检索结果-南通市图书馆

Combination of hydrotreating and delayed coking technologies for conversion of residue

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第11期63卷 209-219页

作者： José A.D.Munoz Gabriel Páez Jorge Ancheyta Instituto Mexicano del Petróleo Eje Central Lázaro Cárdenas Norte 152Col.San Bartolo AtepehuacanMéxico City 07730México

Residue conversion by combining catalytic hydrotreating and delayed coking has been evaluated comparatively with both processes *** operating conditions are defined to achieve the greatest economic benefit for upgrading an atmospheric residue from a heavy crude oil.A literature model was adapted to simulate the hydrotreating reactor,and for delayed coking,correlations reported in the literature were *** results with both approaches were employed to calculate the techno-economic feasibility of the combined process *** combination of hydrotreating and delayed coking presented an increase in light fractions of 29% and a reduction in coke production of 47.8%.Based on the calculated net benefit values,it was demonstrated that the combination of hydrotreating and delayed coking is technically and economically better than using each process alone,with highest benefit of 57.7 USD·m^(-3).

关键词： Economic benefit Heavy oil Hydrotreating Delayed coking

Multilayer transition in a spin-1 Blume Capel model with RKKY interaction and quantum transverse anisotropy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第1期20卷 609-615页

作者： N.Tahiri H.ez-Zahraouy A.Benyoussef Computational Physics Group LMPHEDepartement de PhysiqueFaculte des SciencesUniversite Mohammed V-AgdalB.P.1014RabatMorocco

Using mean-field theory, we have studied the effect of quantum transverse anisotropies with RKKY interaction on the multi-layer transition and magnetic properties of the spin-1 Blume-Capel model of a system formed by two magnetic multi-layer materials, of different thicknesses, separated by a non-magnetic spacer of thickness M. It is found that the multilayer magnetic order-disorder transition temperature depends strongly on the value of the transverse anisotropy. The multilayer transition temperature decreases when increasing the transverse anisotropy. Furthermore, there exists a critical quantum transverse anisotropy △xL beyond which the separate transitions occur in the two magnetic layers. The critical transverse anisotropy AxL decreases （increases） on increasing the non-magnetic spacer of thickness M （on increasing the crystal field）, and AxL undergoes oscillations as a function of the Fermi level.

关键词： quantum transverse anisotropy order-disorder lavering transitions. RKKY interaction

An investigation of merging and diverging cars on a multi-lane road using a cellular automation model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第11期21卷 565-572页

作者： K.Jetto H.ez-Zahraouy A.Benyoussef Laboratoire de Magnétisme et de la Physique des Hautes Energies Universit'e Mohammed V Faculté des Sciences Ecole Hassania des Travaux Publics KM 7 Route DEL JADIDAB.P 8108OasisCasablancaMaroc

In this paper, we have investigated two observed situations in a multi-lane road. The first one concerns a fast merging vehicle. The second situation is related to the case of a fast vehicle leaving the fastest lane back into the slowest lane and targeting a specific way out. We are interested in the relaxation time T, i.e., which is the time that the merging （diverging） vehicle spends before reaching the desired lane. Using analytical treatment and numerical simulations for the NaSch model, we have found two states, namely, the free state in which the merging （diverging） vehicle reaches the desired lane, and the trapped state in which T diverges. We have established phase diagrams for several values of the braking probability. In the second situation, we have shown that diverging from the fast lane targeting a specific way out is not a simple task. Even if the diverging vehicle is in the free phase, two different states can be distinguished. One is the critical state, in which the diverging car can probably reach the desired way out. The other is the safe state, in which the diverging car can surely reach the desired way out. In order to be in the safe state, we have found that the driver of the diverging car must know the critical distance （below which the way out will be out of his reach） in each lane. Furthermore, this critical distance depends on the density of cars, and it follows an exponential law.

