检索结果-南通市图书馆

investigation of the effects of radial clearance on the screw conveyor performances for different inclinations

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第9期92卷 72-80页

作者： Berna Bolat Birgül Aşçıoğlu Temiztaş Enes Sezer Department of Mechanical Engineering Yıldız Technical University34349BeşiktaşİstanbulTurkey

Screw conveyors are widely used for bulk material *** study investigates the critical role of radial clearance,the gap between the screw and the conveyor body,on performance across various inclination *** Discrete Element Method(DEM)is employed to analyze the effects of different radial clearances on conveyor performance for concrete aggregate and sand as bulk *** efficiencies and capacity losses serve as key performance indicators,quantitatively assessed for each radial clearance and inclination *** validation is conducted to corroborate the *** the study,the optimal radial clearance was identified as 1.5 to 3 times of the particle *** optimal clearance minimizes the material jamming and increases the performance for screw conveyors with different inclinations and bulk material types as a result.

关键词： Screw conveyors Radial clearance Discrete element method(DEM) Volumetric efficiency Conveyor performance

Physico−mathematical model of the voltage−current characteristics of light-emitting diodes with quantum wells based on the Sah−Noyce−Shockley recombination mechanism

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

Journal of Semiconductors 2024年第8期45卷 25-33页

作者： Fedor i.Manyakhin Dmitry o.Varlamov Vladimir P.Krylov Lyudmila o.Morketsova Arkady A.Skvortsov Vladimir K.Nikolaev Dinamics Strength of Machines and Resisance of MaterialsMoscow Polytechnic UniversityRussia Biomedical and Electronic Means and Technologies Vladimir State UniversityRussia Computer-Aided Design and Engineering National University of Science and Technology"MISiS"Russia

Herein,a physical and mathematical model of the voltage−current characteristics of a p−n heterostructure with quantum wells(QWs)is prepared using the Sah−Noyce−Shockley(SNS)recombination mechanism to show the SNS recombination rate of the correction function of the distribution of QWs in the space charge region of diode configuration.A comparison of the model voltage−current characteristics(VCCs)with the experimental ones reveals their *** technological parameters of the structure of the VCC model are determined experimentally using a nondestructive capacitive approach for determining the impurity distribution profile in the active region of the diode structure with a profile depth resolution of up to 10Å.The correction function in the expression of the recombination rate shows the possibility of determining the derivative of the VCCs of structures with QWs with a nonideality factor of up to 4.

关键词： light-emitting diodes with quantum wells voltage−current relation nonideality factor recombination mechanism Sah−Noyce−Shockley model

Highly Defective Dark Tio_(2) Modified with Pt: Effects of Precursor Nature and Preparation Method on Photocatalytic Properties

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2024年第2期30卷 198-209页

作者： E.D.Fakhrutdinova o.A.Reutova T.A.Bugrova i.Yu.ovsyuk L.S.Kibis o.A.Stonkus D.B.Vasilchenko o.V.Vodyankina V.A.Svetlychnyi National Research Tomsk State University TomskRussia 634050 Novosibirsk State University NovosibirskRussia 630090 Boreskov institute of Catalysis NovosibirskRussia 630090 Nikolaev institute of inorganic Chemistry NovosibirskRussia 630090

The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed Co adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (oH) _(2) (No _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSi) eff ect of the transfer of electron density from the electron-saturated defects on the Tio _(2) surface to Pt ^(4+) . in the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSi eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/Tio_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.

关键词： Dark(black)Tio_(2) Pulsed laser ablation Platinum reduction method Precursor type Photocatalysis Hydrogen evolution reaction

Development and testing of a high-power S-band klystron at BiNP SB RAS

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 58-67页

作者： A.Levichev A.Barnyakov S.Samoylov D.Nikiforov V.ivanov M.Arsentyeva D.Chekmenev o.Pavlov i.Pivovarov Budker institute of Nuclear Physics Lavrentyeva Av.11NovosibirskRussia630090 Novosibirsk State University Pirogova Str.2NovosibirskRussia630090

This paper details the development and testing of the first working prototype of the S-band high-power klystron,accomplished at the Budker institute of Nuclear Physics,Siberian Branch,Russian Academy of Sciences(BiNP SB RAS).Upon testing,the klystron demonstrated the following parameters:an operating frequency of 2856 MHz and a peak power output of 50 *** paper presents the klystron's design,its constituent units,and pertinent processing procedures,along with discussions on the measurement of its parameters.

关键词： Klystron Linear accelerator Electron beam

optimization of bio-oil production parameters from the pyrolysis of elephant grass (Pennisetum purpureum) using response surface methodology

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2024年第5期8卷 241-251页

作者： Sunday C.ikpeseni Samuel o.Sada Ufuoma J.Efetobor Henry o.orugba Mathias Ekpu Hilary i.owamah Jeremiah L.Chukwuneke Solomon oyebisi Uche P.onochie Department of Mechanical Engineering Delta State UniversityP.M.B.1AbrakaNigeria Department of Mechanical Engineering Delta State PolytechnicP.M.B.3Otefe-OgharaNigeria Department of Chemical Engineering Delta State UniversityP.M.B.1AbrakaNigeria Department of Civil Engineering Delta State UniversityP.M.B.1AbrakaNigeria Department of Mechanical Engineering Nnamdi Azikiwe UniversityP.M.B.2025AwkaNigeria Department of Civil Engineering Covenant UniversityP.M.B.1023OttaNigeria Department of Civil Engineering The University of the South PacificP.M.B.9072SuvaFiji Department of Mechanical Engineering Delta State University of Science and TechnologyP.M.B.5OzoroNigeria

