利用控制头酸化测试联作的新方法

采用采油树进行酸化作业，安全可靠，但在原钻机试油过程中，采用采油树酸化作业工作量大而繁重，存在一些不便之处。利用控制头替代采油树酸化作业，可以解决困扰酸化施工时来回倒换井口的难题，并且可以缩短试油周期，减少管柱起下钻次数，为含硫化氢油气井的施工提供了安全保障。1997年以来，在塔中26井、塔中126井利用控制头实施酸化作业并获得成功，为酸化测试联作及超深高含硫井的施工积累了实际经验。     

Atomic force microscopic analysis of hydrogen peroxide bleached kraft northern black spruce fibres

Hydrogen peroxide is a potent, relatively inexpensive oxidant that chemically degrades chromophoric components in pulps and textiles. Oxidation of cellulose is a byproduct of this process step that decreases the tensile strength of individual fibres. The residence time of pulp in the bleaching reactor must be optimized to achieve the desired brightness and minimizing fibre degradation. To evaluate the impact of peroxide bleaching at the microfibrillar level, a single black spruce tree was chosen and kraft pulped. Peroxide bleaching was conducted via benchtop polyethylene bag bleaching in a temperature-controlled waterbath. Atomic force microscopy (AFM) topographical images acquired before and after the bleaching step show dramatic changes in fibre structure consistent with delignification and defects in the surface topography. This was further verified by X-ray work at Brookhaven National Laboratory, NY, U.S.A.     

20.4K冷氦加温及氧箱的模拟增压试验技术

主要介绍２０．４Ｋ低温氦气经过加温后给液氧贮箱增压的试验技术。对试验设备、试验方法、试验过程及试验结果做了简要的介绍。     

CS3000顺控表的组态和应用

介绍CS3000系统顺控表的结构、参数定义和功能块组态,以聚丙烯加氢控制为例,描述顺控表的组态方法、顺控动作和操作步骤等。     

Investigation of fusion reactions in palladium and titanium tritide using galvanostatic,coulometric, and hydrogen permeation techniques

We describe several electrochemical methods used to investigate the possibility of cold fusion phenomena in palladium and titanium tritide cathodes. We performed long-term (up to 77 days) electrolysis experiments with electrochemical cells of the University of Utah type at current densities as high as 1 A/cm², while monitoring neutron and tritium levels. With some cells, we pulsed the current to determine if neutron bursts would result. In another cell, we used titanium tritide as the cathode to determine if D-T reactions yielding neutrons would occur. In no instance were levels of neutrons or tritium significantly above background except in the titanium tritide cell where isotopic exchange, occcurring between the electrode and the electrolyte, resulted in significant tritium levels. We also combined x-ray photoelectron spectroscopy (XPS) and electrochemical hydrogen permeation experiments to determine the effectiveness of various Pd surface treatment procedures on the resultant electrochemical hydrogen absorption efficiency. Electroanalytical and thermal desorption/gas analysis techniques indicated the maximum loading of H in Pd was to a ratio of HPd=0.8.     

Nondestructive characterization of the mechanical strength of diffusion bonds. II. Application of a quasi-static spring model

It has been shown that the acoustic response of imperfect interfaces may be described by a quasi-static spring model. In the present paper, experimental data on the geometry of the contacts between two diffusion-bonded blocks have been used to determine the spring stiffness of such interfaces which have been correlated with experimentally determined ultrasonic reflection coefficients. The correlation between the theoretical reflection coefficient and the spring stiffness was found to be in excellent agreement with experimentally-observed values, if the disbonds are of infinitesimally small thickness. For disbonds of finite thickness, the agreement is less satisfactory. Reasons for the discrepancy in the latter case are unknown at the present time.     

一种引入通信的多移动机器人编队方法*

提出以视觉跟踪为基础并引入通信进行多机器人的编队控制方法,根据需要编写了一种新的通信协议,采用闭环l-Φ实现编队算法.这种多机器人编队控制避免了视觉系统的局限,能够更好地在复杂未知环境中协作完成任务,解决了编队控制的无反馈和实时性不高的问题,使得机器人能够准确迅速地进行跟踪和通信编队,一起顺利达到目标点.试验结果证明了该方法的有效性.     

Quantification of secondary structure prediction improvement using multiple alignments

The use of multiple sequence alignments for secondary structurepredictions is analysed. Seven different protein families, containingonly sequences of known structure, were considered to providea range of alignment and prediction conditions. Using alignmentsobtained by spatial superposition of main chain atoms in knowntertiary protein structures allowed a mean of 8% in secondarystructure prediction accuracy, when compared to those obtainedfrom the individual sequences. Substitution of these alignmentsby those determined directly from an automated sequence alignmentalgorithm showed variations in the prediction accuracy whichcorrelated with the quality of the multiple alignments and distanceof the primary sequence. Secondary structure predictions canbe reliably improved using alignments from an automatic alignmentprocedure with a mean increase of 6.87percnt;, giving an overallprediction accuracy of 68.5%, if there is a minimum of 25% sequenceidentity between all sequences in a family.     

Catalytic oxidation of hydrogen sulphide on activated carbons

Activated carbon is a suitable adsorbent for removal of hydrogen sulphide from natural, synthesis or other product gases. The process depends predominantly on physical adsorption, though catalytic oxidation is also involved. During catalytic oxidation the H₂S is converted in the presence of oxygen to elemental sulphur, which is adsorbed onto the internal surface of the activated carbon, thus leading to a sulphur load of up to 120% by weight. The oxidation rate depends on the partial pressure of both reactants, H₂S and O₂ and is largely controlled by the characteristics of the activated carbon. The activity of the catalyst can be improved by impregnating the activated carbon with promoters such as iron and iodine. The regeneration of spent carbon is currently carried out using hot gas desorption methods at temperatures around 450 °C.     

The Interlaminar Bond Strength of Flexible Polymer-Metal Laminates

An alternative test method to the traditional 180° “T” peel test has been developed for the measurement of interlaminar bonding in three-ply (polyester/aluminium/polypropylene) flexible-packaging, laminate materials. The new test is thought to involve mixed mode I (opening) and mode II (shearing) failure, and takes into account the yielding of the polypropylene layer during testing. The method allows more direct comparisons between materials to be made, and allows the measurement of strong bonds, where a peel test would result in yield or fracture of the substrate arms before debonding.