检索结果-南通市图书馆

Extraordinary synergy on 3D hierarchical porous Co-Cu nanocomposite for catalytic elimination of VOCs at low temperature and high space velocity

引用

Journal of Environmental Sciences 2025年第5期151卷 714-732页

作者： Jinyan Xiao chi Zhang Lei Yang Shengwei tang Wenxiang tang School of Chemical Engineering Sichuan UniversityChengdu 610065China

It is still a challenge to develop hierarchically nanostructured catalysts with simple approaches to enhance the low-temperature catalytic ***,a set of mesoporous Co-Cu binary metal oxides with different morphologies were successfully prepared via a facile ammonium bicarbonate precipitation method without.any templates or surfactants,which were further applied for catalytic removal of carcinogenic *** the catalysts with different ratios,the CoCu_(0.2)composite oxide presented the best performance,where the temperature required for 90%conversion of toluene was only 237°C at the high weight hour space velocity(WHSV)of 240,000 mL/(gcat·hr).Meanwhile,compared to the related Co-Cu composite oxides prepared by using different precipitants(NaOH and H_(2)C_(2)O_(4)),the NH_(4)HCO_(3)-derived CoCu_(0.2)sample exhibited better catalytic efficiency in toluene oxidation,while the t90 were 22 and 28°C lower t.an those samples prepared by NaOH andH_(2)C_(2)O_(4)routes,*** on various characterizations,it could be deduced that the excellent performance was related to the small crystal size(6.7 nm),large specific surface area(77.0 m2/g),hollow hierarchical nanostructure with abundant high valence Co ions and adsorbed oxygen *** situ DRIFtS further revealed that the possible reaction pathway for the toluene oxidation over CoCu_(0.2)catalyst followed the route of absorbed toluene→benzyl alcohol→benzaldehyde→benzoic acid→carbonate→CO_(2)and H_(2)*** addition,CoCu_(0.2)sample could keep stable with long-time operation and occur little inactivation under humid condition(5 vol.%water),which revealed that the NH_(4)HCO_(3)-derived CoCu_(0.2)nanocatalyst possessed great potential in industrial applications for VOCs abatement.

关键词： toluene oxidation Co-Cu composite Synergistic effect Hollow hierarchical nanostructure Precipitation method

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

the formation, development.and classification of rail corrugation: a survey on chinese metro

引用

RAILWAY ENGINEERING SCIENCE 2025年第1期33卷 43-61页

作者： Wang, Yang Xiao, Hong Zhang, Zhihai Cui, Xuhao chi, Yihao Nadakatti, Mahantesh M. Beijing Jiaotong Univ Sch Civil Engn Beijing 100044 Peoples R China Beijing Jiaotong Univ Beijing Key Lab Track Engn Beijing 100044 Peoples R China Beijing Univ technol Fac Architecture Civil & Transportat Engn Beijing 100124 Peoples R China KLS Gogte Inst technol Dept Mech Engn Belagavi 590008 India

Investigations into rail corrugation within metro systems have traditionally focused on specific mechanisms, thereby limiting the generalizability of proposed theories. Understanding the commonalities in rail corrugation across diverse metro lines remains pivotal for elucidating its underlying mechanisms. the present study conducted extensive field surveys and tracking tests across 14 chinese metro lines. By employing t-distributed stochastic neighbor embedding (t-SNE) for dimensional reduction and employing the unsupervised clustering algorithm DBSCAN, the research redefines the classification of metro rail corrugation based on characteristic information. the analysis encompassed spatial distribution and temporal evolution of this phenomenon. Findings revealed that floating slab tracks exhibited the highest proportion of rail corrugation at 47%. Notably, ordinary monolithic bed tracks employing damping fasteners were more prone to inducing rail corrugation. Corrugation primarily manifested in curve sections with radii between 300 and 500 m, featuring ordinary monolithic bed track and steel-spring floating slab track structures, with wavelengths typically between 30 and 120 mm. Stick-slip vibrations of the wheel-rail system maybe led to short-wavelength corrugations (40-60 mm), while longer wavelengths (200-300 mm) exhibited distinct fatigue damage characteristics, mainly observed in steel-spring floating slab tracks and small-radius curve sections of ordinary monolithic bed tracks and ladder sleeper tracks. A classification system comprising 57 correlated features categorized metro rail corrugation into four distinct types. these research outcomes serve as critical benchmarks for validating various theories pertaining to rail corrugation formation.

