两分

The symmetric difference between two sets is another set where each element is a member of one set but not the other.

两个集合的对称差分是指某集合中的元素，只是这两个集合其中一个的成员。

Estimations of effective parameter in heterogeneous media: Firstly, we clarify the concept of the effective parameter and address the problems of parameter estimation by traditional pumping test. Secondly, we present two estimation approaches (i.e., distance-drawdown and spatial moment analyses) for Seff and Teff, which are consistent with Theis' homogeneous aquifer assumption.

本文探讨的内容主要分两大部分：(1)空间异质性孔隙介质有效参数的推估方法：主要探讨内容包括重新思考有效参数的定义及其观念，探讨传统抽水试验推估异质性含水层有效参数的一些问题，其次提出估计异质性地下水系统有效参数两个合理方法：泄降-距离曲线分析和泄降分布的空间矩分析，并以数值实例解释其合理性，文中藉由分析数值模拟的结果探讨说明该问题。

In this text we used the method of volume integral equation base on tensor Green's function to study the forward of 4D transient electromagnetic response.

本文采用基于张量格林函数的体积分方程法进行四维模型瞬变电磁响应的正演研究，文章中首先说明了四维瞬变电磁法模拟的可行性及程序实现，然后分别设计了两个三维异常体模型，采用两种观测方式(激发与接收平行、激发与接收垂直)进行正演模拟计算，并对所得的二次总场的数据进行了分析。

The paper focuses on the tetraploidy black locust on Loess plaeatu of West Shanxi province, applys steady state promoter method and image processing technology to study the days transpiration water consumption in different weather ,different seasons and different site conditions,has primary analysis on the impact of environment on the transpiration and carries on the calculation to the tetraploidy locust tree by the single leaf water consumption to the single tree water consumption in CaiJiachuan watershed; Uses fast weighing method to measure and analyze the transpiration water consumption of five different herbs under the tetraploidy black locust forest (Capillary Wormwood,Vanilla,Agropyron Sristatum , Common Sowthistle and Medicago Sativa) in short time, in the same and different growcrop,and calculates the average transpiration water consumption per square metres ;the soil colome weighing method was used for determining diumal variation quantity of soil moisture evaporation, analyzing the dynamic variation and caculating the total quantity of soil evaporation water consumption from May to August ; then 5 kind of suppositions about the types of surface vegetation coverage are proposed in experimented site and the total evapotranspiration water consumption are calculated under 5 suppoitions ,aim at providing preliminary theoretic basis for ascertaining the transpiration water consumption of tetraploidy black locust forest,controling standing forest density and optimizing the forest grass deploy on loess plaeatu of west Shanxi province .

本文以两种不同立地条件下的四倍体刺槐林为研究对象，采用了气孔计法对蔡家川流域生长季内不同天气状况下(典型晴天、阴天和半阴天)四倍体刺槐日蒸腾耗水规律、不同季节(生长季初期、中期和末期)的蒸腾耗水规律、两种不同立地条件下四倍体刺槐蒸腾耗水比较以及影响四倍体刺槐蒸腾耗水的环境因子进行初步研究分析，并对四倍体刺槐由单叶耗水量向单株耗水量进行推算；采用经典快速连续称重法对四倍体刺槐林地生长的主要5种草本植物(白蒿、香青兰、冰草、苦苣和苜蓿)短时段内蒸腾耗水规律、不同生长季内蒸腾耗水规律、同一生长季不同种类草本植物蒸腾耗水量进行了比较分析，并且采用面积与重量比的方法推算出了单位面积四倍体刺槐林地几种主要草本植物平均蒸腾耗水量：采用土柱称重法测定了5月份～8月份土壤水分蒸发昼夜变化量、对试验期内土壤蒸发量动态变化作了分析、推算出了试验地5月份～8月份土壤蒸发耗水总量；对试验地地表植被覆盖类型提出了5种假设，推算出5种假设的情景下蒸散耗水总量，旨在为晋西黄土区四倍体刺槐林蒸腾耗水量的确定、林分密度调控以及林草优化配置等提供初步的理论依据。

The guarantee later every day will have two bowls of foods, in two months ministers of the interior10A catty meat, strives for achieves the national defense standard 1/3 59KG Then treats the mirror ululate I----am-----Fat-----Sub-!!!!

保证以后每天吃两碗饭，在两个月内长10斤肉，争取达到国防标准的三分之一59公斤，然后对着镜子大叫我----是-----胖-----子！！！！

This article discusses those ownership dis Public Installation Art putes and tries to work out a general rule of settlement that best balances the rights and interests of the two in order to secure the safety of the social trading

本文试图分析人像摄影作品的权利归属问题并结合实际情况确立两种权利冲突解决的一般规则以此平衡两种权利和利益最终目的是为了更好地保障民事权利定分止争维护社会交易安全。

This thesis is main to divide three part, the first part was detailed to introduce the HLA foundation knowledge; The second part introduce introduces the data to filter two kinds of methods of mechanism, and make use of the software of pRTI of the X-rated edition that company of Pitch provide to filtered the mechanism to do the experiment to these two kinds of data.

本文主要分三大部分，第一部分详细介绍了HLA的基础知识；第二部分介绍了数据过滤机制的两种方法，并利用Pitch公司提供的限制级版本的pRTI软件对这两种数据过滤机制做了实验。

Firstly we introduce the concept of Rees matrix semigroups without zero i.e.

矩形群、左群都是极其重要的半群，在Mario[2]中这两种半群都已有了很好的刻画，本文后两章将给出推广了的矩形群和左群的详细刻画，全文共分三章，具体内容如下：第一章主要对推广之后Rees矩阵半群的刻画进行了描述，在这一章里先介绍了无零Rees矩阵半群的概念，它是一类矩阵半群M=MT；I，？

The amphoteric fatliquor of N-amidel- polyethylene polyamine -β-aminopropionic acid types has been synthesized by nature oil and fat reaction with polyethylene polyamine and acrylic acid .

用天然油脂、多乙烯多胺和丙烯酸合成制得N -酰胺基多乙烯多胺-β-氨基丙酸型两性加脂剂，最佳合成条件分两步的反应温度分别控制在 10 0℃及 12 0℃、两步反应时间分别为 2h和 4h ，天然油脂与多乙烯多胺及丙烯酸的物质量的比为 1：0 。

Around all survey areas there were totally 8 dominant species in 4 seasons,which were Trichiurus japonicus,Pseudosciaena polyactis,Setipinna taty,Acropoma japonicum,Apogon lineatus,Engraulis japonicus,Champsodon capensis,Psenopsis anomala.

生物多样性指数中丰富度指数和Shannon-Wiener多样度指数变化趋势一致，在春、夏两季3个区域相差不大，而在秋、冬两季黄海南部与东海北部和中部有明显分异；种类均匀度指数在四季节3个区域之间相差不大。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。