检索结果-南通市图书馆

Efficient photoelectrochemical conversion of CO_(2)to syngas by photocathode engineering

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2022年第3期7卷 545-553页

作者： sheng Chu pengfei Ou Roksana Tonny Rashid Yuyang Pan Daolun Liang Huiyan Zhang Jun Song Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing210096China Department of Electrical and Computer Engineering McGill UniversityMontrealQC H3A 0E9Canada Department of Mining and Materials Engineering McGill UniversityMontrealQC H3A 0C5Canada

The synthesis of renewable chemical fuels from CO_(2) and H_(2)O via photoelectrochemical(PEC)route reprensents a promising room-temperature approach for transforming greenhouse gas into value-added chemicals(e.g.,syngas),but to date it has been hampered by the lack of efficient photocathode for CO_(2) reduction.Herein,we report efficient PEC CO_(2) reduction into syngas by photocathode engineering.The photocathode is consisting of a planar p-n Si junction for strong light harvesting,GaN nanowires for efficient electron extraction and transfer,and Au/TiO_(2)for rapid electrocatalytic syngas production.The photocathode yields a record-high solar energy conversion efficiency of 2.3%.Furthermore,desirable syngas compositions with CO/H_(2)ratios such as 1:2 and 1:1 can be produced by simply varying the size of Au nanoparticle.Theoretical calculations reveal that the active sites for CO and H_(2)generation are the facet and undercoordinated sites of Au particles,respectively.

关键词： syngas photocathode photoelectrochemical

The Chinese Carbon-Neutral Goal:Challenges and Prospects

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2022年第8期39卷 1229-1238,I0027-I0030页

作者： Ning ZENG Kejun JIANG pengfei HAN Zeke HAUSFATHER Junji CAO Daniel KIRK-DAVIDOFF Shaukat ALI sheng ZHOU Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary CenterUniversity of MarylandCollege Park 20742MarylandUSA State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Energy Research Institute National Development and Reform CommissionBeijing 100045China Carbon Neutrality Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Breakthrough Institute Oakland 94612CaliforniaUSA Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Global Change Impact Study Centre Ministry of Climate ChangeIslamabad 45250Pakistan Institute of Energy Environment and EconomyTsinghua UniversityBeijing 100084China

On 22 September 2020,within the backdrop of the COVID-19 global pandemic,China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060.This carbon-neutral goal is generally considered to cover all anthropogenic greenhouse gases.The planning effort is now in full swing in China,but the pathway to decarbonization is unclear.The needed transition towards non-fossil fuel energy and its impact on China and the world may be more profound than its reform and development over the past 40 years,but the challenges are enormous.Analysis of four representative scenarios shows significant differences in achieving the carbon-neutral goal,particularly the contribution of non-fossil fuel energy sources.The high target values for nuclear,wind,and bioenergy have approached their corresponding resource limitations,with solar energy being the exception,suggesting solar’s critical role.We also found that the near-term policies that allow for a gradual transition,followed by more drastic changes after 2030,can eventually reach the carbon-neutral goal and lead to less of a reduction in cumulative emissions,thus inconsistent with the IPCC 1.5°C scenario.The challenges and prospects are discussed in the historical context of China’s socio-economic reform,globalization,international collaboration,and development.

关键词： carbon neutral carbon dioxide reductions energy system transformation distributed energy system model projections

Redirecting dynamic structural evolution of nickel-contained RuO_(2) catalyst during electrochemical oxygen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第6期31卷 330-337,I0009页

作者： Yuhan Zhao Menghua Xi Yanbin Qi Xuedi sheng pengfei Tian Yihua Zhu Xiaoling Yang Chunzhong Li Hongliang Jiang Shanghai Engineering Research Center of Hierarchical Nanomaterials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China Key Laboratory for Ultrafine Materials of Ministry of Education School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237China

Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instability stems from lattice oxygen oxidation,resulting in the oxidation of Ru^(4+) to soluble Ru^(4+)(x>4) species.Herein,we redirect dynamic structural evolution of Ru-based catalysts through introducing oxidized nickel (Ni) components.By virtue of comprehensive structural characterizations,such as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM),X-ray photoelectron spectroscopy (XPS),operando Raman and so forth,it is demonstrated that when the atomic content of Ni exceeds that of ruthenium (Ru),the Ni components can efficiently inhibit the Ru^(4+) oxidation and structural collapse.Density functional theory (DFT) calculations suggest that the introduction of Ni component hinders the formation of oxygen vacancies,and makes lattice oxygen mediated mechanism turn to adsorbate evolution mechanism,which eventually improves the stability.The optimized nickel-contained RuO_(2) catalyst delivers an effective reactivity with an overpotential of less than 215 m V to attain 10 m A cm^(-2) and remarkable stability with only 5 mV increment after 5000 potential cycles.This work provides insights into the origin of dynamic structural evolution of transition-metalmodified RuO_(2) electrocatalysts.

关键词： Oxygen evolution reaction Ruthenium Structure evolution Electrocatalysis Operando Raman

在线全文

学校读者我要写书评

暂无评论

采用轻量化主干网络的遥感影像目标检测

测绘科学 2023年第5期48卷 58-67页

作者：绳鹏飞杨军兰州交通大学测绘与地理信息学院兰州730070 地理国情监测技术应用国家地方联合工程研究中心兰州730070 甘肃省地理国情监测工程实验室兰州730070

针对遥感影像在背景复杂、目标尺度差异性大的场景中检测困难,而现有的目标检测算法无法同时兼顾检测精度与检测速度等问题,以YOLO v5为基础提出了一种高效的目标检测网络L-YOLO v5。基于残差空洞卷积对其主干网络进行模型压缩,减少模... 详细信息

针对遥感影像在背景复杂、目标尺度差异性大的场景中检测困难,而现有的目标检测算法无法同时兼顾检测精度与检测速度等问题,以YOLO v5为基础提出了一种高效的目标检测网络L-YOLO v5。基于残差空洞卷积对其主干网络进行模型压缩,减少模型的参数量与运算量;为了更好地融合多尺度信息,设计了一种精细化特征融合网络,从而实现更高效的遥感影像目标检测。在DOTA数据集上的实验结果表明,该算法的mAP和FLOPs分别为77.1%和32.5 GB,与YOLO v5相比mAP提高1.2%,FLOPs减少33.7%,在计算复杂度更低的情况下具有更优异的检测效果。

关键词：遥感影像轻量化目标检测特征融合空洞卷积

A General Approach for Synchronization of Chaotic Systems with Parameters Perturbation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第3期43卷 455-458页

作者： LONGMin QIUShui-sheng pengfei CollegeofElectronicandInformationEngineering SouthChinaUniversityofTechnologyGuangzhou510640China

By making use of the theory of stability for dynamical systems, a general approach for synchronization of chaotic systems with parameters perturbation is presented, and a general method for determining control function is introduced. The Rossler system is employed to verify the effectiveness of the method, and the theoretical results are confirmed by simulations.

关键词：混沌系统时间同步参数摄动稳定性控制函数

中国能源效率偏低的解释:技术无效抑或配置无效

在线全文

学校读者我要写书评

暂无评论

产业经济研究 2015年第1期 9-20,60页

作者：盛鹏飞河南大学经济学院河南开封475004

大量研究表明中国的能源利用效率处于较低的水平,然而对能源利用低效的解释却存在较大争议。因此本文通过构建要素影子价格将价格信息引入到全要素能源非效率的分解框架,并利用面板Tobit模型来进一步探析中国能源利用效率偏低的原因,研... 详细信息

大量研究表明中国的能源利用效率处于较低的水平,然而对能源利用低效的解释却存在较大争议。因此本文通过构建要素影子价格将价格信息引入到全要素能源非效率的分解框架,并利用面板Tobit模型来进一步探析中国能源利用效率偏低的原因,研究发现:中国全要素能源非效率从1998年到2010年有一定程度的改善,但是这种改善主要来源于配置无效的降低,而技术无效则呈现出逐年增加的趋势;环境管制的加强、市场化进程和经济水平的提高对能源效率有明显的改善,而经济结构重型化、能源资源禀赋和工业产业占比增加等对能源效率有明显负效应。

