检索结果-南通市图书馆

Dynamically generated resonances from the vector octet-baryon decuplet interaction and their radiative decays into γ-baryon decuplet

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2009年第12期33卷 1366-1368页

作者：孙宝玺 Sourav Sarkar E. Oset m.j. Vicente Vacas Institute of Theoretical Physics College of Applied Sciences Beijing University of Technology Departamento de Física Teórica and IFIC Centro Mixto Universidad de Valencia-CSIC Institutos de Investigación de Paterna Aptdo. 22085 46071 Valencia Spain Variable Energy Cyclotron Centre 1/AF Bidhannagar

The dynarnically generated resonances from vector meson-baryon decuplet are studied using La- grangians of the hidden gauge theory for vector interactions. One shows that some of the generated states can be associated with some known baryon resonances in the PDG data, while others are predictions for new states. Furthermore, we calculate the radiative decay widths of these resonances into a photon and a baryon decuplet.

关键词： dynamically generated resonances chiral dynamics hidden gauge formalism for vector mesoninteraction

Algebraic and group treatments to nonlinear displaced number states and their nonclassicality features:A new approach

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第6期24卷 334-340页

作者： n Asili Firouzabadi m K Tavassoly m.j.Faghihi Atomic and molecular Group Faculty of PhysicsYazd University The Laboratory of Quantum Information Processing Yazd University Physics and Photonics Department Graduate University of Advanced Technology

Recently, nonlinear displaced number states （nDnSs） have been manually introduced, in which the deformation function f（n） has been artificially added to the previously well-known displaced number states （DnSs）. Indeed, just a simple comparison has been performed between the standard coherent state and nonlinear coherent state for the formation of nDnSs. In the present paper, after expressing enough physical motivation of our procedure, four distinct classes of nDnSs are presented by applying algebraic and group treatments. To achieve this purpose, by considering the DnSs and recalling the nonlinear coherent states formalism, the nDnSs are logically defined through an algebraic consideration. In addition, by using a particular class of Gilmore-Perelomov-type of SU（1,1） and a class of SU（2） coherent states, the nDnSs are introduced via group-theoretical approach. Then, in order to examine the nonclassical behavior of these states, sub-Poissonian statistics by evaluating mandel parameter and Wigner quasi-probability distribution function associated with the obtained nDnSs are discussed, in detail.

关键词： displaced number state nonlinear coherent state Wigner function nonclassical state

EFFECT OF QUEnCHInG TEmPERATURE On SHAPE mEmORY EFFECT OF Fe-18mn -5Si-8Cr-4ni ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta metallurgica Sinica(English Letters) 1999年第5期12卷 739-742页

作者： Wen, Y.H. Li, n. Xu, Y.G. Tu, m.j. Li, Y.L. ma, Y.L. Sichuan Univ Chengdu China

The effects of quenching temperature on shape memory effect and microstructure of Fe 18mn 5Si 8Cr 4ni shape memory alloy have been studied. The results show that both the shape recovery ratio and the recovery strain increased as quenching temperature increased, the amount of stress induced ε martensite in the process of cold work decreased with the increase of quenching temperature, the shape recovery ratio and the recovery strain reached maximum at 650℃, and then decreased rapidly with the further increase of quenching temperature,the stress induced ε martensite wholly disappeared at 1023K. But when the quenching temperature is higher than 1023K, the further increase of quenching temperature had little effect on shape recovery ratio, the amount and size of thermal induced ε martensite would increased with the further increase in quenching temperature. The shape memory effect can be improved by the moderate amount of pre exist ε martensite in the matrix before deforming.

关键词： shape memory alloy shape recovery ratio ,martensite transformation

3D printing of patient-specific 316L–stainless–steel medical implants using fused filament fabrication technology: two veterinary case studies

在线全文

学校读者我要写书评

暂无评论

Bio-Design and manufacturing 2022年第4期5卷 808-815页

作者： j.m.Chacón P.j.núñez m.A.Caminero E.García-Plaza j.Vallejo m.Blanco Escuela Técnica Superior de Ingeniería Industrial Universidad de Castilla-La ManchaAvdaCamilo JoséCela213071 Ciudad RealSpain Protresde Ingeniería y Soluciones C/Solana 60nave 313005 Ciudad RealSpain

Biomedical fracture fixation implants have complex sculptured geometries to adapt perfectly to fractured bones,making them difficult and expensive to manufacture with conventional machining methods. Fused filament fabrication(FFF) is a very popular Additive manufacturing technology that simplifies the manufacture of parts with complex geometries, making it ideal for the manufacture of customized medical implants.

