Correlation between Er3+ emission and the microstructure of a-SiOx : H < Er > films

Photoluminescence (PL) from Er-implanted hydrogenated amorphous silicon suboxide (a-SiOX:H(x<2.0)) films was measured. Two luminescence bands with maxima at lambda congruent to 750 nm and lambda congruent to 1.54mum, ascribed to the a-SiOX:H intrinsic emission and Er3+ emission, were observed. Peak intensities of the two bands follow the same trend as a function of annealing temperature from 300 to 1000degreesC. Micro-Raman results indicate that the a-SiOX:H films are a mixture of two phases, an amorphous SiOX matrix and amorphous silicon (a-Si) domains embedded there in. FTIR spectra confirm that hydrogen effusion from a-SiOX:H films occurs during annealing. Hydrogen effusion leads to a reconstruction of the microstructure of a-Si domains, thus having a strong influence on Er3+ emission. Our study emphasizes the role of a-Si domains on Er3+ emission in a-SiOX:H films.

Heat Transfer Problems Induced By Multi-shocks Interaction

Numerical simulations of the multi-shock interactions observable around hypersonic vehicles were carried out by solving Navier-Stokes equations with the AUSMPW scheme and the new type of the IV interaction created by two incident shock waves was investigated in detail. Numerical results show that the intersection point of the second incident shock with the bow shock plays important role on the flow pattern, peak pressures and heat fluxes. In the case of two incident shocks interacting with the bow shock at the same position, the much higher peak pressure and more severe heat transfer rate are induced than the classical IV interaction. The phenomenon is referred to as the multi-shock interaction and higher requirements will be imposed on thermal protection systems.

流体力学半径对估算胶体微球聚集速率常数的影响

胶体粒子聚集速率常数实验值远低于理论值一直是被普遍关注的问题.聚集速率常数的理论推导是基于粒子的几何半径来考虑的,但决定粒子扩散速率及聚集速率的应该是粒子的流体力学半径(大于几何半径),因而它是使聚集速率常数实验值低于理论值的因素之一.影响流体力学半径的因素很多,其中,带电粒子在溶液中因表面存在双电层,会明显增大流体力学半径,造成聚集速率减慢.而双电层的厚度又随溶液中离子强度的不同而改变.本工作在聚集速率的公式中引入了修正因子,即几何半径与其流体力学半径之比,以修正由于用几何半径代替流体力学半径带来的误差.其中几何半径和流体力学半径可以分别用扫描电镜(SEM)和动态光散射(DLS)来测定.以两种粒径的聚苯乙烯带电微球为例,考察了在不同离子强度下,该误差的大小.结果发现,对于半径为30 nm的微球,用流体力学半径计算的慢聚集速率常数比理论值偏低约8%.该误差随离子强度增加而减少.对于快聚集情况,流体力学半径对聚集速率基本没有影响.

