检索结果-南通市图书馆

Synthesizing active and durable cubic ceria catalysts(<6 nm)for fast dehydrogenation of bio-polyols to carboxylic acids coproducing green H_(2)

引用

Green Energy & Environment 2024年第3期9卷 529-543页

作者： Mengyuan Liu Puhua sun guangyu Zhang Xin Jin Chaohe Yang Honghong Shan State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of PetroleumNo.66 Changjiang West RoadQingdaoShandong266580China SINOPEC Research Institute of Safety Engineering Co. Ltd.No.339 Songling RoadQingdaoShandong266000China

Dehydrogenation is considered as one of the most important industrial applications for renewable *** ceria-based catalysts are known to display promising dehydrogenation performances in this *** particle size(>20 nm)and less surface defects,however,hinder further application of ceria ***,an alternative strategy involving lactic acid(LA)assisted hydrothermal method was developed to synthesize active,selective and durable cubic ceria of<6 nm for dehydrogenation *** studies of growth mechanism revealed that,the carboxyl and hydroxyl groups in LA molecule synergistically manipulate the morphological evolution of ceria *** groups determine the cubic shape and particle size,while hydroxyl groups promote compositional transformation of ceria precursors into CeO_(2) ***,enhanced oxygen vacancies(Vo)on the surface of CeO_(2) were obtained owing to continuous removal of O species under reductive *** CeO_(2) catalysts synthesized by the LA-assisted method,immobilized with bimetallic PtCo clusters,exhibit a record high activity(TOF:29,241 h^(-1))and Vo-dependent synergism for dehydrogenation of bio-derived polyols at 200℃.We also found that quenching Vo defects at air atmosphere causes activity loss of PtCo/CeO_(2) *** regenerate Vo defects,a simple strategy was developed by irradiating deactivated catalysts using hernia *** outcome of this work will provide new insights into manufacturing durable catalyst materials for aqueous phase dehydrogenation applications.

关键词： Cubic ceria Oxygen vacancy Dehydrogenation C-H bond activation

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

Effect of coir geotextile and geocell on ephemeral gully erosion in the Mollisol region of Northeast China

引用

Journal of Arid Land 2024年第4期16卷 518-530页

作者： QIN Xijin sun Yiqiu ZHANG Yan GUAN Yinghui WU Hailong WANG Xinyu WANG guangyu School of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China Tianjin Eco-Environmental Protection Design&Research Institute Tianjin 300042China College of Environmental Science and Safety Engineering Tianjin University of TechnologyTianjin 300384China Faculty of Forestry University of British Columbia2424 Main MallVancouver BC V6T 1Z4Canada

The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion and damage during the growth stage,which brings serious problems to the restoration of grass in the early ***,effects of coir geotextile and geocell on EG erosion under four confluence intensities were researched in this *** of the simulated water discharge erosion test showed that when the confluence strength was less than 30 L/min,geocell and coir geotextile had a good effect on controlling EG erosion,and sediment yield of geocell and coir geotextile was reduced by 25.95%–37.82%and 73.73%–88.96%,***,when confluence intensity increased to 40 L/min,protective effect of coir geotextile decreased,and sediment yield rate increased sharply by 189.03%.When confluence intensity increased to 50 L/min,the protective effect of coir geotextile was *** the other hand,geocell showed that the greater the flow rate,the better the protective *** addition,with the increase in confluence intensity,erosion pattern of coir geotextile developed from sheet erosion to intermittent fall and then to completion of main rill,and the protective effect was gradually *** contrast,the protective effect of EG under geocell was gradually enhanced from the continuous rill to the intermittent rill and finally to the intermittent *** study shows that coir geotextile and geocell can prevent EG erosion,and the effect of geocell is better than that of coir geotextile on the surface of EG.

