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Search Results: 1 - 10 of 26644 matches for " 丁莎莎 "
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粗颗粒盐渍土路用填料可用性指标研究
兆民,,杨晓华
冰川冻土 , 2008,
Abstract: 盐渍土盐胀的主要控制因素有土、水、盐、温、力.采用均匀设计方法,通过系列室内单次降温盐胀试验,研究了粗颗粒硫酸盐渍土的盐胀特性及其作为路基填料的可用性.结果表明影响粗颗粒硫酸盐渍土盐胀量大小的主要控制因素是含盐量、含水率及初始干容重,且三个因素互为联系及彼此影响.上覆附加荷载对盐胀量大小具有很强的抑制作用,砾类盐渍土起胀含盐量约0.4%,砂类盐渍土起胀含盐量约为0.2%.盐胀活跃温度区间主要为5~-5℃,活跃温度区间主要控制因素是含水率;如果初始干容重较低,盐胀过程中会发生体缩现象.
谷氨酸钠碳纳米颗粒的荧光光谱及量子产率测定
Measurement of Fluorescence Spectra and Quantum Yield of Carbon Nanoparticles Made from Monosodium Glutamate
 [PDF]

郑楠楠, 楚险峰, 潘立志, 毕森林, , 周兴平
Journal of Advances in Physical Chemistry (JAPC) , 2016, DOI: 10.12677/JAPC.2016.53008
Abstract:
本论文主要以高温热解谷氨酸钠得到的荧光碳纳米颗粒(Glu-FCN)为研究对象,对其荧光光谱及其量子产率进行研究。结果显示:一方面,Glu-FCN存在pH依赖性,当pH在3.0到9.0之间时它的荧光强度最强,而其他范围荧光较弱;另一方面,此荧光碳纳米颗粒水溶液发光位置稳定,最佳激发波长为338 nm和发射波长为391 nm,荧光稳定性极佳。在中性环境下,Glu-FCN水溶液的荧光强度和浓度之间存在很好的线性关系,线性范围在0.2~50 μg/mL,检出下限为0.2 μg/mL。最后,以硫酸奎宁溶液为参比,测量了Glu-FCN在不同激发波长下的荧光量子产率,在最佳激发波长338 nm处的荧光量子产率高达51.5%,适合作为荧光标记物使用。
In this article, fluorescent carbon nanoparticles (Glu-FCN), made by monosodium glutamate pyro-lysis, have been researched, mainly including measurements of Glu-FCN fluorescent spectra and quantum yields. On one hand, pH dependence has been shown to be present in Glu-FCN according to our works. The fluorescence intensity is pretty low when surrounding pH is less than 3.0 or over 12.0. In contrast, it will become quite high when the pH is between 3.0 and 9.0. On the other hand, luminous position of Glu-FCN is very fixed. Optimal excitation and emission wavelengths are respectively located at 338 nm and 391 nm in a stable state. Importantly, good linear relationship exists between fluorescence intensity and concentration of Glu-FCN neutral aqueous solutions. The linear range is 0.20 - 50.0 μg/mL, with 0.20 μg/mL limitation. Eventually, quantum yields of Glu-FCN have been determined using quinine sulfate as a reference under different excitations. And Glu-FCN quantum yield is concluded to be as high as 51.5% under the optimal excitation (338 nm), implying its feasibility for being a fluorescent marker.
