原子磁力仪中的检测光强噪声补偿方法研究

为解决原子磁力仪检测光强残余噪声问题,提出了检测光强噪声数字补偿方法。首先根据原子自 旋进动检测基本理论,通过光弹调制器和锁相放大器进行线偏光的光旋角检测,利用噪声衰减器对检测光功率 进行正弦调制拟合得到补偿系数,然后使用光弹调制器调制频率的二倍频信号对一倍频信号进行后处理修正, 实现检测光强噪声压制。得到补偿系数后可将用于幅度调制的硬件甚至前级稳光强装置移除,仅利用数字补偿 技术即可实现光强噪声抑制。搭建基于K?Rb?21Ne气室的磁力仪实验装置,在无自旋交换弛豫态（Spin?Exchange Relaxation?Free, SERF）下开展检测光强噪声补偿实验, 结果显示光旋角检测信号的噪声被压制了 13. 2 dB@3 Hz。应用此噪声补偿方法,避免了不同光路所引入的非共模噪声,并在前级稳光强的基础上实现了 二次稳光强。此补偿方法可进行补偿系数的定期校准,减小系统状态改变及不稳定性带来的影响,对于提升原 子磁力仪灵敏度具有重要意义。     

XPE操作系统在便携式磁力仪中的开发与应用

介绍了嵌入式Windows XP的基本性能特征,利用嵌入式Windows XP的优点,实现了嵌入式Windows XP在便携式氦光泵磁力仪中的开发与应用。     

高精度磁测(G856磁力仪)在物探中的应用

高精度磁测广泛应用于地质找矿,磁力仪以及相应配套的软件也不断升级。本文作者结合野外的操作,阐述一些实践方法。     

近年来原子吸收光谱法在医药学中的应用进展

本文综述了近年来原子吸收光谱法在医药学中的应用进展。简述了国内外新型原子吸收分光光度计的性能、特点及测试条件;阐述了原子吸收光谱法在测定防治心脑血管及癌症等疾病的药物及其制剂以及临床医学中生物体液中的微量元素。为控制药品质量及临床诊断提供参考数据。     

原子吸收光谱在分析中药微量元素中的应用

本文对近年来原子吸收光谱在分析中药微量元素中的应用现状做一概述。为我国中草药的种植与开发利用提供参考。     

原子层沉积技术及其在半导体中的应用

首先简述原子层沉积（ALD）技术的发展背景，通过分析ALD的互补性和自限制性等工艺基础，介绍了它在膜层的均匀性、保形性以及膜厚控制能力等方面的优势，着重列举ALD在半导体互连技术、高k电介质等方面的应用。同时指出了目前ALD工艺中存在的主要问题。     

原子吸收光谱测试技术在水分析中的应用

探究原子吸收光谱测试技术在水分析中的应用。通过原子吸收光谱测试技术进行水分析,探究水中的各类成分。     

场离子显微镜原子探针在材料科学中的应用

本文将场离子显微镜原子探针(FIM-AP)应用于材料微结构研究,包括氢与难熔金属表面相互作用及在奥氏体不锈钢中扩散、掺杂钨丝晶界观察、Mo 合金短程有序化及磁性材料沉淀相结构研究。讨论了 FIM-AP 在材料科学研究中应用的前景和存在问题。     

原子转移自由基聚合在生物材料中的应用

生物材料表面改性以及具有特定结构与功能的先进生物材料的合成始终是生物材料研究的核心课题.原子转移自由基聚合( ATRP)是一种新型自由基聚合,在生物材料表面改性以及新型生物材料合成方面具有巨大的应用前景.利用ATRP技术可以提高生物材料表面生物相容性、生物适应性以及生物功能性,如提高材料表面的抗生物污染性、血液相容性、细胞相容性以及抗菌性能等;同时,ATRP也可用于合成新型生物医用高分子材料,如两亲性高分子、纳米胶束、智能水凝胶以及一些具有特殊结构的高分子(包括星型、超支化、梳型高分子等).ATRP技术与点击化学结合,可形成新的生物活性表面或者合成新的生物材料,可望产生更多的功能化的材料表面与生物材料.     

原子径向分布函数在材料结构研究中的应用

介绍了原子径向分布函数的基本理论,综述了原子径向分布函数在有机高分子材料、无机碳材料、金属材料等不同类型材料结构研究中的最新进展。阐明了原子径向分布函数相对于传统结构研究方法的特点和优势,并展望了该方法在碳纤维结构研究中的应用前景,该方法能够从原子级别揭示整个碳纤维制备过程中结构的演变规律,这对制备高性能碳纤维具有重要的指导作用。     

Calorimetric electron telescope mission: Search for dark matter and nearby sources

We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module—Exposed Facility, JEM-EF, of the International Space Station, ISS. Major scientific objective is a search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1 GeV–20 TeV and the gamma-rays in 20 MeV-several TeV. CALET has, moreover, a capability to measure cosmic ray H, He and heavy ions up to 1000 TeV. It will also have a function to monitor the solar activity and the gamma-ray bursts. The phase A study has started on a schedule of the launch in early 2014 by the H-II Transfer Vehicle, HTV, for a 5-year observation.     