花椒主效化感物质分离鉴定及化感作用研究

近年来，随着对作物重茬障碍原因的深入研究，植物的化感作用越来越受到国内外众多学者的重视。花椒（Zanthoxy piperitum.）为芸香科植物，是一种收益早、用途广、价值高的经济树种，是川西干旱河谷地区的重要经济作物，其连作障碍也倍受关注，系统研究花椒化感作用将有助于理解和最终解决花椒连作障碍问题。本文首先通过萃取、层析等方法分离花椒主效化感成分；通过外加不同浓度的花椒叶水浸液研究了对土壤氮素养分循环的影响；研究了花椒叶水浸液对苜蓿生理生化、光合作用、氮素养分吸收的影响，并对外施氮肥对这种化感影响的缓解作用做了研究；研究了花椒化感潜力对全球变化——UV-B增强辐射的响应。主要研究结果如下： 1．用不同极性的有机溶剂对花椒叶水浸液浓缩浸膏萃取、柱层析，结合生物活性检测，分离得到主效化感作用组分的一种化感物质——对甲氧基苯酚。采用该物质纯品进行生物活性检测，证明其具有化感作用。 2．花椒叶水浸液处理土壤30天后，土壤硝态氮、铵态氮、无机氮（硝态氮＋铵态氮）与对照相比，随着花椒叶水浸液浓度的增加呈现降低的趋势，其中土壤铵态氮含量显著降低，而硝态氮含量的变化则不显著，无机氮含量也显著降低。土壤脲酶和蛋白酶的活性与无机氮含量的变化趋势相同。随着花椒叶水浸液浓度的增加，氨化细菌数量显著降低，固氮菌的数量变化不显著，硝化细菌和反硝化细菌数量有减少的趋势。60天后，硝态氮含量、铵态氮含量、无机氮随水浸液浓度增加的变化趋势与30天时相似；随着花椒叶水浸液浓度的增加，氨化细菌、固氮菌的数量显著减少，硝化细菌数量、反硝化细菌数量仍呈减少趋势；土壤脲酶、蛋白酶活性与第30天的变化趋势相同。第60天与第30天的结果相比，相同水浸液浓度处理的硝态氮、铵态氮、无机氮均有下降的趋势，但除了25g.L－1水浸液处理的外，其它相同浓度的处理间差异均不显著；除了12.5 g.L的处理外土壤脲酶活性均呈增强的趋势；蛋白酶活性都有不同程度的增加；花椒叶水浸液处理的土壤硝化细菌和反硝化细菌数量呈增加趋势。 3．随着花椒叶水浸液浓度的增加，显著抑制了苜蓿根长、地上地下生物量、叶绿素含量、叶片中可溶性蛋白的含量，净光合速率。苜蓿体内四种抗氧化酶（POD、SOD、CAT、APX） 活性随着水浸液浓度的增加而降低，而丙二醛含量则增加。苜蓿氮初级同化相关酶硝酸还原酶（NR）、谷氨酰合成酶(GS)、谷氨酸脱氢酶（GDH）的活性随着水浸液浓度的增加受到不同程度的影响。总的来说，苜蓿硝酸还原酶、谷氨酰合成酶的活性受到抑制，而谷氨酸脱氢酶活性的变化则比较复杂，根呈先降低后增加的趋势，叶片则无显著变化。外施两种不同浓度的硝酸铵氮肥后，对12.5、25 g.L－1花椒叶水浸液处理的苜蓿化感作用有显著的缓解作用，表现在株高、生物量、光合作用等方面，大多达到与对照（0 g.L－1）未施氮肥无显著差异的水平，而对50 g.L－1水浸液处理的苜蓿幼苗，虽有一定的缓解作用，但这种作用均未达到与对照（0 g.L－1）未施氮肥时无显著差异的水平。 4． UV-B增强辐射处理花椒后，花椒的化感潜力显著增强。花椒叶片内UV-B吸收物质的含量和总酚含量均显著增加。 In recent years, with profound research on the reasons of continuous cropping obstacles, allelopathy received increasing attention to many scholars at home and abroad. Zanthoxy bungeanum as a Rutaceae plant is a high economic value species which gains early and uses widely. Zanthoxylum is an important economic crop in the arid valley of western Sichuan region, and its not even has received much concern for the continuous cropping obstacles. The systematic study of allelopathy of Zanthoxylum will contribute to the understanding and final settlement of this issue. The major allelopathic composition was separated through the extraction, chromatography combined with other methods. The impact on soil nutrient cycling was also studied through the addition of different concentrations of water extracts of Zanthoxylum. Furthermore, the effects of water extracts of Zanthoxylum leaves on alfalfa leaf physiological and biochemical indexes, photosynthesis, soil enzymes and nutrient uptake of nitrogen and the mitigation of allelopathy through using external fertilizer were studied to put forward scientific resolvent for Zanthoxylum continuous cropping obstacles .The response of allelopathic potential of Zanthoxylum to global change - UV-B enhanced radiation was studied . The main findings are as follows: 1. Through extraction with different polar organic solvents on concentrated water extract of Zanthoxylum leaf and then using column chromatography combined with detection of biological activity, one of the main allelopathic components- methoxy-phenol was isolated. The biological activity testing of the pure material of methoxy-phenol proved that it does have allelopathic potential. 