关键词： traffic flow merging and diverging area intelligent transportation system cellular au-tomation

Primmorph extracts and mesohyls of marine sponges inhibit proliferation and migration of hepatocellular carcinoma cells in vitro

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2019年第4期9卷 284-291页

作者： Hanaa Rady Sohair Salem Mohamed ez El-Arab Chemistry of Natural Compound Department National Research Centre Cairo Egypt Molecular Genetics and Enzymology Department National Research Centre Cairo Egypt National Institute of Oceanography and Fisheries (NIOF) Hurghada Egypt

Cancer recurrence and severe side effects of currently being used chemotherapeutic agents reduce their clinical efficacy. Thus, there is a constant need to develop alternative anticancer drugs. Sustainable supply is an important challenge facing marine-based drug discovery. Primmorph, a 3D cell culture system, could provide a sustainable source to produce metabolites for anticancer drugs from marine sponges. In the present work, the anticancer activity of primmorph extracts and mesohyls of Negombata magnifica, Hemimycle arabica, Crella spinulata, and Stylissa carteri sponges was evaluated. Antiproliferative activity was studied in terms of cytotoxicity, colony formation, cell cycle, and apoptosis. Migration was assessed by migration assay and matrix metalloproteinase activity. The expression of proliferation and migration-related genes was analyzed using real time PCR. Migration and proliferation activities of HepG2 cells were inhibited by treatment with primmorph extracts and mesohyls of N. magnifica, H. arabica, and C. spinulata. The mesohyl of S. carteri did not show any anticancer activity although the primmorph extract led to cell cycle arrest. Among the selected sponge species, the primmorph extract of C. spinulata was the most promising anticancer agent regarding antiproliferative and antimigratory activities. In addition, primmorph extracts have the advantage of working under welldefined and controlled conditions, which allows the easy application as a bioreactor.

关键词： Marine sponge Primmorph Mesohyl Proliferation Migration Hepatocellular carcinoma cell line

Synthesis and characterization of bulk composite Fe-Si-B alloys with small concentration of Nb and Mo

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2010年第6期23卷 401-408页

作者： S.Bez I.Betancourt I.A.Figueroa Institute for Materials Research National Autonomous University of Mexico (UNAM)

The preparation and some mechanical, thermal and magnetic properties of the as cast bulk composite ***4 （M=Nb, Mo） alloys obtained by suction casting are presented and discussed. The microstructrural results showed the existence of a crystalline a-Fe（Si） phase embedded in a glassy matrix. The values of microhardness （/Iv） and yield strength （ay） for the Nb-containing alloy are exceptionally high, i.e. （12.65~0.3） GPa and （4.22~0.10） GPa, respectively. The saturation polarization values are found to be as high as 1.24 T for both composite ~11oys. It is thought that the interplay between the secondary crystalline phases and amorphous matrix could be responsible for the mechanical and magnetic behaviour of these alloys.

关键词： Bulk composite alloys Magnetic properties Mechanical proper- ties Thermal stability and suction casting

Are we ready to use new endoscopic scores for ulcerative colitis?

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第10期30卷 1466-1469页

作者： Rodrigo Quera Paulina Núñez F Universidad de los Andes Inflammatory Bowel Disease ProgramClinica Universidad de los AndesDigestive Disease CenterSantiago 7600976RMChile Digestive Disease Center Inflammatory Bowel Disease ProgramClínica Universidad de los AndesSantiago 7620157Chile Department of Gastroenterology Universidad de Chile-Hospital San Juan de DiosSantiago 770123Chile

For ulcerative colitis(UC),the variability in inflammatory activity along the colon poses a challenge in *** focus on achieving endoscopic healing in UC is evident,where the UC Endoscopic Index of Severity and Mayo Endoscopic Subscore are commonly used for ***,these indices primarily consider the most severely affected *** et al recent study validates the Toronto Inflammatory Bowel Disease Global Endoscopic Reporting(TIGER)score offering a comprehensive assessment of inflammatory activity across diverse segments of the colon and rectum and a reliable index correlating strongly with UC Endoscopic Index of Severity and moderately with Mayo Endoscopic Subscore(MES).Despite recommendation,certain aspects warrant further *** calprotectin,an intermediate target,correlates with TIGER and should be *** TIGER scores defining endoscopic remission and response,evaluating agreement with histological activity,and assessing inter-endoscopist agreement for TIGER require *** the correlation between TIGER and intestinal ultrasound,akin to MES,adds value.

