对211例类风湿关节炎患者微量元素的测定

用同位素激发Ｘ射线荧光分析对２１１例类风湿关节炎患者发中１０种常量及微量元素测定，以探索类风湿关节病与微量元素之间的关系．结果表明：全部女性患者发锌含量明显降低，除３０～３９岁及５０～５９岁年龄组Ｐ＜０．０５外，其余各组均Ｐ＜０．０１。而２０～２９岁男性组患者发锌含量也低，Ｐ＜０．０１。男女患者各组发锶含量较对照组均低，且有明显差异（除男性２０～２９岁组及５０￣５９岁组Ｐ＜０．０５，其余各组均ｐ＜０．０１）。提示类风湿关节病患者发中锌、锶含量较正常人低。因此，如临床上补充锌和锶元素，可能是有效治疗类风湿关节病的新途径．     

New 4H silicon carbide metal semiconductor field-effect transistor with a buffer layer between the gate and the channel layer

A new 4H silicon carbide metal semiconductor field-effect transistor (4H-SiC MESFET) structure with a buffer layer between the gate and the channel layer is proposed in this paper for high power microwave applications.The physics-based analytical models for calculating the performance of the proposed device are obtained by solving one-and two-dimensional Poisson’s equations.In the models,we take into account not only two regions under the gate but also a third high field region between the gate and the drain which is usually omitted.The direct-current and the alternatingcurrent performances for the proposed 4H-SiC MESFET with a buffer layer of 0.2 μm are calculated.The calculated results are in good agreement with the experimental data.The current is larger than that of the conventional structure.The cutoff frequency (fT) and the maximum oscillation frequency (f max) are 20.4 GHz and 101.6 GHz,respectively,which are higher than 7.8 GHz and 45.3 GHz of the conventional structure.Therefore,the proposed 4H-SiC MESFET structure has better power and microwave performances than the conventional structure.     

武术套路运动技法的艺术思维本质与方式研究

运用文献资料、逻辑分析和推理法,揭示武术套路运动深层和内在的真实艺术思维本质与方式.研究发现,武术套路的艺术思维基于悠久的历史倾向性——中国人善于将实用技术艺术化.思维的实践来源足人脑对传统搏斗技法信息加工创编的活动过程,这个过程是武术套路创编者在自我意识下完成的,有必然的差异性,并决定了各拳种套路技法的多样与艺术化；辩证思维是主导方式,决定了各拳种武术套路技法的全面性、对立统一和发展变化性.科学地认识武术套路运动的艺术思维本质与方式,对更好地传承与可持续发展武术套路运动有重要的现实意义.     

Vibration Characteristics of Acoustically Levitated Object with Rigid and Elastic Reflectors

Levitation stability is a crucial factor that influences acoustic levitation capability. We present two sample-including models for a single-axis acoustic levitator with either a rigid or elastic reflector. Numerical analysis shows that, with the rigid reflector, both the decay time from initial disturbance and the vibration amplitude increase with sample density, which is unfavorable for levitation stability. However, with the elastic reflector, the decay time and the vibration amplitude are greatly reduced by choosing appropriate parameters of the reflector. Experimental results agree well with theoretical predictions, indicating that levitation stability can be remarkably enhanced by replacing the rigid reflector with an elastic reflector.     

拓扑结构不同金属有机聚合物的电化学聚合行为和光谱电化学性质北大核心CSCD

金属有机聚合物的拓扑结构是影响其光电性质的重要原因之一。通过吡啶配体不同位点引入的电化学活性基团乙烯基或乙炔基,在电极表面电化学聚合制备了拓扑结构不同的钌金属有机聚合物薄膜,并利用循环伏安、紫外-可见吸收光谱、红外反射光谱、扫描电子显微镜等手段对其电化学特性、光电性质、表面形貌等性质进行了表征。结果表明,电活性配合物反应活性位点的空间位阻效应影响了电化学聚合的效率,其不同拓扑结构的聚合产物具有明显的光谱电化学性质差异。     

基于RFID无阻塞扫描控制的机器人室内定位设计

针对RFID移动机器人室内定位中的标签扫描问题,提出一种基于六边形分布模式的RFID无阻塞扫描控制方案,用于机器人的室内定位系统设计和误差检测。首先,将RFID标签根据六边形模式进行分布,减小位置估计的静态误差;然后,阅读器利用固定信道分配(FCA)方法给每个标签分配ID,使阅读范围内标签ID都不相同;最后,当阅读器读取信息时,发送查询请求给范围内的标签,标签根据自身ID决定应答时隙,避免冲突。实验结果表明,相比基于树的扫描控制方案,本文方案能够降低标签/阅读器的复杂度,同时具有较小的位置估计误差和扫描延迟,可帮助机器人实现精确定位。     

空间中半光滑算子方程的不精确牛顿法}

In this paper, we propose two inexact Newton methods forlocally Lipschitzian semismooth function and prove their local convergence results under some conditions. The present inexact Newton methods could be viewed asthe extensions of previous ones with same convergent results in finite-dimensional space.     

单分散α-Fe_2O_3纳米结构空心亚微球的制备及表征

采用一种新的溶液生长法结合多步包覆法在自制的不同粒径SiO2单分散亚微球表面包覆不同厚度的β-FeOOH涂层,得到单分散β-FeOOH/SiO2核壳结构亚微球.实验结果表明,SiO2核心颗粒尺寸对表面涂层的形态和包覆均匀性有很大影响.当SiO2核心颗粒的平均粒径为250 nm左右时,β-FeOOH表面涂层均匀,颗粒间团聚较少,一次包覆后涂层厚度约为35 nm.涂层中β-FeOOH纳米棒的尺寸随着所选SiO2核心颗粒粒径的增大而相应增大.经多次包覆能够显著提高涂层的厚度,3次包覆后β-FeOOH表面涂层厚约100 nm.β-FeOOH/SiO2核壳结构亚微球与质量分数5%的NaOH溶液反应后,于600℃焙烧2 h得到了单分散α-Fe2O3空心微球.单分散α-Fe2O3空心亚微球表层是由α-Fe2O3纳米棒搭建而成的三维网络结构,α-Fe2O3纳米棒的尺寸与核壳结构中β-FeOOH纳米棒的尺寸基本一致.     

链解缠结聚对苯二甲酸乙二酯的结晶行为研究

采用冷冻萃取聚对苯二甲酸乙二酯(PET)溶液(0.1～10g/dL7种不同浓度,3种不同性能溶剂)的方法制备了解缠结PET试样.与链相互穿透且缠结的熔体骤冷试样相比,解缠结PET试样的结晶能力明显增强,且随着制样溶液浓度的降低,链间解缠结程度增加,PET的结晶能力逐渐增强,有序结构含量明显增加,但是如果制样溶液浓度太低,溶液中链间距离太大,则又不利于萃取过程中链间的有序堆砌而结晶.采用接触浓度c*附近的溶液,既可确保链间的有效解缠结又有利于链间的有序堆砌而结晶.PET的结晶能力甚至还受制样所用溶剂性能的影响,这是因为溶剂性能影响了溶液中链间的相互作用以及链的解缠结程度.