期刊文献+
共找到6,590篇文章
< 1 2 250 >
每页显示 20 50 100
Study on the effect of preparation method on denitration performance of Co-modified Ce/TiO_(2) catalyst
1
作者 YU Chao ZHANG Boya +2 位作者 SHEN Kai HAN Yuxuan ZHANG Yaping 《燃料化学学报(中英文)》 北大核心 2026年第3期79-91,共13页
This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s... This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s low-temperature denitrification activity.After identifying optimal preparation parameters via condition screening,multiple characterization techniques-including BET,XRD,XPS,H_(2)-TPR and in situ DRIFTS-were employed to deeply analyze the catalyst’s physicochemical properties and reaction mechanism.Results demonstrated that compared to the impregnation and co-precipitation methods,the Ce-Co_(0.025)/TiO_(2)-SG catalyst(prepared by the sol-gel method with a Co/Ti mass ratio of 0.025)exhibited significantly superior denitrification activity:NO conversion remained stably above 95%in the 225−350℃ temperature range,and it displayed high N_(2) selectivity.Characterization analysis revealed that abundant surface oxygen vacancies,a high proportion of Ce^(3+) species,and prominent acidic sites collectively contributed to enhancing its low-temperature denitrification performance.This work provides reference value for the development of highly efficient low-temperature denitrification catalysts. 展开更多
关键词 preparation method Co Ce/TiO_(2) low-temperature denitration NH3-SCR
在线阅读 下载PDF
Combining Random Forest and Monte Carlo Method to Determine the Driving Factors and Uncertainty of Forest Age Prediction in Northwest China
2
作者 ZENG Jia LIU Jincheng +1 位作者 LI Limin KHAN Tauheed Ullah 《Chinese Geographical Science》 2026年第1期144-156,I0004-I0007,共17页
Stand age plays a crucial role in forest biomass estimation and carbon cycle modeling.Assessing the uncertainty of stand age prediction models and identifying the key driving factors in the modeling process have becom... Stand age plays a crucial role in forest biomass estimation and carbon cycle modeling.Assessing the uncertainty of stand age prediction models and identifying the key driving factors in the modeling process have become major challenges in forestry research.In this study,we selected the Shaanxi-Gansu-Ningxia region of Northeast China as the research area and utilized multi-source datasets from the summer of 2019 to extract information on spectral,textural,climatic,water balance,and stand characteristics.By integrating the Random Forest(RF)model with Monte Carlo(MC)simulation,we constructed six regression models based on different combina-tions of features and evaluated the uncertainty of each model.Furthermore,we investigated the driving factors influencing stand age modeling by analyzing the effects of different types of features on age inversion.Model performance and accuracy were assessed using the root mean square error(RMSE),mean absolute error(MAE),and the coefficient of determination(R^(2)),while the relative root mean square error(rRMSE)was employed to quantify model uncertainty.The results indicate that the scenarios with more obvious improve-ment in accuracy and effective reduction in uncertainty were Scenario 3 with the inclusion of climate and water balance information(RMSE=25.54 yr,MAE=18.03 yr,R^(2)=0.51,rRMSE=19.17%)and Scenario 5 with the inclusion of stand characterization informa-tion(RMSE=18.47 yr,MAE=13.05 yr,R^(2)=0.74,rRMSE=16.99%).Scenario 6,incorporating all feature types,achieved the highest accuracy(RMSE=17.60 yr,MAE=12.06 yr,R^(2)=0.77,rRMSE=14.19%).In this study,elevation,minimum temperature,and diameter at breast height(DBH)emerged as the key drivers of stand-age modeling.The proposed method can be used to identify drivers and to quantify uncertainty in stand-age estimation,providing a useful reference for improving model accuracy and uncertainty assessment. 展开更多
