Spreading Codes Generator for Wireless CDMA Networks

The prime characteristic of spread spectrum modulated signals is that their bandwidth is greater than the information rate. In this way a redundancy is introduced that allows the severe levels of inteference inherent in the transmission of digital information over radio and satellite links to be overcome. Current spread spectrum applications are primarily in military communications; nevertheless, there is growing interest in this technique for third generation mobile radio networks (UMTS, FPLTS, etc.) with open discussion regarding the practicality of using a multiple access system based on spread spectrum techniques (CDMA). However, in order to support as many users in the same bandwidth as other multiple access techniques such as TDMA or FDMA, it is important how to generate large families of sequences that present low cross-correlation. The aim of this paper is to describe a spreading codes generator that can produce a large number of PN sequences with good properties of auto- and cross-correlation. Moreover, the codes generated shows high unpredictability and good statistical behaviour. This also allows the implementation of some features that are common on military networks such as message privacy (increasingly important in commercial networks) without additional cost. The structure presented shows itself to be advantageous for high speed generation of codes at a low cost, low power consumption (allowing longer life for batteries), small size and simplicity of implementation, essential ingredients for commercial equipment. Another attractive feature is its structural parallelism, useful in VLSI implementations. All of these features render it potentially suitable for the implementation of channel bandwidth sharing systems in future wireless personal communications networks.     

低密度MTC固井液在低渗透气井的试验研究

针对陕甘宁盆地低渗透气田天然气井地层漏失等问题，通过室内试验，设计了密度为１．４１～１．６０ｇ／ｃｍ３的二级固井高炉矿渣——ＭＴＣ水泥浆和ＡＰＩＧ级水泥——ＭＴＣ水泥浆。目的提高固井质量、降低固井成本。结果通过对高炉矿渣的水化机理和两种ＭＴＣ水泥浆对比分析，认为高炉矿渣——ＭＴＣ转化法较ＡＰＩＧ级水泥——ＭＴＣ转化法，具有外加剂用量少、抗压强度高、体系简单、固井成本低等特点。结论两种低密度ＭＴＣ水泥浆配方设计合理，性能优良，能满足现场施工的要求。     

由1,4-萘醌催化合成1,4-二烷氧基萘-2,3-二甲腈

研究了以 1 ,4-萘醌为原料 ,通过溴代、氰化和 O-烷基化三步合成 1 ,4-二烷氧基萘 -2 ,3 -二甲腈。在溴代反应中以溴化试剂代替液溴 ;在氰化和 O-烷基化反应中以溴化十二烷基三甲基铵 (DTMAB)和聚乙二醇(PEG)作为相转移催化剂 ,并采用正交设计法考察了相转移催化剂、固体碱、反应温度等因素对反应的影响 ,其中氰化产物收率达 88.7%。     

C5/C6异构化催化剂的首次工业应用

采用中石化金陵分公司研究院研制的CI-50(Pd/丝光沸石)作C5/C6烷烃异构化催化剂.详细介绍了该催化剂的工业放大试验装置的工艺流程、首次开工过程中技术问题及处理方法.     

激光相变硬化性能与工艺参数关系的数学模型

用回归正文分析的方法．建立了中碳结构钢、碳素工具钢和合金结构钢的激光相变硬化性能与工艺参数间关系的数学模型。分析了回归力程的显著性并预测了各硬化指标的精度。     

转向驱动轮轮胎测力仪研究

该测力仪在结构上采用双等速万向节装置，不仅能用于转向轮和非转向轮的测量，并且解决了转向驱动轮的动力测量问题，对于四轮驱动的军用轮式车辆实车测试有着十分重要的意义。测力仪将轮胎动载荷、扭矩、侧向力、回正力矩、驱动力和外倾力矩的测量转化为测力筋拉压力的测量，大大提高了测量精度和抗干扰能力。     

耐高温微生物驱油提高低渗透油藏采收率先导性试验

胜利油田东辛高温低渗透油藏含蜡高,常温微生物无法存活,针对这一问题,引进美国NPC公司耐高温菌种,在Y6-16井组开展高温低渗油藏微生物驱油提高采收率研究和现场试验。施工后Y6-16井日增注52m3,表皮系数由施工前的2.069减小为施工后的-6.31,油层污染得到较好改善;原油含蜡量、胶质沥青质含量降低,轻质组分增加,重质组分降低;井组采收率提高5.09个百分点。     

一种适用于高数据速率和高速移动环境的新型信道估计方法——双正交通道信道估计方法

本文给出了一种适用于高数据速率和高速移动环境下的新型有效的信道估计方法-双正交通道信道估计方法(CETOC,Channel Estimation by using Two Orthogonal Channels),这种信道估计方法通过采用两个独立通道的联合估计,可以有效的克服快衰落的影响,从而使得在快衰落信道下应用多维状态调制成为可能.     

包装机中塑料薄膜常热式热封参数的实验研究

文中通过对包装机中常热式热封过程的分析及有效的实验，获得较为可靠的热封实验数据，并利用专业统计软件spss对实验数据进行处理，得到包装机中塑料薄膜的封口强度与操作参数之间的关系，为设计人员提供了一种获得最优操作参数的有效方法。     

Time-Space Label Switching Protocol (TSL-SP)—A New Paradigm of Network Resource Assignment

In this paper we propose a new protocol called time-space label switching protocol (TSL-SP) in optical burst switching (OBS), and define the terms time-space label (TSL) and time-space routing (TSR). An important concept of response time is introduced in the time label mechanism. The TSL-SP is a new technology that can quickly and efficiently forward data with a label on the optical networks. A two-dimension label switched path (TD-LSP) can be set up, that is maintained and deleted by the TSL-SP. For clearly illuminating the operation principles of the TSL-SP, we propose a new approach of orthogonal time-space coordinates in which the vertical coordinate is the space label and the horizontal coordinate is the time label. The proposed TD-LSP can dramatically reduce the routing failure probability and greatly improve the link network efficiency compared with other signaling protocols. Moreover, we define the time-space label control plane that can achieve the higher efficiency. When the TSL-SP is applied to networks, switching performance can be improved by two orders compared to the switching performance with the conventional OBS signaling protocols. The fundamental goal of TSL-SP is to band the signaling and routing functions together closely. Also, the TSL-SP can reduce the complexity of the network, support automatic service offering, and provide traffic engineering.