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Diffraction property of photorefractive volume grating in Ce: KNSBN for ordinarily polarized reading beam

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Chinese Science Bulletin 2000年第2期45卷 145-149页

作者： Liang, BL Wang, ZQ Mu, gg Guan, JH Fu, RL Nankai Univ Optoelect Informat Sci & Technol Lab Inst Modern Opt Tianjin 300071 Peoples R China

The diffraction efficiency of volume grating written by two wave mixing in Ce:KNSBN photorefractive crystal versus the writing beam ratio for ordinarily polarized reading beam is experimentally studied. The result is different from that for the extraordinarily polarized reading beam. Then the modified coupled-wave theory is used to fit the experimental data. The theoretical results are coincident with the experimental data quite well. This research gives a significant Support to the applications of Ce:KNSBN crystal in holographic recording and optical information processing.

关键词： photofractive grating diffraction efficiency energy transfer.

Herbst矫治器伴头帽牵引治疗安氏Ⅱ类错

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华西口腔医学杂志 2004年第1期22卷 46-48,51页

作者：杜熹 Urban Hgg 四川大学华西口腔医院正畸科四川成都610041 香港大学牙学院正畸专业

目的　研究Herbst矫治器伴头帽牵引逐步前伸下颌对安氏Ⅱ类错的矫治效果。方法　治疗组 2 2例患者 ,对照组 31例患者。治疗组患者均按治疗的前 6个月、后 6个月 (平均 )及维持期 6个月 ,3个阶段治疗并拍摄头侧位定位片观察。对照组患... 详细信息

目的　研究Herbst矫治器伴头帽牵引逐步前伸下颌对安氏Ⅱ类错的矫治效果。方法　治疗组 2 2例患者 ,对照组 31例患者。治疗组患者均按治疗的前 6个月、后 6个月 (平均 )及维持期 6个月 ,3个阶段治疗并拍摄头侧位定位片观察。对照组患者拍摄 2次头侧位定位片 ,其间间隔 6个月。结果　平均治疗 12个月后的疗效是抑制上颌骨生长、刺激下颌骨生长并降低下面高。与对照组相比 ,对上颌骨的抑制作用在治疗的前后 6个月均有统计学意义 ,对下颌骨的刺激作用仅在治疗前 6个月有统计学意义 ,对下面高的降低作用仅在治疗后 6个月有统计学意义。维持阶段上下基骨关系不变而对下面高的降低作用进一步加强。结论　Herbst矫治器伴头帽牵引能有效地矫治安氏Ⅱ类错 ,对上颌骨的作用随时间的增加而加强。

关键词： Herbst矫治器头帽牵引治疗安氏Ⅱ类错He 上颌骨

Orthodontics in China/Hong Kong at Present and in the Future

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Orthodontics in China/Hong Kong at Present and in the Future

CNTs reinforced PVAm/PVA blend CO2-selective FSC membrane

Beijing International Conference on Orthodontics

作者： U Hgg Faculty of Dentistry University of Hong Kong Hong Kong

＜正＞Today the orthodontist/population is by western standard low in Hong Kong and extremely low in *** reach the 1997 HK ratio PRC will need 8,200 orthodontists,27 times the current number (If PRC was aiming for the...

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CNTs reinforced PVAm/PVA blend CO2-selective FSC membrane

Nanosized copper powders prepared by gel-casting method and their application in lubricating oil

第五届中美化学工程学术会议

作者： May-Britt Hgg Department of Chemical Engineering Norwegian University of Science and Technology(NTNU)TrondheimNorway

Polyvinylamine/polyvinylalcohol(PVAm/PVA) blend fix-site-carriers(FSC) membranes have been reported for thenexcellent CO separation performance,which depends to a large extend on the membrane water swelling conditions due to the unique CO facilitated transport *** drawbacks of this type of FSC membranes are,however,that the swelling of the membrane unavoidably causes the loss of its mechanical strength,while the packing effect at high operating pressures diminishes the membrane swelling capacity and hence the CO separation *** Carbon nanotubes (CNTs) reinforced PVAm/PVA blend nanocomposite FSC membrane was designed to overcome these problems.

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Transactions of Nonferrous Metals Society of China 2018年第6期28卷 1186-1191页

作者： Wen-chao CHEN Ji-gui CHENG Hui-pei CHEN Nan-min gg Bang-zheng WEI Lai-ma LUO Yu-cheng WU School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Research Centre for Powder Metallurgy Engineering and Technology of Anhui Province Hefei 230009China

Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide（AM） and N, N′-methylenebisacrylamide（MBAM） as the main raw materials. The as-prepared copper powders were characterized by X-ray diffractometry and scanning electron microscopy, and then added into a 48# industrial white oil. Dispersion and wear properties of the compounded lubricating oil were tested. The results show that the copper powders prepared are of high purity, fine dispersibility with mean particle size of about 60 nm and with a narrow particle size distribution. The nanosized copper powders can be well dispersed in the lubricating oil. The addition of the copper powders obviously improves the anti-wear properties of the lubricating oil owing to their good self-repairing performance. Compared with 48# industrial white lubricating oil, the friction coefficient of GCr15 steel with the compounded oil containing 0.6% copper powders reduces by 0.07 and nearly no wear chippings are found in the scratches of the friction counter parts.

关键词： nanosized copper powder gel-casting method compounded lubricating oil anti-wear property

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建立国际会计准则和审计准则

经济译文 1991年第3期 1-5页

作者：米勒,gg 刘宗柳

Severity of dentofacial deformity, the motivations and the outcome of surgery in skeletal Class Ⅲ patients

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Chinese Medical Journal 2002年第7期115卷 1031-1034页

作者：周彦恒 Urban Hgg ABakr MRabie 香港大学牙医学院

Objective To study the relationship between severity of skeletal Class Ⅲ malocclusion and the patient's emotional status, as well as motivation for seeking surgical correction and satisfaction with the outcome of the surgery Methods One hundred and forty consecutive Chinese patients with skeletal Class Ⅲ malocclusion who had been treated with a combined orthodontic and surgical approach were studied Sixty seven percent (40 males and 54 females) responded to a questionnaire Fifty four percent had two jaw deformities, 32% mandibular hyperplasia and 14% maxillary hypoplasia Surgical procedures: 77% received two jaw surgeries, 15% maxillary advancement and 8% mandibular setback This was a retrospective study based on questionnaires with numerical scale ranked answers (0: not at all; 1: a little; 2: moderately; 3: quite a bit; and 4: extremely) Results ANB angle was significantly negatively correlated with feelings about the nickname related to their facial problems (embarrassment: r =-0 30, P <0 01; worn out r =-0 32, P <0 01; angry r = -0 24, P <0 05) ANB angle also had a significant negative correlation with the reasons for having the surgery (pressure from their friends: r =-0 21, P <0 05, and referred by physician: r =-0 24, P <0 05) Changes in life style as a result of surgery were significantly negatively correlated with the ANB angle before treatment, positive influence on relationships with the opposite sex ( r =-0 25, P <0 05), positive influence in social activiies ( r =-0 22, P <0 05) Conclusion The psychological status before surgery and the outcome following orthognathic surgery in patients with skeletal Class Ⅲ malocclusion were closely related to severity of the malocclusion

关键词： Class Ⅲ malocclusion · psychological status · motivation · outcome

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大脑皮质活动的光学描图术

光学工程 1990年第37期 31-34页

作者： Blas.,gg 谢嘉民