关键词： steel fracture fused

Predicting the spatial distribution of soil erodibility factor using USLE nomograph in an agricultural watershed,Ethiopia

在线全文

学校读者我要写书评

暂无评论

International Soil and Water Conservation Research 2015年第4期3卷 282-290页

作者： Hailu Kendie addis Andreas Klik Institute of Hydraulics and Rural Water management University of Natural Resources and Life SciencesViennaAustria Gondar Agricultural Research Center Soil and Water Management DirectorateGondarEthiopia

Soil erosion in the northwestern Amhara region,Ethiopia has been a subject of anxiety,resulting in a m.j.r environmental threat to the sustainability and productive capacity of agricultural *** study tried to estimate soil erodibility factor(Kfactor)using Universal Soil Loss Equation(USLE)nomograph,and evaluate the spatial distribution of the predicted K-factor in a mountainous agricultural *** investigate the K-factor,the 54 km2 study watershed was divided into a 500 m by 500 m square grid and approximately at the center of each grid,topsoil samples(roughly 10 to 20 cm depth)were collected over 234 ***,silt,clay and organic matter(Om)percentage were analyzed,while soil permeability and structure class codes were obtained using the United States Department of Agriculture(USDA)*** resulting coefficient of variation(CV)of the estimated K-factor was 0.31,suggesting a moderate ***,the value of nugget to sill ratio of K-factor was 0.32,which categorized as moderate spatial *** accuracy and model fitting effect of the Gaussian semivariogram approach was best,suggesting that the Gaussian ordinary Kriging model was more appropriate for predicting *** resulting value of the mean error(mE)was 0 and the mean squared deviation ratio(mSDR)was nearly 1,which indicates the Gaussian model was unbiased and reproduced the experimental variance *** values of K-factor were smaller(0.0217 to 0.0188)in the northern part and gradually increased(0.0273 to 0.033 mg h mj^(-1)mm^(-1))towards the central and south of the study watershed.

关键词： nomograph Semivariogram Soil erodibility factor Spatial variability Watershed

Site Selective Excitation and Energy Transfer in LiKGdF_5 Crystal Co-doped with Er^(3+) and Tb (3+)

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 Rare Earths 2004年第1期22卷 22-26页

作者：尹民 Khaidukov n m Krupa j C Structure Research Laboratory Kurnakov Institute of General and Inorganic Chemistry Institut de Physique nucléaire

Crystals of LiKGdF 5∶Er 3+, Tb 3+ grown by the hydrothermal synthesis technique with concentrations of 2% and 0.4% were analysed. By using site selective excitation measured at low temperature, luminescence and excitation spectra from Er 3+ and Tb 3+ ions embedded in LiKGdF 5 were clearly separated. The lifetimes of the emitting levels 4S 3/2 of Er 3+ and 5D 4 of Tb 3+ were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb 3+ to Er 3+ in the crystal was then investigated via transient experiments.

关键词： optics condensed matter physics energy transfer luminescence LiKGdF 5∶Er3+, Tb3+ rare earths

COmPARATIVE STUDIES OF InORGAnIC CARBOn UTILIZATIOn In EmILIAnIA HUXLEYI AnD SOmE nOn-CALCIFYInG mARInE mICROALGAE

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Oceanology and Limnology 1999年第3期17卷 219-232页

作者：董良峰 merrett m.j. 吴超元 Department of Biology John Tabor Laboratory University of Essex Colchester UK School of Biological Sciences University of Wales Swansea Swansea UK Department of marine Botany Institute of Oceanology Chinese Academy of Sciences Qingdao China

