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Model Writings

2009-11

(The following model writings are collected from your textbook and workbook. It’s strongly recommended that you do the writing tasks first before referring to the answers.)

Part one (Memo, notice, fax, message, short e-mail…)

Task 1 (write to ask someone to book a room for your colleague)

(Workbook, p26)

Sample writing:

To: BMarks@https://www.wendangku.net/doc/903933574.html,

From: Jim.Byrne@https://www.wendangku.net/doc/903933574.html,

Could you book one single room in the name of Robert Dorey. If possible, he would prefer a non-smoking room. He’s arriving on Thursday 5th June and leaving on the 7th in the morning.

Don’t book him into the Royal this time, it’s too far from the center. Could you find him somewhere comfortable, but not too expensive?

Thanks

Jim

Task 2 (write to reply to an e-mail)

(Workbook, p27)

Sample writing:

To Jim.Byrne@https://www.wendangku.net/doc/903933574.html,

From: BMarks@https://www.wendangku.net/doc/903933574.html,

Dear Jim,

We’ve booked Robert Dorey for 2 nights (5th & 6th) into the Astoria. He will be in Room 507, which is on a non-smoking floor.

The Astoria is a very comfortable four-star hotel just 5 minutes from the centre.

Look forward to his visit.

Best wishes,

Brian

Task 3 (write to ask for sick leave)

(Workbook, p23)

Your boss, Daniel duval, wants you to take part in an important seminar tomorrow morning. You cannot go because you have a terrible headache. In fact, you have not slept very well for a week.

Write a message to your boss, in which you:

?Apologise and say why you cannot attend

?Tell him what you plan to do about your health.

The message should be 60-80 words in length.

Model answer:

To: Daniel Duval

From:

I’m very sorry I won’t be able to attend the seminar tomorrow morning. I need to say at home for a couple of days because I can’t shake off these terrible headaches. Moreover, I feel exhausted because I haven’t slept well for a whole week.

These are probably symptoms of stress, so I will see my doctor and perhaps a stess counselor as well.

I shall be back in my office on Wednesday morning.

Task 4 (write to inform the staff about the changes in arrangement)

(Workbook, p35)

Write a memo (35-45 words) to all sales staff, to:

Inform them of the change of time

Encourage everybody to be there

Apologise for possible inconvenience

Model answer:

To: All sales staff

From: Fekete Kati

Re: visit from international Headquarters Stockholm

Date: May 16

Unfortunately our guests from Stockholm cannot be with us on Wednesday 24. So the performance Evaluation is on Thursday 10.30-12.30. We expect all members of the Sales team to be there. Sorry if these changes cause you any inconvenience.

Part two. Letter

Task 1 (write to resign)

(Textbook, p60)

You re Bea Knrad ( see textbook, p59). Write a letter to your boss< John Hardcastle, explaining why you are leaving Ajax. Include these points:

?Say that you are resigning (leaving your job)

?You enjoyed working for Ajoax until takeover by Zenith

?Pressure now too great

?Don’t like the pressure and the long hours since the takeover

?Increased number of tasks and deadlines – very stressful

?Give date you will be leaving ( normal period of notice three months, but you want to leave on Friday )

?End suitably

Model answer:

Dear Mr Hardcastle

This is to let you know that I wish to resign from my job at Ajax. Before the takeover by Zenith I enjoyed working at Ajax, but now the pressure is too great. The long hours and the increased number of tasks and deadlines are very stressful. My normal notice period is three months, but I would like to leave the company on Friday as I cannot continue working in the present conditions.

Yours Sincerely

Bea Konrad

Task 2 (write to thank someone for their help and kindness)

(Textbook, p61)

You organize a conference at the Plaza Hotel and Conference Centre( see page 60). Write a letter (not more than 100 words) to the manager, Melissa Wang, containing these points:

?Thank Ms Wang for making the conference a success

?The staff were friendly and helpful

?All equipment in the conference rooms worked

?Comment on the quality of the food in the two restaurants and the speed of the service (very important at lunchtime when participants only had 45 minutes for lunch)

?Thank Mesissa Wang again

?End suitable

Model answer:

Dear Ms wang

I'm writing to thank you for helping to make our conference so successful. Your staff were very friendly and helpful. The conference rooms were well-equipped and everything worked perfectly.

Please send my special thanks to the staff in your restaurants: the food was excellent and was served quickly. (As you know, this was very important at lunchtime, as we only had a 45-minute break.)

Thank you again for all your help. We will certainly use the Plaza for a similar conference that we are organising in two years' time.

Yours Sincerely

(Workbook, page27)

You were well entertained while you attended a conference in the head office. Write a thank-you letter to the organizer.

Sample writing:

Dear Brian,

This is to thank you for your hospitality during and after the conference.

You gave me a lot of your time and made my visit very memorable. Walking round the Old Town in the evening was really fascinating. Besides, I thought the food in that Mediterranean restaurant where we had supper was just perfect.

It was a great pleasure to meet you. If you come to Canada, I would like to return your kindness and generosity.

Once again, thank you.

Regards,

Robert

Task 3 (write to complain)

(Textbook, p61)

Two years later, you organize another conference at the same hotel, but it is not a success. Write a letter (not more than 100 words) to the new manager, Michael Robinson, about the problems you had.

?You chose the Plaza because of successful conference two years ago, but service not as good this time

?Biggest problem: the interpreters from the agency (recommended by the hotel) were not good – this led to misunderstandings and bad feelings

?Ask for compensation of some kind

?End suitably

Model answer:

Dear Mr Robinson

I'm writing to complain about the facilities and the service during our recent conference. We organised a successful conference at the Plaza two years ago, but this time were very disappointed.

The most serious problem was the interpreters from the agency recommended by you. They did not speak the languages fluently and this led to misunderstandings between the participants and caused a lot of bad feelings.

considering these difficulties, I suggest a 20 percent reduction in the bill for the conference.

I look forward to receiving your comments.

Yours sincerely

Task 4 (write to give advice)

(Textbook, p89)

You are Christine Robison, the newspaper journalist who receives the letter above (see textbook p89). Write a letter (not more than 100 words) to Janet Jones that will appear in the newspaper. Your letter should give advice to the secretary on what to do: should she stay or should she leave the company?

Model answer:

Dear Janet,

Your situation sounds very difficult. You should try to understand your American manager. His

bosses in the US probably expect a lot from him. So try to work in the ways that he wants you to work. Learn from his comments. If the promotion possibilities are good, you shouldn’t throw away a career in an international company just because you want to eat in a reastaurant every day! Try to work hard during the week and relax at weekends.

Yours truly,

Christine Robinson

Task 5 (write to give advice)

(Textbook, p115)

Read the letter on page 115. Write an e-mail (85 – 100 words) to your friend Jessica, advising her what to do.

Model answer:

Jessica

The situation sounds terrible –we had a similar situation in my company once. I don’t think that you and your colleagues should try to deal with Keith yourselves. That could lead to trouble. Is there a manager above Lionel that you could go to see? Instead of talking about Keith directly, you could suggest that some regular performance reviews of employees’ work would be useful. The company will find out sooner or later that Keith is not productive and is just causing problems. Or am I being unrealistic?

Yours

Task 6 (write to review a product)

(Textbook, p117)

Look at the products in the case study on page113. In the end, Minerva A.G. developed all of these products and you bought ONE of them. Write one of these letters (90-110) to Minerva A.G.

