1 Introduction ATLaS a Small but Complete SQL Extension for Data Mining and Data Streams

ATLaS:a Small but Complete SQL Extension for Data Mining and Data Streams 1Haixun Wang2Carlo Zaniolo2Chang Richard Luo

1IBM T.J.Watson Research Center haixun@https://www.wendangku.net/doc/4714049800.html, 2Computer Science Dept,UCLA {zaniolo,lc}@https://www.wendangku.net/doc/4714049800.html,

1Introduction

DBMSs have long suffered from SQL’s lack of power and extensibility.We have implemented ATLaS[1],a powerful database language and system that enables users to develop complete data-intensive applications in SQL—by writing new aggregates and table functions in SQL,rather than in procedural languages as in current Object-Relational sys-tems.As a result,ATLaS’SQL is Turing-complete[7],and is very suitable for advanced data-intensive applications, such as data mining and stream queries.The ATLaS system is now available for download along with a suite of applica-tions[1]including various data mining functions,that have been coded in ATLaS’SQL,and execute with a modest (20–40%)performance overhead with respect to the same applications written in C/C++.Our proposed demo will illustrate the key features and applications of ATLaS.In particular,we will demonstrate:

?ATLaS’SQL features,including its native support for user-de?ned aggregates and table functions.?Advanced database applications supported by ATLaS’SQL,including continuous queries on data streams and data mining applications such as classi?ers main-tained over concept-drifting data streams.

?The ATLaS system,including its architecture,query rewriting and optimization techniques,and the data stream management module.

2ATLaS’SQL

ATLaS adopts from SQL-3the idea of specifying user de-?ned aggregates(UDAs)by an initialize,an iterate,and a terminate computation;however,ATLaS let users express these three computations by a single procedure written in

detected.This gives the UDA of Example2,where the RETURN statements appear in ITERATE instead of TERMI-NATE.The UDA online

avg(Next Int):Real

{T ABLE state(tsum Int,cnt Int);

INITIALIZE:{

INSERT INTO state VALUES(Next,1);

}

ITERA TE:{

UPDA TE state

SET tsum=tsum+Next,cnt=cnt+1;

INSERT INTO RETURN

SELECT sum/cnt FROM state

WHERE cnt%200=0;

}

TERMINA TE:{}

}

Straightforward as it appears to be,ATLaS’approach to aggregate de?nition greatly improves the expressive power and extensibility of SQL.For instance,in ATLaS,UDAs can call other UDAs,including themselves.This enables us to compute,for example,the transitive closure of a graph using a UDA that performs a depth-?rst traversal of the graph by recursively calling itself.In fact,we proved that SQL so extended is Turing-complete on database tables[7]. As a result,we can express in ATLAS advanced applica-tions such as data mining that are dif?cult to support well using the current SQL-compliant DBMSs[6].

3Stream Applications in ATLaS

SQL extensions have been proposed to support continuous queries in SQL[2].ATLaS’SQL is Turing complete,as a result,stream queries can be implemented in ATLaS with-out additional language constructs.

ATLaS supports a delta-based computation of aggre-gates on windows(Example3).UDAs on windows are de-?ned using three states INITIALIZE,ITERATE,and REVISE (which replaces TERMINATE).The?rst two states are ac-tive in the transient situation,when the query is?rst started on the stream,and the boundary of the window have not yet been reached.Once the boundary of the window have been reached then ITERATE is no longer true,and every new incoming tuple is processed by REVISE.In this state, the system maintains the EXPIRED table holding the input tuples that just expired(one for count-based windows,zero, one,or many for time-span based windows).This table has the same schema as the input tuples,(i.e.,EXPIRED(Next Int)for Example3),and it is updated automatically by the system.Thus,the sum and the count of the tuples in EX-PIRED can now be used to update the sum and the count, and then return the average value of the window.

Example3De?ning avg on windows

AGGREGA TE myavg(Next Int):Real

{T ABLE state(tsum Int,cnt Int);

INITIALIZE:{

INSERT INTO state VALUES(Next,1);

}

ITERA TE:{

UPDA TE state

SET tsum=tsum+Next,cnt=cnt+1;

}

REVISE:{

UPDA TE state SET

tsum=tsum+Next-SUM(E.Next),

cnt=cnt+1-count(E.*)

FROM EXPIRED AS E;

INSERT INTO RETURN

SELECT tsum/cnt FROM state

}

}

ATLaS also supports a window speci?cation in the FROM clause along the lines proposed in[2].Thus,a win-dow speci?cation consists of:

1.an optional partitioning clause,which partitions the

data into several groups and maintains a separate win-dow for each group,

2.a window size,using either the count of the elements

in the window,or the range of time covered by the window(i.e.,its time-span).

3.an optional?ltering predicate.

Thus,to compute the average call length,but considering only the ten most recent long-distance calls placed by each customer we will write the following query:

Example4Count-Based Window on a Stream

STREAM calls(customer

4Data Mining Applications in ATLaS

Using table functions and recursive aggregates,Algo-rithm1implements a scalable decision tree classi?er using merely14SQL statements.

