共查询到20条相似文献,搜索用时 15 毫秒
1.
N Ia Ianysheva N V Balenko I A Chernichenko G N Bakanova L P Lemeshko 《Eksperimental?nai?a onkologii?a》1990,12(5):21-24
A modifying influence of ortho-cresol (o-cresol) on the carcinogenic effect of benzo(a)pyrene (B(a)P) in their combined peroral administration to CC57Br mice has been revealed. During the simultaneous administration of the o-cresol (1 mg) and B(a)P (1 mg) the rate of tumours, their multiplicity index, the degree of malignancy increased and the latent period shortened. In case of o-cresol administration before or after B(a)P (in the same doses) the decrease of carcinogenic effect has been revealed. In case of simultaneous administration of 10 mg of the o-cresol and 5 mg of the B(a)P the tumor incidence did not change in comparison with the animals of the control group which received only B(a)P. But their progression was hampered which was confirmed by a decrease of the malignancy rate, frequent occurrence and prolongation of the period of the malignization beginning. 相似文献
2.
非对称多模量子叠加态光场的等幂高次和压缩 总被引:1,自引:0,他引:1
根据量子力学中的态叠加原理,构造了由多模复共轭相干态|{zj(a)*}>q和多模复共轭相干态|{zj(b)*}>q的相反态|{-zj(b)*}>q的线性叠加所组成的非对称两态叠加多模量子叠加态光场|ψ(2)>q,利用多模压缩态理论研究了态|ψ1f(2)>q的等幂高次和压缩特性,结果表明: 1)当Rj(a)=Rj(b)和ψj(a)-ψj(b)=±(2k 1)π(k=0,1,2,3……),态|ψ1f(2)>q的两个正交相位分量均处于N-H最小测不准态的结果;2)当Rj(a)=Rj(b)=Rj和ψj(a)=ψj(b)=ψj,ψ态|1f(2)>q的等幂高次和压缩与文献3的结果相似; 3)当Rj(a)≠Rj(b)=Rj和ψj(a)=ψj(b)=ψj,且和满足一定条件时,无论qN为奇数还是偶数,态|ψ1f(2)>q的两个正交相位分量均可分别呈现周期性变化的等幂高次和压缩效应,但qN为奇数时的压缩深度大于qN为偶数时的压缩深度。 相似文献
3.
In this study, we introduce and investigate a class of neural
architectures of self-organizing neural networks (SONNs) that is
based on a genetically optimized multilayer perceptron with
polynomial neurons (PNs) or fuzzy polynomial neurons (FPNs),
develop a comprehensive design methodology involving mechanisms
of genetic optimization, and carry out a series of numeric
experiments. We distinguish between two kinds of SONN
architectures: (a) PN-based and (b) FPN-based SONNs. The
augmented genetically optimized SONN (gSONN) results in a
structurally optimized structure and comes with a higher level
of flexibility in comparison to the one encountered in the
conventional SONN. The genetic algorithm (GA)-based design
procedure being applied at each layer of SONN leads to the
selection of preferred nodes (PNs or FPNs) with specific local
characteristics (such as the number of input variables, the
order of the polynomial, and a collection of the specific subset
of input variables) available within the network. 相似文献
4.
Andoh E. Kosugi M. Kawamura T. Araki S. Taketoshi K. 《Electron Devices, IEEE Transactions on》1998,45(4):778-784
We developed a novel image intensifier (II) of an amplified metal-oxide-semiconductor (MOS) imager (AMI) overlaid with electron-bombarded (EB) amorphous silicon (a-Si). The electron bombardment gain (EB gain) was 1500 at an accelerating voltage of 10 kV. Since the multiplication process was free from a phosphorescent screen and a coupling fiber plate as in the conventional II, the resolution was high and the picture quality was good and free from granularity noises, white spots, lag and sticking. As for fatigue of X-ray irradiation, the contrasts of a vertical stripe (Smear) are not detectable and damaged areas in AMI are weak whereas both of those in charge-coupled devices (CCDs) are strong 相似文献
5.
A signal remodulation scheme of 10-Gb/s differential phase-shift keying(DPSK) downstream and 10-Gb/s on-off keying(OOK) upstream using a semiconductor optical amplifier(SOA) and a Mach-Zehnder intensity modulator(MZ-IM) at the optical networking unit(ONU) side for wavelength division multiplexed passive optical network(WDM PON) is proposed.Simulation results indicate that error-free operation can be achieved in a 20-km transmission,and the receiver sensitivity of return-to-zero differential phase-shift keying(RZ-DPSK) is higher than nonreturn-to-zero differential phase-shift keying(NRZ-DPSK) in the proposed scheme. 相似文献
6.