Inorganic carbon utilization in the non calcifying marine microalgae, nannochloropsis oculata, Phaeodactylum tricornutum and Porphyridium purpureum was compared with high and low calcifying strains of Emiliania huxleyi grown in artificial seawater medium aerated with either air (0.03% V/V CO 2) or CO 2 free air. For high calcifying strain of E. oculata and P. tricornutem , similar growth patterns were observed in air and CO 2 free air grown cultures. P. purpureum showed a less final cell density in CO 2 free air than in air grown culture. However, low calcifying strain of E. huxleyi was able to grow only in air grown culture, but not in CO 2 free air grown culture. measurements of alkalinity, pH, concentration of dissolved inorganic carbon (DIC) and free CO 2 showed different patterns of DIC utilization. With n. oculata, P. tricornutum and P. purpureum the pattern of DIC utilization was characterized by an increase of pH and a decrease of DIC but a constant alkalinity in the cultures aerated with air or CO 2 free air, suggesting that bicarbonate utilization was concomitant with an efflux of OH -. Both alkalinity and pH were maintained rather constant in air grown culture of low calcifying strain of E. huxleyi, suggesting that diffusive entry of CO 2 could meet the requirement of DIC for its photosynthesis and growth. High calcifying strain of *** , however, showed a pattern of decrease of alkalinity and DIC but an almost constant pH , indicating that bicarbonate was the m.j.r form of inorganic carbon utilised by this organism and bicarbonate uptake is unlikely to be accompanied by an efflux of OH -. The final pH values reached by n. oculata, P. tricornutum and P. purpureum in a closed system were 10.75, 10.60 and 9.85 respectively, showing that bicarbonate utilisation is concomitant with an efflux of OH . While the final pH of 8.4 in high calcifying E. huxleyi suggests that bicarbonate utilization was not accompanied by an efflux of OH -.

关键词： inorganic carbon Emiliania huxleyi non calcifying marine microalgae

K-P-Burgers equation in negative ion-rich relativistic dusty plasma including the effect of kinematic viscosity

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第10期25卷 215-221页

作者： A n Dev m K Deka j Sarma D Saikia n C Adhikary Department of mathematics Siksha ‘O' Anusandhan University Department of Applied Sciences Institute of Science and Technology Gauhati University Department of mathematics R G Baruah College Physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan Path Paschim Boragaon

The stationary solution is obtained for the K–P–Burgers equation that describes the nonlinear propagations of dust ion acoustic waves in a multi-component, collisionless, un-magnetized relativistic dusty plasma consisting of electrons, positive and negative ions in the presence of charged massive dust grains. Here, the Kadomtsev–Petviashvili(K–P) equation, threedimensional(3D) Burgers equation, and K–P–Burgers equations are derived by using the reductive perturbation method including the effects of viscosity of plasma fluid, thermal energy, ion density, and ion temperature on the structure of a dust ion acoustic shock wave(DIASW). The K–P equation predictes the existences of stationary small amplitude solitary wave,whereas the K–P–Burgers equation in the weakly relativistic regime describes the evolution of shock-like structures in such a multi-ion dusty plasma.

关键词： K–P–Burgers equation negative ion relativistic plasma reductive perturbation method

Harnessing the potential of additive manufacturing technologies:Challenges and opportunities for entrepreneurial strategies

在线全文

学校读者我要写书评

暂无评论

International journal of Innovation Studies 2018年第4期2卷 123-136页

作者： marie Lavoie james L.addis York University/Glendon College-Economics Department and Glendon School of Public and International Affairs 2275 Bayview AvenueTorontoOntarioM4N3M6Canada York University/Glendon College-Economics Department 2275 Bayview AvenueTorontoOntarioM4N3M6Canada

Additive manufacturing(Am),a revolutionary production technique that will make many previously inconceivable innovations a reality,is transforming the manufacturing *** technologies behind Am have a generic character and possess immense and transformative potential that will be felt across different sectors of the *** paper studies how entrepreneurs can access,exploit,and diffuse this new disruptive knowledge,as well as the potential challenges that lie ***,we examine the magnitude of the knowledge pool created by the Top 10 countries in Am research from 2011 to 2016;specifically,we determine the leading countries,the pattern of organizational and international collaborations,leading disciplines contributing to Am,and the pattern in authors'*** find that the US is clearly the dominant country,while China witnessed a notable acceleration in Am research between 2014 and 2016;we also show that universities are the predominant actor in codified Am knowledge *** this information,we paint a vivid picture of the technological and market opportunities for entrepreneurs and identify the gaps in the current knowledge production environment;we find that the challenges currently faced by entrepreneurs could be overcome through academic entrepreneurship,collective entrepreneurship,and the actions of an entrepreneurial state.

关键词： Additive manufacturing Knowledge pool Entrepreneurship Innovation systems Innovation policy Evolutionary economics