高分辨距离像辅助的机动目标跟踪算法

宽带相控阵雷达可以获得高分辨距离像,利用此特征获取目标的姿态角成为了一种可能,基于此提出了一种新的机动目标跟踪算法,充分利用高分辨距离像特征,实时估计目标姿态角,并将姿态角信息融合到雷达的量测方程,本文结合先进的非线性滤波算法,提出了利用姿态角的交互多模型不敏卡尔曼滤波算法。通过计算机仿真表明,利用目标姿态角的机动目标跟踪算法相比传统算法目标跟踪精度(位置精度和速度精度)得到很大提高。同时姿态角误差越小,目标跟踪性能越好。     

虚拟服装网校总体设想与研讨

指出了现今开发服装远程教育的现状,提出了虚拟服装网校的总体设想及研究方案,阐述了建立服装网校的经济效益、社会价值及理论意义。     

Hyperthermia-induced apoptosis and the inhibition of DNA laddering by zinc supplementation and withdrawal of calcium and magnesium in suspension culture of tobacco cells

In the present paper we report examination of stereotypic hallmarks of apoptosis in heat-treated tobacco cells. Hyperthermia (44 °C, 4 h) caused apoptosis in 53.6% of cells when assayed 24 h after heat treatment. The induction of apoptosis by heat treatment was confirmed by flow cytometric assay. Cytological observations revealed condensation of the cytoplasm and nucleus, as well as nuclear collapse. DNA ladders were observed in DNA extracted from heat-treated cells, whereas DNA from control cells remained undegraded. The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay revealed that 51.8% of the heat-treated cells (44 °C, 4 h) show positive reaction after a 24-h recovery. When cells were cultured in a medium supplemented with 0.4–5.0 mM ZnSO₄, internucleosomal DNA fragmentation induced by heat shock was completely negated. Strikingly, when cells were cultured in Ca²⁺ and/or Mg²⁺ free medium for 44 h followed by heat treatment, DNA laddering was not observed. The results suggest hyperthermia-induced apoptosis and a correlation between the regula tion of endonucleases and heat shock signal in apoptotic tobacco cells. Received 17 September 1998; received after revision 4 January 1999; accepted 4 January 1999     

FeC_2O_4·2HO磁铁矿样品FeC_2O_4的物相分析

１实验１．１样品制备在４６０Ｋ温度下真空干燥ＦｅＣ２Ｏ４·２ＨＯ１０ｈ，制得ＦｅＣ２Ｏ４；然后在Ａｒ气中升温至９２３Ｋ，保持１０ｈ；待温度下降到室温，在空气中放置４８ｈ，分解得到阳离子缺位的磁铁矿；再装入密闭无梯度反应器中，用４０ｍＬ／ｍｉｎＨ２于６...     

"节能减排"是国企走出经济危机的有效对策

"节能减排"是指节约能源和减少废弃物的排放.文章以晋西集团为例,针对"节能减排"的战略意义、健全法规、存在问题、有效对策及其成效进行了详细论述,必将对国企早日走出经济危机起到一定的借鉴作用.     

一种新型过热保护电路的设计

提出了一种用于集成电路内部的过热保护电路.分析了芯片温度升高的主要原因,介绍PTAT电流产生电路和迟滞电路.此电路通过引入反馈的方法解决了过热保护电路中热振荡带来的危害.     

A novel <Emphasis Type="Italic">in vitro</Emphasis> angiogenesis model based on a microfluidic device

Angiogenesis is very important for many physiological and pathological processes. However, the molecular mechanisms of angiogenesis are unclear. To elucidate the molecular mechanisms of angiogenesis and to develop treatments for "angiogenesis-dependent" diseases, it is essential to establish a suitable in vitro angiogenesis model. In this study, we created a novel in vitro angiogenesis model based on a microfluidic device. Our model provides an in vivo-like microenvironment for endothelial cells (ECs) cultures and monitors the response of ECs to changes in their microenvironment in real time. To evaluate the potential of this microfluidic device for researching angiogenesis, the effects of pro-angiogenic factors on ECs proliferation, migration and tube-like structure formation were investigated. Our results showed the proliferation rate of ECs in 3D matrix was significantly promoted by the pro-angiogenic factors (with an increase of 59.12%). With the stimulation of pro-angiogenic factors gradients, ECs directionally migrated into the Matrigel from low concentrations to high concentrations and consequently formed multi-cell chords and tube-like structures. These results suggest that the device can provide a suitable platform for elucidating the mechanisms of angiogenesis and for screening pro-angiogenic or anti-angiogenic drugs for "angiogenesis-dependent" diseases.     

聊城市中学生闲暇活动的调查研究

以聊城市 6所中学的 12 0 6名学生为对象 ,调查了他们的余暇活动 .结果表明 ,调查对象在闲暇时间以参加体育活动为主 .提出了加强体育课和课外体育活动改革的建议 .     

夹胶建筑玻璃板后破坏强度分析

根据玻璃及胶层材料的物理特性,将塑性绞线理论引入到三阶段模型中,提出了一种计算夹胶玻璃后破坏强度的方法,并运用该方法研究了不同设计参数对夹胶玻璃后破坏强度大小的影响.结果表明:夹胶玻璃板后破坏强度随着玻璃的胶材厚度增加而增加,随着玻璃板长度的增加而减小;框支式夹胶玻璃板比点支式夹胶玻璃板具有更高的后破坏强度.     

三峡绞滩递缆船船型研究

阐述三峡绞滩递缆船的船型选择、型线设计和船模试验研究，给出了较高傅氏数 （Ｆｒ＞ ０．４１） 下尖首涡尾船型线设计的原理和方法，试验分析与实船航行表明本船具有良好的阻力与推进性能