1)Thank them. Tell ZMinerva

?Which product you bought

?Why you bought the product

?How you have used it

?Why you like it

?Whether you think it offers good value for money

?Whether you will buy another one – if so, ask them to send you details of future models

2)Criticise the product. Tell Mineva

?Which product you bought

?Why you bought the product

?How you have used it

?Why you don’t like it

?That you would like a refund

Model answers:

Dear Sir or Madam

I recently bought a weight monitor at one of yours stores. I’m writing to tell you how good it is. I eat a lot of business lunches with clients, and I have been able to control my weight much more easily. It’s easy to read the information –they’re very useful. €45 is a good price for a product like this. Please let me know about any new models that you develop in the future.

Yours faithfully

Dear sir or Madam

I recently bought a Virtual Passenger (VP) in one of your stores. I’m a sales rep. I drive 100,000 kilometres a year and I often feel bored or sleepy. I thought the VP would help me keep awake. However, I soon found that the VP is very boring and its jokes are terrible. Once, when I almost fell asleep, the alarm did not work. The Virtual Passenger is a useless product. I’d be grateful if you could send me a full refund.

Yours faithfully

Task 7 (write to enquire about a product)

(Workbook, p51)

Write an e-mail to Scanlt International on behalf of your company to request further information about the scanner described in exercise B (see workbook, page50)

Organize your message like this:

?Start with Dear Sir/Madam

?Say where you saw the advertisement

?Ask what you need to know: a)Can the JTX2 scan 3-D objects? b) What types of paper can be used?

?Say you are interested in a free trial and ask how long the trial period is

?Finish your message with the correct ending

Model answer:

Dear Sir/Madam,

With reference to your advertisement in the September issue of ‘TechNews’, we would like to request further information about the Alpha JTX2.

In particular, we need to know whether it can scan 3-D objects, and also what types of paper it takes.

We are considering asking for a free trial. Could you tell us how long we would be able to keep the machine.

Thank you in advance.

Looking forward to hearing from you.

Yours faithfully

Task 8 (write to request information)

(Workbook, p39)

You work for Lindcom UK. Read the course advertisement below. Write a letter to request further information about the course.

Model answer:

Dear Sir/Madam,

Further to your advertisement in the Banffshire Herald of May 7, we would like to request further information about your Cultural Differences in the Workplace course.

In particular, we would like to know the start dates and the maximum number of participants on the course.

Finally, any information about discouts for groups of five or more would also be welcome.

We look forward to hearing from you.

Yours sincerely

Sue Lowles

Deputy manager Lindcom UK

Task 9 (write to apologize)

(Workbook, page43)

Write a reply to the following letter:

Model answer:

Dear Ms Clark

Further to your phone call and your letter of March 23, we would like to apologise for the problems you had.

There was obviously a mix-up over your order, and the goods you received were meant for another customer. The correct order was sent by special delivery and should already be with you.

Once again, our apologies for this inconvenience.

We look forward to receiving further orders from you.

Yours sincerely

George Simpson

Task 10 (Write to invite someone to a meeting)

(Workbook, p97)

You are responsible for organizing an international meeting for the marketing managers from each of you company’s subsidiaries worldwide (about 24). Write a letter that you can send to each of the marketing managers. Use the information about the meeting from the box. You should write about 60-80 words.

Model answer:

Dear …

I am writing to invite you to a meeting for all marketing managers from each subsidiary worldwide. The purpose of the meeting is to discuss international marketing strategy and co-ordinate the marketing activities in different countries.

The meeting will take place on 4 and 5 April at the conference suite of the Four Towers Hotel in Toronto, Canada.

Please arrange your flights to arrive on Wednesday, 3 April. Accommodation will be reserved for you on Wednesday and Thursday nights.

Please confirm that you will be able to attend.

Yours sincerely,

International Marketing Manager

Part three (Report)

Task1

(Workbook-p22)

Write a report for the international Health Symposium based on the graph:

2%4%6%8%10%12%14%16%18%1989

1999now

The graph shows the changes in the number of people staying off work because of back trouble and stress-related illness.

To begin with, we can see that absences caused by back trouble have risen gradually since 1989. The number went up from 6% in 1989 to 11% ten years later, and it now stands at about 13%. Secondly, absences caused by stress-related illness showed a similar trend in the period 1989-1999. They increased by 3%, to reach 17% in 1999. Since 1999, however, the number has risen dramatically and now stands at 7%.

In conclusion, back trouble is still a problem today, but we have made excellent progress in bring down the number of people absent from work because of stress. Task 2

(Workbook – p26)

Two thousand executives from different countries named their three favourite forms of entertainment when they are abroad on business.

Look at the bar chart explaining the results of the survey. Write a report to describe the chart.

The bar chart shows the popularity of certain forms of entertainment with executives while they are abroad on business. The most popular activity is clearly going to restaurant: 85% of the executives interviewed mentioned it in their top three.

Secondly, seeing the sights was mentioned by 75% of the respondents and almost as many said they enjoyed being invited round to a colleague’s home for a meal.

Other forms of entertainment were mentioned far less frequently. About 25% of the respondents enjoy going to a disco or nightclub, and 20% to the cinema, the theatre or a concert. Museums and art galleries are popular with very small number of executives: only about 5%. Finally, various activities such as playing tennis, wine or beer tasting, etc. were mentioned by 15% of the respondents.

Task 3

(Workbook –p p38)

Lindcom International’s managers wanted to know if their employees think thy are good managers. So they sent everyone a questionnaire. Look at the summary of the findings and write a conclusion and a recommendation to finish the report.

Sample:

Conclusion

Most of the staff are clearly dissatisfied with the way management listens to their suggestions. In addition, a quarter of the staff say their manager never responds to their concerns.

One third say that they often enjoy working with their manager. On the other hand, almost half say that their manager never praises them.

On the positive side almost everybody is satisfied with the way their manager communicates information.

Recommendations

Management should build on its strengths and continue to communicate information efficiently. We must urgently look into ways of taking into account our employees’ suggestions. Moreover, we should adopt a more sympathetic attitude towards them. We should also remember to praise our employees for their good work. As a result, our people would certainly enjoy working with us more than they do at present.

Task 4

(Workbook, p46-47)

Study the table. Write two short reports: one is about men employed; the other is about women employed.

Sample

A report about men employed

A third o all men employed were in manufacturing in 1989, compared with only a quarter in 1999.

On the other hand, around, around one in six men employed were in health, education and public administration services in1989, whle the same industry accounted for on fifth of men’s job in 1999.

As regards the percentage of men employed in financial and business services, it increased from ten in 1989 to 15 ten years later.

A report about women employed

One fifth of all women employed were in manufacturing in 1989, compared with only one tenth a decade later.

On the other hand, 40% of women employees were in health, education, and public administration services n 1989, while this sector accounted for 45% of all omen employed ten years later.

As regards the percentage of women employed in financial and business services, it doubled from 1989 to 1999, when it accounted for on fifth of women employed.

Task5

(Workbook, p110)

You are a personnel manager. Your company’s administrative offices are open-plan with 60 people working in the same large space.

You have been asked a carry out a survey of employee opinions about office space and working conditions. The results of your survey are given below.

Write a short report to describe the results

Sample writing:

The results from the questionnaire show that most employees (92 percent) think that the company offices are too small. Nearly two-thirds (62 percent) say they do not have enough personal work space. Just over half (58 percent) think that an open-plan office reduces efficiency. The main problems which people described were: noise, not enough space and too many interruptions.

However, the advantages are: easy communication and a friendly atmosphere. When asked if they would prefer to share a small office with two or three people, two-thirds of employees(66 percent) said yes; 18 percent said no; and 16 percent didn’t know.