关键词： Metro Rail corrugation Formation mechanism Development law Field test

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

Prompt fission neutron uranium logging(Ⅱ):dead-time effect of the neutron time spectrum

引用

Nuclear Science and techniques 2025年第2期36卷 82-94页

作者： Yan Zhang chi Liu Shi-Liang Liu Hao-Ran Zhang Hai-tao Wang Jin-Hui Qu Wen-Xing Hu Ren-Bo Wang Bin tang National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing East China University of TechnologyNanchang 330013China Fundamental Science on Radioactive Geology and Exploration technology Laboratory East China University of TechnologyNanchang 330013China

the acquisition of neutron time spectrum data plays a pivotal role in the precise quantification of uranium via prompt fission neutron uranium logging(PFNUL).However,the impact of the detector dead-time effect remains paramount in the accurate acquisition of the neutron time ***,it is imperative for neutron logging instruments to establish a dead-time correction method that is not only uncomplicated but also practical and caters to various logging *** study has formulated an innovative equation for determining dead time and introduced a dead-time correction method for the neutron time spectrum,called the“dual flux method.”Using this approach,a logging instrument captures two neutron time spectra under disparate neutron *** carefully selecting specific“windows”on the neutron time spectrum,the dead time can be accurately *** substantiate its efficacy and discern the influencing factors,experiments were conducted utilizing a deuterium-tritium(D-t)neutron source,a Helium-3(3He)detector,and polyethylene shielding to collate and analyze the neutron time spectrum under varying neutron fluxes(at high voltages).the findings underscore that the“height.and“spacing”of the two windows are the most pivotal influencing ***,the“height”(fd)should surpass 2,and the“spacing”twd should exceed 200μ*** dead time of the 3 He detector determined in the experiment was 7.35μ*** the dead-time correction,the deviation of the decay coefficients from the theoretical values for the neutron time spectrum under varying neutron fluxes decreased from 12.4%to within 5%.Similarly,for the PFNUL instrument,the deviation in the decay coefficients decreased from 22.94 to 0.49%after correcting for the dead-time *** results demonstrate the exceptional efficacy of the proposed method in ensuring precise uranium *** dual flux method was experimentally validated as a universal approach applicable to pulsed neutron logging instrumen

关键词： PFNUL Neutron time spectrum Dead time Pulsed source Correction method

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

the formation, development.and classification of rail corrugation:a survey on chinese metro

引用

Railway Engineering Science 2025年第01期 43-61页

作者： Yang Wang Hong Xiao Zhihai Zhang Xuhao Cui Yihao chi Mahantesh M.Nadakatti School of Civil Engineering Beijing Jiaotong University Beijing Key Laboratory of track Engineering Beijing Jiaotong University Faculty of Architecture Civil and Transportation Engineering Beijing University of Technology Department of Mechanical Engineering KLS Gogte Institute of Technology

Investigations into rail corrugation within metro systems have traditionally focused on specific mechanisms, thereby limiting the generalizability of proposed theories. Understanding the commonalities in rail corrugation across diverse metro lines remains pivotal for elucidating its underlying mechanisms. the present study conducted extensive field surveys and tracking tests across 14 chinese metro lines. By employing t-distributed stochastic neighbor embedding(t-SNE) for dimensional reduction and employing the unsupervised clustering algorithm DBSCAN, the research redefines the classification of metro rail corrugation based on characteristic information. the analysis encompassed spatial distribution and temporal evolution of this phenomenon. Findings revealed that floating slab tracks exhibited the highest proportion of rail corrugation at 47%.Notably, ordinary monolithic bed tracks employing damping fasteners were more prone to inducing rail corrugation. Corrugation primarily manifested in curve sections with radii between 300 and 500 m, featuring ordinary monolithic bed track and steel-spring floating slab track structures, with wavelengths typically between 30 and 120 mm. Stick–slip vibrations of the wheel–rail system maybe led to short-wavelength corrugations(40–60 mm), while longer wavelengths(200–300 mm)exhibited distinct fatigue damage characteristics, mainly observed in steel-spring floating slab tracks and small-radius curve sections of ordinary monolithic bed tracks and ladder sleeper tracks. A classification system comprising 57 correlated features categorized metro rail corrugation into four distinct types. these research outcomes serve as critical benchmarks for validating various theories pertaining to rail corrugation formation.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

