Present Status of the Electron Cyclotron Emission Measurements on HT-7 and EAST

Present status of the diagnostics for electron cyclotron emission measurements on both HT-7 and EAST is reported. A 16-channel heterodyne radiometer system and a 20-channel grating polychromator, have been installed on HT-7 and EAST. A 32-channel heterodyne ra- diometer system, with a wider frequency coverage and better spatial resolution, is being built. In order to provide a reliable electron temperature profi, an in-situ absolute calibration system is currently being built. With the ECE measurements, study on the electron heat transport and the anomalous Doppler resonance is conducted.     

石油馏分中酸性物质的组成分析

针对某炼厂酮苯脱蜡装置原料油(减三线)中酸性物质组成特殊(对装置产生严重的腐蚀)的情况,采用碱醇法提取其中的酸性物质,借助负离子电喷雾-傅里叶变换离子回旋共振质谱(negative-ion ESI FT-ICR MS)研究其酸性组分的组成及分布,并与工业级脱脂环酸进行比较,从分子层面上揭示了其特殊之处.Negative-ion ESI FT-ICR MS结果表明,减三线酸性化合物主要的特点为O₂类化合物中脂肪酸(Z=0)占明显优势,缩合度较大的Z=-8和Z=-10的O₂类化合物中有些碳数的物质相对丰度也比较大,碳数分布有两个中心;O₁类杂原子化合物的相对丰度仅次于O₂类化合物,且大大高出其他类杂原子化合物,O₁类化合物中,烷基酚类化合物占绝对优势.减三线酸性化合物的特殊组成将对进一步探究腐蚀机理和寻求解决设备腐蚀的途径有重要的指导意义.     

Preliminary design of the ITER ECH Upper Launcher

The design of the ITER electron cyclotron launchers recently reached the preliminary design level - the last major milestone before design finalization. The ITER ECH system contains 24 installed gyrotrons providing a maximum ECH injected power of 20 MW through transmission lines towards the tokamak. There are two EC launcher types both using a front steering mirror; one equatorial launcher (EL) for plasma heating and four upper launchers (UL) for plasma mode stabilization (neoclassical tearing modes and the sawtooth instability). A wide steering angle range of the ULs allows focusing of the beam on magnetic islands which are expected on the rational magnetic flux surfaces q = 1 (sawtooth instability), q = 3/2 and q = 2 (NTMs).In this paper the preliminary design of the ITER ECH UL is presented, including the optical system and the structural components. Highlights of the design include the torus CVD-diamond windows, the frictionless, front steering mechanism and the plasma facing blanket shield module (BSM). Numerical simulations as well as prototype tests are used to verify the design     

Dendrimer as nanocarrier for drug delivery

Dendrimers are novel three dimensional, hyperbranched globular nanopolymeric architectures. Attractive features like nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery and cavities in the interior distinguish them amongst the available polymers. Applications of dendrimers in a large variety of fields have been explored. Drug delivery scientists are especially enthusiastic about possible utility of dendrimers as drug delivery tool. Terminal functionalities provide a platform for conjugation of the drug and targeting moieties. In addition, these peripheral functional groups can be employed to tailor-make the properties of dendrimers, enhancing their versatility. The present review highlights the contribution of dendrimers in the field of nanotechnology with intent to aid the researchers in exploring dendrimers in the field of drug delivery.     

基于傅里叶变换-离子回旋共振质谱的离子碰撞截面测量方法及应用

傅里叶变换-离子回旋共振质谱(FT-ICR MS)具有较高的分辨率和串联质谱分析能力。离子在分析池中做回旋运动时,镜像电流会因离子与中性分子发生碰撞而逐渐衰减。基于此,通过选择合适的理论模型,并结合相应的算法,可推算出离子的碰撞截面(CCS)。该方法无需增加仪器硬件成本,可通过直接分析高分辨质谱数据获取离子结构信息。近年来,随着FT-ICR MS仪器的发展和推广,该方法得到快速发展。本文综述了此类方法使用的碰撞模型、利用时域和频域信号进行数据分析的不同方法及特点,虽然提供的离子CCS数据的可靠性和准确度有待进一步提高,但在离子的动态CCS测量以及离子异构化的研究中表现出独特优势。该方法可进一步与离子淌度技术相结合,借助FT-ICR MS较高的质量分辨能力和离子操控能力,提供多维度的离子结构信息。     

