自适应Kalman滤波器在水下被动目标跟踪中的应用

在水下被动目标跟踪系统中，直角坐标系下的扩展卡尔曼滤波器容易发散而导致滤波精度很差，提出了一种修正极坐标系下的自适应卡尔曼滤波算法，对虚拟噪声进行估计，动态补偿模型线性化误差，消减系统的观测误差．对其滤波理论及算法进行了研究和仿真。仿真结果表明，该算法提高了滤波的稳定性、快速性和精确性，优于一般的扩展卡尔曼滤波算法。     

基于特征映射的互联网频繁模式识别算法

提出了一种基于特征映射的互联网频繁模式识别算法,采用特征映射与聚类相结合的方法,解决了SPADE算法不能反映类信息的问题与大量数据聚类时的效率低下,同时,提出了比较合理的频繁模式定量评价体系,从而完成了识别系统的整体设计,对于处理互联网海量用户数据有着相当重要的作用,同时,可以根据此算法提供个性化推荐等服务来提升用户体验.     

无功、负序及谐波电流检测中的数字滤波器研究

数字滤波器是基于瞬时无功理论的无功、负序及谐波电流检测中一个重要部分,其精度和速度直接影响检测的结果。文中在各种电压和电流情况下对电流检测中所需要的数字滤波器进行分析,得出数字滤波器分类设计的想法,并优化设计出三种适用于不同电压和电流情况的数字滤波器。仿真和实验结果证明所设计的数字滤波器与目前电流检测中使用的数字滤波器相比,在保证精度的同时能有效提高速度,且本身算法的复杂性并未显著增加。     

不烧Al-Si复合低碳Al2O3-β-SiAlON材料的抗氧化性能

采用大试样高温热重分析仪研究了不烧Al-Si复合低碳Al2O3-β-SiAlON材料(MAC-F)的抗氧化性,并与Al-Si复合不烧铝碳滑板材料(MAC-S)进行了比较。结果表明(1)两种材料在250~1100℃氧化时的质量变化规律相似,在500℃以前均处于质量损失状态;从500℃开始试样处于质量增加状态,500~1100℃之间两种材料质量变化率的增加量差别不大;1100℃以上材料MAC-S的质量变化率的增加量明显提高,而材料MAC-F质量变化率的增加量稍有降低。(2)1500℃氧化后,材料MAC-F质量增加率明显低于材料MAC-S的,氧化层很薄,厚度仅0.5mm。材料MAC-F的氧化层中有较多的短柱状莫来石晶体,均匀地分布在刚玉骨架结构的空隙中,形成致密的结构,对氧气进入材料的内部起到了阻碍作用。其氧化层表面覆盖着一层由莫来石和少量玻璃相组成的光滑薄膜,更有效阻碍了氧气向内部的渗透。因此,材料MAC-F与材料MAC-S相比,抗氧化性能更为优异。     

Podocyte-Related Mechanisms Underlying Survival Benefit of Long-Term Angiotensin Receptor Blocker

We previously found that short-term treatment (week 8 to 12 after injury) with high-dose angiotensin receptor blocker (ARB) induced the regression of existing glomerulosclerosis in 5/6 nephrectomy rats. We therefore assessed the effects of long-term intervention with ARB vs. nonspecific antihypertensives in this study. Adult rats underwent 5/6 nephrectomy and renal biopsy 8 weeks later. The rats were then divided into three groups with equivalent renal function and glomerular sclerosis and treated with high-dose losartan (ARB), nonspecific antihypertensive triple-therapy (TRX), or left untreated (Control) until week 30. We found that blood pressure, serum creatinine levels, and glomerulosclerosis were lower at sacrifice in ARB and TRX vs. Control. Only ARB reduced proteinuria and maintained the density of WT-1-positive podocytes. Glomerular tufts showed more double-positive cells for CD44, a marker of activated parietal epithelial cells, and synaptopodin after ARB vs. TRX or Control. ARB treatment reduced aldosterone levels. ARB-treated rats had significantly improved survival when compared with TRX or Control. We conclude that both long-term ARB and triple-therapy ameliorate progression, but do not sustain the regression of glomerulosclerosis. ARB resulted in the superior preservation of podocyte integrity and decreased proteinuria and aldosterone, linked to increased survival in the uremic environment.     

Generation and Identification of the Number of Copies of Exogenous Genes and the T-DNA Insertion Site in SCN-Resistance Transformation Event ZHs1-2

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) causes an estimated economic loss of about USD 3 billion each year in soybean (Glycine max L.) production worldwide. Overexpression of resistance genes against SCN provides a powerful approach to develop SCN resistance cultivars in soybean. The clarification of molecular characterization in transformation events is a prerequisite for ecological risk assessment, food safety, and commercial release of genetically modified crops. Here, we generated transgenic events harboring the BCN (beet cyst nematode) resistance Hs1^pro−1 gene using the Agrobacterium-mediated method in soybean, evaluated their resistance to SCN infection, and clarified the molecular characterization of one of the transformation events. Five independent and stable inheritable transformation events were generated by an Agrobacterium-mediated transformation method. SCN resistance tests showed the average number of developed females per plant and female index (FI) in T4 ZHs1-1, ZHs1-2, ZHs1-3, ZHs1-4, and ZHs1-5 transformation events were significantly lower than that in the nontransgenic control. Among these, the ZHs1-2 transformation event had the lowest number of developed females per plant and FI. Southern hybridization showed the exogenous target Hs1^pro−1 gene was inserted in one copy and the Bar gene was inserted two copies in the ZHs1-2 transformation event. The exogenous T-DNA fragment was integrated in the reverse position of Chr02: 5351566–5231578 (mainly the Bar gene expression cassette) and in the forward position of Chr03: 17083358–17083400 (intact T-DNA, including Hs1^pro−1 and Bar gene expression cassette) using a whole genome sequencing method (WGS). The results of WGS method and Southern hybridization were consistent. All the functional elements of exogenous T-DNA fragments were verified by PCR using specific primer pairs in the T5 and T6 ZHs1-2 transformation events. These results demonstrated that the overexpression of Hs1^pro−1 gene enhanced SCN resistance, and provide an important reference for the biosafety assessment and the labeling detection in transformation event ZHs1-2.     

氧弹式量热计测定燃烧焓实验操作条件的改进

GR-3500型氧弹式量热计做燃烧焓的测定实验时间长,操作难度大,实验一次性成功率低.通过放宽对实验过程中夹层与量热容器的水温差值要求,实验结果表明夹层水温高于量热容器水温的0.5～3.0℃都是可行的,这样便于学生调节水温,缩短实验时间,取得良好的实验效果.     

SO_4~（2－）／ZrO_2超强酸催化剂的结构表征

用ＢＥＴ法分析了制备条件对ＳＯ＿４￣（２－）／ＺｒＯ＿２超强酸催化剂的比表面和孔结构的影响，用ＳＥＭ观察了催化剂的表面形貌。结果表明，引人ＳＯ＿４￣（２－）后催化剂的比表面和比表面的热稳定性都增大了，在Ｈ＿２ＳＯ＿４浓度为１．０ｍｏｌ／１和焙烧温度约７７３Ｋ时催化剂的比表面较大。制备Ｚｒ（ＯＨ）＿４时用浓氨水得到的催化剂的比表面、平均孔径和孔体积都较大。ＳＯ＿４￣（２－）／ＺｒＯ＿２催化剂的孔为平均孔径３－５ｎｍ的中孔。ＳＥＭ结果表明，ＳＯ＿４￣（２－）／ＺｒＯ＿２催化剂的表面为很不平整的蜂窝状。