1:AGGREGA TE classify(iNode Int,RecId Int,iCol Int,

iValue Int,iYorN Int)

2:{T ABLE treenodes(RecId Int,Node Int,Col Int,

Value Int,YorN Int);

3:T ABLE mincol(Col Int);

4:T ABLE summary(Col Int,Value Int,Yc Int,Nc Int)

INDEX(Col,Value);

5:T ABLE ginitable(Col Int,Gini Int);

6:INITIALIZE:ITERA TE:{

7:INSERT INTO treenodes

VALUES(RecId,iNode,iCol,iValue,iYorN);

8:UPDA TE summary

SET Yc=Yc+iYorN,Nc=Nc+1-iYorN

WHERE Col=iCol AND Value=iValue;

9:INSERT INTO summary

SELECT iCol,iValue,iYorN,1-iYorN

WHERE SQLCODE<>0;

}

10:TERMINA TE:{

11:INSERT INTO ginitable

SELECT Col,sum((Yc*Nc)/(Yc+Nc))/sum(Yc+Nc)

FROM summary GROUP BY Col;

HAVING count(Value)>1

AND sum(Yc)>0AND sum(Nc)>0;

12:INSERT INTO mincol

SELECT minpair(Col,Gini)→mPoint

FROM ginitable;

13:INSERT INTO result

SELECT iNode,Col FROM mincol;

{Call classify()recusively to partition each of its}

{subnodes unless it is pure.}

14:SELECT classify(t.Node*MAXV ALUE+m.Value+1,

t.RecId,t.Col,t.Value,t.YorN)

FROM treenodes AS t,

(SELECT tt.RecId RecId,tt.Value Value

FROM treenodes AS tt,mincol AS m

WHERE tt.Col=m.Col)AS m

WHERE t.RecId=m.RecId

GROUP BY m.Value;

}

}

and in-memory table optimization,is carried out during this

step.While ATLaS performs sophisticated local query op-timization,it does not attempt to perform major changes in the overall execution plan,which therefore remains under

programmer’s control.After rewriting,the code generator translates the query graphs into C++code.

The runtime model of ATLaS is based on data pipelin-ing.In particular,all UDAs,including recursive UDAs that

call themselves,are pipelined;thus,tuples inserted into the RETURN relation during the INITIALIZE/ITERATE steps are returned to their caller immediately.Therefore,local tables

declared in a UDA can not reside on the stack.Instead,they are assembled into a state structure which is then passed to the UDA for each INITIALIZE/ITERATE/TERMINATE call,so that these internal data are retained between calls.

The data stream management engine is responsible for

ef?ciently maintaining records in windows and the EX-PIRED table.Records in a window are stored in a disk?le. Count-based windows have?xed sizes,while time-based windows may require dynamic allocation of disk buffers.

A window speci?cation with a PARTITION clause may cor-respond to multiple windows,one for each unique partition key.Records of the windows are clustered by the partition key and stored in a same disk?le.ATLaS also supports data sharing among multiple queries that access the same external data stream concurrently.A single procedure is responsible for reading the data from the external stream and delivering them to the disk buffers of each individ-ual query.Furthermore,window speci?cations of different queries can share disk buffers if the speci?cations have the same?ltering predicate and PARTITION clause.

6About the Demo

Our demonstration consists of the following parts. ATLaS Language Features

The only extension introduced by ATLaS is the ability of de?ning UDAs and table functions in SQL,yet this mini-malist approach makes SQL Turing complete.We demon-strate ATLaS’expressive power and ease-of-use through a suite of UDAs and table functions that implement,for example,temporal databases operators(e.g.coalescing), greedy graph-optimization algorithms(e.g.the shortest path algorithm),OLAP operators(e.g.ROLLUP,CUBE), and many others.

ATLaS provides a GUI IDE for writing ATLaS pro-grams.An ATLaS program may consist of several mod-ules,which are either source code in ATLaS’SQL,source code in C/C++,or libraries to be dynamically linked with other modules.ATLaS also provides query plan visualiza-tion tools so that users can track the effect of query rewrit-ing and optimization.

Continuous Queries on Data Streams

We showcase ATLaS’ability of handling con-tinuous queries using the schema and queries in Stanford’s Stream Query Repository(https://www.wendangku.net/doc/4714049800.html,/stream/sqr).We implement each query in two different approaches.The?rst approach uses ATLaS’windows-on-streams construct similar to that proposed in[2].But ATLaS is Turing complete without this construct.The second approach implements the same query using ATLaS’UDAs and table functions.We will compare the pros and cons of the two approaches.

Data Mining Applications

Substantial extensions have been added to SQL over the years,yet data mining applications remain an unsolved challenge for DBMSs.We demonstrate how ATLaS’min-imalist approach attacks this problem.The demonstration package consists of data mining applications such as the de-cision tree classi?er,the Aprior algorithm for association rule mining,and the density-based clustering algorithm DBSCAN.All applications are written entirely in ATLaS’SQL,and can be applied directly on relational data[6].

Recently,stream data mining has been a?eld of intense research.The demonstration also includes a stream classi-?er that handles time-changing drifts in the streaming data. It is realized by leveraging ATLaS’continuous-query and data mining ability.

Our demonstration will show ATLaS incurs only a mod-est performance overhead with respect to the same applica-tions written in C/C++.

The ATLaS System

The demonstration will reveal ATLaS’internal architecture by focusing on several of its key components,such as the query rewrite module,the query plan generation module, and the stream data management engine. References

[1]https://www.wendangku.net/doc/4714049800.html,/atlas

[2]Brian Babcock,Shivnath Babu,Rajeev Motwani,

and Jennifer Widom.“Models and Issues in Data

Streaming Systems”,SIGMOD Record,V ol.30No.

3,pp.109-120(September2001).

