检索结果-南通市图书馆

Free radicals trigger the closure of open pores in lignin-derived hard carbons toward improved sodium-storage capacity

引用

Journal of Energy Chemistry 2024年第7期94卷 551-559页

作者： Wen-Jun Ji Zong-Lin yi Ming-Xin Song Xiao-Qian Guo yi-Lin Wang yi-xuan mao Fang-Yuan Su Jing-Peng Chen Xian-Xian Wei Li-Jing Xie Cheng-Meng Chen CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001ShanxiChina University of Chinese Academy of Sciences Beijing 100049China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030001ShanxiChina

The chemical activation of various precursors is effective for creating additional closed pores in hard carbons for sodium ***,the formation mechanism of closed pores under the influence of pore-forming agents is not well ***,an effective chemical activation followed by a high-temperature self-healing strategy is employed to generate interconnected closed pores in lignin-derived hard carbon(HCs).By systematic experimental design combined with electron paramagnetic res-onance spectroscopy,it can be found that the content of free radicals in the carbon matrix influences the closure of open pores at high *** high activation temperature(>700 C)leads to a low free radical concentration,making it difficult to achieve self-healing of open pores at high *** activation at 700°C,a balance between pore making and self-healing is achieved in the final hard carbon.A large number of free radicals triggers rapid growth and aggregation of carbon microcrys-tals,blocking pre-formed open micropores and creating additional interconnected closed pores in as-obtained hard *** a result,the optimized carbon anode(LK-700-1300)delivers a high reversible capacity of 330.8 mA h g^(-1) at 0.03 A g^(-1),which is an increase of 86 mA h g^(-1) compared to the pristine lignin-derived carbon anode(L-700-1300),and exhibits a good rate performance(202.1 mA h g^(-1) at 1 A g^(-1)).This work provides a universal and effective guidance for tuning closed pores of hard carbons from otherprecursors.

关键词： Hard carbon Chemical activation Free radical Self-healing Closed pores Sodium ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Homologous CoS2 interface with directed electron transfer and strong chloridion repulsion for efficient seawater oxidation

引用

Science China Chemistry 2025年

作者： Yuan Tian Jiang-Bo Chen Jie ying Ge Tian Yu-xuan Xiao yi Lu Si-Ming Wu Wei Geng Ling Shen Xiao-Yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing and School of Materials Science and Engineering and Shenzhen Research Institute & Laoshan Laboratory Wuhan University of Technology School of Chemical Engineering and Technology Sun Yat-Sen University National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

Seawater electrolysis is a highly promising method to produce high energy density hydrogen,especially in dry areas that have scarce freshwater ***,application of seawater electrolysis is confronted by two major problems associated with catalysts employed for the anodic oxygen evolution reaction （OER） including the competitive hypochlorite evolution reaction（HCER） and strong chloridion （Cl–） triggered *** studies aimed at overcoming these problems,a facile method has been developed to synthesize a homologous CoS2heterojunction as an OER *** to a difference in work functions at the interface and increased electron density,this material has directed electron transfer and strong chloridion repulsion properties,*** have shown that CoS2achieves low overpotentials of 289 and 322 mV at 10 mA cm-2current density in respective alkaline （1 M KOH） and alkaline simulated seawater ***,the outstanding stability of CoS2is reflected in a negligible decline in activity during promotion of the OER for 100 *** of density functional theory calculations reveal that the homologous CoS2heterojunction promotes directed electron transport for optimizing adsorption/desorption of reactive species and heightens the Cl-adsorption energy for strongly repulsing Cl-,phenomena that enhance OER performance in alkaline simulated seawater.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

浑水入渗对粗粒土柱孔隙及渗透性影响试验研究

引用

岩土工程学报 2025年第1期47卷 173-183页

作者：毛海涛张超袁古城何涛谷易山西农业大学城乡建设学院山西太原030000 重庆三峡学院土木工程学院重庆404120

浑水渗流在水利工程的反滤设计、浑水浇灌、堤坝渗流控制等方面都有较大影响,目前理论多采用稳定渗流计算方法,忽略了渗流过程中粗细颗粒与水力的耦合作用。自制渗流装置,将不同控制粒径浑水、不均匀系数粗粒土柱和水头等作为基本控制因... 详细信息