2. Thirty days after treating soil with water extract of Zanthoxylum leaf, as compared with the control, the contents of soil nitrate, ammonium, nitrate plus ammonium nitrogen showed a trend of decrease with the increase of the concentration of water extract whereas the content of ammonium nitrogen showed a significant reduction, and the content of nitrate did not change significantly, the content of nitrate plus ammonium nitrogen also showed a significant (P <0.05) redction. The activity of soil urease and protease showed the same trend as the content of nitrate nitrogen plus ammonium nitrogen. With the increase in the concentration of water extract, the number of ammonification bacteria significantly reduced but nitrogen-fixing bacteria did not change significantly and there was a decreasing trend in the number of nitrifying bacteria and denitrifying bacteria. Sixty days after the treatment, with the increase in solution concentration of water extract of Zanthoxylum leaf, the content of nitrate、 ammonium nitrogen, nitrate plus ammonium nitrogen showed a similar change trend to 30 days’; the number of ammonification bacteria, nitrogen-fixing bacteria significantly reduced ; the number of nitrifying bacteria, denitrifying bacteria was still an downward trend; the activity of soil urease and protease showed the same trend as the 30th days’. Compared to the results of the 30th days’, the content of nitrate, ammonium, nitrate plus ammonium nitrogen showed a decrease trend between the treatment of same concentration, but there was no significant difference except the treatment of 25g.L-1 between the same concentration; the activity of soil urease showed enhanced trend except the treatment of 12.5 g.L-1; the activity of protease increased to varying degrees; the number of ammonification bacteria、 nitrifying bacteria and denitrifying bacteria were growing while nitrogen-fixing bacteria reduced.. 3. With the increase of the concentration of water extract of Zanthoxylum leaf, the water extract significantly inhibited the root length, aboveground biomass, content of chlorophyll and soluble protein in leaf and net photosynthetic rate. The activity of four antioxidant enzymes (POD, SOD, CAT, APX) reduced with the increase in concentration of the water extract but the content of MDA increased. The activity of enzymes related to primary nitrogen assimilation such nitrate reductase (NR), glutamyl synthetase (GS), glutamate dehydrogenase (GDH) were subject to different degrees with an increase in the concentration of water extracts. In general, the activity of nitrate reductase, glutamyl synthetase were inhibited, while change in the activity of glutamate dehydrogenase was more complex. The activity of glutamate dehydrogenase in leaf was first reduced and then increase,but did not change significantly in root. After using two external different concentrations of nitrogen fertilizer, there was a significant mitigation in inhibiton in plant height, biomass, photosynthesis, etc. in the treatment of 12.5,25 gL-1 of water extract of Zanthoxylum leaf, and most of these indexes showed no significant difference with the control (0 g.L-1, no external fertilizer was added) .Although there showed a certain degree of ease in the treatment of 50 g.L-1 , there was still a significant difference compared with the control (0 gL-1) in which no external fertilizer was used. 4.The allelopathic potential of Zanthoxylum positively responded to enhanced UV-B significantly. The content of UV-B absorbing compounds and the total phenol also significant increased.

