三峡库区黄泥巴蹬坎滑坡变形机制

[目的]研究黄泥巴蹬坎滑坡的变形规律及失稳机制,旨在为库区同类型滑坡的研究提供借鉴。[方法]分析该滑坡的宏观变形特征,结合专业监测数据,研究其变形规律及失稳机制,并运用数值模拟计算研究库水位下降的致滑机理。[结果]黄泥巴蹬坎Ⅰ号滑体变形严重,分别于2007年4—6月,2009年4—6月,2012年4—6月发生加速变形,且加速变形速率逐次呈快速增长趋势。库水位下降对该滑坡稳定性的影响表现为坡体外部卸荷效应和内部动水压力推动作用。一方面,库水位下降使得指向坡内的静水压力消失,导致抗滑力减小。另一方面,库水位下降引起坡内地下水位下降,地下水沿滑带方向渗流,产生的动水压力推动滑坡向外发生变形。[结论]目前黄泥巴蹬坎滑坡处于欠稳定状态,库水位下降加之连续强降雨是导致黄泥巴蹬坎滑坡变形失稳的主要因素。     

Spatial distribution of earthworms [Lumbricidae] in recultivated soils of the Rhenish lignite‐mining area,Germany

The spatial distribution of earthworms was studied by means of combined formalin expulsion and hand sorting in three arable fields of the Rhenish lignite‐mining area that differed in their recultivation age (6, 12, 24 yr). In addition, pH and the spatial distribution of penetration resistances were measured to see if they are corresponding with the distribution of earthworms. Already the 6 yr old field had a rich population of endogeic, anecic, and epigeic earthworms (119 ind. m^–2, 48 g m^–2, 6 species). This quantity was similar to the 24 yr old site. The 12 yr old field was only sparsely populated by earthworms (5 ind. m^–2, 5 g m^–2, 3 species). In the 6 yr old field, the spatial distribution pattern showed a center of maximal earthworm abundances, corresponding to the distributional pattern of penetration resistances. In the old field (24 yr), the species varied in their spatial distribution, and there was no correspondence with the distribution of penetration resistance. In general, the penetration resistance at the youngest site was clearly lower than at the two older sites. The earthworm population in the 6 yr old field can be explained by cocoons contained in the dumped material. A calculation using literature data on earthworm‐population dynamics shows that a founding population of 400–600 reproductive individuals per hectare and a continuity of favorable growth conditions during the time of soil management is necessary for the development of the situation found at the 6 yr old site in this study.     

Are meadows with high ecological and patrimonial value endangered by heathland invasion in the French central Pyrenees?

Due to their high ecological and patrimonial value Festuca eskia and Nardus stricta meadows and Rhododendron ferrugineum heathlands need to be locally preserved in the Pyrenees. This could pose dilemmas to conservation managers if heathlands invade and replace the meadows. However, studies showing that the heathlands do actually invade meadows are lacking in the Pyrenees and the invasion hypothesis therefore remains to be proved. So, vegetation pattern changes in a particularly vulnerable site from the central Pyrenees was investigated by two means: (i) interpretation of stereo pairs of aerial photographs and (ii) analysis of the demography of Rhododendron populations in ten 150 m² experimental plots. The main results from photo interpretation indicated that, during the period between 1954 and 1995, 15% of a 17 ha meadow area shifted to heathland. This corresponded with a 592 m² year⁻¹ colonization rate and to an overall front progression of heathland over meadows of 3-60 m. Demographic data showed that meadow colonization by heathland passed through successive phases but appeared to be a rather slow process that can take as long as 120-320 years. During the process the cover rate over the 150 m² plots varied between 1 and 0.4 m² year⁻¹. Heathland extension does not seem to have been favored by the decrease in grazing pressure. Despite this, the progression of heathlands over meadows seems endangering the meadows. Finally we propose practices locally to limit the progression of Rhododendron.     

