在线固相萃取结合液相色谱-线性离子阱多级质谱法同时检测生物样品中7种乌头类生物碱

建立了在线固相萃取(on-line SPE)结合液相色谱-线性离子阱多级质谱(LC-LIT/MSⁿ)同时测定全血、尿液和肝组织样品中7种乌头类生物碱的分析方法,并根据7种乌头类生物碱的多级质谱碎片对裂解规律进行了推测和总结。用乙腈沉淀样品中的蛋白质,于稀释和离心后直接进样。经Waters Oasis^® HLB在线SPE柱富集纯化,以0.1%(v/v)甲酸/乙酸铵溶液-0.1%(v/v)甲酸/甲醇溶液为流动相,以Accucore C18为分析柱进行梯度洗脱;在电喷雾电离(ESI)正离子模式下测定;扫描方式为连续反应监测(CRM)。在考察的质量浓度范围内,7种乌头类生物碱的标准曲线符合二阶方程(权重因子1/x),相关系数为0.9991~0.9999;在全血和尿液中的方法检出限为0.02~0.60 ng/mL,在肝组织中的方法检出限为0.02~0.40 ng/g;加标回收率为91.1%~104.7%,日内精密度和日间精密度分别为0.2%~10.7%、1.0%~13.7%(n=6)。该方法简单准确,灵敏度高,能够满足生物样品中7种乌头类生物碱的快速分析。     

Ge-Sb-S硫系玻璃的光谱特性及网络结构阈值行为研究

用熔融淬冷技术制备了两组Ge-Sb-S三元体系的硫系玻璃,获得了在不同Ge和Sb元素含量下制备所得玻璃的一系列物化及光谱学特性,并结合拉曼光谱从玻璃微观结构层面对光学特性的变化进行了系统的分析。利用基于平均配位数(Z)的玻璃网络限制理论直观地描述了网络结构的变化趋势,发现当玻璃的Z值超过2.6时,其相应的拉曼谱上会有明显的新峰出现,说明玻璃的网络结构产生了阈值行为且结构组成发生了明显变化,具体表现为非金属化合键的减少和金属化合键的增加。玻璃网络中新功能团的形成改变了玻璃整体键能的大小,进而影响了玻璃的能带结构,从而玻璃的光学带隙(E_opg)值也随着Z值的变化表征出相应的阈值行为。     

North west cape-induced electron precipitation and theoretical simulation

Enhancement of the electron fluxes in the inner radiation belt,which is induced by the powerful North West Cape(NWC) very-low-frequency(VLF) transmitter,have been observed and analyzed by several research groups.However,all of the previous publications have focused on NWC-induced 100-keV electrons only,based on observations from the Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions(DEMETER) and the Geostationary Operational Environmental Satellite(GOES) satellites.Here,we present flux enhancements with 30-100-keV electrons related to NWC transmitter for the first time,which were observed by the GOES satellite at night.Similar to the 100-300-keV precipitated-electron behavior,the low energy 30-100-keV electron precipitation is primarily located east of the transmitter.However,the latter does not drift eastward to the same extent as the former,possibly because of the lower electron velocity.The 30-100-keV electrons are distributed in the L = 1.8-2.1 L-shell range,in contrast to the100-300-keV electrons which are at L= 1.67-1.9.This is consistent with the perspective that the energy of the VLF-waveinduced electron flux enhancement decreases with higher L-shell values.We expand upon the rationality of the simultaneous enhancement of the 30-100- and 100-300-keV electron fluxes through comparison with the cyclotron resonance theory for the quasi-linear wave-particle interaction.In addition,we interpret the asymmetry characteristics of NWC electric power distribution in north and south hemisphere by ray tracing model.Finally,we present considerable discussion and show that good agreement exists between the observation of satellites and theory.     

Accurate reconstruction of the optical parameter distribution in participating medium based on the frequency-domain radiative transfer equation

Reconstructing the distribution of optical parameters in the participating medium based on the frequency-domain radiative transfer equation(FD-RTE) to probe the internal structure of the medium is investigated in the present work.The forward model of FD-RTE is solved via the finite volume method(FVM). The regularization term formatted by the generalized Gaussian Markov random field model is used in the objective function to overcome the ill-posed nature of the inverse problem. The multi-start conjugate gradient(MCG) method is employed to search the minimum of the objective function and increase the efficiency of convergence. A modified adjoint differentiation technique using the collimated radiative intensity is developed to calculate the gradient of the objective function with respect to the optical parameters. All simulation results show that the proposed reconstruction algorithm based on FD-RTE can obtain the accurate distributions of absorption and scattering coefficients. The reconstructed images of the scattering coefficient have less errors than those of the absorption coefficient, which indicates the former are more suitable to probing the inner structure.     

