Feynman's path-integral approach for intense-laser-atom interactions     

Salières P  Carré B  Le Déroff L  Grasbon F  Paulus GG  Walther H  Kopold R  Becker W  Milosević DB  Sanpera A  Lewenstein M 《Science (New York, N.Y.)》2001,292(5518):902-905

Atoms interacting with intense laser fields can emit electrons and photons of very high energies. An intuitive and quantitative explanation of these highly nonlinear processes can be found in terms of a generalization of classical Newtonian particle trajectories, the so-called quantum orbits. Very few quantum orbits are necessary to reproduce the experimental results. These orbits are clearly identified, thus opening the way for an efficient control as well as previously unknown applications of these processes.  相似文献   

National character does not reflect mean personality trait levels in 49 cultures     

Terracciano A  Abdel-Khalek AM  Adám N  Adamovová L  Ahn CK  Ahn HN  Alansari BM  Alcalay L  Allik J  Angleitner A  Avia MD  Ayearst LE  Barbaranelli C  Beer A  Borg-Cunen MA  Bratko D  Brunner-Sciarra M  Budzinski L  Camart N  Dahourou D  De Fruyt F  de Lima MP  del Pilar GE  Diener E  Falzon R  Fernando K  Ficková E  Fischer R  Flores-Mendoza C  Ghayur MA  Gülgöz S  Hagberg B  Halberstadt J  Halim MS  Hrebícková M  Humrichouse J  Jensen HH  Jocic DD  Jónsson FH  Khoury B  Klinkosz W  Knezević G  Lauri MA  Leibovich N  Martin TA 《Science (New York, N.Y.)》2005,310(5745):96-100

Most people hold beliefs about personality characteristics typical of members of their own and others' cultures. These perceptions of national character may be generalizations from personal experience, stereotypes with a "kernel of truth," or inaccurate stereotypes. We obtained national character ratings of 3989 people from 49 cultures and compared them with the average personality scores of culture members assessed by observer ratings and self-reports. National character ratings were reliable but did not converge with assessed traits. Perceptions of national character thus appear to be unfounded stereotypes that may serve the function of maintaining a national identity.  相似文献   

Mass spectrometry of intact V-type ATPases reveals bound lipids and the effects of nucleotide binding     

Zhou M  Morgner N  Barrera NP  Politis A  Isaacson SC  Matak-Vinković D  Murata T  Bernal RA  Stock D  Robinson CV 《Science (New York, N.Y.)》2011,334(6054):380-385

The ability of electrospray to propel large viruses into a mass spectrometer is established and is rationalized by analogy to the atmospheric transmission of the common cold. Much less clear is the fate of membrane-embedded molecular machines in the gas phase. Here we show that rotary adenosine triphosphatases (ATPases)/synthases from Thermus thermophilus and Enterococcus hirae can be maintained intact with membrane and soluble subunit interactions preserved in vacuum. Mass spectra reveal subunit stoichiometries and the identity of tightly bound lipids within the membrane rotors. Moreover, subcomplexes formed in solution and gas phases reveal the regulatory effects of nucleotide binding on both ATP hydrolysis and proton translocation. Consequently, we can link specific lipid and nucleotide binding with distinct regulatory roles.  相似文献   

Dynamics of public attitudes toward bears and the role of bear hunting in Croatia     

Aleksandra Maji?  Agnese Marino Taussig de Bodonia  ?uro Huber  Nils Bunnefeld 《Biological conservation》2011,144(12):3018-3027

Successful carnivore conservation depends on public attitudes and acceptance levels of carnivores, and these are likely to change as circumstances change. Attitude studies repeated in time that can demonstrate such change are rare. Our study surveyed Croatian rural inhabitants in 2002 and in 2008 and analyzed their responses to detect a change in attitudes toward brown bears (Ursus arctos) over time. Important developments occurring in Croatia at the time of our research included a more centralized and more clearly defined bear management strategy, and an increase in the bear population. We constructed models to explain respondent’s value orientations, their level of perceived threat and their acceptance capacity for bears. Findings show that while value orientations and the overall level of perceived threat did not change over time, bear acceptance capacity was reduced. This suggests that the increase in the bear population and perhaps the more centralized bear management reduced respondents’ willingness to accept a larger bear population. We conclude that continuous public involvement in bear management is essential in order to maintain a feeling of control over the bear among the local population. Furthermore we argue that hunting is an important form of public involvement in the region, serving to reinforce existence and bequest values of the bear and increase its public acceptance.  相似文献   

Organic-geochemical Differentiation of Petroleum-type Pollutants and Study of Their Fate in Danube Alluvial Sediments and Corresponding Water (Pančevo Oil Refinery, Serbia)     

Branimir Jovančićević  Miroslav Vrvić  Jan Schwarzbauer  Hermann Wehner  Georg Scheeder  Dragomir Vitorović 《Water, air, and soil pollution》2007,183(1-4):225-238