The adhesion and interaction properties of functionalised surfaces (substrate or cantilever) were investigated by means of atomic force microscope (AFM)-related force measurements. The surfaces were functionalised with a polyelectrolyte - poly(allylamine hydrochloride) (PAH) - or with silanes - 3-(ethoxydimethylsilyl) propyl amine (APTES) or (3-aminopropyl) triethoxysilane (APDMES). Measurements of forces acting between a bare glass sphere (functionalised or not) and a functionalised surface indicated repulsive or attractive forces, depending on functionalisation and medium (wet or dry). Adhesion forces (pull-off) can be observed in dry medium, whereas in wet medium this phenomenon can be cancelled. Now, the pull-off forces represent an important problem in the automation of micro-object manipulations. The cancellation of this force by chemical functionalisation is thus a promising way of improving micro-assembly in the future. 相似文献
7.
Jensen J.F. Raghavan G. Cosand A.E. Walden R.H. 《Solid-State Circuits, IEEE Journal of》1995,30(10):1119-1127
This paper presents a second-order delta-sigma (ΔΣ) modulator fabricated in a 70 GHz (fT), 90 GHz (fmax) AlInAs-GaInAs heterojunction bipolar transistor (HBT) process on InP substrates. The modulator is a continuous time, fully differential circuit operated from ±5 volt supplies and dissipates 1 W. At a sample rate of 3.2 GHz and a signal bandwidth of 50 MHz (OSR=32100 MSPS Nyquist rate) the modulator demonstrates a Spur Free Dynamic Range (SFDR) of 71 dB (12-b dynamic range). The modulator achieves the ideal signal-to-noise ratio (SNR) of 55 dB for a second-order modulator at an oversampling ratio (OSR) of 32. The design of a digital decimation filter for this modulator is complete and the filter is currently in fabrication in the same technology. This work demonstrates the first ΔΣ modulator in III-V technology with ideal performance and provides the foundation for extending the use of ΔΣ modulator analog-to-digital converters (ADC's) to radio frequencies (RF) 相似文献
8.
Mandal R. Basu S.K. Kar A. Chowdhury S.P. 《Industrial Electronics, IEEE Transactions on》1994,41(3):361-371
The paper reports a laboratory model of a microcomputer-based power factor controller (PFC) for compensating the reactive power of rapidly varying loads by switching capacitors sized in a binary ratio, with the help of zero voltage static switches. Four types of control strategies were tried, viz., (1) unity step control method, (2) binary search method, (3) successive approximation method, and (4) look-up table method. Features like (a) independent control of current in each phase, (b) reactive current sensing and capacitor switching in one cycle, (c) zero voltage switching of static switches to prevent the occurrence of transients and harmonics, and (d) switch failure detection logic and their display, are all incorporated in the software programming. A comparative assessment of their performances using different control strategies has been reported. A number of experiments have been performed on this controller, viz., (i) experiments to verify the operating performance of the PFC under the four control strategies, (ii) experiments to prove its performance as a power factor controller and also (iii) as a static VAr compensator 相似文献
9.
Javier Ramírez Antonio García Uwe Meyer-Bäse Fred Taylor Antonio Lloris 《The Journal of VLSI Signal Processing》2003,33(1-2):171-190
Currently there are design barriers inhibiting the implementation of high-precision digital signal processing (DSP) objects with field programmable logic (FPL) devices. This paper explores overcoming these barriers by fusing together the popular distributed arithmetic (DA) method with the residue number system (RNS) for use in FPL-centric designs. The new design paradigm is studied in the context of a high-performance filter bank and a discrete wavelet transform (DWT). The proposed design paradigm is facilitated by a new RNS accumulator structure based on a carry save adder (CSA). The reported methodology also introduces a polyphase filter structure that results in a reduced look-up table (LUT) budget. The 2C-DA and RNS-DA are compared, in the context of a FPL implementation strategy, using a discrete wavelet transform (DWT) filter bank as a common design theme. The results show that the RNS-DA, compared to a traditional 2C-DA design, enjoys a performance advantage that increases with precision (wordlength). 相似文献
10.
