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Chinese j.urnal of Polymer Science 2004年第3期22卷 279-287页

作者：徐君庭 Anthony j. Ryan Department of Polymer Science & Engineering Zhejiang University Hangzhou 310027 China Chemistry Department The University of Sheffield Sheffield S3 7HF UK

The fractions of one metallocene-based (mPE) and one conventional (znPE) ethylene-butene copolymer eluted at from temperature rising elution fractionation were selected for DSC and time-resolved small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) characterization. The DSC and WAXS results show that two crystal structures exist in both mPE and znPE: structure A with higher melting temperature and structure B with lower melting temperature. It was found that original znPE (s-znPE) contains more highly ordered structure A than original mPE (s-mPE) in spite of the higher comonomer content of znPE. Another structure C is also identified because of higher crystallinity measured by WAXS than by DSC and is attributed to the interfacial region. The SAXS data were analyzed with correlation function and two maxima were observed in s-mPE and s-znPE, in agreement with the conclusion of two crystal populations drawn from DSC and WAXS results. These two crystal populations have close long periods in s-mPE, but very different long periods in s-znPE. In contrast, freshly crystallized mPE and znPE (f-mPE and f-znPE) contain only a single crystal population with a broader distribution of long period

关键词： SAXS WAXS Microstructure Metallocene Ethylene-butene copolymer

Cell Wall Microstructure Analysis Implicates Hemicellulose Polysaccharides in Cell Adhesion in Tomato Fruit Pericarp Parenchyma

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Molecular Plant 2009年第5期2卷 910-921页

作者： j.se j. Ordaz-Ortiz Susan E. Marcus j. Paul Knox Centre for Plant Sciences Faculty of Biological Sciences University of Leeds Leeds LS2 9JT United Kingdom

Methods developed to isolate intact cells from both unripe and ripe tomato fruit pericarp parenchyma have allowed the cell biological analysis of polysaccharide epitopes at the surface of separated cells. The LM7 pectic homogalacturonan epitope is a marker of the j.nctions of adhesion planes and intercellular spaces in parenchyma systems. The LM7 epitope persistently marked the former edge of adhesion planes at the surface of cells separated from unripe and ripened tomato fruit and also from fruits with the Cnr mutation. The LM 11 xylan epitope was associated, in sections, with cell walls lining intercellular space but the epitope was not detected at the surface of isolated cells, being lost during cell isolation. The LM15 xyloglucan epitope was present at the surface of cells isolated from unripe fruit in a pattern reflecting the former edge of cell adhesion planes/intercellular space but with gaps and apparent breaks. An equivalent pattern of LM15 epitope occurrence was revealed at the surface of cells isolated by pectate lyase action but was not present in cells isolated from ripe fruit or from Cnr fruit. In contrast to wild-type cells, the LM5 galactan and LM21 mannan epitopes occurred predominantly in positions reflecting intercellular space in Cnr, suggesting a concerted alteration in cell wall microstructure in response to this mutation. Galactanase and mannanase, along with pectic homogalacturonan-degrading enzymes, were capable of releasing cells from unripe fruit parenchyma. These observations indicate that hemicellulose polymers are present in architectural contexts reflecting cell adhesion and that several cell wall polysaccharide classes are likely to contribute to cell adhesion/cell separation in tomato fruit pericarp parenchyma.

关键词： Cell walls fruit development tomato cell adhesion cell separation polysaccharide.

Dietary supplementation of valine,isoleucine,and tryptophan may overcome the negative effects of excess leucine in diets for weanling pigs containing corn fermented protein

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j.urnal of Animal Science and Biotechnology 2025年第1期16卷 267-281页

作者： Andrea P.Mallea Charmaine D.Espinosa Su A Lee Minoy A.Cristobal Leidy j.Torrez‑Mendoza Hans H.Stein Division of Nutritional Sciences University of IllinoisUrbanaIL 61801USA Department of Animal Sciences University of IllinoisUrbanaIL 61801USA Present Address:EnviroFlight RaleighNCUSA.