关键词 stand age Randon Forest(RF)model Monte Carlo(MC)method Sentinel-2 National Forest Inventory(NFI) Shaanxi-Gansu-Ningxia(SGN) Northwest China
在线阅读 下载PDF
Numerical analysis of solid–liquid interface shape during largesize single crystalline silicon with Czochralski method 被引量:7
3
作者 Ran Teng Qing Chang +3 位作者 Yang Li Bin Cui Qing-Hua Xiao Guo-Hu Zhang 《Rare Metals》 SCIE EI CAS CSCD 2017年第4期289-294,共6页
Numerical analysis is an effective tool to research the industrial Czochralski (CZ) crystal growth aiming to improve crystal quality and reduce manufactur- ing costs. In this study, a set of global simulations were ... Numerical analysis is an effective tool to research the industrial Czochralski (CZ) crystal growth aiming to improve crystal quality and reduce manufactur- ing costs. In this study, a set of global simulations were carried out to investigate the effect of crystal-crucible rotation and pulling rate on melt convection and solid- liquid (SL) interface shape. Through analyses of the sim- ulation data, it is found that the interface deformation and inherent stress increase during the crystal growth process. The interface deflection increases from 7.4 to 51.3 mm with an increase in crystal size from 150 to 400 mm. In addition, the SL interface shape and flow pattern are sen- sitive to pulling rate and rotation rate. Reducing pulling rate can flat SL interface shape and add energy-consuming. Interface with low deflection can be achieved by adopting certain combination of crystal and crucible rotation rates. The effect of crystal rotation on SL interface shape is less significant at higher crucible rotation rates. 展开更多
关键词 czochralski method Numerical analysis Pullrate Crucible rotation Crystal rotation Solid/liquidinterface shape
原文传递
Structure and Optical Properties of ZnO Thin Films Prepared by the Czochralski Method
4
作者 MA Zhanhong REN Fengzhang YANG Zhouya 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第5期823-828,共6页
The zinc oxide seed film was coated on conductive glass (FTO) substrate by the Czochralski method,Zinc acetate and hexamethylenetetramine were used as raw materials to prepare growth solution,and then ZnO film was pre... The zinc oxide seed film was coated on conductive glass (FTO) substrate by the Czochralski method,Zinc acetate and hexamethylenetetramine were used as raw materials to prepare growth solution,and then ZnO film was prepared by a low-temperature solution method.The effects of annealing temperature on the morphology,structure,stress and optical properties of ZnO films were studied.The thin films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),UV-visible absorption spectra (UV-vis),photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS).The results show that the films are ZnO nanorods.With the increase of annealing temperature,the diameter of the rod increases,and the nanorods tend to be oriented.The band gap of the sample obtained from the light absorption spectra first increases and then decreases with the increase of annealing temperature.When the annealing temperature is 350 ℃,the crystallinity of zinc oxide film is the highest,the band gap is close to the theoretical value of pure ZnO. 展开更多
关键词 czochralski method ZnO film annealing temperature optical properties MICRO-MORPHOLOGY internal stress