Task 6

(Textbook, p86)

Study the following questionnaire about holidays. Write a report about Mr and Mrs Quinn, who have bought a ski holiday.

You should:

?Use the questions and answers in the questionnaire above.

?End the report by making a recommendation about how to improve the type of holiday you described for people like Mr and Mrs Quinn

Sample writing:

I interviewed Mr and Mrs Quinn about their holidays. They are in the 35 to 40 age group. They

have two children, boys aged 8 and 10. Mr and Mrs Quinn both work and together they earn $45,000 a year after tax. They usually take two holidays a year, one in summer and one in winter. They always take their children.

Their last holiday was in January, when they went skiing in Colorado. They arranged this themselves by booking their hotel and flying from Chicago, where they live, to Aspen. They went for a week. They thought the ski facilities were excellent, but they thought there was not enough for the children to do, apart from ski.

My main recommendation to the tourist industry in Aspen is to provide more activities for children, especially in the evening so that parents can have more time to themselves.

Task 7

(Textbook, p88)

You are regional sales director for a soft drink called Quench. Three years ago you forecast sales in your region for the following year. The three years have now passed.

Write a report:

?Gives figures for forecast and actual sales

?Explains the differences between the two set of figures

?Gives conclusions about a) whether the sales department is responsible for the poor sales, and

b) how sales can be improved in the future.

Sample writing:

Three years ago we made a sales forecast for Year1 of 1.5 million units. Unfortunately, we only had sales of 1.1 million. This was mainly because of the very bad weather we had during the summer-it was very cold and wet, so people did not want to buy soft drinks.

Our forecast for Year 2 was 1.7 million units, but we only sold1.35 million. The weather during the summer was good but there were production difficulties and we could not satisfy the demand for quench.

For Year 3, we had forecast sales of 2 million units, but a strike by delivery drivers in July meant that again we could not satisfy the demand, and we only had sales of 1.8 million.

The sales department has not been responsible for the difficulties. If we want to in crease sales in the future, we must avoid production problems at our factory and make sure that the delivery drivers do not go on strike again.

Task 8

(Textbook, p116)

You work for the Euphoria Development Agency. Write a report about the economy of euphoria for the head of Teknos, a company that is considering investing in a high-tech factory in Euphoria to make computer chips.

Summarise the information below and recommend at the end of it that teknos should make this investment.

Euphoria: key facts

Model answer:

Euphoria is an investor’s dream. The economy is in a very good state: growth is high, unemployment is low and inflation is under control.

There is an excellent labour force: school and university education is excellent, and managers and workers are highly skilled.

The roads are very crowded: people and goods can be held up in traffic but, on the other hand, train services, both for goods and passengers, are fast and cheap.

Some say that younger Euphorians are becoming lazy and too used to having money, but this is a relatively small problem.

I do not hesitate to recommend Euphoria as an ideal country for a high-tech factory of the kind you are considering.

(For more sample writings, please read the Writing File on your textbook p130-135)

磁场中的几种模型

磁场中的几个仪器一、质谱仪 1、如图是测量带电粒子质量的仪器工作原理示意图。设法使某有机化合物的气态分子导入图中所示的容器A中，使它受到电子束轰击，失去一个电子变成正一价的分子离子。分子离子从狭缝s1以很小的速度进入电压为U 的加速电场区（初速不计），加速后，再通过狭缝s2、s3射入磁感应强度为B的匀强磁场，方向垂直于磁场区的界面 PQ。最后，分子离子打到感光片上，形成垂直于纸面而且平行于狭缝s3的细线。若测得细线到狭缝s3的距离为d，导出分子离子的质量m的表达式。 2、如图为质谱仪原理示意图，电荷量为q、质量为m的带正电的粒子从静止开始经过电势差为U的加速电场后进入粒子速度选择器。选择器中存在相互垂直的匀强电场和匀强磁场，匀强电场的场强为E、方向水平向右。已知带电粒子能够沿直线穿过速度选择器，从G点垂直MN进入偏转磁场，该偏转磁场是一个以直线MN为边界、方向垂直纸面向外的匀强磁场。带电粒子经偏转磁场后，最终到达照相底片的H点。可测量出G、H间的距离为L。带电粒子的重力可忽略不计。求：（1）粒子从加速电场射出时速度v的大小。（2）粒子速度选择器中匀强磁场的磁感应强度 B1的大小和方向。（3）偏转磁场的磁感应强度B2的大小。 3、如图所示是某种质谱仪的原理示意图，它由加速电场、静电分析器和磁分析器等组成，若静电分析器通道的半径为R，均匀辐向电场的场强为E，磁分析器中有垂直纸面向外的匀强磁场，磁感应强度为B，忽略重力的影响，试问：（1）为了使位于A处电量为q、质量为m的离子，从静止开始经加速电场加速后沿图中虚线通过静电分析器，加速电场的电压U应为多大？（2）离子由P点进入磁分析器后，最终打在感光胶片上的Q 点，该点距入射点P有多远？若有一群离子从静止开始通过该质谱仪后落在同一点Q，则该群离子具有什么共同特征？

地磁磁场的基本特征及应用

地磁磁场的基本特征及应用地球磁场：地球周围存在的磁场，包括磁层顶以下的固体地球内部和外部所有场源产生的磁场。地球磁场不是孤立的，它受到外界扰动的影响，宇宙飞船就已经探测到太阳风的存在。因为太阳风是一种等离子体，所以它也有磁场，太阳风磁场对地球磁场施加作用，好像要把地球磁场从地球上吹走似的。尽管这样，地球磁场仍有效地阻止了太阳风长驱直入。在地球磁场的反抗下，太阳风绕过地球磁场，继续向前运动，于是形成了一个被太阳风包围的、彗星状的地球磁场区域，这就是磁层。地球磁层位于距大气层顶600～1000公里高处，磁层的外边界叫磁层顶，离地面5～7万公里。在太阳风的压缩下，地球磁力线向背着太阳一面的空间延伸得很远，形成一条长长的尾巴，称为磁尾。在磁赤道附近，有一个特殊的界面，在界面两边，磁力线突然改变方向，此界面称为中性片。中性片上的磁场强度微乎其微，厚度大约有1000公里。中性片将磁尾部分成两部分：北面的磁力线向着地球，南面的磁力线离开地球。地磁学：是研究地磁场的时间变化、空间分布、起源及其规律的学科。固体地球物理学的一个分支。

时间范围：已可追溯到太古代（约35亿年前）——现代空间范围：从地核至磁层边界（磁层顶），磁层离地心最近的距离： 8～ 13个地球半径组成和变化规律及应用：磁偶极子：带等量异号磁量的两个磁荷，如果观测点距离远大于它们之间的距离，那么这两个磁荷组成的系统称为磁偶极子。地磁场的构成地球磁场近似于一个置于地心的同轴偶极子的磁场。这是地球磁场的基本特征。这个偶极子的磁轴和地轴斜交一个角度，。如图1.1所示，N、S 分别表示地磁北极和地磁南极。按磁性来说，地磁两极和磁针两极正好相反。同时，磁极的位置并不是固定的，每年会移动数英里，两个磁极的移动彼此之间是独立的，关于地磁极的概念有两种不同的思路和结果：理论的和实测的。理论的地磁极是从地球基本磁场中的偶极子磁场出发的。实测的地磁极是从全球地磁图（等偏角地磁图和等倾角地磁图）上找出的磁倾角为90°的两个小区域，这两个地点不在地球同一直径的两端，大约偏离2500千米。由