Background Diets with high inclusion of corn co-products such as corn fermented protein(CFP)may contain excess Leu,which has a negative impact on feed intake and growth performance of pigs due to increased catabolism of Val and Ile and reduced availability of Trp in the brain for serotonin ***,we hypothesized that the negative effect of using CFP in diets for weanling pigs may be overcome if diets are fortified with crystalline sources of Val,Trp,and(or)*** Three hundred and twenty weanling pigs were randomly allotted to one of 10 dietary treatments in a com-pletely randomized design,with 4 pigs per pen and 8 replicate pens per treatment.A corn-soybean meal diet and 2 basal diets based on corn and 10%CFP or corn and 20%CFP were *** additional diets were formu-lated by fortifying the basal diet with 20%CFP with Ile,Trp,Val,Ile and Val,Ile and Trp,Trp and Val,or Ile,Trp and Val.A two-phase feeding program was used,with d 1 to 14 being phase 1 and d 15 to 28 being phase *** scores were recorded every other *** samples were collected on d 14 and 28 from one pig per *** d 14,fecal samples were collected from one pig per pen in 3 of the 10 treatments to determine volatile fatty acids,ammonium concen-tration,and microbial *** pigs were also euthanized and ileal tissue was *** There were no effects of dietary treatments on any of the parameters evaluated in phase *** of 10%or 20%CFP in diets reduced(P<0.05)final body weight on d 28,and average daily gain(ADG)and average daily feed intake(ADFI)in phase 2 and for the entire experimental ***,pigs fed the CFP diet supplemented with Val,Ile,and Trp had final body weight,ADFI,ADG and gain to feed ratio in phase 2 and for the entire experiment that was not different from pigs fed the control *** scores in phase 2 were reduced(P<0.05)if CFP was *** Corn fermented protein may be included by up to 20%in diets for weanling pi

关键词： Branched-chain amino acids Corn fermented protein Leucine Tryptophan Valine Weanling pigs

MANY-SERVER QUEUES WITH CUSTOMER ABANDONMENT:A SURVEY OF DIFFUSION AND FLUID APPROXIMATIONS

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j.urnal of Systems Science and Systems Engineering 2012年第1期21卷 1-36页

作者： j. G. DAI Shuangchi HE H. Milton Stewart School of Industrial and Systems Engineering Georgia Institute of Technology Atlanta GA 30332 USA. Department of Industrial and Systems Engineering National University of Singapore Singapore 11757

The performance of a call center is sensitive to customer abandonment. In this survey paper, we focus on G/GI/n ＋ GI parallel-server queues that serve as a building block to model call center operations. Such a queue has a general arrival process （the G ）, independent and identically distributed （iid） service times with a general distribution （the first G1 ）, and iid patience times with a general distribution （the ＋GI）. Following the square-root safety staffing rule, this queue can be operated in the quality- and efficiency-driven （QED） regime, which is characterized by large customer volume, the waiting times being a fraction of the service times, only a small fraction of customers abandoning the system, and high server utilization. Operational efficiency is the central target in a system whose staffing costs dominate other expenses. If a moderate fraction of customer abandonment is allowed, such a system should be operated in an overloaded regime known as the efficiency-driven （ED） regime. We survey recent results on the many-server queues that are operated in the QED and ED regimes. These results include the performance insensitivity to patience time distributions and diffusion and fluid approximate models as practical tools for performance analysis.

关键词： Heavy traffic square-root safety staffing quality- and efficiency-driven regime efficiency-driven regime piecewise OU process

Performance investigation of artificial intelligence based controller for three phase four leg shunt active filter

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Frontiers in Energy 2015年第4期9卷 446-460页

作者： j. j.YACHANDRAN R. MURALI SACHITHANANDAM Department of Electrical and Electronics Engineering SASTRA University Thanjavur 613401 India

In this paper, the choice of power quality compensator is a DSTATCOM which constitutes a three phase four leg voltage source converter （VSC） with a DC capacitor. The control strategy proposed for the DSTAT- COM is a neural network based one cycle control （OCC）. This control strategy involves neural network block, digital circuits and linear elements, which eliminates the sensors required for sensing the load current and coupling inductor current in addition to the multiplier employed in the conventional method. The calculation of harmonic and reactive currents for the reference current generation is also eliminated, thus minimizing the complexity in the control strategy. The control strategy mitigates harmonic/reactive currents, ensures balanced and sinusoidal source current from the supply mains that are nearly in phase with the supply voltage, compensates neutral current, and maintains voltage across the capacitor under unbalanced source and load conditions. The performance of the DSTATCOM with the proposed artificial neural network （ANN） controllers is validated and investigated through simulations using Matlab software. The simulation results prove the efficacy of the proposed neural network based control strategy under varying source and load conditions.