基于GPU的大规模基因片段并行匹配的方法
The new approach of multiple genome sequence matching based on GPU

,赵士元,林涛
- , 2017,
Abstract: 后缀树和后缀数组广泛用于生物信息学领域中,特别是通过启发式算法在对DNA基因片段进行匹配的阶段。本文提出了在GPU 的平台下,利用多核和超多核体系构成的后缀树以及后缀数组并行匹配大规模基因片段,从而加速基因搜索匹配过程。相对于后缀树,后缀数组二分搜素算法具有内存占用少,缓存使用率高等优点。在GPU的性能评估中,后缀数组执行效率明显超过后缀树,后缀数组占用的空间仅为后缀树的20%―30%。相对于CPU的串行实现,后缀树组达到了约99倍的加速比。实验结果表明在基因片段匹配的过程中,基于GPU的后缀数组二分搜索是一种高效且实用的方法。
Suffix trees and suffix arrays have been used widely in bioinformatics applications, especially for DNA sequence alignments in the initial exact match phase of heuristic algorithms. In this paper, a new GPU implementation and optimization of the suffix tree and suffix array on both multi-core and many-core platforms to accelerate multiple genome sequence searching is presented. The comparative performance evaluation between the suffix tree and suffix array is then carried out. The results showed that the suffix array needed only 20?C30% of memory space compared with the suffix tree, and that the mean search time of the suffix array was significantly shorter than the mean search time of the suffix tree because of the use of a binary search with coalesced memory access and tile optimization under the GPU architecture. Moreover, the GPU implementation of the suffix array gained a speedup of approximate 99 times compared with the corresponding CPU serial implementation. This study showed that the massively parallel sequence matching algorithm based on suffix array was an efficient approach with the high-performance in the process of multiple DNA sequence matching
自来水生产中去除硝酸盐氮的研究
The Study on Removal of Nitrate Nitrogen in Processing of Tap Water
 [PDF]

, 伍联营
Water pollution and treatment (WPT) , 2016, DOI: 10.12677/WPT.2016.43014
Abstract:
地下水或自来水中硝酸盐、亚硝酸盐的去除是目前研究的热点和难点问题之一。本文对还原铁粉去除水中硝酸盐氮的方法进行了研究,探讨了反应时间、酸的滴加方式、pH值、铁粉添加量、搅拌转速等因素对硝酸盐氮去除效果的影响。结果表明:酸的滴加方式对硝酸盐氮的去除效果影响显著,反应过程中持续加酸比只在初始时调pH效果好,且维持初始pH越低,硝酸盐氮的去除效果越好;增大铁粉用量、提高反应时间均有利于硝酸盐氮的去除;搅拌器的转速对还原脱氮也有一定的影响,且随着转速的增加酸和铁的消耗也相应增加。其最佳工艺条件为:铁粉添加量为50 g/L,维持pH为4,搅拌速度为300 r/min,反应时间为45 min (其中前30 min持续加酸维持pH,后15 min不加酸)。
At present, the removal of nitrate and nitrite in groundwater or tap water is one of the hot and dif-ficult problems. In this paper, the removal method of nitrate nitrogen by Zero Valent Iron is studied and the influencing factors on nitrate removal efficiency such as the reaction time, the add way of acid, the pH value, the additive amount of Zero Valent Iron and the stirring rate are discussed. The results show that the add way of acid significantly influences the effect on the removal of nitrate and nitrite. The mode of continuing to add acid during the reaction has a better effect than only adjust pH in the initial. The lower the initial pH value is, the better removal efficiency will be. Increasing of the amount of iron powder and the reaction time are beneficial to the removal of nitrate. In addition, the stirring rate also has certain influence on the removal of nitrogen. The consumption of acid and iron powder also increases when the stirring rate is high. The optimum process conditions are: 50 g/L Zero Valent Iron, pH = 4, stirring rate: 300 r/min, the reaction time: 45 min (The acid is continually added at initial 30 min to maintain pH value and is stopped in the latter 15 min).