广义线性模型

广义线性模型一、广义模型的概念以及指数函数族 1.多元线性回归和正态线性模型 2.指数函数族 3.The Tweedie distribution：特殊的指数指数族一员；在0点有很大的概率并且在非0点有合适的分布；方差与均值的p次幂成正比4.GLM的结构：连接函数、设计矩阵、预估变量、offset变量每个观测的方差取决于：1.模型的方差方程；2.幅度变量；3.每个变量的权重二、构建GLM模型 1.单因子分析：无法反映变量之间的关系,GLM可以排除这类关系，得到相对数的真实值 2.变量、分类因子、交互项目以及线性预测值：（1）权重/暴露（2）反应：模型视图预测的值一般地，模型的名称与反应/权重的含义相同（3）categorical factors and naturally ordered value （4）interaction terms:当某种不同变量的特定组合与分别直接乘以不同变量相对数的经验差异很大时要用到 3. 变量估计：通过逆矩阵相关方法求解三、分析因子的显著性 1. chi-squared、F-statistics、AIC 等统计量

（1）偏离：比较观测值与设定值之间的差距，考虑到权重的影响，并且当方差小时给予误差更大的影响。（2）偏离度调整（3）chi-squared 统计量：模型的自由度定义为观测的数量减去变量的数量 Nested models:可以利用chi-squared来检验偏离度的变化 (4) F-statistics (5)AIC：主要用于模型选择的统计量 AIC=-2*log likelihood+2*number of parameters 是在likelihood 与变量数量之间的权衡，AIC数值越小越好 2.模型变量的不确定性 Hat matrix Likelihood的二阶导数与变量的方差反比例相关 Steep curvature表明变量tightly defined， Shallow curvature 表明变量poorly defined 3.其他方法（1）与预期值相比：每种水平下相对值的变动幅度，同时考虑每个水平下得标准偏差，其值的（2）Comparison with time：model fit line；variation的大小应该与exposure的大小相反不同渠道数据收集上的差异可能导致不一致的发生四、测试模型的适当性

高中物理模型：常见的磁场整理

模型/题型：常见的磁场整理条形磁体①在磁体的外部磁感线从磁体的N极出来进入磁场的S极，在内部也有相应条数的磁感线与外部的磁感线衔接组成闭合曲线； ②磁感线分布有两个对称轴，一是磁铁的中轴线，二是磁铁的中垂线(从空间上来说为两个对称面)； ③条形磁铁的磁感线在磁铁的外部的两端(磁极)最密，中间稀疏。蹄形磁铁①与条形磁铁相同,在磁体的外部磁感线从磁体的N极出来进入磁场的S极，在内部也有相应条数的磁感线(未画出)与外部的磁感线衔接组成闭合曲线； ②磁感线分布有一个对称轴，即磁铁的对称轴； ③蹄形磁铁的磁感线在磁铁外部是两端(磁极)最密，中间稀疏。异名磁极①当两异名磁极相距较近时，两极间的磁场除边缘区域外是匀强磁场，磁感线相互平行、疏密均匀； ②当两异名磁极相距较远时，两极间靠中心位置越近磁感应强度越弱，磁感线越稀疏。类似于两等量异种电荷(点电荷)的磁场。同名磁极 ①两同名磁极间的磁感线分布类似于两等量同种电荷(点电荷)的磁感线分布 ②磁感线有两条对称轴，分别为(1)两磁极的中轴线(2)两磁极间的中轴线安培定则立体图横截面图纵截面图直线电流一组以导线上任意点为圆心的多组同心圆，距导线越远磁感线越稀疏，磁场越弱环形电流环形电流的两侧可等效为小磁针的N极和S极,内部磁场比环外强,磁感线越向外越稀疏

通电螺线管内部为匀强磁场且比外部强，方向由S极→N极，外部类似条形磁铁的磁场，管外为非匀强磁场 1.用右手握住导线,让伸直的大拇指所指的方向跟电流的方向一致,弯曲的四指所指的就是磁感线的环绕方向。 2.让右手弯曲的四指和环形电流的方向一致，伸直的大拇指所指的方向就是环形导线轴线上磁感线的方向。 3.让右手弯曲的四指和螺线管中的电流方向一致,伸直的大拇指所指的方向就是螺线管中轴线上磁感线的方向。三、地磁场的特点 ①地理南北极和地磁南北极相反 ②存在磁偏角 ③地球的磁场外部由南极到北极，内部由北极到南极 ④南半球地磁场磁感线斜向上，北半球斜向下，赤道与地面平行四、磁场基础知识梳理 (一).磁感线 1、磁感线：在磁场中画出一系列有方向的曲线，曲线上每一点的切线方向表示该点的磁场方向，曲线的疏密程度表示磁场的强弱。 2.磁感线的基本特点：（1）磁体外部磁感线从N极出发指向S极，在磁体内部由S极到N极，形成闭合曲线。（2）磁感线上每一点的切线方向表示该处的磁场方向。（3）磁感线的疏密程度表示该处的磁场的强弱。（4）任意两条磁感线不相交（不相切）。（5）磁感线是假想线。 (二).匀强磁场 1.定义：磁场强弱、方向处处相同的磁场 2.磁感线分布特点:匀强磁场的磁感线是一些间隔相同的平行直线 (三).磁通量 1．磁通量的定义公式Φ＝BS中的B应是匀强磁场的磁感应强度，S是与磁场方向垂直的面积，因此，可以理解为Φ＝BS⊥.如果平面与磁场方向不垂直，应把面积S投影到与磁场垂直的方向上，求出投影面积S⊥，代入到Φ＝BS⊥中计算，应避免硬套公式Φ＝BSsin θ或Φ＝BScos θ. 2．磁通量的变化：一般有下列三种情况： (1)磁感应强度B不变，有效面积S变化，则ΔΦ＝Φt－Φ0＝B·ΔS. (2)磁感应强度B变化，磁感线穿过的有效面积S不变，则穿过回路中的磁通量的变化是：ΔΦ＝Φt－Φ0＝ΔB·S. (3)磁感应强度B和有效面积S同时发生变化的情况，则ΔΦ＝Φt－Φ0. ?特别提醒 ①平面S与磁场方向不垂直时，要把面积S投影到与磁场垂直的方向上，即求出有效面积． ②可以把磁通量理解为穿过面积S的磁感线净条数.相反方向穿过面积S的磁感线可以互相抵消．

皖北矿区地下水化学组成控制因素及水源识别研究进展 ——基于水岩相互作用和EPA Unmix 模型的思考

Open Journal of Nature Science 自然科学, 2019, 7(3), 129-136 Published Online May 2019 in Hans. https://www.wendangku.net/doc/903933574.html,/journal/ojns https://https://www.wendangku.net/doc/903933574.html,/10.12677/ojns.2019.73019 Research Progresses on Controlling Factors of Chemical Constitution and Water Source Identification of Groundwater in Mining Area, Northern Anhui Province —Consideration of Water-Rock Interaction and EPA Unmix Model Kai Chen1,2, Linhua Sun1,2 1School of Earth and Environment, Anhui University of Science and Technology, Huainan Anhui 2School of Resources and Civil Engineering, Suzhou University, Suzhou Anhui Received: Apr. 23rd, 2019; accepted: May 7th, 2019; published: May 14th, 2019 Abstract It is a key point to identify the water-rock interaction mechanism in the aquifers of coal mining area in northern Anhui province. This paper summarized the work of the predecessors and pointed out some problems existing in the current research: 1) the qualitative analysis of major ion sources of groundwater in mining area needs to be verified and 2) the major ion sources re-quire further quantitative analysis. These problems can be solved by combining the water-rock interaction experiment with the EPA Unmix model analysis: the dissolution spectra of various minerals/rocks can be obtained by using the water-rock interaction experiment, whereas the EPA Unmix model can obtain quantitative information of ion sources. Their combination can provide new methods and ideas for identifying water inrush sources based on water-rock interactions in the future. Keywords Groundwater, Coal Mine, Hydrochemistry, Water-Rock Interaction, Unmix Model 皖北矿区地下水化学组成控制因素及水源识别研究进展 ——基于水岩相互作用和EPA Unmix模型的思考陈凯1,2，孙林华1,2

