检索结果-南通市图书馆

Quantitative discrimination of surface adsorbed NOx species on CeO_(2) via spectrophotometry for SCR denitration investigation

引用

Journal of Rare Earths 2024年第6期42卷 1066-1072,I0003页

作者： Songil Sin jiawei ji Lijun Cheng Zhiwen Gu Chong Tan Kwangchol Ri Changjin Tang School of Environment Nanjing Normal UniversityNanjing210023China Department of Mining Engineering Kim Chaek University of TechnologyPyongyang999093Democratic People's Republic of Korea Laboratory of Mesoscopic Chemistry of MOE School of Chemistry and Chemical EngineeringNanjing UniversityNanjing20023China Institute of Chemical Engineering Hamhung University of Chemical EngineeringHamhungDemocratic People's Republic of Korea jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology Nanjing210023China

CeO_(2)-based catalysts are widely investigated for selective catalytic reduction(SCR)of NO with NH3.Interaction of NO/O_(2) with CeO_(2) generally produces two surface species,i.e.,nitrates and nitrites.However,the explicit quantification of these two species is still unresolved.Herein,we reported that spectrophotometry characterization was effective in determining surface adsorbed NOx species on CeO_(2) by measuring the corresponding ions(NO_(2)-and NO_(3)^(-))dissolved in aqueous solution.Experimental results show that both nitrate(-NO_(3))and nitrite(-NO_(2))species can be quantitatively evaluated and the accuracy is verified by calibrating with NOx-TPD result.Exclusive transfer of adsorbed NOx from catalyst surface to aqueous solution is confirmed and the dissolution process can be accelerated by ultrasonic treatment.Moreover,useful information related to evolution of surface NOx species under various conditions(O_(2) treatment,different adsorption temperature and duration)and over different catalysts(Fe_(2)O_(3),MnO_(2) and MnOx—CeO_(2))are provided.The result of present study demonstrates the potential of spectrophotometry for quantitative discrimination of surface NOx species on CeO_(2) and other oxide-based materials,which is conducive to mechanism analysis of SCR reaction.

关键词： Quantitative evaluation Spectrophotometry analysis Nitrate species Nitrite species CeO_(2)catalyst NH_(3)-SCR

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

Promotion effect of bulk sulfates over CeO_(2)for selective catalytic reduction of NO by NH_(3)at high temperatures

引用

Chinese Chemical Letters 2023年第5期34卷 311-314页

作者： jiawei ji Li Han Wang Song jingfang Sun Weixin Zou Changjin Tang Lin Dong Laboratory of Mesoscopic Chemistry of MOE School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China School of the Environment Nanjing UniversityNanjing 210023China School of Environment Nanjing Normal UniversityNanjing 210023China jiangsu Key Laboratory of Vehicle Emission Control Center of Modern AnalysisNanjing UniversityNanjing 210023China

Understanding the influence of sulfates over catalysts for selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR)is crucial due to the universal presence of SO_(2)in exhaust gas.Depending on the degree of sulfation,there mainly exist surface and bulk sulfates and NH_(3)-SCR activity is generally considered to suffer more from bulk sulfates.Herein,the unique function of bulk sulfates over Ce O_(2)in promoting hightemperature SCR reaction is revealed.Notably,compared with CeO_(2)dominated with surface sulfates(S-CeO_(2)-4h)and commercial V_2O_5-WO_(3)/TiO_(2),CeO_(2)with bulk sulfates(S-Ce O_(2)-72h)exhibits admirable NO conversion at the temperature range of 400-550℃.Bulk sulfates provide more Br?nsted acid sites with stronger strength for NH_(3)adsorption.Moreover,the oxidation ability of Ce O_(2)is significantly inhibited due to electron-withdrawing effect from bulk sulfates,which alleviates NH_(3)oxidation at high temperatures.More NH_(3)adsorption with high stability and limited NH_(3)oxidation capacity ensure the excellent catalytic performance for S-CeO_(2)-72h in high-temperature denitration.This work provides new insight of bulk sulfates in promoting SCR activity and open a new avenue to design de NO_xcatalysts employed at high temperatures.

