检索结果-南通市图书馆

Preparation of La-Mo-V mixed-oxide systems and their application in the direct synthesis of acetic acid

Journal of Natural Gas Chemistry 2008年第3期17卷 213-224页

作者： Hamid Reza Arandiyan matin parvari Chemical Engineering Department Iran University of Science and Technology

In this study, mixed metal oxides developed with a perovskite-type structure that show great potential for use in catalysis. Perovskite oxide catalysts with the composition LaMoxV1-xOn （x = 0.1, 0.3, 0.5, 0.7, and 0.9） have been synthesized by the sol-gel method and then used in the ethane dry reforming reaction for the direct synthesis of acetic acid. The influence of the nature of the metallic source （metal, nitrate, acetylacetonate, and ammonium） on gel formation has been studied by Fourier-transform infrared spectroscopy （FT-IR） and thermogravimetric analysis （TGA-DTA）. After calcination, the obtained perovskites were characterized by X-ray diffraction （XRD） and energy-dispersive X-ray spectrometry （EDS） coupled with scanning electron microscopy （SEM）. The catalysts were then subjected to thermo-programmed reduction （TPR）. The surface area （BET） was found to increase from 2.6 m^2/g （x = 0.1） to 5.1 m2/g （x = 1.0） with increasing molybdenum content following calcinations at 750 °C, and pure LaMoxV1-xOn perovskite was obtained with good homogeneity. The catalysts have been characterized by XRD, SEM, EDS, and carbon analysis （CA）. The results indicate that through this synthesis it is possible to obtain highly crystalline, homogeneous and pure solids, with well-defined structures. The direct synthesis of acetic acid from ethane over the perovskite catalysts was studied at temperatures between 450 and 850 °C and elevated pressures between 1 and 8 bar. It was found that the yield of acetic acid and the selectivity of its formation could be increased by incorporating more molybdenum into the perovskite structure. The experimental studies have shown that the calcination temperature and the molybdenum content have a significant influence on the catalytic activity. Amongst the catalysts tested, LaMo0.7V0.3O4.2 exhibited the best activity and stability.

关键词： acetic acid catalyst perovskite activity LaMoxV1-xOn

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

用于甲烷水蒸气重整的镍基催化剂的失活和再生(英文)

引用

催化学报 2011年第2期32卷 273-279页

作者： Seyed Meysam HASHEMNEJAD matin parvari School of Chemical Engineering Iran University of Science and Technology

The deactivation of nickel catalysts used in Arak and Razi petrochemical complexes followed by catalyst regeneration was evalu-ated. The characterization of the different structures was made by powder X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),transmission electron microscopy(TEM),and carbon & sulfur analyzer. The Ni particle size was estimated from XRD patterns and TEM graphs. The agglomeration of nickel particle and the poison by sulfur components were recognized as the main reasons in deactivation of Arak and Razi catalysts,respectively. The activity of the used catalysts before and after regeneration was measured on methane steam reforming at a CH4:H2O ratio of 1:3 at 850 oC. The regeneration processes for Arak and Razi samples were performed with CO2 as an oxidative atmosphere and steam as a regenerating agent,respectively. The results show that,(1) no residual sulfur components were on the regenerated Razi catalyst surface without changing the structure of the catalyst and the regenerated catalyst has gained 80% of its catalytic activity,and that(2) the nickel particle size of regenerated Arak specimen decreased remarkably as measured by Debye-Scherrer equation from XRD patterns. TEM images were in agreement with the XRD results and indicated a decrease in nickel particle size of regenerated catalyst. Additionally,in both regenerated catalysts all the coke on the surface of the support was eliminated after regeneration.

