SIR-C data quality and calibration results

The SIR-C/X-SAR imaging radar took its first flight on the Space Shuttle Endeavour in April 1994 and flew for a second time in October 1994. This multifrequency radar has fully polarimetric capability at L- and C-band, and a single polarization at X-band (X-SAR). The Endeavour missions were designated the Space Radar Laboratory-1 (SRL-1) and -2 (SRL-2). Calibration of polarimetric L- and C-band data for all the different modes SIR-C offers is an especially complicated problem. The solution involves extensive analysis of pre-flight test data to come up with a model of the system, analysis of in-flight test data to determine the antenna pattern and gains of the system during operation, and analysis of data from over fourteen calibration sites distributed around the SIR-C/X-SAR orbit track. The SRL missions were the first time a multifrequency polarimetric imaging radar employing a phased array antenna has been flown in space. Calibration of SIR-C data products involved some unique technical problems given the complexity of the radar system. In this paper, the approach adopted for calibration of SIR-C data is described and the calibration performance of the data products is presented     

新型耐磨蚀铸造高铬钢的研制

本文设计了用于含有磨粒的强酸介质的新型耐磨蚀钢的化学成分，采用金相显微镜、Ｘ射线衍射、扫描电子显微镜、腐蚀与磨蚀试验等方法，观察与分析了钢的显微组织与磨蚀形貌，研究了新型铸造高铬钢的性能，并对其磨蚀机理进行了较为深入的探讨。试验结果表明，较高的含铬量和含碳量与适量的钼、铜的复合使用，使新型高铬钢具有比高合金化的ＺＳ２８合金更好的抗磨蚀性能，而且成本比较低，具有广阔的应用前景。     

Operation of strained-layer (In,Ga)As quantum well lasers preparedon (112)B GaAs substrate

The operation of (In,Ga)As quantum well lasers prepared on [112]-oriented GaAs substrates is reported. Threshold current densities as low as 187 A/cm² for a 1.57 mm-long device have been obtained under pulsed-mode operation. The demonstration of laser action in a heterostructure grown on the [112]-oriented substrate is important for the design of blue-green light emitters by second harmonic generation     

微波高压提取快速测定饲料含氟量的探讨

采用微波高压制样技术,快速提取饲料中的氟元素,结合氟离子选择性电极标准添加和电位极差测试方法,能够快速、准确地测试饲料中的含氟量     

Analogue implementation of a neural network controller for UPSinverter applications

An analogue neural-network controller for UPS inverter applications is presented. The proposed neural-network controller is trained off-line using patterns obtained from a simulated controller, which had an idealized load-current-reference. Simulation results show that the proposed neural-network controller can achieve low total harmonic distortion under nonlinear loading condition and good dynamic responses under transient loading condition. To verify the performance of the proposed NN controller, a hardware inverter with an analogue neural network (NN) controller (using mainly operational amplifiers and resistors) is built. Additionally, for comparison purposes, a PI controller with optimized parameters is built. Experimental results confirm the simulation results and show the superior performance of the NN controller especially under rectifier-type loading condition. Implementing the analogue neural-network controller using programmable integrated circuits is also discussed     

河间东营油藏微生物驱替现场试验

针对河间东营油藏的地质条件和开发特点,开展了微生物采油室内试验和评价,优选适合油藏特点的耐高温微生物菌种,优化驱替试验参数。在室内试验的基础上进行了微生物驱替现场实施方案论证和编制。通过5个注水井组微生物驱替现场试验,取得了较好的增油效果,进一步提高了油藏采收率。     

高精度合成地震记录制作技术研究

制作高精度的合成地震记录是精细储层描述的基础，本文在分析合成地震记录原理的基础上，从地震剖面的极性判断、平均速度的选取，反射系数的准确提取，子波的精确估算等方面对制作合成记录的要点进行了分析，通过提高以上四方面的精度，提高了制作合成地震记录的精度，并提出了一套可行的合成地震记录的检查方法。     

立式钢制油罐罐底外腐蚀原因分析及对策

分析了立式钢制油罐罐底外腐蚀产生的原因,介绍了防范措施。指出氧浓差电池腐蚀和微生物腐蚀是罐底外腐蚀产生的主要原因,防止外部水分进入罐底下部最关键。     

激光焊接超细基胎体金刚石薄壁钻

采用激光焊接超细预合金粉胎体，开发了新的薄壁钻产品，通过对与现有的产品工艺、性能测试以及实际使用分析对比，结果表明：激光焊接与普通钎焊相比结合强度提高2－3倍，克服了胎体脱落问题，胎体耐磨性提高了50％－120％，其中轴向磨损速率提高1．2倍；钻削速度提高30．4％，工矿适应性增加，使用寿命提高25％－108％。