原文传递
Study Coefficient and Optical Application of KCI Single Crystal with Sn Impurity Growth on Czochralski Method under Visible Radiation
5
作者 Feridoun Samavat Ebrahim Haji Ali Somayeh Solgi 《材料科学与工程(中英文A版)》 2012年第12期799-802,共4页
关键词 可见光辐射 光学系数 杂质 SN 提拉法 系数和 晶体生长 单晶
在线阅读 下载PDF
Synthesis of Nano-CuF_(2) with Superior Electrochemical Performances via a Mixed Solvent Coprecipitation Method
6
作者 DU Suni YU Zhiyong +5 位作者 JI Erte XU Hanchen ZHAO Yichun LIU Hanxing LAI Caiting YUAN Zhongzhi 《Journal of Wuhan University of Technology(Materials Science)》 2025年第5期1206-1212,共7页
Nano-scale CuF_(2) with superior electrochemical activity was successfully prepared by a mixed solvent co-precipitation method.The SEM and TEM analyses demonstrated that the methanol concentration had a pronounced eff... Nano-scale CuF_(2) with superior electrochemical activity was successfully prepared by a mixed solvent co-precipitation method.The SEM and TEM analyses demonstrated that the methanol concentration had a pronounced effect on both the particle size and the extent of agglomeration.With the increase in methanol content,the particle size and agglomeration of CuF_(2) decreased first and then increased.When the volume ratio of methanol to deionized water was 1:1,the CuF_(2) particles exhibited the smallest size and the lowest degree of agglomeration.CuF_(2) synthesized with 50%methanol exhibited superior electrochemical performances with a voltage plateau above 3 V and a 1st discharge capacity of 525.8 mAh·g^(-1) at 0.01 C due to the synergistic influence of the particle size and dispersion.The analysis results using electrochemical impedance spectroscopy(EIS)and constant current intermittent titration technique(GITT)affirmed the addition of methanol was beneficial for promoting Li+diffusion and accelerating electrochemical reaction kinetics of CuF_(2). 展开更多
关键词 CuF_(2) lithium-ion battery mixed solvent co-precipitation method electrochemical performances
原文传递
The Construction of Exact Solutions of the Two-Dimensional Gardner Equation via the∂¯-Dressing Method
7
作者 Binlu FENG Linlin GUI Yufeng ZHANG 《Journal of Mathematical Research with Applications》 2025年第6期758-772,共15页
The(2+1)-dimensional integrable generalization of the Gardner(2DG)equation is solved via the inverse scattering transform method in this paper.A kind of general solution of the equation is obtained by introducing long... The(2+1)-dimensional integrable generalization of the Gardner(2DG)equation is solved via the inverse scattering transform method in this paper.A kind of general solution of the equation is obtained by introducing long derivatives V_(x),V_(y),V_(t).Two different constraints on the kernel function K are introduced under the reality of the solution u of the 2DG equation.Then,two classes of exact solutions with constant asymptotic values at infinity u|x^(2)+y^(2)→∞→0 are constructed by means of the∂¯-dressing method for the casesσ=1 andσ=i.The rational and multiple pole solutions of the 2DG equation are obtained with the kernel functions of zero-order and higher-order Dirac delta functions,respectively. 展开更多
关键词 2DG equation kernel function ∂¯-dressing method rational solution multiple pole solution
原文传递
An improved and robust method of estimating ice sheet elevation changes with ICESat-2 altimetry data
8
作者 Benxin Zhu Shengkai Zhang +3 位作者 Feng Xiao Xiao Li Tingguo Lu Xing Yuan 《Geodesy and Geodynamics》 2025年第6期717-726,共10页
