Laser Rapid Prototyping of Photonic Band-Gap Microstructures   总被引：1，自引：0，他引：1  

MC Wanke  O Lehmann  K Muller  Q Wen  M Stuke 《Science (New York, N.Y.)》1997,275(5304):1284-1286

Three-dimensional periodic microstructures of aluminum oxide, which are important for creating photonic band-gap structures (PBGs), were fabricated by laser rapid prototyping by means of laser-induced direct-write deposition from the gas phase. The structures consisted of layers of parallel rods forming a face-centered tetragonal lattice with lattice constants of 66 and 133 micrometers. These structures showed transmission minima centered around 4 terahertz (75 micrometers) and 2 terahertz (150 micrometers), respectively. PBGs will allow precise control of the optical properties of materials, including lasers without threshold.  相似文献   

LETA S. HOLLINGWORTH     

Gates AI 《Science (New York, N.Y.)》1940,91(2349):9-11

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Iron reduction and changes in cation exchange capacity in intermittently waterlogged soil   总被引：10，自引：0，他引：10  

F. Favre    D. Tessier    M. Abdelmoula    J. M. Génin    W. P. Gates  & P. Boivin 《European Journal of Soil Science》2002,53(2):175-183

The long-term effects of intermittent flooding on soil properties were studied in field experiments on a Vertisol cropped with rice in Senegal. The dominant clay minerals were smectite and kaolinite. When the soil was reduced after flooding, its cation exchange capacity (CEC) increased to twice that of its oxidized, unflooded state. Mössbauer spectroscopy showed an increase in smectite structural Fe^II upon reduction, which explained a part of the increase in CEC. The rest of the increase was attributed to the removal of iron oxyhydroxide coatings by reductive dissolution. The reduction and dissolution of oxides under the field conditions were substantiated by analysis of the surfaces of vermiculites buried in the Ap horizons of the cropped and the non-cropped soils. The redox-induced CEC changes were found to be reversible after 22 cycles of rice cropping. Nevertheless, the structural Fe and free Fe contents of the rice field Ap horizon were less than those of soil in uncropped neighbouring land, suggesting that inundation induced weathering and eluviation of the minerals. The observed changes in CEC and related redox reactions may substantially modify proton, anion and cation balances in intermittently flooded soils.  相似文献   

Comparison of chemiluminescent and AOAC methods for determining nitrite in commercial cured meat products   总被引：1，自引：0，他引：1  

W Fiddler  R C Doerr  R A Gates  J B Fox 《Journal of the Association of Official Analytical Chemists》1984,67(3):525-528

A chemiluminescent detector was used to measure nitrite in a variety of commercial cured meat products, using the AOAC sample preparation procedure, 24.041. A comparison of the NaNO2 values obtained by using sulfanilamide/N-(1-naphthyl)ethylenediamine (SAN/NED) reagent, sulfanilamide/1-naphthylamine reagent, and chemiluminescent detection (CLD) revealed no significant differences between the latter 2 detection methods. The AOAC SAN/NED reagent combination gave an average of 24.6% lower NaNO2 results than CLD. Examination of the sample preparation extraction and heating steps indicated that the procedure could not be made more rapid because of the need to destroy residual reductants and release "bound-complexed-reacted" nitrite from the meat samples.  相似文献   

Spawning habitat suitability for coastal cutthroat trout: Microhabitat and mesohabitat     

Steven N. Boessow  Hal A. Beecher  Kiza K. Gates 《水产资源保护:海洋与淡水生态系统》2021,31(3):480-493

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Variation in pollen viability in the onion (Allium cepa L.)     

D. J. Ockendon  P. J. Gates 《Euphytica》1976,25(1):753-759

Summary The pollen viability of onions in a glasshouse was recorded from May to October 1975, using the fluorescein test. The average viability was 60–95% for most of this period but fell to less than 1% during the last two weeks of August. There was great variation in pollen viability between anthers within a flower and between flowers within a head. Attempts to induce pollen inviability by low temperature treatments at various stages of inflorescence development were unsuccessful. Low levels of pollen inviability appear to be a characteristic feature of onions, but the high level of inviability which was found both in this and in a previous season was associated particularly with the August period.  相似文献   

Porcine abortion caused by Bacillus sp     

C A Kirkbride  J E Collins  C E Gates 《Journal of the American Veterinary Medical Association》1986,188(9):1060-1061

Bacillus sp is known to cause abortion in cattle and sheep, but it is rarely reported to cause abortion in swine. Bacillus sp was isolated from aborted fetuses, and lesions compatible with a bacterial infection were detected in 4 of 962 aborted porcine fetuses examined. The infection apparently results in sporadic abortions and is not likely to cause economically significant reproductive failures within a herd.  相似文献   

Successful treatment of hypereosinophilic syndrome in a dog     

MC PERKINS  ADJ WATSON 《Australian veterinary journal》2001,79(10):686-689

An 11-year-old crossbred dog was presented with a history of episodic vomiting, diarrhoea, abdominal discomfort and coughing. These signs had been present for several years. Marked peripheral eosinophilia (10.3 x 10(9)/L) was found. No underlying cause of reactive eosinophilia was apparent. Bone marrow aspiration biopsy showed hyperplasia of the eosinophilic cell line, with some increase in immaturity, although all cells were morphologically normal. There were numerous eosinophils in bronchial wash fluid and eosinophilic infiltrates were evident in biopsies of pancreas, liver, small intestine and colon but not stomach. Hypereosinophilic syndrome was diagnosed. The dog responded well to twice daily treatment with hydroxyurea and prednisolone. Clinical signs are well-controlled 16 months later.  相似文献   

Does resource‐mediated stress affect colony personality in leaf‐cutting ants?     

Lailla C Gandra  Karina D Amaral  Joel C Couceiro  Raul NC Guedes  Terezinha MC Della Lucia 《Pest management science》2021,77(1):96-103

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Concurrent gastro-oesophageal intussusception,trichobezoar and hiatal hernia in a cat     

MC Owen  PJ Morris  RS Bateman 《New Zealand veterinary journal》2013,61(5):371-374

CASE HISTORY: An adult male Birman cat was evaluated for recurrent, intermittent vomiting or regurgitation, occasionally associated with abdominal discomfort.

CLINICAL FINDINGS AND DIAGNOSIS: Radiographs, including an oesophogram, indicated an oesophageal obstruction. Prior to treatment, the cat's condition deteriorated and it was euthanised at the owner's request. Post-mortem examination revealed a gastro-oesophageal intussusception, a trichobezoar impacted into the intussusceptum, and a dilated oesophageal hiatus consistent with a chronic hiatal hernia.

CLINICAL RELEVANCE: Gastro-oesophageal intussusception is a rare condition in cats. Its aetiology in relation to a pre-existing hiatal hernia and a trichobezoar is discussed.  相似文献