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71.
The aqueous ring-opening metathesis polymerization of the exo-Diels-Alder adduct of furan and maleimide was accomplished using an “activated Ruthenium” catalyst present in the supernatant of a RuCl3-catalyzed aqueous polymerization of furan-dimethylacetylene dicarboxylate adduct. The polymer was characterized by solution 1H? and 13C-NMR, IR, DSC, and viscometry. Characterization revealed an intact imide group and the possibility of high-temperature applications. © 1993 John Wiley & Sons, Inc. 相似文献
72.
R Viswanathan S N Yedave S T Bendre S M Kanetkar S M Chaudhari S B Ogale 《Bulletin of Materials Science》1991,14(2):435-441
Ion beam and thermally-induced interface reactions between highT
c superconducting thin film of Y1Ba2Cu3O7−x
and metal overlayer of Ag are studied with a view to control the interfacial property of contact resistance. The interface
reaction is induced by 100 keV Ar+ ion beam with different ion dose values ranging from 5 × 1013 to 3×1014 ions/cm2. The YBaCuO film-metal interface is characterized by using the small angle XRD to study the structural properties of the
interfacial phases. The electrical property of the interface, specifically contact resistance, has been investigated for different
dose values and thermal treatments. Three-probe vs four-probe configuration has been adopted to measure the contact resistance. 相似文献
73.
F Khanum KR Anilakumar KR Sudarshanakrishna KR Viswanathan 《Canadian Metallurgical Quarterly》1998,68(3):208-213
Two studies were conducted during which 23 patients with chronic migraine were exposed to pulsing electromagnetic fields over the inner thigh. In an open study, 11 subjects kept a 2-week headache log before and after 2 to 3 weeks of exposure to pulsing electromagnetic fields for 1 hour per day, 5 days per week. The number of headaches per week decreased from 4.03 during the baseline period to 0.43 during the initial 2-week follow-up period and to 0.14 during the extended follow-up which averaged 8.1 months. In a double-blind study, 9 subjects kept a 3-week log of headache activity and were randomly assigned to receive 2 weeks of real or placebo pulsing electromagnetic field exposures as described above. They were subsequently switched to 2 weeks of the other mode, after which they kept a final 3-week log. Three additional subjects in the blind study inadvertently received half-power pulsing electromagnetic field exposures. The 6 subjects exposed to the actual device first showed a change in headache activity from 3.32 per week to 0.58 per week. The 3 subjects exposed to only half the dose showed no change in headache activity. Large controlled studies should be performed to determine whether this intervention is actually effective. 相似文献
74.
R Govindaraj R Rajaraman K P Gopinathan B Viswanathan 《Bulletin of Materials Science》1998,21(5):427-431
Time differential perturbed angular correlation (TDPAC) and positron life-time measurements on cold-worked and hydrogen chargedNbHf indicate a strong binding of hydrogen decorated vacancy clusters with Hf impurities. Both TDPAC and positron lifetime results
are mutually consistent on this aspect. Transformation of H-vacancy clusters into H-bubbles is indicated by the positron lifetime
behaviour at annealing temperatures beyond 900 K. Impurity effects like oxygen pickup and coating of voids cannot be ruled
out at elevated temperatures. 相似文献
75.
U. K. Viswanathan G. K. Dey M. K. Asundi 《Metallurgical and Materials Transactions A》1993,24(11):2429-2442
Evolution of microstructure in a 350 grade commercial maraging steel has been examined. In the earlier stages of aging, the
strengthening phases are formed by the heterogeneous precipitation, and these phases have been identified as intermetallic
compounds of the Ni3 (Ti, Mo) and Fe2Mo types. The kinetics of precipitation are studied in terms of the activation energy by carrying out isothermal hardness
measurements of aged material. The mechanical properties in the peak-aged and overaged conditions were evaluated and the flow
behavior examined. The overaging behavior of the steel has been studied and the formation of austenite of different morphologies
identified. The crystallography of the austenite has been examined in detail. From the microstructural examination of peak-aged
and deformed samples, it could be inferred that the dislocation-precipitate interaction is by precipitate shearing. Increased
work hardening of the material in the overaged condition was suggestive of looping of precipitates by dislocations. 相似文献
76.
A method developed recently for measuring instantaneous permeability in the mushy zone of aluminum-copper alloys is used to
measure permeability in aluminum-silicon alloys. Permeability was also measured in packed glass beads using water, because
measurements could be conducted in the absence of microstructural coarsening. Experimental data are compared with the Kozeny-Carman
equation to determine the value of k
C
, the Kozeny-Carman constant. The results indicate that when k
C
=5.0, all the instantaneous permeability data agree well with the Kozeny-Carman equation. Factors affecting the accuracy of
permeability measurements, such as surface oxidation of the sample, flow channeling during the test, microstructural coarsening,
and liquid fraction reduction due to back diffusion in the solid are discussed. An experimental technique that minimizes errors
due to these factors is outlined. 相似文献
77.
78.
AIM: To compare the performance of PROGRESSOR (pointwise linear regression) and STATPAC 2 (comparison with baseline values) in detecting early deterioration in the visual fields of glaucoma patients. METHODS: Visual field series from 19 untreated normal tension glaucoma eyes which were deteriorating on clinical grounds were analysed by PROGRESSOR and STATPAC 2. Progression criteria for PROGRESSOR were (1) inner points: slope < -1 dB/year, p < 0.05 and (2) edge points: slope < -2 dB/year, p < 0.05. Criteria for STATPAC 2 were p < 0.05 change probability for any point on three consecutive fields. Detection time was defined as the time interval between the initial field and the first field in which at least one progressing point was identified. Detection times produced by the two techniques were compared. RESULTS: PROGRESSOR and STATPAC 2 agreed on progression in all 19 eyes. Mean detection time for PROGRESSOR was 1.077 (SD 0.985) years and for STATPAC 2 was 2.161 (1.357) years. PROGRESSOR detected progression sooner than STATPAC 2 in 18 eyes (p < 0.01), Wilcoxon matched pairs signed rank test). PROGRESSOR detected progression earlier by a mean of 1.085 (0.936) years. CONCLUSIONS: PROGRESSOR consistently detected progression earlier than STATPAC 2. The PROGRESSOR software is a useful tool for the early detection of visual field deterioration in glaucoma. 相似文献
79.
80.
Viswanathan Ganesan 《通讯世界》2002,8(4):46
测试项目在蓝牙环境中,哪些方面需要测试?蓝牙模块包括连接到主机设备的无线电 (硬件)和堆栈 (软件)。协议是构成堆栈的一套代码,在生产车间中将不会测试协议。修订系统软件可能会改变硬件性能,但必须在设计集成阶段对其进行粼选。需要使用的一些重要参数,如误码率(BER)、功率电平等对功能进行测试。选择测试必需理解由于无线电的设计方式哪些内容可能会改变,并根据测试的项目查看其发挥的作用。它是否提供了独特的功能?没有提供哪些功能?如打印机使用的蓝牙链路。在技术得到验证前,打印机可能仍会通过电缆提供打印功能,因此测… 相似文献