关键词： NH_(3)-SCR CeO_(2) Bulk sulfates High temperature denitration NH_(3)adsorption NH_(3)oxidation

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

Enhancing low-temperature NH_(3)-SCR performance of Fe-Mn/CeO_(2)catalyst by Al_(2)O_(3)modification

引用

Journal of Rare Earths 2022年第9期40卷 1454-1461,I0005页

作者： Lulu Li jiawei ji Wei Tan Wang Song Xin Wang Xiaoqian Wei Kai Guo Wanyu Zhang Changjin Tang Lin Dong School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China jiangsu Key Laboratory of Vehicle Emissions Control School of EnvironmentCenter of Modern AnalysisNanjing UniversityNanjing 210093China School of Environment Nanjing Normal UniversityNanjing 210093China

In the work,supported catalysts of FeO_(x) and MnO_(x) co-supported on aluminum-modified CeO_(2)was synthesized for low-temperature NH_(3)-selective catalytic reduction(NH_(3)-SCR)of NO.Impressively,the SCR activity of the obtained catalyst is markedly influenced by the adding amount of Al and the appropriate Ce/Al molar ratio is 1/2.The activity tests demonstrate that Fe-Mn/Ce1 Al2 catalyst shows over 90%NO conversion at 75-250℃and exhibits better SO_(2)resistance compared to Fe-Mn/CeO_(2).Fe-Mn/Ce1 Al2 shows the expected physicochemical characters of the ideal catalyst including the larger surface and increased active reaction active sites by controlling the amount of Al doping.Also,the better catalytic activity is well correlated with the present advantaged surface adsorption oxygen species,Mn^(4+)species,Ce^(3+)species and the enhanced reducibility of Fe-Mn/Ce1 Al2,which is superior to the Fe-Mn/CeO_(2)catalyst.More importantly,we further demonstrate that the amount and strength of surface acid sites are improved by Al-doping and more active intermediates(monodentate nitrate)is generated during NH_(3)-SCR reaction.This work provides certain insight into the rational creation of simple and practical denitration catalyst environmental purification.

关键词： Selectivity catalytic reduction NO removal Low-temperature activity Al doping Cerium dioxide Rare earths

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

Solid-phase impregnation promotes Ce doping in TiO_(2) for boosted denitration of CeO_(2)/TiO_(2) catalysts

引用

Chinese Chemical Letters 2022年第2期33卷 935-938页

作者： Wang Song jiawei ji Kai Guo Xin Wang Xiaoqian Wei Yandi Cai Wei Tan Lulu Li jingfang Sun Changjin Tang Lin Dong School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China Key Laboratory of Vehicles Emission Control of jiangsu Province Center of Modern AnalysisNanjing UniversityNanjing 210093China School of Environment Nanjing Normal UniversityNanjing 210023China School of the Environment Nanjing UniversityNanjing 210093China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

CeO_(2)/TiO_(2)(denoted as Ce Ti) catalysts obtained by solid-phase impregnation behaved better in lowtemperature selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR) than that by conventional wet impregnation.To explore the main factors for activity distinction,the texture property,CeO_(2)dispersion and structure changes of TiO_(2)were comprehensively analyzed.It was found that surface changes of TiO_(2)had a significant impact on the improved activity.From results of inductively coupled plasma atomic emission spectrometer (ICP-AES),diffuse reflectance UV-vis spectroscopy (UV-vis-DRS) and Raman,it was inferred that Ce ions were partially incorporated into TiO_(2)lattice,accompanied with the formation of defects and vacancies during solid-phase impregnation.Accordingly,Ce Ti catalysts from solid-phase impregnation exhibited superiority in adsorption and activation of reactants.Further result from monitoring the preparation process indicated that the evolved NO played an important role in promoting Ce doping through depriving oxygen atoms on TiO_(2)surface.The interaction between Ce and Ti was enhanced.The catalyst performed better in NH_(3)-SCR,especially at low temperature,which testified the solid-phase impregnation could be an effective method to modulate interface structure for designing efficient catalyst.

