In-package P/G planes analysis and optimization based on transmission matrix method

Power integrity （PI） has become a limiting factor for the chip＇s overall performance, and how to place in-package decoupling capacitors to improve a chip＇s PI performance has become a hot issue. In this paper, we propose an improved transmission matrix method （TMM） for fast decoupling capacitance allocation. An irregular grid partition mechanism is proposed, which helps speed up the impedance computation and complies better with the irregular power/ground （P/G） plane or planes with many vias and decoupling capacitors. Furthermore, we also ameliorate the computation procedure of the impedance matrix whenever decoupling capacitors are inserted or removed at specific ports. With the fast computation of impedance change, in-package decoupling capacitor allocation is done with an efficient change based method in the frequency domain. Experimental results show that our approach can gain about 5× speedup compared with a general TMM, and is efficient in restraining the noise on the P/G plane.     

宽阻带小型化低通滤波器的设计

This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The equivalent circuit model is proposed and the circuit parameters are extracted by the circuit simulation software. The parameters measured are 3 dB cutoff frequency fc of 5.2 GHz, the insertion loss less than 0.5 dB from DC to 4.0 GHz and S21 less than -20 dB within the wide stopband from 6 GHz to 16 GHz. The results of the circuit optimization agree well with those of the full wave simulation and the measured ones, which validate the effectiveness of the equivalent circuit model. The size of the proposed LPF is decreased compared with normal LPF. This LPF can be applied in rectennas to eliminate high order harmonics.     

地下基坑施工方法与问题的探讨

介绍某地下基坑施工过程中采取的主要施工方法与技术措施,并探讨出现的问题.     

基于指标差异化的双集团DEA效率研究——以某高校人文类-理工类学科效率评价为例

研究如何公平有效实现具有不同投入产出指标集的两个集团间决策单元DEA效率比较问题,通过设计"求同存异"的指标融合运算,针对形成的多种效率评价结果,运用OWA算子,进行集成计算,实现对双集团DEA效率的综合分析。所提出的方法突破了传统DEA固定指标体系的限制,拓展了DEA的应用范围。最后通过案例演算方法的可行性。     

铅直不均匀大气流场中污染物扩散规律的研究

运用三年的实测资料,将水平流场存在明显转折的层次定为分界层。当实际源强排放的污染物,由扩散作用铅直通过该层,相应产生了一个新的污染源,从而得到了形成分界层下各处的污染浓度解。上下层风向不同时,污染物的横向扩散范围变大,且地面污染浓度轴线随着距离增加,具有逐渐向下层的下风处偏移的规律。     

Study on arsenic level in ground water of Delhi using hydride generator accessory coupled with atomic absorption spectrophotometer

Surveillance of drinking water is essentially a health measure intended to protect the public from water borne diseases. Hydride generator accessory coupled with atomic absorption spectrophotometer was used to analyze arsenic level in 49 ground water samples collected from different areas of Delhi. Arsenic level in ground water samples was in the range of 0.0170 to 0.100 ppm (Mean-0.0431, Standard Deviation-0.0136, Std. error of Mean-0.00194) with minimum concentration at Raney Well No. 7 (0.0170 ppm) and maximum at Kotla Mubarak Pur (0.100 ppm). Arsenic containing sediments and percolation of chemicals into soil as the result of dumping of garbage rich in chemicals into open landfills could be the possible source of arsenic in ground water of Delhi. Extensive survey and continuous monitoring is required to be made to assess the magnitude of problem and earlier intervention.     

女子自由式摔跤跪撑技术的发展趋势

对2004年全国女子自由式摔跳锦标赛和冠军赛跪撑技术进行分析,认为女子自由式摔跤跪撑技术的发展是获得女子自由式摔跤比赛胜利的关键.同时指出,在跪撑技术的使用中应侧重于滚桥和交叉抱小腿这两种跪撑技术动作.     

《贺新郎·别友》考析--兼述毛泽东的"人间知己"陶毅

对毛泽东《贺新郎·别友》的写赠对象 ,学界一直认为是杨开慧。笔者经某些启示 ,力证是陶毅。随着对写赠对象认识的更易 ,写作时地和所写内容就有重新考析的必要。为充分展示作品的所写内容 ,本文借助史料进行推理并对这方面的史料进行甄别 ,以期为推进毛生平研究稍尽绵力。     

氟原子基态能量的计算

以对角和不变法则为基础,导出了氟原子(含类氟离子)基态(电子组态为1s22s22p5)非相对论性能量的解析表达式,并利用变分法计算了能量值,计算结果与实验数据符合的较好,误差小于0.5%。     

地面运动目标与合成孔径雷达的讨论

本文主要讨论了地面运动目标与合成孔径雷达的关系，并进一步介绍了地面运动目标对合成孔径雷达的影响。