Numerical wave flume study on wave motion around submerged plates

Nonlinear interaction between surface waves and a submerged horizontal plate is investigated in the absorbed numerical wave flume developed based on the volume of fluid (VOF) method. The governing equations of the numerical model are the continuity equation and the Reynolds-Averaged Navier-Stokes (RANS) equations with the k-epsilon turbulence equations. Incident waves are generated by an absorbing wave-maker that eliminates the waves reflected from structures. Results are obtained for a range of parameters, with consideration of the condition under which the reflection coefficient becomes maximal and the transmission coefficient minimal. Wave breaking over the plate, vortex shedding downwave, and pulsating flow below the plate are observed. Time-averaged hydrodynamic force reveals a negative drift force. All these characteristics provide a reference for construction of submerged plate breakwaters.

改进的基于区域的运动目标分割方法

针对视频监控系统,提出了一种改进的基于区域的运动目标分割方法。与传统方法相比,在运动检测阶段,结合时域差分和背景差分进行运动检测,并通过自适应方法进行背景更新;在差分图像二值化时,采用自适应阈值方法来代替传统的手工确定阈值法;对于区域分割,使用基于加权平方欧式距离的均值聚类算法代替传统的均值聚类算法。实验结果表明该改进方法比传统方法具有更好的实时性、鲁棒性和有效性。

海上时移地震综合解释技术研究与应用

The practical application and development of the time-lapse seismic reservoir monitor technology has indicated which has already become one of most important development technologies in seeking the surplus oil distribution and improving the reservoir recovering. The paper, first obtained the rock physics experiment analysis data according to the Bohai Sea loose sandstone in-situ measure technical, and determined the feasibility research of the S oil-field on the time-lapse seismic reservoir monitoring combining with the time-lapse numeric simulation technology, which was used to analyze the time-lapse seismic respond raw of the reservoir parameters change and pointed out the attentive problems during the real time-lapse seismic processing and interpretation. Next, simply introduced the technical link and the effect of the time-lapse mutual constrained fidelity and match processing aiming at the local complex gathering condition, geological condition, development engineering condition. Third, introduced the time-lapse integrated interpretation and the technical system with the innovative key technology that includes the time-lapse difference explanation technology, the time-lapse seismic multi-attributes integrated interpretation technology, and the time-lapse constrained reservoir parameters inversion technology, and so on. Using the time-lapse difference direct explanation technology, directly obtained the surplus oil macroscopic distribution through the difference seismic data; Using the presenting 8 big principles of the sublayer isochronisms comparison, carried on the time-lapse integrated interpretation analysis on the fine sublayer comparison and the thin oil-layer(group) contrast and the oil layer (group); The paper putted up the research, contrast, applications of the multi-sides sensitive attribute analysis and the RBF nerve network on the nearest study algorithm, and predicted the reservoir parameters and the surplus oil distribution with them; Combining with innovative researches and the time-lapse seismic constrained reservoir parameters inversion technology realized the good combination of the seismic and the reservoir engineering. Fourth, under fully analyzing the geology condition, the reservoir condition, the exploit dynamic data, and the seismic data of the S oil-field, and analyzing the time-lapse difference factors with reservoir dynamic exploit data, calibrated the oil-gas saturation change, the pressure change, the water saturation change, and determined the rationality of the time-lapse seismic difference, and finally obtained the surplus oil distribution, the water flood characteristic understanding, reservoir degasification, and pressure drop raw, and so on, which had been used in the well pattern tightening plan proof of the S oil-field development adjustment plan. Finally, the paper summarized the knowledge and understanding of the marine time-lapse seismic integrated interpretation, also had pointed out the further need researched question.

影响生育价值观因素的研究－传统回归分析与多层线性模型分析结果的比较

Based on the research of predictors of VOC, this study explores the predictive effect of factors, such as generation, urban/rural context, collectivism/individualism orientation, family value, independent/interdependent self, adult attachment, on the Emotional and Traditional factors of VOC. Considering the hierarchical data structure of the VOC study, which resulted from the original research design, this dissertation applies Hierarchical Linear Model (HLM) after using traditional regression. A comparison between the results from the tow statistical methods is made, and the results are as follows: 1) Reliability coefficients of questionnaires used in this study are satisfactory, and most of them can be used in further research. 2) Samples from different generation and urban/rural context show significant differences on the score of collectivism/individualism orientation, family value, independent/interdependent self, adult attachment, and VOC. 3) Regression equations with VOC as outcome variable differ from each other when using data from sample with restricted generation or urban/rural context. 4) Results by HLM shows that interdependent self and mother identity have positive effect on emotional factor of VOC. Emotional factor’s variation on family level is not significant. 5) Results by HLM shows that Individualism, Interdependent Self and Grandmother Identity can predict Traditional factor of VOC. Traditional factor’s variation is significant on family level, which can be explained by family income and it’s area-urban or rural. Based on the results above, the researcher concludes that a) generation identity and urban/rural context have important effect on VOC; b) Interdependent Self is an important predictive factor of VOC’s Emotional factor, which is nearly subjective to other factors; d) VOC’s traditional factor varies with other factors, which show its strong relation with culture and tradition; e) more exact results can be gotten from HLM analysis, which beyond tradition regression.

