超导体核辐射探测器的探测原理

一、引言对于某些核辐射探测器,降低它们的工作温度便可得到较好的探测器性能,例如硅和锗探测器,当工作温度为77K时,能量分辨可提高很多。一些金属和它们的氧化物在极低温度下成为超导体,利用这种超导现象有可能得到性能极好的探测器,也有可能比现在已实用的半导体(?)测器的能量分辨要提高一个量级。高分辨测量有可能在许多领域内得到应用。关于在极低温度下((?)IK)对超导体核辐射探测器已有一些评论,这里仅介绍超导体核辐射探测器的探测原理。     

加载单极子天线的时域辐射特性

基本的单极子天线由于其本身的特社会在天线内部对馈入的信号进行多次反射，严重,制约着它的辐射性能。采用时域有限差分法对比计算了加载与非加载单极子天线的时域辐射特性。计算结果表明，加载是改善单极子天线时域辐射性能的最佳选择，但需要以牺牲辐射效率为代价。     

Properties of ligno‐cellulose fiber Hildegardia

Studies on some properties such as the density, the degradation temperatures, the morphology and the spectral features of the ligno‐cellulose fiber Hildegardia were carried out in both untreated and alkali treated form. The fibers are found to have good morphology and moderate initial and final degradation temperatures. On alkali treatment, the lignin was found to be eliminated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2216–2221, 2002     

计算抛物面天线支杆对方向图影响的简化方法

本文基于物理光学球面波展开法，提出一种计算抛物面天线支杆对其方向图影响的简化方法，文中导出了计入支杆散射的天线辐射方向图的解析表达式，并给出了支杆对其方向图旁瓣电平影响的计算实例，数值结果表明，本文所提出的新方法不仅计算结果精度高，而且所需计算机容量小，运算速度快，可应用于天线工程设计。     

硅片和硅器件工艺中的背面损伤吸除技术

本文介绍了硅片背面的三种主要损伤吸除技术：机械损伤、激光辐照和离子注入技术。对这三种吸除技术的机理、工艺条件、应用情况和近来进展，作了详细的评述。     

AN EXTENDED MODELING OF TIDE-WAVE MOTION

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＴｏｓｔｕｄｙｔｈｅｍｏｔｉｏｎｏｆｔｈｅｔｉｄｅ ｗａｖｅｓ,ｔｈｅｓｈａｌｌｏｗｗａｔｅｒｅｑｕａｔｉｏｎｓ ,ｉ.ｅ .ｔｈｅｖｅｒｔｉｃａｌｉｎｔｅｒｇｒａ ｔｉｏｎｏｆｔｈｅｃｏｎｔｉｎｕｉｔｙｅｑｕａｔｉｏｎａｎｄｍｏｍｅｎｔｕｍｅｑｕａ ｔｉｏｎ ,ｉｓｃｏｎｓｉｄｅｒｅｄａｓｔｈｅｇｏｖｅｒｎｉｎｇｅｑｕａｔｉｏｎｓ.Ｂｙａｂｏｖｅｅｑｕａｔｉｏｎｓｔｗｏｅｑｕａｔｉｏｎｓｒｅｌａｔｅｄｔｏｔｈｅｈｏｒｉｚｏｎ ｔａｌｆｌｕｘｏｆｔｈｅｔｉｄｅ ｃｕｒｒｅｎｔｓａ…     

基于谱相关的正弦调频和脉间伪码调相复合体制侦查信号识别

推导了正弦调频和脉间伪码调相复合体制信号的谱相关函数(SCF)，基于谱相关特征给出了对该复合体制侦察信号的自动识别算法。分析了宽带调频和窄带调频两种情况下谱相关函数的特征,对载频、调制频率、调制系数以及伪码的子脉冲宽度、子脉冲重复周期、编码个数进行了盲估计,分析了信噪比对参数估计精度的影响。仿真分析表明，在SNR为-5dB时,对载频和调制频率估计的归ー化均方根误差（NRMSE)小于2.5%,在SNR>0dB时,对伪码参数估计的NRMSE小于7.5%.     

Surface designing of polypropylene by critical monitoring of the grafting conditions

The grafting of acrylic acid onto electron beam‐irradiated polypropylene was carried out using preirradiation method. The stability of peroxy radicals was investigated by electron spin resonance. It was found that the decay of peroxy radicals is much faster at 70°C than at 40°C and ambient temperature. The grafting has been observed to be strongly dependent on the monomer dilution in the reaction medium. The grafting was ascertained by attenuated total reflectance (ATR). The distribution of grafts across the samples was monitored by infrared microscopy. It was found that the graft management is considerably influenced by composition of the grafting medium. The grafting involving pure monomer leads to the surface enrichment with the polyacrylic acid chains. The samples grafted in pure monomer led to much lower contact angles as compared to the diluted monomer solution. The swelling of the grafted samples also showed a trend that was governed by the graft management. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 546–553, 2006     

Solar radiation climate in Malawi

Recently, Diabaté et al. [Diabaté, L., Blanc, Ph., Wald, L., 2004. Solar climate in Africa. Solar Energy 76, 733–744] created a map of solar radiation climate in Africa using clearness index for 62 sites. They established a solar climate class II located in Malawi and Madagascar. However, their analysis did not include any irradiation data from a site in Malawi. In this study, the solar radiation climate of Malawi has been studied using long-term global radiation data from a local site. The mean monthly (K_tm) and seasonal (K_ts) daily clearness indices for the site were computed. It is observed that K_tm has two maxima in a year (K_tm = 0.58 in May and K_tm = 0.64 in September), in close conformity with findings of Diabaté et al. (2004). Other results are presented and discussed.     

Preparation of an anion‐exchange adsorbent by the radiation‐induced grafting of vinylbenzyltrimethylammonium chloride onto cotton cellulose and its application for protein adsorption

Poly(vinylbenzyltrimethylammonium chloride)‐graft‐cotton cellulose, an anion‐exchange matrix, was synthesized by a mutual radiation‐induced grafting technique with a ⁶⁰Co γ‐radiation source. The grafted matrix was characterized by grafting yield estimation, elemental analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The grafting yield decreased with the increase in the dose rate. However, the grafting yield and nitrogen content of grafted samples increased almost linearly with an increase in the total irradiation dose. To evaluate the performance of the grafted anion‐exchange matrix, the protein adsorption and elution behavior were investigated in a continuous column process under various experimental conditions, with bovine serum albumin used as a model protein. The binding and elution behavior of the anion‐exchange matrix depended on different experimental parameters, such as the grafting yield, ionic strength, pH of the medium, and amount of protein loaded. From a breakthrough curve, the equilibrium binding capacity and elution percentage of the grafted anion‐exchange matrix were estimated to be 40 mg/g and 94%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5512–5521, 2006