials Science and Engineering Education Ministry Key Laboratory of Non-ferrous Materials Science and Engineering Central South University College of Mechanical & Electrical Engineering Central South University of Forestry & Technology

A serial of pure (M,Ba)Eu(BO) (M=Ca,Sr) phosphors have been synthesized by the solid-state reaction *** lattice expansion and occupation change were triggered by the substitution of Bainto Ca/*** comparison with the MEu(BO) cell with one 4e and two 8d crystallographic sites co-occupied by Ca/Eu or Sr/Eu atoms,the 4e site is occupied mainly by Eu atoms in (M,Ba)Eu(BO) lattice,even monopolized by Eu atoms in BaEu(BO) *** phosphors show a deep red emission from D-F transition along with an anomalously strong D-F transition of Euion,with emission intensity keeping ***,the fluorescence lifetime of BaEu(BO) is slightly shorter than those of both (CaBa)Eu(BO) and(SrBa)Eu(BO).According to the local-structure analysis by virtue of Judd-Ofelt theory,BaEu(BO)phosphor has the largerΩ value,apart from the smallerΩ value,indicating a lower symmetry in comparison with the original *** addition,the larger distance of the nearest-neighbor sites for activators could be beneficial for the emission reinforce.

关键词： wLEDs structural distortion crystal field enhancement of luminescence

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 70-79页

作者： yong Hou Shuo Zhang Jie Dang jia Guo Hanghang Zhou Xuewei Lü College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this *** most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-siO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina *** results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO *** transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[siO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and si-O-Al bending became progressively deeper with increased MgO *** of the Raman spectra showed that the average number of bridging oxygens per si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[siO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents *** analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO ***,bond strength is another important factor affecting the slag *** occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[siO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.

关键词： aluminosilicate viscosity structure spectroscopy

Merging bound states in the continuum in an open acoustic resonator

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 124-131页

作者： Lujun Huang Bin jia Artem S.Pilipchuk sibo Huang Chen Shen Almas F.Sadreev yong Li Andrey E.Miroshnichenko School of Physics and Electronic Sciences East China Normal University Institute of Acoustics Tongji University L.V.Kirensky Institute of Physics Department of Mechanical Engineering Rowan University School of Engineering and Technology University of New South Wales at Canberra

Bound states in the continuum （BICs） are perfectly localized resonances despite embedding in the continuum ***,an isolated BIC is very sensitive to the structure ***,we report merging acoustic BICs in a single open resonator,robust against the structure *** find that both symmetry-protected BIC and Friedrich-Wintgen BIC are sustained in a single coupled waveguide-resonator *** varying the height and length of the resonator,these two BICs move toward each other and merge into a single one at a critical *** to an individual BIC,the merged BIC is robust against fabrication error because its Q-factor is proportional to ΔL-4,whereΔL embodies the structure *** essence of this extraordinary phenomenon is perfectly explained by the two-and three-level approximations of the effective nonHermitian ***,we present direct experimental demonstrations of the moving and merging of BICs in a coupled 3D waveguide-resonator,which are evidenced by the vanishing of the linewidth of Fano resonance in the transmission *** results may find exciting applications in designing high-quality acoustic sources,sensors and filters.

关键词： acoustic resonances bound state in the continuum high-Q resonances

Deciphering the role of ultra-low-loaded rhodium in NiFe-MIL-53 for superior oxygen evolution reaction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 77-86页

作者： Jinzhi jia Jinhua Zhang Kailu Guo Lanyue Zhang Gening Du Hao You Junfeng Huang Mudong Tu Hua Li yong Peng Wei Dou Cailing Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering School of Materials and Energy Lanzhou University College of Chemistry and Chemical Engineering Luoyang Normal University

Designing highly active and stable electrocatalysts of oxygen evolution reaction （OER） is one of the crucial *** this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium（Rh@NiFe-MIL-53）,is successfully prepared via the hydrothermal ***-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active *** importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe（OH）2after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@***,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center （εd）,accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining ***,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity （240 mV） with a small Tafel slope of 48.2 mV dec-1and long-term durability (over1270 h at 10 m A cm-2and 110 h at 200 mA cm-2).This work presents a new perspective on designing highly efficient OER electrocatalysts.

关键词： X ray photoelectron spectroscopy

Multivariate synergy for heightening ionic HOF robustness and proton conductivity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Xiang-Tian Bai Li-Hui Cao Xu-yong Chen jia-Yu Wang Zi-Ye Zhou Shaanxi Key Laboratory of Chemical Additives for Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and Technology

Multicomponent crystalline materials construct more complex and diversified structures with different combinations and modes,which expands the material structure space and application *** this work,we have successfully synthesized two twocomponent ionic hydrogen-bonded organic frameworks （iHOF-32 and iHOF-33） and a three-component iHOF （iHOF-34）.Guanidine hydrochloride which is rich in N and H and has a short chain length strengthens the hydrogen bonding network of iHOF,thereby aiding in the efficient migration of *** rigid architecture of 1,1'-diamino-4,4'-bipyridine diiodide furnishes additional scaffolding for the iHOFs and enhances its robustness under harsh ***-34 accomplishes the combination of the ultra-high proton conductivity of iHOF-32 and the robustness of iHOF-33 by the synergistic interaction among the three components of *** addition,iHOF-34 was fabricated as a composite membrane with a peak proton conductivity of 1.55×10-1S cm-1,which is 3.8 times higher than that of recast Nafion,and has extensive potential in fuel *** self-assembly strategy of multicomponent HOFs opens up new avenues for constructing diverse structures while promising new opportunities for applications in the fields of proton conduction and energy storage.