Elevation change monitoring of the Antarctic ice sheet has been a key issue in global change research.Satellite altimetry has been proven to be effective in detecting ice sheet variations. With the development of ICES... Elevation change monitoring of the Antarctic ice sheet has been a key issue in global change research.Satellite altimetry has been proven to be effective in detecting ice sheet variations. With the development of ICESat-2, many elevation observations can be used to derive elevation changes. However, the large amount of multitemporal data may include anomalous data points, increasing the uncertainty of the results. In this work, we improved the traditional repeat track method by introducing the Institute of Geodesy and Geophysics Ⅲ(IGGⅢ) method to obtain high-accuracy estimates of elevation change. The improved method was applied to analyze elevation changes along the transect from Zhongshan Station to Dome A in East Antarctica via ICESat-2 satellite altimetry data. The results show that the improved and traditional methods yield consistent numerical and spatial elevation change distributions. The elevation change calculated via the traditional method is 0.033 ± 0.131 m/yr, whereas the elevation change estimated via the IGGⅢ robust estimation method is 0.033 ± 0.109 m/yr from March 2019 to December 2021.In terms of spatial distribution, elevation changes in inland areas remain close to equilibrium, whereas regions with steeper ice sheet margins exhibit positive accumulation trends in elevation changes. The improved method reduces the standard error of the adjustment function from 0.975 to 0.691 m/yr. The improvement is particularly remarkable in the area between 72°S and 77°S. The results demonstrate that the IGGⅢ method effectively reduces errors caused by the inclusion of anomalous data and maintains the high data utilization rate of repeat-orbit methods. 展开更多
关键词 Satellite altimetry Repeat tracks method Ice sheet elevation change Robust estimation ICESat-2
原文传递
Ontology Matching Method Based on Gated Graph Attention Model
9
作者 Mei Chen Yunsheng Xu +1 位作者 Nan Wu Ying Pan 《Computers, Materials & Continua》 2025年第3期5307-5324,共18页
With the development of the Semantic Web,the number of ontologies grows exponentially and the semantic relationships between ontologies become more and more complex,understanding the true semantics of specific terms o... With the development of the Semantic Web,the number of ontologies grows exponentially and the semantic relationships between ontologies become more and more complex,understanding the true semantics of specific terms or concepts in an ontology is crucial for the matching task.At present,the main challenges facing ontology matching tasks based on representation learning methods are how to improve the embedding quality of ontology knowledge and how to integrate multiple features of ontology efficiently.Therefore,we propose an Ontology Matching Method Based on the Gated Graph Attention Model(OM-GGAT).Firstly,the semantic knowledge related to concepts in the ontology is encoded into vectors using the OWL2Vec^(*)method,and the relevant path information from the root node to the concept is embedded to understand better the true meaning of the concept itself and the relationship between concepts.Secondly,the ontology is transformed into the corresponding graph structure according to the semantic relation.Then,when extracting the features of the ontology graph nodes,different attention weights are assigned to each adjacent node of the central concept with the help of the attention mechanism idea.Finally,gated networks are designed to further fuse semantic and structural embedding representations efficiently.To verify the effectiveness of the proposed method,comparative experiments on matching tasks were carried out on public datasets.The results show that the OM-GGAT model can effectively improve the efficiency of ontology matching. 展开更多
