一种控制盐层段井眼闭合率的钻井液密度新公式

针对钻井过程中钻遇的盐层段井眼蠕变缩径问题,利用弹塑性力学理论,蠕变本构方程采用Heard蠕变方程,在平面应变和均匀地应力假设下,推导出控制井眼收缩的钻井液密度新公式,该公式与前人推导的公式不同。通过理论分析,指出产生差异的根本原因在于蠕变应力差(极坐标下表示的径向应力与切向应力之差)公式的推导上,用有限元法计算结果对理论公式进行检验,证明是可行的。对文中的力学模型采用有限元法建模、求解,利用求解结果对各应力差公式进行验证,得出:根据文中公式计算结果与有限元法计算结果完全一致,而据前人公式计算结果偏离有限元计算值较大,从而间接证明了该钻井液密度新公式的推导更严密,更准确。     

疏水缔合型聚丙烯酰胺的合成与性能评价

为了提高高相对分子质量的聚丙烯酰胺的抗温抗盐性能,利用自制的两亲表面活性单体与丙烯酰胺共聚合成了疏水缔合型聚丙烯酰胺并进行室内评价。结果表明,在高温、高盐、高钙条件下,合成的疏水缔合型聚丙烯酰胺具有良好的增粘性和较强的热稳定性;克服了疏水缔合型聚合物在盐水中溶解性差的问题,可用各种矿化度的盐水和油田产出污水配制;具有良好的无机盐增粘性能和抗温性能。     

The relative effects of transection of the gustatory branches of the seventh and ninth cranial nerves on NaCl taste detection in rats.

Chorda tympani nerve (CT) transection in rats severely impairs NaCl taste detection. These rats can detect higher concentrations of NaCl, however, suggesting that remaining oral nerves maintain some salt sensibility. Rats were tested in a gustometer with a 2-response operant taste-detection task before and after sham surgery (n = 5), combined transection of the CT and the greater superficial petrosal nerves (GSP; 7x, n = 6), or transection of the glossopharyngeal nerve (GL; 9x, n = 4). Thresholds did not significantly change after sham surgery. Although the GL responds to NaCl and innervates nearly 60% of total taste buds, 9x surgery had no effect. However, 7x surgery increased NaCl detection threshold by ～2.5 log?? units, greater than that reported for CT transection alone. These results suggest that the GSP contributes to NaCl sensitivity in rats and also demonstrate that the GL and perhaps the superior laryngeal and lingual nerve proper can maintain some NaCl detectability at high concentrations. These findings confirm the primacy of the 7th nerve relative to the 9th nerve in sensibility of NaCl in the rat model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Surface movements in Bologna (Po Plain — Italy) detected by multitemporal DInSAR

We studied the surface deformations affecting the southeastern sector of the Po Plain sedimentary basin, in particular the area of Bologna. To this aim an advanced DInSAR technique, referred to as DInSAR-SBAS (Small BAseline Subset), has been applied. This technique allows monitoring the temporal evolution of a deformation phenomenon, via the generation of mean deformation velocity maps and displacement time series from a data set of acquired SAR images. In particular, we have processed a set of SAR data acquired by the European Remote Sensing Satellite (ERS) sensors and compared the achieved results with optical levelling measurements, assumed as reference. The surface displacements detected by DInSAR SBAS from 1992 to 2000 are between 10 mm/year in the historical part of Bologna town, and up to 59 mm/year in the NE industrial and agricultural areas. Former measurements from optical levelling referred to 1897 show 2-3 mm/year vertical movements. This trend of displacement increased in the second half of the 20th century and the subsidence rate reached 60 mm/year. We compared the more recent levelling campaigns (in 1992 and late 1999) and DInSAR results from 1992 to 1999. The standard deviation of the difference between levelling data, projected onto the satellite Line Of Sight, and DInSAR results is 2 mm/year. This highlights a good agreement between the measurements provided by two different techniques. The explanation of soil movements based on interferometric results, ground data and geological observations, allowed confirming the anthropogenic cause (surface effect due to the overexploitation of the aquifers) and highlights a natural, tectonic, subsidence.     

Antimicrobial finishing of regular and modified polyethylene terephthalate fabrics

An effective two-stage method has been developed for imparting antimicrobial properties to regular polyethylene terephthalate (R-PET), polyethylene glycol modified polyethylene terephthalate (PEG-M-PET), R-PET/Cotton blend (R-PET/C) and PEG-M-PET/Cotton blend (PEG-M-PET/C) fabrics. The method consists of partial hydrolysis of the fabrics to create carboxylic groups in PET macromolecules followed by subsequent reaction with dimethylalkylbenzyl ammonium chloride (DMABAC) under alkaline conditions. The reaction conditions such as pH, reaction temperature and time, carboxylic content, and DMABAC concentration were studied. Characterization of the finished fabrics was carried out through scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). All the modified PET fabrics showed excellent antibacterial activity towards Gram-positive (Bacillus mycoides), Gram-negative (Escherichia coli), and nonfilamentous fungus (Candida albicans). The achieved antimicrobial functions on the PET fabrics are durable in repeated laundering processes. Even after laundering 10 times the fabrics could still provide more than 85% of its antimicrobial activity against B. mycoides, E. coli, and C. albicans. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mechanistic investigation into the electrolytic formation of iron from iron(III) oxide in molten sodium hydroxide