综合scRNA-Seq和Bulk RNA-Seq技术建立与肝癌CD8^(+)t细胞相关的预后模型

引用

西安交通大学学报(医学版) 2025年第1期46卷 169-177页

作者：刘洋池晴佳田菲菲西南交通大学生命科学与工程学院四川成都610031 武汉理工大学物理与力学学院湖北武汉430070

目的通过单细胞测序(scRNA-Seq)和Bulk转录组测序(Bulk RNA-Seq)技术鉴定出与肝癌CD8^(+)t细胞相关的生物标志物并建立预后模型。方法从GEO数据库中下载肝癌的单细胞数据集,通过scRNA-Seq技术提取患者与对照组间CD8^(+)t细胞的差异表... 详细信息

目的通过单细胞测序(scRNA-Seq)和Bulk转录组测序(Bulk RNA-Seq)技术鉴定出与肝癌CD8^(+)t细胞相关的生物标志物并建立预后模型。方法从GEO数据库中下载肝癌的单细胞数据集,通过scRNA-Seq技术提取患者与对照组间CD8^(+)t细胞的差异表达基因。从tCGA数据库中下载肝癌的基因表达谱数据及临床数据,使用CIBERSORt算法、WGCNA技术筛选出与CD8^(+)t细胞具有相关性的模块基因。将差异基因与模块基因取交集基因并进行GO、KEGG分析,应用单因素COX回归分析和LASSO算法建立预后模型。通过K-M曲线和ROC曲线对模型在内、外部数据集中的预测效果进行验证。根据风险评分的中位值划分高低风险组,对高低风险组间的浸润性免疫细胞分布情况和肿瘤突变情况进行分析。结果构建出具有9个基因的预后模型,K-M曲线及ROC曲线表明模型在内、外部数据集中均具有良好的预测能力,在高低风险组中,浸润性免疫细胞的分布情况和基因突变情况均存在显著差异。结论本研究结合scRNA-Seq和Bulk RNA-Seq技术利用生物信息学方法开发出了一种基于CD8^(+)t细胞的新型预后模型,为肝癌患者的预后改善和生存预测提供了可靠的理论依据。

关键词：肝癌单细胞测序(scRNA-Seq) Bulk转录组测序(Bulk RNA-Seq) CD8^(+)t细胞预后模型

来源：

维普期刊数据库

同方期刊数据库

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

Free vibration and t.ansient response of double curved beams connected by intermediate straight beams

引用

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHAtIR t.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and t.ansient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. the strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. the curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and t.ansient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and t.ansient response of the considered structure.

关键词： double curved beam finite element method functionally graded porous (FGP) material intermediate straight beam O313 vibration analysis

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

NHC-mediated photocatalytic para-selective C–H acylation of aryl alcohols: regioselectivity control via remote radical spiro cyclization

引用

Science china Chemistry 2025年

作者： tinglei Zhang Lala Wang Xiaolin Peng t.anhui Liao Dongmei Chen ting tu Donghan Liu Ziye Cheng Shiqing Huang Shi-Chao Ren Xinglong Zhang Yonggui Robin chi State Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Qiannan Medical College for Nationalities School of Chemistry Chemical Engineering and Biotechnology Nanyang Technological University Department of Chemistry The Chinese University of Hong Kong Institute of High Performance Computing Agency for Science Technology and Research

Friedel-Crafts reaction and t.ansition-metal catalysis represent primary methodologies for arene acylation; however, suffer from certain limitations, such as electronic effect-dependent reactivity, regioselectivity issues, the necessity of directing group, and relatively exceptionally limited exploration in meta-and para-acylations. N-heterocyclic carbene(NHC) catalysis has recently emerged as a promising alternative strategy for arene acylation, offering distinct regioselectivity profiles that are challenging to achieve through known methods. Herein, an NHC-mediated photo-catalytic para-selective C–H acylation of aryl alcohols is disclosed. the reaction employs a remote radical-induced temporary spiro cyclization strategy, proceeding via tandem radical dearomatization, radical acylation, rearomatization processes. Combined experimental and computational mechanistic studies support the proposed reaction pathway and observe an exclusive para-selectivity regardless of the nature of the substituents on the substrates. Despite the less satisfactory yields, the current method exhibits non-electronic nature-based reactivity and regioselectivity, enabling quick access to acylated arenes that are difficult or impossible for reported methods.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Determination of fuel burnup distribution of a research reactor based on measurements at subcritical conditions