关键词 Ontology matching representation learning OWL2Vec*method graph attention model
在线阅读 下载PDF
An Efficient Molten Salt Method to Fabricate Lightcolored Conductive Whiskers for Fibers
10
作者 PANG Zengyuan GAO Pengxiang +3 位作者 MENG Haonan CHENG Zhenyu LI Shen ZHU Yanan 《Journal of Wuhan University of Technology(Materials Science)》 2025年第4期905-913,共9页
One-dimensional titanium dioxide(TiO_(2))whiskers with controllable aspect ratios were synthesized by molten salt method adopting anatase TiO_(2)nanoparticles as precursor,sodium chloride(NaCl)and dibasic sodium phosp... One-dimensional titanium dioxide(TiO_(2))whiskers with controllable aspect ratios were synthesized by molten salt method adopting anatase TiO_(2)nanoparticles as precursor,sodium chloride(NaCl)and dibasic sodium phosphate(Na_(2)HPO_(4))as medium.The particle size of TiO_(2)nanoparticles and ratio of precursor and medium that can help to generate high aspect ratio TiO_(2)whiskers were studied and selected.Light-colored antimony-doped tin oxide@titanium dioxide(ATO@TiO_(2))conductive whiskers were prepared by coating ATO on TiO_(2)whiskers through coprecipitation then.Finally,the ATO@TiO_(2)light-colored conductive whiskers were dispersed in polyacrylonitrile(PAN)to fabricate light-colored conductive fibers.The experimental results show that the ATO@TiO_(2)whiskers exhibits ideal whiteness and conductivity with 65.5 Wb and 106Ω·cm,respectively,and the resistivity of conductive fibers was 6.07×10^(6)Ω·cm with 15wt%whisker content. 展开更多
关键词 molten salt method light-colored conductive fibers antimony-doped tin oxide@titanium dioxide(ATO@TiO_(2))
原文传递
Simulation of CO_(2)-water two-phase fluid displacement characteristics based on the phase field method
11
作者 Changnu Zeng Yiyang Zhang +1 位作者 Hu Lu Zhao Lu 《Deep Underground Science and Engineering》 2025年第4期725-738,共14页
The two-phase flow in porous media is affected by multiple factors.In the present study,a two-dimensional numerical model of porous media was developed using the actual pore structure of the core sample.The phase fiel... The two-phase flow in porous media is affected by multiple factors.In the present study,a two-dimensional numerical model of porous media was developed using the actual pore structure of the core sample.The phase field method was utilized to simulate the impact of displacement velocity,the water-gas viscosity ratio,and the density ratio on the flow behavior of two-phase fluids in porous media.The effectiveness of displacement was evaluated by analyzing CO_(2)saturation levels.The results indicate that the saturation of CO_(2)in porous media increased as the displacement velocity increased.When the displacement velocity exceeded 0.01 m/s,there was a corresponding increase in CO_(2)saturation.Conversely,when the displacement velocity was below this threshold,the impact on CO_(2)saturation was minimal.An“inflection point,”M3,was present in the viscosity ratio.When the viscosity of CO_(2)is less than 8.937×10^(-5)Pa·s(viscosity ratio below M3),variations in the viscosity of CO_(2)had little impact on its saturation.Conversely,when the viscosity of CO_(2)exceeded 8.937×10^(-5)Pa·s(viscosity ratio greater than M3),saturation increased with an increase in the viscosity ratio.In terms of the density ratio,the saturation of CO_(2)increased monotonically with an increase in the density ratio.Similarly,increasing density ratios resulted in a monotonic increase in CO_(2)saturation,though this trend was less pronounced in numerical simulations.Analysis results of displacement within dead-end pores using pressure and velocity diagrams reveal eddy currents as contributing factors.Finally,the impact of pore throat structure on the formation of dominant channels was examined. 展开更多