关键词： neural network DSTATCOM neutral currentmitigation total harmonic distortion (THD) three phasefour wire distribution system unbalanced and/or distortedsource

MODELING OF MICROSTRUCTURAL EVOLUTION IN MICROALLOYED STEEL DURING HOT FORGING PROCESS

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 279-286页

作者： j. Wang j. Chen Z. Zhao X.Y. Ruan National Die ＆. Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030 China

The microstractural evolution of microalloyed steel during hot forging process was investigated using physical simulation experiments. The dynamic recrystallized fraction was described by modifying Avrami＇s equation, the parameters of which were determined by single hit compression tests. Double hit compression tests were performed to model the equation describing the static recrystallized fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as： Dinc^5 = D0^5 ＋ 1.6 × 10^32t·exp （ -716870/RT ） using isothermal tests. Furthermore, an equation describing the dynamic recrystallized grain size was given as Ddyn=3771·Z^-0.2. The models of microstructural evolution could be applied to the numerical simulation of hot forging.

关键词： microalloyed forging steel flow stress recrystallized fraction grain size

First Search for Pulsed CH Maser Emission Stimulated by a Pulsar

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Research in Astronomy and Astrophysics 2025年第2期25卷 62-71页

作者： Mengting Liu Di Li j.R.Dawson j.el M.Weisberg George Hobbs Ningyu Tang Gan Luo Duo Xu Donghui Quan Research Center for Astronomical Computing Zhejiang Laboratory Department of Astronomy Tsinghua University National Astronomical Observatories Chinese Academy of Sciences CSIRO Astronomy & Space Science Australia Telescope National Facility School of Mathematical and Physical Sciences and Astrophysics and Space Technologies Research Centre Macquarie University Department of Physics and Astronomy Carleton College Department of Physics Anhui Normal University Institut de Radioastronomie Millimetrique 300 Rue de la Piscine Canadian Institute for Theoretical Astrophysics University of Toronto 60 St.George Street

We present the first search for pulsed CH maser emission potentially stimulated by PSR j.644-4559,conducted using the ultra-wide-bandwidth low-frequency receiver on Murriyang,CSIRO's Parkes Radio *** targeted three CHΛ-doublet transitions at 3264,3335,and 3349 MHz,with a variability timescale of78 *** detected ten CH emission features at 3335 and 3349 MHz,and seven features at 3264 MHz,during both pulsar-ON and pulsar-OFF *** observed velocities align with the OH emission and absorption reported by a previous study,suggesting a close spatial association between CH and OH *** derived column densities for CH clouds within the Parkes beam range from 0.05 to 9.8×1013cm-2,indicating that these clouds are likely in diffuse and translucent *** limits for CH column densities within the pulsar beam ranged from 0.3 to 9.8×*** of these column densities suggests that CH clouds may exhibit clumpiness and *** significant stimulated emission feature was detected in the optical depth ***,as part of our search for pulsed stimulated emission,we investigated the potential CH absorption of the pulsar signal and found none,in agreement with astrophysical *** upper limits for the potential maser amplification factors towards PSR j.644-4559 at 3264,3335,and 3349 MHz are 1.014,1.009,and 1.009,*** study demonstrates the feasibility of detecting pulsed CH maser emission in the interstellar medium stimulated by pulsar photons.

关键词： (stars:) pulsars: general ISM: molecules masers

Metal Dusting-Mechanisms and Preventions

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中国腐蚀与防护学报 2009年第4期29卷 262-276页

作者： j. Q. ZHANG D. j. YOUNG School of Materials Science and Engineering University of New South Wales Sydney NSW 2052 Australia

