检索结果-南通市图书馆

Effects of Al and Co doping on the structural stability and high temperature cycling performance of liNi_(0.5)Mn_(1.5)O_(4) spinel cathode materials

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第9期61卷 201-209页

作者： Jianfeng Cheng Meixuan li Yutong Wang jiexiang li Jiawei Wen Chunxia Wang Guoyong Huang College of New Energy and Materials China University of Petroleum(Beijing)Beijing 102249China State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of Petroleum(Beijing)Beijing 102249China

The poor structural stability and capacity retention of the high-voltage spinel-type liNi_(0.5)Mn_(1.5)O_(4)(LNMO)limits their further ***,Al and Co were doped in LNMO materials for a more stable structure and *** LNMO,liNi_(0.45)Al_(0.05)Mn_(1.5)O_(4)(LNAMO)and liNi_(0.45)Co_(0.05)Mn_(1.5)O_(4)(LNCMO)were synthesized by calcination at 900℃ for 8 h,which was called as solid-phase method and applied universally in ***,FT-IR and CV test results showed the synthesized samples have cation disordering Fd-3m space group ***,the incorporation of Al and Co increased the cation disordering of LNMO,thereby increasing the transfer rate of li+.The SEM results showed that the doped samples performed more regular and *** EDS elemental analysis confirmed the uniform distribution of each metal element in the ***,the doped samples showed better electrochemical properties than undoped *** LNAMO and LNCMO samples were discharged with specific capacities of 116.3 mA·h·g^(-1)and 122.8 mA·h·g^(-1)at 1 C charge/discharge rate with good capacity retention of 95.8% and 94.8% after 200 cycles at room temperature,*** capacity fading phenomenon of the doped samples at 50℃ and 1 C rate was significantly ***,cations doping also enhanced the rate performance,especially for the LNCMO,the discharge specific capacity of 117.9 mA·h·g^(-1)can be obtained at a rate of 5 C.

关键词： High voltage spinel Al/Co doping High temperature cycling stability

Hydrochemical Constraints on the Flowing Paths of Groundwater in limestone Reservoirs beneath the Pingdingshan Coalfield in North China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第6期98卷 1615-1636页

作者： WU Zhanhui WANG Xinyi li jiexiang CUI Junchao ZHANG Bo Institute of Resources and Environment Henan Polytechnic UniversityJiaozuoHenan 454000China Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region JiaozuoHenan 454100China State Collaborative Innovation Center of Coal Work Safety and Clean-Efficiency Utilization JiaozuoHenan 454100China Pingdingshan Tian'an Coal Industry Co. Ltd.PingdingshanHenan 467000China Institute of Energy and Chemical Industry China Pingmei Shenma GroupPingdingshanHenan 467000China

The karst groundwater of Cambrian limestone may become an important water source for industry and agriculture in the Pingdingshan area,and is also a potential threat to mining ***,to find out the origin,flow paths,and hydrogeochemical processes of karst groundwater beneath the Pingdingshan coalfield,a total of 16 water samples were *** findings confirmed that the karst groundwater is mainly recharged by *** precipitation can directly supply the deep aquifer of the karst water system through the southwest limestone outcrops,and this area mostly includes the southern part of mines No.11,No.9,and the hidden outcrops in the southern part of mine *** is more,the areas adjacent to the synclinal axis,including mines No.10,No.12,and No.8,may be the main discharge areas.A mixing model of^(87)Sr/^(86)Sr and Sr showed that in the southwest Pingdingshan coalfield,the proportion of precipitation decreased gradually from the recharge area to the discharge area,ranging from 89.1%to 17.1%.Besides,the northeast Pingdingshan coalfield is another recharge area for the whole karst system,thus,the infiltrating groundwater will indirectly supply the deep aquifer through Quaternary deposition near the mine *** research results can provide theoretical support for the prevention and control of groundwater disasters and the development and utilization of regional groundwater resources in the coalfield in Northern China.

