基于磁盘阵列的超高速SAR原始回波数据记录技术研究

该文介绍了基于磁盘阵列的合成孔径雷达超高速原始回波数据记录器的结构组成、工作原理及性能特点,讨论了两种数据包的分配方案：基于先后顺序的数据包分配方案和基于统计特性的动态数据包分配方案,并指出了这两种方案各自的优缺点。最后,给出了两种方案实现结果的性能参数对比表。     

合成孔径雷达数据压缩算法性能分析

随着合成孔径雷达(SAR)向高分辨率、宽测绘带和多模式方向发展,星载SAR系统存在高数据率下传和处理的问题.原始数据压缩成为减小数据率的重要手段.文中在详细分析SAR原始数据压缩算法性能的影响因素的基础上,从工程应用的角度结合高分辨率SAR实际数据.从原始数据域和图像域等方面对目前存在的BAQ、AP和WT-AP等6种SAR原始数据压缩算法的性能做了深入的比较分析,为星载合成孔径雷达系统设计提供有益的参考.     

Addition of phytochemical-rich plant extracts mitigate the antimicrobial activity of essential oil/wine mixtures against Escherichia coli O157:H7 but not against Salmonella enterica

Marinades for preparing raw meats for cooking are frequently made of wine and herbs. We simulated several formulations of potential antimicrobial marinades with these components and other food compatible/food derived extracts. Red wine formulations containing essential oils from oregano or thyme, or their primary active components carvacrol and thymol, respectively, and a mixture of plant extract powders from phytochemical-rich apple skin, green tea, and olive, were evaluated for inhibitory activity against the foodborne pathogens Escherichia coli O157:H7 and Salmonella enterica. Red wine alone exhibited low activity, as did the plant extract suspended in the wine. Surprisingly, the high activity of oregano or thyme essential oils in red wine was reduced in E. coli, but not in Salmonella, by addition of the plant extract. This study shows that essential oils in red wine can be an effective antimicrobial in food, however the possibility exists that phytochemicals, added to the treatment solution or natively present in the food itself, could adversely impact the antimicrobial activity and should be addressed with future studies.     

A novel developed method based on single primer isothermal amplification for rapid detection of Alicyclobacillus acidoterrestris in apple juice

Alicyclobacillus acidoterrestris (A. acidoterrestris), as one of the most major spoilage-causing species within the Alicyclobacillus genus, can survive and multiply in the pasteurization process. Nowadays, A. acidoterrestris has become worldwide issue in the fruit juice industry due to its spore-forming and thermo-acidophilic features. A novel single primer isothermal amplification assay (SPIA) was developed for the rapid detection of A. acidoterrestris in apple juice. This assay was designed to target the 16S rRNA gene with a DNA/RNA chimeric primer. Detection of gene amplification was accomplished by amplification curve, turbidity and addition of single strand DNA binding dye SYBR Green II allowing visualization under ultra violet light. The specificity of the assay was confirmed using 7 strains of A. acidoterrestris and 30 strains of non-A. acidoterrestris. The SPIA was highly sensitive and the detection limit was as low as 4.8 CFU/mL. Furthermore, the apple juice inoculated with 61 CFU/mL of A. acidoterrestris could be detected as positive. The novel SPIA with visualization results was successfully applied for the detection of A. acidoterrestris and exhibited high specificity and sensitivity, making it a powerful tool for the detection of A. acidoterrestris in fruit juice industry and being conveniently applied in developing countries with limited resource.     

原料特性对曲奇饼干品质和丙烯酰胺生成的影响

以面粉、油、糖为主要原料制作曲奇饼干,通过测量其水分含量、色度、质地、感官和丙烯酰胺含量,研究原料特性对曲奇饼干品质和丙烯酰胺生成的影响。实验表明:面粉中蛋白质的含量显著影响曲奇饼干的品质和丙烯酰胺的生成。与高筋粉和中筋粉相比,低筋粉粗蛋白含量仅为7.67%,其制作的曲奇饼干水分含量低,硬度小,柔软和酥松程度表现更好,品质最佳且丙烯酰胺生成量最低。普通黄油和发酵黄油制作的曲奇饼干酥脆,香味浓郁,品质优良,发酵黄油在焙烤过程脂肪氧化较为缓慢,生成的丙烯酰胺含量低为212μg/kg。红糖制作的曲奇饼干呈棕褐色,具有独特的香味,但丙烯酰胺含量高达828μg/kg。白砂糖、冰糖和绵白糖制作的曲奇饼干品质差异较小,其中白砂糖制作的曲奇饼干感官评价得分最高,丙烯酰胺含量最低为230μg/kg。综上,低筋面粉、发酵黄油和白砂糖制作的曲奇饼干品质较优,丙烯酰胺生成量较少。     

X射线荧光光谱法在鹿鸣矿业钼选矿流程中的应用

采用粉末压片法制样,建立了X射线荧光光谱仪快速测定鹿鸣矿业钼选矿流程中的原矿、尾矿、快浮尾矿中Mo、Cu、S等3种元素的分析方法。由于钼矿石标准样品较少,因此实验选取钼选矿流程中不同阶段且含量呈梯度的多个经湿法准确定值的样品作为校准样品建立校准曲线。将样品研磨至0.074mm以下,采用经验系数法校正元素间的影响,消除基体效应、粒度效应,降低谱线重叠干扰。各元素的检出限在3~10μg/g之间,各组分测定结果的相对标准偏差(RSD)在0~5.1%之间。对钼选矿流程中原矿、尾矿、快浮尾矿样品进行正确度考察,测定值与湿法值一致。分别选取流程中原矿、尾矿、快浮尾矿样品在不同时间进行长期稳定性考察,3个元素测定结果的相对标准偏差在0.18%~7.9%之间。     

ZSX-84型生丝纤度仪在绢丝支数检验中的应用

简单地介绍用ZSX-84型生丝纤度仪检验绢丝支数不匀率的原理和操作方法。     

镁质碳酸盐岩微细浸染型金矿原矿焙烧试验

提出了原矿焙烧—氰化提金工艺处理某镁质碳酸盐岩微细浸染型金矿。试验表明,在原矿粒度-0.074mm占80%,焙烧温度650℃,焙烧时间1h,焙砂再磨粒度-0.038 mm占90%,NaCN用量3kg/t,液固比L/S=2,氰化时间36h的最佳条件下,渣含金降至1.92g/t,金浸出回收率达到94.90%。对300t/d规模原矿焙烧项目的经济评估表明该工艺经济效益显著。     

加卸载条件下原煤渗透率与有效应力的规律

为研究采动过程中有效应力的变化对渗透率的动态演化的影响,基于自行研制的"含瓦斯煤热流固耦合三轴伺服渗流实验装置",进行了单调加载和不同初始应力状态加卸载条件下原煤渗流特性的试验研究。考虑瓦斯力学作用和瓦斯吸附作用两个方面对有效应力系数的影响,得到了加卸载条件下原煤的有效应力计算公式及渗透率与有效应力关系的公式,根据初始孔隙率、吸附常数等试验数据和不同条件下渗流试验数据对建立的渗透率与有效应力表达式进行验证。研究结果表明,理论计算值和试验结果吻合度比较高,单调加载与加卸载条件下原煤的渗透率随着有效应力的增加呈负指数关系下降。     

长江埠供水系统存在问题分析及其对策

针对长江埠供水系统所存在的地下源水腐蚀性较强、局部管网流向设置不合理和局部建筑内给水管道严重老化等问题，提出了一整套系统改造措施。