关键词： geocell coir geotextile ephemeral gully confluence intensity erosion control

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

Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

引用

International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao Liang Dong Wang Guanghe Li guangyu sun Mingyu Yu Dong Xia Chunjian Ding College of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua Coal Industry Co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy Co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability ***,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical ***,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope *** the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding *** integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is ***,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is *** analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear *** spatial form equation of the sliding mass comprises an ellipsoid and weak plane *** analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite ***,the3D stability coefficient of the composite slope exhibits an exponential co

关键词： Composite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability Coordinated development distance

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 general synthetic strategy for N, P co-doped graphene supported metal-rich noble metal phosphides for hydrogen generation

引用

Green Energy & Environment 2024年第1期9卷 152-162页

作者： Jingwen Ma Xiang Li guangyu Lei Jun Wang Juan Wang Jian Liu Ming Ke Yang Li Chunwen sun School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing100083China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Lab of Advanced Nano-structures&Transfer Processes Department of Chemical EngineeringTianjin UniversityTianjin300354China PetroChina Planning and Engineering Institute Beijing100083China

The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a *** have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction ***,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked *** obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/*** addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,*** superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the ***,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for *** work provides an effective strategy for designing NMP-based electrocatalysts.

关键词： Noble metal phosphides Electrocatalyst Deoxyribonucleic acid Hydrogen evolution pH universal

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

Reconstitution of double-negative T cells after cord blood transplantation and its predictive value for acute graft-versus-host disease

引用

Chinese Medical Journal 2024年第10期137卷 1207-1217页

作者： Tianzhong Pan Peng Ding Aijie Huang Baolin Tang Kaidi Song guangyu sun Yue Wu Shiying Yang Xingchi Chen Dongyao Wang Xiaoyu Zhu Department of Hematology The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui 230001China Anhui Provincial Key Laboratory of Blood Research and Applications HefeiAnhui230001China Blood and Cell Therapy Institute Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui 230001China Division of Life Sciences and Medicine University of Science and Technology of ChinaHefeiAnhui 230001China The First Affiliated Hospital of USTC Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui 230001China

Background:With an increasing number of patients with hematological malignancies being treated with umbilical cord blood transplantation(UCBT),the correlation between immune reconstitution(IR)after UCBT and graft-versus-host disease(GVHD)has been reported successively,but reports on double-negative T(DNT)cell reconstitution and its association with acute GVHD(aGVHD)after UCBT are ***:A population-based observational study was conducted among 131 patients with hematological malignancies who underwent single-unit UCBT as their first transplant at the Department of Hematology,the First Affiliated Hospital of USTC,between August 2018 and June *** differences were compared between the patients with and without ***:The absolute number of DNT cells in the healthy Chinese population was 109(70-157)/μL,accounting for 5.82(3.98-8.19)%of *** cells showed delayed recovery and could not reach their normal levels even one year after ***,the absolute number and percentage of DNT cells were significantly higher in UCBT patients without aGVHD than in those with aGVHD within one year(F=4.684,P=0.039 and F=5.583,P=0.026,respectively).In addition,the number of DNT cells in the first month after transplantation decreased significantly with the degree of aGVHD increased,and faster DNT cell reconstitution in the first month after UCBT was an independent protective factor for aGVHD(HR=0.46,95%confidence interval[CI]:0.23-0.93;P=0.031).Conclusions:Compared to the number of DNT cells in Chinese healthy people,the reconstitution of DNT cells in adults with hematological malignancies after UCBT was *** addition,the faster reconstitution of DNT cells in the early stage after transplantation was associated with a lower incidence of aGVHD.