Kishida K Miyata M Wada N Okamoto NL Tanaka K Inui H Koyama H Hattori T Iriyama Y Ogumi Z 《Journal of electron microscopy》2007,56(6):225-234
The crystal and defect structures of coarse-grained crystals of La(2/3-x)Li(3x)TiO3 grown from the melt by the Tammann-St?ber method were studied by transmission electron microscopy and powder X-ray diffraction. The as-grown crystals of La(2/3-x)Li(3x)TiO3 have a Li-poor composition of La(0.57)Li(0.29)TiO3 and a diagonal-type unit cell of 2(1/2)a(p) x 2(1/2)a(p) x 2a(p) with the tetragonal symmetry [space group: P4/nbm (#125)] due to both the La-cation ordering and the tilting of TiO6 octahedra. The secondary La2Ti2O7 phase precipitates in the form of plates in the La(2/3-x)Li(3x)TiO3 phase with the orientation relationships of 001(p)//[100](La2Ti2O7) and {110}(p)//(001)(La2Ti2O7), which may cause detrimental effects to ionic conductivity. 相似文献
11.
M. L. Seaford D. H. Tomich K. G. Eyink L. Grazulis K. Mahalingham Z. Yang W. I. Wang 《Journal of Electronic Materials》2000,29(7):906-908
Gallium arsenide (GaAs) films were grown by molecular beam epitaxy (MBE) on a (511) silicon substrate and a compliant (511) silicon-on-insulator (SOI) substrate. The top silicon layer of the compliant (511) SOI was thinned to ~1000 Å. The five inch diameter SOI wafer was created by wafer bonding. The GaAs (004) x-ray diffraction (XRD) reflection showed a 25% reduction in the full width half maximum (FWHM) for GaAs on a compliant (511) SOI as compared to GaAs on a silicon substrate. Cross section transmission electron microscopy (XTEM) clearly indicates a different dislocation structure for the two substrates. The threading dislocation density is reduced by at least an order of magnitude in the compliant (511) SOI as compared to the (511) silicon. XTEM found dislocations and damage was generated in the top silicon layer of the compliant SOI substrate after GaAs growth. 相似文献
12.
M. Sh. Levin 《Journal of Communications Technology and Electronics》2013,58(6):584-593
The paper addresses modular design and improvement/extension of the management system in the smart home and the building automation system (BAS). The design procedure is based on the hierarchical morphological multicriteria design (HMMD) approach: (a) construction of a tree-like system model, (b) generation of design alternatives for leaf nodes of the system model, (c) the bottom-up process: (i) selection of design alternatives for system parts/components and (ii) composition of the selected alternatives into a resultant combination. Here, the HMMD approach with interval multiset estimates for design alternatives is used. The system improvement scheme is based on the following: (a) upgrade of the system components (strategy 1), (b) system extension by adding an additional part (strategy 2). The multiple choice problem with interval multiset estimates for improvement operations is used in system improvement procedure. Two basic applied illustrative numerical examples are considered: (1) a modular management system for the smart home and (2) a modular building automation system consisting of four parts. 相似文献
13.
HRTEM study of new series of oxycarbonitrate superconductors (Cu,C,N)Sr2Ca(n - 1)Cu(n)O(y) (n = 1-6)
Anan Y Asaka T Hatano J Zhigadlo ND Takayama-Muromachi E Kimoto K Matsui Y 《Journal of electron microscopy》2001,50(6):457-463
Arrangements of Cu and anion groups (CO3 and NO3) in the charge-reservoir (CR) blocks of a series of new oxycarbonitrate superconductors (Cu,C,N)Sr2Ca(n - 1)Cu(n)O(y) (n = 1-6) were examined by means of electron diffraction and high-resolution transmission electron microscopy (HRTEM). The first three members with n = 1-3 [Tc = 33 K (n = 1), 91 K (n = 2), 90 K (n = 3)] show the 4a0-type superstructures with periodic arrangements, [-Cu-X-X-X-Cu-X-X-X-Cu-] (X = CO3, NO3), in the CR blocks. The third member (n = 3) partly contains the 2a0-type of superstructure with [-Cu-X-Cu-X-Cu] in the CR blocks. The fourth member with n = 4 (Tc = 113 K) contains only the 2a0-type of superstructure. The higher members, with n = 5 (Tc = 65 K) and n = 6 (Tc = 52 K), show no evidence of ordering in the CR blocks, suggesting random arrangements of Cu and anion groups. 相似文献
14.
