检索结果-南通市图书馆

CO oxidation and 4-nitrophenol reduction over ceria-promoted platinum nanoparticles impregnated with ZSM-5 zeolite

Journal of Rare Earths 2022年第8期40卷 1247-1254页

作者： Zeinhom M.El-Bahy mohammed t.alotaibi Salah M.El-Bahy Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt Department of Chemistry Turabah University CollegeTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

Active new ceria-promoted platinum supported on ZSM-5 catalysts were prepared and characterized by X-ray diffraction(XRD),Fourier transform infrared spectra(FtIR),transform electron microscopy(tEM),temperature programmed desorption(tPD),and FtIR of CO *** samples were prepared by the incipient wetness impregnation method and calcined at 500℃.the XRD patterns and FtIR spectra prove that the zeolite framework is kept unaltered after metal *** images prove the presence of Pt nanoparticles with particle size starting from 14 to 27 *** FtIR data suggest the formation of Pt-O-Ce ***-situ FtIR of CO adsorption over reduced samples proves the presence of Pt~0 only,and no Pt^(n+)-CO species are *** prepared catalysts were tested in both oxidation reaction(CO oxidation) in the gas phase and in reduction reaction(4-nitrophenol reduction) in the aqueous ***,CO oxidation by O_(2) results in the formation of a CO_(2) peak at 2347 cm^(-1) as the only CO oxidation product in the studied frequency *** intensity of the CO_(2) peak increases after the addition of Ce,and it is 4 times higher in Pt_(1) Ce_(0.5)ZSM-5 than that in the Ce-free *** to the FtIR data and previous reports,the increase in the catalytic activity may be due to the formation of Pt-O-Ce ***,Ce-promoted Pt_(1) ZSM5 also exhibits enhanced catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol by NaBH_(4) in the aqueous *** first-order rate constant of the reduction increases ≈13 times after incorporating equal ratios of Pt and Ce(Pt_(1) Ce_(1)ZSM-5),and the activation energy(E_(a)) decreases to 40% of that in the reaction over Pt_(1) ZSM-5.

关键词： 4-Nitrophenol CO oxidation tPD-CO Platinum-cerium ZSM-5 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

treating wastewater under zero waste principle using wetland mesocosms

引用

Frontiers of Environmental Science & Engineering 2021年第4期15卷 155-168页

作者： Safaa M.Ezzat mohammed t.Moustafa Microbiology Deptartment Central Laboratory for Environmental Quality Monitoring(CLEQM)National Water Research Center(NWRC)CairoEgypt

the present investigation demonstrates the synergistic action of using a sedimentation unit together with Cyperus papyrus(L.)wetland enriched with zeolite mineral in one-year round experiment for treating *** system was designed to support a horizontal surface flow pattern and showed satisfactory removal efficiencies for both physicochemical and bacteriological contaminants within 3 days of residence *** removal efficiencies ranged between 76.3%and 98.8%for total suspended solids,turbidity,iron,biological oxygen demand,and *** bacterial indicators(total and fecal coliforms,as well as fecal streptococci)and the potential pathogens(Escherichia coli,Staphylococcus aureus,and Pseudomonas aeruginosa)showed removal efficiencies ranged between 96.9%and 99.8%.We expect the system to offer a smart management for every component according to zero waste *** treated effluent was reused to irrigate the landscape of pilot area,and the excess sludge was recycled as fertilizer and soil *** zeolite mineral did not require regeneration for almost 36 weeks of operation,and enhanced the density of shoots(14.11%)and the height of shoots(15.88%).the harvested plant biomass could be a profitable resource for potent antibacterial and antioxidant bioactive *** could certainly offset part of the operation and maintenance costs and optimize the system implementation *** the experiment was designed under local conditions,its results could provide insights to upgrade and optimize the performance of other analogous large-scale constructed wetlands.

关键词： Wastewater Dynamic roughing filter Cyperus papyrus(L.) Zeolite Zero waste

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

Photocatalytic degradation of Chicago Sky Blue 6B and Benzopurpurin 4B using titanium dioxide thin film

引用

Journal of Environmental Sciences 2005年第5期17卷 869-872页

作者： Abdul K. mohammed Katrina t. McKenzie Department of Chemistry Winston-Salem State UniversityDepartment of Chemistry North Carolina Agricultural and Technical State University 601 S. Martin Luther King Jr. Drive Winston-Salem North Carolina 27110 USA1601 E. Market Street Greensboro North Carolina 27411 USA

Aqueous solutions of azo dyes undergo degradation to form harmless intermediates and colorless products following irradiation by visible light in the presence of titanium dioxide thin films. the dyes that were studied in this work are： Chicago Sky Blue 6B and Benzopurpurin 4B. Results obtained indicated that complete mineralization of the dyes took place under the experimental conditions. there was an increase in conductivity after the complete mineralization experiments possibly indicating the formation of ions such as NO3^- and SO4^2-. Chemical oxygen demand（COD） measurements show a decrease in organic matter for both dyes following complete degradation. the effect of how changing experimental conditions such as pH, temperature and starting concentrations of dyes affected the rate of dye degradation was measured. there was an increase in the rate of disappearance of the dye color at lower pH. High concentrations of dye solutions reauired Iona dearadation time.

