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排序方式: 共有375条查询结果,搜索用时 15 毫秒
1.
Theoretical Foundations of Chemical Engineering - The extraction of nitric and oxalic acids by neutral compounds TBP, DBBP, and TBPO have been studied. The optimal conditions of their separation... 相似文献
2.
Kazantsev Yu. N. Kraftmakher G. A. Mal’tsev V. P. 《Journal of Communications Technology and Electronics》2019,64(6):550-554
Journal of Communications Technology and Electronics - Approximate formulas for calculating the coefficient of reflection from an artificial magnetic conductor (AMC) based on a capacitive lattice... 相似文献
3.
Identification of critical erosion prone areas in the small agricultural watershed using USLE,GIS and remote sensing 总被引:10,自引:1,他引:9
In the present study, Karso watershed of Hazaribagh, Jharkhand State, India was divided into 200 × 200 grid cells and average
annual sediment yields were estimated for each grid cell of the watershed to identify the critical erosion prone areas of
watershed for prioritization purpose. Average annual sediment yield data on grid basis was estimated using Universal Soil
Loss Equation (USLE). In general, a major limitation in the use of hydrological models has been their inability to handle
the large amounts of input data that describe the heterogeneity of the natural system. Remote sensing (RS) technology provides
the vital spatial and temporal information on some of these parameters. A recent and emerging technology represented by Geographic
Information System (GIS) was used as the tool to generate, manipulate and spatially organize disparate data for sediment yield
modeling. Thus, the Arc Info 7.2 GIS software and RS (ERDAS IMAGINE 8.4 image processing software) provided spatial input
data to the erosion model, while the USLE was used to predict the spatial distribution of the sediment yield on grid basis.
The deviation of estimated sediment yield from the observed values in the range of 1.37 to 13.85 percent indicates accurate
estimation of sediment yield from the watershed. 相似文献
4.
5.
OE Santana Rodríguez ML Malé Gil JF HernándezSantana JM Limi?ana Ca?al AM Martín Sánchez 《Canadian Metallurgical Quarterly》1998,14(6):555-561
Von Hippel-Lindau disease (VHL) is an autosomal dominant tumour syndrome caused by germline mutations of the VHL tumour suppressor gene located on chromosome 3p25-26. In VHL tumours may occur in 14 different target organs, including the eye. Retinal angiomas are considered the first manifestation of VHL disease in 43% of cases, and the cumulative probability of developing a retinal angioma in one or both eyes rises during each decade of life, reaching 80% for patients over 80 years old. Since 1976 patients with VHL at the University Hospital of Utrecht and their at-risk relatives have been screened periodically by a multidisciplinary team. Long-term follow-up ophthalmological data were analysed with special attention to natural course and results of treatment. In addition, we looked for a genotype-phenotype correlation. Retinal angiomas were found in all families. In one large family with a missense mutation (V170D) of the VHL gene, in which the complete spectrum of visceral- and central nervous system (CNS) features of VHL is present, macular, parapapillary, optic disc and ora serrata angiomas were also found. In general, however, a clear-cut genotype-phenotype correlation could not be found. Only early detection and treatment of peripheral retinal angiomas can be expected to decrease the percentage of patients with decreased visual acuity. Therefore, early detection and treatment of these tumours is of paramount importance. Ophthalmological screening of patients and persons at risk should start as early as possible. In patients with apparently sporadic retinal angiomas it is advisable to perform germline DNA analysis, since the risk of developing VHL is high, especially if the angiomas are bilateral, or unilateral and multifocal, if the patient is young, or if there is a family history suggestive of VHL. 相似文献
6.
Seong Ik Yoo Tae Yeon Lee Jin‐San Yoon Ik‐Mo Lee Mal‐Nam Kim Han Sup Lee 《应用聚合物科学杂志》2002,83(4):767-776
The interfacial reaction of the polyethylene (PE)/starch blend system containing the reactive compatibilizer maleated polyethylene (m‐PE) was directly characterized by Fourier transform infrared (FTIR) spectroscopy. A significant amount of anhydride groups on m‐PE existed as hydrolyzed forms, resulting in a large amount of carboxyl groups. Using a vacuum‐heating‐cell designed in the laboratory, the carboxyl groups were successfully transformed into the dehydrolyzed state (i.e., anhydride group). This result enabled the direct spectroscopic observation of chemical reaction occurring at the interface. For the PE/starch blend system containing m‐PE, the chemical reaction at the interface was verified by the evolution of ester and carboxyl groups in the FTIR spectra. The effect of the reactive compatibilizer on the interfacial morphology was also examined by scanning electron micrography (SEM). Enhanced interfacial adhesion was clearly observed for the blend system containing reactive compatibilizer. Tensile strengths of blend systems containing m‐PE also increased noticeably compared with the corresponding system without compatibilizer. A similar observation was made for the breaking elongation data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 767–776, 2002 相似文献
7.
Shirshova E. P. Mal’tseva A. L. Astashkina O. V. Lysenko A. A. Fomenko Yu. A. 《Fibre Chemistry》2021,53(3):189-193
Fibre Chemistry - The article is devoted to the development of two-layer composites with a fluoroplastic matrix and fiberglass reinforcing elements. The fluoroplastic matrix acts as a protective... 相似文献
8.
Kazantsev Yu. N. Kraftmakher G. A. Mal’tsev V. P. Solosin V. S. 《Journal of Communications Technology and Electronics》2022,67(8):930-937
Journal of Communications Technology and Electronics - The characteristics of an artificial magnetic conductor (AMC) based on an anisotropic composite material consisting of capacitive gratings... 相似文献
9.
S. V. Antonenko O. S. Malinovskaya S. N. Mal’tsev 《Instruments and Experimental Techniques》2007,50(4):543-544
A new method for manufacturing multiwall carbon nanotubes by the current annealing in vacuum of the graphite paper saturated with Ni, Co, and Fe catalysts is designed. By using a scanning tunnel microscope, structural characteristics of the modified graphite paper are studied. Y- and V-shaped nanotubes are found. 相似文献