广义相加模型

广义相加模型当因变量和自变量不呈线性关系时，可用广义相加模型（GAM）。GAM可对部分或全部的自变量采用平滑函数的方法建立模型，函数可以是非参数的形式，适用于多种分布类型、多种复杂非线性关系的分析。广义相加模型中因变量的分布类型、联系函数和广义线性模型相同。根据Y 软件自动检测应变量的类型，如果是连续性变量，自动默认采用正态分布和identity作为联系函数。如是两分类的，自动用logit做联系函数。平滑拟合自由度 GAM用s(X)替换β*X。β*X使用的自由度为1。s(X)的自由度取决于平滑程度，越平滑自由度越小。最极端的情况是用一个参数估计的一条直线是最平滑的；另一极端是连接每个实际的数据点是最不平滑的，这种情况下我们用尽了所有的自由度。广义相加模型可以指定平滑拟合自由度。自由度越小，平滑程度越高，但拟合程度降低；自由度越大，平滑程度越低，拟合度越高。默认值是用最低GCV或GACV值（广义交叉验证）的方法找到适当的平滑拟合自由度。本模块不仅输出模型，而且输出每个观察记录的预测值及其标准误。不仅可以建模，还可用于预测。输入数据文件中，应变量缺失的记录，只要模型中的自变量齐全，都可得出预测值及其标准误。右击输出文件可以看到 XX_PRED.XLS文件，它含原数据文件（自变量完整的记录）加预测值及其标准误两个变量。例, DEMO数据曲线拟合AGE、BMI与SBP的关系，同时调整SMOKE、ALH、EDU、OCCU，按性别分层拟合。输入界面如下：

输出结果结局变量: Systolic BP, mmhg 变量分布: gaussian 模型: SBP ~ s(AGE,fx=FALSE,by=factor(SEX))+s(BMI,fx=FALSE,by=factor(SEX))+factor(SEX)+SMOKE+ALH +OCCU.NEW+factor(EDU.NEW)

第二章地球磁场

第二章地球磁场（Lisa Tauxe著，常燎译）建议补充读物 Butler (1992)，3－7页，10－11页。更多信息可参看：Merrill et al. (1996) 第一、二章。 2.1 地球磁场古地磁学主要研究过去的地球磁场行为。人类的直接测量仅仅能够追溯到几个世纪前，因此，古地磁学仍然是研究过去地球磁场行为的唯一手段。由于古地磁学涉及地球磁场，因此有必要了解一些有关地球磁场的知识。这一讲我们主要回顾现今地球磁场的一些基本性质。地磁场由地球液态外核的对流引起（外核由铁、镍和一些未知的较轻成分构成）。产生对流的能量的来源目前还不清楚，但是一般认为一部分来源于是地球的冷却过程，另外一部分则来源于由铁/镍构成的液态外核的浮力，这一浮力则由纯铁内核的冷却引起。这个导电流体的运动受控于液态外核的浮力、地球自传以及导电流体和磁场的相互作用（这是一个异常复杂的非线性过程）。确定导电流体的运动方式以及其产生的磁场状态是一个极具挑战性的课题，但是我们已经知道这种导电流体的运动是一种自激发电机过程，它可以产生并维持巨大的磁场。 2.1.1 地球参考场在很多情况下，确定地球磁场在一特定时间的空间分布非常有用。对地球磁场及其变化率的数学近似可以比较准确地估计地球磁场在给定时间和地点的值（最少在几百年以内）。由第一章可知，地表的磁场大致是个标量的势场，并服从拉普拉斯方程：这个方程可以改写为：这个方程的一个解是：对地球磁场，一般可以写作半径为r，纬度余弦θ，经度?的标量势：

其中，g 和h 是高斯系数，可以从特定的年代计算得出，单位为nT ，或磁通量（注意，公式中μ0由tesla [B ]转换到Am -1 [H ]）。角标e 和i 代表外场或者内场的起源，a 是地球半径（6.371 х 106 m ），μ0是自由空间的磁导率（参看第一讲中的表1.1），m l P 正比于勒让德多项式，其由传统的施密特多项式归一化而来（可参看建议的读物）。图2.2展示了三种矢量场的全球倾角分布及对应的面谐函数的：即轴向的（m ＝0）偶极子场（l ＝1），四极子场（l ＝2），以及八极子场（l ＝3）。它们的贡献分别由0 1g ，0 2g 和0 3g 确定。相关的多项式（图2.1）为：如果转动图2.2a 中的轴向偶极子场，使其北极指向格林威治子午线，那么它就由系数0 1 h 确定，如果指向90?E ，则将由系数1 1h 而定。所以，总的偶极子贡献将是轴向和两个沿赤道的偶极子项的矢量相加，即。总的四极子贡献（l ＝2）由五个系数而定，总的八极子（l ＝3）贡献则由七个系数而定。一般来讲，如果下标（l ）和上标（m ）的差为奇数（比如，轴向偶极子0 1g 和八极子0 3g ），则相应的地球磁场对于赤道是非对称的。然而，如果l 和m 的差为偶数（如，轴向四极子0 2g ），则相应的地球磁场是对称的。图2.2a 表示，由与现今地磁场方向一致的单一偶极子场产生的倾角。在北半球，倾角都是正的（向下），而在南半球是负的（向上）。相反，由四极子场产生的倾角（图 2.2b ）是在极区是向下的，在赤道处则是向上的。由轴向八极子场（图2.2c ）产生的倾角关于赤道也是非对称的，在两个极区的方向相反，并在中纬度地区被具有相反方向的条带分开。地球磁场是一个矢量场，所以在每个点都有方向和强度（图2.3）。无论选择怎样的坐

