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排序方式: 共有153条查询结果,搜索用时 15 毫秒
91.
92.
In this paper, multiuser detection in code division multiple access (CDMA) was performed by using neural network (NN) and parallel interference cancellation (PIC). Neural network is used as a front-end stage of one stage PIC circuit. PIC is a classical technique in multi user detection process and its bit error rate (BER) performance is not good in one stage for most of the applications. For improving its BER performance, generally multi stage PIC which has high computational complexity is used. In this study, we have got better BER performance than the three stage PIC receiver in AWGN channel, almost same BER performance with the three stages PIC receiver in the Rayleigh fading channel.  相似文献   
93.
This study aims on the effect of nucleon mean free path on differential cross sections of tritium-emission spectra for (p, 3H) reactions on 27Al, 54, 56Fe, 89Y, 120Sn, 197Au, 208Pb and 209Bi induced by 62 MeV protons in the pre-equilibrium reaction mechanisms. The pre-equilibrium calculations were carried out by using the geometry dependent hybrid model. The calculated results are compared with experimental data existing in literature and found to be in good agreement. Furthermore, using different multiplication factor for the mean free path in the calculation changes the differential cross sections of tritium emission spectra.  相似文献   
94.
Cone yoghurt is a yoghurt variety produced by adding only pine cones to milk without culture in a limited area of Turkey. The present study was conducted to identify and characterize lactic flora in traditional cone yoghurt. Morphological, cultural, physiological, biochemical, and genotypic characteristics were employed to identify lactic acid bacteria isolates from cones and cone yoghurts. Streptococcus salivarius subsp. thermophilus (S. thermophilus) and Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) were obtained from both cones and yoghurts. Among the isolates, L. plantarum was frequently isolated except for these two bacteria (S. thermophilus and L. bulgaricus). The results indicate that the cone yoghurt has a mixed microflora contrary to the yoghurt produced by the addition of a starter culture and S. thermophilus, and L. bulgaricus in cone yoghurt originates from the pine cones.  相似文献   
95.
96.
In this study, stable isotope signatures (δ13C, δ15N, and δD) of both tea leaves and tea infusions were investigated to identify the geographical origin of Turkish domestic and imported tea samples. Sixteen domestic tea samples collected from different locations in the Black Sea Region, which produces almost 100% of tea in Turkey, and 11 imported tea samples (Kenya, India, Sri Lanka, Indonesia, and China) purchased from importers were studied. δ13C, δ15N, and δD in the samples were determined using isotope ratio mass spectrometry (IR-MS). δ13C in the samples ranged from ?29.18 ± 0.01 to ?25.7 ± 0.2, while δ15N ranged between 1.1 ± 0.2 and 5.2 ± 0.8. However, δD in the samples were found to be in the range from 56.5 ± 0.3 to 72 ± 1. The classifications of the tea samples into domestic and imported tea samples were achieved with 100% accuracy using multivariate statistical analyses (principal component analysis, PCA, and hierarchical cluster analysis, HCA). In conclusion, the domestic tea samples had a distinctive isotopic fingerprint and the isotopic ratios used in the study can be significant predictors in determination of the geographical source of Turkish tea.  相似文献   
97.
The Sideritis species are widely used in the treatment of gastrointestinal disorders, rheumatism, cough, the common cold and as a diuretic, and they are commonly used as an herbal tea in folk medicine in Turkey. The teas of Sideritis have unique tastes, pleasant aromas and a transparent yellow colour, and are preferred as a hot beverage. In order to evaluate this information, the crude methanolic extract and the water soluble part of the methanolic extract after partition with chloroform and n-butanol were investigated for their anti-inflammatory and antinociceptive activities. Phytochemical studies performed on the n-butanol extract of the overground parts of Sideritis brevibracteata, which is rich in phenolic compounds with promising activities, resulted in the isolation of six acetylated allose containing 8-hydroxyflavone glycosides and a phenylethanoid glycoside. The structures of the compounds were established by spectroscopic evidence (UV, IR, NMR, MS). Furthermore, these phenolic compounds of S. brevibracteata were studied for anti-inflammatory, antinociceptive, antioxidant and aldose reductase inhibitory activities. The experimental data demonstrated that S. brevibracteata displayed remarkable anti-inflammatory, antinociceptive and antioxidant activities.  相似文献   
98.
Quantum Information Processing - In this paper, we introduce quasi-Bell states as a result of two-mode superposition of two “Near” coherent states, $$|alpha ,delta theta rangle $$ ,...  相似文献   
99.
The adsorption kinetics of the cationic dye, methylene blue, onto clay   总被引:2,自引:0,他引:2  
In this study, adsorption kinetics of a cationic dye, methylene blue, onto clay from aqueous solution with respect to the initial dye concentration, temperature, pH, mixing rate and sorbent dosage were investigated. In order to understand the adsorption mechanism in detail, zeta potentials and the conductivities of clay suspensions at various pH (1-11) and cation exchange capacity (CEC) were measured. Porosity and BET surface area of clay studied were determined. The results showed that the adsorption has been reached to equilibrium in 1 h. It was found that the amount adsorbed of methylene blue increases with decreasing temperature and also with increasing both sorbent dosage and increasing initial dye concentration. Adsorption capacity decreases with increasing pH, except for the natural pH (5.6) of clay suspensions. The adsorption kinetics of methylene blue has been studied in terms of pseudo-first-order, pseudo-second-order sorption and intraparticle diffusion processes thus comparing chemical sorption and diffusion sorption processes. It was found that the pseudo-second-order mechanism is predominant and the overall rate of the dye adsorption process appears to be controlled by the more than one-step.  相似文献   
100.
In this paper, discrete-time adaptive control of linearly parameterized fully actuated Port-controlled Hamiltonian systems with parameter uncertainties in energy function is considered. A discrete-time adaptive interconnection and damping assignment passivity-based control (IDA-PBC) method, utilizing the immersion and invariance (I&I) approach, for the considered uncertain Hamiltonian system, is presented. A discrete-time parameter estimator based on the immersion and invariance approach is derived to obtain an automatic tuning mechanism for the IDA-PBC controller. The stability analysis for the estimator and the closed-loop system is done using the Lyapunov theory. The proposed method is applied to two fully actuated physical systems and its performance is tested by simulations. Simulation results show that the proposed I&I-based adaptive IDA-PBC controller successfully preserves the performance of the IDA-PBC controller designed with true parameters under a large amount of uncertainty.  相似文献   
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