海南省2006年中考数学科模拟试题(一)

(含超量题,全卷满分110分,考试时间100分钟)一、选择题(本大题满分20分,每小题2分)(在下列各题的四个备选答案中,只有一个是正确的,请把正确的答案的字母代号填写在下表相应的方格内)题号12345678910答案1·|-2|的相反数是()·A·-21B·-2C·12D·22·下列计算中,正确的是()·A     

海南省2012年中考数学科模拟试题(9)

(本试题满分110分,考试时间100分钟)特别提醒:1.选择题用2B铅笔填涂,其余答案一律用黑色笔填写在答题卡上,写在试题卷上无效.2.答题前请认真阅读试题及有关说明.3.请合理安排好答题时间.一、选择题(本大题满分42分,每小题3分)在下列各题的四个备选答案中,只有一个是正确的,请在答题卡上把你认为正确的答案的字母代号按獉要求用2B铅笔涂黑.     

八年级(上)数学期末测试题(北师大版)

说明:本卷含超量题满分110分,考试时间100分钟·一、选择题(在下列各题的四个备选答案中,只有一个是正确的,请把你认为正确的答案的字母代号填入括号里.本大题每小题2分,满分20分)1、一个圆桶,底面直径为9cm,高12cm,则桶内所能容下的最长木棒为()·A.10cmB.15cmC.18cmD.20cm2、     

中学数学选择题的常用解法

作为标准化试题的主要组成部分,选择题以共结构巧妙,解法灵活,答案简明、批阅圆方便等诸多优点而被各学科广泛采用,数学选择题的实质,是由题干(题设条件)和选择支(几个备选结论)组成的若干命题,共中错误的备选结论又称为干扰支。常见的选择题,除有特别说明者外,均属“给出的四个结论中有且只有一个正确”即所谓“四择一”的类型,称为单项选择题。数学选择题的覆盖面广,因共结构特征的不同而有多种解法,概括起来,可分为直接解法与间接解法两大类。     

浅谈初中数学单一选择题的解法

数学选择题是近三、四十年发展起来的新颖题型,它以其结构巧妙、解法灵活、答案简明、批阅方便等诸多优点而被作为标准化试题的主要组成部分,在数学竞赛试题中也占有重要位置。一般初中数学选择题是由一个问句或一个不完整的句子和至少三个备选答案组成,大都是“只有一个正确答案”的单一选择题。数学选择题的覆盖面广,因其结构特征的不同而有多种解法,概括起来,可分为直接解法与间接解法两大类。1 直接解法直接解法实质是把选择题当作常规题,即直接从题设条件出发,运用定义、定理、公式及有关性质进行     

高考选择题填空题之解题策略

高考数学满分150分,其中选择题填空题共占分值70分,接近一半．它既涵盖基础知识基本技能,又关注考生数学能力的考查．在考试中,选择题和填空题无需写出解答过程,无需严格推理论证,甚至无需真正明白其背景含义和数学实质,只需选出正确的选项、写出正确的答案．     

海南省2007年中考数学科模拟试题(八)

(含超量题满分110分,考试时间100分钟)特别提醒:1·选择题用2B铅笔填涂,其余答案一律用黑色笔填写在答题卡上,写在试题卷上无效.2·答题前请认真阅读试题及有关说明.3·请合理安排好答题时间.一、选择题(本大题满分20分,每小题2分)1·计算4-6的结果是()·A·10B·-10C·2D·-22     

2005年海南省(课改区域)中考数学科模拟试题(二)

说明 :同学们 ,这是一份超量给题的试卷 ,请认真审题 ,看清题目要求 本试卷满分 1 0 0分 ,超量给题最高分达1 1 0分 根据难易度可选作或超量作答 　　一、选择题 (本大题有 1 0小题 ,每小题 2分 ,共 2 0分 )在下列各题的四个备选答案中 ,只有一个是正确的 ,请把你认为正确的     

海南省2006年中考数学科模拟试题(四)

(全卷满分110分,考试时间100分钟)一、选择题(本大题满分20分,每小题2分)1.如果a与2互为倒数,那么a是()1A.-2B.-12C.0D.212.下列图形中是正方体展开图的是()13.某皮鞋销售商在进行市场占有率的调查时,他最应该关注的是()1A.皮鞋型号的平均数B.皮鞋型号的众数C.皮鞋型号的中位数     

奇思妙想解选择题

考试是一种限时作业 ,要想取得理想的成绩 ,节约时间和解题的正确性同样重要 .即使解题正确 ,但耗时太多 ,在整体上也是一个败笔 .因此 ,在考试中 ,若突破常规的解题方法 ,不仅能提高答案的准确率 ,还能节省大量的时间 ,在考试中占有极大的优势 .目前考试中的数学选择题多为单项选择 ,因此选择题的目标应是肯定某个选项或通过否定某些选项而达到肯定某个选项 ,针对选择题的这一特点 ,一些奇妙的解法应运而生 ,下面举例说明 .例 1　ａｒｃｃｏｓ( -ｘ)大于ａｒｃｃｏｓｘ的充分必要条件是 (　　 )(Ａ)ｘ∈ ( 0 ,1 ].　　 (Ｂ)ｘ∈ ( - 1 ,0 )…     

On some questions concerning strong compactness

A question of Woodin asks if κ is strongly compact and GCH holds below κ, then must GCH hold everywhere? One variant of this question asks if κ is strongly compact and GCH fails at every regular cardinal δ?< κ, then must GCH fail at some regular cardinal δ?≥ κ? Another variant asks if it is possible for GCH to fail at every limit cardinal less than or equal to a strongly compact cardinal κ. We get a negative answer to the first of these questions and positive answers to the second of these questions for a supercompact cardinal κ in the context of the absence of the full Axiom of Choice.     