引用

Nuclear Science and techniques 2018年第12期29卷 30-38页

作者： Quang Binh Do Hoai-Nam t.an Quang Huy ngo Giang t. t. Phan Ho chi Minh City University of technology and Education 1 Vo Van Ngan Thu Duc HCMC Vietnam Institute of Fundamental and Applied Sciences Duy Tan University Ho Chi Minh city Vietnam

this paper presents the determination of the fuel burnup distribution of the Dalat nuclear research reactor(DNRR) using a method of measurements at subcritical conditions. the method is based on the assumption of linear dependence of the reactivity on the burnup of fuel bundles and the measurements at subcritical *** measurements were taken for seven selected fuel bundles in two different measuring sequences. the measured burnup values have also been compared with the calculations for verifying the method and the measurement procedure. the results obtained with the three detectors have a good agreement with each other with a discrepancy less t.an 1.0%. the errors of the measured burnup values are within 6%. Comparison between the calculated and measured burnup values shows that the discrepancy of the C/E ratio is within 9% compared to unity. the results indicate that the method of measurements at subcritical conditions could be well applied to determine the relative burnup distribution of the DNRR.

关键词：研究反应堆燃料分发测量过程验证方法方法论价值计算

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

Epithelioid angiosarcoma of the cervical spine:A case report

引用

World Journal of Clinical Cases 2025年第17期13卷 43-50页

作者： Yu-Han Nan Cheng-Di chiu Wei-Liang Chen Liang-chi Chen Chun-Chung Chen Der-Yang Cho Jeng-Hung Guo Department of Neurosurgery China Medical University HospitalTaichung 404327Taiwan Graduate Institute of Biomedical Science China Medical UniversityTaichung 404328Taiwan Spine Center China Medical University HospitalTaichung 404327Taiwan Department of Interventional and Diagnostic Neuroradiology China Medical University HospitalTaichung 404327Taiwan Department of Pathology China Medical University HospitalTaichung 404327Taiwan Graduate Institute of Integrated Medicine China Medical UniversityTaichung 404328Taiwan

BACKGROUND Epithelioid angiosarcoma(EA)is an aggressive,malignant endothelial-cell tumor of vascular or lymphatic *** often arises from deep soft tissues such as pleura,breast,bone and gastrointestinal *** usually affects patients aged 60-70 years and is associated with high recurrence and metastasis rates with surgical resection as the primary treatment of *** survivals are generally poor,ranging from 6 to 16 *** t.an 50%of patients died of disease within 2 to 3 years of *** SUMMARY We present a rare case of EA of the cervical spine causing a C6 pathological fracture complicated by severe *** patient received C4-7 posterior laminectomy and C2/3/4/7/t1 t.anspedicular screw fixation,followed by anterior C5-6 corpectomy with allograft bone fusion and cervical plate *** radiotherapy was administered without ***,the patient died of rapidly progressive acute respiratory distress syndrome 3 weeks after the second *** EA with spinal involvement is extremely *** detection and cord decompression may prevent neurological deterioration and preserve better quality of life.

关键词： Cervical spine Epithelioid angiosarcoma Pathologic fracture Vertebral body Spinal cord compression Case report

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

A Correlation Coefficient Approach for Evaluation of Stiffness Degradation of Beams Under Moving Load

引用

Computers, Materials & Continua 2019年第7期61卷 27-53页

作者： t.anh Q.Nguyen thao t.D.Nguyen H.Nguyen-Xuan Nhi K.ngo Laboratory of Applied Mechanics(LAM) Ho Chi Minh City University of TechnologyHo Chi Minh City740030Vietnam Saigon Hi-tech Park training Center Ho Chi Minh City715650Vietnam Ho chi Minh City Department of t.ansportation and Communication Ho Chi Minh City710100Vietnam CIRtECH Institute Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh City717349Vietnam Department of Physical therapy Graduate Institute of Rehabilitation ScienceChina Medical UniversityTaichung40402Taiwan

this paper presents a new approach using correlation and cross-correlation coefficients to evaluate the stiffness degradation of beams under moving *** theoretical study of identifying defects by vibration methods showed that the traditional methods derived from the vibration measurement data have not met the needs of the actual *** show that the correlation coefficients allow us to evaluate the degree and the effectiveness of the defects on *** the same time,the cross-correlation model is the basis for determining the relative position of *** results of this study are experimentally conducted to confirm the relationship between the correlation coefficients and the existence of the *** particular,the manuscript shows that the sensitivity of the correlation coefficients and cross-correlation is much higher t.an the parameters such as changes in stiffness(EJ)and natural frequency values(Δf).this study suggests using the above parameters to evaluate the stiffness degradation of beams by vibration measurement data in practice.

关键词： Correlation coefficient cross-correlation vibration signal vibration amplitude frequency

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

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：