Existence of positive solutions for three-point boundary value problems at resonance

With the help of the theorem of a fixed point index for A-proper semilinear operators established by Cremins, we get a existence theorem concerning the existence of positive solution for the second order ordinary differential equation of three-point boundary value problems at resonance.     

（Φ，Δ）型概率收缩与Menger PN－空间中非线性算子方程的解

本文在Ｍｅｎｓｅｒ概率赋范空间中引入了（Φ，Δ）型概率收缩的概念，研究了Ｍｅｎｇｅｒ概率赋范空间中具有这类概率收缩的非线性算子方程的解的存在性与唯一性．发展和改进了引文［１］、［４～８］的相应结果．     

Synthesis and properties of tadpole-shaped gold nanoparticles

In this communication, gold nanoparticles with a tadpole shape were synthesized by a simple aqueous-phase chemical method. The unusual three-dimensional and crystallized structures were demonstrated by TEM, AFM, and HRTEM methods. The SEM and UV-visible absorption measurements and electrophoresis experiments revealed that the tadpoles had novel optical and electrical properties. These attractive structures and properties are expected to find uses in many fields such as electrics, optics, electrochemistry, and biological sensing.     

关于线性算子的概率范数与算子空间

由于满足(PN-5)条件的PN空间(E,F)就是MangerPN空间(E,F,min),因此,肖建中等给出的关于PN空间上线性算子概率范数的结果有较大的局限性.本文中,在较一般的MengerPN空间上研究有关线性算子的概率范数和算子空间的问题,改进和推广了肖建中等的结果.     

（Φ，△）－TYPE PROBABILISTIC CONTRACTOR AND SOLUTIONS FOR A NONLINEAR OPERATOR EQUATIONS IN MENGER PN－SPACES

（Φ，△）－ＴＹＰＥＰＲＯＢＡＢＩＬＩＳＴＩＣＣＯＮＴＲＡＣＴＯＲＡＮＤＳＯＬＵＴＩＯＮＳＦＯＲＡＮＯＮＬＩＮＥＡＲＯＰＥＲＡＴＯＲＥＱＵＡＴＩＯＮＳＩＮＭＥＮＧＥＲＰＮ－ＳＰＡＣＥＳ￥ＦａｎｇＪｉｎｘｕａｎ（方锦暄）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔ...     

转镜式高速相机扫描速度及其不均匀性测量

介绍了高速相机扫描速度不均匀性产生的原因、扫描速度测量的方法，简要地介绍了测量系统的工作原理，测时精度达到３ｎｓ，测速精度达到 ３，最后给出了测量 ＧＳＪ型和ＳＪＺ－１５型相机的结果。     

DL－32／16型多路时间间隔测量仪及其应用

基于模拟内插原理，研制了一种精密多路时间间隔测量仪。该仪器有一个公共起始通道和３２或１６路停止通道，测时范围５０ｎｓ～８２０ｍｓ，分辨力１ｎｓ，精度优于±５ｎｓ。由于采用了内部微处理器，仪器具有内部自检、通道识别、差错指示和测量数据自动显示，打印、处理及掉电保护等功能，并能给出多次测量的平均值、最大值和最小值。实验测量了Ｔ／Γ炸药的爆速和钨合金中的冲击波速度，得到满意的结果。     

Rapid and ultrasensitive colorimetric detection of mercury(II) by chemically initiated aggregation of gold nanoparticles

The article describes a method for rapid and visual determination of Hg(II) ion using unmodified gold nanoparticles (Au-NPs). It involves the addition of Au-NPs to a solution containing Hg(II) ions which, however, does not induce a color change. Next, a solution of lysine is added which induces the aggregation of the Au-NPs and causes the color of the solution to change from wine-red to purple. The whole on-site detection process can be executed in less than 15 min. Other amines (ethylenediamine, arginine, and melamine) were also investigated with respect to their capability to induce aggregation. Notably, only amines containing more than one amino group were found to be effective, but a 0.4 μM and pH 8 solution of lysine was found to give the best results. The detection limits for Hg (II) are 8.4 pM (for instrumental read-out) and 10 pM (for visual read-out). To the best of our knowledge, this LOD is better than those reported for any other existing rapid screening methods. The assay is not interfered by the presence of other common metal ions even if present in 1000-fold excess over Hg(II) concentration. It was successfully applied to the determination of Hg(II) in spiked tap water samples. We perceive that this method provides an excellent tool for rapid and ultrasensitive on-site determination of Hg(II) ions at low cost, with relative ease and minimal operation.

Rapid and ultrasensitive detection of mercury ions using gold nanoparticle based label-free colorimetric method with excellent sensitivity, easy operation and low cost.