以Cymer公司为例归纳总结了ArF准分子激光器双腔放大结构及相应的脉冲能量稳定性的发展历程，讨论了双腔能量放大机制对脉冲能量稳定性的影响，重点分析了MOPRA结构较MOPA结构在能量稳定性方面的优缺点。着重阐述了放电腔内工作气体成分、配比、电极间流速对脉冲能量稳定性的影响以及相应的改善措施，并结合影响脉冲能量稳定性的因素简述能量控制系统在稳定脉冲能量上的应用。

The development of the dual- chamber amplification structure of ArF excimer laser in Cymer was reviewed. Corresponding pulse energy stability was also concluded. The effect of dual- chamber amplification mechanism on pulse energy stability was analyzed. Especially, the MOPRA structure and the MOPA structure are compared. The gas components, proportion of working gases and gas flow rate between electrodes in the discharge chamber,which have strong influence on the pulse energy stability, were also discussed. Corresponding measures were presented to improve energy stability. Finally, the energy servo system was introduced briefly.

目的探讨DSCT双能量判断体内结石成分的可行性和准确性。方法收集2012年9月—2013年6月行CT平扫双能量泌尿系检查并经手术证实,红外波普分析的患者118例(结石共127颗)为研究对象,对其予以DSCT双能量扫描后,在工作站(MMWP)上完成结石成分分析;比较外光谱成分分析与DSCT双能量扫描所得结果。结果双源CT双能量技术能准确的区分纯尿酸结石和非尿酸结石(敏感性、特异度均为100%),较准确的区分纯草酸钙结石(敏感性为100%,特异度为89.8%),纯羟基磷灰石(敏感性为84.6%,特异度为100%)。结论双源CT双能量技术能在治疗前对尿路结石的成分进行初步分析,对尿路结石的预防和治疗有着重要的指导意义。

Objective To investigate the feasibility and accuracy of dual energy DSCT judgment component calculus in vivo. Methods From 2012 September to 2013 June underwent CT scan in dual energy urinary examination and confirmed by operation, 118 patients with infrared pop analysis (stone 127) as the research object, by DSCT dual energy scan on the post, in the worksta-tion (MMWP) on stone composition analysis; analysis and DSCT spectra comparison dual energy scan results. Results Dual ener-gy technique of dual source CT can accurately differentiate between pure uric acid calculi and non uric acid calculi (sensitivity, specificity was 100%), to distinguish pure calcium oxalate stones accurately (sensitivity 100%, specificity 89.8%), pure hydroxyap-atite (sensitivity 84.6%, specificity 100%). Conclusion Dual energy technique of dual source CT can carry on the composition of urinary stones in the treatment of preliminary analysis, has the important guiding significance for the prevention and treat

目的 探讨双能量脑动脉CT血管造影(CTA)在脑动脉瘤诊断中的价值.方法 以数字减影血管造影(DSA)结果为金标准,回顾性分析30例经DSA证实为脑动脉瘤患者的双能量脑动脉CTA影像学特点,比较双能量脑动脉CTA和DSA检查对脑动脉瘤诊断准确性.结果 双能量脑动脉CTA能较好地显示脑动脉瘤的直接征象,对颈内动脉虹吸段的动脉瘤征象显示优于常规脑动脉CTA扫描.对瘤体及瘤颈的测量与DSA有较高的一致性,两种方法比较差异无统计学意义(P＞0.05).双能量脑动脉CTA辐射剂量为19.1～25.4(21.7±0.5) mSv.结论 双能量脑动脉CTA能够清晰显示脑动脉瘤的瘤体大小及瘤颈,对脑动脉瘤的诊断有较高的临床应用价值.

