检索结果-南通市图书馆

Acidic electroreduction CO_(2)to formic acid via interfacial modification of Bi nanoparticles at industrial-level current

引用

Nano Research 2024年第7期17卷 5817-5825页

作者： tian Dong Hongdong Li Zhenhui Wang Yanling Geng Rui Chang xiaofeng tian Jianping Lai Shouhua Feng Lei Wang Key Laboratory of Eco-Chemical Engineering International Science and Technology Cooperation Base of Eco-Chemical Engineering and Green ManufacturingCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China Shandong Engineering Research Center for Marine Environment Corrosion and Safety Protection College of Environment and Safety EngineeringQingdao University of Science and TechnologyQingdao 266042China

Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)in acidic media is a promising approach to overcome the unavoidable formation of carbonates in alkaline or neutral ***,the proton-rich environment near the catalyst surface favors hydrogen evolution reactions(HER),leading to lower energy efficiency of the desired products,especially in industrial-level current ***,quaternary ammonium cationic surfactant(cetyltrimethylammonium bromide(CTAB))was introduced into acidic electrolyte to modulate the interfacial microenvironment,which greatly enhanced CO_(2)electroreduction to formic acid(HCOOH)at the Bi/C nanoparticles *** a Bi/C nanoparticles electrode with CTAB added,constant production of formic acid was enabled with a cathodic energy efficiency of>40%and maximum FE_(HCOOH)(FE=Faradaic efficiency)of 86.2%at−400 mA·cm^(−2)over 24 *** with in-situ attenuated total reflection Fourier transform infrared spectroscopy,the concentration of*OCHO intermediates significantly increased after CTAB modification,confirming that the hydrophobic interface microenvironment formed by dynamic adsorption of positively charged long alkyl chains on Bi/C nanoparticle electrodes inhibited HER and improved the selectivity of CO_(2)RR to HCOOH.

关键词： acidic media CO_(2)electrolysis electrolyte additive hydrophobic interfacial microenvironment industrial-level current

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 sedimentary structure characteristics and spatial distribution pattern of the Zhaoji Salt Mine derived from dense array ambient noise tomography

引用

Journal of Earth Science 2024年

作者： Hongwei Wang xiaofeng tian Qiaoxia Liu Jia Cheng Ming Zhou Zhiping Xu Jiyan Lin Shuaipeng Zhu Geophysics Exploration Center China Earthquake Administration School of Earth Sciences and Resources， China University of Geosciences (Beijing)

Due to the lack of the three-dimensional structure of the Zhaoji salt basin， the salt mining enterprises have obvious clustering when choosing sites. Production capacity declines rapidly as mining deepens， the enterprises are entering a stage of stagnation in production. In this study， a dense seismic array of 125 short-period stations was deployed around the core mining area and its vicinity of the salt mine industry， we use the ambient noise tomography (ANT) method to image the three-dimensional shear wave velocity structure at the depth shallower than 3 km. The results indicate: (1) The overall shear wave velocity in the study area is relatively lower， ranging from 0.8 and 1.8 km/s， which could be related to the loose and thick deposition of the Zhaoji Sub-Depression. (2) The three-dimensional shear wave velocity structure reveals that the sedimentary thickness of the Zhaoji Sub-Depression is deeper in the southeast and shallower in the northwest， with the sedimentary center located around Heping Town and Dahuangzhuang Town. (3) The Zhaoji salt mine is a low-velocity anomalous zone in the shear wave velocity structure with an inverse 'C' character spreading along Nanchenji Town and Zhaoji Town， with a depth ranging from approximately 1.2 to 2.8 km， it may be caused by the development of rock fissures due to water extraction and injection. The surrounding rock exhibits relatively high velocity， which reflects the morphological characteristics of the Zhaoji salt basin. The three-dimensional shear wave velocity model obtained in this study provides scientific guidance for the industrial exploitation of the Zhaoji salt mine and reference for salt exploration of the Hongze Salt Basin. It also provides an important basis for the seismic risk assessment of the salt basins. Simultaneously， it holds significant implications for exploring the application of ambient noise tomography method in spatial detection of salt mine belt.