浑水渗流在水利工程的反滤设计、浑水浇灌、堤坝渗流控制等方面都有较大影响,目前理论多采用稳定渗流计算方法,忽略了渗流过程中粗细颗粒与水力的耦合作用。自制渗流装置,将不同控制粒径浑水、不均匀系数粗粒土柱和水头等作为基本控制因素,研究不同工况下浑水中悬浮颗粒对粗粒土土柱中的渗透特性影响;推导了变渗透系数浑水渗流计算微分方程,通过对比验证和公式修正,结果表明:粗粒土中颗粒淤积率与控制粒径C_(0.075)含量符合Boltzmann函数关系;C_(0.075)是重要的影响因子,浑水颗粒在粗粒土柱的运移、沉积和淤堵形态过程大致可分为4种形态:表层堆积淤堵形态(S型);表层-内部双重淤堵形态(S-I型);内部孔隙淤堵形态(I型);暂态孔隙淤堵形态(P型)。土柱C_(u)越大,孔隙度越小,浑水颗粒在粗粒土中运移也越困难,土柱填充性就越差;水头加剧了颗粒在土柱内部运移的速度,但也加速了其在顶部的沉积并封堵;S型时土柱0~2cm渗透系数下降速率最大,封堵时总体渗透系数最小,2cm以下相对孔隙率及随深度逐渐减小;S-I和I型土柱下部渗透系数明显滞后于上部,相对孔隙率存在临界深度(约为4~6cm);P型时土柱整体相对孔隙率基本无变化。

关键词：颗粒渗流粗粒土浑水堵塞

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optimization Study on Expansion Energy Used Air-Powered Vehicle with Pneumatic-Hydraulic Transmission

引用

Chinese Journal of Mechanical Engineering 2018年第1期31卷 220-229页

作者： Xiang-Heng Fu mao-Lin Cai yi-xuan Wang Yan Shi School of Automation Science and Electrical Engineering Beihang University The State Key Laboratory of Fluid Power & Mechatronic Systems Zhejiang University

Pneumatic-hydraulic transmission has been developed for years. However, its dynamic properties are not good enough for application. In this paper, in order to increase the output characteristics, a late-model air-powered vehicle using expansion energy is proposed which can boost energy through a pneumatic-hydraulic transmission. The dynamic characteristics of the air-powered vehicle is modeled and verified by conducting experiment. In addition,the influence of the key parameters of the air-powered vehicle is researched for the optimization of the system performance. Through the results, the author got the conclusion that, firstly, comparison of the results of model and experiment proves the built model to be effective; secondly, input air pressure should be set according to the request of the practical loads, and range of 0.65 to 0.75 MPa can be chosen; thirdly, as a key structure parameter of the airpowered vehicle, ratio of the areas is considered to be set to approximate 8; what’s more, a bigger orifice with a limit will promote the system dynamic characteristic property, and the limit is about 3.5 mm; last but not the least, not too farther position of the rings will increase the quality of output dynamic characteristics. This paper can be a reference for system design of air-powered vehicle and dynamic improvement.

关键词： Air-powered vehicle Expansion energy Pneumatic-hydraulic transmission Output dynamic characteristics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

从句子图到篇章图——基于抽象语义表示的篇章级共指标注体系研究

引用

外语学刊 2025年第1期 19-28页

作者：张艺璇李斌许智星南京师范大学文学院南京210097 南京师范大学语言大数据与计算人文研究中心南京210097

篇章级共指关系是语言学和计算语言学的研究难点之一。本文在梳理共指理论研究与趋势的基础上,回顾共指语料库的构建与自动解析方法,指出共指语料的构建主要存在以下两个问题:共指关系的标注较为粗疏,也基本不考虑与句子语义结构本身的... 详细信息