水文地球化学

水文地球化学研究现状、基本模型与进展摘要：1938 年, “水文地球化学”术语提出, 至今水文地球化学作为一门独立的学科得到长足的发展, 其服务领域不断扩大。当今水文地球化学研究的理论已经广泛地应用在油田水、海洋水、地热水、地下水质与地方病以及地下水微生物等诸多领域的研究。其研究方法也日臻完善。随着化学热力学和化学动力学方法及同位素方法的深入研究, 以及人类开发资源和保护生态的需要, 水文地球化学必将在多学科的交叉和渗透中拓展研究领域, 并在基础理论及定量化研究方面取得新的进展。早期的水文地球化学工作主要围绕查明区域水文地质条件而展开, 在地下水的勘探开发利用方面取得了可喜的成果( 沈照理, 1985) 。水文地球化学在利用地下水化学成分资料, 特别是在查明地下水的补给、迳流与排泄条件及阐明地下水成因与资源的性质上卓有成效。20 世纪60 年代后, 水文地球化学向更深更广的领域延伸, 更多地是注重地下水在地壳层中所起的地球化学作用( 任福弘, 1993) 。 1981 年, Stumm W 等出版了5水化学) ) ) 天然水化学平衡导论6 专著, 较系统地提供了定量处理天然水环境中各种化学过程的方法。1992 年, C P 克拉依诺夫等著5水文地球化学6分为理论水文地球化学及应用水文地球化学两部分, 全面论述了地下水地球化学成分的形成、迁移及化学热力学引入水文地球化学研究的理论问题, 以及水文地球化学在饮用水、矿水、地下热水、工业原料水、找矿、地震预报、防止地下水污染、水文地球化学预测及模拟中的应用等, 概括了20 世纪80 年代末期水文地球化学的研究水平。特别是近二十年来计算机科学的飞速发展使得水文地球化学研究中的一些非线性问题得到解答( 谭凯旋, 1998) , 逐渐构架起更为严密的科学体系。 1 应用水文地球化学学科的研究现状 1. 1 油田水研究水文地球化学的研究在对油气资源的勘查和预测以及提高勘探成效和采收率等方面作出了重要的贡献。早期油田水地球化学的研究只是对单个盆地或单个坳陷, 甚至单个凹陷进行研究, 并且对于找油标志存在不同见解。此时油田水化学成分分类主要沿用B A 苏林于1946 年形成的分类。1965 年, E C加费里连科在其所著5根据地下水化学组分和同位素成分确定含油气性的水文地球化学指标6中系统论述了油气田水文地球化学特征及寻找油气田的水文地球化学方法。1975 年, A G Collins 在其5油田水地球化学6中论述了油田水中有机及无机组分形成的地球化学作用( 汪蕴璞, 1987) 。1994 年, 汪蕴璞等对中国典型盆地油田水进行了系统和完整的研究, 总结了中国油田水化学成分的形成分布和成藏规律性, 特别是总结了陆相油田水地球化学理论, 对油田水中宏量组分、微量组分、同位素等开展了研究, 并对油田水成分进行种类计算, 从水化学的整体上研究其聚散、共生规律和综合评价找油标志和形成机理。同时还开展了模拟实验、化学动力学和热力学计算, 从定量上探索油田水化学组分的地球化学行为和形成机理。 1. 2 洋底矿藏研究

广义加性模型GAM

你这也没分析啊，就是用head命令把前6行输出出来了。你是说你用广义加性模型gam—— gam(formula,family=gaussian(),data=list(),weights=NULL,subset=NULL, na.action,offset=NULL,method="GCV.Cp", optimizer=c("outer","newton"),control=list(),scale=0, select=FALSE,knots=NULL,sp=NULL,min.sp=NULL,H=NULL,gamma=1, fit=TRUE,paraPen=NULL,G=NULL,in.out,...) 1. formula：GAM的公式 2. family：服从的分布 3. data：所需的一个数据框或列表包含模型响应变量，协变量 4. weights：现有的数据上的权重 5. subset：可以使用的观测值的一个子集。 6. na.action：一个函数，它表示时会发生什么数据包含“NA”。 7. offset：模型偏移量 8. control：控制参数，以取代默认值返回gam.control 9. method：平滑参数估计方法 10. optimizer：指定的数值优化方法 11. scale：如果这是正的，尺度参数；负的，规模参数未知。0说明是泊松分布和二项分布和未知的，否则，尺度参数为1。

12. select：如果这是TRUE然后gam可以添加一个额外的惩罚变量，以每学期，以便它可以被扣分零。这意味着平滑参数估计是拟合的一部分的，可以完全除去从模型中的条款。如果相应的平滑参数估计值为零，那么额外的惩罚没有任何效果。下面是一个例子—— Family: gaussian Link function: identity Formula: y ~ s(x0) + s(x1) + s(x2) + s(x3) Parametric coefficients: Estimate Std. Error t value Pr(>|t|) #线性变量的回归系数和显著性检验结果 (Intercept) 7.83328 0.09878 79.3 <2e-16 *** p值＜0.05，没有通过原假设，有显著的统计意义。 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

地球磁场

地球磁场地球磁场地球磁场言是偶极型的，近似于把一个磁铁棒放到地球中心，使它的北极大体上对着南极而产生的磁场形状，但并不与地理上的南北极重合，存在磁偏角。当然，地球中心并没有磁铁棒，而是通过电流在导电液体核中流动的发电机效应产生磁场的。简介自然地球磁场图片地球磁场The Earth magnetic field不是孤立的，它受到外界扰动的影响，宇宙飞船就已经探测到太阳风的存在。太阳风是从太阳日冕层向行星际空间抛射出的高温高速低密度的粒子流，主要成分是电离氢和电离氦。因为太阳风是一种等离子体，所以它也有磁场，太阳风磁场对地球磁场施加作用，好像要把地球磁场从地球上吹走似的。尽管这样，地球磁场仍有效地阻止了太阳风长驱直入。在地球磁场的反抗下，太阳风绕过地球磁场，继续向前运动，于是形成了一个被太阳风包围的、彗星状的地球磁场区域，这就是磁层。[1] 地球磁层位于距大气层顶600～1000公里高处，磁层的外边界叫磁层顶，离地面5～7万公里。在太阳风的压缩下，地球磁力线向背着太阳一面的空间延伸得很远，形成一条长长的尾巴，称为磁尾。在磁赤道附近，有一个特殊的界面，在界面两边，磁力线突然改变方向，此界面称为中性片。中性片上的磁场强度微乎其微，厚度大约有1000公里。中性片将磁尾部分成两部分：北面的磁力线向着地球，南面的磁力线离开地球。地球磁场 1967年发现，在中性片两侧约10个地球半径的范围里，充满了密度较大的等离子体，这一区域称作等离子体片。当太阳活动剧烈时，等离子片中的高能粒子增多，并且快速地沿磁力线向地球极区沉降，于是便出现了千姿百态、绚丽多彩的极光。由于太阳风以高速接近地球磁场的边缘，便形成了一个无碰撞的地球弓形激波的波阵面。波阵面与磁层顶之间的过渡区叫做磁鞘，厚度为3～4个地球半径。

广义线性模型

广义线性模型
1．概述
广义线性模型是传统的线性模型的延伸，它是总体均值通过一个非线性连接函数依赖于线性预测值，有许多广泛应用的统计模型都属于广义线性模型，其中包括正态误差的经典性模型，二元数据的对数和概率单位模型以及多项数据的对数线性模型，还有其它许多有用的统计模型，如果选择合适的连接函数和响应概率分布，也可以表示为广义线性模型。
2．线性模型
线性模型也称经典线性模型或一般线性模型，其模型的形式为：
Y ? XT? ??
其中， yi ?Y ? { y1 , y2 ,?, yn } 是因变量的第 i 次观测， xi ? X ? {x1 , x2 ,?, xn } 是自变量，它是一个列向量，表示第 i 次观测数据。未知系数向量 ? 可以通过对 Y 的最小二乘拟合估计， ? 是均值为零，方差为常数的随机变量。模型的几个基本假设： ? ? ? ? ? ? 因变量是连续随机变量自变量相互独立每一个数值型自变量与因变量呈线性关系每一个数值型自变量与随机误差相互独立观察个体的随机误差之间相互独立随机误差 {? i } ~ N (0,? ) 。
然而，实践中常不满足此假设