关键词： groundwater flowing path hydrochemistry strontium isotope Pingdingshan coalfield

Tailoring crystal plane of short-process regenerated liFePO_(4) towards enhanced rate properties

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第12期99卷 458-465页

作者： Shuya Lei jiexiang li Lei Hu Dongbin Qiao Wei Sun Peng Ge Yue Yang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization Central South UniversityChangsha 410083HunanChina Guangxi Huayou Resources Recycling Technology Co. LtdYulin 537006GuangxiChina Huayou New Energy Technology Co. LtdQuzhou 324000ZhejiangChina

Captured by the environmental and economic value,the recycling of spent lithium iron phosphate(LFP)batteries has attracted numerous ***,hydrometallurgical method still suffers from complex process,and hydrothermal method is limited by morphology control,ascribed to the strong polarity of ***,supported by ethanol as crystal surface modifier,the regular(010)orientation and short b-axis are effectively tailored for regenerated *** li-storage cathode,the capacities of as-optimized LFP could reach up to 157.07 mA h g^(-1)at 1 C,and the stable capacity of 150.50 mA h g^(-1)could be remained with retention of 93.48%after 400 cycles at 1 *** at 10 C,their capacity could be still kept about 119.3 m A h g^(-1).Assisted by the detail analysis of adsorption energy,the clear growth mechanism is proposed,the lowest adsorbing energy(-4.66 eV)of ethanol on(010)crystal plane renders the ordered growth along(010)crystal *** this,the work is expected to shed light on the tailoring mechanism of internal plane about regenerated materials,whilst providing effective strategies for highperformance regenerated LFP.

关键词： Spent lithium-ion battery liFePO_(4) Regeneration Crystal orientation Electrochemical performance

Estimation of reservoir temperature using silica and cationic solutes geothermometers:a case study in the Tengchong geothermal area

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of Geochemistry 2015年第2期34卷 233-240页

作者： Xiaobo Zhang Qinghai Guo jiexiang li Mingliang liu Yanxin Wang Yijun Yang School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences

Reservoir temperature estimation is vitally important for assessing the exploitation potential of a geothermal *** this study,the concentrations of major chemical constituents in geothermal water sampled from boiling and hot springs in the Tengchong hydrothermal area were measured,and quartz and cationic solutes geothermometers were used to calculate subsurface ***(Q/K) diagrams and Na-K-Mg triangular diagrams were applied to evaluating the equilibrium status of geothermal water samples with regard to reservoir minerals,and results were used to select suitable *** results show that samples RH01,RH03,RH04,RH05,and LL16 were in or very close to full equilibrium with the selected minerals,and therefore a NaK geothermometer is appropriate.A K/Mg geothermometer,however,is applicable to LP08 and PZH18 whose chemical compositions adjusted to the shallow reservoir temperatures during their re-equilibrium *** contrast,cationic solute geothermometers are unsuitable for SQ20 and RH07,which are categorized as immature water in the Na-K-Mg diagram;a quartz geothermometer was adopted to evaluate the corresponding subsurface temperatures of these *** to the reservoir temperature estimation made in this study,there is at least one high-temperature reservoir below Rehai with a possible temperature range of 210-270 ℃.

关键词：温度采样地热区阳离子地温溶质腾冲储层地质温度计

Cation-doped liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode with high rate performance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 139-148页

作者： Long Zhang Dongsheng Yang lilei Miao Chunmeng Zhang jiexiang li Jiawei Wen Chunxia Wang Tiantian Cao Guoyong Huang Shengming Xu College of New Energy and Materials China University of PetroleumBeijing 102249China State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of PetroleumBeijing 102249China Beijing Spacecrafts Beijing 100094China SINOPEC Sales Co. Ltd.Beijing 100728China SINOPEC Research Institute of Petroleum Processing Co. LtdBeijing 100083China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Beijing Key Laboratary of Fine Ceramics Tsinghua UniversityBeijing 100084China

