孔径

The design of four-mirror anastigmat was analyzed, then a system with effective focal length of 1 200 mm and field of view of 0.8°×0.8° was designed , total length and f-number are 300 mm and F/6,respectively.The system has advantages of long focal length, relative short physical size and excellent ability in restraining stray lights.

分析了离轴四反的设计步骤，设计了一个焦距为1 200 mm，视场为0.8°×0.8°，相对孔径为F/6的光学系统，系统总长只有300 mm，并达到很好的光学性能，具有长焦距、小尺寸、良好的杂散光抑制能力等特点。

Using the hotwire anemometry,the experimental study is carried out on a novel multi-diaphragm piezoelectric synthetic jet actuator.

利用热线风速仪，在最佳激振频率f=560 Hz时，研究了不同孔径、不同孔深、不同小孔出口几何形状等对多压电膜式零质量射流激励器性能的影响。

The results abtained will provide a basis for the design of AOTF with large angular aperture.

本文所得结果对改善大角孔径的声光可调谐滤波器设计提供了理论依据。

Solid angular aperture of non-collinear acousto-optic interaction tunable filter［J］.

非同向互作用声光可调谐滤光器的立体角孔径［J］。

Based on thin annular electron beam approximation, the focusing effect of plasma is investigated.

比较了在不同气压和空心阴极孔径下虚阳极的形成时间和扩展速度。

MATERIALS: Composite scaffold was made with collagen/chitosan/β-tricalcium phosphate. Upper layer was mainly collagen/chitosan, and lower layer was mainly collagen/chitosan/β-tricalcium phosphate. The factor of porosity was 90%, with antilinear of 100 μm.

材料：以胶原、壳聚糖、β-磷酸三钙制备复合支架，上层以胶原／壳聚糖为主，下层以胶原／壳聚糖／β-磷酸三钙为主，孔隙率≥90%，孔径100μm。

2 Will be the first of many invasive balance wheel spindle small aperture, so tight hole card. Wheel balance with the vertical center axis.

4.2.2.2 将平衡心轴小头一端穿入砂轮孔径内，使之卡紧孔壁，砂轮应与平衡心轴垂直。

Then threekind of hard X-ray space telescopes, namely the collimator, the rotating col-limator and coded aperture mask telescopes, are introduced. Finally the softX-ray imaging telescope is introduced.

然后分别介绍了三种类型的硬X射线空间望远镜，包括准直型、旋转调制型和编码孔径型望远镜，最后简略介绍掠入射型软X射线成像望远镜。

It is always a challenge of not able to get a good aperture ratio as the resolution density increases.

它始终是一个挑战，无法获得良好的孔径比为第密度增加。

Use Wide Aperture to improve the signal-to-noise ratio and spatial resolution for better penetration in deeper structures.

使用宽孔径比，提高空间分辨率为更好地渗透在更深的结构噪声信号对。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了