[3]J.M.Hellerstein,P.J.Haas,and H.J.Wang.“On-

line Aggregation”.SIGMOD,1997.

[4]Haixun Wang and Carlo Zaniolo.“Using SQL to

Build New Aggregates and Extenders for Object-

Relational Systems”.VLDB2000.

[5]Haixun Wang and Carlo Zaniolo.“Extending SQL

for Decision Support Applications”.DMDW2002.

[6]Haixun Wang and Carlo Zaniolo.“ATLaS:A Na-

tive Extension of SQL for Data Mining and Stream

Computations”.SIAM Data Mining,May2003.

[7]Haixun Wang and Carlo Zaniolo.“On the Proper-

ties of a Native Extension of SQL for Data Streams

and Data Mining”.Submitted to VLDB2003.

1 Introduction On

On choice-o?ering imperatives Maria Aloni? 1Introduction The law of propositional logic that states the deducibility of either A or B from A is not valid for imperatives(Ross’s paradox,cf.[9]).The command (or request,advice,etc.)in(1a)does not imply(1a)(unless it is taken in its alternative-presenting sense),otherwise when told the former,I would be justi?ed in burning the letter rather then posting it. (1) a.Post this letter!? b.Post this letter or burn it! Intuitively the most natural interpretation of the second imperative is as one presenting a choice between two actions.Following[2](and[6])I call these choice-o?ering imperatives.Another example of a choice-o?ering imperative is (2)with an occurence of Free Choice‘any’which,interestingly,is licensed in this context. (2)Take any card! Like(1a),this imperative should be interpreted as carrying with it a permission that explicates the fact that a choice is being o?ered. Possibility statements behave similarly(see[8]).Sentence(3b)has a read-ing under which it cannot be deduced from(3a),and‘any’is licensed in(4). (3) a.You may post this letter.? b.You may post this letter or burn it. (4)You may take any card. In[1]I presented an analysis of modal expressions which explains the phe-nomena in(3)and(4).That analysis maintains a standard treatment of‘or’as logical disjunction(contra[11])and a Kadmon&Landman style analysis of‘any’as existential quanti?er(contra[3]and[4])assuming,however,an in-dependently motivated‘Hamblin analysis’for∨and?as introducing sets of alternative propositions.Modal expressions are treated as operators over sets of propositional alternatives.In this way,since their interpretation can depend on the alternatives introduced by‘or’(∨)or‘any’(?)in their scope,we can account for the free choice e?ect which arises in sentences like(3b)or(4).In this article I would like to extend this analysis to imperatives.The resulting theory will allow a uni?ed account of the phenomena in(1)-(4).We will start by presenting our‘alternative’analysis for inde?nites and disjunction. ?ILLC-Department of Philosophy,University of Amsterdam,NL,e-mail:M.D.Aloni@uva.nl

空气压缩机操作规程标准版本

文件编号：RHD-QB-K3394 （操作规程范本系列） 编辑：XXXXXX 查核：XXXXXX 时间：XXXXXX 空气压缩机操作规程标 准版本

空气压缩机操作规程标准版本 操作指导：该操作规程文件为日常单位或公司为保证的工作、生产能够安全稳定地有效运转而制定的，并由相关人员在办理业务或操作时必须遵循的程序或步骤。，其中条款可根据自己现实基础上调整，请仔细浏览后进行编辑与保存。 1.0作业条件 1.1固定式空气压缩机必须安装平稳牢固，基础要符合规定，移动式空气压缩机停置后，应保持水平，轮胎应楔紧。 1.2空气压缩机作业环境应保持清洁和干燥。贮气罐须放在通风良好处，半径15m以内不得进行焊接或热加工作业。 1.3贮气罐和输气管路每三年应作水压试验一次，试验压力为额定工作压力的150％。压力表和安全阀每年至少应校验一次。 1.4移动式空气压缩机拖运前，应检查行走装置

的紧固、润滑等情况，拖行速度不超过20Km/h。 2.0作业前的检查 2.1曲轴箱内的润滑油量应在标尺规定范围内。加添润滑油的品种、标号必须符合规定。 2.2各联结部位应紧固，各运动部位及各部阀门开闭应灵活，并处于起动前位置。 2.3冷却水必须用清洁的软水，并保持畅通。 2.4起动空气压缩机在无载荷状态下进行，待运转正常后，再逐步进入载荷运转。 2.5开启送气阀前，应将输气管道联接好,输气管道应保持通畅，不得扭曲，并通知有关人员后，方可送气，在出气口前不准有人工作或站立。 3.0作业中安全注意事项 3.1空气压缩机运转正常后，各种仪表指示值，应符合原厂说明书的要求。

3.2贮气罐内最大压力不得超过铭牌规定，安全阀应灵敏有效。 3.3进、排气阀、轴承及各部件应无异响或过热现象。 3.4每工作二小时需将油水分离器，中间冷却器，后冷却器内的油水排放一次，贮气罐内的油水每班必须排放一至二次。 3.5发现下列情况之一时，应立即停机检查，找出原因并待故障排除后，方可作业。 a.漏水、漏电或冷却水突然中断。 b.压力表、温度表、电流表的指示值超过规定。 c.排气压力突然升高，排气阀、安全阀失效。 d.机械有异响或电动机电刷发生强烈火花。 3.6运转中如因缺水致使气缸过热而停机时，不得立即添加冷水，必须待气缸体自然降温至60℃以

1.introduction

Introdution

Mike Jian

INTRODUCTION ?Section A: ?Comprises 8 two mark and 4 one mark multiple choice questions. ?Section B: ?Four 10 mark questions. ?Two 20 mark questions.