多晶莫来石纤维纺丝原液制备与可纺性研究

以铝粉、盐酸和硅溶胶、聚乙烯醇为原料,去离子水为溶剂,采用溶胶-凝胶法制备了水溶性的莫来石纤维纺丝原液及其前驱体纤维.探讨了纺丝助剂加入量对纺丝原液可纺性的影响,采用红外吸收光谱FTIR和旋转流变仪分别研究了纺丝原液的红外吸收特性和流变学行为,借助XRD表征了前驱体纤维热处理后的物相组成.结果表明,纺丝助剂PVA的加入量为2; ～ 4;时,纺丝原液为剪切变稀的非牛顿型流体,呈现无管虹吸现象;固含量在30;～ 40;,粘度在4～7 Pa·s时,溶胶可纺性指标25 ～ 26 cm/s,纺丝性能最佳;纺丝原液中存在着利于成纤的Al-O-Si的链状结构的线性高分子聚合物.经过1050℃热处理后纤维的主晶相为莫来石.     

在线固相萃取/液相色谱-线性离子阱质谱法同时定性定量检测全血和尿液中7种抗凝血杀鼠药

建立了同时测定全血和尿液样品中7种抗凝血杀鼠药的在线固相萃取/液相色谱-线性离子阱质谱(on-line SPE/LC-LIT/MS)分析方法。用乙腈沉淀样品中的蛋白质,于稀释、离心、过滤后直接进样。经在线固相萃取柱富集纯化;以C18柱为分析柱,甲醇-乙酸铵水溶液(0.02 mol/L)为流动相进行梯度洗脱;在电喷雾电离(ESI)负离子模式下,记录目标母离子在锁定保留时间窗口内的二级全扫描信号,通过自建数据库进行定性确证,挑选高灵敏度与专属性的二级子离子进行定量,从而实现7种杀鼠药的同时定性和定量分析。7种杀鼠药在各自质量浓度范围内线性关系良好,相关系数为0.9946~0.9997,检出限和定量限分别为0.02~1.00 ng/mL和0.10~4.00 ng/mL, 3个添加水平的回收率为81.0%~113.9%,相对标准偏差为0.1%~6.2% (n=6)。该方法简单方便,灵敏度高,能够满足全血和尿液样品中7种抗凝血杀鼠药的快速筛查和准确定量。     

荷包红鲤自噬相关基因LC3B的克隆及在重金属镉胁迫下的表达

微管相关蛋白1轻链3(microtubule-associated protein 1light chain 3,LC3)是哺乳动物细胞中酵母自噬相关基因8(ATG8)的同源物,其LC3B亚型的表达强度与自噬泡数量的多少成正相关,为自噬发生的标志蛋白之一。应用RACE-PCR技术克隆了婺源荷包红鲤LC3B基因的cDNA全长序列,用RT-PCR方法检测了该基因在荷包红鲤主要组织中的表达,并用Real-time quantitative PCR方法检测了该基因在镉胁迫下转录水平的变化,以初步揭示该基因在镉胁迫下的作用。结果表明,荷包红鲤LC3B基因cDNA全长为2 138bp,其中开放阅读框长378bp,编码125个氨基酸,预测分子量为14.73kDa,等电点为8.76。序列比对显示,其编码的氨基酸序列和斑马鱼LC3B具有最高的一致性和相似性,并在系统发育树上聚为一支。该基因在荷包红鲤肌肉、脑、鳃、脾脏、肝脏、血液、头肾、肾脏和心脏组织中均有表达;在镉胁迫下,镉诱导显著影响了该基因在肾脏组织中的转录水平。LC3B基因参与的自噬反应可能参与了抗镉毒性作用。     

偏振拉曼光谱在研究分子空间构象中的应用

偏振拉曼光谱是拉曼光谱中的一种,所有的激发光源和收集的散射光都有确定的偏振方向,不同方向的偏振光检测到样品的特点不同。因此,偏振拉曼光谱在表征样品时,一定要注意偏振方向的选取,以保证样品检测的准确性。文中主要以四氯化碳(CCl₄)分子为主要研究对象,通过对其退偏度的计算,推测CCl₄的振动方式。所计算的理论值,与实验值相差不大,证明了实验的准确性,同时也说明了偏振拉曼光谱的方向性。     

关于吸热反应的研究

对于铵盐冷却性能的实验研究结果表明,铵盐作为固/固式冷却剂时,其冷却效果与室温、溶剂盐和溶质盐的配比组成有关,八水氢氧化钡与氯化铵的冷却效果最好,但污染环境;十二水磷酸氢二钠与硝酸铵、十水碳酸钠与硝酸铵不仅有较佳的制冷效果,而且可再生重复利用,不会造成环境污染,不仅可望在社会生活中得到应用,而且可用作教科书“化学反应中的能量变化”内容学习中的“吸热反应实验”。     

A method for phase reconstruction in the optical three-dimensional shape measurement

In the optical three-dimensional shape measurement, a method of improving the measurement precision for phase reconstruction without phase unwrapping is analyzed in detail. Intensities of any five consecutive pixels that lie in the x-axis direction of the phase domain are given. Partial derivatives of the phase function in the x- and y-axis directions are obtained with a phase-shifting mechanism, the origin of which is analysed. Furthermore, to avoid the phase unwrapping in the phase reconstruction, we derive the gradient of the phase function and perform a two-dimensional integral along the x- and y-axis directions. The reconstructed phase can be obtained directly by performing the numerical integration, and thus it is of great convenience for phase reconstruction. Finally, the results of numerical simulations and practical experiments verify the correctness of the proposed method.