Iron(III) oxide tablets were electrolytically reduced to iron in molten sodium hydroxide at 530 °C and recovered to produce iron with 2 wt.% oxygen suitable for re-melting. The cell was operated at 1.7 V and an inert nickel anode was used. The thermodynamics and mechanism of the process was also investigated. By controlling the activity of sodium oxide in the melt, the cell could be operated below the decomposition voltage of the electrolyte with the net sequence of events being the ionization of oxygen, its subsequent transport to the anode and discharge leaving behind iron at the cathode. A reduction time of 1 h was achieved for a 1 g oxide tablet (close to the theoretical reduction time predicted by Faraday’s laws) at a current density of 520 mA cm⁻² with iron phase yields of ∼90 wt.%. The energy consumption was 2.8 kWh kg⁻¹.     

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我国的西气东输工程从新疆塔里木油田到上海，管线长度达4000公里，为确保对长江三角洲地区安全稳定的供气，就必须在长江三角洲地区建设地下储气库，从而保证在管线故障期间应急供气，同时利用地下储气库调节冬季和夏季用气量的差异，保证长输管线的高效、平稳运行。在长江三角洲地区经地库址选择，目前准备将常州盆地的金坛盐矿用以建设地下储气库。盐穴地下储气库主要选择在盐层或盐兵上，利用水溶方式形成地下溶腔进行储气，选择合适的建库地址要结合地质、水、工程等诸多因素，造腔过程中需要采取一系列控制技术，在造腔过程中还要及时采取声纳测井技术进行跟踪监测，造腔过程的检测及腔体完成后的密封安全性检测是气库能否投入运行的关键。     

Preparation of the TiB2 coatings by electroplating in molten salts

The improvement of titanium diboride (TiB₂) coatings over the molybdenum substrate was investigated by comparing the electrochemical techniques of continuous current plating (CCP) and periodically interrupted current (PIC). The solvent used was a eutectic Flinak mixture (LiF-NaF-KF, 46.5:11.5:42 molar ratio) with solutes K₂TiF₆ and KBF₄ with the electrochemically-active components in the molar ratio of one to five. The coatings produced by PIC show improvements in morphology and microstructure for the suitable conditions: i = 0.5 A/cm², frequency = 100 Hz, the time ratio t_c/t_off (current on/current off) = 4/1. X-ray diffraction (XRD) analyses indicated that the coatings are composed of the relatively pure TiB₂ and the preferred orientation is [001] + [110], which is in accordance with the prediction of the two-dimensional crystal nuclei theory.     

熔融盐法合成高密度锂离子电池正极材料LiNi_(0.8)Co_(0.2)O_2

采用热分析法对不同组成的LiOH-LiNO3二元体系进行研究,绘制了具有最低共熔点的该二元体系的步冷曲线和t-x相图,该体系的最低共熔点为175.7℃。利用低共熔混合物LiNO3-LiOH为锂盐,与高密度前驱体Ni0.8Co0.2(OH)2混合经2个恒温阶段烧结(600℃恒温6 h、800℃恒温24 h)制备出了振实密度高达3.23 g/cm3的锂离子电池正极材料LiNi0.8Co0.2O2。X射线衍射分析表明合成的LiNi0.8Co0.2O2具有规整的层状NaFeO2结构。电性能测试表明:在0.5 mA/cm2放电电流密度和3.0—4.3 V的电压范围内,LiNi0.8Co0.2O2首次放电比容量达175(mA.h)/g,放电比容量为163(mA.h)/g,库仑效率为93%。实验结果表明采用该工艺能够制备出电化学性能良好的锂离子正极材料。     

Charge density dependence of elastic modulus of strong polyelectrolyte hydrogels

The mechanical behavior of a series of strong polyelectrolyte hydrogels based on acrylamide and 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS) was investigated. The hydrogels were prepared at a fixed crosslinker ratio and monomer concentration, but at various charge densities, i.e. AMPS contents between 0 and 100 mol%. The elastic modulus of the hydrogels after their preparation first increases with increasing charge density but then decreases continuously. Investigation of the swollen state properties of the hydrogels shows existence of a large number of ionic groups inside the gel that are ineffective in gel swelling. The results indicate two opposite effects of charged groups on the elastic modulus of the hydrogels: formation of multiplets acting as additional crosslinks in the gel increases the elastic modulus of ionic hydrogels, whereas the effect of the electrostatic interaction of charged groups on elastic free energy decreases the modulus.