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Five-quark components in baryons

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Chinese Physics C 2010年第9期34卷 1201-1204页

作者： D.O.Riska Helsinki Institute of Physics POB 64FIN-00014 University of Helsinki Finland

While several experiments based on the Drell-Yan process have revealed the presence of light antiquarks in the proton,the experimental signatures for strange quark components remain consistent with *** studies of meson photoproduction on nucleons with hadronic models indicate that the underprediction of the NΔ transition strengths by the three quark model may be attributed to the missing ＂meson cloud＂ *** qqqqq configurations are included in the baryon wave functions the conclusions that emerge are that （a） a combination of at least three different qqqqq configurations are required for a satisfactory description of the nucleon properties and （b） that the vanishing of the axial form factor of the N（1535） resonance is a natural consequence of the cancellation of the contributions of the qqq and qqqqq configurations.

关键词： quark model baryons

From gene editing to genome engineering: restructuring plant chromosomes via CRISPR/Cas

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aBIOTECH 2020年第1期1卷 21-31页

作者： Carla Schmidt Patrick Schindele Holger Puchta Botanical Institute Karlsruhe Institute of TechnologyPOB 698076133 KarlsruheGermany

In the last years,tremendous progress has been achieved in the field of gene editing in *** the induction of single site-specific double-strand breaks(DSBs),the knockout of genes by non-homologous end joining has become routine in many plant ***,the efficiency of inducing pre-planned mutations by homologous recombination has also been improved ***,very little effort has been undertaken until now to achieve more complex changes in plant genomes by the simultaneous induction of several *** reports have been published on the efficient induction of ***,the induction of intrachromosomal inversions and interchromosomal recombination by the use of CRISPR/Cas has only recently been *** this review,we want to sum up these results and put them into context with regards to what is known about natural chromosome rearrangements in ***,we review the recent progress in CRISPR/Cas-based mammalian chromosomal rearrangements,which might be inspiring for plant *** the long run,the controlled restructuring of plant genomes should enable us to link or break linkage of traits at will,thus defining a new area of plant breeding.

关键词： Chromosomal rearrangements CRISPR/Cas Genome engineering Inversion Translocation

LIQUID-LIQUID PHASE EQUILIBRIUM OF POLYMER SOLUTIONS AND POLYMER BLENDS UNDER POSITIVE AND NEGATIVE PRESSURE

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Chinese Journal of Polymer Science 2003年第2期21卷 241-250页

作者： Attila R.Imre KFKI Atomic Energy Research Institute H-1525 Budapest POB 49 Hungary

In this paper we would like to give a brief review about the extensibility of the liquid-liquid locus into the negativepressure region. Negative pressure states are hardly explored; most researchers believe that the pressure scale ends at p = *** would like to show that this is not true, the p = 0 point is not a special point for liquids, it can be 'easily' crossed. We aregoing to give a few example, where the extension of liquid-liquid locus for polymer blends and solutions below p = 0 givesus some interesting results, like the merging of UCST and LCST branches in weakly interacting polymer solutions or thereason why most UCST blends exhibit pressure induced immiscibility. Also, we will see what happens with the immiscibilityisland of aqueous polymer solutions when -- reaching the critical molar mass -- it 'disappears'.

关键词： Pressure Negative pressure Polymer Solubility Phase transition

Physical aspects of f(R,G_(μν)T^(μν))modified gravity theories

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Chinese Physics C 2023年第10期47卷 237-248页

作者： Mihai Marciu Dana Maria Ioan Faculty of Physics University of Bucharest405 AtomistilorPOB MG-11RO-077125Bucharest-MagureleRomania

The paper extends basic Einstein–Hilbert action by incorporating an invariant derived from a specific contraction between the Einstein tensor and energy momentum *** represents a non–minimal coupling between the space–time geometry and matter *** fundamental Einstein–Hilbert action is extended by considering a generic function f(R,GμνTμν).This function is subsequently dissected into its primary components:a geometric part reliant on the scalar curvature,and another segment encapsulating the interaction between geometry and matter *** cosmological models are formulated at the backdrop of these dynamics,rooted in specific associations between the matter energy-momentum tensor and Einstein *** deriving the consequent field equations,the cosmological model's physical implications are explored through a dynamical system analysis applied to diverse coupling *** exploration reveals that the current model aligns with various phases in the Universe's evolution,potentially elucidating several late-time historical epochs.

关键词： dark energy cosmology modified gravity theories

Analysis of Karst Tufa from Guangxi, China

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Acta Geologica Sinica(English Edition) 2003年第2期77卷 267-275页

作者： StanislavFRANCISKOVIC-BILINKI HalkaBILINSKI DelkoBARISIC NadaHORVATINCIC YUANDaoxian InstituteRuderBoskovic POB180HR-10001ZagrebCroatia InstituteofKarstGeology GuilinGuangxi541004China

The paper presents an analysis of characteristic karst tufa from Guangxi, China, which has not been studied before. A comparison with tufa from Dinaric Karst of Croatia is discussed in view of the C-type climate. The major mineral is calcite. Minor minerals are quartz and dolomite, depending on location. The content of calcium carbonate varies from 65% to 92%, and that of magnesium carbonate from 0.03% to 1.77%. Among other elements, the most abundant are Fe, from 0.02% to 1.50%, and Ti, from 0.15% to 0.27%. Many other trace elements (V, Cr, Mn, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Hg and Pb) are also present. Specific activity of radionuclides 40K, 232Th, 137Cs, 226Ra and 238U varies from sample to sample. Concentration of U in tufa is close to that reported for sedimentary carbonate. Low concentration of 137Cs indicates that this part of the world was not exposed to nuclear explosions. The concentration of 226Ra is the highest in Mashan County. The ratio 238U/226Ra (0.21-0.71) in tufa from Mashan County is significantly lower than the theoretical value of 1. In 5 of the 11 studied samples, stable isotopes δ13C and δ18O were analyzed. They were dated by means of the 14C method. One tufa sample originated in the Pleistocene and the others in the Holocene. Because all of the tufa samples contain traces of Na and K, and K < Na, the tufa from Guangxi belong to the CO2-outgassing 'N' type according to the classification of Liu and He (1994).