INTRODUCTION The examination is a three hour paper with 15 minutes reading and planning time. All questions are compulsory. Some questions will adopt a scenario/case study approach. All those questions will require some form of written response although questions on planning or review may require the calculation and interpretation of some basic ratios.

1.Which TWO of the following should be included in an audit engagement letter? ①Objective and scope of the audit ②Results of previous audits ③Management’s responsibilities ④Need to maintain professional scepticism A.① and ② B.① and ③ C.② and ④ D.③ and ④ (2 marks)

外文翻译关于Linux的介绍(Introduction to Linux)

毕业设计说明书 英文文献及中文翻译 学 专 指导教师： 2014 年 6 月

Introduction to Linux 1.1 History 1.1.1 UNIX In order to understand the popularity of Linux, we need to travel back in time, ab out 30 years ago... Imagine computers as big as houses, even stadiums. While the sizes of those com puters posed substantial problems, there was one thing that made this even worse: eve ry computer had a different operating system. Software was always customized to ser ve a specific purpose, and software for one given system didn't run on another system. Being able to work with one system didn't automatically mean that you could work w ith another. It was difficult, both for the users and the system administrators. Computers were extremely expensive then, and sacrifices had to be made even after th e original purchase just to get the users to understand how they worked. The total cost of IT was enormous. Technologically the world was not quite that advanced, so they had to live with t he size for another decade. In 1969, a team of developers in the Bell Labs laboratories started working on a solution for the software problem, to address these compatibility issues. They developed a new operating system, which was simple and elegant written in the C programming language instead of in assembly code able to recycle code. The Bell Labs developers named their project "UNIX." The code recycling features were very important. Until then, all commercially av ailable computer systems were written in a code specifically developed for one system . UNIX on the other hand needed only a small piece of that special code, which is now commonly named the kernel. This kernel is the only piece of code that needs to be ad apted for every specific system and forms the base of the UNIX system. The operating system and all other functions were built around this kernel and written in a higher pr ogramming language, C. This language was especially developed for creating the UNI

压缩机技术指南手册(B型)

压缩机使用手册 大金工业株式会社 压缩机开发中心

第一节大金压缩机概述 一、特点： 1. 高性能 2大金压缩机是一种无余隙（即无冷媒二次膨胀），且运转范围很宽的高效率压缩机。 2在室外低温制热时，柔性结构压缩机有很强的能力。 2. 低噪音、低震动 2无吸、排气阀，压缩机吸排气噪音大大降低。 2通过采用高精度，非接触式涡旋盘，压缩机的噪音性能得到进一步的提高。 2在空调系统安装时压缩机无须增加隔音盖板、消音棉。 2由于压缩机的振动小，这样大大提高了管路抗共振、断裂能力。使空调产 品的管路设计可以达到越简单越好。 3. 小型、重量轻 2因压缩机筒体径小、细长，从而为室外机的小型、轻量化提供了最佳选择。 2为了节约空间位置设计的灵活性，在原有四脚底盘的基础上新增加了三脚底盘的机型。使用户有更多的选择。 4. 高可靠性 2压缩机零部件数量少、且可靠性极高。 2压缩机能经受热泵系统的极其残酷的试验。 5. 便于使用 2压缩机中只有电机的保护装置是内置式，其它保护均由系统匹配。这样使系统设计人员可以根据需要在系统设置保护，使产品设计者更好的控制使用的 压缩机。

二、 构造： 电机转子 电机定子 动盘 静盘 排气孔 高压腔 支 架 曲轴 低压腔 冷冻机油 油 泵 欧氏机构 轴承支架 吸气管 吸入冷媒 排气管

三、 产品系列： 基本系列为以下7种： 四、 部件规格 1. 性能： ⑴ 按照下表条件进行试验，完全合格： ⑵ 冷冻能力、消耗功率、工作电流： 应确保在规格书中所规定的冷冻能 力、消耗功率、工作电流的±5％以内。 ⑶ 起动特性： 应按照下列条件进行起动。 ⑷ 绝缘电阻： 用500V 绝缘电阻表按照GB 方法进行测定，如果充电部和非充电部的绝缘电阻如 下时应为正常。 2 干燥时： 30M Ω以上 2 冷媒寝入时： 1M Ω以上 ⑸ 耐电压性能： 在AC2400V 、历时一秒的条件下，确保其无绝缘损坏。

自我介绍(self-introduction)

自我介绍(self-introduction) ??? 1. Good morning. I am glad to be here for this interview. First let me introduce myself. My name is ***, 24. I come from ******,the capital of *******Province. I graduated from the ******* department of *****University in July ,2001.In the past two years I have been preparing for the postgraduate examination while I have been teaching *****in NO.****middle School and I was a head-teacher of a class in junior grade two. Now all my hard work has got a result since I have a chance to be interview by you . I am open-minded ,quick in thought and very fond of history.In my spare time,I have broad interests like many other youngsters.I like reading books, especially those about *******.Frequently I exchange with other people by making comments in the forum on line.