The nickel-rich layered cathode material liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has high energy density,lower cost and is a promising cathode material currently under ***,its electrochemical and structural stability is poor during *** the many modification methods,cation doping has been consistently proven to be an effective strategy for enhancing electrochemical ***,the NCM811 cathode material was modified by solid-phase reactions with Mg and Al *** addition,the corresponding mechanism of NCM811 cathode material-doped modification is explored by density functional theory(DFT)calculations,and we have extended this approach to other ternary cathode materials with different ratios and obtained universal *** with DFT calculations,the results show that Mg2+occupies the li+site and reduces the degree of li^(+)/Ni^(2+) mixture;Al^(3+) acts as a structural support during charging and discharging to prevent structural *** electrochemical properties were tested by an electrochemical workstation and the LAND system,and the results showed that the capacity retention rate increased to varying degrees from 63.66%to 69.87%and 89.05%for NCM811-Mg and NCM811-Al at room temperature after 300 cycles,*** study provides a theoretical basis and design strategy for commercializing cationic-doped modification of nickel-rich cathode materials.

关键词： li-ion batteries Cathode materials Doped Electrochemical properties DFT calculation

A Permutation Test for Unit Root in an Autoregressive Model

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics 2013年第12期4卷 1629-1634页

作者： jiexiang li Lanh Tran Sa-aat Niwitpong Department of Applied Statistics King Mongkut’s University of Technology Bangkok Thailand Department of Mathematics College of Charleston Charleston USA Department of Statistics Indiana University Bloomington USA

A permutation test (based on a finite random sample of permutations) for unit root in an autoregressive process is considered. The test can easily be carried out in practice and the proposed permutation test is neither limited to large sample sizes nor normal white noises. Simulations show that the power of the permutation test is reasonable when sample sizes are small or when the white noises have a heavy tailed distribution. The test is shown to be consistent.

关键词： Permutation Test Autoregressive Nonstationary

CoTCPP integrates with BiOBr microspheres for improved solar-driven CO_(2)reduction performance

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

Green Energy & Environment 2025年第1期10卷 193-202页

作者： lina li Yi Zhang Gaopeng liu Tiange Wei Junze Zhao Bin Wang Mengxia Ji Yuanbin She jiexiang Xia Huaming li School of Chemistry and Chemical Engineering Institute for Energy ResearchJiangsu University301 Xuefu RoadZhenjiang212013China State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology College of Chemical EngineeringZhejiang University of TechnologyHangzhou310014China

CO_(2) photoreduction into carbon-based chemicals has been considered as an appropriate way to alleviate the energy issue and greenhouse ***,the 5,10,15,20-tetra(4-carboxyphenyl)porphyrin cobalt(II)(CoTCPP)has been integrated with BiOBr microspheres and formed the CoTCPP/BiOBr *** as-prepared CoTCPP/BiOBr-2 composite shows optimized photocatalytic performance for CO_(2) conversion into CO and CH_(4) upon irradiation with 300 W Xe lamp,which is 2.03 and 2.58 times compared to that of BiOBr,*** introduced CoTCPP significantly enhanced light absorption properties,promoted rapid separation of photogenerated carriers and boosted the chemisorption of CO_(2) *** metal Co^(2+) at the center of the porphyrin molecules also acts as adsorption center for CO_(2) molecules,accelerating the CO_(2) conversion into CO and CH_(4).The possible mechanism of CO_(2) photoreduction was explored by in-situ FT-IR *** work offers a new possibility for the preparation of advanced photocatalysts.