Middle School Students' Understanding of Number Sense Related to Percent

This study examined middle school students' understanding of percent, focusing on number sense. Participants in the study were 106 seventh-grade and 93 eighth-grade students. Students were given a written test that included 21 multiple-choice questions and an open-ended item. Research interviews were conducted with 28 selected students. Students performed better interpreting a quantity expressed as a percent given a pictorial continuous region than when a pictorial discrete set of circles was given. Students had difficulty interpreting a quantity expressed as a percent of a number. The strategies used by students to make comparisons about percents represent a wide range of correct and incorrect approaches to the questions. In addition to the use of 50% and 100% as common reference points, students successfully applied fractional relationships, estimation and mental computation to make comparisons. A variety of inappropriate strategies which included computational procedures and numerical comparisons were also employed, some of which resulted in the correct multiple-choice response.     

The difficulty of “length × width”: Is a square the unit of measurement?

In individual interviews, 220 students in grades 4, 6, 8, and 9 were given one task, and 72 eighth graders were given three tasks to answer two questions: (a) Is a square the unit of measurement for an area for students in grades 4-8? and (b) Does a square have a space-covering characteristic for students in grade 8? The answers to both questions were No (except for eighth (and ninth) graders in advanced sections of mathematics). The difficulty of “length × width” is explained in light of Piaget's theory, and educational implications are discussed.     

On the development of decision rules for bar quiz handicapping

Some competitions involve teams comprising different numbers of players. For informal games, such as the popular ‘pub quiz’, we argue that teams with fewer players are at a disadvantage. This paper investigates the properties of these games and develops several methods for allocating handicaps within such competitions, so that the competitions may be considered fair, based on a simple Bernoulli model for correctly answering questions and assuming exchangeability of participants. We recommend a natural conjugate prior subjective handicapping rule; with this rule handicaps may be set beforehand given the judgement of the quiz setter regarding the difficulty of the questions. We also describe a posterior rule that provides improved accuracy but is calculated after the quiz is complete. Finally, the paper considers modifications of the proposed rules to cope with multiple-choice questions and progressive quizzes.     

THE SIZE OF FARSIGHTED STABLE COALITIONS IN A GAME OF POLLUTION ABATEMENT

Abstract The game theoretical analysis of international environmental problems has received increasing attention in recent years. Major issues are as follows. Under which conditions will an international environmental agreement (IEA) be signed? Will the agreement be stable? Game theory has given different answers to these questions; in particular, it is possible to show that if countries are myopic then only small stable coalitions occur, but if they are farsighted then both large and small stable coalitions exist. This paper studies the size of a farsighted stable IEA by considering a quadratic cost function in a pollution abatement model. Following Rubio and Ulph [2006] , we consider both the case of non‐negative emissions as well as the case of unrestricted ones.     

分离向量与自反性

设A是B(X)的子代数,且A具有分离向量x0,本文讨论它的2-自反性和亚自反性,并就具有分离向量的交换算子代数.部分地回答了J.A.Deddens在文献[7]中提出的一些关于自反性的问题.     

Integrated machine scheduling and vehicle routing with time windows

This paper integrates production and outbound distribution scheduling in order to minimize total tardiness. The overall problem consists of two subproblems. The first addresses scheduling a set of jobs on parallel machines with machine-dependent ready times. The second focusses on the delivery of completed jobs with a fleet of vehicles which may differ in their loading capacities and ready times. Job-dependent processing times, delivery time windows, service times, and destinations are taken into account. A genetic algorithm approach is introduced to solve the integrated problem as a whole. Two main questions are examined. Are the results of integrating machine scheduling and vehicle routing significantly better than those of classic decomposition approaches which break down the overall problem, solve the two subproblems successively, and merge the subsolutions to form a solution to the overall problem? And if so, is it possible to capitalize on these potentials despite the complexity of the integrated problem? Both questions are tackled by means of a numerical study. The genetic algorithm outperforms the classic decomposition approaches in case of small-size instances and is able to generate relatively good solutions for instances with up to 50 jobs, 5 machines, and 10 vehicles.     

The Problem of Universals, Realism, and God

There has been much discussion of late on what exactly the Problem of Universals is and is not. Of course answers to these questions and many more like it depend on what is supposed to be explained by a solution to the Problem of Universals. In this paper, I seek to establish two claims: first, that when the facts (explanada) to be explained and the kind of explanation needed are elucidated, it will be shown that the Problem of Universals is a real metaphysical problem, not a pseudo problem; secondly, the facts whose explanation posed the problem in the Problem of Universals still provide reason to think realism regarding universals is true, even if God exists.     

Quasiaffinity and invariant subspaces

Special classes of intertwining transformations between Hilbert spaces are introduced and investigated, whose purposes are to provide partial answers to some classical questions on the existence of nontrivial invariant subspaces for operators acting on separable Hilbert spaces. The main result ensures that if an operator is \({{\mathcal D}}\)-intertwined to a normal operator, then it has a nontrivial invariant subspace.     

The spectral picture and the closure of the similarity orbit of strongly irreducible operators

An operator on a complex, separable, infinite dimensional Hilbert space is strongly irreducible if it does not commute with any nontrivial idempotent. This article answers the following questions of D. A. Herrero: (i) Given an operatorT with connected spectrum, can we find a strongly irreducible operatorL such that they have same spectral picture? (ii) When we use a sequence of irreducible operators to approximateT, can the approximation be the “most economic”? i.e., does there exist a strongly irreducible operatorL such thatT ∈S(L) ^? (the closure of the similarity orbit ofL)? It is shown that the answer for the two questions is yes.