空压机作业指导书

空压机作业指导书 1. 开机程序 1.1 检查空压机的供电电压是否与额定工作电压一致； 1.2 检查油位是否正确，油位必须在油标刻度线位置； 1.3 排放储气罐的冷凝水； 1.4 检查各阀门动作是否灵活； 1.5 打开出截止阀； 1.6 接通电源，电源指示灯亮，检查面板有无报警提示，如有应先解除报警； 1.7 按启动按钮，空压机正在执行正常的延时启动，预先设定的启动时间到空压机即自动启动； 1.8 注意观察控制面板上的压力，湿度以及电流的波动情况，作好数据记录（每4小时记录一次）； 1.9 确保机器平稳运行，没有意外的振动。 注意：在停机60秒之内，不要启动机器，必须将油气分离筒内压力完成释放（防止空压机在有背压情况下启动）

2. 停机程序 2.1按停机按钮，空压机开始延时停机状态，备机指示灯闪烁； 2.2经过一段时候，空压机自动停机，备机指示灯亮（如果空压机在运行时已经停机，按停止按钮完全停机）。 2.3切断电源。 2.4注意： 2.4.1空压机在备机状态时可能会停机，也可能在某一时刻启动，即使电机没有转动也不要认为是停机，必须查看备机的灯是否亮着！ 2.4.2只有当螺杆压缩机停止运行并释放压力后，才可进行检查和操作！ 2.4.3没装上空气过滤器时，决不要运行螺杆压缩机（在没有该过滤器情况下即使只运行一段时间也会给机器造成很大的损坏）！ 2.4.4到保养时间时，必须清洗或更换堵塞的空气过滤器。 A．每周至少检查一次空气过滤器中堆积的灰尘。需要时，应每天检查。 B.保养时，注意别让脏物进入空气过滤器中清洁的那一侧。 3.空气过滤器的保养 空气过滤器必须进行中间清洗或用新的空气过滤器芯替换（请参阅有关中间清洗的指南）。

加拿大介绍Canada Introduction

Canada Introduction Canada has a population just less than 30 million people in a country twice the area of the United States. The heritage of Canada was French and English; however, significant immigration from Asia and Europe's non-French and English countries has broadened Canada's cultural richness. This cultural diversity is considered a national asset, and the Constitution Act prohibits discrimination against individual citizens on the basis of race, color, religion, or sex. The great majority of Canadians are Christian. Although the predominant language in Canada is English, there are at least three varieties of French that are recognized: Quebecois in Quebec, Franco-Manitoban throughout Manitoba and particularly in the St. Boniface area of Winnipeg, and Acadian. The Italian language is a strong third due to a great influx of Italian immigrants following W.W.II. Canada's three major cities are distinctively, even fiercely different from one another even though each is a commercially thriving metropolitan center. Montreal, established in the 17th century and the largest French city outside France, has a strong influence of French architecture and culture. It is a financial and manufacturing center

空压机作业指导书_

作业指导书 LW-10/10空压机操作、安全操作规程 编号：盛祥ZS-001 一、目的 本规程用于指导操作者正确操作和使用设备。 二、适用范围 本规程适用于指导本公司空压机的操作与安全操作。 三、管理内容 （一）操作规程 1、操作者必须熟悉空压机操作顺序和性能，严禁超性能使用设备。 2、操作者必须经过培训、考试合格后，持证上岗。 3、开机前的准备： （1）检查标尺查看润滑油是否在规定范围。 （2）打开循环水泵，打开进、排水截门，检查冷却水是否畅通。 （3）打开放散，保证二级排气处于无压力状态，关闭减荷阀。 （4）长期未开机前，必须用手转动皮带轮，检查是否有撞击、震动或异常。 （5）清除机器附近及配电柜上的杂物。 （6）检查干燥器工作是否正常。 4、开车 （1）首先，将电源手动控制搬到“合”的位置。

接通电源，使空压机无负荷运转，检查运转是否正常，有无异声。 （2）用手逐渐转动手轮，打开减荷阀。 （3）运转中随时检查一二级排气压力、减荷阀切换（0.65MPa－0.8MPa）是否正常。 （4）操作人员每小时巡视一次，做好记录。 5、停车 （1）逐渐关闭减荷阀，使设备无负荷运转。 （2）断开设备电源，使机器停止运转5-10分钟后关闭进水阀门，关闭循环水泵。 （3）将电源搬到“分”的位置。 （4）对空压机前冷却器和后冷却器进行排污。冬季要将放水阀打开放尽存水，以免冻裂机器。 （5）对气液分离罐和储气罐排污。 （二）安全操作规程 1、操作者必须熟悉设备一般结构及性能，严禁超性能使用设备。 2、运行中，油压应在(0.1～0.3MPa)之间，如发现油压低于0.1MPa或高于0.3MPa及润滑油进水时，应立即停车检修。 3、运行中，发现机身温度过高，应立即检修。 4、停车后如温度过高，再开车时，先不要往机器注水，应让气缸自然冷却，防止爆裂。 5、运行中如发现有异常响声或安全隐患，应立即停车报修。 6、运行中如发现压力、温度、电流、仪表超过规定值 (一级压力0.19～0.23MPa；二级压力不超过1MPa；排气温度<180℃)，应立即停车报修。

英语口语集锦-介绍(introduction)

英语口语集锦－介绍(introduction) making introductions 给人作介绍 1. jane, tom. tom, jane. 2. jane, this is tom, tom, this is jane. 3. jane, i’d like you to meet my friend tom. 4. jane, have you met tom? 5. jane, do you know tom? 6. look, tom’s he re. tome, come and meet jane. 7. jane, this is tom. he’s a friend from college. 8. jane, tom is the guy i was telling you about. 9. do you know each other? 10. have you two met ? 11. have you two been introduced? 12. allow me to introduce professor linda ferguson of harvard university. 13. let me introduce our guest of honor, mr.david morris. 14. if you want to be introduced to the author, i think i can arrange it.