基于关联规则的湖北短期气候预测应用初探

分析了数据挖掘技术中关联规则分析方法的原理和一般数据挖掘的系统结构和主要步骤,通过收集、加工和处理大气环流指数等大量信息,以湖北省汛期异常气候现象为对象,使用关联规则挖掘方法试图找出各物理量和气象要素与未来一段时间内湖北的汛期降水之间的关系.基于Apriori算法2013年针对湖北短期气候预测,初步建立了一个关联规则挖掘系统,实现了参数配置、关联挖掘和规则显示等功能.     

水稻纹枯病发生规律与化学防治技术研究

通过7种药剂对水稻纹枯病的防治效果的试验研究,结果表明：防治纹枯病的最好时期应在7月上中旬;防治效果以爱苗防效最高,其次为百菌清和纹曲宁;产量性状以爱苗、纹曲宁、百菌清较好。     

Colonization of the canine skin with bacteria

Abstract Aspects of colonization of the canine skin with bacteria are reviewed. Owing to variability in sampling techniques, anatomical sites involved and lack of temporal studies, there is still controversy as to which bacteria are residents or transients on the canine skin. The establishment of the cutaneous flora is determined by the ability of bacteria to adhere to canine corneocytes, to use available nutrients from skin secretions and to resist challenge from competing bacteria. Variations in humidity and temperature due to environment, skin folds or differences in the haircoat are also likely to have an effect. Much research has focused around Staphylococcus intermedius, the main pathogen of the canine skin but its cutaneous residency status remains questionable. Pathological conditions such as atopy and seborrhoea favour the colonization of S. intermedius and predispose to infection. Recent studies indicate that bacterial interference as a method of preventing colonization of pathogenic staphylococci may be feasible. Résumé— Les aspects de la colonisation de la peau canine par des bactéries sont étudiées. A cause de la variabilité des techniques de prélèvements, des sites anatomiques, et du caratère ponctuel des études, le doute subsiste toujours quant à savoir quelle sont les bactéries résidentes ou transitoires sur la peau de chien. L'établissement d'une flore cutanée est déterminée par la capacité de la bactérie à adhérer aux cornéocytes canines, à utiliser les nutriments disponibles à partir des sécrétions cutanées et à résister aux autres bactéries qui concourent à l'occupation des memes sites. Les variations d'humidité et de température, dues à l'environnement, aux plis de peau et aux différences de pelage jouent probablement un role. La plupart des études concernent Staphylococcus intermedius, l'agent pathogène principal de la peau du chien, mais son statut de résident cutané est toujours débattu. Des conditions pathologiques telles que l'atopie et la séborrhée favorisent la colonisation par S. intermedius et prédisposent à l'infection. Des études récentes indiquent que l'interférence bactérienne peut être envisagée comme une méthode de prévention de la colonisation cutanée par un staphylocoque pathogène. [Saijonmaa-Koulumies, L. & Lloyd, D. H. Colonization of the canine skin with bacteria (Colonisation de la peau canine par des bactéries). Veterinary Dermatology 1996; 7 : 153–162.] Resumen Se revisan algunos aspectos de la colonización bacteriana en la piel canina. Existe aún controversia sobre qué bacterias son résidentes o transitorias en la piel del perro, debido a la variabilidad en las técnicas de recolección, localización y falta de estudios temporales. El establecimiento de la flora cutánea depende de su capacidad de adhesión a los corneocitos, de utilizar los nutrientes de las secreciones cutáneas y de resistir la competencia de otras bacterias. También es probable que tengan un papel los cambios de humedad y temperatura por los pliegues cutáneos o las diferencias en el pelaje. Se ha centrado mucha investigación en Staphylococcus intermedius, el principal patógeno de la piel canina, aunque se sigue cuestionando su existencia como residente cutáneo. Situaciones patológicas como la atopia o la seborrea favorecen la colonización por S. intermedius y predisponen a infección. Algunos estudios recientes indican que es factible la interferencia bacteriana como método de prevenir la colonización por estafilococos patógenos. [Saijonmaa-Koulumies, L. & Lloyd, D. H. Colonization of the canine skin with bacteria (Colonizacion de la piel cannina con bacterias). Veterinary Dermatology 1996; 7 : 153–162.] Zusammenfassung— Es werden Aspekte der Besiedelung der Hundehaut mit Bakterien dargestellt. Entsprechend der Variabilität in der Probenentnahme, verwendeten anatomischen Regionen und dem Mangel an temporären Studien exisitieren immer noch unterschiedliche Ansichten, ob Bakterien auf der Haut des Hundes als resident oder transient gelten. Die Aufstellung der kutanen Flora wird durch die Fähigkeit der Bakterien bestimmt, sich an die kaninen Korneozyten anzuheften, verfügbare Nährstoffe aus den Hautsekretionen zu verwenden und sich gegenüber konkurrierenden Keimen zu behaupten. Veränderungen in Feuchtigkeit und Temperatur in Abhängigkeit von Umgebung, Hautfalten oder Unterschieden im Haarkleid scheinen ebenfalls einen Effekt zu besitzen. Viele Untersuchungen konzentrierten sich auf Staphylococcus aureus, der hauptpathogene Keim auf der Hundehaut, aber sein Status als residenter Keim bleibt fraglich. Pathologische Zustände wie Atopie und Seborrhoe begünstigen die Besiedelung mit S. intermedius und prädisponieren für eine Infektion. Kürzliche Studien zeigen, daß bakterielle Interferenzen als Methode zur Verhinderung der Ansiedlung von pathogenen Staphylokokken möglich sein könnten. [Saijonmaa-Koulumies, L., Lloyd, D.H. Colonization of the canine skin with bacteria (Besiedelung der Haut des Hundes mit Bakterien). Veterinary Dermatology 1996; 7 : 153–162.]     

