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排序方式: 共有233条查询结果,搜索用时 15 毫秒
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The present study was undertaken to evaluate the postoperative relapse from the period of unwiring to 1 year postoperatively and its correlation to the amount of mandibular setback and change in vertical dimension after mandibular bilateral sagittal split osteotomy. Twenty-seven patients were evaluated cephalometrically by the time preoperatively, 6 weeks, 6 months and 1 year postoperatively. It was found that 1) the average amount of mandibular setback at pogonion point, 6 weeks postoperatively, is 7.6mm backward and 1.9mm downward, 2) the average amount of horizontal relapse at pogonion point, 6 months and 1 year postoperatively, are 1.9mm and 2.3mm respectively. 86% of the horizontal relapse, 1 year postoperatively, occurs in the first 6 months after removal of intermaxillary fixation, 3) the average amount of vertical relapse at pogonion point, 6 months and 1 year postoperatively, are 0.9mm and 1.1mm upward. 82% of the vertical relapse, 1 year postoperatively, occurs in the first 6 months after removal of intermaxillary fixation, 4) the amount of 1 year postoperatively horizontal relapse is significantly correlated both with the amount of horizontal mandibular set back and vertical downward change (r = 0.58, 0.67, p < 0.001), whereas the amount of vertical relapse is with the vertical downward change only, but horizontal setback isn't. 相似文献
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Watchareeya Kaveevivitchai Ashfia Huq Shaofei Wang Min Je Park Arumugam Manthiram 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(34)
Rechargeable batteries based on an abundant metal such as aluminum with a three‐electron transfer per atom are promising for large‐scale electrochemical energy storage. Aluminum can be handled in air, thus offering superior safety, easy fabrication, and low cost. However, the development of Al‐ion batteries has been challenging due to the difficulties in identifying suitable cathode materials. This study presents the use of a highly open framework Mo2.5 + y VO9 + z as a cathode for Al‐ion batteries. The open‐tunnel oxide allows a facile diffusion of the guest species and provides sufficient redox centers to help redistribute the charge within the local host lattice during the multivalent‐ion insertion, thus leading to good rate capability with a specific capacity among the highest reported in the literature for Al‐based batteries. This study also presents the use of Mo2.5 + y VO9 + z as a model host to develop a novel ultrafast technique for chemical insertion of Al ions into host structures. The microwave‐assisted method employing diethylene glycol and aluminum diacetate (Al(OH)(C2H3O2)2) can be performed in air in as little as 30 min, which is far superior to the traditional chemical insertion techniques involving moisture‐sensitive organometallic reagents. The Al‐inserted Al x Mo2.5 + y VO9 + z obtained by the microwave‐assisted chemical insertion can be used in Al‐based rechargeable batteries. 相似文献
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TEM studies of anti-wear films/wear particles generated under boundary conditions lubrication 总被引:2,自引:0,他引:2
Friction and wear performance of engine oil were studied in presence of Zinc-dialkyldithiophosphate (ZDDP) and ZDDP–iron fluoride (FeF3) combination using a ball-on-ring wear testing device under boundary conditions. Friction and wear performance of engine oil improves in presence of ZDDP–FeF3 combination. In order to understand the wear mechanisms the microstructure and the chemical composition of wear debris generated during wear process were investigated using TEM together with EDX analyzes. Novel observations on the wear debris generated at different testing loads are presented. Independent of normal loads, amorphous debris containing P, O, Fe and Zn elements and crystalline debris of Fe2O3 are formed. No trace of S is present in amorphous debris under low load (2.32 GPa) conditions while S is a dominating element under high loaded (3.68 GPa) conditions. On the other hand, at lower loads a few iron oxide is formed while at higher loads larger sizes of iron oxides are formed resulting in larger friction and wear. 相似文献
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This paper proposes a methodology for cell performance evaluation and improvement which considers multiple cell inputs and outputs. A specific technique in data envelopment analysis called 'window analysis', which captures the cell efficiency changes over time, is modified and utilized in the methodology. The evaluation is performed by considering the local part families (manufactured in single cells) and the infrequent parts (manufactured in multiple cells) processed by a cell. A major contribution of this research is in proposing a new 'modified window analysis' technique for cell performance evaluation, and in demonstrating its effectiveness over the 'traditional window analysis'. Another contribution is in using the cross efficiency matrix to identify periods of best cell operating practices which aid management in cell process improvement. 相似文献
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Mohammad Maududul Huq Md. Robiur Rahman Masnun Naher Mohammad Mizanur Rahman Khan Mostafa Kamal Masud Golam Mohammad Golzar Hossain Nianyong Zhu Yih Hsing Lo Muhammad Younus Wai-Yeung Wong 《Journal of Inorganic and Organometallic Polymers and Materials》2016,26(6):1243-1252
Two palladium(II) nitroaryl complexes trans-[bromo(p-nitrophenyl)bis(triphenylphosphine)palladium(II)] 1 and trans-[bromo(2,4-dinitrophenyl)bis(triphenylphosphine)palladium(II)] 2 have been synthesized. The complexes were characterized by FTIR and NMR (1H, 13C and 31P) spectroscopy and elemental analysis. The molecular structure of complex 2, as confirmed by X-ray crystallography, reveals that the Pd atom and its neighboring groups (two PPh3, Br and phenylene group) lie in a slightly distorted square plane. In the UV–Vis spectra of the complexes 1 and 2, the palladium to aryl charge transfer bands were observed. The emission peaks from the singlet excited states (S1 → S0) were observed in the photoluminescence spectra of the complexes. The thermal stability of the complexes has been studied by thermal gravimetric analysis (TGA). TGA data showed that both complexes are thermally stable up to 200 °C, and complex 1 is more stable than 2. The catalytic efficiency of the new palladium(II) complexes was studied as demonstrated using the Sonogashira coupling reactions with good yields. The experimental results suggest that the Sonogashira coupling reactions can be performed at moderate temperature (50 °C) using these new palladium(II) complexes as catalysts. 相似文献
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A. Schneider B. Su T. W. Button L. Singleton O. Wilhelmi S. E. Huq P. D. Prewett R. A. Lawes 《Microsystem Technologies》2002,8(2-3):88-92
In this paper results are presented from a range of experiments to explore the feasibility of inserting a ceramic material
PZT (lead zirconium titanate) into different kinds of high-aspect-ratio resist moulds. Polymethylmethacrylate (PMMA) and SU-8
on silicon substrates and free-standing SU-8 membranes with micro-cavities or through-holes (defined by X-ray lithography)
have been used as moulding medium. Processing conditions for the resist materials including pre-bake, exposure, post-bake,
development and stripping have been compared. The advantages of different types of resist mould for the LIGA process has been
evaluated. Additionally a comparison of photosensitivity of PMMA and SU-8 has been carried out. Using a range of load pressures
(5 to 60 MPa), appropriate conditions for PZT embossing into resist moulds have been determined (ensuring minimum void formation
in the final PZT structures). In the final form, SU-8 moulds have been removed by laser ablation. This is the first reporting
of high-aspect-ratio ceramic microstructures fabricated using a combination of SU-8 moulds and PZT embossing.
Received: 10 August 2001/Accepted: 24 September 2001 相似文献
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