THE SAMPLE SURVEY SCHEME AND ITS EFFECTEVALUATION FOR THE STUDY ON WOMEN'SSTATUS IN CONTEMPORARY CHINA

1.SamplingScheme1.1SUInmaryofSamplingMethodsThesamplepOPulationofthesurveyonwomen'sstatusisthetotalpopulationinrelatedprovinces(municipalitiesorautonomousregions),excludingsmallpartsofmountainousareasinoutlyingdistrictsandthoseareashavingasparsepopulation.Aschemeofstratifiedfourstagesamplingwithunequalprobabilitiesisadopted.Andatwo--phasesamplingtechniqueisalsoused.Weregardurbanareasandruralareasasrelatedtotwosubpopulationsforwhcihweshallestimatethetaxgetvaxiables.Soeveryprovince(municipal…     

电池电动势和内阻的非等精度测量

以非等精度法用电势差计测量电池的电动势和内阻，通过这一尝试，说明非等精度测量是一种误差小、准确度高、能使学生实验操作能力得到充分训练的好方法。     

Nonlinear Combination Forecasting Model and Its Application

Ｔｈｅｂａｓｉｃｍｅａｎｉｎｇｏｆｃｏｍｂｉｎａｔｉｏｎｆｏｒｅｃａｓｔｉｓｃｏｍｂｉｎｉｎｇｍａｎｙｆｏｒｅｃａｓｔｉｎｇｍｏｄｅｌｓｔｏｇｅｔｈｅｒｔｏｆｏｒｅｃａｓｔ，ａｎｄｉｔｉｓｕｓｕａｌｙｌｉｎｅａｒｃｏｍｂｉｎａｔｉｏｎａｇｏ．Ｉｎｆａ...     

小型酒瓶装卸箱机机构的轨迹优化

选用简单的四杆机构作为小型装卸箱机的装卸机构， 采用目标函数修正的方法， 对该机构进行了轨迹优化和精度分析， 得出了比较理想的优化结果， 符合装卸机构的要求     

AFS—2201原子荧光光度计氢焰波动对精密度影响研究

ＡＦＳ－２２０１型双道原子荧光光度计原子化器氢焰易受外界环境空气流动的影响产生波动，造成仪器样品测试的精密度不稳定而影响仪器的正常使用。     

Mechanisms and assessment of water eutrophication

Water eutrophication has become a worldwide environmental problem in recent years, and understanding the mechanisms of water eutrophication will help for prevention and remediation of water eutrophication. In this paper, recent advances in current status and major mechanisms of water eutrophication, assessment and evaluation criteria, and the influencing factors were reviewed. Water eutrophication in lakes, reservoirs, estuaries and rivers is widespread all over the world and the severity is increasing, especially in the developing countries like China. The assessment of water eutrophication has been advanced from simple individual parameters like total phosphorus, total nitrogen, etc., to comprehensive indexes like total nutrient status index. The major influencing factors on water eutrophication include nutrient enrichment, hydrodynamics, environmental factors such as temperature, salinity, carbon dioxide, element balance, etc., and microbial and biodiversity. The occurrence of water eutrophication is actually a complex function of all the possible influencing factors. The mechanisms of algal blooming are not fully understood and need to be further investigated.     

灰色系统建模方法的研究

提出了估计ＧＭ（１，１）模型参数的新方法。并给出了ＧＭ（１，１）模型的显著性检验的方法。实例分析表明，新方法提高了预测模型的精度     

工程陶瓷精密研磨技术

研究外圆柱表面和平面的新型研磨方法，并分析加工效率和表面粗糙度的主要影响因素，当初削参数最佳时，表面粗糙度值大约为Ｒａ０．０１６－０．０２１μｍ。     

UJ34A直流电位差计中精密稳压源的维修代换

本文介绍了用常见的三端可调稳压元件LM317代换精密稳压源MC1403。从实验结果看，该方法是可行的。     

强反射层屏蔽下薄煤层三维地震勘探应用研究

在淮南矿区三维地震勘探中，主要煤层（13－1煤层）地震反射波很强，对下部煤层（薄且不稳定）构成强屏蔽，几乎得不到反射波。通过分析研究，采取新的技术方法， 解决了困惑多年薄煤层地震探测的难题，取得了很好的效果，并得到很好的验证。