大轴

With reasonable analysis of optical path, a new type beam expander with wide aperture and bigger field angle and large relative aperture in which the on-axis and off-axis aberration are both perfectly corrected is designed.

通过合理的光路分析，设计出一种轴上和轴外像差都得到很好校正、大口径大相对孔径、视场可增大的、光学性能优于伽里略和开卜勒扩束器的新型扩束器。

The off-axis reflection system composed of four aspheric mirrors was designed, but the system structure was not so simple and the performance can also be improved, besides, manufacture and test for large aspheric mirrors are difficult; and then the spherical Fresnel mirror which is easier to be manufactured and tested was used to replace the aspheric mirror, the spherical Fresnel mirror has low cost of replication, but this design also can\'t be used in projection lens because it was only feasible in narrow wavebands; Furthermore, the design making use of catadioptric projection lens was accomplished, this design is greatly applied in rear projector because it has merits of both refraction and reflection. But it had difficulties in color aberration correction and had complex structure.

设计了四片非球面组成的离轴式反射系统，然而，仅采用非球面设计系统结构不够精简，性能也有待进一步提高，且非球面面形较大时加工和检测都存在一定的困难；继而提出了用球面Fresnel反射镜代替非球面的设计方法，虽然Fresnel反射镜加工和检测更为简单，且复制成本低，但对波长具有选择性；进而，应用折反系统结合的方式设计了离轴式投影镜头，该方法因兼具折射和反射的优点，在大屏幕超薄背投系统的设计中广为应用，缺点是会产生难以校正的色差，且结构复杂。

Regarding the frequent occurrence of speed stalling of boiler axial flow primary fan in the operation of 600 mw unit in china,the cause of speed stalling was analyzed based on the actual measured data.the problem is mainly caused by primary air pipe resistance property variation,which caused the excessive opening of movable blades,the primary fan is working on the condition of higher wind pressure and lower flow.the approaches to reduce the speed stalling of primary fan and preventive measures are put forwa...

针对目前国内600 mw大容量机组锅炉轴流式一次风机运行中失速事故频繁发生的问题，在了解造成轴流式一次风机失速原理的基础上，根据实测数据对一次风机失速原因进行分析。主要原因为一次风管阻力特性的变化，使一次风机动叶开度过大，一次风机工作点处在高风压区低流量的工况点，是造成一次风机失速的主要原因，提出了运行中减少一次风机失速机率的处理方法及预防措施。

With the development of the electric power industry, the capacitance of a turbo-generator has increasingly become larger, which risk the torsional oscillation in the flexible shaft system of large turbine-generators. The problem of shaft torsional oscillation has become the key technology need to be solved urgently in the development of large power system and unit.

随着电力工业的发展，汽轮发电机组的单机容量正日益大型化，导致机组轴系扭转振动的危害性日益突出，轴系扭振问题已成为发展大电网和大机组所急需解决的关键技术问题。

D1.1 of the AISI Specification limits the maximum longitudinal spacing of connections to ... where smax = maximum permissible longitudinal spacing of connectors L= unbraced length of compression member rI = radius of gyration of I-section about the axis perpendicular to the direction in which buckling would occur for the given conditions of end support and intermediate bracing rcy = radius of gyration of one C-section about its centroidal axis parallel to the web.....

因此，AISI规范第D1.1节限定连接的最大纵向间隙为：，式中 smax =连接体允许的最大纵向间隙 L=抗压构件的自由长度 rI =工字钢对垂直于给定端承和中间肋条件下可能产生纵向弯曲方向的轴的回转半径 rcy =一段U型钢对其平行于筋的质心轴的回转半径。。。。。。。

Experimental Research on FBG Sensor for Large Curvature Detection;2. For large curvature arch, the neutral axis does not pass through the centroidal line of the cross-section, so the moment of inertia is not consistent with the second moment of area.

大曲率拱中，截面形心轴与中性轴不重合，其截面抗弯惯性矩与不考虑曲率影响的截面面积二阶矩有一定的差别；当截面尺寸相对拱弧长来说较大时，此时拱为深拱，剪切变形的影响不能忽略。

Cylinder body endophragm and the live pump plunger shaft plate the hard chromium, has the very good abrasion resistance; Between all glide part has the oil-free lubrication axis and the guidance link reduces the friction coefficient, the extension service life, AW the air operated actuator U curved characteristic

输出扭矩大，动作灵活平稳；缸体内壁和活塞轴镀硬铬，具有很好的抗磨性；所有滑动部件之间配有无油润滑轴和导向环以降低摩擦系数，延长使用寿命，AW气动执行器的U型曲线特性输出扭矩更适用于大口径球阀、蝶阀。

The maximum fittable length is 225 cm for short wheelbase versions and 280 cm for long wheelbase versions; the maximum outfitting width is 187 cm for both versions: this values vary according to outfit type and weight distribution.

fittable的最大长度为225短轴距版本和280长轴距版本厘米厘米，最大宽度为187舾装两种版本厘米：此值根据装备不同类型和重量分配。

From the base to the crown in axial, the vessel-elements proportion increases in fluctuation, contrary to the ray proportion. The fiber proportions in the regions of base and crown are less than that in the trunk of tree, and fluctuate at 65% or so. The parenchym proportion increases quickly to the 1.3m height of tree, reaching the maximum at 9.52%, and then decreases quickly to the 3.3m height of tree (8.90%); afterward it leveled off and increases slightly.

组织比量轴向变异表现为随树高增加导管比量波动性递增，与木射线比量相反；纤维比量在近根区和近冠区稍小，而主干部稍大，并在65%左右波动；轴向薄壁细胞比量先随树高增加急剧增加，到1.3m树高处达最大值（9.52%）后又急剧降低至3.3m树高处的8.90%，以后基本稳定并在波动中略有增加。

Production of various major domestic and international pressure feed granulators the roll, eccentric shaft, the drive wheel, Central-and pulley, bushings, flanged, bearings, shaft and various marine accessories, such as forging, and to undertake various forging processing (forging The largest diameter up to 2000 cm, the largest weighs 2,000 kilograms).

主要生产国内外各种饲料制粒机的压辊、偏心轴、传动轮、环模以及滑轮、衬套、法兰、轴承、各种轴和船用锻件等配件，同时承接各种锻件加工（锻件最大直径可达2000cm，最大的重量为2000公斤）。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。