We discuss various possibilities for determining the orientation of CdTe layers grown on (001) GaAs and in particular, determining
the (001) orientation. This growth orientation is characterized by a three dimensional growth mechanism which controls the
growth in the (111) orientation. We show that a thin layer of ZnTe deposited directly on the oxide free GaAs surface can be
used to determine the (001) orientation, eliminate (111) phases and enhance a two dimensional growth of the CdTe layer, resulting
in an improved crystalline quality and a smooth surface morphology. CdTe layers grown in the (111) direction on oxide free
(001) GaAs substrates contain (111) microtwins and an intermixed (001) phase.
This work is a part of a Ph.D. thesis to be submitted to the Weizmann Institute of Science. 相似文献
15.
Echo cancellers (ECs) are in wide use in both electrical (four-wire to two-wire mismatch) and acoustic (speaker-microphone coupling) applications. One of the main design problems is the control logic for adaptation. Basically, the algorithm weights should be frozen in the presence of double-talk and adapt quickly in the absence of double-talk. The control logic can be quite complicated since it is often not easy to discriminate between the echo signal and the near-end speaker. This paper derives a log-likelihood ratio test (LRT) for deciding between double-talk (freeze weights) and a channel change (adapt quickly) using a stationary Gaussian stochastic input signal model. The probability density function (pdf) of a sufficient statistic under each hypothesis is obtained, and the performance of the test is evaluated as a function of the system parameters. The receiver operating characteristics (ROCs) indicate that it is difficult to correctly decide between double-talk and a channel change based upon a single look. However, postdetection integration of approximately 100 sufficient statistic samples yields a detection probability close to unity (0.99) with a small false-alarm probability (0.01) 相似文献
16.
Bisanthracene‐Based Donor–Acceptor‐type Light‐Emitting Dopants: Highly Efficient Deep‐Blue Emission in Organic Light‐Emitting Devices
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jian‐Yong Hu Yong‐Jin Pu Fumiya Satoh So Kawata Hiroshi Katagiri Hisahiro Sasabe Junji Kido 《Advanced functional materials》2014,24(14):2064-2071
Deep‐blue fluorescent compounds are particularly important in organic light‐emitting devices (OLEDs). A donor–accepotor (DA)‐type blue‐emitting compound, 1‐(10‐(4‐methoxyphenyl)anthracen‐9‐yl)‐4‐(10‐(4‐cyanophenyl)anthracen‐9‐yl)benzene ( BD3 ), is synthesized, and for comparison, a nonDA‐type compound, 1,4‐bis(10‐phenylanthracene‐9‐yl)benzene ( BD1 ) and a weak DA‐type compound, 1‐(10‐phenylanthracen‐9‐yl)‐4‐(10‐(4‐cyanophenyl)anthracen‐9‐yl)‐benzene ( BD2 ), are also synthesized. The twisted conformations of the two anthracene units in the compounds, confirmed by single crystal X‐ray analysis, effectively prevent π‐conjugation, and the compound shows deep‐blue photoluminescence (PL) with a high PL quantum efficiency, almost independent of the solvent polarity, resulting from the absence of an intramolecular charge transfer state. The DA‐type molecule BD3 in a non‐doped device exhibits a maximum external quantum efficiency (EQE) of 4.2% with a slight roll‐off, indicating good charge balance due to the DA‐type molecular design. In the doped device with 4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl (CBP) host, the BD3 exhibits higher EQE than 10% with Commission International de L'Eclairge (CIE) coordinates of (0.15, 0.06) and a narrow full‐width at half‐maximum of 45 nm, which is close to the CIE of the high definition television standard blue. 相似文献
17.
Kanchumarthy V.R. Viswanathan R. Madishetty M. 《Signal Processing, IEEE Transactions on》2008,56(5):1761-1769
We provide new results on the performance of wireless sensor networks in which a number of identical sensor nodes transmit their binary decisions, regarding a binary hypothesis, to a fusion center (FC) by means of a modulation scheme. Each link between a sensor and the fusion center is modeled independent and identically distibuted (i.i.d.) either as slow Rayleigh-fading or as nonfading. The FC employs a counting rule (CR) or another combining scheme to make a final decision. Main results obtained are the following: 1) in slow fading, a) the correctness of using an average bit error rate of a link, averaged with respect to the fading distribution, for assessing the performance of a CR and b) with proper choice of threshold, on/off keying (OOK), in addition to energy saving, exhibits asymptotic (large number of sensors) performance comparable to that of FSK; and 2) for a large number of sensors, a) for slow fading and a counting rule, given a minimum sensor-to-fusion link SNR, we determine a minimum sensor decision quality, in order to achieve zero asymptotic errors and b) for Rayleigh-fading and nonfading channels and PSK (FSK) modulation, using a large deviation theory, we derive asymptotic error exponents of counting rule, maximal ratio (square law), and equal gain combiners. 相似文献
18.