关键词 CO_(2)geological storage displacement efficiency enhancement phase field method real core two-phase flow
原文传递
TCMLCM:an intelligent question-answering model for traditional Chinese medicine lung cancer based on the KG2TRAG method
12
作者 Chunfang ZHOU Qingyue GONG +2 位作者 Wendong ZHAN Jinyang ZHU Huidan LUAN 《Digital Chinese Medicine》 2025年第1期36-45,共10页
Objective To improve the accuracy and professionalism of question-answering(QA)model in traditional Chinese medicine(TCM)lung cancer by integrating large language models with structured knowledge graphs using the know... Objective To improve the accuracy and professionalism of question-answering(QA)model in traditional Chinese medicine(TCM)lung cancer by integrating large language models with structured knowledge graphs using the knowledge graph(KG)to text-enhanced retrievalaugmented generation(KG2TRAG)method.Methods The TCM lung cancer model(TCMLCM)was constructed by fine-tuning Chat-GLM2-6B on the specialized datasets Tianchi TCM,HuangDi,and ShenNong-TCM-Dataset,as well as a TCM lung cancer KG.The KG2TRAG method was applied to enhance the knowledge retrieval,which can convert KG triples into natural language text via ChatGPT-aided linearization,leveraging large language models(LLMs)for context-aware reasoning.For a comprehensive comparison,MedicalGPT,HuatuoGPT,and BenTsao were selected as the baseline models.Performance was evaluated using bilingual evaluation understudy(BLEU),recall-oriented understudy for gisting evaluation(ROUGE),accuracy,and the domain-specific TCM-LCEval metrics,with validation from TCM oncology experts assessing answer accuracy,professionalism,and usability.Results The TCMLCM model achieved the optimal performance across all metrics,including a BLEU score of 32.15%,ROUGE-L of 59.08%,and an accuracy rate of 79.68%.Notably,in the TCM-LCEval assessment specific to the field of TCM,its performance was 3%−12%higher than that of the baseline model.Expert evaluations highlighted superior performance in accuracy and professionalism.Conclusion TCMLCM can provide an innovative solution for TCM lung cancer QA,demonstrating the feasibility of integrating structured KGs with LLMs.This work advances intelligent TCM healthcare tools and lays a foundation for future AI-driven applications in traditional medicine. 展开更多
关键词 Traditional Chinese medicine(TCM) Lung cancer Question-answering Large language model Fine-tuning Knowledge graph KG2TRAG method
暂未订购
A data-driven identification method for reaction rate constant and diffusion coefficient in the P2D model
13
作者 Gaoyang Li Xiaoyu Guo +8 位作者 Yongshuai Li Jialong Huang Zhirui Wang Yizheng Ma Litao Zhu Hui Pan Feng Shao Hao Ling Yulin Min 《Chinese Journal of Chemical Engineering》 2025年第12期188-197,共10页
