HISPANIC MIGRATION AND POPULATION REDISTRIBUTION IN THE UNITED STATES*

The US Hispanic population has grown rapidly over the last two decades and remains geographically concentrated in nine states. Redistribution away from core states through internal migration has been largely offset by heavy immigration to traditional areas of Hispanic concentration. Geographical patterns of Hispanic miration show broad similarities to overall patterns of population redistribution in the United States. New York and California serve as key spatial redistributors or pivots in the Hispanic migration system.     

广西云开地区金银矿成矿地质特征及找矿远景

广西云开地区属我国粤西—桂东重要的金银多金属成矿带，区内有金银矿床（点）近８０处，受博白—岑溪深断裂带控制，产于前寒武系变质—混合杂岩内，沿ＮＥ、ＮＮＥ向呈带状展布。在论述该区金银矿成矿地质背景基础上，分析了构造控矿特征，赋矿地层及岩浆演化与金银矿化的关系，矿床成因类型及典型矿床地质特征，矿化富集规律等矿床地质特征。在总结该区金银矿成矿条件、找矿标志的基础上指出了找矿远景。     

CO_2 CONCENTRATION AND FLUX NEAR GROUND IN MARSH OF THE SANJIANG PLAIN OF NORTHEAST CHINA

I.INTRODUCTIONIntherecentyears,theresearchershavepaidattentiontotheproblemsofcarbonbalanceandcarboncycleintheearthecosystem,withtheincreaseofCQZamountintheearthatmosphere.Mireisoneoftheecotypesinwhichcarbonaccumulationrateisthefastest,anditisthestrongestsinkforac(Branirgd,1980).Butthereislicitedinformationavailableaboutopconcentrationovermire.SomemeasurementsaboutthetemPOralandspatialgradientofopconcentrationhavebeenmadewithinoraboveasugarbeetcanopy(Brown,1970),corncanopy(Alien,1971;R…     

辽宁四道沟金矿地球化学基本特征研究

四道沟金矿床的矿脉群规模较大且复杂，单个矿体较零碎，连续性不好。各矿体及矿化体的成晕相互干扰较大。通过对典型矿脉群中的矿体、蚀变带、围岩及构造带、预测点系统取样分析，据热液成矿成晕原理对矿区基本地球化学参数进行了多元统计分析的若干方法处理得出并分析了元素组合规律；确定了成矿指示元素并解释了指示元素的地质地球化学意义；总结了矿脉群中矿体原生晕中元素的轴向组合分带序列。     

STRATEGY OF MAIZE'S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE

Jilin Province is one of the main grain-producing provinces of China, which has dominant position in maize production, by the view of its advantages in policy, location, breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize, analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages, carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province, cast the agricultural predicament off and promote the agricultural development into a new stage.     

锤击桩基动测的导纳谱研究

本文从集中参数模型入手，讨论了单自由度和多自由度振动系统的导纳谱形式与特征，给出了完整桩与各种缺损桩的导纳振幅谱判断依据及计算处理方法，为导纳谱法在实际中的更好应用提供了理论说明。     

阳极焙烧炉的燃烧计算与分析

采用计算燃烧学的原理和模型以及CFD软件对以重油作为燃料的阳极焙烧炉炉内的流动、燃烧过程进行了模拟计算,讨论了炉内温度场、流场和各组分浓度场的分布规律,分析了这些因素对碳阳极焙烧质量的影响.研究表明,在设计阳极焙烧炉结构时应考虑火道中挡板对气流分布的影响.     

一种网元管理系统的设计

根据电信管理网络 (TMN)思想 ,提出一种网元管理系统的设计 ,该系统包含系统监测、性能分析、操作支持、故障管理、访问接口 5个功能。通过合理设计系统结构 ,利用网元管理器与网元Agent间的通信 ,旨在建立一个检测、控制和管理网元及为管理员提供一个友好的界面的系统 ,以提高网络管理水平。     

云南天文台太阳望远镜光学系统的光学传递函数检验

摘要：给出了太阳光谱望远镜光学系统成像质量的测定方法．以及给出了我们用星光作为目标来测定望远镜光学系统传递函数时必须考虑的条件和理论基础。实测结果给出望远镜空间分辨率的上限为0．6“，95％光能集中度在1．2“以内。     

Latitudinal distribution of CO2 and CH4 on the route of the Chinese Arctic Research Expedition 2003

1 Introduction From July 10th to September 26, 2003,“Xuelong”scientific expedition icebreaker executed the 2nd Chinese Arctic Research Expedition (CHINARE2003). The voyage star- ted from Shanghai to Dalian via Yellow Sea and Bo Hai and the cruising rout…