关键词： Umbilical cord blood transplantation Graft-versus-host disease Immune reconstitution Double negative T Hematological Malignancies Treg cell Breg cell

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

How Sense of Ritual in Tourism Impacts Tourists’Co-Creation of Tourism Experience Values:A Study Based on the Theory of Value Co-Creation

引用

Contemporary Social Sciences 2024年第2期9卷 67-84页

作者： Yi Min Zhang guangyu sun Genjin Southwest Minzu University ChengduSichuan610041China Sichuan Agricultural University

Establishing a sense of ritual within tourism consumption scenarios offers tourists the opportunity for interactive *** upon the value co-creation theory,this study constructed an influence mechanism model to examine tourists'active engagement in the process of co-creating tourism experience *** employed Partial Least Squares Structural Equation Modeling(PLS-SEM)to empirically test the proposed *** findings demonstrate that the model constructed in the present study exhibits robust reliability,validity,and explanatory *** perception of the sense of ritual in tourism exerts a significant positive influence on tourists’co-creation of tourism experience values,thereby significantly enhancing both the communitas and flow experienced by tourists during their ***,such communitas and flow can mediate the influence of the sense of ritual in tourism on tourists’co-creation of tourism experience *** study contributes to advancing the current research on tourists’co-creation of tourism experience values and the sense of ritual in tourism,thereby providing theoretical foundations for cultivating a sense of ritual within tourism consumption scenarios.

关键词： sense of ritual in tourism tourists’co-creation of tourism experience values theory of value co-creation theory of Interaction Ritual Chains

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

宏观经济环境对企业融资决策的动态影响研究

引用

工业技术经济 2024年第2期43卷 29-38页

作者：孙光宇中国光大集团博士后科研工作站北京100033 中国人民大学财政金融学院博士后科研流动站北京100872

本文从总体视角研究了我国宏观经济环境变化对于企业融资决策的动态影响,从个体视角研究了这一影响的作用机制,进一步探讨了地区金融发展水平和融资约束带来的影响差异。研究结果表明:从总体视角,在宏观经济环境变化的恢复阶段,企业偏... 详细信息

本文从总体视角研究了我国宏观经济环境变化对于企业融资决策的动态影响,从个体视角研究了这一影响的作用机制,进一步探讨了地区金融发展水平和融资约束带来的影响差异。研究结果表明:从总体视角,在宏观经济环境变化的恢复阶段,企业偏好内部融资;在扩张阶段,企业偏好债权融资;在衰退阶段,企业偏好股权融资;在紧缩阶段,企业偏好短期债权融资。从个体视角,宏观经济环境会通过影响企业的托宾Q和内部现金流来影响企业的债权和股权融资。宏观经济环境对于企业融资决策的影响也会因地区金融发展水平和融资约束的不同存在差异。本文提出,建立多层次的股票市场和债券市场、采取精准匹配的信贷政策、推出更多直达实体经济的货币政策工具对于推动金融供给侧结构性改革、支持实体经济高质量发展具有十分重要的意义。

关键词：宏观经济环境企业融资决策融资约束股权融资债权融资异质性分析

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

经济政策不确定性对中国银行业经营效率影响研究

引用

云南财经大学学报 2024年第6期40卷 47-62页

作者：孙光宇中国光大集团博士后科研工作站北京100033 中国人民大学财政金融学院博士后科研流动站北京100872

立足于中国经济政策不确定性和银行业经营的实际情况,分析经济政策不确定性对中国银行业经营效率的影响。研究结果显示,经济政策的不确定性会降低银行经营效率,且影响程度会随时间变化而降低,该结论经过一系列稳健性检验后仍然成立;经... 详细信息

立足于中国经济政策不确定性和银行业经营的实际情况,分析经济政策不确定性对中国银行业经营效率的影响。研究结果显示,经济政策的不确定性会降低银行经营效率,且影响程度会随时间变化而降低,该结论经过一系列稳健性检验后仍然成立;经济政策不确定性通过银行风险承担和银行利息净收入两个影响机制对银行经营效率产生作用;经济政策不确定性对银行经营效率的影响在不同类型银行之间存在异质性;金融科技发展可以缓解经济政策不确定性对银行经营效率的负面影响。

