STRUCTURE-PROPERTY RELATIONSHIP OF POLYELECTROLYTES AND ITS APPLICATION IN STABILIZING DRILLING-MUD IN PRESENCE OF SALTS

A new polyelectrolyte (SPU) has been prepared. It can depress the water-loss of drilling-mud much more effective than the commonly used acrylic polyelectrolytes even in 30% NaCl solution. SPU has phenyl group in the backbone with -SO_3~- in the side chain while the acrylic polyelectrolytes have C—C and -COO~- respectively, there exists an intrinsic relationship between the structure of polymer and its tolerance to salts, it has been found: 1) The adsorption amount of polymer on clay is related closely to the flexibility of polymer chain. 2) The salt-tolerance of -SO_3~- is superior to -COO-. 3) Both SPU-mud and HPAN-mud are plastic fluids. The dependence of yield point on salts relates to the molecular weight of polymer and hydration of ionogenic group, which is quite different for SPU-mud and HPAN-mud. 4 ) The extent of raising zeta-potential of base-mud by SPU is greater than by HPAN, but the extent of dropping zeta-potential of SPU-mud by NaCI is smaller than HPAN-mud. According to these results we suppose the salt-tolerance of SPU-mud is attributed mainly to hydration of -SO_3~- and that of HPAN-mud mainly to network structure formed in the drilling-mud.     

光学适配体传感器检测赭曲霉毒素A的应用进展

赭曲霉毒素A(OTA)是由曲霉和青霉产生的一种真菌毒素,具有强烈的肝肾毒性,并有致畸、致癌的危害。OTA广泛存在于如小麦、玉米、咖啡、葡萄等谷物及食品中,严重危害人类健康。鉴于其危害的严重性和分布的广泛性,发展方便快捷、高灵敏度的OTA检测技术具有重要意义。目前检测OTA的方法有薄层色谱法、高效液相色谱法、荧光分析法及酶联免疫吸附测定法等,这些方法通常成本高、操作复杂且费时。光学适配体传感器发展迅速,在OTA检测领域表现出巨大优势,因此综述了荧光型（包括标记型和免标记型）、比色型、化学发光型以及其他类型（表面等离子体共振、侧向层析、表面增强拉曼散射型）光学适配体传感器检测OTA的原理、性能及在2011-2023年间的相关应用,并对方法面临的问题进行了总结以及未来的的发展趋势进行了展望（引用文献81篇）。     

锌的添加方式对氢氧化镍结构和性能的影响

研究了以共沉淀、包覆、机械混合等不同方式添加或不添加锌对微乳液法合成的氢氧化镍结构和性质的影响。XRD、循环伏安和恒电流充放电测试结果表明：微乳液法的合成物仍是具有六方晶体结构的B-Ni(0H)2,但其晶粒度很小,且化学计量比不等于1／2,所以材料的活性和放电比容量下降;锌的添加增加了Ni(OH)2的晶体缺陷,改善了Ni(OH)2的结构,增加了电极中电子和质子的传递能力,从而提高了氢氧化镍电极的可逆性,强化了电极的析氧极化,其充电效率和放电比容量也随之提高;其中,以共沉淀方式添加锌,氢氧化镍电极的性能最好。     

求复折射率波导本征值的打靶法

给出了求一维缓变复折射率波导本征值的打靶法，它是对求一维实折射率波导本征值的打靶法的推广，利用它可以分析增益或损耗对ＴＥ和ＴＭ模式的影响，并给出了计算实例。     

峰蜜中杀虫脒的快速测定法

 建立了测定峰蜜中杀虫脒的薄层色谱法,不需要大型仪器和特殊试剂,不受基体干扰,整个测定过程仅需３ｈ,回收率在７０％以上,能满足蜂蜜生产和加工现场检验工作需要。     

Ultra-low temperature radio-frequency performance of partially depleted silicon-on-insulator n-type metal-oxide-semiconductor field-effect transistors with tunnel diode body contact structures

Radio-frequency(RF) characteristics under ultra-low temperature of multi-finger partially depleted silicon-oninsulator(PD SOI) n-type metal-oxide-semiconductor field-effect transistors(nMOSFETs) with tunnel diode body-contact(TDBC) structure and T-gate body-contact(TB) structure are investigated in this paper.When operating at 77 K,TDBC device suppresses floating-body effect(FBE) as well as the TB device.For TB device and TDBC device,cut-off frequency(f_T) improves as the temperature decreases to liquid-helium temperature(77 K) while that of the maximum oscillation frequency(/max) is opposite due to the decrease of the unilateral power gain.While operating under 77 K,f_T and f_(max) of TDBC device reach to 125 GHz and 77 GHz,representing 8%and 15% improvements compared with those of TB device,respectively,which is mainly due to the lower parasitic resistances and capacitances.The results indicate that TDBC SOI MOSFETs could be considered as promising candidates for analog and RF applications over a wide range of temperatures and there is immense potential for the development of RF CMOS integrated circuits for cryogenic applications.     

弹性层内部有集中力的精确解

利用Ｈａｎｋｅｌ变换及矩阵理论，获得了位于水平刚性基础上的弹性层在其内部受垂直于边界的集中力作用了的精确率，推广了已有的结论。Ｋｅｌｖｉｎ解，Ｍｉｎｄｌｉｎ解及弹性层表面受集中的用的解都是其特殊情形下的结论。     

X波段3 GW高功率微波辐射喇叭的设计

依据数值模拟结果研制了一套X波段多模微波喇叭,采用3次变张角喇叭结构,设计要求辐射功率大于3 GW,E面和H面方向图在10 dB范围内等化度良好,10 dB波束宽度为40°。近场冷测结果表明,H面10 dB波束宽度为43°,E面10 dB波束宽度为40°。远场热测结果表明,H面10 dB波束宽度为40°,E面10 dB波束宽度为41°,在初步测试中,通过对比在线测量结果和辐射场测量结果,证明研制的喇叭输出功率达1.3 GW时不会出现击穿现象。     

TEM study on hollow and prepared from porous Cu20 nanoparticles solution phase

In this paper, hollow and porous Cu2O nanoparticles were prepared by adjusting the cationic surfactant cetyltrimethylammonium （CTAB） concentration in the solution-phase reaction. Structural investigations reveal that Cu2Onanoparticles can be either well-defined hollow nanoboxes or porous nanocubes depending on the synthesis conditions. The transmission electron microscopy （TEM） observations demonstrated that the nanoparticles in general are composed of small grains coherently growing along certain preferred orientations.     

大学物理学研究性教学

20 0 3年 12月 19～ 2 1日 ,受清华大学物理系和高等教育出版社以及教育部高等学校物理学与天文学教学指导委员会支持的大学物理学研究性教学高级研讨班在清华大学举行 .在连续 3天的时间内首届国家级教学名师奖获得者卢德馨教授作了主题报告 .本刊将连续刊出报告的主要内容 ,以飨读者