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

小学英语教学中学生思维品质的培养方法探析

引用

英语教师 2024年第8期24卷 177-179,184页

作者：田小凤江苏省海安市南莫镇中心小学江苏南通226681

英语是小学阶段的主要学科之一,小学阶段是学生语言发展的重要阶段,也是思维发展的起始阶段。因此,重视小学英语教学,注重学生思维品质的培养是小学英语教学的重要内容。基于此,结合实际教学案例,探讨小学英语教学中学生思维品质的培养... 详细信息

英语是小学阶段的主要学科之一,小学阶段是学生语言发展的重要阶段,也是思维发展的起始阶段。因此,重视小学英语教学,注重学生思维品质的培养是小学英语教学的重要内容。基于此,结合实际教学案例,探讨小学英语教学中学生思维品质的培养方法,以期对教学起到良好的促进作用。

关键词：英语教学小学英语思维品质

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

Resolution assessment of the three-dimensional acquisition geometry of the Anhui experiment in"Geoscience Yangtze Plan"

引用

Earthquake Science 2019年第2期32卷 47-56页

作者： Yiqing Li xiaofeng tian Geophysical Exploration Center China Earthquake AdministrationZhengzhou450002China

According to the actual observation conditions of the Yangtze River valley from Anqing city to Maanshan city,we designed the 3D acquisition geometry,and applied the multi-scale checkerboard semblance analysis to assess the preliminary resolution of the designed *** checkerboard semblance tests use the refraction and reflection travel-time simultaneous inversion algorithm to quantitatively provide both resolution assessment of velocity structure and Moho *** multi-scale checker-board semblance recovery results show that while the chec-kerboard semblance threshold value is 0.5,the preliminary resolution of the designed acquisition geometry is better than 10 km in the upper crust(the depth is less than 10 km),around 15 km in the mid-crust(the depth is 10?25 km),and better than 20 km in the lower crust(the depth is 25?33 km).The preliminary tomographic resolution for the Moho topography is about 20 km in the ray-path coverage area beneath the acquisition *** the checkerboard semblance threshold value is 0.75,the preliminary resolution is 20 km in the upper crust,around 20?25 km in the mid-crust and 25 km in the lower *** the preliminary tomographic resolution for the Moho topography is better than 30 km in the ray-path coverage area beneath the acquisition *** non-linear checkerboard tests reveal that the designed acquisition geometry is suitable to image the crustal velocity structure of the Yangtze River valley in the Anhui province.

关键词： artificial seismic sourc air gun 3D seismic tomo-graphy acquisition geometry resolution assessment

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

Feature-point-extracting-based automatically mosaic for composite microscopic images

引用

Chinese Science Bulletin 2007年第9期52卷 1291-1295页

作者： YIN YanSheng ZHAO XiuYang tian xiaofeng LI Jia School of Materials Ocean University of China Qingdao 266003 China Shandong Key Laboratory of Engineering Ceramics Shandong University Jinan 250061 China School of Materials Jinan University Jinan 250022 China

Image mosaic is a crucial step in the three-dimensional reconstruction of composite materials to align the serial images. A novel method is adopted to mosaic two SiC/Al microscopic images with an ampli-fication coefficient of 1000. The two images are denoised by Gaussian model,and feature points are then extracted by using Harris corner detector. The feature points are filtered through Canny edge de-tector. A 40×40 feature template is chosen by sowing a seed in an overlapped area of the reference image,and the homologous region in floating image is acquired automatically by the way of correlation analysis. The feature points in matched templates are used as feature point-sets. Using the transfor-mational parameters acquired by SVD-ICP method,the two images are transformed into the universal coordinates and merged to the final mosaic image.

关键词：复合材料特征点提取自动镶嵌工艺显微成像图象镶嵌

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

不同来源烯丙孕素对有无初情期后备母猪定时输精效果的影响

引用

畜牧与兽医 2024年第5期56卷 10-14页

作者：周振民张彬彬李晗星田晓丰李俊杰河北农业大学动物科技学院河北保定071000

为探究国内外两种不同品牌烯丙孕素对后备母猪定时输精效果的影响,随机选取67头有初情期和54头无初情期的后备母猪,将有初情期后备母猪分为国产药物A组(52头)、国外药物B组(15头),无初情期后备母猪分为国产药物A组(27头)、国外药物B组(2... 详细信息