篇章级共指关系是语言学和计算语言学的研究难点之一。本文在梳理共指理论研究与趋势的基础上,回顾共指语料库的构建与自动解析方法,指出共指语料的构建主要存在以下两个问题:共指关系的标注较为粗疏,也基本不考虑与句子语义结构本身的关系。本文在句子级语义标注体系(中文抽象语义表示)的基础上,设计篇章共指的标注体系,以“概念同一性”为基本原则,从词形的异同和概念的表述角度区分9种篇章共指关系,标注了500个篇章的共指信息。与已完整标注的52种句内语义关系相结合,构建出带有篇章共指信息的篇章抽象语义图库。该语料库选自CTB新闻语料,体裁涵盖经济、体育及生活类,规模为6237句,16万词例。该语料库的构建为篇章级语义分析提供了新框架与数据资源。

关键词：篇章共指抽象语义表示概念同一性篇章语义结构语料库中文信息处理

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Incompressible Limit of the Compressible Q-tensor System of Liquid Crystals

引用

Acta Mathematicae Applicatae Sinica 2023年第1期39卷 179-201页

作者： yi-xuan WANG University of Pittsburgh PA 15260USA

We study the connection between the compressible Navier-Stokes equations coupled by the Qtensor equation for liquid crystals with the incompressible system in the periodic case, when the Mach number is low. To be more specific, the convergence of the weak solutions of the compressible nematic liquid crystal model to the incompressible one is proved as the Mach number approaches zero, and we also obtain the similar results in the stochastic setting when the equations are driven by a stochastic force. Our approach is based on the uniform estimates of the weak solutions and the martingale solutions, then we justify the limits using various compactness criteria.

关键词： compressible liquid crystal system Q-tensor weak solutions martingale solution stochastic compactness Mach number incompressible limit

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

环钻手术、药物注射联合PDL治疗瘢痕疙瘩疗效评价

引用

中国麻风皮肤病杂志 2025年第1期41卷 33-36页

作者：林萱毛华荣庞凯临沂市高新医院皮肤科山东临沂276014

目的:探讨环钻手术、药物注射联合脉冲染料激光(PDL)治疗瘢痕疙瘩的临床疗效。方法:选取2022年1月至2023年6月我院皮肤科治疗的瘢痕疙瘩10例,采用环钻手术、药物注射(曲安奈德5 mL、5-氟尿嘧啶0.6 mL、2%利多卡因1 mL)联合脉冲染料激光... 详细信息

目的:探讨环钻手术、药物注射联合脉冲染料激光(PDL)治疗瘢痕疙瘩的临床疗效。方法:选取2022年1月至2023年6月我院皮肤科治疗的瘢痕疙瘩10例,采用环钻手术、药物注射(曲安奈德5 mL、5-氟尿嘧啶0.6 mL、2%利多卡因1 mL)联合脉冲染料激光治疗。结果:所有患者均完成临床治疗与随访,术后随访12个月,术区瘢痕平软,肤色与周边正常皮肤接近,疼痛、瘙痒等症状明显缓解或消失;治愈率80%,有效率90%,90%患者对治疗效果满意。结论:环钻手术配合药物注射加脉冲染料激光进行联合治疗是治疗瘢痕疙瘩安全有效的方法,患者满意度较高。

关键词：瘢痕疙瘩环钻手术药物注射 595脉冲染料激光

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient circularly polarized photoluminescence and electroluminescence of chiral spiro-skeleton-based thermally activated delayed fluorescence molecules

引用

Science China Chemistry 2022年第7期65卷 1347-1355页

作者： yi-Pin Zhang Shi-Quan Song Meng-Xi mao Cheng-Hui Li You-xuan Zheng Jing-Lin Zuo State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China MaAnShan High-Tech Research Institute of Nanjing University Maanshan 238200China

