HPMBP与伯胺N_(1923)对希土元素(Ⅲ)的协同萃取

本文研究了HPMBP与伯胺N_(1923)的二甲苯溶液,从盐酸介质中协同萃取希土(Ⅲ)的机理。用斜率法、恒摩尔法确定了协萃配合物的组成为:RNH_3Ln(PMBP)_4。求得关于Pr(Ⅲ)协萃反应的平衡常数及协萃配合物的生成常数分别为:logK_(12)=-1.95;logβ_(12)=3.94。实验发现,协萃系数(R)随希土元素的原子序数(Z)递变而呈现“双峰效应”。还研究了协萃配合物的IR,NMR谱。     

生态平衡的伦理学意蕴解读

20世纪以来，人类采用技术工程治理、法律制裁和经济惩罚等措施，一定意义上改善了局部的生态环境，但是未能遏制住全球环境问题的恶化态势。生态危机的根本解决，关键在于人类自身必须进行深刻的利益观念和价值观念的变革。重新审视人与自然界的关系，对自然进行伦理关怀，寻求和建立以保护地球环境和人类生存与可持续发展的生态平衡理念。     

Diameter NASREQ协议在卫星移动通信系统中的应用研究

如何对接入网络的用户进行身份认证、授予相应权限并进行计费,是卫星移动通信系统网络管理需解决的重要问题。简要介绍认证、授权、计费(AAA)的基本概念,分析Diameter协议框架、协议原理以及协议应用于网络接入的特点。阐述协议中包含的各种应用,给出Diameter NASREQ应用的一种系统模型。重点研究Diameter NASREQ协议在卫星移动通信系统中的应用,详述应用中客户机和服务器中各模块的功能和工作原理。通过分析,说明该应用的可行性及有效性。     

Algorithm for cosine transform of Toeplitz matrices

An algorithm for calculating the 2D cosine transform of a Toeplitz matrix is presented. The algorithm is based on the application of 1D cosine transforms. More specifically, four 1D cosine transforms of size N are needed to obtain the transform of a Toeplitz matrix of size N×N. This is an improvement over previously published algorithms. The algorithm is also simple and regular     

Ultrasound‐activated Knoevenagel condensation of malononitrile with carbonylic compounds catalysed by alkaline‐doped saponites

α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li⁺‐ and Cs⁺‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs⁺‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry     

赛汉塔拉凹陷滑塌浊积岩的发现与勘探意义

通过研究二连盆地赛汉塔拉凹陷中洼槽陡坡带的含鲕粒块状细砂岩从岩性特征、沉积结构及构造特征、粒度特征、测井曲线特征、地震反射特征以及对其形成机理的分析,认为赛83x含油砂岩体为在半深湖一深湖环境形成的滑塌浊积扇沉积.这种类型的滑塌浊积扇具备分选、磨圆度、物性较好等条件,尤其是此类砂岩体往往被形成于深湖一半深湖相还原环境的深灰色、灰黑色泥岩--成熟烃源岩所包围,易形成岩性圈闭,有利于油气的运移和聚集成藏,是断陷湖盆陡坡带油气勘探的重要目标.     

Respective importance of the different risk factors for osteoporosis

Among the factors which influence accumulation of bone mass, genetic factors related to race and family are preponderant: they account for approximately 80% of the variance observed in adulthood. At puberty, nutritional factors and physical activity modulate the accumulation of bone and determine whether or not optimal bone mass is achieved. In women, estrogen deprivation following menopause, and also more minor disorders of gonad function, are the main causes of decreased bone mass; their respective contributions are analyzed.