高频红外碳硫仪测定区域地球化学样品中的硫

高频红外碳硫仪由于便捷高效,常应用于区域地球化学样品中硫的分析检测。本文采用高频红外碳硫仪测定低中高含量的硫,以纯铁屑、锡粒和钨粒为助熔剂,对样品称样量、助熔剂的种类、加入顺序和用量等因素进行探讨,确定了最佳分析岩石、土壤和水系沉积物中硫含量的条件,并且用国家一级标准物质验证了该方法的准确度和精密度。结果表明,当样品和助熔剂的加入顺序和质量分别为：0.05 g样品、0.5 g铁助熔剂、1.7 g钨粒时,土壤和水系沉积物中硫的测定结果最稳定,岩石标准样品额外的加入0.5 g锡改善样品流动性,提高分析准确度。该方法的相对标准偏差（RSD）小于6%（n= 12）,相对误差绝对值小于8%。此方法具有操作简单、高效、稳定性好的特点,适合于大批量区域地球化学样品中硫的检测。     

铝单晶体滑移的电子显微镜颧察(二)

金屠的纯度和试样表面的处理等因素能影响品体滑移的形熊.     

氯甲基聚苯乙烯的鋰金属化反应及其在接枝聚合上的应用

使用不同条件,如不同溶剂、温度、反应时间、丁基锂用量及加料次序,将氯甲基化聚苯乙烯与丁基锂反应;然后选择没有交联的产物,使其与甲基丙烯酸甲酯进行接枝聚合。另外,又用氯甲基化聚苯乙烯在金属锂的存在下与甲基丙烯酸甲酯反应。 在乙醚溶液制得的聚苯乙烯次甲基锂与甲基丙烯酸甲酯反应不能分离出聚甲基丙烯酸甲酯及它的接枝共聚物。在甲苯溶液所制得的聚苯乙烯次甲基锂(表1甲_(45)及甲_(46))与甲基丙烯酸甲酯反应,产物通过分离提钝后,由元素分析,水解与交换量测定,浊度滴定,及红外光谱证明系接枝共聚物。甲基丙烯酸甲酯约占该接枝体重量的50％左右。 氯甲基化聚苯乙烯在金属锂存在下与甲基丙烯酸甲酯反应,产物通过分离提钝后,用浊度测定、水解后滴定交换量与热机械曲线也证明是接枝共聚物,但甲基丙烯酸甲酯只占该接枝体重量的3—3.5％左右。     

THE APPROXIMATE B-S WAVE FUNCTIOPiS FOR (XU) ATOM AND THE DECAY RATE FOR E°→(∑+μ-)+νμ

In this paper, the Bethe-Salpeter equation for a Coulombic bound system consisting of a fermion (mass m_l and spin 1/2) and an anti-fermion (mass m₂ and spin 1/2) is solved. The approximate B-S wave functions for (∑U) atom are given. Utilizing the perturbative expansion of the quantum field theory of composite particles, the decay rate and branching ratio for E°→(∑⁺μ^-)+ν_μ are calculated with accuracy up to order O(α).     

周期场聚焦电子束

引言 自从发现“强聚焦效应”可以应用在粒子加速器内以后,人们知道利用周期磁场能把离子束控制得更细,于是可以减少磁铁的需要量。因此近年来为了改建或新设计各种类型粒子加速器,对周期场聚焦离子束或电子束方面曾进行了很多研究工作。另一方面人们也开始研究用周期电场和磁场聚焦各种电子管内的电子束,例如行波管内电子束的聚焦等。聚焦电子束的主要特点在於必要考虑空间电荷。     

核裂变材料核素成份的γ特征谱分析

研究对裂变核材料及有关核装置进行了无损探测与识别的物理可行性。其要点是由测量得到的γ特征能谱出发，通过对γ射线输运过程的物理分析并引入相应的参量描述，以推 论有关核材料的特征信息。数值计算模拟实验的结果表明，据此方法可以在有效的精度范围内由所测量到的裂变核材料的出射γ特征谱推算出其同位素成份等重要信息。研究结果还表明，考虑源区核材料的自吸收修正（称几何自屏蔽修正）是提高计算分析精度的关键因素之一。     

ADDENDUM

Abstract

Experiments have been performed to provide basic heat transfer data for thermal convection in a horizontal concentric annulus partially filled with water. A real-time holographic interferometry was employed to map the temperature distribution and a laser shadowgraph system was used to measure local heat transfer coefficients along the heated inner cylinder. Experimental results demonstrate that a minimum average Nusselt number for the water-wetted portion of the inner cylinder occurs at the air-water interface situated flush with the top of the inner cylinder. Corresponding numerical simulations were conducted for the cases of either fully or half-filled with water and the predictions agree well with the experimental results.     

HOW TO DETERMINE THE NUCLEAR MATRIX ELEMENT IN 2β-Decay?-A DISCUSSION OF PCAC, 2β-DECAY AND DOUBLE-CHARGE EXCHANGE REACTION OF PIONS ON NUCLEI

It is shown that by applying PCAC, the 2β-decay process can be directly related to double-charge-exchange reaction. Therefore, by studying double-charge-exchange reactions one is able to determine the nuclear matrix element of the relevant 2β-decay experimentally. A preliminary analysis has indicated that if the experimental data of forward-angle cross section on Ca⁴⁰ with pion beam at 164 Mev^[9] are used and extrapolated to Ca⁴⁸, then the squared nuclear matrix element thus determined is smaller than that calculated for Ca⁴⁰→Ti⁴⁸+2e^-+2v^[11] by 10⁵～10⁶.     

Optimizing Design of Breakdown Voltage to Eliminate Back Gate Bias Effect in Silicon-on-Insulator Diode Using Low Doping Buried Layer

This work presents the optimal design of a silicon-on-insulator （SOI） diode structure to eliminate the back gate bias effect and to improve breakdown voltage. The SOI structure is characterized by inserting a silicon low doping buried layer （LDBL） between the silicon layer and the buried oxide layer. The LDBL thickness is a key parameter that affects the strong inversion condition of the back MOS capacitor of the new SOI diode. The optimal LDBL thickness in the SOI diode is 2.65μm.The LDBL shielding layer improved the breakdown voltage.     

Doob's inequality,Burkholder-Gundy inequality and martingale transforms on martingale Morrey spaces

We introduce the martingale Morrey spaces built on Banach function spaces. We establish the Doob's inequality, the Burkholder-Gundy inequality and the boundedness of martingale transforms for our martingale Morrey spaces. We also introduce the martingale block spaces. By the Doob's inequality on martingale block spaces, we obtain the Davis' decompositions for martingale Morrey spaces.