检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

语境折叠视角下新媒体词汇语义的互动化趋势

语言文字应用 2024年第2期 57-69页

作者：贺天琪刘美君中南大学人文学院长沙410083 香港城市大学翻译及语言学系香港999077

本文基于互动语言学和使用语法理论,从语义、语法两个层面,考察近十年新浪微博上109个网络热词的使用状况,系统梳理其语义范畴转移和语法功能变异的路径,并根据社交网络和语境折叠理论,探讨其语义延伸和词类转移的动因。研究发现,新媒... 详细信息

本文基于互动语言学和使用语法理论,从语义、语法两个层面,考察近十年新浪微博上109个网络热词的使用状况,系统梳理其语义范畴转移和语法功能变异的路径,并根据社交网络和语境折叠理论,探讨其语义延伸和词类转移的动因。研究发现,新媒体词汇语义呈互动化演变趋势:语义上不断趋近社会交际相关的语义范畴;语法上词类转移更加活跃,且呈单向性特征,互动性不断增强。这与高互动社交需求和高折叠新媒体语境密切相关。

关键词：新兴词汇互动化语境折叠新媒体网络语言

同方期刊数据库

南京市高淳区村域尺度土地利用功能变化及生态系统服务价值响应研究

在线全文

学校读者我要写书评

暂无评论

地理科学 2024年第2期44卷 340-350页

作者：程玉恒乔伟峰何天祺刘倩倩南京师范大学地理科学学院江苏南京210023 江苏金宁达房地产评估测绘咨询有限公司江苏南京210036 江苏省地理信息资源开发与利用协同创新中心江苏南京210023 四川省国土整治中心四川成都610045

基于2009—2019年土地利用调查数据,以高淳区145个行政村为研究单元,利用土地利用变化模型和生态系统服务价值评估方法,研究高淳区土地利用功能转型的时空演变格局,并评估该区域生态系统服务的价值损益情况,同时,利用敏感性系数来衡量... 详细信息

基于2009—2019年土地利用调查数据,以高淳区145个行政村为研究单元,利用土地利用变化模型和生态系统服务价值评估方法,研究高淳区土地利用功能转型的时空演变格局,并评估该区域生态系统服务的价值损益情况,同时,利用敏感性系数来衡量生态系统服务价值对土地利用功能转型的敏感程度。结果表明:①高淳区生产生态功能、生态生产功能既是研究区分布最广的土地利用功能类型,也是转型最剧烈的土地利用功能类型。生产生态功能的转移面积和比重最大,而且转移速率远高于其同期的新增速率,属于转型收缩型土地利用功能;生态生产功能空间、生活生产功能空间和生态功能空间的新增速度大于同期转移速度,属于转型扩张型功能空间。②2009—2019年,高淳区生态系统服务价值增加了33.78亿元,其中,水域用地、耕地和林地是对生态系统服务价值贡献最大的3种土地类型;水文调节和废物处理是高淳区最主要的生态系统服务功能。③当土地利用功能从低利用指数向高利用指数转变时,生态系统服务价值减少,此时土地利用程度引起区域生态系统服务价值的变化强度也较小。当土地利用功能呈现高利用指数向低利用指数的转变趋势时,生态系统服务价值呈现增加的趋势,土地利用程度变化对区域生态系统服务价值的贡献率越大。④具体来说,高淳区生态系统服务价值呈现增加显著,生态系统服务价值对不同土地利用功能转型的响应程度不尽相同,生产生态功能空间转向生活生产功能空间对生态系统服务价值降低的贡献度达到15.02%,生产生态功能空间转为生态生产功能空间对生态系统服务价值增加的贡献度达到44.57%。

关键词：村域尺度土地利用功能转型生态系统服务价值南京市高淳区

蜂窝状多孔碳材料装载硫单质及其在锂硫电池中的储能性能研究

在线全文

学校读者我要写书评

暂无评论

材料导报 2024年第16期38卷 6-11页

作者：康小雅何天启朱福良冉奋兰州理工大学材料科学与工程学院省部共建有色金属先进加工与再利用国家重点实验室兰州730050

单质硫及其放电最终产物Li_(2)S的绝缘性以及两者密度差异引起的结构坍塌等问题严重阻碍了锂硫电池的进一步发展,找寻合适的基体材料是解决上述问题的有效策略。本工作选用一种蜂窝状多孔碳作为硫正极的基体材料,通过常规的熔融扩散法... 详细信息

