Cuphea a rich source of medium chain triglycerides: Fatty acid composition and oil diversity in Cuphea procumbens

The phenological characteristics, oil content, and fatty acid composition of 34 selections of Cuphea procumbens have been studied. The mean seed yield per plant was 9.7 ± 0.43 g. Maximum seed yield (16.7 g) was noticed in NBC‐27, while the average number of fruits per plant was 124.9 ± 10.7. The oil content in the seeds ranged from 16.7—28.7%, maximum being in NBC‐34. The fatty acid composition revealed the presence of capric acid (C10:0) in all the selections of C. procumbens as the major constituent of the oil ranging from 87.7—94.6%. C. procumbens showed its novelty as an alternative source of capric acid and may be utilized as a renewable resource in the production of plasticizers and lubricants which wholly depend on petrochemical import. Researches are in progress in order to obtain tolerant cultivars against wild plant characteristics and some delayed seed shattering plants have been identified.     

Biodegradation of phenol in the presence of heavy metals

A microbial growth model was presented for estimating the dynamic behavior of cell growth and substrate consumption in the biodegradation of phenol containing a heavy metal, such as zinc or copper ions. The application of the model for experiments in a batch culture and a continuous culture was examined. The values calculated according to the model corresponded satisfactorily with experimental data, such as the optical density of cells and the concentration of phenol. Using the model, the stability of steady states in a continuous culture was analytically evaluated based on the eigenvalues. The steady states were separated into three categories: (i) a stable steady state where phenol was consumed, (ii) an unstable steady state where phenol was consumed, and (iii) a washout state where phenol was not consumed. The number, kind, and stability of steady states varied significantly with operational conditions such as dilution rate, feed concentration of phenol, and feed concentration of heavy metal ions. The operational conditions required to obtain the stable steady state where phenol was consumed are shown graphically. © 2000 Society of Chemical Industry     

一种改进单脉冲技术的低角跟踪性能分析

在低仰角跟踪过程中,空域飞行目标发射的电磁波可通过不同路径传播到达相控阵系统接收端;由于各分量场的到达时间不同,它们按各自相位相互叠加而造成干扰,导致相控阵天线无法通过传统单脉冲测角技术准确获得目标的角度信息;为了消除多径效应对于系统低角跟踪性能的影响,提出了一种改进单脉冲测角技术方法：该方法利用相邻脉冲差波束相位跳变构造对称波束,并采用频率分集技术,通过对不同工作频率下得到的和差波束进行一系列运算,能够准确得到目标与镜像目标的角度信息;在典型二径环境下,测角误差由之前的一度左右降低到零点一度以下;改进单脉冲测角技术的应用使得系统的跟踪性能明显提高,并且计算复杂度较低,较容易实现,因此具有良好的工程实用价值。     

P/O-丁酰基苯酚的土壤微生物生态效应

研究了P／O-丁酰基苯酚对土壤微生物活性的影响,结果表明：P／O-丁酰基苯酚在所设计的浓度下,对土壤呼吸作用、过氧化氢酶和脲酶活性没有显著影响。对土壤放线菌数量没有影响;对真菌数量影响不大;对细菌数量的影响则为先抑制,且随浓度增大抑制作用增强,后逐渐恢复稳定。     

丙烷脒类似物抑菌活性研究

以番茄灰霉病菌和白菜黑斑病菌等植物病原菌作为供试生物,用抑制菌丝生长速率法测定了合成的10个丙烷脒类似物的抑菌活性。结果表明：在供试浓度为10mg／L时,化合物A1-A5对番茄灰霉病菌、白菜黑斑病菌、苹果干腐病菌和烟草赤星病菌菌丝生长抑制率均在80％以上;化合物B5对小麦纹枯病菌菌丝生长抑制率为82．2％,值得进一步研究。     

我国高新区经济发展规模数学模拟与区域差异比较研究

利用MATLAB工具,选择我国高新区1991—2000年10年间的出口额、工业总产值、技工贸收入和企业数量4个指标进行数学模拟,利用模拟函数的数值积分研究东、中、西部地区高新区发展的规模差异．结果表明：东、中、西部差异最大的是出口创汇的规模与水平,且随着时间的推移西部地区与东部的差距在不断扩大;工业产值、技工贸收入、企业数量指标与出口额相比,东、中、西部地区的差距相对要小,但西部地区与中、东部的差距仍然突出．工业产值西部与东部的比例平均为1：4．3,与中部的比例为1：1．5;技工贸收入差距在不断缩小,不过中部地区技工贸收入的增长比西部地区的增长幅度要大．     

面向文献评价的引文网络结构多样性研究

鉴于从海量文献中寻找高质量文献的重要性,提出了文献评价指标——引文网络结构多样性。大规模数据集上的数据分析实验分析了该模型作为文献评价指标的可行性,并针对数据集引用关系存在缺失的情况提出改进模型,使之更加适用于引文网络分析。数据分析实验结果显示文献引文网络结构多样性与引用量显著线性相关,且引文网络结构多样性是影响文献发表后引用量变化趋势的重要因素。在引用量预测实验中,各结构多样性在85.8%的实验中提升了模型的预测性能,其中组合结构多样性在长期引用量预测实验中效果突出,对决定系数R2最高提升22.19%,平均提升14.55%,对均方误差MSE最高提升22.76%,平均提升17.34%。     

靖一联采出水处理及回注工艺技术研究与应用

主要针对靖一联絮凝罐+精细过滤处理工艺处理后水质达不到回注标准的现状,借鉴油一联微生物处理的成功经验,通过室内菌种筛选,优选出了适合靖一联采出水的微生物菌群,并在现场进行了微生物处理工艺改造,使靖一联采出水处理水质得到了明显改善,达到了油田采出水的回注要求,实现了靖一联全部采出水的有效回注,节约了大量的清水资源和运行费用。     

低压水敏储层清防蜡技术

介绍了为解决低压水敏储层油井结蜡所开展的声波防蜡、微生物防蜡、磁防蜡技术的研究及应用。在对原油性质及储层特征进行研究的基础上,对油田常规热洗清蜡工艺进行了分析,提出了常规热洗清蜡工艺在解决低压水敏储层油井结蜡中存在的问题。通过几年的研究与应用,优选出适用于低压水敏储层油井的清防蜡工艺,确定了各清防蜡技术的技术界限。清防蜡新工艺与油井检泵周期结合,不仅达到杜绝储层污染、防止油井结蜡、保证油井稳定生产的目的,而且防蜡不影响油井正常生产,提高了油井生产时率、降低了油井清防蜡成本,提高了油田开发效率。现场共实施各种清防蜡措施456井次,减少热洗4256井次,节约热洗费用1414万元,创造经济效益1239万元,投入产出比达到1∶3。     

Single and multiple satellite visibility statistics of first-generation non-GEO constellations for personal communications

The first generation of global satellite systems for personal and mobile communications is preparing to start commercial services. Service quality and availability are paramount to the user's acceptance of the service. For satellite systems, service quality and availability build up from satellite visibility, propagation conditions and equipment availability. This paper discusses the impact of elevation angle on visibility and propagation, that of azimuth separation between visible satellites, and compares multiple visibility statistics of all first-generation non-geostationary communications systems, namely Iridium, Globalstar, ICO, Ellipso and ECCO. © 1998 John Wiley & Sons, Ltd.