making a self-introduction 作自我介绍 1. may i introduce myself 2. hello, i’m hanson smith. 3. excuse me, i don’t think we’ve met. my name’s hanson smith. 4. how do you do? i’m hanson smith. 5. i’m david anderson. i don’t believe i’ve had the pleasure. 6. first let me introduce myself. i’m peter white, production manager. 7. my name is david. i work in the marketing department. after being introduced. 被介绍与对方认识后. 1. i’m glad to meet you. 很高兴认识你. 2. nice meeting you. 很高兴认识你. (平时用得最多的是nice to meet you ) 3. how nice to meet you. 认识你真高兴. 4. i’ve heard so much about you. 我知道很多关于你的事儿. 5. helen has told me all about you. 海伦对我将了好多你的事儿. 6. i’ve been wanting to meet you for some time.

空压机岗位作业指导书

空压机岗位作业指导书 一、岗位责任制 1、遵守各项规章制度，以及安全、技术操作和设备维护规程，做到“三不伤害”，杜绝“三违”现象。 2、严禁酒后上班。 3、上班时严禁串岗、睡岗、做与本岗位无关的事。 4、操作人员必须懂得作业现场设备操作的基本要领，使用性能、技术参数和了解本机的结构及工作原理，能处理一般性的机械故障。并通过培训考试合格后方可独立进行操作。 5、按规定正常供风。每小时检查油泵油量，每半小时检查水、风、油路是否畅通，每二小时检查各联接件及润滑点，并做好检查记录。设备上的安全设施 （安全阀、继电保护等）不得任意调节和拆除。机房保持通风，严禁烟火，若因工作需要电气焊时，应采取相应的安全措施。对发现的问题及时处理或上报，

配合做好整改处理工作。 6、作业过程中互相提醒、相互协配、互相监督, 确保作业安全。 7、发生事故要及时报告，并积极抢救。保护好事 故现场，把事故损失降到最低程度。 8、做好设备设施维护保养工作，积极开展现场的清洁生产、“三证合一”管理体系、5S管理活动，保持作业环境清洁、舒适，每班清扫包干区一次。 二、岗位安全操作规程 1、空压机必须经专门培训，考核合格并取得操作 资格证书后，方可进行作业，上班了解设备安全状况。 按技术操作规程对设备进行全面检查，确认安全后方可作业。 2、运行中冷却水突然中断，发觉后应马上停机, 严禁立即放入冷却水，待气缸冷却后再逐渐加水，以免气缸爆炸。 3、冬季若较长时间停转，须放净气缸水套之存水,

以防冰冻。 4、传动皮带的防护罩应保持完好，禁止用电机烘烤东西，安全气阀定期测试。 5、停车后做好场地、设备的“5S”保洁工作。

全厂用空压机规范书

嘉峪关宏晟电热有限责任公司工程 2X300MW机组 全厂用空压机 技术规范书

目录 1概述 (1) 2空压机技术规范 (1) 3设备安装及使用条件 (3) 4技术要求 (5) 5质量保证及技术服务 (6) 6供货范围 (7) 7包装、运输和储存 (8) 8技术文件 (9)

1概述 1.1嘉峪关宏晟电热有限责任公司新建2 300MW机组，需设置4台空气压缩机用于全 厂仪表用气和检修用气。本技术规范书是对该工程所用空压机的技术要求做出规定，空项部分由投标商填写。 1.2本技术规范书所提出的是最低限度的技术要求，并未对一切技术细节做出规定，也 未充分引述有关标准和规范的条文。供方应保证提供符合本规范书和现行工业标准的优质产品。 1.3如果供方没有以书面方式对本规范书的条文提出异议，那么需方将认为供方提出的 产品完全符合本规范书的要求。 1.4在签订合同之后，到供方开始制造之日的这段时间内，需方有权提出因规范、标准 和规程发生变化而产生的一些补充修改要求，供方应遵守这个要求，具体款项内容由供、需双方商定。 1.5本技术规范书所使用的标准，如遇与供方所执行的标准不一致时，按较高的标准执 行。如果本规范书与现行使用的有关国家标准以及部颁标准有明显抵触的条文，供方应及时书面通知需方进行解决。 1.6本技术规范书为订货合同的附件，与合同正文具有同等效力。 2空压机技术规范 2.1型式：螺杆式喷油润滑 2.2压缩介质：空气 2.3排气量：≥30m3/min（吸入状态：20℃，1个大气压） 2.4排气压力：0.8MP a（g） 2.5台数： 4 台 2.6排气温度：≤40 ℃ 2.7型号：； 2.8压缩机轴功率： 额定排气量：kw ， 空载：kw； 2.9配用电动机型号：(Y型)； 电动机功率：kW；

空气压缩机安全操作作业指导书示范文本

空气压缩机安全操作作业指导书示范文本 In The Actual Work Production Management, In Order To Ensure The Smooth Progress Of The Process, And Consider The Relationship Between Each Link, The Specific Requirements Of Each Link To Achieve Risk Control And Planning 某某管理中心 XX年XX月

