摘要：目的:这是一项回顾性研究,旨在分析普萘洛尔治疗婴幼儿血管瘤(IH)的临床疗效。研究设计:IH患者用普萘洛尔(2~4.5mg/kg·d)治疗。那些对普萘洛尔反应不佳的患者接受了平阳霉素的瘤内注射或手术治疗。结果:51例患者对普萘洛尔的相对治疗反应如下:优良率为31.37%(16/51)。

摘要：在原油价格较低的情况下。化学驱油主要的问题是降低成本。在美国采用化学驱油方法提高原油产量的主要对象是轻质油油田。进行了与经济模型相结合使用模拟的结果来优选表面活性剂和聚合物化学驱油的设计。不同的表面活性剂浓度对工程效益有显著的影响。最理想的结果是聚合物和表面活性剂二者是低浓度并同时注进油层。有时选用低张力聚合物。设计的敏感性分析表明，最重要的经济变量是油价。折扣率。经营费用和化学制剂的价格。在敏感性分析中，也包括了不同聚合物的浓度，油田的实际渗透率和垂直与水平渗透率的比率。蒙特卡伦模拟就是用作对表面活性剂／聚合的注水风险评估的演示。结论表明，应用实际的油藏模拟与现代工艺技术（如水平井积最优化经济评价法，是能改进化学注水工程的设计。

摘要：姿态解算是小型多旋翼无人机研究的核心问题之一。为进一步提高姿态反馈数据的准确度和实时性,设计了低成本姿态解算系统,根据不同姿态传感器的信号特点,结合卡尔曼滤波融合算法和改进型互补滤波融合算法的优势,提出了一种基于前置卡尔曼滤波器的互补滤波融合姿态解算方法,并进行了飞行姿态解算实验。结果表明,代码的运行周期比改进型互补滤波融合算法增加了0.253 ms,比基于加权滑动方差的卡尔曼滤波融合算法减少了0.246 ms;姿态更新时间提前了约1 ms。悬停状态下,俯仰角和翻滚角的解算误差控制在±0.2°以内;航向角的解算误差控制在±0.6°以内。该方法集合了卡尔曼滤波算法和互补滤波算法的优势,准确度更高,实时性更强。

摘要：以单管Boost型PFC电路作为研究对象,分别针对电流断续、电流临界连续和电流连续3种工作模态,详细讨论了数字控制PFC的实现方法和设计过程,并分别给出了样机实验结果;此外,结合M C 56F 8013的外设资源特点,给出了基于DSP的PFC详细的系统接口设计,包括PwM控制策略和同步控制AD采样环节。对PFC的数字控制方案进行了系统研究,提供了不同工作模式下的完整数字控制解决方案,为功率因数的数字控制技术应用提供了较好的参考作用。

摘要：数字控制技术和电力电子应用之间结合逐渐紧密,功率因数校正(PFC)是电力电子技术的一个重要应用,本文利用Freescale公司新数字信号控制器(DSC)MC56F8323,完成了基于DSC的功率因数校正模块应用研究。本文提供了PFC变换器的完整数字控制解决方案,包括改进的数字PFC算法设计、适用于数字控制特点的变换器模型分析和控制参数推导、基于DSC的PFC变换器的系统软件设计、以及PwM控制信号产生策略等,最后用一台500w实验样机验证了数字控制的优良系统性能。

摘要：In the Hefei Light Source （HLS） storage ring, multibunch operation is used to obtain a high luminosity. Multibunch instabilities can severely limit light source performance with a variety of negative impacts, including beam loss, low injection efficiency, and overall degradation of the beam quality. Instabilities of a multibunch beam can be mitigated using certain techniques including increasing natural damping （operating at a higher energy）, lowering the beam current, and increasing Landau damping. However, these methods are not adequate to stabilize a multibunch electron beam at a low energy and with a high current. In order to combat beam instabilities in the HLS storage ring, active feedback systems including a longitudinal feedback system （LFB） and a transverse feedback system （TFB） will be developed as part of the HLS upgrade project, the HLS-Ⅱ storage ring project. As a key component of the longitudinal bunch-by-bunch feedback system, an LFB kicker cavity with a wide bandwidth and high shunt impedance is required. In this paper we report our work on the design of the LFB kicker cavity for the HLS-Ⅱ storage ring and present the new tuning and optimization techniques developed in designing this high performance LFB kicker.

摘要：数字控制由于高集成度带来的低成本、设计沿继性、控制灵活等优点而应用逐渐广泛,电力电子应用逐渐朝着高频化方向发展,这也对高频开关电源的数字控制提出了要求。利用Freescale新型号数字信号控制器(DigitalSingnalController,DSC)MC56F8323的高性能特性,完成了基于DSC的带同步整流的高频软开关移相全桥变换器的数字控制,描述了DSC产生软件移相控制策略,并给出了详细的数字控制系统设计和软件结构设计,最后用一台500w实验样机验证了数字控制所带来的优良的系统性能。

摘要：脉宽调制数字快速电磁阀作为重要的电液转换元件,在燃油控制系统的作用日益突出。针对断电常开型快速电磁阀的需求,开展断电常开型脉宽调制数字快速电磁阀的方案设计及仿真研究,并通过工程验证使该脉宽调制数字快速电磁阀的设计方案得到优化。

摘要：In order to solve the problem of high missed rate of camellia fruits and high damage rate of flower buds during vibratory picking,through the study on the biological characteristics of camellia tree,the crown of camellia tree was divided into upper and lower canopy at the maximum canopy diameter.A kind of vibration plate type camellia fruit picking machine was *** structure and working principle of the whole machine were *** the analysis of the factors of camellia fruit abscission,it is concluded that frequency,amplitude and working time are the main factors affecting the magnitude of inertia *** preliminary research and coupling simulation,the horizontal range of each factor is determined:operation time is 5 s,10 s,15 s,frequency is 3 Hz,5 Hz,7 Hz and amplitude is 50 mm,60 mm,70 *** tests were carried out on the upper and lower canopies successively,and the comprehensive scoring method was used to analyze the orthogonal test *** results showed that the optimal combination of working parameters for picking camellia in the upper canopy was A3B3C2,that is,the operation time was 15 s,the amplitude was 70 mm and the frequency was 5 *** this condition,the missed picking rate of camellia fruits was 8.21%and the rate of flower buds damage was 9.12%.The optimal combination of working parameters for picking camellia fruits in the lower canopy was A3B1C3,that is,the operation time was 15 s,the amplitude was 50 mm and the frequency was 7 *** this condition,the rate of missing picking of camellia fruits was 6.84%and the rate of flower buds damage was 6.92%.

摘要：新音乐概念中的“新”与肯定性文化互不相容,其本质在于一种批判冲动。新音乐最初保持着“新”与传统之间的内在张力,后来却逐渐失去了这种张力,也失去了审美实质性与连贯性。新音乐表现出了种种老化症状,甚至体现在最优秀、主观上最不妥协的音乐家的音乐作品中,这些音乐家多少出于文化哲学的立场放弃了新音乐,但仍然在一定程度上保留音乐的意义。但在新音乐的后继者中越来越出现了一种妥协倾向,十二音技术在他们那里已经不再具有批判性和实际作用,而是沦为技术化、专家化的玩物。他们尝试对音乐加以一种整体的合理化,消除音乐中所有主体的情感活动,将音乐素材扩展到极端,从而将音乐推向激进主义乃至空虚。但无论是用数学操作来实现纯粹音乐,还是试图通过这种整体合理化而将艺术变成一种科学或技术的做法都是徒劳的。