LNG冷量优化集成利用技术

我国将相继在沿海地区建成多个LNG接收站，每年将进口数以千万吨计的LNG，同时携带数着巨额冷量，而这些冷量可用于发电、空气分离、制造干冰、低温冷库等众多领域。基于国外LNG冷量利用现状，指出我国即将展开和实施此项技术还存在着：过程火用损较大，缺乏系统、全面的LNG冷量利用技术的研发指导机制，以及宏观调控力度薄弱等问题，进而提出了发展LNG冷量的集成利用方案，可为此类技术的研发利用提供新思路。以福建即将进口的LNG为例，模拟了空气分离与干冰制备的集成工艺流程，结果表明：福建每年进口的260×10⁴t LNG可以冷却290×10⁴t空气，相当于60000 m³/h的氧气制备规模，还可以生产100×10⁴t的干冰，其过程火用损较小；其剩余的高温位冷量可应用于低温冻结库或冰灯等项目，这对主体装置的实施效果和过程火用损的影响较小。该技术的优点在于可灵活控制冷却空气的液化率，基本不用冷却循环水，流程简单，设备投资少，能耗低等。     

Reciprocal Relationships Between Collective Efficacy and Team Performance in Women's Ice Hockey.

This study examined reciprocal relationships between collective efficacy and team performance over a season of competition in women's intercollegiate ice hockey within weekends where the opponent was constant for 2 games. Collective efficacy beliefs within 12 teams were assessed prior to both games for at least 7 weekends. Team performance indexes produced an overall measure of performance for each game. The average influence of Saturday collective efficacy on Saturday performance was moderate and positive after controlling for Friday performance. The average influence of Friday performance on Saturday collective efficacy was small and positive after removing the influence of Friday collective efficacy from Friday performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Critical-point drying versus freeze drying for scanning electron microscopy: a quantitative and qualitative study on isolated hepatocytes

Critical-point drying and freeze drying were compared both quantitatively and qualitatively as preparative procedures for scanning electron microscopy. Isolated hepatocytes were used as model cells. Nomarski differential interference contrast microscopy was used for light microscopic measurements of the hepatocytes in the unfixed, the glutaraldehyde fixed, the glutaraldehyde + OsO₄ fixed, the critical-point dried and the freeze dried states. Critical-point dried hepatocytes were found to shrink to 38% of glutaraldehyde + OsO₄ fixed volume, whereas optimal freeze dried hepatocytes (frozen in water saturated with chloroform and freeze dried at 183 K for 84 h) were found to shrink to 51% of glutaraldehyde + OsO₄ fixed volume. Transmission and scanning electron micrographs of the critical-point dried cells showed well-preserved ultrastructure and surface structure. Micrographs of the freeze dried cells showed ultrastructure destroyed by internal ice crystals and surface structure destroyed by external ice crystals. Double-fixed isolated hepatocytes were shown to swell during storage in buffer and to shrink during storage after critical-point drying. For low magnification scanning electron microscopy (up to about 3000 times) both critical-point drying and freeze drying can be used. However, for high magnification scanning electron microscopy, critical-point drying is superior to freeze drying.     

Modeling of Calcium Chloride and Pectin Methylesterase Prefreezing Treatments of Strawberries and Jams

ABSTRACT: :
Different calcium chloride (CaCl₂) and pectin methylesterase (PME) prefreezing treatments in a vacuum were used to clarify the most effective prefreezing factors for strawberries and traditional jams. Fractional factorial design and modeling were used. CaCl₂ had the greatest effect on the majority of the 15 studied responses ( p < 0.001). The pretreatment time should be short (about 5 to 10 min), the temperature low (less than 20 °C), the vacuum level high (pressure less than 10 kPa), the CaCl₂ concentration moderate (about 1%) and the dosage of PME comparatively low (about 50 to 100 nkat/g) in order to yield high quality frozen strawberries for jam making.     