关键词： tufa in Guangxi mineral composition elements radionuclides chronological data climatic optimum

Stratification of selected hydrolytic enzyme activities in the sediment in two lakes in Finland

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International Journal of Sediment Research 2012年第2期27卷 250-258页

作者： Mika A.KHKNEN Risto HAKULINEN Department of Food and Environmental Sciences Division of MicrobiologyPOB 56Viikki BiocenterHelsinki UniversityFIN 00014Finland

To investigate the stratification of hydrolytic enzyme activities and importance of subsurface layers in depolymerization of detritus biopolymers,nine hydrolytic enzyme activities involved in the cycling of carbon,phosphorus,nitrogen and sulphur were measured in various sediment layers and their extracts at Kylaniemi in Lake Saimaa in southern Finland and in Lake Ahvenjarvi in northern Finland. The results show that for each lake all nine hydrolytic enzyme activities were higher in all sediment layers than in comparable sediment extracts indicating that the major part of enzymes was bound to the sediment particles in all layers in both ***,P-cellobiosidase,activities did not show any gradient with sediment depth at Kylaniemi in Lake Saimaa indicating that there was rapid turnover of carbohydrates in the entire sediment *** activities of acetate esterase,butyrate esterase,phosphomonoesterase,aminopeptidase,N-acetyl glucosaminidase,sulphatase andβ-glucosidase in the deepest layers were 19-53%of those in the surface sediment indicating that depolymerization of biopolymers involved in the cycling of carbon,nitrogen,phosphorus and sulphur was substantial in subsurface sediment.

关键词： Detritus Hydrolytic enzyme activities Lake sediment

Early Analogue Modeling Experiments and Related Studies to Today's Problems of Geo-electromagnetic Exploration

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Journal of China University of Geosciences 2009年第3期20卷 618-625页

作者： László Szarka Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences University of West-HungaryH-9401 Sopron POB 5 Hungary

As I learned it from extensive geo-electromagnetic analogue modeling experiments, some specific nonconventional interpretation parameters, in certain conditions, give more detailed information about the geometry of subsurface resistivity inhomogeneities than the routinely used parameters. In this article, I show several examples, and I present how these early results influenced our later research. An enhanced geometric sensitivity may be due to special array geometry （as we call it ＂null array＂）, or it may be due to a narrow and very special frequency range （i.e., the so-called ＂keyhole＂ range）. Nonconventional but physically based interpretation parameters （like the Poynting vector） or higher order invariants of resistivity or impedance tensors may also give useful additional information about the shape of subsurface bodies. One should be very careful in their application because a large part of these nontraditional approaches are strongly constrained by measuring errors and geological noise.

关键词： electromagnetic method analogue modeling null component rotational invariant.

Effect of diode size and series resistance on barrier height and ideality factor in nearly ideal Au/n type-GaAs micro Schottky contact diodes

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Chinese Physics B 2010年第10期19卷 477-484页

作者： M. A. Yeganeh Sh. Rahmatallahpur A. Nozad R. K. Mamedov Faculty of Physics Baku State University Academic Zahid Xlilov Küsi-23 AZ 1148 Iran Material Research School POB 55515196 Binab Iran

Small high-quality Au/n type-GaAs Schottky barrier diodes （SBDs） with low reverse leakage current are produced using lithography. Their effective barrier heights （BHs） and ideality factors from current-voltage （I-V） characteristics are measured by a Pico ampere meter and home-built I-V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in ideality factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope （AFM） shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100-200 nm. Between barrier height and ideality factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its ideality factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and ideality factor.

关键词： Schottky barrier diodes conducting probe-atomic force microscope barrier height andideality factor

The cis-trans Isomerisation of Homologous 2-Hydroxycycloalkanecarboxylic Acids under Basic Conditions

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Chinese Journal of Chemistry 2006年第12期24卷 1792-1795页

作者： GYARMATI Cs. Zsuzsanna PALINKO lstván BOKROS Attila MARTINEK A. Tamás BERNATH Gábor Institute of Pharmaceutical Chemistry University ofSzeged Szeged POB 121 H-6701 Hungary Research Group for Heterocyclic Chemistry of the Hungarian Academy of Sciences and University of Szeged Szeged POB 121 H-6701 Hungary Department of Organic Chemistry University of Szeged Szeged Ddm tér 8 H.6720 Hungary

The cis→trans isomerisation of homologous 2-hydroxycycloalkanecarboxylic acids in strongly basic aqueous solution was studied starting from the cis isomers. It was found that the cyclopentane, cyclohexane and cycloheptane homologues afforded synthetically useful amounts of the trans acids and the procedure resulted in relatively small quantities of the corresponding olefinic acids. In contrast, the isomerisation of the cis-2-hydroxycyclooctanecarboxylic acid produced roughly equal amounts of the cis and trans isomers and the 1-cyclooctenecarboxylic acid at equilibrium. Molecular modelling with the PM3 semiempirical method of the reactants, products and the intermediates applying explicit water molecules as reaction medium gave a fair estimate for the rate sequence of the idealised （dehydration-free） isomerisation reactions in aqueous base solution.

关键词： geometric isomerisation base catalysis reaction mechanism molecular modelling