曲面面积求解方法

建立4种曲面面积的求解方法,为实际应用提供了选择性.第1种方法是根据平面面积等于其正投影面积除以该平面与投影面夹角的余弦,将此原理转移到曲面面积的求解;第2种方法是用传统数学方法求曲面面积;第3种方法是应用展开方法求曲面面积;第4种方法是用计算机表示的方法求曲面面积,这种方法将形、数、计算机相结合,适合于各种曲面面积的求解.     

生态信息表达的尺度问题

尺度是生态学中的核心问题,时间和空间尺度包含于任何生态过程中,揭示和把握复杂的生态学规律依赖于研究所采纳的尺度。于分文揭示了生态信息科学中尺度的内涵,综述了生态信息表达的四种最优尺度选择方法,即基于局部方差的方法、基于变异函数的方法、基于离散度的方法和基于信息熵的方法,分别阐述了四种方法的基本思路、优点及不足。目前基于信息熵的方法是考虑最全面的最优尺度选择方法,但仍需改进。论述了生态信息表达中2种上推转换方法、4种下推转换方法和1种综合尺度上推和尺度下推两种范式的方法的特点,认为每一种尺度转换的方法都存在一定的优势和不足,需不断完善目前已有的转换方法或引入和应用新的转换方法,充实和完善尺度转换方法体系。     

两种维生素C注射液含量测定方法的比较

用折光法、碘量法两种方法测定了维生素C注射液的含量,并对两种方法进行了比较。结果显示两种方法所测的维生素C的含量、标示量百分比相近,误差均小于5%,碘量法的结果略低于折光法。折光法是一种可以快速、准确测定维生素C含量的方法。     

时间序列非平稳检测方法的对比分析

对比分析了检测时间序列是否平稳的两种方法: 一种是基于简单的统计方法检测时间序列非平稳性的run-test (简称RT)方法(考虑了3种典型方法: 均值RT、方差RT和标准差RT), 另一种是利用动力非平稳检测的图示方法(space time-index, STI)。 通过分析人工生成的已知平稳性的时间序列和实际湍流时间序列, 对比了两种方法在时间序列非平稳检测上各自的优劣: RT方法简单、高效, 但精确度低; STI方法精确度高, 但复杂、低效。同时, 分析了3种不同的RT方法对不同类型时间序列的平稳性检测能力, 表明方差RT方法最适用于湍流时间序列非平稳性检测。     

质的研究与量的研究孰轻孰重

质的研究与量的研究是心理学研究的两种范式,并且就应使用哪一种方法更为合适而一直是处在激烈的争论之中。本文从两种方法的对立、两种方法的各自的优缺点阐明,最终是要坚持走两种方法整合的道路。     

活性污泥活性的检测方法简述

简述了检测活性污泥活性的三种方法,ATP法、耗氧量法和脱氢酶活性法。对每一种方法介绍了其原理、测定方法和影响测定的因素。三种方法各有优缺点,在工作中可以根据检测条件和检测要求选择不同的检测方法。     

计算机维修的思路与故障诊断方法

介绍了计算机维修的思路及故障诊断中采用的观察、替换、隔离、插拔、测量等5种方法，并对5种方法进行了相应的举例说明。实践表明，5种方法在计算机维修及故障排除上起到了积极作用。     

二进制非线性联合变换器的阈值方法

介绍了二进制联合变换器中用于对联合功率谱进行二进制化取阈值的三种方法：固定法、中值方法、子集中值法,并分别对这三种取阈方法的ＪＴＣ以及传统ＪＴＣ的性能进行了比较．结果表明由于第二、第三种阈值方法中阈值受目标图象背景噪音的影响,在背景噪音较大的情况下,使用阈值随噪音而定的后两种方法比第一种固定阈值的方法具有更好的相关性．     

二次曲线方程化简与作图的简易方法

针对二次曲线方程化简与作图的方法,有的化简简单,但难于作图;有的化简繁琐,但易于作图.寻找一种既易于化简又易于作图的简便方法是一个值得研究的问题.文章在深入探讨二次曲线方程化简并作图的四种方法:坐标变换法、主直径主方向法、不变量与半不变量法、因式分解法的基础上,通过分析,归纳这四种方法之间的联系,给出一种相对于前四种方法对化简二次曲线方程并作图更为简便的方法,得到两个主要结论.     

用水量预测的三种方法

该文以大连长兴岛临港工业区为例,介绍的三种城市用水量预测的三种方法,三种方法互相验算、互相修正、互相补充,确保预测值准确可靠.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that