3．广义线性模型
广义线性模型，是为了克服一般线性模型的缺点出现的，是一般线性模型的推广。 ? 广义线性模型在两个方面对一般线性模型进行了推广： ? 一般线性模型中要求因变量是连续的且服从正态分布，在广义线性模型中，因变量的分布可扩展到非连续的资料，如二项分布、Poisson 分布、负二项分布等。 ? 一般线性模型中，自变量的线性预测值 ? 就是因变量的估计值 ? ，而广义线性模型中，自变量的线性预测值 ? 是因变量的函数估计值 g ( ? ) 。 ? 广义线性模型包括一下组成部分： ? 线性部分正好是一般线性模型所定义的：
?i ? ?0 ? ?1 x1i ? ?2 x2i ? ? ? ?m xmi
? 连接函数( link function)：
?i ? g (?i )
连接函数为一单调可微（连续且充分光滑）的函数。连接函数起了关联“Y 的估计值 ? ”与“自变量的线性预测值 ? ”的作用。在经典的线性模型中，“Y 的估计值”与“自变量的线性预测”是一回事。 ? 广义线性模型建立通过对数据选定因变量和自变量，以及选择合适的连接函数和响应概率分布，既可以建立一个广义线性模型。例如： ? 一般线性模型因变量：连续变量分布：正态分布连接函数： ? ? ? ? Logistic 回归模型因变量：（0，1）分布：二项分布连接函数： ? ? log(
?
1? ? )
? Poisson 回归模型因变量：计数和个数分布：Poisson 分布

磁场及其描述汇总

磁场及其描述目标认知学习目标 1．了解磁现象，理解电流的磁效应及其伟大意义。 2．通过磁的相互作用现象，知道磁场的存在和磁场的基本性质。 3．了解地磁场的分布以及地磁场对地球生命及人类活动的意义。 4．理解磁感线的意义，能够熟练地运用安培定则确定电流的磁场方向。 5．理解磁场的方向；理解磁感应强度的定义、磁通量的定义和计算方法；理解匀强磁场的特点以及在匀强磁场中磁通量的计算。学习重点难点 1．对磁现象及其电本质的理解，对地磁的理解。 2．电流的磁场及方向的判断——安培定则。 3．磁感强度的定义及磁通量的计算。知识要点梳理知识点一：磁现象要点诠释： 1．磁性、磁体物质具有吸引铁、钴、镍等物质的性质叫磁性。具有磁性的物体叫磁体。 2．磁极磁体的各部分磁性强弱不同，磁性最强的区域叫磁极。任何磁体都有两个磁极，一个叫南极（又称S极），另一个叫北极（又称N极）。 3．磁极间的相互作用同名磁极相互排斥，异名磁极相互吸引。 4．磁化、磁性材料变无磁性物体为有磁性物体叫磁化，变有磁性物体为无磁性物体叫退磁。磁性材料可分为软磁性材料和硬磁性材料。磁化后容易去掉磁性的物质叫软磁性材料，不容易去磁的物质叫硬磁性材料。一般来讲软磁性材料剩磁较小，硬磁性材料剩磁较大。软磁性材料可应用于需被反复磁化的场合，例如振片磁头、计算机记忆元件、电磁铁等；硬磁性材料可应用于制作永久磁铁。知识点二：电流的磁效应要点诠释： 1．电流对小磁针的作用 1820年，丹麦物理学家奥斯特发现，导线通电后，其下方与导线平行的小磁针发生偏转，如图所示。

说明：在做奥斯特实验时，为排除地球磁场的影响，小磁针应南北放置，通电导线也应南北放置。2．磁铁对通电导线的作用如图所示，磁铁会对通电导线产生力的作用，使导体棒偏转。 3．电流和电流间的相互作用如图所示，有互相平行而且距离较近的两条导线，当导线中分别通以方向相同和方向相反的电流时，观察到发生的现象是：同向电流相吸，异向电流相斥。知识点三：磁场要点诠释： 1．定义磁体或电流周围存在一种特殊物质，能够传递磁体与磁体、磁体与电流之间、电流与电流之间的相互作用，这种特殊的物质叫磁场。（说明：所有的磁作用都是通过磁场发生的，磁场和电场一样，是物质存在的另一种形式，是客观存在的。 2．磁场的基本性质对放入其中的磁极、电流或运动电荷产生力的作用。 3．磁场的产生（1）永磁体周围存在磁场；（2）电流周围存在磁场——电流的磁效应；（3）运动的电荷周围存在磁场——磁现象的电本质。电流是大量运动电荷形成的，所以运动电荷周围空间也有磁场。静止电荷周围空间没有磁场。4．磁场的方向

水文地球化学基础知识

《水文地球化学基础知识》 ——（绝对一个字一个字打出来的，正版资料！）名词解释

目录第一章水化学基础第一节溶解平衡 (3) 第二节碳酸平衡 (4) 第三节地下水中络合物的计算 (4) 第四节氧化还原反应 (5) 第二章地下水的化学成分的组成第一节天然水的组成 (6) 第二节天然水的化学特性 (6) 第三节元素的水文地球化学特性 (7) 第四节天然化学成分的综合指标（三种） (7) 第五节地下水化学成分的数据处理 (7) 第三章地下水化学成分的形成与特征第一节地下水基本成因类型的概念 (7) 第二节渗入成因地下水化学成分的形成与特征 (8) 第三节沉积成因地下水化学成分的形成与特征 (8) 第四章水的地球化学循环第一节地下水圈的概念 (8) 第二节地壳中水的地球化学循环 (9) 第三节成矿过程中水的地球化学循环 (9) 第五章水文地球化学的应用第六章补充部分 (10)

第一章<水化学基础> 第一节溶解平衡质量作用定律：一个化学反应的驱动力与反应物及生成物的浓度有关化学平衡与自由能体系：把所研究对象一个物体或一组相互作用的物体称为体系或系统，而体系（或系统）周围的其他物质称为环境。状态及状态参数：热力学状态分为平衡状态和非平衡状态。热力学平衡体系特性是由系列参数来表示当体系没有外界影响时，各状态参数若能保持长久不变，此体系称为热力学平衡状态。焓：它是一种化学反应向环境提供的热量总值。以符号“H”表示。在标准状态下，最稳定的单质生成1摩尔纯物质时的焓变化，称为“标准生成焓”。 △H r=△H(生成物)-△H（反应物）△H r为正值，属吸热反应，△H r为负值，属放热反应自由能：在热力学中，自由能的含义是指一个反应在恒温恒压下所能做的最大有用功，以符号“G”表示。在标准状态下，最稳定的单质生成1摩尔纯物质时的自由能变化，称为“标准生成自由能”，以“△Gf”表示 △Gr=△G(生成物)- △G（反应物）△Gr为正值，反应在恒温恒压条件下不能自发进行，△Gr 为负值，反应在恒温恒压条件下可以自发反应；△G=0，反应处于平衡状态。活度及活度系数为了保证计算的精确程度，就必须对水中组分的实测浓度加以校正，校正后的浓度为校正浓度，也就是活度。质量作用定律中，浓度是以活度表示的。活度是真实浓度（实测浓度）的函数，一般情况下，活度小于实测浓度。活度与实测浓度的函数表示式为:a=rm m为实测浓度（mol/L）,r为活度系数。活度系数随水中溶解固体（矿化度）增加而减小，但一般都小于1 理想溶液：从理论上讲，溶液中离子之间或分子之间没有相互作用，这种溶液称为理想溶液。地下水中的溶解-沉淀全等溶解：矿物与水接触产生溶解反应时，其反应产物都是溶解组分，这种溶解反应称为全等反应；非全等溶解：矿物与水接触产生溶解反应时，其反应产物除溶解组分外，还有新生成的组分，这种反应称为非全等溶解溶度积：当难溶电解质溶于水而成饱和溶液时，溶液中同时存在的溶解离子和未溶解的固体。按质量作用定律，在给定的温压下，溶液中相应方次的离子的活度乘积是一个常数，称为平衡常数K，对于难溶盐来说，这个常数称为“容积度”，或者“溶度积常数”常用KSP表示。溶解度：在给定温压下，达到溶解平衡时，溶液中溶解物质的总量。在水文地球化学研究中，溶解度常用mg/L表示。同离子效应：一种矿物溶解于水溶液中，若水溶液中有与矿物溶解相同的离子，则这种矿物的溶解度就会降低，这种现象在化学上称为同离子效应。盐效应：矿物在纯水中的溶解度低于矿物在高含量水中的溶解度，这种含盐量升高使矿物溶解度增大的现象，在化学上称为盐效应。其主要原因是，水中含盐量升高，离子强度I也升高，而活度系数则降低。注：就对溶解度的影响而言，同离子效应大于盐效应。所以，在盐效应和同离子效应同时存在时，盐效应往往可忽略；如无同离子效应时，盐效应是应考虑的。饱和指数饱和指数是确定水与矿物出于何种状态的参数，以符号“SI”表示。一般来说，根据饱和指数值判断水

