撞击式滑套分段压裂新技术试验应用

随着苏里格气田开发的持续深入,为提高单口水平井产量及节约综合建井成本,部署长水平段（一般大于1000m）水平井是有效手段之一。常规水力喷射或裸眼分隔器分段压裂技术必然需增加分段数,同时也增加了压裂施工的作业风险。为进一步提高单井产量,针对长水平段水平井开展撞击式滑套分段压裂试验。通过采用“分段多簇”压裂方式,同段内形成多裂缝,增大了泄流面积,实现储层充分改造。本文开展了撞击式滑套分段压裂技术的试验研究,旨在缩短长水平段的整体分段数,增加单段内的改造程度,提高单井产量。通过在苏里格气田开展了2口水平井撞击式滑套分段压裂技术试验,施工过程中撞击式滑套开启迹象明显,相比单个滑套,同长度水平段水平井改造后取得较好的增产效果。该技术的成功试验,为长水平段水平井改造提供了新技术储备。     

内积能量与边缘检测

提出了一种新型的边缘检测算子--基于内积能量的边缘检测算子.在基于内积能量的边缘榆测算子中,内积能量在增强图像边缘的同时能够有效地抑制图像中的噪声和细节,因而它能较好地解决传统边缘检测算子的噪音抑制和边缘定位精度之间的矛盾.实验结果表明:与经典的Canny边缘检测算子相比,在具有相当边缘定位精度的条件下,基于内积能量的边缘检测算子对图像噪音和细节具有更强的抑制能力.此外,它还具有对参数调节不敏感的优良性质.     

Formation of Cu(OH)2 in ammoniacal atmospheric corrosion tests on copper

The corrosion of 99·95%Cu in atmospheres saturated with water and containing differentconcentrations of gaseous NH₃ (0·27–5·0%) was studied. The analysis of the weight changes of the specimens and of the X-ray diffraction pattern of the corrosion products established the formation of a layer of Cu(OH)₂.     

Water Disinfection: A Relationship Between Ozone and Aldehyde Production

In the water potabilization plant of Turin city (Italy), the oxidation process is carried out with ozone. Due to its well-known insufficient performance, it is necessary to add alternative oxidants (hypochlorite ion and chlorine dioxide). In this paper, we discuss the formation of linear carbonyl groups during surface water treatment in Turin.

The results obtained in the field confirm the synthesis of some aliphatic carbonyl compounds of low molecular weight. This phenomenon happens preeminently during the ozone disinfection process and, secondarily, during the other disinfection processes.

Experimental results show that, in this last event, chlorine reacts with organic substances, and in a second moment, after organics consumption, if chlorine is still in a sufficient concentration, oxidizing them.     

Parallel Krylov Methods for Econometric Model Simulation

This paper investigates parallel solution methods to simulate large-scalemacroeconometric models with forward-looking variables. The method chosen isthe Newton-Krylov algorithm, and we concentrate on a parallel solution to thesparse linear system arising in the Newton algorithm. We empirically analyzethe scalability of the GMRES method, which belongs to the class of so-calledKrylov subspace methods. The results obtained using an implementation of thePETSc 2.0 software library on an IBM SP2 show a near linear scalability forthe problem tested.     

Causes and risks of hyperlipidemia during dialysis and after renal transplantation

The most widely studied hyperlipidemies in patients affected by renal insufficiency or subsequent to kidney transplant present phenotype IIa, IIb or IV. The lipidic alteration most frequently observed in chronic renal insufficiency and/or dialytic treatment is represented by hypertrigliceridemia as a result of: 1) altered VLDL metabolism; 2) reduced activity of lecithin cholesterol acyltransferase (LCAT); 3) decrease in Apo-A1 and HDL3. Furthermore, marked anomalies in lipoprotein Lp (a) have been reported in hemodialysis. In patients undergoing peritoneal dialysis, hyperlipidemia arises from both an anomalous retrograde absorption of glucose and protein dispersion. Following kidney transplant the most frequent hyperlipidemia is hypercholesterolemia, consequent to immunosuppressive treatment (mainly steroids and cyclosporin). The documented significant increase of cardiovascular risk in the presence of hyperlipidemia points to the need for a clearer etiopathogenic definition of this anomaly, as well as the necessity to find an efficacious pharmacological treatment.     

A mixed time-frequency-domain approach for the analysis of a hysteretic oscillator

The global dynamic behavior of a hysteretic oscillator is investigated. It is shown that the most significant bifurcation phenomena can be accurately detected through the joint application of two frequency-domain techniques, i.e., describing function and harmonic balance, and of a suitable time-domain method for computing limit-cycle Floquet's multipliers. The proposed approach can be effectively applied for investigating nonlinear oscillators and circuits that do not admit of a simple Lur'e representation and that exhibit a complex dynamic behavior.     

Absence importance and its application to feature detection and matching

Feature detection and matching play important roles in many fields of computer vision, such as image understanding, feature recognition, 3D-reconstruction, video analysis, etc. Extracting features is usually the first step for feature detection or matching, and the gradient feature is one of the most used selections. In this paper, a new image feature-absence importance (AI) feature, which can directly characterize the local structure information, is proposed. Greatly different from the most existing features, the proposed absence importance feature is mainly based on the consideration that the absence of the important pixel will have a great effect on the local structure. Two absence importance features, mean absence importance (MAI) and standard deviation absence importance (SDAI), are defined and used subsequently to construct new algorithms for feature detection and matching. Experiments demonstrate that the proposed absence importance features can be used as an important complement of the gradient feature and applied successfully to the fields of feature detection and matching.     

Spatial-temporal traffic data analysis based on global data management using MAS

The spatial-temporal traffic data analysis based on global data management is a newly developed and crucial approach to help traffic managers having the global view of urban traffic status in the level of road network, which is very clearly useful in traffic control and route guidance. The multiagent systems are used in traffic data management with full consideration of the characteristics of traffic data and the cooperation and workflow among them. In software implementation of data management, the agent-based common object request broker architecture is adopted taking the distributed urban traffic data in the large area under network environments into account. Based on the global traffic data, the approach of visualized spatial-temporal analysis is then induced. The similarity of traffic data is analyzed first for each link and its profile is achieved to undertake the primary processing of urban traffic data. Furthermore, analysis results are shown on the basis of the geographic information systems for transportation. The two types of visualization, pseudocolor and contour maps, are adopted in the demonstration to display the traffic status graphically and its changing frames. Among the applications in some big cities in China, the case of urban traffic analysis for Beijing is studied to demonstrate the implementation of the approach.