()溶解时,必须克服链间大部或全部的次价键作用力,因此难溶解或不溶解。
A.柔性分子链
B.刚性分子链
C.短支链分子链
D.碳碳饱和链
参考答案:B
汽油机排气冲程结束,这时温度约为()。
A、100~200K
B、900~1200K
C、600~900K
D、500~600K
本题的功能是对图形进行操作,包括旋转、移位、放大和剪切。窗口中有4个单选按钮和一个图形面板,图形面板中有一个矩形和该矩形移位操作后的图形,任选其中一个单选按钮,则图形面板中将显示该操作后的图形。单选按钮,则图形面板中将显示该操作后的图形。 import java. awt. * ; import java. awt. event. * ; import java. awt. geom. * ; import java. util. * ; import javax. swing. * ; public class java3 public static void main(String[] args) JFrame frame=new TransformTestFrame(); frame. setDefaultCloseOperation(JFrame. EXIT_ON_CLOSE); frame. show(); class TransformTest extends JFrame public TransformTestFrame() setTitle("java3"); setSize(WIDTH, HEIGHT); Container contentPane=getContentPane(); canvas=new TransformPanel(); contentPane. add(canvas, BorderLayout. CENTER); JPanel buttonPanel=new JPanel(); ButtonGroup group=new ButtonGroup(); JRadioButton rotateButton =new JRadioButton("旋转", true); buttonPanel. add(rotateButton); group. add(rotateButton); rotateButton. addActionListener(new ActionListener() public void actionPerformed(ActionEvent event) canvas. setRotate(); ); JRadioButton translateButton =new JRadioButton("移位", false); buttonPanel. add (translateButton); group. add(translateButton); translateButton. addActionListener (new ActionListener() public void actionPerformed(ActionEvent event) canvas. setTranslate(); ); JRadioButton scaleButton =new JRadioButton("放大", false); buttonPanel. add(scaleButton); group. add(scaleButton); scaleButton. addActionListener(new ActionListener() public void actionPerformed(ActionEvent event) canvas. setScale(); ); JRadioButton shearButton =new JRadioButton("剪切", false); buttonPanel. add(shearButton); group. add(shearButton); shearButton. addActionListener(new ActionListener() public void actionPerformed(AetionEvent event) canvas. setShear(); ); contentPane. add(buttonPanel. BorderLayout. NORTH); private TransformPanel canvas; private static final int WIDTH=300; private static final int HEIGHT=300; class TransformPanel extend JPanel public TransformPanel() square = new Rectangle2D. Double(-50,-50,100,100); t=new AffineTransform(); setRotate(); public void paintComponent() super. paintComponent(g); Graphics2D g2=(Graphics2D)g; g2. translate(getWidth()/2, getHeight()/2); g2. setPaint(Color, gray); g2. draw(square); g2. transform(t); g2. setPaint(Color. black); g2. draw(square); public void setRotate() t. setToRotation(Math. toRadians(30)); repaint(); public void setTranslate() t. setToTranslation(20,15); repaint(); public void setScale() t. setToScale(2.0,1.5); repaint(); public void setShear() t. setToShear(-0.2,0); repaint(); private Rectangle2D square; private AffineTransform t;