基于GridSim的网格调度模拟

详细分析了GridSim工具,并与当前几个主要的网格模拟工具进行了对比,然后探讨了GridSim工具的改进,扩展了计算资源的功能,增加了数据存储资源模型。最后提出了基于GridSim工具的分模块的调度模拟开发方法,按照这种方法建立了Min—min调度算法模拟平台,展示了GridSim工具的功能。     

新一代多模型迭代算法在70 kVp成人副鼻窦CT扫描中的应用

探讨成人在70 kVp副鼻窦CT检查中降低有效辐射剂量的同时,获取最佳图像质量的新一代多模型迭代算法(Adaptive Statistical Iterative Reconstruction-V,Asir-V)的权重。本研究对20例成人患者进行副鼻窦Revolution CT检查,采用70 kVp、230 mA条件下进行螺旋CT扫描,扫描完成后对每例患者的原始数据采用不同权重(0,20%,40%,60%,80%,100%)的后置新一代多模型迭代算法(Adaptive Statistical Iterative Reconstruction-V,Asir-V)重建的方法,共获得120幅图像,并对每例6组图像进行客观评价及主观评分。客观评价包括噪声(standard deviations, SD)和对比噪声比(contrast noise ratio,CNR),主观评价由2名评价医生对图像质量评分并对两者的主观一致性进行评价。每例患者扫描完成后,记录其剂量长度乘积(dose-length product,DLP)和CT容积剂量指数(CT dose index volume,CTDI_vol),并计算其平均有效辐射剂量(effective dose,ED)。客观评价结果表明不同权重的Asir-V图像噪声随着Asir-V权重的提升而降低,CNR值随着Asir-V权重的提升而升高,且有效辐射剂量ED较常规头颈部CT检查的平均辐射剂量明显减少;主观评价结果表明不同权重的Asir-V图像评分不同,在Asir-V 60% 时评分最高,且2名医生主观评价一致性好。结合主客观评价结果,认为在70 kVp、230 mA成人副鼻窦Revolution CT检查中,Asir-V 60％的图像既可满足临床诊断的需要,也可明显降低有效辐射剂量。     

Frequency and Spectrum of Mutations Induced by Gamma Rays Revealed by Phenotype Screening and Whole-Genome Re-Sequencing in Arabidopsis thaliana

Genetic variations are an important source of germplasm diversity, as it provides an allele resource that contributes to the development of new traits for plant breeding. Gamma rays have been widely used as a physical agent for mutation creation in plants, and their mutagenic effect has attracted extensive attention. However, few studies are available on the comprehensive mutation profile at both the large-scale phenotype mutation screening and whole-genome mutation scanning. In this study, biological effects on M₁ generation, large-scale phenotype screening in M₂ generation, as well as whole-genome re-sequencing of seven M₃ phenotype-visible lines were carried out to comprehensively evaluate the mutagenic effects of gamma rays on Arabidopsis thaliana. A total of 417 plants with visible mutated phenotypes were isolated from 20,502 M₂ plants, and the phenotypic mutation frequency of gamma rays was 2.03% in Arabidopsis thaliana. On average, there were 21.57 single-base substitutions (SBSs) and 11.57 small insertions and deletions (InDels) in each line. Single-base InDels accounts for 66.7% of the small InDels. The genomic mutation frequency was 2.78 × 10⁻¹⁰/bp/Gy. The ratio of transition/transversion was 1.60, and 64.28% of the C > T events exhibited the pyrimidine dinucleotide sequence; 69.14% of the small InDels were located in the sequence with 1 to 4 bp terminal microhomology that was used for DNA end rejoining, while SBSs were less dependent on terminal microhomology. Nine genes, on average, were predicted to suffer from functional alteration in each re-sequenced line. This indicated that a suitable mutation gene density was an advantage of gamma rays when trying to improve elite materials for one certain or a few traits. These results will aid the full understanding of the mutagenic effects and mechanisms of gamma rays and provide a basis for suitable mutagen selection and parameter design, which can further facilitate the development of more controlled mutagenesis methods for plant mutation breeding.     