关键词：镍催化剂冒热气改过释放 sintering 毒害的硫新生

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

铜取代和制备方法对LaMnO_(3±δ)结构和催化甲烷燃烧和CO氧化的影响(英文)

引用

催化学报 2010年第4期31卷 394-403页

作者： Maryam ABDOLRAHMANI matin parvari Mehdi HABIBPOOR School of Chemical Engineering Iran University of Science and Technology

LaMn1-xCuxO3±δ perovskite oxides (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were prepared by two different methods, the Pechini and sol-gel methods. The catalysts were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray fluorescence spectroscopy, N2 adsorption, and temperature-programmed reduction. Their catalytic activity in the oxidation of methane and CO was evaluated. EDS and SEM results showed that the Pechini samples had more homogeneity and smaller particles (higher specific surface area). The catalytic activity for methane combustion was highest for x = 0.2. In CO oxidation, the oxides with x = 0.2 and x = 0.4 were the most active. The Pechini samples had higher activity and stability than the sol-gel samples.

关键词： perovskite Pechini 大音阶的第五音胶化甲烷燃烧碳一氧化物氧化

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

La-Ni-Al钙钛矿氧化物中Sr和Ca取代La对甲醇重整的影响(英文)

引用

催化学报 2008年第10期29卷 960-968页

作者： Alieh KHALESI Hamid R. ARANDIYAN matin parvari Chemical Engineering Department Iran University of Science and Technology Tehran Iran

Mixed perovskite oxides with CaxLa1-xNi0.3Al0.7O3-d and SrxLa1-xNi0.3Al0.7O3-d(x=0,0.2,0.5,0.8,and 1.0;d=0.5x)components have been prepared by a sol-gel *** effects of the partial substitution of La by Ca and Sr in dry CH4 reforming were investigated at 500-800 ℃ and 101 *** resulting oxides were examined by Fourier-transform infrared spectroscopy,X-ray diffraction,temperature-programmed reduction,scanning electron microscopy,energy dispersive X-ray spectrometry,and BET surface area *** following the catalytic tests by carbon analysis show some carbon deposition on this catalytic *** results indicate that all initial salt entered into a propionate structure,and that most of the solid solution has well defined perovskite structure with surface areas between 3.5 and 9.5 m2/*** of the catalysts performed well in the dry reforming,with CH4 conversions up to 90%,H2 yields up to 80%,and H2 selectivity up to 90%.Among the samples,Sr0.2La0.8Ni0.3Al0.7O2.9 showed an excellent catalytic performance in CH4 dry reforming,with a H2/CO ratio of 1,whereas Ca0.8La0.2Ni0.3Al0.7O2.6 showed the lowest coke formation(approximately 0.71%).

关键词：镧镍铝氧化物钙钛矿重整技术甲烷催化技术

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

Public perception of connected and automated vehicles:Benefits,concerns,and barriers from an Australian perspective

引用

Journal of Intelligent and Connected Vehicles 2024年第2期7卷 108-128页

作者： Ali matin Hussein Dia Department of Civil and Construction Engineering Swinburne University of TechnologyMelbourne 3122Australia

This study investigates the attitudes and concerns of the Australian public toward connected and autonomous vehicles(CAVs),and the factors influencing their willingness to adopt this *** a comprehensive survey,a diverse group of respondents provided valuable insights toward various CAV scenarios such as riding in a vehicle with no driver,self-driving public transport,self-driving taxis,and heavy vehicles without *** results highlight the significant impact of safety concerns about automated vehicles on individuals’attitudes across all *** levels of concern were associated with more negative attitudes,and a strong correlation between concerns and opposition underlines the necessity of addressing these apprehensions to build public trust and promote CAV ***,nearly 70%of respondents felt uncomfortable driving next to a CAV,but they displayed more confidence in adopting automated public transport in the near ***,around 40%of participants indicated a strong willingness to purchase a CAV,primarily driven by the desire to reduce their carbon footprint and safety ***,respondents with health conditions or disability exhibited heightened interest(almost double those without health conditions)in CAV *** differences emerged in attitudes and preferences toward CAVs,with women expressing a greater level of concern and perceiving higher barriers to CAV *** emphasizes the importance of employing targeted approaches to address the specific concerns of different *** study also underscores the role of trust in technology as a significant barrier to CAV deployment,ranking high among respondents’*** overcome these challenges and facilitate successful CAV deployment,various strategies are suggested,including live demonstrations,dedicated routes for automated public transport,adoption incentives,and addressing liability *** findings from this st

关键词： connected and automated vehicles(CAVs) autonomous vehicles public acceptance stakeholder consultations road safety

