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381.
Bernard L. S. Lin 《The Ramanujan Journal》2014,33(2):269-279
In this work, we consider various arithmetic properties of the function ped ?2(n) that denotes the number of bipartitions of n with even parts distinct. We prove two infinite families of congruences for p ?2(n) modulo 3. We also give characterizations of ped ?2(n) modulo 2 and 4. Furthermore, for a fixed positive integer k, we show that ped ?2(n) is divisible by 2 k for almost all n. 相似文献
382.
The confidence of target detection can be used to evaluate the reliability and risk level of the detected targets and can effective help to exclude the false alarms, but very little investigation was involved in the past. In this letter, a confidence-driven infrared target detection method is proposed. We develop three confidence evaluating methods: (1) the median classification confidence of the cascade classifier; (2) the context confidence based on the number and the confidence of the merged detection rectangles around the detected target; and (3) the contrast confidence based on the difference between the detected target distribution and the around background distribution. The three confidences are combined to form the final confidence of the detected targets. We then use the confidence to refine the localization of the targets. The evaluation using real infrared images demonstrates the good performance of the proposed confidence-driven infrared detection algorithm on both undetected error and false alarm. 相似文献
383.
Nonlinear Dynamics - In this paper, we investigate a ratio-dependent prey–predator model with state-dependent impulsive harvesting where the prey growth rate is subject to a strong Allee... 相似文献
384.
385.
进行了两种环境敏感高分子在相分离免疫分析嗜水气单胞菌外膜蛋白(outer membrane protein, OMP)中的比较研究. 首先合成温度敏感高分子聚N-异丙基丙烯酰胺和pH敏感高分子聚(N-异丙基丙烯酰胺-甲基丙烯酸), 分别以N-羟基琥珀酰亚胺丙烯酸酯(NAS)和碳二亚胺(EDCI)作为偶联剂与抗OMP抗体(Ab)偶联形成抗体复合物(Ab-polymer), 在竞争型免疫测定中, OMP标准溶液与异硫氰酸荧光素标记OMP在均相条件下竞争性地与Ab-polymer反应, 调节外界环境分离出高分子免疫复合物沉淀, 重新溶解后荧光法定量, 两种体系的OMP浓度均在400~3000 ng/mL范围内与荧光强度呈良好线性关系, 检出限分别为84.7和39.6 ng/mL. pH敏感高分子相比于温度敏感高分子具有以下优点: 可以在37 ℃的生理温度进行免疫反应, 进一步提高了免疫反应的速度和效率; 可利用高分子本身的活性基团进行Ab的固定, 固定化效率、固定Ab的免疫反应活性较之NAS偶联法得到了提高; 有更高的检测灵敏度. 因此, pH敏感高分子更适合于作为相分离免疫分析的载体. 相似文献
386.
《Radiation Physics and Chemistry》2009,78(9):796-799
Alginate with the weight-average molecular weight (Mw) approximately 900 kDa and ratio of M (mannuronate)/G (guluronate) about 1.3 was irradiated by gamma Co-60 in aqueous solution at doses up to 200 kGy. The irradiation dose was shown to be a function for reducing Mw and molecular weight distribution of irradiated alginates. The distribution of oligomer fractions in irradiated products was also investigated by separation using ultrafiltration membranes. The irradiated alginate with Mw approximately 14.2 kDa was found to have a positive influence for growing of barley and soybean. The irradiated oligoalginate fraction with Mw ranging from 1 to 3 kDa displayed the strongest effect on the growth and development of the mentioned plants at low concentration (20 ppm). It is suggested that oligoalginate with Mw in the range 1–3 kDa is a trigger for the growth and development of plants. 相似文献
387.
The resistance distance between any two vertices of a connected graph is defined as the effective resistance between them in the electrical network constructed from the graph by replacing each edge with a unit resistor. Let \(B_n\) denote the linear polyomino chain with \(n-1\) squares. In this paper, first by using resistance sum rules along with series and parallel principles, explicit formulae for the resistance distances between any two vertices of \(B_n\) are given. Then based on these formulae, the largest and the smallest resistance distances in \(B_n\) are determined. Finally, the monotonicity and some asymptotic properties of resistance distances in \(B_n\) are given. 相似文献
388.
《Current Applied Physics》2003,3(4):345-350
We report measurements on the electrical properties of thermally evaporated zinc phthalocyanine, ZnPc, semiconductor thin films. Aluminum and gold metal electrodes were used and both proved to act as ohmic contacts. A relative permittivity, εr, of 1.56 was estimated from the dependence of capacitance on film thickness. The room temperature current density–voltage measurements indicated an ohmic conduction at low voltages, while a space–charge-limited conduction at higher voltages. An average value of a thermally generated hole concentration of the order 1013 m−3 was estimated at room temperature.The ac conductivity, capacitance and loss tangent were measured over a wide range of temperature (from 170 to 430 K) and frequency (between 0.1 and 20 kHz). The ac conductivity of ZnPc films was observed to be proportional to ωs, where ω is the angular frequency, and the index s is a temperature and frequency-dependent constant. At low temperatures and for higher frequencies the ac conduction was due to hopping. The capacitance, as well as the loss tangent, was found to be dependent on both temperature and frequency, but was constant for all frequencies at low temperatures. Such dependences were accounted for the equivalent-circuit model consisting of inherent capacitance in parallel with a temperature dependent resistive element. 相似文献
389.
390.
研究具有巢寄生行为的两种群模型,两个种群都具有阶段结构.利用微分方程比较定理得到该系统持续生存的充分性条件,进一步利用Liapunov函数方法,证明了在适当的条件下,周期解及概周期解的全局渐近稳定性. 相似文献