关键词： CeO_(2)/TiO_(2) NH_(3)-SCR Solid-phase impregnation Interfacial interaction NO induced incorporation

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

A 3-Node Co-Rotational Triangular Finite Element for Non-Smooth,Folded and Multi-Shell Laminated Composite Structures

引用

Computer Modeling in Engineering & Sciences 2021年第11期129卷 485-518页

作者： Zhongxue Li jiawei ji Loc Vu-Quoc Bassam A.Izzuddin Xin Zhuo Department of Civil Engineering Zhejiang UniversityHangzhou310058China Aerospace Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA Department of Civil and Environmental Engineering Imperial College LondonLondonSW72BUUK

Based on the first-order shear deformation theory,a 3-node co-rotational triangular finite element formulation is developed for large deformation modeling of non-smooth,folded and multi-shell laminated composite structures.The two smaller components of the mid-surface normal vector of shell at a node are defined as nodal rotational variables in the co-rotational local coordinate system.In the global coordinate system,two smaller components of one vector,together with the smallest or second smallest component of another vector,of an orthogonal triad at a node on a non-smooth intersection of plates and/or shells are defined as rotational variables,whereas the two smaller components of the mid-surface normal vector at a node on the smooth part of the plate or shell(away from non-smooth intersections)are defined as rotational variables.All these vectorial rotational variables can be updated in an additive manner during an incremental solution procedure,and thus improve the computational efficiency in the nonlinear solution of these composite shell structures.Due to the commutativity of all nodal variables in calculating of the second derivatives of the local nodal variables with respect to global nodal variables,and the second derivatives of the strain energy functional with respect to local nodal variables,symmetric tangent stiffness matrices in local and global coordinate systems are obtained.To overcome shear locking,the assumed transverse shear strains obtained from the line-integration approach are employed.The reliability and computational accuracy of the present 3-node triangular shell finite element are verified through modeling two patch tests,several smooth and non-smooth laminated composite shells undergoing large displacements and large rotations.

关键词： Co-rotational approach 3-node triangular finite element laminated composite shells folded and multi-shell structures vectorial rotational variable line integration approach large deformation analysis

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

Influence of CeO2 loading on structure and catalytic activity for NH3-SCR over TiO2-supported CeO2

引用

Journal of Rare Earths 2020年第8期38卷 883-890,I0002页

作者： Hongliang Zhang Long Ding Hongming Long jiaxin Li Wei Tan jiawei ji jingfang Sun Changjin Tang Lin Dong School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243032China Key Laboratory of Metallurgical Emission Reduction&Resources Recycling(Anhui University of Technology) Ministry of EducationMa'anshan 243002China Analysis and Testing Central Facility Anhui University of TechnologyMa'anshan 243002China jiangsu Key Laboratory of Vehicle Emissions Control School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China

A series of supported CeO2/TiO2 catalysts were prepared to explore the influence of CeO2 loading on these catalysts for the selective catalytic reduction of NO3 by NH3(NH3-SCR).The catalysts were investigated in detail by means of XRD,Raman,H2-TPR,NH3-TPD,XPS,in situ DRIFTS,and NH3-SCR reaction.The activity of the catalyst is closely related to the content of CeO2.When the loading of CeO2 is near the dispersion capacity(1.16 mmol Ce4+/100 m^2 TiO2),the catalytic activity is better.This may be because that the dispersed CeO2 is the active species and the catalyst has appropriate redox property,along with the larger amounts of surface Ce content and surface adsorbed oxygen species.Finally,a possible reaction mechanism via the Langmuir-Hinshelwood(L-H)mechanism is tentatively proposed to further understand the NH3-SCR reaction.