关键词：影子价格能源效率配置无效技术无效非效率分解

Health Care Expenditure Inequality Associated With Pollution in China

在线全文

学校读者我要写书评

暂无评论

Economics World 2018年第6期6卷 482-486页

作者： Pengfei SHENG Henan University KaifengChina

This research builds an index to describe the inequality in health care expenditure related to pollution,and the measurement with Chinese provincial data set suggests that health care expenditure inequality related to pollution is obvious negative,which confirms that residents located in high-polluted areas cannot get the better health care resources.Meanwhile,the absolute value of health care expenditure inequality related to pollution is even larger than that related to income,which suggests the inequality related to pollution cannot be ignored.

关键词： health care expenditure inequality pollution

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

稳定同位素古食谱分析在历史研究中的应用

学术月刊 2022年第9期54卷 201-211页

作者：生膨菲朱思媚复旦大学文物与博物馆学系上海200433 郑州大学历史文化学院河南郑州450001

稳定同位素古食谱分析是利用地球化学和生态学的研究方法,以考古出土的古代人、动物个体身体组织样本为研究对象开展同位素分析来重建先民及动物食物结构和生存方式的研究。在我国经过近40年的发展,稳定同位素古食谱分析已经基本理清我... 详细信息

稳定同位素古食谱分析是利用地球化学和生态学的研究方法,以考古出土的古代人、动物个体身体组织样本为研究对象开展同位素分析来重建先民及动物食物结构和生存方式的研究。在我国经过近40年的发展,稳定同位素古食谱分析已经基本理清我国史前人类的食物结构变化格局。近十年来,学者们对历史时期人和动物骨骼样品开展同位素分析,在探讨麦作、稻作农业与粟黍农业的兴衰历程、国家祭祀用牲的征集与管理,农牧人群的交融与互动、妇女和儿童的日常生活历史以及个体生活历史的重建五个方面取得了新的突破,值得关注。未来历史学、考古学与稳定同位素分析的深度融合,将从饮食生活方式的角度进一步解读人类的过去、现在与未来。

关键词：稳定同位素分析古食谱历史学考古学饮食生活方式

Microstructure refinement-homogenization and flexural strength improvement of Al_(2)O_(3) ceramics fabricated by DLP-stereolithography integrated with chemical precipitation coating process

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2021年第4期10卷 790-808页

作者： Guanglin NIE Yehua LI Pengfei SHENG Fei ZUO Haolin WU Leiren LIU Xin DENG Yiwang BAO Shanghua WU School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China State Key Laboratory of Green Building Materials China Building Materials AcademyBeijing 100024China

In this study,the chemical precipitation coating(CP)process was creatively integrated with DLP-stereolithography based 3D printing for refining and homogenizing the microstructure of 3D printed Al_(2)O_(3) ceramic.Based on this novel approach,Al_(2)O_(3)powder was coated with a homogeneous layer of amorphous Y2O3,with the coated AI2O3 powder found to make the microstructure of 3D printed Al_(2)O_(3) ceramic more uniform and refined,as compared with the conventional mechanical mixing(MM)of Al_(2)O_(3) and Y_(2)O_(3) powders.The grain size of Al_(2)O_(3) in Sample CP is 64.44%and 51.43%lower than those in the monolithic Al_(2)O_(3) ceramic and Sample MM,respectively.Sample CP has the highest flexural strength of 455.37±32.17 MPa,which is 14.85%and 25.45%higher than those of Samples MM and AL,respectively;also Sample CP has the highest Weibull modulus of 16.88 among the three kinds of samples.Moreover,the fine grained Sample CP has a close thermal conductivity to the coarse grained Sample MM because of the changes in morphology of Y_(3)Al_(5)O_(12) phase from semi-connected(Sample MM)to isolated(Sample CP).Finally,specially designed fin-type Al_(2)O_(3) ceramic heat sinks were successfully fabricated via the novel integrated process,which has been proven to be an effective method for fabricating complex-shaped Al_(2)O_(3) ceramic components with enhanced flexural strength and reliability.

关键词： Al_(2)O_(3)ceramic stereolithography flexural strength reliability thermal conductivity microstructure