Using proteomics platform to develop a potential immunoassay method of royal jelly freshness

So far royal jelly (RJ) has been widely used as a kind of popular and traditional food for health promotion. However, the quality of RJ is vulnerable to improper storage conditions. In order to prohibit the low quality RJ products entering the market and consequently affect the health of humans, it is necessary to define the quality parameters and establish corresponding detection methods for the freshness of RJ. In this research, we applied two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometry to research major royal jelly proteins (MRJPs) changes under different storage conditions after 6-month storage, looking for a stable and reliable protein marker which was also feasible to detect the freshness of RJ. Further research with the help of Western blotting analysis (WB) confirmed that, under room temperature, MRJP5 began to hydrolyze within 30 days and would completely degrade within 75 days, indicating that MRJP5 can be adapted as a freshness marker for RJ products. Moreover, the assessment results of the freshness of 12 commercial RJ products with WB showed that MRJP5 was present in twelve RJ samples at different abundance levels which further confirmed the detection of MRJP5 could be a feasible method to assess the quality and freshness of commercial RJ products.     

《烟草控制框架公约》的法律适用浅析

从国际条约的性质及在我国国内法上的适用为出发点,对《烟草控制框架公约》及其实施指南的法律地位和适用原则进行分析,试图为《公约》及其实施指南在中国的法律适用和具体实践提供法理依据.     

天然植物活性物质阿魏酸糖酯的研究进展

阿魏酸糖酯具有降血糖,抗氧化,改善肠道环境等多种生物活性,由此赋予其极高的开发价值和广阔的市场前景。本文对阿魏酸糖酯的分布、结构、营养价值、制备方法等方面的研究现状进行综述。     

超临界直流锅炉的EDTA化学清洗

结合超临界直流锅炉特点及国内常规的几种锅炉化学清洗方案进行分析,同时结合自己负责清洗的几台该类型锅炉化学清洗经验,提出采用EDTA钠盐利用高压加热器进行加热清洗该类型机组是比较理想的方案.     

我国油菜生产形势分析及科研对策研究

分析了我国油菜生产的现状和存在的问题,提出了油菜科研对策：（1）加强油菜杂种优势利用研究,进一步提高油菜产量;（2）挖掘高含油量油菜资源,加强油脂形成的基础研究,进一步提高油菜的含油量;（3）改善菜籽油脂肪酸组成,改良其营养品质,提高商业价值;（4）加强早熟品种和适合机械化收获品种的培育;（5）加大油菜转基因研究。     

复合硅源在大理石表面仿生合成二氧化硅保护膜的研究

使用硅酸钠/氟硅酸钠复合硅源,通过仿生合成方法在大理石表面制备得到了一层SiO2为主要成分的保护膜,并对该膜的性能进行了检测评价.运用傅里叶变换红外光谱仪和扫描电子显微镜对膜的结构和形貌进行了表征,探讨了SiO2的成膜机理.结果表明,运用复合硅源可在近中性条件下在大理石表面形成SiO2膜,SiO2颗粒以球形形态沉积在大理石表面,表现出成核、颗粒长大和颗粒堆聚3个阶段.24 h可形成较完整、均匀致密的保护层.该膜不仅具有优良的耐酸、耐候性,还具有良好的透气性能.     

超深基坑支护综合施工技术

北京绿地中心工程地下水含量丰富且分布复杂,基础地下5层,深度超过30 m,且基坑施工周期长,经冬季寒冷、开春化冻、雨季降雨等多种复杂情况。基坑支护方式综合使用了护坡桩、止水帷幕及土钉墙支护等相结合的方式。通过科技创新的方式优化了基坑支护方案,降低了施工成本,提前实现了工期目标。