二羟基苯二磺酸锰配合物的合成、晶体结构及热稳定性

在水溶剂中,采用回流法合成了两个二羟基苯二磺酸单核Mn(Ⅱ)含氮配体配合物Na[Mn(3,5-(SO3)2HCat)(phen)2H2O](1)和[Mn(3,5-(SO3)2H2Cat)(phen)2H2O]·H2O(2)(H2Cat=1,2-二羟基苯,phen=1,10-邻菲罗啉)。采用X射线单晶衍射、红外光谱、元素分析、紫外可见光谱和热重分析等方法对配合物进行了表征。X射线单晶衍射表征结果表明:两个配合物晶体均属于单斜晶系,晶族分别为P2(1)/c和P2(1)/n。两个配合物的配位方式相似,锰离子均与两个1,10-邻菲罗啉、一个水分子以及磺酸基配位。锰离子是六配位的。     

Approaching the fundamental noise limit in Mo/Au TES bolometers with transverse normal metal bars

Recent efforts in the Transition Edge Sensor (TES) bolometer/calorimeter community have focused on developing detectors whose noise properties are near the fundamental limits. These include the in-band phonon noise, the out-of-band Johnson noise, and the 1/f noise. We have investigated the noise performance of Mo/Au-bilayer TES bolometers designed for infrared detectors. These detectors use normal metal regions for the suppression of excess noise, which are oriented either parallel to (“bars”) or transverse to (“stripes”) the direction of current flow. Two nearly identical detectors, one with stripes and one with bars, were fabricated at the NASA/GSFC detector development facility. Significantly lower noise is found with the normal metal regions oriented transversely. We compare the detailed noise measurement and quantitative analysis of the noise level in each device as a function of the detector resistance. Our preliminary result is that the best detector features only moderate excess noise in both the in-band region and in the out-of-band region. This noise performance is suitable for instruments with multiplexed TES arrays, such as GSFC's FIBRE and SAFIRE.     

Micro-Raman spectroscopy used to identify and grade human skin pilomatrixoma

Raman microspectroscopy was applied to analyze the changes in structural conformation and chemical composition of the mass of human skin pilomatrixoma (PMX). The normal skin dermis, collagen type I, and hydroxyapatite (HA) were used as control. The excised specimens from two patients diagnosed as a typical PMX were detected, in which one specimen was a soft mass, but the other was a hard mass with somewhat calcified deposits via histopathological examination. The Raman spectrum of normal skin dermis was found to be similar to the Raman spectrum of collagen type I, confirming that the collagen type I was a predominant component in normal skin dermis. The differences of Raman peak intensity between normal skin dermis and soft or hard PMX mass were obvious at 1,622-1,558, 1,400-1,230, 1,128, 1,000-850, 749, and 509 cm(-1). In particular, the peak at 1,665 cm(-1) assigned to amide I band shifted to 1,655 cm(-1) and the peak at 1,246 cm(-1) corresponding to amide III band was reduced in its intensity in hard PMX mass. The significant changes in collagen content and its structural conformation, the higher content of tryptophan, and disulfide formation in PMX masses were markedly evidenced. In addition, the shoulder and weak peak at 960 cm(-1) assigned to the stretching vibration of PO(4) (3-) of HA also appeared respectively in the Raman spectra of soft and hard PMX masses, suggesting the occurrence of calcification of HA in the PMX tissue, particularly in the hard PMX mass. The result indicates that the micro-Raman spectroscopy may provide a highly sensitive and specific method for identifying normal skin dermis and how it differs in chemical composition from different PMX tissues.     

基于区块链的电子病历数据共享方案

以区块链为数据存储平台的电子病历系统是当下研究的热点. 存储在区块链上的数据是不可变的, 这加强了数据的安全性. 提出了一个基于区块链的电子病历数据共享方案, 实现了患者和第三方数据用户在不侵犯患者隐私的前提下共享患者电子病历. 使用私有链与联盟链构造方案的系统模型, 医院服务器上存储患者的电子病历密文, 私有链上存储患者病历密文的哈希值和关键字索引, 联盟链上存储由关键字索引构成的安全索引. 同时利用可搜索加密技术实现了联盟链上对关键字的安全搜索, 运用代理重加密算法实现了第三方数据用户对患者电子病历的共享. 通过数值实验对方案进行了性能评估.     