关键词：

基于SBAS-InSAR和光学遥感的天津市北部山区潜在滑坡识别研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

灾害学 2025年第1期40卷 30-35页

作者：王勇邢振涛李锁闫勇司甜天津城建大学地质与测绘学院天津300384 天津市地质工程勘测设计院有限公司天津300191

以天津市北部山区为研究对象,开展潜在滑坡识别研究,利用差分干涉测量短基线集时序分析技术(SBAS-InSAR)处理2018-01—2022-08的56景Sentinel-1A数据,并结合2018—2022年的Landsat8光学遥感影像,分析形变与光学遥感影像特征以及NDVI,筛... 详细信息

以天津市北部山区为研究对象,开展潜在滑坡识别研究,利用差分干涉测量短基线集时序分析技术(SBAS-InSAR)处理2018-01—2022-08的56景Sentinel-1A数据,并结合2018—2022年的Landsat8光学遥感影像,分析形变与光学遥感影像特征以及NDVI,筛选出潜在滑坡区域。研究结果表明:基于SBAS-InSAR技术识别的天津北部山区的形变较大区域有20处,使用光学遥感影像结合各发育环境要素进行处理确定的区域有19处,其中5处经两种技术确认为滑坡隐患,通过对该5处沉降信息进行识别分析,该5处区域最大年形变速率可达-12 mm/a,需要进行重点监测预警,使用两种技术结合对滑坡隐患区域进行识别可以有效地提高识别准确度,为天津北部山区灾害监测提供新的方式。

关键词：潜在滑坡 SBAS-InSAR 光学遥感影像天津市北部山区

Design for Isothermal Forging of Ti-46.5Al-2.5V-1.0Cr-0.3Ni Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2010年第8期17卷 67-73页

作者： si jia-yong HAN Peng-biao ZHANG Ji Institute of Processing Technologies of Materials Central South University of Forestry and TechnologyChangsha 410004HunanChina High Temperature Material Research Division Central Iron andSteel Research InstituteBeijing 100081China

The three-dimensional finite element method was utilized to investigate the isothermal forging of Ti-46.5Al-2.5V-1.0Cr-0.3Ni（atomic percent,%）*** partition of height reduction,effective strain,and damage of the alloy during the forging were *** simulation results were verified by *** results show that large plastic deformation can improve the homogeneity of the deformed microstructure and the higher accumulative height reduction can be achieved through two-step *** the isothermal forging of two-step reduction of 60%＋62.5%（total height reduction of 85%）,the entire forged pancake can acquire refined microstructure and expand the uniform flow zone to almost the entire volume.

关键词： titanium aluminide isothermal forging multistep forging FEM simulation

新高考背景下深化高中教育教学改革应重视的几个问题

在线全文

学校读者我要写书评

暂无评论

教学与管理 2025年第1期 12-14页

作者：司晓宏马永昊陕西师范大学教育学部西安710062 陕西省社会科学院西安710061

自2014年新高考改革启动以来,已在全国29个省市逐步推进。调研发现,新高考在实际推进中给普通高中传统的教育、教学和管理带来了诸多压力与挑战,这突出表现为:“选课走班制”在实际推行中存在许多堵点;“学生综合素质评价”面临着评价... 详细信息

自2014年新高考改革启动以来,已在全国29个省市逐步推进。调研发现,新高考在实际推进中给普通高中传统的教育、教学和管理带来了诸多压力与挑战,这突出表现为:“选课走班制”在实际推行中存在许多堵点;“学生综合素质评价”面临着评价标准不一、结果应用受限等困境;“学生生涯规划教育”存在着专业性不强、效果不佳等问题;学生多样化自由选课凸显教师队伍结构性缺编等。针对上述问题,应加强普通高中选课走班制的资源条件支持,健全学生综合素质评价的体制机制,提高学生生涯规划教育的专业性和精准度,积极破解改革所导致的教师结构性缺编问题,以推动和确保新高考改革各项政策有效落地实施。

关键词：新高考改革选课走班制学生综合素质评价生涯规划教育教育教学改革

Glucose-sensitive Membrane with PBA-based Contraction-type Linear Polymer as Chemical Valves Prepared by Surface Grafting

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第8期42卷 1067-1076页

作者： Chun-Peng Zhang si-jia Gao Ying Luo Lei Zou yong-Jun Zhang State Key Laboratory of Separation Membranes and Membrane Processes School of Material Science and EngineeringTiangong UniversityTianjin 300387China State Key Laboratory of Separation Membranes and Membrane Processes School of Pharmaceutical SciencesTiangong UniversityTianjin 300387China Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases Institute of Hepatobiliary DiseaseNankai University Affiliated Third Center HospitalTianjin 300170China Cangzhou Institute of Tiangong University Cangzhou 061000China

Glucose-sensitive membrane has potential application in self-regulating insulin *** acid(PBA)is a well-known glucose ***,most PBA-based glucose-sensitive materials are expansion-type,which are not suitable as chemical valves in membrane pores for self-regulating insulin *** to a new glucose-sensitive mechanism,we synthesized PBA-based contraction-type glucose-sensitive liner polymer and ***,a glucose-sensitive membrane was prepared by grafting PBA-based contraction-type glucose-sensitive linear polymer on the membrane *** adjusting the chain length and chain density,the glucose-sensitivity of the membrane was *** membrane can reversibly regulate insulin release at physiologically relevant glucose concentrations in simulates body fluids and fetal bovine *** membrane also has good stability,anti-fouling and biocom *** has potential application in selfregulating insulin release.

关键词： Phenylboronic acid Glucose-sensitive Membrane Surface grafting Insulin