射线中心

Alternatively, the spectral softening above 2 GeV could be due to gamma-ray absorption via photon-photon pair production on the soft X-ray photon field of the host active galactic nucleus, but such an interpretation would require the dissipation region to be located very close (l~100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

另外的关于2 GeV以上能谱变软的可能解释是高能光子和寄主活动星系核的软X射线辐射场通过电子对产生反应而被吸收，但是这个解释要求反应区域要很靠近中心黑洞(1~100倍引力半径)，这和3C 454.3的X射线测量谱相矛盾。

The company produces the processing equipment to be advanced, check-out facility excellent, has the numerical control lathe, the numerical control drilling machine, the machining center, the numerical control gear-hobbing machine, the gear shaper, the fine borer, the universal milling machines, each kind of grinder, the table planer, the booklet bender, the large-scale lathe, the mechanical slicer, high intermediate frequency quenching, the well type, the box-type hardening furnace, the tempering furnace, the automatic welding machine, the X-ray crack detection machine, the cloth, the Rockwell tester; Electric hoist test platform, sound-level meter, varnish film thickness gauge, altazimuth, level; The material analysis laboratory, the metallography analysis room and so on full had guaranteed strictly the vehicle, the mill, dig, rub, pull, the boring, to drill, the ramming, cutting, the angle iron, the chemical examination and the heat treatment and so on complete technical process.

公司生产加工设备先进，检测设备精良，拥有数控车床、数控钻床、加工中心、数控滚齿机、插齿机、精密镗床、万能铣床、各种磨床、龙门刨床、折弯机、大型车床、刨床、高中频淬火、井式、箱式淬火炉、回火炉、自动焊机、 X射线探伤机、布、洛氏硬度计；电动葫芦试验台、声级计、漆膜测厚仪、经纬仪、水准仪；材料分析化验室，金相分析室等充分严格保证了车、铣、刨、磨、拉、镗、钻、冲压、切割、弯板、化验及热处理等全部工艺流程。

Central projection: When the lines of projection meet at a point

中心投影法：投射线汇交于一点的投影法称为中心投影法。

During 2008 Beijing Olympic Game, Ray Center is appointed as the only disinfection and sterilization unit for the game.

北京奥运期间，射线中心被指定为唯一为奥运会提供医疗卫生用品消毒的单位。

This company specializes in the production of x-ray protection staffs domestically with largest scale, rich experience and advanced tech. This company covers an area of 8,000 m2 . The series of supper soft interposition protection take the place of exported products."Intervention Protection Gloves" developed with Ray Protection Products Quality Testing Center of the Ministry of Sanitation fill in the domestic blank.

工厂占地面积8000平方米，是国内生产X射线防护用品规模最大、经验丰富、技术先进的专业公司，生产的超柔软型介入防护系列产品替代了进口产品，与卫生部射线防护器材质量检测中心共同研制出的"介入放射防护手套"填补了国内空白。

Loaded the simulated acetabular cup at an inclination of 35°, 40°, 45°, 50°, 55° to 6 cadaver pelves. Made the pelves tilt around the frontal axis and sagittal axis with 5° each time in a scope of ± 30°. Take standard radiograph of the pelvis accordingly.

按35°，40°，45°，50°，55°外展角分别放置于6具防腐骨盆标本髋臼窝内，使骨盆标本沿冠状轴、矢状轴在±30°的范围内按5°/次分别旋转，保持X射线投照中心点始终与标准骨盆正位片投照中心点一致。

The results show that the study on transimittivity can be done using the points along the circle arc centered at the roadway or the boring core, the transimittivity at the joints along the right angle ray can be studied using one single point behind the joint, and the studies on transimittivity can be done on any reasonable radius value of the roadway or boring core in a typical rock.

分析结果表明：单节理后各节点透射率的研究，可以通过单节理后某一以巷道或钻孔中心为中心的圆弧上各节点的透射率来展开；射线角为90°的射线上节理后各节点透射率的研究，可以通过节理后某一节点的透射率来展开；单节理的透射率的研究可以在一个固定半径值的巷道或钻孔的模型上用一种典型的岩石进行。

Soft X ray laser radiation ranged from 40 nm to 110 nm is obtained by the 7th to the 19th order harmonic generation in krypton with femtosecond Ti∶sapphire laser operating at 780 nm, and the same phenomena especially the spectral shift is observed after the central wavelength of Ti∶sapphire laser is tuned to 795 nm.

利用中心波长在 780nm线偏振的掺钛蓝宝石超短脉冲激光，在氪气中观察到 40nm～ 110nm第 7～ 19次谐波的软X射线激光辐射，把中心波长调至 795nm时再次观察到相同的现象，特别是观察到谱线的移动，证实观察到的谱线是高次谐波，实验中还观察了谱线强度随气压的变化规律。

Nanostructured ZnO films with grain size of 28～35 nm have been prepared on quartz glass substrates by pulse laser ablation of Zn target in oxygen atmosphere. The structural and optical properties of the films were studied. ZnO thin films with typical c-axis (002) orientation were successfully deposited at a range of 100～250 ℃. The results obtained by X-ray diffraction and photoluminescence measurements show that the strong UV emission centering is about 378～385 nm and deep-level emission centering about 518～558 nm in the room temperature PL spectra of the ZnO films.

利用脉冲激光沉积法在氧气氛中烧蚀锌靶制备了纳米晶氧化锌薄膜，衬底为石英玻璃，晶粒尺寸约为28～35 nm.X射线衍射结果和光致发光光谱的测量表明，当衬底温度在100～250 ℃范围内时，所获得的ZnO薄膜具有c轴的择优取向，所有样品的强紫外发射中心均在378～385 nm范围内，深能级发射中心约518～558 nm，衬底温度为200 ℃时，得到了单一的紫外光发射。

This paper introduces the studies of the ultra-short Thomson scattering X-ray source at the accelerator laboratory of Tsinghua University in recent years. Properties such as the photon yield,the pulse length and time jitter of the produced photon pulse were predicted theoretically from the parameters of the electron bunch and the laser pulse,and the scattering angle. Preliminary experiments were successfully carried out with a 16 MeV backward-traveling-wave accelerator and the ns-Q switched laser provided by China Academy of Engineering Physics. This paper also introduces the 1.6-cell electron gun that was fabricated on site and the experiment with high RF power including the measurement of the electron bunche parameters. Based on these,we have designed an X-ray source,which is now under construction.

介绍了清华大学加速器实验室近年来关于汤姆逊散射超短X射线源的研究工作；研究了在任意散射角度下电子束参数和激光束参数对散射光子参数的影响，给出了散射光子的参数如光子产额、脉冲长度、时间抖动等与电子束参数、激光束参数和散射角度的关系；利用实验室已有的16 MeV反波行波加速器与中国工程物理研究院激光聚变研究中心提供的ns调Q激光搭建了汤姆逊散射初步实验平台并开展了实验研究；加工了1.6-cell光阴极微波电子枪，搭建了高功率实验平台，对产生的电子束参数进行了初步测量；对汤姆逊散射超短X射线源进行了设计并开展了相关的平台建设工作，对产生的X射线脉冲参数进行了模拟。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。