2-硫代巴比妥酸修饰金纳米探针高灵敏比色检测三聚氰胺

以2-硫代巴比妥酸(TBA)修饰金纳米粒子为探针,TBA与三聚氰胺通过氢键作用诱导金纳米探针团聚,进而使金纳米胶体颜色由酒红色变为蓝色。 实验优化得最佳反应条件为在乙酸缓冲溶液（pH=7.0）介质中,室温反应15 min。 对不同浓度三聚氰胺进行检测时发现,在0.062~0.18 μmol/L和0.18~6.0 μmol/L之间,A660/A520吸收比率与三聚氰胺浓度呈现良好的线性关系,检出限为0.043 μmol/L。 该方法用于检测牛奶样品中的三聚氰胺的加标回收率为102.8%～105.3%。     

牛磺酸通过上调MST1蛋白表达诱导宫颈癌细胞凋亡

为观察牛磺酸(Tau)对宫颈癌细胞凋亡的诱导作用及初步机制。以人宫颈癌细胞系SiHa细胞为对象,MTT比色法检测细胞增殖活性,将pEGFP-N1-MST1重组质粒转染SiHa细胞,流式细胞术检测细胞凋亡及Western blot检测细胞中MST1,Bcl-2及Bax蛋白水平。结果显示:Tau能抑制SiHa细胞增殖并诱导其凋亡;上调SiHa细胞MST1及Bax蛋白表达(P<0.01),下调Bcl-2表达水平(P<0.01),且MST1过表达能增强Tau对凋亡的诱导作用(P<0.01)。结果表明牛磺酸通过上调MST1蛋白表达,进而引起Bax蛋白表达上调和Bcl-2蛋白下调,诱导宫颈癌SiHa细胞凋亡。     

电化学发光生物传感技术在快速检测心肌梗死标志物中的研究进展

设计和发展简便、高灵敏、高选择性的分析手段以检测低浓度急性心肌梗死生物标志物是目前临床诊断迫切的需求。 电化学发光分析法由于具有稳定性好、灵敏度高、线性范围宽及可控性强等优点,能有效地进行低浓度样品检测。 该方法与生物传感技术相结合,有利于实现生物体液等复杂样品中极低含量急性心肌梗死生物标志物的快速检测。 本文综述了电化学发光生物传感技术在快速检测心肌梗死标志物中近5年的进展,介绍了电化学发光探针和共反应物,以及多组分生物传感检测技术等,并对其在心肌梗死标志物分析中的应用进行了总结。     

复杂背景目标自动识别谱面处理技术研究

应用光电混合联合变换相关器对目标进行探测和识别时,由于实际拍摄的图像背景非常复杂,对比度较低,亮度不足等原因,使得相关峰很弱甚至根本得不到相关峰,不能达到探测和识别的目的.为此提出在光电混合联合变换相关器的功率谱面应用小波变换处理技术,有效地抑制了联合变换功率谱中的噪声干扰,提高了有用信息衍射光的能量,从而增强了应用光电混合联合变换相关器对复杂背景目标进行探测和识别的能力.实验证明利用经过小波变换处理后的联合变换功率谱所获得相关峰的对比度,较处理前由联合变换功率谱所获得相关峰的对比度能够达到百分之百的增强效果.作为实例文中给出了湖中小船处理前后的光学实验结果,从实验结果中可以明显看出此种处理方法的有效性.     

近阈处238U(n,f)反应裂变碎片角分布

用载铀核乳胶和固体径迹探测器在中子能量为0.86—1.80MeV区域研究了²³⁸U(n,f)反应的裂变碎片角分布。在等效单峰裂变位垒模型框架内,用带宽度涨落修正的Hauser-Feshbach理论,计算了碎片角分布和裂变截面。结果表明,各向异性随能量变化上有肯定的结构存在。     

Efficient Three-Party Quantum Secret Sharing with Single Photons

A scheme for three-party quantum secret sharing of a private key is presented with single photons. The agent Bob first prepares a sequence of single photons with two biased bases and then sends them to the boss Alice who checks the security of the transmission with measurements and produces some decoy photons by rearranging the orders of some sample photons. Alice encodes her bits with two unitary operations on the photons and then sends them to the other agent. The security of this scheme is equivalent to that in the modified Bennett Brassard 1984 quantum key distribution protocol. Moreover, each photon can carry one bit of the private key and the intrinsic efficiency for qubits and the total efficiency both approach the maximal value 100% when the number of the bits in the key is very large.     

全反射棱镜式激光陀螺标度因数补偿技术

针对全反射棱镜式激光陀螺标度因数随温度周期性变化的现象,根据矩阵光学方法研究了稳频状态下温度变化对环形激光面积的影响,获得了全反射棱镜式激光陀螺标度因数与稳频电压的关系,并得出光束偏移是引起标度因数随温度周期性变化的原因。根据标度因数与稳频电压的关系,建立了全反射棱镜式激光陀螺标度因数补偿模型,通过实验对比了补偿前后标度因数的非线性度。结果表明,根据该补偿模型对全反射棱镜式激光陀螺标度因数进行补偿,标度因数非线性度提高了一个数量级以上,对提高全反射棱镜式激光陀螺的性能具有一定的参考价值。     

High-order harmonic generation of the cyclo[18]carbon molecule irradiated by circularly polarized laser pulse

High-order harmonic generation of the cyclo[18]carbon (C₁₈) molecule under few-cycle circularly polarized laser pulse is studied by time-dependent density functional theory. Compared with the harmonic emission of the ring molecule C₆ H₆ having similar ionization potential, the C₁₈ molecule has higher efficiency and cutoff energy than C₆ H₆ with the same laser field parameters. Further researches indicate that the harmonic efficiency and cutoff energy of the C₁₈ molecule increase gradually with the increase of the laser intensity of the driving laser or decrease of the wavelength, both are larger than those of the C₆ H₆ molecule. Through the analysis of the time-dependent evolution of the electronic wave packets, it is also found that the higher efficiency of harmonic generation can be attributed to the larger spatial scale of the C₁₈ molecule, which leads to a greater chance for the ionized electrons from one atom to recombine with others of the parent molecule. Selecting the suitable driving laser pulse, it is demonstrated that high-order harmonic generation in the C₁₈ molecule has a wide range of applications in producing circularly polarized isolated attosecond pulse.     

利用Ferguson曲面构造中厚壳广义协调元

本文根据广义协调原理，利用Ｆｅｒｇｕｓｏｎ曲面构造含有剪切变形影响的法向位移，与面内位移结合，得出适用于中厚度壳体的平直单元模型．算例说明本单元性能良好．     

LiKSO4的低温衰减峰和弹性反常

本文报道了利用超声回波法,观察了在170—273K 温区,LiKSO_4的声速和声衰减系数随温度的变化,发现在此温区,LiKSO_4有两次相变发生,即 I 相■Ⅱ 相,Ⅱ 相■Ⅲ相.对实验结果进行了讨论.