The Minimum PAPR Code for OFDM Systems

In this letter, a block code that minimizes the peak‐to‐average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals is proposed. It is shown that peak envelope power is invariant to cyclic shift and codeword inversion. The systematic encoding rule for the proposed code is composed of searching for a seed codeword, shifting the register elements, and determining codeword inversion. This eliminates the look‐up table for one‐to‐one correspondence between the source and the coded data. Computer simulation confirms that OFDM systems with the proposed code always have the minimum PAPR.     

SOC设计中的浮动压焊块电源/地线网络设计和优化

随着VLSI工艺技术的发展和芯片规模的不断增加，尤其是在SOC设计中，原有的那种供电压焊块只能位于芯片边缘的确定益的模式已经不能够满足整个电路性能的需要。在很多情况下，依靠在电源线的拓扑结构确定后的线宽优化，还是无法保证在有限的布线资源下为电路提供可靠的高性能的供电需求。由此，出现了在芯片边缘上浮动放置压焊块及在芯片的顶部放置供电压焊块阵列的方法。文中提出了一种用于SOC设计中新的基于树型结构的浮动压焊块的电源／地线网络优化算法，经过MCNC电路实例测试后得到明显的优化结果。     

岔河集油田开发调整的主要做法与成效

岔河集油田有多个受构造、岩性双重因素控制的中低渗透复杂断块油藏,其主要储集层为河流相沉积。油田20余年的开发历程是典型的滚动勘探开发过程。通过精细科学的地质研究,不断的实践和认识,制定出与其油田地质特点相适应的开发方针,完善了井网部署与加密、产吸剖面调整、油水井配套综合治理等一系列开发对策,并取得了比较好的开发效果。岔河集油田的开发实践对于类似油田开发不乏成功的经验。     

韶关电厂9#200MW机组DEH控制系统的改造

在对韶关电厂200MW机组DEH系统改造过程中，控制系统采用数字式电液控制系统(DEH)，汽机基本控制部分采用一对互为冗余数据处理单元(DPU)完成，并采用专用的硬件来实现超速控制和超速保护功能。汽机保护系统(ETS)采用独立的系统可编程控制器PLC来实现。     

液晶光阀光电导层光吸收系数的研究

用化学气相沉积法制备了液晶光阀中光电导层———非晶硅薄膜,从实验中得出最佳制备工艺的参数取值。给出了用包络线法测量非晶硅薄膜光吸收系数的原理,测量了样品的光吸收系数随波长的变化规律。得到样品在最佳工艺条件下的光吸收系数高于1×103cm-1。     

Highly ordered microstructures of poly(styrene-b-isoprene) block copolymers induced by solution meniscus

Microstructures of hundreds of micron thick poly(styrene-block-isoprene) copolymer films solution-cast in a cylindrical tube with the solvent evaporation controlled were investigated by transmission electron microscope (TEM), small angle X-ray scattering (SAXS) and optical microscope (OM). In a block copolymer with cylindrical polyisoprene microdomains, the orientation of the cylinders was varied along radial direction of the cylindrical tube. Highly aligned hexagonal arrays of in-plane polyisoprene cylinders were formed with their cylindrical axis parallel to the circumference of the tube in the regimes close to the wall edge. In contrast randomly ordered microdomains were observed at the center of the tube. We have also found that the orientation depends on the solvent evaporation rate and an intermediate rate (∼2.3 nL/s) provides the best orientation. In the case of a block copolymer with a bicontinuous double gyroid structure, we obtained a globally ordered microstructure where [111] crystallographic direction was parallel to the circumference of the tube. For both block copolymers, the area of highly ordered arrays of nanoscopic domains is over 1 mm². Development of the orientation was explained by coupling two orthogonal fields: (1) The flow of a solution induced by strong capillary force at a meniscus between the cylindrical tube wall and the block copolymer solution and (2) the solvent evaporation.     

油气井智能电子防盗阀门

为了有效扼制油田油井原油被盗的现象，减少因被盗及破坏带来的经济损失，研制出GMS3000油气井智能电子防盗阀门。该电子防盗阀门采用了新颖的防盗控制电路和精密的机械联动机构，通过计算机和管理软件得到相应的阀门授权控制，测量结果自动记录、控制阀门的编号和阀门的联动方式，并给予相应的显示。具有可靠、安全、便捷的特点。应用效果表明，达到了油井防盗、防破坏的目的，收到了良好的使用效果，为油田生产安全和提高经济效益提供了可靠的保障。     

安棚深层系凝析气井射孔压井液技术研究

介绍了一种保护油气层的射孔压井液技术，该技术所用的配方具有低密度，低表面张力且具有较强的防膨能力等特点，在安棚深层系低孔低渗油田安3003等凝析气井作业中现场试验，解决了安棚深层系低压气井的水锁伤害等问题，对低孔低渗油气田作业入井流体的研究与应用具有较好的借鉴意义。     

电接点压力表补水泵定压系统的应用

阐述了电接点压力表补水泵定压系统的一些应用问题 ,给出了电接点压力表定压点的上、下限计算公式 ,并提出了该系统补给水泵、补给水箱及安全阀的设计选型方法