To ensure the safe operation of batteries,accurately obtaining key internal state parameters is essential.However,traditional parameter measurement methods either require opening the battery or long-term measurements,... To ensure the safe operation of batteries,accurately obtaining key internal state parameters is essential.However,traditional parameter measurement methods either require opening the battery or long-term measurements,which are impractical.Therefore,the fixed values are commonly used for these parameters in electrochemical models and have significant limitations.To overcome these limitations,this paper proposes a deep neural network(DNN)based data-driven evaluation method to determine model parameters.By coupling an improved one-dimensional isothermal pseudo-twodimensional(P2D)model with DNN,this study identified concentration-dependent parameters through detailed discharge curve analysis.The results show that the data-driven method can effectively obtain the change trend of concentration-dependent parameters through the charge and discharge curve,and the method can be extended to different battery systems in different discharge rates and aging applications.This work is expected to provide new parameter selection insights for data-driven battery prediction and monitoring models. 展开更多
关键词 Internal state parameters of batteries P2D model Parameter identification Deep neural network(DNN) Data-driven evaluation method
在线阅读 下载PDF
基于响应曲面法和NSGA2的内斜齿轮成形磨削参数优化
14
作者 金明选 苏建新 +1 位作者 张祥 李明宇 《机电工程》 北大核心 2025年第9期1649-1658,共10页
内斜齿轮是斜齿行星减速器的重要传动件,其表面质量直接影响减速器的运动精度和可靠性。为提升齿轮成形磨削加工的质量和效率,确定最佳成形磨削工艺参数,对内斜齿轮成形磨削过程中的磨削工艺参数进行了优化研究。首先,建立了磨齿温度场... 内斜齿轮是斜齿行星减速器的重要传动件,其表面质量直接影响减速器的运动精度和可靠性。为提升齿轮成形磨削加工的质量和效率,确定最佳成形磨削工艺参数,对内斜齿轮成形磨削过程中的磨削工艺参数进行了优化研究。首先,建立了磨齿温度场热量分配数学模型,并依据有限元仿真得到了磨削温度数据;然后,结合响应曲面法分析了成形磨削过程中不同工艺参数对磨削温度的影响,将磨削温度设成响应性能指标,建立了相应的响应回归模型;最后,以磨削温度、磨削效率和磨削质量为优化目标,利用第二代非支配排序遗传算法(NSGA2)进行了多目标工艺参数的优化,并进行了实验验证。研究结果表明:在湿磨工况下,磨削工艺参数对磨削温度的影响排序依次为a_(p)>v_(w)>v_(s);磨削温度与磨削深度、进给速度呈正相关,与砂轮线速度呈负相关;在保证成形磨削温度的前提下,磨削加工过程中使用优化后的最佳磨削工艺参数得到的粗磨阶段加工时间减少了50%,精磨阶段左右齿面偏差分别减少了46.7%和26.6%。由此证明了优化得到的最佳磨削工艺参数是合理有效的,对磨削过程中磨削参数的选择具有指导意义。 展开更多
关键词 齿轮传动 斜齿行星减速器 成形磨削 响应曲面法 第二代非支配排序遗传算法 磨削工艺参数优化 磨削温度
在线阅读 下载PDF
固碳轻质土制备方法与物理力学性能研究
15
作者 刘松玉 张翔 +3 位作者 蔡光华 袁振扬 安景峰 陈光伟 《岩土工程学报》 北大核心 2026年第1期15-23,共9页
为减少碳排放、探寻岩土工程的二氧化碳(CO_(2))利用技术,基于氧化镁(MgO)碳化固化原理,提出了一种固碳轻质土(carbon sequestration lightweight soil,C-LS)原理,该原理采用MgO和渣土替代水泥作为固化材料、CO_(2)替代空气发泡,将MgO... 为减少碳排放、探寻岩土工程的二氧化碳(CO_(2))利用技术,基于氧化镁(MgO)碳化固化原理,提出了一种固碳轻质土(carbon sequestration lightweight soil,C-LS)原理,该原理采用MgO和渣土替代水泥作为固化材料、CO_(2)替代空气发泡,将MgO、粉质黏土、水和CO_(2)泡沫按一定比例混合后形成密度<1 g/cm3的C-LS。通过无侧限抗压强度、扫描电镜和热重等宏微观试验,研究了不同MgO掺量、设计湿密度、水固比与碳化养护条件对C-LS的流值、凝结时间、干密度、强度、碳化产物及固碳能力的影响规律。结果表明:随MgO掺量和湿密度增加,C-LS流值和凝结时间减小,抗压强度提高,同时其固碳量提高。确定了C-LS的最优配比,在自然养护下,其28 d强度可满足高速公路路堤填筑和其它填筑材料要求,在外部加速碳化条件下,C-LS强度可进一步提高。根据C-LS强度与碳化产物产量及固碳量的内在联系,研究揭示了C-LS强度形成微观机理。C-LS技术能大量消耗CO_(2)和工程渣土,为岩土工程固碳利用提供了崭新的技术途径。 展开更多
关键词 C-LS MGO 二氧化碳泡沫 制备方法 物理力学特性
原文传递
钠离子电池用氟磷酸钒钠正极材料的制备及其电化学性能
16
作者 瞿小兰 史国帅 +5 位作者 薛永萍 尚永飞 汤璐 谷云铮 邹征云 曾静 《化学与生物工程》 北大核心 2026年第2期34-39,共6页
以偏钒酸铵为钒源,采用溶胶凝胶法制备了钠离子电池用氟磷酸钒钠[Na_(3)V_(2)(PO_(4))_(2)F_(3),NVPF]正极材料,并对其电化学性能进行了研究。结果表明,NVPF正极材料在1 C倍率下的首圈充、放电比容量分别为113.68、102.87 mAh·g^(-... 以偏钒酸铵为钒源,采用溶胶凝胶法制备了钠离子电池用氟磷酸钒钠[Na_(3)V_(2)(PO_(4))_(2)F_(3),NVPF]正极材料,并对其电化学性能进行了研究。结果表明,NVPF正极材料在1 C倍率下的首圈充、放电比容量分别为113.68、102.87 mAh·g^(-1),首圈库仑效率为90.49%,循环100圈后的容量保有率为92.35%;而10 C倍率下的首圈充、放电比容量分别为72.48、64.25 mAh·g^(-1),库仑效率为88.64%。NVPF不仅放电比容量显著提高,同时还具备更好的循环稳定性和倍率性能,可用作钠离子电池的正极材料。为制备低成本、优电化学性能且易于工业化的NVPF正极材料提供了实验依据。 展开更多
关键词 磷酸钒钠 溶胶凝胶法 电化学性能 钠离子电池
在线阅读 下载PDF
溶剂热法制备Fe^(2+)掺杂LiCoPO_(4)及其电极性能
17
作者 李志义 王成伟 +3 位作者 孙海礼 魏炜 刘凤霞 刘志军 《精细化工》 北大核心 2026年第1期42-49,59,共9页