关键词： titanium dioxide photocatalysis photocatalytic degradation azo dyes

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

Yeast-generated CO2:A convenient source of carbon dioxide for mosquito trapping using the BG-Sentinel?traps

引用

Asian Pacific Journal of tropical Biomedicine 2017年第10期7卷 896-900页

作者： dhanique c.t.jerry terry mohammed azad mohammed University of the West Indies St AugustineTrinidad and Tobago

Objectives: to evaluates carbon dioxide(CO_2) production from yeast/sugar mixtures and its efficiency as an attractant in BG-Sentinel ***: the rate of CO_2 production was optimized for different yeast/sugar *** optimized mixture was then used as bait in BG-Sentinel traps. the efficiency of this bait was then compared to octenol baited ***: the yeast/sugar(5g: 280g) in 300 m L water generated the highest volume of CO_2. the CO_2 baited traps caught significantly more mosquitoes than octenol baited ***: Yeast-produced CO_2 can effectively replace octenol baits in BG *** will significantly reduce costs and allow sustainable mass-application of the CO_2 baited traps in large scale surveillance programs.

关键词： trinidad and tobago Carbon dioxide bait BG sentinel trap Attractant

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

Investigation of photon energy absorption properties for some biomolecules

引用

Nuclear Science and techniques 2019年第7期30卷 1-9页

作者： mohammed Sultan Al-Buriahi Halil Arslan Baris t. tonguc Department of Physics Sakarya University Sakarya Turkey Electrical and Electronics Engineering Sakarya University of Applied Sciences Sakarya Turkey

the mass energy absorption coefficient (len=q), effective atomic number (ZPEAeff ), and electron density (NPEAeff ) of some biomolecules with potential application in radiation dosimetry were calculated for their photon energy absorption (PEA) in the energy region of 1–20 MeV. It was noticed that the values of len=q, ZPEAeff , and NPEAeff vary with the energy and composition of the biomolecules. the results for ZPEAeff were compared with effective atomic numbers (ZPIeff ) owing to the photon interaction (PI). Significant differences were noted between ZPEAeff and ZPIeff in the energy region of 10–150 keV for all of the biomolecules involved. A maximum difference of 45.36% was observed at 50 keV for creatinine hydrochloride. Moreover, the studied attenuation parameters were found to be sharply affected at the K-absorption edge of relatively high-Z elements present in the biomolecules.

关键词： Photon energy absorption Effective atomic number Electron density Biomolecule

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 New Paradigm for Waste Classification Based on YOLOv5

引用

Instrumentation 2021年第4期8卷 9-17页

作者： mohammed SAJID Nimali t MEDAGEDARA Department of Mechanical Engineering University of West of England Department of Mechanical En-gineering Faculty of Engineering TechnologyThe Open University of Sri LankaNugegodaSri Lanka

Classification of garbage is of paramount importance prior to process them to categorise physically and this process helps to manage wastes by maintaining pollution free *** systems that have capability segregate garbage are on the rise,but efficient and accurate segmentation with recognition mechanisms draw the attention of researchers.A computer vision approach for classifying garbage into respective recyclable categories could be one of the effective and economical ways of processing *** project mainly focused on capturing real-time images of a single piece of garbage and classifying it into three divisions:paper,or metal,or biodegradable(food)*** garbage class contains around 2000 images obtained from an open-source dataset and images collected from Google and personally collected custom *** developed intelligent models provide the effectiveness of the machine and deep learning in classification with structural and non-structural *** model used was a Convolutional Neural Network(CNN)named *** project showcased vision based approach capable of maintaining an accuracy of 61%.the CNN was not trained to its maximum capacity due to the difficulty of finding optimal hyperparameters,as most of the images were gathered from Google Images.

关键词： Waste Classification YOLOv5

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

Efficient Image Captioning Based on Vision transformer Models

引用

Computers, Materials & Continua 2022年第10期73卷 1483-1500页

作者： Samar Elbedwehy t.Medhat taher Hamza mohammed F.Alrahmawy Department of Data Science Faculty of Artificial IntelligenceKafrelsheikh UniversityEgypt Department of Electrical Engineering Faculty of EngineeringKafrelsheikh UniversityEgypt Department of Computer Science Faculty of Computer and Information ScienceMansouraEgypt

Image captioning is an emerging field in machine *** refers to the ability to automatically generate a syntactically and semantically meaningful sentence that describes the content of an *** captioning requires a complex machine learning process as it involves two sub models:a vision sub-model for extracting object features and a language sub-model that use the extracted features to generate meaningful ***-based vision transformers models have a great impact in vision field *** this paper,we studied the effect of using the vision transformers on the image captioning process by evaluating the use of four different vision transformer models for the vision sub-models of the image captioning the first vision transformers used is DINO(self-distillation with no labels).the second is PVt(Pyramid Vision transformer)which is a vision transformer that is not using convolutional *** third is XCIt(cross-Covariance Image transformer)which changes the operation in self-attention by focusing on feature dimension instead of token *** last one is SWIN(Shifted windows),it is a vision transformer which,unlike the other transformers,uses shifted-window in splitting the *** a deeper evaluation,the four mentioned vision transformers have been tested with their different versions and different configuration,we evaluate the use of DINO model with five different backbones,PVt with two versions:PVt_v1and PVt_v2,one model of XCIt,SWIN *** results show the high effectiveness of using SWIN-transformer within the proposed image captioning model with regard to the other models.