Objective To study the value of dual energy cerebral arteries computed tomographic angiography (CTA) in diagnosis of cerebral aneurysm.Methods As a gold standard of digital subtraction angiography (DSA) findings,the dual energy cerebral arteries CTA imaging features of 30 cases confirmed by DSA for cerebral aneurysm were retrospectively analyzed.The diagnosis accuracy of cerebral aneurysm between dual energy cerebral arteries and DSA was compared.Results Dual energy cerebral arteries CTA could display the direct signs of cerebral aneurysms,it played better in the signs of aneurysm of the siphon segment of internal carotid artery than that by conventional cerebral arteries CTA.The measurement of the size and neck by dual energy cerebral arteries CTA had good agreement to DSA,there was no statistical difference (P ＞ 0.05).The radiation dose of dual energy cerebral arteries CTA was 19.1-25.4(21.7 ± 0.5)mSv.Conclusion The dual energy cerebral arteries CTA can show the size and

目的：评价双源CT单能量成像技术在骨折后金属内固定术后的应用价值。方法对48处不同部位骨折内固定术后43例患者采用西门子（Siemens）公司生产的Somatom Definition型双源多层螺旋CT进行双能量扫描，并将扫描所得到的双能量数据调入工作站Dual-Energy软件内，应用Monoenergetic处理。根据软件所提供的光子能量范围，采用不同的光子能量对数据进行处理，将上述数据与用于常规诊断的120 KV融合图像应用相同的多平面重组、容积再现技术进行重组。由两位医生对以上图像的质量进行评价，并进行比较。结果120 KV时，有45处内固定物有条纹伪影。在80 KeV、120 KeV、160 KeV条件下，图像质量均好于120 KV,其中80 KeV条件下，7处内固定处没有伪影，41处内固定部位仅在金属厚重的部位有少量伪影。结论双源CT的单能量成像技术可以显著提高图像质量，并降低金属内固物产生的伪影。而且80 KeV的光子能量可以提供最佳的图像质量。

Purpose To evaluate the value of dual energy CT techniques with monoenergy after fracture fixation with metal. Materials and Methods 48 different parts of the fracture fixations of 43 patients were included in this study. Dual energy scan was performed at dual energy multislice spiral CT (SomatomDefinition, Siemens), dual energy date was transferred to the Dual Energy software, Monoenergetic was appled for processing. Different photon energies that according to the photon energy range which the software provided for data processing, the data above and the 120 KV routine diagnostic fusioned imaging were restructure by the same multiplanar reformation (MPR), volume rendering (VR) technique respectively. Two doctors evaluated and compared the quality of the images. Results 45 fixtures had striped artifacts when 120KV. In 80KeV, 120 KeV, 160KeV conditions, the image quality was better than 120KV, 7 fixtures artifacts disappeared when under 80KV, and only at the part of heavy meta

本文介绍了压电振动能量采集器的工作原理,阐述了振动能量采集器中的单/双晶片、Rainbow型、Cymbal型、褶皱型等几种常见和新研发的压电换能元件的结构形式和相应特点。然后,针对如何提高压电振动能量采集器的环境适应能力,介绍了振动能量采集宽频带和多方向两个研究方向,以及国内外在这两个方面的最新研究进展。着重阐述了压电振动能量采集器的拓宽频带宽度、调整共振频率等宽频带能量收集的实现方法,以及非线性磁力耦合结构、立方体-球结构、蒲公英状结构等多方向能量收集的实现方式。最后,对多方向宽频带压电式振动能量采集器的发展趋势进行了展望。

The principles of multi-directional wideband piezoelectric vibration energy harvesters are introduced in this paper. The structures and their characteristics of several traditional and newly developed piezoelectric energy conversion elements used in the vibration energy harvesters are presented, such as Unimorph/Bimorph, Rainbow, Wrinkled and Cymbal type. Afterwards, two research fields of multi-directional and wideband vibration energy harvesting to improve the environmental adaptability are introduced, along with their recent research advances at home and abroad. For wideband vibration energy harvesting, such methods as bandwidth broaden and resonance frequency tuning are elaborated, and for the other field, three structures, namely, nonlinear magnetic coupling, cube-sphere and dandelion-like structure are demonstrated. Finally, the trend of development of the multi-directional wideband piezoelectric vibration energy harvesting technology is prospected.