为探究国内外两种不同品牌烯丙孕素对后备母猪定时输精效果的影响,随机选取67头有初情期和54头无初情期的后备母猪,将有初情期后备母猪分为国产药物A组(52头)、国外药物B组(15头),无初情期后备母猪分为国产药物A组(27头)、国外药物B组(27头),比较两种烯丙孕素对后备母猪发情率、发情持续时间、发情集中度、妊娠率、分娩率、产仔数、产活仔数、健仔数和仔猪初生重的影响。结果显示:无论母猪是否具有初情期,两种烯丙孕素药物组在发情和妊娠方面均无显著性差异(P>0.05),但国产药物A组要略优于国外药物B组。在产仔性能上,两种药物对有初情期后备母猪无显著性差异(P>0.05);对无初情期后备母猪,国产药物A组的产仔数显著高于国外药物B组(P<0.05),在产活仔数上,国产药物A组极显著高于国外药物B组(P<0.01)。综上,相较于国外烯丙孕素药物,国产药物可有效提高无初情期后备母猪的产仔数和产活仔数;此外,有初情期可在一定程度上提高后备母猪繁殖性能。

关键词：初情期烯丙孕素后备母猪繁殖性能

来源：

维普期刊数据库博看期刊

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

Crustal P-and S-Wave Velocity Structure of the North China Craton at 36°N from Active-Source Seismic Data and Its Tectonic Implications

引用

Journal of Earth Science 2022年第3期33卷 642-663页

作者： xiaofeng tian Walter DMooney Xiaoguo Deng Songlin Li Baofeng Liu Hanqi Liu Geophysical Exploration Center China Earthquake AdministrationZhengzhou 450003China U.S.Geological Survey Menlo Park CA94025USA

We present crustal models for seismic P-waves(Vp),S-waves(Vs)and the Vp/Vs ratio across the southern North China Craton along latitude 36°*** results are based on inverse and forward modeling of long-range wide-angle reflection/refraction *** crust of the southern Ordos Block has high lower crustal velocity(7.0 km/s)and a Moho depth of~42 *** contrast,thick sediments and a lower average velocity(compared with the Ordos block)found underneath the Shanxi Graben are likely to be the products of rifting that has occurred since the *** Moho dips,exposed basement rock and higher average crustal velocity beneath the Lüliang Mountain and the Taihang Mountain are characteristic of an orogenic *** Tanlu fault and the Liaocheng-Lankao fault show sharp crustal velocity variations and a Moho *** seismic profile sampled the entire region of the Eastern North China Craton where the cratonic root has been destroyed and the unique crustal structure is correlated with the substantially modified *** crustal seismic velocity model shows a strong correspondence between surface geology,local tectonics and the deep crustal structure.

关键词： North China Craton crustal velocity structure craton destructure tectonics wideangle reflection/refraction

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

Force-position collaborative optimization of rope-driven snake manipulator for capturing non-cooperative space targets

引用

CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 369-384页

作者： Li, xiaofeng tian, Jian Wei, Cheng Cao, Xibin Harbin Inst Technol Sch Astronaut Harbin 150001 Peoples R China China Acad Space Technol Beijing Inst Spacecraft Syst Engn Beijing 100094 Peoples R China

With the rapid development of space activities, non-cooperative space targets increase swiftly, such as failed satellites and upper stages, threating normal spacecrafts seriously. As there are some problems in the capture process, such as excessive collision and fast tumbling of targets, manipulator with redundant Degrees of Freedom (DOFs) can be used to improve the compliance and therefore solve these problems. The Rope-Driven Snake Manipulator (RDSM) is a combination of hyper-redundant DOFs and better compliance, and therefore it is suitable for capturing mission. In this paper, a snake manipulator mechanism is designed, and the complete kinematic model and system dynamic model considering RDSM, target and contact is established. Then, to obtain the configuration of joint with hyper-redundant DOFs, an improved motion dexterity index is proposed as the joint motion optimization target. Besides, the force-position collaborative optimization index is designed to adjust active stiffness, and the impedance control method based on the modified index is used to capture the space target. Finally, the proposed force-position collaborative optimization method is verified by virtual prototype co-simulation. The results demonstrate that based on the proposed method, the collision force is reduced by about 25% compared to normal impedance control, showing higher safety. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Capturing non-cooperative space targets Rope-driven snake manipu- lator Force-position collaborative optimization Redundant degrees of free- dom Active stiffness adjustment DUAL-ARM SPACE IMPEDANCE CONTROL ROBOT DEXTERITY INDEX

