大型天然气平台火炬系统设计新思路

在南海某区域大型天然气处理平台的火炬系统设计中,火灾时BDV泄放为控制工况。若考虑火灾时平台全部BDV同时泄放,泄放量将达112万m 3/h,火炬臂长度为104 m,如此长的火炬臂将对于平台的结构设计造成较大影响。为此提出采用了分层分火区延时泄放和BDV采用备用仪表气瓶等方法,将火炬泄放能力由常规设计的112万m3/h降低至81万m3/h,火炬臂的长度由104 m缩短至90 m的设计思路。数值模拟计算结果表明,该方案可行。

抽油烟机使用误区

多数人认为抽油烟机是专为抽烹饪油烟而用的,因此,只有在炒菜时才开抽油烟机。殊不知,这是使用抽油烟机观念上的一个误区。 实际上,抽油烟机的功能不仅仅是抽走烹饪油烟,而且能根除燃气污染。特别是石油液化气含有多种强致癌物质,比烹饪油烟更有害健康。 燃气污染来自两方面:每次点火、熄火时泄漏的燃气和燃气在燃烧过程中产生的废气。这些飘散性气体,是沿着锅边向四周自由扩散的,只有采用主动式排烟装置即柜式抽油烟机,才能将其控制在柜内并及时抽走。 因此,不管是否烹饪,只要使用燃气灶就应该打开抽油烟机。

CO_2 Leakage Identification in Geosequestration Based on Real Time Correlation Analysis Between Atmospheric O_2 and CO_2

The paper describes a method for monitoring CO2 leakage in geological carbon dioxide sequestration. A real time monitoring parameter, apparent leakage flux(ALF), is presented to monitor abnormal CO2 leakage, which can be calculated by atmospheric CO2 and O2 data. The computation shows that all ALF values are close to zero-line without the leakage. With a step change or linear perturbation of concentration to the initial CO2 concentration data with no leakage, ALF will deviate from background line. Perturbation tests prove that ALF method is sensitive to linear perturbation but insensitive to step change of concentration. An improved method is proposed based on real time analysis of surplus CO2 concentration in least square regression process, called apparent leakage flux from surplus analysis(ALFs), which is sensitive to both step perturbation and linear perturbations of concentration. ALF is capable of detecting concentration increase when the leakage occurs while ALFs is useful in all periods of leakage. Both ALF and ALFs are potential approaches to monitor CO2 leakage in geosequestration project.

Personalized Management of Anastomotic Leak after Surgery for Esophageal Carcinoma

Objective To summarize the management of anastomotic leak following surgery for esophageal car-cinoma. Methods The medical records of the patients developing digestive tract leak after surgery for esophageal carcinoma in our hospital from January 2003 to March 2011 were retrospectively analyzed. Results A total of 36 patients were included, in whom 13 developed cervical anastomotic leak, 18 had intra-thoracic anastomotic leak, and 5 had intra-thoracic gastric necrosis. Of these patients, 7 were treated with resurgery, 6 with esophageal stent implantation, and 23 with conservative treatment. Treatment lasted for 5 to 181 days, averagely 47.0±31.9 days. After management, 9 patients died (25.0%). Among seven patients with resurgery, four had deceased, two were cured, and one developed leak again and was switched to conservative treatment until discharged. All the 6 patients treated with stent implantation were cured. Of the 24 patients receiving conservative treatment (including one switched from resurgery), 18 (75.0%) were cured and 1 was not cured but survived. Conclusions Anastomotic leak following surgery for esophageal carcinoma should be treated individually based on the onset time, location, size, and extent of the leakage. Conservative treatment is still a safe and effective method.The efficacy of stent implantation needs further investigation to confirm.

TCP负压射孔工具对真实负压值的影响研究

TCP负压射孔工艺在渤海油田广泛应用,但目前采用的TCP负压射孔工具从设计原理上忽略了负压阀联通孔泄压延时性和点火棒在短油管内下落速度非瞬时性等问题,常常导致泄压未完成即触发点火,产生的真实负压值小于设计值。为此,综合考虑TCP负压射孔井下流体、工具等实际情况,建立了负压阀联通孔流体流动模型和点火棒下落速度模型,并对影响真实负压值的相关参数进行了分析,为负压值设计和现场计算提供更准确的理论指导。

Prediction of Gas Emission Based on Infor-mation Fusion and Chaotic Time Series

In order to make more exact predictions of gas emissions, information fusion and chaos time series are com- bined to predict the amount of gas emission in pits. First, a multi-sensor information fusion frame is established. The frame includes a data level, a character level and a decision level. Functions at every level are interpreted in detail in this paper. Then, the process of information fusion for gas emission is introduced. On the basis of those data processed at the data and character levels, the chaos time series and neural network are combined to predict the amount of gas emission at the decision level. The weights of the neural network are gained by training not by manual setting, in order to avoid subjectivity introduced by human intervention. Finally, the experimental results were analyzed in Matlab 6.0 and prove that the method is more accurate in the prediction of the amount of gas emission than the traditional method.

Study on Detection Technique for Pipeline Leakage

Pipeline in te grity defect is a considerable portion in all the defects.Therefore, the study o n detection technique is of great concern to the owners of pipelines. A real ti me monitoring system of pipeline defect is established. For unexpected accidents of pipeline leakage, several methods of signal processing, including wavelet an alysis are utilized. The leakage can be located accurately in time. This system is applied to many long distance pipelines in China, which has made great contri butions to the economy.

A Combinational Power Analysis Method against Cryptographic Hardware

Power analysis is a non-invaslve attack against cryptographic hardware, which effectively exploits runtime power consumption characteristics of circuits. This paper proposes a new power model which combines Hamming Distance model and the model based on the template value of power consumption in combinational logic circuit. The new model can describe the power consumption characteristics of sequential logic circuits and those of combinational logic as well. The new model can be used to improve the existing power analysis methods and detect the information leakage of power consumption. Experimental results show that, compared to CPA（Correlation Power Analysis） method, our proposed attack which adopt the combinational model is more efficient in terms of the number of required power traces.