Ververidis D Van Gils M Passath C Takala J Brander L 《IEEE transactions on bio-medical engineering》2011,58(9):2598-2606
Neurally adjusted ventilatory assist (NAVA) delivers airway pressure (P(aw)) in proportion to the electrical activity of the diaphragm (EAdi) using an adjustable proportionality constant (NAVA level, cm·H(2)O/μV). During systematic increases in the NAVA level, feedback-controlled down-regulation of the EAdi results in a characteristic two-phased response in P(aw) and tidal volume (Vt). The transition from the 1st to the 2nd response phase allows identification of adequate unloading of the respiratory muscles with NAVA (NAVA(AL)). We aimed to develop and validate a mathematical algorithm to identify NAVA(AL). P(aw), Vt, and EAdi were recorded while systematically increasing the NAVA level in 19 adult patients. In a multistep approach, inspiratory P(aw) peaks were first identified by dividing the EAdi into inspiratory portions using Gaussian mixture modeling. Two polynomials were then fitted onto the curves of both P(aw) peaks and Vt. The beginning of the P(aw) and Vt plateaus, and thus NAVA(AL), was identified at the minimum of squared polynomial derivative and polynomial fitting errors. A graphical user interface was developed in the Matlab computing environment. Median NAVA(AL) visually estimated by 18 independent physicians was 2.7 (range 0.4 to 5.8) cm·H(2)O/μV and identified by our model was 2.6 (range 0.6 to 5.0) cm·H(2)O/μV. NAVA(AL) identified by our model was below the range of visually estimated NAVA(AL) in two instances and was above in one instance. We conclude that our model identifies NAVA(AL) in most instances with acceptable accuracy for application in clinical routine and research. 相似文献
19.
Consider a three-dimensional "scene" in which a density f(x, y, z) is assigned to every point (x, y, z). In a discretized version of the scene the density D(i, j, k) assigned to the (i, j, k) th volume element (voxel) is the average value of f(x, y, z) over the voxel. Suppose that the points in the original scene can be meaningfully segmented into classes 1, 2, and 3 separated by two threshold values l and u. Partial volume artifact is the phenomenon that a voxel (i, j, k) which is at the interface of class 1 and class 3 (and thus contains only points with low and high densities) usually has a density D(i, j, k) between l and u, and so cannot be distinguished by density alone from a voxel which contains only points in class 2. We describe how a two-dimensional (gradient, density) feature space can be used for the segmentation of such discrete scenes into three classes in a meaningful way. We illustrate the method using examples from medical imaging. 相似文献
20.
Ravi Shankar 《International Journal of Communication Systems》2023,36(16):e5585
In this work, a deep learning (DL)-based massive multiple-input multiple-output (mMIMO) orthogonal frequency division multiplexing (OFDM) system is investigated over the tapped delay line type C (TDL-C) model with a Rayleigh fading distribution at frequencies ranging from 0.5 to 100 GHz. The proposed bi-directional long short-term memory (Bi-LSTM) channel state information (CSI) estimator uses online learning during training and offline learning during the practical implementation phase. The design of the estimator takes into account situations in which prior knowledge of channel statistics is limited and targets excellent performance, even with limited pilot symbols (PS). Three separate loss functions (mean square logarithmic error [MSLE], Huber, and Kullback–Leibler Distance [KLD]) are assessed in three classification layers. The symbol error rate (SER) and outage probability performance of the proposed estimator are evaluated using a number of optimization techniques, such as stochastic gradient descent (SGD), momentum, and the adaptive gradient (AdaGrad) algorithm. The Bi-LSTM-based CSI estimator is trained considering a specific number of PS. It can be readily seen that by incorporating a cyclic prefix (CP), the system becomes more resilient to channel impairments, resulting in a lower SER. Simulations show that the SGD optimization approach and Huber loss function-trained Bi-LSTM-based CSI estimator have the lowest SER and very high estimation accuracy. By using deep neural networks (DNNs), the Bi-LSTM method for CSI estimation achieves a superior channel capacity (in bps/Hz) at 10 dB than long short-term memory (LSTM) and other conventional CSI estimators, such as minimum mean square error (MMSE) and least squares (LS). The simulation results validate the analytical results in the study. 相似文献