以一水合氢氧化锂、四水合醋酸钴为原料,采用抗坏血酸辅助的温和溶剂热法制备了LiCoPO_(4)前驱体,再经煅烧后制备了LiCoPO_(4),最后制备了不同Fe^(2+)掺杂量(x)的LiCo_(1–x)Fe_(x)PO_(4)。通过XRD、SEM表征和电化学性能测试,考察了溶... 以一水合氢氧化锂、四水合醋酸钴为原料,采用抗坏血酸辅助的温和溶剂热法制备了LiCoPO_(4)前驱体,再经煅烧后制备了LiCoPO_(4),最后制备了不同Fe^(2+)掺杂量(x)的LiCo_(1–x)Fe_(x)PO_(4)。通过XRD、SEM表征和电化学性能测试,考察了溶剂热反应时间、煅烧温度和Fe^(2+)掺杂量对LiCoPO_(4)及LiCo_(1–x)Fe_(x)PO_(4)形貌和作为正极材料性能的影响。结果表明,对溶剂热反应时间与煅烧温度的调控可以实现LiCoPO_(4)的形貌和颗粒粒径的优化,进而改善其电化学性能。在溶剂热反应时间为9 h、煅烧温度为700℃的条件下可制备出形貌为板状的LiCoPO_(4)颗粒,其首次放电比容量达到163.21 mA·h/g;当x=0.09时,LiCo_(0.91)Fe_(0.09)PO_(4)表现出最佳的循环性能和倍率性能,在0.1 C倍率下经过30次循环,LiCo_(0.91)Fe_(0.09)PO_(4)与未经Fe^(2+)掺杂的LiCoPO_(4)相比,放电比容量从52.12 mA·h/g提升至111.75 mA·h/g,容量保留率由31.93%提升至77.66%。 展开更多
关键词 磷酸钴锂 溶剂热法 抗坏血酸 形貌 电化学性能 Fe^(2+)掺杂 功能材料
原文传递
MoS_(2)@镀Ni多壁碳纳米管复合材料的制备及表征综合实验设计
18
作者 张敏 张巍巍 杨波 《广东化工》 2026年第2期165-168,共4页
通过系统设计综合实验内容,引导学生掌握材料制备、性能测试与结构分析等方面的基本原理与方法,实现实验教学与理论知识的有机融合,进一步加深对材料科学核心概念的理解。本实验以水热法制备MoS_(2)@镀Ni多壁碳纳米管复合材料为研究对象... 通过系统设计综合实验内容,引导学生掌握材料制备、性能测试与结构分析等方面的基本原理与方法,实现实验教学与理论知识的有机融合,进一步加深对材料科学核心概念的理解。本实验以水热法制备MoS_(2)@镀Ni多壁碳纳米管复合材料为研究对象,围绕产物的相组成、表面形貌及微波电磁性能开展系统的结构与性能分析。通过该实验过程,着重培养学生的创新思维与实践能力,为未来从事材料相关的科学研究、技术开发和工艺设计等工作奠定坚实基础。 展开更多
关键词 MoS_(2)@镀Ni多壁碳纳米管 水热法 电磁参数 综合实验
在线阅读 下载PDF
Integrated process of large-scale and size-controlled SnO_2 nanoparticles by hydrothermal method 被引量:3
19
作者 曹雪 舒永春 +2 位作者 胡永能 李广平 刘畅 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第3期725-730,共6页
SnO2 nanoparticles with the average particle size of 5-30 nm were synthesized using SnCl4·5H2O as the precursor and NH3·H2O as the mineralizing agent by hydrothermal method.In the case of 1 kg/batch producti... SnO2 nanoparticles with the average particle size of 5-30 nm were synthesized using SnCl4·5H2O as the precursor and NH3·H2O as the mineralizing agent by hydrothermal method.In the case of 1 kg/batch production,the effects of synthesis conditions including solution concentration,reaction temperature,pressure,time and pH value on the grain size,particle morphology and crystal structure of SnO2 were systematically studied.The particles were characterized by X-ray diffraction(XRD) and transmission electron microscopy(TEM).The results show that,the particle size can be well controlled in the range of 5-30 nm by adjusting the processing parameters such as reaction temperature and time when the crystal structure and particle morphology remain unchanged.The previous reports,the unusual dependences of the grain size of SnO2 on reaction temperature and time were found.The mechanism for such abnormal grain growth behavior was tentatively elucidated. 展开更多
关键词 SNO2 NANOPARTICLES hydrothermal method
在线阅读 下载PDF
Preparation of long alumina fibers by sol-gel method using malic acid 被引量:12
20
作者 谭宏斌 郭从盛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1563-1567,共5页
The precursor sol of alumina was prepared by sol-gel method with aluminum nitrate and malic acid as raw materials.The effects of content of malic acid and polyvinylpyrrolidone (PVP) on sol spinnability were explored... The precursor sol of alumina was prepared by sol-gel method with aluminum nitrate and malic acid as raw materials.The effects of content of malic acid and polyvinylpyrrolidone (PVP) on sol spinnability were explored.The gel fibers with above 80 cm in length were obtained by mixing aluminum nitrate,malic acid and PVP on mass ratio of 10 3 1.5.Thermogravimetry-differential scanning calorimetry (TG-DSC),Fourier transform infrared (FTIR) spectrum,X-ray diffractometry (XRD),and scanning electron microscopy (SEM) were used to characterize the properties of the gel and ceramic fibers.The alumina fibers with a smooth surface and about 20μm in diameter were obtained by sintering at 1 200℃,and their main phase was indentified to be α-Al2O3. 展开更多
关键词 AL2O3 long fiber sol-gel method POLYVINYLPYRROLIDONE
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部