Efficient 3-d capacitance extraction considering lossy substrate with multilayered green's function

An efficient algorithm for extraction of three-dimensional (3-D) capacitance on multilayered and lossy substrates is presented. The new algorithm presents a major improvement over the quasi-3-D approach used in a Green's function-based solver and takes into consideration the sidewalls of 3-D conductors. To improve the efficiency of the computation and the transformation of the Green's function, a nonuniform grid is adopted. The most computationally intensive part in the transformation of the Green's function is computed separately as technology-independent matrices Tk foremost. Once computed, Tk can be stored and used for any technology, thus the storage requirement and computational complexity are reduced from O (S/sup 2/) and O (S/sup 2/ log S/sup 2/), respectively, to just O [(log S/sub max/)/sup 2/]. Extensive tests have been performed to verify the new algorithm, and its accuracy has been established by comparing with other programs.     

黄坛口水电站水工钢闸门更新改造

黄坛口水电站建于20世纪50年代。在第二次大坝安全定期检查中。发现钢闸门和启闭机存在许多缺陷。闸门和启闭机的更新改造已经进行，并取得良好效果。     

新型热红外伪装涂料用填料中空微珠性能研究

分析了温度对涂层发射率的影响，并据此重点研究了一种新型热红外伪装涂料用填料——中空微珠——的常规使用性能、降温效果以及对涂层发射率的影响。研究认为，中空微殊用量小于20％、粒径为200目左右时常规使用性能最好。60目的中空微殊降温效果最好，而且当其用量小于20％时，中空微珠对涂层的发射率基本没有影响。     

Dynamic bandwidth allocation for quality-of-service over Ethernet PONs

Ethernet-based passive optical network (EPON) technology is being considered as a promising solution for next-generation broadband access networks due to the convergence of low-cost Ethernet equipment and low-cost fiber infrastructures. A major feature for this new architecture is the use of a shared transmission media between all users; hence, medium access control arbitration mechanisms are essential for the successful implementation of EPON: i.e., to ensure a contention-free transmission and provide end users with equal access to the shared media. We propose to use the multipoint control protocol defined by the IEEE 802.3ah task force to arbitrate the transmission of different users, and we present different dynamic bandwidth allocation (DBA) algorithms to allocate bandwidths effectively and fairly between end users. These DBA algorithms are also augmented to support differentiated services, a crucial requirement for a converged broadband access network with heterogeneous traffic. We show that queueing delays under strict bandwidth allocation algorithms result in an unexpected behavior for certain traffic classes, and we suggest the use of DBA with appropriate local queue management to alleviate this inappropriate behavior. We conduct detailed simulation experiments to study the performance and validate the effectiveness of the proposed protocols.     

Performance of Alamouti transmit diversity over time-varying Rayleigh-fading channels

We analyze the impact of a time-varying Rayleigh-fading channel on the performance of an Alamouti transmit-diversity scheme. We propose several optimal and suboptimal detection strategies for mitigating the effects of a time-varying channel, and derive expressions for their bit-error probability as a function of the channel correlation coefficient /spl rho/. We find that the maximum-likelihood detector that optimally compensates for the time-varying channel is very tolerant to time-varying fading, attaining full diversity order even for the extreme case of /spl rho/=0. In contrast, although lower in complexity, the suboptimal schemes suffer a diversity penalty and are thus suitable only for slowly fading channels.     

一个面积和功耗优化且适用于10/100 Base-T以太网的CMOS时钟恢复电路

提出了一个新的用于10 / 10 0 Base- T以太网中面积和功耗优化的时钟恢复电路.它采用双环路的结构,加快了锁相环路的捕获和跟踪速度;采用复用的方式,通过选择信号控制电路可分别在10 Mbps或10 0 Mbps模式下独立工作且能方便地实现模式间的互换,与采用两个独立的CDR电路相比节省了一半的面积;同时,电路中采用一般的延迟单元来取代DL L,并能保证环路性能不随工艺温度等条件引起的延迟单元、延迟时间的变化而变化,从而节省了功耗.Hspice模拟结果显示,在Vdd=2 .5 V时,10 0 Mbps模式下电路的功耗约为75 m W,稳态相差为0 .3 ns;10 Mbps模式时电路功耗为5 8m W     

锌钾硼对甜菜产质量效应及最佳施肥措施的研究

本文利用最优回归设计“310”方案,研究了黑土地甜菜 Zn、K_2O、B的效果及合理施用问题。得出甜菜块根产量、含糖、产糖量、灰分 K 和有害 N 与 ZnK_2O、B 肥回归关系显著的回归模型,分析了 Zn、K_2O、B 对上述五个指标的效应,明确了 Zn 是影响各项指标的主要因子,并采用频率筛选法,提出了兼顾上述五项指标的优质高产施肥措施。     

辐射对血液流变效应的研究及动物全身照射后全血粘度的变化规律

本文结果表明经一次大剂量全身照射后的机体血液流变的主要特性为全血表观粘度先高粘后低粘的双向性变化,从照后第一天起即升高。随着放射病病程的发展,在早期有一个高粘峰,其峰均值比照前升高47.80％。但因不同动物、不同剂量、不同均速,不同血源而变化不同。     

Induction of immune tolerance with heart-thymus composite allotransplantation in rats

Objective To study on the role of thymus transplantation for heart allograft in rats. Methods Vascularized heart-thymus combined transplantation was performed with microsurgical technique. Graft survival, histopathology, level of IL-2, IL-4 and its mRNA expression in serum and cardiac grafts were investigated. Results Heart-thymus combined transplantation achieved effect in the prolongation of cardiac graft survival with short-term administration of cyclosporine. Conclusions Vascularized thymus transplantation induced immune tolerance in thymectomized rats.