The need to increase bio-oil yield from biomass and enhance its fuel properties has driven research into optimizing the pyrolysis *** study investigated the influence of three key process parameters—temperature,heating rate,and nitrogen flow rate—on the pyrolysis of elephant grass(Pennisetum purpureum)in a fixed-bed *** surface methodology was used to study the im-pact of the aforementioned variables on bio-oil yield to improve its production *** analysis of the biomass revealed 79.24 wt%volatile matter,14.22 wt%fixed carbon,and 5.86%ash,with ultimate analysis showing 45.44%carbon,5.59%hydrogen,and 40.95%*** high volatile matter content and favourable carbon and hydrogen percentages indicate that elephant grass is a vi-able energy source due to its potential for high bio-oil yield and energy *** resulting bio-oil exhibited a higher heating value of 20.9 MJ/kg,indicating its suitability for various heating applications.A second-order regression model was developed for bio-oil yield,with optimal conditions identified as a temperature of 550°C,a heating rate of 17°C/min,and a nitrogen flow rate of 6 ml/*** study achieved an optimal bio-oil yield of 59.03 wt%,and the model’s high R²value of 0.8683 from analysis of variance analysis confirmed its predictive *** research highlights elephant grass as a sustainable feedstock for bio-oil production,offering valuable insights into optimizing pyrolysis conditions to enhance bio-oil yield,thus advancing biofuel technology.

关键词： renewable energy biomass sustainable feedstock regression model fixed-bed reactor

Biofabrication of nanocomposite-based scaffolds containing human bone extracellularmatrix for the differentiation of skeletal stem and progenitor cells

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

Bio-Design and Manufacturing 2024年第2期7卷 121-136页

作者： Yang-Hee Kim Janos M.Kanczler Stuart Lanham Andrew Rawlings Marta Roldo Gianluca Tozzi Jonathan i.Dawson Gianluca Cidonio Richard o.C.oreffo Faculty of Medicine Bone and Joint Research GroupCentre for Human DevelopmentStem Cells and RegenerationInstitute of Developmental SciencesUniversity of SouthamptonSouthampton SO166YDUK School of Pharmacy and Biomedical Science University of PortsmouthPortsmouth PO12DTUK School of Engineering Faculty of Engineering and ScienceUniversity of GreenwichGreenwich ME44TBUK Center for Life Nano-and Neuro-Science(CLN2S) Italian Institute of Technology00161 RomeItaly

Autograft or metal implants are routinely used in skeletal ***,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering *** use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor ***,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HBMSCs)to proliferate and differentiate along the osteogenic *** this study,we engineered a novel material ink(LAB)by blending human bone-ECM(B)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based *** inclusion of the nanoﬁller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HBMSCs viability upon *** composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(VEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)*** inclusion of bone morphogenetic protein-2(BMP-2)with the HBMSCs further enhanced vascularization and mineralization after only seven *** study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair.

关键词： Extracellular matrix Nanoclay Bone 3D bioprinting

Therapeutic smart-footwear approach for management of neuropathic diabetic foot ulcers:Current challenges and focus for future perspective

在线全文

学校读者我要写书评

暂无评论

Medicine in Novel Technology and Devices 2024年第3期23卷 1-13页

作者： Stanley i.R.okoduwa Bernard E.igiri Jerry i.Tagang Ugochi J.okoduwa Abraham o.Adeyi Directorate of Research and Development Nigerian Institute of Leather and Science TechnologyZariaNigeria Department of Biochemistry School of Basic Medical SciencesBabcock UniversityIlishan-RemoNigeria Department of Footwear Technology Nigerian Institute of Leather and Science TechnologyZariaNigeria industrial and Environmental Pollution Department National Research Institute for Chemical TechnologyZariaNigeria

Diabetic foot ulcers(DFU)have been connected to rising global mortality *** increased plantar tissue stress beneath the numb foot of neuropathy patients is associated with *** article summarises essential therapeutic footwear concepts for the treatment of DFUs and shows how new sensor technologies have made this *** with neuropathic DFUs can address their foot problems with therapeutic footwear without being constrained in their daily *** intervention in maintaining DFUs must be discrete,power-efficient,accurate,and user-friendly in order to offer a trustworthy and acceptable way for effective health *** device can be inserted into a person's shoes from the plantar aspect of the foot to gather more information about their *** findings showed that weight-bearing activities and sensor offloading devices can be employed as effective offloading therapies to heal *** article examines the therapeutic footwear-based technological sensor system,which keeps track of many elements that are helpful in tracking foot ulcers,available treatments,and potential research areas in the future.

关键词： Diabetic foot ulcer Therapeutic footwear Sensors Neuropathy Plantar pressure

Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

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

Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry o El-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis El-Dib's frequency formula

Sensing nanoscale electromagnetic forces when the heat is on

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第7期11卷 64-65页

作者： Eric o.Potma Department of Chemistry University of California

in scanning probe microscopy(SPM),a sharp tip scans across a sample to produce an image with nanometer-scale resolution or better. SPM contrast is derived from the physical interplay between the tip and the sample. A special class of SPM techniques measures forces when the tip–sample junction is illuminated by an external light source. Photo-induced forces can be sensitive to the optical properties of the sample, thus enabling nanoscale imaging with spectroscopic,material-specific contrast.

关键词：