关键词： CeO2 Selective catalytic reduction Redox property Dispersion capacity Structure-activity relationship Rare earths

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

超声引导下腹股沟上髂筋膜阻滞对游离股前外侧皮瓣修复术后早期恢复质量的影响

引用

临床麻醉学杂志 2024年第3期40卷 272-276页

作者：刘艳季加伟王晔刘坤焦宇倩江南大学附属医院麻醉科无锡市214000 无锡市第九人民医院麻醉科

目的探讨术前超声引导下腹股沟上髂筋膜阻滞对四肢毁损伤患者游离股前外侧皮瓣修复术后早期疼痛及恢复质量的影响。方法选择因四肢毁损伤择期行游离股前外侧皮瓣修复术的患者79例,男47例,女32例,年龄18~60岁,BMI 16~28 kg/m^(2),ASAⅠ... 详细信息

目的探讨术前超声引导下腹股沟上髂筋膜阻滞对四肢毁损伤患者游离股前外侧皮瓣修复术后早期疼痛及恢复质量的影响。方法选择因四肢毁损伤择期行游离股前外侧皮瓣修复术的患者79例,男47例,女32例,年龄18~60岁,BMI 16~28 kg/m^(2),ASAⅠ—Ⅲ级。采用随机数字表法将患者分为两组:超声引导下腹股沟上髂筋膜阻滞组(F组,n=39)和对照组(C组,n=40)。F组在麻醉诱导前行超声引导下腹股沟上髂筋膜阻滞,注射0.375%罗哌卡因和地塞米松5 mg混合液共30 ml;C组不行神经阻滞,所有患者全麻用药方案相同。记录术中丙泊酚、瑞芬太尼、舒芬太尼、血管活性药物用量、拔管时间、PACU停留时间;出PACU时、术后2、6、12、24、48 h静息时NRS疼痛评分;术后第1、2天镇痛泵有效按压次数及补救镇痛情况;术前、术后第1、2天15项恢复质量量表(QoR-15)评分;术后48 h内不良反应(头晕、恶心呕吐、皮肤瘙痒、呼吸抑制、低氧血症等)发生情况;出院时皮瓣供区伤口愈合、受区存活情况及住院时间。结果与C组比较,F组术中瑞芬太尼、舒芬太尼用量及使用血管活性药的例数明显降低,拔管时间、PACU停留时间明显缩短(P<0.05);术后2、6 h静息时NRS疼痛评分和术后第1天镇痛泵有效按压次数、补救镇痛率均明显降低(P<0.05);术后第1、2天的QoR-15评分均明显提高(P<0.05);术后48 h内头晕、恶心呕吐的发生率明显降低(P<0.05)。两组术中丙泊酚用量,出PACU时、术后12、24、48 h静息时NRS疼痛评分,术后第2天镇痛泵有效按压次数及补救镇痛率,术后皮肤瘙痒、呼吸抑制、低氧血症发生率,皮瓣供区愈合率、受区存活率及住院时间差异均无统计学意义。结论超声引导腹股沟上髂筋膜阻滞应用于游离股前外侧皮瓣修复四肢毁损伤可减少围术期镇痛药用量,缩短麻醉复苏时间,缓解术后早期疼痛,减少术后不良反应发生,提高术后早期恢复质量。

关键词：髂筋膜阻滞超声引导全身麻醉股前外侧皮瓣

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

个性化护理干预在儿童功能性腹痛护理中的应用效果分析

引用

中国社区医师 2024年第13期40卷 123-125页

作者：张惠青高俊芳姬嘉玮滨州医学院附属医院儿童消化与肾病科山东滨州256600

目的:探讨个性化护理干预在儿童功能性腹痛护理中的应用效果。方法:选取2022年4-10月滨州医学院附属医院收治的80例功能性腹痛患儿作为研究对象,使用随机数字表法分为观察组、对照组,各40例。对照组进行常规护理,观察组进行个性化护理... 详细信息

