交插式边耦合驻波加速结构两组腔列偏谐对能量增益的影响

文章分析了交插式边耦合驻波加速结构两组腔列偏谐对其能量增益的影响,导出了理论计算公式,并用计算机粒子动力学计算验证,对一些作者已发表的结果提出了修正意见。     

A rain attenuation model for satellite link attenuation predictions incorporating the spatial inhomogeneity of rainrate

A model describing the spatial inhomogeneity of rainrate within a rain cell is derived and incorporated into a specific attenuation model to yield a more exact relationship than has been used heretofore relating rainrate and the attendant attenuation at frequencies above 10 GHz. The resulting unified attenuation model relates terrestrial and slant path attenuation, effective propagation distance and path diversity gain to parameters characterizing the earth-station or stations (e.g. location, height, latitude, elevation angle and baseline distance from another station), the frequency of operation, and the two possible raintypes admitted into the model (i.e. convective rain and residual or debris rain). The model is particularly suited for the theoretical investigation of path diversity gain since this concept owes its existence to spatial inhomogeneity of rainrate. This inhomogeneous rain attenuation model can be interfaced with an appropriate statistical rainrate prediction model, such as the Crane two-component model, to yield more precise attenuation predictions.     

The communication system

The paper discusses the salient features of system design considerations for both uplink and downlink, subsystem details and the in-orbit performance of the communication system forAryabhata.     

应用小波尺度域地震波衰减属性检测气层

本文从小波域瞬时参数和尺度能量方程出发,提出小波尺度域的能量属性和瞬时属性在一定的尺度范围内可以表征地震信号的衰减特征,并把它们定义为小波尺度域地震波衰减属性。其含义为：①实际地震信号的尺度能量在极值点尺度达到最大,从该尺度起的“带通”范围内,随尺度的减小,反射信号的尺度能量呈指数降低;②由极值点尺度起向小尺度方向的“带通”区域内所计算的尺度能量称为地震波尺度能量衰减属性,相应尺度的瞬时参数剖面也归结为地震波小渡尺度域衰减属性范畴。理论模型研究和实例分析表明,小波衰减属性较常规的瞬时振幅属性对气层的敏感性强。当检测薄的含气地层或地震记录中含噪声时。小波衰减属性的检测效果明显好于常规的瞬时振幅属性。     

Research on the chemical adsorption precursor state of CaCl_2-NH_3 for adsorption refrigeration

Environment and energy resources are two critical global problems. Adsorption re-frigeration, as an environmental friendly and energy saving technology [1], attracts moreand more attention in recent years. Adsorption refrigeration mainly includes physical adsorption and chemical adsorp-tion. As a type of chemical adsorption working pair, CaCl2-NH3 has the prominent ad-vantage of large adsorption quantity. However, CaCl2-NH3 also has several disadvan-tages, such as performance attenuat…     

Some theory and data concerning the attenuation of aggression.

The relationship of anxiety to aggression was postulated, with anxiety seen as both an inhibitor as well as a stimulus for aggression under the appropriate conditions. The data was derived from a previous study by Sears (see 21: 4422) re childrens' play with dolls. It was hypothesized that aggression would be more frequently directed towards adult rather than child dolls; the hypothesis was interpreted as being supported. In conclusion, the author states, "In fantasy as compared with real life, anxiety functions more as a stimulus than as an inhibitor." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

聚硅氧烷侧链高分子液晶的合成

合成了烯丙氧基苯甲酸对甲氧基苯酚酯（ＡＢＰＭ）和烯丙基胆甾醚（ＡＣＥ），用ＮＭＲ及ＭＳ对其结构进行了鉴定。通过上述两种化合物的末端双键与含氢硅油的Ｓｉ－Ｈ进行催化加成反应，得到了含侧链的聚硅氧烷，红外光谱证明，大部分Ｓｉ－Ｈ已参加了反应。聚合物具有液晶性，聚物和共聚物的液晶相具有不同的特点，分属于向列型，近晶型和胆甾型。     

试述挤压油膜阻尼器发展及应用

简述了挤压油膜阻尼器（SFD）的发展概况，以挤压油膜阻尼器在内圆磨削中的应用为例论述了转子要用挤压油膜阻尼器进行减振特性分析的基本方法。分析结果表明设计合理的SFD对系统具有优良的减振性能。     

1.06μm激光在对流层传输中的衰减预测

激光在大气中的传输特性是研究激光探测设备中光电系统设计的一个关键问题。本文分析了对流层中影响激光传输的各种因素,给出了在晴朗、雾、霾、雨、雪等各种天气状况下1.06μm激光在大气传输中的衰减预测算法及数值,对1.06μm的激光通信、激光雷达和激光制导等红外激光系统的设计有一定的参考价值。     

基于DSP的骨质疏松症定量超声检测技术研究

根据骨质疏松症定量超声关键参数的检测原理,研制单晶片、非聚焦的收发两用超声传感器,采用脉冲透射方法,研究以DSP为核心的定量超声关键参数检测技术,解决超声波信号在骨骼中衰减前后的数据高速采集,以及信号的同步发送与接收问题,利用DSP在线高速处理特点,对采集的波形数据进行数字滤波、FFT变换及互相关处理,实现宽带超声衰减参数BUA和超声传播速度参数SOS的在线检测。通过对人体在体检测,表明该技术能实现人体骨密度超声参数的有效检测。