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

Efficient Algorithm for Prolonging Network Lifetime of Wireless Sensor Networks

引用

Tsinghua Science and Technology 2011年第6期16卷 561-568页

作者： Md Nafees Rahman M A matin Department of Electrical Engineering and Computer Science North South University

One of the fundamental design challenges in designing a Wireless Sensor Network （WSN） is to maximize the network lifetime, as each sensor node of the network is equipped with a limited power battery. To overcome this challenge, different methods were developed in the last few years using such techniques as network protocols, data fusion algorithms using low power, energy efficient routing, and locating optimal sink position. This paper focuses on finding the optimal sink position. Relay nodes are introduced in conjunction with the sensor nodes to mitigate network geometric deficiencies since in most other approaches the sensor nodes close to the sink become heavily involved in data forwarding and, thus, their batteries are quickly depleted. A Particle Swarm Optimization （PSO） based algorithm is used to locate the optimal sink position with respect to those relay nodes to make the network more energy efficient. The relay nodes communicate with the sink instead of the sensor nodes. Tests show that this approach can save at least 40% of the energy and prolong the network lifetime.

关键词： wireless sensor network lifetime sensor node relay node particle swarm optimization sink

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

Assessing land transformation and associated degradation of the Indian Ganga River Basin using forest cover land use mapping and residual trend analysis

引用

Journal of Arid Land 2019年第1期11卷 29-42页

作者： Shafique matin Sujit GHOSH Mukunda D BEHERA Centre for Oceans Rivers Atmosphere and Land Sciences Indian Institute of Technology Kharagpur

The Indian Ganga River Basin（IGRB） has experienced continuous land transformation since the Indus Valley Civilisation shifted from the Indus basin to the Ganga basin. Particularly in the last few decades the land transformation has increased many-folds due to the changing climate and rapid increase in population. In this paper, we assessed land transformation and associated degradation in the IGRB based on the forest cover land use（FCLU） mapping and residual trend analysis（RTA）. The FCLU maps for 1975 and 2010 were generated using 216 Landsat satellite images and validated using 1509 ground points. We mapped 29 forest and 18 non-forest types and estimated a total loss of 5571 km2forest cover and expansion in settlement areas（5396 km2）. Other major changes mapped include a decrease in wetlands and water bodies, while an increase in agriculture and barren lands with an overall mapping accuracy of 85.3%（kappa, 0.82） and 88.43%（kappa, 0.84） for 1975 and 2010, respectively. We also performed the RTA analysis using GIMMS-NDVI3 g to identify areas of significant negative vegetative photosynthetic change as an indicator for land degradation. All the RTA models showed monotonic nature of the residual trends and resulted as moderately positive but highly significant（P<0.001）. Land degradation in the form of barren land accompanied by a decline in vegetation quality and coverage was found prominent in the basin with a possibility of an accelerated rate of land degradation in future due to the rapid loss of permanent forest cover.

关键词： land degradation remote sensing NDVI GIMMS Ganga River Basin

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

A Coupled Soil-Fluid-Structure Simulation of the Near-Field Earthquake Effects on Gravity Type Quay-Walls

引用

China Ocean Engineering 2013年第4期27卷 481-494页

作者： M.Zeinoddini H.matin Nikoo F.Ahmadpour Faculty of Civil Engineering K.N.Toosi University of Technology

This study focuses on non-linear seismic response of concrete gravity quay-wall structures subjected to near-fault ground motions, a subject which seems not to have received much attention in the literature. A two-dimensional coupled fluid-structure-soil finite element modelling is employed to obtain the quay-wall response. The seawater medium is represented by acoustic type, potential based fluid elements. The elasto-plastic behavior of the soil medium is idealized using Drucker-Prager yield criterion based on associated flow rule assumption. Four nodded plane strain elements are used to model the concrete wall, foundation, subsoil, backfill and seabed zones. Fluid Structure Interface （FSI） elements are considered between the seawater interfaces with the quay-wall and the seabed. Frictional contact elements are employed between the wall and soil interfaces. The numerical model is validated using field measurements available for permanent drifts in a quay-wall damaged during Kobe earthquake. Reasonable agreements are obtained between the model predictions and the field measurements. Non-linear seismic analyses of the selected quay-wall subjected to both near-fault and far-fault ground motions are performed. An incremental dynamic analysis approach （IDA） is used. In general, at least for models examined in the current study, the gravity quay-walls are found to be more vulnerable to near-field, in comparison with the corresponding far-field, earthquakes.