Quantum Flows as Markovian Limit of Emission, Absorption and Scattering Interactions

Gough, John, (2004) 'Quantum Flows as Markovian Limit of Emission, Absorption and Scattering Interactions', Communications in Mathematical Physics 254 pp.498-512 RAE2008

Asymptotic behaviour of the elastic solution near the tip of a crack situated at a nonideal interface

Mishuris, G; Kuhn, G., (2001) 'Asymptotic behaviour of the elastic solution near the tip of a crack situated at a nonideal interface', Zeitschrift f?r Angewandte Mathematik und Mechanik 81(12) pp.811-826 RAE2008

Biomass?Diversity Responses and Spatial Dependencies in Disturbed Tallgrass Prairies

Javier G. P. Gamarra and Ricard V. Sole (2002). Biomass-diversity responses and spatial dependencies in disturbed tallgrass prairies. Journal of Theoretical Biology, 215 (4) pp.469-480 RAE2008

Twierdzenia o punktach stałych pewnych klas operatorów nieliniowych wraz z ich zastosowaniami

Wydział Matematyki i Informatyki

Optimized strong stability preserving IMEX Runge-Kutta methods

Esta es la versión no revisada del artículo: Inmaculada Higueras, Natalie Happenhofer, Othmar Koch, and Friedrich Kupka. 2014. Optimized strong stability preserving IMEX Runge-Kutta methods. J. Comput. Appl. Math. 272 (December 2014), 116-140. Se puede consultar la versión final en https://doi.org/10.1016/j.cam.2014.05.011

The Construction of Arbitrary Stable Dynamics in Non-Linear Neural Networks

In this paper, two methods for constructing systems of ordinary differential equations realizing any fixed finite set of equilibria in any fixed finite dimension are introduced; no spurious equilibria are possible for either method. By using the first method, one can construct a system with the fewest number of equilibria, given a fixed set of attractors. Using a strict Lyapunov function for each of these differential equations, a large class of systems with the same set of equilibria is constructed. A method of fitting these nonlinear systems to trajectories is proposed. In addition, a general method which will produce an arbitrary number of periodic orbits of shapes of arbitrary complexity is also discussed. A more general second method is given to construct a differential equation which converges to a fixed given finite set of equilibria. This technique is much more general in that it allows this set of equilibria to have any of a large class of indices which are consistent with the Morse Inequalities. It is clear that this class is not universal, because there is a large class of additional vector fields with convergent dynamics which cannot be constructed by the above method. The easiest way to see this is to enumerate the set of Morse indices which can be obtained by the above method and compare this class with the class of Morse indices of arbitrary differential equations with convergent dynamics. The former set of indices are a proper subclass of the latter, therefore, the above construction cannot be universal. In general, it is a difficult open problem to construct a specific example of a differential equation with a given fixed set of equilibria, permissible Morse indices, and permissible connections between stable and unstable manifolds. A strict Lyapunov function is given for this second case as well. This strict Lyapunov function as above enables construction of a large class of examples consistent with these more complicated dynamics and indices. The determination of all the basins of attraction in the general case for these systems is also difficult and open.

Monopoles for gravitation and for higher spin fields

We consider massless higher spin gauge theories with both electric and magnetic sources, with a special emphasis on the spin two case. We write the equations of motion at the linear level (with conserved external sources) and introduce Dirac strings so as to derive the equations from a variational principle. We then derive a quantization condition that generalizes the familiar Dirac quantization condition, and which involves the conserved charges associated with the asymptotic symmetries for higher spins. Next we discuss briefly how the result extends to the nonlinear theory. This is done in the context of gravitation, where the Taub-NUT solution provides the exact solution of the field equations with both types of sources. We rederive, in analogy with electromagnetism, the quantization condition from the quantization of the angular momentum. We also observe that the Taub-NUT metric is asymptotically flat at spatial infinity in the sense of Regge and Teitelboim (including their parity conditions). It follows, in particular, that one can consistently consider in the variational principle configurations with different electric and magnetic masses. © 2006 The American Physical Society.