应用数字图像技术诊断苎麻氮素营养的研究简报
李朝东,崔国贤,谢宁,,陈兵兵,白玉超
植物营养与肥料学报 , 2011, DOI: 10.11674/zwyf.2011.0441
Abstract: 为了实现苎麻氮素营养快速诊断,通过盆栽培养3个施氮水平的苎麻,使用信息技术和常规方法,分别获取了不同生育时期两个苎麻品种叶片的图像和氮营养元素含量。通过自主开发的苎麻叶片数字图像处理系统软件对叶片图像进行处理,并提取颜色特征值,分析叶片颜色特征值与叶片全氮营养含量之间的关系。结果表明,大部分颜色特征都与叶片全氮含量呈极显著相关。根据筛选的能有效预测苎麻叶片全氮营养的颜色特征,建立预测苎麻叶片全氮含量的6个模型,预测精度在75.95%~91.50%之间。说明应用数字图像技术诊断苎麻氮素营养是可行的。
CO2-冷海水保鲜技术在南美白对虾中的应用
刘书来,,吕飞,玉庭
农业机械学报 , 2012, DOI: 10.6041/j.issn.1000-1298.2012.12.029
Abstract: 研究了CO2-冷海水浸泡处理技术对南美白对虾保鲜贮藏过程中品质的影响。研究结果表明,CO2-冷海水浸泡处理后虾的菌落总数、大肠杆菌数、产H2S菌数和嗜冷菌数均比对照组低。同时,贮藏期间挥发性盐基氮(TVB-N)、pH值和K值的增加也显著低于对照组。CO2-冷海水中贮藏8d的虾仍在二级鲜度范围内,其TVB-N为19.5mg/(100g)和K值为20.3%,而对照组虾已严重腐败。贮藏期间虾肉的剪切力略有下降,但无显著性差异。CO2-冷海水处理能有效抑制虾内PPO的活性,延缓虾体的褐变和感官品质的下降。
CaSO4-C-H2O体系研究:模拟实验与热力学探讨
康乐,罗跃,单敬福,关富佳,
地质学报 , 2013,
Abstract: 传统认为TSR成因的固态沥青(焦沥青)属于热化学反应的终端产物,不会对TSR的反应进程起到重要作用。本文以活性炭作为固态沥青(焦沥青)的模型化合物,开展了CaSO4-C-H2O体系的热模拟实验研究,探讨了CaSO4-C-H2O体系发生TSR的热力学特征。实验结果表明,CaSO4-C-H2O体系在300℃时即可启动TSR,主要生成CaCO3、H2S和CO2等产物。这一TSR门限温度要远低于以往室内利用气态或液态烃类进行的TSR模拟实验温度范围,与热力学计算结果一致。利用HSCChemistry5.0软件进行TSR过程模拟,发现25-200℃时CaSO4-C-H2O体系发生的TSR完全受动力学控制,在温度保持不变情况下,压力增大不利于CaSO4-C-H2O体系发生TSR。较少的含水量对TSR有一定促进作用,而含水量过多则可能抑制TSR的进行,含水量对TSR的影响可能与CaSO4在水中的饱和浓度有关。在一定的温度下,当体系pH≤2时,随着pH逐渐降低,CaSO4的量呈线性递减,但在沉积盆地地层水pH范围内(pH>4),pH对TSR的作用可以忽略不计。CaSO4-C-H2O体系发生的TSR反应是一个放热过程,并且随着温度升高,反应热逐渐增大。在25-200℃范围内,TSR反应热为12.9-133J/(mol)CaSO4。热力学计算以及模拟实验结果均暗示,固态沥青(焦沥青)可能比烃类更容易参与TSR。
儿茶素衍生物合成及药理作用研究进展
,阳平,罗赛,高明珠,龚正礼
食品科学 , 2012,
Abstract: ?儿茶素是茶叶中多酚类的主要成分,具有多种药理功能,广泛用于食品、医药及日用化工等领域。但其脂溶性及稳定性差,生物利用率低等缺点使其应用范围受到限制。因此对儿茶素的结构修饰应运而生。本文重点综述儿茶素衍生物主要合成方法——酶法和化学法,简述其生理活性,并对其前景作出展望。
碱性盐类对冷冻鱼糜保水性的影响
,安玥琦,玉琴,赵思明,熊善柏
食品科学 , 2012,
Abstract: ?以白鲢鱼糜为研究对象,研究添加柠檬酸钠、乳酸钠对冷冻鱼糜保水品质的影响。结果表明,添加柠檬酸钠、乳酸钠及两者的混合物可有效提高冷冻鱼糜的保水特性,且添加柠檬酸钠与乳酸钠的混合物优于单独添加柠檬酸钠或乳酸钠。经正交试验优化,在鱼糜中添加0.25%乳酸钠和0.50%柠檬酸钠时,冷冻鱼糜的解冻损失率最低,其离心损失率、煮制损失率与添加0.50%的复合磷酸盐的冷冻鱼糜无显著差异(p>0.05),按一定比例混合的柠檬酸钠与乳酸钠可替代复合磷酸盐保水剂。
会厌囊肿术后并发会厌部分缺损1例
刘艳,,李波蓬,蔡洁,
- , 2017, DOI: 10.3969/j.issn.1007-1989.2017.02.027
Abstract: 摘要:
Abstract:
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