Metal dusting attacks iron,low and high alloy steels and nickel-or cobalt-base alloys by disintegrating bulk metals and alloys into metal particles in a coke *** occurs in strongly carburising gas atmospheres(carbon activity a_C>1) at elevated temperatures(400℃～1000℃).This phenomenon has been studied for decades,but the detailed mechanism is still not well *** methods of protection against metal dusting are either directed to the process conditions-temperature and gas composition-or to the development of a dense adherent oxide layer on the surface of the alloy by selective ***,metal dusting still occurs by carbon dissolving in the base metal via defects in the oxide *** research work at UNSW is aimed at determining the detailed mechanism of metal dusting of both ferritic and austenitic alloys,in particular the microprocesses of graphite deposition,nanoparticle formation and underlying metal *** work was carried out using surface observation,crosssection analysis by focused ion beam and electron microscopic examination of coke deposits at different stages of the *** was found that surface orientation affected carbon deposition and metal dusting at the initial stage of the *** dusting occurred only when graphite grew into the metal interior where the volume expansion is responsible for metal disintegration and *** was also found that the metal dusting process could be significantly changed by alterations in alloy *** was found to affect the iron dusting process by destabilising Fe_3C but increasing the rate of carbon deposition and dusting,which questions the role of cementite in ferritic alloy *** adding copper to iron did not change the carburisation kinetics,cementite formation and coke morphology,copper alloying reduced nickel and nickel-base alloy dusting rates *** of these fundamental results to the dusting behaviour of engineering al

关键词：金属腐蚀氧化防护机械装置

Late Paleozoic–Early Mesozoic tectonic evolution of the Zongwulong Shan-Qinghai Nanshan tectonic belt in the northern Qaidam continent， northern Tibet

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j.urnal of Earth Science 2025年

作者： Yonghui Zhao Chen Wu j.e Li Peter j.Haproff Lin Ding State Key Laboratory of Tibetan Plateau Earth System and Resources Environment (TPESRE)， Institute of Tibetan Plateau Research， Chinese Academy of Sciences University of Chinese Academy of Sciences Chongqing Key Laboratory of Complex Oil and Gas Field Exploration and Development， Chongqing University of Science and Technology Department of Earth and Ocean Sciences， University of North Carolina Wilmington

The Zongwulong Shan-Qinghai Nanshan tectonic belt of the northern Tibet Plateau experienced a protracted tectonic history， including the openings and closures of the Proto- and Paleo-Tethyan Oceans. Although the tectonic belt has been extensively studied， details regarding the tectonic processes involved in its development remain controversial. To better constrain the tectonic processes of this tectonic belt， we conducted detailed field geological mapping， zircon U-Pb geochronology， and whole-rock geochemical and Sr-Nd isotopic analyses. Our results show that intrusive rocks in the tectonic belt crystallized in ca. 292–233 Ma， perhaps in an arc/subduction setting. Geochemical and Sr-Nd isotopic data suggest that early Permian–late Triassic ultramafic-intermediate intrusions were sourced from the enriched mantle， whereas intermediate-acidic rocks were sourced from mixed crust-mantle. We present the tectonic model that involves: (1) Early Devonian–early Permian intracontinental extension occurred in the northern margin of the Qaidam continent (ca. 416 Ma–292 Ma); (2) Early Permian–late Triassic northward subduction of the Paleo-Tethyan Ocean resulted in arc magmatism (ca. 292 Ma–233 Ma); and (3) subsequent late Triassic intracontinental extension (ca. 233 Ma–215 Ma). Our results suggest that the late Paleozoic–early Mesozoic development of the Zongwulong Shan-Qinghai Nanshan was related to the opening， subduction， and slab retreat of the Paleo-Tethyan Ocean， which has key implications for the tectonic evolution of the northern Tibetan Plateau.

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Stochastic SIS metapopulation models for the spread of disease among species in a fragmented landscape

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International j.urnal of Biomathematics 2016年第4期9卷 97-119页

作者： Amy j. Ekanayake Department of Mathematics Western Illinois University 1 University Circle Maeomb Illinois 61455 USA

Two stochastic models are derived for a susceptible-infectious-susceptible epidemic spreading through a metapopulation： a continuous time Markov chain （CTMC） model and an It6 stochastic differential equation （SDE） model. The stochastic models are numerically compared. Close agreement suggests that computationally intense CTMC simulations can be approximated by simpler SDE simulations. Differential equations for the moments of the SDE probability distribution are also derived, the steady states are solved numerically using a moment closure technique, and these results are compared to simulations. The moment closure technique only coarsely approximates simulation results. The effect of model parameters on stability of the disease-free equilibrium is also numerically investigated.

关键词： Epidemic metapopulation Ito stochastic differential equation Markov chain moment closure.