简单的优化模型

第三章部分习题 1. 在3.1节存储模型的总费用中增加购买货物本身的费用，重新确定最优定货周期和定货批量。证明在不允许缺货模型中结果与原来的一样，而在允许缺货模型中最优定货周期和定货批量都比原来结果减小 3. 在3.3节森林救火模型中，如果考虑消防队员的灭火速度λ与开始救火时的火势b 有关，试假设一个合理的函数关系，重新求解模型。 4. 在3.4节`最优价格模型中，如果考虑到成本q 随着产量x 的增加而降低，试做出合理的假设，重新求解模型。 7. 要在雨中从一处沿直线跑到另一处，若雨速为常数且方向不变，试建立数学，模型讨论是否跑都越快，淋雨量越少。将人体简化成一个长方体，高m a 5.1=（颈部以下），宽m b 5.0=厚m c 2.0=，设跑步距离 ,1000m d =跑步最大速度s m v m /5=，雨速s m u /4= ，降雨量h cm w /2=，记跑步速度为v ，按以下步骤进行讨论；（1）不考虑雨的方向，设降雨淋遍全身，以最大速度跑步，估计跑完全程的总淋雨量（2）雨从迎面吹来，雨线与跑步方向在同一铅直平面内，且与人体的夹角为θ，如图1建立总淋雨量与速度v 及参数θ,,,,,,w u d c b a 之间的关系，问速度v 多大，总淋雨量最少，计算0 30,0==θθ时的总淋雨量。（3））雨从背面吹来，雨线方向与跑步方向在同一铅直平面内，且与人体的夹角为?，如图2建立总淋雨量与速度v 及参数?,,,,,,w u d c b a 之间的关系，问速度v 多大，总淋雨量最少，计算030=θ时的总淋雨量。（4）以总淋雨量为纵轴，速度v 为横轴，对（3）作图（考虑α的影响），并解释结果的实际意义。（5）若雨线方向与跑步方向不在同一平面内，模型会有什么变化。

水文地球化学研究现状与进展

本文由国土资源部地质调查项目“全国水资源评价”和“鄂尔多斯自留盆地地下水赋存运移规律的研究”项目资助。改回日期:2001212217;责任编辑:宫月萱。第一作者:叶思源,女,1963年生,在读博士生,副研究员,从事矿水、地热水及水文地球化学研究。水文地球化学研究现状与进展叶思源1)　孙继朝2)　姜春永3) (1)中国矿业大学,北京,100083;2)中国地质科学院水文地质环境地质研究所,河北正定,050803; 3)山东地质工程勘查院,山东济南,250014) 摘　要　1938年,“水文地球化学”术语提出,至今水文地球化学作为一门独立的学科得到长足的发展,其服务领域不断扩大。当今水文地球化学研究的理论已经广泛地应用在油田水、海洋水、地热水、地下水质与地方病以及地下水微生物等诸多领域的研究。其研究方法也日臻完善。随着化学热力学和化学动力学方法及同位素方法的深入研究,以及人类开发资源和保护生态的需要,水文地球化学必将在多学科的交叉和渗透中拓展研究领域,并在基础理论及定量化研究方面取得新的进展。关键词　水文地球化学　研究现状　进展 Current Situ ation and Advances in H ydrogeochemical R esearches YE Siyuan 1) 　SUN Jichao 2) 　J IAN G Chunyong 3 ) (1)Chi na U niversity of Mi ni ng and Technology ,Beiji ng ,100083;2)Instit ute of Hydrogeology and Envi ronmental Geology ,CA GS , Zhengdi ng ,Hebei ,050803;3)S handong Instit ute of Geological Engi neeri ng S urvey ,Ji nan ,S handong ,240014) Abstract Hydrogeochemistry ,as an independent discipline ,has made substantial development since the term “hydrogeochemistry ”was created in 1938.At present hydrogeochemical theories have been applied to various fields such as oil field water ,ocean water ,geothermal water ,groundwater quality ,endemic diseases and groundwater microorganism ,and related research methods have also become mature.With the further development of chemical thermodynamics ,kinetics method and isotope method ,hydrogeochemistry will surely extend its research fields in the course of multi 2discipline interaction and make new progress in basic theory and quantifica 2tion research ,so as to meet the demand of human exploration and exploitation as well as ecological protection.K ey w ords hydrogeochemistry current state of research advance 早期的水文地球化学工作主要围绕查明区域水文地质条件而展开,在地下水的勘探开发利用方面取得了可喜的成果(沈照理,1985)。水文地球化学在利用地下水化学成分资料,特别是在查明地下水的补给、迳流与排泄条件及阐明地下水成因与资源的性质上卓有成效。20世纪60年代后,水文地球化学向更深更广的领域延伸,更多地是注重地下水在地壳层中所起的地球化学作用(任福弘,1993)。1981年,Stumm W 等出版了《水化学———天然水化学平衡导论》专著,较系统地提供了定量处理天然水环境中各种化学过程的方法。1992年,C P 克拉依诺夫等著《水文地球化学》分为理论水文地球化学及应用水文地球化学两部分,全面论述了地下水地球化学成分的形成、迁移及化学热力学引入水文地球化学研究的理论问题,以及水文地球化学在饮用水、矿水、地下热水、工业原料水、找矿、地震预报、防止地下水污染、水文地球化学预测及模拟中的应用等,概括了20世纪80年代末期水文地球化学的研究水平。特别是近二十年来计算机科学的飞速发展使得水文地球化学研究中的一些非线性问题得到解答(谭凯旋,1998),逐渐构架起更为严密的科学体系。第23卷　第5期2002210/4772482 地　球　学　报ACTA GEOSCIEN TIA SIN ICA Vol.23 No.5 Oct.2002/4772482

Model Writings

磁场中的几种模型

地磁磁场的基本特征及应用

广义线性模型

高中物理模型：常见的磁场整理

皖北矿区地下水化学组成控制因素及水源识别 研究进展 ——基于水岩相互作用和EPA Unmix 模型的思考

广义相加模型

第二章地球磁场

水文地球化学

广义加性模型GAM

地球磁场

最新地下水系统平衡化学模型的研究现状及发展方向

广义线性模型

磁场及其描述汇总

水文地球化学基础知识

简单的优化模型

水文地球化学研究现状与进展

皖北矿区地下水化学组成控制因素及水源识别研究进展 ——基于水岩相互作用和EPA Unmix 模型的思考