空气压缩机安全操作作业指导书示范文 本 使用指引：此管理制度资料应用在实际工作生产管理中为了保障过程顺利推进，同时考虑各个环节之间的关系，每个环节实现的具体要求而进行的风险控制与规划，并将危害降低到最小，文档经过下载可进行自定义修改，请根据实际需求进行调整与使用。 1.0. 目的: 1.1. 为保证产品质量,规范空气压缩机作业，确保设备 安全性和产品质量的稳定性。 2.0. 适用范围: 2.1. 本程序适用于空气压缩机作业以及新员工培训。 3.0. 空气压缩机安全控制要求： 3.3. 空压机的内燃机和电动机的使用应符合安全操作 规定。 3.4. 空压机环境要保持清洁和干净。贮气罐应放在通 风良好处,距罐15M以内不得焊接和热加工作业。 3.5. 贮气罐与输气管路每三年应作水压试验一次,试验

压力应为额定压力的150%。压力表和安全阀应每年至少校验一次 4.0. 本设备的使用方法： 4.1. 打开压缩机主电源开关，扭动急停按挚。 4.2. 将选择按钮置于自动，启动电机。 4.3. 打开送气输出开关各储气瓶开关。 4.4. 检查气压表达到0.8aps是否会自动跳载。 4.5. 生产完成或下班按下急停挚关闭电源、气源开关，清理环境卫生。 5.0. 本设备生产注意事项： 5.1. 润滑油料均添加充足， 5.2. 各连接部位紧固,各运动机构及各部阀门开闭灵活； 5.3. 各防护装置齐全良好,贮气罐内无存水； 5.4. 电动空压机的电动机及启动器外壳接地良好,接地

螺杆空压机使用说明书

目录 第一章前言 (2) 第二章安全规程 (3) 一．安装预防措施 (3) 二．操作预防措施 (3) 三．保养预防措施………………………………………………… 四．失火时的预防措施…………………………………………… 第三章空压机机组简介……………………………………………… 一．主要技术规格………………………………………………… 二．概述…………………………………………………………… 第四章空压机机组的安装…………………………………………… 一．安装场所的选择……………………………………………… 二．安装基础……………………………………………………… 三．安装管道……………………………………………………… 四．供电状况……………………………………………………… 第五章系统流程及各部件功能……………………………………… 一．气路系统……………………………………………………… 二．油路系统……………………………………………………… 三．冷却系统……………………………………………………… 四．电气控制、调节系统及安全保护…………………………… 第六章操作…………………………………………………………… 一．初次启动前的准备工作……………………………………… 二．开车与停车…………………………………………………… 三．运行中的注意事项…………………………………………… 四．基本操作……………………………………………………… 第七章保养及调整…………………………………………………… 一．保养周期……………………………………………………… 二．选择润滑油及定期更换……………………………………… 三．长期停机保养………………………………………………… 四．空气滤清器的更换及保养…………………………………… 五．冷却器的保养………………………………………………… 六．安全保护装置的调整与检查………………………………… 第八章故障及修理…………………………………………………… 一．空压机可能发生的故障及维修……………………………… 二．电气系统可能发生的故障及维修……………………………

医用静音无油空压机选型指导书

医用静音无油空压机选型指导书 编制： 审核： 批准： 版本号： A.0 实施日期： 文件编号： 成都老肯科技股份有限公司 一、适用范围

现在市面上静音空气压缩机生产厂家和销售种类较多，根据对空气质量要求，基本可分为有油润滑和无油润滑两种。 医用静音无油空气压缩机主要是为需要气源的医疗保健设备提供充足、洁净的气源，适用于牙科设备制氧机设备、呼吸机设备、医药设备等。 本指导书所述医用空气压缩机（以下简称空压机），包括但不限于在高温高压蒸汽灭菌器（含脉动真空灭菌器）、内镜清洗设备、清洗消毒器、牙科综合治疗机等方面的应用。 本指导书用于指导高温高压灭菌器的选购、检验、供应商开发，但不能替代采购合同中技术附件里的相关技术要求。其他类似空压机的选型参考本指导书进行。 二、空压机性能特点： 1、体积小 紧凑、合理的结构设计，可以有效地降低产品的占地面积。 2、噪音低 输出气体平稳无波动、合理的减震降噪设计，可以最大限度减少噪音污染。 3、抑菌内喷涂 采用了纳米抗菌喷涂技术的空压机，能有效抑制大肠埃希氏菌、金黄色葡萄球菌、白色念珠菌等。 4、安装方便 只需与用气设备连接，然后接通电源即可正常工作。 5、使用寿命 选购空压机时，应充分考虑使用寿命，通常无故障工作时间都应超过12000小时。 6、免维护 应采用无油润滑设计，这样可解决普通空压机定期加油保养和因漏油造成的环境污染。 三、技术参数 1、电源： 电压、频率应适合最终用户所在地区的电源要求；空压机功率，通常都会≤4000W. 市场销售人员、采购人员、品质检验人员，应充分关注空压机的电源是否需目的