关键词： Ulcerative colitis Sigmoidoscopy Colonoscopy Score index

One-Generated Nilpotent Bicommutative Algebras

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

Algebra Colloquium 2022年第3期29卷 453-474页

作者： Ivan Kaygorodov Pilar Páez-Guillán Vasily Voronin Centro de Matemática e Aplicacōes Universidade da Beira InteriorCovilhãPortugal Institute of Mathematics and Mathematical ModelingAlmatyKazakhstan University of Santiago de Compostela Santiago de CompostelaSpain University of ViennaViennaAustria Novosibirsk State University NovosibirskRussia

We give a classification of 5-and 6-dimensional complex one-generated nilpotent bicommutative algebras.

关键词： bicommutative algebras nilpotent algebras algebraic classification central extension

Temporal dynamics of shallow subtidal meiobenthos from a beach in Tenerife (Canary Islands, northeast Atlantic Ocean)

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

Acta Oceanologica Sinica 2013年第8期32卷 44-54页

作者： Rodrigo Riera Jorge Núez María del Carmen Brito Centro de Investigaciones Medioambientales del Atlántico (CIMA SL) Arzobispo Elías Yanes 4438206 La Laguna Tenerife Canary Islands Spain Benthos Laboratory Department of Animal Biology Faculty of Biology University of La Laguna

A shallow subtidal （3 m deep） meiofaunal assemblage in Los Abrigos Bay, Tenerife, Canary Islands was sam- pled during May 2000-April 2001. The main aims were to （1） find temporal variations in meiofaunal assem- blage structure and overall abundance, as well as in the most abundant meiofaunal species throughout the study period, and （2） identify environmental variables （sedimentary composition, organic matter content, and total nitrogen） that better explain meiofaunal assemblage structure during the study year. The most abundant species were the nematodes Siphonolaimus sp. 2 and Catanema sp., which represented 46.2% of the overall meiofaunal abundances and varied significantly throughout the study duration. Overall meio- faunal abundance and the most abundant taxonomic groups （nematodes, copepods, and oligochaetes） showed significant temporal variations during the study period. Nematodes overwhelmingly dominated during the study period, ranging from 78% in May to 97.34% in February. Multivariate analyses showed seasonality in meiofaunal community structure during the study year, with the lowest abundances in May. Keywords： Meiofauna, assemblage structure, subtidal, Canary Islands, Atlantic Ocean

关键词： Meiofauna assemblage structure subtidal Canary Islands Atlantic Ocean

Indirect determination of shear wave velocity in slow formations using full-wave sonic logging technique

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1226-1233页

作者： Francisco Beltran Alvaro Yañez-gonza.ez María J.Crespo Belgar Engineering Consultants Gabriel García Márquez 9Collado-Villalba28400Spain ESTEYCO Menéndez Pidal 17Madrid28036Spain Principia Engineering Consuxltants Velázquez 94Madrid28006Spain

This article presents a case study concerning a seismic characterization ***-wave sonic logging was used to characterize the shallow compressional wave and shear wave velocity profiles in the *** values of the Poisson’s ratio derived from the velocity profiles suggested that the boreholes might have traversed slow formations(*** shear wave velocity smaller than the borehole fluid compressional wave velocity or“mud-wave speed”)and that conventional processing of the sonic logs might have misinterpreted the direct arrivals of fluid acoustic waves as arrivals caused by shear wave propagation in the ***,the shear wave velocity profiles provided by the contractor were considered to be unreliable by the project *** address these problems,a non-conventional determination of the shear wave velocity was implemented,based on the relationship between the Poisson’s ratio of the rock formation and the shape of the first train of sonic waves which arrived to the receivers in the sonic *** relationship was determined based on several hundreds of finite element simulations of the acoustic wave propagation in boreholes with the same diameter as used in the *** present article describes how this non-conventional approach was developed and implemented to obtain the shear wave velocity profiles from the raw sonic *** approach allows an extension of the range of applicability of full-wave sonic logging to determination of shear wave velocity profiles in formations with low compressional wave *** method could be used to obtain shear wave velocity profiles where compressional wave velocity is as low as slightly larger than the mud-wave speed.A sample sonic log in Log ASCII Standard(LAS)format is provided as supplementary material to this paper via Mendeley Data,together with the FORTRAN source code used to process the log following the approach described in this study.

关键词： Sonic logging Slow formation Shear wave velocity Poisson’s ratio P-wave packet