Fourier transform ion cyclotron resonance mass spectrometry at the true cyclotron frequency

Ion cyclotron resonance (ICR) cells provide stability and coherence of ion oscillations in crossed electric and magnetic fields over extended periods of time. Using the Fourier transform enables precise measurements of ion oscillation frequencies. These precisely measured frequencies are converted into highly accurate mass-to-charge ratios of the analyte ions by calibration procedures. In terms of resolution and mass accuracy, Fourier transform ICR mass spectrometry (FT-ICR MS) offers the highest performance of any MS technology. This is reflected in its wide range of applications. However, in the most challenging MS application, for example, imaging, enhancements in the mass accuracy of fluctuating ion fluxes are required to continue advancing the field. One approach is to shift the ion signal power into the peak corresponding to the true cyclotron frequency instead of the reduced cyclotron frequency peak. The benefits of measuring the true cyclotron frequency include increased tolerance to electric fields within the ICR cell, which enhances frequency measurement precision. As a result, many attempts to implement this mode of FT-ICR MS operation have occurred. Examples of true cyclotron frequency measurements include detection of magnetron inter-harmonics of the reduced cyclotron frequency (i.e., the sidebands), trapping field-free (i.e., screened) ICR cells, and hyperbolic ICR cells with quadrupolar ion detection. More recently, ICR cells with spatially distributed ion clouds have demonstrated attractive performance characteristics for true cyclotron frequency ion detection. Here, we review the corresponding developments in FT-ICR MS over the past 40 years.     

正电子发射计算机断层扫描、医用回旋加速器在地下室的安装要点

正电子发射计算机断层扫描是一种先进的核医学影像设备,医用回旋加速器主要为正电子发射计算机断层扫描检查提供所需示踪剂中的放射性核素。上述设备涉及放射物理、放射化学、医学工程、药物学等各方面知识,且机器结构比较复杂,环境条件要求高。本文针对在大型地下室安装正电子发射计算机断层扫描设备和医用回旋加速器需供应商、专业使用部门及工程建设部门协调和解决的相关问题,将笔者在负责安装该设备时所获得的一些经验总结出来,与各位同行探讨。     

医院PET中心暖通空调系统的设计探讨

简要介绍了PET中心主要组成部分的功能及工作流程,包括回旋加速器、合成热室和PET-CT,并论述了各医疗设备房间的暖通空调设计。以上海某肿瘤医院的PET中心为例,介绍了通风系统的设置。     

小型回旋加速器虚拟样机技术

小型回旋加速器虚拟样机技术是把小型回旋加速器的理论计算、分析、信息技术与机械设计、加工、装配、调试、运行、维修等专家知识进行有机结合，在系统仿真和虚拟现实基础上发展起来的一种新概念技术。基于虚拟样机，可以实现创新设计，有效降低探索风险。文章探讨了回旋加速器虚拟样机系统框架，讨论了虚拟样机系统的体系结构和回旋加速器产品的全生命周期仿真，提出了基于全生命周期集成和多学科协同设计的回旋加速器虚拟样机的开发思路。     

Control of the electron temperature by varying the resonance zone width in ECR plasma

The electron temperature (T_e) in an electron cyclotron resonance plasma is clarified to depend on the spatial profiles of the microwave-power absorption by both the electromagnetic-waves measurement and the simulation of microwave power absorption. It is found that T_e is controlled by varying the magnetic field configuration and/or the microwave frequency since the power absorption profile is influenced by the effective resonance width. In fact, T_e is observed to decrease with decreasing the magnetic field gradient at the resonance point for N₂, Ar and O₂/Ar plasma.