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

Shallow velocity structure of the Luoyang basin derived from dense array observations of urban ambient noise

引用

Earthquake Science 2018年第5期31卷 252-261页

作者： Ming Zhou xiaofeng tian Fuyun Wang Yunhao Wei Hailiang Xin Geophysical Exploration Center China Earthquake Administration

Determining the shallow structure of a sediment basin is important when evaluating potential seismic hazards given that such basins can significantly amplify seismic energy. The Luoyang basin is located in the western He’nan uplift and is a Meso-Cenozoic depression basin. To characterize the shallow structure of the basin, we develop a model of the shallow high-resolution three-dimensional(3D)shear-wave velocity structure of the basin by applying ambient noise tomography to a dense array of 107 portable digital seismometers deployed over the basin. More than 1,400 Rayleigh-wave dispersion curves for periods in the range 0.5–5 s are extracted. The 3D variations of shear-wave velocity in the shallow crust are inverted using a direct surface-wave tomographic method with period-dependent ray tracing, with all the surface-wave group-velocity dispersion data being inverted simultaneously. The results show that in the shallow crust of the study area, the velocity distribution corresponds to surface geology and geological features. The Luoyang basin exhibits a low shear-wave velocity feature that is consistent with the distribution of sediment in the region,while the Xiongershan and Songshan uplifts exhibit higher shear-wave velocity structures. The results provide a shallow high-resolution 3D velocity model that can be used as a basis for simulation of strong ground motion and evaluation of potential seismic hazards.

关键词： ambient noise tomography three-dimensional velocity structure Luoyang basin dense array

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

Crustal P-wave velocity structure in the northeastern margin of the Qinghai-Tibetan Plateau and insights into crustal deformation

引用

Science China Earth Sciences 2018年第9期61卷 1221-1237页

作者： Shuaijun WANG Baojin LIU xiaofeng tian Baofeng LIU Xianghui SONG Xiaoguo DENG Yinan SUN Cejun MA Yudong YANG Geophysical Exploration Center of China Earthquake Administration Zhengzhou 450002 China

The transitional area between the northeastern margin of the Qinghai-Tibetan Plateau, Ordos Block and Alxa Block, also being the northern segment of the North-South Seismic Belt, is characterized by considerably high seismicity level and high risk of strong earthquakes. In view of the special tectonic environment and deep tectonic setting in this area, this study used two seismic wide-angle reflection/refraction cross profiles for double constraining, so as to more reliably obtain the fine-scale velocity structure characteristics in both the shallow and deep crust of individual blocks and their boundaries in the study area, and further discuss the seismogenic environment in seismic zones with strong historical earthquakes. In this paper, the P-wave data from the two profiles are processed and interpreted, and two-dimensional crustal velocity structure models along the two profiles are constructed by travel time forward modeling. The results show that there are great differences in velocity structure, shape of intra-crustal interfaces and crustal thickness among different blocks sampled by the two seismic profiles. The crustal thickness along the Lanzhou-Huianbu-Yulin seismic sounding profile （L1） increases from -43 km in the western margin of Ordos Block to -56 km in the Qilian Block to the west. In the Ordos Block, the velocity contours vary gently, and the average velocity of the crust is about 6.30 km s^-1; On the other hand, the velocity structures in the crust of the Qilian Block and the arc-like tectonic zone vary dramatically, and the average crustal velocities in these areas are about 0.10 km s^-1 lower than that of the Ordos Block. In addition, discontinuous low-velocity bodies （LVZ1 and LVZ2） are identified in the crust of the Qilian Block and the arc-like tectonic zone, the velocity of which is 0.10-0.20 krn s^-1 lower than that of the surroundings. The average crustal thickness of the Ordos Block is consistently estimated to be around 43 km along both Pr

关键词： Northeastern margin of the Qinghai-Tibetan Plateau The Ordos Block Crustal velocity structure Deep seismicsounding

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：