目的:探讨个性化护理干预在儿童功能性腹痛护理中的应用效果。方法:选取2022年4-10月滨州医学院附属医院收治的80例功能性腹痛患儿作为研究对象,使用随机数字表法分为观察组、对照组,各40例。对照组进行常规护理,观察组进行个性化护理干预。比较两组护理效果。结果:观察组护理总有效率高于对照组,差异有统计学意义(P=0.048)。护理前,两组腹痛频率、腹痛程度评分比较,差异无统计学意义(P>0.05);护理后,两组腹痛频率、腹痛程度评分低于护理前,且观察组低于对照组,差异有统计学意义(P<0.05)。观察组患儿家属护理总满意度高于对照组,差异有统计学意义(P=0.040)。结论:个性化护理干预在儿童功能性腹痛护理中的应用效果显著,能够减少患儿腹痛发作次数,减轻腹痛程度,提高患儿家属护理满意度,值得临床应用。

关键词：功能性腹痛儿童个性化护理干预

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

公文中介词“在”字句的语用探究

引用

秘书 2022年第2期 70-81页

作者：籍佳伟首都师范大学文学院

公文语言注重规范性、实效性和准确性。从语用角度对公文中的介词“在”字句进行研究,有助于公文发文者精准表意,收文者准确理解,但目前对此问题尚缺乏关注。立足于公文文本特点,以比较研究法和跨学科研究法,对公文中的介词“在”字句... 详细信息

公文语言注重规范性、实效性和准确性。从语用角度对公文中的介词“在”字句进行研究,有助于公文发文者精准表意,收文者准确理解,但目前对此问题尚缺乏关注。立足于公文文本特点,以比较研究法和跨学科研究法,对公文中的介词“在”字句进行筛选和统计分析,研究发现,公文中存在“PP+VP”和“VP+PP”两种基本句式。从公文语境以及公文中介词“在”的引介对象来看,公文中上述两种基本句式的语用意义存在特殊之处。从语用功能来看,公文中的介词“在”字句与其他文本相比,在篇章衔接等方面无显著差异,但是在公文内部,上述两种基本句式的辖域和强调重点等却有所不同;而受到语用因素不同程度的影响,居于句首和句中的介词“在”的隐现也有着不同表现。

关键词： “在”字句公文语用介词存现句

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

微观凸织构及润湿性对橡胶滑动接触界面摩擦特性的影响

引用

中国表面工程 2022年第1期35卷 162-172页

作者：裴宁刘小君季佳伟张涛王兆长焦云龙刘焜合肥工业大学摩擦学研究所合肥230026

橡胶材料在日常生活和工业发展中有着广泛的应用,现有研究主要针对橡胶材料的黏弹特性、表面改性等方面展开,而固体表面微观织构对橡胶滑动接触界面摩擦特性的影响研究较少。针对橡胶滑动接触界面,在往复式摩擦试验机上以钢球和PDMS橡... 详细信息

橡胶材料在日常生活和工业发展中有着广泛的应用,现有研究主要针对橡胶材料的黏弹特性、表面改性等方面展开,而固体表面微观织构对橡胶滑动接触界面摩擦特性的影响研究较少。针对橡胶滑动接触界面,在往复式摩擦试验机上以钢球和PDMS橡胶块组成摩擦副进行往复摩擦试验,通过改变织构类型和形貌参数来对不同表面形貌下的橡胶滑动摩擦特性进行相关探究,同时还考虑表面润湿性对界面摩擦因数的影响。试验研究表明:润滑状态下橡胶表面添加适当凸织构会降低滑动摩擦因数,微织构形状、面积占有率、高度和直径对橡胶表面滑动摩擦因数和接触角大小都有影响,尤其对于长槽织构,其摩擦因数和接触角大小呈现出方向性。结合摩擦因数和润湿性规律发现,一定范围内增大凸织构直径,橡胶表面润湿性变好,摩擦因数减小;增大凸织构面积占有率、高度时橡胶表面润湿性变差,摩擦因数反而减小。研究橡胶表面微观凸织构及其诱发的润湿性变化对橡胶滑动接触界面摩擦特性的影响,可为橡胶材料表面的摩擦学设计提供理论基础。

关键词：微观凸织构润湿性橡胶滑动接触界面摩擦特性

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：