关键词： BiOBr CoTCPP CO_(2)photoreduction Carriers transfer CO_(2)adsorption-activation

在线全文

学校读者我要写书评

暂无评论

传统水化学地热温度计的适用性分析

地学前缘 2024年第6期31卷 145-157页

作者：李洁祥许亚东蔺文静河南理工大学资源环境学院河南焦作454100 煤炭安全生产与清洁高效利用省部共建协同创新中心河南焦作454100 中国地质科学院水文地质环境地质研究所河北石家庄050061 自然资源部地热与干热岩勘查开发技术创新中心河北石家庄050061

水化学地热温度计是估算水热型地热系统热储温度的一种重要手段,为了厘清传统水化学地热温度计的局限性和有效性,此次将对水化学地热温度计展开全面分析。结果表明:部分水化学平衡体系受区域地质条件的影响,致使对应的水化学地热温度计(... 详细信息

水化学地热温度计是估算水热型地热系统热储温度的一种重要手段,为了厘清传统水化学地热温度计的局限性和有效性,此次将对水化学地热温度计展开全面分析。结果表明:部分水化学平衡体系受区域地质条件的影响,致使对应的水化学地热温度计(Na-li地热温度计、li-Mg地热温度计、Ca-Mg地热度计和SO_(4)-F地热温度计等)缺乏普适性,而Na-K-Ca地热温度计(β=1/3)可能受多种水化学因素的制约,在中低温地热系统中应谨慎使用;Na-K地热温度计、K-Mg地热温度计和SiO_(2)温度计更适用于水热型热储温度的计算,高温热储层(>200℃)中水岩相互作用强烈,Na-K地热温度计的计算结果相对准确,在估算中低温热储层温度时,K-Mg地热温度计和SiO_(2)温度计则更为合适,而在沉积盆地型地热系统,不建议使用水化学地热温度计直接估算地热水的平衡温度。除此之外,判识热储层的存在和地热水水岩平衡状态的分析是选取水化学地热温度计的前提条件,然而即使在水化学地热温度计的适用范围内,对水化学地热温度计计算结果的对比验证仍然必不可少;高温地热系统中地热水的混合过程可用于验证水化学地热温度计的准确性,而在中低温地热系统,随着水岩相互作用程度降低,水化学地热温度计估算结果的不确定性也随之增加,综合多种方法对热储温度值的分析验证就显得更为重要。此次研究可为合理选取水化学地热温度计提供一定的理论参考。

关键词：水热型地热系统水化学地热温度计水岩反应平衡

高温地热系统中粘土矿物形成对Na-K和K-Mg地球化学温标准确性的影响

在线全文

学校读者我要写书评

暂无评论

地球科学（中国地质大学学报） 2017年第1期42卷 142-154页

作者：李洁祥郭清海余正艳中国地质大学生物地质与环境地质国家重点实验室湖北武汉430074 中国地质大学环境学院湖北武汉430074

传统地球化学温标在估算高温地热系统内浅层热储温度(一般为100~200℃)时存在局限性,其中应用广泛的Na-K温标和K-Mg温标出现误差的原因仍不清楚.在收集了全球代表性热田内采自地热井的201个流体样品的水文地球化学数据后,利用软件WATCH... 详细信息

传统地球化学温标在估算高温地热系统内浅层热储温度(一般为100~200℃)时存在局限性,其中应用广泛的Na-K温标和K-Mg温标出现误差的原因仍不清楚.在收集了全球代表性热田内采自地热井的201个流体样品的水文地球化学数据后,利用软件WATCH将井口流体地球化学数据还原为热储条件下的对应值;在此基础上,对Na-K温标和K-Mg温标进行了评价,发现钾长石和常见富钾双八面体粘土矿物均可能对浅层热储内地热流体中的钾含量产生影响,富镁双八面体粘土矿物也可达到与地热流体的平衡,而地热流体中钠含量则受水-岩相互作用的影响很小.因此,浅层地热流体的Na-K比值与热储温度不具有对应关系,而K-Mg温标在计算浅层热储温度时虽然具有一定指示意义,但仍无法得到足够准确的结果.

关键词：高温地热系统浅层热储 Na-K温标 K-Mg温标双八面体粘土矿物水文地质