A review is given in this paper of the up-to-date results observed in differentiation and transformation studies on petroleum-type pollutants in underground and surface waters. Water and particulate matter derived from the locality of Pan?evo Petroleum Refinery, Serbia (River Danube alluvial formations). It was shown that distributions of n-alkanes, steranes and triterpanes, and δ¹³C_PDB values of n-alkanes may successfully be used for qualitatively differentiating the petroleum-type pollutants from native organic matter in recent sedimentary formations. In underground waters, a petroleum-type pollutant is exposed to microbiological degradation which is manifested through relatively fast degradation of n-alkanes. Following an almost complete degradation of crude oil n-alkanes in underground water, the biosynthesis of novel, even carbon-number C₁₆–C₃₀ n-alkanes may be observed. It is shown that the n-alkane distribution observed in a petroleum-type pollutant may depend on the intensity of its previous interaction with water. The fate of petroleum-type pollutants in environmental waters may be predicted through laboratory simulative microbiological degradation experiments by using microorganism consortiums similar to those observed under relevant natural conditions, as well as on corresponding nutrient base.  相似文献   

Spatial and vertical distribution of <Superscript>137</Superscript>Cs in soils in the erosive area of southeastern Serbia (Pčinja and South Morava River Basins)     

Jelena Petrović  Snežana Dragović  Ranko Dragović  Milan Đorđević  Mrđan Đokić  Mirjana Ćujić 《Journal of Soils and Sediments》2016,16(4):1168-1175

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Effects of root exudates and humic substances on weathering kinetics     

Michael Ochs  Ivano Brunner  Werner Stumm  BoŽena ćosović 《Water, air, and soil pollution》1993,68(1-2):213-229

The effect of complex natural organic ligands on the weathering kinetics of aluminum oxide was investigated in laboratory experiments. A peat-derived humic substance and root exudates obtained from ectomycorrhizal (Picea abies — Hebeloma crustuliniforme) and non-mycorrhizal Norway Spruce trees; and γ-Al₂O₃ were used as a model system. The experimental weathering rates are in accordance with a surface-controlled dissolution mechanism. The effect of the humic material on dissolution rates appears to depend on the degree of protonation of the humic (macro)molecules: we observed dissolution-enhancement or -inhibition at pH 3 and 4, respectively. Ectomycorrhizal exudates proved to be effective weathering agents at pH 4, as opposed to humic material and non-mycorrhizal exudates. Our results suggest that (i) the role of humic materials in mineral weathering and podzolization is different from what is commonly thought, and (ii) mineral weathering rates in the rhizosphere may be higher than in the bulk soil.  相似文献   

Principal component analysis of trace elements in Serbian wheat     

Skrbić B  Durisić-Mladenović N  Cvejanov J 《Journal of agricultural and food chemistry》2005,53(6):2171-2175

Trace elements (Cu, Fe, Pb, Hg, Cd, As, Mn, Zn) were analyzed quantitatively in 14 wheat samples collected from fields in all Serbian growing regions, harvested in 2002. Microelements were determined according to an atomic absorption spectrophotometric method. Principal component analyses (PCA) were performed on data matrices consisting of contents of trace elements in wheats (columns) and all Serbian wheat-growing regions (rows). It was found that four principal components account for 87.2% of the total variance in the data. The plot of component loadings showed significant groupings for concentration of some microelements. The component scores indicated the similarities among the Serbian wheat-growing regions. The loading plot reveals that there is no need to measure all of the variables to achieve the same classification. It is enough to measure one variable per group. Naturally, this conclusion is valid only within the limits of the present study of wheat grain samples from different parts of Serbia.  相似文献   

Puerperal disease control in sows     

M Varadin  L Sentov  M Jovi?  P Nikoli?  K Salahovi? 《Schweizer Archiv für Tierheilkunde》1984,126(10):511-520

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Influence of grain type on the insecticidal efficacy of two diatomaceous earth formulations against Rhyzopertha dominica (F) (Coleoptera: Bostrychidae)     

Kavallieratos NG  Athanassiou CG  Pashalidou FG  Andris NS  Tomanović Z 《Pest management science》2005,61(7):660-666

Laboratory bioassays were carried out in order to evaluate the effectiveness of two diatomaceous earth (DE) formulations, Insecto and SilicoSec, against adults of Rhyzopertha dominica (F) in eight different grain commodities. The adherence of the two DEs to each grain was also measured. The eight grains tested were wheat, whole barley, peeled barley, oats, rye, triticale, rice and maize. These commodities were treated with the DEs at three rates, 0.75, 1.0 and 1.5 g DE kg(-1) grain. The mortality of R dominica adults was measured after 24 h, 48 h, 7 days and 14 days of exposure in the treated grains at 26 degrees C and 55% RH. After the 14-day mortality count, all adults were removed and the treated grains retained under the same conditions for a further 60 days. The treated grains were subsequently examined for F1 progeny. Significant differences were recorded among the eight grain types as well as between the DE formulations tested. After 14 days of exposure, even at the lowest DE rate for both formulations, adult mortality was high (>90%) in wheat and triticale. In contrast, adult mortality was significantly lower in peeled barley. Increasing the rate improved the efficacy of the DEs significantly in only some of the grains tested. Reproductive capacity in all the treated grains was significantly suppressed when compared with untreated grains. Generally, more F1 individuals of R dominica were noted in the treated peeled barley than in the other commodities. Significant differences in the percentage of DE retention were noted among the eight grains. The highest retention level was noted in rice (>87%) and the lowest in maize (<6%). However, the degree of DE adherence to a given grain was not always indicative of the effectiveness of DE against R dominica.  相似文献