用途相一致。 2、流量、压力 首先要根据设备额定压力下的空气流量来选择空压机的型号。所选择的空气压缩机最好流量稍大于所需流量，这样以防一些管路接头泄露造成流量跟不上，从而压力达不到需求。气体流量单位通常有M3/Hour（立方米/小时）和L/Min （升/分钟）。1M3等于1000L。 结合我公司实际，通常需要选择62L/min左右的空压机。 压力也是一个关键因素，空压机最高排气压力必须和设备所需压力相符，小了则无法满足设备需求，大了会使采购成本上升。压力表示单位通常有Bar,kg/cm2(俗称公斤压力)。 3、过滤效果 应查验空压机的过滤效果，通常要求至少0.3um或更好。 4、静音效果 应用噪音计实际测试静音效果与供方宣传资料所述静音效果的符合性。 5、干燥器（选配） 带干燥功能的空压机，应详细说明干燥原理和干燥指标。 6、供气能力匹配 当实现“一拖多”使用时，应根据使用的实际需求选型，并应预留足够的安全裕量。具体请咨询相关产品负责人和空压机供应商。 四、法规标准 空压机应首先符合相应的国内、国际标准和（或）行业标准；其次，供方应提供其注册检验报告、注册检验标准。 五、资质要求 制造商应必须具有与之相适应的生产许可资质。 优先选用通过了ISO9001体系认证的制造商的产品。 通过了CE、UL等认证的制造商应作为优先考虑的供方。 能提供第三方权威检测报告的制造商有限考虑。 应查验供方相关生产、经营资质、认证等证书与其有效期。 该产品属于医疗器械，还应提供产品医疗器械注册证、医疗器械登记表。

包装车间空压机作业指导书

包装车间空压机作业指导书 1、目的：熟悉空压机的工作原理与操作规程，掌握设备的维护与保养的方法，保证设备的正常运转； 2、范围：脱腊操作工 3、操作规程 （1）空压机型号 空压机的型号为：LS16-75 两台； （2）空压机安全操作规程 为避免发生伤害人身及毁坏及其的事故，客户应制定详细的安全操作规程。以下几点可供参考。 ①操作人员实现必须经过严格培训，并仔细阅读和理解本手册。 ②及其安装，使用和操作，应遵守国家和当地的的有关法律和法规。 ③严禁随意改动机器的结构和控制方式，除非有制造厂的书面许可。

④发现异常情况，应立即停机，并切断所有电源。 ⑤周围环境中不存在易燃、易爆、有毒和有腐蚀性气体。 ⑥维修或调整机构之前，必须停机卸压，并切断电源。 （3）空压机检查电动机转向 接好电气线路之后，首先应检查电动机转向。方法如下： 如果是仪表监控器机型，将选择按钮置“手动”档，按下“启动”按钮，紧接着按下“停机”按钮，让电动机试转一下。若从电动机后部看过去，传动轴是顺时针转动，则转向正确。若转向不正确，则断开电源，交换任意两根火线，接好后再试一次。电机与压缩机之间的接筒上有以箭头指明转向。如果是电脑监控器机型，在监控器控制面板上，拉出紧急停机按钮，按“I”键(启动)，紧接着马上按“O”键（停机）让电机试转一下。若从电动机后看过去，传动是顺时

针转动，则转向正确。若转向不正确，则断开电源，交换任意两根火线，接好后再试一次。电机与压缩机之间的接筒上有一箭头指明转向。 （4）空压机初次启动前的准备工作 ①检查电气接线是否可靠； ②检查油位，应在油试镜中心线附近，不足则加； ③打开排气阀； ④接通电源； ⑤检查电机的转向； ⑥再次启动压缩机，并缓缓关闭排气截止阀，检查机组的卸载压力是否与设定值一致。若不一致，应重新设定。 ⑦检查各系统工作是否正常，是否有漏油、漏气等现象，是否油不正常的声音，如有异常，应停机检查。 ⑧停机停机前，线关闭排气截止阀，让压缩机在卸载状态下至少运行30秒，然后再停机。

英语自我介绍(self-introduction)模板

英语自我介绍例文模板： Sample1 My name is ________. I am graduate from ________ senior high school and major in ________. There are ________ people in my family. My father works in a computer company. And my mother is a housewife. I am the youngest one in my family. In my spare time, I like to read novels. I think reading could enlarge my knowledge. As for novels, I could imagine whatever I like such as a well-known scientist or a kung-fu master. In addition to reading, I also like to play PC games. A lot of grownups think playing PC games hinders the students from learning. But I think PC games could motivate me to learn something such as English or Japanese. My favorite course is English because I think it is interesting to say one thing via different sounds. I wish my English could be improved in the next four years and be able to speak fluent English in the future. Sample2: I am . I was born in . I graduate from senior high school and major in English. I started learning English since I was 12 years old. My parents ha ve a lot of American friends. That’s why I have no problem communicating with Americans or others by speaking English. In my spare time, I like to do anything relating to English such as listening to English songs, watching English movies or TV programs, or even attending the activities held by some English clubs or institutes. I used to go abroad for a short- term English study. During that time, I learned a lot of daily life English and saw a lot of different things. I think language is very interesting. I could express one substance by using different sounds. So I wish I could study and read more English literatures and enlarge my knowledge. Sample3: My name is . There are 4 people in my family. My father is a Chemistry teacher. He teaches chemistry in senior high school. My mother is an English teacher. She teaches English in the university. I have a younger brother, he is a junior high school student and is preparing for the entrance exam. I like to read English story books in my free time. Sometimes I surf the Internet and download the E- books to read. Reading E- books is fun. In addition, it also enlarges my vocabulary words because of the advanced technology and the vivid animations. I hope to study both English and computer technology because I am interested in both of the subjects. Maybe one day I could combine both of them and apply to my research in the future. Sample4: My name is . I am from . There are people in my family. My father works in a computer company. He is a computer engineer. My mother works in a international trade company. She is also a busy woman. I have a older sister and a younger brother. My sister is a junior in National Taiwan University. She majors in