Pyrolysis of peat: Product yield and characterization

Pyrolysis of peat obtained from Yeniça?a, Bolu, Turkey was conducted in a fixed-bed tube furnace under various conditions, and variations in the structure of the char, tar and gas products were examined. The chars produced were studied by proximate and ultimate analyses. The maximum tar yield of 20.41% was obtained at a heating rate of 20 °C/min, a temperature of 450 °C, a sweeping gas flow rate of 100 ml/min and a 0.5–2.0 mm size range. The chemical composition of the tar was examined by elemental analysis, FTIR spectroscopy, ¹H-NMR spectroscopy and column chromatography. The chemical composition of the tar with dense aliphatic structure was established to be CH_1.22O_0.25N_0.02. The composition of the gases obtained at a heating rate of 20 °C/min for the 0.5–2.0 mm size range was examined by gas chromatography.     

计算甘油代谢目标函数的一种新算法

通量平衡分析是代谢工程研究中能够定量预测细胞内通量分布情况的有效工具,然而其预测准确性的前提是需要设计合理的代谢目标函数。研究了克雷伯氏杆菌歧化甘油生产1,3-丙二醇的代谢目标函数计算问题。该问题的数学形式是一个双层规划模型,首先应用线性规划的对偶理论将其转化为等价的单层非线性优化问题,然后采用非线性优化算法对其进行求解。与已有的研究结果相比,所提方法获得了克雷伯氏杆菌歧化甘油代谢的全局最优通量分布情况。     

Hadoop平台下改进的LATE调度算法

对Hadoop平台下的MapReduce现有的调度器进行分析研究。针对LATE调度算法在分配节点执行落后任务的备份任务时的不足,结合Hadoop集群的异构性和工作负载的特殊性,在LATE调度算法的基础上提出了一种改进的LATE调度算法。对该算法进行实验和性能分析,表明该算法在完成时间和负载均衡方面有很大改进。     

Efective Error-Tolerant Keyword Search for Secure Cloud Computing简

The existing solutions to keyword search in the cloud can be divided into two categories： searching on exact keywords and searching on error-tolerant keywords. An error-tolerant keyword search scheme permits to make searches on encrypted data with only an approximation of some keyword. The scheme is suitable to the case where users＇ searching input might not exactly match those pre-set keywords. In this paper, we first present a general framework for searching on error-tolerant keywords. Then we propose a concrete scheme, based on a fuzzy extractor, which is proved secure against an adaptive adversary under well-defined security definition. The scheme is suitable for all similarity metrics including Hamming distance, edit distance, and set difference. It does not require the user to construct or store anything in advance, other than the key used to calculate the trapdoor of keywords and the key to encrypt data documents. Thus, our scheme tremendously eases the users＇ burden. What is more, our scheme is able to transform the servers＇ searching for error-tolerant keywords on ciphertexts to the searching for exact keywords on plaintexts. The server can use any existing approaches of exact keywords search to search plaintexts on an index table.     

含硫纤维素衍生物的研究进展

简述了近年来在含硫纤维素衍生物方面的研究进展。将含硫纤维素衍生物分为巯基纤维素与费原酯棉、水溶性含硫纤维素衍生物和聚硫醚纤维素三大类，对含硫纤维素衍生物的合成、应用及其与金属离子作用机理作了论述。     

霍尔传感器在气动健身器材中的应用

为了能更好地掌握运动者的运动力度,尽可能地减小运动中由于运动过剧造成的损伤,设计了一种气动健身器材,通过实际的气缸压力与霍尔传感器检测出气缸活塞的位移来计算器材使用者所承受的拉力,并结合记录气缸活塞的运动次数来计算运动者消耗的热量,更直观地显示出运动者的运动情况。经过测试,霍尔传感器反应灵敏,检测结果准确,系统稳定性良好,有较高的实用性。     

Prevention from Soft Errors via Architecture Elasticity

Due to the decreasing threshold voltages, shrinking feature size, as well as the exponential growth of on-chip transistors, modern processors are increasingly vulnerable to soft errors. However, traditional mechanisms of soft error mitigation take actions to deal with soft errors only after they have been detected. Instead of the passive responses, this paper proposes a novel mechanism which proactively prevents from the occurrence of soft errors via architecture elasticity. In the light of a predictive model, we adapt the processor architectures h01istically and dynamically. The predictive model provides the ability to quickly and accurately predict the simulation target across different program execution phases on any architecture configurations by leveraging an artificial neural network model. Experimental results on SPEC CPU 2000 benchmarks show that our method inherently reduces the soft error rate by 33.2% and improves the energy efficiency by 18.3% as compared with the static configuration processor.     

CaCO3/natural rubber latex nanometer composite and its properties

Calcium carbonate/natural rubber (NR) latex nanometer composites were prepared by adding nanometer CaCO₃ whose surface had been treated to natural rubber latex (NRL) before sulfuration. The physical, thermooxidative aging, and thermal degradation properties and the ultra‐microstructure were analyzed with a multipurpose material testing meter, a thermal analysis meter and a Philips XL‐30 SEM, respectively. The results showed that the structures and properties of nanometer composites could be clearly improved by NRL mixed with surface‐treated nanometer CaCO₃. The physical properties of the nanometer composites were best when the content of surface treatment agent was 2.5% (to nanometer CaCO₃), the nanometer CaCO₃/NRL content was 3:100, and the stirring time for treating the surface of the nanometer CaCO₃ was 20 min. Simultaneously, the thermooxidative aging resistance of the nanometer composites also was significantly improved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3442–3447, 2006     

高压脉冲放电等离子体降解苯酚废水

考察了多种因素对高压脉冲放电低温等离子体降解水中苯酚效果的影响。降低放电电极直径、放电距离、废水的电导率和提高废水的pH值以及向废水中通气体和加入硫酸亚铁等均可提高废水中苯酚的降解速率 ,而加入碳酸钠则会降低苯酚的降解速率。初始质量浓度为 10 0mg/L的苯酚废水经放电处理 180min后降解率达 5 0 9%。     

Effect of water pretreatment on CO<Subscript>2</Subscript> capture using a potassium-based solid sorbent in a bubbling fluidized bed reactor

A bubbling fluidized bed reactor was used to study CO₂ capture from flue gas by using a potassium-based solid sorbent, sorbKX35 which was manufactured by the Korea Electric Power Research Institute. A dry sorbent, sorbKX35, consists of K₂CO₃ for absorption and supporters for mechanical strength. To increase initial CO₂ removal, some amount of H₂O was absorbed in the sorbent before injecting simulated flue gas. It was possible to achieve 100% CO₂ removal for more than 10 minutes at 60°C and a residence time of 2 s with H₂O pretreatment. When H₂O pretreatment time was long enough to convert K₂CO₃ of sorbKX35 into K₂CO₃ · 1.5H₂O, CO₂ removal was excellent. The results obtained in this study can be used as basic data for designing and operating a large scale CO₂ capture process with two fluidized bed reactors. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.