沙棘新梢生长节律与果实发育关系的初步研究

通过对沙棘新梢生长节律与果实发育关系的调查研究,探讨了新梢生长和果实生长发育各自的客观 规律,以及树木生长和果实发育间的关系,为沙棘集约化栽培管理提供了科学的依据。     

基于粗糙熵的时序数据属性约简及规则提取研究

分析了近似质量在提取非确定性规则方面的不足，并基于粗糙熵的预测成功度概念，结合时序数据特点，提出一种属性约简及规则提取策略．该策略在对时序数据进行属性约简时，采用粗糙熵与时间距离相结合的方法，使得最终得到的约简在时序方面是较优的,最后使用UCI数据库进行仿真实验，效果良好．该策略在工程领域处理时序数据方面有一定的应用价值．     

Movement rules for herbivores in spatially heterogeneous environments: responses to small scale pattern

Foraging herbivores respond to the spatial pattern of resources at a variety of scales. At small scales of space and time, existing models capture the essence of the feeding process and successfully predict intake rates. Models that operate over larger scales have not exhibited a similar success, in part because we have a limited understanding of the rules used by animals to make decisions in spatially complex environments, or of the consequences of departing from these rules. To evaluate the rules that large herbivores use when navigating between forages, we examined movements of bighorn sheep foraging on apparent prey (alfalfa plants) in hand-constructed patches of plants. Observations of movements and path lengths were compared to simulations that used a variety of different rules-of-thumb to determine a search path. Rules used in simulations ranged from a random walk with various detection distances, to more complicated rules that solved a variant of the travelling salesman problem. Simulations of a random walk yielded movement lengths that exceeded observations by a factor of 3 for long detection distances, and by 30-fold for short detection distances. Observed move distances were most closely approximated by simulations based on a nearest-neighbor ruleover 75 % of all moves by bighorn sheep were to the closest available plant. Movement rules based on random walks are clearly inappropriate for many herbivores that typically consume visually apparent plants, and we suggest the use of a nearest-neighbor rule for modelling foraging by large herbivores.