单质硫及其放电最终产物Li_(2)S的绝缘性以及两者密度差异引起的结构坍塌等问题严重阻碍了锂硫电池的进一步发展,找寻合适的基体材料是解决上述问题的有效策略。本工作选用一种蜂窝状多孔碳作为硫正极的基体材料,通过常规的熔融扩散法将硫单质固定在碳孔隙中,并利用SEM、XRD、XPS和BET等方法对多孔碳@单质硫复合材料进行了表征。结果表明,硫单质均匀地负载在碳骨架中。同时,蜂窝状结构碳不仅为硫单质提供了电子导电网络,也保证了正极的稳定性。更重要的是,蜂窝状的结构为循环过程中硫正极的体积膨胀提供了一定的缓冲空间,缓解了结构坍塌这一问题。此外,碳基体丰富的孔隙度在一定程度上减少了多硫化物的穿梭。因此,在0.1C的倍率下,多孔碳@单质硫复合材料首次放电比容量高达1125.9 mAh/g,300次循环后比容量可保持305.1 mAh/g。

关键词：锂硫电池正极材料蜂窝状多孔碳电化学性能

在线全文

学校读者我要写书评

暂无评论

浅谈大豆油厂技术改造项目管理

粮食与食品工业 2024年第1期31卷 12-15页

作者：李万振何天齐中粮集团有限公司北京100020

技术改造是大豆油厂每年都实施的一项投资活动,特别是建厂时间长、运行时间久的老工厂,更加注重技改项目实施。本文简要梳理了国内技术改造的历史和大豆油厂的技改管理现状,探讨了技改项目管理措施,以期为油脂同行在技改管理提升方面提... 详细信息

技术改造是大豆油厂每年都实施的一项投资活动,特别是建厂时间长、运行时间久的老工厂,更加注重技改项目实施。本文简要梳理了国内技术改造的历史和大豆油厂的技改管理现状,探讨了技改项目管理措施,以期为油脂同行在技改管理提升方面提供参考。

关键词：大豆油厂技术改造管理

Maslinic acid supplementation prevents di(2-ethylhexyl)phthalate-induced apoptosis via PRDX6 in peritubular myoid cells of Chinese forest musk deer

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第9期143卷 47-59页

作者： heran Cao Zhenpeng Li tianqi Jin Shuyang he Shujuan Liu Long Li Yang Wang Ye Gong Gang Wang Fangxia Yang Wuzi Dong College of Animal Science and Technology Northwest A&F UniversityShaanxi 712100China College of Forestry Northwest A&F UniversityShaanxi 712100China Biology Research Centre of Qin-Mountains Wildlife Northwest A&F UniversityShaanxi 712100China Shaanxi Qiyuan-Times Agri-Tech Development Co.Ltd. Shaanxi 725000China

Chinese forest musk deer(FMD),an endangered species,have exhibited low reproductive rates even in captivity due to stress *** revealed the presence of di(2-ethylhexyl)phthalate(DEHP),an environmental endocrine disruptor,in the serum and skin of captive *** FMDs with maslinic acid(MA)has been observed to alleviate the stress response and improve reproductive rates,although the precise molecular mechanisms remain ***,this study aims to investigate the molecular mechanisms underlying the alleviation of DEHP-induced oxidative stress and cell apoptosis in primary peritubular myoid cells(PMCs)through MA *** PMCs were isolated and exposed to DEHP in *** results demonstrated that DEHP significantly suppressed antioxidant levels and promoted cell apoptosis in primary ***,interfering with the expression of PRDX6 was found to induce excessive reactive oxygen species(ROS)production and cell apoptosis in primary *** with MA significantly upregulated the expression of PRDX6,thereby attenuating DEHP-induced oxidative stress and cell apoptosis in primary *** findings provide a theoretical foundation for mitigating stress levels and enhancing reproductive capacity of in captive FMDs.

关键词： Maslinic acid Forest musk deer Di(2-ethylhexyl)phthalate Peritubular myoid cells PRDX6

Time-history performance optimization of flapping wing motion using a deep learning based prediction model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 317-331页

作者： tianqi WANG Liu LIU Jun LI Lifang ZENG School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China Huanjiang Laboratory Zhuji 311800China

Flapping Wing Micro Aerial Vehicles(FWMAVs)have caused great concern in various fields because of their high efficiency and *** wing motion is a very important factor that affects the performance of the aircraft,and previous works have always focused on the time-averaged performance ***,the time-history performance is equally important in the design of motion mechanism and flight control *** this paper,a time-history performance optimization framework based on deep learning and multi-island genetic algorithm is presented,which is designed in order to obtain the optimal two-dimensional flapping wing ***,the training dataset for deep learning neural network is constructed based on a validated computational fluid dynamics *** aerodynamic surrogate model for flapping wing is obtained after the convergence of *** surrogate model is tested and proved to be able to accurately and quickly predict the time-history curves of lift,thrust and ***,the optimization framework is used to optimize the flapping wing motion in two specific cases,in which the optimized propulsive efficiencies have been improved by over 40%compared with the ***,a dimensionless parameter C_(variation)is proposed to describe the variation of the time-history characteristics,and it is found that C_(variation)of lift varies significantly even under close time-averaged *** the importance of time-history performance in practical applications,the optimization that integrates the propulsion efficiency as well as C_(variation)is carried *** final optimal flapping wing motion balances good time-averaged and time-history performance.