关键词： Image captioning sequence-to-sequence self-distillation transformer convolutional layer

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

Numerical Modeling Strategy for the Simulation of Nonlinear Response of Slender Reinforced Concrete Structural Walls

引用

Computer Modeling in Engineering & Sciences 2019年第9期120卷 583-627页

作者： mohammed A.mohammed Andre R.Barbosa School of Civil and Construction Engineering Oregon State UniversityCorvallisORUSA

A three-dimensional nonlinear modeling strategy for simulating the seismic response of slender reinforced concrete structural walls with different cross-sectional shapes is presented in this paper.A combination of nonlinear multi-layer shell elements and displacement-based beam-column elements are used to model the unconfined and confined parts of the walls,respectively.A uniaxial material model for reinforcing steel bars that includes buckling and low-cyclic fatigue effects is used to model the longitudinal steel bars within the structural *** material model parameters related to the buckling length are defined based on an analytical expression for reinforcing steel bars embedded in reinforced concrete elements,which are developed based on beam-on-springs model,and validated with experimental tests of boundary elements of structural walls available in the *** experimental case studies of reinforced concrete walls with rectangularshape,t-shape,and U-shape cross-section are used to validate the structural wall numerical modeling strategy.

关键词： Bar buckling finite element modeling low-cycle fatigue reinforced concrete structural walls

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

Spherically Symmetric Cosmological Solutions of Einstein’s Equations

引用

Chinese Physics Letters 1999年第4期16卷 247-248页

作者： mohammed Ashraful Islam Department of Mathematics and Research Centre for Mathematical and Physical SciencesChittagong UniversityChittagongBangladesh

two sets of solution of the Einstein’s equations of general theory of relativity which is spherically-symmetric and nonstatic homogeneous isotropic universe for perfect fluid are *** first solution is the Einstein de-Sitter type containing a scale factor(√6πкGt+a)^(4/3)and an arbitrary function f(R)of radial space *** second solution is for stiff equation of state p=ρc2,which also has a scale factor[3√8πaG∫^(t)_(0)ξ(t)dt]^(2/3)and an arbitrary function h(R)of radial space coordinates.

关键词： Einstein arbitrary radial

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

Genesis and tectonic Implications of the Kabr El-Bonaya Ultramafic Rocks,Sinai Peninsula,Egypt:Constraints from Mineralogical and Geochemical Characteristics

引用

Acta Geologica Sinica(English Edition) 2021年第2期95卷 393-418页

作者： Moustafa mohammed MOGAHED Geology Department Benha University-EgyptBenhaEgypt

the Kabr El-Bonaya mafic–ultramafic intrusion is exposed along the southeastern border of the Sinai Peninsula and the northernmost segment of the Arabian-Nubian Shield(ANS).It occurs as an elliptical intrusive body that is located along the major NE–SW trending fracture zones that prevail in the Kid metamorphic *** ultramafic rocks in the complex comprise ultramafic cumulates of peridotites(dunite,harzburgite and wehrlite)and *** rocks are generally unmetamorphosed and have intrusive contacts with the country *** chemistry and whole-rock chemical compositions of these ultramafic rocks are mostly consistent with those of residual mantle peridotites from refractory suprasubduction tectonic *** on the variations of the major elements,the studied ultramafic rocks are consistent with those of a supra-subduction zone mantle,as it seems to have melted at 1–2 GPa and 1300–1450℃.Linear variations of Al2O3,Ca O,V and Ni with Mg O,coupled with incompatible and rare-earth-element depletion and mineral compositions,suggest prior events of partial melting in both wehrlites and *** LREE enrichment in the harzburgite,as well as the development of Cr-rich spinel,is consistent with a history of melt–peridotite *** calculated(Sm/Yb)N variations for the studied peridotites indicate a general increase in the addition of fluids with an increasing degree of melting from the wehrlite(~13–15 wt%of fluid)in the source,after initial spinel peridotite melting to the harzburgite(~20–25 wt%of fluid)in the same source,which is contrary to normal abyssal *** estimated equilibration temperature ranges from 1214 to 1321℃for the studied wehrlites and from 1297 to 1374℃for *** Mg-rich nature of the analysed olivines from the studied ultramafic rocks(Fo=81.41 to 91.77)reflect their primary composition and are similar to olivines in Alaskan-type ultramafic *** Fo content of the analyzed olivines decrease sli

关键词： cumulate ultramafic rocks Alaskan-type rocks partial melting hydrous melting conditions supra-subduction zone Kabr El-Bonaya South Sinai Arabian-Nubian Shield

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：