Chiral thermally activated delayed fluorescence(TADF) molecules showing circularly polarized luminescence(CPL) have great potential in 3D displays. However, the relationships among CPL property, device performance and molecule structure are still not clear. In this article, we develop a strategy to promote dissymmetry factors without sacrifice in device performance and study the impact of molecule structures towards CPL property. Three novel TADF enantiomers are synthesized and studied.(R/S)-SCN with diminutive cyano group as an acceptor shows dissymmetry factor |gPL| ≈ 1.4×10^(-3) and noticeable organic light-emitting diode(OLED) performances with a maximum external quantum efficiency(EQEmax) of 23.0%. For(R/S)-SPHCN, the prolonged electron withdrawing group benzonitrile enhances |gPL| up to 3.6×10^(-3) with decreased device EQEmaxof 15.4%. By further replacing benzonitrile with(trifluoromethyl)pyridine, the enantiomers of(R/S)-SCFPY show similar |gPL| factors of 3.5×10^(-3) and device EQE_(max)up to 23.3%, which represents the highest efficiency among sprio-type TADF materials based OLEDs. Furthermore, the OLEDs also show obvious circularly polarized electroluminescence with gELfactors of-1.4/1.8×10^(-3),-3.6/3.6×10^(-3) and-3.7/3.6×10^(-3), respectively. These results indecate by delicate functional group engineering, high g factor can be achieved while maintaining decent device performances. Besides,(R/S)-SCFPY represents an impressive TADF emitter, which shows promoted g factor and recorded high device EQE_(max)among similar molecules.

关键词： chiral spiro-skeleton thermally activated delayed fluorescence circularly polarized photoluminescence circularly polarized electroluminescence dissymmetry factor

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly coupled off-resonance lattice design in diffraction-limited light sources

引用

Nuclear Science and Techniques 2024年第9期35卷 92-102页

作者： yi-Hao Gong Shun-Qiang Tian Xin-Zhong Liu Shou-Zhi xuan Li-Yuan Tan Ling-Long mao Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204 ShanghaiChina Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 ShanghaiChina University of Chinese Academy of Sciences 100049 BeijingChina

The round-beam operation presents many benefits for scientific experiments regarding synchrotron radiation and the weak-ening influences of intra-beam scattering in diffraction-limited synchrotron light sources.A round-beam generation method based on the global setting of skew quadrupoles and the application of a non-dominated sorting genetic algorithm was pro-posed in this *** schemes,including large-emittance coupling introduced via betatron coupling and vertical disper-sion,were explored in a candidate lattice for an upgrade-proposal of the Shanghai synchrotron radiation *** variations with lattice imperfections and their influence on the beam dynamics of beam optic distortions were *** results demonstrated that a precise coupling control ranging from 10 to 100%was achieved under low optical distortion,whereas full-coupling generation and its robustness were achieved by our proposed method by adjusting the skew quadrupole components located in the dispersion-free *** Touschek lifetime increased by a factor of 2–2.5.

关键词： Diffraction-limited storage ring(DLSR) Shanghai synchrotron radiation facility upgrade(SSRF-U) Round beam Off-resonance coupling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Water hammer prediction and control:the Green's function method

引用

Acta Mechanica Sinica 2012年第2期28卷 266-273页

作者： Li-Jun xuan Feng mao Jie-Zhi Wu State Key Laboratory of Turbulence and Complex System College of EngineeringPeking University100871 BeijingChina

By Green＇s function method we show that the water hammer （WH） can be analytically predicted for both laminar and turbulent flows （for the latter, with an eddy vis- cosity depending solely on the space coordinates）, and thus its hazardous effect can be rationally controlled and mini- mized. To this end, we generalize a laminar water hammer equation of Wang et al. （J. Hydrodynamics, B2, 51, 1995） to include arbitrary initial condition and variable viscosity, and obtain its solution by Green＇s function method. The pre- dicted characteristic WH behaviors by the solutions are in excellent agreement with both direct numerical simulation of the original governing equations and, by adjusting the eddy viscosity coefficient, experimentally measured turbulent flow data. Optimal WH control principle is thereby constructed and demonstrated.

关键词： Water hammer Two-dimensional analytical theory - Pressure transients Pipe-valve flow control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：