扫描SAR成像中SPECAN算法的FPGA实现

为满足扫描成像合成孔径雷达( SAR)系统小型化和低功耗的迫切需求,给出一种频谱分析( SPECAN)算法的现场可编程逻辑门阵列( FPGA)实现,整个成像流程被划分为多个时分的阶段并分配到可复用的运算单元和控制逻辑中,并且提出一种基于FPGA的优化处理结构,将所有的信号处理功能集成在单片FPGA中。在实验与验证部分,通过FPGA处理结果与MATLAB运算结果的对比,以及实际成像试验结果表明了设计正确性和结构的工程实用性,适用于机场跑道、汽车高速公路的检测和定位。     

考虑爬坡特性的短期风电功率概率预测

短期风电功率概率预测有助于调度部门提前安排发电计划,提高风电的消纳能力。提出一种考虑爬坡特性的风电功率概率预测方法,首先通过分析不同风电爬坡定义的特点,阐述互补组合预测的思路;然后采用小波神经网络建立风电功率确定性预测模型,并在其基础上建立不同功率分区内风电爬坡率和风电功率预测误差的二维核密度估计概率预测模型;最后由二者的联合概率分布求取后者的条件概率分布,得到风电功率概率预测结果。仿真结果表明,所提模型具有很高的短期风电功率概率预测精度。     

抑制型降滤失剂AMSC的合成与应用

针对水基钻井液长期存在黏土膨胀、钻井液滤失量大等问题,以2-丙烯酰胺-2-甲基丙磺酸、丙烯酰胺、甲基丙烯酰胺氧基氯化铵及丙烯酸钾为原料合成了一种抑制型降滤失剂AMSC,用响应面法优化了反应条件,并对AMSC的黏土膨胀抑制性和降滤失性能进行了评价。结果表明:在原料单体质量比为2:1:7:1、温度为50℃、单体浓度为15%、引发剂浓度为0.5%、反应4 h时,AMSC防膨率达到84.76%。在100℃以内,AMSC的抑制性与市场同类型抑制剂相比效果相当,同时该抑制剂对钻井液和水泥浆有较好的降滤失效果。应用添加AMSC的缓速酸体系在遭受钻井液污染的碳酸盐岩区块进行了洗井作业,储层岩心的渗透率恢复率达到87%,提高了产能。      

Corrosion of Artificial Aged Magnesium Alloy AZ80 in 3.5 wt pct NaCl Solutions

The corrosion morphologies of aged magnesium alloy AZ80 were investigated by immersion corrosion tests, scanning electron microscopy （SEM）, electrochemical measurement. The T5 heat treatment was carried out in a vacuum furnace, holding for 16 h at 177℃, and then cooling in air. The results showed intergranular corrosion （IGC） occurred as an aged AZ80 sample was immersed in 3.5 wt pct NaCI aqueous solution for 1 h and the narrow path attack progressed predominantly along the bulk β phase in the grain boundaries or took place in the eutectic areas. IGC was attributed to the network distribution of β phase along the grain boundaries, the depleted aluminium in the precipitation areas and the breakdown potential.     

BUTTERFLY MARTENSITE NUCLEATION IN AN Fe-Ni-V-C ALLOY

The butterfly martensite nuclei in an Fe-Ni-V-C alloy were observed under TEM,they con-sist of enveloping dislocations with Burger's vector(1/2)[(?)]_(fcc) and arrays of dislocationswith Burger's vector(1/2)[(?)10]_(fcc) piled up within the former.The enveloping dislocationsand the arrays of dislocations provide the required shear when the planes((?)11)_(fcc)move witheach other to alter their stacking order and change into the planes(110)_(bcc) respectively.Thenecessary adjustment of the spacings is provided by the dislocations in martensite.Thecrystallographic relationship after double-shear is K-S one.     

ACOUSTIC EMISSION DURING CORROSION FATIGUE

Acoustic emisssion(AE)behavior during fatigue in either airer or 3.5% NaCl solution hasbeen studied for a structural steel(SM5OB-Zc)as quenched and normalized states.The ex-perimental results show that AE activity is strongly affected by the heat treatment and thecondition of environment.Some material constants about A E related with fatigue behaviorwere obtained and the AE sources in corrosion fatigue were discussed.     

STATISTICAL EVALUATION OF CRITICAL INCLUSION FACTOR FOR SECONDARY RECRYSTALLIZATON IN 3%Si STEEL Lecturer,Department of Materials Engineering,Southwestern Jiaotong University,Chengdu 610031,China

On the basis of statistical data of MnS in the conventional 3% Si steel sheeets after variousannealing processes,the critical inclusion factor has been evaluated to be 20 mm~(-1).The inhi-bition of MnS to grain growth has been exactly described.     

不同塑性变形路径下α黄铜加工各向异性的研究

本文用“平面应变转轴压缩试验”的方法研究和确定了不同塑性变形路径下α黄铜加工各向异性的加载函数。结果表明,本试验方法对研究大塑性形变下的加载函数很有成效。对α黄铜,混合模型加载函数在不同变形路径下均能成立。     

Enhancement of cellular immune response in HIV-1 seropositive individuals: A DNA-based trial

A DNA-based vaccine containing HIV-1 Env and Rev genes was tested for safety and host immune response in 15 HIV-infected asymptomatic patients with CD4-positive lymphocyte counts >/=500/microl of blood and receiving no antiviral therapy. Successive groups of patients received three doses of vaccine at 30, 100, or 300 microg at 10-week intervals in a dose-escalation trial. Some changes were noted in cytotoxic T-lymphocyte activity against gp160-bearing targets. Importantly, enhanced specific lymphocyte proliferative activity against HIV-1 envelope was observed in multiple patients. Three of three patients in the 300-microg dose group also developed increased MIP-1alpha levels which were detectable in their serum. Interestingly patients in the lowest dose group showed no overall changes in the immune parameters measured. The majority of patients who exhibited increases in any immune parameters were contained within the 300 microg, which was the highest dose group. These studies support further investigation of this technology for the production of antigen-specific immune responses in humans.