单桩腿有限元分析

为保证桩腿在冬季冰区海域的安全使用,对桩腿结构进行冰载荷作用下的强度分析。应用ANSYS软件建立桩腿、地基、冰相互作用的仿真计算模型,实现桩腿的力学分析。对桩腿进行了强度校核,计算出冰载荷作用下桩腿的变形及其应力状态。计算结果表明,桩腿在此冰载荷作用下强度满足安全要求。     

Satellite SAR Remote Sensing of Great Lakes Ice Cover,Part 2. Ice Classification and Mapping

During the 1997 winter season, shipborne polarimetric backscatter measurements of Great Lakes (freshwater) ice types using the Jet Propulsion Laboratory C-band scatterometer, together with surface-based ice physical characterization measurements and environmental parameters, were acquired concurrently with Earth Resource Satellite 2 (ERS-2) and RADARSAT Synthetic Aperture Radar (SAR) data. This polarimetric data set, composed of over 20 variations of different ice types measured at incident angles from 0° to 60° for all polarizations, was processed to radar cross-section to establish a library of signatures (look-up table) for different ice types. The library is used in the computer classification of calibrated satellite SAR data. Computer analysis of ERS-2 and RADARSAT ScanSAR images of Great Lakes ice cover using a supervised classification technique indicates that different ice types in the ice cover can be identified and mapped, and that wind speed and direction can have an influence on the classification of water as ice based on single frequency, single polarization data. Once satellite SAR data are classified into ice types, the ice map provides important and necessary input for environmental protection and management, ice control and ice breaking operations, and ice forecasting and modeling efforts.     

油气输送管线冰堵定位检测技术的开发与应用

冬季油气输送管线的冰堵时刻威胁着高寒地区石油化工装置的安全运行，带式传感器动态应变定位检测技术的研制与开发解决了这一难题，它能迅速而准确地查找冰堵点，从而保证炼化装置的冬季正常运行。     

NUMERICAL SIMULATION OF STREAMBED HEAT TRANSFER

１．　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｉｍｕｌａｔｉｏｎｏｆｓｔｒｅａｍｗａｔｅｒｔｅｍｐｅｒａｔｕｒｅｉｓｓｉｇｎｉｆｉｃａｎｔｌｙｉｍｐｏｒｔａｎｔｆｏｒｔｈｅｓｔｕｄｙｏｆｎｕｍｅｒｉｃａｌｍｏｄｅｌｉｎｇｏｆｒｉｖｅｒｉｃｅｐｒｏｃｅｓｓｅｓ［１］　．Ｈｉｓｔｏｒｉｃａｌｌｙ，ｔｈｅｍａｔｈｅｍａｔｉｃａｌｍｏｄｅｌｉｎｇｏｆｔｈｅｔｒａｎｓｐｏｒｔａｎｄｆａｔｅｏｆｈｅａｔｉｎａｗａｔｅｒｂｏｄｙｈａｓｂｅｅｎｔｈｅｓｕｂｊｅｃｔｏｆｅｘｔｅｎｓｉｖｅｓｔｕｄｙｆｏｒｖａｒｉｏｕｓｒｅ…     

20CrMnTiH钢水口堵塞机理研究与解决措施

研究了转炉生产20CrMnTiH钢时连铸水口堵塞的机理，主要通过精炼造CaO—Al2O3-SiO2-CaF2系渣，保持熔渣良好的流动性和高碱度、低熔点、低氧化铁，提高吸附夹杂能力并针对引起水口堵塞的物质，对钙处理、软吹及进站S含量进行严格的要求，成功解决了水口堵塞问题。     

塑料布"V"形铺设法在水库引冰爬坡中的应用

通过塑料布“Ｖ”形铺设法在胜利水库引冰爬坡的应用与实践，证明了此法与传统贴坡式塑料布铺设法相 比，大大削减了冰推力对坝坡的破坏，减少了坝坡的修复费用，起到了良好的效果。