关键词： coastal structure gravity quay-wall near-fault earthquake Incremental Dynamic Analysis (IDA)

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

GIS-based method for detecting high-crash-risk road segments using network kernel density estimation

引用

Geo-Spatial Information Science 2013年第2期16卷 113-119页

作者： Afshin Shariat MOHAYMANY matin SHAHRI Babak MIRBAGHERI Faculty of Civil Engineering Iran University of Science&TechnologyTehranIran Faculty of Earth Sciences Shahid Beheshti UniversityTehranIra

Identifying high-crash-risk road segments provides safety specialists with an insight to better understanding of crash patterns and enhancing road safety *** common hotspot identification methods are not robust enough to visualize the underlying shape of crash patterns since they neglect the spatial properties of crash *** traffic accidents have the tendency to be dependent,a phenomenon known as spatial *** over distance are more or less similar than expected for randomly associated *** the spatial variations can properly be explained in terms of first-and second-order *** first-order properties,describe the way of varying the expected value of point pattern in space which can be due to changes in the substantial properties of the local environment,while second-order effects describe the interactive effects of events explaining on how the events are *** the discrete nature of crash data and the limited access to exact locations where crashes occur,it is likely that a continuous surface drawn from discrete points will better reflect crash density,present a more realistic picture of crash *** kernel density estimation(NKDE)is a nonparametric approach for events distributed over one-dimensional space which facilitates estimating the density at any location in the study region not just at the location where the event *** for road safety applications enables the extraction and visualization of crash density along roadways The application of suggested method was illustrated for Arak-Khomein rural road in Markazi province,Iran and the stability of hazardous segments by examining the resulted network estimated density during the three years of study(2006–2008)was *** result of this paper helps the traffic engineers and safety specialists to determine the segments which demand more safety attentions from both transportation authorities and drivers and

关键词： crash density NKDE Spatial-temporal 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

Experimental evaluation of mechanically stabilized earth walls with recycled crumb rubbers

引用

Journal of Rock Mechanics and Geotechnical Engineering 2018年第5期10卷 947-957页

作者： matin Jalali Moghadam Amirali Zad Nima Mehrannia Nader Dastaran Department of Geotechnical Engineering Islamic Azad UniversityCentral Tehran Branch

Traditional techniques for treatment of waste rubber, such as burning, generate some highly non- degradable synthetic materials that cause unrepairable environmental damages by releasing heavy metals, such as arsenic, chromium, lead, manganese and nickel. For this, scrap tires are used as light- weight alternative materials in many engineering applications, such as retaining wall backfilling. In the present study, 90 laboratory models were prepared to evaluate the stability of mechanically stabilized earth （MSE） walls with plate anchors. Then, the bearing capacity and horizontal displacements of the retaining walls were monitored by exerting a static loading to investigate the effects of adding different contents （5 wt%, 10 wt%, 15 wt% and 20 wt%） of recycled crumb rubber （RCR） to the fill of a mechanically stabilized retaining wall with plate anchors. To visualize the critical slip surface of the wall, the particle image velocimetry （PIV） technique was employed. Results showed that the circular anchor plates almost continually provided a higher bearing capacity and wall stability than the square plates. Moreover, the backfill with 15 wt% RCR provided the maximum bearing capacity of the wall. Increasing the weight percentage of RCR to 20 wt% resulted in a significant reduction in horizontal displacement of the wall, which occurred due to the decrease in lateral earth pressure against the whole walls. An increase in RCR content resulted in the decrease in the formation of failure wedge and the expansion of the wall slip surface, and the failure wedge did not form in the sand mixtures with 15 wt% and 20 wt% RCRs.

关键词： Mechanically stabilized earth (MSE) wall Plate anchor Recycled crumb rubber (RCR) Particle image velocimetry (PIV)

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：