Nanofabrication with atomic force microscopy

Atomic force microscopy (AFM) was developed in 1986. It is an important and versatile surface technique, and is used in many research fields. In this review, we have summarized the methods and applications of AFM, with emphasis on nanofabrication. AFM is capable of visualizing surface properties at high spatial resolution and determining biomolecular interaction as well as fabricating nanostructures. Recently, AFM-based nanotechnologies such as nanomanipulation, force lithography, nanografting, nanooxidation and dip-pen nanolithography were developed rapidly. AFM tip (typical radius ranged from several nanometers to tens of nanometers) is used to modify the sample surface, either physically or chemically, at nanometer scale. Nanopatterns composed of semiconductors, metal, biomolecules, polymers, etc., were constructed with various AFM-based nanotechnologies, thus making AFM a promising technique for nanofabrication. AFM-based nanotechnologies have potential applications in nanoelectronics, bioanalysis, biosensors, actuators and high-density data storage devices.     

Data acquisition system for dark matter detectors

Progress in Ge detector technology has resulted in ultralow backgrounds of less than 0.3 counts keV^–1 kg^–1 d^–1 at energies between 5 and 12 keV, and less than 1.0 counts kev^–1 kg^–1 d^–1 for energies between 3 and 5 keV. Coupled with good energy resolution, 0.4 keV FWHM at 10 keV, this allows searches for DM particles with m 8 GeV/c².Electromagnetic interference and acoustical pick-up are the main sources of background in the best Ge detectors. These problems are even more important in cryogenic WIMP detectors under development. A PC-based on line pulse shape analysis system is presented which permits rejection of about 95% percent of the EMI/ acoustical background. The hardware uses a low cost, commercially available digital storage oscilloscope. The software consists of about 20,000 lines of code in Pascal and assembly language. We tested this system using a low radioactive background Ge-system on the Earth's surface. For low energy events (27 keV photons) this system permits improvement in the background from 0.1 cpm to 2 cpd.     

Coaxial atomic force microscope probes for imaging with dielectrophoresis

We demonstrate atomic force microscope (AFM) imaging using dielectrophoresis (DEP) with coaxial probes. DEP provides force contrast allowing coaxial probes to image with enhanced spatial resolution. We model a coaxial probe as an electric dipole to provide analytic formulas for DEP between a dipole, dielectric spheres, and a dielectric substrate. AFM images taken of dielectric spheres with and without an applied electric field show the disappearance of artifacts when imaging with DEP. Quantitative agreement between our model and experiment shows that we are imaging with DEP.     

Cresst-II: dark matter search with scintillating absorbers

In the CRESST-II experiment, scintillating CaWO₄ crystals are used as absorbers for direct weakly interacting massive particles (WIMP) detection. Nuclear recoils can be discriminated against electron recoils by measuring phonons and scintillation light simultaneously. The absorber crystal and the silicon light detector are read out by tungsten superconducting phase transition thermometers. Results on the sensitivity of the phonon and the light channel, radiopurity, the scintillation properties of CaWO₄, and on the WIMP sensitivity are presented.     

Microfluidics and chromatography with an atomic force microscope

A combined atomic force microscope (AFM) and Raman spectrometer is presented as a microfluidic device for pumping, sampling, and trace chemical analysis. The AFM tip-cantilever provides a mechanism for shear-driven pumping of fluids in microchannels. Shear-driven pumping allows rapid flow rates and avoids the limitations of conventional pumping. The AFM's ability to translate sub-femtoliter volumes of fluid also proves a mechanism for fluidic switching and sample injection. In addition, the AFM is used to image liquid surfaces in microchannels and remove samples for very sensitive spectral analysis. Surface-enhanced Raman spectroscopy localized near the AFM tip provides chemical information of the sampled fluids. The results demonstrate the feasibility of integrating the AFM with microfluidic circuits and shear-driven chromatography and the potential for nanometer-scale chromatography.     

Single-molecule switching with non-contact atomic force microscopy

We report upon controlled switching of a single 3,4,9,10-perylene tetracarboxylic diimide derivative molecule on a rutile TiO(2)(110) surface using a non-contact atomic force microscope at room temperature. After submonolayer deposition, the molecules adsorb tilted on the bridging oxygen row. Individual molecules can be manipulated by the atomic force microscope tip in a well-controlled manner. The molecules are switched from one side of the row to the other using a simple approach, taking benefit of the sample tilt and the topography of the titania substrate. From density functional theory investigations we obtain the adsorption energies of different positions of the molecule. These adsorption energies are in very good agreement with our experimental observations.     

Spiral scanning method for atomic force microscopy

A spiral scanning method is proposed for atomic force microscopy with thoroughgoing analysis and implementation. Comparing with the traditional line-by-line scanning method, the spiral scanning method demonstrates higher imaging speed, minor image distortion, and lower acceleration, which can damage the piezoelectric scanner. Employing the spiral scanning method to replace the line-by-line scanning method, the experiment shows that the time to complete an imaging cycle can be reduced from 800 s to 314 s without sacrificing the image resolution.