关键词：经济政策不确定性银行经营效率银行异质性

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

利用GPS数据反演震源参数的单纯形组合加权距离灰狼优化算法

引用

武汉大学学报（信息科学版） 2024年第7期49卷 1140-1154页

作者：王乐洋孙龙翔许光煜东华理工大学测绘与空间信息工程学院江西南昌330013 武汉大学测绘学院湖北武汉430079 自然资源部环鄱阳湖区域矿山环境监测与治理重点实验室江西南昌330013

针对地震震源参数反演优化问题,提出了一种改进的灰狼优化(grey wolf optimizer, GWO)算法来反演震源参数。首先,采用基于余弦规律的非线性递减收敛因子策略的加权距离GWO(weighted distance GWO, wdGWO)算法来代替原来的线性递减算法... 详细信息

针对地震震源参数反演优化问题,提出了一种改进的灰狼优化(grey wolf optimizer, GWO)算法来反演震源参数。首先,采用基于余弦规律的非线性递减收敛因子策略的加权距离GWO(weighted distance GWO, wdGWO)算法来代替原来的线性递减算法。随后,配置了改进wdGWO算法和单纯形算法的组合方法,引入后者算法是为了稳定前者算法的性能。因此,组合算法(简称GWOS)在收敛性和稳定性方面都具有良好的优势。最后,通过实验测试来评估基本的wdGWO算法、遗传算法(genetic algorithm,GA)和GWOS的性能。仿真实验结果表明,GWOS对震源参数的估计优于wdGWO算法,具有良好的稳定性和准确性;GWOS既可以达到GA的反演精度,又表现出了更好的参数稳定性。将该算法应用于2014年纳帕地震和2017年博德鲁姆-科斯地震,不同类型地震的反演结果表明GWOS具有良好的实用性和可靠性。

关键词：震源参数反演灰狼优化算法单纯形算法组合算法纳帕地震博德鲁姆-科斯地震

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

基于LIO-SAM建图和激光视觉融合定位的温室自主行走系统

引用

农业工程学报 2024年第3期40卷 227-239页

作者：孙国祥黄银锋汪小旵袁云鹏陈光宇南京农业大学工学院南京210031 江苏省现代设施农业技术与装备实验室南京210031

为解决传统导航方案在温室内无法应对光照变化大、作物行间距窄、接收GPS信号差等问题,该研究提出了基于即时定位与地图构建技术的激光视觉融合式自主导航算法。该系统利用三维激光雷达VLP-16(Velodyne LiDAR,VLP-16)和惯性测量单元获... 详细信息

为解决传统导航方案在温室内无法应对光照变化大、作物行间距窄、接收GPS信号差等问题,该研究提出了基于即时定位与地图构建技术的激光视觉融合式自主导航算法。该系统利用三维激光雷达VLP-16(Velodyne LiDAR,VLP-16)和惯性测量单元获取温室环境信息,采用基于紧耦合的雷达惯导定位建图(tightly-coupled lidar inertial odometry via smoothing and mapping,LIO-SAM)算法构建导航地图,基于轮式里程计和视觉里程计采用扩展卡尔曼滤波器算法实现局部定位,融合激光点云配准算法和自适应蒙特卡洛定位算法实现全局定位。同时,在自主行走系统应用A*算法规划全局路径和动态窗口算法规划局部路径,从而实现自主导航。试验结果表明,LIO-SAM算法构建的温室导航地图最大相对误差、最大绝对误差和均方根误差分别为9.9%、0.081和0.063 m,在温室内改进后的定位算法横向偏差小于0.020 m,纵向偏差小于0.090 m;当自主行走系统以0.15、0.30和0.50 m/s的速度运行时,横向偏差、纵向偏差和航向偏角的平均值分别小于0.120 m、0.10 m和8.5°,标准差分别小于0.070 m、0.140 m和6.6°。该导航方案满足自主行走系统在温室内高精度建图、定位和导航的需求,可为自主移动平台提供理论与技术支撑。

关键词：温室自主导航视觉里程计即时定位与地图构建自适应蒙特卡洛定位卡尔曼滤波

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

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：