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1.
任何准静态过程都可在P—V图上表示出来,其中如果过程在P—V图上为一线性图线,我们就称之为P—V图上的线性过程(如图1所示的各过程),一般其过程方程可表为P=kV+b(0—1式)根据不同的k,可表示不同的过程。显见图1中①、②、③所示过程在系统变化的过程中无论是温度变化还是系统从外者吸取热量(或放出热量)都是单一的,然而对于④过程  相似文献   

2.
一定质量的某种理想气体的状态变化过程常用P—V图、P—T图和V—T图三种图像来描述.图像描述简洁直观,但三种图像之间的相互变换,大多学生都无从下手.笔者就理想气体状态方程的图像变化问题谈一些具体操作方法.  相似文献   

3.
多数热学教科书中对理想气体在 P—V 图上的四个等值过程及其热容量都作了详细的论述。本文将对理想气体在 P—V 图上的负斜率直线过程及其热容量进行论述。 1 两个转换点理想气体在 P—V 图上负斜率直线过程中,有两个转换点,即一个是温度转换点 M;另一个是吸、放热转换点 N,如图1所示。对此问题的论述多是根据热力学第一定律和理想气体的内能公式求出了 M、N 点。此外也可以用下列方法简单求出 M、N 点。因为 M 点是温度  相似文献   

4.
在研究气体状态变化规律时,常用P—V图、P—T图和V—T图表示气体的状态和变化过程。掌握三种图像所表述的气体规律和意义,明确图像的点和线与气体的状态和过程相对应的关系,以及气体图像的特点,是运用气体图像解决气体有关问题的关键。  相似文献   

5.
国家教委考试中心《物理科考试说明》将P—V、P—T图象列为C级,同时强调理解P—V、P—T图象的物理意义。笔者对1987年以来的高考物理试题作了一定的分析研究,发现高考对P—V、P—T图象问题的考查可以分为以下三类:①图象转换类——已知给出P—V图(或P—T图)画P—T图(或P—V图);②作图类——根据题目的文字叙述,在图中作出要求的点或是状态变化曲线;③添线析图类——在题目所给的图象基础上,添加适当的辅助线,进行分析解题。下面就这三类题结合高考试题作些分析。 一、图象转换类  相似文献   

6.
在讨论气体的三个实验定律时,理想气体的状态发生变化,往往使用P-V图线、P-T图线及V-T图线来表示,分析气体定律的图线,可以加深对气体状态和变化过程的理解,从而开阔思路,提高分析问题和解决问题的能力.1玻意耳-马略特定律与P-V图线玻意耳-马略特定律可表示为PV=恒量.在P-V图上,等温过程表示为双曲线.(1)在图1中,给出了不同温度时,等温变化过程的一组等温线①、②、③,根据理想气体的状态方程PV=值量,可知PV的值与T值成正比,因而不难确定不同等温线温度之间的相互关系:因为P3V3>P2V2>P1V1,所以T3>…  相似文献   

7.
题 在图1所示的电路中,电源电压保持不变,R1、R2为定值电阻,R为滑动变阻器,闭合电键S,将滑动变阻器的滑片P从右端滑到左端的过程中,电压表V1、V2的示数随电流表A示数变化的完整图线如图2中①、②图线所示.在图3中能正确反映该过程的电压表V3随电流表A示数变化的完整图线是()  相似文献   

8.
讨论理想气体P-V图上几种直角边分别和P轴、V轴平行的直角三角形循环的效率。通过讨论,分别计算出循环过程中系统吸收的热量\内能的变化以及系统对外界所作的功.并着重分析过程中系统与外界的热交换。通过对特例的分析得出计算P-V图上直角边分别和P轴、V轴平行的直角三角形循环的效率的一般计算方法  相似文献   

9.
理想气体直线过程AB的吸放热转换点N,在P-V图上是AB过程所在轴线与P、V两轴线交点间的有向线段DC的内分点,且分DC为两有向线段的比值为γ,即DN/NC=γ,同时N点的状态参量可用有向线段的定比分点的坐标公式求出。  相似文献   

10.
本文讨论P—V图中斜率为负直线过程,提出一种几何判别法则,并从理论上加以证明.  相似文献   

11.
汉字倒说     
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。  相似文献   

12.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

13.
一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/  相似文献   

14.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?  相似文献   

15.
钱生钱!     
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了  相似文献   

16.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

17.
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.  相似文献   

18.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

19.
现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!  相似文献   

20.
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator's Garden. Translating building data to the Virtual Reality Modeling Language (VRML) is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching.  相似文献   

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