重庆西山坪西园建材厂滑坡应急抢险治理工程设计与研究

以西山坪西园建材厂滑坡体工程地质勘察资料为依据,分析了滑坡体的岩土组成和物理力学性质以及造成滑坡的原因.认为影响山体滑坡的因素除与边坡地层岩性、微地貌特征、气象及水文条件有关外,修建厂房开挖与切割边坡坡脚则是重要的诱发原因.定性得出该滑坡的形成机制和类型为牵引式、浅层、小型土质新型滑坡.在此基础上,应用规范所推荐的极限平衡法,对该滑坡体的3个主要地质剖面(A-A'、B-B'、C-C')进行了稳定性计算与分析,得到不同工况下滑坡体稳定系数值.其中,在最不利组合工况(自重+暴雨+地震)下,滑坡体稳定系数仅为0.99～1.03,处于不稳定状态.根据计算结果,按照<长江三峡库区滑坡灾害防治规范>要求及"技术可行、安全可靠、经济合理、简单易实施"的设计原则,对该滑坡的应急抢险方案进行了设计,提出以抗滑桩拦挡工程为主、坡顶修筑截排水沟、地表裂缝回填夯实等综合治理方案.抗滑桩设置1排,分3段,根据每段不同的剩余下滑力设计抗滑桩的断面尺寸和埋设深度,使该滑坡体治理后,其安全系数分别满足不同工况下的规范要求.该方案已通过了三峡库区滑坡灾害防治专家组的审核,目前,正处于实施阶段.

semantic oriented ontology cohesion metrics for ontology-based systems

Ontologies play a core role to provide shared knowledge models to semantic-driven applications targeted by Semantic Web. Ontology metrics become an important area because they can help ontology engineers to assess ontology and better control project management and development of ontology based systems, and therefore reduce the risk of project failures. In this paper, we propose a set of ontology cohesion metrics which focuses on measuring (possibly inconsistent) ontologies in the context of dynamic and changing Web. They are: Number of Ontology Partitions (NOP), Number of Minimally Inconsistent Subsets (NMIS) and Average Value of Axiom Inconsistencies (AVAI). These ontology metrics are used to measure ontological semantics rather than ontological structure. They are theoretically validated for ensuring their theoretical soundness, and further empirically validated by a standard test set of debugging ontologies. The related algorithms to compute these ontology metrics also are discussed. These metrics proposed in this paper can be used as a very useful complementarity of existing ontology cohesion metrics.

中国水土流失的概况及其综合治理

本文以翔实的数据说明了我国水土流失严重的现状 ,并从良化生态环境 ,坚持综合整治、搞好小流域治理、提高防洪综合能力、加大执法力度、增强保水保土意识等方面 ,提出了防治我国水土流失的具体途径。

水库建设选址方案的决策分析

水库建设方案的评价,涉及投入和效益两方面。投入包括资金和工期等,称为“输入”:效益包括工农业用水增加、防洪能力强增等。称为“输出”。分析这种多输入,多输出的系统,应用数据包络分析方法是非常有效的。

Physical modeling of localized scour for the Yangtze Estuary Waterway Improvement Project, Phase I

In order to examine the effectiveness of engineering protection against localized scour in front of the south groin-group of the Yangtze Estuary Waterway Improvement Project, Phase I, an undistorted physical model on a geometric scale of 1:250 is built in this study, covering two groins and their adacent estuarine areas. By use of rinsing fix-bed model as well as localized mobile-bed model the experiment is undertaken under bi-directional steady flow. According to the experimental results, waterway dredging leads to the increase in steram velocity, the increase being larger during the ebb than during the flood. Construction of the upstream groin has some influence on the flow patterns near the downstream groin. Localized scour in front of the groin-heads is controlled mainly by ebb flow. In the case of a riverbed composed entirely of silt, the depths of localized scour in front of the two groin-heads are 27 m and 29 m, respectively. In reality, the underneath sediment of the prototype riverbed is clay whose threshold velocity is much higher than the stream velocity in the Yangtze Estuary; therefore, the depths of localized scour will not be much larger than the thickness of the silt layer, i. e. 7.4 m and 4.7 m, respectively. The designed aprons covering the riverbed in fron of the groin-heads are very effective in scour control. Aprons of slightly smaller size can also fulfill the task of protection, but the area of localized scour increases significantly.

A Dynamic Comprehensive Method for Landslide Control

A slope failure is developed due to progressive external loads and deteriorations of slope geomaterials, thus forming a progressive and dynamic development and occurrence of landslides. Site geological properties and other active factors such as hydrodynamic load and human activities are complex and usually unknown, thus this dynamic development and occurrence of landslides can only be understood through the progressive accumulation of knowledge on the landslides. For such a progressive process, this paper proposes a dynamic comprehensive control method for landslide control. This control method takes full advantage of updated monitoring data and site investigations of landslides, and emphasizes the implementation of possible measures for landslide control at reasonable stages and in different groups. These measures are to prevent the occurrence of a landslide disaster. As a case study, a landslide project at the Panluo open-pit iron mine is analyzed to illustrate this dynamic comprehensive control method.

Linear chirp control of infrared signal in a biased semiconductor thin film

Ultrashort light-matter interactions between a linear chirped pulse and a biased semiconductor thin film GaAs are investigated. Using different chirped pulses, the dependence of infrared spectra on chirp rate is demonstrated for a 5 fs pulse. It is found that the infrared spectra can be controlled by the linear chirp of the pulse. Furthermore, the infrared spectral intensity could be enhanced by two orders of magnitude via appropriately choosing values of the linear chirp rates. Our results suggest a possible scheme to control the infrared signal.

Control of the lasing wavelength by a sampled grating in a complex-coupled DFB laser

The lasing wavelength of a complex-coupled DFB laser is controlled by a sampled grating. The key concepts of the approach are to utilize the -1st order (negative first order) reflection of a sampled grating for laser single mode operation, and use conventional holographic exposure combined with the usual photolithography to fabricate the sampled grating. The typical threshold current of the sampled grating based DFB laser is 32 mA, and the optical output is about 10 mW at an injected current of 100 mA. The lasing wavelength of the device is 1.5356 mu m, which is the -1st order wavelength of the sampled grating.