关键词： FWMAV Flapping wing motion Deep learning Unsteady aerodynamic performance Optimization Time-history curve

Chirality transfer induced circularly polarized luminescence of achiral dye molecules by plasmonic nanohelicoid

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8408-8414页

作者： Han Gao ChunLian Zhan tianqi Zhao Jianzhong Zheng College of Optical and Electronic Technology China Jiliang UniversityHangzhou 310018China School of Environmental Science and Engineering Nanjing Tech UniversityNanjing 211816China

Optical materials with circularly polarized luminescence(CPL)features have attracted a growing interest due to their crucial role in biological sensing,display,spintronics,information storage,and so ***,CPL emissions in hybrid nanoparticle systems,in particular,chirality transfer induced CPL from chiral plasmonic nanoparticles,have rarely been explored due to a lack of effective bottom-up synthesis ***,we creatively take advantage of the newly introduced chiral plasmonic nanoparticles-gold nanohelicoid(GNH)to excite the CPL of achiral Rhodamine 6G(R6G).The fabricated GNH@R6G-SiO_(2)shows obvious CPL signals with|g_(lum)|up to *** with the single GNH,the photoluminescence(PL)dissymmetry factor of the single GNH@R6G-SiO_(2)is similar,but with 25 folds higher PL intensities under different circular *** research not only offers an effective and feasible method to fabricate single-particle level CPL-active materials,but also provides guidelines on how to regulate the CPL of achiral luminophores from chiral plasmonic nanostructures,thereby enlarging the category and quantity of CPL-active materials that can be applied for photonic technologies and visualization biosensing,especially some intracellular chirality related detection.

关键词： circularly polarized luminescence gold nanohelicoids chiral plasmonic

Bifunctional interstitial phosphorous doping strategy boosts platinum-zinc alloy for efficient ammonia oxidation reaction and hydrogen evolution reaction

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

Nano Research 2024年第3期17卷 1182-1189页

作者： tianqi Yu Kexin Tan Jia Wu Yongjin Zou Shibin Yin Guangxi Key Laboratory of Electrochemical Energy Materials School of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China Guangxi Key Laboratory of Information Materials Guilin University of Electronic TechnologyGuilin 541004China

It is still a lack of bifunctional catalysts for ammonia oxidation reaction(AOR)and hydrogen evolution reaction(heR)due to their different reaction *** this work,P is doped into PtZn alloy by calcination with NaH_(2)PO_(2) as P source to induce the lattice tensile strain of Pt and the electronic interaction between P and Zn,which optimizes the AOR and heR activity *** sample with the optimal P content can drive the AOR peak current density of 293.6 mA·mgPt^(-1),which is almost 2.7 times of *** heR,the overpotential at^(-1)0 mA·cm^(-2) is only 23 mV with Tafel slope of 34.1 mV·dec^(-1).Furthermore,only 0.59 V is needed to obtain 50 mA·mgPt^(-1) for ammonia electrolysis under a two-electrode ***,this work shows an ingenious method to design bifunctional catalysts for ammonia electrolysis.

关键词： PtZn alloy phosphorous doping ammonia oxidation reaction hydrogen evolution reaction bifunctional catalyst

Light-triggered fluorochromic cholesteric liquid crystal elastomer with hydrogen-bonded fluorescent switch: dualmodal-switchable circularly polarized luminescence

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

Science China Chemistry 2024年第8期67卷 2719-2727页

作者： Siyang Lin tianqi Ren Xianyu Meng Wenxin Kang Jinbao Guo Key Laboratory of Carbon Fibers and Functional Polymers Ministry of EducationCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Solid materials with dynamically tunable circularly polarized luminescence(CPL) feature higher security levels and devicefriendly characteristics, showing great superiority in the field of information technology and anti-counterfeiting. To address the limited photoisomerization of fluorescent photoswitch in CPL-active solid materials, here a cholesteric liquid crystal elastomer(CLCE) containing a hydrogen-bonded(H-bonded) polymerizable fluorescent switch AHBA-PSD is prepared. Owing to the good flexibility and low glass-transition temperature of CLCE, AHBA-PSD shows a fast and fully reversible photocyclization/cycloreversion with fluorochromic behavior in CLCE. Further, by controlling the spectral overlapping area between the emission and reflection bands, the CLCE exhibits a strong CPL with a g_(lum) value of up to 0.76 accompanied by a reversible phototunable CPL signal. Meanwhile, the H-bond helps to stabilize the mechanical property, and the force-induced switching-off of CPL signal could be achieved due to the destroyed helical structures by external force. Finally, an automatically-recognized identification card with abundant chiroptical information is demonstrated.

关键词： cholesteric liquid crystal elastomer circularly polarized luminescence fluorescent photoswitch diarylethene photoismerization

同方期刊数据库