Monolithic SiGe Up‐/Down‐Conversion Mixers with Active Baluns

The purpose of this paper is to describe the implementation of monolithically matching circuits, interface circuits, and RF core circuits to the same substrate. We designed and fabricated on‐chip 1 to 6 GHz up‐conversion and 1 to 8 GHz down‐conversion mixers using a 0.8 µm SiGe hetero‐junction bipolar transistor (HBT) process technology. To fabricate a SiGe HBT, we used a reduced pressure chemical vapor deposition (RPCVD) system to grow a base epitaxial layer, and we adopted local oxidation of silicon (LOCOS) isolation to separate the device terminals. An up‐conversion mixer was implemented on‐chip using an intermediate frequency (IF) matching circuit, local oscillator (LO)/radio frequency (RF) wideband matching circuits, LO/IF input balun circuits, and an RF output balun circuit. The measured results of the fabricated up‐conversion mixer show a positive power conversion gain from 1 to 6 GHz and a bandwidth of about 4.5 GHz. Also, the down‐conversion mixer was implemented on‐chip using LO/RF wideband matching circuits, LO/RF input balun circuits, and an IF output balun circuit. The measured results of the fabricated down‐conversion mixer show a positive power conversion gain from 1 to 8 GHz and a bandwidth of about 4.5 GHz.     

我国锦纶帘子布市场发展态势及对策

通过对我国当前帘布市场态势的分析和今后三年的需求预测，探讨了锦纶帘线的生产发展对策。认为“八五”期间，我国锦纶帘布市场将呈现供大于求的局面，在一段时期内，锦纶帘布仍将是主要的橡胶骨架材料，其占比例为７０％左右。预计１９９３～１９９５年，锦纶橡胶骨架材料的市场需求量分别为９．１６，１０．３７．１１．６９万ｔ。     

Dynamic Survivability in WDM Mesh Networks Under Dynamic Traffic

Network survivability is a crucial requirement in WDM mesh networks. In this paper, we systematically consider the problem of dynamic survivability with dynamic single link failure in WDM networks under dynamic traffic demands. Specifically, we investigate various protection schemes, such as dedicated path protection (DPP), shared path protection (SPP), dedicated link protection (DLP), shared link protection (SLP), and two restoration schemes, path restoration (PR) and link restoration (LR). Moreover, two new shared protection methods are proposed, i.e., SRLG-based shared link protection (SRLG-SLP) and SRLG-based shared path protection (SRLG-SPP). The SRLG (shared risk link group) constraint defines the availability of protection resources to a working path, which requires that any two working paths sharing the same risk of failure (or in the same SRLG) cannot share the same protection resources. Furthermore, in our study, we consider a more practical dynamic single-link failure model, in which the link-failure-interarrival time and link-failure-holding time are considered as two independent parameters. Based on this link-failure model, extensive simulations are done to analyze and compare the dynamic survivable performance of various protection and restoration schemes. Resource utilization, protection efficiency, restoration efficiency, and service disruption ratio are employed as survivable performance metrics versus traffic load, link-failure frequency, and link-failure reparation time to evaluate the survivable performance. Many meaningful results are given. In addition, we show that the developed SRLG-SLP and SRLG-SPP protection schemes perform very well in terms of protection efficiency and service disruption ratio, while sacrificing some performance in terms of resource utilization.     

远洋山水居住区(西区)"九年一贯制"学校

远洋山水居住区（西区）的教育优势突出，在居住区的西南角规划设计了一所36班的“九年一贯制”示范学校。其中，小学部24班，初中部12班。该学校隶属于石景山教委，主要招生服务对象为远洋山水居住区（西区）和周边社区的居民。学校占地3.6ha，总建筑面积约23800m^2。     

Application-aware buffer management: new metrics and techniques

An important issue for video transmission over IP networks is preservation of perceived video quality despite packet loss. Packet loss can be detrimental to compressed video. However, reducing packet loss to a very low level is difficult with current loss control techniques. Furthermore, even a very low objective loss probability can still seriously distort perceived video quality. This paper presents two buffer management schemes using video characteristics. They increase maximum loss tolerance for a desired level of video quality, providing better quality at equal loss ratios, when compared to a conventional buffer management scheme. Meanwhile, service fairness and network efficiency are also improved.     

P-channel Ge/Si Hetero-nanocrystal Based MOSFET Memory

The charge storage characteristics of P-channel Ge/Si hetero-nanocrystal based MOSFET memory has been investigated and a logical array has been constructed using this memory cell. In the case of the thickness of tunneling oxide T_ox=2nm and the dimensions of Si- and Ge-nanocrystal D_Si=D_Ge=5nm, the retention time of this device can reach ten years(~1×10~8s) while the programming and erasing time achieve the orders of microsecond and millisecond at the control gate voltage |V_g|=3V with respect to N-wells, respectively. Therefore, this novel device, as an excellent nonvolatile memory operating at room temperature, is desired to obtain application in future VLSI.     

东营凹陷古近系烃源岩超压特征及分布规律

统计分析1307口探井实测压力系数和83l口探井使用的钻井液密度数据，发现东营凹陷古近系沙三段、沙四段普遍存在异常超压，超压(压力系数1．1-1．5)主要出现在2100-3500m深度，强超压(压力系数大于1．5)主要出现在2800-3500m深度。东营凹陷沙三段、沙四段主力烃源岩超压平面分布具有北高南低、东高西低的总体特点，超压主要分布在洼陷带、断裂构造带和中央背斜带上。烃源岩压力系数等值线北部陡坡带比较密集，南部缓坡带相对稀疏。生油洼陷中心附近异常高压带的分布与生油洼陷基本一致，洼陷深陷区压力系数很大，向周围斜坡和构造高部位呈辐射状逐渐减小至正常，压力分布带与洼陷、边缘斜坡和构造较高部位的欠压实与压实带发育、分布规律的一致性很好。图3表l参9