查询词典 intra-uterine device

Recent studies have shown that ultrasound-guided percutaneous microwave ablation is a simple, safe and potentially effective treatment for patients with liver tumors. To facilitate normative application of this technology further and make it more objective and predictive, there are many problems should been solved, such as pre-operative planning, intra-procedural target localization, precise and consistent placement of the tissue ablator device, and quantitative procedure evaluations.

近十年来的大量研究结果表明超声引导经皮微波消融治疗肝肿瘤是一项微创、安全、有效的治疗方法，为进一步推进该技术的规范化应用，使之建立在更加客观和可预见性的基础上，便于该技术的普及应用，需解决治疗前的科学规划、治疗中的准确定位、稳定穿刺及对治疗过程的量化评估等问题。

The most parts of thesis as follows:1. Five symmetrical intra-molecular charge transfer oligomeric phenylene vinylene light emitting materials were designed and synthesized using oligomeric phenylene vinylene as a framework.2. The structures of target molecule were characterized by ~1HNMR,~(13)CNMR, IR, MS and element analysis.3. In order to study the influence of the location and numbers of electron-donor and electron-acceptor on their photoelectric performance by changing length of OPV chain, the UV spectra and fluorescence spectra of target compounds has been compared. We have researched into main factors effecting on material emitting red-shift; organic electroluminescence device was prepared using the compound P4. The capability of eletroluminescence was researched.4. The photoelectric properties of P4 was explained by quantum chemical calculation (the Gaussian 98 quantum chemistry program). It is greatly contributed know the whole process of charge transfer to guide the design of red emitters.

本文研究的内容主要包括以下部分：(1)设计并合成5个对称的以齐聚苯乙烯类为骨架的分子内电荷转移型齐聚苯乙烯类发光材料；(2)通过IR，MS，~1H-NMR，~(13)C-NMR和元素分析对所合成的目标化合物进行表征；(3)通过对目标化合物的紫外光谱和荧光光谱比较分析，研究改变OPV的长度，电子给体和电子受体的位置及数量对其光电性能的影响，探讨材料发射红移的主要因素；选取性能良好的目标化合物P4制备成OELD器件，对其电致发光性能进行研究；(4)运用Gaussian98量子化学程序包，采用量子化学方法对目标化合物P4的光电性能从理论加以解释，进一步认识荷移跃迁的整个过程，为红光材料的设计加以指导。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。