气相色谱法测定羟丙基魔芋葡甘露聚糖的摩尔取代度

目的 建立气相色谱法(gas chromatography, GC)测定羟丙基魔芋葡甘露聚糖(hydroxypropyl konjac glucomannan, HP-KGM)的摩尔取代度(molar substitution degree, MS)的方法。方法 首先制备不同MS的HP-KGM样品, 通过傅里叶红外光谱(Fourier transform infrared spectroscopy, FTIR)和1H核磁共振(1H nuclear magnetic resonance, 1H NMR)对其进行结构表征, 然后利用GC测定氢碘酸与HP-KGM在高温密封环境下反应所产生的2-碘丙烷, 以推算其羟丙基的MS, 并将所得结果与1H NMR法得到的MS进行比较。结果 FTIR和1H NMR的结果表明, 羟丙基化过程中HP-KGM的原料—魔芋葡甘露聚糖(konjac glucomannan, KGM)所固有的乙酰基已全部脱落, 因此对HP-KGM的MS测定无干扰, 由此所测得的MS与1H NMR法的结果呈线性关系, 单点法和标准曲线法校正系数分别为1.159 (R2=0.9965)和1.164 (R2=0.9965), 无显著性差异(P=0.862>0.05)。结论 本研究所测定的HP-KGM的羟丙氧基含量在7.6%~40.8% (MS 0.16~1.33)之间, 低于美国药典规定的测定羟丙基纤维素中羟丙氧基含量的范围53.4%~80.5% (MS 2.2~7.8), 由此拓宽了GC测定HP-KGM中羟丙基MS的范围, 这对于食品行业的低取代HP-KGM的质量控制具有重要意义。     

红枣热风微波耦合干燥工艺优化及干燥特性和微观结构研究

为提高红枣干燥产品品质,本文采用热风微波耦合干燥技术,通过响应面法,在单因素试验的基础上,以热风温度、微波功率、载重量为影响因素,以VC含量、色差和复水比为评价指标,优化红枣热风微波耦合干燥工艺参数,分别建立各因素与红枣VC含量、色差、复水比的回归模型。同时研究不同条件对红枣热风微波耦合干燥特性的影响,将最优工艺与相同条件下的单一干燥进行品质及微观结构的比较。结果表明：各因素对色差、VC含量、复水比影响顺序均为热风温度>微波功率>载重量;响应面得到最优的工艺参数为：热风温度48℃、微波功率94 W、载重量为190 g;耦合干燥下产品的品质均高于单一干燥,热风微波耦合干燥后产品微观结构较平整紧凑,有利于提高干燥效率。因此,热风微波耦合干燥是一种绿色高效的干燥方式,该研究为高品质红枣干燥加工工艺的选择提供了一定的理论依据。     

基于ResNet双注意力机制的遥感图像场景分类

针对基于传统机器学习遥感图像场景分类无法快速有效提取图像特征造成分类结果不准确的问题,提出一种基于注意力残差网络的遥感图像场景分类的方法,以残差网络为基准模型,在通道和空间两个维度上建立注意力模块,实验过程中对参数进行合理有效的设置,调整网络层数优化模型,达到对UC Merced Land-Use数据集的有效分类.实验...     

荧光法在食品理化检验标准中的应用进展

近年来,荧光检测法以其灵敏度高、特异性强、易于操作及定量精准等优点,在食品理化检验领域获得了越来越多的应用,其相应的检验标准,包括国家标准、农业部标准、检验检疫行业标准、农业部公告、地方标准等也日渐增多,其更新修订的频率与数量也逐年递增。本文对我国现行有效的理化标准中所采用的荧光检测方法,包括荧光分光光度法、薄层色谱-荧光法、高效液相色谱-荧光法、原子荧光法等进行了总结,并着重对液相色谱荧光法中的目标物提取、免疫亲和净化、分离检测条件等进行了论述,最后对荧光检测的当前热点以及未来发展趋势进行了展望。本文为相关科研人员在荧光检测领域的标准起草、草案建议、方法开发及日常食品安全分析检验提供了有力的技术支持。     

高效液相色谱-串联质谱法测定猪肉中3种β-受体激动剂残留量

目的建立猪肉中3种β-受体激动剂(沙丁胺醇、莱克多巴胺、克伦特罗)残留量的高效液相色谱-串联质谱联用检测方法。方法样品经SPE柱净化处理后,以乙酸胺和乙腈为流动相梯度洗脱,电喷雾离子化为离子源,多反应检测方式,使用高效液相色谱-串联质谱仪测定。结果 3种β-受体激动剂在0.5～10.0μg/L范围内呈良好线性关系,相关系数均大于0.999,检出限为0.13～0.15μg/kg,加标回收率在79.25%～112.82%之间,相对标准偏差在7.14%～17.80%之间。结论建立的方法专属性好,灵敏度高,检出限低,操作可行,可实现动物源性食品中多种β-受体激动剂残留量的同时测定。     

食品添加剂桑椹红产品标准的制定

目的 确定食品添加剂桑椹红产品标准拟设置的技术指标,并建立各指标的实验方法.方法 参考现有的桑椹红国内外资料、标准以及现行的相关天然色素国家标准,确定技术指标和试验方法,并对14批次桑椹红产品进行实样验证.结果 桑椹红产品标准拟设置的技术指标有色泽、状态、气味、干燥减量(≤8.0％,仅限粉末产品)、色价(符合声称)、二...