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排序方式: 共有989条查询结果,搜索用时 15 毫秒
91.
The effect of introducing a thin Mo2C (30 nm) layer between Ti and Cu on the thermal stability of Si/SiO2/Ti/Cu system was studied using four-point probe (FPP), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD) techniques. The measured value of the sheet resistance in the bi-layered diffusion barrier structure does not show any change up to an annealing temperature of 750??C. The sheet resistance when measured after annealing at 800??C marginally increases but less than twice its value at room temperature. The XRD analysis indicated no copper diffusion and the formation of Cu3Si phase up to 800??C. The bi-layered barrier structure annealed at elevated temperature shows copper-depleted and agglomerated regions. The sheet resistance measurement, study of surface morphology and the XRD analysis confirm that the insertion of thin Mo2C layer increases the thermal stability of the system from 400??C to 750??C. The increased thermal stability of the system is ascribed to longer diffusion path length in the bi-layered system probably because of grain boundaries mismatch at Ti-Mo2C interface. 相似文献
92.
Zhang Q Willison LN Tripathi P Sathe SK Roux KH Emmett MR Blakney GT Zhang HM Marshall AG 《Analytical chemistry》2011,83(18):7129-7136
The epitopes of a homohexameric food allergen protein, cashew Ana o 2, identified by two monoclonal antibodies, 2B5 and 1F5, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and the results were compared to previous mapping by immunological and mutational analyses. Antibody 2B5 defines a conformational epitope, and 1F5 defines a linear epitope. Intact murine IgG antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen-monoclonal antibody (Ag-mAb) complexes. mAb-complexed and uncomplexed (free) rAna o 2 were then subjected to HDX. HDX instrumentation and automation were optimized to achieve high sequence coverage by protease XIII digestion. The regions protected from H/D exchange upon antibody binding overlap and thus confirm the previously identified epitope-bearing segments: the first extension of HDX monitored by mass spectrometry to a full-length antigen-antibody complex in solution. 相似文献
93.
Rajiv Manohar A. K. Srivastava Pankaj K. Tripathi Dharmendra P. Singh 《Journal of Materials Science》2011,46(18):5969-5976
Addition of Nano rods results change in the dielectric and electro-optical properties of pure Ferroelectric Liquid Crystal
(FLC) considerably. The present study is devoted to characterize the dielectric and electro-optical parameters of the FLC
nano rods composite system. The size of nano rods is usually much bigger than that of FLC molecules, therefore, when they
are doped in different concentrations, in pure FLC, their volume fraction plays considerable role in deciding the molecular
dynamics of the resultant composite system. For the lesser concentrations, the nano rods offer mechanical strength to system
geometry while at higher concentration of nano rods, they offer additional constraints on the system. In present report both
of these aspects have been analyzed and explained. 相似文献
94.
This study reports the results of some voluntary Italian radiologists performing 103 proficiency tests in clinical (100 patients, 32 cancers) and screening mammography (150 patients, 17 cancers). Relative to the average accuracy of a panel of expert radiologists, 12 of 49 readers (27%) and 32 of 54 readers (56%) passed the clinical and screening mammography test, respectively. The results were significantly correlated with the readers' previous experience (years of mammographic practice [< 2, 2-4, > 4] and number of mammograms read [< 5,000, 5-10,000, > 10,000]). The rate of passed test was: < 2 years = 0%, 2-4 years = 40%, > 4 years = 66.6% (P = 0.002); < 5,000 mammograms read = 15.3%, 5-10,000 = 28.5%, > 10,000 = 69.2% (P = 0.02). The best results were achieved by the readers with a previous reading experience of at least 10,000 mammograms, a figure which might be used as the reference for a future criterion of accreditation on a national basis. Proper training before reporting mammography is fundamental to ensure a good diagnostic performance. The low number of tests performed in most Italian mammographic practice facilities makes local training highly questionable and requires quite a long time. Reference centers, adequately equipped for training, should be identified for this purpose. Proficiency tests such as those described in the present study are useful to assess individual performance and should be a part of a training program. 相似文献
95.
BACKGROUND: Tamoxifen has been used extensively as adjuvant therapy in the treatment of pre- and post-menopausal patients with breast cancer. One of its known complications is venous thromboembolism. However, arterial thrombosis has been reported rarely. METHODS: A 49-year-old patient with breast cancer had had a total mastectomy 3 years earlier. She was receiving tamoxifen therapy when she developed a sudden onset of pain and numbness of the left foot and calf. An arteriogram showed thrombosis of her tibial arteries. RESULTS: This thrombosis was lysed successfully with urokinase therapy, and tamoxifen therapy was discontinued. At follow-up 4 months later, the patient had normal circulation to both legs. CONCLUSIONS: Patients receiving tamoxifen should be monitored closely for the development of venous or arterial thromboembolism. 相似文献
96.
This paper examines how the use of novel hybrid inorganic membrane technology is enabling natural gas processing and the production of high density hydrogen without any impurities. 相似文献
97.
98.
An indoor simulation study was carried out to evaluate heat and mass transfer relation for a semi-cylindrical metallic (opaque) condensing cover for higher yields at different operating temperatures under free and forced modes of operation. The objective is to design a distillation unit for higher yield for commercialization, particularly in India. Experiments have been conducted for the operating temperature range of 40°C to 80°C in a steady-state condition by using constant temperature bath. Data (temperature and yield) obtained from experimentation have been used to determine the values of coefficient C and n and, consequently, convective as well as evaporative heat transfer coefficients. It is inferred that a higher yield is obtained with an increase of temperature in the forced mode of operation as compared to that in the natural mode of operation due to a fast release of heat from the condensing cover. 相似文献
99.
Carbonic anhydrase enzyme activity could be measured by manometeric and colorimetric techniques. A simpler and modified method of carbonic anhydrase enzyme activity assessment in blood is proposed. In the present method differences in pH by hydration of CO2 in absence and presence of carbonic anhydrase inhibitor have been used to measure the carbonic anhydrase activity in the blood. 相似文献
100.
Direct method of overmodulation with integrated closed loop stator flux vector control 总被引:1,自引:0,他引:1
Tripathi A. Khambadkone A.M. Panda S.K. 《Power Electronics, IEEE Transactions on》2005,20(5):1161-1168
Overmodulation achieves full utilization of installed dc link voltage, by modifying the magnitude and the phase of reference voltage vector. Due to the nonlinear behavior in this region, closed loop vector control becomes difficult. A simple method of overmodulation with closed loop control of stator flux vector is proposed in this paper. Instead of modifying the voltage reference by nonlinear equations or look up table, we propose a direct method to generate the switching times. In so doing, the average angular velocity of the stator flux vector is controlled linearly throughout the modulation range. The proposed method shows lower harmonic distortion compared with existing methods. It greatly reduces the complexity and cost of achieving overmodulation over existing schemes. 相似文献